new file mode 100644
@@ -0,0 +1,6756 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/ext4/inode.c
+ *
+ * Copyright (C) 1992, 1993, 1994, 1995
+ * Remy Card (card@masi.ibp.fr)
+ * Laboratoire MASI - Institut Blaise Pascal
+ * Universite Pierre et Marie Curie (Paris VI)
+ *
+ * from
+ *
+ * linux/fs/minix/inode.c
+ *
+ * Copyright (C) 1991, 1992 Linus Torvalds
+ *
+ * 64-bit file support on 64-bit platforms by Jakub Jelinek
+ * (jj@sunsite.ms.mff.cuni.cz)
+ *
+ * Assorted race fixes, rewrite of ext4_get_block() by Al Viro, 2000
+ */
+
+#include <linux/fs.h>
+#include <linux/mount.h>
+#include <linux/time.h>
+#include <linux/highuid.h>
+#include <linux/pagemap.h>
+#include <linux/dax.h>
+#include <linux/quotaops.h>
+#include <linux/string.h>
+#include <linux/buffer_head.h>
+#include <linux/writeback.h>
+#include <linux/pagevec.h>
+#include <linux/mpage.h>
+#include <linux/rmap.h>
+#include <linux/namei.h>
+#include <linux/uio.h>
+#include <linux/bio.h>
+#include <linux/workqueue.h>
+#include <linux/kernel.h>
+#include <linux/printk.h>
+#include <linux/slab.h>
+#include <linux/bitops.h>
+#include <linux/iomap.h>
+#include <linux/iversion.h>
+
+#include "ext4_jbd2.h"
+#include "xattr.h"
+#include "acl.h"
+#include "truncate.h"
+
+#include <trace/events/ext4.h>
+
+static void ext4_journalled_zero_new_buffers(handle_t *handle,
+ struct inode *inode,
+ struct folio *folio,
+ unsigned from, unsigned to);
+
+static __u32 ext4_inode_csum(struct inode *inode, struct ext4_inode *raw,
+ struct ext4_inode_info *ei)
+{
+ __u32 csum;
+ __u16 dummy_csum = 0;
+ int offset = offsetof(struct ext4_inode, i_checksum_lo);
+ unsigned int csum_size = sizeof(dummy_csum);
+
+ csum = ext4_chksum(ei->i_csum_seed, (__u8 *)raw, offset);
+ csum = ext4_chksum(csum, (__u8 *)&dummy_csum, csum_size);
+ offset += csum_size;
+ csum = ext4_chksum(csum, (__u8 *)raw + offset,
+ EXT4_GOOD_OLD_INODE_SIZE - offset);
+
+ if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
+ offset = offsetof(struct ext4_inode, i_checksum_hi);
+ csum = ext4_chksum(csum, (__u8 *)raw + EXT4_GOOD_OLD_INODE_SIZE,
+ offset - EXT4_GOOD_OLD_INODE_SIZE);
+ if (EXT4_FITS_IN_INODE(raw, ei, i_checksum_hi)) {
+ csum = ext4_chksum(csum, (__u8 *)&dummy_csum,
+ csum_size);
+ offset += csum_size;
+ }
+ csum = ext4_chksum(csum, (__u8 *)raw + offset,
+ EXT4_INODE_SIZE(inode->i_sb) - offset);
+ }
+
+ return csum;
+}
+
+static int ext4_inode_csum_verify(struct inode *inode, struct ext4_inode *raw,
+ struct ext4_inode_info *ei)
+{
+ __u32 provided, calculated;
+
+ if (EXT4_SB(inode->i_sb)->s_es->s_creator_os !=
+ cpu_to_le32(EXT4_OS_LINUX) ||
+ !ext4_has_feature_metadata_csum(inode->i_sb))
+ return 1;
+
+ provided = le16_to_cpu(raw->i_checksum_lo);
+ calculated = ext4_inode_csum(inode, raw, ei);
+ if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE &&
+ EXT4_FITS_IN_INODE(raw, ei, i_checksum_hi))
+ provided |= ((__u32)le16_to_cpu(raw->i_checksum_hi)) << 16;
+ else
+ calculated &= 0xFFFF;
+
+ return provided == calculated;
+}
+
+void ext4_inode_csum_set(struct inode *inode, struct ext4_inode *raw,
+ struct ext4_inode_info *ei)
+{
+ __u32 csum;
+
+ if (EXT4_SB(inode->i_sb)->s_es->s_creator_os !=
+ cpu_to_le32(EXT4_OS_LINUX) ||
+ !ext4_has_feature_metadata_csum(inode->i_sb))
+ return;
+
+ csum = ext4_inode_csum(inode, raw, ei);
+ raw->i_checksum_lo = cpu_to_le16(csum & 0xFFFF);
+ if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE &&
+ EXT4_FITS_IN_INODE(raw, ei, i_checksum_hi))
+ raw->i_checksum_hi = cpu_to_le16(csum >> 16);
+}
+
+static inline int ext4_begin_ordered_truncate(struct inode *inode,
+ loff_t new_size)
+{
+ trace_ext4_begin_ordered_truncate(inode, new_size);
+ /*
+ * If jinode is zero, then we never opened the file for
+ * writing, so there's no need to call
+ * jbd2_journal_begin_ordered_truncate() since there's no
+ * outstanding writes we need to flush.
+ */
+ if (!EXT4_I(inode)->jinode)
+ return 0;
+ return jbd2_journal_begin_ordered_truncate(EXT4_JOURNAL(inode),
+ EXT4_I(inode)->jinode,
+ new_size);
+}
+
+/*
+ * Test whether an inode is a fast symlink.
+ * A fast symlink has its symlink data stored in ext4_inode_info->i_data.
+ */
+int ext4_inode_is_fast_symlink(struct inode *inode)
+{
+ if (!ext4_has_feature_ea_inode(inode->i_sb)) {
+ int ea_blocks = EXT4_I(inode)->i_file_acl ?
+ EXT4_CLUSTER_SIZE(inode->i_sb) >> 9 : 0;
+
+ if (ext4_has_inline_data(inode))
+ return 0;
+
+ return (S_ISLNK(inode->i_mode) && inode->i_blocks - ea_blocks == 0);
+ }
+ return S_ISLNK(inode->i_mode) && inode->i_size &&
+ (inode->i_size < EXT4_N_BLOCKS * 4);
+}
+
+/*
+ * Called at the last iput() if i_nlink is zero.
+ */
+void ext4_evict_inode(struct inode *inode)
+{
+ handle_t *handle;
+ int err;
+ /*
+ * Credits for final inode cleanup and freeing:
+ * sb + inode (ext4_orphan_del()), block bitmap, group descriptor
+ * (xattr block freeing), bitmap, group descriptor (inode freeing)
+ */
+ int extra_credits = 6;
+ struct ext4_xattr_inode_array *ea_inode_array = NULL;
+ bool freeze_protected = false;
+
+ trace_ext4_evict_inode(inode);
+
+ dax_break_layout_final(inode);
+
+ if (EXT4_I(inode)->i_flags & EXT4_EA_INODE_FL)
+ ext4_evict_ea_inode(inode);
+ if (inode->i_nlink) {
+ truncate_inode_pages_final(&inode->i_data);
+
+ goto no_delete;
+ }
+
+ if (is_bad_inode(inode))
+ goto no_delete;
+ dquot_initialize(inode);
+
+ if (ext4_should_order_data(inode))
+ ext4_begin_ordered_truncate(inode, 0);
+ truncate_inode_pages_final(&inode->i_data);
+
+ /*
+ * For inodes with journalled data, transaction commit could have
+ * dirtied the inode. And for inodes with dioread_nolock, unwritten
+ * extents converting worker could merge extents and also have dirtied
+ * the inode. Flush worker is ignoring it because of I_FREEING flag but
+ * we still need to remove the inode from the writeback lists.
+ */
+ if (!list_empty_careful(&inode->i_io_list))
+ inode_io_list_del(inode);
+
+ /*
+ * Protect us against freezing - iput() caller didn't have to have any
+ * protection against it. When we are in a running transaction though,
+ * we are already protected against freezing and we cannot grab further
+ * protection due to lock ordering constraints.
+ */
+ if (!ext4_journal_current_handle()) {
+ sb_start_intwrite(inode->i_sb);
+ freeze_protected = true;
+ }
+
+ if (!IS_NOQUOTA(inode))
+ extra_credits += EXT4_MAXQUOTAS_DEL_BLOCKS(inode->i_sb);
+
+ /*
+ * Block bitmap, group descriptor, and inode are accounted in both
+ * ext4_blocks_for_truncate() and extra_credits. So subtract 3.
+ */
+ handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE,
+ ext4_blocks_for_truncate(inode) + extra_credits - 3);
+ if (IS_ERR(handle)) {
+ ext4_std_error(inode->i_sb, PTR_ERR(handle));
+ /*
+ * If we're going to skip the normal cleanup, we still need to
+ * make sure that the in-core orphan linked list is properly
+ * cleaned up.
+ */
+ ext4_orphan_del(NULL, inode);
+ if (freeze_protected)
+ sb_end_intwrite(inode->i_sb);
+ goto no_delete;
+ }
+
+ if (IS_SYNC(inode))
+ ext4_handle_sync(handle);
+
+ /*
+ * Set inode->i_size to 0 before calling ext4_truncate(). We need
+ * special handling of symlinks here because i_size is used to
+ * determine whether ext4_inode_info->i_data contains symlink data or
+ * block mappings. Setting i_size to 0 will remove its fast symlink
+ * status. Erase i_data so that it becomes a valid empty block map.
+ */
+ if (ext4_inode_is_fast_symlink(inode))
+ memset(EXT4_I(inode)->i_data, 0, sizeof(EXT4_I(inode)->i_data));
+ inode->i_size = 0;
+ err = ext4_mark_inode_dirty(handle, inode);
+ if (err) {
+ ext4_warning(inode->i_sb,
+ "couldn't mark inode dirty (err %d)", err);
+ goto stop_handle;
+ }
+ if (inode->i_blocks) {
+ err = ext4_truncate(inode);
+ if (err) {
+ ext4_error_err(inode->i_sb, -err,
+ "couldn't truncate inode %lu (err %d)",
+ inode->i_ino, err);
+ goto stop_handle;
+ }
+ }
+
+ /* Remove xattr references. */
+ err = ext4_xattr_delete_inode(handle, inode, &ea_inode_array,
+ extra_credits);
+ if (err) {
+ ext4_warning(inode->i_sb, "xattr delete (err %d)", err);
+stop_handle:
+ ext4_journal_stop(handle);
+ ext4_orphan_del(NULL, inode);
+ if (freeze_protected)
+ sb_end_intwrite(inode->i_sb);
+ ext4_xattr_inode_array_free(ea_inode_array);
+ goto no_delete;
+ }
+
+ /*
+ * Kill off the orphan record which ext4_truncate created.
+ * AKPM: I think this can be inside the above `if'.
+ * Note that ext4_orphan_del() has to be able to cope with the
+ * deletion of a non-existent orphan - this is because we don't
+ * know if ext4_truncate() actually created an orphan record.
+ * (Well, we could do this if we need to, but heck - it works)
+ */
+ ext4_orphan_del(handle, inode);
+ EXT4_I(inode)->i_dtime = (__u32)ktime_get_real_seconds();
+
+ /*
+ * One subtle ordering requirement: if anything has gone wrong
+ * (transaction abort, IO errors, whatever), then we can still
+ * do these next steps (the fs will already have been marked as
+ * having errors), but we can't free the inode if the mark_dirty
+ * fails.
+ */
+ if (ext4_mark_inode_dirty(handle, inode))
+ /* If that failed, just do the required in-core inode clear. */
+ ext4_clear_inode(inode);
+ else
+ ext4_free_inode(handle, inode);
+ ext4_journal_stop(handle);
+ if (freeze_protected)
+ sb_end_intwrite(inode->i_sb);
+ ext4_xattr_inode_array_free(ea_inode_array);
+ return;
+no_delete:
+ /*
+ * Check out some where else accidentally dirty the evicting inode,
+ * which may probably cause inode use-after-free issues later.
+ */
+ WARN_ON_ONCE(!list_empty_careful(&inode->i_io_list));
+
+ if (!list_empty(&EXT4_I(inode)->i_fc_list))
+ ext4_fc_mark_ineligible(inode->i_sb, EXT4_FC_REASON_NOMEM, NULL);
+ ext4_clear_inode(inode); /* We must guarantee clearing of inode... */
+}
+
+#ifdef CONFIG_QUOTA
+qsize_t *ext4_get_reserved_space(struct inode *inode)
+{
+ return &EXT4_I(inode)->i_reserved_quota;
+}
+#endif
+
+/*
+ * Called with i_data_sem down, which is important since we can call
+ * ext4_discard_preallocations() from here.
+ */
+void ext4_da_update_reserve_space(struct inode *inode,
+ int used, int quota_claim)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+ struct ext4_inode_info *ei = EXT4_I(inode);
+
+ spin_lock(&ei->i_block_reservation_lock);
+ trace_ext4_da_update_reserve_space(inode, used, quota_claim);
+ if (unlikely(used > ei->i_reserved_data_blocks)) {
+ ext4_warning(inode->i_sb, "%s: ino %lu, used %d "
+ "with only %d reserved data blocks",
+ __func__, inode->i_ino, used,
+ ei->i_reserved_data_blocks);
+ WARN_ON(1);
+ used = ei->i_reserved_data_blocks;
+ }
+
+ /* Update per-inode reservations */
+ ei->i_reserved_data_blocks -= used;
+ percpu_counter_sub(&sbi->s_dirtyclusters_counter, used);
+
+ spin_unlock(&ei->i_block_reservation_lock);
+
+ /* Update quota subsystem for data blocks */
+ if (quota_claim)
+ dquot_claim_block(inode, EXT4_C2B(sbi, used));
+ else {
+ /*
+ * We did fallocate with an offset that is already delayed
+ * allocated. So on delayed allocated writeback we should
+ * not re-claim the quota for fallocated blocks.
+ */
+ dquot_release_reservation_block(inode, EXT4_C2B(sbi, used));
+ }
+
+ /*
+ * If we have done all the pending block allocations and if
+ * there aren't any writers on the inode, we can discard the
+ * inode's preallocations.
+ */
+ if ((ei->i_reserved_data_blocks == 0) &&
+ !inode_is_open_for_write(inode))
+ ext4_discard_preallocations(inode);
+}
+
+static int __check_block_validity(struct inode *inode, const char *func,
+ unsigned int line,
+ struct ext4_map_blocks *map)
+{
+ journal_t *journal = EXT4_SB(inode->i_sb)->s_journal;
+
+ if (journal && inode == journal->j_inode)
+ return 0;
+
+ if (!ext4_inode_block_valid(inode, map->m_pblk, map->m_len)) {
+ ext4_error_inode(inode, func, line, map->m_pblk,
+ "lblock %lu mapped to illegal pblock %llu "
+ "(length %d)", (unsigned long) map->m_lblk,
+ map->m_pblk, map->m_len);
+ return -EFSCORRUPTED;
+ }
+ return 0;
+}
+
+int ext4_issue_zeroout(struct inode *inode, ext4_lblk_t lblk, ext4_fsblk_t pblk,
+ ext4_lblk_t len)
+{
+ int ret;
+
+ if (IS_ENCRYPTED(inode) && S_ISREG(inode->i_mode))
+ return fscrypt_zeroout_range(inode, lblk, pblk, len);
+
+ ret = sb_issue_zeroout(inode->i_sb, pblk, len, GFP_NOFS);
+ if (ret > 0)
+ ret = 0;
+
+ return ret;
+}
+
+/*
+ * For generic regular files, when updating the extent tree, Ext4 should
+ * hold the i_rwsem and invalidate_lock exclusively. This ensures
+ * exclusion against concurrent page faults, as well as reads and writes.
+ */
+#ifdef CONFIG_EXT4_DEBUG
+void ext4_check_map_extents_env(struct inode *inode)
+{
+ if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
+ return;
+
+ if (!S_ISREG(inode->i_mode) ||
+ IS_NOQUOTA(inode) || IS_VERITY(inode) ||
+ is_special_ino(inode->i_sb, inode->i_ino) ||
+ (inode->i_state & (I_FREEING | I_WILL_FREE | I_NEW)) ||
+ ext4_test_inode_flag(inode, EXT4_INODE_EA_INODE) ||
+ ext4_verity_in_progress(inode))
+ return;
+
+ WARN_ON_ONCE(!inode_is_locked(inode) &&
+ !rwsem_is_locked(&inode->i_mapping->invalidate_lock));
+}
+#else
+void ext4_check_map_extents_env(struct inode *inode) {}
+#endif
+
+#define check_block_validity(inode, map) \
+ __check_block_validity((inode), __func__, __LINE__, (map))
+
+#ifdef ES_AGGRESSIVE_TEST
+static void ext4_map_blocks_es_recheck(handle_t *handle,
+ struct inode *inode,
+ struct ext4_map_blocks *es_map,
+ struct ext4_map_blocks *map,
+ int flags)
+{
+ int retval;
+
+ map->m_flags = 0;
+ /*
+ * There is a race window that the result is not the same.
+ * e.g. xfstests #223 when dioread_nolock enables. The reason
+ * is that we lookup a block mapping in extent status tree with
+ * out taking i_data_sem. So at the time the unwritten extent
+ * could be converted.
+ */
+ down_read(&EXT4_I(inode)->i_data_sem);
+ if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
+ retval = ext4_ext_map_blocks(handle, inode, map, 0);
+ } else {
+ retval = ext4_ind_map_blocks(handle, inode, map, 0);
+ }
+ up_read((&EXT4_I(inode)->i_data_sem));
+
+ /*
+ * We don't check m_len because extent will be collpased in status
+ * tree. So the m_len might not equal.
+ */
+ if (es_map->m_lblk != map->m_lblk ||
+ es_map->m_flags != map->m_flags ||
+ es_map->m_pblk != map->m_pblk) {
+ printk("ES cache assertion failed for inode: %lu "
+ "es_cached ex [%d/%d/%llu/%x] != "
+ "found ex [%d/%d/%llu/%x] retval %d flags %x\n",
+ inode->i_ino, es_map->m_lblk, es_map->m_len,
+ es_map->m_pblk, es_map->m_flags, map->m_lblk,
+ map->m_len, map->m_pblk, map->m_flags,
+ retval, flags);
+ }
+}
+#endif /* ES_AGGRESSIVE_TEST */
+
+static int ext4_map_query_blocks_next_in_leaf(handle_t *handle,
+ struct inode *inode, struct ext4_map_blocks *map,
+ unsigned int orig_mlen)
+{
+ struct ext4_map_blocks map2;
+ unsigned int status, status2;
+ int retval;
+
+ status = map->m_flags & EXT4_MAP_UNWRITTEN ?
+ EXTENT_STATUS_UNWRITTEN : EXTENT_STATUS_WRITTEN;
+
+ WARN_ON_ONCE(!(map->m_flags & EXT4_MAP_QUERY_LAST_IN_LEAF));
+ WARN_ON_ONCE(orig_mlen <= map->m_len);
+
+ /* Prepare map2 for lookup in next leaf block */
+ map2.m_lblk = map->m_lblk + map->m_len;
+ map2.m_len = orig_mlen - map->m_len;
+ map2.m_flags = 0;
+ retval = ext4_ext_map_blocks(handle, inode, &map2, 0);
+
+ if (retval <= 0) {
+ ext4_es_insert_extent(inode, map->m_lblk, map->m_len,
+ map->m_pblk, status, false);
+ return map->m_len;
+ }
+
+ if (unlikely(retval != map2.m_len)) {
+ ext4_warning(inode->i_sb,
+ "ES len assertion failed for inode "
+ "%lu: retval %d != map->m_len %d",
+ inode->i_ino, retval, map2.m_len);
+ WARN_ON(1);
+ }
+
+ status2 = map2.m_flags & EXT4_MAP_UNWRITTEN ?
+ EXTENT_STATUS_UNWRITTEN : EXTENT_STATUS_WRITTEN;
+
+ /*
+ * If map2 is contiguous with map, then let's insert it as a single
+ * extent in es cache and return the combined length of both the maps.
+ */
+ if (map->m_pblk + map->m_len == map2.m_pblk &&
+ status == status2) {
+ ext4_es_insert_extent(inode, map->m_lblk,
+ map->m_len + map2.m_len, map->m_pblk,
+ status, false);
+ map->m_len += map2.m_len;
+ } else {
+ ext4_es_insert_extent(inode, map->m_lblk, map->m_len,
+ map->m_pblk, status, false);
+ }
+
+ return map->m_len;
+}
+
+static int ext4_map_query_blocks(handle_t *handle, struct inode *inode,
+ struct ext4_map_blocks *map, int flags)
+{
+ unsigned int status;
+ int retval;
+ unsigned int orig_mlen = map->m_len;
+
+ flags &= EXT4_EX_QUERY_FILTER;
+ if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
+ retval = ext4_ext_map_blocks(handle, inode, map, flags);
+ else
+ retval = ext4_ind_map_blocks(handle, inode, map, flags);
+
+ if (retval <= 0)
+ return retval;
+
+ if (unlikely(retval != map->m_len)) {
+ ext4_warning(inode->i_sb,
+ "ES len assertion failed for inode "
+ "%lu: retval %d != map->m_len %d",
+ inode->i_ino, retval, map->m_len);
+ WARN_ON(1);
+ }
+
+ /*
+ * No need to query next in leaf:
+ * - if returned extent is not last in leaf or
+ * - if the last in leaf is the full requested range
+ */
+ if (!(map->m_flags & EXT4_MAP_QUERY_LAST_IN_LEAF) ||
+ map->m_len == orig_mlen) {
+ status = map->m_flags & EXT4_MAP_UNWRITTEN ?
+ EXTENT_STATUS_UNWRITTEN : EXTENT_STATUS_WRITTEN;
+ ext4_es_insert_extent(inode, map->m_lblk, map->m_len,
+ map->m_pblk, status, false);
+ return retval;
+ }
+
+ return ext4_map_query_blocks_next_in_leaf(handle, inode, map,
+ orig_mlen);
+}
+
+static int ext4_map_create_blocks(handle_t *handle, struct inode *inode,
+ struct ext4_map_blocks *map, int flags)
+{
+ struct extent_status es;
+ unsigned int status;
+ int err, retval = 0;
+
+ /*
+ * We pass in the magic EXT4_GET_BLOCKS_DELALLOC_RESERVE
+ * indicates that the blocks and quotas has already been
+ * checked when the data was copied into the page cache.
+ */
+ if (map->m_flags & EXT4_MAP_DELAYED)
+ flags |= EXT4_GET_BLOCKS_DELALLOC_RESERVE;
+
+ /*
+ * Here we clear m_flags because after allocating an new extent,
+ * it will be set again.
+ */
+ map->m_flags &= ~EXT4_MAP_FLAGS;
+
+ /*
+ * We need to check for EXT4 here because migrate could have
+ * changed the inode type in between.
+ */
+ if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
+ retval = ext4_ext_map_blocks(handle, inode, map, flags);
+ } else {
+ retval = ext4_ind_map_blocks(handle, inode, map, flags);
+
+ /*
+ * We allocated new blocks which will result in i_data's
+ * format changing. Force the migrate to fail by clearing
+ * migrate flags.
+ */
+ if (retval > 0 && map->m_flags & EXT4_MAP_NEW)
+ ext4_clear_inode_state(inode, EXT4_STATE_EXT_MIGRATE);
+ }
+ if (retval <= 0)
+ return retval;
+
+ if (unlikely(retval != map->m_len)) {
+ ext4_warning(inode->i_sb,
+ "ES len assertion failed for inode %lu: "
+ "retval %d != map->m_len %d",
+ inode->i_ino, retval, map->m_len);
+ WARN_ON(1);
+ }
+
+ /*
+ * We have to zeroout blocks before inserting them into extent
+ * status tree. Otherwise someone could look them up there and
+ * use them before they are really zeroed. We also have to
+ * unmap metadata before zeroing as otherwise writeback can
+ * overwrite zeros with stale data from block device.
+ */
+ if (flags & EXT4_GET_BLOCKS_ZERO &&
+ map->m_flags & EXT4_MAP_MAPPED && map->m_flags & EXT4_MAP_NEW) {
+ err = ext4_issue_zeroout(inode, map->m_lblk, map->m_pblk,
+ map->m_len);
+ if (err)
+ return err;
+ }
+
+ /*
+ * If the extent has been zeroed out, we don't need to update
+ * extent status tree.
+ */
+ if (flags & EXT4_GET_BLOCKS_PRE_IO &&
+ ext4_es_lookup_extent(inode, map->m_lblk, NULL, &es)) {
+ if (ext4_es_is_written(&es))
+ return retval;
+ }
+
+ status = map->m_flags & EXT4_MAP_UNWRITTEN ?
+ EXTENT_STATUS_UNWRITTEN : EXTENT_STATUS_WRITTEN;
+ ext4_es_insert_extent(inode, map->m_lblk, map->m_len, map->m_pblk,
+ status, flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE);
+
+ return retval;
+}
+
+/*
+ * The ext4_map_blocks() function tries to look up the requested blocks,
+ * and returns if the blocks are already mapped.
+ *
+ * Otherwise it takes the write lock of the i_data_sem and allocate blocks
+ * and store the allocated blocks in the result buffer head and mark it
+ * mapped.
+ *
+ * If file type is extents based, it will call ext4_ext_map_blocks(),
+ * Otherwise, call with ext4_ind_map_blocks() to handle indirect mapping
+ * based files
+ *
+ * On success, it returns the number of blocks being mapped or allocated.
+ * If flags doesn't contain EXT4_GET_BLOCKS_CREATE the blocks are
+ * pre-allocated and unwritten, the resulting @map is marked as unwritten.
+ * If the flags contain EXT4_GET_BLOCKS_CREATE, it will mark @map as mapped.
+ *
+ * It returns 0 if plain look up failed (blocks have not been allocated), in
+ * that case, @map is returned as unmapped but we still do fill map->m_len to
+ * indicate the length of a hole starting at map->m_lblk.
+ *
+ * It returns the error in case of allocation failure.
+ */
+int ext4_map_blocks(handle_t *handle, struct inode *inode,
+ struct ext4_map_blocks *map, int flags)
+{
+ struct extent_status es;
+ int retval;
+ int ret = 0;
+ unsigned int orig_mlen = map->m_len;
+#ifdef ES_AGGRESSIVE_TEST
+ struct ext4_map_blocks orig_map;
+
+ memcpy(&orig_map, map, sizeof(*map));
+#endif
+
+ map->m_flags = 0;
+ ext_debug(inode, "flag 0x%x, max_blocks %u, logical block %lu\n",
+ flags, map->m_len, (unsigned long) map->m_lblk);
+
+ /*
+ * ext4_map_blocks returns an int, and m_len is an unsigned int
+ */
+ if (unlikely(map->m_len > INT_MAX))
+ map->m_len = INT_MAX;
+
+ /* We can handle the block number less than EXT_MAX_BLOCKS */
+ if (unlikely(map->m_lblk >= EXT_MAX_BLOCKS))
+ return -EFSCORRUPTED;
+
+ /*
+ * Callers from the context of data submission are the only exceptions
+ * for regular files that do not hold the i_rwsem or invalidate_lock.
+ * However, caching unrelated ranges is not permitted.
+ */
+ if (flags & EXT4_GET_BLOCKS_IO_SUBMIT)
+ WARN_ON_ONCE(!(flags & EXT4_EX_NOCACHE));
+ else
+ ext4_check_map_extents_env(inode);
+
+ /* Lookup extent status tree firstly */
+ if (ext4_es_lookup_extent(inode, map->m_lblk, NULL, &es)) {
+ if (ext4_es_is_written(&es) || ext4_es_is_unwritten(&es)) {
+ map->m_pblk = ext4_es_pblock(&es) +
+ map->m_lblk - es.es_lblk;
+ map->m_flags |= ext4_es_is_written(&es) ?
+ EXT4_MAP_MAPPED : EXT4_MAP_UNWRITTEN;
+ retval = es.es_len - (map->m_lblk - es.es_lblk);
+ if (retval > map->m_len)
+ retval = map->m_len;
+ map->m_len = retval;
+ } else if (ext4_es_is_delayed(&es) || ext4_es_is_hole(&es)) {
+ map->m_pblk = 0;
+ map->m_flags |= ext4_es_is_delayed(&es) ?
+ EXT4_MAP_DELAYED : 0;
+ retval = es.es_len - (map->m_lblk - es.es_lblk);
+ if (retval > map->m_len)
+ retval = map->m_len;
+ map->m_len = retval;
+ retval = 0;
+ } else {
+ BUG();
+ }
+
+ if (flags & EXT4_GET_BLOCKS_CACHED_NOWAIT)
+ return retval;
+#ifdef ES_AGGRESSIVE_TEST
+ ext4_map_blocks_es_recheck(handle, inode, map,
+ &orig_map, flags);
+#endif
+ if (!(flags & EXT4_GET_BLOCKS_QUERY_LAST_IN_LEAF) ||
+ orig_mlen == map->m_len)
+ goto found;
+
+ map->m_len = orig_mlen;
+ }
+ /*
+ * In the query cache no-wait mode, nothing we can do more if we
+ * cannot find extent in the cache.
+ */
+ if (flags & EXT4_GET_BLOCKS_CACHED_NOWAIT)
+ return 0;
+
+ /*
+ * Try to see if we can get the block without requesting a new
+ * file system block.
+ */
+ down_read(&EXT4_I(inode)->i_data_sem);
+ retval = ext4_map_query_blocks(handle, inode, map, flags);
+ up_read((&EXT4_I(inode)->i_data_sem));
+
+found:
+ if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) {
+ ret = check_block_validity(inode, map);
+ if (ret != 0)
+ return ret;
+ }
+
+ /* If it is only a block(s) look up */
+ if ((flags & EXT4_GET_BLOCKS_CREATE) == 0)
+ return retval;
+
+ /*
+ * Returns if the blocks have already allocated
+ *
+ * Note that if blocks have been preallocated
+ * ext4_ext_map_blocks() returns with buffer head unmapped
+ */
+ if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED)
+ /*
+ * If we need to convert extent to unwritten
+ * we continue and do the actual work in
+ * ext4_ext_map_blocks()
+ */
+ if (!(flags & EXT4_GET_BLOCKS_CONVERT_UNWRITTEN))
+ return retval;
+
+
+ ext4_fc_track_inode(handle, inode);
+ /*
+ * New blocks allocate and/or writing to unwritten extent
+ * will possibly result in updating i_data, so we take
+ * the write lock of i_data_sem, and call get_block()
+ * with create == 1 flag.
