Re: [PATCH] f2fs: avoid stale FI_COMPRESS_RELEASED on release failure

[Chao Yu <chao@kernel.org>]

On 7/24/26 21:50, Wenjie Qi wrote:
> F2FS_IOC_RELEASE_COMPRESS_BLOCKS sets FI_COMPRESS_RELEASED before walking
> data nodes. If release_compress_blocks() fails before freeing any reserved
> block, the inode keeps the flag while i_compr_blocks is still non-zero.
> 
> Then F2FS_IOC_RESERVE_COMPRESS_BLOCKS returns success with zero reserved
> blocks, and regular writes keep failing with -EPERM.
> 
> Set the flag only after the ioctl succeeds, or after it has actually
> released some blocks. This preserves the existing partial-release error
> handling and leaves a failed zero-release attempt unchanged.
> 
> Fixes: ef8d563f184e ("f2fs: introduce F2FS_IOC_RELEASE_COMPRESS_BLOCKS")
> Cc: stable@kernel.org
> Signed-off-by: Wenjie Qi <qiwenjie@xiaomi.com>
> ---
> QEMU fault-injection test with FAULT_BLKADDR_VALIDITY:
> - before: release failed with -EFSCORRUPTED, reserve returned 0 blocks,
>    and pwrite kept failing with -EPERM after remount.
> - after: release still failed, reserve returned -EINVAL, and pwrite succeeded.
> - normal release/reserve still released and reserved 192 blocks.
> 
>   fs/f2fs/file.c | 10 ++++++----
>   1 file changed, 6 insertions(+), 4 deletions(-)
> 
> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
> index c54897a25981..dca1722f92b3 100644
> --- a/fs/f2fs/file.c
> +++ b/fs/f2fs/file.c
> @@ -3916,10 +3916,6 @@ static int f2fs_release_compress_blocks(struct file *filp, unsigned long arg)
>   		goto out;
>   	}
>   
> -	set_inode_flag(inode, FI_COMPRESS_RELEASED);
> -	inode_set_ctime_current(inode);
> -	f2fs_mark_inode_dirty_sync(inode, true);
> -
>   	f2fs_down_write(&fi->i_gc_rwsem[WRITE]);
>   	filemap_invalidate_lock(inode->i_mapping);
>   
> @@ -3963,6 +3959,12 @@ static int f2fs_release_compress_blocks(struct file *filp, unsigned long arg)
>   
>   	filemap_invalidate_unlock(inode->i_mapping);
>   	f2fs_up_write(&fi->i_gc_rwsem[WRITE]);
> +
> +	if (ret >= 0 || released_blocks) {

We will set FI_COMPRESS_RELEASED if ret < 0 and released_blocks > 0?

Thanks,

> +		set_inode_flag(inode, FI_COMPRESS_RELEASED);
> +		inode_set_ctime_current(inode);
> +		f2fs_mark_inode_dirty_sync(inode, true);
> +	}
>   out:
>   	if (released_blocks)
>   		f2fs_update_time(sbi, REQ_TIME);