new file mode 100644
@@ -0,0 +1,268 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2003-2006, Cluster File Systems, Inc, info@clusterfs.com
+ * Written by Alex Tomas <alex@clusterfs.com>
+ */
+
+#ifndef _EXT4_EXTENTS
+#define _EXT4_EXTENTS
+
+#include "ext4.h"
+
+/*
+ * With AGGRESSIVE_TEST defined, the capacity of index/leaf blocks
+ * becomes very small, so index split, in-depth growing and
+ * other hard changes happen much more often.
+ * This is for debug purposes only.
+ */
+#define AGGRESSIVE_TEST_
+
+/*
+ * With EXTENTS_STATS defined, the number of blocks and extents
+ * are collected in the truncate path. They'll be shown at
+ * umount time.
+ */
+#define EXTENTS_STATS__
+
+/*
+ * If CHECK_BINSEARCH is defined, then the results of the binary search
+ * will also be checked by linear search.
+ */
+#define CHECK_BINSEARCH__
+
+/*
+ * ext4_inode has i_block array (60 bytes total).
+ * The first 12 bytes store ext4_extent_header;
+ * the remainder stores an array of ext4_extent.
+ * For non-inode extent blocks, ext4_extent_tail
+ * follows the array.
+ */
+
+/*
+ * This is the extent tail on-disk structure.
+ * All other extent structures are 12 bytes long. It turns out that
+ * block_size % 12 >= 4 for at least all powers of 2 greater than 512, which
+ * covers all valid ext4 block sizes. Therefore, this tail structure can be
+ * crammed into the end of the block without having to rebalance the tree.
+ */
+struct ext4_extent_tail {
+ __le32 et_checksum; /* crc32c(uuid+inum+extent_block) */
+};
+
+/*
+ * This is the extent on-disk structure.
+ * It's used at the bottom of the tree.
+ */
+struct ext4_extent {
+ __le32 ee_block; /* first logical block extent covers */
+ __le16 ee_len; /* number of blocks covered by extent */
+ __le16 ee_start_hi; /* high 16 bits of physical block */
+ __le32 ee_start_lo; /* low 32 bits of physical block */
+};
+
+/*
+ * This is index on-disk structure.
+ * It's used at all the levels except the bottom.
+ */
+struct ext4_extent_idx {
+ __le32 ei_block; /* index covers logical blocks from 'block' */
+ __le32 ei_leaf_lo; /* pointer to the physical block of the next *
+ * level. leaf or next index could be there */
+ __le16 ei_leaf_hi; /* high 16 bits of physical block */
+ __u16 ei_unused;
+};
+
+/*
+ * Each block (leaves and indexes), even inode-stored has header.
+ */
+struct ext4_extent_header {
+ __le16 eh_magic; /* probably will support different formats */
+ __le16 eh_entries; /* number of valid entries */
+ __le16 eh_max; /* capacity of store in entries */
+ __le16 eh_depth; /* has tree real underlying blocks? */
+ __le32 eh_generation; /* generation of the tree */
+};
+
+#define EXT4_EXT_MAGIC cpu_to_le16(0xf30a)
+#define EXT4_MAX_EXTENT_DEPTH 5
+
+#define EXT4_EXTENT_TAIL_OFFSET(hdr) \
+ (sizeof(struct ext4_extent_header) + \
+ (sizeof(struct ext4_extent) * le16_to_cpu((hdr)->eh_max)))
+
+static inline struct ext4_extent_tail *
+find_ext4_extent_tail(struct ext4_extent_header *eh)
+{
+ return (struct ext4_extent_tail *)(((void *)eh) +
+ EXT4_EXTENT_TAIL_OFFSET(eh));
+}
+
+/*
+ * Array of ext4_ext_path contains path to some extent.
+ * Creation/lookup routines use it for traversal/splitting/etc.
+ * Truncate uses it to simulate recursive walking.
+ */
+struct ext4_ext_path {
+ ext4_fsblk_t p_block;
+ __u16 p_depth;
+ __u16 p_maxdepth;
+ struct ext4_extent *p_ext;
+ struct ext4_extent_idx *p_idx;
+ struct ext4_extent_header *p_hdr;
+ struct buffer_head *p_bh;
+};
+
+/*
+ * Used to record a portion of a cluster found at the beginning or end
+ * of an extent while traversing the extent tree during space removal.
+ * A partial cluster may be removed if it does not contain blocks shared
+ * with extents that aren't being deleted (tofree state). Otherwise,
+ * it cannot be removed (nofree state).
+ */
+struct partial_cluster {
+ ext4_fsblk_t pclu; /* physical cluster number */
+ ext4_lblk_t lblk; /* logical block number within logical cluster */
+ enum {initial, tofree, nofree} state;
+};
+
+/*
+ * structure for external API
+ */
+
+/*
+ * EXT_INIT_MAX_LEN is the maximum number of blocks we can have in an
+ * initialized extent. This is 2^15 and not (2^16 - 1), since we use the
+ * MSB of ee_len field in the extent datastructure to signify if this
+ * particular extent is an initialized extent or an unwritten (i.e.
+ * preallocated).
+ * EXT_UNWRITTEN_MAX_LEN is the maximum number of blocks we can have in an
+ * unwritten extent.
+ * If ee_len is <= 0x8000, it is an initialized extent. Otherwise, it is an
+ * unwritten one. In other words, if MSB of ee_len is set, it is an
+ * unwritten extent with only one special scenario when ee_len = 0x8000.
+ * In this case we can not have an unwritten extent of zero length and
+ * thus we make it as a special case of initialized extent with 0x8000 length.
+ * This way we get better extent-to-group alignment for initialized extents.
+ * Hence, the maximum number of blocks we can have in an *initialized*
+ * extent is 2^15 (32768) and in an *unwritten* extent is 2^15-1 (32767).
+ */
+#define EXT_INIT_MAX_LEN (1UL << 15)
+#define EXT_UNWRITTEN_MAX_LEN (EXT_INIT_MAX_LEN - 1)
+
+
+#define EXT_FIRST_EXTENT(__hdr__) \
+ ((struct ext4_extent *) (((char *) (__hdr__)) + \
+ sizeof(struct ext4_extent_header)))
+#define EXT_FIRST_INDEX(__hdr__) \
+ ((struct ext4_extent_idx *) (((char *) (__hdr__)) + \
+ sizeof(struct ext4_extent_header)))
+#define EXT_HAS_FREE_INDEX(__path__) \
+ (le16_to_cpu((__path__)->p_hdr->eh_entries) \
+ < le16_to_cpu((__path__)->p_hdr->eh_max))
+#define EXT_LAST_EXTENT(__hdr__) \
+ (EXT_FIRST_EXTENT((__hdr__)) + le16_to_cpu((__hdr__)->eh_entries) - 1)
+#define EXT_LAST_INDEX(__hdr__) \
+ (EXT_FIRST_INDEX((__hdr__)) + le16_to_cpu((__hdr__)->eh_entries) - 1)
+#define EXT_MAX_EXTENT(__hdr__) \
+ ((le16_to_cpu((__hdr__)->eh_max)) ? \
+ ((EXT_FIRST_EXTENT((__hdr__)) + le16_to_cpu((__hdr__)->eh_max) - 1)) \
+ : NULL)
+#define EXT_MAX_INDEX(__hdr__) \
+ ((le16_to_cpu((__hdr__)->eh_max)) ? \
+ ((EXT_FIRST_INDEX((__hdr__)) + le16_to_cpu((__hdr__)->eh_max) - 1)) \
+ : NULL)
+
+static inline struct ext4_extent_header *ext_inode_hdr(struct inode *inode)
+{
+ return (struct ext4_extent_header *) EXT4_I(inode)->i_data;
+}
+
+static inline struct ext4_extent_header *ext_block_hdr(struct buffer_head *bh)
+{
+ return (struct ext4_extent_header *) bh->b_data;
+}
+
+static inline unsigned short ext_depth(struct inode *inode)
+{
+ return le16_to_cpu(ext_inode_hdr(inode)->eh_depth);
+}
+
+static inline void ext4_ext_mark_unwritten(struct ext4_extent *ext)
+{
+ /* We can not have an unwritten extent of zero length! */
+ BUG_ON((le16_to_cpu(ext->ee_len) & ~EXT_INIT_MAX_LEN) == 0);
+ ext->ee_len |= cpu_to_le16(EXT_INIT_MAX_LEN);
+}
+
+static inline int ext4_ext_is_unwritten(struct ext4_extent *ext)
+{
+ /* Extent with ee_len of 0x8000 is treated as an initialized extent */
+ return (le16_to_cpu(ext->ee_len) > EXT_INIT_MAX_LEN);
+}
+
+static inline int ext4_ext_get_actual_len(struct ext4_extent *ext)
+{
+ return (le16_to_cpu(ext->ee_len) <= EXT_INIT_MAX_LEN ?
+ le16_to_cpu(ext->ee_len) :
+ (le16_to_cpu(ext->ee_len) - EXT_INIT_MAX_LEN));
+}
+
+static inline void ext4_ext_mark_initialized(struct ext4_extent *ext)
+{
+ ext->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ext));
+}
+
+/*
+ * ext4_ext_pblock:
+ * combine low and high parts of physical block number into ext4_fsblk_t
+ */
+static inline ext4_fsblk_t ext4_ext_pblock(struct ext4_extent *ex)
+{
+ ext4_fsblk_t block;
+
+ block = le32_to_cpu(ex->ee_start_lo);
+ block |= ((ext4_fsblk_t) le16_to_cpu(ex->ee_start_hi) << 31) << 1;
+ return block;
+}
+
+/*
+ * ext4_idx_pblock:
+ * combine low and high parts of a leaf physical block number into ext4_fsblk_t
+ */
+static inline ext4_fsblk_t ext4_idx_pblock(struct ext4_extent_idx *ix)
+{
+ ext4_fsblk_t block;
+
+ block = le32_to_cpu(ix->ei_leaf_lo);
+ block |= ((ext4_fsblk_t) le16_to_cpu(ix->ei_leaf_hi) << 31) << 1;
+ return block;
+}
+
+/*
+ * ext4_ext_store_pblock:
+ * stores a large physical block number into an extent struct,
+ * breaking it into parts
+ */
+static inline void ext4_ext_store_pblock(struct ext4_extent *ex,
+ ext4_fsblk_t pb)
+{
+ ex->ee_start_lo = cpu_to_le32((unsigned long) (pb & 0xffffffff));
+ ex->ee_start_hi = cpu_to_le16((unsigned long) ((pb >> 31) >> 1) &
+ 0xffff);
+}
+
+/*
+ * ext4_idx_store_pblock:
+ * stores a large physical block number into an index struct,
+ * breaking it into parts
+ */
+static inline void ext4_idx_store_pblock(struct ext4_extent_idx *ix,
+ ext4_fsblk_t pb)
+{
+ ix->ei_leaf_lo = cpu_to_le32((unsigned long) (pb & 0xffffffff));
+ ix->ei_leaf_hi = cpu_to_le16((unsigned long) ((pb >> 31) >> 1) &
+ 0xffff);
+}
+
+#endif /* _EXT4_EXTENTS */
+
new file mode 100644
@@ -0,0 +1,6189 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2003-2006, Cluster File Systems, Inc, info@clusterfs.com
+ * Written by Alex Tomas <alex@clusterfs.com>
+ *
+ * Architecture independence:
+ * Copyright (c) 2005, Bull S.A.
+ * Written by Pierre Peiffer <pierre.peiffer@bull.net>
+ */
+
+/*
+ * Extents support for EXT4
+ *
+ * TODO:
+ * - ext4*_error() should be used in some situations
+ * - analyze all BUG()/BUG_ON(), use -EIO where appropriate
+ * - smart tree reduction
+ */
+
+#include <linux/fs.h>
+#include <linux/time.h>
+#include <linux/jbd2.h>
+#include <linux/highuid.h>
+#include <linux/pagemap.h>
+#include <linux/quotaops.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/fiemap.h>
+#include <linux/iomap.h>
+#include <linux/sched/mm.h>
+#include "ext4_jbd2.h"
+#include "ext4_extents.h"
+#include "xattr.h"
+
+#include <trace/events/ext4.h>
+
+/*
+ * used by extent splitting.
+ */
+#define EXT4_EXT_MAY_ZEROOUT 0x1 /* safe to zeroout if split fails \
+ due to ENOSPC */
+#define EXT4_EXT_MARK_UNWRIT1 0x2 /* mark first half unwritten */
+#define EXT4_EXT_MARK_UNWRIT2 0x4 /* mark second half unwritten */
+
+#define EXT4_EXT_DATA_VALID1 0x8 /* first half contains valid data */
+#define EXT4_EXT_DATA_VALID2 0x10 /* second half contains valid data */
+
+static __le32 ext4_extent_block_csum(struct inode *inode,
+ struct ext4_extent_header *eh)
+{
+ struct ext4_inode_info *ei = EXT4_I(inode);
+ __u32 csum;
+
+ csum = ext4_chksum(ei->i_csum_seed, (__u8 *)eh,
+ EXT4_EXTENT_TAIL_OFFSET(eh));
+ return cpu_to_le32(csum);
+}
+
+static int ext4_extent_block_csum_verify(struct inode *inode,
+ struct ext4_extent_header *eh)
+{
+ struct ext4_extent_tail *et;
+
+ if (!ext4_has_feature_metadata_csum(inode->i_sb))
+ return 1;
+
+ et = find_ext4_extent_tail(eh);
+ if (et->et_checksum != ext4_extent_block_csum(inode, eh))
+ return 0;
+ return 1;
+}
+
+static void ext4_extent_block_csum_set(struct inode *inode,
+ struct ext4_extent_header *eh)
+{
+ struct ext4_extent_tail *et;
+
+ if (!ext4_has_feature_metadata_csum(inode->i_sb))
+ return;
+
+ et = find_ext4_extent_tail(eh);
+ et->et_checksum = ext4_extent_block_csum(inode, eh);
+}
+
+static struct ext4_ext_path *ext4_split_extent_at(handle_t *handle,
+ struct inode *inode,
+ struct ext4_ext_path *path,
+ ext4_lblk_t split,
+ int split_flag, int flags);
+
+static int ext4_ext_trunc_restart_fn(struct inode *inode, int *dropped)
+{
+ /*
+ * Drop i_data_sem to avoid deadlock with ext4_map_blocks. At this
+ * moment, get_block can be called only for blocks inside i_size since
+ * page cache has been already dropped and writes are blocked by
+ * i_rwsem. So we can safely drop the i_data_sem here.
+ */
+ BUG_ON(EXT4_JOURNAL(inode) == NULL);
+ ext4_discard_preallocations(inode);
+ up_write(&EXT4_I(inode)->i_data_sem);
+ *dropped = 1;
+ return 0;
+}
+
+static inline void ext4_ext_path_brelse(struct ext4_ext_path *path)
+{
+ brelse(path->p_bh);
+ path->p_bh = NULL;
+}
+
+static void ext4_ext_drop_refs(struct ext4_ext_path *path)
+{
+ int depth, i;
+
+ if (IS_ERR_OR_NULL(path))
+ return;
+ depth = path->p_depth;
+ for (i = 0; i <= depth; i++, path++)
+ ext4_ext_path_brelse(path);
+}
+
+void ext4_free_ext_path(struct ext4_ext_path *path)
+{
+ if (IS_ERR_OR_NULL(path))
+ return;
+ ext4_ext_drop_refs(path);
+ kfree(path);
+}
+
+/*
+ * Make sure 'handle' has at least 'check_cred' credits. If not, restart
+ * transaction with 'restart_cred' credits. The function drops i_data_sem
+ * when restarting transaction and gets it after transaction is restarted.
+ *
+ * The function returns 0 on success, 1 if transaction had to be restarted,
+ * and < 0 in case of fatal error.
+ */
+int ext4_datasem_ensure_credits(handle_t *handle, struct inode *inode,
+ int check_cred, int restart_cred,
+ int revoke_cred)
+{
+ int ret;
+ int dropped = 0;
+
+ ret = ext4_journal_ensure_credits_fn(handle, check_cred, restart_cred,
+ revoke_cred, ext4_ext_trunc_restart_fn(inode, &dropped));
+ if (dropped)
+ down_write(&EXT4_I(inode)->i_data_sem);
+ return ret;
+}
+
+/*
+ * could return:
+ * - EROFS
+ * - ENOMEM
+ */
+static int ext4_ext_get_access(handle_t *handle, struct inode *inode,
+ struct ext4_ext_path *path)
+{
+ int err = 0;
+
+ if (path->p_bh) {
+ /* path points to block */
+ BUFFER_TRACE(path->p_bh, "get_write_access");
+ err = ext4_journal_get_write_access(handle, inode->i_sb,
+ path->p_bh, EXT4_JTR_NONE);
+ /*
+ * The extent buffer's verified bit will be set again in
+ * __ext4_ext_dirty(). We could leave an inconsistent
+ * buffer if the extents updating procudure break off du
+ * to some error happens, force to check it again.
+ */
+ if (!err)
+ clear_buffer_verified(path->p_bh);
+ }
+ /* path points to leaf/index in inode body */
+ /* we use in-core data, no need to protect them */
+ return err;
+}
+
+/*
+ * could return:
+ * - EROFS
+ * - ENOMEM
+ * - EIO
+ */
+static int __ext4_ext_dirty(const char *where, unsigned int line,
+ handle_t *handle, struct inode *inode,
+ struct ext4_ext_path *path)
+{
+ int err;
+
+ WARN_ON(!rwsem_is_locked(&EXT4_I(inode)->i_data_sem));
+ if (path->p_bh) {
+ ext4_extent_block_csum_set(inode, ext_block_hdr(path->p_bh));
+ /* path points to block */
+ err = __ext4_handle_dirty_metadata(where, line, handle,
+ inode, path->p_bh);
+ /* Extents updating done, re-set verified flag */
+ if (!err)
+ set_buffer_verified(path->p_bh);
+ } else {
+ /* path points to leaf/index in inode body */
+ err = ext4_mark_inode_dirty(handle, inode);
+ }
+ return err;
+}
+
+#define ext4_ext_dirty(handle, inode, path) \
+ __ext4_ext_dirty(__func__, __LINE__, (handle), (inode), (path))
+
+static ext4_fsblk_t ext4_ext_find_goal(struct inode *inode,
+ struct ext4_ext_path *path,
+ ext4_lblk_t block)
+{
+ if (path) {
+ int depth = path->p_depth;
+ struct ext4_extent *ex;
+
+ /*
+ * Try to predict block placement assuming that we are
+ * filling in a file which will eventually be
+ * non-sparse --- i.e., in the case of libbfd writing
+ * an ELF object sections out-of-order but in a way
+ * the eventually results in a contiguous object or
+ * executable file, or some database extending a table
+ * space file. However, this is actually somewhat
+ * non-ideal if we are writing a sparse file such as
+ * qemu or KVM writing a raw image file that is going
+ * to stay fairly sparse, since it will end up
+ * fragmenting the file system's free space. Maybe we
+ * should have some hueristics or some way to allow
+ * userspace to pass a hint to file system,
+ * especially if the latter case turns out to be
+ * common.
+ */
+ ex = path[depth].p_ext;
+ if (ex) {
+ ext4_fsblk_t ext_pblk = ext4_ext_pblock(ex);
+ ext4_lblk_t ext_block = le32_to_cpu(ex->ee_block);
+
+ if (block > ext_block)
+ return ext_pblk + (block - ext_block);
+ else
+ return ext_pblk - (ext_block - block);
+ }
+
+ /* it looks like index is empty;
+ * try to find starting block from index itself */
+ if (path[depth].p_bh)
+ return path[depth].p_bh->b_blocknr;
+ }
+
+ /* OK. use inode's group */
+ return ext4_inode_to_goal_block(inode);
+}
+
+/*
+ * Allocation for a meta data block
+ */
+static ext4_fsblk_t
+ext4_ext_new_meta_block(handle_t *handle, struct inode *inode,
+ struct ext4_ext_path *path,
+ struct ext4_extent *ex, int *err, unsigned int flags)
+{
+ ext4_fsblk_t goal, newblock;
+
+ goal = ext4_ext_find_goal(inode, path, le32_to_cpu(ex->ee_block));
+ newblock = ext4_new_meta_blocks(handle, inode, goal, flags,
+ NULL, err);
+ return newblock;
+}
+
+static inline int ext4_ext_space_block(struct inode *inode, int check)
+{
+ int size;
+
+ size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
+ / sizeof(struct ext4_extent);
+#ifdef AGGRESSIVE_TEST
+ if (!check && size > 6)
+ size = 6;
+#endif
+ return size;
+}
+
+static inline int ext4_ext_space_block_idx(struct inode *inode, int check)
+{
+ int size;
+
+ size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
+ / sizeof(struct ext4_extent_idx);
+#ifdef AGGRESSIVE_TEST
+ if (!check && size > 5)
+ size = 5;
+#endif
+ return size;
+}
+
+static inline int ext4_ext_space_root(struct inode *inode, int check)
+{
+ int size;
+
+ size = sizeof(EXT4_I(inode)->i_data);
+ size -= sizeof(struct ext4_extent_header);
+ size /= sizeof(struct ext4_extent);
+#ifdef AGGRESSIVE_TEST
+ if (!check && size > 3)
+ size = 3;
+#endif
+ return size;
+}
+
+static inline int ext4_ext_space_root_idx(struct inode *inode, int check)
+{
+ int size;
+
+ size = sizeof(EXT4_I(inode)->i_data);
+ size -= sizeof(struct ext4_extent_header);
+ size /= sizeof(struct ext4_extent_idx);
+#ifdef AGGRESSIVE_TEST
+ if (!check && size > 4)
+ size = 4;
+#endif
+ return size;
+}
+
+static inline struct ext4_ext_path *
+ext4_force_split_extent_at(handle_t *handle, struct inode *inode,
+ struct ext4_ext_path *path, ext4_lblk_t lblk,
+ int nofail)
+{
+ int unwritten = ext4_ext_is_unwritten(path[path->p_depth].p_ext);
+ int flags = EXT4_EX_NOCACHE | EXT4_GET_BLOCKS_PRE_IO;
+
+ if (nofail)
+ flags |= EXT4_GET_BLOCKS_METADATA_NOFAIL | EXT4_EX_NOFAIL;
+
+ return ext4_split_extent_at(handle, inode, path, lblk, unwritten ?
+ EXT4_EXT_MARK_UNWRIT1|EXT4_EXT_MARK_UNWRIT2 : 0,
+ flags);
+}
+
+static int
+ext4_ext_max_entries(struct inode *inode, int depth)
+{
+ int max;
+
+ if (depth == ext_depth(inode)) {
+ if (depth == 0)
+ max = ext4_ext_space_root(inode, 1);
+ else
+ max = ext4_ext_space_root_idx(inode, 1);
+ } else {
+ if (depth == 0)
+ max = ext4_ext_space_block(inode, 1);
+ else
+ max = ext4_ext_space_block_idx(inode, 1);
+ }
+
+ return max;
+}
+
+static int ext4_valid_extent(struct inode *inode, struct ext4_extent *ext)
+{
+ ext4_fsblk_t block = ext4_ext_pblock(ext);
+ int len = ext4_ext_get_actual_len(ext);
+ ext4_lblk_t lblock = le32_to_cpu(ext->ee_block);
+
+ /*
+ * We allow neither:
+ * - zero length
+ * - overflow/wrap-around
+ */
+ if (lblock + len <= lblock)
+ return 0;
+ return ext4_inode_block_valid(inode, block, len);
+}
+
+static int ext4_valid_extent_idx(struct inode *inode,
+ struct ext4_extent_idx *ext_idx)
+{
+ ext4_fsblk_t block = ext4_idx_pblock(ext_idx);
+
+ return ext4_inode_block_valid(inode, block, 1);
+}
+
+static int ext4_valid_extent_entries(struct inode *inode,
+ struct ext4_extent_header *eh,
+ ext4_lblk_t lblk, ext4_fsblk_t *pblk,
+ int depth)
+{
+ unsigned short entries;
+ ext4_lblk_t lblock = 0;
+ ext4_lblk_t cur = 0;
+
+ if (eh->eh_entries == 0)
+ return 1;
+
+ entries = le16_to_cpu(eh->eh_entries);
+
+ if (depth == 0) {
+ /* leaf entries */
+ struct ext4_extent *ext = EXT_FIRST_EXTENT(eh);
+
+ /*
+ * The logical block in the first entry should equal to
+ * the number in the index block.
+ */
+ if (depth != ext_depth(inode) &&
+ lblk != le32_to_cpu(ext->ee_block))
+ return 0;
+ while (entries) {
+ if (!ext4_valid_extent(inode, ext))
+ return 0;
+
+ /* Check for overlapping extents */
+ lblock = le32_to_cpu(ext->ee_block);
+ if (lblock < cur) {
+ *pblk = ext4_ext_pblock(ext);
+ return 0;
+ }
+ cur = lblock + ext4_ext_get_actual_len(ext);
+ ext++;
+ entries--;
+ }
+ } else {
+ struct ext4_extent_idx *ext_idx = EXT_FIRST_INDEX(eh);
+
+ /*
+ * The logical block in the first entry should equal to
+ * the number in the parent index block.