+ */
+ down_write(&EXT4_I(inode)->i_data_sem);
+ retval = ext4_map_create_blocks(handle, inode, map, flags);
+ up_write((&EXT4_I(inode)->i_data_sem));
+ if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) {
+ ret = check_block_validity(inode, map);
+ if (ret != 0)
+ return ret;
+
+ /*
+ * Inodes with freshly allocated blocks where contents will be
+ * visible after transaction commit must be on transaction's
+ * ordered data list.
+ */
+ if (map->m_flags & EXT4_MAP_NEW &&
+ !(map->m_flags & EXT4_MAP_UNWRITTEN) &&
+ !(flags & EXT4_GET_BLOCKS_ZERO) &&
+ !ext4_is_quota_file(inode) &&
+ ext4_should_order_data(inode)) {
+ loff_t start_byte =
+ (loff_t)map->m_lblk << inode->i_blkbits;
+ loff_t length = (loff_t)map->m_len << inode->i_blkbits;
+
+ if (flags & EXT4_GET_BLOCKS_IO_SUBMIT)
+ ret = ext4_jbd2_inode_add_wait(handle, inode,
+ start_byte, length);
+ else
+ ret = ext4_jbd2_inode_add_write(handle, inode,
+ start_byte, length);
+ if (ret)
+ return ret;
+ }
+ }
+ if (retval > 0 && (map->m_flags & EXT4_MAP_UNWRITTEN ||
+ map->m_flags & EXT4_MAP_MAPPED))
+ ext4_fc_track_range(handle, inode, map->m_lblk,
+ map->m_lblk + map->m_len - 1);
+ if (retval < 0)
+ ext_debug(inode, "failed with err %d\n", retval);
+ return retval;
+}
+
+/*
+ * Update EXT4_MAP_FLAGS in bh->b_state. For buffer heads attached to pages
+ * we have to be careful as someone else may be manipulating b_state as well.
+ */
+static void ext4_update_bh_state(struct buffer_head *bh, unsigned long flags)
+{
+ unsigned long old_state;
+ unsigned long new_state;
+
+ flags &= EXT4_MAP_FLAGS;
+
+ /* Dummy buffer_head? Set non-atomically. */
+ if (!bh->b_folio) {
+ bh->b_state = (bh->b_state & ~EXT4_MAP_FLAGS) | flags;
+ return;
+ }
+ /*
+ * Someone else may be modifying b_state. Be careful! This is ugly but
+ * once we get rid of using bh as a container for mapping information
+ * to pass to / from get_block functions, this can go away.
+ */
+ old_state = READ_ONCE(bh->b_state);
+ do {
+ new_state = (old_state & ~EXT4_MAP_FLAGS) | flags;
+ } while (unlikely(!try_cmpxchg(&bh->b_state, &old_state, new_state)));
+}
+
+/*
+ * Make sure that the current journal transaction has enough credits to map
+ * one extent. Return -EAGAIN if it cannot extend the current running
+ * transaction.
+ */
+static inline int ext4_journal_ensure_extent_credits(handle_t *handle,
+ struct inode *inode)
+{
+ int credits;
+ int ret;
+
+ /* Called from ext4_da_write_begin() which has no handle started? */
+ if (!handle)
+ return 0;
+
+ credits = ext4_chunk_trans_blocks(inode, 1);
+ ret = __ext4_journal_ensure_credits(handle, credits, credits, 0);
+ return ret <= 0 ? ret : -EAGAIN;
+}
+
+static int _ext4_get_block(struct inode *inode, sector_t iblock,
+ struct buffer_head *bh, int flags)
+{
+ struct ext4_map_blocks map;
+ int ret = 0;
+
+ if (ext4_has_inline_data(inode))
+ return -ERANGE;
+
+ map.m_lblk = iblock;
+ map.m_len = bh->b_size >> inode->i_blkbits;
+
+ ret = ext4_map_blocks(ext4_journal_current_handle(), inode, &map,
+ flags);
+ if (ret > 0) {
+ map_bh(bh, inode->i_sb, map.m_pblk);
+ ext4_update_bh_state(bh, map.m_flags);
+ bh->b_size = inode->i_sb->s_blocksize * map.m_len;
+ ret = 0;
+ } else if (ret == 0) {
+ /* hole case, need to fill in bh->b_size */
+ bh->b_size = inode->i_sb->s_blocksize * map.m_len;
+ }
+ return ret;
+}
+
+int ext4_get_block(struct inode *inode, sector_t iblock,
+ struct buffer_head *bh, int create)
+{
+ return _ext4_get_block(inode, iblock, bh,
+ create ? EXT4_GET_BLOCKS_CREATE : 0);
+}
+
+/*
+ * Get block function used when preparing for buffered write if we require
+ * creating an unwritten extent if blocks haven't been allocated. The extent
+ * will be converted to written after the IO is complete.
+ */
+int ext4_get_block_unwritten(struct inode *inode, sector_t iblock,
+ struct buffer_head *bh_result, int create)
+{
+ int ret = 0;
+
+ ext4_debug("ext4_get_block_unwritten: inode %lu, create flag %d\n",
+ inode->i_ino, create);
+ ret = _ext4_get_block(inode, iblock, bh_result,
+ EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT);
+
+ /*
+ * If the buffer is marked unwritten, mark it as new to make sure it is
+ * zeroed out correctly in case of partial writes. Otherwise, there is
+ * a chance of stale data getting exposed.
+ */
+ if (ret == 0 && buffer_unwritten(bh_result))
+ set_buffer_new(bh_result);
+
+ return ret;
+}
+
+/* Maximum number of blocks we map for direct IO at once. */
+#define DIO_MAX_BLOCKS 4096
+
+/*
+ * `handle' can be NULL if create is zero
+ */
+struct buffer_head *ext4_getblk(handle_t *handle, struct inode *inode,
+ ext4_lblk_t block, int map_flags)
+{
+ struct ext4_map_blocks map;
+ struct buffer_head *bh;
+ int create = map_flags & EXT4_GET_BLOCKS_CREATE;
+ bool nowait = map_flags & EXT4_GET_BLOCKS_CACHED_NOWAIT;
+ int err;
+
+ ASSERT((EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
+ || handle != NULL || create == 0);
+ ASSERT(create == 0 || !nowait);
+
+ map.m_lblk = block;
+ map.m_len = 1;
+ err = ext4_map_blocks(handle, inode, &map, map_flags);
+
+ if (err == 0)
+ return create ? ERR_PTR(-ENOSPC) : NULL;
+ if (err < 0)
+ return ERR_PTR(err);
+
+ if (nowait)
+ return sb_find_get_block(inode->i_sb, map.m_pblk);
+
+ /*
+ * Since bh could introduce extra ref count such as referred by
+ * journal_head etc. Try to avoid using __GFP_MOVABLE here
+ * as it may fail the migration when journal_head remains.
+ */
+ bh = getblk_unmovable(inode->i_sb->s_bdev, map.m_pblk,
+ inode->i_sb->s_blocksize);
+
+ if (unlikely(!bh))
+ return ERR_PTR(-ENOMEM);
+ if (map.m_flags & EXT4_MAP_NEW) {
+ ASSERT(create != 0);
+ ASSERT((EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
+ || (handle != NULL));
+
+ /*
+ * Now that we do not always journal data, we should
+ * keep in mind whether this should always journal the
+ * new buffer as metadata. For now, regular file
+ * writes use ext4_get_block instead, so it's not a
+ * problem.
+ */
+ lock_buffer(bh);
+ BUFFER_TRACE(bh, "call get_create_access");
+ err = ext4_journal_get_create_access(handle, inode->i_sb, bh,
+ EXT4_JTR_NONE);
+ if (unlikely(err)) {
+ unlock_buffer(bh);
+ goto errout;
+ }
+ if (!buffer_uptodate(bh)) {
+ memset(bh->b_data, 0, inode->i_sb->s_blocksize);
+ set_buffer_uptodate(bh);
+ }
+ unlock_buffer(bh);
+ BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
+ err = ext4_handle_dirty_metadata(handle, inode, bh);
+ if (unlikely(err))
+ goto errout;
+ } else
+ BUFFER_TRACE(bh, "not a new buffer");
+ return bh;
+errout:
+ brelse(bh);
+ return ERR_PTR(err);
+}
+
+struct buffer_head *ext4_bread(handle_t *handle, struct inode *inode,
+ ext4_lblk_t block, int map_flags)
+{
+ struct buffer_head *bh;
+ int ret;
+
+ bh = ext4_getblk(handle, inode, block, map_flags);
+ if (IS_ERR(bh))
+ return bh;
+ if (!bh || ext4_buffer_uptodate(bh))
+ return bh;
+
+ ret = ext4_read_bh_lock(bh, REQ_META | REQ_PRIO, true);
+ if (ret) {
+ put_bh(bh);
+ return ERR_PTR(ret);
+ }
+ return bh;
+}
+
+/* Read a contiguous batch of blocks. */
+int ext4_bread_batch(struct inode *inode, ext4_lblk_t block, int bh_count,
+ bool wait, struct buffer_head **bhs)
+{
+ int i, err;
+
+ for (i = 0; i < bh_count; i++) {
+ bhs[i] = ext4_getblk(NULL, inode, block + i, 0 /* map_flags */);
+ if (IS_ERR(bhs[i])) {
+ err = PTR_ERR(bhs[i]);
+ bh_count = i;
+ goto out_brelse;
+ }
+ }
+
+ for (i = 0; i < bh_count; i++)
+ /* Note that NULL bhs[i] is valid because of holes. */
+ if (bhs[i] && !ext4_buffer_uptodate(bhs[i]))
+ ext4_read_bh_lock(bhs[i], REQ_META | REQ_PRIO, false);
+
+ if (!wait)
+ return 0;
+
+ for (i = 0; i < bh_count; i++)
+ if (bhs[i])
+ wait_on_buffer(bhs[i]);
+
+ for (i = 0; i < bh_count; i++) {
+ if (bhs[i] && !buffer_uptodate(bhs[i])) {
+ err = -EIO;
+ goto out_brelse;
+ }
+ }
+ return 0;
+
+out_brelse:
+ for (i = 0; i < bh_count; i++) {
+ brelse(bhs[i]);
+ bhs[i] = NULL;
+ }
+ return err;
+}
+
+int ext4_walk_page_buffers(handle_t *handle, struct inode *inode,
+ struct buffer_head *head,
+ unsigned from,
+ unsigned to,
+ int *partial,
+ int (*fn)(handle_t *handle, struct inode *inode,
+ struct buffer_head *bh))
+{
+ struct buffer_head *bh;
+ unsigned block_start, block_end;
+ unsigned blocksize = head->b_size;
+ int err, ret = 0;
+ struct buffer_head *next;
+
+ for (bh = head, block_start = 0;
+ ret == 0 && (bh != head || !block_start);
+ block_start = block_end, bh = next) {
+ next = bh->b_this_page;
+ block_end = block_start + blocksize;
+ if (block_end <= from || block_start >= to) {
+ if (partial && !buffer_uptodate(bh))
+ *partial = 1;
+ continue;
+ }
+ err = (*fn)(handle, inode, bh);
+ if (!ret)
+ ret = err;
+ }
+ return ret;
+}
+
+/*
+ * Helper for handling dirtying of journalled data. We also mark the folio as
+ * dirty so that writeback code knows about this page (and inode) contains
+ * dirty data. ext4_writepages() then commits appropriate transaction to
+ * make data stable.
+ */
+static int ext4_dirty_journalled_data(handle_t *handle, struct buffer_head *bh)
+{
+ struct folio *folio = bh->b_folio;
+ struct inode *inode = folio->mapping->host;
+
+ /* only regular files have a_ops */
+ if (S_ISREG(inode->i_mode))
+ folio_mark_dirty(folio);
+ return ext4_handle_dirty_metadata(handle, NULL, bh);
+}
+
+int do_journal_get_write_access(handle_t *handle, struct inode *inode,
+ struct buffer_head *bh)
+{
+ if (!buffer_mapped(bh) || buffer_freed(bh))
+ return 0;
+ BUFFER_TRACE(bh, "get write access");
+ return ext4_journal_get_write_access(handle, inode->i_sb, bh,
+ EXT4_JTR_NONE);
+}
+
+int ext4_block_write_begin(handle_t *handle, struct folio *folio,
+ loff_t pos, unsigned len,
+ get_block_t *get_block)
+{
+ unsigned int from = offset_in_folio(folio, pos);
+ unsigned to = from + len;
+ struct inode *inode = folio->mapping->host;
+ unsigned block_start, block_end;
+ sector_t block;
+ int err = 0;
+ unsigned blocksize = inode->i_sb->s_blocksize;
+ unsigned bbits;
+ struct buffer_head *bh, *head, *wait[2];
+ int nr_wait = 0;
+ int i;
+ bool should_journal_data = ext4_should_journal_data(inode);
+
+ BUG_ON(!folio_test_locked(folio));
+ BUG_ON(to > folio_size(folio));
+ BUG_ON(from > to);
+
+ head = folio_buffers(folio);
+ if (!head)
+ head = create_empty_buffers(folio, blocksize, 0);
+ bbits = ilog2(blocksize);
+ block = (sector_t)folio->index << (PAGE_SHIFT - bbits);
+
+ for (bh = head, block_start = 0; bh != head || !block_start;
+ block++, block_start = block_end, bh = bh->b_this_page) {
+ block_end = block_start + blocksize;
+ if (block_end <= from || block_start >= to) {
+ if (folio_test_uptodate(folio)) {
+ set_buffer_uptodate(bh);
+ }
+ continue;
+ }
+ if (WARN_ON_ONCE(buffer_new(bh)))
+ clear_buffer_new(bh);
+ if (!buffer_mapped(bh)) {
+ WARN_ON(bh->b_size != blocksize);
+ err = ext4_journal_ensure_extent_credits(handle, inode);
+ if (!err)
+ err = get_block(inode, block, bh, 1);
+ if (err)
+ break;
+ if (buffer_new(bh)) {
+ /*
+ * We may be zeroing partial buffers or all new
+ * buffers in case of failure. Prepare JBD2 for
+ * that.
+ */
+ if (should_journal_data)
+ do_journal_get_write_access(handle,
+ inode, bh);
+ if (folio_test_uptodate(folio)) {
+ /*
+ * Unlike __block_write_begin() we leave
+ * dirtying of new uptodate buffers to
+ * ->write_end() time or
+ * folio_zero_new_buffers().
+ */
+ set_buffer_uptodate(bh);
+ continue;
+ }
+ if (block_end > to || block_start < from)
+ folio_zero_segments(folio, to,
+ block_end,
+ block_start, from);
+ continue;
+ }
+ }
+ if (folio_test_uptodate(folio)) {
+ set_buffer_uptodate(bh);
+ continue;
+ }
+ if (!buffer_uptodate(bh) && !buffer_delay(bh) &&
+ !buffer_unwritten(bh) &&
+ (block_start < from || block_end > to)) {
+ ext4_read_bh_lock(bh, 0, false);
+ wait[nr_wait++] = bh;
+ }
+ }
+ /*
+ * If we issued read requests, let them complete.
+ */
+ for (i = 0; i < nr_wait; i++) {
+ wait_on_buffer(wait[i]);
+ if (!buffer_uptodate(wait[i]))
+ err = -EIO;
+ }
+ if (unlikely(err)) {
+ if (should_journal_data)
+ ext4_journalled_zero_new_buffers(handle, inode, folio,
+ from, to);
+ else
+ folio_zero_new_buffers(folio, from, to);
+ } else if (fscrypt_inode_uses_fs_layer_crypto(inode)) {
+ for (i = 0; i < nr_wait; i++) {
+ int err2;
+
+ err2 = fscrypt_decrypt_pagecache_blocks(folio,
+ blocksize, bh_offset(wait[i]));
+ if (err2) {
+ clear_buffer_uptodate(wait[i]);
+ err = err2;
+ }
+ }
+ }
+
+ return err;
+}
+
+/*
+ * To preserve ordering, it is essential that the hole instantiation and
+ * the data write be encapsulated in a single transaction. We cannot
+ * close off a transaction and start a new one between the ext4_get_block()
+ * and the ext4_write_end(). So doing the jbd2_journal_start at the start of
+ * ext4_write_begin() is the right place.
+ */
+static int ext4_write_begin(const struct kiocb *iocb,
+ struct address_space *mapping,
+ loff_t pos, unsigned len,
+ struct folio **foliop, void **fsdata)
+{
+ struct inode *inode = mapping->host;
+ int ret, needed_blocks;
+ handle_t *handle;
+ int retries = 0;
+ struct folio *folio;
+ pgoff_t index;
+ unsigned from, to;
+
+ ret = ext4_emergency_state(inode->i_sb);
+ if (unlikely(ret))
+ return ret;
+
+ trace_ext4_write_begin(inode, pos, len);
+ /*
+ * Reserve one block more for addition to orphan list in case
+ * we allocate blocks but write fails for some reason
+ */
+ needed_blocks = ext4_chunk_trans_extent(inode,
+ ext4_journal_blocks_per_folio(inode)) + 1;
+ index = pos >> PAGE_SHIFT;
+
+ if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) {
+ ret = ext4_try_to_write_inline_data(mapping, inode, pos, len,
+ foliop);
+ if (ret < 0)
+ return ret;
+ if (ret == 1)
+ return 0;
+ }
+
+ /*
+ * write_begin_get_folio() can take a long time if the
+ * system is thrashing due to memory pressure, or if the folio
+ * is being written back. So grab it first before we start
+ * the transaction handle. This also allows us to allocate
+ * the folio (if needed) without using GFP_NOFS.
+ */
+retry_grab:
+ folio = write_begin_get_folio(iocb, mapping, index, len);
+ if (IS_ERR(folio))
+ return PTR_ERR(folio);
+
+ if (pos + len > folio_pos(folio) + folio_size(folio))
+ len = folio_pos(folio) + folio_size(folio) - pos;
+
+ from = offset_in_folio(folio, pos);
+ to = from + len;
+
+ /*
+ * The same as page allocation, we prealloc buffer heads before
+ * starting the handle.
+ */
+ if (!folio_buffers(folio))
+ create_empty_buffers(folio, inode->i_sb->s_blocksize, 0);
+
+ folio_unlock(folio);
+
+retry_journal:
+ handle = ext4_journal_start(inode, EXT4_HT_WRITE_PAGE, needed_blocks);
+ if (IS_ERR(handle)) {
+ folio_put(folio);
+ return PTR_ERR(handle);
+ }
+
+ folio_lock(folio);
+ if (folio->mapping != mapping) {
+ /* The folio got truncated from under us */
+ folio_unlock(folio);
+ folio_put(folio);
+ ext4_journal_stop(handle);
+ goto retry_grab;
+ }
+ /* In case writeback began while the folio was unlocked */
+ folio_wait_stable(folio);
+
+ if (ext4_should_dioread_nolock(inode))
+ ret = ext4_block_write_begin(handle, folio, pos, len,
+ ext4_get_block_unwritten);
+ else
+ ret = ext4_block_write_begin(handle, folio, pos, len,
+ ext4_get_block);
+ if (!ret && ext4_should_journal_data(inode)) {
+ ret = ext4_walk_page_buffers(handle, inode,
+ folio_buffers(folio), from, to,
+ NULL, do_journal_get_write_access);
+ }
+
+ if (ret) {
+ bool extended = (pos + len > inode->i_size) &&
+ !ext4_verity_in_progress(inode);
+
+ folio_unlock(folio);
+ /*
+ * ext4_block_write_begin may have instantiated a few blocks
+ * outside i_size. Trim these off again. Don't need
+ * i_size_read because we hold i_rwsem.
+ *
+ * Add inode to orphan list in case we crash before
+ * truncate finishes
+ */
+ if (extended && ext4_can_truncate(inode))
+ ext4_orphan_add(handle, inode);
+
+ ext4_journal_stop(handle);
+ if (extended) {
+ ext4_truncate_failed_write(inode);
+ /*
+ * If truncate failed early the inode might
+ * still be on the orphan list; we need to
+ * make sure the inode is removed from the
+ * orphan list in that case.
+ */
+ if (inode->i_nlink)
+ ext4_orphan_del(NULL, inode);
+ }
+
+ if (ret == -EAGAIN ||
+ (ret == -ENOSPC &&
+ ext4_should_retry_alloc(inode->i_sb, &retries)))
+ goto retry_journal;
+ folio_put(folio);
+ return ret;
+ }
+ *foliop = folio;
+ return ret;
+}
+
+/* For write_end() in data=journal mode */
+static int write_end_fn(handle_t *handle, struct inode *inode,
+ struct buffer_head *bh)
+{
+ int ret;
+ if (!buffer_mapped(bh) || buffer_freed(bh))
+ return 0;
+ set_buffer_uptodate(bh);
+ ret = ext4_dirty_journalled_data(handle, bh);
+ clear_buffer_meta(bh);
+ clear_buffer_prio(bh);
+ clear_buffer_new(bh);
+ return ret;
+}
+
+/*
+ * We need to pick up the new inode size which generic_commit_write gave us
+ * `iocb` can be NULL - eg, when called from page_symlink().
+ *
+ * ext4 never places buffers on inode->i_mapping->i_private_list. metadata
+ * buffers are managed internally.
+ */
+static int ext4_write_end(const struct kiocb *iocb,
+ struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned copied,
+ struct folio *folio, void *fsdata)
+{
+ handle_t *handle = ext4_journal_current_handle();
+ struct inode *inode = mapping->host;
+ loff_t old_size = inode->i_size;
+ int ret = 0, ret2;
+ int i_size_changed = 0;
+ bool verity = ext4_verity_in_progress(inode);
+
+ trace_ext4_write_end(inode, pos, len, copied);
+
+ if (ext4_has_inline_data(inode) &&
+ ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA))
+ return ext4_write_inline_data_end(inode, pos, len, copied,
+ folio);
+
+ copied = block_write_end(pos, len, copied, folio);
+ /*
+ * it's important to update i_size while still holding folio lock:
+ * page writeout could otherwise come in and zero beyond i_size.
+ *
+ * If FS_IOC_ENABLE_VERITY is running on this inode, then Merkle tree
+ * blocks are being written past EOF, so skip the i_size update.
+ */
+ if (!verity)
+ i_size_changed = ext4_update_inode_size(inode, pos + copied);
+ folio_unlock(folio);
+ folio_put(folio);
+
+ if (old_size < pos && !verity) {
+ pagecache_isize_extended(inode, old_size, pos);
+ ext4_zero_partial_blocks(handle, inode, old_size, pos - old_size);
+ }
+ /*
+ * Don't mark the inode dirty under folio lock. First, it unnecessarily
+ * makes the holding time of folio lock longer. Second, it forces lock
+ * ordering of folio lock and transaction start for journaling
+ * filesystems.
+ */
+ if (i_size_changed)
+ ret = ext4_mark_inode_dirty(handle, inode);
+
+ if (pos + len > inode->i_size && !verity && ext4_can_truncate(inode))
+ /* if we have allocated more blocks and copied
+ * less. We will have blocks allocated outside
+ * inode->i_size. So truncate them
+ */
+ ext4_orphan_add(handle, inode);
+
+ ret2 = ext4_journal_stop(handle);
+ if (!ret)
+ ret = ret2;
+
+ if (pos + len > inode->i_size && !verity) {
+ ext4_truncate_failed_write(inode);
+ /*
+ * If truncate failed early the inode might still be
+ * on the orphan list; we need to make sure the inode
+ * is removed from the orphan list in that case.
+ */
+ if (inode->i_nlink)
+ ext4_orphan_del(NULL, inode);
+ }
+
+ return ret ? ret : copied;
+}
+
+/*
+ * This is a private version of folio_zero_new_buffers() which doesn't
+ * set the buffer to be dirty, since in data=journalled mode we need
+ * to call ext4_dirty_journalled_data() instead.
+ */
+static void ext4_journalled_zero_new_buffers(handle_t *handle,
+ struct inode *inode,
+ struct folio *folio,
+ unsigned from, unsigned to)
+{
+ unsigned int block_start = 0, block_end;
+ struct buffer_head *head, *bh;
+
+ bh = head = folio_buffers(folio);
+ do {
+ block_end = block_start + bh->b_size;
+ if (buffer_new(bh)) {
+ if (block_end > from && block_start < to) {
+ if (!folio_test_uptodate(folio)) {
+ unsigned start, size;
+
+ start = max(from, block_start);
+ size = min(to, block_end) - start;
+
+ folio_zero_range(folio, start, size);
+ }
+ clear_buffer_new(bh);
+ write_end_fn(handle, inode, bh);
+ }
+ }
+ block_start = block_end;
+ bh = bh->b_this_page;
+ } while (bh != head);
+}
+
+static int ext4_journalled_write_end(const struct kiocb *iocb,
+ struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned copied,
+ struct folio *folio, void *fsdata)
+{
+ handle_t *handle = ext4_journal_current_handle();
+ struct inode *inode = mapping->host;
+ loff_t old_size = inode->i_size;
+ int ret = 0, ret2;
+ int partial = 0;
+ unsigned from, to;
+ int size_changed = 0;
+ bool verity = ext4_verity_in_progress(inode);
+
+ trace_ext4_journalled_write_end(inode, pos, len, copied);
+ from = pos & (PAGE_SIZE - 1);
+ to = from + len;
+
+ BUG_ON(!ext4_handle_valid(handle));
+
+ if (ext4_has_inline_data(inode))
+ return ext4_write_inline_data_end(inode, pos, len, copied,
+ folio);
+
+ if (unlikely(copied < len) && !folio_test_uptodate(folio)) {
+ copied = 0;
+ ext4_journalled_zero_new_buffers(handle, inode, folio,
+ from, to);
+ } else {
+ if (unlikely(copied < len))
+ ext4_journalled_zero_new_buffers(handle, inode, folio,
+ from + copied, to);
+ ret = ext4_walk_page_buffers(handle, inode,
+ folio_buffers(folio),
+ from, from + copied, &partial,
+ write_end_fn);
+ if (!partial)
+ folio_mark_uptodate(folio);
+ }
+ if (!verity)
+ size_changed = ext4_update_inode_size(inode, pos + copied);
+ EXT4_I(inode)->i_datasync_tid = handle->h_transaction->t_tid;
+ folio_unlock(folio);
+ folio_put(folio);
+
+ if (old_size < pos && !verity) {
+ pagecache_isize_extended(inode, old_size, pos);
+ ext4_zero_partial_blocks(handle, inode, old_size, pos - old_size);
+ }
+
+ if (size_changed) {
+ ret2 = ext4_mark_inode_dirty(handle, inode);
+ if (!ret)
+ ret = ret2;
+ }
+
+ if (pos + len > inode->i_size && !verity && ext4_can_truncate(inode))
+ /* if we have allocated more blocks and copied
+ * less. We will have blocks allocated outside
+ * inode->i_size. So truncate them
+ */
+ ext4_orphan_add(handle, inode);
+
+ ret2 = ext4_journal_stop(handle);
+ if (!ret)
+ ret = ret2;
+ if (pos + len > inode->i_size && !verity) {
+ ext4_truncate_failed_write(inode);
+ /*
+ * If truncate failed early the inode might still be
+ * on the orphan list; we need to make sure the inode
+ * is removed from the orphan list in that case.
+ */
+ if (inode->i_nlink)
+ ext4_orphan_del(NULL, inode);
+ }
+
+ return ret ? ret : copied;
+}
+
+/*
+ * Reserve space for 'nr_resv' clusters
+ */
+static int ext4_da_reserve_space(struct inode *inode, int nr_resv)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+ struct ext4_inode_info *ei = EXT4_I(inode);
+ int ret;
+
+ /*
+ * We will charge metadata quota at writeout time; this saves
+ * us from metadata over-estimation, though we may go over by
+ * a small amount in the end. Here we just reserve for data.
+ */
+ ret = dquot_reserve_block(inode, EXT4_C2B(sbi, nr_resv));
+ if (ret)
+ return ret;
+
+ spin_lock(&ei->i_block_reservation_lock);
+ if (ext4_claim_free_clusters(sbi, nr_resv, 0)) {
+ spin_unlock(&ei->i_block_reservation_lock);
+ dquot_release_reservation_block(inode, EXT4_C2B(sbi, nr_resv));
+ return -ENOSPC;
+ }
+ ei->i_reserved_data_blocks += nr_resv;
+ trace_ext4_da_reserve_space(inode, nr_resv);
+ spin_unlock(&ei->i_block_reservation_lock);
+
+ return 0; /* success */
+}
+
+void ext4_da_release_space(struct inode *inode, int to_free)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+ struct ext4_inode_info *ei = EXT4_I(inode);
+
+ if (!to_free)
+ return; /* Nothing to release, exit */
+
+ spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
+
+ trace_ext4_da_release_space(inode, to_free);
+ if (unlikely(to_free > ei->i_reserved_data_blocks)) {
+ /*
+ * if there aren't enough reserved blocks, then the
+ * counter is messed up somewhere. Since this
+ * function is called from invalidate page, it's
+ * harmless to return without any action.
+ */
+ ext4_warning(inode->i_sb, "ext4_da_release_space: "
+ "ino %lu, to_free %d with only %d reserved "
+ "data blocks", inode->i_ino, to_free,
+ ei->i_reserved_data_blocks);
+ WARN_ON(1);
+ to_free = ei->i_reserved_data_blocks;
+ }
+ ei->i_reserved_data_blocks -= to_free;
+
+ /* update fs dirty data blocks counter */
+ percpu_counter_sub(&sbi->s_dirtyclusters_counter, to_free);
+
+ spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
+
+ dquot_release_reservation_block(inode, EXT4_C2B(sbi, to_free));
+}
+
+/*
+ * Delayed allocation stuff
+ */
+
+struct mpage_da_data {
+ /* These are input fields for ext4_do_writepages() */
+ struct inode *inode;
+ struct writeback_control *wbc;
+ unsigned int can_map:1; /* Can writepages call map blocks? */
+
+ /* These are internal state of ext4_do_writepages() */
+ loff_t start_pos; /* The start pos to write */
+ loff_t next_pos; /* Current pos to examine */
+ loff_t end_pos; /* Last pos to examine */
+
+ /*
+ * Extent to map - this can be after start_pos because that can be
+ * fully mapped. We somewhat abuse m_flags to store whether the extent
+ * is delalloc or unwritten.
