On Thu 24-09-20 21:01:42, Zhang Xiaoxu wrote:
> If some errors has occurred on the device, and the orphan list not empty,
> then mount the device with 'ro', the bdev write error check will failed:
> ext4_check_bdev_write_error:193: comm mount: Error while async write back metadata
>
> Since the sbi->s_bdev_wb_err wouldn't be initialized when mount file system
> with 'ro', when clean up the orphan list and access the iloc buffer, bdev
> write error check will failed.
>
> So we should always initialize the sbi->s_bdev_wb_err even if mount the
> file system with 'ro'.
Let me rephrase the changelog a little bit for better readability:
Consider a situation when a filesystem was uncleanly shutdown and the orphan
list is not empty and a read-only mount is attempted. The orphan list
cleanup during mount will fail with:
ext4_check_bdev_write_error:193: comm mount: Error while async write back metadata
This happens because sbi->s_bdev_wb_err is not initialized when mounting
the filesystem in read only mode and so ext4_check_bdev_write_error()
falsely triggers.
Initialize sbi->s_bdev_wb_err unconditionally to avoid this problem.
>
> Fixes: bc71726c7257 ("ext4: abort the filesystem if failed to async write metadata buffer")
> Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@xxxxxxxxxx>
Otherwise the patch looks good so feel free to add:
Reviewed-by: Jan Kara <jack@xxxxxxx>
Honza
> ---
> fs/ext4/super.c | 13 ++-----------
> 1 file changed, 2 insertions(+), 11 deletions(-)
>
> diff --git a/fs/ext4/super.c b/fs/ext4/super.c
> index ea425b49b345..0303e6e17190 100644
> --- a/fs/ext4/super.c
> +++ b/fs/ext4/super.c
> @@ -4814,9 +4814,8 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
> * used to detect the metadata async write error.
> */
> spin_lock_init(&sbi->s_bdev_wb_lock);
> - if (!sb_rdonly(sb))
> - errseq_check_and_advance(&sb->s_bdev->bd_inode->i_mapping->wb_err,
> - &sbi->s_bdev_wb_err);
> + errseq_check_and_advance(&sb->s_bdev->bd_inode->i_mapping->wb_err,
> + &sbi->s_bdev_wb_err);
> sb->s_bdev->bd_super = sb;
> EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
> ext4_orphan_cleanup(sb, es);
> @@ -5707,14 +5706,6 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data)
> goto restore_opts;
> }
>
> - /*
> - * Update the original bdev mapping's wb_err value
> - * which could be used to detect the metadata async
> - * write error.
> - */
> - errseq_check_and_advance(&sb->s_bdev->bd_inode->i_mapping->wb_err,
> - &sbi->s_bdev_wb_err);
> -
> /*
> * Mounting a RDONLY partition read-write, so reread
> * and store the current valid flag. (It may have
> --
> 2.25.4
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
