new file mode 100644
@@ -0,0 +1,304 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/ext4/acl.c
+ *
+ * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
+ */
+
+#include <linux/quotaops.h>
+#include "ext4_jbd2.h"
+#include "ext4.h"
+#include "xattr.h"
+#include "acl.h"
+
+/*
+ * Convert from filesystem to in-memory representation.
+ */
+static struct posix_acl *
+ext4_acl_from_disk(const void *value, size_t size)
+{
+ const char *end = (char *)value + size;
+ int n, count;
+ struct posix_acl *acl;
+
+ if (!value)
+ return NULL;
+ if (size < sizeof(ext4_acl_header))
+ return ERR_PTR(-EINVAL);
+ if (((ext4_acl_header *)value)->a_version !=
+ cpu_to_le32(EXT4_ACL_VERSION))
+ return ERR_PTR(-EINVAL);
+ value = (char *)value + sizeof(ext4_acl_header);
+ count = ext4_acl_count(size);
+ if (count < 0)
+ return ERR_PTR(-EINVAL);
+ if (count == 0)
+ return NULL;
+ acl = posix_acl_alloc(count, GFP_NOFS);
+ if (!acl)
+ return ERR_PTR(-ENOMEM);
+ for (n = 0; n < count; n++) {
+ ext4_acl_entry *entry =
+ (ext4_acl_entry *)value;
+ if ((char *)value + sizeof(ext4_acl_entry_short) > end)
+ goto fail;
+ acl->a_entries[n].e_tag = le16_to_cpu(entry->e_tag);
+ acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm);
+
+ switch (acl->a_entries[n].e_tag) {
+ case ACL_USER_OBJ:
+ case ACL_GROUP_OBJ:
+ case ACL_MASK:
+ case ACL_OTHER:
+ value = (char *)value +
+ sizeof(ext4_acl_entry_short);
+ break;
+
+ case ACL_USER:
+ value = (char *)value + sizeof(ext4_acl_entry);
+ if ((char *)value > end)
+ goto fail;
+ acl->a_entries[n].e_uid =
+ make_kuid(&init_user_ns,
+ le32_to_cpu(entry->e_id));
+ break;
+ case ACL_GROUP:
+ value = (char *)value + sizeof(ext4_acl_entry);
+ if ((char *)value > end)
+ goto fail;
+ acl->a_entries[n].e_gid =
+ make_kgid(&init_user_ns,
+ le32_to_cpu(entry->e_id));
+ break;
+
+ default:
+ goto fail;
+ }
+ }
+ if (value != end)
+ goto fail;
+ return acl;
+
+fail:
+ posix_acl_release(acl);
+ return ERR_PTR(-EINVAL);
+}
+
+/*
+ * Convert from in-memory to filesystem representation.
+ */
+static void *
+ext4_acl_to_disk(const struct posix_acl *acl, size_t *size)
+{
+ ext4_acl_header *ext_acl;
+ char *e;
+ size_t n;
+
+ *size = ext4_acl_size(acl->a_count);
+ ext_acl = kmalloc(sizeof(ext4_acl_header) + acl->a_count *
+ sizeof(ext4_acl_entry), GFP_NOFS);
+ if (!ext_acl)
+ return ERR_PTR(-ENOMEM);
+ ext_acl->a_version = cpu_to_le32(EXT4_ACL_VERSION);
+ e = (char *)ext_acl + sizeof(ext4_acl_header);
+ for (n = 0; n < acl->a_count; n++) {
+ const struct posix_acl_entry *acl_e = &acl->a_entries[n];
+ ext4_acl_entry *entry = (ext4_acl_entry *)e;
+ entry->e_tag = cpu_to_le16(acl_e->e_tag);
+ entry->e_perm = cpu_to_le16(acl_e->e_perm);
+ switch (acl_e->e_tag) {
+ case ACL_USER:
+ entry->e_id = cpu_to_le32(
+ from_kuid(&init_user_ns, acl_e->e_uid));
+ e += sizeof(ext4_acl_entry);
+ break;
+ case ACL_GROUP:
+ entry->e_id = cpu_to_le32(
+ from_kgid(&init_user_ns, acl_e->e_gid));
+ e += sizeof(ext4_acl_entry);
+ break;
+
+ case ACL_USER_OBJ:
+ case ACL_GROUP_OBJ:
+ case ACL_MASK:
+ case ACL_OTHER:
+ e += sizeof(ext4_acl_entry_short);
+ break;
+
+ default:
+ goto fail;
+ }
+ }
+ return (char *)ext_acl;
+
+fail:
+ kfree(ext_acl);
+ return ERR_PTR(-EINVAL);
+}
+
+/*
+ * Inode operation get_posix_acl().
+ *
+ * inode->i_rwsem: don't care
+ */
+struct posix_acl *
+ext4_get_acl(struct inode *inode, int type, bool rcu)
+{
+ int name_index;
+ char *value = NULL;
+ struct posix_acl *acl;
+ int retval;
+
+ if (rcu)
+ return ERR_PTR(-ECHILD);
+
+ switch (type) {
+ case ACL_TYPE_ACCESS:
+ name_index = EXT4_XATTR_INDEX_POSIX_ACL_ACCESS;
+ break;
+ case ACL_TYPE_DEFAULT:
+ name_index = EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT;
+ break;
+ default:
+ BUG();
+ }
+ retval = ext4_xattr_get(inode, name_index, "", NULL, 0);
+ if (retval > 0) {
+ value = kmalloc(retval, GFP_NOFS);
+ if (!value)
+ return ERR_PTR(-ENOMEM);
+ retval = ext4_xattr_get(inode, name_index, "", value, retval);
+ }
+ if (retval > 0)
+ acl = ext4_acl_from_disk(value, retval);
+ else if (retval == -ENODATA || retval == -ENOSYS)
+ acl = NULL;
+ else
+ acl = ERR_PTR(retval);
+ kfree(value);
+
+ return acl;
+}
+
+/*
+ * Set the access or default ACL of an inode.
+ *
+ * inode->i_rwsem: down unless called from ext4_new_inode
+ */
+static int
+__ext4_set_acl(handle_t *handle, struct inode *inode, int type,
+ struct posix_acl *acl, int xattr_flags)
+{
+ int name_index;
+ void *value = NULL;
+ size_t size = 0;
+ int error;
+
+ switch (type) {
+ case ACL_TYPE_ACCESS:
+ name_index = EXT4_XATTR_INDEX_POSIX_ACL_ACCESS;
+ break;
+
+ case ACL_TYPE_DEFAULT:
+ name_index = EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT;
+ if (!S_ISDIR(inode->i_mode))
+ return acl ? -EACCES : 0;
+ break;
+
+ default:
+ return -EINVAL;
+ }
+ if (acl) {
+ value = ext4_acl_to_disk(acl, &size);
+ if (IS_ERR(value))
+ return (int)PTR_ERR(value);
+ }
+
+ error = ext4_xattr_set_handle(handle, inode, name_index, "",
+ value, size, xattr_flags);
+
+ kfree(value);
+ if (!error)
+ set_cached_acl(inode, type, acl);
+
+ return error;
+}
+
+int
+ext4_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
+ struct posix_acl *acl, int type)
+{
+ handle_t *handle;
+ int error, credits, retries = 0;
+ size_t acl_size = acl ? ext4_acl_size(acl->a_count) : 0;
+ struct inode *inode = d_inode(dentry);
+ umode_t mode = inode->i_mode;
+ int update_mode = 0;
+
+ error = dquot_initialize(inode);
+ if (error)
+ return error;
+retry:
+ error = ext4_xattr_set_credits(inode, acl_size, false /* is_create */,
+ &credits);
+ if (error)
+ return error;
+
+ handle = ext4_journal_start(inode, EXT4_HT_XATTR, credits);
+ if (IS_ERR(handle))
+ return PTR_ERR(handle);
+
+ if ((type == ACL_TYPE_ACCESS) && acl) {
+ error = posix_acl_update_mode(idmap, inode, &mode, &acl);
+ if (error)
+ goto out_stop;
+ if (mode != inode->i_mode)
+ update_mode = 1;
+ }
+
+ error = __ext4_set_acl(handle, inode, type, acl, 0 /* xattr_flags */);
+ if (!error && update_mode) {
+ inode->i_mode = mode;
+ inode_set_ctime_current(inode);
+ error = ext4_mark_inode_dirty(handle, inode);
+ }
+out_stop:
+ ext4_journal_stop(handle);
+ if (error == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
+ goto retry;
+ return error;
+}
+
+/*
+ * Initialize the ACLs of a new inode. Called from ext4_new_inode.
+ *
+ * dir->i_rwsem: down
+ * inode->i_rwsem: up (access to inode is still exclusive)
+ */
+int
+ext4_init_acl(handle_t *handle, struct inode *inode, struct inode *dir)
+{
+ struct posix_acl *default_acl, *acl;
+ int error;
+
+ error = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
+ if (error)
+ return error;
+
+ if (default_acl) {
+ error = __ext4_set_acl(handle, inode, ACL_TYPE_DEFAULT,
+ default_acl, XATTR_CREATE);
+ posix_acl_release(default_acl);
+ } else {
+ inode->i_default_acl = NULL;
+ }
+ if (acl) {
+ if (!error)
+ error = __ext4_set_acl(handle, inode, ACL_TYPE_ACCESS,
+ acl, XATTR_CREATE);
+ posix_acl_release(acl);
+ } else {
+ inode->i_acl = NULL;
+ }
+ return error;
+}
new file mode 100644
@@ -0,0 +1,74 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ File: fs/ext4/acl.h
+
+ (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
+*/
+
+#include <linux/posix_acl_xattr.h>
+
+#define EXT4_ACL_VERSION 0x0001
+
+typedef struct {
+ __le16 e_tag;
+ __le16 e_perm;
+ __le32 e_id;
+} ext4_acl_entry;
+
+typedef struct {
+ __le16 e_tag;
+ __le16 e_perm;
+} ext4_acl_entry_short;
+
+typedef struct {
+ __le32 a_version;
+} ext4_acl_header;
+
+static inline size_t ext4_acl_size(int count)
+{
+ if (count <= 4) {
+ return sizeof(ext4_acl_header) +
+ count * sizeof(ext4_acl_entry_short);
+ } else {
+ return sizeof(ext4_acl_header) +
+ 4 * sizeof(ext4_acl_entry_short) +
+ (count - 4) * sizeof(ext4_acl_entry);
+ }
+}
+
+static inline int ext4_acl_count(size_t size)
+{
+ ssize_t s;
+ size -= sizeof(ext4_acl_header);
+ s = size - 4 * sizeof(ext4_acl_entry_short);
+ if (s < 0) {
+ if (size % sizeof(ext4_acl_entry_short))
+ return -1;
+ return size / sizeof(ext4_acl_entry_short);
+ } else {
+ if (s % sizeof(ext4_acl_entry))
+ return -1;
+ return s / sizeof(ext4_acl_entry) + 4;
+ }
+}
+
+#ifdef CONFIG_EXT4_FS_POSIX_ACL
+
+/* acl.c */
+struct posix_acl *ext4_get_acl(struct inode *inode, int type, bool rcu);
+int ext4_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
+ struct posix_acl *acl, int type);
+extern int ext4_init_acl(handle_t *, struct inode *, struct inode *);
+
+#else /* CONFIG_EXT4_FS_POSIX_ACL */
+#include <linux/sched.h>
+#define ext4_get_acl NULL
+#define ext4_set_acl NULL
+
+static inline int
+ext4_init_acl(handle_t *handle, struct inode *inode, struct inode *dir)
+{
+ return 0;
+}
+#endif /* CONFIG_EXT4_FS_POSIX_ACL */
+
new file mode 100644
@@ -0,0 +1,1003 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/ext4/balloc.c
+ *
+ * Copyright (C) 1992, 1993, 1994, 1995
+ * Remy Card (card@masi.ibp.fr)
+ * Laboratoire MASI - Institut Blaise Pascal
+ * Universite Pierre et Marie Curie (Paris VI)
+ *
+ * Enhanced block allocation by Stephen Tweedie (sct@redhat.com), 1993
+ * Big-endian to little-endian byte-swapping/bitmaps by
+ * David S. Miller (davem@caip.rutgers.edu), 1995
+ */
+
+#include <linux/time.h>
+#include <linux/capability.h>
+#include <linux/fs.h>
+#include <linux/quotaops.h>
+#include <linux/buffer_head.h>
+#include "ext4.h"
+#include "ext4_jbd2.h"
+#include "mballoc.h"
+
+#include <trace/events/ext4.h>
+#include <kunit/static_stub.h>
+
+static unsigned ext4_num_base_meta_clusters(struct super_block *sb,
+ ext4_group_t block_group);
+/*
+ * balloc.c contains the blocks allocation and deallocation routines
+ */
+
+/*
+ * Calculate block group number for a given block number
+ */
+ext4_group_t ext4_get_group_number(struct super_block *sb,
+ ext4_fsblk_t block)
+{
+ ext4_group_t group;
+
+ if (test_opt2(sb, STD_GROUP_SIZE))
+ group = (block -
+ le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block)) >>
+ (EXT4_BLOCK_SIZE_BITS(sb) + EXT4_CLUSTER_BITS(sb) + 3);
+ else
+ ext4_get_group_no_and_offset(sb, block, &group, NULL);
+ return group;
+}
+
+/*
+ * Calculate the block group number and offset into the block/cluster
+ * allocation bitmap, given a block number
+ */
+void ext4_get_group_no_and_offset(struct super_block *sb, ext4_fsblk_t blocknr,
+ ext4_group_t *blockgrpp, ext4_grpblk_t *offsetp)
+{
+ struct ext4_super_block *es = EXT4_SB(sb)->s_es;
+ ext4_grpblk_t offset;
+
+ blocknr = blocknr - le32_to_cpu(es->s_first_data_block);
+ offset = do_div(blocknr, EXT4_BLOCKS_PER_GROUP(sb)) >>
+ EXT4_SB(sb)->s_cluster_bits;
+ if (offsetp)
+ *offsetp = offset;
+ if (blockgrpp)
+ *blockgrpp = blocknr;
+
+}
+
+/*
+ * Check whether the 'block' lives within the 'block_group'. Returns 1 if so
+ * and 0 otherwise.