+ */
+ struct ext4_map_blocks map;
+ struct ext4_io_submit io_submit; /* IO submission data */
+ unsigned int do_map:1;
+ unsigned int scanned_until_end:1;
+ unsigned int journalled_more_data:1;
+};
+
+static void mpage_release_unused_pages(struct mpage_da_data *mpd,
+ bool invalidate)
+{
+ unsigned nr, i;
+ pgoff_t index, end;
+ struct folio_batch fbatch;
+ struct inode *inode = mpd->inode;
+ struct address_space *mapping = inode->i_mapping;
+
+ /* This is necessary when next_pos == 0. */
+ if (mpd->start_pos >= mpd->next_pos)
+ return;
+
+ mpd->scanned_until_end = 0;
+ if (invalidate) {
+ ext4_lblk_t start, last;
+ start = EXT4_B_TO_LBLK(inode, mpd->start_pos);
+ last = mpd->next_pos >> inode->i_blkbits;
+
+ /*
+ * avoid racing with extent status tree scans made by
+ * ext4_insert_delayed_block()
+ */
+ down_write(&EXT4_I(inode)->i_data_sem);
+ ext4_es_remove_extent(inode, start, last - start);
+ up_write(&EXT4_I(inode)->i_data_sem);
+ }
+
+ folio_batch_init(&fbatch);
+ index = mpd->start_pos >> PAGE_SHIFT;
+ end = mpd->next_pos >> PAGE_SHIFT;
+ while (index < end) {
+ nr = filemap_get_folios(mapping, &index, end - 1, &fbatch);
+ if (nr == 0)
+ break;
+ for (i = 0; i < nr; i++) {
+ struct folio *folio = fbatch.folios[i];
+
+ if (folio_pos(folio) < mpd->start_pos)
+ continue;
+ if (folio_next_index(folio) > end)
+ continue;
+ BUG_ON(!folio_test_locked(folio));
+ BUG_ON(folio_test_writeback(folio));
+ if (invalidate) {
+ if (folio_mapped(folio))
+ folio_clear_dirty_for_io(folio);
+ block_invalidate_folio(folio, 0,
+ folio_size(folio));
+ folio_clear_uptodate(folio);
+ }
+ folio_unlock(folio);
+ }
+ folio_batch_release(&fbatch);
+ }
+}
+
+static void ext4_print_free_blocks(struct inode *inode)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+ struct super_block *sb = inode->i_sb;
+ struct ext4_inode_info *ei = EXT4_I(inode);
+
+ ext4_msg(sb, KERN_CRIT, "Total free blocks count %lld",
+ EXT4_C2B(EXT4_SB(inode->i_sb),
+ ext4_count_free_clusters(sb)));
+ ext4_msg(sb, KERN_CRIT, "Free/Dirty block details");
+ ext4_msg(sb, KERN_CRIT, "free_blocks=%lld",
+ (long long) EXT4_C2B(EXT4_SB(sb),
+ percpu_counter_sum(&sbi->s_freeclusters_counter)));
+ ext4_msg(sb, KERN_CRIT, "dirty_blocks=%lld",
+ (long long) EXT4_C2B(EXT4_SB(sb),
+ percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
+ ext4_msg(sb, KERN_CRIT, "Block reservation details");
+ ext4_msg(sb, KERN_CRIT, "i_reserved_data_blocks=%u",
+ ei->i_reserved_data_blocks);
+ return;
+}
+
+/*
+ * Check whether the cluster containing lblk has been allocated or has
+ * delalloc reservation.
+ *
+ * Returns 0 if the cluster doesn't have either, 1 if it has delalloc
+ * reservation, 2 if it's already been allocated, negative error code on
+ * failure.
+ */
+static int ext4_clu_alloc_state(struct inode *inode, ext4_lblk_t lblk)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+ int ret;
+
+ /* Has delalloc reservation? */
+ if (ext4_es_scan_clu(inode, &ext4_es_is_delayed, lblk))
+ return 1;
+
+ /* Already been allocated? */
+ if (ext4_es_scan_clu(inode, &ext4_es_is_mapped, lblk))
+ return 2;
+ ret = ext4_clu_mapped(inode, EXT4_B2C(sbi, lblk));
+ if (ret < 0)
+ return ret;
+ if (ret > 0)
+ return 2;
+
+ return 0;
+}
+
+/*
+ * ext4_insert_delayed_blocks - adds a multiple delayed blocks to the extents
+ * status tree, incrementing the reserved
+ * cluster/block count or making pending
+ * reservations where needed
+ *
+ * @inode - file containing the newly added block
+ * @lblk - start logical block to be added
+ * @len - length of blocks to be added
+ *
+ * Returns 0 on success, negative error code on failure.
+ */
+static int ext4_insert_delayed_blocks(struct inode *inode, ext4_lblk_t lblk,
+ ext4_lblk_t len)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+ int ret;
+ bool lclu_allocated = false;
+ bool end_allocated = false;
+ ext4_lblk_t resv_clu;
+ ext4_lblk_t end = lblk + len - 1;
+
+ /*
+ * If the cluster containing lblk or end is shared with a delayed,
+ * written, or unwritten extent in a bigalloc file system, it's
+ * already been accounted for and does not need to be reserved.
+ * A pending reservation must be made for the cluster if it's
+ * shared with a written or unwritten extent and doesn't already
+ * have one. Written and unwritten extents can be purged from the
+ * extents status tree if the system is under memory pressure, so
+ * it's necessary to examine the extent tree if a search of the
+ * extents status tree doesn't get a match.
+ */
+ if (sbi->s_cluster_ratio == 1) {
+ ret = ext4_da_reserve_space(inode, len);
+ if (ret != 0) /* ENOSPC */
+ return ret;
+ } else { /* bigalloc */
+ resv_clu = EXT4_B2C(sbi, end) - EXT4_B2C(sbi, lblk) + 1;
+
+ ret = ext4_clu_alloc_state(inode, lblk);
+ if (ret < 0)
+ return ret;
+ if (ret > 0) {
+ resv_clu--;
+ lclu_allocated = (ret == 2);
+ }
+
+ if (EXT4_B2C(sbi, lblk) != EXT4_B2C(sbi, end)) {
+ ret = ext4_clu_alloc_state(inode, end);
+ if (ret < 0)
+ return ret;
+ if (ret > 0) {
+ resv_clu--;
+ end_allocated = (ret == 2);
+ }
+ }
+
+ if (resv_clu) {
+ ret = ext4_da_reserve_space(inode, resv_clu);
+ if (ret != 0) /* ENOSPC */
+ return ret;
+ }
+ }
+
+ ext4_es_insert_delayed_extent(inode, lblk, len, lclu_allocated,
+ end_allocated);
+ return 0;
+}
+
+/*
+ * Looks up the requested blocks and sets the delalloc extent map.
+ * First try to look up for the extent entry that contains the requested
+ * blocks in the extent status tree without i_data_sem, then try to look
+ * up for the ondisk extent mapping with i_data_sem in read mode,
+ * finally hold i_data_sem in write mode, looks up again and add a
+ * delalloc extent entry if it still couldn't find any extent. Pass out
+ * the mapped extent through @map and return 0 on success.
+ */
+static int ext4_da_map_blocks(struct inode *inode, struct ext4_map_blocks *map)
+{
+ struct extent_status es;
+ int retval;
+#ifdef ES_AGGRESSIVE_TEST
+ struct ext4_map_blocks orig_map;
+
+ memcpy(&orig_map, map, sizeof(*map));
+#endif
+
+ map->m_flags = 0;
+ ext_debug(inode, "max_blocks %u, logical block %lu\n", map->m_len,
+ (unsigned long) map->m_lblk);
+
+ ext4_check_map_extents_env(inode);
+
+ /* Lookup extent status tree firstly */
+ if (ext4_es_lookup_extent(inode, map->m_lblk, NULL, &es)) {
+ map->m_len = min_t(unsigned int, map->m_len,
+ es.es_len - (map->m_lblk - es.es_lblk));
+
+ if (ext4_es_is_hole(&es))
+ goto add_delayed;
+
+found:
+ /*
+ * Delayed extent could be allocated by fallocate.
+ * So we need to check it.
+ */
+ if (ext4_es_is_delayed(&es)) {
+ map->m_flags |= EXT4_MAP_DELAYED;
+ return 0;
+ }
+
+ map->m_pblk = ext4_es_pblock(&es) + map->m_lblk - es.es_lblk;
+ if (ext4_es_is_written(&es))
+ map->m_flags |= EXT4_MAP_MAPPED;
+ else if (ext4_es_is_unwritten(&es))
+ map->m_flags |= EXT4_MAP_UNWRITTEN;
+ else
+ BUG();
+
+#ifdef ES_AGGRESSIVE_TEST
+ ext4_map_blocks_es_recheck(NULL, inode, map, &orig_map, 0);
+#endif
+ return 0;
+ }
+
+ /*
+ * Try to see if we can get the block without requesting a new
+ * file system block.
+ */
+ down_read(&EXT4_I(inode)->i_data_sem);
+ if (ext4_has_inline_data(inode))
+ retval = 0;
+ else
+ retval = ext4_map_query_blocks(NULL, inode, map, 0);
+ up_read(&EXT4_I(inode)->i_data_sem);
+ if (retval)
+ return retval < 0 ? retval : 0;
+
+add_delayed:
+ down_write(&EXT4_I(inode)->i_data_sem);
+ /*
+ * Page fault path (ext4_page_mkwrite does not take i_rwsem)
+ * and fallocate path (no folio lock) can race. Make sure we
+ * lookup the extent status tree here again while i_data_sem
+ * is held in write mode, before inserting a new da entry in
+ * the extent status tree.
+ */
+ if (ext4_es_lookup_extent(inode, map->m_lblk, NULL, &es)) {
+ map->m_len = min_t(unsigned int, map->m_len,
+ es.es_len - (map->m_lblk - es.es_lblk));
+
+ if (!ext4_es_is_hole(&es)) {
+ up_write(&EXT4_I(inode)->i_data_sem);
+ goto found;
+ }
+ } else if (!ext4_has_inline_data(inode)) {
+ retval = ext4_map_query_blocks(NULL, inode, map, 0);
+ if (retval) {
+ up_write(&EXT4_I(inode)->i_data_sem);
+ return retval < 0 ? retval : 0;
+ }
+ }
+
+ map->m_flags |= EXT4_MAP_DELAYED;
+ retval = ext4_insert_delayed_blocks(inode, map->m_lblk, map->m_len);
+ up_write(&EXT4_I(inode)->i_data_sem);
+
+ return retval;
+}
+
+/*
+ * This is a special get_block_t callback which is used by
+ * ext4_da_write_begin(). It will either return mapped block or
+ * reserve space for a single block.
+ *
+ * For delayed buffer_head we have BH_Mapped, BH_New, BH_Delay set.
+ * We also have b_blocknr = -1 and b_bdev initialized properly
+ *
+ * For unwritten buffer_head we have BH_Mapped, BH_New, BH_Unwritten set.
+ * We also have b_blocknr = physicalblock mapping unwritten extent and b_bdev
+ * initialized properly.
+ */
+int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
+ struct buffer_head *bh, int create)
+{
+ struct ext4_map_blocks map;
+ sector_t invalid_block = ~((sector_t) 0xffff);
+ int ret = 0;
+
+ BUG_ON(create == 0);
+ BUG_ON(bh->b_size != inode->i_sb->s_blocksize);
+
+ if (invalid_block < ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es))
+ invalid_block = ~0;
+
+ map.m_lblk = iblock;
+ map.m_len = 1;
+
+ /*
+ * first, we need to know whether the block is allocated already
+ * preallocated blocks are unmapped but should treated
+ * the same as allocated blocks.
+ */
+ ret = ext4_da_map_blocks(inode, &map);
+ if (ret < 0)
+ return ret;
+
+ if (map.m_flags & EXT4_MAP_DELAYED) {
+ map_bh(bh, inode->i_sb, invalid_block);
+ set_buffer_new(bh);
+ set_buffer_delay(bh);
+ return 0;
+ }
+
+ map_bh(bh, inode->i_sb, map.m_pblk);
+ ext4_update_bh_state(bh, map.m_flags);
+
+ if (buffer_unwritten(bh)) {
+ /* A delayed write to unwritten bh should be marked
+ * new and mapped. Mapped ensures that we don't do
+ * get_block multiple times when we write to the same
+ * offset and new ensures that we do proper zero out
+ * for partial write.
+ */
+ set_buffer_new(bh);
+ set_buffer_mapped(bh);
+ }
+ return 0;
+}
+
+static void mpage_folio_done(struct mpage_da_data *mpd, struct folio *folio)
+{
+ mpd->start_pos += folio_size(folio);
+ mpd->wbc->nr_to_write -= folio_nr_pages(folio);
+ folio_unlock(folio);
+}
+
+static int mpage_submit_folio(struct mpage_da_data *mpd, struct folio *folio)
+{
+ size_t len;
+ loff_t size;
+ int err;
+
+ WARN_ON_ONCE(folio_pos(folio) != mpd->start_pos);
+ folio_clear_dirty_for_io(folio);
+ /*
+ * We have to be very careful here! Nothing protects writeback path
+ * against i_size changes and the page can be writeably mapped into
+ * page tables. So an application can be growing i_size and writing
+ * data through mmap while writeback runs. folio_clear_dirty_for_io()
+ * write-protects our page in page tables and the page cannot get
+ * written to again until we release folio lock. So only after
+ * folio_clear_dirty_for_io() we are safe to sample i_size for
+ * ext4_bio_write_folio() to zero-out tail of the written page. We rely
+ * on the barrier provided by folio_test_clear_dirty() in
+ * folio_clear_dirty_for_io() to make sure i_size is really sampled only
+ * after page tables are updated.
+ */
+ size = i_size_read(mpd->inode);
+ len = folio_size(folio);
+ if (folio_pos(folio) + len > size &&
+ !ext4_verity_in_progress(mpd->inode))
+ len = size & (len - 1);
+ err = ext4_bio_write_folio(&mpd->io_submit, folio, len);
+
+ return err;
+}
+
+#define BH_FLAGS (BIT(BH_Unwritten) | BIT(BH_Delay))
+
+/*
+ * mballoc gives us at most this number of blocks...
+ * XXX: That seems to be only a limitation of ext4_mb_normalize_request().
+ * The rest of mballoc seems to handle chunks up to full group size.
+ */
+#define MAX_WRITEPAGES_EXTENT_LEN 2048
+
+/*
+ * mpage_add_bh_to_extent - try to add bh to extent of blocks to map
+ *
+ * @mpd - extent of blocks
+ * @lblk - logical number of the block in the file
+ * @bh - buffer head we want to add to the extent
+ *
+ * The function is used to collect contig. blocks in the same state. If the
+ * buffer doesn't require mapping for writeback and we haven't started the
+ * extent of buffers to map yet, the function returns 'true' immediately - the
+ * caller can write the buffer right away. Otherwise the function returns true
+ * if the block has been added to the extent, false if the block couldn't be
+ * added.
+ */
+static bool mpage_add_bh_to_extent(struct mpage_da_data *mpd, ext4_lblk_t lblk,
+ struct buffer_head *bh)
+{
+ struct ext4_map_blocks *map = &mpd->map;
+
+ /* Buffer that doesn't need mapping for writeback? */
+ if (!buffer_dirty(bh) || !buffer_mapped(bh) ||
+ (!buffer_delay(bh) && !buffer_unwritten(bh))) {
+ /* So far no extent to map => we write the buffer right away */
+ if (map->m_len == 0)
+ return true;
+ return false;
+ }
+
+ /* First block in the extent? */
+ if (map->m_len == 0) {
+ /* We cannot map unless handle is started... */
+ if (!mpd->do_map)
+ return false;
+ map->m_lblk = lblk;
+ map->m_len = 1;
+ map->m_flags = bh->b_state & BH_FLAGS;
+ return true;
+ }
+
+ /* Don't go larger than mballoc is willing to allocate */
+ if (map->m_len >= MAX_WRITEPAGES_EXTENT_LEN)
+ return false;
+
+ /* Can we merge the block to our big extent? */
+ if (lblk == map->m_lblk + map->m_len &&
+ (bh->b_state & BH_FLAGS) == map->m_flags) {
+ map->m_len++;
+ return true;
+ }
+ return false;
+}
+
+/*
+ * mpage_process_page_bufs - submit page buffers for IO or add them to extent
+ *
+ * @mpd - extent of blocks for mapping
+ * @head - the first buffer in the page
+ * @bh - buffer we should start processing from
+ * @lblk - logical number of the block in the file corresponding to @bh
+ *
+ * Walk through page buffers from @bh upto @head (exclusive) and either submit
+ * the page for IO if all buffers in this page were mapped and there's no
+ * accumulated extent of buffers to map or add buffers in the page to the
+ * extent of buffers to map. The function returns 1 if the caller can continue
+ * by processing the next page, 0 if it should stop adding buffers to the
+ * extent to map because we cannot extend it anymore. It can also return value
+ * < 0 in case of error during IO submission.
+ */
+static int mpage_process_page_bufs(struct mpage_da_data *mpd,
+ struct buffer_head *head,
+ struct buffer_head *bh,
+ ext4_lblk_t lblk)
+{
+ struct inode *inode = mpd->inode;
+ int err;
+ ext4_lblk_t blocks = (i_size_read(inode) + i_blocksize(inode) - 1)
+ >> inode->i_blkbits;
+
+ if (ext4_verity_in_progress(inode))
+ blocks = EXT_MAX_BLOCKS;
+
+ do {
+ BUG_ON(buffer_locked(bh));
+
+ if (lblk >= blocks || !mpage_add_bh_to_extent(mpd, lblk, bh)) {
+ /* Found extent to map? */
+ if (mpd->map.m_len)
+ return 0;
+ /* Buffer needs mapping and handle is not started? */
+ if (!mpd->do_map)
+ return 0;
+ /* Everything mapped so far and we hit EOF */
+ break;
+ }
+ } while (lblk++, (bh = bh->b_this_page) != head);
+ /* So far everything mapped? Submit the page for IO. */
+ if (mpd->map.m_len == 0) {
+ err = mpage_submit_folio(mpd, head->b_folio);
+ if (err < 0)
+ return err;
+ mpage_folio_done(mpd, head->b_folio);
+ }
+ if (lblk >= blocks) {
+ mpd->scanned_until_end = 1;
+ return 0;
+ }
+ return 1;
+}
+
+/*
+ * mpage_process_folio - update folio buffers corresponding to changed extent
+ * and may submit fully mapped page for IO
+ * @mpd: description of extent to map, on return next extent to map
+ * @folio: Contains these buffers.
+ * @m_lblk: logical block mapping.
+ * @m_pblk: corresponding physical mapping.
+ * @map_bh: determines on return whether this page requires any further
+ * mapping or not.
+ *
+ * Scan given folio buffers corresponding to changed extent and update buffer
+ * state according to new extent state.
+ * We map delalloc buffers to their physical location, clear unwritten bits.
+ * If the given folio is not fully mapped, we update @mpd to the next extent in
+ * the given folio that needs mapping & return @map_bh as true.
+ */
+static int mpage_process_folio(struct mpage_da_data *mpd, struct folio *folio,
+ ext4_lblk_t *m_lblk, ext4_fsblk_t *m_pblk,
+ bool *map_bh)
+{
+ struct buffer_head *head, *bh;
+ ext4_io_end_t *io_end = mpd->io_submit.io_end;
+ ext4_lblk_t lblk = *m_lblk;
+ ext4_fsblk_t pblock = *m_pblk;
+ int err = 0;
+ int blkbits = mpd->inode->i_blkbits;
+ ssize_t io_end_size = 0;
+ struct ext4_io_end_vec *io_end_vec = ext4_last_io_end_vec(io_end);
+
+ bh = head = folio_buffers(folio);
+ do {
+ if (lblk < mpd->map.m_lblk)
+ continue;
+ if (lblk >= mpd->map.m_lblk + mpd->map.m_len) {
+ /*
+ * Buffer after end of mapped extent.
+ * Find next buffer in the folio to map.
+ */
+ mpd->map.m_len = 0;
+ mpd->map.m_flags = 0;
+ io_end_vec->size += io_end_size;
+
+ err = mpage_process_page_bufs(mpd, head, bh, lblk);
+ if (err > 0)
+ err = 0;
+ if (!err && mpd->map.m_len && mpd->map.m_lblk > lblk) {
+ io_end_vec = ext4_alloc_io_end_vec(io_end);
+ if (IS_ERR(io_end_vec)) {
+ err = PTR_ERR(io_end_vec);
+ goto out;
+ }
+ io_end_vec->offset = (loff_t)mpd->map.m_lblk << blkbits;
+ }
+ *map_bh = true;
+ goto out;
+ }
+ if (buffer_delay(bh)) {
+ clear_buffer_delay(bh);
+ bh->b_blocknr = pblock++;
+ }
+ clear_buffer_unwritten(bh);
+ io_end_size += (1 << blkbits);
+ } while (lblk++, (bh = bh->b_this_page) != head);
+
+ io_end_vec->size += io_end_size;
+ *map_bh = false;
+out:
+ *m_lblk = lblk;
+ *m_pblk = pblock;
+ return err;
+}
+
+/*
+ * mpage_map_buffers - update buffers corresponding to changed extent and
+ * submit fully mapped pages for IO
+ *
+ * @mpd - description of extent to map, on return next extent to map
+ *
+ * Scan buffers corresponding to changed extent (we expect corresponding pages
+ * to be already locked) and update buffer state according to new extent state.
+ * We map delalloc buffers to their physical location, clear unwritten bits,
+ * and mark buffers as uninit when we perform writes to unwritten extents
+ * and do extent conversion after IO is finished. If the last page is not fully
+ * mapped, we update @map to the next extent in the last page that needs
+ * mapping. Otherwise we submit the page for IO.
+ */
+static int mpage_map_and_submit_buffers(struct mpage_da_data *mpd)
+{
+ struct folio_batch fbatch;
+ unsigned nr, i;
+ struct inode *inode = mpd->inode;
+ int bpp_bits = PAGE_SHIFT - inode->i_blkbits;
+ pgoff_t start, end;
+ ext4_lblk_t lblk;
+ ext4_fsblk_t pblock;
+ int err;
+ bool map_bh = false;
+
+ start = mpd->map.m_lblk >> bpp_bits;
+ end = (mpd->map.m_lblk + mpd->map.m_len - 1) >> bpp_bits;
+ pblock = mpd->map.m_pblk;
+
+ folio_batch_init(&fbatch);
+ while (start <= end) {
+ nr = filemap_get_folios(inode->i_mapping, &start, end, &fbatch);
+ if (nr == 0)
+ break;
+ for (i = 0; i < nr; i++) {
+ struct folio *folio = fbatch.folios[i];
+
+ lblk = folio->index << bpp_bits;
+ err = mpage_process_folio(mpd, folio, &lblk, &pblock,
+ &map_bh);
+ /*
+ * If map_bh is true, means page may require further bh
+ * mapping, or maybe the page was submitted for IO.
+ * So we return to call further extent mapping.
+ */
+ if (err < 0 || map_bh)
+ goto out;
+ /* Page fully mapped - let IO run! */
+ err = mpage_submit_folio(mpd, folio);
+ if (err < 0)
+ goto out;
+ mpage_folio_done(mpd, folio);
+ }
+ folio_batch_release(&fbatch);
+ }
+ /* Extent fully mapped and matches with page boundary. We are done. */
+ mpd->map.m_len = 0;
+ mpd->map.m_flags = 0;
+ return 0;
+out:
+ folio_batch_release(&fbatch);
+ return err;
+}
+
+static int mpage_map_one_extent(handle_t *handle, struct mpage_da_data *mpd)
+{
+ struct inode *inode = mpd->inode;
+ struct ext4_map_blocks *map = &mpd->map;
+ int get_blocks_flags;
+ int err, dioread_nolock;
+
+ /* Make sure transaction has enough credits for this extent */
+ err = ext4_journal_ensure_extent_credits(handle, inode);
+ if (err < 0)
+ return err;
+
+ trace_ext4_da_write_pages_extent(inode, map);
+ /*
+ * Call ext4_map_blocks() to allocate any delayed allocation blocks, or
+ * to convert an unwritten extent to be initialized (in the case
+ * where we have written into one or more preallocated blocks). It is
+ * possible that we're going to need more metadata blocks than
+ * previously reserved. However we must not fail because we're in
+ * writeback and there is nothing we can do about it so it might result
+ * in data loss. So use reserved blocks to allocate metadata if
+ * possible. In addition, do not cache any unrelated extents, as it
+ * only holds the folio lock but does not hold the i_rwsem or
+ * invalidate_lock, which could corrupt the extent status tree.
+ */
+ get_blocks_flags = EXT4_GET_BLOCKS_CREATE |
+ EXT4_GET_BLOCKS_METADATA_NOFAIL |
+ EXT4_GET_BLOCKS_IO_SUBMIT |
+ EXT4_EX_NOCACHE;
+
+ dioread_nolock = ext4_should_dioread_nolock(inode);
+ if (dioread_nolock)
+ get_blocks_flags |= EXT4_GET_BLOCKS_IO_CREATE_EXT;
+
+ err = ext4_map_blocks(handle, inode, map, get_blocks_flags);
+ if (err < 0)
+ return err;
+ if (dioread_nolock && (map->m_flags & EXT4_MAP_UNWRITTEN)) {
+ if (!mpd->io_submit.io_end->handle &&
+ ext4_handle_valid(handle)) {
+ mpd->io_submit.io_end->handle = handle->h_rsv_handle;
+ handle->h_rsv_handle = NULL;
+ }
+ ext4_set_io_unwritten_flag(mpd->io_submit.io_end);
+ }
+
+ BUG_ON(map->m_len == 0);
+ return 0;
+}
+
+/*
+ * This is used to submit mapped buffers in a single folio that is not fully
+ * mapped for various reasons, such as insufficient space or journal credits.
+ */
+static int mpage_submit_partial_folio(struct mpage_da_data *mpd)
+{
+ struct inode *inode = mpd->inode;
+ struct folio *folio;
+ loff_t pos;
+ int ret;
+
+ folio = filemap_get_folio(inode->i_mapping,
+ mpd->start_pos >> PAGE_SHIFT);
+ if (IS_ERR(folio))
+ return PTR_ERR(folio);
+ /*
+ * The mapped position should be within the current processing folio
+ * but must not be the folio start position.
+ */
+ pos = ((loff_t)mpd->map.m_lblk) << inode->i_blkbits;
+ if (WARN_ON_ONCE((folio_pos(folio) == pos) ||
+ !folio_contains(folio, pos >> PAGE_SHIFT)))
+ return -EINVAL;
+
+ ret = mpage_submit_folio(mpd, folio);
+ if (ret)
+ goto out;
+ /*
+ * Update start_pos to prevent this folio from being released in
+ * mpage_release_unused_pages(), it will be reset to the aligned folio
+ * pos when this folio is written again in the next round. Additionally,
+ * do not update wbc->nr_to_write here, as it will be updated once the
+ * entire folio has finished processing.
+ */
+ mpd->start_pos = pos;
+out:
+ folio_unlock(folio);
+ folio_put(folio);
+ return ret;
+}
+
+/*
+ * mpage_map_and_submit_extent - map extent starting at mpd->lblk of length
+ * mpd->len and submit pages underlying it for IO
+ *
+ * @handle - handle for journal operations
+ * @mpd - extent to map
+ * @give_up_on_write - we set this to true iff there is a fatal error and there
+ * is no hope of writing the data. The caller should discard
+ * dirty pages to avoid infinite loops.
+ *
+ * The function maps extent starting at mpd->lblk of length mpd->len. If it is
+ * delayed, blocks are allocated, if it is unwritten, we may need to convert
+ * them to initialized or split the described range from larger unwritten
+ * extent. Note that we need not map all the described range since allocation
+ * can return less blocks or the range is covered by more unwritten extents. We
+ * cannot map more because we are limited by reserved transaction credits. On
+ * the other hand we always make sure that the last touched page is fully
+ * mapped so that it can be written out (and thus forward progress is
+ * guaranteed). After mapping we submit all mapped pages for IO.
+ */
+static int mpage_map_and_submit_extent(handle_t *handle,
+ struct mpage_da_data *mpd,
+ bool *give_up_on_write)
+{
+ struct inode *inode = mpd->inode;
+ struct ext4_map_blocks *map = &mpd->map;
+ int err;
+ loff_t disksize;
+ int progress = 0;
+ ext4_io_end_t *io_end = mpd->io_submit.io_end;
+ struct ext4_io_end_vec *io_end_vec;
+
+ io_end_vec = ext4_alloc_io_end_vec(io_end);
+ if (IS_ERR(io_end_vec))
+ return PTR_ERR(io_end_vec);
+ io_end_vec->offset = ((loff_t)map->m_lblk) << inode->i_blkbits;
+ do {
+ err = mpage_map_one_extent(handle, mpd);
+ if (err < 0) {
+ struct super_block *sb = inode->i_sb;
+
+ if (ext4_emergency_state(sb))
+ goto invalidate_dirty_pages;
+ /*
+ * Let the uper layers retry transient errors.
+ * In the case of ENOSPC, if ext4_count_free_blocks()
+ * is non-zero, a commit should free up blocks.
+ */
+ if ((err == -ENOMEM) || (err == -EAGAIN) ||
+ (err == -ENOSPC && ext4_count_free_clusters(sb))) {
+ /*
+ * We may have already allocated extents for
+ * some bhs inside the folio, issue the
+ * corresponding data to prevent stale data.
+ */
+ if (progress) {
+ if (mpage_submit_partial_folio(mpd))
+ goto invalidate_dirty_pages;
+ goto update_disksize;
+ }
+ return err;
+ }
+ ext4_msg(sb, KERN_CRIT,
+ "Delayed block allocation failed for "
+ "inode %lu at logical offset %llu with"
+ " max blocks %u with error %d",
+ inode->i_ino,
+ (unsigned long long)map->m_lblk,
+ (unsigned)map->m_len, -err);
+ ext4_msg(sb, KERN_CRIT,
+ "This should not happen!! Data will "
+ "be lost\n");
+ if (err == -ENOSPC)
+ ext4_print_free_blocks(inode);
+ invalidate_dirty_pages:
+ *give_up_on_write = true;
+ return err;
+ }
+ progress = 1;
+ /*
+ * Update buffer state, submit mapped pages, and get us new
+ * extent to map
+ */
+ err = mpage_map_and_submit_buffers(mpd);
+ if (err < 0)
+ goto update_disksize;
+ } while (map->m_len);
+
+update_disksize:
+ /*
+ * Update on-disk size after IO is submitted. Races with
+ * truncate are avoided by checking i_size under i_data_sem.