+ */
+ if (depth != ext_depth(inode) &&
+ lblk != le32_to_cpu(ext_idx->ei_block))
+ return 0;
+ while (entries) {
+ if (!ext4_valid_extent_idx(inode, ext_idx))
+ return 0;
+
+ /* Check for overlapping index extents */
+ lblock = le32_to_cpu(ext_idx->ei_block);
+ if (lblock < cur) {
+ *pblk = ext4_idx_pblock(ext_idx);
+ return 0;
+ }
+ ext_idx++;
+ entries--;
+ cur = lblock + 1;
+ }
+ }
+ return 1;
+}
+
+static int __ext4_ext_check(const char *function, unsigned int line,
+ struct inode *inode, struct ext4_extent_header *eh,
+ int depth, ext4_fsblk_t pblk, ext4_lblk_t lblk)
+{
+ const char *error_msg;
+ int max = 0, err = -EFSCORRUPTED;
+
+ if (unlikely(eh->eh_magic != EXT4_EXT_MAGIC)) {
+ error_msg = "invalid magic";
+ goto corrupted;
+ }
+ if (unlikely(le16_to_cpu(eh->eh_depth) != depth)) {
+ error_msg = "unexpected eh_depth";
+ goto corrupted;
+ }
+ if (unlikely(eh->eh_max == 0)) {
+ error_msg = "invalid eh_max";
+ goto corrupted;
+ }
+ max = ext4_ext_max_entries(inode, depth);
+ if (unlikely(le16_to_cpu(eh->eh_max) > max)) {
+ error_msg = "too large eh_max";
+ goto corrupted;
+ }
+ if (unlikely(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max))) {
+ error_msg = "invalid eh_entries";
+ goto corrupted;
+ }
+ if (unlikely((eh->eh_entries == 0) && (depth > 0))) {
+ error_msg = "eh_entries is 0 but eh_depth is > 0";
+ goto corrupted;
+ }
+ if (!ext4_valid_extent_entries(inode, eh, lblk, &pblk, depth)) {
+ error_msg = "invalid extent entries";
+ goto corrupted;
+ }
+ if (unlikely(depth > 32)) {
+ error_msg = "too large eh_depth";
+ goto corrupted;
+ }
+ /* Verify checksum on non-root extent tree nodes */
+ if (ext_depth(inode) != depth &&
+ !ext4_extent_block_csum_verify(inode, eh)) {
+ error_msg = "extent tree corrupted";
+ err = -EFSBADCRC;
+ goto corrupted;
+ }
+ return 0;
+
+corrupted:
+ ext4_error_inode_err(inode, function, line, 0, -err,
+ "pblk %llu bad header/extent: %s - magic %x, "
+ "entries %u, max %u(%u), depth %u(%u)",
+ (unsigned long long) pblk, error_msg,
+ le16_to_cpu(eh->eh_magic),
+ le16_to_cpu(eh->eh_entries),
+ le16_to_cpu(eh->eh_max),
+ max, le16_to_cpu(eh->eh_depth), depth);
+ return err;
+}
+
+#define ext4_ext_check(inode, eh, depth, pblk) \
+ __ext4_ext_check(__func__, __LINE__, (inode), (eh), (depth), (pblk), 0)
+
+int ext4_ext_check_inode(struct inode *inode)
+{
+ return ext4_ext_check(inode, ext_inode_hdr(inode), ext_depth(inode), 0);
+}
+
+static void ext4_cache_extents(struct inode *inode,
+ struct ext4_extent_header *eh)
+{
+ struct ext4_extent *ex = EXT_FIRST_EXTENT(eh);
+ ext4_lblk_t prev = 0;
+ int i;
+
+ for (i = le16_to_cpu(eh->eh_entries); i > 0; i--, ex++) {
+ unsigned int status = EXTENT_STATUS_WRITTEN;
+ ext4_lblk_t lblk = le32_to_cpu(ex->ee_block);
+ int len = ext4_ext_get_actual_len(ex);
+
+ if (prev && (prev != lblk))
+ ext4_es_cache_extent(inode, prev, lblk - prev, ~0,
+ EXTENT_STATUS_HOLE);
+
+ if (ext4_ext_is_unwritten(ex))
+ status = EXTENT_STATUS_UNWRITTEN;
+ ext4_es_cache_extent(inode, lblk, len,
+ ext4_ext_pblock(ex), status);
+ prev = lblk + len;
+ }
+}
+
+static struct buffer_head *
+__read_extent_tree_block(const char *function, unsigned int line,
+ struct inode *inode, struct ext4_extent_idx *idx,
+ int depth, int flags)
+{
+ struct buffer_head *bh;
+ int err;
+ gfp_t gfp_flags = __GFP_MOVABLE | GFP_NOFS;
+ ext4_fsblk_t pblk;
+
+ if (flags & EXT4_EX_NOFAIL)
+ gfp_flags |= __GFP_NOFAIL;
+
+ pblk = ext4_idx_pblock(idx);
+ bh = sb_getblk_gfp(inode->i_sb, pblk, gfp_flags);
+ if (unlikely(!bh))
+ return ERR_PTR(-ENOMEM);
+
+ if (!bh_uptodate_or_lock(bh)) {
+ trace_ext4_ext_load_extent(inode, pblk, _RET_IP_);
+ err = ext4_read_bh(bh, 0, NULL, false);
+ if (err < 0)
+ goto errout;
+ }
+ if (buffer_verified(bh) && !(flags & EXT4_EX_FORCE_CACHE))
+ return bh;
+ err = __ext4_ext_check(function, line, inode, ext_block_hdr(bh),
+ depth, pblk, le32_to_cpu(idx->ei_block));
+ if (err)
+ goto errout;
+ set_buffer_verified(bh);
+ /*
+ * If this is a leaf block, cache all of its entries
+ */
+ if (!(flags & EXT4_EX_NOCACHE) && depth == 0) {
+ struct ext4_extent_header *eh = ext_block_hdr(bh);
+ ext4_cache_extents(inode, eh);
+ }
+ return bh;
+errout:
+ put_bh(bh);
+ return ERR_PTR(err);
+
+}
+
+#define read_extent_tree_block(inode, idx, depth, flags) \
+ __read_extent_tree_block(__func__, __LINE__, (inode), (idx), \
+ (depth), (flags))
+
+/*
+ * This function is called to cache a file's extent information in the
+ * extent status tree
+ */
+int ext4_ext_precache(struct inode *inode)
+{
+ struct ext4_inode_info *ei = EXT4_I(inode);
+ struct ext4_ext_path *path = NULL;
+ struct buffer_head *bh;
+ int i = 0, depth, ret = 0;
+
+ if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
+ return 0; /* not an extent-mapped inode */
+
+ ext4_check_map_extents_env(inode);
+
+ down_read(&ei->i_data_sem);
+ depth = ext_depth(inode);
+
+ /* Don't cache anything if there are no external extent blocks */
+ if (!depth) {
+ up_read(&ei->i_data_sem);
+ return ret;
+ }
+
+ path = kcalloc(depth + 1, sizeof(struct ext4_ext_path),
+ GFP_NOFS);
+ if (path == NULL) {
+ up_read(&ei->i_data_sem);
+ return -ENOMEM;
+ }
+
+ path[0].p_hdr = ext_inode_hdr(inode);
+ ret = ext4_ext_check(inode, path[0].p_hdr, depth, 0);
+ if (ret)
+ goto out;
+ path[0].p_idx = EXT_FIRST_INDEX(path[0].p_hdr);
+ while (i >= 0) {
+ /*
+ * If this is a leaf block or we've reached the end of
+ * the index block, go up
+ */
+ if ((i == depth) ||
+ path[i].p_idx > EXT_LAST_INDEX(path[i].p_hdr)) {
+ ext4_ext_path_brelse(path + i);
+ i--;
+ continue;
+ }
+ bh = read_extent_tree_block(inode, path[i].p_idx++,
+ depth - i - 1,
+ EXT4_EX_FORCE_CACHE);
+ if (IS_ERR(bh)) {
+ ret = PTR_ERR(bh);
+ break;
+ }
+ i++;
+ path[i].p_bh = bh;
+ path[i].p_hdr = ext_block_hdr(bh);
+ path[i].p_idx = EXT_FIRST_INDEX(path[i].p_hdr);
+ }
+ ext4_set_inode_state(inode, EXT4_STATE_EXT_PRECACHED);
+out:
+ up_read(&ei->i_data_sem);
+ ext4_free_ext_path(path);
+ return ret;
+}
+
+#ifdef EXT_DEBUG
+static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path)
+{
+ int k, l = path->p_depth;
+
+ ext_debug(inode, "path:");
+ for (k = 0; k <= l; k++, path++) {
+ if (path->p_idx) {
+ ext_debug(inode, " %d->%llu",
+ le32_to_cpu(path->p_idx->ei_block),
+ ext4_idx_pblock(path->p_idx));
+ } else if (path->p_ext) {
+ ext_debug(inode, " %d:[%d]%d:%llu ",
+ le32_to_cpu(path->p_ext->ee_block),
+ ext4_ext_is_unwritten(path->p_ext),
+ ext4_ext_get_actual_len(path->p_ext),
+ ext4_ext_pblock(path->p_ext));
+ } else
+ ext_debug(inode, " []");
+ }
+ ext_debug(inode, "\n");
+}
+
+static void ext4_ext_show_leaf(struct inode *inode, struct ext4_ext_path *path)
+{
+ int depth = ext_depth(inode);
+ struct ext4_extent_header *eh;
+ struct ext4_extent *ex;
+ int i;
+
+ if (IS_ERR_OR_NULL(path))
+ return;
+
+ eh = path[depth].p_hdr;
+ ex = EXT_FIRST_EXTENT(eh);
+
+ ext_debug(inode, "Displaying leaf extents\n");
+
+ for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ex++) {
+ ext_debug(inode, "%d:[%d]%d:%llu ", le32_to_cpu(ex->ee_block),
+ ext4_ext_is_unwritten(ex),
+ ext4_ext_get_actual_len(ex), ext4_ext_pblock(ex));
+ }
+ ext_debug(inode, "\n");
+}
+
+static void ext4_ext_show_move(struct inode *inode, struct ext4_ext_path *path,
+ ext4_fsblk_t newblock, int level)
+{
+ int depth = ext_depth(inode);
+ struct ext4_extent *ex;
+
+ if (depth != level) {
+ struct ext4_extent_idx *idx;
+ idx = path[level].p_idx;
+ while (idx <= EXT_MAX_INDEX(path[level].p_hdr)) {
+ ext_debug(inode, "%d: move %d:%llu in new index %llu\n",
+ level, le32_to_cpu(idx->ei_block),
+ ext4_idx_pblock(idx), newblock);
+ idx++;
+ }
+
+ return;
+ }
+
+ ex = path[depth].p_ext;
+ while (ex <= EXT_MAX_EXTENT(path[depth].p_hdr)) {
+ ext_debug(inode, "move %d:%llu:[%d]%d in new leaf %llu\n",
+ le32_to_cpu(ex->ee_block),
+ ext4_ext_pblock(ex),
+ ext4_ext_is_unwritten(ex),
+ ext4_ext_get_actual_len(ex),
+ newblock);
+ ex++;
+ }
+}
+
+#else
+#define ext4_ext_show_path(inode, path)
+#define ext4_ext_show_leaf(inode, path)
+#define ext4_ext_show_move(inode, path, newblock, level)
+#endif
+
+/*
+ * ext4_ext_binsearch_idx:
+ * binary search for the closest index of the given block
+ * the header must be checked before calling this
+ */
+static void
+ext4_ext_binsearch_idx(struct inode *inode,
+ struct ext4_ext_path *path, ext4_lblk_t block)
+{
+ struct ext4_extent_header *eh = path->p_hdr;
+ struct ext4_extent_idx *r, *l, *m;
+
+
+ ext_debug(inode, "binsearch for %u(idx): ", block);
+
+ l = EXT_FIRST_INDEX(eh) + 1;
+ r = EXT_LAST_INDEX(eh);
+ while (l <= r) {
+ m = l + (r - l) / 2;
+ ext_debug(inode, "%p(%u):%p(%u):%p(%u) ", l,
+ le32_to_cpu(l->ei_block), m, le32_to_cpu(m->ei_block),
+ r, le32_to_cpu(r->ei_block));
+
+ if (block < le32_to_cpu(m->ei_block))
+ r = m - 1;
+ else
+ l = m + 1;
+ }
+
+ path->p_idx = l - 1;
+ ext_debug(inode, " -> %u->%lld ", le32_to_cpu(path->p_idx->ei_block),
+ ext4_idx_pblock(path->p_idx));
+
+#ifdef CHECK_BINSEARCH
+ {
+ struct ext4_extent_idx *chix, *ix;
+ int k;
+
+ chix = ix = EXT_FIRST_INDEX(eh);
+ for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ix++) {
+ if (k != 0 && le32_to_cpu(ix->ei_block) <=
+ le32_to_cpu(ix[-1].ei_block)) {
+ printk(KERN_DEBUG "k=%d, ix=0x%p, "
+ "first=0x%p\n", k,
+ ix, EXT_FIRST_INDEX(eh));
+ printk(KERN_DEBUG "%u <= %u\n",
+ le32_to_cpu(ix->ei_block),
+ le32_to_cpu(ix[-1].ei_block));
+ }
+ BUG_ON(k && le32_to_cpu(ix->ei_block)
+ <= le32_to_cpu(ix[-1].ei_block));
+ if (block < le32_to_cpu(ix->ei_block))
+ break;
+ chix = ix;
+ }
+ BUG_ON(chix != path->p_idx);
+ }
+#endif
+
+}
+
+/*
+ * ext4_ext_binsearch:
+ * binary search for closest extent of the given block
+ * the header must be checked before calling this
+ */
+static void
+ext4_ext_binsearch(struct inode *inode,
+ struct ext4_ext_path *path, ext4_lblk_t block)
+{
+ struct ext4_extent_header *eh = path->p_hdr;
+ struct ext4_extent *r, *l, *m;
+
+ if (eh->eh_entries == 0) {
+ /*
+ * this leaf is empty:
+ * we get such a leaf in split/add case
+ */
+ return;
+ }
+
+ ext_debug(inode, "binsearch for %u: ", block);
+
+ l = EXT_FIRST_EXTENT(eh) + 1;
+ r = EXT_LAST_EXTENT(eh);
+
+ while (l <= r) {
+ m = l + (r - l) / 2;
+ ext_debug(inode, "%p(%u):%p(%u):%p(%u) ", l,
+ le32_to_cpu(l->ee_block), m, le32_to_cpu(m->ee_block),
+ r, le32_to_cpu(r->ee_block));
+
+ if (block < le32_to_cpu(m->ee_block))
+ r = m - 1;
+ else
+ l = m + 1;
+ }
+
+ path->p_ext = l - 1;
+ ext_debug(inode, " -> %d:%llu:[%d]%d ",
+ le32_to_cpu(path->p_ext->ee_block),
+ ext4_ext_pblock(path->p_ext),
+ ext4_ext_is_unwritten(path->p_ext),
+ ext4_ext_get_actual_len(path->p_ext));
+
+#ifdef CHECK_BINSEARCH
+ {
+ struct ext4_extent *chex, *ex;
+ int k;
+
+ chex = ex = EXT_FIRST_EXTENT(eh);
+ for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ex++) {
+ BUG_ON(k && le32_to_cpu(ex->ee_block)
+ <= le32_to_cpu(ex[-1].ee_block));
+ if (block < le32_to_cpu(ex->ee_block))
+ break;
+ chex = ex;
+ }
+ BUG_ON(chex != path->p_ext);
+ }
+#endif
+
+}
+
+void ext4_ext_tree_init(handle_t *handle, struct inode *inode)
+{
+ struct ext4_extent_header *eh;
+
+ eh = ext_inode_hdr(inode);
+ eh->eh_depth = 0;
+ eh->eh_entries = 0;
+ eh->eh_magic = EXT4_EXT_MAGIC;
+ eh->eh_max = cpu_to_le16(ext4_ext_space_root(inode, 0));
+ eh->eh_generation = 0;
+ ext4_mark_inode_dirty(handle, inode);
+}
+
+struct ext4_ext_path *
+ext4_find_extent(struct inode *inode, ext4_lblk_t block,
+ struct ext4_ext_path *path, int flags)
+{
+ struct ext4_extent_header *eh;
+ struct buffer_head *bh;
+ short int depth, i, ppos = 0;
+ int ret;
+ gfp_t gfp_flags = GFP_NOFS;
+
+ if (flags & EXT4_EX_NOFAIL)
+ gfp_flags |= __GFP_NOFAIL;
+
+ eh = ext_inode_hdr(inode);
+ depth = ext_depth(inode);
+ if (depth < 0 || depth > EXT4_MAX_EXTENT_DEPTH) {
+ EXT4_ERROR_INODE(inode, "inode has invalid extent depth: %d",
+ depth);
+ ret = -EFSCORRUPTED;
+ goto err;
+ }
+
+ if (path) {
+ ext4_ext_drop_refs(path);
+ if (depth > path[0].p_maxdepth) {
+ kfree(path);
+ path = NULL;
+ }
+ }
+ if (!path) {
+ /* account possible depth increase */
+ path = kcalloc(depth + 2, sizeof(struct ext4_ext_path),
+ gfp_flags);
+ if (unlikely(!path))
+ return ERR_PTR(-ENOMEM);
+ path[0].p_maxdepth = depth + 1;
+ }
+ path[0].p_hdr = eh;
+ path[0].p_bh = NULL;
+
+ i = depth;
+ if (!(flags & EXT4_EX_NOCACHE) && depth == 0)
+ ext4_cache_extents(inode, eh);
+ /* walk through the tree */
+ while (i) {
+ ext_debug(inode, "depth %d: num %d, max %d\n",
+ ppos, le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
+
+ ext4_ext_binsearch_idx(inode, path + ppos, block);
+ path[ppos].p_block = ext4_idx_pblock(path[ppos].p_idx);
+ path[ppos].p_depth = i;
+ path[ppos].p_ext = NULL;
+
+ bh = read_extent_tree_block(inode, path[ppos].p_idx, --i, flags);
+ if (IS_ERR(bh)) {
+ ret = PTR_ERR(bh);
+ goto err;
+ }
+
+ eh = ext_block_hdr(bh);
+ ppos++;
+ path[ppos].p_bh = bh;
+ path[ppos].p_hdr = eh;
+ }
+
+ path[ppos].p_depth = i;
+ path[ppos].p_ext = NULL;
+ path[ppos].p_idx = NULL;
+
+ /* find extent */
+ ext4_ext_binsearch(inode, path + ppos, block);
+ /* if not an empty leaf */
+ if (path[ppos].p_ext)
+ path[ppos].p_block = ext4_ext_pblock(path[ppos].p_ext);
+
+ ext4_ext_show_path(inode, path);
+
+ return path;
+
+err:
+ ext4_free_ext_path(path);
+ return ERR_PTR(ret);
+}
+
+/*
+ * ext4_ext_insert_index:
+ * insert new index [@logical;@ptr] into the block at @curp;
+ * check where to insert: before @curp or after @curp
+ */
+static int ext4_ext_insert_index(handle_t *handle, struct inode *inode,
+ struct ext4_ext_path *curp,
+ int logical, ext4_fsblk_t ptr)
+{
+ struct ext4_extent_idx *ix;
+ int len, err;
+
+ err = ext4_ext_get_access(handle, inode, curp);
+ if (err)
+ return err;
+
+ if (unlikely(logical == le32_to_cpu(curp->p_idx->ei_block))) {
+ EXT4_ERROR_INODE(inode,
+ "logical %d == ei_block %d!",
+ logical, le32_to_cpu(curp->p_idx->ei_block));
+ return -EFSCORRUPTED;
+ }
+
+ if (unlikely(le16_to_cpu(curp->p_hdr->eh_entries)
+ >= le16_to_cpu(curp->p_hdr->eh_max))) {
+ EXT4_ERROR_INODE(inode,
+ "eh_entries %d >= eh_max %d!",
+ le16_to_cpu(curp->p_hdr->eh_entries),
+ le16_to_cpu(curp->p_hdr->eh_max));
+ return -EFSCORRUPTED;
+ }
+
+ if (logical > le32_to_cpu(curp->p_idx->ei_block)) {
+ /* insert after */
+ ext_debug(inode, "insert new index %d after: %llu\n",
+ logical, ptr);
+ ix = curp->p_idx + 1;
+ } else {
+ /* insert before */
+ ext_debug(inode, "insert new index %d before: %llu\n",
+ logical, ptr);
+ ix = curp->p_idx;
+ }
+
+ if (unlikely(ix > EXT_MAX_INDEX(curp->p_hdr))) {
+ EXT4_ERROR_INODE(inode, "ix > EXT_MAX_INDEX!");
+ return -EFSCORRUPTED;
+ }
+
+ len = EXT_LAST_INDEX(curp->p_hdr) - ix + 1;
+ BUG_ON(len < 0);
+ if (len > 0) {
+ ext_debug(inode, "insert new index %d: "
+ "move %d indices from 0x%p to 0x%p\n",
+ logical, len, ix, ix + 1);
+ memmove(ix + 1, ix, len * sizeof(struct ext4_extent_idx));
+ }
+
+ ix->ei_block = cpu_to_le32(logical);
+ ext4_idx_store_pblock(ix, ptr);
+ le16_add_cpu(&curp->p_hdr->eh_entries, 1);
+
+ if (unlikely(ix > EXT_LAST_INDEX(curp->p_hdr))) {
+ EXT4_ERROR_INODE(inode, "ix > EXT_LAST_INDEX!");
+ return -EFSCORRUPTED;
+ }
+
+ err = ext4_ext_dirty(handle, inode, curp);
+ ext4_std_error(inode->i_sb, err);
+
+ return err;
+}
+
+/*
+ * ext4_ext_split:
+ * inserts new subtree into the path, using free index entry
+ * at depth @at:
+ * - allocates all needed blocks (new leaf and all intermediate index blocks)
+ * - makes decision where to split
+ * - moves remaining extents and index entries (right to the split point)
+ * into the newly allocated blocks
+ * - initializes subtree
+ */
+static int ext4_ext_split(handle_t *handle, struct inode *inode,
+ unsigned int flags,
+ struct ext4_ext_path *path,
+ struct ext4_extent *newext, int at)
+{
+ struct buffer_head *bh = NULL;
+ int depth = ext_depth(inode);
+ struct ext4_extent_header *neh;
+ struct ext4_extent_idx *fidx;
+ int i = at, k, m, a;
+ ext4_fsblk_t newblock, oldblock;
+ __le32 border;
+ ext4_fsblk_t *ablocks = NULL; /* array of allocated blocks */
+ gfp_t gfp_flags = GFP_NOFS;
+ int err = 0;
+ size_t ext_size = 0;
+
+ if (flags & EXT4_EX_NOFAIL)
+ gfp_flags |= __GFP_NOFAIL;
+
+ /* make decision: where to split? */
+ /* FIXME: now decision is simplest: at current extent */
+
+ /* if current leaf will be split, then we should use
+ * border from split point */
+ if (unlikely(path[depth].p_ext > EXT_MAX_EXTENT(path[depth].p_hdr))) {
+ EXT4_ERROR_INODE(inode, "p_ext > EXT_MAX_EXTENT!");
+ return -EFSCORRUPTED;
+ }
+ if (path[depth].p_ext != EXT_MAX_EXTENT(path[depth].p_hdr)) {
+ border = path[depth].p_ext[1].ee_block;
+ ext_debug(inode, "leaf will be split."
+ " next leaf starts at %d\n",
+ le32_to_cpu(border));
+ } else {
+ border = newext->ee_block;
+ ext_debug(inode, "leaf will be added."
+ " next leaf starts at %d\n",
+ le32_to_cpu(border));
+ }
+
+ /*
+ * If error occurs, then we break processing
+ * and mark filesystem read-only. index won't
+ * be inserted and tree will be in consistent
+ * state. Next mount will repair buffers too.
+ */
+
+ /*
+ * Get array to track all allocated blocks.
+ * We need this to handle errors and free blocks
+ * upon them.
+ */
+ ablocks = kcalloc(depth, sizeof(ext4_fsblk_t), gfp_flags);
+ if (!ablocks)
+ return -ENOMEM;
+
+ /* allocate all needed blocks */
+ ext_debug(inode, "allocate %d blocks for indexes/leaf\n", depth - at);
+ for (a = 0; a < depth - at; a++) {
+ newblock = ext4_ext_new_meta_block(handle, inode, path,
+ newext, &err, flags);
+ if (newblock == 0)
+ goto cleanup;
+ ablocks[a] = newblock;
+ }
+
+ /* initialize new leaf */
+ newblock = ablocks[--a];
+ if (unlikely(newblock == 0)) {
+ EXT4_ERROR_INODE(inode, "newblock == 0!");
+ err = -EFSCORRUPTED;
+ goto cleanup;
+ }
+ bh = sb_getblk_gfp(inode->i_sb, newblock, __GFP_MOVABLE | GFP_NOFS);
+ if (unlikely(!bh)) {
+ err = -ENOMEM;
+ goto cleanup;
+ }
+ lock_buffer(bh);
+
+ err = ext4_journal_get_create_access(handle, inode->i_sb, bh,
+ EXT4_JTR_NONE);
+ if (err)
+ goto cleanup;
+
+ neh = ext_block_hdr(bh);
+ neh->eh_entries = 0;
+ neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0));
+ neh->eh_magic = EXT4_EXT_MAGIC;
+ neh->eh_depth = 0;
+ neh->eh_generation = 0;
+
+ /* move remainder of path[depth] to the new leaf */
+ if (unlikely(path[depth].p_hdr->eh_entries !=
+ path[depth].p_hdr->eh_max)) {
+ EXT4_ERROR_INODE(inode, "eh_entries %d != eh_max %d!",
+ path[depth].p_hdr->eh_entries,
+ path[depth].p_hdr->eh_max);
+ err = -EFSCORRUPTED;
+ goto cleanup;
+ }
+ /* start copy from next extent */
+ m = EXT_MAX_EXTENT(path[depth].p_hdr) - path[depth].p_ext++;
+ ext4_ext_show_move(inode, path, newblock, depth);
+ if (m) {
+ struct ext4_extent *ex;
+ ex = EXT_FIRST_EXTENT(neh);
+ memmove(ex, path[depth].p_ext, sizeof(struct ext4_extent) * m);
+ le16_add_cpu(&neh->eh_entries, m);
+ }
+
+ /* zero out unused area in the extent block */
+ ext_size = sizeof(struct ext4_extent_header) +
+ sizeof(struct ext4_extent) * le16_to_cpu(neh->eh_entries);
+ memset(bh->b_data + ext_size, 0, inode->i_sb->s_blocksize - ext_size);
+ ext4_extent_block_csum_set(inode, neh);
+ set_buffer_uptodate(bh);
+ unlock_buffer(bh);
+
+ err = ext4_handle_dirty_metadata(handle, inode, bh);
+ if (err)
+ goto cleanup;
+ brelse(bh);
+ bh = NULL;
+
+ /* correct old leaf */
+ if (m) {
+ err = ext4_ext_get_access(handle, inode, path + depth);
+ if (err)
+ goto cleanup;
+ le16_add_cpu(&path[depth].p_hdr->eh_entries, -m);
+ err = ext4_ext_dirty(handle, inode, path + depth);
+ if (err)
+ goto cleanup;
+
+ }
+
+ /* create intermediate indexes */
+ k = depth - at - 1;
+ if (unlikely(k < 0)) {
+ EXT4_ERROR_INODE(inode, "k %d < 0!", k);
+ err = -EFSCORRUPTED;
+ goto cleanup;
+ }
+ if (k)
+ ext_debug(inode, "create %d intermediate indices\n", k);
+ /* insert new index into current index block */
+ /* current depth stored in i var */
+ i = depth - 1;
+ while (k--) {
+ oldblock = newblock;
+ newblock = ablocks[--a];
+ bh = sb_getblk(inode->i_sb, newblock);
+ if (unlikely(!bh)) {
+ err = -ENOMEM;
+ goto cleanup;
+ }
+ lock_buffer(bh);
+
+ err = ext4_journal_get_create_access(handle, inode->i_sb, bh,
+ EXT4_JTR_NONE);
+ if (err)
+ goto cleanup;
+
+ neh = ext_block_hdr(bh);
+ neh->eh_entries = cpu_to_le16(1);
+ neh->eh_magic = EXT4_EXT_MAGIC;
+ neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0));
+ neh->eh_depth = cpu_to_le16(depth - i);
+ neh->eh_generation = 0;
+ fidx = EXT_FIRST_INDEX(neh);
+ fidx->ei_block = border;
+ ext4_idx_store_pblock(fidx, oldblock);
+
+ ext_debug(inode, "int.index at %d (block %llu): %u -> %llu\n",
+ i, newblock, le32_to_cpu(border), oldblock);
+
+ /* move remainder of path[i] to the new index block */
+ if (unlikely(EXT_MAX_INDEX(path[i].p_hdr) !=
+ EXT_LAST_INDEX(path[i].p_hdr))) {
+ EXT4_ERROR_INODE(inode,
+ "EXT_MAX_INDEX != EXT_LAST_INDEX ee_block %d!",
+ le32_to_cpu(path[i].p_ext->ee_block));
+ err = -EFSCORRUPTED;
+ goto cleanup;
+ }
+ /* start copy indexes */
+ m = EXT_MAX_INDEX(path[i].p_hdr) - path[i].p_idx++;
+ ext_debug(inode, "cur 0x%p, last 0x%p\n", path[i].p_idx,
+ EXT_MAX_INDEX(path[i].p_hdr));
+ ext4_ext_show_move(inode, path, newblock, i);
+ if (m) {
+ memmove(++fidx, path[i].p_idx,
+ sizeof(struct ext4_extent_idx) * m);
+ le16_add_cpu(&neh->eh_entries, m);
+ }
+ /* zero out unused area in the extent block */
+ ext_size = sizeof(struct ext4_extent_header) +
+ (sizeof(struct ext4_extent) * le16_to_cpu(neh->eh_entries));
+ memset(bh->b_data + ext_size, 0,
+ inode->i_sb->s_blocksize - ext_size);
+ ext4_extent_block_csum_set(inode, neh);
+ set_buffer_uptodate(bh);
+ unlock_buffer(bh);
+
+ err = ext4_handle_dirty_metadata(handle, inode, bh);
+ if (err)
+ goto cleanup;
+ brelse(bh);
+ bh = NULL;
+
+ /* correct old index */
+ if (m) {
+ err = ext4_ext_get_access(handle, inode, path + i);
+ if (err)
+ goto cleanup;
+ le16_add_cpu(&path[i].p_hdr->eh_entries, -m);
+ err = ext4_ext_dirty(handle, inode, path + i);
+ if (err)
+ goto cleanup;
+ }
+
+ i--;
+ }
+
+ /* insert new index */
+ err = ext4_ext_insert_index(handle, inode, path + at,
+ le32_to_cpu(border), newblock);
+
+cleanup:
+ if (bh) {
+ if (buffer_locked(bh))
+ unlock_buffer(bh);
+ brelse(bh);
+ }
+
+ if (err) {
+ /* free all allocated blocks in error case */
+ for (i = 0; i < depth; i++) {
+ if (!ablocks[i])
+ continue;
+ ext4_free_blocks(handle, inode, NULL, ablocks[i], 1,
+ EXT4_FREE_BLOCKS_METADATA);
+ }
+ }
+ kfree(ablocks);
+
+ return err;
+}
+
+/*
+ * ext4_ext_grow_indepth:
+ * implements tree growing procedure:
+ * - allocates new block
+ * - moves top-level data (index block or leaf) into the new block
+ * - initializes new top-level, creating index that points to the
+ * just created block
+ */
+static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
+ unsigned int flags)
+{
+ struct ext4_extent_header *neh;
+ struct buffer_head *bh;
+ ext4_fsblk_t newblock, goal = 0;
+ struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
+ int err = 0;
+ size_t ext_size = 0;
+
+ /* Try to prepend new index to old one */
+ if (ext_depth(inode))
+ goal = ext4_idx_pblock(EXT_FIRST_INDEX(ext_inode_hdr(inode)));
+ if (goal > le32_to_cpu(es->s_first_data_block)) {
+ flags |= EXT4_MB_HINT_TRY_GOAL;
+ goal--;
+ } else
+ goal = ext4_inode_to_goal_block(inode);
+ newblock = ext4_new_meta_blocks(handle, inode, goal, flags,
+ NULL, &err);
+ if (newblock == 0)
+ return err;
+
+ bh = sb_getblk_gfp(inode->i_sb, newblock, __GFP_MOVABLE | GFP_NOFS);
+ if (unlikely(!bh))
+ return -ENOMEM;
+ lock_buffer(bh);
+
+ err = ext4_journal_get_create_access(handle, inode->i_sb, bh,
+ EXT4_JTR_NONE);
+ if (err) {
+ unlock_buffer(bh);
+ goto out;
+ }
+
+ ext_size = sizeof(EXT4_I(inode)->i_data);
+ /* move top-level index/leaf into new block */
+ memmove(bh->b_data, EXT4_I(inode)->i_data, ext_size);
+ /* zero out unused area in the extent block */
+ memset(bh->b_data + ext_size, 0, inode->i_sb->s_blocksize - ext_size);
+
+ /* set size of new block */
+ neh = ext_block_hdr(bh);
+ /* old root could have indexes or leaves
+ * so calculate e_max right way */
+ if (ext_depth(inode))
+ neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0));
+ else
+ neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0));
+ neh->eh_magic = EXT4_EXT_MAGIC;
+ ext4_extent_block_csum_set(inode, neh);
+ set_buffer_uptodate(bh);
+ set_buffer_verified(bh);
+ unlock_buffer(bh);
+
+ err = ext4_handle_dirty_metadata(handle, inode, bh);
+ if (err)
+ goto out;
+
+ /* Update top-level index: num,max,pointer */
+ neh = ext_inode_hdr(inode);
+ neh->eh_entries = cpu_to_le16(1);
+ ext4_idx_store_pblock(EXT_FIRST_INDEX(neh), newblock);
+ if (neh->eh_depth == 0) {
+ /* Root extent block becomes index block */
+ neh->eh_max = cpu_to_le16(ext4_ext_space_root_idx(inode, 0));
+ EXT_FIRST_INDEX(neh)->ei_block =
+ EXT_FIRST_EXTENT(neh)->ee_block;
+ }
+ ext_debug(inode, "new root: num %d(%d), lblock %d, ptr %llu\n",
+ le16_to_cpu(neh->eh_entries), le16_to_cpu(neh->eh_max),
+ le32_to_cpu(EXT_FIRST_INDEX(neh)->ei_block),
+ ext4_idx_pblock(EXT_FIRST_INDEX(neh)));
+
+ le16_add_cpu(&neh->eh_depth, 1);
+ err = ext4_mark_inode_dirty(handle, inode);
+out:
+ brelse(bh);
+
+ return err;
+}
+
+/*
+ * ext4_ext_create_new_leaf:
+ * finds empty index and adds new leaf.