+ */
+static inline int ext4_block_in_group(struct super_block *sb,
+ ext4_fsblk_t block,
+ ext4_group_t block_group)
+{
+ ext4_group_t actual_group;
+
+ actual_group = ext4_get_group_number(sb, block);
+ return (actual_group == block_group) ? 1 : 0;
+}
+
+/*
+ * Return the number of clusters used for file system metadata; this
+ * represents the overhead needed by the file system.
+ */
+static unsigned ext4_num_overhead_clusters(struct super_block *sb,
+ ext4_group_t block_group,
+ struct ext4_group_desc *gdp)
+{
+ unsigned base_clusters, num_clusters;
+ int block_cluster = -1, inode_cluster;
+ int itbl_cluster_start = -1, itbl_cluster_end = -1;
+ ext4_fsblk_t start = ext4_group_first_block_no(sb, block_group);
+ ext4_fsblk_t end = start + EXT4_BLOCKS_PER_GROUP(sb) - 1;
+ ext4_fsblk_t itbl_blk_start, itbl_blk_end;
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+
+ /* This is the number of clusters used by the superblock,
+ * block group descriptors, and reserved block group
+ * descriptor blocks */
+ base_clusters = ext4_num_base_meta_clusters(sb, block_group);
+ num_clusters = base_clusters;
+
+ /*
+ * Account and record inode table clusters if any cluster
+ * is in the block group, or inode table cluster range is
+ * [-1, -1] and won't overlap with block/inode bitmap cluster
+ * accounted below.
+ */
+ itbl_blk_start = ext4_inode_table(sb, gdp);
+ itbl_blk_end = itbl_blk_start + sbi->s_itb_per_group - 1;
+ if (itbl_blk_start <= end && itbl_blk_end >= start) {
+ itbl_blk_start = max(itbl_blk_start, start);
+ itbl_blk_end = min(itbl_blk_end, end);
+
+ itbl_cluster_start = EXT4_B2C(sbi, itbl_blk_start - start);
+ itbl_cluster_end = EXT4_B2C(sbi, itbl_blk_end - start);
+
+ num_clusters += itbl_cluster_end - itbl_cluster_start + 1;
+ /* check if border cluster is overlapped */
+ if (itbl_cluster_start == base_clusters - 1)
+ num_clusters--;
+ }
+
+ /*
+ * For the allocation bitmaps, we first need to check to see
+ * if the block is in the block group. If it is, then check
+ * to see if the cluster is already accounted for in the clusters
+ * used for the base metadata cluster and inode tables cluster.
+ * Normally all of these blocks are contiguous, so the special
+ * case handling shouldn't be necessary except for *very*
+ * unusual file system layouts.
+ */
+ if (ext4_block_in_group(sb, ext4_block_bitmap(sb, gdp), block_group)) {
+ block_cluster = EXT4_B2C(sbi,
+ ext4_block_bitmap(sb, gdp) - start);
+ if (block_cluster >= base_clusters &&
+ (block_cluster < itbl_cluster_start ||
+ block_cluster > itbl_cluster_end))
+ num_clusters++;
+ }
+
+ if (ext4_block_in_group(sb, ext4_inode_bitmap(sb, gdp), block_group)) {
+ inode_cluster = EXT4_B2C(sbi,
+ ext4_inode_bitmap(sb, gdp) - start);
+ /*
+ * Additional check if inode bitmap is in just accounted
+ * block_cluster
+ */
+ if (inode_cluster != block_cluster &&
+ inode_cluster >= base_clusters &&
+ (inode_cluster < itbl_cluster_start ||
+ inode_cluster > itbl_cluster_end))
+ num_clusters++;
+ }
+
+ return num_clusters;
+}
+
+static unsigned int num_clusters_in_group(struct super_block *sb,
+ ext4_group_t block_group)
+{
+ unsigned int blocks;
+
+ if (block_group == ext4_get_groups_count(sb) - 1) {
+ /*
+ * Even though mke2fs always initializes the first and
+ * last group, just in case some other tool was used,
+ * we need to make sure we calculate the right free
+ * blocks.
+ */
+ blocks = ext4_blocks_count(EXT4_SB(sb)->s_es) -
+ ext4_group_first_block_no(sb, block_group);
+ } else
+ blocks = EXT4_BLOCKS_PER_GROUP(sb);
+ return EXT4_NUM_B2C(EXT4_SB(sb), blocks);
+}
+
+/* Initializes an uninitialized block bitmap */
+static int ext4_init_block_bitmap(struct super_block *sb,
+ struct buffer_head *bh,
+ ext4_group_t block_group,
+ struct ext4_group_desc *gdp)
+{
+ unsigned int bit, bit_max;
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ ext4_fsblk_t start, tmp;
+
+ ASSERT(buffer_locked(bh));
+
+ if (!ext4_group_desc_csum_verify(sb, block_group, gdp)) {
+ ext4_mark_group_bitmap_corrupted(sb, block_group,
+ EXT4_GROUP_INFO_BBITMAP_CORRUPT |
+ EXT4_GROUP_INFO_IBITMAP_CORRUPT);
+ return -EFSBADCRC;
+ }
+ memset(bh->b_data, 0, sb->s_blocksize);
+
+ bit_max = ext4_num_base_meta_clusters(sb, block_group);
+ if ((bit_max >> 3) >= bh->b_size)
+ return -EFSCORRUPTED;
+
+ for (bit = 0; bit < bit_max; bit++)
+ ext4_set_bit(bit, bh->b_data);
+
+ start = ext4_group_first_block_no(sb, block_group);
+
+ /* Set bits for block and inode bitmaps, and inode table */
+ tmp = ext4_block_bitmap(sb, gdp);
+ if (ext4_block_in_group(sb, tmp, block_group))
+ ext4_set_bit(EXT4_B2C(sbi, tmp - start), bh->b_data);
+
+ tmp = ext4_inode_bitmap(sb, gdp);
+ if (ext4_block_in_group(sb, tmp, block_group))
+ ext4_set_bit(EXT4_B2C(sbi, tmp - start), bh->b_data);
+
+ tmp = ext4_inode_table(sb, gdp);
+ for (; tmp < ext4_inode_table(sb, gdp) +
+ sbi->s_itb_per_group; tmp++) {
+ if (ext4_block_in_group(sb, tmp, block_group))
+ ext4_set_bit(EXT4_B2C(sbi, tmp - start), bh->b_data);
+ }
+
+ /*
+ * Also if the number of blocks within the group is less than
+ * the blocksize * 8 ( which is the size of bitmap ), set rest
+ * of the block bitmap to 1
+ */
+ ext4_mark_bitmap_end(num_clusters_in_group(sb, block_group),
+ sb->s_blocksize * 8, bh->b_data);
+ return 0;
+}
+
+/* Return the number of free blocks in a block group. It is used when
+ * the block bitmap is uninitialized, so we can't just count the bits
+ * in the bitmap. */
+unsigned ext4_free_clusters_after_init(struct super_block *sb,
+ ext4_group_t block_group,
+ struct ext4_group_desc *gdp)
+{
+ return num_clusters_in_group(sb, block_group) -
+ ext4_num_overhead_clusters(sb, block_group, gdp);
+}
+
+/*
+ * The free blocks are managed by bitmaps. A file system contains several
+ * blocks groups. Each group contains 1 bitmap block for blocks, 1 bitmap
+ * block for inodes, N blocks for the inode table and data blocks.
+ *
+ * The file system contains group descriptors which are located after the
+ * super block. Each descriptor contains the number of the bitmap block and
+ * the free blocks count in the block. The descriptors are loaded in memory
+ * when a file system is mounted (see ext4_fill_super).
+ */
+
+/**
+ * ext4_get_group_desc() -- load group descriptor from disk
+ * @sb: super block
+ * @block_group: given block group
+ * @bh: pointer to the buffer head to store the block
+ * group descriptor
+ */
+struct ext4_group_desc * ext4_get_group_desc(struct super_block *sb,
+ ext4_group_t block_group,
+ struct buffer_head **bh)
+{
+ unsigned int group_desc;
+ unsigned int offset;
+ ext4_group_t ngroups = ext4_get_groups_count(sb);
+ struct ext4_group_desc *desc;
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ struct buffer_head *bh_p;
+
+ KUNIT_STATIC_STUB_REDIRECT(ext4_get_group_desc,
+ sb, block_group, bh);
+
+ if (block_group >= ngroups) {
+ ext4_error(sb, "block_group >= groups_count - block_group = %u,"
+ " groups_count = %u", block_group, ngroups);
+
+ return NULL;
+ }
+
+ group_desc = block_group >> EXT4_DESC_PER_BLOCK_BITS(sb);
+ offset = block_group & (EXT4_DESC_PER_BLOCK(sb) - 1);
+ bh_p = sbi_array_rcu_deref(sbi, s_group_desc, group_desc);
+ /*
+ * sbi_array_rcu_deref returns with rcu unlocked, this is ok since
+ * the pointer being dereferenced won't be dereferenced again. By
+ * looking at the usage in add_new_gdb() the value isn't modified,
+ * just the pointer, and so it remains valid.
+ */
+ if (!bh_p) {
+ ext4_error(sb, "Group descriptor not loaded - "
+ "block_group = %u, group_desc = %u, desc = %u",
+ block_group, group_desc, offset);
+ return NULL;
+ }
+
+ desc = (struct ext4_group_desc *)(
+ (__u8 *)bh_p->b_data +
+ offset * EXT4_DESC_SIZE(sb));
+ if (bh)
+ *bh = bh_p;
+ return desc;
+}
+
+static ext4_fsblk_t ext4_valid_block_bitmap_padding(struct super_block *sb,
+ ext4_group_t block_group,
+ struct buffer_head *bh)
+{
+ ext4_grpblk_t next_zero_bit;
+ unsigned long bitmap_size = sb->s_blocksize * 8;
+ unsigned int offset = num_clusters_in_group(sb, block_group);
+
+ if (bitmap_size <= offset)
+ return 0;
+
+ next_zero_bit = ext4_find_next_zero_bit(bh->b_data, bitmap_size, offset);
+
+ return (next_zero_bit < bitmap_size ? next_zero_bit : 0);
+}
+
+struct ext4_group_info *ext4_get_group_info(struct super_block *sb,
+ ext4_group_t group)
+{
+ struct ext4_group_info **grp_info;
+ long indexv, indexh;
+
+ if (unlikely(group >= EXT4_SB(sb)->s_groups_count))
+ return NULL;
+ indexv = group >> (EXT4_DESC_PER_BLOCK_BITS(sb));
+ indexh = group & ((EXT4_DESC_PER_BLOCK(sb)) - 1);
+ grp_info = sbi_array_rcu_deref(EXT4_SB(sb), s_group_info, indexv);
+ return grp_info[indexh];
+}
+
+/*
+ * Return the block number which was discovered to be invalid, or 0 if
+ * the block bitmap is valid.