+ */
+ disksize = mpd->start_pos;
+ if (disksize > READ_ONCE(EXT4_I(inode)->i_disksize)) {
+ int err2;
+ loff_t i_size;
+
+ down_write(&EXT4_I(inode)->i_data_sem);
+ i_size = i_size_read(inode);
+ if (disksize > i_size)
+ disksize = i_size;
+ if (disksize > EXT4_I(inode)->i_disksize)
+ EXT4_I(inode)->i_disksize = disksize;
+ up_write(&EXT4_I(inode)->i_data_sem);
+ err2 = ext4_mark_inode_dirty(handle, inode);
+ if (err2) {
+ ext4_error_err(inode->i_sb, -err2,
+ "Failed to mark inode %lu dirty",
+ inode->i_ino);
+ }
+ if (!err)
+ err = err2;
+ }
+ return err;
+}
+
+static int ext4_journal_folio_buffers(handle_t *handle, struct folio *folio,
+ size_t len)
+{
+ struct buffer_head *page_bufs = folio_buffers(folio);
+ struct inode *inode = folio->mapping->host;
+ int ret, err;
+
+ ret = ext4_walk_page_buffers(handle, inode, page_bufs, 0, len,
+ NULL, do_journal_get_write_access);
+ err = ext4_walk_page_buffers(handle, inode, page_bufs, 0, len,
+ NULL, write_end_fn);
+ if (ret == 0)
+ ret = err;
+ err = ext4_jbd2_inode_add_write(handle, inode, folio_pos(folio), len);
+ if (ret == 0)
+ ret = err;
+ EXT4_I(inode)->i_datasync_tid = handle->h_transaction->t_tid;
+
+ return ret;
+}
+
+static int mpage_journal_page_buffers(handle_t *handle,
+ struct mpage_da_data *mpd,
+ struct folio *folio)
+{
+ struct inode *inode = mpd->inode;
+ loff_t size = i_size_read(inode);
+ size_t len = folio_size(folio);
+
+ folio_clear_checked(folio);
+ mpd->wbc->nr_to_write -= folio_nr_pages(folio);
+
+ if (folio_pos(folio) + len > size &&
+ !ext4_verity_in_progress(inode))
+ len = size & (len - 1);
+
+ return ext4_journal_folio_buffers(handle, folio, len);
+}
+
+/*
+ * mpage_prepare_extent_to_map - find & lock contiguous range of dirty pages
+ * needing mapping, submit mapped pages
+ *
+ * @mpd - where to look for pages
+ *
+ * Walk dirty pages in the mapping. If they are fully mapped, submit them for
+ * IO immediately. If we cannot map blocks, we submit just already mapped
+ * buffers in the page for IO and keep page dirty. When we can map blocks and
+ * we find a page which isn't mapped we start accumulating extent of buffers
+ * underlying these pages that needs mapping (formed by either delayed or
+ * unwritten buffers). We also lock the pages containing these buffers. The
+ * extent found is returned in @mpd structure (starting at mpd->lblk with
+ * length mpd->len blocks).
+ *
+ * Note that this function can attach bios to one io_end structure which are
+ * neither logically nor physically contiguous. Although it may seem as an
+ * unnecessary complication, it is actually inevitable in blocksize < pagesize
+ * case as we need to track IO to all buffers underlying a page in one io_end.
+ */
+static int mpage_prepare_extent_to_map(struct mpage_da_data *mpd)
+{
+ struct address_space *mapping = mpd->inode->i_mapping;
+ struct folio_batch fbatch;
+ unsigned int nr_folios;
+ pgoff_t index = mpd->start_pos >> PAGE_SHIFT;
+ pgoff_t end = mpd->end_pos >> PAGE_SHIFT;
+ xa_mark_t tag;
+ int i, err = 0;
+ int blkbits = mpd->inode->i_blkbits;
+ ext4_lblk_t lblk;
+ struct buffer_head *head;
+ handle_t *handle = NULL;
+ int bpp = ext4_journal_blocks_per_folio(mpd->inode);
+
+ if (mpd->wbc->sync_mode == WB_SYNC_ALL || mpd->wbc->tagged_writepages)
+ tag = PAGECACHE_TAG_TOWRITE;
+ else
+ tag = PAGECACHE_TAG_DIRTY;
+
+ mpd->map.m_len = 0;
+ mpd->next_pos = mpd->start_pos;
+ if (ext4_should_journal_data(mpd->inode)) {
+ handle = ext4_journal_start(mpd->inode, EXT4_HT_WRITE_PAGE,
+ bpp);
+ if (IS_ERR(handle))
+ return PTR_ERR(handle);
+ }
+ folio_batch_init(&fbatch);
+ while (index <= end) {
+ nr_folios = filemap_get_folios_tag(mapping, &index, end,
+ tag, &fbatch);
+ if (nr_folios == 0)
+ break;
+
+ for (i = 0; i < nr_folios; i++) {
+ struct folio *folio = fbatch.folios[i];
+
+ /*
+ * Accumulated enough dirty pages? This doesn't apply
+ * to WB_SYNC_ALL mode. For integrity sync we have to
+ * keep going because someone may be concurrently
+ * dirtying pages, and we might have synced a lot of
+ * newly appeared dirty pages, but have not synced all
+ * of the old dirty pages.
+ */
+ if (mpd->wbc->sync_mode == WB_SYNC_NONE &&
+ mpd->wbc->nr_to_write <=
+ mpd->map.m_len >> (PAGE_SHIFT - blkbits))
+ goto out;
+
+ /* If we can't merge this page, we are done. */
+ if (mpd->map.m_len > 0 &&
+ mpd->next_pos != folio_pos(folio))
+ goto out;
+
+ if (handle) {
+ err = ext4_journal_ensure_credits(handle, bpp,
+ 0);
+ if (err < 0)
+ goto out;
+ }
+
+ folio_lock(folio);
+ /*
+ * If the page is no longer dirty, or its mapping no
+ * longer corresponds to inode we are writing (which
+ * means it has been truncated or invalidated), or the
+ * page is already under writeback and we are not doing
+ * a data integrity writeback, skip the page
+ */
+ if (!folio_test_dirty(folio) ||
+ (folio_test_writeback(folio) &&
+ (mpd->wbc->sync_mode == WB_SYNC_NONE)) ||
+ unlikely(folio->mapping != mapping)) {
+ folio_unlock(folio);
+ continue;
+ }
+
+ folio_wait_writeback(folio);
+ BUG_ON(folio_test_writeback(folio));
+
+ /*
+ * Should never happen but for buggy code in
+ * other subsystems that call
+ * set_page_dirty() without properly warning
+ * the file system first. See [1] for more
+ * information.
+ *
+ * [1] https://lore.kernel.org/linux-mm/20180103100430.GE4911@quack2.suse.cz
+ */
+ if (!folio_buffers(folio)) {
+ ext4_warning_inode(mpd->inode, "page %lu does not have buffers attached", folio->index);
+ folio_clear_dirty(folio);
+ folio_unlock(folio);
+ continue;
+ }
+
+ if (mpd->map.m_len == 0)
+ mpd->start_pos = folio_pos(folio);
+ mpd->next_pos = folio_pos(folio) + folio_size(folio);
+ /*
+ * Writeout when we cannot modify metadata is simple.
+ * Just submit the page. For data=journal mode we
+ * first handle writeout of the page for checkpoint and
+ * only after that handle delayed page dirtying. This
+ * makes sure current data is checkpointed to the final
+ * location before possibly journalling it again which
+ * is desirable when the page is frequently dirtied
+ * through a pin.
+ */
+ if (!mpd->can_map) {
+ err = mpage_submit_folio(mpd, folio);
+ if (err < 0)
+ goto out;
+ /* Pending dirtying of journalled data? */
+ if (folio_test_checked(folio)) {
+ err = mpage_journal_page_buffers(handle,
+ mpd, folio);
+ if (err < 0)
+ goto out;
+ mpd->journalled_more_data = 1;
+ }
+ mpage_folio_done(mpd, folio);
+ } else {
+ /* Add all dirty buffers to mpd */
+ lblk = ((ext4_lblk_t)folio->index) <<
+ (PAGE_SHIFT - blkbits);
+ head = folio_buffers(folio);
+ err = mpage_process_page_bufs(mpd, head, head,
+ lblk);
+ if (err <= 0)
+ goto out;
+ err = 0;
+ }
+ }
+ folio_batch_release(&fbatch);
+ cond_resched();
+ }
+ mpd->scanned_until_end = 1;
+ if (handle)
+ ext4_journal_stop(handle);
+ return 0;
+out:
+ folio_batch_release(&fbatch);
+ if (handle)
+ ext4_journal_stop(handle);
+ return err;
+}
+
+static int ext4_do_writepages(struct mpage_da_data *mpd)
+{
+ struct writeback_control *wbc = mpd->wbc;
+ pgoff_t writeback_index = 0;
+ long nr_to_write = wbc->nr_to_write;
+ int range_whole = 0;
+ int cycled = 1;
+ handle_t *handle = NULL;
+ struct inode *inode = mpd->inode;
+ struct address_space *mapping = inode->i_mapping;
+ int needed_blocks, rsv_blocks = 0, ret = 0;
+ struct ext4_sb_info *sbi = EXT4_SB(mapping->host->i_sb);
+ struct blk_plug plug;
+ bool give_up_on_write = false;
+
+ trace_ext4_writepages(inode, wbc);
+
+ /*
+ * No pages to write? This is mainly a kludge to avoid starting
+ * a transaction for special inodes like journal inode on last iput()
+ * because that could violate lock ordering on umount
+ */
+ if (!mapping->nrpages || !mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
+ goto out_writepages;
+
+ /*
+ * If the filesystem has aborted, it is read-only, so return
+ * right away instead of dumping stack traces later on that
+ * will obscure the real source of the problem. We test
+ * fs shutdown state instead of sb->s_flag's SB_RDONLY because
+ * the latter could be true if the filesystem is mounted
+ * read-only, and in that case, ext4_writepages should
+ * *never* be called, so if that ever happens, we would want
+ * the stack trace.
+ */
+ ret = ext4_emergency_state(mapping->host->i_sb);
+ if (unlikely(ret))
+ goto out_writepages;
+
+ /*
+ * If we have inline data and arrive here, it means that
+ * we will soon create the block for the 1st page, so
+ * we'd better clear the inline data here.
+ */
+ if (ext4_has_inline_data(inode)) {
+ /* Just inode will be modified... */
+ handle = ext4_journal_start(inode, EXT4_HT_INODE, 1);
+ if (IS_ERR(handle)) {
+ ret = PTR_ERR(handle);
+ goto out_writepages;
+ }
+ BUG_ON(ext4_test_inode_state(inode,
+ EXT4_STATE_MAY_INLINE_DATA));
+ ext4_destroy_inline_data(handle, inode);
+ ext4_journal_stop(handle);
+ }
+
+ /*
+ * data=journal mode does not do delalloc so we just need to writeout /
+ * journal already mapped buffers. On the other hand we need to commit
+ * transaction to make data stable. We expect all the data to be
+ * already in the journal (the only exception are DMA pinned pages
+ * dirtied behind our back) so we commit transaction here and run the
+ * writeback loop to checkpoint them. The checkpointing is not actually
+ * necessary to make data persistent *but* quite a few places (extent
+ * shifting operations, fsverity, ...) depend on being able to drop
+ * pagecache pages after calling filemap_write_and_wait() and for that
+ * checkpointing needs to happen.
+ */
+ if (ext4_should_journal_data(inode)) {
+ mpd->can_map = 0;
+ if (wbc->sync_mode == WB_SYNC_ALL)
+ ext4_fc_commit(sbi->s_journal,
+ EXT4_I(inode)->i_datasync_tid);
+ }
+ mpd->journalled_more_data = 0;
+
+ if (ext4_should_dioread_nolock(inode)) {
+ int bpf = ext4_journal_blocks_per_folio(inode);
+ /*
+ * We may need to convert up to one extent per block in
+ * the folio and we may dirty the inode.
+ */
+ rsv_blocks = 1 + ext4_ext_index_trans_blocks(inode, bpf);
+ }
+
+ if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
+ range_whole = 1;
+
+ if (wbc->range_cyclic) {
+ writeback_index = mapping->writeback_index;
+ if (writeback_index)
+ cycled = 0;
+ mpd->start_pos = writeback_index << PAGE_SHIFT;
+ mpd->end_pos = LLONG_MAX;
+ } else {
+ mpd->start_pos = wbc->range_start;
+ mpd->end_pos = wbc->range_end;
+ }
+
+ ext4_io_submit_init(&mpd->io_submit, wbc);
+retry:
+ if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
+ tag_pages_for_writeback(mapping, mpd->start_pos >> PAGE_SHIFT,
+ mpd->end_pos >> PAGE_SHIFT);
+ blk_start_plug(&plug);
+
+ /*
+ * First writeback pages that don't need mapping - we can avoid
+ * starting a transaction unnecessarily and also avoid being blocked
+ * in the block layer on device congestion while having transaction
+ * started.
+ */
+ mpd->do_map = 0;
+ mpd->scanned_until_end = 0;
+ mpd->io_submit.io_end = ext4_init_io_end(inode, GFP_KERNEL);
+ if (!mpd->io_submit.io_end) {
+ ret = -ENOMEM;
+ goto unplug;
+ }
+ ret = mpage_prepare_extent_to_map(mpd);
+ /* Unlock pages we didn't use */
+ mpage_release_unused_pages(mpd, false);
+ /* Submit prepared bio */
+ ext4_io_submit(&mpd->io_submit);
+ ext4_put_io_end_defer(mpd->io_submit.io_end);
+ mpd->io_submit.io_end = NULL;
+ if (ret < 0)
+ goto unplug;
+
+ while (!mpd->scanned_until_end && wbc->nr_to_write > 0) {
+ /* For each extent of pages we use new io_end */
+ mpd->io_submit.io_end = ext4_init_io_end(inode, GFP_KERNEL);
+ if (!mpd->io_submit.io_end) {
+ ret = -ENOMEM;
+ break;
+ }
+
+ WARN_ON_ONCE(!mpd->can_map);
+ /*
+ * We have two constraints: We find one extent to map and we
+ * must always write out whole page (makes a difference when
+ * blocksize < pagesize) so that we don't block on IO when we
+ * try to write out the rest of the page. Journalled mode is
+ * not supported by delalloc.
+ */
+ BUG_ON(ext4_should_journal_data(inode));
+ /*
+ * Calculate the number of credits needed to reserve for one
+ * extent of up to MAX_WRITEPAGES_EXTENT_LEN blocks. It will
+ * attempt to extend the transaction or start a new iteration
+ * if the reserved credits are insufficient.
+ */
+ needed_blocks = ext4_chunk_trans_blocks(inode,
+ MAX_WRITEPAGES_EXTENT_LEN);
+ /* start a new transaction */
+ handle = ext4_journal_start_with_reserve(inode,
+ EXT4_HT_WRITE_PAGE, needed_blocks, rsv_blocks);
+ if (IS_ERR(handle)) {
+ ret = PTR_ERR(handle);
+ ext4_msg(inode->i_sb, KERN_CRIT, "%s: jbd2_start: "
+ "%ld pages, ino %lu; err %d", __func__,
+ wbc->nr_to_write, inode->i_ino, ret);
+ /* Release allocated io_end */
+ ext4_put_io_end(mpd->io_submit.io_end);
+ mpd->io_submit.io_end = NULL;
+ break;
+ }
+ mpd->do_map = 1;
+
+ trace_ext4_da_write_folios_start(inode, mpd->start_pos,
+ mpd->next_pos, wbc);
+ ret = mpage_prepare_extent_to_map(mpd);
+ if (!ret && mpd->map.m_len)
+ ret = mpage_map_and_submit_extent(handle, mpd,
+ &give_up_on_write);
+ /*
+ * Caution: If the handle is synchronous,
+ * ext4_journal_stop() can wait for transaction commit
+ * to finish which may depend on writeback of pages to
+ * complete or on page lock to be released. In that
+ * case, we have to wait until after we have
+ * submitted all the IO, released page locks we hold,
+ * and dropped io_end reference (for extent conversion
+ * to be able to complete) before stopping the handle.
+ */
+ if (!ext4_handle_valid(handle) || handle->h_sync == 0) {
+ ext4_journal_stop(handle);
+ handle = NULL;
+ mpd->do_map = 0;
+ }
+ /* Unlock pages we didn't use */
+ mpage_release_unused_pages(mpd, give_up_on_write);
+ /* Submit prepared bio */
+ ext4_io_submit(&mpd->io_submit);
+
+ /*
+ * Drop our io_end reference we got from init. We have
+ * to be careful and use deferred io_end finishing if
+ * we are still holding the transaction as we can
+ * release the last reference to io_end which may end
+ * up doing unwritten extent conversion.
+ */
+ if (handle) {
+ ext4_put_io_end_defer(mpd->io_submit.io_end);
+ ext4_journal_stop(handle);
+ } else
+ ext4_put_io_end(mpd->io_submit.io_end);
+ mpd->io_submit.io_end = NULL;
+ trace_ext4_da_write_folios_end(inode, mpd->start_pos,
+ mpd->next_pos, wbc, ret);
+
+ if (ret == -ENOSPC && sbi->s_journal) {
+ /*
+ * Commit the transaction which would
+ * free blocks released in the transaction
+ * and try again
+ */
+ jbd2_journal_force_commit_nested(sbi->s_journal);
+ ret = 0;
+ continue;
+ }
+ if (ret == -EAGAIN)
+ ret = 0;
+ /* Fatal error - ENOMEM, EIO... */
+ if (ret)
+ break;
+ }
+unplug:
+ blk_finish_plug(&plug);
+ if (!ret && !cycled && wbc->nr_to_write > 0) {
+ cycled = 1;
+ mpd->end_pos = (writeback_index << PAGE_SHIFT) - 1;
+ mpd->start_pos = 0;
+ goto retry;
+ }
+
+ /* Update index */
+ if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
+ /*
+ * Set the writeback_index so that range_cyclic
+ * mode will write it back later
+ */
+ mapping->writeback_index = mpd->start_pos >> PAGE_SHIFT;
+
+out_writepages:
+ trace_ext4_writepages_result(inode, wbc, ret,
+ nr_to_write - wbc->nr_to_write);
+ return ret;
+}
+
+static int ext4_writepages(struct address_space *mapping,
+ struct writeback_control *wbc)
+{
+ struct super_block *sb = mapping->host->i_sb;
+ struct mpage_da_data mpd = {
+ .inode = mapping->host,
+ .wbc = wbc,
+ .can_map = 1,
+ };
+ int ret;
+ int alloc_ctx;
+
+ ret = ext4_emergency_state(sb);
+ if (unlikely(ret))
+ return ret;
+
+ alloc_ctx = ext4_writepages_down_read(sb);
+ ret = ext4_do_writepages(&mpd);
+ /*
+ * For data=journal writeback we could have come across pages marked
+ * for delayed dirtying (PageChecked) which were just added to the
+ * running transaction. Try once more to get them to stable storage.
+ */
+ if (!ret && mpd.journalled_more_data)
+ ret = ext4_do_writepages(&mpd);
+ ext4_writepages_up_read(sb, alloc_ctx);
+
+ return ret;
+}
+
+int ext4_normal_submit_inode_data_buffers(struct jbd2_inode *jinode)
+{
+ struct writeback_control wbc = {
+ .sync_mode = WB_SYNC_ALL,
+ .nr_to_write = LONG_MAX,
+ .range_start = jinode->i_dirty_start,
+ .range_end = jinode->i_dirty_end,
+ };
+ struct mpage_da_data mpd = {
+ .inode = jinode->i_vfs_inode,
+ .wbc = &wbc,
+ .can_map = 0,
+ };
+ return ext4_do_writepages(&mpd);
+}
+
+static int ext4_dax_writepages(struct address_space *mapping,
+ struct writeback_control *wbc)
+{
+ int ret;
+ long nr_to_write = wbc->nr_to_write;
+ struct inode *inode = mapping->host;
+ int alloc_ctx;
+
+ ret = ext4_emergency_state(inode->i_sb);
+ if (unlikely(ret))
+ return ret;
+
+ alloc_ctx = ext4_writepages_down_read(inode->i_sb);
+ trace_ext4_writepages(inode, wbc);
+
+ ret = dax_writeback_mapping_range(mapping,
+ EXT4_SB(inode->i_sb)->s_daxdev, wbc);
+ trace_ext4_writepages_result(inode, wbc, ret,
+ nr_to_write - wbc->nr_to_write);
+ ext4_writepages_up_read(inode->i_sb, alloc_ctx);
+ return ret;
+}
+
+static int ext4_nonda_switch(struct super_block *sb)
+{
+ s64 free_clusters, dirty_clusters;
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+
+ /*
+ * switch to non delalloc mode if we are running low
+ * on free block. The free block accounting via percpu
+ * counters can get slightly wrong with percpu_counter_batch getting
+ * accumulated on each CPU without updating global counters
+ * Delalloc need an accurate free block accounting. So switch
+ * to non delalloc when we are near to error range.
+ */
+ free_clusters =
+ percpu_counter_read_positive(&sbi->s_freeclusters_counter);
+ dirty_clusters =
+ percpu_counter_read_positive(&sbi->s_dirtyclusters_counter);
+ /*
+ * Start pushing delalloc when 1/2 of free blocks are dirty.
+ */
+ if (dirty_clusters && (free_clusters < 2 * dirty_clusters))
+ try_to_writeback_inodes_sb(sb, WB_REASON_FS_FREE_SPACE);
+
+ if (2 * free_clusters < 3 * dirty_clusters ||
+ free_clusters < (dirty_clusters + EXT4_FREECLUSTERS_WATERMARK)) {
+ /*
+ * free block count is less than 150% of dirty blocks
+ * or free blocks is less than watermark
+ */
+ return 1;
+ }
+ return 0;
+}
+
+static int ext4_da_write_begin(const struct kiocb *iocb,
+ struct address_space *mapping,
+ loff_t pos, unsigned len,
+ struct folio **foliop, void **fsdata)
+{
+ int ret, retries = 0;
+ struct folio *folio;
+ pgoff_t index;
+ struct inode *inode = mapping->host;
+
+ ret = ext4_emergency_state(inode->i_sb);
+ if (unlikely(ret))
+ return ret;
+
+ index = pos >> PAGE_SHIFT;
+
+ if (ext4_nonda_switch(inode->i_sb) || ext4_verity_in_progress(inode)) {
+ *fsdata = (void *)FALL_BACK_TO_NONDELALLOC;
+ return ext4_write_begin(iocb, mapping, pos,
+ len, foliop, fsdata);
+ }
+ *fsdata = (void *)0;
+ trace_ext4_da_write_begin(inode, pos, len);
+
+ if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) {
+ ret = ext4_generic_write_inline_data(mapping, inode, pos, len,
+ foliop, fsdata, true);
+ if (ret < 0)
+ return ret;
+ if (ret == 1)
+ return 0;
+ }
+
+retry:
+ folio = write_begin_get_folio(iocb, mapping, index, len);
+ if (IS_ERR(folio))
+ return PTR_ERR(folio);
+
+ if (pos + len > folio_pos(folio) + folio_size(folio))
+ len = folio_pos(folio) + folio_size(folio) - pos;
+
+ ret = ext4_block_write_begin(NULL, folio, pos, len,
+ ext4_da_get_block_prep);
+ if (ret < 0) {
+ folio_unlock(folio);
+ folio_put(folio);
+ /*
+ * ext4_block_write_begin may have instantiated a few blocks
+ * outside i_size. Trim these off again. Don't need
+ * i_size_read because we hold inode lock.
+ */
+ if (pos + len > inode->i_size)
+ ext4_truncate_failed_write(inode);
+
+ if (ret == -ENOSPC &&
+ ext4_should_retry_alloc(inode->i_sb, &retries))
+ goto retry;
+ return ret;
+ }
+
+ *foliop = folio;
+ return ret;
+}
+
+/*
+ * Check if we should update i_disksize
+ * when write to the end of file but not require block allocation
+ */
+static int ext4_da_should_update_i_disksize(struct folio *folio,
+ unsigned long offset)
+{
+ struct buffer_head *bh;
+ struct inode *inode = folio->mapping->host;
+ unsigned int idx;
+ int i;
+
+ bh = folio_buffers(folio);
+ idx = offset >> inode->i_blkbits;
+
+ for (i = 0; i < idx; i++)
+ bh = bh->b_this_page;
+
+ if (!buffer_mapped(bh) || (buffer_delay(bh)) || buffer_unwritten(bh))
+ return 0;
+ return 1;
+}
+
+static int ext4_da_do_write_end(struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned copied,
+ struct folio *folio)
+{
+ struct inode *inode = mapping->host;
+ loff_t old_size = inode->i_size;
+ bool disksize_changed = false;
+ loff_t new_i_size, zero_len = 0;
+ handle_t *handle;
+
+ if (unlikely(!folio_buffers(folio))) {
+ folio_unlock(folio);
+ folio_put(folio);
+ return -EIO;
+ }
+ /*
+ * block_write_end() will mark the inode as dirty with I_DIRTY_PAGES
+ * flag, which all that's needed to trigger page writeback.
+ */
+ copied = block_write_end(pos, len, copied, folio);
+ new_i_size = pos + copied;
+
+ /*
+ * It's important to update i_size while still holding folio lock,
+ * because folio writeout could otherwise come in and zero beyond
+ * i_size.
+ *
+ * Since we are holding inode lock, we are sure i_disksize <=
+ * i_size. We also know that if i_disksize < i_size, there are
+ * delalloc writes pending in the range up to i_size. If the end of
+ * the current write is <= i_size, there's no need to touch
+ * i_disksize since writeback will push i_disksize up to i_size
+ * eventually. If the end of the current write is > i_size and
+ * inside an allocated block which ext4_da_should_update_i_disksize()
+ * checked, we need to update i_disksize here as certain
+ * ext4_writepages() paths not allocating blocks and update i_disksize.
+ */
+ if (new_i_size > inode->i_size) {
+ unsigned long end;
+
+ i_size_write(inode, new_i_size);
+ end = offset_in_folio(folio, new_i_size - 1);
+ if (copied && ext4_da_should_update_i_disksize(folio, end)) {
+ ext4_update_i_disksize(inode, new_i_size);
+ disksize_changed = true;
+ }
+ }
+
+ folio_unlock(folio);
+ folio_put(folio);
+
+ if (pos > old_size) {
+ pagecache_isize_extended(inode, old_size, pos);
+ zero_len = pos - old_size;
+ }
+
+ if (!disksize_changed && !zero_len)
+ return copied;
+
+ handle = ext4_journal_start(inode, EXT4_HT_INODE, 2);
+ if (IS_ERR(handle))
+ return PTR_ERR(handle);
+ if (zero_len)
+ ext4_zero_partial_blocks(handle, inode, old_size, zero_len);
+ ext4_mark_inode_dirty(handle, inode);
+ ext4_journal_stop(handle);
+
+ return copied;
+}
+
+static int ext4_da_write_end(const struct kiocb *iocb,
+ struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned copied,
+ struct folio *folio, void *fsdata)
+{
+ struct inode *inode = mapping->host;
+ int write_mode = (int)(unsigned long)fsdata;
+
+ if (write_mode == FALL_BACK_TO_NONDELALLOC)
+ return ext4_write_end(iocb, mapping, pos,
+ len, copied, folio, fsdata);
+
+ trace_ext4_da_write_end(inode, pos, len, copied);
+
+ if (write_mode != CONVERT_INLINE_DATA &&
+ ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA) &&
+ ext4_has_inline_data(inode))
+ return ext4_write_inline_data_end(inode, pos, len, copied,
+ folio);
+
+ if (unlikely(copied < len) && !folio_test_uptodate(folio))
+ copied = 0;
+
+ return ext4_da_do_write_end(mapping, pos, len, copied, folio);
+}
+
+/*
+ * Force all delayed allocation blocks to be allocated for a given inode.
+ */
+int ext4_alloc_da_blocks(struct inode *inode)
+{
+ trace_ext4_alloc_da_blocks(inode);
+
+ if (!EXT4_I(inode)->i_reserved_data_blocks)
+ return 0;
+
+ /*
+ * We do something simple for now. The filemap_flush() will
+ * also start triggering a write of the data blocks, which is
+ * not strictly speaking necessary (and for users of
+ * laptop_mode, not even desirable). However, to do otherwise
+ * would require replicating code paths in:
+ *
+ * ext4_writepages() ->
+ * write_cache_pages() ---> (via passed in callback function)
+ * __mpage_da_writepage() -->
+ * mpage_add_bh_to_extent()
+ * mpage_da_map_blocks()
+ *
+ * The problem is that write_cache_pages(), located in
+ * mm/page-writeback.c, marks pages clean in preparation for
+ * doing I/O, which is not desirable if we're not planning on
+ * doing I/O at all.
+ *
+ * We could call write_cache_pages(), and then redirty all of
+ * the pages by calling redirty_page_for_writepage() but that
+ * would be ugly in the extreme. So instead we would need to
+ * replicate parts of the code in the above functions,
+ * simplifying them because we wouldn't actually intend to
+ * write out the pages, but rather only collect contiguous
+ * logical block extents, call the multi-block allocator, and
+ * then update the buffer heads with the block allocations.
+ *
+ * For now, though, we'll cheat by calling filemap_flush(),
+ * which will map the blocks, and start the I/O, but not
+ * actually wait for the I/O to complete.
+ */
+ return filemap_flush(inode->i_mapping);
+}
+
+/*
+ * bmap() is special. It gets used by applications such as lilo and by
+ * the swapper to find the on-disk block of a specific piece of data.
+ *
+ * Naturally, this is dangerous if the block concerned is still in the
+ * journal. If somebody makes a swapfile on an ext4 data-journaling
+ * filesystem and enables swap, then they may get a nasty shock when the
+ * data getting swapped to that swapfile suddenly gets overwritten by
+ * the original zero's written out previously to the journal and
+ * awaiting writeback in the kernel's buffer cache.
+ *
+ * So, if we see any bmap calls here on a modified, data-journaled file,
+ * take extra steps to flush any blocks which might be in the cache.
