Re: [PATCH v2] ext4: handle errors on ext4_commit_super

From: Jan Kara
Date: Sat Apr 21 2018 - 19:19:46 EST


On Thu 19-04-18 08:59:57, Jaegeuk Kim wrote:
> When remounting ext4 from ro to rw, currently it allows its transition,
> even if ext4_commit_super() returns EIO. Even worse thing is, after that,
> fs/buffer complains buffer dirty bits like:
>
> Call trace:
> [<ffffff9750c259dc>] mark_buffer_dirty+0x184/0x1a4
> [<ffffff9750cb398c>] __ext4_handle_dirty_super+0x4c/0xfc
> [<ffffff9750c7a9fc>] ext4_file_open+0x154/0x1c0
> [<ffffff9750bea51c>] do_dentry_open+0x114/0x2d0
> [<ffffff9750bea75c>] vfs_open+0x5c/0x94
> [<ffffff9750bf879c>] path_openat+0x668/0xfe8
> [<ffffff9750bf8088>] do_filp_open+0x74/0x120
> [<ffffff9750beac98>] do_sys_open+0x148/0x254
> [<ffffff9750beade0>] SyS_openat+0x10/0x18
> [<ffffff9750a83ab0>] el0_svc_naked+0x24/0x28
> EXT4-fs (dm-1): previous I/O error to superblock detected
> Buffer I/O error on dev dm-1, logical block 0, lost sync page write
> EXT4-fs (dm-1): re-mounted. Opts: (null)
> Buffer I/O error on dev dm-1, logical block 80, lost async page write
>
> Cc: "Theodore Ts'o" <tytso@xxxxxxx>
> Cc: Andreas Dilger <adilger.kernel@xxxxxxxxx>
> Cc: linux-ext4@xxxxxxxxxxxxxxx
> Cc: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
> Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>

Looks mostly good. Just:

> @@ -5190,8 +5190,10 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data)
> }
>
> ext4_setup_system_zone(sb);
> - if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY))
> - ext4_commit_super(sb, 1);
> + if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY)) {
> + err = ext4_commit_super(sb, 1);
> + goto restore_opts;
> + }

Why is goto restore_opts unconditional here?

Honza
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR