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ext4: add missing xattr hash update

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When updating an extended attribute, if the padded value sizes are the
same, a shortcut is taken to avoid the bulk of the work. This was fine
until the xattr hash update was moved inside ext4_xattr_set_entry().
With that change, the hash update got missed in the shortcut case.

Thanks to ZhangYi (yizhang089@gmail.com) for root causing the problem.

Fixes: daf8328172df ("ext4: eliminate xattr entry e_hash recalculation for removes")

Reported-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
This commit is contained in:
Tahsin Erdogan 2017-08-14 08:30:06 -04:00 committed by Theodore Ts'o
parent b80b32b6d5
commit 32aaf19420
1 changed files with 4 additions and 2 deletions
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6
fs/ext4/xattr.c
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@ -1543,7 +1543,7 @@ static int ext4_xattr_set_entry(struct ext4_xattr_info *i,
/* Clear padding bytes. */ /* Clear padding bytes. */
memset(val + i->value_len, 0, new_size - i->value_len); memset(val + i->value_len, 0, new_size - i->value_len);
} }
return 0; goto update_hash;
} }
/* Compute min_offs and last. */ /* Compute min_offs and last. */
@ -1707,6 +1707,7 @@ static int ext4_xattr_set_entry(struct ext4_xattr_info *i,
here->e_value_size = cpu_to_le32(i->value_len); here->e_value_size = cpu_to_le32(i->value_len);
} }
update_hash:
if (i->value) { if (i->value) {
__le32 hash = 0; __le32 hash = 0;
@ -1725,7 +1726,8 @@ static int ext4_xattr_set_entry(struct ext4_xattr_info *i,
here->e_name_len, here->e_name_len,
&crc32c_hash, 1); &crc32c_hash, 1);
} else if (is_block) { } else if (is_block) {
__le32 *value = s->base + min_offs - new_size; __le32 *value = s->base + le16_to_cpu(
here->e_value_offs);
hash = ext4_xattr_hash_entry(here->e_name, hash = ext4_xattr_hash_entry(here->e_name,
here->e_name_len, value, here->e_name_len, value,