+ */
+static sector_t ext4_bmap(struct address_space *mapping, sector_t block)
+{
+ struct inode *inode = mapping->host;
+ sector_t ret = 0;
+
+ inode_lock_shared(inode);
+ /*
+ * We can get here for an inline file via the FIBMAP ioctl
+ */
+ if (ext4_has_inline_data(inode))
+ goto out;
+
+ if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY) &&
+ (test_opt(inode->i_sb, DELALLOC) ||
+ ext4_should_journal_data(inode))) {
+ /*
+ * With delalloc or journalled data we want to sync the file so
+ * that we can make sure we allocate blocks for file and data
+ * is in place for the user to see it
+ */
+ filemap_write_and_wait(mapping);
+ }
+
+ ret = iomap_bmap(mapping, block, &ext4_iomap_ops);
+
+out:
+ inode_unlock_shared(inode);
+ return ret;
+}
+
+static int ext4_read_folio(struct file *file, struct folio *folio)
+{
+ int ret = -EAGAIN;
+ struct inode *inode = folio->mapping->host;
+
+ trace_ext4_read_folio(inode, folio);
+
+ if (ext4_has_inline_data(inode))
+ ret = ext4_readpage_inline(inode, folio);
+
+ if (ret == -EAGAIN)
+ return ext4_mpage_readpages(inode, NULL, folio);
+
+ return ret;
+}
+
+static void ext4_readahead(struct readahead_control *rac)
+{
+ struct inode *inode = rac->mapping->host;
+
+ /* If the file has inline data, no need to do readahead. */
+ if (ext4_has_inline_data(inode))
+ return;
+
+ ext4_mpage_readpages(inode, rac, NULL);
+}
+
+static void ext4_invalidate_folio(struct folio *folio, size_t offset,
+ size_t length)
+{
+ trace_ext4_invalidate_folio(folio, offset, length);
+
+ /* No journalling happens on data buffers when this function is used */
+ WARN_ON(folio_buffers(folio) && buffer_jbd(folio_buffers(folio)));
+
+ block_invalidate_folio(folio, offset, length);
+}
+
+static int __ext4_journalled_invalidate_folio(struct folio *folio,
+ size_t offset, size_t length)
+{
+ journal_t *journal = EXT4_JOURNAL(folio->mapping->host);
+
+ trace_ext4_journalled_invalidate_folio(folio, offset, length);
+
+ /*
+ * If it's a full truncate we just forget about the pending dirtying
+ */
+ if (offset == 0 && length == folio_size(folio))
+ folio_clear_checked(folio);
+
+ return jbd2_journal_invalidate_folio(journal, folio, offset, length);
+}
+
+/* Wrapper for aops... */
+static void ext4_journalled_invalidate_folio(struct folio *folio,
+ size_t offset,
+ size_t length)
+{
+ WARN_ON(__ext4_journalled_invalidate_folio(folio, offset, length) < 0);
+}
+
+static bool ext4_release_folio(struct folio *folio, gfp_t wait)
+{
+ struct inode *inode = folio->mapping->host;
+ journal_t *journal = EXT4_JOURNAL(inode);
+
+ trace_ext4_release_folio(inode, folio);
+
+ /* Page has dirty journalled data -> cannot release */
+ if (folio_test_checked(folio))
+ return false;
+ if (journal)
+ return jbd2_journal_try_to_free_buffers(journal, folio);
+ else
+ return try_to_free_buffers(folio);
+}
+
+static bool ext4_inode_datasync_dirty(struct inode *inode)
+{
+ journal_t *journal = EXT4_SB(inode->i_sb)->s_journal;
+
+ if (journal) {
+ if (jbd2_transaction_committed(journal,
+ EXT4_I(inode)->i_datasync_tid))
+ return false;
+ if (test_opt2(inode->i_sb, JOURNAL_FAST_COMMIT))
+ return !list_empty(&EXT4_I(inode)->i_fc_list);
+ return true;
+ }
+
+ /* Any metadata buffers to write? */
+ if (!list_empty(&inode->i_mapping->i_private_list))
+ return true;
+ return inode->i_state & I_DIRTY_DATASYNC;
+}
+
+static void ext4_set_iomap(struct inode *inode, struct iomap *iomap,
+ struct ext4_map_blocks *map, loff_t offset,
+ loff_t length, unsigned int flags)
+{
+ u8 blkbits = inode->i_blkbits;
+
+ /*
+ * Writes that span EOF might trigger an I/O size update on completion,
+ * so consider them to be dirty for the purpose of O_DSYNC, even if
+ * there is no other metadata changes being made or are pending.
+ */
+ iomap->flags = 0;
+ if (ext4_inode_datasync_dirty(inode) ||
+ offset + length > i_size_read(inode))
+ iomap->flags |= IOMAP_F_DIRTY;
+
+ if (map->m_flags & EXT4_MAP_NEW)
+ iomap->flags |= IOMAP_F_NEW;
+
+ /* HW-offload atomics are always used */
+ if (flags & IOMAP_ATOMIC)
+ iomap->flags |= IOMAP_F_ATOMIC_BIO;
+
+ if (flags & IOMAP_DAX)
+ iomap->dax_dev = EXT4_SB(inode->i_sb)->s_daxdev;
+ else
+ iomap->bdev = inode->i_sb->s_bdev;
+ iomap->offset = (u64) map->m_lblk << blkbits;
+ iomap->length = (u64) map->m_len << blkbits;
+
+ if ((map->m_flags & EXT4_MAP_MAPPED) &&
+ !ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
+ iomap->flags |= IOMAP_F_MERGED;
+
+ /*
+ * Flags passed to ext4_map_blocks() for direct I/O writes can result
+ * in m_flags having both EXT4_MAP_MAPPED and EXT4_MAP_UNWRITTEN bits
+ * set. In order for any allocated unwritten extents to be converted
+ * into written extents correctly within the ->end_io() handler, we
+ * need to ensure that the iomap->type is set appropriately. Hence, the
+ * reason why we need to check whether the EXT4_MAP_UNWRITTEN bit has
+ * been set first.
+ */
+ if (map->m_flags & EXT4_MAP_UNWRITTEN) {
+ iomap->type = IOMAP_UNWRITTEN;
+ iomap->addr = (u64) map->m_pblk << blkbits;
+ if (flags & IOMAP_DAX)
+ iomap->addr += EXT4_SB(inode->i_sb)->s_dax_part_off;
+ } else if (map->m_flags & EXT4_MAP_MAPPED) {
+ iomap->type = IOMAP_MAPPED;
+ iomap->addr = (u64) map->m_pblk << blkbits;
+ if (flags & IOMAP_DAX)
+ iomap->addr += EXT4_SB(inode->i_sb)->s_dax_part_off;
+ } else if (map->m_flags & EXT4_MAP_DELAYED) {
+ iomap->type = IOMAP_DELALLOC;
+ iomap->addr = IOMAP_NULL_ADDR;
+ } else {
+ iomap->type = IOMAP_HOLE;
+ iomap->addr = IOMAP_NULL_ADDR;
+ }
+}
+
+static int ext4_map_blocks_atomic_write_slow(handle_t *handle,
+ struct inode *inode, struct ext4_map_blocks *map)
+{
+ ext4_lblk_t m_lblk = map->m_lblk;
+ unsigned int m_len = map->m_len;
+ unsigned int mapped_len = 0, m_flags = 0;
+ ext4_fsblk_t next_pblk;
+ bool check_next_pblk = false;
+ int ret = 0;
+
+ WARN_ON_ONCE(!ext4_has_feature_bigalloc(inode->i_sb));
+
+ /*
+ * This is a slow path in case of mixed mapping. We use
+ * EXT4_GET_BLOCKS_CREATE_ZERO flag here to make sure we get a single
+ * contiguous mapped mapping. This will ensure any unwritten or hole
+ * regions within the requested range is zeroed out and we return
+ * a single contiguous mapped extent.
+ */
+ m_flags = EXT4_GET_BLOCKS_CREATE_ZERO;
+
+ do {
+ ret = ext4_map_blocks(handle, inode, map, m_flags);
+ if (ret < 0 && ret != -ENOSPC)
+ goto out_err;
+ /*
+ * This should never happen, but let's return an error code to
+ * avoid an infinite loop in here.
+ */
+ if (ret == 0) {
+ ret = -EFSCORRUPTED;
+ ext4_warning_inode(inode,
+ "ext4_map_blocks() couldn't allocate blocks m_flags: 0x%x, ret:%d",
+ m_flags, ret);
+ goto out_err;
+ }
+ /*
+ * With bigalloc we should never get ENOSPC nor discontiguous
+ * physical extents.
+ */
+ if ((check_next_pblk && next_pblk != map->m_pblk) ||
+ ret == -ENOSPC) {
+ ext4_warning_inode(inode,
+ "Non-contiguous allocation detected: expected %llu, got %llu, "
+ "or ext4_map_blocks() returned out of space ret: %d",
+ next_pblk, map->m_pblk, ret);
+ ret = -EFSCORRUPTED;
+ goto out_err;
+ }
+ next_pblk = map->m_pblk + map->m_len;
+ check_next_pblk = true;
+
+ mapped_len += map->m_len;
+ map->m_lblk += map->m_len;
+ map->m_len = m_len - mapped_len;
+ } while (mapped_len < m_len);
+
+ /*
+ * We might have done some work in above loop, so we need to query the
+ * start of the physical extent, based on the origin m_lblk and m_len.
+ * Let's also ensure we were able to allocate the required range for
+ * mixed mapping case.
+ */
+ map->m_lblk = m_lblk;
+ map->m_len = m_len;
+ map->m_flags = 0;
+
+ ret = ext4_map_blocks(handle, inode, map,
+ EXT4_GET_BLOCKS_QUERY_LAST_IN_LEAF);
+ if (ret != m_len) {
+ ext4_warning_inode(inode,
+ "allocation failed for atomic write request m_lblk:%u, m_len:%u, ret:%d\n",
+ m_lblk, m_len, ret);
+ ret = -EINVAL;
+ }
+ return ret;
+
+out_err:
+ /* reset map before returning an error */
+ map->m_lblk = m_lblk;
+ map->m_len = m_len;
+ map->m_flags = 0;
+ return ret;
+}
+
+/*
+ * ext4_map_blocks_atomic: Helper routine to ensure the entire requested
+ * range in @map [lblk, lblk + len) is one single contiguous extent with no
+ * mixed mappings.
+ *
+ * We first use m_flags passed to us by our caller (ext4_iomap_alloc()).
+ * We only call EXT4_GET_BLOCKS_ZERO in the slow path, when the underlying
+ * physical extent for the requested range does not have a single contiguous
+ * mapping type i.e. (Hole, Mapped, or Unwritten) throughout.
+ * In that case we will loop over the requested range to allocate and zero out
+ * the unwritten / holes in between, to get a single mapped extent from
+ * [m_lblk, m_lblk + m_len). Note that this is only possible because we know
+ * this can be called only with bigalloc enabled filesystem where the underlying
+ * cluster is already allocated. This avoids allocating discontiguous extents
+ * in the slow path due to multiple calls to ext4_map_blocks().
+ * The slow path is mostly non-performance critical path, so it should be ok to
+ * loop using ext4_map_blocks() with appropriate flags to allocate & zero the
+ * underlying short holes/unwritten extents within the requested range.
+ */
+static int ext4_map_blocks_atomic_write(handle_t *handle, struct inode *inode,
+ struct ext4_map_blocks *map, int m_flags,
+ bool *force_commit)
+{
+ ext4_lblk_t m_lblk = map->m_lblk;
+ unsigned int m_len = map->m_len;
+ int ret = 0;
+
+ WARN_ON_ONCE(m_len > 1 && !ext4_has_feature_bigalloc(inode->i_sb));
+
+ ret = ext4_map_blocks(handle, inode, map, m_flags);
+ if (ret < 0 || ret == m_len)
+ goto out;
+ /*
+ * This is a mixed mapping case where we were not able to allocate
+ * a single contiguous extent. In that case let's reset requested
+ * mapping and call the slow path.
+ */
+ map->m_lblk = m_lblk;
+ map->m_len = m_len;
+ map->m_flags = 0;
+
+ /*
+ * slow path means we have mixed mapping, that means we will need
+ * to force txn commit.
+ */
+ *force_commit = true;
+ return ext4_map_blocks_atomic_write_slow(handle, inode, map);
+out:
+ return ret;
+}
+
+static int ext4_iomap_alloc(struct inode *inode, struct ext4_map_blocks *map,
+ unsigned int flags)
+{
+ handle_t *handle;
+ u8 blkbits = inode->i_blkbits;
+ int ret, dio_credits, m_flags = 0, retries = 0;
+ bool force_commit = false;
+
+ /*
+ * Trim the mapping request to the maximum value that we can map at
+ * once for direct I/O.
+ */
+ if (map->m_len > DIO_MAX_BLOCKS)
+ map->m_len = DIO_MAX_BLOCKS;
+
+ /*
+ * journal credits estimation for atomic writes. We call
+ * ext4_map_blocks(), to find if there could be a mixed mapping. If yes,
+ * then let's assume the no. of pextents required can be m_len i.e.
+ * every alternate block can be unwritten and hole.
+ */
+ if (flags & IOMAP_ATOMIC) {
+ unsigned int orig_mlen = map->m_len;
+
+ ret = ext4_map_blocks(NULL, inode, map, 0);
+ if (ret < 0)
+ return ret;
+ if (map->m_len < orig_mlen) {
+ map->m_len = orig_mlen;
+ dio_credits = ext4_meta_trans_blocks(inode, orig_mlen,
+ map->m_len);
+ } else {
+ dio_credits = ext4_chunk_trans_blocks(inode,
+ map->m_len);
+ }
+ } else {
+ dio_credits = ext4_chunk_trans_blocks(inode, map->m_len);
+ }
+
+retry:
+ /*
+ * Either we allocate blocks and then don't get an unwritten extent, so
+ * in that case we have reserved enough credits. Or, the blocks are
+ * already allocated and unwritten. In that case, the extent conversion
+ * fits into the credits as well.
+ */
+ handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS, dio_credits);
+ if (IS_ERR(handle))
+ return PTR_ERR(handle);
+
+ /*
+ * DAX and direct I/O are the only two operations that are currently
+ * supported with IOMAP_WRITE.
+ */
+ WARN_ON(!(flags & (IOMAP_DAX | IOMAP_DIRECT)));
+ if (flags & IOMAP_DAX)
+ m_flags = EXT4_GET_BLOCKS_CREATE_ZERO;
+ /*
+ * We use i_size instead of i_disksize here because delalloc writeback
+ * can complete at any point during the I/O and subsequently push the
+ * i_disksize out to i_size. This could be beyond where direct I/O is
+ * happening and thus expose allocated blocks to direct I/O reads.
+ */
+ else if (((loff_t)map->m_lblk << blkbits) >= i_size_read(inode))
+ m_flags = EXT4_GET_BLOCKS_CREATE;
+ else if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
+ m_flags = EXT4_GET_BLOCKS_IO_CREATE_EXT;
+
+ if (flags & IOMAP_ATOMIC)
+ ret = ext4_map_blocks_atomic_write(handle, inode, map, m_flags,
+ &force_commit);
+ else
+ ret = ext4_map_blocks(handle, inode, map, m_flags);
+
+ /*
+ * We cannot fill holes in indirect tree based inodes as that could
+ * expose stale data in the case of a crash. Use the magic error code
+ * to fallback to buffered I/O.
+ */
+ if (!m_flags && !ret)
+ ret = -ENOTBLK;
+
+ ext4_journal_stop(handle);
+ if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
+ goto retry;
+
+ /*
+ * Force commit the current transaction if the allocation spans a mixed
+ * mapping range. This ensures any pending metadata updates (like
+ * unwritten to written extents conversion) in this range are in
+ * consistent state with the file data blocks, before performing the
+ * actual write I/O. If the commit fails, the whole I/O must be aborted
+ * to prevent any possible torn writes.
+ */
+ if (ret > 0 && force_commit) {
+ int ret2;
+
+ ret2 = ext4_force_commit(inode->i_sb);
+ if (ret2)
+ return ret2;
+ }
+
+ return ret;
+}
+
+
+static int ext4_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
+ unsigned flags, struct iomap *iomap, struct iomap *srcmap)
+{
+ int ret;
+ struct ext4_map_blocks map;
+ u8 blkbits = inode->i_blkbits;
+ unsigned int orig_mlen;
+
+ if ((offset >> blkbits) > EXT4_MAX_LOGICAL_BLOCK)
+ return -EINVAL;
+
+ if (WARN_ON_ONCE(ext4_has_inline_data(inode)))
+ return -ERANGE;
+
+ /*
+ * Calculate the first and last logical blocks respectively.
+ */
+ map.m_lblk = offset >> blkbits;
+ map.m_len = min_t(loff_t, (offset + length - 1) >> blkbits,
+ EXT4_MAX_LOGICAL_BLOCK) - map.m_lblk + 1;
+ orig_mlen = map.m_len;
+
+ if (flags & IOMAP_WRITE) {
+ /*
+ * We check here if the blocks are already allocated, then we
+ * don't need to start a journal txn and we can directly return
+ * the mapping information. This could boost performance
+ * especially in multi-threaded overwrite requests.
+ */
+ if (offset + length <= i_size_read(inode)) {
+ ret = ext4_map_blocks(NULL, inode, &map, 0);
+ /*
+ * For atomic writes the entire requested length should
+ * be mapped.
+ */
+ if (map.m_flags & EXT4_MAP_MAPPED) {
+ if ((!(flags & IOMAP_ATOMIC) && ret > 0) ||
+ (flags & IOMAP_ATOMIC && ret >= orig_mlen))
+ goto out;
+ }
+ map.m_len = orig_mlen;
+ }
+ ret = ext4_iomap_alloc(inode, &map, flags);
+ } else {
+ /*
+ * This can be called for overwrites path from
+ * ext4_iomap_overwrite_begin().
+ */
+ ret = ext4_map_blocks(NULL, inode, &map, 0);
+ }
+
+ if (ret < 0)
+ return ret;
+out:
+ /*
+ * When inline encryption is enabled, sometimes I/O to an encrypted file
+ * has to be broken up to guarantee DUN contiguity. Handle this by
+ * limiting the length of the mapping returned.
+ */
+ map.m_len = fscrypt_limit_io_blocks(inode, map.m_lblk, map.m_len);
+
+ /*
+ * Before returning to iomap, let's ensure the allocated mapping
+ * covers the entire requested length for atomic writes.
+ */
+ if (flags & IOMAP_ATOMIC) {
+ if (map.m_len < (length >> blkbits)) {
+ WARN_ON_ONCE(1);
+ return -EINVAL;
+ }
+ }
+ ext4_set_iomap(inode, iomap, &map, offset, length, flags);
+
+ return 0;
+}
+
+static int ext4_iomap_overwrite_begin(struct inode *inode, loff_t offset,
+ loff_t length, unsigned flags, struct iomap *iomap,
+ struct iomap *srcmap)
+{
+ int ret;
+
+ /*
+ * Even for writes we don't need to allocate blocks, so just pretend
+ * we are reading to save overhead of starting a transaction.
+ */
+ flags &= ~IOMAP_WRITE;
+ ret = ext4_iomap_begin(inode, offset, length, flags, iomap, srcmap);
+ WARN_ON_ONCE(!ret && iomap->type != IOMAP_MAPPED);
+ return ret;
+}
+
+const struct iomap_ops ext4_iomap_ops = {
+ .iomap_begin = ext4_iomap_begin,
+};
+
+const struct iomap_ops ext4_iomap_overwrite_ops = {
+ .iomap_begin = ext4_iomap_overwrite_begin,
+};
+
+static int ext4_iomap_begin_report(struct inode *inode, loff_t offset,
+ loff_t length, unsigned int flags,
+ struct iomap *iomap, struct iomap *srcmap)
+{
+ int ret;
+ struct ext4_map_blocks map;
+ u8 blkbits = inode->i_blkbits;
+
+ if ((offset >> blkbits) > EXT4_MAX_LOGICAL_BLOCK)
+ return -EINVAL;
+
+ if (ext4_has_inline_data(inode)) {
+ ret = ext4_inline_data_iomap(inode, iomap);
+ if (ret != -EAGAIN) {
+ if (ret == 0 && offset >= iomap->length)
+ ret = -ENOENT;
+ return ret;
+ }
+ }
+
+ /*
+ * Calculate the first and last logical block respectively.
+ */
+ map.m_lblk = offset >> blkbits;
+ map.m_len = min_t(loff_t, (offset + length - 1) >> blkbits,
+ EXT4_MAX_LOGICAL_BLOCK) - map.m_lblk + 1;
+
+ /*
+ * Fiemap callers may call for offset beyond s_bitmap_maxbytes.
+ * So handle it here itself instead of querying ext4_map_blocks().
+ * Since ext4_map_blocks() will warn about it and will return
+ * -EIO error.
+ */
+ if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+
+ if (offset >= sbi->s_bitmap_maxbytes) {
+ map.m_flags = 0;
+ goto set_iomap;
+ }
+ }
+
+ ret = ext4_map_blocks(NULL, inode, &map, 0);
+ if (ret < 0)
+ return ret;
+set_iomap:
+ ext4_set_iomap(inode, iomap, &map, offset, length, flags);
+
+ return 0;
+}
+
+const struct iomap_ops ext4_iomap_report_ops = {
+ .iomap_begin = ext4_iomap_begin_report,
+};
+
+/*
+ * For data=journal mode, folio should be marked dirty only when it was
+ * writeably mapped. When that happens, it was already attached to the
+ * transaction and marked as jbddirty (we take care of this in
+ * ext4_page_mkwrite()). On transaction commit, we writeprotect page mappings
+ * so we should have nothing to do here, except for the case when someone
+ * had the page pinned and dirtied the page through this pin (e.g. by doing
+ * direct IO to it). In that case we'd need to attach buffers here to the
+ * transaction but we cannot due to lock ordering. We cannot just dirty the
+ * folio and leave attached buffers clean, because the buffers' dirty state is
+ * "definitive". We cannot just set the buffers dirty or jbddirty because all
+ * the journalling code will explode. So what we do is to mark the folio
+ * "pending dirty" and next time ext4_writepages() is called, attach buffers
+ * to the transaction appropriately.
+ */
+static bool ext4_journalled_dirty_folio(struct address_space *mapping,
+ struct folio *folio)
+{
+ WARN_ON_ONCE(!folio_buffers(folio));
+ if (folio_maybe_dma_pinned(folio))
+ folio_set_checked(folio);
+ return filemap_dirty_folio(mapping, folio);
+}
+
+static bool ext4_dirty_folio(struct address_space *mapping, struct folio *folio)
+{
+ WARN_ON_ONCE(!folio_test_locked(folio) && !folio_test_dirty(folio));
+ WARN_ON_ONCE(!folio_buffers(folio));
+ return block_dirty_folio(mapping, folio);
+}
+
+static int ext4_iomap_swap_activate(struct swap_info_struct *sis,
+ struct file *file, sector_t *span)
+{
+ return iomap_swapfile_activate(sis, file, span,
+ &ext4_iomap_report_ops);
+}
+
+static const struct address_space_operations ext4_aops = {
+ .read_folio = ext4_read_folio,
+ .readahead = ext4_readahead,
+ .writepages = ext4_writepages,
+ .write_begin = ext4_write_begin,
+ .write_end = ext4_write_end,
+ .dirty_folio = ext4_dirty_folio,
+ .bmap = ext4_bmap,
+ .invalidate_folio = ext4_invalidate_folio,
+ .release_folio = ext4_release_folio,
+ .migrate_folio = buffer_migrate_folio,
+ .is_partially_uptodate = block_is_partially_uptodate,
+ .error_remove_folio = generic_error_remove_folio,
+ .swap_activate = ext4_iomap_swap_activate,
+};
+
+static const struct address_space_operations ext4_journalled_aops = {
+ .read_folio = ext4_read_folio,
+ .readahead = ext4_readahead,
+ .writepages = ext4_writepages,
+ .write_begin = ext4_write_begin,
+ .write_end = ext4_journalled_write_end,
+ .dirty_folio = ext4_journalled_dirty_folio,
+ .bmap = ext4_bmap,
+ .invalidate_folio = ext4_journalled_invalidate_folio,
+ .release_folio = ext4_release_folio,
+ .migrate_folio = buffer_migrate_folio_norefs,
+ .is_partially_uptodate = block_is_partially_uptodate,
+ .error_remove_folio = generic_error_remove_folio,
+ .swap_activate = ext4_iomap_swap_activate,
+};
+
+static const struct address_space_operations ext4_da_aops = {
+ .read_folio = ext4_read_folio,
+ .readahead = ext4_readahead,
+ .writepages = ext4_writepages,
+ .write_begin = ext4_da_write_begin,
+ .write_end = ext4_da_write_end,
+ .dirty_folio = ext4_dirty_folio,
+ .bmap = ext4_bmap,
+ .invalidate_folio = ext4_invalidate_folio,
+ .release_folio = ext4_release_folio,
+ .migrate_folio = buffer_migrate_folio,
+ .is_partially_uptodate = block_is_partially_uptodate,
+ .error_remove_folio = generic_error_remove_folio,
+ .swap_activate = ext4_iomap_swap_activate,
+};
+
+static const struct address_space_operations ext4_dax_aops = {
+ .writepages = ext4_dax_writepages,
+ .dirty_folio = noop_dirty_folio,
+ .bmap = ext4_bmap,
+ .swap_activate = ext4_iomap_swap_activate,
+};
+
+void ext4_set_aops(struct inode *inode)
+{
+ switch (ext4_inode_journal_mode(inode)) {
+ case EXT4_INODE_ORDERED_DATA_MODE:
+ case EXT4_INODE_WRITEBACK_DATA_MODE:
+ break;
+ case EXT4_INODE_JOURNAL_DATA_MODE:
+ inode->i_mapping->a_ops = &ext4_journalled_aops;
+ return;
+ default:
+ BUG();
+ }
+ if (IS_DAX(inode))
+ inode->i_mapping->a_ops = &ext4_dax_aops;
+ else if (test_opt(inode->i_sb, DELALLOC))
+ inode->i_mapping->a_ops = &ext4_da_aops;
+ else
+ inode->i_mapping->a_ops = &ext4_aops;
+}
+
+/*
+ * Here we can't skip an unwritten buffer even though it usually reads zero
+ * because it might have data in pagecache (eg, if called from ext4_zero_range,
+ * ext4_punch_hole, etc) which needs to be properly zeroed out. Otherwise a
+ * racing writeback can come later and flush the stale pagecache to disk.
+ */
+static int __ext4_block_zero_page_range(handle_t *handle,
+ struct address_space *mapping, loff_t from, loff_t length)
+{
+ unsigned int offset, blocksize, pos;
+ ext4_lblk_t iblock;
+ struct inode *inode = mapping->host;
+ struct buffer_head *bh;
+ struct folio *folio;
+ int err = 0;
+
+ folio = __filemap_get_folio(mapping, from >> PAGE_SHIFT,
+ FGP_LOCK | FGP_ACCESSED | FGP_CREAT,
+ mapping_gfp_constraint(mapping, ~__GFP_FS));
+ if (IS_ERR(folio))
+ return PTR_ERR(folio);
+
+ blocksize = inode->i_sb->s_blocksize;
+
+ iblock = folio->index << (PAGE_SHIFT - inode->i_sb->s_blocksize_bits);
+
+ bh = folio_buffers(folio);
+ if (!bh)
+ bh = create_empty_buffers(folio, blocksize, 0);
+
+ /* Find the buffer that contains "offset" */
+ offset = offset_in_folio(folio, from);
+ pos = blocksize;
+ while (offset >= pos) {
+ bh = bh->b_this_page;
+ iblock++;
+ pos += blocksize;
+ }
+ if (buffer_freed(bh)) {
+ BUFFER_TRACE(bh, "freed: skip");
+ goto unlock;
+ }
+ if (!buffer_mapped(bh)) {
+ BUFFER_TRACE(bh, "unmapped");
+ ext4_get_block(inode, iblock, bh, 0);
+ /* unmapped? It's a hole - nothing to do */
+ if (!buffer_mapped(bh)) {
+ BUFFER_TRACE(bh, "still unmapped");
+ goto unlock;
+ }
+ }
+
+ /* Ok, it's mapped. Make sure it's up-to-date */
+ if (folio_test_uptodate(folio))
+ set_buffer_uptodate(bh);
+
+ if (!buffer_uptodate(bh)) {
+ err = ext4_read_bh_lock(bh, 0, true);
+ if (err)
+ goto unlock;
+ if (fscrypt_inode_uses_fs_layer_crypto(inode)) {
+ /* We expect the key to be set. */
+ BUG_ON(!fscrypt_has_encryption_key(inode));
+ err = fscrypt_decrypt_pagecache_blocks(folio,
+ blocksize,
+ bh_offset(bh));
+ if (err) {
+ clear_buffer_uptodate(bh);
+ goto unlock;
+ }
+ }
+ }
+ if (ext4_should_journal_data(inode)) {
+ BUFFER_TRACE(bh, "get write access");
+ err = ext4_journal_get_write_access(handle, inode->i_sb, bh,
+ EXT4_JTR_NONE);
+ if (err)
+ goto unlock;
+ }
+ folio_zero_range(folio, offset, length);
+ BUFFER_TRACE(bh, "zeroed end of block");
+
+ if (ext4_should_journal_data(inode)) {
+ err = ext4_dirty_journalled_data(handle, bh);
+ } else {
+ err = 0;
+ mark_buffer_dirty(bh);
+ if (ext4_should_order_data(inode))
+ err = ext4_jbd2_inode_add_write(handle, inode, from,
+ length);
+ }
+
+unlock:
+ folio_unlock(folio);
+ folio_put(folio);
+ return err;
+}
+
+/*
+ * ext4_block_zero_page_range() zeros out a mapping of length 'length'
+ * starting from file offset 'from'. The range to be zero'd must
+ * be contained with in one block. If the specified range exceeds
+ * the end of the block it will be shortened to end of the block
+ * that corresponds to 'from'
+ */
+static int ext4_block_zero_page_range(handle_t *handle,
+ struct address_space *mapping, loff_t from, loff_t length)
+{
+ struct inode *inode = mapping->host;
+ unsigned offset = from & (PAGE_SIZE-1);
+ unsigned blocksize = inode->i_sb->s_blocksize;
+ unsigned max = blocksize - (offset & (blocksize - 1));
+
+ /*
+ * correct length if it does not fall between
+ * 'from' and the end of the block
+ */
+ if (length > max || length < 0)
+ length = max;
+
+ if (IS_DAX(inode)) {
+ return dax_zero_range(inode, from, length, NULL,
+ &ext4_iomap_ops);
+ }
+ return __ext4_block_zero_page_range(handle, mapping, from, length);
+}
+
+/*
+ * ext4_block_truncate_page() zeroes out a mapping from file offset `from'
+ * up to the end of the block which corresponds to `from'.
+ * This required during truncate. We need to physically zero the tail end
+ * of that block so it doesn't yield old data if the file is later grown.
+ */
+static int ext4_block_truncate_page(handle_t *handle,
+ struct address_space *mapping, loff_t from)
+{
+ unsigned offset = from & (PAGE_SIZE-1);
+ unsigned length;
+ unsigned blocksize;
+ struct inode *inode = mapping->host;
+
+ /* If we are processing an encrypted inode during orphan list handling */
+ if (IS_ENCRYPTED(inode) && !fscrypt_has_encryption_key(inode))
+ return 0;
+
+ blocksize = inode->i_sb->s_blocksize;
+ length = blocksize - (offset & (blocksize - 1));
+
+ return ext4_block_zero_page_range(handle, mapping, from, length);
+}
+
+int ext4_zero_partial_blocks(handle_t *handle, struct inode *inode,
+ loff_t lstart, loff_t length)
+{
+ struct super_block *sb = inode->i_sb;
+ struct address_space *mapping = inode->i_mapping;
+ unsigned partial_start, partial_end;
+ ext4_fsblk_t start, end;
+ loff_t byte_end = (lstart + length - 1);
+ int err = 0;
+
+ partial_start = lstart & (sb->s_blocksize - 1);
+ partial_end = byte_end & (sb->s_blocksize - 1);
+
+ start = lstart >> sb->s_blocksize_bits;
+ end = byte_end >> sb->s_blocksize_bits;
+
+ /* Handle partial zero within the single block */
+ if (start == end &&
+ (partial_start || (partial_end != sb->s_blocksize - 1))) {
+ err = ext4_block_zero_page_range(handle, mapping,
+ lstart, length);
+ return err;
+ }
+ /* Handle partial zero out on the start of the range */
+ if (partial_start) {
+ err = ext4_block_zero_page_range(handle, mapping,
+ lstart, sb->s_blocksize);
+ if (err)
+ return err;
+ }
+ /* Handle partial zero out on the end of the range */
+ if (partial_end != sb->s_blocksize - 1)
+ err = ext4_block_zero_page_range(handle, mapping,
+ byte_end - partial_end,
+ partial_end + 1);
+ return err;
+}
+
+int ext4_can_truncate(struct inode *inode)
+{
+ if (S_ISREG(inode->i_mode))
+ return 1;
+ if (S_ISDIR(inode->i_mode))
+ return 1;
+ if (S_ISLNK(inode->i_mode))
+ return !ext4_inode_is_fast_symlink(inode);
+ return 0;
+}
+
+/*
+ * We have to make sure i_disksize gets properly updated before we truncate
+ * page cache due to hole punching or zero range. Otherwise i_disksize update
+ * can get lost as it may have been postponed to submission of writeback but
+ * that will never happen if we remove the folio containing i_size from the
+ * page cache. Also if we punch hole within i_size but above i_disksize,
+ * following ext4_page_mkwrite() may mistakenly allocate written blocks over
+ * the hole and thus introduce allocated blocks beyond i_disksize which is
+ * not allowed (e2fsck would complain in case of crash).
