On Mon, Apr 23, 2018 at 08:46:26AM -0600, 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>
Applied with a fix up to ext4_fill_super() when it calls
ext4_setup_super() with the changed error return semantics.
- Ted
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index aac33c155363..1388e56bb3f5 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -4254,8 +4254,12 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
goto failed_mount4;
}
- if (ext4_setup_super(sb, es, sb_rdonly(sb)))
+ ret = ext4_setup_super(sb, es, sb_rdonly(sb));
+ if (ret == -EROFS) {
sb->s_flags |= SB_RDONLY;
+ ret = 0;
+ } else if (ret)
+ goto failed_mount4a;
/* determine the minimum size of new large inodes, if present */
if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE &&