+ * if no free index is found, then it requests in-depth growing.
+ */
+static struct ext4_ext_path *
+ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode,
+ unsigned int mb_flags, unsigned int gb_flags,
+ struct ext4_ext_path *path,
+ struct ext4_extent *newext)
+{
+ struct ext4_ext_path *curp;
+ int depth, i, err = 0;
+ ext4_lblk_t ee_block = le32_to_cpu(newext->ee_block);
+
+repeat:
+ i = depth = ext_depth(inode);
+
+ /* walk up to the tree and look for free index entry */
+ curp = path + depth;
+ while (i > 0 && !EXT_HAS_FREE_INDEX(curp)) {
+ i--;
+ curp--;
+ }
+
+ /* we use already allocated block for index block,
+ * so subsequent data blocks should be contiguous */
+ if (EXT_HAS_FREE_INDEX(curp)) {
+ /* if we found index with free entry, then use that
+ * entry: create all needed subtree and add new leaf */
+ err = ext4_ext_split(handle, inode, mb_flags, path, newext, i);
+ if (err)
+ goto errout;
+
+ /* refill path */
+ path = ext4_find_extent(inode, ee_block, path, gb_flags);
+ return path;
+ }
+
+ /* tree is full, time to grow in depth */
+ err = ext4_ext_grow_indepth(handle, inode, mb_flags);
+ if (err)
+ goto errout;
+
+ /* refill path */
+ path = ext4_find_extent(inode, ee_block, path, gb_flags);
+ if (IS_ERR(path))
+ return path;
+
+ /*
+ * only first (depth 0 -> 1) produces free space;
+ * in all other cases we have to split the grown tree
+ */
+ depth = ext_depth(inode);
+ if (path[depth].p_hdr->eh_entries == path[depth].p_hdr->eh_max) {
+ /* now we need to split */
+ goto repeat;
+ }
+
+ return path;
+
+errout:
+ ext4_free_ext_path(path);
+ return ERR_PTR(err);
+}
+
+/*
+ * search the closest allocated block to the left for *logical
+ * and returns it at @logical + it's physical address at @phys
+ * if *logical is the smallest allocated block, the function
+ * returns 0 at @phys
+ * return value contains 0 (success) or error code
+ */
+static int ext4_ext_search_left(struct inode *inode,
+ struct ext4_ext_path *path,
+ ext4_lblk_t *logical, ext4_fsblk_t *phys)
+{
+ struct ext4_extent_idx *ix;
+ struct ext4_extent *ex;
+ int depth, ee_len;
+
+ if (unlikely(path == NULL)) {
+ EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical);
+ return -EFSCORRUPTED;
+ }
+ depth = path->p_depth;
+ *phys = 0;
+
+ if (depth == 0 && path->p_ext == NULL)
+ return 0;
+
+ /* usually extent in the path covers blocks smaller
+ * then *logical, but it can be that extent is the
+ * first one in the file */
+
+ ex = path[depth].p_ext;
+ ee_len = ext4_ext_get_actual_len(ex);
+ if (*logical < le32_to_cpu(ex->ee_block)) {
+ if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) {
+ EXT4_ERROR_INODE(inode,
+ "EXT_FIRST_EXTENT != ex *logical %d ee_block %d!",
+ *logical, le32_to_cpu(ex->ee_block));
+ return -EFSCORRUPTED;
+ }
+ while (--depth >= 0) {
+ ix = path[depth].p_idx;
+ if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) {
+ EXT4_ERROR_INODE(inode,
+ "ix (%d) != EXT_FIRST_INDEX (%d) (depth %d)!",
+ ix != NULL ? le32_to_cpu(ix->ei_block) : 0,
+ le32_to_cpu(EXT_FIRST_INDEX(path[depth].p_hdr)->ei_block),
+ depth);
+ return -EFSCORRUPTED;
+ }
+ }
+ return 0;
+ }
+
+ if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) {
+ EXT4_ERROR_INODE(inode,
+ "logical %d < ee_block %d + ee_len %d!",
+ *logical, le32_to_cpu(ex->ee_block), ee_len);
+ return -EFSCORRUPTED;
+ }
+
+ *logical = le32_to_cpu(ex->ee_block) + ee_len - 1;
+ *phys = ext4_ext_pblock(ex) + ee_len - 1;
+ return 0;
+}
+
+/*
+ * Search the closest allocated block to the right for *logical
+ * and returns it at @logical + it's physical address at @phys.
+ * If not exists, return 0 and @phys is set to 0. We will return
+ * 1 which means we found an allocated block and ret_ex is valid.
+ * Or return a (< 0) error code.
+ */
+static int ext4_ext_search_right(struct inode *inode,
+ struct ext4_ext_path *path,
+ ext4_lblk_t *logical, ext4_fsblk_t *phys,
+ struct ext4_extent *ret_ex, int flags)
+{
+ struct buffer_head *bh = NULL;
+ struct ext4_extent_header *eh;
+ struct ext4_extent_idx *ix;
+ struct ext4_extent *ex;
+ int depth; /* Note, NOT eh_depth; depth from top of tree */
+ int ee_len;
+
+ if (unlikely(path == NULL)) {
+ EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical);
+ return -EFSCORRUPTED;
+ }
+ depth = path->p_depth;
+ *phys = 0;
+
+ if (depth == 0 && path->p_ext == NULL)
+ return 0;
+
+ /* usually extent in the path covers blocks smaller
+ * then *logical, but it can be that extent is the
+ * first one in the file */
+
+ ex = path[depth].p_ext;
+ ee_len = ext4_ext_get_actual_len(ex);
+ if (*logical < le32_to_cpu(ex->ee_block)) {
+ if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) {
+ EXT4_ERROR_INODE(inode,
+ "first_extent(path[%d].p_hdr) != ex",
+ depth);
+ return -EFSCORRUPTED;
+ }
+ while (--depth >= 0) {
+ ix = path[depth].p_idx;
+ if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) {
+ EXT4_ERROR_INODE(inode,
+ "ix != EXT_FIRST_INDEX *logical %d!",
+ *logical);
+ return -EFSCORRUPTED;
+ }
+ }
+ goto found_extent;
+ }
+
+ if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) {
+ EXT4_ERROR_INODE(inode,
+ "logical %d < ee_block %d + ee_len %d!",
+ *logical, le32_to_cpu(ex->ee_block), ee_len);
+ return -EFSCORRUPTED;
+ }
+
+ if (ex != EXT_LAST_EXTENT(path[depth].p_hdr)) {
+ /* next allocated block in this leaf */
+ ex++;
+ goto found_extent;
+ }
+
+ /* go up and search for index to the right */
+ while (--depth >= 0) {
+ ix = path[depth].p_idx;
+ if (ix != EXT_LAST_INDEX(path[depth].p_hdr))
+ goto got_index;
+ }
+
+ /* we've gone up to the root and found no index to the right */
+ return 0;
+
+got_index:
+ /* we've found index to the right, let's
+ * follow it and find the closest allocated
+ * block to the right */
+ ix++;
+ while (++depth < path->p_depth) {
+ /* subtract from p_depth to get proper eh_depth */
+ bh = read_extent_tree_block(inode, ix, path->p_depth - depth,
+ flags);
+ if (IS_ERR(bh))
+ return PTR_ERR(bh);
+ eh = ext_block_hdr(bh);
+ ix = EXT_FIRST_INDEX(eh);
+ put_bh(bh);
+ }
+
+ bh = read_extent_tree_block(inode, ix, path->p_depth - depth, flags);
+ if (IS_ERR(bh))
+ return PTR_ERR(bh);
+ eh = ext_block_hdr(bh);
+ ex = EXT_FIRST_EXTENT(eh);
+found_extent:
+ *logical = le32_to_cpu(ex->ee_block);
+ *phys = ext4_ext_pblock(ex);
+ if (ret_ex)
+ *ret_ex = *ex;
+ if (bh)
+ put_bh(bh);
+ return 1;
+}
+
+/*
+ * ext4_ext_next_allocated_block:
+ * returns allocated block in subsequent extent or EXT_MAX_BLOCKS.
+ * NOTE: it considers block number from index entry as
+ * allocated block. Thus, index entries have to be consistent
+ * with leaves.
+ */
+ext4_lblk_t
+ext4_ext_next_allocated_block(struct ext4_ext_path *path)
+{
+ int depth;
+
+ BUG_ON(path == NULL);
+ depth = path->p_depth;
+
+ if (depth == 0 && path->p_ext == NULL)
+ return EXT_MAX_BLOCKS;
+
+ while (depth >= 0) {
+ struct ext4_ext_path *p = &path[depth];
+
+ if (depth == path->p_depth) {
+ /* leaf */
+ if (p->p_ext && p->p_ext != EXT_LAST_EXTENT(p->p_hdr))
+ return le32_to_cpu(p->p_ext[1].ee_block);
+ } else {
+ /* index */
+ if (p->p_idx != EXT_LAST_INDEX(p->p_hdr))
+ return le32_to_cpu(p->p_idx[1].ei_block);
+ }
+ depth--;
+ }
+
+ return EXT_MAX_BLOCKS;
+}
+
+/*
+ * ext4_ext_next_leaf_block:
+ * returns first allocated block from next leaf or EXT_MAX_BLOCKS
+ */
+static ext4_lblk_t ext4_ext_next_leaf_block(struct ext4_ext_path *path)
+{
+ int depth;
+
+ BUG_ON(path == NULL);
+ depth = path->p_depth;
+
+ /* zero-tree has no leaf blocks at all */
+ if (depth == 0)
+ return EXT_MAX_BLOCKS;
+
+ /* go to index block */
+ depth--;
+
+ while (depth >= 0) {
+ if (path[depth].p_idx !=
+ EXT_LAST_INDEX(path[depth].p_hdr))
+ return (ext4_lblk_t)
+ le32_to_cpu(path[depth].p_idx[1].ei_block);
+ depth--;
+ }
+
+ return EXT_MAX_BLOCKS;
+}
+
+/*
+ * ext4_ext_correct_indexes:
+ * if leaf gets modified and modified extent is first in the leaf,
+ * then we have to correct all indexes above.
+ * TODO: do we need to correct tree in all cases?
+ */
+static int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode,
+ struct ext4_ext_path *path)
+{
+ struct ext4_extent_header *eh;
+ int depth = ext_depth(inode);
+ struct ext4_extent *ex;
+ __le32 border;
+ int k, err = 0;
+
+ eh = path[depth].p_hdr;
+ ex = path[depth].p_ext;
+
+ if (unlikely(ex == NULL || eh == NULL)) {
+ EXT4_ERROR_INODE(inode,
+ "ex %p == NULL or eh %p == NULL", ex, eh);
+ return -EFSCORRUPTED;
+ }
+
+ if (depth == 0) {
+ /* there is no tree at all */
+ return 0;
+ }
+
+ if (ex != EXT_FIRST_EXTENT(eh)) {
+ /* we correct tree if first leaf got modified only */
+ return 0;
+ }
+
+ /*
+ * TODO: we need correction if border is smaller than current one
+ */
+ k = depth - 1;
+ border = path[depth].p_ext->ee_block;
+ err = ext4_ext_get_access(handle, inode, path + k);
+ if (err)
+ return err;
+ path[k].p_idx->ei_block = border;
+ err = ext4_ext_dirty(handle, inode, path + k);
+ if (err)
+ return err;
+
+ while (k--) {
+ /* change all left-side indexes */
+ if (path[k+1].p_idx != EXT_FIRST_INDEX(path[k+1].p_hdr))
+ break;
+ err = ext4_ext_get_access(handle, inode, path + k);
+ if (err)
+ goto clean;
+ path[k].p_idx->ei_block = border;
+ err = ext4_ext_dirty(handle, inode, path + k);
+ if (err)
+ goto clean;
+ }
+ return 0;
+
+clean:
+ /*
+ * The path[k].p_bh is either unmodified or with no verified bit
+ * set (see ext4_ext_get_access()). So just clear the verified bit
+ * of the successfully modified extents buffers, which will force
+ * these extents to be checked to avoid using inconsistent data.
+ */
+ while (++k < depth)
+ clear_buffer_verified(path[k].p_bh);
+
+ return err;
+}
+
+static int ext4_can_extents_be_merged(struct inode *inode,
+ struct ext4_extent *ex1,
+ struct ext4_extent *ex2)
+{
+ unsigned short ext1_ee_len, ext2_ee_len;
+
+ if (ext4_ext_is_unwritten(ex1) != ext4_ext_is_unwritten(ex2))
+ return 0;
+
+ ext1_ee_len = ext4_ext_get_actual_len(ex1);
+ ext2_ee_len = ext4_ext_get_actual_len(ex2);
+
+ if (le32_to_cpu(ex1->ee_block) + ext1_ee_len !=
+ le32_to_cpu(ex2->ee_block))
+ return 0;
+
+ if (ext1_ee_len + ext2_ee_len > EXT_INIT_MAX_LEN)
+ return 0;
+
+ if (ext4_ext_is_unwritten(ex1) &&
+ ext1_ee_len + ext2_ee_len > EXT_UNWRITTEN_MAX_LEN)
+ return 0;
+#ifdef AGGRESSIVE_TEST
+ if (ext1_ee_len >= 4)
+ return 0;
+#endif
+
+ if (ext4_ext_pblock(ex1) + ext1_ee_len == ext4_ext_pblock(ex2))
+ return 1;
+ return 0;
+}
+
+/*
+ * This function tries to merge the "ex" extent to the next extent in the tree.
+ * It always tries to merge towards right. If you want to merge towards
+ * left, pass "ex - 1" as argument instead of "ex".
+ * Returns 0 if the extents (ex and ex+1) were _not_ merged and returns
+ * 1 if they got merged.
+ */
+static int ext4_ext_try_to_merge_right(struct inode *inode,
+ struct ext4_ext_path *path,
+ struct ext4_extent *ex)
+{
+ struct ext4_extent_header *eh;
+ unsigned int depth, len;
+ int merge_done = 0, unwritten;
+
+ depth = ext_depth(inode);
+ BUG_ON(path[depth].p_hdr == NULL);
+ eh = path[depth].p_hdr;
+
+ while (ex < EXT_LAST_EXTENT(eh)) {
+ if (!ext4_can_extents_be_merged(inode, ex, ex + 1))
+ break;
+ /* merge with next extent! */
+ unwritten = ext4_ext_is_unwritten(ex);
+ ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
+ + ext4_ext_get_actual_len(ex + 1));
+ if (unwritten)
+ ext4_ext_mark_unwritten(ex);
+
+ if (ex + 1 < EXT_LAST_EXTENT(eh)) {
+ len = (EXT_LAST_EXTENT(eh) - ex - 1)
+ * sizeof(struct ext4_extent);
+ memmove(ex + 1, ex + 2, len);
+ }
+ le16_add_cpu(&eh->eh_entries, -1);
+ merge_done = 1;
+ WARN_ON(eh->eh_entries == 0);
+ if (!eh->eh_entries)
+ EXT4_ERROR_INODE(inode, "eh->eh_entries = 0!");
+ }
+
+ return merge_done;
+}
+
+/*
+ * This function does a very simple check to see if we can collapse
+ * an extent tree with a single extent tree leaf block into the inode.
+ */
+static void ext4_ext_try_to_merge_up(handle_t *handle,
+ struct inode *inode,
+ struct ext4_ext_path *path)
+{
+ size_t s;
+ unsigned max_root = ext4_ext_space_root(inode, 0);
+ ext4_fsblk_t blk;
+
+ if ((path[0].p_depth != 1) ||
+ (le16_to_cpu(path[0].p_hdr->eh_entries) != 1) ||
+ (le16_to_cpu(path[1].p_hdr->eh_entries) > max_root))
+ return;
+
+ /*
+ * We need to modify the block allocation bitmap and the block
+ * group descriptor to release the extent tree block. If we
+ * can't get the journal credits, give up.
+ */
+ if (ext4_journal_extend(handle, 2,
+ ext4_free_metadata_revoke_credits(inode->i_sb, 1)))
+ return;
+
+ /*
+ * Copy the extent data up to the inode
+ */
+ blk = ext4_idx_pblock(path[0].p_idx);
+ s = le16_to_cpu(path[1].p_hdr->eh_entries) *
+ sizeof(struct ext4_extent_idx);
+ s += sizeof(struct ext4_extent_header);
+
+ path[1].p_maxdepth = path[0].p_maxdepth;
+ memcpy(path[0].p_hdr, path[1].p_hdr, s);
+ path[0].p_depth = 0;
+ path[0].p_ext = EXT_FIRST_EXTENT(path[0].p_hdr) +
+ (path[1].p_ext - EXT_FIRST_EXTENT(path[1].p_hdr));
+ path[0].p_hdr->eh_max = cpu_to_le16(max_root);
+
+ ext4_ext_path_brelse(path + 1);
+ ext4_free_blocks(handle, inode, NULL, blk, 1,
+ EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET);
+}
+
+/*
+ * This function tries to merge the @ex extent to neighbours in the tree, then
+ * tries to collapse the extent tree into the inode.
+ */
+static void ext4_ext_try_to_merge(handle_t *handle,
+ struct inode *inode,
+ struct ext4_ext_path *path,
+ struct ext4_extent *ex)
+{
+ struct ext4_extent_header *eh;
+ unsigned int depth;
+ int merge_done = 0;
+
+ depth = ext_depth(inode);
+ BUG_ON(path[depth].p_hdr == NULL);
+ eh = path[depth].p_hdr;
+
+ if (ex > EXT_FIRST_EXTENT(eh))
+ merge_done = ext4_ext_try_to_merge_right(inode, path, ex - 1);
+
+ if (!merge_done)
+ (void) ext4_ext_try_to_merge_right(inode, path, ex);
+
+ ext4_ext_try_to_merge_up(handle, inode, path);
+}
+
+/*
+ * check if a portion of the "newext" extent overlaps with an
+ * existing extent.
+ *
+ * If there is an overlap discovered, it updates the length of the newext
+ * such that there will be no overlap, and then returns 1.
+ * If there is no overlap found, it returns 0.
+ */
+static unsigned int ext4_ext_check_overlap(struct ext4_sb_info *sbi,
+ struct inode *inode,
+ struct ext4_extent *newext,
+ struct ext4_ext_path *path)
+{
+ ext4_lblk_t b1, b2;
+ unsigned int depth, len1;
+ unsigned int ret = 0;
+
+ b1 = le32_to_cpu(newext->ee_block);
+ len1 = ext4_ext_get_actual_len(newext);
+ depth = ext_depth(inode);
+ if (!path[depth].p_ext)
+ goto out;
+ b2 = EXT4_LBLK_CMASK(sbi, le32_to_cpu(path[depth].p_ext->ee_block));
+
+ /*
+ * get the next allocated block if the extent in the path
+ * is before the requested block(s)
+ */
+ if (b2 < b1) {
+ b2 = ext4_ext_next_allocated_block(path);
+ if (b2 == EXT_MAX_BLOCKS)
+ goto out;
+ b2 = EXT4_LBLK_CMASK(sbi, b2);
+ }
+
+ /* check for wrap through zero on extent logical start block*/
+ if (b1 + len1 < b1) {
+ len1 = EXT_MAX_BLOCKS - b1;
+ newext->ee_len = cpu_to_le16(len1);
+ ret = 1;
+ }
+
+ /* check for overlap */
+ if (b1 + len1 > b2) {
+ newext->ee_len = cpu_to_le16(b2 - b1);
+ ret = 1;
+ }
+out:
+ return ret;
+}
+
+/*
+ * ext4_ext_insert_extent:
+ * tries to merge requested extent into the existing extent or
+ * inserts requested extent as new one into the tree,
+ * creating new leaf in the no-space case.
+ */
+struct ext4_ext_path *
+ext4_ext_insert_extent(handle_t *handle, struct inode *inode,
+ struct ext4_ext_path *path,
+ struct ext4_extent *newext, int gb_flags)
+{
+ struct ext4_extent_header *eh;
+ struct ext4_extent *ex, *fex;
+ struct ext4_extent *nearex; /* nearest extent */
+ int depth, len, err = 0;
+ ext4_lblk_t next;
+ int mb_flags = 0, unwritten;
+
+ if (gb_flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
+ mb_flags |= EXT4_MB_DELALLOC_RESERVED;
+ if (unlikely(ext4_ext_get_actual_len(newext) == 0)) {
+ EXT4_ERROR_INODE(inode, "ext4_ext_get_actual_len(newext) == 0");
+ err = -EFSCORRUPTED;
+ goto errout;
+ }
+ depth = ext_depth(inode);
+ ex = path[depth].p_ext;
+ eh = path[depth].p_hdr;
+ if (unlikely(path[depth].p_hdr == NULL)) {
+ EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
+ err = -EFSCORRUPTED;
+ goto errout;
+ }
+
+ /* try to insert block into found extent and return */
+ if (ex && !(gb_flags & EXT4_GET_BLOCKS_PRE_IO)) {
+
+ /*
+ * Try to see whether we should rather test the extent on
+ * right from ex, or from the left of ex. This is because
+ * ext4_find_extent() can return either extent on the
+ * left, or on the right from the searched position. This
+ * will make merging more effective.
+ */
+ if (ex < EXT_LAST_EXTENT(eh) &&
+ (le32_to_cpu(ex->ee_block) +
+ ext4_ext_get_actual_len(ex) <
+ le32_to_cpu(newext->ee_block))) {
+ ex += 1;
+ goto prepend;
+ } else if ((ex > EXT_FIRST_EXTENT(eh)) &&
+ (le32_to_cpu(newext->ee_block) +
+ ext4_ext_get_actual_len(newext) <
+ le32_to_cpu(ex->ee_block)))
+ ex -= 1;
+
+ /* Try to append newex to the ex */
+ if (ext4_can_extents_be_merged(inode, ex, newext)) {
+ ext_debug(inode, "append [%d]%d block to %u:[%d]%d"
+ "(from %llu)\n",
+ ext4_ext_is_unwritten(newext),
+ ext4_ext_get_actual_len(newext),
+ le32_to_cpu(ex->ee_block),
+ ext4_ext_is_unwritten(ex),
+ ext4_ext_get_actual_len(ex),
+ ext4_ext_pblock(ex));
+ err = ext4_ext_get_access(handle, inode,
+ path + depth);
+ if (err)
+ goto errout;
+ unwritten = ext4_ext_is_unwritten(ex);
+ ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
+ + ext4_ext_get_actual_len(newext));
+ if (unwritten)
+ ext4_ext_mark_unwritten(ex);
+ nearex = ex;
+ goto merge;
+ }
+
+prepend:
+ /* Try to prepend newex to the ex */
+ if (ext4_can_extents_be_merged(inode, newext, ex)) {
+ ext_debug(inode, "prepend %u[%d]%d block to %u:[%d]%d"
+ "(from %llu)\n",
+ le32_to_cpu(newext->ee_block),
+ ext4_ext_is_unwritten(newext),
+ ext4_ext_get_actual_len(newext),
+ le32_to_cpu(ex->ee_block),
+ ext4_ext_is_unwritten(ex),
+ ext4_ext_get_actual_len(ex),
+ ext4_ext_pblock(ex));
+ err = ext4_ext_get_access(handle, inode,
+ path + depth);
+ if (err)
+ goto errout;
+
+ unwritten = ext4_ext_is_unwritten(ex);
+ ex->ee_block = newext->ee_block;
+ ext4_ext_store_pblock(ex, ext4_ext_pblock(newext));
+ ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
+ + ext4_ext_get_actual_len(newext));
+ if (unwritten)
+ ext4_ext_mark_unwritten(ex);
+ nearex = ex;
+ goto merge;
+ }
+ }
+
+ depth = ext_depth(inode);
+ eh = path[depth].p_hdr;
+ if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max))
+ goto has_space;
+
+ /* probably next leaf has space for us? */
+ fex = EXT_LAST_EXTENT(eh);
+ next = EXT_MAX_BLOCKS;
+ if (le32_to_cpu(newext->ee_block) > le32_to_cpu(fex->ee_block))
+ next = ext4_ext_next_leaf_block(path);
+ if (next != EXT_MAX_BLOCKS) {
+ struct ext4_ext_path *npath;
+
+ ext_debug(inode, "next leaf block - %u\n", next);
+ npath = ext4_find_extent(inode, next, NULL, gb_flags);
+ if (IS_ERR(npath)) {
+ err = PTR_ERR(npath);
+ goto errout;
+ }
+ BUG_ON(npath->p_depth != path->p_depth);
+ eh = npath[depth].p_hdr;
+ if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) {
+ ext_debug(inode, "next leaf isn't full(%d)\n",
+ le16_to_cpu(eh->eh_entries));
+ ext4_free_ext_path(path);
+ path = npath;
+ goto has_space;
+ }
+ ext_debug(inode, "next leaf has no free space(%d,%d)\n",
+ le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
+ ext4_free_ext_path(npath);
+ }
+
+ /*
+ * There is no free space in the found leaf.
+ * We're gonna add a new leaf in the tree.
+ */
+ if (gb_flags & EXT4_GET_BLOCKS_METADATA_NOFAIL)
+ mb_flags |= EXT4_MB_USE_RESERVED;
+ path = ext4_ext_create_new_leaf(handle, inode, mb_flags, gb_flags,
+ path, newext);
+ if (IS_ERR(path))
+ return path;
+ depth = ext_depth(inode);
+ eh = path[depth].p_hdr;
+
+has_space:
+ nearex = path[depth].p_ext;
+
+ err = ext4_ext_get_access(handle, inode, path + depth);
+ if (err)
+ goto errout;
+
+ if (!nearex) {
+ /* there is no extent in this leaf, create first one */
+ ext_debug(inode, "first extent in the leaf: %u:%llu:[%d]%d\n",
+ le32_to_cpu(newext->ee_block),
+ ext4_ext_pblock(newext),
+ ext4_ext_is_unwritten(newext),
+ ext4_ext_get_actual_len(newext));
+ nearex = EXT_FIRST_EXTENT(eh);
+ } else {
+ if (le32_to_cpu(newext->ee_block)
+ > le32_to_cpu(nearex->ee_block)) {
+ /* Insert after */
+ ext_debug(inode, "insert %u:%llu:[%d]%d before: "
+ "nearest %p\n",
+ le32_to_cpu(newext->ee_block),
+ ext4_ext_pblock(newext),
+ ext4_ext_is_unwritten(newext),
+ ext4_ext_get_actual_len(newext),
+ nearex);
+ nearex++;
+ } else {
+ /* Insert before */
+ BUG_ON(newext->ee_block == nearex->ee_block);
+ ext_debug(inode, "insert %u:%llu:[%d]%d after: "
+ "nearest %p\n",
+ le32_to_cpu(newext->ee_block),
+ ext4_ext_pblock(newext),
+ ext4_ext_is_unwritten(newext),
+ ext4_ext_get_actual_len(newext),
+ nearex);
+ }
+ len = EXT_LAST_EXTENT(eh) - nearex + 1;
+ if (len > 0) {
+ ext_debug(inode, "insert %u:%llu:[%d]%d: "
+ "move %d extents from 0x%p to 0x%p\n",
+ le32_to_cpu(newext->ee_block),
+ ext4_ext_pblock(newext),
+ ext4_ext_is_unwritten(newext),
+ ext4_ext_get_actual_len(newext),
+ len, nearex, nearex + 1);
+ memmove(nearex + 1, nearex,
+ len * sizeof(struct ext4_extent));
+ }
+ }
+
+ le16_add_cpu(&eh->eh_entries, 1);
+ path[depth].p_ext = nearex;
+ nearex->ee_block = newext->ee_block;
+ ext4_ext_store_pblock(nearex, ext4_ext_pblock(newext));
+ nearex->ee_len = newext->ee_len;
+
+merge:
+ /* try to merge extents */
+ if (!(gb_flags & EXT4_GET_BLOCKS_PRE_IO))
+ ext4_ext_try_to_merge(handle, inode, path, nearex);
+
+ /* time to correct all indexes above */
+ err = ext4_ext_correct_indexes(handle, inode, path);
+ if (err)
+ goto errout;
+
+ err = ext4_ext_dirty(handle, inode, path + path->p_depth);
+ if (err)
+ goto errout;
+
+ return path;
+
+errout:
+ ext4_free_ext_path(path);
+ return ERR_PTR(err);
+}
+
+static int ext4_fill_es_cache_info(struct inode *inode,
+ ext4_lblk_t block, ext4_lblk_t num,
+ struct fiemap_extent_info *fieinfo)
+{
+ ext4_lblk_t next, end = block + num - 1;
+ struct extent_status es;
+ unsigned char blksize_bits = inode->i_sb->s_blocksize_bits;
+ unsigned int flags;
+ int err;
+
+ while (block <= end) {
+ next = 0;
+ flags = 0;
+ if (!ext4_es_lookup_extent(inode, block, &next, &es))
+ break;
+ if (ext4_es_is_unwritten(&es))
+ flags |= FIEMAP_EXTENT_UNWRITTEN;
+ if (ext4_es_is_delayed(&es))
+ flags |= (FIEMAP_EXTENT_DELALLOC |
+ FIEMAP_EXTENT_UNKNOWN);
+ if (ext4_es_is_hole(&es))
+ flags |= EXT4_FIEMAP_EXTENT_HOLE;
+ if (next == 0)
+ flags |= FIEMAP_EXTENT_LAST;
+ if (flags & (FIEMAP_EXTENT_DELALLOC|
+ EXT4_FIEMAP_EXTENT_HOLE))
+ es.es_pblk = 0;
+ else
+ es.es_pblk = ext4_es_pblock(&es);
+ err = fiemap_fill_next_extent(fieinfo,
+ (__u64)es.es_lblk << blksize_bits,
+ (__u64)es.es_pblk << blksize_bits,
+ (__u64)es.es_len << blksize_bits,
+ flags);
+ if (next == 0)
+ break;
+ block = next;
+ if (err < 0)
+ return err;
+ if (err == 1)
+ return 0;
+ }
+ return 0;
+}
+
+
+/*
+ * ext4_ext_find_hole - find hole around given block according to the given path
+ * @inode: inode we lookup in
+ * @path: path in extent tree to @lblk
+ * @lblk: pointer to logical block around which we want to determine hole
+ *
+ * Determine hole length (and start if easily possible) around given logical
+ * block. We don't try too hard to find the beginning of the hole but @path
+ * actually points to extent before @lblk, we provide it.
