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ext4: optimize ea_inode block expansion 

commit 1e9d62d252 upstream.

Copy ea data from inode entry when expanding ea block if possible.
Then remove the ea entry if expansion success. Thus memcpy to a
temporary buffer may be avoided.

If the expansion fails, we do not need to recovery the removed ea
entry neither in this way.

Reported-by: syzbot+2dacb8f015bf1420155f@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?id=3613786cb88c93aa1c6a279b1df6a7b201347d08
Link: https://lore.kernel.org/r/20230103014517.495275-2-jun.nie@linaro.org
Cc: stable@kernel.org
Signed-off-by: Jun Nie <jun.nie@linaro.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Jun Nie 2023-01-03 09:45:16 +08:00 committed by Greg Kroah-Hartman
parent c325350d0c
commit a6744e14ce
1 changed files with 17 additions and 11 deletions
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28
fs/ext4/xattr.c
View File

@ -2549,9 +2549,8 @@ static int ext4_xattr_move_to_block(handle_t *handle, struct inode *inode,
is = kzalloc(sizeof(struct ext4_xattr_ibody_find), GFP_NOFS);
bs = kzalloc(sizeof(struct ext4_xattr_block_find), GFP_NOFS);
buffer = kvmalloc(value_size, GFP_NOFS);
b_entry_name = kmalloc(entry->e_name_len + 1, GFP_NOFS);
if (!is || !bs || !buffer || !b_entry_name) {
if (!is || !bs || !b_entry_name) {
error = -ENOMEM;
goto out;
}
@ -2563,12 +2562,18 @@ static int ext4_xattr_move_to_block(handle_t *handle, struct inode *inode,
/* Save the entry name and the entry value */
if (entry->e_value_inum) {
buffer = kvmalloc(value_size, GFP_NOFS);
if (!buffer) {
error = -ENOMEM;
goto out;
}
error = ext4_xattr_inode_get(inode, entry, buffer, value_size);
if (error)
goto out;
} else {
size_t value_offs = le16_to_cpu(entry->e_value_offs);
memcpy(buffer, (void *)IFIRST(header) + value_offs, value_size);
buffer = (void *)IFIRST(header) + value_offs;
}
memcpy(b_entry_name, entry->e_name, entry->e_name_len);
@ -2583,25 +2588,26 @@ static int ext4_xattr_move_to_block(handle_t *handle, struct inode *inode,
if (error)
goto out;
/* Remove the chosen entry from the inode */
error = ext4_xattr_ibody_set(handle, inode, &i, is);
if (error)
goto out;
i.value = buffer;
i.value_len = value_size;
error = ext4_xattr_block_find(inode, &i, bs);
if (error)
goto out;
/* Add entry which was removed from the inode into the block */
/* Move ea entry from the inode into the block */
error = ext4_xattr_block_set(handle, inode, &i, bs);
if (error)
goto out;
error = 0;
/* Remove the chosen entry from the inode */
i.value = NULL;
i.value_len = 0;
error = ext4_xattr_ibody_set(handle, inode, &i, is);
out:
kfree(b_entry_name);
kvfree(buffer);
if (entry->e_value_inum && buffer)
kvfree(buffer);
if (is)
brelse(is->iloc.bh);
if (bs)