+ */
+static ext4_fsblk_t ext4_valid_block_bitmap(struct super_block *sb,
+ struct ext4_group_desc *desc,
+ ext4_group_t block_group,
+ struct buffer_head *bh)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ ext4_grpblk_t offset;
+ ext4_grpblk_t next_zero_bit;
+ ext4_grpblk_t max_bit = EXT4_CLUSTERS_PER_GROUP(sb);
+ ext4_fsblk_t blk;
+ ext4_fsblk_t group_first_block;
+
+ if (ext4_has_feature_flex_bg(sb)) {
+ /* with FLEX_BG, the inode/block bitmaps and itable
+ * blocks may not be in the group at all
+ * so the bitmap validation will be skipped for those groups
+ * or it has to also read the block group where the bitmaps
+ * are located to verify they are set.
+ */
+ return 0;
+ }
+ group_first_block = ext4_group_first_block_no(sb, block_group);
+
+ /* check whether block bitmap block number is set */
+ blk = ext4_block_bitmap(sb, desc);
+ offset = blk - group_first_block;
+ if (offset < 0 || EXT4_B2C(sbi, offset) >= max_bit ||
+ !ext4_test_bit(EXT4_B2C(sbi, offset), bh->b_data))
+ /* bad block bitmap */
+ return blk;
+
+ /* check whether the inode bitmap block number is set */
+ blk = ext4_inode_bitmap(sb, desc);
+ offset = blk - group_first_block;
+ if (offset < 0 || EXT4_B2C(sbi, offset) >= max_bit ||
+ !ext4_test_bit(EXT4_B2C(sbi, offset), bh->b_data))
+ /* bad block bitmap */
+ return blk;
+
+ /* check whether the inode table block number is set */
+ blk = ext4_inode_table(sb, desc);
+ offset = blk - group_first_block;
+ if (offset < 0 || EXT4_B2C(sbi, offset) >= max_bit ||
+ EXT4_B2C(sbi, offset + sbi->s_itb_per_group - 1) >= max_bit)
+ return blk;
+ next_zero_bit = ext4_find_next_zero_bit(bh->b_data,
+ EXT4_B2C(sbi, offset + sbi->s_itb_per_group - 1) + 1,
+ EXT4_B2C(sbi, offset));
+ if (next_zero_bit <
+ EXT4_B2C(sbi, offset + sbi->s_itb_per_group - 1) + 1)
+ /* bad bitmap for inode tables */
+ return blk;
+ return 0;
+}
+
+static int ext4_validate_block_bitmap(struct super_block *sb,
+ struct ext4_group_desc *desc,
+ ext4_group_t block_group,
+ struct buffer_head *bh)
+{
+ ext4_fsblk_t blk;
+ struct ext4_group_info *grp;
+
+ if (EXT4_SB(sb)->s_mount_state & EXT4_FC_REPLAY)
+ return 0;
+
+ grp = ext4_get_group_info(sb, block_group);
+
+ if (buffer_verified(bh))
+ return 0;
+ if (!grp || EXT4_MB_GRP_BBITMAP_CORRUPT(grp))
+ return -EFSCORRUPTED;
+
+ ext4_lock_group(sb, block_group);
+ if (buffer_verified(bh))
+ goto verified;
+ if (unlikely(!ext4_block_bitmap_csum_verify(sb, desc, bh) ||
+ ext4_simulate_fail(sb, EXT4_SIM_BBITMAP_CRC))) {
+ ext4_unlock_group(sb, block_group);
+ ext4_error(sb, "bg %u: bad block bitmap checksum", block_group);
+ ext4_mark_group_bitmap_corrupted(sb, block_group,
+ EXT4_GROUP_INFO_BBITMAP_CORRUPT);
+ return -EFSBADCRC;
+ }
+ blk = ext4_valid_block_bitmap(sb, desc, block_group, bh);
+ if (unlikely(blk != 0)) {
+ ext4_unlock_group(sb, block_group);
+ ext4_error(sb, "bg %u: block %llu: invalid block bitmap",
+ block_group, blk);
+ ext4_mark_group_bitmap_corrupted(sb, block_group,
+ EXT4_GROUP_INFO_BBITMAP_CORRUPT);
+ return -EFSCORRUPTED;
+ }
+ blk = ext4_valid_block_bitmap_padding(sb, block_group, bh);
+ if (unlikely(blk != 0)) {
+ ext4_unlock_group(sb, block_group);
+ ext4_error(sb, "bg %u: block %llu: padding at end of block bitmap is not set",
+ block_group, blk);
+ ext4_mark_group_bitmap_corrupted(sb, block_group,
+ EXT4_GROUP_INFO_BBITMAP_CORRUPT);
+ return -EFSCORRUPTED;
+ }
+ set_buffer_verified(bh);
+verified:
+ ext4_unlock_group(sb, block_group);
+ return 0;
+}
+
+/**
+ * ext4_read_block_bitmap_nowait()
+ * @sb: super block
+ * @block_group: given block group
+ * @ignore_locked: ignore locked buffers
+ *
+ * Read the bitmap for a given block_group,and validate the
+ * bits for block/inode/inode tables are set in the bitmaps
+ *
+ * Return buffer_head on success or an ERR_PTR in case of failure.
+ */
+struct buffer_head *
+ext4_read_block_bitmap_nowait(struct super_block *sb, ext4_group_t block_group,
+ bool ignore_locked)
+{
+ struct ext4_group_desc *desc;
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ struct buffer_head *bh;
+ ext4_fsblk_t bitmap_blk;
+ int err;
+
+ KUNIT_STATIC_STUB_REDIRECT(ext4_read_block_bitmap_nowait,
+ sb, block_group, ignore_locked);
+
+ desc = ext4_get_group_desc(sb, block_group, NULL);
+ if (!desc)
+ return ERR_PTR(-EFSCORRUPTED);
+ bitmap_blk = ext4_block_bitmap(sb, desc);
+ if ((bitmap_blk <= le32_to_cpu(sbi->s_es->s_first_data_block)) ||
+ (bitmap_blk >= ext4_blocks_count(sbi->s_es))) {
+ ext4_error(sb, "Invalid block bitmap block %llu in "
+ "block_group %u", bitmap_blk, block_group);
+ ext4_mark_group_bitmap_corrupted(sb, block_group,
+ EXT4_GROUP_INFO_BBITMAP_CORRUPT);
+ return ERR_PTR(-EFSCORRUPTED);
+ }
+ bh = sb_getblk(sb, bitmap_blk);
+ if (unlikely(!bh)) {
+ ext4_warning(sb, "Cannot get buffer for block bitmap - "
+ "block_group = %u, block_bitmap = %llu",
+ block_group, bitmap_blk);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ if (ignore_locked && buffer_locked(bh)) {
+ /* buffer under IO already, return if called for prefetching */
+ put_bh(bh);
+ return NULL;
+ }
+
+ if (bitmap_uptodate(bh))
+ goto verify;
+
+ lock_buffer(bh);
+ if (bitmap_uptodate(bh)) {
+ unlock_buffer(bh);
+ goto verify;
+ }
+ ext4_lock_group(sb, block_group);
+ if (ext4_has_group_desc_csum(sb) &&
+ (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) {
+ if (block_group == 0) {
+ ext4_unlock_group(sb, block_group);
+ unlock_buffer(bh);
+ ext4_error(sb, "Block bitmap for bg 0 marked "
+ "uninitialized");
+ err = -EFSCORRUPTED;
+ goto out;
+ }
+ err = ext4_init_block_bitmap(sb, bh, block_group, desc);
+ if (err) {
+ ext4_unlock_group(sb, block_group);
+ unlock_buffer(bh);
+ ext4_error(sb, "Failed to init block bitmap for group "
+ "%u: %d", block_group, err);
+ goto out;
+ }
+ set_bitmap_uptodate(bh);
+ set_buffer_uptodate(bh);
+ set_buffer_verified(bh);
+ ext4_unlock_group(sb, block_group);
+ unlock_buffer(bh);
+ return bh;
+ }
+ ext4_unlock_group(sb, block_group);
+ if (buffer_uptodate(bh)) {
+ /*
+ * if not uninit if bh is uptodate,
+ * bitmap is also uptodate
+ */
+ set_bitmap_uptodate(bh);
+ unlock_buffer(bh);
+ goto verify;
+ }
+ /*
+ * submit the buffer_head for reading
+ */
+ set_buffer_new(bh);
+ trace_ext4_read_block_bitmap_load(sb, block_group, ignore_locked);
+ ext4_read_bh_nowait(bh, REQ_META | REQ_PRIO |
+ (ignore_locked ? REQ_RAHEAD : 0),
+ ext4_end_bitmap_read,
+ ext4_simulate_fail(sb, EXT4_SIM_BBITMAP_EIO));
+ return bh;
+verify:
+ err = ext4_validate_block_bitmap(sb, desc, block_group, bh);
+ if (err)
+ goto out;
+ return bh;
+out:
+ put_bh(bh);
+ return ERR_PTR(err);
+}
+
+/* Returns 0 on success, -errno on error */
+int ext4_wait_block_bitmap(struct super_block *sb, ext4_group_t block_group,
+ struct buffer_head *bh)
+{
+ struct ext4_group_desc *desc;
+
+ KUNIT_STATIC_STUB_REDIRECT(ext4_wait_block_bitmap,
+ sb, block_group, bh);
+
+ if (!buffer_new(bh))
+ return 0;
+ desc = ext4_get_group_desc(sb, block_group, NULL);
+ if (!desc)
+ return -EFSCORRUPTED;
+ wait_on_buffer(bh);
+ if (!buffer_uptodate(bh)) {
+ ext4_error_err(sb, EIO, "Cannot read block bitmap - "
+ "block_group = %u, block_bitmap = %llu",
+ block_group, (unsigned long long) bh->b_blocknr);
+ ext4_mark_group_bitmap_corrupted(sb, block_group,
+ EXT4_GROUP_INFO_BBITMAP_CORRUPT);
+ return -EIO;
+ }
+ clear_buffer_new(bh);
+ /* Panic or remount fs read-only if block bitmap is invalid */
+ return ext4_validate_block_bitmap(sb, desc, block_group, bh);
+}
+
+struct buffer_head *
+ext4_read_block_bitmap(struct super_block *sb, ext4_group_t block_group)
+{
+ struct buffer_head *bh;
+ int err;
+
+ bh = ext4_read_block_bitmap_nowait(sb, block_group, false);
+ if (IS_ERR(bh))
+ return bh;
+ err = ext4_wait_block_bitmap(sb, block_group, bh);
+ if (err) {
+ put_bh(bh);
+ return ERR_PTR(err);
+ }
+ return bh;
+}
+
+/**
+ * ext4_has_free_clusters()
+ * @sbi: in-core super block structure.
+ * @nclusters: number of needed blocks
+ * @flags: flags from ext4_mb_new_blocks()
+ *
+ * Check if filesystem has nclusters free & available for allocation.
+ * On success return 1, return 0 on failure.
+ */
+static int ext4_has_free_clusters(struct ext4_sb_info *sbi,
+ s64 nclusters, unsigned int flags)
+{
+ s64 free_clusters, dirty_clusters, rsv, resv_clusters;
+ struct percpu_counter *fcc = &sbi->s_freeclusters_counter;
+ struct percpu_counter *dcc = &sbi->s_dirtyclusters_counter;
+
+ free_clusters = percpu_counter_read_positive(fcc);
+ dirty_clusters = percpu_counter_read_positive(dcc);
+ resv_clusters = atomic64_read(&sbi->s_resv_clusters);
+
+ /*
+ * r_blocks_count should always be multiple of the cluster ratio so
+ * we are safe to do a plane bit shift only.