+ *
+ * The function returns the length of a hole starting at @lblk. We update @lblk
+ * to the beginning of the hole if we managed to find it.
+ */
+static ext4_lblk_t ext4_ext_find_hole(struct inode *inode,
+ struct ext4_ext_path *path,
+ ext4_lblk_t *lblk)
+{
+ int depth = ext_depth(inode);
+ struct ext4_extent *ex;
+ ext4_lblk_t len;
+
+ ex = path[depth].p_ext;
+ if (ex == NULL) {
+ /* there is no extent yet, so gap is [0;-] */
+ *lblk = 0;
+ len = EXT_MAX_BLOCKS;
+ } else if (*lblk < le32_to_cpu(ex->ee_block)) {
+ len = le32_to_cpu(ex->ee_block) - *lblk;
+ } else if (*lblk >= le32_to_cpu(ex->ee_block)
+ + ext4_ext_get_actual_len(ex)) {
+ ext4_lblk_t next;
+
+ *lblk = le32_to_cpu(ex->ee_block) + ext4_ext_get_actual_len(ex);
+ next = ext4_ext_next_allocated_block(path);
+ BUG_ON(next == *lblk);
+ len = next - *lblk;
+ } else {
+ BUG();
+ }
+ return len;
+}
+
+/*
+ * ext4_ext_rm_idx:
+ * removes index from the index block.
+ */
+static int ext4_ext_rm_idx(handle_t *handle, struct inode *inode,
+ struct ext4_ext_path *path, int depth)
+{
+ int err;
+ ext4_fsblk_t leaf;
+ int k = depth - 1;
+
+ /* free index block */
+ leaf = ext4_idx_pblock(path[k].p_idx);
+ if (unlikely(path[k].p_hdr->eh_entries == 0)) {
+ EXT4_ERROR_INODE(inode, "path[%d].p_hdr->eh_entries == 0", k);
+ return -EFSCORRUPTED;
+ }
+ err = ext4_ext_get_access(handle, inode, path + k);
+ if (err)
+ return err;
+
+ if (path[k].p_idx != EXT_LAST_INDEX(path[k].p_hdr)) {
+ int len = EXT_LAST_INDEX(path[k].p_hdr) - path[k].p_idx;
+ len *= sizeof(struct ext4_extent_idx);
+ memmove(path[k].p_idx, path[k].p_idx + 1, len);
+ }
+
+ le16_add_cpu(&path[k].p_hdr->eh_entries, -1);
+ err = ext4_ext_dirty(handle, inode, path + k);
+ if (err)
+ return err;
+ ext_debug(inode, "index is empty, remove it, free block %llu\n", leaf);
+ trace_ext4_ext_rm_idx(inode, leaf);
+
+ ext4_free_blocks(handle, inode, NULL, leaf, 1,
+ EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET);
+
+ while (--k >= 0) {
+ if (path[k + 1].p_idx != EXT_FIRST_INDEX(path[k + 1].p_hdr))
+ break;
+ err = ext4_ext_get_access(handle, inode, path + k);
+ if (err)
+ goto clean;
+ path[k].p_idx->ei_block = path[k + 1].p_idx->ei_block;
+ err = ext4_ext_dirty(handle, inode, path + k);
+ if (err)
+ goto clean;
+ }
+ return 0;
+
+clean:
+ /*
+ * The path[k].p_bh is either unmodified or with no verified bit
+ * set (see ext4_ext_get_access()). So just clear the verified bit
+ * of the successfully modified extents buffers, which will force
+ * these extents to be checked to avoid using inconsistent data.
+ */
+ while (++k < depth)
+ clear_buffer_verified(path[k].p_bh);
+
+ return err;
+}
+
+/*
+ * ext4_ext_calc_credits_for_single_extent:
+ * This routine returns max. credits that needed to insert an extent
+ * to the extent tree.
+ * When pass the actual path, the caller should calculate credits
+ * under i_data_sem.
+ */
+int ext4_ext_calc_credits_for_single_extent(struct inode *inode, int nrblocks,
+ struct ext4_ext_path *path)
+{
+ if (path) {
+ int depth = ext_depth(inode);
+ int ret = 0;
+
+ /* probably there is space in leaf? */
+ if (le16_to_cpu(path[depth].p_hdr->eh_entries)
+ < le16_to_cpu(path[depth].p_hdr->eh_max)) {
+
+ /*
+ * There are some space in the leaf tree, no
+ * need to account for leaf block credit
+ *
+ * bitmaps and block group descriptor blocks
+ * and other metadata blocks still need to be
+ * accounted.
+ */
+ /* 1 bitmap, 1 block group descriptor */
+ ret = 2 + EXT4_META_TRANS_BLOCKS(inode->i_sb);
+ return ret;
+ }
+ }
+
+ return ext4_chunk_trans_blocks(inode, nrblocks);
+}
+
+/*
+ * How many index/leaf blocks need to change/allocate to add @extents extents?
+ *
+ * If we add a single extent, then in the worse case, each tree level
+ * index/leaf need to be changed in case of the tree split.
+ *
+ * If more extents are inserted, they could cause the whole tree split more
+ * than once, but this is really rare.
+ */
+int ext4_ext_index_trans_blocks(struct inode *inode, int extents)
+{
+ int index;
+
+ /* If we are converting the inline data, only one is needed here. */
+ if (ext4_has_inline_data(inode))
+ return 1;
+
+ /*
+ * Extent tree can change between the time we estimate credits and
+ * the time we actually modify the tree. Assume the worst case.
+ */
+ if (extents <= 1)
+ index = (EXT4_MAX_EXTENT_DEPTH * 2) + extents;
+ else
+ index = (EXT4_MAX_EXTENT_DEPTH * 3) +
+ DIV_ROUND_UP(extents, ext4_ext_space_block(inode, 0));
+
+ return index;
+}
+
+static inline int get_default_free_blocks_flags(struct inode *inode)
+{
+ if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode) ||
+ ext4_test_inode_flag(inode, EXT4_INODE_EA_INODE))
+ return EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET;
+ else if (ext4_should_journal_data(inode))
+ return EXT4_FREE_BLOCKS_FORGET;
+ return 0;
+}
+
+/*
+ * ext4_rereserve_cluster - increment the reserved cluster count when
+ * freeing a cluster with a pending reservation
+ *
+ * @inode - file containing the cluster
+ * @lblk - logical block in cluster to be reserved
+ *
+ * Increments the reserved cluster count and adjusts quota in a bigalloc
+ * file system when freeing a partial cluster containing at least one
+ * delayed and unwritten block. A partial cluster meeting that
+ * requirement will have a pending reservation. If so, the
+ * RERESERVE_CLUSTER flag is used when calling ext4_free_blocks() to
+ * defer reserved and allocated space accounting to a subsequent call
+ * to this function.
+ */
+static void ext4_rereserve_cluster(struct inode *inode, ext4_lblk_t lblk)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+ struct ext4_inode_info *ei = EXT4_I(inode);
+
+ dquot_reclaim_block(inode, EXT4_C2B(sbi, 1));
+
+ spin_lock(&ei->i_block_reservation_lock);
+ ei->i_reserved_data_blocks++;
+ percpu_counter_add(&sbi->s_dirtyclusters_counter, 1);
+ spin_unlock(&ei->i_block_reservation_lock);
+
+ percpu_counter_add(&sbi->s_freeclusters_counter, 1);
+ ext4_remove_pending(inode, lblk);
+}
+
+static int ext4_remove_blocks(handle_t *handle, struct inode *inode,
+ struct ext4_extent *ex,
+ struct partial_cluster *partial,
+ ext4_lblk_t from, ext4_lblk_t to)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+ unsigned short ee_len = ext4_ext_get_actual_len(ex);
+ ext4_fsblk_t last_pblk, pblk;
+ ext4_lblk_t num;
+ int flags;
+
+ /* only extent tail removal is allowed */
+ if (from < le32_to_cpu(ex->ee_block) ||
+ to != le32_to_cpu(ex->ee_block) + ee_len - 1) {
+ ext4_error(sbi->s_sb,
+ "strange request: removal(2) %u-%u from %u:%u",
+ from, to, le32_to_cpu(ex->ee_block), ee_len);
+ return 0;
+ }
+
+#ifdef EXTENTS_STATS
+ spin_lock(&sbi->s_ext_stats_lock);
+ sbi->s_ext_blocks += ee_len;
+ sbi->s_ext_extents++;
+ if (ee_len < sbi->s_ext_min)
+ sbi->s_ext_min = ee_len;
+ if (ee_len > sbi->s_ext_max)
+ sbi->s_ext_max = ee_len;
+ if (ext_depth(inode) > sbi->s_depth_max)
+ sbi->s_depth_max = ext_depth(inode);
+ spin_unlock(&sbi->s_ext_stats_lock);
+#endif
+
+ trace_ext4_remove_blocks(inode, ex, from, to, partial);
+
+ /*
+ * if we have a partial cluster, and it's different from the
+ * cluster of the last block in the extent, we free it
+ */
+ last_pblk = ext4_ext_pblock(ex) + ee_len - 1;
+
+ if (partial->state != initial &&
+ partial->pclu != EXT4_B2C(sbi, last_pblk)) {
+ if (partial->state == tofree) {
+ flags = get_default_free_blocks_flags(inode);
+ if (ext4_is_pending(inode, partial->lblk))
+ flags |= EXT4_FREE_BLOCKS_RERESERVE_CLUSTER;
+ ext4_free_blocks(handle, inode, NULL,
+ EXT4_C2B(sbi, partial->pclu),
+ sbi->s_cluster_ratio, flags);
+ if (flags & EXT4_FREE_BLOCKS_RERESERVE_CLUSTER)
+ ext4_rereserve_cluster(inode, partial->lblk);
+ }
+ partial->state = initial;
+ }
+
+ num = le32_to_cpu(ex->ee_block) + ee_len - from;
+ pblk = ext4_ext_pblock(ex) + ee_len - num;
+
+ /*
+ * We free the partial cluster at the end of the extent (if any),
+ * unless the cluster is used by another extent (partial_cluster
+ * state is nofree). If a partial cluster exists here, it must be
+ * shared with the last block in the extent.
+ */
+ flags = get_default_free_blocks_flags(inode);
+
+ /* partial, left end cluster aligned, right end unaligned */
+ if ((EXT4_LBLK_COFF(sbi, to) != sbi->s_cluster_ratio - 1) &&
+ (EXT4_LBLK_CMASK(sbi, to) >= from) &&
+ (partial->state != nofree)) {
+ if (ext4_is_pending(inode, to))
+ flags |= EXT4_FREE_BLOCKS_RERESERVE_CLUSTER;
+ ext4_free_blocks(handle, inode, NULL,
+ EXT4_PBLK_CMASK(sbi, last_pblk),
+ sbi->s_cluster_ratio, flags);
+ if (flags & EXT4_FREE_BLOCKS_RERESERVE_CLUSTER)
+ ext4_rereserve_cluster(inode, to);
+ partial->state = initial;
+ flags = get_default_free_blocks_flags(inode);
+ }
+
+ flags |= EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER;
+
+ /*
+ * For bigalloc file systems, we never free a partial cluster
+ * at the beginning of the extent. Instead, we check to see if we
+ * need to free it on a subsequent call to ext4_remove_blocks,
+ * or at the end of ext4_ext_rm_leaf or ext4_ext_remove_space.
+ */
+ flags |= EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER;
+ ext4_free_blocks(handle, inode, NULL, pblk, num, flags);
+
+ /* reset the partial cluster if we've freed past it */
+ if (partial->state != initial && partial->pclu != EXT4_B2C(sbi, pblk))
+ partial->state = initial;
+
+ /*
+ * If we've freed the entire extent but the beginning is not left
+ * cluster aligned and is not marked as ineligible for freeing we
+ * record the partial cluster at the beginning of the extent. It
+ * wasn't freed by the preceding ext4_free_blocks() call, and we
+ * need to look farther to the left to determine if it's to be freed
+ * (not shared with another extent). Else, reset the partial
+ * cluster - we're either done freeing or the beginning of the
+ * extent is left cluster aligned.
+ */
+ if (EXT4_LBLK_COFF(sbi, from) && num == ee_len) {
+ if (partial->state == initial) {
+ partial->pclu = EXT4_B2C(sbi, pblk);
+ partial->lblk = from;
+ partial->state = tofree;
+ }
+ } else {
+ partial->state = initial;
+ }
+
+ return 0;
+}
+
+/*
+ * ext4_ext_rm_leaf() Removes the extents associated with the
+ * blocks appearing between "start" and "end". Both "start"
+ * and "end" must appear in the same extent or EIO is returned.
+ *
+ * @handle: The journal handle
+ * @inode: The files inode
+ * @path: The path to the leaf
+ * @partial_cluster: The cluster which we'll have to free if all extents
+ * has been released from it. However, if this value is
+ * negative, it's a cluster just to the right of the
+ * punched region and it must not be freed.
+ * @start: The first block to remove
+ * @end: The last block to remove
+ */
+static int
+ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
+ struct ext4_ext_path *path,
+ struct partial_cluster *partial,
+ ext4_lblk_t start, ext4_lblk_t end)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+ int err = 0, correct_index = 0;
+ int depth = ext_depth(inode), credits, revoke_credits;
+ struct ext4_extent_header *eh;
+ ext4_lblk_t a, b;
+ unsigned num;
+ ext4_lblk_t ex_ee_block;
+ unsigned short ex_ee_len;
+ unsigned unwritten = 0;
+ struct ext4_extent *ex;
+ ext4_fsblk_t pblk;
+
+ /* the header must be checked already in ext4_ext_remove_space() */
+ ext_debug(inode, "truncate since %u in leaf to %u\n", start, end);
+ if (!path[depth].p_hdr)
+ path[depth].p_hdr = ext_block_hdr(path[depth].p_bh);
+ eh = path[depth].p_hdr;
+ if (unlikely(path[depth].p_hdr == NULL)) {
+ EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
+ return -EFSCORRUPTED;
+ }
+ /* find where to start removing */
+ ex = path[depth].p_ext;
+ if (!ex)
+ ex = EXT_LAST_EXTENT(eh);
+
+ ex_ee_block = le32_to_cpu(ex->ee_block);
+ ex_ee_len = ext4_ext_get_actual_len(ex);
+
+ trace_ext4_ext_rm_leaf(inode, start, ex, partial);
+
+ while (ex >= EXT_FIRST_EXTENT(eh) &&
+ ex_ee_block + ex_ee_len > start) {
+
+ if (ext4_ext_is_unwritten(ex))
+ unwritten = 1;
+ else
+ unwritten = 0;
+
+ ext_debug(inode, "remove ext %u:[%d]%d\n", ex_ee_block,
+ unwritten, ex_ee_len);
+ path[depth].p_ext = ex;
+
+ a = max(ex_ee_block, start);
+ b = min(ex_ee_block + ex_ee_len - 1, end);
+
+ ext_debug(inode, " border %u:%u\n", a, b);
+
+ /* If this extent is beyond the end of the hole, skip it */
+ if (end < ex_ee_block) {
+ /*
+ * We're going to skip this extent and move to another,
+ * so note that its first cluster is in use to avoid
+ * freeing it when removing blocks. Eventually, the
+ * right edge of the truncated/punched region will
+ * be just to the left.
+ */
+ if (sbi->s_cluster_ratio > 1) {
+ pblk = ext4_ext_pblock(ex);
+ partial->pclu = EXT4_B2C(sbi, pblk);
+ partial->state = nofree;
+ }
+ ex--;
+ ex_ee_block = le32_to_cpu(ex->ee_block);
+ ex_ee_len = ext4_ext_get_actual_len(ex);
+ continue;
+ } else if (b != ex_ee_block + ex_ee_len - 1) {
+ EXT4_ERROR_INODE(inode,
+ "can not handle truncate %u:%u "
+ "on extent %u:%u",
+ start, end, ex_ee_block,
+ ex_ee_block + ex_ee_len - 1);
+ err = -EFSCORRUPTED;
+ goto out;
+ } else if (a != ex_ee_block) {
+ /* remove tail of the extent */
+ num = a - ex_ee_block;
+ } else {
+ /* remove whole extent: excellent! */
+ num = 0;
+ }
+ /*
+ * 3 for leaf, sb, and inode plus 2 (bmap and group
+ * descriptor) for each block group; assume two block
+ * groups plus ex_ee_len/blocks_per_block_group for
+ * the worst case
+ */
+ credits = 7 + 2*(ex_ee_len/EXT4_BLOCKS_PER_GROUP(inode->i_sb));
+ if (ex == EXT_FIRST_EXTENT(eh)) {
+ correct_index = 1;
+ credits += (ext_depth(inode)) + 1;
+ }
+ credits += EXT4_MAXQUOTAS_TRANS_BLOCKS(inode->i_sb);
+ /*
+ * We may end up freeing some index blocks and data from the
+ * punched range. Note that partial clusters are accounted for
+ * by ext4_free_data_revoke_credits().
+ */
+ revoke_credits =
+ ext4_free_metadata_revoke_credits(inode->i_sb,
+ ext_depth(inode)) +
+ ext4_free_data_revoke_credits(inode, b - a + 1);
+
+ err = ext4_datasem_ensure_credits(handle, inode, credits,
+ credits, revoke_credits);
+ if (err) {
+ if (err > 0)
+ err = -EAGAIN;
+ goto out;
+ }
+
+ err = ext4_ext_get_access(handle, inode, path + depth);
+ if (err)
+ goto out;
+
+ err = ext4_remove_blocks(handle, inode, ex, partial, a, b);
+ if (err)
+ goto out;
+
+ if (num == 0)
+ /* this extent is removed; mark slot entirely unused */
+ ext4_ext_store_pblock(ex, 0);
+
+ ex->ee_len = cpu_to_le16(num);
+ /*
+ * Do not mark unwritten if all the blocks in the
+ * extent have been removed.
+ */
+ if (unwritten && num)
+ ext4_ext_mark_unwritten(ex);
+ /*
+ * If the extent was completely released,
+ * we need to remove it from the leaf
+ */
+ if (num == 0) {
+ if (end != EXT_MAX_BLOCKS - 1) {
+ /*
+ * For hole punching, we need to scoot all the
+ * extents up when an extent is removed so that
+ * we dont have blank extents in the middle
+ */
+ memmove(ex, ex+1, (EXT_LAST_EXTENT(eh) - ex) *
+ sizeof(struct ext4_extent));
+
+ /* Now get rid of the one at the end */
+ memset(EXT_LAST_EXTENT(eh), 0,
+ sizeof(struct ext4_extent));
+ }
+ le16_add_cpu(&eh->eh_entries, -1);
+ }
+
+ err = ext4_ext_dirty(handle, inode, path + depth);
+ if (err)
+ goto out;
+
+ ext_debug(inode, "new extent: %u:%u:%llu\n", ex_ee_block, num,
+ ext4_ext_pblock(ex));
+ ex--;
+ ex_ee_block = le32_to_cpu(ex->ee_block);
+ ex_ee_len = ext4_ext_get_actual_len(ex);
+ }
+
+ if (correct_index && eh->eh_entries)
+ err = ext4_ext_correct_indexes(handle, inode, path);
+
+ /*
+ * If there's a partial cluster and at least one extent remains in
+ * the leaf, free the partial cluster if it isn't shared with the
+ * current extent. If it is shared with the current extent
+ * we reset the partial cluster because we've reached the start of the
+ * truncated/punched region and we're done removing blocks.
+ */
+ if (partial->state == tofree && ex >= EXT_FIRST_EXTENT(eh)) {
+ pblk = ext4_ext_pblock(ex) + ex_ee_len - 1;
+ if (partial->pclu != EXT4_B2C(sbi, pblk)) {
+ int flags = get_default_free_blocks_flags(inode);
+
+ if (ext4_is_pending(inode, partial->lblk))
+ flags |= EXT4_FREE_BLOCKS_RERESERVE_CLUSTER;
+ ext4_free_blocks(handle, inode, NULL,
+ EXT4_C2B(sbi, partial->pclu),
+ sbi->s_cluster_ratio, flags);
+ if (flags & EXT4_FREE_BLOCKS_RERESERVE_CLUSTER)
+ ext4_rereserve_cluster(inode, partial->lblk);
+ }
+ partial->state = initial;
+ }
+
+ /* if this leaf is free, then we should
+ * remove it from index block above */
+ if (err == 0 && eh->eh_entries == 0 && path[depth].p_bh != NULL)
+ err = ext4_ext_rm_idx(handle, inode, path, depth);
+
+out:
+ return err;
+}
+
+/*
+ * ext4_ext_more_to_rm:
+ * returns 1 if current index has to be freed (even partial)
+ */
+static int
+ext4_ext_more_to_rm(struct ext4_ext_path *path)
+{
+ BUG_ON(path->p_idx == NULL);
+
+ if (path->p_idx < EXT_FIRST_INDEX(path->p_hdr))
+ return 0;
+
+ /*
+ * if truncate on deeper level happened, it wasn't partial,
+ * so we have to consider current index for truncation
+ */
+ if (le16_to_cpu(path->p_hdr->eh_entries) == path->p_block)
+ return 0;
+ return 1;
+}
+
+int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start,
+ ext4_lblk_t end)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+ int depth = ext_depth(inode);
+ struct ext4_ext_path *path = NULL;
+ struct partial_cluster partial;
+ handle_t *handle;
+ int i = 0, err = 0;
+ int flags = EXT4_EX_NOCACHE | EXT4_EX_NOFAIL;
+
+ partial.pclu = 0;
+ partial.lblk = 0;
+ partial.state = initial;
+
+ ext_debug(inode, "truncate since %u to %u\n", start, end);
+
+ /* probably first extent we're gonna free will be last in block */
+ handle = ext4_journal_start_with_revoke(inode, EXT4_HT_TRUNCATE,
+ depth + 1,
+ ext4_free_metadata_revoke_credits(inode->i_sb, depth));
+ if (IS_ERR(handle))
+ return PTR_ERR(handle);
+
+again:
+ trace_ext4_ext_remove_space(inode, start, end, depth);
+
+ /*
+ * Check if we are removing extents inside the extent tree. If that
+ * is the case, we are going to punch a hole inside the extent tree
+ * so we have to check whether we need to split the extent covering
+ * the last block to remove so we can easily remove the part of it
+ * in ext4_ext_rm_leaf().
+ */
+ if (end < EXT_MAX_BLOCKS - 1) {
+ struct ext4_extent *ex;
+ ext4_lblk_t ee_block, ex_end, lblk;
+ ext4_fsblk_t pblk;
+
+ /* find extent for or closest extent to this block */
+ path = ext4_find_extent(inode, end, NULL, flags);
+ if (IS_ERR(path)) {
+ ext4_journal_stop(handle);
+ return PTR_ERR(path);
+ }
+ depth = ext_depth(inode);
+ /* Leaf not may not exist only if inode has no blocks at all */
+ ex = path[depth].p_ext;
+ if (!ex) {
+ if (depth) {
+ EXT4_ERROR_INODE(inode,
+ "path[%d].p_hdr == NULL",
+ depth);
+ err = -EFSCORRUPTED;
+ }
+ goto out;
+ }
+
+ ee_block = le32_to_cpu(ex->ee_block);
+ ex_end = ee_block + ext4_ext_get_actual_len(ex) - 1;
+
+ /*
+ * See if the last block is inside the extent, if so split
+ * the extent at 'end' block so we can easily remove the
+ * tail of the first part of the split extent in
+ * ext4_ext_rm_leaf().
+ */
+ if (end >= ee_block && end < ex_end) {
+
+ /*
+ * If we're going to split the extent, note that
+ * the cluster containing the block after 'end' is
+ * in use to avoid freeing it when removing blocks.
+ */
+ if (sbi->s_cluster_ratio > 1) {
+ pblk = ext4_ext_pblock(ex) + end - ee_block + 1;
+ partial.pclu = EXT4_B2C(sbi, pblk);
+ partial.state = nofree;
+ }
+
+ /*
+ * Split the extent in two so that 'end' is the last
+ * block in the first new extent. Also we should not
+ * fail removing space due to ENOSPC so try to use
+ * reserved block if that happens.
+ */
+ path = ext4_force_split_extent_at(handle, inode, path,
+ end + 1, 1);
+ if (IS_ERR(path)) {
+ err = PTR_ERR(path);
+ goto out;
+ }
+ } else if (sbi->s_cluster_ratio > 1 && end >= ex_end &&
+ partial.state == initial) {
+ /*
+ * If we're punching, there's an extent to the right.
+ * If the partial cluster hasn't been set, set it to
+ * that extent's first cluster and its state to nofree
+ * so it won't be freed should it contain blocks to be
+ * removed. If it's already set (tofree/nofree), we're
+ * retrying and keep the original partial cluster info
+ * so a cluster marked tofree as a result of earlier
+ * extent removal is not lost.
+ */
+ lblk = ex_end + 1;
+ err = ext4_ext_search_right(inode, path, &lblk, &pblk,
+ NULL, flags);
+ if (err < 0)
+ goto out;
+ if (pblk) {
+ partial.pclu = EXT4_B2C(sbi, pblk);
+ partial.state = nofree;
+ }
+ }
+ }
+ /*
+ * We start scanning from right side, freeing all the blocks
+ * after i_size and walking into the tree depth-wise.
+ */
+ depth = ext_depth(inode);
+ if (path) {
+ int k = i = depth;
+ while (--k > 0)
+ path[k].p_block =
+ le16_to_cpu(path[k].p_hdr->eh_entries)+1;
+ } else {
+ path = kcalloc(depth + 1, sizeof(struct ext4_ext_path),
+ GFP_NOFS | __GFP_NOFAIL);
+ if (path == NULL) {
+ ext4_journal_stop(handle);
+ return -ENOMEM;
+ }
+ path[0].p_maxdepth = path[0].p_depth = depth;
+ path[0].p_hdr = ext_inode_hdr(inode);
+ i = 0;
+
+ if (ext4_ext_check(inode, path[0].p_hdr, depth, 0)) {
+ err = -EFSCORRUPTED;
+ goto out;
+ }
+ }
+ err = 0;
+
+ while (i >= 0 && err == 0) {
+ if (i == depth) {
+ /* this is leaf block */
+ err = ext4_ext_rm_leaf(handle, inode, path,
+ &partial, start, end);
+ /* root level has p_bh == NULL, brelse() eats this */
+ ext4_ext_path_brelse(path + i);
+ i--;
+ continue;
+ }
+
+ /* this is index block */
+ if (!path[i].p_hdr) {
+ ext_debug(inode, "initialize header\n");
+ path[i].p_hdr = ext_block_hdr(path[i].p_bh);
+ }
+
+ if (!path[i].p_idx) {
+ /* this level hasn't been touched yet */
+ path[i].p_idx = EXT_LAST_INDEX(path[i].p_hdr);
+ path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries)+1;
+ ext_debug(inode, "init index ptr: hdr 0x%p, num %d\n",
+ path[i].p_hdr,
+ le16_to_cpu(path[i].p_hdr->eh_entries));
+ } else {
+ /* we were already here, see at next index */
+ path[i].p_idx--;
+ }
+
+ ext_debug(inode, "level %d - index, first 0x%p, cur 0x%p\n",
+ i, EXT_FIRST_INDEX(path[i].p_hdr),
+ path[i].p_idx);
+ if (ext4_ext_more_to_rm(path + i)) {
+ struct buffer_head *bh;
+ /* go to the next level */
+ ext_debug(inode, "move to level %d (block %llu)\n",
+ i + 1, ext4_idx_pblock(path[i].p_idx));
+ memset(path + i + 1, 0, sizeof(*path));
+ bh = read_extent_tree_block(inode, path[i].p_idx,
+ depth - i - 1, flags);
+ if (IS_ERR(bh)) {
+ /* should we reset i_size? */
+ err = PTR_ERR(bh);
+ break;
+ }
+ /* Yield here to deal with large extent trees.