+ */
+int ext4_update_disksize_before_punch(struct inode *inode, loff_t offset,
+ loff_t len)
+{
+ handle_t *handle;
+ int ret;
+
+ loff_t size = i_size_read(inode);
+
+ WARN_ON(!inode_is_locked(inode));
+ if (offset > size)
+ return 0;
+
+ if (offset + len < size)
+ size = offset + len;
+ if (EXT4_I(inode)->i_disksize >= size)
+ return 0;
+
+ handle = ext4_journal_start(inode, EXT4_HT_MISC, 1);
+ if (IS_ERR(handle))
+ return PTR_ERR(handle);
+ ext4_update_i_disksize(inode, size);
+ ret = ext4_mark_inode_dirty(handle, inode);
+ ext4_journal_stop(handle);
+
+ return ret;
+}
+
+static inline void ext4_truncate_folio(struct inode *inode,
+ loff_t start, loff_t end)
+{
+ unsigned long blocksize = i_blocksize(inode);
+ struct folio *folio;
+
+ /* Nothing to be done if no complete block needs to be truncated. */
+ if (round_up(start, blocksize) >= round_down(end, blocksize))
+ return;
+
+ folio = filemap_lock_folio(inode->i_mapping, start >> PAGE_SHIFT);
+ if (IS_ERR(folio))
+ return;
+
+ if (folio_mkclean(folio))
+ folio_mark_dirty(folio);
+ folio_unlock(folio);
+ folio_put(folio);
+}
+
+int ext4_truncate_page_cache_block_range(struct inode *inode,
+ loff_t start, loff_t end)
+{
+ unsigned long blocksize = i_blocksize(inode);
+ int ret;
+
+ /*
+ * For journalled data we need to write (and checkpoint) pages
+ * before discarding page cache to avoid inconsitent data on disk
+ * in case of crash before freeing or unwritten converting trans
+ * is committed.
+ */
+ if (ext4_should_journal_data(inode)) {
+ ret = filemap_write_and_wait_range(inode->i_mapping, start,
+ end - 1);
+ if (ret)
+ return ret;
+ goto truncate_pagecache;
+ }
+
+ /*
+ * If the block size is less than the page size, the file's mapped
+ * blocks within one page could be freed or converted to unwritten.
+ * So it's necessary to remove writable userspace mappings, and then
+ * ext4_page_mkwrite() can be called during subsequent write access
+ * to these partial folios.
+ */
+ if (!IS_ALIGNED(start | end, PAGE_SIZE) &&
+ blocksize < PAGE_SIZE && start < inode->i_size) {
+ loff_t page_boundary = round_up(start, PAGE_SIZE);
+
+ ext4_truncate_folio(inode, start, min(page_boundary, end));
+ if (end > page_boundary)
+ ext4_truncate_folio(inode,
+ round_down(end, PAGE_SIZE), end);
+ }
+
+truncate_pagecache:
+ truncate_pagecache_range(inode, start, end - 1);
+ return 0;
+}
+
+static void ext4_wait_dax_page(struct inode *inode)
+{
+ filemap_invalidate_unlock(inode->i_mapping);
+ schedule();
+ filemap_invalidate_lock(inode->i_mapping);
+}
+
+int ext4_break_layouts(struct inode *inode)
+{
+ if (WARN_ON_ONCE(!rwsem_is_locked(&inode->i_mapping->invalidate_lock)))
+ return -EINVAL;
+
+ return dax_break_layout_inode(inode, ext4_wait_dax_page);
+}
+
+/*
+ * ext4_punch_hole: punches a hole in a file by releasing the blocks
+ * associated with the given offset and length
+ *
+ * @inode: File inode
+ * @offset: The offset where the hole will begin
+ * @len: The length of the hole
+ *
+ * Returns: 0 on success or negative on failure
+ */
+
+int ext4_punch_hole(struct file *file, loff_t offset, loff_t length)
+{
+ struct inode *inode = file_inode(file);
+ struct super_block *sb = inode->i_sb;
+ ext4_lblk_t start_lblk, end_lblk;
+ loff_t max_end = sb->s_maxbytes;
+ loff_t end = offset + length;
+ handle_t *handle;
+ unsigned int credits;
+ int ret;
+
+ trace_ext4_punch_hole(inode, offset, length, 0);
+ WARN_ON_ONCE(!inode_is_locked(inode));
+
+ /*
+ * For indirect-block based inodes, make sure that the hole within
+ * one block before last range.
+ */
+ if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
+ max_end = EXT4_SB(sb)->s_bitmap_maxbytes - sb->s_blocksize;
+
+ /* No need to punch hole beyond i_size */
+ if (offset >= inode->i_size || offset >= max_end)
+ return 0;
+
+ /*
+ * If the hole extends beyond i_size, set the hole to end after
+ * the page that contains i_size.
+ */
+ if (end > inode->i_size)
+ end = round_up(inode->i_size, PAGE_SIZE);
+ if (end > max_end)
+ end = max_end;
+ length = end - offset;
+
+ /*
+ * Attach jinode to inode for jbd2 if we do any zeroing of partial
+ * block.
+ */
+ if (!IS_ALIGNED(offset | end, sb->s_blocksize)) {
+ ret = ext4_inode_attach_jinode(inode);
+ if (ret < 0)
+ return ret;
+ }
+
+
+ ret = ext4_update_disksize_before_punch(inode, offset, length);
+ if (ret)
+ return ret;
+
+ /* Now release the pages and zero block aligned part of pages*/
+ ret = ext4_truncate_page_cache_block_range(inode, offset, end);
+ if (ret)
+ return ret;
+
+ if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
+ credits = ext4_chunk_trans_extent(inode, 2);
+ else
+ credits = ext4_blocks_for_truncate(inode);
+ handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits);
+ if (IS_ERR(handle)) {
+ ret = PTR_ERR(handle);
+ ext4_std_error(sb, ret);
+ return ret;
+ }
+
+ ret = ext4_zero_partial_blocks(handle, inode, offset, length);
+ if (ret)
+ goto out_handle;
+
+ /* If there are blocks to remove, do it */
+ start_lblk = EXT4_B_TO_LBLK(inode, offset);
+ end_lblk = end >> inode->i_blkbits;
+
+ if (end_lblk > start_lblk) {
+ ext4_lblk_t hole_len = end_lblk - start_lblk;
+
+ ext4_fc_track_inode(handle, inode);
+ ext4_check_map_extents_env(inode);
+ down_write(&EXT4_I(inode)->i_data_sem);
+ ext4_discard_preallocations(inode);
+
+ ext4_es_remove_extent(inode, start_lblk, hole_len);
+
+ if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
+ ret = ext4_ext_remove_space(inode, start_lblk,
+ end_lblk - 1);
+ else
+ ret = ext4_ind_remove_space(handle, inode, start_lblk,
+ end_lblk);
+ if (ret) {
+ up_write(&EXT4_I(inode)->i_data_sem);
+ goto out_handle;
+ }
+
+ ext4_es_insert_extent(inode, start_lblk, hole_len, ~0,
+ EXTENT_STATUS_HOLE, 0);
+ up_write(&EXT4_I(inode)->i_data_sem);
+ }
+ ext4_fc_track_range(handle, inode, start_lblk, end_lblk);
+
+ ret = ext4_mark_inode_dirty(handle, inode);
+ if (unlikely(ret))
+ goto out_handle;
+
+ ext4_update_inode_fsync_trans(handle, inode, 1);
+ if (IS_SYNC(inode))
+ ext4_handle_sync(handle);
+out_handle:
+ ext4_journal_stop(handle);
+ return ret;
+}
+
+int ext4_inode_attach_jinode(struct inode *inode)
+{
+ struct ext4_inode_info *ei = EXT4_I(inode);
+ struct jbd2_inode *jinode;
+
+ if (ei->jinode || !EXT4_SB(inode->i_sb)->s_journal)
+ return 0;
+
+ jinode = jbd2_alloc_inode(GFP_KERNEL);
+ spin_lock(&inode->i_lock);
+ if (!ei->jinode) {
+ if (!jinode) {
+ spin_unlock(&inode->i_lock);
+ return -ENOMEM;
+ }
+ ei->jinode = jinode;
+ jbd2_journal_init_jbd_inode(ei->jinode, inode);
+ jinode = NULL;
+ }
+ spin_unlock(&inode->i_lock);
+ if (unlikely(jinode != NULL))
+ jbd2_free_inode(jinode);
+ return 0;
+}
+
+/*
+ * ext4_truncate()
+ *
+ * We block out ext4_get_block() block instantiations across the entire
+ * transaction, and VFS/VM ensures that ext4_truncate() cannot run
+ * simultaneously on behalf of the same inode.
+ *
+ * As we work through the truncate and commit bits of it to the journal there
+ * is one core, guiding principle: the file's tree must always be consistent on
+ * disk. We must be able to restart the truncate after a crash.
+ *
+ * The file's tree may be transiently inconsistent in memory (although it
+ * probably isn't), but whenever we close off and commit a journal transaction,
+ * the contents of (the filesystem + the journal) must be consistent and
+ * restartable. It's pretty simple, really: bottom up, right to left (although
+ * left-to-right works OK too).
+ *
+ * Note that at recovery time, journal replay occurs *before* the restart of
+ * truncate against the orphan inode list.
+ *
+ * The committed inode has the new, desired i_size (which is the same as
+ * i_disksize in this case). After a crash, ext4_orphan_cleanup() will see
+ * that this inode's truncate did not complete and it will again call
+ * ext4_truncate() to have another go. So there will be instantiated blocks
+ * to the right of the truncation point in a crashed ext4 filesystem. But
+ * that's fine - as long as they are linked from the inode, the post-crash
+ * ext4_truncate() run will find them and release them.
+ */
+int ext4_truncate(struct inode *inode)
+{
+ struct ext4_inode_info *ei = EXT4_I(inode);
+ unsigned int credits;
+ int err = 0, err2;
+ handle_t *handle;
+ struct address_space *mapping = inode->i_mapping;
+
+ /*
+ * There is a possibility that we're either freeing the inode
+ * or it's a completely new inode. In those cases we might not
+ * have i_rwsem locked because it's not necessary.
+ */
+ if (!(inode->i_state & (I_NEW|I_FREEING)))
+ WARN_ON(!inode_is_locked(inode));
+ trace_ext4_truncate_enter(inode);
+
+ if (!ext4_can_truncate(inode))
+ goto out_trace;
+
+ if (inode->i_size == 0 && !test_opt(inode->i_sb, NO_AUTO_DA_ALLOC))
+ ext4_set_inode_state(inode, EXT4_STATE_DA_ALLOC_CLOSE);
+
+ if (ext4_has_inline_data(inode)) {
+ int has_inline = 1;
+
+ err = ext4_inline_data_truncate(inode, &has_inline);
+ if (err || has_inline)
+ goto out_trace;
+ }
+
+ /* If we zero-out tail of the page, we have to create jinode for jbd2 */
+ if (inode->i_size & (inode->i_sb->s_blocksize - 1)) {
+ err = ext4_inode_attach_jinode(inode);
+ if (err)
+ goto out_trace;
+ }
+
+ if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
+ credits = ext4_chunk_trans_extent(inode, 1);
+ else
+ credits = ext4_blocks_for_truncate(inode);
+
+ handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits);
+ if (IS_ERR(handle)) {
+ err = PTR_ERR(handle);
+ goto out_trace;
+ }
+
+ if (inode->i_size & (inode->i_sb->s_blocksize - 1))
+ ext4_block_truncate_page(handle, mapping, inode->i_size);
+
+ /*
+ * We add the inode to the orphan list, so that if this
+ * truncate spans multiple transactions, and we crash, we will
+ * resume the truncate when the filesystem recovers. It also
+ * marks the inode dirty, to catch the new size.
+ *
+ * Implication: the file must always be in a sane, consistent
+ * truncatable state while each transaction commits.
+ */
+ err = ext4_orphan_add(handle, inode);
+ if (err)
+ goto out_stop;
+
+ ext4_fc_track_inode(handle, inode);
+ ext4_check_map_extents_env(inode);
+
+ down_write(&EXT4_I(inode)->i_data_sem);
+ ext4_discard_preallocations(inode);
+
+ if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
+ err = ext4_ext_truncate(handle, inode);
+ else
+ ext4_ind_truncate(handle, inode);
+
+ up_write(&ei->i_data_sem);
+ if (err)
+ goto out_stop;
+
+ if (IS_SYNC(inode))
+ ext4_handle_sync(handle);
+
+out_stop:
+ /*
+ * If this was a simple ftruncate() and the file will remain alive,
+ * then we need to clear up the orphan record which we created above.
+ * However, if this was a real unlink then we were called by
+ * ext4_evict_inode(), and we allow that function to clean up the
+ * orphan info for us.
+ */
+ if (inode->i_nlink)
+ ext4_orphan_del(handle, inode);
+
+ inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
+ err2 = ext4_mark_inode_dirty(handle, inode);
+ if (unlikely(err2 && !err))
+ err = err2;
+ ext4_journal_stop(handle);
+
+out_trace:
+ trace_ext4_truncate_exit(inode);
+ return err;
+}
+
+static inline u64 ext4_inode_peek_iversion(const struct inode *inode)
+{
+ if (unlikely(EXT4_I(inode)->i_flags & EXT4_EA_INODE_FL))
+ return inode_peek_iversion_raw(inode);
+ else
+ return inode_peek_iversion(inode);
+}
+
+static int ext4_inode_blocks_set(struct ext4_inode *raw_inode,
+ struct ext4_inode_info *ei)
+{
+ struct inode *inode = &(ei->vfs_inode);
+ u64 i_blocks = READ_ONCE(inode->i_blocks);
+ struct super_block *sb = inode->i_sb;
+
+ if (i_blocks <= ~0U) {
+ /*
+ * i_blocks can be represented in a 32 bit variable
+ * as multiple of 512 bytes
+ */
+ raw_inode->i_blocks_lo = cpu_to_le32(i_blocks);
+ raw_inode->i_blocks_high = 0;
+ ext4_clear_inode_flag(inode, EXT4_INODE_HUGE_FILE);
+ return 0;
+ }
+
+ /*
+ * This should never happen since sb->s_maxbytes should not have
+ * allowed this, sb->s_maxbytes was set according to the huge_file
+ * feature in ext4_fill_super().
+ */
+ if (!ext4_has_feature_huge_file(sb))
+ return -EFSCORRUPTED;
+
+ if (i_blocks <= 0xffffffffffffULL) {
+ /*
+ * i_blocks can be represented in a 48 bit variable
+ * as multiple of 512 bytes
+ */
+ raw_inode->i_blocks_lo = cpu_to_le32(i_blocks);
+ raw_inode->i_blocks_high = cpu_to_le16(i_blocks >> 32);
+ ext4_clear_inode_flag(inode, EXT4_INODE_HUGE_FILE);
+ } else {
+ ext4_set_inode_flag(inode, EXT4_INODE_HUGE_FILE);
+ /* i_block is stored in file system block size */
+ i_blocks = i_blocks >> (inode->i_blkbits - 9);
+ raw_inode->i_blocks_lo = cpu_to_le32(i_blocks);
+ raw_inode->i_blocks_high = cpu_to_le16(i_blocks >> 32);
+ }
+ return 0;
+}
+
+static int ext4_fill_raw_inode(struct inode *inode, struct ext4_inode *raw_inode)
+{
+ struct ext4_inode_info *ei = EXT4_I(inode);
+ uid_t i_uid;
+ gid_t i_gid;
+ projid_t i_projid;
+ int block;
+ int err;
+
+ err = ext4_inode_blocks_set(raw_inode, ei);
+
+ raw_inode->i_mode = cpu_to_le16(inode->i_mode);
+ i_uid = i_uid_read(inode);
+ i_gid = i_gid_read(inode);
+ i_projid = from_kprojid(&init_user_ns, ei->i_projid);
+ if (!(test_opt(inode->i_sb, NO_UID32))) {
+ raw_inode->i_uid_low = cpu_to_le16(low_16_bits(i_uid));
+ raw_inode->i_gid_low = cpu_to_le16(low_16_bits(i_gid));
+ /*
+ * Fix up interoperability with old kernels. Otherwise,
+ * old inodes get re-used with the upper 16 bits of the
+ * uid/gid intact.
+ */
+ if (ei->i_dtime && !ext4_inode_orphan_tracked(inode)) {
+ raw_inode->i_uid_high = 0;
+ raw_inode->i_gid_high = 0;
+ } else {
+ raw_inode->i_uid_high =
+ cpu_to_le16(high_16_bits(i_uid));
+ raw_inode->i_gid_high =
+ cpu_to_le16(high_16_bits(i_gid));
+ }
+ } else {
+ raw_inode->i_uid_low = cpu_to_le16(fs_high2lowuid(i_uid));
+ raw_inode->i_gid_low = cpu_to_le16(fs_high2lowgid(i_gid));
+ raw_inode->i_uid_high = 0;
+ raw_inode->i_gid_high = 0;
+ }
+ raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
+
+ EXT4_INODE_SET_CTIME(inode, raw_inode);
+ EXT4_INODE_SET_MTIME(inode, raw_inode);
+ EXT4_INODE_SET_ATIME(inode, raw_inode);
+ EXT4_EINODE_SET_XTIME(i_crtime, ei, raw_inode);
+
+ raw_inode->i_dtime = cpu_to_le32(ei->i_dtime);
+ raw_inode->i_flags = cpu_to_le32(ei->i_flags & 0xFFFFFFFF);
+ if (likely(!test_opt2(inode->i_sb, HURD_COMPAT)))
+ raw_inode->i_file_acl_high =
+ cpu_to_le16(ei->i_file_acl >> 32);
+ raw_inode->i_file_acl_lo = cpu_to_le32(ei->i_file_acl);
+ ext4_isize_set(raw_inode, ei->i_disksize);
+
+ raw_inode->i_generation = cpu_to_le32(inode->i_generation);
+ if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
+ if (old_valid_dev(inode->i_rdev)) {
+ raw_inode->i_block[0] =
+ cpu_to_le32(old_encode_dev(inode->i_rdev));
+ raw_inode->i_block[1] = 0;
+ } else {
+ raw_inode->i_block[0] = 0;
+ raw_inode->i_block[1] =
+ cpu_to_le32(new_encode_dev(inode->i_rdev));
+ raw_inode->i_block[2] = 0;
+ }
+ } else if (!ext4_has_inline_data(inode)) {
+ for (block = 0; block < EXT4_N_BLOCKS; block++)
+ raw_inode->i_block[block] = ei->i_data[block];
+ }
+
+ if (likely(!test_opt2(inode->i_sb, HURD_COMPAT))) {
+ u64 ivers = ext4_inode_peek_iversion(inode);
+
+ raw_inode->i_disk_version = cpu_to_le32(ivers);
+ if (ei->i_extra_isize) {
+ if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi))
+ raw_inode->i_version_hi =
+ cpu_to_le32(ivers >> 32);
+ raw_inode->i_extra_isize =
+ cpu_to_le16(ei->i_extra_isize);
+ }
+ }
+
+ if (i_projid != EXT4_DEF_PROJID &&
+ !ext4_has_feature_project(inode->i_sb))
+ err = err ?: -EFSCORRUPTED;
+
+ if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE &&
+ EXT4_FITS_IN_INODE(raw_inode, ei, i_projid))
+ raw_inode->i_projid = cpu_to_le32(i_projid);
+
+ ext4_inode_csum_set(inode, raw_inode, ei);
+ return err;
+}
+
+/*
+ * ext4_get_inode_loc returns with an extra refcount against the inode's
+ * underlying buffer_head on success. If we pass 'inode' and it does not
+ * have in-inode xattr, we have all inode data in memory that is needed
+ * to recreate the on-disk version of this inode.
+ */
+static int __ext4_get_inode_loc(struct super_block *sb, unsigned long ino,
+ struct inode *inode, struct ext4_iloc *iloc,
+ ext4_fsblk_t *ret_block)
+{
+ struct ext4_group_desc *gdp;
+ struct buffer_head *bh;
+ ext4_fsblk_t block;
+ struct blk_plug plug;
+ int inodes_per_block, inode_offset;
+
+ iloc->bh = NULL;
+ if (ino < EXT4_ROOT_INO ||
+ ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
+ return -EFSCORRUPTED;
+
+ iloc->block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
+ gdp = ext4_get_group_desc(sb, iloc->block_group, NULL);
+ if (!gdp)
+ return -EIO;
+
+ /*
+ * Figure out the offset within the block group inode table
+ */
+ inodes_per_block = EXT4_SB(sb)->s_inodes_per_block;
+ inode_offset = ((ino - 1) %
+ EXT4_INODES_PER_GROUP(sb));
+ iloc->offset = (inode_offset % inodes_per_block) * EXT4_INODE_SIZE(sb);
+
+ block = ext4_inode_table(sb, gdp);
+ if ((block <= le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block)) ||
+ (block >= ext4_blocks_count(EXT4_SB(sb)->s_es))) {
+ ext4_error(sb, "Invalid inode table block %llu in "
+ "block_group %u", block, iloc->block_group);
+ return -EFSCORRUPTED;
+ }
+ block += (inode_offset / inodes_per_block);
+
+ bh = sb_getblk(sb, block);
+ if (unlikely(!bh))
+ return -ENOMEM;
+ if (ext4_buffer_uptodate(bh))
+ goto has_buffer;
+
+ lock_buffer(bh);
+ if (ext4_buffer_uptodate(bh)) {
+ /* Someone brought it uptodate while we waited */
+ unlock_buffer(bh);
+ goto has_buffer;
+ }
+
+ /*
+ * If we have all information of the inode in memory and this
+ * is the only valid inode in the block, we need not read the
+ * block.
+ */
+ if (inode && !ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
+ struct buffer_head *bitmap_bh;
+ int i, start;
+
+ start = inode_offset & ~(inodes_per_block - 1);
+
+ /* Is the inode bitmap in cache? */
+ bitmap_bh = sb_getblk(sb, ext4_inode_bitmap(sb, gdp));
+ if (unlikely(!bitmap_bh))
+ goto make_io;
+
+ /*
+ * If the inode bitmap isn't in cache then the
+ * optimisation may end up performing two reads instead
+ * of one, so skip it.
+ */
+ if (!buffer_uptodate(bitmap_bh)) {
+ brelse(bitmap_bh);
+ goto make_io;
+ }
+ for (i = start; i < start + inodes_per_block; i++) {
+ if (i == inode_offset)
+ continue;
+ if (ext4_test_bit(i, bitmap_bh->b_data))
+ break;
+ }
+ brelse(bitmap_bh);
+ if (i == start + inodes_per_block) {
+ struct ext4_inode *raw_inode =
+ (struct ext4_inode *) (bh->b_data + iloc->offset);
+
+ /* all other inodes are free, so skip I/O */
+ memset(bh->b_data, 0, bh->b_size);
+ if (!ext4_test_inode_state(inode, EXT4_STATE_NEW))
+ ext4_fill_raw_inode(inode, raw_inode);
+ set_buffer_uptodate(bh);
+ unlock_buffer(bh);
+ goto has_buffer;
+ }
+ }
+
+make_io:
+ /*
+ * If we need to do any I/O, try to pre-readahead extra
+ * blocks from the inode table.
+ */
+ blk_start_plug(&plug);
+ if (EXT4_SB(sb)->s_inode_readahead_blks) {
+ ext4_fsblk_t b, end, table;
+ unsigned num;
+ __u32 ra_blks = EXT4_SB(sb)->s_inode_readahead_blks;
+
+ table = ext4_inode_table(sb, gdp);
+ /* s_inode_readahead_blks is always a power of 2 */
+ b = block & ~((ext4_fsblk_t) ra_blks - 1);
+ if (table > b)
+ b = table;
+ end = b + ra_blks;
+ num = EXT4_INODES_PER_GROUP(sb);
+ if (ext4_has_group_desc_csum(sb))
+ num -= ext4_itable_unused_count(sb, gdp);
+ table += num / inodes_per_block;
+ if (end > table)
+ end = table;
+ while (b <= end)
+ ext4_sb_breadahead_unmovable(sb, b++);
+ }
+
+ /*
+ * There are other valid inodes in the buffer, this inode
+ * has in-inode xattrs, or we don't have this inode in memory.
+ * Read the block from disk.
+ */
+ trace_ext4_load_inode(sb, ino);
+ ext4_read_bh_nowait(bh, REQ_META | REQ_PRIO, NULL,
+ ext4_simulate_fail(sb, EXT4_SIM_INODE_EIO));
+ blk_finish_plug(&plug);
+ wait_on_buffer(bh);
+ if (!buffer_uptodate(bh)) {
+ if (ret_block)
+ *ret_block = block;
+ brelse(bh);
+ return -EIO;
+ }
+has_buffer:
+ iloc->bh = bh;
+ return 0;
+}
+
+static int __ext4_get_inode_loc_noinmem(struct inode *inode,
+ struct ext4_iloc *iloc)
+{
+ ext4_fsblk_t err_blk = 0;
+ int ret;
+
+ ret = __ext4_get_inode_loc(inode->i_sb, inode->i_ino, NULL, iloc,
+ &err_blk);
+
+ if (ret == -EIO)
+ ext4_error_inode_block(inode, err_blk, EIO,
+ "unable to read itable block");
+
+ return ret;
+}
+
+int ext4_get_inode_loc(struct inode *inode, struct ext4_iloc *iloc)
+{
+ ext4_fsblk_t err_blk = 0;
+ int ret;
+
+ ret = __ext4_get_inode_loc(inode->i_sb, inode->i_ino, inode, iloc,
+ &err_blk);
+
+ if (ret == -EIO)
+ ext4_error_inode_block(inode, err_blk, EIO,
+ "unable to read itable block");
+
+ return ret;
+}
+
+
+int ext4_get_fc_inode_loc(struct super_block *sb, unsigned long ino,
+ struct ext4_iloc *iloc)
+{
+ return __ext4_get_inode_loc(sb, ino, NULL, iloc, NULL);
+}
+
+static bool ext4_should_enable_dax(struct inode *inode)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+
+ if (test_opt2(inode->i_sb, DAX_NEVER))
+ return false;
+ if (!S_ISREG(inode->i_mode))
+ return false;
+ if (ext4_should_journal_data(inode))
+ return false;
+ if (ext4_has_inline_data(inode))
+ return false;
+ if (ext4_test_inode_flag(inode, EXT4_INODE_ENCRYPT))
+ return false;
+ if (ext4_test_inode_flag(inode, EXT4_INODE_VERITY))
+ return false;
+ if (!test_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags))
+ return false;
+ if (test_opt(inode->i_sb, DAX_ALWAYS))
+ return true;
+
+ return ext4_test_inode_flag(inode, EXT4_INODE_DAX);
+}
+
+void ext4_set_inode_flags(struct inode *inode, bool init)
+{
+ unsigned int flags = EXT4_I(inode)->i_flags;
+ unsigned int new_fl = 0;
+
+ WARN_ON_ONCE(IS_DAX(inode) && init);
+
+ if (flags & EXT4_SYNC_FL)
+ new_fl |= S_SYNC;
+ if (flags & EXT4_APPEND_FL)
+ new_fl |= S_APPEND;
+ if (flags & EXT4_IMMUTABLE_FL)
+ new_fl |= S_IMMUTABLE;
+ if (flags & EXT4_NOATIME_FL)
+ new_fl |= S_NOATIME;
+ if (flags & EXT4_DIRSYNC_FL)
+ new_fl |= S_DIRSYNC;
+
+ /* Because of the way inode_set_flags() works we must preserve S_DAX
+ * here if already set. */
+ new_fl |= (inode->i_flags & S_DAX);
+ if (init && ext4_should_enable_dax(inode))
+ new_fl |= S_DAX;
+
+ if (flags & EXT4_ENCRYPT_FL)
+ new_fl |= S_ENCRYPTED;
+ if (flags & EXT4_CASEFOLD_FL)
+ new_fl |= S_CASEFOLD;
+ if (flags & EXT4_VERITY_FL)
+ new_fl |= S_VERITY;
+ inode_set_flags(inode, new_fl,
+ S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC|S_DAX|
+ S_ENCRYPTED|S_CASEFOLD|S_VERITY);
+}
+
+static blkcnt_t ext4_inode_blocks(struct ext4_inode *raw_inode,
+ struct ext4_inode_info *ei)
+{
+ blkcnt_t i_blocks ;
+ struct inode *inode = &(ei->vfs_inode);
+ struct super_block *sb = inode->i_sb;
+
+ if (ext4_has_feature_huge_file(sb)) {
+ /* we are using combined 48 bit field */
+ i_blocks = ((u64)le16_to_cpu(raw_inode->i_blocks_high)) << 32 |
+ le32_to_cpu(raw_inode->i_blocks_lo);
+ if (ext4_test_inode_flag(inode, EXT4_INODE_HUGE_FILE)) {
+ /* i_blocks represent file system block size */
+ return i_blocks << (inode->i_blkbits - 9);
+ } else {
+ return i_blocks;
+ }
+ } else {
+ return le32_to_cpu(raw_inode->i_blocks_lo);
+ }
+}
+
+static inline int ext4_iget_extra_inode(struct inode *inode,
+ struct ext4_inode *raw_inode,
+ struct ext4_inode_info *ei)
+{
+ __le32 *magic = (void *)raw_inode +
+ EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize;
+
+ if (EXT4_INODE_HAS_XATTR_SPACE(inode) &&
+ *magic == cpu_to_le32(EXT4_XATTR_MAGIC)) {
+ int err;
+
+ err = xattr_check_inode(inode, IHDR(inode, raw_inode),
+ ITAIL(inode, raw_inode));
+ if (err)
+ return err;
+
+ ext4_set_inode_state(inode, EXT4_STATE_XATTR);
+ err = ext4_find_inline_data_nolock(inode);
+ if (!err && ext4_has_inline_data(inode))
+ ext4_set_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA);
+ return err;
+ } else
+ EXT4_I(inode)->i_inline_off = 0;
+ return 0;
+}
+
+int ext4_get_projid(struct inode *inode, kprojid_t *projid)
+{
+ if (!ext4_has_feature_project(inode->i_sb))
+ return -EOPNOTSUPP;
+ *projid = EXT4_I(inode)->i_projid;
+ return 0;
+}
+
+/*
+ * ext4 has self-managed i_version for ea inodes, it stores the lower 32bit of
+ * refcount in i_version, so use raw values if inode has EXT4_EA_INODE_FL flag
+ * set.