+ */
+ rsv = (ext4_r_blocks_count(sbi->s_es) >> sbi->s_cluster_bits) +
+ resv_clusters;
+
+ if (free_clusters - (nclusters + rsv + dirty_clusters) <
+ EXT4_FREECLUSTERS_WATERMARK) {
+ free_clusters = percpu_counter_sum_positive(fcc);
+ dirty_clusters = percpu_counter_sum_positive(dcc);
+ }
+ /* Check whether we have space after accounting for current
+ * dirty clusters & root reserved clusters.
+ */
+ if (free_clusters >= (rsv + nclusters + dirty_clusters))
+ return 1;
+
+ /* Hm, nope. Are (enough) root reserved clusters available? */
+ if (uid_eq(sbi->s_resuid, current_fsuid()) ||
+ (!gid_eq(sbi->s_resgid, GLOBAL_ROOT_GID) && in_group_p(sbi->s_resgid)) ||
+ (flags & EXT4_MB_USE_ROOT_BLOCKS) ||
+ capable(CAP_SYS_RESOURCE)) {
+
+ if (free_clusters >= (nclusters + dirty_clusters +
+ resv_clusters))
+ return 1;
+ }
+ /* No free blocks. Let's see if we can dip into reserved pool */
+ if (flags & EXT4_MB_USE_RESERVED) {
+ if (free_clusters >= (nclusters + dirty_clusters))
+ return 1;
+ }
+
+ return 0;
+}
+
+int ext4_claim_free_clusters(struct ext4_sb_info *sbi,
+ s64 nclusters, unsigned int flags)
+{
+ if (ext4_has_free_clusters(sbi, nclusters, flags)) {
+ percpu_counter_add(&sbi->s_dirtyclusters_counter, nclusters);
+ return 0;
+ } else
+ return -ENOSPC;
+}
+
+/**
+ * ext4_should_retry_alloc() - check if a block allocation should be retried
+ * @sb: superblock
+ * @retries: number of retry attempts made so far
+ *
+ * ext4_should_retry_alloc() is called when ENOSPC is returned while
+ * attempting to allocate blocks. If there's an indication that a pending
+ * journal transaction might free some space and allow another attempt to
+ * succeed, this function will wait for the current or committing transaction
+ * to complete and then return TRUE.
+ */
+int ext4_should_retry_alloc(struct super_block *sb, int *retries)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+
+ if (!sbi->s_journal)
+ return 0;
+
+ if (++(*retries) > 3) {
+ percpu_counter_inc(&sbi->s_sra_exceeded_retry_limit);
+ return 0;
+ }
+
+ /*
+ * if there's no indication that blocks are about to be freed it's
+ * possible we just missed a transaction commit that did so
+ */
+ smp_mb();
+ if (atomic_read(&sbi->s_mb_free_pending) == 0) {
+ if (test_opt(sb, DISCARD)) {
+ atomic_inc(&sbi->s_retry_alloc_pending);
+ flush_work(&sbi->s_discard_work);
+ atomic_dec(&sbi->s_retry_alloc_pending);
+ }
+ return ext4_has_free_clusters(sbi, 1, 0);
+ }
+
+ /*
+ * it's possible we've just missed a transaction commit here,
+ * so ignore the returned status
+ */
+ ext4_debug("%s: retrying operation after ENOSPC\n", sb->s_id);
+ (void) jbd2_journal_force_commit_nested(sbi->s_journal);
+ return 1;
+}
+
+/*
+ * ext4_new_meta_blocks() -- allocate block for meta data (indexing) blocks
+ *
+ * @handle: handle to this transaction
+ * @inode: file inode
+ * @goal: given target block(filesystem wide)
+ * @count: pointer to total number of clusters needed
+ * @errp: error code
+ *
+ * Return 1st allocated block number on success, *count stores total account
+ * error stores in errp pointer
+ */
+ext4_fsblk_t ext4_new_meta_blocks(handle_t *handle, struct inode *inode,
+ ext4_fsblk_t goal, unsigned int flags,
+ unsigned long *count, int *errp)
+{
+ struct ext4_allocation_request ar;
+ ext4_fsblk_t ret;
+
+ memset(&ar, 0, sizeof(ar));
+ /* Fill with neighbour allocated blocks */
+ ar.inode = inode;
+ ar.goal = goal;
+ ar.len = count ? *count : 1;
+ ar.flags = flags;
+
+ ret = ext4_mb_new_blocks(handle, &ar, errp);
+ if (count)
+ *count = ar.len;
+ /*
+ * Account for the allocated meta blocks. We will never
+ * fail EDQUOT for metdata, but we do account for it.
+ */
+ if (!(*errp) && (flags & EXT4_MB_DELALLOC_RESERVED)) {
+ dquot_alloc_block_nofail(inode,
+ EXT4_C2B(EXT4_SB(inode->i_sb), ar.len));
+ }
+ return ret;
+}
+
+/**
+ * ext4_count_free_clusters() -- count filesystem free clusters
+ * @sb: superblock
+ *
+ * Adds up the number of free clusters from each block group.
+ */
+ext4_fsblk_t ext4_count_free_clusters(struct super_block *sb)
+{
+ ext4_fsblk_t desc_count;
+ struct ext4_group_desc *gdp;
+ ext4_group_t i;
+ ext4_group_t ngroups = ext4_get_groups_count(sb);
+ struct ext4_group_info *grp;
+#ifdef EXT4FS_DEBUG
+ struct ext4_super_block *es;
+ ext4_fsblk_t bitmap_count;
+ unsigned int x;
+ struct buffer_head *bitmap_bh = NULL;
+
+ es = EXT4_SB(sb)->s_es;
+ desc_count = 0;
+ bitmap_count = 0;
+ gdp = NULL;
+
+ for (i = 0; i < ngroups; i++) {
+ gdp = ext4_get_group_desc(sb, i, NULL);
+ if (!gdp)
+ continue;
+ grp = NULL;
+ if (EXT4_SB(sb)->s_group_info)
+ grp = ext4_get_group_info(sb, i);
+ if (!grp || !EXT4_MB_GRP_BBITMAP_CORRUPT(grp))
+ desc_count += ext4_free_group_clusters(sb, gdp);
+ brelse(bitmap_bh);
+ bitmap_bh = ext4_read_block_bitmap(sb, i);
+ if (IS_ERR(bitmap_bh)) {
+ bitmap_bh = NULL;
+ continue;
+ }
+
+ x = ext4_count_free(bitmap_bh->b_data,
+ EXT4_CLUSTERS_PER_GROUP(sb) / 8);
+ printk(KERN_DEBUG "group %u: stored = %d, counted = %u\n",
+ i, ext4_free_group_clusters(sb, gdp), x);
+ bitmap_count += x;
+ }
+ brelse(bitmap_bh);
+ printk(KERN_DEBUG "ext4_count_free_clusters: stored = %llu"
+ ", computed = %llu, %llu\n",
+ EXT4_NUM_B2C(EXT4_SB(sb), ext4_free_blocks_count(es)),
+ desc_count, bitmap_count);
+ return bitmap_count;
+#else
+ desc_count = 0;
+ for (i = 0; i < ngroups; i++) {
+ gdp = ext4_get_group_desc(sb, i, NULL);
+ if (!gdp)
+ continue;
+ grp = NULL;
+ if (EXT4_SB(sb)->s_group_info)
+ grp = ext4_get_group_info(sb, i);
+ if (!grp || !EXT4_MB_GRP_BBITMAP_CORRUPT(grp))
+ desc_count += ext4_free_group_clusters(sb, gdp);
+ }
+
+ return desc_count;
+#endif
+}
+
+static inline int test_root(ext4_group_t a, int b)
+{
+ while (1) {
+ if (a < b)
+ return 0;
+ if (a == b)
+ return 1;
+ if ((a % b) != 0)
+ return 0;
+ a = a / b;
+ }
+}
+
+/**
+ * ext4_bg_has_super - number of blocks used by the superblock in group
+ * @sb: superblock for filesystem
+ * @group: group number to check
+ *
+ * Return the number of blocks used by the superblock (primary or backup)
+ * in this group. Currently this will be only 0 or 1.
+ */
+int ext4_bg_has_super(struct super_block *sb, ext4_group_t group)
+{
+ struct ext4_super_block *es = EXT4_SB(sb)->s_es;
+
+ if (group == 0)
+ return 1;
+ if (ext4_has_feature_sparse_super2(sb)) {
+ if (group == le32_to_cpu(es->s_backup_bgs[0]) ||
+ group == le32_to_cpu(es->s_backup_bgs[1]))
+ return 1;
+ return 0;
+ }
+ if ((group <= 1) || !ext4_has_feature_sparse_super(sb))
+ return 1;
+ if (!(group & 1))
+ return 0;
+ if (test_root(group, 3) || (test_root(group, 5)) ||
+ test_root(group, 7))
+ return 1;
+
+ return 0;
+}
+
+static unsigned long ext4_bg_num_gdb_meta(struct super_block *sb,
+ ext4_group_t group)
+{
+ unsigned long metagroup = group / EXT4_DESC_PER_BLOCK(sb);
+ ext4_group_t first = metagroup * EXT4_DESC_PER_BLOCK(sb);
+ ext4_group_t last = first + EXT4_DESC_PER_BLOCK(sb) - 1;
+
+ if (group == first || group == first + 1 || group == last)
+ return 1;
+ return 0;
+}
+
+static unsigned long ext4_bg_num_gdb_nometa(struct super_block *sb,
+ ext4_group_t group)
+{
+ if (!ext4_bg_has_super(sb, group))
+ return 0;
+
+ if (ext4_has_feature_meta_bg(sb))
+ return le32_to_cpu(EXT4_SB(sb)->s_es->s_first_meta_bg);
+ else
+ return EXT4_SB(sb)->s_gdb_count;
+}
+
+/**
+ * ext4_bg_num_gdb - number of blocks used by the group table in group
+ * @sb: superblock for filesystem
+ * @group: group number to check
+ *
+ * Return the number of blocks used by the group descriptor table
+ * (primary or backup) in this group. In the future there may be a
+ * different number of descriptor blocks in each group.
+ */
+unsigned long ext4_bg_num_gdb(struct super_block *sb, ext4_group_t group)
+{
+ unsigned long first_meta_bg =
+ le32_to_cpu(EXT4_SB(sb)->s_es->s_first_meta_bg);
+ unsigned long metagroup = group / EXT4_DESC_PER_BLOCK(sb);
+
+ if (!ext4_has_feature_meta_bg(sb) || metagroup < first_meta_bg)
+ return ext4_bg_num_gdb_nometa(sb, group);
+
+ return ext4_bg_num_gdb_meta(sb,group);
+
+}
+
+/*
+ * This function returns the number of file system metadata blocks at
+ * the beginning of a block group, including the reserved gdt blocks.
+ */
+unsigned int ext4_num_base_meta_blocks(struct super_block *sb,
+ ext4_group_t block_group)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ unsigned num;
+
+ /* Check for superblock and gdt backups in this group */
+ num = ext4_bg_has_super(sb, block_group);
+
+ if (!ext4_has_feature_meta_bg(sb) ||
+ block_group < le32_to_cpu(sbi->s_es->s_first_meta_bg) *
+ sbi->s_desc_per_block) {
+ if (num) {
+ num += ext4_bg_num_gdb_nometa(sb, block_group);
+ num += le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks);
+ }
+ } else { /* For META_BG_BLOCK_GROUPS */
+ num += ext4_bg_num_gdb_meta(sb, block_group);
+ }
+ return num;
+}
+
+static unsigned int ext4_num_base_meta_clusters(struct super_block *sb,
+ ext4_group_t block_group)
+{
+ return EXT4_NUM_B2C(EXT4_SB(sb), ext4_num_base_meta_blocks(sb, block_group));
+}
+
+/**
+ * ext4_inode_to_goal_block - return a hint for block allocation
+ * @inode: inode for block allocation
+ *
+ * Return the ideal location to start allocating blocks for a
+ * newly created inode.