+ * Should be a no-op if we did IO above. */
+ cond_resched();
+ if (WARN_ON(i + 1 > depth)) {
+ err = -EFSCORRUPTED;
+ break;
+ }
+ path[i + 1].p_bh = bh;
+
+ /* save actual number of indexes since this
+ * number is changed at the next iteration */
+ path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries);
+ i++;
+ } else {
+ /* we finished processing this index, go up */
+ if (path[i].p_hdr->eh_entries == 0 && i > 0) {
+ /* index is empty, remove it;
+ * handle must be already prepared by the
+ * truncatei_leaf() */
+ err = ext4_ext_rm_idx(handle, inode, path, i);
+ }
+ /* root level has p_bh == NULL, brelse() eats this */
+ ext4_ext_path_brelse(path + i);
+ i--;
+ ext_debug(inode, "return to level %d\n", i);
+ }
+ }
+
+ trace_ext4_ext_remove_space_done(inode, start, end, depth, &partial,
+ path->p_hdr->eh_entries);
+
+ /*
+ * if there's a partial cluster and we have removed the first extent
+ * in the file, then we also free the partial cluster, if any
+ */
+ if (partial.state == tofree && err == 0) {
+ int flags = get_default_free_blocks_flags(inode);
+
+ if (ext4_is_pending(inode, partial.lblk))
+ flags |= EXT4_FREE_BLOCKS_RERESERVE_CLUSTER;
+ ext4_free_blocks(handle, inode, NULL,
+ EXT4_C2B(sbi, partial.pclu),
+ sbi->s_cluster_ratio, flags);
+ if (flags & EXT4_FREE_BLOCKS_RERESERVE_CLUSTER)
+ ext4_rereserve_cluster(inode, partial.lblk);
+ partial.state = initial;
+ }
+
+ /* TODO: flexible tree reduction should be here */
+ if (path->p_hdr->eh_entries == 0) {
+ /*
+ * truncate to zero freed all the tree,
+ * so we need to correct eh_depth
+ */
+ err = ext4_ext_get_access(handle, inode, path);
+ if (err == 0) {
+ ext_inode_hdr(inode)->eh_depth = 0;
+ ext_inode_hdr(inode)->eh_max =
+ cpu_to_le16(ext4_ext_space_root(inode, 0));
+ err = ext4_ext_dirty(handle, inode, path);
+ }
+ }
+out:
+ ext4_free_ext_path(path);
+ path = NULL;
+ if (err == -EAGAIN)
+ goto again;
+ ext4_journal_stop(handle);
+
+ return err;
+}
+
+/*
+ * called at mount time
+ */
+void ext4_ext_init(struct super_block *sb)
+{
+ /*
+ * possible initialization would be here
+ */
+
+ if (ext4_has_feature_extents(sb)) {
+#if defined(AGGRESSIVE_TEST) || defined(CHECK_BINSEARCH) || defined(EXTENTS_STATS)
+ printk(KERN_INFO "EXT4-fs: file extents enabled"
+#ifdef AGGRESSIVE_TEST
+ ", aggressive tests"
+#endif
+#ifdef CHECK_BINSEARCH
+ ", check binsearch"
+#endif
+#ifdef EXTENTS_STATS
+ ", stats"
+#endif
+ "\n");
+#endif
+#ifdef EXTENTS_STATS
+ spin_lock_init(&EXT4_SB(sb)->s_ext_stats_lock);
+ EXT4_SB(sb)->s_ext_min = 1 << 30;
+ EXT4_SB(sb)->s_ext_max = 0;
+#endif
+ }
+}
+
+/*
+ * called at umount time
+ */
+void ext4_ext_release(struct super_block *sb)
+{
+ if (!ext4_has_feature_extents(sb))
+ return;
+
+#ifdef EXTENTS_STATS
+ if (EXT4_SB(sb)->s_ext_blocks && EXT4_SB(sb)->s_ext_extents) {
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ printk(KERN_ERR "EXT4-fs: %lu blocks in %lu extents (%lu ave)\n",
+ sbi->s_ext_blocks, sbi->s_ext_extents,
+ sbi->s_ext_blocks / sbi->s_ext_extents);
+ printk(KERN_ERR "EXT4-fs: extents: %lu min, %lu max, max depth %lu\n",
+ sbi->s_ext_min, sbi->s_ext_max, sbi->s_depth_max);
+ }
+#endif
+}
+
+static void ext4_zeroout_es(struct inode *inode, struct ext4_extent *ex)
+{
+ ext4_lblk_t ee_block;
+ ext4_fsblk_t ee_pblock;
+ unsigned int ee_len;
+
+ ee_block = le32_to_cpu(ex->ee_block);
+ ee_len = ext4_ext_get_actual_len(ex);
+ ee_pblock = ext4_ext_pblock(ex);
+
+ if (ee_len == 0)
+ return;
+
+ ext4_es_insert_extent(inode, ee_block, ee_len, ee_pblock,
+ EXTENT_STATUS_WRITTEN, false);
+}
+
+/* FIXME!! we need to try to merge to left or right after zero-out */
+static int ext4_ext_zeroout(struct inode *inode, struct ext4_extent *ex)
+{
+ ext4_fsblk_t ee_pblock;
+ unsigned int ee_len;
+
+ ee_len = ext4_ext_get_actual_len(ex);
+ ee_pblock = ext4_ext_pblock(ex);
+ return ext4_issue_zeroout(inode, le32_to_cpu(ex->ee_block), ee_pblock,
+ ee_len);
+}
+
+/*
+ * ext4_split_extent_at() splits an extent at given block.
+ *
+ * @handle: the journal handle
+ * @inode: the file inode
+ * @path: the path to the extent
+ * @split: the logical block where the extent is splitted.
+ * @split_flags: indicates if the extent could be zeroout if split fails, and
+ * the states(init or unwritten) of new extents.
+ * @flags: flags used to insert new extent to extent tree.
+ *
+ *
+ * Splits extent [a, b] into two extents [a, @split) and [@split, b], states
+ * of which are determined by split_flag.
+ *
+ * There are two cases:
+ * a> the extent are splitted into two extent.
+ * b> split is not needed, and just mark the extent.
+ *
+ * Return an extent path pointer on success, or an error pointer on failure.
+ */
+static struct ext4_ext_path *ext4_split_extent_at(handle_t *handle,
+ struct inode *inode,
+ struct ext4_ext_path *path,
+ ext4_lblk_t split,
+ int split_flag, int flags)
+{
+ ext4_fsblk_t newblock;
+ ext4_lblk_t ee_block;
+ struct ext4_extent *ex, newex, orig_ex, zero_ex;
+ struct ext4_extent *ex2 = NULL;
+ unsigned int ee_len, depth;
+ int err = 0;
+
+ BUG_ON((split_flag & (EXT4_EXT_DATA_VALID1 | EXT4_EXT_DATA_VALID2)) ==
+ (EXT4_EXT_DATA_VALID1 | EXT4_EXT_DATA_VALID2));
+
+ ext_debug(inode, "logical block %llu\n", (unsigned long long)split);
+
+ ext4_ext_show_leaf(inode, path);
+
+ depth = ext_depth(inode);
+ ex = path[depth].p_ext;
+ ee_block = le32_to_cpu(ex->ee_block);
+ ee_len = ext4_ext_get_actual_len(ex);
+ newblock = split - ee_block + ext4_ext_pblock(ex);
+
+ BUG_ON(split < ee_block || split >= (ee_block + ee_len));
+ BUG_ON(!ext4_ext_is_unwritten(ex) &&
+ split_flag & (EXT4_EXT_MAY_ZEROOUT |
+ EXT4_EXT_MARK_UNWRIT1 |
+ EXT4_EXT_MARK_UNWRIT2));
+
+ err = ext4_ext_get_access(handle, inode, path + depth);
+ if (err)
+ goto out;
+
+ if (split == ee_block) {
+ /*
+ * case b: block @split is the block that the extent begins with
+ * then we just change the state of the extent, and splitting
+ * is not needed.
+ */
+ if (split_flag & EXT4_EXT_MARK_UNWRIT2)
+ ext4_ext_mark_unwritten(ex);
+ else
+ ext4_ext_mark_initialized(ex);
+
+ if (!(flags & EXT4_GET_BLOCKS_PRE_IO))
+ ext4_ext_try_to_merge(handle, inode, path, ex);
+
+ err = ext4_ext_dirty(handle, inode, path + path->p_depth);
+ goto out;
+ }
+
+ /* case a */
+ memcpy(&orig_ex, ex, sizeof(orig_ex));
+ ex->ee_len = cpu_to_le16(split - ee_block);
+ if (split_flag & EXT4_EXT_MARK_UNWRIT1)
+ ext4_ext_mark_unwritten(ex);
+
+ /*
+ * path may lead to new leaf, not to original leaf any more
+ * after ext4_ext_insert_extent() returns,
+ */
+ err = ext4_ext_dirty(handle, inode, path + depth);
+ if (err)
+ goto fix_extent_len;
+
+ ex2 = &newex;
+ ex2->ee_block = cpu_to_le32(split);
+ ex2->ee_len = cpu_to_le16(ee_len - (split - ee_block));
+ ext4_ext_store_pblock(ex2, newblock);
+ if (split_flag & EXT4_EXT_MARK_UNWRIT2)
+ ext4_ext_mark_unwritten(ex2);
+
+ path = ext4_ext_insert_extent(handle, inode, path, &newex, flags);
+ if (!IS_ERR(path))
+ goto out;
+
+ err = PTR_ERR(path);
+ if (err != -ENOSPC && err != -EDQUOT && err != -ENOMEM)
+ return path;
+
+ /*
+ * Get a new path to try to zeroout or fix the extent length.
+ * Using EXT4_EX_NOFAIL guarantees that ext4_find_extent()
+ * will not return -ENOMEM, otherwise -ENOMEM will cause a
+ * retry in do_writepages(), and a WARN_ON may be triggered
+ * in ext4_da_update_reserve_space() due to an incorrect
+ * ee_len causing the i_reserved_data_blocks exception.
+ */
+ path = ext4_find_extent(inode, ee_block, NULL, flags | EXT4_EX_NOFAIL);
+ if (IS_ERR(path)) {
+ EXT4_ERROR_INODE(inode, "Failed split extent on %u, err %ld",
+ split, PTR_ERR(path));
+ return path;
+ }
+ depth = ext_depth(inode);
+ ex = path[depth].p_ext;
+
+ if (EXT4_EXT_MAY_ZEROOUT & split_flag) {
+ if (split_flag & (EXT4_EXT_DATA_VALID1|EXT4_EXT_DATA_VALID2)) {
+ if (split_flag & EXT4_EXT_DATA_VALID1) {
+ err = ext4_ext_zeroout(inode, ex2);
+ zero_ex.ee_block = ex2->ee_block;
+ zero_ex.ee_len = cpu_to_le16(
+ ext4_ext_get_actual_len(ex2));
+ ext4_ext_store_pblock(&zero_ex,
+ ext4_ext_pblock(ex2));
+ } else {
+ err = ext4_ext_zeroout(inode, ex);
+ zero_ex.ee_block = ex->ee_block;
+ zero_ex.ee_len = cpu_to_le16(
+ ext4_ext_get_actual_len(ex));
+ ext4_ext_store_pblock(&zero_ex,
+ ext4_ext_pblock(ex));
+ }
+ } else {
+ err = ext4_ext_zeroout(inode, &orig_ex);
+ zero_ex.ee_block = orig_ex.ee_block;
+ zero_ex.ee_len = cpu_to_le16(
+ ext4_ext_get_actual_len(&orig_ex));
+ ext4_ext_store_pblock(&zero_ex,
+ ext4_ext_pblock(&orig_ex));
+ }
+
+ if (!err) {
+ /* update the extent length and mark as initialized */
+ ex->ee_len = cpu_to_le16(ee_len);
+ ext4_ext_try_to_merge(handle, inode, path, ex);
+ err = ext4_ext_dirty(handle, inode, path + path->p_depth);
+ if (!err)
+ /* update extent status tree */
+ ext4_zeroout_es(inode, &zero_ex);
+ /* If we failed at this point, we don't know in which
+ * state the extent tree exactly is so don't try to fix
+ * length of the original extent as it may do even more
+ * damage.
+ */
+ goto out;
+ }
+ }
+
+fix_extent_len:
+ ex->ee_len = orig_ex.ee_len;
+ /*
+ * Ignore ext4_ext_dirty return value since we are already in error path
+ * and err is a non-zero error code.
+ */
+ ext4_ext_dirty(handle, inode, path + path->p_depth);
+out:
+ if (err) {
+ ext4_free_ext_path(path);
+ path = ERR_PTR(err);
+ }
+ ext4_ext_show_leaf(inode, path);
+ return path;
+}
+
+/*
+ * ext4_split_extent() splits an extent and mark extent which is covered
+ * by @map as split_flags indicates
+ *
+ * It may result in splitting the extent into multiple extents (up to three)
+ * There are three possibilities:
+ * a> There is no split required
+ * b> Splits in two extents: Split is happening at either end of the extent
+ * c> Splits in three extents: Somone is splitting in middle of the extent
+ *
+ */
+static struct ext4_ext_path *ext4_split_extent(handle_t *handle,
+ struct inode *inode,
+ struct ext4_ext_path *path,
+ struct ext4_map_blocks *map,
+ int split_flag, int flags,
+ unsigned int *allocated)
+{
+ ext4_lblk_t ee_block;
+ struct ext4_extent *ex;
+ unsigned int ee_len, depth;
+ int unwritten;
+ int split_flag1, flags1;
+
+ depth = ext_depth(inode);
+ ex = path[depth].p_ext;
+ ee_block = le32_to_cpu(ex->ee_block);
+ ee_len = ext4_ext_get_actual_len(ex);
+ unwritten = ext4_ext_is_unwritten(ex);
+
+ if (map->m_lblk + map->m_len < ee_block + ee_len) {
+ split_flag1 = split_flag & EXT4_EXT_MAY_ZEROOUT;
+ flags1 = flags | EXT4_GET_BLOCKS_PRE_IO;
+ if (unwritten)
+ split_flag1 |= EXT4_EXT_MARK_UNWRIT1 |
+ EXT4_EXT_MARK_UNWRIT2;
+ if (split_flag & EXT4_EXT_DATA_VALID2)
+ split_flag1 |= EXT4_EXT_DATA_VALID1;
+ path = ext4_split_extent_at(handle, inode, path,
+ map->m_lblk + map->m_len, split_flag1, flags1);
+ if (IS_ERR(path))
+ return path;
+ /*
+ * Update path is required because previous ext4_split_extent_at
+ * may result in split of original leaf or extent zeroout.
+ */
+ path = ext4_find_extent(inode, map->m_lblk, path, flags);
+ if (IS_ERR(path))
+ return path;
+ depth = ext_depth(inode);
+ ex = path[depth].p_ext;
+ if (!ex) {
+ EXT4_ERROR_INODE(inode, "unexpected hole at %lu",
+ (unsigned long) map->m_lblk);
+ ext4_free_ext_path(path);
+ return ERR_PTR(-EFSCORRUPTED);
+ }
+ unwritten = ext4_ext_is_unwritten(ex);
+ }
+
+ if (map->m_lblk >= ee_block) {
+ split_flag1 = split_flag & EXT4_EXT_DATA_VALID2;
+ if (unwritten) {
+ split_flag1 |= EXT4_EXT_MARK_UNWRIT1;
+ split_flag1 |= split_flag & (EXT4_EXT_MAY_ZEROOUT |
+ EXT4_EXT_MARK_UNWRIT2);
+ }
+ path = ext4_split_extent_at(handle, inode, path,
+ map->m_lblk, split_flag1, flags);
+ if (IS_ERR(path))
+ return path;
+ }
+
+ if (allocated) {
+ if (map->m_lblk + map->m_len > ee_block + ee_len)
+ *allocated = ee_len - (map->m_lblk - ee_block);
+ else
+ *allocated = map->m_len;
+ }
+ ext4_ext_show_leaf(inode, path);
+ return path;
+}
+
+/*
+ * This function is called by ext4_ext_map_blocks() if someone tries to write
+ * to an unwritten extent. It may result in splitting the unwritten
+ * extent into multiple extents (up to three - one initialized and two
+ * unwritten).
+ * There are three possibilities:
+ * a> There is no split required: Entire extent should be initialized
+ * b> Splits in two extents: Write is happening at either end of the extent
+ * c> Splits in three extents: Somone is writing in middle of the extent
+ *
+ * Pre-conditions:
+ * - The extent pointed to by 'path' is unwritten.
+ * - The extent pointed to by 'path' contains a superset
+ * of the logical span [map->m_lblk, map->m_lblk + map->m_len).
+ *
+ * Post-conditions on success:
+ * - the returned value is the number of blocks beyond map->l_lblk
+ * that are allocated and initialized.
+ * It is guaranteed to be >= map->m_len.
+ */
+static struct ext4_ext_path *
+ext4_ext_convert_to_initialized(handle_t *handle, struct inode *inode,
+ struct ext4_map_blocks *map, struct ext4_ext_path *path,
+ int flags, unsigned int *allocated)
+{
+ struct ext4_sb_info *sbi;
+ struct ext4_extent_header *eh;
+ struct ext4_map_blocks split_map;
+ struct ext4_extent zero_ex1, zero_ex2;
+ struct ext4_extent *ex, *abut_ex;
+ ext4_lblk_t ee_block, eof_block;
+ unsigned int ee_len, depth, map_len = map->m_len;
+ int err = 0;
+ int split_flag = EXT4_EXT_DATA_VALID2;
+ unsigned int max_zeroout = 0;
+
+ ext_debug(inode, "logical block %llu, max_blocks %u\n",
+ (unsigned long long)map->m_lblk, map_len);
+
+ sbi = EXT4_SB(inode->i_sb);
+ eof_block = (EXT4_I(inode)->i_disksize + inode->i_sb->s_blocksize - 1)
+ >> inode->i_sb->s_blocksize_bits;
+ if (eof_block < map->m_lblk + map_len)
+ eof_block = map->m_lblk + map_len;
+
+ depth = ext_depth(inode);
+ eh = path[depth].p_hdr;
+ ex = path[depth].p_ext;
+ ee_block = le32_to_cpu(ex->ee_block);
+ ee_len = ext4_ext_get_actual_len(ex);
+ zero_ex1.ee_len = 0;
+ zero_ex2.ee_len = 0;
+
+ trace_ext4_ext_convert_to_initialized_enter(inode, map, ex);
+
+ /* Pre-conditions */
+ BUG_ON(!ext4_ext_is_unwritten(ex));
+ BUG_ON(!in_range(map->m_lblk, ee_block, ee_len));
+
+ /*
+ * Attempt to transfer newly initialized blocks from the currently
+ * unwritten extent to its neighbor. This is much cheaper
+ * than an insertion followed by a merge as those involve costly
+ * memmove() calls. Transferring to the left is the common case in
+ * steady state for workloads doing fallocate(FALLOC_FL_KEEP_SIZE)
+ * followed by append writes.
+ *
+ * Limitations of the current logic:
+ * - L1: we do not deal with writes covering the whole extent.
+ * This would require removing the extent if the transfer
+ * is possible.
+ * - L2: we only attempt to merge with an extent stored in the
+ * same extent tree node.
+ */
+ *allocated = 0;
+ if ((map->m_lblk == ee_block) &&
+ /* See if we can merge left */
+ (map_len < ee_len) && /*L1*/
+ (ex > EXT_FIRST_EXTENT(eh))) { /*L2*/
+ ext4_lblk_t prev_lblk;
+ ext4_fsblk_t prev_pblk, ee_pblk;
+ unsigned int prev_len;
+
+ abut_ex = ex - 1;
+ prev_lblk = le32_to_cpu(abut_ex->ee_block);
+ prev_len = ext4_ext_get_actual_len(abut_ex);
+ prev_pblk = ext4_ext_pblock(abut_ex);
+ ee_pblk = ext4_ext_pblock(ex);
+
+ /*
+ * A transfer of blocks from 'ex' to 'abut_ex' is allowed
+ * upon those conditions:
+ * - C1: abut_ex is initialized,
+ * - C2: abut_ex is logically abutting ex,
+ * - C3: abut_ex is physically abutting ex,
+ * - C4: abut_ex can receive the additional blocks without
+ * overflowing the (initialized) length limit.
+ */
+ if ((!ext4_ext_is_unwritten(abut_ex)) && /*C1*/
+ ((prev_lblk + prev_len) == ee_block) && /*C2*/
+ ((prev_pblk + prev_len) == ee_pblk) && /*C3*/
+ (prev_len < (EXT_INIT_MAX_LEN - map_len))) { /*C4*/
+ err = ext4_ext_get_access(handle, inode, path + depth);
+ if (err)
+ goto errout;
+
+ trace_ext4_ext_convert_to_initialized_fastpath(inode,
+ map, ex, abut_ex);
+
+ /* Shift the start of ex by 'map_len' blocks */
+ ex->ee_block = cpu_to_le32(ee_block + map_len);
+ ext4_ext_store_pblock(ex, ee_pblk + map_len);
+ ex->ee_len = cpu_to_le16(ee_len - map_len);
+ ext4_ext_mark_unwritten(ex); /* Restore the flag */
+
+ /* Extend abut_ex by 'map_len' blocks */
+ abut_ex->ee_len = cpu_to_le16(prev_len + map_len);
+
+ /* Result: number of initialized blocks past m_lblk */
+ *allocated = map_len;
+ }
+ } else if (((map->m_lblk + map_len) == (ee_block + ee_len)) &&
+ (map_len < ee_len) && /*L1*/
+ ex < EXT_LAST_EXTENT(eh)) { /*L2*/
+ /* See if we can merge right */
+ ext4_lblk_t next_lblk;
+ ext4_fsblk_t next_pblk, ee_pblk;
+ unsigned int next_len;
+
+ abut_ex = ex + 1;
+ next_lblk = le32_to_cpu(abut_ex->ee_block);
+ next_len = ext4_ext_get_actual_len(abut_ex);
+ next_pblk = ext4_ext_pblock(abut_ex);
+ ee_pblk = ext4_ext_pblock(ex);
+
+ /*
+ * A transfer of blocks from 'ex' to 'abut_ex' is allowed
+ * upon those conditions:
+ * - C1: abut_ex is initialized,
+ * - C2: abut_ex is logically abutting ex,
+ * - C3: abut_ex is physically abutting ex,
+ * - C4: abut_ex can receive the additional blocks without
+ * overflowing the (initialized) length limit.
+ */
+ if ((!ext4_ext_is_unwritten(abut_ex)) && /*C1*/
+ ((map->m_lblk + map_len) == next_lblk) && /*C2*/
+ ((ee_pblk + ee_len) == next_pblk) && /*C3*/
+ (next_len < (EXT_INIT_MAX_LEN - map_len))) { /*C4*/
+ err = ext4_ext_get_access(handle, inode, path + depth);
+ if (err)
+ goto errout;
+
+ trace_ext4_ext_convert_to_initialized_fastpath(inode,
+ map, ex, abut_ex);
+
+ /* Shift the start of abut_ex by 'map_len' blocks */
+ abut_ex->ee_block = cpu_to_le32(next_lblk - map_len);
+ ext4_ext_store_pblock(abut_ex, next_pblk - map_len);
+ ex->ee_len = cpu_to_le16(ee_len - map_len);
+ ext4_ext_mark_unwritten(ex); /* Restore the flag */
+
+ /* Extend abut_ex by 'map_len' blocks */
+ abut_ex->ee_len = cpu_to_le16(next_len + map_len);
+
+ /* Result: number of initialized blocks past m_lblk */
+ *allocated = map_len;
+ }
+ }
+ if (*allocated) {
+ /* Mark the block containing both extents as dirty */
+ err = ext4_ext_dirty(handle, inode, path + depth);
+
+ /* Update path to point to the right extent */
+ path[depth].p_ext = abut_ex;
+ if (err)
+ goto errout;
+ goto out;
+ } else
+ *allocated = ee_len - (map->m_lblk - ee_block);
+
+ WARN_ON(map->m_lblk < ee_block);
+ /*
+ * It is safe to convert extent to initialized via explicit
+ * zeroout only if extent is fully inside i_size or new_size.
+ */
+ split_flag |= ee_block + ee_len <= eof_block ? EXT4_EXT_MAY_ZEROOUT : 0;
+
+ if (EXT4_EXT_MAY_ZEROOUT & split_flag)
+ max_zeroout = sbi->s_extent_max_zeroout_kb >>
+ (inode->i_sb->s_blocksize_bits - 10);
+
+ /*
+ * five cases:
+ * 1. split the extent into three extents.
+ * 2. split the extent into two extents, zeroout the head of the first
+ * extent.
+ * 3. split the extent into two extents, zeroout the tail of the second
+ * extent.
+ * 4. split the extent into two extents with out zeroout.
+ * 5. no splitting needed, just possibly zeroout the head and / or the
+ * tail of the extent.
+ */
+ split_map.m_lblk = map->m_lblk;
+ split_map.m_len = map->m_len;
+
+ if (max_zeroout && (*allocated > split_map.m_len)) {
+ if (*allocated <= max_zeroout) {
+ /* case 3 or 5 */
+ zero_ex1.ee_block =
+ cpu_to_le32(split_map.m_lblk +
+ split_map.m_len);
+ zero_ex1.ee_len =
+ cpu_to_le16(*allocated - split_map.m_len);
+ ext4_ext_store_pblock(&zero_ex1,
+ ext4_ext_pblock(ex) + split_map.m_lblk +
+ split_map.m_len - ee_block);
+ err = ext4_ext_zeroout(inode, &zero_ex1);
+ if (err)
+ goto fallback;
+ split_map.m_len = *allocated;
+ }
+ if (split_map.m_lblk - ee_block + split_map.m_len <
+ max_zeroout) {
+ /* case 2 or 5 */
+ if (split_map.m_lblk != ee_block) {
+ zero_ex2.ee_block = ex->ee_block;
+ zero_ex2.ee_len = cpu_to_le16(split_map.m_lblk -
+ ee_block);
+ ext4_ext_store_pblock(&zero_ex2,
+ ext4_ext_pblock(ex));
+ err = ext4_ext_zeroout(inode, &zero_ex2);
+ if (err)
+ goto fallback;
+ }
+
+ split_map.m_len += split_map.m_lblk - ee_block;
+ split_map.m_lblk = ee_block;
+ *allocated = map->m_len;
+ }
+ }
+
+fallback:
+ path = ext4_split_extent(handle, inode, path, &split_map, split_flag,
+ flags, NULL);
+ if (IS_ERR(path))
+ return path;
+out:
+ /* If we have gotten a failure, don't zero out status tree */
+ ext4_zeroout_es(inode, &zero_ex1);
+ ext4_zeroout_es(inode, &zero_ex2);
+ return path;
+
+errout:
+ ext4_free_ext_path(path);
+ return ERR_PTR(err);
+}
+
+/*
+ * This function is called by ext4_ext_map_blocks() from
+ * ext4_get_blocks_dio_write() when DIO to write
+ * to an unwritten extent.
+ *
+ * Writing to an unwritten extent may result in splitting the unwritten
+ * extent into multiple initialized/unwritten extents (up to three)
+ * There are three possibilities:
+ * a> There is no split required: Entire extent should be unwritten
+ * b> Splits in two extents: Write is happening at either end of the extent
+ * c> Splits in three extents: Somone is writing in middle of the extent
+ *
+ * This works the same way in the case of initialized -> unwritten conversion.
+ *
+ * One of more index blocks maybe needed if the extent tree grow after
+ * the unwritten extent split. To prevent ENOSPC occur at the IO
+ * complete, we need to split the unwritten extent before DIO submit
+ * the IO. The unwritten extent called at this time will be split
+ * into three unwritten extent(at most). After IO complete, the part
+ * being filled will be convert to initialized by the end_io callback function
+ * via ext4_convert_unwritten_extents().
+ *
+ * The size of unwritten extent to be written is passed to the caller via the
+ * allocated pointer. Return an extent path pointer on success, or an error
+ * pointer on failure.
+ */
+static struct ext4_ext_path *ext4_split_convert_extents(handle_t *handle,
+ struct inode *inode,
+ struct ext4_map_blocks *map,
+ struct ext4_ext_path *path,
+ int flags, unsigned int *allocated)
+{
+ ext4_lblk_t eof_block;
+ ext4_lblk_t ee_block;
+ struct ext4_extent *ex;
+ unsigned int ee_len;
+ int split_flag = 0, depth;
+
+ ext_debug(inode, "logical block %llu, max_blocks %u\n",
+ (unsigned long long)map->m_lblk, map->m_len);
+
+ eof_block = (EXT4_I(inode)->i_disksize + inode->i_sb->s_blocksize - 1)
+ >> inode->i_sb->s_blocksize_bits;
+ if (eof_block < map->m_lblk + map->m_len)
+ eof_block = map->m_lblk + map->m_len;
+ /*
+ * It is safe to convert extent to initialized via explicit
+ * zeroout only if extent is fully inside i_size or new_size.
+ */
+ depth = ext_depth(inode);
+ ex = path[depth].p_ext;
+ ee_block = le32_to_cpu(ex->ee_block);
+ ee_len = ext4_ext_get_actual_len(ex);
+
+ /* Convert to unwritten */
+ if (flags & EXT4_GET_BLOCKS_CONVERT_UNWRITTEN) {
+ split_flag |= EXT4_EXT_DATA_VALID1;
+ /* Convert to initialized */
+ } else if (flags & EXT4_GET_BLOCKS_CONVERT) {
+ split_flag |= ee_block + ee_len <= eof_block ?