+ */
+static inline void ext4_inode_set_iversion_queried(struct inode *inode, u64 val)
+{
+ if (unlikely(EXT4_I(inode)->i_flags & EXT4_EA_INODE_FL))
+ inode_set_iversion_raw(inode, val);
+ else
+ inode_set_iversion_queried(inode, val);
+}
+
+static int check_igot_inode(struct inode *inode, ext4_iget_flags flags,
+ const char *function, unsigned int line)
+{
+ const char *err_str;
+
+ if (flags & EXT4_IGET_EA_INODE) {
+ if (!(EXT4_I(inode)->i_flags & EXT4_EA_INODE_FL)) {
+ err_str = "missing EA_INODE flag";
+ goto error;
+ }
+ if (ext4_test_inode_state(inode, EXT4_STATE_XATTR) ||
+ EXT4_I(inode)->i_file_acl) {
+ err_str = "ea_inode with extended attributes";
+ goto error;
+ }
+ } else {
+ if ((EXT4_I(inode)->i_flags & EXT4_EA_INODE_FL)) {
+ /*
+ * open_by_handle_at() could provide an old inode number
+ * that has since been reused for an ea_inode; this does
+ * not indicate filesystem corruption
+ */
+ if (flags & EXT4_IGET_HANDLE)
+ return -ESTALE;
+ err_str = "unexpected EA_INODE flag";
+ goto error;
+ }
+ }
+ if (is_bad_inode(inode) && !(flags & EXT4_IGET_BAD)) {
+ err_str = "unexpected bad inode w/o EXT4_IGET_BAD";
+ goto error;
+ }
+ return 0;
+
+error:
+ ext4_error_inode(inode, function, line, 0, "%s", err_str);
+ return -EFSCORRUPTED;
+}
+
+static bool ext4_should_enable_large_folio(struct inode *inode)
+{
+ struct super_block *sb = inode->i_sb;
+
+ if (!S_ISREG(inode->i_mode))
+ return false;
+ if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA ||
+ ext4_test_inode_flag(inode, EXT4_INODE_JOURNAL_DATA))
+ return false;
+ if (ext4_has_feature_verity(sb))
+ return false;
+ if (ext4_has_feature_encrypt(sb))
+ return false;
+
+ return true;
+}
+
+/*
+ * Limit the maximum folio order to 2048 blocks to prevent overestimation
+ * of reserve handle credits during the folio writeback in environments
+ * where the PAGE_SIZE exceeds 4KB.
+ */
+#define EXT4_MAX_PAGECACHE_ORDER(i) \
+ umin(MAX_PAGECACHE_ORDER, (11 + (i)->i_blkbits - PAGE_SHIFT))
+void ext4_set_inode_mapping_order(struct inode *inode)
+{
+ if (!ext4_should_enable_large_folio(inode))
+ return;
+
+ mapping_set_folio_order_range(inode->i_mapping, 0,
+ EXT4_MAX_PAGECACHE_ORDER(inode));
+}
+
+struct inode *__ext4_iget(struct super_block *sb, unsigned long ino,
+ ext4_iget_flags flags, const char *function,
+ unsigned int line)
+{
+ struct ext4_iloc iloc;
+ struct ext4_inode *raw_inode;
+ struct ext4_inode_info *ei;
+ struct ext4_super_block *es = EXT4_SB(sb)->s_es;
+ struct inode *inode;
+ journal_t *journal = EXT4_SB(sb)->s_journal;
+ long ret;
+ loff_t size;
+ int block;
+ uid_t i_uid;
+ gid_t i_gid;
+ projid_t i_projid;
+
+ if ((!(flags & EXT4_IGET_SPECIAL) && is_special_ino(sb, ino)) ||
+ (ino < EXT4_ROOT_INO) ||
+ (ino > le32_to_cpu(es->s_inodes_count))) {
+ if (flags & EXT4_IGET_HANDLE)
+ return ERR_PTR(-ESTALE);
+ __ext4_error(sb, function, line, false, EFSCORRUPTED, 0,
+ "inode #%lu: comm %s: iget: illegal inode #",
+ ino, current->comm);
+ return ERR_PTR(-EFSCORRUPTED);
+ }
+
+ inode = iget_locked(sb, ino);
+ if (!inode)
+ return ERR_PTR(-ENOMEM);
+ if (!(inode->i_state & I_NEW)) {
+ ret = check_igot_inode(inode, flags, function, line);
+ if (ret) {
+ iput(inode);
+ return ERR_PTR(ret);
+ }
+ return inode;
+ }
+
+ ei = EXT4_I(inode);
+ iloc.bh = NULL;
+
+ ret = __ext4_get_inode_loc_noinmem(inode, &iloc);
+ if (ret < 0)
+ goto bad_inode;
+ raw_inode = ext4_raw_inode(&iloc);
+
+ if ((flags & EXT4_IGET_HANDLE) &&
+ (raw_inode->i_links_count == 0) && (raw_inode->i_mode == 0)) {
+ ret = -ESTALE;
+ goto bad_inode;
+ }
+
+ if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
+ ei->i_extra_isize = le16_to_cpu(raw_inode->i_extra_isize);
+ if (EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize >
+ EXT4_INODE_SIZE(inode->i_sb) ||
+ (ei->i_extra_isize & 3)) {
+ ext4_error_inode(inode, function, line, 0,
+ "iget: bad extra_isize %u "
+ "(inode size %u)",
+ ei->i_extra_isize,
+ EXT4_INODE_SIZE(inode->i_sb));
+ ret = -EFSCORRUPTED;
+ goto bad_inode;
+ }
+ } else
+ ei->i_extra_isize = 0;
+
+ /* Precompute checksum seed for inode metadata */
+ if (ext4_has_feature_metadata_csum(sb)) {
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+ __u32 csum;
+ __le32 inum = cpu_to_le32(inode->i_ino);
+ __le32 gen = raw_inode->i_generation;
+ csum = ext4_chksum(sbi->s_csum_seed, (__u8 *)&inum,
+ sizeof(inum));
+ ei->i_csum_seed = ext4_chksum(csum, (__u8 *)&gen, sizeof(gen));
+ }
+
+ if ((!ext4_inode_csum_verify(inode, raw_inode, ei) ||
+ ext4_simulate_fail(sb, EXT4_SIM_INODE_CRC)) &&
+ (!(EXT4_SB(sb)->s_mount_state & EXT4_FC_REPLAY))) {
+ ext4_error_inode_err(inode, function, line, 0,
+ EFSBADCRC, "iget: checksum invalid");
+ ret = -EFSBADCRC;
+ goto bad_inode;
+ }
+
+ inode->i_mode = le16_to_cpu(raw_inode->i_mode);
+ i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low);
+ i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low);
+ if (ext4_has_feature_project(sb) &&
+ EXT4_INODE_SIZE(sb) > EXT4_GOOD_OLD_INODE_SIZE &&
+ EXT4_FITS_IN_INODE(raw_inode, ei, i_projid))
+ i_projid = (projid_t)le32_to_cpu(raw_inode->i_projid);
+ else
+ i_projid = EXT4_DEF_PROJID;
+
+ if (!(test_opt(inode->i_sb, NO_UID32))) {
+ i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16;
+ i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16;
+ }
+ i_uid_write(inode, i_uid);
+ i_gid_write(inode, i_gid);
+ ei->i_projid = make_kprojid(&init_user_ns, i_projid);
+ set_nlink(inode, le16_to_cpu(raw_inode->i_links_count));
+
+ ext4_clear_state_flags(ei); /* Only relevant on 32-bit archs */
+ ei->i_inline_off = 0;
+ ei->i_dir_start_lookup = 0;
+ ei->i_dtime = le32_to_cpu(raw_inode->i_dtime);
+ /* We now have enough fields to check if the inode was active or not.
+ * This is needed because nfsd might try to access dead inodes
+ * the test is that same one that e2fsck uses
+ * NeilBrown 1999oct15
+ */
+ if (inode->i_nlink == 0) {
+ if ((inode->i_mode == 0 || flags & EXT4_IGET_SPECIAL ||
+ !(EXT4_SB(inode->i_sb)->s_mount_state & EXT4_ORPHAN_FS)) &&
+ ino != EXT4_BOOT_LOADER_INO) {
+ /* this inode is deleted or unallocated */
+ if (flags & EXT4_IGET_SPECIAL) {
+ ext4_error_inode(inode, function, line, 0,
+ "iget: special inode unallocated");
+ ret = -EFSCORRUPTED;
+ } else
+ ret = -ESTALE;
+ goto bad_inode;
+ }
+ /* The only unlinked inodes we let through here have
+ * valid i_mode and are being read by the orphan
+ * recovery code: that's fine, we're about to complete
+ * the process of deleting those.
+ * OR it is the EXT4_BOOT_LOADER_INO which is
+ * not initialized on a new filesystem. */
+ }
+ ei->i_flags = le32_to_cpu(raw_inode->i_flags);
+ ext4_set_inode_flags(inode, true);
+ /* Detect invalid flag combination - can't have both inline data and extents */
+ if (ext4_test_inode_flag(inode, EXT4_INODE_INLINE_DATA) &&
+ ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
+ ext4_error_inode(inode, function, line, 0,
+ "inode has both inline data and extents flags");
+ ret = -EFSCORRUPTED;
+ goto bad_inode;
+ }
+ inode->i_blocks = ext4_inode_blocks(raw_inode, ei);
+ ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl_lo);
+ if (ext4_has_feature_64bit(sb))
+ ei->i_file_acl |=
+ ((__u64)le16_to_cpu(raw_inode->i_file_acl_high)) << 32;
+ inode->i_size = ext4_isize(sb, raw_inode);
+ size = i_size_read(inode);
+ if (size < 0 || size > ext4_get_maxbytes(inode)) {
+ ext4_error_inode(inode, function, line, 0,
+ "iget: bad i_size value: %lld", size);
+ ret = -EFSCORRUPTED;
+ goto bad_inode;
+ }
+ /*
+ * If dir_index is not enabled but there's dir with INDEX flag set,
+ * we'd normally treat htree data as empty space. But with metadata
+ * checksumming that corrupts checksums so forbid that.
+ */
+ if (!ext4_has_feature_dir_index(sb) &&
+ ext4_has_feature_metadata_csum(sb) &&
+ ext4_test_inode_flag(inode, EXT4_INODE_INDEX)) {
+ ext4_error_inode(inode, function, line, 0,
+ "iget: Dir with htree data on filesystem without dir_index feature.");
+ ret = -EFSCORRUPTED;
+ goto bad_inode;
+ }
+ ei->i_disksize = inode->i_size;
+#ifdef CONFIG_QUOTA
+ ei->i_reserved_quota = 0;
+#endif
+ inode->i_generation = le32_to_cpu(raw_inode->i_generation);
+ ei->i_block_group = iloc.block_group;
+ ei->i_last_alloc_group = ~0;
+ /*
+ * NOTE! The in-memory inode i_data array is in little-endian order
+ * even on big-endian machines: we do NOT byteswap the block numbers!
+ */
+ for (block = 0; block < EXT4_N_BLOCKS; block++)
+ ei->i_data[block] = raw_inode->i_block[block];
+ INIT_LIST_HEAD(&ei->i_orphan);
+ ext4_fc_init_inode(&ei->vfs_inode);
+
+ /*
+ * Set transaction id's of transactions that have to be committed
+ * to finish f[data]sync. We set them to currently running transaction
+ * as we cannot be sure that the inode or some of its metadata isn't
+ * part of the transaction - the inode could have been reclaimed and
+ * now it is reread from disk.
+ */
+ if (journal) {
+ transaction_t *transaction;
+ tid_t tid;
+
+ read_lock(&journal->j_state_lock);
+ if (journal->j_running_transaction)
+ transaction = journal->j_running_transaction;
+ else
+ transaction = journal->j_committing_transaction;
+ if (transaction)
+ tid = transaction->t_tid;
+ else
+ tid = journal->j_commit_sequence;
+ read_unlock(&journal->j_state_lock);
+ ei->i_sync_tid = tid;
+ ei->i_datasync_tid = tid;
+ }
+
+ if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
+ if (ei->i_extra_isize == 0) {
+ /* The extra space is currently unused. Use it. */
+ BUILD_BUG_ON(sizeof(struct ext4_inode) & 3);
+ ei->i_extra_isize = sizeof(struct ext4_inode) -
+ EXT4_GOOD_OLD_INODE_SIZE;
+ } else {
+ ret = ext4_iget_extra_inode(inode, raw_inode, ei);
+ if (ret)
+ goto bad_inode;
+ }
+ }
+
+ EXT4_INODE_GET_CTIME(inode, raw_inode);
+ EXT4_INODE_GET_ATIME(inode, raw_inode);
+ EXT4_INODE_GET_MTIME(inode, raw_inode);
+ EXT4_EINODE_GET_XTIME(i_crtime, ei, raw_inode);
+
+ if (likely(!test_opt2(inode->i_sb, HURD_COMPAT))) {
+ u64 ivers = le32_to_cpu(raw_inode->i_disk_version);
+
+ if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
+ if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi))
+ ivers |=
+ (__u64)(le32_to_cpu(raw_inode->i_version_hi)) << 32;
+ }
+ ext4_inode_set_iversion_queried(inode, ivers);
+ }
+
+ ret = 0;
+ if (ei->i_file_acl &&
+ !ext4_inode_block_valid(inode, ei->i_file_acl, 1)) {
+ ext4_error_inode(inode, function, line, 0,
+ "iget: bad extended attribute block %llu",
+ ei->i_file_acl);
+ ret = -EFSCORRUPTED;
+ goto bad_inode;
+ } else if (!ext4_has_inline_data(inode)) {
+ /* validate the block references in the inode */
+ if (!(EXT4_SB(sb)->s_mount_state & EXT4_FC_REPLAY) &&
+ (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
+ (S_ISLNK(inode->i_mode) &&
+ !ext4_inode_is_fast_symlink(inode)))) {
+ if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
+ ret = ext4_ext_check_inode(inode);
+ else
+ ret = ext4_ind_check_inode(inode);
+ }
+ }
+ if (ret)
+ goto bad_inode;
+
+ if (S_ISREG(inode->i_mode)) {
+ inode->i_op = &ext4_file_inode_operations;
+ inode->i_fop = &ext4_file_operations;
+ ext4_set_aops(inode);
+ } else if (S_ISDIR(inode->i_mode)) {
+ inode->i_op = &ext4_dir_inode_operations;
+ inode->i_fop = &ext4_dir_operations;
+ } else if (S_ISLNK(inode->i_mode)) {
+ /* VFS does not allow setting these so must be corruption */
+ if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) {
+ ext4_error_inode(inode, function, line, 0,
+ "iget: immutable or append flags "
+ "not allowed on symlinks");
+ ret = -EFSCORRUPTED;
+ goto bad_inode;
+ }
+ if (IS_ENCRYPTED(inode)) {
+ inode->i_op = &ext4_encrypted_symlink_inode_operations;
+ } else if (ext4_inode_is_fast_symlink(inode)) {
+ inode->i_op = &ext4_fast_symlink_inode_operations;
+ if (inode->i_size == 0 ||
+ inode->i_size >= sizeof(ei->i_data) ||
+ strnlen((char *)ei->i_data, inode->i_size + 1) !=
+ inode->i_size) {
+ ext4_error_inode(inode, function, line, 0,
+ "invalid fast symlink length %llu",
+ (unsigned long long)inode->i_size);
+ ret = -EFSCORRUPTED;
+ goto bad_inode;
+ }
+ inode_set_cached_link(inode, (char *)ei->i_data,
+ inode->i_size);
+ } else {
+ inode->i_op = &ext4_symlink_inode_operations;
+ }
+ } else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
+ S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
+ inode->i_op = &ext4_special_inode_operations;
+ if (raw_inode->i_block[0])
+ init_special_inode(inode, inode->i_mode,
+ old_decode_dev(le32_to_cpu(raw_inode->i_block[0])));
+ else
+ init_special_inode(inode, inode->i_mode,
+ new_decode_dev(le32_to_cpu(raw_inode->i_block[1])));
+ } else if (ino == EXT4_BOOT_LOADER_INO) {
+ make_bad_inode(inode);
+ } else {
+ ret = -EFSCORRUPTED;
+ ext4_error_inode(inode, function, line, 0,
+ "iget: bogus i_mode (%o)", inode->i_mode);
+ goto bad_inode;
+ }
+ if (IS_CASEFOLDED(inode) && !ext4_has_feature_casefold(inode->i_sb)) {
+ ext4_error_inode(inode, function, line, 0,
+ "casefold flag without casefold feature");
+ ret = -EFSCORRUPTED;
+ goto bad_inode;
+ }
+
+ ext4_set_inode_mapping_order(inode);
+
+ ret = check_igot_inode(inode, flags, function, line);
+ /*
+ * -ESTALE here means there is nothing inherently wrong with the inode,
+ * it's just not an inode we can return for an fhandle lookup.
+ */
+ if (ret == -ESTALE) {
+ brelse(iloc.bh);
+ unlock_new_inode(inode);
+ iput(inode);
+ return ERR_PTR(-ESTALE);
+ }
+ if (ret)
+ goto bad_inode;
+ brelse(iloc.bh);
+
+ unlock_new_inode(inode);
+ return inode;
+
+bad_inode:
+ brelse(iloc.bh);
+ iget_failed(inode);
+ return ERR_PTR(ret);
+}
+
+static void __ext4_update_other_inode_time(struct super_block *sb,
+ unsigned long orig_ino,
+ unsigned long ino,
+ struct ext4_inode *raw_inode)
+{
+ struct inode *inode;
+
+ inode = find_inode_by_ino_rcu(sb, ino);
+ if (!inode)
+ return;
+
+ if (!inode_is_dirtytime_only(inode))
+ return;
+
+ spin_lock(&inode->i_lock);
+ if (inode_is_dirtytime_only(inode)) {
+ struct ext4_inode_info *ei = EXT4_I(inode);
+
+ inode->i_state &= ~I_DIRTY_TIME;
+ spin_unlock(&inode->i_lock);
+
+ spin_lock(&ei->i_raw_lock);
+ EXT4_INODE_SET_CTIME(inode, raw_inode);
+ EXT4_INODE_SET_MTIME(inode, raw_inode);
+ EXT4_INODE_SET_ATIME(inode, raw_inode);
+ ext4_inode_csum_set(inode, raw_inode, ei);
+ spin_unlock(&ei->i_raw_lock);
+ trace_ext4_other_inode_update_time(inode, orig_ino);
+ return;
+ }
+ spin_unlock(&inode->i_lock);
+}
+
+/*
+ * Opportunistically update the other time fields for other inodes in
+ * the same inode table block.
+ */
+static void ext4_update_other_inodes_time(struct super_block *sb,
+ unsigned long orig_ino, char *buf)
+{
+ unsigned long ino;
+ int i, inodes_per_block = EXT4_SB(sb)->s_inodes_per_block;
+ int inode_size = EXT4_INODE_SIZE(sb);
+
+ /*
+ * Calculate the first inode in the inode table block. Inode
+ * numbers are one-based. That is, the first inode in a block
+ * (assuming 4k blocks and 256 byte inodes) is (n*16 + 1).
+ */
+ ino = ((orig_ino - 1) & ~(inodes_per_block - 1)) + 1;
+ rcu_read_lock();
+ for (i = 0; i < inodes_per_block; i++, ino++, buf += inode_size) {
+ if (ino == orig_ino)
+ continue;
+ __ext4_update_other_inode_time(sb, orig_ino, ino,
+ (struct ext4_inode *)buf);
+ }
+ rcu_read_unlock();
+}
+
+/*
+ * Post the struct inode info into an on-disk inode location in the
+ * buffer-cache. This gobbles the caller's reference to the
+ * buffer_head in the inode location struct.
+ *
+ * The caller must have write access to iloc->bh.
+ */
+static int ext4_do_update_inode(handle_t *handle,
+ struct inode *inode,
+ struct ext4_iloc *iloc)
+{
+ struct ext4_inode *raw_inode = ext4_raw_inode(iloc);
+ struct ext4_inode_info *ei = EXT4_I(inode);
+ struct buffer_head *bh = iloc->bh;
+ struct super_block *sb = inode->i_sb;
+ int err;
+ int need_datasync = 0, set_large_file = 0;
+
+ spin_lock(&ei->i_raw_lock);
+
+ /*
+ * For fields not tracked in the in-memory inode, initialise them
+ * to zero for new inodes.
+ */
+ if (ext4_test_inode_state(inode, EXT4_STATE_NEW))
+ memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size);
+
+ if (READ_ONCE(ei->i_disksize) != ext4_isize(inode->i_sb, raw_inode))
+ need_datasync = 1;
+ if (ei->i_disksize > 0x7fffffffULL) {
+ if (!ext4_has_feature_large_file(sb) ||
+ EXT4_SB(sb)->s_es->s_rev_level == cpu_to_le32(EXT4_GOOD_OLD_REV))
+ set_large_file = 1;
+ }
+
+ err = ext4_fill_raw_inode(inode, raw_inode);
+ spin_unlock(&ei->i_raw_lock);
+ if (err) {
+ EXT4_ERROR_INODE(inode, "corrupted inode contents");
+ goto out_brelse;
+ }
+
+ if (inode->i_sb->s_flags & SB_LAZYTIME)
+ ext4_update_other_inodes_time(inode->i_sb, inode->i_ino,
+ bh->b_data);
+
+ BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
+ err = ext4_handle_dirty_metadata(handle, NULL, bh);
+ if (err)
+ goto out_error;
+ ext4_clear_inode_state(inode, EXT4_STATE_NEW);
+ if (set_large_file) {
+ BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get write access");
+ err = ext4_journal_get_write_access(handle, sb,
+ EXT4_SB(sb)->s_sbh,
+ EXT4_JTR_NONE);
+ if (err)
+ goto out_error;
+ lock_buffer(EXT4_SB(sb)->s_sbh);
+ ext4_set_feature_large_file(sb);
+ ext4_superblock_csum_set(sb);
+ unlock_buffer(EXT4_SB(sb)->s_sbh);
+ ext4_handle_sync(handle);
+ err = ext4_handle_dirty_metadata(handle, NULL,
+ EXT4_SB(sb)->s_sbh);
+ }
+ ext4_update_inode_fsync_trans(handle, inode, need_datasync);
+out_error:
+ ext4_std_error(inode->i_sb, err);
+out_brelse:
+ brelse(bh);
+ return err;
+}
+
+/*
+ * ext4_write_inode()
+ *
+ * We are called from a few places:
+ *
+ * - Within generic_file_aio_write() -> generic_write_sync() for O_SYNC files.
+ * Here, there will be no transaction running. We wait for any running
+ * transaction to commit.
+ *
+ * - Within flush work (sys_sync(), kupdate and such).
+ * We wait on commit, if told to.
+ *
+ * - Within iput_final() -> write_inode_now()
+ * We wait on commit, if told to.
+ *
+ * In all cases it is actually safe for us to return without doing anything,
+ * because the inode has been copied into a raw inode buffer in
+ * ext4_mark_inode_dirty(). This is a correctness thing for WB_SYNC_ALL
+ * writeback.
+ *
+ * Note that we are absolutely dependent upon all inode dirtiers doing the
+ * right thing: they *must* call mark_inode_dirty() after dirtying info in
+ * which we are interested.
+ *
+ * It would be a bug for them to not do this. The code:
+ *
+ * mark_inode_dirty(inode)
+ * stuff();
+ * inode->i_size = expr;
+ *
+ * is in error because write_inode() could occur while `stuff()' is running,
+ * and the new i_size will be lost. Plus the inode will no longer be on the
+ * superblock's dirty inode list.
+ */
+int ext4_write_inode(struct inode *inode, struct writeback_control *wbc)
+{
+ int err;
+
+ if (WARN_ON_ONCE(current->flags & PF_MEMALLOC))
+ return 0;
+
+ err = ext4_emergency_state(inode->i_sb);
+ if (unlikely(err))
+ return err;
+
+ if (EXT4_SB(inode->i_sb)->s_journal) {
+ if (ext4_journal_current_handle()) {
+ ext4_debug("called recursively, non-PF_MEMALLOC!\n");
+ dump_stack();
+ return -EIO;
+ }
+
+ /*
+ * No need to force transaction in WB_SYNC_NONE mode. Also
+ * ext4_sync_fs() will force the commit after everything is
+ * written.
+ */
+ if (wbc->sync_mode != WB_SYNC_ALL || wbc->for_sync)
+ return 0;
+
+ err = ext4_fc_commit(EXT4_SB(inode->i_sb)->s_journal,
+ EXT4_I(inode)->i_sync_tid);
+ } else {
+ struct ext4_iloc iloc;
+
+ err = __ext4_get_inode_loc_noinmem(inode, &iloc);
+ if (err)
+ return err;
+ /*
+ * sync(2) will flush the whole buffer cache. No need to do
+ * it here separately for each inode.
+ */
+ if (wbc->sync_mode == WB_SYNC_ALL && !wbc->for_sync)
+ sync_dirty_buffer(iloc.bh);
+ if (buffer_req(iloc.bh) && !buffer_uptodate(iloc.bh)) {
+ ext4_error_inode_block(inode, iloc.bh->b_blocknr, EIO,
+ "IO error syncing inode");
+ err = -EIO;
+ }
+ brelse(iloc.bh);
+ }
+ return err;
+}
+
+/*
+ * In data=journal mode ext4_journalled_invalidate_folio() may fail to invalidate
+ * buffers that are attached to a folio straddling i_size and are undergoing
+ * commit. In that case we have to wait for commit to finish and try again.
+ */
+static void ext4_wait_for_tail_page_commit(struct inode *inode)
+{
+ unsigned offset;
+ journal_t *journal = EXT4_SB(inode->i_sb)->s_journal;
+ tid_t commit_tid;
+ int ret;
+ bool has_transaction;
+
+ offset = inode->i_size & (PAGE_SIZE - 1);
+ /*
+ * If the folio is fully truncated, we don't need to wait for any commit
+ * (and we even should not as __ext4_journalled_invalidate_folio() may
+ * strip all buffers from the folio but keep the folio dirty which can then
+ * confuse e.g. concurrent ext4_writepages() seeing dirty folio without
+ * buffers). Also we don't need to wait for any commit if all buffers in
+ * the folio remain valid. This is most beneficial for the common case of
+ * blocksize == PAGESIZE.
+ */
+ if (!offset || offset > (PAGE_SIZE - i_blocksize(inode)))
+ return;
+ while (1) {
+ struct folio *folio = filemap_lock_folio(inode->i_mapping,
+ inode->i_size >> PAGE_SHIFT);
+ if (IS_ERR(folio))
+ return;
+ ret = __ext4_journalled_invalidate_folio(folio, offset,
+ folio_size(folio) - offset);
+ folio_unlock(folio);
+ folio_put(folio);
+ if (ret != -EBUSY)
+ return;
+ has_transaction = false;
+ read_lock(&journal->j_state_lock);
+ if (journal->j_committing_transaction) {
+ commit_tid = journal->j_committing_transaction->t_tid;
+ has_transaction = true;
+ }
+ read_unlock(&journal->j_state_lock);
+ if (has_transaction)
+ jbd2_log_wait_commit(journal, commit_tid);
+ }
+}
+
+/*
+ * ext4_setattr()
+ *
+ * Called from notify_change.
+ *
+ * We want to trap VFS attempts to truncate the file as soon as
+ * possible. In particular, we want to make sure that when the VFS
+ * shrinks i_size, we put the inode on the orphan list and modify
+ * i_disksize immediately, so that during the subsequent flushing of
+ * dirty pages and freeing of disk blocks, we can guarantee that any
+ * commit will leave the blocks being flushed in an unused state on
+ * disk. (On recovery, the inode will get truncated and the blocks will
+ * be freed, so we have a strong guarantee that no future commit will
+ * leave these blocks visible to the user.)
+ *
+ * Another thing we have to assure is that if we are in ordered mode
+ * and inode is still attached to the committing transaction, we must
+ * we start writeout of all the dirty pages which are being truncated.
+ * This way we are sure that all the data written in the previous
+ * transaction are already on disk (truncate waits for pages under
+ * writeback).
+ *
+ * Called with inode->i_rwsem down.
+ */
+int ext4_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
+ struct iattr *attr)
+{
+ struct inode *inode = d_inode(dentry);
+ int error, rc = 0;
+ int orphan = 0;
+ const unsigned int ia_valid = attr->ia_valid;
+ bool inc_ivers = true;
+
+ error = ext4_emergency_state(inode->i_sb);
+ if (unlikely(error))
+ return error;
+
+ if (unlikely(IS_IMMUTABLE(inode)))
+ return -EPERM;
+
+ if (unlikely(IS_APPEND(inode) &&
+ (ia_valid & (ATTR_MODE | ATTR_UID |
+ ATTR_GID | ATTR_TIMES_SET))))
+ return -EPERM;
+
+ error = setattr_prepare(idmap, dentry, attr);
+ if (error)
+ return error;
+
+ error = fscrypt_prepare_setattr(dentry, attr);
+ if (error)
+ return error;
+
+ error = fsverity_prepare_setattr(dentry, attr);
+ if (error)
+ return error;
+
+ if (is_quota_modification(idmap, inode, attr)) {
+ error = dquot_initialize(inode);
+ if (error)
+ return error;
+ }
+
+ if (i_uid_needs_update(idmap, attr, inode) ||
+ i_gid_needs_update(idmap, attr, inode)) {
+ handle_t *handle;
+
+ /* (user+group)*(old+new) structure, inode write (sb,
+ * inode block, ? - but truncate inode update has it) */
+ handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
+ (EXT4_MAXQUOTAS_INIT_BLOCKS(inode->i_sb) +
+ EXT4_MAXQUOTAS_DEL_BLOCKS(inode->i_sb)) + 3);
+ if (IS_ERR(handle)) {
+ error = PTR_ERR(handle);
+ goto err_out;
+ }
+
+ /* dquot_transfer() calls back ext4_get_inode_usage() which
+ * counts xattr inode references.