+ */
+ext4_fsblk_t ext4_inode_to_goal_block(struct inode *inode)
+{
+ struct ext4_inode_info *ei = EXT4_I(inode);
+ ext4_group_t block_group;
+ ext4_grpblk_t colour;
+ int flex_size = ext4_flex_bg_size(EXT4_SB(inode->i_sb));
+ ext4_fsblk_t bg_start;
+ ext4_fsblk_t last_block;
+
+ block_group = ei->i_block_group;
+ if (flex_size >= EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME) {
+ /*
+ * If there are at least EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME
+ * block groups per flexgroup, reserve the first block
+ * group for directories and special files. Regular
+ * files will start at the second block group. This
+ * tends to speed up directory access and improves
+ * fsck times.
+ */
+ block_group &= ~(flex_size-1);
+ if (S_ISREG(inode->i_mode))
+ block_group++;
+ }
+ bg_start = ext4_group_first_block_no(inode->i_sb, block_group);
+ last_block = ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es) - 1;
+
+ /*
+ * If we are doing delayed allocation, we don't need take
+ * colour into account.
+ */
+ if (test_opt(inode->i_sb, DELALLOC))
+ return bg_start;
+
+ if (bg_start + EXT4_BLOCKS_PER_GROUP(inode->i_sb) <= last_block)
+ colour = (task_pid_nr(current) % 16) *
+ (EXT4_BLOCKS_PER_GROUP(inode->i_sb) / 16);
+ else
+ colour = (task_pid_nr(current) % 16) *
+ ((last_block - bg_start) / 16);
+ return bg_start + colour;
+}
+
new file mode 100644
@@ -0,0 +1,99 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/ext4/bitmap.c
+ *
+ * Copyright (C) 1992, 1993, 1994, 1995
+ * Remy Card (card@masi.ibp.fr)
+ * Laboratoire MASI - Institut Blaise Pascal
+ * Universite Pierre et Marie Curie (Paris VI)
+ */
+
+#include <linux/buffer_head.h>
+#include "ext4.h"
+
+unsigned int ext4_count_free(char *bitmap, unsigned int numchars)
+{
+ return numchars * BITS_PER_BYTE - memweight(bitmap, numchars);
+}
+
+int ext4_inode_bitmap_csum_verify(struct super_block *sb,
+ struct ext4_group_desc *gdp,
+ struct buffer_head *bh)
+{
+ __u32 hi;
+ __u32 provided, calculated;
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ int sz;
+
+ if (!ext4_has_feature_metadata_csum(sb))
+ return 1;
+
+ sz = EXT4_INODES_PER_GROUP(sb) >> 3;
+ provided = le16_to_cpu(gdp->bg_inode_bitmap_csum_lo);
+ calculated = ext4_chksum(sbi->s_csum_seed, (__u8 *)bh->b_data, sz);
+ if (sbi->s_desc_size >= EXT4_BG_INODE_BITMAP_CSUM_HI_END) {
+ hi = le16_to_cpu(gdp->bg_inode_bitmap_csum_hi);
+ provided |= (hi << 16);
+ } else
+ calculated &= 0xFFFF;
+
+ return provided == calculated;
+}
+
+void ext4_inode_bitmap_csum_set(struct super_block *sb,
+ struct ext4_group_desc *gdp,
+ struct buffer_head *bh)
+{
+ __u32 csum;
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ int sz;
+
+ if (!ext4_has_feature_metadata_csum(sb))
+ return;
+
+ sz = EXT4_INODES_PER_GROUP(sb) >> 3;
+ csum = ext4_chksum(sbi->s_csum_seed, (__u8 *)bh->b_data, sz);
+ gdp->bg_inode_bitmap_csum_lo = cpu_to_le16(csum & 0xFFFF);
+ if (sbi->s_desc_size >= EXT4_BG_INODE_BITMAP_CSUM_HI_END)
+ gdp->bg_inode_bitmap_csum_hi = cpu_to_le16(csum >> 16);
+}
+
+int ext4_block_bitmap_csum_verify(struct super_block *sb,
+ struct ext4_group_desc *gdp,
+ struct buffer_head *bh)
+{
+ __u32 hi;
+ __u32 provided, calculated;
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ int sz = EXT4_CLUSTERS_PER_GROUP(sb) / 8;
+
+ if (!ext4_has_feature_metadata_csum(sb))
+ return 1;
+
+ provided = le16_to_cpu(gdp->bg_block_bitmap_csum_lo);
+ calculated = ext4_chksum(sbi->s_csum_seed, (__u8 *)bh->b_data, sz);
+ if (sbi->s_desc_size >= EXT4_BG_BLOCK_BITMAP_CSUM_HI_END) {
+ hi = le16_to_cpu(gdp->bg_block_bitmap_csum_hi);
+ provided |= (hi << 16);
+ } else
+ calculated &= 0xFFFF;
+
+ return provided == calculated;
+}
+
+void ext4_block_bitmap_csum_set(struct super_block *sb,
+ struct ext4_group_desc *gdp,
+ struct buffer_head *bh)
+{
+ int sz = EXT4_CLUSTERS_PER_GROUP(sb) / 8;
+ __u32 csum;
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+
+ if (!ext4_has_feature_metadata_csum(sb))
+ return;
+
+ csum = ext4_chksum(sbi->s_csum_seed, (__u8 *)bh->b_data, sz);
+ gdp->bg_block_bitmap_csum_lo = cpu_to_le16(csum & 0xFFFF);
+ if (sbi->s_desc_size >= EXT4_BG_BLOCK_BITMAP_CSUM_HI_END)
+ gdp->bg_block_bitmap_csum_hi = cpu_to_le16(csum >> 16);
+}
new file mode 100644
@@ -0,0 +1,370 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/ext4/block_validity.c
+ *
+ * Copyright (C) 2009
+ * Theodore Ts'o (tytso@mit.edu)
+ *
+ * Track which blocks in the filesystem are metadata blocks that
+ * should never be used as data blocks by files or directories.
+ */
+
+#include <linux/time.h>
+#include <linux/fs.h>
+#include <linux/namei.h>
+#include <linux/quotaops.h>
+#include <linux/buffer_head.h>
+#include <linux/swap.h>
+#include <linux/pagemap.h>
+#include <linux/blkdev.h>
+#include <linux/slab.h>
+#include "ext4.h"
+
+struct ext4_system_zone {
+ struct rb_node node;
+ ext4_fsblk_t start_blk;
+ unsigned int count;
+ u32 ino;
+};
+
+static struct kmem_cache *ext4_system_zone_cachep;
+
+int __init ext4_init_system_zone(void)
+{
+ ext4_system_zone_cachep = KMEM_CACHE(ext4_system_zone, 0);
+ if (ext4_system_zone_cachep == NULL)
+ return -ENOMEM;
+ return 0;
+}
+
+void ext4_exit_system_zone(void)
+{
+ rcu_barrier();
+ kmem_cache_destroy(ext4_system_zone_cachep);
+}
+
+static inline int can_merge(struct ext4_system_zone *entry1,
+ struct ext4_system_zone *entry2)
+{
+ if ((entry1->start_blk + entry1->count) == entry2->start_blk &&
+ entry1->ino == entry2->ino)
+ return 1;
+ return 0;
+}
+
+static void release_system_zone(struct ext4_system_blocks *system_blks)
+{
+ struct ext4_system_zone *entry, *n;
+
+ rbtree_postorder_for_each_entry_safe(entry, n,
+ &system_blks->root, node)
+ kmem_cache_free(ext4_system_zone_cachep, entry);
+}
+
+/*
+ * Mark a range of blocks as belonging to the "system zone" --- that
+ * is, filesystem metadata blocks which should never be used by
+ * inodes.
+ */
+static int add_system_zone(struct ext4_system_blocks *system_blks,
+ ext4_fsblk_t start_blk,
+ unsigned int count, u32 ino)
+{
+ struct ext4_system_zone *new_entry, *entry;
+ struct rb_node **n = &system_blks->root.rb_node, *node;
+ struct rb_node *parent = NULL, *new_node;
+
+ while (*n) {
+ parent = *n;
+ entry = rb_entry(parent, struct ext4_system_zone, node);
+ if (start_blk < entry->start_blk)
+ n = &(*n)->rb_left;
+ else if (start_blk >= (entry->start_blk + entry->count))
+ n = &(*n)->rb_right;
+ else /* Unexpected overlap of system zones. */
+ return -EFSCORRUPTED;
+ }
+
+ new_entry = kmem_cache_alloc(ext4_system_zone_cachep,
+ GFP_KERNEL);
+ if (!new_entry)
+ return -ENOMEM;
+ new_entry->start_blk = start_blk;
+ new_entry->count = count;
+ new_entry->ino = ino;
+ new_node = &new_entry->node;
+
+ rb_link_node(new_node, parent, n);
+ rb_insert_color(new_node, &system_blks->root);
+
+ /* Can we merge to the left? */
+ node = rb_prev(new_node);
+ if (node) {
+ entry = rb_entry(node, struct ext4_system_zone, node);
+ if (can_merge(entry, new_entry)) {
+ new_entry->start_blk = entry->start_blk;
+ new_entry->count += entry->count;
+ rb_erase(node, &system_blks->root);
+ kmem_cache_free(ext4_system_zone_cachep, entry);
+ }
+ }
+
+ /* Can we merge to the right? */
+ node = rb_next(new_node);
+ if (node) {
+ entry = rb_entry(node, struct ext4_system_zone, node);
+ if (can_merge(new_entry, entry)) {
+ new_entry->count += entry->count;
+ rb_erase(node, &system_blks->root);
+ kmem_cache_free(ext4_system_zone_cachep, entry);
+ }
+ }
+ return 0;
+}
+
+static void debug_print_tree(struct ext4_sb_info *sbi)
+{
+ struct rb_node *node;
+ struct ext4_system_zone *entry;
+ struct ext4_system_blocks *system_blks;
+ int first = 1;
+
+ printk(KERN_INFO "System zones: ");
+ rcu_read_lock();
+ system_blks = rcu_dereference(sbi->s_system_blks);
+ node = rb_first(&system_blks->root);
+ while (node) {
+ entry = rb_entry(node, struct ext4_system_zone, node);
+ printk(KERN_CONT "%s%llu-%llu", first ? "" : ", ",
+ entry->start_blk, entry->start_blk + entry->count - 1);
+ first = 0;
+ node = rb_next(node);
+ }
+ rcu_read_unlock();
+ printk(KERN_CONT "\n");
+}
+
+static int ext4_protect_reserved_inode(struct super_block *sb,
+ struct ext4_system_blocks *system_blks,
+ u32 ino)
+{
+ struct inode *inode;
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ struct ext4_map_blocks map;
+ u32 i = 0, num;
+ int err = 0, n;
+
+ if ((ino < EXT4_ROOT_INO) ||
+ (ino > le32_to_cpu(sbi->s_es->s_inodes_count)))
+ return -EINVAL;
+ inode = ext4_iget(sb, ino, EXT4_IGET_SPECIAL);
+ if (IS_ERR(inode))
+ return PTR_ERR(inode);
+ num = (inode->i_size + sb->s_blocksize - 1) >> sb->s_blocksize_bits;
+ while (i < num) {
+ cond_resched();
+ map.m_lblk = i;
+ map.m_len = num - i;
+ n = ext4_map_blocks(NULL, inode, &map, 0);
+ if (n < 0) {
+ err = n;
+ break;
+ }
+ if (n == 0) {
+ i++;
+ } else {
+ err = add_system_zone(system_blks, map.m_pblk, n, ino);
+ if (err < 0) {
+ if (err == -EFSCORRUPTED) {
+ EXT4_ERROR_INODE_ERR(inode, -err,
+ "blocks %llu-%llu from inode overlap system zone",
+ map.m_pblk,
+ map.m_pblk + map.m_len - 1);
+ }
+ break;
+ }
+ i += n;
+ }
+ }
+ iput(inode);
+ return err;
+}
+
+static void ext4_destroy_system_zone(struct rcu_head *rcu)
+{
+ struct ext4_system_blocks *system_blks;
+
+ system_blks = container_of(rcu, struct ext4_system_blocks, rcu);
+ release_system_zone(system_blks);
+ kfree(system_blks);
+}
+
+/*
+ * Build system zone rbtree which is used for block validity checking.
+ *
+ * The update of system_blks pointer in this function is protected by
+ * sb->s_umount semaphore. However we have to be careful as we can be
+ * racing with ext4_inode_block_valid() calls reading system_blks rbtree
+ * protected only by RCU. That's why we first build the rbtree and then
+ * swap it in place.