+ EXT4_EXT_MAY_ZEROOUT : 0;
+ split_flag |= (EXT4_EXT_MARK_UNWRIT2 | EXT4_EXT_DATA_VALID2);
+ }
+ flags |= EXT4_GET_BLOCKS_PRE_IO;
+ return ext4_split_extent(handle, inode, path, map, split_flag, flags,
+ allocated);
+}
+
+static struct ext4_ext_path *
+ext4_convert_unwritten_extents_endio(handle_t *handle, struct inode *inode,
+ struct ext4_map_blocks *map,
+ struct ext4_ext_path *path)
+{
+ struct ext4_extent *ex;
+ ext4_lblk_t ee_block;
+ unsigned int ee_len;
+ int depth;
+ int err = 0;
+
+ depth = ext_depth(inode);
+ ex = path[depth].p_ext;
+ ee_block = le32_to_cpu(ex->ee_block);
+ ee_len = ext4_ext_get_actual_len(ex);
+
+ ext_debug(inode, "logical block %llu, max_blocks %u\n",
+ (unsigned long long)ee_block, ee_len);
+
+ /* If extent is larger than requested it is a clear sign that we still
+ * have some extent state machine issues left. So extent_split is still
+ * required.
+ * TODO: Once all related issues will be fixed this situation should be
+ * illegal.
+ */
+ if (ee_block != map->m_lblk || ee_len > map->m_len) {
+#ifdef CONFIG_EXT4_DEBUG
+ ext4_warning(inode->i_sb, "Inode (%ld) finished: extent logical block %llu,"
+ " len %u; IO logical block %llu, len %u",
+ inode->i_ino, (unsigned long long)ee_block, ee_len,
+ (unsigned long long)map->m_lblk, map->m_len);
+#endif
+ path = ext4_split_convert_extents(handle, inode, map, path,
+ EXT4_GET_BLOCKS_CONVERT, NULL);
+ if (IS_ERR(path))
+ return path;
+
+ path = ext4_find_extent(inode, map->m_lblk, path, 0);
+ if (IS_ERR(path))
+ return path;
+ depth = ext_depth(inode);
+ ex = path[depth].p_ext;
+ }
+
+ err = ext4_ext_get_access(handle, inode, path + depth);
+ if (err)
+ goto errout;
+ /* first mark the extent as initialized */
+ ext4_ext_mark_initialized(ex);
+
+ /* note: ext4_ext_correct_indexes() isn't needed here because
+ * borders are not changed
+ */
+ ext4_ext_try_to_merge(handle, inode, path, ex);
+
+ /* Mark modified extent as dirty */
+ err = ext4_ext_dirty(handle, inode, path + path->p_depth);
+ if (err)
+ goto errout;
+
+ ext4_ext_show_leaf(inode, path);
+ return path;
+
+errout:
+ ext4_free_ext_path(path);
+ return ERR_PTR(err);
+}
+
+static struct ext4_ext_path *
+convert_initialized_extent(handle_t *handle, struct inode *inode,
+ struct ext4_map_blocks *map,
+ struct ext4_ext_path *path,
+ unsigned int *allocated)
+{
+ struct ext4_extent *ex;
+ ext4_lblk_t ee_block;
+ unsigned int ee_len;
+ int depth;
+ int err = 0;
+
+ /*
+ * Make sure that the extent is no bigger than we support with
+ * unwritten extent
+ */
+ if (map->m_len > EXT_UNWRITTEN_MAX_LEN)
+ map->m_len = EXT_UNWRITTEN_MAX_LEN / 2;
+
+ depth = ext_depth(inode);
+ ex = path[depth].p_ext;
+ ee_block = le32_to_cpu(ex->ee_block);
+ ee_len = ext4_ext_get_actual_len(ex);
+
+ ext_debug(inode, "logical block %llu, max_blocks %u\n",
+ (unsigned long long)ee_block, ee_len);
+
+ if (ee_block != map->m_lblk || ee_len > map->m_len) {
+ path = ext4_split_convert_extents(handle, inode, map, path,
+ EXT4_GET_BLOCKS_CONVERT_UNWRITTEN, NULL);
+ if (IS_ERR(path))
+ return path;
+
+ path = ext4_find_extent(inode, map->m_lblk, path, 0);
+ if (IS_ERR(path))
+ return path;
+ depth = ext_depth(inode);
+ ex = path[depth].p_ext;
+ if (!ex) {
+ EXT4_ERROR_INODE(inode, "unexpected hole at %lu",
+ (unsigned long) map->m_lblk);
+ err = -EFSCORRUPTED;
+ goto errout;
+ }
+ }
+
+ err = ext4_ext_get_access(handle, inode, path + depth);
+ if (err)
+ goto errout;
+ /* first mark the extent as unwritten */
+ ext4_ext_mark_unwritten(ex);
+
+ /* note: ext4_ext_correct_indexes() isn't needed here because
+ * borders are not changed
+ */
+ ext4_ext_try_to_merge(handle, inode, path, ex);
+
+ /* Mark modified extent as dirty */
+ err = ext4_ext_dirty(handle, inode, path + path->p_depth);
+ if (err)
+ goto errout;
+ ext4_ext_show_leaf(inode, path);
+
+ ext4_update_inode_fsync_trans(handle, inode, 1);
+
+ map->m_flags |= EXT4_MAP_UNWRITTEN;
+ if (*allocated > map->m_len)
+ *allocated = map->m_len;
+ map->m_len = *allocated;
+ return path;
+
+errout:
+ ext4_free_ext_path(path);
+ return ERR_PTR(err);
+}
+
+static struct ext4_ext_path *
+ext4_ext_handle_unwritten_extents(handle_t *handle, struct inode *inode,
+ struct ext4_map_blocks *map,
+ struct ext4_ext_path *path, int flags,
+ unsigned int *allocated, ext4_fsblk_t newblock)
+{
+ int err = 0;
+
+ ext_debug(inode, "logical block %llu, max_blocks %u, flags 0x%x, allocated %u\n",
+ (unsigned long long)map->m_lblk, map->m_len, flags,
+ *allocated);
+ ext4_ext_show_leaf(inode, path);
+
+ /*
+ * When writing into unwritten space, we should not fail to
+ * allocate metadata blocks for the new extent block if needed.
+ */
+ flags |= EXT4_GET_BLOCKS_METADATA_NOFAIL;
+
+ trace_ext4_ext_handle_unwritten_extents(inode, map, flags,
+ *allocated, newblock);
+
+ /* get_block() before submitting IO, split the extent */
+ if (flags & EXT4_GET_BLOCKS_PRE_IO) {
+ path = ext4_split_convert_extents(handle, inode, map, path,
+ flags | EXT4_GET_BLOCKS_CONVERT, allocated);
+ if (IS_ERR(path))
+ return path;
+ /*
+ * shouldn't get a 0 allocated when splitting an extent unless
+ * m_len is 0 (bug) or extent has been corrupted
+ */
+ if (unlikely(*allocated == 0)) {
+ EXT4_ERROR_INODE(inode,
+ "unexpected allocated == 0, m_len = %u",
+ map->m_len);
+ err = -EFSCORRUPTED;
+ goto errout;
+ }
+ map->m_flags |= EXT4_MAP_UNWRITTEN;
+ goto out;
+ }
+ /* IO end_io complete, convert the filled extent to written */
+ if (flags & EXT4_GET_BLOCKS_CONVERT) {
+ path = ext4_convert_unwritten_extents_endio(handle, inode,
+ map, path);
+ if (IS_ERR(path))
+ return path;
+ ext4_update_inode_fsync_trans(handle, inode, 1);
+ goto map_out;
+ }
+ /* buffered IO cases */
+ /*
+ * repeat fallocate creation request
+ * we already have an unwritten extent
+ */
+ if (flags & EXT4_GET_BLOCKS_UNWRIT_EXT) {
+ map->m_flags |= EXT4_MAP_UNWRITTEN;
+ goto map_out;
+ }
+
+ /* buffered READ or buffered write_begin() lookup */
+ if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
+ /*
+ * We have blocks reserved already. We
+ * return allocated blocks so that delalloc
+ * won't do block reservation for us. But
+ * the buffer head will be unmapped so that
+ * a read from the block returns 0s.
+ */
+ map->m_flags |= EXT4_MAP_UNWRITTEN;
+ goto out1;
+ }
+
+ /*
+ * Default case when (flags & EXT4_GET_BLOCKS_CREATE) == 1.
+ * For buffered writes, at writepage time, etc. Convert a
+ * discovered unwritten extent to written.
+ */
+ path = ext4_ext_convert_to_initialized(handle, inode, map, path,
+ flags, allocated);
+ if (IS_ERR(path))
+ return path;
+ ext4_update_inode_fsync_trans(handle, inode, 1);
+ /*
+ * shouldn't get a 0 allocated when converting an unwritten extent
+ * unless m_len is 0 (bug) or extent has been corrupted
+ */
+ if (unlikely(*allocated == 0)) {
+ EXT4_ERROR_INODE(inode, "unexpected allocated == 0, m_len = %u",
+ map->m_len);
+ err = -EFSCORRUPTED;
+ goto errout;
+ }
+
+out:
+ map->m_flags |= EXT4_MAP_NEW;
+map_out:
+ map->m_flags |= EXT4_MAP_MAPPED;
+out1:
+ map->m_pblk = newblock;
+ if (*allocated > map->m_len)
+ *allocated = map->m_len;
+ map->m_len = *allocated;
+ ext4_ext_show_leaf(inode, path);
+ return path;
+
+errout:
+ ext4_free_ext_path(path);
+ return ERR_PTR(err);
+}
+
+/*
+ * get_implied_cluster_alloc - check to see if the requested
+ * allocation (in the map structure) overlaps with a cluster already
+ * allocated in an extent.
+ * @sb The filesystem superblock structure
+ * @map The requested lblk->pblk mapping
+ * @ex The extent structure which might contain an implied
+ * cluster allocation
+ *
+ * This function is called by ext4_ext_map_blocks() after we failed to
+ * find blocks that were already in the inode's extent tree. Hence,
+ * we know that the beginning of the requested region cannot overlap
+ * the extent from the inode's extent tree. There are three cases we
+ * want to catch. The first is this case:
+ *
+ * |--- cluster # N--|
+ * |--- extent ---| |---- requested region ---|
+ * |==========|
+ *
+ * The second case that we need to test for is this one:
+ *
+ * |--------- cluster # N ----------------|
+ * |--- requested region --| |------- extent ----|
+ * |=======================|
+ *
+ * The third case is when the requested region lies between two extents
+ * within the same cluster:
+ * |------------- cluster # N-------------|
+ * |----- ex -----| |---- ex_right ----|
+ * |------ requested region ------|
+ * |================|
+ *
+ * In each of the above cases, we need to set the map->m_pblk and
+ * map->m_len so it corresponds to the return the extent labelled as
+ * "|====|" from cluster #N, since it is already in use for data in
+ * cluster EXT4_B2C(sbi, map->m_lblk). We will then return 1 to
+ * signal to ext4_ext_map_blocks() that map->m_pblk should be treated
+ * as a new "allocated" block region. Otherwise, we will return 0 and
+ * ext4_ext_map_blocks() will then allocate one or more new clusters
+ * by calling ext4_mb_new_blocks().
+ */
+static int get_implied_cluster_alloc(struct super_block *sb,
+ struct ext4_map_blocks *map,
+ struct ext4_extent *ex,
+ struct ext4_ext_path *path)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ ext4_lblk_t c_offset = EXT4_LBLK_COFF(sbi, map->m_lblk);
+ ext4_lblk_t ex_cluster_start, ex_cluster_end;
+ ext4_lblk_t rr_cluster_start;
+ ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block);
+ ext4_fsblk_t ee_start = ext4_ext_pblock(ex);
+ unsigned short ee_len = ext4_ext_get_actual_len(ex);
+
+ /* The extent passed in that we are trying to match */
+ ex_cluster_start = EXT4_B2C(sbi, ee_block);
+ ex_cluster_end = EXT4_B2C(sbi, ee_block + ee_len - 1);
+
+ /* The requested region passed into ext4_map_blocks() */
+ rr_cluster_start = EXT4_B2C(sbi, map->m_lblk);
+
+ if ((rr_cluster_start == ex_cluster_end) ||
+ (rr_cluster_start == ex_cluster_start)) {
+ if (rr_cluster_start == ex_cluster_end)
+ ee_start += ee_len - 1;
+ map->m_pblk = EXT4_PBLK_CMASK(sbi, ee_start) + c_offset;
+ map->m_len = min(map->m_len,
+ (unsigned) sbi->s_cluster_ratio - c_offset);
+ /*
+ * Check for and handle this case:
+ *
+ * |--------- cluster # N-------------|
+ * |------- extent ----|
+ * |--- requested region ---|
+ * |===========|
+ */
+
+ if (map->m_lblk < ee_block)
+ map->m_len = min(map->m_len, ee_block - map->m_lblk);
+
+ /*
+ * Check for the case where there is already another allocated
+ * block to the right of 'ex' but before the end of the cluster.
+ *
+ * |------------- cluster # N-------------|
+ * |----- ex -----| |---- ex_right ----|
+ * |------ requested region ------|
+ * |================|
+ */
+ if (map->m_lblk > ee_block) {
+ ext4_lblk_t next = ext4_ext_next_allocated_block(path);
+ map->m_len = min(map->m_len, next - map->m_lblk);
+ }
+
+ trace_ext4_get_implied_cluster_alloc_exit(sb, map, 1);
+ return 1;
+ }
+
+ trace_ext4_get_implied_cluster_alloc_exit(sb, map, 0);
+ return 0;
+}
+
+/*
+ * Determine hole length around the given logical block, first try to
+ * locate and expand the hole from the given @path, and then adjust it
+ * if it's partially or completely converted to delayed extents, insert
+ * it into the extent cache tree if it's indeed a hole, finally return
+ * the length of the determined extent.
+ */
+static ext4_lblk_t ext4_ext_determine_insert_hole(struct inode *inode,
+ struct ext4_ext_path *path,
+ ext4_lblk_t lblk)
+{
+ ext4_lblk_t hole_start, len;
+ struct extent_status es;
+
+ hole_start = lblk;
+ len = ext4_ext_find_hole(inode, path, &hole_start);
+again:
+ ext4_es_find_extent_range(inode, &ext4_es_is_delayed, hole_start,
+ hole_start + len - 1, &es);
+ if (!es.es_len)
+ goto insert_hole;
+
+ /*
+ * There's a delalloc extent in the hole, handle it if the delalloc
+ * extent is in front of, behind and straddle the queried range.
+ */
+ if (lblk >= es.es_lblk + es.es_len) {
+ /*
+ * The delalloc extent is in front of the queried range,
+ * find again from the queried start block.
+ */
+ len -= lblk - hole_start;
+ hole_start = lblk;
+ goto again;
+ } else if (in_range(lblk, es.es_lblk, es.es_len)) {
+ /*
+ * The delalloc extent containing lblk, it must have been
+ * added after ext4_map_blocks() checked the extent status
+ * tree so we are not holding i_rwsem and delalloc info is
+ * only stabilized by i_data_sem we are going to release
+ * soon. Don't modify the extent status tree and report
+ * extent as a hole, just adjust the length to the delalloc
+ * extent's after lblk.
+ */
+ len = es.es_lblk + es.es_len - lblk;
+ return len;
+ } else {
+ /*
+ * The delalloc extent is partially or completely behind
+ * the queried range, update hole length until the
+ * beginning of the delalloc extent.
+ */
+ len = min(es.es_lblk - hole_start, len);
+ }
+
+insert_hole:
+ /* Put just found gap into cache to speed up subsequent requests */
+ ext_debug(inode, " -> %u:%u\n", hole_start, len);
+ ext4_es_insert_extent(inode, hole_start, len, ~0,
+ EXTENT_STATUS_HOLE, false);
+
+ /* Update hole_len to reflect hole size after lblk */
+ if (hole_start != lblk)
+ len -= lblk - hole_start;
+
+ return len;
+}
+
+/*
+ * Block allocation/map/preallocation routine for extents based files
+ *
+ *
+ * Need to be called with
+ * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system block
+ * (ie, flags is zero). Otherwise down_write(&EXT4_I(inode)->i_data_sem)
+ *
+ * return > 0, number of blocks already mapped/allocated
+ * if flags doesn't contain EXT4_GET_BLOCKS_CREATE and these are pre-allocated blocks
+ * buffer head is unmapped
+ * otherwise blocks are mapped
+ *
+ * return = 0, if plain look up failed (blocks have not been allocated)
+ * buffer head is unmapped
+ *
+ * return < 0, error case.
+ */
+int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
+ struct ext4_map_blocks *map, int flags)
+{
+ struct ext4_ext_path *path = NULL;
+ struct ext4_extent newex, *ex, ex2;
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+ ext4_fsblk_t newblock = 0, pblk;
+ int err = 0, depth;
+ unsigned int allocated = 0, offset = 0;
+ unsigned int allocated_clusters = 0;
+ struct ext4_allocation_request ar;
+ ext4_lblk_t cluster_offset;
+
+ ext_debug(inode, "blocks %u/%u requested\n", map->m_lblk, map->m_len);
+ trace_ext4_ext_map_blocks_enter(inode, map->m_lblk, map->m_len, flags);
+
+ /* find extent for this block */
+ path = ext4_find_extent(inode, map->m_lblk, NULL, flags);
+ if (IS_ERR(path)) {
+ err = PTR_ERR(path);
+ goto out;
+ }
+
+ depth = ext_depth(inode);
+
+ /*
+ * consistent leaf must not be empty;
+ * this situation is possible, though, _during_ tree modification;
+ * this is why assert can't be put in ext4_find_extent()
+ */
+ if (unlikely(path[depth].p_ext == NULL && depth != 0)) {
+ EXT4_ERROR_INODE(inode, "bad extent address "
+ "lblock: %lu, depth: %d pblock %lld",
+ (unsigned long) map->m_lblk, depth,
+ path[depth].p_block);
+ err = -EFSCORRUPTED;
+ goto out;
+ }
+
+ ex = path[depth].p_ext;
+ if (ex) {
+ ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block);
+ ext4_fsblk_t ee_start = ext4_ext_pblock(ex);
+ unsigned short ee_len;
+
+
+ /*
+ * unwritten extents are treated as holes, except that
+ * we split out initialized portions during a write.
+ */
+ ee_len = ext4_ext_get_actual_len(ex);
+
+ trace_ext4_ext_show_extent(inode, ee_block, ee_start, ee_len);
+
+ /* if found extent covers block, simply return it */
+ if (in_range(map->m_lblk, ee_block, ee_len)) {
+ newblock = map->m_lblk - ee_block + ee_start;
+ /* number of remaining blocks in the extent */
+ allocated = ee_len - (map->m_lblk - ee_block);
+ ext_debug(inode, "%u fit into %u:%d -> %llu\n",
+ map->m_lblk, ee_block, ee_len, newblock);
+
+ /*
+ * If the extent is initialized check whether the
+ * caller wants to convert it to unwritten.
+ */
+ if ((!ext4_ext_is_unwritten(ex)) &&
+ (flags & EXT4_GET_BLOCKS_CONVERT_UNWRITTEN)) {
+ path = convert_initialized_extent(handle,
+ inode, map, path, &allocated);
+ if (IS_ERR(path))
+ err = PTR_ERR(path);
+ goto out;
+ } else if (!ext4_ext_is_unwritten(ex)) {
+ map->m_flags |= EXT4_MAP_MAPPED;
+ map->m_pblk = newblock;
+ if (allocated > map->m_len)
+ allocated = map->m_len;
+ map->m_len = allocated;
+ ext4_ext_show_leaf(inode, path);
+ goto out;
+ }
+
+ path = ext4_ext_handle_unwritten_extents(
+ handle, inode, map, path, flags,
+ &allocated, newblock);
+ if (IS_ERR(path))
+ err = PTR_ERR(path);
+ goto out;
+ }
+ }
+
+ /*
+ * requested block isn't allocated yet;
+ * we couldn't try to create block if flags doesn't contain EXT4_GET_BLOCKS_CREATE
+ */
+ if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
+ ext4_lblk_t len;
+
+ len = ext4_ext_determine_insert_hole(inode, path, map->m_lblk);
+
+ map->m_pblk = 0;
+ map->m_len = min_t(unsigned int, map->m_len, len);
+ goto out;
+ }
+
+ /*
+ * Okay, we need to do block allocation.
+ */
+ newex.ee_block = cpu_to_le32(map->m_lblk);
+ cluster_offset = EXT4_LBLK_COFF(sbi, map->m_lblk);
+
+ /*
+ * If we are doing bigalloc, check to see if the extent returned
+ * by ext4_find_extent() implies a cluster we can use.
+ */
+ if (cluster_offset && ex &&
+ get_implied_cluster_alloc(inode->i_sb, map, ex, path)) {
+ ar.len = allocated = map->m_len;
+ newblock = map->m_pblk;
+ goto got_allocated_blocks;
+ }
+
+ /* find neighbour allocated blocks */
+ ar.lleft = map->m_lblk;
+ err = ext4_ext_search_left(inode, path, &ar.lleft, &ar.pleft);
+ if (err)
+ goto out;
+ ar.lright = map->m_lblk;
+ err = ext4_ext_search_right(inode, path, &ar.lright, &ar.pright,
+ &ex2, flags);
+ if (err < 0)
+ goto out;
+
+ /* Check if the extent after searching to the right implies a
+ * cluster we can use. */
+ if ((sbi->s_cluster_ratio > 1) && err &&
+ get_implied_cluster_alloc(inode->i_sb, map, &ex2, path)) {
+ ar.len = allocated = map->m_len;
+ newblock = map->m_pblk;
+ err = 0;
+ goto got_allocated_blocks;
+ }
+
+ /*
+ * See if request is beyond maximum number of blocks we can have in
+ * a single extent. For an initialized extent this limit is
+ * EXT_INIT_MAX_LEN and for an unwritten extent this limit is
+ * EXT_UNWRITTEN_MAX_LEN.
+ */
+ if (map->m_len > EXT_INIT_MAX_LEN &&
+ !(flags & EXT4_GET_BLOCKS_UNWRIT_EXT))
+ map->m_len = EXT_INIT_MAX_LEN;
+ else if (map->m_len > EXT_UNWRITTEN_MAX_LEN &&
+ (flags & EXT4_GET_BLOCKS_UNWRIT_EXT))
+ map->m_len = EXT_UNWRITTEN_MAX_LEN;
+
+ /* Check if we can really insert (m_lblk)::(m_lblk + m_len) extent */
+ newex.ee_len = cpu_to_le16(map->m_len);
+ err = ext4_ext_check_overlap(sbi, inode, &newex, path);
+ if (err)
+ allocated = ext4_ext_get_actual_len(&newex);
+ else
+ allocated = map->m_len;
+
+ /* allocate new block */
+ ar.inode = inode;
+ ar.goal = ext4_ext_find_goal(inode, path, map->m_lblk);
+ ar.logical = map->m_lblk;
+ /*
+ * We calculate the offset from the beginning of the cluster
+ * for the logical block number, since when we allocate a
+ * physical cluster, the physical block should start at the
+ * same offset from the beginning of the cluster. This is
+ * needed so that future calls to get_implied_cluster_alloc()
+ * work correctly.
+ */
+ offset = EXT4_LBLK_COFF(sbi, map->m_lblk);
+ ar.len = EXT4_NUM_B2C(sbi, offset+allocated);
+ ar.goal -= offset;
+ ar.logical -= offset;
+ if (S_ISREG(inode->i_mode))
+ ar.flags = EXT4_MB_HINT_DATA;
+ else
+ /* disable in-core preallocation for non-regular files */
+ ar.flags = 0;
+ if (flags & EXT4_GET_BLOCKS_NO_NORMALIZE)
+ ar.flags |= EXT4_MB_HINT_NOPREALLOC;
+ if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
+ ar.flags |= EXT4_MB_DELALLOC_RESERVED;
+ if (flags & EXT4_GET_BLOCKS_METADATA_NOFAIL)
+ ar.flags |= EXT4_MB_USE_RESERVED;
+ newblock = ext4_mb_new_blocks(handle, &ar, &err);
+ if (!newblock)
+ goto out;
+ allocated_clusters = ar.len;
+ ar.len = EXT4_C2B(sbi, ar.len) - offset;
+ ext_debug(inode, "allocate new block: goal %llu, found %llu/%u, requested %u\n",
+ ar.goal, newblock, ar.len, allocated);
+ if (ar.len > allocated)
+ ar.len = allocated;
+
+got_allocated_blocks:
+ /* try to insert new extent into found leaf and return */
+ pblk = newblock + offset;
+ ext4_ext_store_pblock(&newex, pblk);
+ newex.ee_len = cpu_to_le16(ar.len);
+ /* Mark unwritten */
+ if (flags & EXT4_GET_BLOCKS_UNWRIT_EXT) {
+ ext4_ext_mark_unwritten(&newex);
+ map->m_flags |= EXT4_MAP_UNWRITTEN;
+ }
+
+ path = ext4_ext_insert_extent(handle, inode, path, &newex, flags);
+ if (IS_ERR(path)) {
+ err = PTR_ERR(path);
+ if (allocated_clusters) {
+ int fb_flags = 0;
+
+ /*
+ * free data blocks we just allocated.
+ * not a good idea to call discard here directly,
+ * but otherwise we'd need to call it every free().
+ */
+ ext4_discard_preallocations(inode);
+ if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
+ fb_flags = EXT4_FREE_BLOCKS_NO_QUOT_UPDATE;
+ ext4_free_blocks(handle, inode, NULL, newblock,
+ EXT4_C2B(sbi, allocated_clusters),
+ fb_flags);
+ }
+ goto out;
+ }
+
+ /*
+ * Cache the extent and update transaction to commit on fdatasync only
+ * when it is _not_ an unwritten extent.
+ */
+ if ((flags & EXT4_GET_BLOCKS_UNWRIT_EXT) == 0)
+ ext4_update_inode_fsync_trans(handle, inode, 1);
+ else
+ ext4_update_inode_fsync_trans(handle, inode, 0);
+
+ map->m_flags |= (EXT4_MAP_NEW | EXT4_MAP_MAPPED);
+ map->m_pblk = pblk;
+ map->m_len = ar.len;
+ allocated = map->m_len;
+ ext4_ext_show_leaf(inode, path);
+out:
+ /*
+ * We never use EXT4_GET_BLOCKS_QUERY_LAST_IN_LEAF with CREATE flag.
+ * So we know that the depth used here is correct, since there was no
+ * block allocation done if EXT4_GET_BLOCKS_QUERY_LAST_IN_LEAF is set.
+ * If tomorrow we start using this QUERY flag with CREATE, then we will
+ * need to re-calculate the depth as it might have changed due to block
+ * allocation.
+ */
+ if (flags & EXT4_GET_BLOCKS_QUERY_LAST_IN_LEAF) {
+ WARN_ON_ONCE(flags & EXT4_GET_BLOCKS_CREATE);
+ if (!err && ex && (ex == EXT_LAST_EXTENT(path[depth].p_hdr)))
+ map->m_flags |= EXT4_MAP_QUERY_LAST_IN_LEAF;
+ }
+
+ ext4_free_ext_path(path);
+
+ trace_ext4_ext_map_blocks_exit(inode, flags, map,
+ err ? err : allocated);
+ return err ? err : allocated;
+}
+
+int ext4_ext_truncate(handle_t *handle, struct inode *inode)
+{
+ struct super_block *sb = inode->i_sb;
+ ext4_lblk_t last_block;
+ int err = 0;
+
+ /*
+ * TODO: optimization is possible here.
+ * Probably we need not scan at all,
+ * because page truncation is enough.
+ */
+
+ /* we have to know where to truncate from in crash case */
+ EXT4_I(inode)->i_disksize = inode->i_size;
+ err = ext4_mark_inode_dirty(handle, inode);
+ if (err)
+ return err;
+
+ last_block = (inode->i_size + sb->s_blocksize - 1)
+ >> EXT4_BLOCK_SIZE_BITS(sb);
+ ext4_es_remove_extent(inode, last_block, EXT_MAX_BLOCKS - last_block);
+
+retry_remove_space:
+ err = ext4_ext_remove_space(inode, last_block, EXT_MAX_BLOCKS - 1);
+ if (err == -ENOMEM) {
+ memalloc_retry_wait(GFP_ATOMIC);
+ goto retry_remove_space;
+ }
+ return err;
+}
+
+static int ext4_alloc_file_blocks(struct file *file, ext4_lblk_t offset,
+ ext4_lblk_t len, loff_t new_size,
+ int flags)
+{
+ struct inode *inode = file_inode(file);
+ handle_t *handle;
+ int ret = 0, ret2 = 0, ret3 = 0;
+ int retries = 0;
+ int depth = 0;
+ struct ext4_map_blocks map;
+ unsigned int credits;
+ loff_t epos, old_size = i_size_read(inode);
+ unsigned int blkbits = inode->i_blkbits;
+ bool alloc_zero = false;
+
+ BUG_ON(!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS));
+ map.m_lblk = offset;
+ map.m_len = len;
+ /*
+ * Don't normalize the request if it can fit in one extent so
+ * that it doesn't get unnecessarily split into multiple
+ * extents.