+ */
+ down_read(&EXT4_I(inode)->xattr_sem);
+ error = dquot_transfer(idmap, inode, attr);
+ up_read(&EXT4_I(inode)->xattr_sem);
+
+ if (error) {
+ ext4_journal_stop(handle);
+ return error;
+ }
+ /* Update corresponding info in inode so that everything is in
+ * one transaction */
+ i_uid_update(idmap, attr, inode);
+ i_gid_update(idmap, attr, inode);
+ error = ext4_mark_inode_dirty(handle, inode);
+ ext4_journal_stop(handle);
+ if (unlikely(error)) {
+ return error;
+ }
+ }
+
+ if (attr->ia_valid & ATTR_SIZE) {
+ handle_t *handle;
+ loff_t oldsize = inode->i_size;
+ loff_t old_disksize;
+ int shrink = (attr->ia_size < inode->i_size);
+
+ if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+
+ if (attr->ia_size > sbi->s_bitmap_maxbytes) {
+ return -EFBIG;
+ }
+ }
+ if (!S_ISREG(inode->i_mode)) {
+ return -EINVAL;
+ }
+
+ if (attr->ia_size == inode->i_size)
+ inc_ivers = false;
+
+ if (shrink) {
+ if (ext4_should_order_data(inode)) {
+ error = ext4_begin_ordered_truncate(inode,
+ attr->ia_size);
+ if (error)
+ goto err_out;
+ }
+ /*
+ * Blocks are going to be removed from the inode. Wait
+ * for dio in flight.
+ */
+ inode_dio_wait(inode);
+ }
+
+ filemap_invalidate_lock(inode->i_mapping);
+
+ rc = ext4_break_layouts(inode);
+ if (rc) {
+ filemap_invalidate_unlock(inode->i_mapping);
+ goto err_out;
+ }
+
+ if (attr->ia_size != inode->i_size) {
+ /* attach jbd2 jinode for EOF folio tail zeroing */
+ if (attr->ia_size & (inode->i_sb->s_blocksize - 1) ||
+ oldsize & (inode->i_sb->s_blocksize - 1)) {
+ error = ext4_inode_attach_jinode(inode);
+ if (error)
+ goto out_mmap_sem;
+ }
+
+ handle = ext4_journal_start(inode, EXT4_HT_INODE, 3);
+ if (IS_ERR(handle)) {
+ error = PTR_ERR(handle);
+ goto out_mmap_sem;
+ }
+ if (ext4_handle_valid(handle) && shrink) {
+ error = ext4_orphan_add(handle, inode);
+ orphan = 1;
+ }
+ /*
+ * Update c/mtime and tail zero the EOF folio on
+ * truncate up. ext4_truncate() handles the shrink case
+ * below.
+ */
+ if (!shrink) {
+ inode_set_mtime_to_ts(inode,
+ inode_set_ctime_current(inode));
+ if (oldsize & (inode->i_sb->s_blocksize - 1))
+ ext4_block_truncate_page(handle,
+ inode->i_mapping, oldsize);
+ }
+
+ if (shrink)
+ ext4_fc_track_range(handle, inode,
+ (attr->ia_size > 0 ? attr->ia_size - 1 : 0) >>
+ inode->i_sb->s_blocksize_bits,
+ EXT_MAX_BLOCKS - 1);
+ else
+ ext4_fc_track_range(
+ handle, inode,
+ (oldsize > 0 ? oldsize - 1 : oldsize) >>
+ inode->i_sb->s_blocksize_bits,
+ (attr->ia_size > 0 ? attr->ia_size - 1 : 0) >>
+ inode->i_sb->s_blocksize_bits);
+
+ down_write(&EXT4_I(inode)->i_data_sem);
+ old_disksize = EXT4_I(inode)->i_disksize;
+ EXT4_I(inode)->i_disksize = attr->ia_size;
+
+ /*
+ * We have to update i_size under i_data_sem together
+ * with i_disksize to avoid races with writeback code
+ * running ext4_wb_update_i_disksize().
+ */
+ if (!error)
+ i_size_write(inode, attr->ia_size);
+ else
+ EXT4_I(inode)->i_disksize = old_disksize;
+ up_write(&EXT4_I(inode)->i_data_sem);
+ rc = ext4_mark_inode_dirty(handle, inode);
+ if (!error)
+ error = rc;
+ ext4_journal_stop(handle);
+ if (error)
+ goto out_mmap_sem;
+ if (!shrink) {
+ pagecache_isize_extended(inode, oldsize,
+ inode->i_size);
+ } else if (ext4_should_journal_data(inode)) {
+ ext4_wait_for_tail_page_commit(inode);
+ }
+ }
+
+ /*
+ * Truncate pagecache after we've waited for commit
+ * in data=journal mode to make pages freeable.
+ */
+ truncate_pagecache(inode, inode->i_size);
+ /*
+ * Call ext4_truncate() even if i_size didn't change to
+ * truncate possible preallocated blocks.
+ */
+ if (attr->ia_size <= oldsize) {
+ rc = ext4_truncate(inode);
+ if (rc)
+ error = rc;
+ }
+out_mmap_sem:
+ filemap_invalidate_unlock(inode->i_mapping);
+ }
+
+ if (!error) {
+ if (inc_ivers)
+ inode_inc_iversion(inode);
+ setattr_copy(idmap, inode, attr);
+ mark_inode_dirty(inode);
+ }
+
+ /*
+ * If the call to ext4_truncate failed to get a transaction handle at
+ * all, we need to clean up the in-core orphan list manually.
+ */
+ if (orphan && inode->i_nlink)
+ ext4_orphan_del(NULL, inode);
+
+ if (!error && (ia_valid & ATTR_MODE))
+ rc = posix_acl_chmod(idmap, dentry, inode->i_mode);
+
+err_out:
+ if (error)
+ ext4_std_error(inode->i_sb, error);
+ if (!error)
+ error = rc;
+ return error;
+}
+
+u32 ext4_dio_alignment(struct inode *inode)
+{
+ if (fsverity_active(inode))
+ return 0;
+ if (ext4_should_journal_data(inode))
+ return 0;
+ if (ext4_has_inline_data(inode))
+ return 0;
+ if (IS_ENCRYPTED(inode)) {
+ if (!fscrypt_dio_supported(inode))
+ return 0;
+ return i_blocksize(inode);
+ }
+ return 1; /* use the iomap defaults */
+}
+
+int ext4_getattr(struct mnt_idmap *idmap, const struct path *path,
+ struct kstat *stat, u32 request_mask, unsigned int query_flags)
+{
+ struct inode *inode = d_inode(path->dentry);
+ struct ext4_inode *raw_inode;
+ struct ext4_inode_info *ei = EXT4_I(inode);
+ unsigned int flags;
+
+ if ((request_mask & STATX_BTIME) &&
+ EXT4_FITS_IN_INODE(raw_inode, ei, i_crtime)) {
+ stat->result_mask |= STATX_BTIME;
+ stat->btime.tv_sec = ei->i_crtime.tv_sec;
+ stat->btime.tv_nsec = ei->i_crtime.tv_nsec;
+ }
+
+ /*
+ * Return the DIO alignment restrictions if requested. We only return
+ * this information when requested, since on encrypted files it might
+ * take a fair bit of work to get if the file wasn't opened recently.
+ */
+ if ((request_mask & STATX_DIOALIGN) && S_ISREG(inode->i_mode)) {
+ u32 dio_align = ext4_dio_alignment(inode);
+
+ stat->result_mask |= STATX_DIOALIGN;
+ if (dio_align == 1) {
+ struct block_device *bdev = inode->i_sb->s_bdev;
+
+ /* iomap defaults */
+ stat->dio_mem_align = bdev_dma_alignment(bdev) + 1;
+ stat->dio_offset_align = bdev_logical_block_size(bdev);
+ } else {
+ stat->dio_mem_align = dio_align;
+ stat->dio_offset_align = dio_align;
+ }
+ }
+
+ if ((request_mask & STATX_WRITE_ATOMIC) && S_ISREG(inode->i_mode)) {
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+ unsigned int awu_min = 0, awu_max = 0;
+
+ if (ext4_inode_can_atomic_write(inode)) {
+ awu_min = sbi->s_awu_min;
+ awu_max = sbi->s_awu_max;
+ }
+
+ generic_fill_statx_atomic_writes(stat, awu_min, awu_max, 0);
+ }
+
+ flags = ei->i_flags & EXT4_FL_USER_VISIBLE;
+ if (flags & EXT4_APPEND_FL)
+ stat->attributes |= STATX_ATTR_APPEND;
+ if (flags & EXT4_COMPR_FL)
+ stat->attributes |= STATX_ATTR_COMPRESSED;
+ if (flags & EXT4_ENCRYPT_FL)
+ stat->attributes |= STATX_ATTR_ENCRYPTED;
+ if (flags & EXT4_IMMUTABLE_FL)
+ stat->attributes |= STATX_ATTR_IMMUTABLE;
+ if (flags & EXT4_NODUMP_FL)
+ stat->attributes |= STATX_ATTR_NODUMP;
+ if (flags & EXT4_VERITY_FL)
+ stat->attributes |= STATX_ATTR_VERITY;
+
+ stat->attributes_mask |= (STATX_ATTR_APPEND |
+ STATX_ATTR_COMPRESSED |
+ STATX_ATTR_ENCRYPTED |
+ STATX_ATTR_IMMUTABLE |
+ STATX_ATTR_NODUMP |
+ STATX_ATTR_VERITY);
+
+ generic_fillattr(idmap, request_mask, inode, stat);
+ return 0;
+}
+
+int ext4_file_getattr(struct mnt_idmap *idmap,
+ const struct path *path, struct kstat *stat,
+ u32 request_mask, unsigned int query_flags)
+{
+ struct inode *inode = d_inode(path->dentry);
+ u64 delalloc_blocks;
+
+ ext4_getattr(idmap, path, stat, request_mask, query_flags);
+
+ /*
+ * If there is inline data in the inode, the inode will normally not
+ * have data blocks allocated (it may have an external xattr block).
+ * Report at least one sector for such files, so tools like tar, rsync,
+ * others don't incorrectly think the file is completely sparse.
+ */
+ if (unlikely(ext4_has_inline_data(inode)))
+ stat->blocks += (stat->size + 511) >> 9;
+
+ /*
+ * We can't update i_blocks if the block allocation is delayed
+ * otherwise in the case of system crash before the real block
+ * allocation is done, we will have i_blocks inconsistent with
+ * on-disk file blocks.
+ * We always keep i_blocks updated together with real
+ * allocation. But to not confuse with user, stat
+ * will return the blocks that include the delayed allocation
+ * blocks for this file.
+ */
+ delalloc_blocks = EXT4_C2B(EXT4_SB(inode->i_sb),
+ EXT4_I(inode)->i_reserved_data_blocks);
+ stat->blocks += delalloc_blocks << (inode->i_sb->s_blocksize_bits - 9);
+ return 0;
+}
+
+static int ext4_index_trans_blocks(struct inode *inode, int lblocks,
+ int pextents)
+{
+ if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
+ return ext4_ind_trans_blocks(inode, lblocks);
+ return ext4_ext_index_trans_blocks(inode, pextents);
+}
+
+/*
+ * Account for index blocks, block groups bitmaps and block group
+ * descriptor blocks if modify datablocks and index blocks
+ * worse case, the indexs blocks spread over different block groups
+ *
+ * If datablocks are discontiguous, they are possible to spread over
+ * different block groups too. If they are contiguous, with flexbg,
+ * they could still across block group boundary.
+ *
+ * Also account for superblock, inode, quota and xattr blocks
+ */
+int ext4_meta_trans_blocks(struct inode *inode, int lblocks, int pextents)
+{
+ ext4_group_t groups, ngroups = ext4_get_groups_count(inode->i_sb);
+ int gdpblocks;
+ int idxblocks;
+ int ret;
+
+ /*
+ * How many index and leaf blocks need to touch to map @lblocks
+ * logical blocks to @pextents physical extents?
+ */
+ idxblocks = ext4_index_trans_blocks(inode, lblocks, pextents);
+
+ /*
+ * Now let's see how many group bitmaps and group descriptors need
+ * to account
+ */
+ groups = idxblocks + pextents;
+ gdpblocks = groups;
+ if (groups > ngroups)
+ groups = ngroups;
+ if (groups > EXT4_SB(inode->i_sb)->s_gdb_count)
+ gdpblocks = EXT4_SB(inode->i_sb)->s_gdb_count;
+
+ /* bitmaps and block group descriptor blocks */
+ ret = idxblocks + groups + gdpblocks;
+
+ /* Blocks for super block, inode, quota and xattr blocks */
+ ret += EXT4_META_TRANS_BLOCKS(inode->i_sb);
+
+ return ret;
+}
+
+/*
+ * Calculate the journal credits for modifying the number of blocks
+ * in a single extent within one transaction. 'nrblocks' is used only
+ * for non-extent inodes. For extent type inodes, 'nrblocks' can be
+ * zero if the exact number of blocks is unknown.
+ */
+int ext4_chunk_trans_extent(struct inode *inode, int nrblocks)
+{
+ int ret;
+
+ ret = ext4_meta_trans_blocks(inode, nrblocks, 1);
+ /* Account for data blocks for journalled mode */
+ if (ext4_should_journal_data(inode))
+ ret += nrblocks;
+ return ret;
+}
+
+/*
+ * Calculate the journal credits for a chunk of data modification.
+ *
+ * This is called from DIO, fallocate or whoever calling
+ * ext4_map_blocks() to map/allocate a chunk of contiguous disk blocks.
+ *
+ * journal buffers for data blocks are not included here, as DIO
+ * and fallocate do no need to journal data buffers.
+ */
+int ext4_chunk_trans_blocks(struct inode *inode, int nrblocks)
+{
+ return ext4_meta_trans_blocks(inode, nrblocks, 1);
+}
+
+/*
+ * The caller must have previously called ext4_reserve_inode_write().
+ * Give this, we know that the caller already has write access to iloc->bh.
+ */
+int ext4_mark_iloc_dirty(handle_t *handle,
+ struct inode *inode, struct ext4_iloc *iloc)
+{
+ int err = 0;
+
+ err = ext4_emergency_state(inode->i_sb);
+ if (unlikely(err)) {
+ put_bh(iloc->bh);
+ return err;
+ }
+ ext4_fc_track_inode(handle, inode);
+
+ /* the do_update_inode consumes one bh->b_count */
+ get_bh(iloc->bh);
+
+ /* ext4_do_update_inode() does jbd2_journal_dirty_metadata */
+ err = ext4_do_update_inode(handle, inode, iloc);
+ put_bh(iloc->bh);
+ return err;
+}
+
+/*
+ * On success, We end up with an outstanding reference count against
+ * iloc->bh. This _must_ be cleaned up later.
+ */
+
+int
+ext4_reserve_inode_write(handle_t *handle, struct inode *inode,
+ struct ext4_iloc *iloc)
+{
+ int err;
+
+ err = ext4_emergency_state(inode->i_sb);
+ if (unlikely(err))
+ return err;
+
+ err = ext4_get_inode_loc(inode, iloc);
+ if (!err) {
+ BUFFER_TRACE(iloc->bh, "get_write_access");
+ err = ext4_journal_get_write_access(handle, inode->i_sb,
+ iloc->bh, EXT4_JTR_NONE);
+ if (err) {
+ brelse(iloc->bh);
+ iloc->bh = NULL;
+ }
+ ext4_fc_track_inode(handle, inode);
+ }
+ ext4_std_error(inode->i_sb, err);
+ return err;
+}
+
+static int __ext4_expand_extra_isize(struct inode *inode,
+ unsigned int new_extra_isize,
+ struct ext4_iloc *iloc,
+ handle_t *handle, int *no_expand)
+{
+ struct ext4_inode *raw_inode;
+ struct ext4_xattr_ibody_header *header;
+ unsigned int inode_size = EXT4_INODE_SIZE(inode->i_sb);
+ struct ext4_inode_info *ei = EXT4_I(inode);
+ int error;
+
+ /* this was checked at iget time, but double check for good measure */
+ if ((EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize > inode_size) ||
+ (ei->i_extra_isize & 3)) {
+ EXT4_ERROR_INODE(inode, "bad extra_isize %u (inode size %u)",
+ ei->i_extra_isize,
+ EXT4_INODE_SIZE(inode->i_sb));
+ return -EFSCORRUPTED;
+ }
+ if ((new_extra_isize < ei->i_extra_isize) ||
+ (new_extra_isize < 4) ||
+ (new_extra_isize > inode_size - EXT4_GOOD_OLD_INODE_SIZE))
+ return -EINVAL; /* Should never happen */
+
+ raw_inode = ext4_raw_inode(iloc);
+
+ header = IHDR(inode, raw_inode);
+
+ /* No extended attributes present */
+ if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR) ||
+ header->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC)) {
+ memset((void *)raw_inode + EXT4_GOOD_OLD_INODE_SIZE +
+ EXT4_I(inode)->i_extra_isize, 0,
+ new_extra_isize - EXT4_I(inode)->i_extra_isize);
+ EXT4_I(inode)->i_extra_isize = new_extra_isize;
+ return 0;
+ }
+
+ /*
+ * We may need to allocate external xattr block so we need quotas
+ * initialized. Here we can be called with various locks held so we
+ * cannot affort to initialize quotas ourselves. So just bail.
+ */
+ if (dquot_initialize_needed(inode))
+ return -EAGAIN;
+
+ /* try to expand with EAs present */
+ error = ext4_expand_extra_isize_ea(inode, new_extra_isize,
+ raw_inode, handle);
+ if (error) {
+ /*
+ * Inode size expansion failed; don't try again
+ */
+ *no_expand = 1;
+ }
+
+ return error;
+}
+
+/*
+ * Expand an inode by new_extra_isize bytes.
+ * Returns 0 on success or negative error number on failure.
+ */
+static int ext4_try_to_expand_extra_isize(struct inode *inode,
+ unsigned int new_extra_isize,
+ struct ext4_iloc iloc,
+ handle_t *handle)
+{
+ int no_expand;
+ int error;
+
+ if (ext4_test_inode_state(inode, EXT4_STATE_NO_EXPAND))
+ return -EOVERFLOW;
+
+ /*
+ * In nojournal mode, we can immediately attempt to expand
+ * the inode. When journaled, we first need to obtain extra
+ * buffer credits since we may write into the EA block
+ * with this same handle. If journal_extend fails, then it will
+ * only result in a minor loss of functionality for that inode.
+ * If this is felt to be critical, then e2fsck should be run to
+ * force a large enough s_min_extra_isize.
+ */
+ if (ext4_journal_extend(handle,
+ EXT4_DATA_TRANS_BLOCKS(inode->i_sb), 0) != 0)
+ return -ENOSPC;
+
+ if (ext4_write_trylock_xattr(inode, &no_expand) == 0)
+ return -EBUSY;
+
+ error = __ext4_expand_extra_isize(inode, new_extra_isize, &iloc,
+ handle, &no_expand);
+ ext4_write_unlock_xattr(inode, &no_expand);
+
+ return error;
+}
+
+int ext4_expand_extra_isize(struct inode *inode,
+ unsigned int new_extra_isize,
+ struct ext4_iloc *iloc)
+{
+ handle_t *handle;
+ int no_expand;
+ int error, rc;
+
+ if (ext4_test_inode_state(inode, EXT4_STATE_NO_EXPAND)) {
+ brelse(iloc->bh);
+ return -EOVERFLOW;
+ }
+
+ handle = ext4_journal_start(inode, EXT4_HT_INODE,
+ EXT4_DATA_TRANS_BLOCKS(inode->i_sb));
+ if (IS_ERR(handle)) {
+ error = PTR_ERR(handle);
+ brelse(iloc->bh);
+ return error;
+ }
+
+ ext4_write_lock_xattr(inode, &no_expand);
+
+ BUFFER_TRACE(iloc->bh, "get_write_access");
+ error = ext4_journal_get_write_access(handle, inode->i_sb, iloc->bh,
+ EXT4_JTR_NONE);
+ if (error) {
+ brelse(iloc->bh);
+ goto out_unlock;
+ }
+
+ error = __ext4_expand_extra_isize(inode, new_extra_isize, iloc,
+ handle, &no_expand);
+
+ rc = ext4_mark_iloc_dirty(handle, inode, iloc);
+ if (!error)
+ error = rc;
+
+out_unlock:
+ ext4_write_unlock_xattr(inode, &no_expand);
+ ext4_journal_stop(handle);
+ return error;
+}
+
+/*
+ * What we do here is to mark the in-core inode as clean with respect to inode
+ * dirtiness (it may still be data-dirty).
+ * This means that the in-core inode may be reaped by prune_icache
+ * without having to perform any I/O. This is a very good thing,
+ * because *any* task may call prune_icache - even ones which
+ * have a transaction open against a different journal.
+ *
+ * Is this cheating? Not really. Sure, we haven't written the
+ * inode out, but prune_icache isn't a user-visible syncing function.
+ * Whenever the user wants stuff synced (sys_sync, sys_msync, sys_fsync)
+ * we start and wait on commits.
+ */
+int __ext4_mark_inode_dirty(handle_t *handle, struct inode *inode,
+ const char *func, unsigned int line)
+{
+ struct ext4_iloc iloc;
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+ int err;
+
+ might_sleep();
+ trace_ext4_mark_inode_dirty(inode, _RET_IP_);
+ err = ext4_reserve_inode_write(handle, inode, &iloc);
+ if (err)
+ goto out;
+
+ if (EXT4_I(inode)->i_extra_isize < sbi->s_want_extra_isize)
+ ext4_try_to_expand_extra_isize(inode, sbi->s_want_extra_isize,
+ iloc, handle);
+
+ err = ext4_mark_iloc_dirty(handle, inode, &iloc);
+out:
+ if (unlikely(err))
+ ext4_error_inode_err(inode, func, line, 0, err,
+ "mark_inode_dirty error");
+ return err;
+}
+
+/*
+ * ext4_dirty_inode() is called from __mark_inode_dirty()
+ *
+ * We're really interested in the case where a file is being extended.
+ * i_size has been changed by generic_commit_write() and we thus need
+ * to include the updated inode in the current transaction.
+ *
+ * Also, dquot_alloc_block() will always dirty the inode when blocks
+ * are allocated to the file.
+ *
+ * If the inode is marked synchronous, we don't honour that here - doing
+ * so would cause a commit on atime updates, which we don't bother doing.
+ * We handle synchronous inodes at the highest possible level.
+ */
+void ext4_dirty_inode(struct inode *inode, int flags)
+{
+ handle_t *handle;
+
+ handle = ext4_journal_start(inode, EXT4_HT_INODE, 2);
+ if (IS_ERR(handle))
+ return;
+ ext4_mark_inode_dirty(handle, inode);
+ ext4_journal_stop(handle);
+}
+
+int ext4_change_inode_journal_flag(struct inode *inode, int val)
+{
+ journal_t *journal;
+ handle_t *handle;
+ int err;
+ int alloc_ctx;
+
+ /*
+ * We have to be very careful here: changing a data block's
+ * journaling status dynamically is dangerous. If we write a
+ * data block to the journal, change the status and then delete
+ * that block, we risk forgetting to revoke the old log record
+ * from the journal and so a subsequent replay can corrupt data.
+ * So, first we make sure that the journal is empty and that
+ * nobody is changing anything.
+ */
+
+ journal = EXT4_JOURNAL(inode);
+ if (!journal)
+ return 0;
+ if (is_journal_aborted(journal))
+ return -EROFS;
+
+ /* Wait for all existing dio workers */
+ inode_dio_wait(inode);
+
+ /*
+ * Before flushing the journal and switching inode's aops, we have
+ * to flush all dirty data the inode has. There can be outstanding
+ * delayed allocations, there can be unwritten extents created by
+ * fallocate or buffered writes in dioread_nolock mode covered by
+ * dirty data which can be converted only after flushing the dirty
+ * data (and journalled aops don't know how to handle these cases).
+ */
+ if (val) {
+ filemap_invalidate_lock(inode->i_mapping);
+ err = filemap_write_and_wait(inode->i_mapping);
+ if (err < 0) {
+ filemap_invalidate_unlock(inode->i_mapping);
+ return err;
+ }
+ }
+
+ alloc_ctx = ext4_writepages_down_write(inode->i_sb);
+ jbd2_journal_lock_updates(journal);
+
+ /*
+ * OK, there are no updates running now, and all cached data is
+ * synced to disk. We are now in a completely consistent state
+ * which doesn't have anything in the journal, and we know that
+ * no filesystem updates are running, so it is safe to modify
+ * the inode's in-core data-journaling state flag now.
+ */
+
+ if (val)
+ ext4_set_inode_flag(inode, EXT4_INODE_JOURNAL_DATA);
+ else {
+ err = jbd2_journal_flush(journal, 0);
+ if (err < 0) {
+ jbd2_journal_unlock_updates(journal);
+ ext4_writepages_up_write(inode->i_sb, alloc_ctx);
+ return err;
+ }
+ ext4_clear_inode_flag(inode, EXT4_INODE_JOURNAL_DATA);
+ }
+ ext4_set_aops(inode);
+
+ jbd2_journal_unlock_updates(journal);
+ ext4_writepages_up_write(inode->i_sb, alloc_ctx);
+
+ if (val)
+ filemap_invalidate_unlock(inode->i_mapping);
+
+ /* Finally we can mark the inode as dirty. */
+
+ handle = ext4_journal_start(inode, EXT4_HT_INODE, 1);
+ if (IS_ERR(handle))
+ return PTR_ERR(handle);
+
+ ext4_fc_mark_ineligible(inode->i_sb,
+ EXT4_FC_REASON_JOURNAL_FLAG_CHANGE, handle);
+ err = ext4_mark_inode_dirty(handle, inode);
+ ext4_handle_sync(handle);
+ ext4_journal_stop(handle);
+ ext4_std_error(inode->i_sb, err);
+
+ return err;
+}
+
+static int ext4_bh_unmapped(handle_t *handle, struct inode *inode,
+ struct buffer_head *bh)
+{
+ return !buffer_mapped(bh);
+}
+
+static int ext4_block_page_mkwrite(struct inode *inode, struct folio *folio,
+ get_block_t get_block)
+{
+ handle_t *handle;
+ loff_t size;
+ unsigned long len;
+ int credits;
+ int ret;
+
+ credits = ext4_chunk_trans_extent(inode,
+ ext4_journal_blocks_per_folio(inode));
+ handle = ext4_journal_start(inode, EXT4_HT_WRITE_PAGE, credits);
+ if (IS_ERR(handle))
+ return PTR_ERR(handle);
+
+ folio_lock(folio);
+ size = i_size_read(inode);
+ /* Page got truncated from under us? */
+ if (folio->mapping != inode->i_mapping || folio_pos(folio) > size) {
+ ret = -EFAULT;
+ goto out_error;
+ }
+
+ len = folio_size(folio);
+ if (folio_pos(folio) + len > size)
+ len = size - folio_pos(folio);
+
+ ret = ext4_block_write_begin(handle, folio, 0, len, get_block);
+ if (ret)
+ goto out_error;
+
+ if (!ext4_should_journal_data(inode)) {
+ block_commit_write(folio, 0, len);
+ folio_mark_dirty(folio);
+ } else {
+ ret = ext4_journal_folio_buffers(handle, folio, len);
+ if (ret)
+ goto out_error;
+ }
+ ext4_journal_stop(handle);
+ folio_wait_stable(folio);
+ return ret;
+
+out_error:
+ folio_unlock(folio);
+ ext4_journal_stop(handle);
+ return ret;
+}
+
+vm_fault_t ext4_page_mkwrite(struct vm_fault *vmf)
+{
+ struct vm_area_struct *vma = vmf->vma;
+ struct folio *folio = page_folio(vmf->page);
+ loff_t size;
+ unsigned long len;
+ int err;
+ vm_fault_t ret;
+ struct file *file = vma->vm_file;
+ struct inode *inode = file_inode(file);
+ struct address_space *mapping = inode->i_mapping;
+ get_block_t *get_block = ext4_get_block;
+ int retries = 0;
+
+ if (unlikely(IS_IMMUTABLE(inode)))
+ return VM_FAULT_SIGBUS;
+
+ sb_start_pagefault(inode->i_sb);
+ file_update_time(vma->vm_file);
+
+ filemap_invalidate_lock_shared(mapping);
+
+ err = ext4_convert_inline_data(inode);
+ if (err)
+ goto out_ret;
+
+ /*
+ * On data journalling we skip straight to the transaction handle:
+ * there's no delalloc; page truncated will be checked later; the
+ * early return w/ all buffers mapped (calculates size/len) can't
+ * be used; and there's no dioread_nolock, so only ext4_get_block.
+ */
+ if (ext4_should_journal_data(inode))
+ goto retry_alloc;
+
+ /* Delalloc case is easy... */
+ if (test_opt(inode->i_sb, DELALLOC) &&
+ !ext4_nonda_switch(inode->i_sb)) {
+ do {
+ err = block_page_mkwrite(vma, vmf,
+ ext4_da_get_block_prep);
+ } while (err == -ENOSPC &&
+ ext4_should_retry_alloc(inode->i_sb, &retries));
+ goto out_ret;
+ }
+
+ folio_lock(folio);
+ size = i_size_read(inode);
+ /* Page got truncated from under us? */
+ if (folio->mapping != mapping || folio_pos(folio) > size) {
+ folio_unlock(folio);
+ ret = VM_FAULT_NOPAGE;
+ goto out;
+ }
+
+ len = folio_size(folio);
+ if (folio_pos(folio) + len > size)
+ len = size - folio_pos(folio);
+ /*
+ * Return if we have all the buffers mapped. This avoids the need to do
+ * journal_start/journal_stop which can block and take a long time
+ *
+ * This cannot be done for data journalling, as we have to add the
+ * inode to the transaction's list to writeprotect pages on commit.
+ */
+ if (folio_buffers(folio)) {
+ if (!ext4_walk_page_buffers(NULL, inode, folio_buffers(folio),
+ 0, len, NULL,
+ ext4_bh_unmapped)) {
+ /* Wait so that we don't change page under IO */
+ folio_wait_stable(folio);
+ ret = VM_FAULT_LOCKED;
+ goto out;
+ }
+ }
+ folio_unlock(folio);
+ /* OK, we need to fill the hole... */
+ if (ext4_should_dioread_nolock(inode))
+ get_block = ext4_get_block_unwritten;
+retry_alloc:
+ /* Start journal and allocate blocks */
+ err = ext4_block_page_mkwrite(inode, folio, get_block);
+ if (err == -EAGAIN ||
+ (err == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries)))
+ goto retry_alloc;
+out_ret:
+ ret = vmf_fs_error(err);
+out:
+ filemap_invalidate_unlock_shared(mapping);
+ sb_end_pagefault(inode->i_sb);
+ return ret;
+}