2024-05-10 03:33:53

by Chao Yu

Subject: [PATCH v3 5/5] f2fs: compress: don't allow unaligned truncation on released compress inode

f2fs image may be corrupted after below testcase:
- mkfs.f2fs -O extra_attr,compression -f /dev/vdb
- mount /dev/vdb /mnt/f2fs
- touch /mnt/f2fs/file
- f2fs_io setflags compression /mnt/f2fs/file
- dd if=/dev/zero of=/mnt/f2fs/file bs=4k count=4
- f2fs_io release_cblocks /mnt/f2fs/file
- truncate -s 8192 /mnt/f2fs/file
- umount /mnt/f2fs
- fsck.f2fs /dev/vdb

[ASSERT] (fsck_chk_inode_blk:1256) --> ino: 0x5 has i_blocks: 0x00000002, but has 0x3 blocks
[FSCK] valid_block_count matching with CP [Fail] [0x4, 0x5]
[FSCK] other corrupted bugs [Fail]

The reason is: partial truncation assume compressed inode has reserved
blocks, after partial truncation, valid block count may change w/o
i_blocks and .total_valid_block_count update, result in corruption.

This patch only allow cluster size aligned truncation on released
compress inode for fixing.

Fixes: c61404153eb6 ("f2fs: introduce FI_COMPRESS_RELEASED instead of using IMMUTABLE bit")
Signed-off-by: Chao Yu <[email protected]>
---
v3:
- fix typo in commit description: w/ -> w/o
fs/f2fs/file.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 7371f485b3f7..15f4222da891 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -952,9 +952,14 @@ int f2fs_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
ATTR_GID | ATTR_TIMES_SET))))
return -EPERM;

- if ((attr->ia_valid & ATTR_SIZE) &&
- !f2fs_is_compress_backend_ready(inode))
- return -EOPNOTSUPP;
+ if ((attr->ia_valid & ATTR_SIZE)) {
+ if (!f2fs_is_compress_backend_ready(inode))
+ return -EOPNOTSUPP;
+ if (is_inode_flag_set(inode, FI_COMPRESS_RELEASED) &&
+ !IS_ALIGNED(attr->ia_size,
+ F2FS_BLK_TO_BYTES(F2FS_I(inode)->i_cluster_size)))
+ return -EINVAL;
+ }

err = setattr_prepare(idmap, dentry, attr);
if (err)
--
2.40.1

2024-05-11 00:55:40

by patchwork-bot+f2fs

Subject: Re: [f2fs-dev] [PATCH v3 5/5] f2fs: compress: don't allow unaligned truncation on released compress inode

Hello:

This patch was applied to jaegeuk/f2fs.git (dev)
by Jaegeuk Kim <[email protected]>:

On Fri, 10 May 2024 11:33:39 +0800 you wrote:
> f2fs image may be corrupted after below testcase:
> - mkfs.f2fs -O extra_attr,compression -f /dev/vdb
> - mount /dev/vdb /mnt/f2fs
> - touch /mnt/f2fs/file
> - f2fs_io setflags compression /mnt/f2fs/file
> - dd if=/dev/zero of=/mnt/f2fs/file bs=4k count=4
> - f2fs_io release_cblocks /mnt/f2fs/file
> - truncate -s 8192 /mnt/f2fs/file
> - umount /mnt/f2fs
> - fsck.f2fs /dev/vdb
>
> [...]

Here is the summary with links:
- [f2fs-dev,v3,5/5] f2fs: compress: don't allow unaligned truncation on released compress inode
https://git.kernel.org/jaegeuk/f2fs/c/29ed2b5dd521

You are awesome, thank you!
--
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