+ */
+ if (len <= EXT_UNWRITTEN_MAX_LEN)
+ flags |= EXT4_GET_BLOCKS_NO_NORMALIZE;
+
+ /*
+ * Do the actual write zero during a running journal transaction
+ * costs a lot. First allocate an unwritten extent and then
+ * convert it to written after zeroing it out.
+ */
+ if (flags & EXT4_GET_BLOCKS_ZERO) {
+ flags &= ~EXT4_GET_BLOCKS_ZERO;
+ flags |= EXT4_GET_BLOCKS_UNWRIT_EXT;
+ alloc_zero = true;
+ }
+
+ /*
+ * credits to insert 1 extent into extent tree
+ */
+ credits = ext4_chunk_trans_blocks(inode, len);
+ depth = ext_depth(inode);
+
+retry:
+ while (len) {
+ /*
+ * Recalculate credits when extent tree depth changes.
+ */
+ if (depth != ext_depth(inode)) {
+ credits = ext4_chunk_trans_blocks(inode, len);
+ depth = ext_depth(inode);
+ }
+
+ handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS,
+ credits);
+ if (IS_ERR(handle)) {
+ ret = PTR_ERR(handle);
+ break;
+ }
+ ret = ext4_map_blocks(handle, inode, &map, flags);
+ if (ret <= 0) {
+ ext4_debug("inode #%lu: block %u: len %u: "
+ "ext4_ext_map_blocks returned %d",
+ inode->i_ino, map.m_lblk,
+ map.m_len, ret);
+ ext4_mark_inode_dirty(handle, inode);
+ ext4_journal_stop(handle);
+ break;
+ }
+ /*
+ * allow a full retry cycle for any remaining allocations
+ */
+ retries = 0;
+ epos = (loff_t)(map.m_lblk + ret) << blkbits;
+ inode_set_ctime_current(inode);
+ if (new_size) {
+ if (epos > new_size)
+ epos = new_size;
+ if (ext4_update_inode_size(inode, epos) & 0x1)
+ inode_set_mtime_to_ts(inode,
+ inode_get_ctime(inode));
+ if (epos > old_size) {
+ pagecache_isize_extended(inode, old_size, epos);
+ ext4_zero_partial_blocks(handle, inode,
+ old_size, epos - old_size);
+ }
+ }
+ ret2 = ext4_mark_inode_dirty(handle, inode);
+ ext4_update_inode_fsync_trans(handle, inode, 1);
+ ret3 = ext4_journal_stop(handle);
+ ret2 = ret3 ? ret3 : ret2;
+ if (unlikely(ret2))
+ break;
+
+ if (alloc_zero &&
+ (map.m_flags & (EXT4_MAP_MAPPED | EXT4_MAP_UNWRITTEN))) {
+ ret2 = ext4_issue_zeroout(inode, map.m_lblk, map.m_pblk,
+ map.m_len);
+ if (likely(!ret2))
+ ret2 = ext4_convert_unwritten_extents(NULL,
+ inode, (loff_t)map.m_lblk << blkbits,
+ (loff_t)map.m_len << blkbits);
+ if (ret2)
+ break;
+ }
+
+ map.m_lblk += ret;
+ map.m_len = len = len - ret;
+ }
+ if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
+ goto retry;
+
+ return ret > 0 ? ret2 : ret;
+}
+
+static int ext4_collapse_range(struct file *file, loff_t offset, loff_t len);
+
+static int ext4_insert_range(struct file *file, loff_t offset, loff_t len);
+
+static long ext4_zero_range(struct file *file, loff_t offset,
+ loff_t len, int mode)
+{
+ struct inode *inode = file_inode(file);
+ handle_t *handle = NULL;
+ loff_t new_size = 0;
+ loff_t end = offset + len;
+ ext4_lblk_t start_lblk, end_lblk;
+ unsigned int blocksize = i_blocksize(inode);
+ unsigned int blkbits = inode->i_blkbits;
+ int ret, flags, credits;
+
+ trace_ext4_zero_range(inode, offset, len, mode);
+ WARN_ON_ONCE(!inode_is_locked(inode));
+
+ /* Indirect files do not support unwritten extents */
+ if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
+ return -EOPNOTSUPP;
+
+ if (!(mode & FALLOC_FL_KEEP_SIZE) &&
+ (end > inode->i_size || end > EXT4_I(inode)->i_disksize)) {
+ new_size = end;
+ ret = inode_newsize_ok(inode, new_size);
+ if (ret)
+ return ret;
+ }
+
+ flags = EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT;
+ /* Preallocate the range including the unaligned edges */
+ if (!IS_ALIGNED(offset | end, blocksize)) {
+ ext4_lblk_t alloc_lblk = offset >> blkbits;
+ ext4_lblk_t len_lblk = EXT4_MAX_BLOCKS(len, offset, blkbits);
+
+ ret = ext4_alloc_file_blocks(file, alloc_lblk, len_lblk,
+ new_size, flags);
+ if (ret)
+ return ret;
+ }
+
+ ret = ext4_update_disksize_before_punch(inode, offset, len);
+ 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;
+
+ /* Zero range excluding the unaligned edges */
+ start_lblk = EXT4_B_TO_LBLK(inode, offset);
+ end_lblk = end >> blkbits;
+ if (end_lblk > start_lblk) {
+ ext4_lblk_t zero_blks = end_lblk - start_lblk;
+
+ if (mode & FALLOC_FL_WRITE_ZEROES)
+ flags = EXT4_GET_BLOCKS_CREATE_ZERO | EXT4_EX_NOCACHE;
+ else
+ flags |= (EXT4_GET_BLOCKS_CONVERT_UNWRITTEN |
+ EXT4_EX_NOCACHE);
+ ret = ext4_alloc_file_blocks(file, start_lblk, zero_blks,
+ new_size, flags);
+ if (ret)
+ return ret;
+ }
+ /* Finish zeroing out if it doesn't contain partial block */
+ if (IS_ALIGNED(offset | end, blocksize))
+ return ret;
+
+ /*
+ * In worst case we have to writeout two nonadjacent unwritten
+ * blocks and update the inode
+ */
+ credits = (2 * ext4_ext_index_trans_blocks(inode, 2)) + 1;
+ if (ext4_should_journal_data(inode))
+ credits += 2;
+ handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
+ if (IS_ERR(handle)) {
+ ret = PTR_ERR(handle);
+ ext4_std_error(inode->i_sb, ret);
+ return ret;
+ }
+
+ /* Zero out partial block at the edges of the range */
+ ret = ext4_zero_partial_blocks(handle, inode, offset, len);
+ if (ret)
+ goto out_handle;
+
+ if (new_size)
+ ext4_update_inode_size(inode, new_size);
+ ret = ext4_mark_inode_dirty(handle, inode);
+ if (unlikely(ret))
+ goto out_handle;
+
+ ext4_update_inode_fsync_trans(handle, inode, 1);
+ if (file->f_flags & O_SYNC)
+ ext4_handle_sync(handle);
+
+out_handle:
+ ext4_journal_stop(handle);
+ return ret;
+}
+
+static long ext4_do_fallocate(struct file *file, loff_t offset,
+ loff_t len, int mode)
+{
+ struct inode *inode = file_inode(file);
+ loff_t end = offset + len;
+ loff_t new_size = 0;
+ ext4_lblk_t start_lblk, len_lblk;
+ int ret;
+
+ trace_ext4_fallocate_enter(inode, offset, len, mode);
+ WARN_ON_ONCE(!inode_is_locked(inode));
+
+ start_lblk = offset >> inode->i_blkbits;
+ len_lblk = EXT4_MAX_BLOCKS(len, offset, inode->i_blkbits);
+
+ /* We only support preallocation for extent-based files only. */
+ if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
+ ret = -EOPNOTSUPP;
+ goto out;
+ }
+
+ if (!(mode & FALLOC_FL_KEEP_SIZE) &&
+ (end > inode->i_size || end > EXT4_I(inode)->i_disksize)) {
+ new_size = end;
+ ret = inode_newsize_ok(inode, new_size);
+ if (ret)
+ goto out;
+ }
+
+ ret = ext4_alloc_file_blocks(file, start_lblk, len_lblk, new_size,
+ EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT);
+ if (ret)
+ goto out;
+
+ if (file->f_flags & O_SYNC && EXT4_SB(inode->i_sb)->s_journal) {
+ ret = ext4_fc_commit(EXT4_SB(inode->i_sb)->s_journal,
+ EXT4_I(inode)->i_sync_tid);
+ }
+out:
+ trace_ext4_fallocate_exit(inode, offset, len_lblk, ret);
+ return ret;
+}
+
+/*
+ * preallocate space for a file. This implements ext4's fallocate file
+ * operation, which gets called from sys_fallocate system call.
+ * For block-mapped files, posix_fallocate should fall back to the method
+ * of writing zeroes to the required new blocks (the same behavior which is
+ * expected for file systems which do not support fallocate() system call).
+ */
+long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
+{
+ struct inode *inode = file_inode(file);
+ struct address_space *mapping = file->f_mapping;
+ int ret;
+
+ /*
+ * Encrypted inodes can't handle collapse range or insert
+ * range since we would need to re-encrypt blocks with a
+ * different IV or XTS tweak (which are based on the logical
+ * block number).
+ */
+ if (IS_ENCRYPTED(inode) &&
+ (mode & (FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_INSERT_RANGE)))
+ return -EOPNOTSUPP;
+ /*
+ * Don't allow writing zeroes if the underlying device does not
+ * enable the unmap write zeroes operation.
+ */
+ if ((mode & FALLOC_FL_WRITE_ZEROES) &&
+ !bdev_write_zeroes_unmap_sectors(inode->i_sb->s_bdev))
+ return -EOPNOTSUPP;
+
+ /* Return error if mode is not supported */
+ if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE |
+ FALLOC_FL_ZERO_RANGE | FALLOC_FL_COLLAPSE_RANGE |
+ FALLOC_FL_INSERT_RANGE | FALLOC_FL_WRITE_ZEROES))
+ return -EOPNOTSUPP;
+
+ inode_lock(inode);
+ ret = ext4_convert_inline_data(inode);
+ if (ret)
+ goto out_inode_lock;
+
+ /* Wait all existing dio workers, newcomers will block on i_rwsem */
+ inode_dio_wait(inode);
+
+ ret = file_modified(file);
+ if (ret)
+ goto out_inode_lock;
+
+ if ((mode & FALLOC_FL_MODE_MASK) == FALLOC_FL_ALLOCATE_RANGE) {
+ ret = ext4_do_fallocate(file, offset, len, mode);
+ goto out_inode_lock;
+ }
+
+ /*
+ * Follow-up operations will drop page cache, hold invalidate lock
+ * to prevent page faults from reinstantiating pages we have
+ * released from page cache.
+ */
+ filemap_invalidate_lock(mapping);
+
+ ret = ext4_break_layouts(inode);
+ if (ret)
+ goto out_invalidate_lock;
+
+ switch (mode & FALLOC_FL_MODE_MASK) {
+ case FALLOC_FL_PUNCH_HOLE:
+ ret = ext4_punch_hole(file, offset, len);
+ break;
+ case FALLOC_FL_COLLAPSE_RANGE:
+ ret = ext4_collapse_range(file, offset, len);
+ break;
+ case FALLOC_FL_INSERT_RANGE:
+ ret = ext4_insert_range(file, offset, len);
+ break;
+ case FALLOC_FL_ZERO_RANGE:
+ case FALLOC_FL_WRITE_ZEROES:
+ ret = ext4_zero_range(file, offset, len, mode);
+ break;
+ default:
+ ret = -EOPNOTSUPP;
+ }
+
+out_invalidate_lock:
+ filemap_invalidate_unlock(mapping);
+out_inode_lock:
+ inode_unlock(inode);
+ return ret;
+}
+
+/*
+ * This function converts a range of blocks to written extents. The caller of
+ * this function will pass the start offset and the size. all unwritten extents
+ * within this range will be converted to written extents.
+ *
+ * This function is called from the direct IO end io call back function for
+ * atomic writes, to convert the unwritten extents after IO is completed.
+ *
+ * Note that the requirement for atomic writes is that all conversion should
+ * happen atomically in a single fs journal transaction. We mainly only allocate
+ * unwritten extents either on a hole on a pre-exiting unwritten extent range in
+ * ext4_map_blocks_atomic_write(). The only case where we can have multiple
+ * unwritten extents in a range [offset, offset+len) is when there is a split
+ * unwritten extent between two leaf nodes which was cached in extent status
+ * cache during ext4_iomap_alloc() time. That will allow
+ * ext4_map_blocks_atomic_write() to return the unwritten extent range w/o going
+ * into the slow path. That means we might need a loop for conversion of this
+ * unwritten extent split across leaf block within a single journal transaction.
+ * Split extents across leaf nodes is a rare case, but let's still handle that
+ * to meet the requirements of multi-fsblock atomic writes.
+ *
+ * Returns 0 on success.
+ */
+int ext4_convert_unwritten_extents_atomic(handle_t *handle, struct inode *inode,
+ loff_t offset, ssize_t len)
+{
+ unsigned int max_blocks;
+ int ret = 0, ret2 = 0, ret3 = 0;
+ struct ext4_map_blocks map;
+ unsigned int blkbits = inode->i_blkbits;
+ unsigned int credits = 0;
+ int flags = EXT4_GET_BLOCKS_IO_CONVERT_EXT | EXT4_EX_NOCACHE;
+
+ map.m_lblk = offset >> blkbits;
+ max_blocks = EXT4_MAX_BLOCKS(len, offset, blkbits);
+
+ if (!handle) {
+ /*
+ * TODO: An optimization can be added later by having an extent
+ * status flag e.g. EXTENT_STATUS_SPLIT_LEAF. If we query that
+ * it can tell if the extent in the cache is a split extent.
+ * But for now let's assume pextents as 2 always.
+ */
+ credits = ext4_meta_trans_blocks(inode, max_blocks, 2);
+ }
+
+ if (credits) {
+ handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS, credits);
+ if (IS_ERR(handle)) {
+ ret = PTR_ERR(handle);
+ return ret;
+ }
+ }
+
+ while (ret >= 0 && ret < max_blocks) {
+ map.m_lblk += ret;
+ map.m_len = (max_blocks -= ret);
+ ret = ext4_map_blocks(handle, inode, &map, flags);
+ if (ret != max_blocks)
+ ext4_msg(inode->i_sb, KERN_INFO,
+ "inode #%lu: block %u: len %u: "
+ "split block mapping found for atomic write, "
+ "ret = %d",
+ inode->i_ino, map.m_lblk,
+ map.m_len, ret);
+ if (ret <= 0)
+ break;
+ }
+
+ ret2 = ext4_mark_inode_dirty(handle, inode);
+
+ if (credits) {
+ ret3 = ext4_journal_stop(handle);
+ if (unlikely(ret3))
+ ret2 = ret3;
+ }
+
+ if (ret <= 0 || ret2)
+ ext4_warning(inode->i_sb,
+ "inode #%lu: block %u: len %u: "
+ "returned %d or %d",
+ inode->i_ino, map.m_lblk,
+ map.m_len, ret, ret2);
+
+ return ret > 0 ? ret2 : ret;
+}
+
+/*
+ * This function convert a range of blocks to written extents
+ * The caller of this function will pass the start offset and the size.
+ * all unwritten extents within this range will be converted to
+ * written extents.
+ *
+ * This function is called from the direct IO end io call back
+ * function, to convert the fallocated extents after IO is completed.
+ * Returns 0 on success.
+ */
+int ext4_convert_unwritten_extents(handle_t *handle, struct inode *inode,
+ loff_t offset, ssize_t len)
+{
+ unsigned int max_blocks;
+ int ret = 0, ret2 = 0, ret3 = 0;
+ struct ext4_map_blocks map;
+ unsigned int blkbits = inode->i_blkbits;
+ unsigned int credits = 0;
+
+ map.m_lblk = offset >> blkbits;
+ max_blocks = EXT4_MAX_BLOCKS(len, offset, blkbits);
+
+ if (!handle) {
+ /*
+ * credits to insert 1 extent into extent tree
+ */
+ credits = ext4_chunk_trans_blocks(inode, max_blocks);
+ }
+ while (ret >= 0 && ret < max_blocks) {
+ map.m_lblk += ret;
+ map.m_len = (max_blocks -= ret);
+ if (credits) {
+ handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS,
+ credits);
+ if (IS_ERR(handle)) {
+ ret = PTR_ERR(handle);
+ break;
+ }
+ }
+ /*
+ * Do not cache any unrelated extents, as it does not hold the
+ * i_rwsem or invalidate_lock, which could corrupt the extent
+ * status tree.
+ */
+ ret = ext4_map_blocks(handle, inode, &map,
+ EXT4_GET_BLOCKS_IO_CONVERT_EXT |
+ EXT4_EX_NOCACHE);
+ if (ret <= 0)
+ ext4_warning(inode->i_sb,
+ "inode #%lu: block %u: len %u: "
+ "ext4_ext_map_blocks returned %d",
+ inode->i_ino, map.m_lblk,
+ map.m_len, ret);
+ ret2 = ext4_mark_inode_dirty(handle, inode);
+ if (credits) {
+ ret3 = ext4_journal_stop(handle);
+ if (unlikely(ret3))
+ ret2 = ret3;
+ }
+
+ if (ret <= 0 || ret2)
+ break;
+ }
+ return ret > 0 ? ret2 : ret;
+}
+
+int ext4_convert_unwritten_io_end_vec(handle_t *handle, ext4_io_end_t *io_end)
+{
+ int ret = 0, err = 0;
+ struct ext4_io_end_vec *io_end_vec;
+
+ /*
+ * This is somewhat ugly but the idea is clear: When transaction is
+ * reserved, everything goes into it. Otherwise we rather start several
+ * smaller transactions for conversion of each extent separately.
+ */
+ if (handle) {
+ handle = ext4_journal_start_reserved(handle,
+ EXT4_HT_EXT_CONVERT);
+ if (IS_ERR(handle))
+ return PTR_ERR(handle);
+ }
+
+ list_for_each_entry(io_end_vec, &io_end->list_vec, list) {
+ ret = ext4_convert_unwritten_extents(handle, io_end->inode,
+ io_end_vec->offset,
+ io_end_vec->size);
+ if (ret)
+ break;
+ }
+
+ if (handle)
+ err = ext4_journal_stop(handle);
+
+ return ret < 0 ? ret : err;
+}
+
+static int ext4_iomap_xattr_fiemap(struct inode *inode, struct iomap *iomap)
+{
+ __u64 physical = 0;
+ __u64 length = 0;
+ int blockbits = inode->i_sb->s_blocksize_bits;
+ int error = 0;
+ u16 iomap_type;
+
+ /* in-inode? */
+ if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
+ struct ext4_iloc iloc;
+ int offset; /* offset of xattr in inode */
+
+ error = ext4_get_inode_loc(inode, &iloc);
+ if (error)
+ return error;
+ physical = (__u64)iloc.bh->b_blocknr << blockbits;
+ offset = EXT4_GOOD_OLD_INODE_SIZE +
+ EXT4_I(inode)->i_extra_isize;
+ physical += offset;
+ length = EXT4_SB(inode->i_sb)->s_inode_size - offset;
+ brelse(iloc.bh);
+ iomap_type = IOMAP_INLINE;
+ } else if (EXT4_I(inode)->i_file_acl) { /* external block */
+ physical = (__u64)EXT4_I(inode)->i_file_acl << blockbits;
+ length = inode->i_sb->s_blocksize;
+ iomap_type = IOMAP_MAPPED;
+ } else {
+ /* no in-inode or external block for xattr, so return -ENOENT */
+ error = -ENOENT;
+ goto out;
+ }
+
+ iomap->addr = physical;
+ iomap->offset = 0;
+ iomap->length = length;
+ iomap->type = iomap_type;
+ iomap->flags = 0;
+out:
+ return error;
+}
+
+static int ext4_iomap_xattr_begin(struct inode *inode, loff_t offset,
+ loff_t length, unsigned flags,
+ struct iomap *iomap, struct iomap *srcmap)
+{
+ int error;
+
+ error = ext4_iomap_xattr_fiemap(inode, iomap);
+ if (error == 0 && (offset >= iomap->length))
+ error = -ENOENT;
+ return error;
+}
+
+static const struct iomap_ops ext4_iomap_xattr_ops = {
+ .iomap_begin = ext4_iomap_xattr_begin,
+};
+
+static int ext4_fiemap_check_ranges(struct inode *inode, u64 start, u64 *len)
+{
+ u64 maxbytes = ext4_get_maxbytes(inode);
+
+ if (*len == 0)
+ return -EINVAL;
+ if (start > maxbytes)
+ return -EFBIG;
+
+ /*
+ * Shrink request scope to what the fs can actually handle.
+ */
+ if (*len > maxbytes || (maxbytes - *len) < start)
+ *len = maxbytes - start;
+ return 0;
+}
+
+int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
+ u64 start, u64 len)
+{
+ int error = 0;
+
+ inode_lock_shared(inode);
+ if (fieinfo->fi_flags & FIEMAP_FLAG_CACHE) {
+ error = ext4_ext_precache(inode);
+ if (error)
+ goto unlock;
+ fieinfo->fi_flags &= ~FIEMAP_FLAG_CACHE;
+ }
+
+ /*
+ * For bitmap files the maximum size limit could be smaller than
+ * s_maxbytes, so check len here manually instead of just relying on the
+ * generic check.
+ */
+ error = ext4_fiemap_check_ranges(inode, start, &len);
+ if (error)
+ goto unlock;
+
+ if (fieinfo->fi_flags & FIEMAP_FLAG_XATTR) {
+ fieinfo->fi_flags &= ~FIEMAP_FLAG_XATTR;
+ error = iomap_fiemap(inode, fieinfo, start, len,
+ &ext4_iomap_xattr_ops);
+ } else {
+ error = iomap_fiemap(inode, fieinfo, start, len,
+ &ext4_iomap_report_ops);
+ }
+unlock:
+ inode_unlock_shared(inode);
+ return error;
+}
+
+int ext4_get_es_cache(struct inode *inode, struct fiemap_extent_info *fieinfo,
+ __u64 start, __u64 len)
+{
+ ext4_lblk_t start_blk, len_blks;
+ __u64 last_blk;
+ int error = 0;
+
+ if (ext4_has_inline_data(inode)) {
+ int has_inline;
+
+ down_read(&EXT4_I(inode)->xattr_sem);
+ has_inline = ext4_has_inline_data(inode);
+ up_read(&EXT4_I(inode)->xattr_sem);
+ if (has_inline)
+ return 0;
+ }
+
+ if (fieinfo->fi_flags & FIEMAP_FLAG_CACHE) {
+ inode_lock_shared(inode);
+ error = ext4_ext_precache(inode);
+ inode_unlock_shared(inode);
+ if (error)
+ return error;
+ fieinfo->fi_flags &= ~FIEMAP_FLAG_CACHE;
+ }
+
+ error = fiemap_prep(inode, fieinfo, start, &len, 0);
+ if (error)
+ return error;
+
+ error = ext4_fiemap_check_ranges(inode, start, &len);
+ if (error)
+ return error;
+
+ start_blk = start >> inode->i_sb->s_blocksize_bits;
+ last_blk = (start + len - 1) >> inode->i_sb->s_blocksize_bits;
+ if (last_blk >= EXT_MAX_BLOCKS)
+ last_blk = EXT_MAX_BLOCKS-1;
+ len_blks = ((ext4_lblk_t) last_blk) - start_blk + 1;
+
+ /*
+ * Walk the extent tree gathering extent information
+ * and pushing extents back to the user.
+ */
+ return ext4_fill_es_cache_info(inode, start_blk, len_blks, fieinfo);
+}
+
+/*
+ * ext4_ext_shift_path_extents:
+ * Shift the extents of a path structure lying between path[depth].p_ext
+ * and EXT_LAST_EXTENT(path[depth].p_hdr), by @shift blocks. @SHIFT tells
+ * if it is right shift or left shift operation.
+ */
+static int
+ext4_ext_shift_path_extents(struct ext4_ext_path *path, ext4_lblk_t shift,
+ struct inode *inode, handle_t *handle,
+ enum SHIFT_DIRECTION SHIFT)
+{
+ int depth, err = 0;
+ struct ext4_extent *ex_start, *ex_last;
+ bool update = false;
+ int credits, restart_credits;
+ depth = path->p_depth;
+
+ while (depth >= 0) {
+ if (depth == path->p_depth) {
+ ex_start = path[depth].p_ext;
+ if (!ex_start)
+ return -EFSCORRUPTED;
+
+ ex_last = EXT_LAST_EXTENT(path[depth].p_hdr);
+ /* leaf + sb + inode */
+ credits = 3;
+ if (ex_start == EXT_FIRST_EXTENT(path[depth].p_hdr)) {
+ update = true;
+ /* extent tree + sb + inode */
+ credits = depth + 2;
+ }
+
+ restart_credits = ext4_chunk_trans_extent(inode, 0);
+ err = ext4_datasem_ensure_credits(handle, inode, credits,
+ restart_credits, 0);
+ if (err) {
+ if (err > 0)
+ err = -EAGAIN;
+ goto out;
+ }
+
+ err = ext4_ext_get_access(handle, inode, path + depth);
+ if (err)
+ goto out;
+
+ while (ex_start <= ex_last) {
+ if (SHIFT == SHIFT_LEFT) {
+ le32_add_cpu(&ex_start->ee_block,
+ -shift);
+ /* Try to merge to the left. */
+ if ((ex_start >
+ EXT_FIRST_EXTENT(path[depth].p_hdr))
+ &&
+ ext4_ext_try_to_merge_right(inode,
+ path, ex_start - 1))
+ ex_last--;
+ else
+ ex_start++;
+ } else {
+ le32_add_cpu(&ex_last->ee_block, shift);
+ ext4_ext_try_to_merge_right(inode, path,
+ ex_last);
+ ex_last--;
+ }
+ }
+ err = ext4_ext_dirty(handle, inode, path + depth);
+ if (err)
+ goto out;
+
+ if (--depth < 0 || !update)
+ break;
+ }
+
+ /* Update index too */
+ err = ext4_ext_get_access(handle, inode, path + depth);
+ if (err)
+ goto out;
+
+ if (SHIFT == SHIFT_LEFT)
+ le32_add_cpu(&path[depth].p_idx->ei_block, -shift);
+ else
+ le32_add_cpu(&path[depth].p_idx->ei_block, shift);
+ err = ext4_ext_dirty(handle, inode, path + depth);
+ if (err)
+ goto out;
+
+ /* we are done if current index is not a starting index */
+ if (path[depth].p_idx != EXT_FIRST_INDEX(path[depth].p_hdr))
+ break;
+
+ depth--;
+ }
+
+out:
+ return err;
+}
+
+/*
+ * ext4_ext_shift_extents:
+ * All the extents which lies in the range from @start to the last allocated
+ * block for the @inode are shifted either towards left or right (depending
+ * upon @SHIFT) by @shift blocks.
+ * On success, 0 is returned, error otherwise.
+ */
+static int
+ext4_ext_shift_extents(struct inode *inode, handle_t *handle,
+ ext4_lblk_t start, ext4_lblk_t shift,
+ enum SHIFT_DIRECTION SHIFT)
+{
+ struct ext4_ext_path *path;
+ int ret = 0, depth;
+ struct ext4_extent *extent;
+ ext4_lblk_t stop, *iterator, ex_start, ex_end;
+ ext4_lblk_t tmp = EXT_MAX_BLOCKS;
+
+ /* Let path point to the last extent */
+ path = ext4_find_extent(inode, EXT_MAX_BLOCKS - 1, NULL,
+ EXT4_EX_NOCACHE);
+ if (IS_ERR(path))
+ return PTR_ERR(path);
+
+ depth = path->p_depth;
+ extent = path[depth].p_ext;
+ if (!extent)
+ goto out;
+
+ stop = le32_to_cpu(extent->ee_block);
+
+ /*
+ * For left shifts, make sure the hole on the left is big enough to
+ * accommodate the shift. For right shifts, make sure the last extent
+ * won't be shifted beyond EXT_MAX_BLOCKS.
+ */
+ if (SHIFT == SHIFT_LEFT) {
+ path = ext4_find_extent(inode, start - 1, path,
+ EXT4_EX_NOCACHE);
+ if (IS_ERR(path))
+ return PTR_ERR(path);
+ depth = path->p_depth;
+ extent = path[depth].p_ext;
+ if (extent) {
+ ex_start = le32_to_cpu(extent->ee_block);
+ ex_end = le32_to_cpu(extent->ee_block) +
+ ext4_ext_get_actual_len(extent);
+ } else {
+ ex_start = 0;
+ ex_end = 0;
+ }
+
+ if ((start == ex_start && shift > ex_start) ||
+ (shift > start - ex_end)) {
+ ret = -EINVAL;
+ goto out;
+ }
+ } else {
+ if (shift > EXT_MAX_BLOCKS -
+ (stop + ext4_ext_get_actual_len(extent))) {
+ ret = -EINVAL;
+ goto out;
+ }
+ }
+
+ /*
+ * In case of left shift, iterator points to start and it is increased
+ * till we reach stop. In case of right shift, iterator points to stop
+ * and it is decreased till we reach start.
+ */
+again:
+ ret = 0;
+ if (SHIFT == SHIFT_LEFT)
+ iterator = &start;
+ else
+ iterator = &stop;
+
+ if (tmp != EXT_MAX_BLOCKS)
+ *iterator = tmp;
+
+ /*
+ * Its safe to start updating extents. Start and stop are unsigned, so
+ * in case of right shift if extent with 0 block is reached, iterator
+ * becomes NULL to indicate the end of the loop.