+ */
+int ext4_setup_system_zone(struct super_block *sb)
+{
+ ext4_group_t ngroups = ext4_get_groups_count(sb);
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ struct ext4_system_blocks *system_blks;
+ struct ext4_group_desc *gdp;
+ ext4_group_t i;
+ int ret;
+
+ system_blks = kzalloc(sizeof(*system_blks), GFP_KERNEL);
+ if (!system_blks)
+ return -ENOMEM;
+
+ for (i=0; i < ngroups; i++) {
+ unsigned int meta_blks = ext4_num_base_meta_blocks(sb, i);
+
+ cond_resched();
+ if (meta_blks != 0) {
+ ret = add_system_zone(system_blks,
+ ext4_group_first_block_no(sb, i),
+ meta_blks, 0);
+ if (ret)
+ goto err;
+ }
+ gdp = ext4_get_group_desc(sb, i, NULL);
+ ret = add_system_zone(system_blks,
+ ext4_block_bitmap(sb, gdp), 1, 0);
+ if (ret)
+ goto err;
+ ret = add_system_zone(system_blks,
+ ext4_inode_bitmap(sb, gdp), 1, 0);
+ if (ret)
+ goto err;
+ ret = add_system_zone(system_blks,
+ ext4_inode_table(sb, gdp),
+ sbi->s_itb_per_group, 0);
+ if (ret)
+ goto err;
+ }
+ if (ext4_has_feature_journal(sb) && sbi->s_es->s_journal_inum) {
+ ret = ext4_protect_reserved_inode(sb, system_blks,
+ le32_to_cpu(sbi->s_es->s_journal_inum));
+ if (ret)
+ goto err;
+ }
+
+ /*
+ * System blks rbtree complete, announce it once to prevent racing
+ * with ext4_inode_block_valid() accessing the rbtree at the same
+ * time.
+ */
+ rcu_assign_pointer(sbi->s_system_blks, system_blks);
+
+ if (test_opt(sb, DEBUG))
+ debug_print_tree(sbi);
+ return 0;
+err:
+ release_system_zone(system_blks);
+ kfree(system_blks);
+ return ret;
+}
+
+/*
+ * Called when the filesystem is unmounted or when remounting it with
+ * noblock_validity specified.
+ *
+ * The update of system_blks pointer in this function is protected by
+ * sb->s_umount semaphore. However we have to be careful as we can be
+ * racing with ext4_inode_block_valid() calls reading system_blks rbtree
+ * protected only by RCU. So we first clear the system_blks pointer and
+ * then free the rbtree only after RCU grace period expires.
+ */
+void ext4_release_system_zone(struct super_block *sb)
+{
+ struct ext4_system_blocks *system_blks;
+
+ system_blks = rcu_dereference_protected(EXT4_SB(sb)->s_system_blks,
+ lockdep_is_held(&sb->s_umount));
+ rcu_assign_pointer(EXT4_SB(sb)->s_system_blks, NULL);
+
+ if (system_blks)
+ call_rcu(&system_blks->rcu, ext4_destroy_system_zone);
+}
+
+int ext4_sb_block_valid(struct super_block *sb, struct inode *inode,
+ ext4_fsblk_t start_blk, unsigned int count)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ struct ext4_system_blocks *system_blks;
+ struct ext4_system_zone *entry;
+ struct rb_node *n;
+ int ret = 1;
+
+ if ((start_blk <= le32_to_cpu(sbi->s_es->s_first_data_block)) ||
+ (start_blk + count < start_blk) ||
+ (start_blk + count > ext4_blocks_count(sbi->s_es)))
+ return 0;
+
+ /*
+ * Lock the system zone to prevent it being released concurrently
+ * when doing a remount which inverse current "[no]block_validity"
+ * mount option.
+ */
+ rcu_read_lock();
+ system_blks = rcu_dereference(sbi->s_system_blks);
+ if (system_blks == NULL)
+ goto out_rcu;
+
+ n = system_blks->root.rb_node;
+ while (n) {
+ entry = rb_entry(n, struct ext4_system_zone, node);
+ if (start_blk + count - 1 < entry->start_blk)
+ n = n->rb_left;
+ else if (start_blk >= (entry->start_blk + entry->count))
+ n = n->rb_right;
+ else {
+ ret = 0;
+ if (inode)
+ ret = (entry->ino == inode->i_ino);
+ break;
+ }
+ }
+out_rcu:
+ rcu_read_unlock();
+ return ret;
+}
+
+/*
+ * Returns 1 if the passed-in block region (start_blk,
+ * start_blk+count) is valid; 0 if some part of the block region
+ * overlaps with some other filesystem metadata blocks.
+ */
+int ext4_inode_block_valid(struct inode *inode, ext4_fsblk_t start_blk,
+ unsigned int count)
+{
+ return ext4_sb_block_valid(inode->i_sb, inode, start_blk, count);
+}
+
+int ext4_check_blockref(const char *function, unsigned int line,
+ struct inode *inode, __le32 *p, unsigned int max)
+{
+ __le32 *bref = p;
+ unsigned int blk;
+ journal_t *journal = EXT4_SB(inode->i_sb)->s_journal;
+
+ if (journal && inode == journal->j_inode)
+ return 0;
+
+ while (bref < p+max) {
+ blk = le32_to_cpu(*bref++);
+ if (blk &&
+ unlikely(!ext4_inode_block_valid(inode, blk, 1))) {
+ ext4_error_inode(inode, function, line, blk,
+ "invalid block");
+ return -EFSCORRUPTED;
+ }
+ }
+ return 0;
+}
+
new file mode 100644
@@ -0,0 +1,241 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/quotaops.h>
+#include <linux/uuid.h>
+
+#include "ext4.h"
+#include "xattr.h"
+#include "ext4_jbd2.h"
+
+static void ext4_fname_from_fscrypt_name(struct ext4_filename *dst,
+ const struct fscrypt_name *src)
+{
+ memset(dst, 0, sizeof(*dst));
+
+ dst->usr_fname = src->usr_fname;
+ dst->disk_name = src->disk_name;
+ dst->hinfo.hash = src->hash;
+ dst->hinfo.minor_hash = src->minor_hash;
+ dst->crypto_buf = src->crypto_buf;
+}
+
+int ext4_fname_setup_filename(struct inode *dir, const struct qstr *iname,
+ int lookup, struct ext4_filename *fname)
+{
+ struct fscrypt_name name;
+ int err;
+
+ err = fscrypt_setup_filename(dir, iname, lookup, &name);
+ if (err)
+ return err;
+
+ ext4_fname_from_fscrypt_name(fname, &name);
+
+ err = ext4_fname_setup_ci_filename(dir, iname, fname);
+ if (err)
+ ext4_fname_free_filename(fname);
+
+ return err;
+}
+
+int ext4_fname_prepare_lookup(struct inode *dir, struct dentry *dentry,
+ struct ext4_filename *fname)
+{
+ struct fscrypt_name name;
+ int err;
+
+ err = fscrypt_prepare_lookup(dir, dentry, &name);
+ if (err)
+ return err;
+
+ ext4_fname_from_fscrypt_name(fname, &name);
+
+ err = ext4_fname_setup_ci_filename(dir, &dentry->d_name, fname);
+ if (err)
+ ext4_fname_free_filename(fname);
+ return err;
+}
+
+void ext4_fname_free_filename(struct ext4_filename *fname)
+{
+ struct fscrypt_name name;
+
+ name.crypto_buf = fname->crypto_buf;
+ fscrypt_free_filename(&name);
+
+ fname->crypto_buf.name = NULL;
+ fname->usr_fname = NULL;
+ fname->disk_name.name = NULL;
+
+ ext4_fname_free_ci_filename(fname);
+}
+
+static bool uuid_is_zero(__u8 u[16])
+{
+ int i;
+
+ for (i = 0; i < 16; i++)
+ if (u[i])
+ return false;
+ return true;
+}
+
+int ext4_ioctl_get_encryption_pwsalt(struct file *filp, void __user *arg)
+{
+ struct super_block *sb = file_inode(filp)->i_sb;
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ int err, err2;
+ handle_t *handle;
+
+ if (!ext4_has_feature_encrypt(sb))
+ return -EOPNOTSUPP;
+
+ if (uuid_is_zero(sbi->s_es->s_encrypt_pw_salt)) {
+ err = mnt_want_write_file(filp);
+ if (err)
+ return err;
+ handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1);
+ if (IS_ERR(handle)) {
+ err = PTR_ERR(handle);
+ goto pwsalt_err_exit;
+ }
+ err = ext4_journal_get_write_access(handle, sb, sbi->s_sbh,
+ EXT4_JTR_NONE);
+ if (err)
+ goto pwsalt_err_journal;
+ lock_buffer(sbi->s_sbh);
+ generate_random_uuid(sbi->s_es->s_encrypt_pw_salt);
+ ext4_superblock_csum_set(sb);
+ unlock_buffer(sbi->s_sbh);
+ err = ext4_handle_dirty_metadata(handle, NULL, sbi->s_sbh);
+pwsalt_err_journal:
+ err2 = ext4_journal_stop(handle);
+ if (err2 && !err)
+ err = err2;
+pwsalt_err_exit:
+ mnt_drop_write_file(filp);
+ if (err)
+ return err;
+ }
+
+ if (copy_to_user(arg, sbi->s_es->s_encrypt_pw_salt, 16))
+ return -EFAULT;
+ return 0;
+}
+
+static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
+{
+ return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
+ EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
+}
+
+static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
+ void *fs_data)
+{
+ handle_t *handle = fs_data;
+ int res, res2, credits, retries = 0;
+
+ /*
+ * Encrypting the root directory is not allowed because e2fsck expects
+ * lost+found to exist and be unencrypted, and encrypting the root
+ * directory would imply encrypting the lost+found directory as well as
+ * the filename "lost+found" itself.
+ */
+ if (inode->i_ino == EXT4_ROOT_INO)
+ return -EPERM;
+
+ if (WARN_ON_ONCE(IS_DAX(inode) && i_size_read(inode)))
+ return -EINVAL;
+
+ if (ext4_test_inode_flag(inode, EXT4_INODE_DAX))
+ return -EOPNOTSUPP;
+
+ res = ext4_convert_inline_data(inode);
+ if (res)
+ return res;
+
+ /*
+ * If a journal handle was specified, then the encryption context is
+ * being set on a new inode via inheritance and is part of a larger
+ * transaction to create the inode. Otherwise the encryption context is
+ * being set on an existing inode in its own transaction. Only in the
+ * latter case should the "retry on ENOSPC" logic be used.
