Re: [PATCH, RFC] Ext4: Mount partition as read only if during orphancleanup truncate fails to obtain journal handle.

[Namjae Jeon]

Add Cc in mail loop.

Thanks.

2012/10/24, Ashish Sangwan <ashishsangwan2@xxxxxxxxx>:
> During orphan cleanup while doing truncate, if we fail to obtain journal
> handle, the inode for which truncate was called would not be removed from
> both the on-disk and in-memory orphan lists as the call to ext4_orphan_del
> would not be executed.
>
> This would have following consequences:
> a) As the inode is not removed from the on-disk list, truncate would be
> called again for the same inode. Each call would add the inode to the
> in-memory list. This operation would continue endlessly or until truncate
> is succeed.
>
> b) If somehow, after some iterations, truncate is succeed, ext4_orphan_del
> will only remove the inode from in-memory list just 1 time. This will
> trigger
> j_assert during put super.
>
> This patch handles both the problems. If truncate fails, first in-memory
> list is cleared and than the partition is mounted as read only.
> Failure to obtain journal handle during mount may suggest that journal
> device is corrupted.
>
> Signed-off-by: Ashish Sangwan <ashish.sangwan2@xxxxxxxxx>
> Signed-off-by: Namjae Jeon <linkinjeon@xxxxxxxxx>
> ---
>  fs/ext4/super.c | 16 +++++++++++++++-
>  1 file changed, 15 insertions(+), 1 deletion(-)
>
> diff --git a/fs/ext4/super.c b/fs/ext4/super.c
> index 4e2aacb..859eccb 100644
> --- a/fs/ext4/super.c
> +++ b/fs/ext4/super.c
> @@ -2201,7 +2201,21 @@ static void ext4_orphan_cleanup(struct super_block
> *sb,
>  			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
>  				  inode->i_ino, inode->i_size);
>  			ext4_truncate(inode);
> -			nr_truncates++;
> +			if (list_empty(&EXT4_I(inode)->i_orphan)) {
> +				nr_truncates++;
> +			} else {
> +				/* Remove inode from in-memory orphan list */
> +				list_del_init(&EXT4_I(inode)->i_orphan);
> +				ext4_msg(sb, KERN_ERR, "Truncate failed for "
> +					 "orphan  inode = %lu. Running e2fsck"
> +					 " is recommended", inode->i_ino);
> +				if (!(s_flags & MS_RDONLY)) {
> +					ext4_msg(sb, KERN_INFO, "FS would be"
> +						" mounted as readonly");
> +					s_flags |= MS_RDONLY;
> +				}
> +				break;
> +			}
>  		} else {
>  			ext4_msg(sb, KERN_DEBUG,
>  				"%s: deleting unreferenced inode %lu",
> --
> 1.7.11.4
>
>
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