+ */
+ while (iterator && start <= stop) {
+ path = ext4_find_extent(inode, *iterator, path,
+ EXT4_EX_NOCACHE);
+ if (IS_ERR(path))
+ return PTR_ERR(path);
+ depth = path->p_depth;
+ extent = path[depth].p_ext;
+ if (!extent) {
+ EXT4_ERROR_INODE(inode, "unexpected hole at %lu",
+ (unsigned long) *iterator);
+ return -EFSCORRUPTED;
+ }
+ if (SHIFT == SHIFT_LEFT && *iterator >
+ le32_to_cpu(extent->ee_block)) {
+ /* Hole, move to the next extent */
+ if (extent < EXT_LAST_EXTENT(path[depth].p_hdr)) {
+ path[depth].p_ext++;
+ } else {
+ *iterator = ext4_ext_next_allocated_block(path);
+ continue;
+ }
+ }
+
+ tmp = *iterator;
+ if (SHIFT == SHIFT_LEFT) {
+ extent = EXT_LAST_EXTENT(path[depth].p_hdr);
+ *iterator = le32_to_cpu(extent->ee_block) +
+ ext4_ext_get_actual_len(extent);
+ } else {
+ extent = EXT_FIRST_EXTENT(path[depth].p_hdr);
+ if (le32_to_cpu(extent->ee_block) > start)
+ *iterator = le32_to_cpu(extent->ee_block) - 1;
+ else if (le32_to_cpu(extent->ee_block) == start)
+ iterator = NULL;
+ else {
+ extent = EXT_LAST_EXTENT(path[depth].p_hdr);
+ while (le32_to_cpu(extent->ee_block) >= start)
+ extent--;
+
+ if (extent == EXT_LAST_EXTENT(path[depth].p_hdr))
+ break;
+
+ extent++;
+ iterator = NULL;
+ }
+ path[depth].p_ext = extent;
+ }
+ ret = ext4_ext_shift_path_extents(path, shift, inode,
+ handle, SHIFT);
+ /* iterator can be NULL which means we should break */
+ if (ret == -EAGAIN)
+ goto again;
+ if (ret)
+ break;
+ }
+out:
+ ext4_free_ext_path(path);
+ return ret;
+}
+
+/*
+ * ext4_collapse_range:
+ * This implements the fallocate's collapse range functionality for ext4
+ * Returns: 0 and non-zero on error.
+ */
+static int ext4_collapse_range(struct file *file, loff_t offset, loff_t len)
+{
+ struct inode *inode = file_inode(file);
+ struct super_block *sb = inode->i_sb;
+ struct address_space *mapping = inode->i_mapping;
+ loff_t end = offset + len;
+ ext4_lblk_t start_lblk, end_lblk;
+ handle_t *handle;
+ unsigned int credits;
+ loff_t start, new_size;
+ int ret;
+
+ trace_ext4_collapse_range(inode, offset, len);
+ WARN_ON_ONCE(!inode_is_locked(inode));
+
+ /* Currently just for extent based files */
+ if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
+ return -EOPNOTSUPP;
+ /* Collapse range works only on fs cluster size aligned regions. */
+ if (!IS_ALIGNED(offset | len, EXT4_CLUSTER_SIZE(sb)))
+ return -EINVAL;
+ /*
+ * There is no need to overlap collapse range with EOF, in which case
+ * it is effectively a truncate operation
+ */
+ if (end >= inode->i_size)
+ return -EINVAL;
+
+ /*
+ * Write tail of the last page before removed range and data that
+ * will be shifted since they will get removed from the page cache
+ * below. We are also protected from pages becoming dirty by
+ * i_rwsem and invalidate_lock.
+ * Need to round down offset to be aligned with page size boundary
+ * for page size > block size.
+ */
+ start = round_down(offset, PAGE_SIZE);
+ ret = filemap_write_and_wait_range(mapping, start, offset);
+ if (!ret)
+ ret = filemap_write_and_wait_range(mapping, end, LLONG_MAX);
+ if (ret)
+ return ret;
+
+ truncate_pagecache(inode, start);
+
+ credits = ext4_chunk_trans_extent(inode, 0);
+ handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits);
+ if (IS_ERR(handle))
+ return PTR_ERR(handle);
+
+ ext4_fc_mark_ineligible(sb, EXT4_FC_REASON_FALLOC_RANGE, handle);
+
+ start_lblk = offset >> inode->i_blkbits;
+ end_lblk = (offset + len) >> inode->i_blkbits;
+
+ 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, EXT_MAX_BLOCKS - start_lblk);
+
+ ret = ext4_ext_remove_space(inode, start_lblk, end_lblk - 1);
+ if (ret) {
+ up_write(&EXT4_I(inode)->i_data_sem);
+ goto out_handle;
+ }
+ ext4_discard_preallocations(inode);
+
+ ret = ext4_ext_shift_extents(inode, handle, end_lblk,
+ end_lblk - start_lblk, SHIFT_LEFT);
+ if (ret) {
+ up_write(&EXT4_I(inode)->i_data_sem);
+ goto out_handle;
+ }
+
+ new_size = inode->i_size - len;
+ i_size_write(inode, new_size);
+ EXT4_I(inode)->i_disksize = new_size;
+
+ up_write(&EXT4_I(inode)->i_data_sem);
+ ret = ext4_mark_inode_dirty(handle, inode);
+ if (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;
+}
+
+/*
+ * ext4_insert_range:
+ * This function implements the FALLOC_FL_INSERT_RANGE flag of fallocate.
+ * The data blocks starting from @offset to the EOF are shifted by @len
+ * towards right to create a hole in the @inode. Inode size is increased
+ * by len bytes.
+ * Returns 0 on success, error otherwise.
+ */
+static int ext4_insert_range(struct file *file, loff_t offset, loff_t len)
+{
+ struct inode *inode = file_inode(file);
+ struct super_block *sb = inode->i_sb;
+ struct address_space *mapping = inode->i_mapping;
+ handle_t *handle;
+ struct ext4_ext_path *path;
+ struct ext4_extent *extent;
+ ext4_lblk_t start_lblk, len_lblk, ee_start_lblk = 0;
+ unsigned int credits, ee_len;
+ int ret, depth, split_flag = 0;
+ loff_t start;
+
+ trace_ext4_insert_range(inode, offset, len);
+ WARN_ON_ONCE(!inode_is_locked(inode));
+
+ /* Currently just for extent based files */
+ if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
+ return -EOPNOTSUPP;
+ /* Insert range works only on fs cluster size aligned regions. */
+ if (!IS_ALIGNED(offset | len, EXT4_CLUSTER_SIZE(sb)))
+ return -EINVAL;
+ /* Offset must be less than i_size */
+ if (offset >= inode->i_size)
+ return -EINVAL;
+ /* Check whether the maximum file size would be exceeded */
+ if (len > inode->i_sb->s_maxbytes - inode->i_size)
+ return -EFBIG;
+
+ /*
+ * Write out all dirty pages. Need to round down to align start offset
+ * to page size boundary for page size > block size.
+ */
+ start = round_down(offset, PAGE_SIZE);
+ ret = filemap_write_and_wait_range(mapping, start, LLONG_MAX);
+ if (ret)
+ return ret;
+
+ truncate_pagecache(inode, start);
+
+ credits = ext4_chunk_trans_extent(inode, 0);
+ handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits);
+ if (IS_ERR(handle))
+ return PTR_ERR(handle);
+
+ ext4_fc_mark_ineligible(sb, EXT4_FC_REASON_FALLOC_RANGE, handle);
+
+ /* Expand file to avoid data loss if there is error while shifting */
+ inode->i_size += len;
+ EXT4_I(inode)->i_disksize += len;
+ ret = ext4_mark_inode_dirty(handle, inode);
+ if (ret)
+ goto out_handle;
+
+ start_lblk = offset >> inode->i_blkbits;
+ len_lblk = len >> inode->i_blkbits;
+
+ ext4_check_map_extents_env(inode);
+
+ down_write(&EXT4_I(inode)->i_data_sem);
+ ext4_discard_preallocations(inode);
+
+ path = ext4_find_extent(inode, start_lblk, NULL, 0);
+ if (IS_ERR(path)) {
+ up_write(&EXT4_I(inode)->i_data_sem);
+ ret = PTR_ERR(path);
+ goto out_handle;
+ }
+
+ depth = ext_depth(inode);
+ extent = path[depth].p_ext;
+ if (extent) {
+ ee_start_lblk = le32_to_cpu(extent->ee_block);
+ ee_len = ext4_ext_get_actual_len(extent);
+
+ /*
+ * If start_lblk is not the starting block of extent, split
+ * the extent @start_lblk
+ */
+ if ((start_lblk > ee_start_lblk) &&
+ (start_lblk < (ee_start_lblk + ee_len))) {
+ if (ext4_ext_is_unwritten(extent))
+ split_flag = EXT4_EXT_MARK_UNWRIT1 |
+ EXT4_EXT_MARK_UNWRIT2;
+ path = ext4_split_extent_at(handle, inode, path,
+ start_lblk, split_flag,
+ EXT4_EX_NOCACHE |
+ EXT4_GET_BLOCKS_PRE_IO |
+ EXT4_GET_BLOCKS_METADATA_NOFAIL);
+ }
+
+ if (IS_ERR(path)) {
+ up_write(&EXT4_I(inode)->i_data_sem);
+ ret = PTR_ERR(path);
+ goto out_handle;
+ }
+ }
+
+ ext4_free_ext_path(path);
+ ext4_es_remove_extent(inode, start_lblk, EXT_MAX_BLOCKS - start_lblk);
+
+ /*
+ * if start_lblk lies in a hole which is at start of file, use
+ * ee_start_lblk to shift extents
+ */
+ ret = ext4_ext_shift_extents(inode, handle,
+ max(ee_start_lblk, start_lblk), len_lblk, SHIFT_RIGHT);
+ up_write(&EXT4_I(inode)->i_data_sem);
+ if (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;
+}
+
+/**
+ * ext4_swap_extents() - Swap extents between two inodes
+ * @handle: handle for this transaction
+ * @inode1: First inode
+ * @inode2: Second inode
+ * @lblk1: Start block for first inode
+ * @lblk2: Start block for second inode
+ * @count: Number of blocks to swap
+ * @unwritten: Mark second inode's extents as unwritten after swap
+ * @erp: Pointer to save error value
+ *
+ * This helper routine does exactly what is promise "swap extents". All other
+ * stuff such as page-cache locking consistency, bh mapping consistency or
+ * extent's data copying must be performed by caller.
+ * Locking:
+ * i_rwsem is held for both inodes
+ * i_data_sem is locked for write for both inodes
+ * Assumptions:
+ * All pages from requested range are locked for both inodes
+ */
+int
+ext4_swap_extents(handle_t *handle, struct inode *inode1,
+ struct inode *inode2, ext4_lblk_t lblk1, ext4_lblk_t lblk2,
+ ext4_lblk_t count, int unwritten, int *erp)
+{
+ struct ext4_ext_path *path1 = NULL;
+ struct ext4_ext_path *path2 = NULL;
+ int replaced_count = 0;
+
+ BUG_ON(!rwsem_is_locked(&EXT4_I(inode1)->i_data_sem));
+ BUG_ON(!rwsem_is_locked(&EXT4_I(inode2)->i_data_sem));
+ BUG_ON(!inode_is_locked(inode1));
+ BUG_ON(!inode_is_locked(inode2));
+
+ ext4_es_remove_extent(inode1, lblk1, count);
+ ext4_es_remove_extent(inode2, lblk2, count);
+
+ while (count) {
+ struct ext4_extent *ex1, *ex2, tmp_ex;
+ ext4_lblk_t e1_blk, e2_blk;
+ int e1_len, e2_len, len;
+ int split = 0;
+
+ path1 = ext4_find_extent(inode1, lblk1, path1, EXT4_EX_NOCACHE);
+ if (IS_ERR(path1)) {
+ *erp = PTR_ERR(path1);
+ goto errout;
+ }
+ path2 = ext4_find_extent(inode2, lblk2, path2, EXT4_EX_NOCACHE);
+ if (IS_ERR(path2)) {
+ *erp = PTR_ERR(path2);
+ goto errout;
+ }
+ ex1 = path1[path1->p_depth].p_ext;
+ ex2 = path2[path2->p_depth].p_ext;
+ /* Do we have something to swap ? */
+ if (unlikely(!ex2 || !ex1))
+ goto errout;
+
+ e1_blk = le32_to_cpu(ex1->ee_block);
+ e2_blk = le32_to_cpu(ex2->ee_block);
+ e1_len = ext4_ext_get_actual_len(ex1);
+ e2_len = ext4_ext_get_actual_len(ex2);
+
+ /* Hole handling */
+ if (!in_range(lblk1, e1_blk, e1_len) ||
+ !in_range(lblk2, e2_blk, e2_len)) {
+ ext4_lblk_t next1, next2;
+
+ /* if hole after extent, then go to next extent */
+ next1 = ext4_ext_next_allocated_block(path1);
+ next2 = ext4_ext_next_allocated_block(path2);
+ /* If hole before extent, then shift to that extent */
+ if (e1_blk > lblk1)
+ next1 = e1_blk;
+ if (e2_blk > lblk2)
+ next2 = e2_blk;
+ /* Do we have something to swap */
+ if (next1 == EXT_MAX_BLOCKS || next2 == EXT_MAX_BLOCKS)
+ goto errout;
+ /* Move to the rightest boundary */
+ len = next1 - lblk1;
+ if (len < next2 - lblk2)
+ len = next2 - lblk2;
+ if (len > count)
+ len = count;
+ lblk1 += len;
+ lblk2 += len;
+ count -= len;
+ continue;
+ }
+
+ /* Prepare left boundary */
+ if (e1_blk < lblk1) {
+ split = 1;
+ path1 = ext4_force_split_extent_at(handle, inode1,
+ path1, lblk1, 0);
+ if (IS_ERR(path1)) {
+ *erp = PTR_ERR(path1);
+ goto errout;
+ }
+ }
+ if (e2_blk < lblk2) {
+ split = 1;
+ path2 = ext4_force_split_extent_at(handle, inode2,
+ path2, lblk2, 0);
+ if (IS_ERR(path2)) {
+ *erp = PTR_ERR(path2);
+ goto errout;
+ }
+ }
+ /* ext4_split_extent_at() may result in leaf extent split,
+ * path must to be revalidated. */
+ if (split)
+ continue;
+
+ /* Prepare right boundary */
+ len = count;
+ if (len > e1_blk + e1_len - lblk1)
+ len = e1_blk + e1_len - lblk1;
+ if (len > e2_blk + e2_len - lblk2)
+ len = e2_blk + e2_len - lblk2;
+
+ if (len != e1_len) {
+ split = 1;
+ path1 = ext4_force_split_extent_at(handle, inode1,
+ path1, lblk1 + len, 0);
+ if (IS_ERR(path1)) {
+ *erp = PTR_ERR(path1);
+ goto errout;
+ }
+ }
+ if (len != e2_len) {
+ split = 1;
+ path2 = ext4_force_split_extent_at(handle, inode2,
+ path2, lblk2 + len, 0);
+ if (IS_ERR(path2)) {
+ *erp = PTR_ERR(path2);
+ goto errout;
+ }
+ }
+ /* ext4_split_extent_at() may result in leaf extent split,
+ * path must to be revalidated. */
+ if (split)
+ continue;
+
+ BUG_ON(e2_len != e1_len);
+ *erp = ext4_ext_get_access(handle, inode1, path1 + path1->p_depth);
+ if (unlikely(*erp))
+ goto errout;
+ *erp = ext4_ext_get_access(handle, inode2, path2 + path2->p_depth);
+ if (unlikely(*erp))
+ goto errout;
+
+ /* Both extents are fully inside boundaries. Swap it now */
+ tmp_ex = *ex1;
+ ext4_ext_store_pblock(ex1, ext4_ext_pblock(ex2));
+ ext4_ext_store_pblock(ex2, ext4_ext_pblock(&tmp_ex));
+ ex1->ee_len = cpu_to_le16(e2_len);
+ ex2->ee_len = cpu_to_le16(e1_len);
+ if (unwritten)
+ ext4_ext_mark_unwritten(ex2);
+ if (ext4_ext_is_unwritten(&tmp_ex))
+ ext4_ext_mark_unwritten(ex1);
+
+ ext4_ext_try_to_merge(handle, inode2, path2, ex2);
+ ext4_ext_try_to_merge(handle, inode1, path1, ex1);
+ *erp = ext4_ext_dirty(handle, inode2, path2 +
+ path2->p_depth);
+ if (unlikely(*erp))
+ goto errout;
+ *erp = ext4_ext_dirty(handle, inode1, path1 +
+ path1->p_depth);
+ /*
+ * Looks scarry ah..? second inode already points to new blocks,
+ * and it was successfully dirtied. But luckily error may happen
+ * only due to journal error, so full transaction will be
+ * aborted anyway.
+ */
+ if (unlikely(*erp))
+ goto errout;
+
+ lblk1 += len;
+ lblk2 += len;
+ replaced_count += len;
+ count -= len;
+ }
+
+errout:
+ ext4_free_ext_path(path1);
+ ext4_free_ext_path(path2);
+ return replaced_count;
+}
+
+/*
+ * ext4_clu_mapped - determine whether any block in a logical cluster has
+ * been mapped to a physical cluster
+ *
+ * @inode - file containing the logical cluster
+ * @lclu - logical cluster of interest
+ *
+ * Returns 1 if any block in the logical cluster is mapped, signifying
+ * that a physical cluster has been allocated for it. Otherwise,
+ * returns 0. Can also return negative error codes. Derived from
+ * ext4_ext_map_blocks().
+ */
+int ext4_clu_mapped(struct inode *inode, ext4_lblk_t lclu)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+ struct ext4_ext_path *path;
+ int depth, mapped = 0, err = 0;
+ struct ext4_extent *extent;
+ ext4_lblk_t first_lblk, first_lclu, last_lclu;
+
+ /*
+ * if data can be stored inline, the logical cluster isn't
+ * mapped - no physical clusters have been allocated, and the
+ * file has no extents
+ */
+ if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA) ||
+ ext4_has_inline_data(inode))
+ return 0;
+
+ /* search for the extent closest to the first block in the cluster */
+ path = ext4_find_extent(inode, EXT4_C2B(sbi, lclu), NULL, 0);
+ if (IS_ERR(path))
+ return PTR_ERR(path);
+
+ depth = ext_depth(inode);
+
+ /*
+ * A consistent leaf must not be empty. This situation is possible,
+ * though, _during_ tree modification, and it's why an assert can't
+ * be put in ext4_find_extent().
+ */
+ if (unlikely(path[depth].p_ext == NULL && depth != 0)) {
+ EXT4_ERROR_INODE(inode,
+ "bad extent address - lblock: %lu, depth: %d, pblock: %lld",
+ (unsigned long) EXT4_C2B(sbi, lclu),
+ depth, path[depth].p_block);
+ err = -EFSCORRUPTED;
+ goto out;
+ }
+
+ extent = path[depth].p_ext;
+
+ /* can't be mapped if the extent tree is empty */
+ if (extent == NULL)
+ goto out;
+
+ first_lblk = le32_to_cpu(extent->ee_block);
+ first_lclu = EXT4_B2C(sbi, first_lblk);
+
+ /*
+ * Three possible outcomes at this point - found extent spanning
+ * the target cluster, to the left of the target cluster, or to the
+ * right of the target cluster. The first two cases are handled here.
+ * The last case indicates the target cluster is not mapped.
+ */
+ if (lclu >= first_lclu) {
+ last_lclu = EXT4_B2C(sbi, first_lblk +
+ ext4_ext_get_actual_len(extent) - 1);
+ if (lclu <= last_lclu) {
+ mapped = 1;
+ } else {
+ first_lblk = ext4_ext_next_allocated_block(path);
+ first_lclu = EXT4_B2C(sbi, first_lblk);
+ if (lclu == first_lclu)
+ mapped = 1;
+ }
+ }
+
+out:
+ ext4_free_ext_path(path);
+
+ return err ? err : mapped;
+}
+
+/*
+ * Updates physical block address and unwritten status of extent
+ * starting at lblk start and of len. If such an extent doesn't exist,
+ * this function splits the extent tree appropriately to create an
+ * extent like this. This function is called in the fast commit
+ * replay path. Returns 0 on success and error on failure.
+ */
+int ext4_ext_replay_update_ex(struct inode *inode, ext4_lblk_t start,
+ int len, int unwritten, ext4_fsblk_t pblk)
+{
+ struct ext4_ext_path *path;
+ struct ext4_extent *ex;
+ int ret;
+
+ path = ext4_find_extent(inode, start, NULL, 0);
+ if (IS_ERR(path))
+ return PTR_ERR(path);
+ ex = path[path->p_depth].p_ext;
+ if (!ex) {
+ ret = -EFSCORRUPTED;
+ goto out;
+ }
+
+ if (le32_to_cpu(ex->ee_block) != start ||
+ ext4_ext_get_actual_len(ex) != len) {
+ /* We need to split this extent to match our extent first */
+ down_write(&EXT4_I(inode)->i_data_sem);
+ path = ext4_force_split_extent_at(NULL, inode, path, start, 1);
+ up_write(&EXT4_I(inode)->i_data_sem);
+ if (IS_ERR(path)) {
+ ret = PTR_ERR(path);
+ goto out;
+ }
+
+ path = ext4_find_extent(inode, start, path, 0);
+ if (IS_ERR(path))
+ return PTR_ERR(path);
+
+ ex = path[path->p_depth].p_ext;
+ WARN_ON(le32_to_cpu(ex->ee_block) != start);
+
+ if (ext4_ext_get_actual_len(ex) != len) {
+ down_write(&EXT4_I(inode)->i_data_sem);
+ path = ext4_force_split_extent_at(NULL, inode, path,
+ start + len, 1);
+ up_write(&EXT4_I(inode)->i_data_sem);
+ if (IS_ERR(path)) {
+ ret = PTR_ERR(path);
+ goto out;
+ }
+
+ path = ext4_find_extent(inode, start, path, 0);
+ if (IS_ERR(path))
+ return PTR_ERR(path);
+ ex = path[path->p_depth].p_ext;
+ }
+ }
+ if (unwritten)
+ ext4_ext_mark_unwritten(ex);
+ else
+ ext4_ext_mark_initialized(ex);
+ ext4_ext_store_pblock(ex, pblk);
+ down_write(&EXT4_I(inode)->i_data_sem);
+ ret = ext4_ext_dirty(NULL, inode, &path[path->p_depth]);
+ up_write(&EXT4_I(inode)->i_data_sem);
+out:
+ ext4_free_ext_path(path);
+ ext4_mark_inode_dirty(NULL, inode);
+ return ret;
+}
+
+/* Try to shrink the extent tree */
+void ext4_ext_replay_shrink_inode(struct inode *inode, ext4_lblk_t end)
+{
+ struct ext4_ext_path *path = NULL;
+ struct ext4_extent *ex;
+ ext4_lblk_t old_cur, cur = 0;
+
+ while (cur < end) {
+ path = ext4_find_extent(inode, cur, NULL, 0);
+ if (IS_ERR(path))
+ return;
+ ex = path[path->p_depth].p_ext;
+ if (!ex) {
+ ext4_free_ext_path(path);
+ ext4_mark_inode_dirty(NULL, inode);
+ return;
+ }
+ old_cur = cur;
+ cur = le32_to_cpu(ex->ee_block) + ext4_ext_get_actual_len(ex);
+ if (cur <= old_cur)
+ cur = old_cur + 1;
+ ext4_ext_try_to_merge(NULL, inode, path, ex);
+ down_write(&EXT4_I(inode)->i_data_sem);
+ ext4_ext_dirty(NULL, inode, &path[path->p_depth]);
+ up_write(&EXT4_I(inode)->i_data_sem);
+ ext4_mark_inode_dirty(NULL, inode);
+ ext4_free_ext_path(path);
+ }
+}
+
+/* Check if *cur is a hole and if it is, skip it */
+static int skip_hole(struct inode *inode, ext4_lblk_t *cur)
+{
+ int ret;
+ struct ext4_map_blocks map;
+
+ map.m_lblk = *cur;
+ map.m_len = ((inode->i_size) >> inode->i_sb->s_blocksize_bits) - *cur;
+
+ ret = ext4_map_blocks(NULL, inode, &map, 0);
+ if (ret < 0)
+ return ret;
+ if (ret != 0)
+ return 0;
+ *cur = *cur + map.m_len;
+ return 0;
+}
+
+/* Count number of blocks used by this inode and update i_blocks */
+int ext4_ext_replay_set_iblocks(struct inode *inode)
+{
+ struct ext4_ext_path *path = NULL, *path2 = NULL;
+ struct ext4_extent *ex;
+ ext4_lblk_t cur = 0, end;
+ int numblks = 0, i, ret = 0;
+ ext4_fsblk_t cmp1, cmp2;
+ struct ext4_map_blocks map;
+
+ /* Determin the size of the file first */
+ path = ext4_find_extent(inode, EXT_MAX_BLOCKS - 1, NULL,
+ EXT4_EX_NOCACHE);
+ if (IS_ERR(path))
+ return PTR_ERR(path);
+ ex = path[path->p_depth].p_ext;
+ if (!ex)
+ goto out;
+ end = le32_to_cpu(ex->ee_block) + ext4_ext_get_actual_len(ex);
+
+ /* Count the number of data blocks */
+ cur = 0;
+ while (cur < end) {
+ map.m_lblk = cur;
+ map.m_len = end - cur;
+ ret = ext4_map_blocks(NULL, inode, &map, 0);
+ if (ret < 0)
+ break;
+ if (ret > 0)
+ numblks += ret;
+ cur = cur + map.m_len;
+ }
+
+ /*
+ * Count the number of extent tree blocks. We do it by looking up
+ * two successive extents and determining the difference between
+ * their paths. When path is different for 2 successive extents
+ * we compare the blocks in the path at each level and increment
+ * iblocks by total number of differences found.
+ */
+ cur = 0;
+ ret = skip_hole(inode, &cur);
+ if (ret < 0)
+ goto out;
+ path = ext4_find_extent(inode, cur, path, 0);
+ if (IS_ERR(path))
+ goto out;
+ numblks += path->p_depth;
+ while (cur < end) {
+ path = ext4_find_extent(inode, cur, path, 0);
+ if (IS_ERR(path))
+ break;
+ ex = path[path->p_depth].p_ext;
+ if (!ex)
+ goto cleanup;
+
+ cur = max(cur + 1, le32_to_cpu(ex->ee_block) +
+ ext4_ext_get_actual_len(ex));
+ ret = skip_hole(inode, &cur);
+ if (ret < 0)
+ break;
+
+ path2 = ext4_find_extent(inode, cur, path2, 0);
+ if (IS_ERR(path2))
+ break;
+
+ for (i = 0; i <= max(path->p_depth, path2->p_depth); i++) {
+ cmp1 = cmp2 = 0;
+ if (i <= path->p_depth)
+ cmp1 = path[i].p_bh ?
+ path[i].p_bh->b_blocknr : 0;
+ if (i <= path2->p_depth)
+ cmp2 = path2[i].p_bh ?
+ path2[i].p_bh->b_blocknr : 0;
+ if (cmp1 != cmp2 && cmp2 != 0)
+ numblks++;
+ }
+ }
+
+out:
+ inode->i_blocks = numblks << (inode->i_sb->s_blocksize_bits - 9);
+ ext4_mark_inode_dirty(NULL, inode);
+cleanup:
+ ext4_free_ext_path(path);
+ ext4_free_ext_path(path2);
+ return 0;
+}
+
+int ext4_ext_clear_bb(struct inode *inode)
+{
+ struct ext4_ext_path *path = NULL;
+ struct ext4_extent *ex;
+ ext4_lblk_t cur = 0, end;
+ int j, ret = 0;
+ struct ext4_map_blocks map;
+
+ if (ext4_test_inode_flag(inode, EXT4_INODE_INLINE_DATA))
+ return 0;
+
+ /* Determin the size of the file first */
+ path = ext4_find_extent(inode, EXT_MAX_BLOCKS - 1, NULL,
+ EXT4_EX_NOCACHE);
+ if (IS_ERR(path))
+ return PTR_ERR(path);
+ ex = path[path->p_depth].p_ext;
+ if (!ex)
+ goto out;
+ end = le32_to_cpu(ex->ee_block) + ext4_ext_get_actual_len(ex);
+
+ cur = 0;
+ while (cur < end) {
+ map.m_lblk = cur;
+ map.m_len = end - cur;
+ ret = ext4_map_blocks(NULL, inode, &map, 0);
+ if (ret < 0)
+ break;
+ if (ret > 0) {
+ path = ext4_find_extent(inode, map.m_lblk, path, 0);
+ if (!IS_ERR(path)) {
+ for (j = 0; j < path->p_depth; j++) {
+ ext4_mb_mark_bb(inode->i_sb,
+ path[j].p_block, 1, false);
+ ext4_fc_record_regions(inode->i_sb, inode->i_ino,
+ 0, path[j].p_block, 1, 1);
+ }
+ } else {
+ path = NULL;
+ }
+ ext4_mb_mark_bb(inode->i_sb, map.m_pblk, map.m_len, false);
+ ext4_fc_record_regions(inode->i_sb, inode->i_ino,
+ map.m_lblk, map.m_pblk, map.m_len, 1);
+ }
+ cur = cur + map.m_len;
+ }
+
+out:
+ ext4_free_ext_path(path);
+ return 0;
+}