+ */
+
+ if (handle) {
+ res = ext4_xattr_set_handle(handle, inode,
+ EXT4_XATTR_INDEX_ENCRYPTION,
+ EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
+ ctx, len, 0);
+ if (!res) {
+ ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
+ ext4_clear_inode_state(inode,
+ EXT4_STATE_MAY_INLINE_DATA);
+ /*
+ * Update inode->i_flags - S_ENCRYPTED will be enabled,
+ * S_DAX may be disabled
+ */
+ ext4_set_inode_flags(inode, false);
+ }
+ return res;
+ }
+
+ res = dquot_initialize(inode);
+ if (res)
+ return res;
+retry:
+ res = ext4_xattr_set_credits(inode, len, false /* is_create */,
+ &credits);
+ if (res)
+ return res;
+
+ handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
+ if (IS_ERR(handle))
+ return PTR_ERR(handle);
+
+ res = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_ENCRYPTION,
+ EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
+ ctx, len, 0);
+ if (!res) {
+ ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
+ /*
+ * Update inode->i_flags - S_ENCRYPTED will be enabled,
+ * S_DAX may be disabled
+ */
+ ext4_set_inode_flags(inode, false);
+ res = ext4_mark_inode_dirty(handle, inode);
+ if (res)
+ EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
+ }
+ res2 = ext4_journal_stop(handle);
+
+ if (res == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
+ goto retry;
+ if (!res)
+ res = res2;
+ return res;
+}
+
+static const union fscrypt_policy *ext4_get_dummy_policy(struct super_block *sb)
+{
+ return EXT4_SB(sb)->s_dummy_enc_policy.policy;
+}
+
+static bool ext4_has_stable_inodes(struct super_block *sb)
+{
+ return ext4_has_feature_stable_inodes(sb);
+}
+
+const struct fscrypt_operations ext4_cryptops = {
+ .inode_info_offs = (int)offsetof(struct ext4_inode_info, i_crypt_info) -
+ (int)offsetof(struct ext4_inode_info, vfs_inode),
+ .needs_bounce_pages = 1,
+ .has_32bit_inodes = 1,
+ .supports_subblock_data_units = 1,
+ .legacy_key_prefix = "ext4:",
+ .get_context = ext4_get_context,
+ .set_context = ext4_set_context,
+ .get_dummy_policy = ext4_get_dummy_policy,
+ .empty_dir = ext4_empty_dir,
+ .has_stable_inodes = ext4_has_stable_inodes,
+};
new file mode 100644
@@ -0,0 +1,693 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/ext4/dir.c
+ *
+ * Copyright (C) 1992, 1993, 1994, 1995
+ * Remy Card (card@masi.ibp.fr)
+ * Laboratoire MASI - Institut Blaise Pascal
+ * Universite Pierre et Marie Curie (Paris VI)
+ *
+ * from
+ *
+ * linux/fs/minix/dir.c
+ *
+ * Copyright (C) 1991, 1992 Linus Torvalds
+ *
+ * ext4 directory handling functions
+ *
+ * Big-endian to little-endian byte-swapping/bitmaps by
+ * David S. Miller (davem@caip.rutgers.edu), 1995
+ *
+ * Hash Tree Directory indexing (c) 2001 Daniel Phillips
+ *
+ */
+
+#include <linux/fs.h>
+#include <linux/buffer_head.h>
+#include <linux/slab.h>
+#include <linux/iversion.h>
+#include <linux/unicode.h>
+#include "ext4.h"
+#include "xattr.h"
+
+static int ext4_dx_readdir(struct file *, struct dir_context *);
+
+/**
+ * is_dx_dir() - check if a directory is using htree indexing
+ * @inode: directory inode
+ *
+ * Check if the given dir-inode refers to an htree-indexed directory
+ * (or a directory which could potentially get converted to use htree
+ * indexing).
+ *
+ * Return 1 if it is a dx dir, 0 if not
+ */
+static int is_dx_dir(struct inode *inode)
+{
+ struct super_block *sb = inode->i_sb;
+
+ if (ext4_has_feature_dir_index(inode->i_sb) &&
+ ((ext4_test_inode_flag(inode, EXT4_INODE_INDEX)) ||
+ ((inode->i_size >> sb->s_blocksize_bits) == 1) ||
+ ext4_has_inline_data(inode)))
+ return 1;
+
+ return 0;
+}
+
+static bool is_fake_dir_entry(struct ext4_dir_entry_2 *de)
+{
+ /* Check if . or .. , or skip if namelen is 0 */
+ if ((de->name_len > 0) && (de->name_len <= 2) && (de->name[0] == '.') &&
+ (de->name[1] == '.' || de->name[1] == '\0'))
+ return true;
+ /* Check if this is a csum entry */
+ if (de->file_type == EXT4_FT_DIR_CSUM)
+ return true;
+ return false;
+}
+
+/*
+ * Return 0 if the directory entry is OK, and 1 if there is a problem
+ *
+ * Note: this is the opposite of what ext2 and ext3 historically returned...
+ *
+ * bh passed here can be an inode block or a dir data block, depending
+ * on the inode inline data flag.
+ */
+int __ext4_check_dir_entry(const char *function, unsigned int line,
+ struct inode *dir, struct file *filp,
+ struct ext4_dir_entry_2 *de,
+ struct buffer_head *bh, char *buf, int size,
+ unsigned int offset)
+{
+ const char *error_msg = NULL;
+ const int rlen = ext4_rec_len_from_disk(de->rec_len,
+ dir->i_sb->s_blocksize);
+ const int next_offset = ((char *) de - buf) + rlen;
+ bool fake = is_fake_dir_entry(de);
+ bool has_csum = ext4_has_feature_metadata_csum(dir->i_sb);
+
+ if (unlikely(rlen < ext4_dir_rec_len(1, fake ? NULL : dir)))
+ error_msg = "rec_len is smaller than minimal";
+ else if (unlikely(rlen % 4 != 0))
+ error_msg = "rec_len % 4 != 0";
+ else if (unlikely(rlen < ext4_dir_rec_len(de->name_len,
+ fake ? NULL : dir)))
+ error_msg = "rec_len is too small for name_len";
+ else if (unlikely(next_offset > size))
+ error_msg = "directory entry overrun";
+ else if (unlikely(next_offset > size - ext4_dir_rec_len(1,
+ has_csum ? NULL : dir) &&
+ next_offset != size))
+ error_msg = "directory entry too close to block end";
+ else if (unlikely(le32_to_cpu(de->inode) >
+ le32_to_cpu(EXT4_SB(dir->i_sb)->s_es->s_inodes_count)))
+ error_msg = "inode out of bounds";
+ else if (unlikely(next_offset == size && de->name_len == 1 &&
+ de->name[0] == '.'))
+ error_msg = "'.' directory cannot be the last in data block";
+ else
+ return 0;
+
+ if (filp)
+ ext4_error_file(filp, function, line, bh->b_blocknr,
+ "bad entry in directory: %s - offset=%u, "
+ "inode=%u, rec_len=%d, size=%d fake=%d",
+ error_msg, offset, le32_to_cpu(de->inode),
+ rlen, size, fake);
+ else
+ ext4_error_inode(dir, function, line, bh->b_blocknr,
+ "bad entry in directory: %s - offset=%u, "
+ "inode=%u, rec_len=%d, size=%d fake=%d",
+ error_msg, offset, le32_to_cpu(de->inode),
+ rlen, size, fake);
+
+ return 1;
+}
+
+static int ext4_readdir(struct file *file, struct dir_context *ctx)
+{
+ unsigned int offset;
+ int i;
+ struct ext4_dir_entry_2 *de;
+ int err;
+ struct inode *inode = file_inode(file);
+ struct super_block *sb = inode->i_sb;
+ struct buffer_head *bh = NULL;
+ struct fscrypt_str fstr = FSTR_INIT(NULL, 0);
+ struct dir_private_info *info = file->private_data;
+
+ err = fscrypt_prepare_readdir(inode);
+ if (err)
+ return err;
+
+ if (is_dx_dir(inode)) {
+ err = ext4_dx_readdir(file, ctx);
+ if (err != ERR_BAD_DX_DIR)
+ return err;
+
+ /* Can we just clear INDEX flag to ignore htree information? */
+ if (!ext4_has_feature_metadata_csum(sb)) {
+ /*
+ * We don't set the inode dirty flag since it's not
+ * critical that it gets flushed back to the disk.
+ */
+ ext4_clear_inode_flag(inode, EXT4_INODE_INDEX);
+ }
+ }
+
+ if (ext4_has_inline_data(inode)) {
+ int has_inline_data = 1;
+ err = ext4_read_inline_dir(file, ctx,
+ &has_inline_data);
+ if (has_inline_data)
+ return err;
+ }
+
+ if (IS_ENCRYPTED(inode)) {
+ err = fscrypt_fname_alloc_buffer(EXT4_NAME_LEN, &fstr);
+ if (err < 0)
+ return err;
+ }
+
+ while (ctx->pos < inode->i_size) {
+ struct ext4_map_blocks map;
+
+ if (fatal_signal_pending(current)) {
+ err = -ERESTARTSYS;
+ goto errout;
+ }
+ cond_resched();
+ offset = ctx->pos & (sb->s_blocksize - 1);
+ map.m_lblk = ctx->pos >> EXT4_BLOCK_SIZE_BITS(sb);
+ map.m_len = 1;
+ err = ext4_map_blocks(NULL, inode, &map, 0);
+ if (err == 0) {
+ /* m_len should never be zero but let's avoid
+ * an infinite loop if it somehow is */
+ if (map.m_len == 0)
+ map.m_len = 1;
+ ctx->pos += map.m_len * sb->s_blocksize;
+ continue;
+ }
+ if (err > 0) {
+ pgoff_t index = map.m_pblk >>
+ (PAGE_SHIFT - inode->i_blkbits);
+ if (!ra_has_index(&file->f_ra, index))
+ page_cache_sync_readahead(
+ sb->s_bdev->bd_mapping,
+ &file->f_ra, file,
+ index, 1);
+ file->f_ra.prev_pos = (loff_t)index << PAGE_SHIFT;
+ bh = ext4_bread(NULL, inode, map.m_lblk, 0);
+ if (IS_ERR(bh)) {
+ err = PTR_ERR(bh);
+ bh = NULL;
+ goto errout;
+ }
+ }
+
+ if (!bh) {
+ /* corrupt size? Maybe no more blocks to read */
+ if (ctx->pos > inode->i_blocks << 9)
+ break;
+ ctx->pos += sb->s_blocksize - offset;
+ continue;
+ }
+
+ /* Check the checksum */
+ if (!buffer_verified(bh) &&
+ !ext4_dirblock_csum_verify(inode, bh)) {
+ EXT4_ERROR_FILE(file, 0, "directory fails checksum "
+ "at offset %llu",
+ (unsigned long long)ctx->pos);
+ ctx->pos += sb->s_blocksize - offset;
+ brelse(bh);
+ bh = NULL;
+ continue;
+ }
+ set_buffer_verified(bh);
+
+ /* If the dir block has changed since the last call to
+ * readdir(2), then we might be pointing to an invalid
+ * dirent right now. Scan from the start of the block
+ * to make sure. */
+ if (!inode_eq_iversion(inode, info->cookie)) {
+ for (i = 0; i < sb->s_blocksize && i < offset; ) {
+ de = (struct ext4_dir_entry_2 *)
+ (bh->b_data + i);
+ /* It's too expensive to do a full
+ * dirent test each time round this
+ * loop, but we do have to test at
+ * least that it is non-zero. A
+ * failure will be detected in the
+ * dirent test below. */
+ if (ext4_rec_len_from_disk(de->rec_len,
+ sb->s_blocksize) < ext4_dir_rec_len(1,
+ inode))
+ break;
+ i += ext4_rec_len_from_disk(de->rec_len,
+ sb->s_blocksize);
+ }
+ offset = i;
+ ctx->pos = (ctx->pos & ~(sb->s_blocksize - 1))
+ | offset;
+ info->cookie = inode_query_iversion(inode);
+ }
+
+ while (ctx->pos < inode->i_size
+ && offset < sb->s_blocksize) {
+ de = (struct ext4_dir_entry_2 *) (bh->b_data + offset);
+ if (ext4_check_dir_entry(inode, file, de, bh,
+ bh->b_data, bh->b_size,
+ offset)) {
+ /*
+ * On error, skip to the next block
+ */
+ ctx->pos = (ctx->pos |
+ (sb->s_blocksize - 1)) + 1;
+ break;
+ }
+ offset += ext4_rec_len_from_disk(de->rec_len,
+ sb->s_blocksize);
+ if (le32_to_cpu(de->inode)) {
+ if (!IS_ENCRYPTED(inode)) {
+ if (!dir_emit(ctx, de->name,
+ de->name_len,
+ le32_to_cpu(de->inode),
+ get_dtype(sb, de->file_type)))
+ goto done;
+ } else {
+ int save_len = fstr.len;
+ struct fscrypt_str de_name =
+ FSTR_INIT(de->name,
+ de->name_len);
+ u32 hash;
+ u32 minor_hash;
+
+ if (IS_CASEFOLDED(inode)) {
+ hash = EXT4_DIRENT_HASH(de);
+ minor_hash = EXT4_DIRENT_MINOR_HASH(de);
+ } else {
+ hash = 0;
+ minor_hash = 0;
+ }
+
+ /* Directory is encrypted */
+ err = fscrypt_fname_disk_to_usr(inode,
+ hash, minor_hash, &de_name, &fstr);
+ de_name = fstr;
+ fstr.len = save_len;
+ if (err)
+ goto errout;
+ if (!dir_emit(ctx,
+ de_name.name, de_name.len,
+ le32_to_cpu(de->inode),
+ get_dtype(sb, de->file_type)))
+ goto done;
+ }
+ }
+ ctx->pos += ext4_rec_len_from_disk(de->rec_len,
+ sb->s_blocksize);
+ }
+ if ((ctx->pos < inode->i_size) && !dir_relax_shared(inode))
+ goto done;
+ brelse(bh);
+ bh = NULL;
+ }
+done:
+ err = 0;
+errout:
+ fscrypt_fname_free_buffer(&fstr);
+ brelse(bh);
+ return err;
+}
+
+static inline int is_32bit_api(void)
+{
+#ifdef CONFIG_COMPAT
+ return in_compat_syscall();
+#else
+ return (BITS_PER_LONG == 32);
+#endif
+}
+
+/*
+ * These functions convert from the major/minor hash to an f_pos
+ * value for dx directories
+ *
+ * Upper layer (for example NFS) should specify FMODE_32BITHASH or
+ * FMODE_64BITHASH explicitly. On the other hand, we allow ext4 to be mounted
+ * directly on both 32-bit and 64-bit nodes, under such case, neither
+ * FMODE_32BITHASH nor FMODE_64BITHASH is specified.
+ */
+static inline loff_t hash2pos(struct file *filp, __u32 major, __u32 minor)
+{
+ if ((filp->f_mode & FMODE_32BITHASH) ||
+ (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api()))
+ return major >> 1;
+ else
+ return ((__u64)(major >> 1) << 32) | (__u64)minor;
+}
+
+static inline __u32 pos2maj_hash(struct file *filp, loff_t pos)
+{
+ if ((filp->f_mode & FMODE_32BITHASH) ||
+ (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api()))
+ return (pos << 1) & 0xffffffff;
+ else
+ return ((pos >> 32) << 1) & 0xffffffff;
+}
+
+static inline __u32 pos2min_hash(struct file *filp, loff_t pos)
+{
+ if ((filp->f_mode & FMODE_32BITHASH) ||
+ (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api()))
+ return 0;
+ else
+ return pos & 0xffffffff;
+}
+
+/*
+ * Return 32- or 64-bit end-of-file for dx directories
+ */
+static inline loff_t ext4_get_htree_eof(struct file *filp)
+{
+ if ((filp->f_mode & FMODE_32BITHASH) ||
+ (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api()))
+ return EXT4_HTREE_EOF_32BIT;
+ else
+ return EXT4_HTREE_EOF_64BIT;
+}
+
+
+/*
+ * ext4_dir_llseek() calls generic_file_llseek_size to handle htree
+ * directories, where the "offset" is in terms of the filename hash
+ * value instead of the byte offset.
+ *
+ * Because we may return a 64-bit hash that is well beyond offset limits,
+ * we need to pass the max hash as the maximum allowable offset in
+ * the htree directory case.
+ *
+ * For non-htree, ext4_llseek already chooses the proper max offset.
+ */
+static loff_t ext4_dir_llseek(struct file *file, loff_t offset, int whence)
+{
+ struct inode *inode = file->f_mapping->host;
+ struct dir_private_info *info = file->private_data;
+ int dx_dir = is_dx_dir(inode);
+ loff_t ret, htree_max = ext4_get_htree_eof(file);
+
+ if (likely(dx_dir))
+ ret = generic_file_llseek_size(file, offset, whence,
+ htree_max, htree_max);
+ else
+ ret = ext4_llseek(file, offset, whence);
+ info->cookie = inode_peek_iversion(inode) - 1;
+ return ret;
+}
+
+/*
+ * This structure holds the nodes of the red-black tree used to store
+ * the directory entry in hash order.
+ */
+struct fname {
+ __u32 hash;
+ __u32 minor_hash;
+ struct rb_node rb_hash;
+ struct fname *next;
+ __u32 inode;
+ __u8 name_len;
+ __u8 file_type;
+ char name[] __counted_by(name_len);
+};
+
+/*
+ * This function implements a non-recursive way of freeing all of the
+ * nodes in the red-black tree.
+ */
+static void free_rb_tree_fname(struct rb_root *root)
+{
+ struct fname *fname, *next;
+
+ rbtree_postorder_for_each_entry_safe(fname, next, root, rb_hash)
+ while (fname) {
+ struct fname *old = fname;
+ fname = fname->next;
+ kfree(old);
+ }
+
+ *root = RB_ROOT;
+}
+
+static void ext4_htree_init_dir_info(struct file *filp, loff_t pos)
+{
+ struct dir_private_info *p = filp->private_data;
+
+ if (is_dx_dir(file_inode(filp)) && !p->initialized) {
+ p->curr_hash = pos2maj_hash(filp, pos);
+ p->curr_minor_hash = pos2min_hash(filp, pos);
+ p->initialized = true;
+ }
+}
+
+void ext4_htree_free_dir_info(struct dir_private_info *p)
+{
+ free_rb_tree_fname(&p->root);
+ kfree(p);
+}
+
+/*
+ * Given a directory entry, enter it into the fname rb tree.
+ *
+ * When filename encryption is enabled, the dirent will hold the
+ * encrypted filename, while the htree will hold decrypted filename.
+ * The decrypted filename is passed in via ent_name. parameter.
+ */
+int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
+ __u32 minor_hash,
+ struct ext4_dir_entry_2 *dirent,
+ struct fscrypt_str *ent_name)
+{
+ struct rb_node **p, *parent = NULL;
+ struct fname *fname, *new_fn;
+ struct dir_private_info *info;
+
+ info = dir_file->private_data;
+ p = &info->root.rb_node;
+
+ /* Create and allocate the fname structure */
+ new_fn = kzalloc(struct_size(new_fn, name, ent_name->len + 1),
+ GFP_KERNEL);
+ if (!new_fn)
+ return -ENOMEM;
+ new_fn->hash = hash;
+ new_fn->minor_hash = minor_hash;
+ new_fn->inode = le32_to_cpu(dirent->inode);
+ new_fn->name_len = ent_name->len;
+ new_fn->file_type = dirent->file_type;
+ memcpy(new_fn->name, ent_name->name, ent_name->len);
+
+ while (*p) {
+ parent = *p;
+ fname = rb_entry(parent, struct fname, rb_hash);
+
+ /*
+ * If the hash and minor hash match up, then we put
+ * them on a linked list. This rarely happens...
+ */
+ if ((new_fn->hash == fname->hash) &&
+ (new_fn->minor_hash == fname->minor_hash)) {
+ new_fn->next = fname->next;
+ fname->next = new_fn;
+ return 0;
+ }
+
+ if (new_fn->hash < fname->hash)
+ p = &(*p)->rb_left;
+ else if (new_fn->hash > fname->hash)
+ p = &(*p)->rb_right;
+ else if (new_fn->minor_hash < fname->minor_hash)
+ p = &(*p)->rb_left;
+ else /* if (new_fn->minor_hash > fname->minor_hash) */
+ p = &(*p)->rb_right;
+ }
+
+ rb_link_node(&new_fn->rb_hash, parent, p);
+ rb_insert_color(&new_fn->rb_hash, &info->root);
+ return 0;
+}
+
+
+
+/*
+ * This is a helper function for ext4_dx_readdir. It calls filldir
+ * for all entries on the fname linked list. (Normally there is only
+ * one entry on the linked list, unless there are 62 bit hash collisions.)
+ */
+static int call_filldir(struct file *file, struct dir_context *ctx,
+ struct fname *fname)
+{
+ struct dir_private_info *info = file->private_data;
+ struct inode *inode = file_inode(file);
+ struct super_block *sb = inode->i_sb;
+
+ if (!fname) {
+ ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: comm %s: "
+ "called with null fname?!?", __func__, __LINE__,
+ inode->i_ino, current->comm);
+ return 0;
+ }
+ ctx->pos = hash2pos(file, fname->hash, fname->minor_hash);
+ while (fname) {
+ if (!dir_emit(ctx, fname->name,
+ fname->name_len,
+ fname->inode,
+ get_dtype(sb, fname->file_type))) {
+ info->extra_fname = fname;
+ return 1;
+ }
+ fname = fname->next;
+ }
+ return 0;
+}
+
+static int ext4_dx_readdir(struct file *file, struct dir_context *ctx)
+{
+ struct dir_private_info *info = file->private_data;
+ struct inode *inode = file_inode(file);
+ struct fname *fname;
+ int ret = 0;
+
+ ext4_htree_init_dir_info(file, ctx->pos);
+
+ if (ctx->pos == ext4_get_htree_eof(file))
+ return 0; /* EOF */
+
+ /* Some one has messed with f_pos; reset the world */
+ if (info->last_pos != ctx->pos) {
+ free_rb_tree_fname(&info->root);
+ info->curr_node = NULL;
+ info->extra_fname = NULL;
+ info->curr_hash = pos2maj_hash(file, ctx->pos);
+ info->curr_minor_hash = pos2min_hash(file, ctx->pos);
+ }
+
+ /*
+ * If there are any leftover names on the hash collision
+ * chain, return them first.
+ */
+ if (info->extra_fname) {
+ if (call_filldir(file, ctx, info->extra_fname))
+ goto finished;
+ info->extra_fname = NULL;
+ goto next_node;
+ } else if (!info->curr_node)
+ info->curr_node = rb_first(&info->root);
+
+ while (1) {
+ /*
+ * Fill the rbtree if we have no more entries,
+ * or the inode has changed since we last read in the
+ * cached entries.
+ */
+ if ((!info->curr_node) ||
+ !inode_eq_iversion(inode, info->cookie)) {
+ info->curr_node = NULL;
+ free_rb_tree_fname(&info->root);
+ info->cookie = inode_query_iversion(inode);
+ ret = ext4_htree_fill_tree(file, info->curr_hash,
+ info->curr_minor_hash,
+ &info->next_hash);
+ if (ret < 0)
+ goto finished;
+ if (ret == 0) {
+ ctx->pos = ext4_get_htree_eof(file);
+ break;
+ }
+ info->curr_node = rb_first(&info->root);
+ }
+
+ fname = rb_entry(info->curr_node, struct fname, rb_hash);
+ info->curr_hash = fname->hash;
+ info->curr_minor_hash = fname->minor_hash;
+ if (call_filldir(file, ctx, fname))
+ break;
+ next_node:
+ info->curr_node = rb_next(info->curr_node);
+ if (info->curr_node) {
+ fname = rb_entry(info->curr_node, struct fname,
+ rb_hash);
+ info->curr_hash = fname->hash;
+ info->curr_minor_hash = fname->minor_hash;
+ } else {
+ if (info->next_hash == ~0) {
+ ctx->pos = ext4_get_htree_eof(file);
+ break;
+ }
+ info->curr_hash = info->next_hash;
+ info->curr_minor_hash = 0;
+ }
+ }
+finished:
+ info->last_pos = ctx->pos;
+ return ret < 0 ? ret : 0;
+}
+
+static int ext4_release_dir(struct inode *inode, struct file *filp)
+{
+ if (filp->private_data)
+ ext4_htree_free_dir_info(filp->private_data);
+
+ return 0;
+}
+
+int ext4_check_all_de(struct inode *dir, struct buffer_head *bh, void *buf,
+ int buf_size)
+{
+ struct ext4_dir_entry_2 *de;
+ int rlen;
+ unsigned int offset = 0;
+ char *top;
+
+ de = buf;
+ top = buf + buf_size;
+ while ((char *) de < top) {
+ if (ext4_check_dir_entry(dir, NULL, de, bh,
+ buf, buf_size, offset))
+ return -EFSCORRUPTED;
+ rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
+ de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
+ offset += rlen;
+ }
+ if ((char *) de > top)
+ return -EFSCORRUPTED;
+
+ return 0;
+}
+
+static int ext4_dir_open(struct inode *inode, struct file *file)
+{
+ struct dir_private_info *info;
+
+ info = kzalloc(sizeof(*info), GFP_KERNEL);
+ if (!info)
+ return -ENOMEM;
+ file->private_data = info;
+ return 0;
+}
+
+const struct file_operations ext4_dir_operations = {
+ .open = ext4_dir_open,
+ .llseek = ext4_dir_llseek,
+ .read = generic_read_dir,
+ .iterate_shared = ext4_readdir,
+ .unlocked_ioctl = ext4_ioctl,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = ext4_compat_ioctl,
+#endif
+ .fsync = ext4_sync_file,
+ .release = ext4_release_dir,
+};