On Mon 09-10-23 14:33:41, Christian Brauner wrote:
> We can't open devices with s_umount held without risking deadlocks.
> So drop s_umount and reacquire it when opening the journal device.
>
> Reported-by: syzbot+062317ea1d0a6d5e29e7@xxxxxxxxxxxxxxxxxxxxxxxxx
> Signed-off-by: Christian Brauner <brauner@xxxxxxxxxx>
Looks good. Feel free to add:
Reviewed-by: Jan Kara <jack@xxxxxxx>
Honza
> ---
> fs/reiserfs/journal.c | 22 ++++++++++++++++------
> 1 file changed, 16 insertions(+), 6 deletions(-)
>
> diff --git a/fs/reiserfs/journal.c b/fs/reiserfs/journal.c
> index e001a96fc76c..0c680de72d43 100644
> --- a/fs/reiserfs/journal.c
> +++ b/fs/reiserfs/journal.c
> @@ -2714,7 +2714,7 @@ int journal_init(struct super_block *sb, const char *j_dev_name,
> struct reiserfs_journal_header *jh;
> struct reiserfs_journal *journal;
> struct reiserfs_journal_list *jl;
> - int ret;
> + int ret = 1;
>
> journal = SB_JOURNAL(sb) = vzalloc(sizeof(struct reiserfs_journal));
> if (!journal) {
> @@ -2727,6 +2727,13 @@ int journal_init(struct super_block *sb, const char *j_dev_name,
> INIT_LIST_HEAD(&journal->j_working_list);
> INIT_LIST_HEAD(&journal->j_journal_list);
> journal->j_persistent_trans = 0;
> +
> + /*
> + * blkdev_put() can't be called under s_umount, see the comment
> + * in get_tree_bdev() for more details
> + */
> + up_write(&sb->s_umount);
> +
> if (reiserfs_allocate_list_bitmaps(sb, journal->j_list_bitmap,
> reiserfs_bmap_count(sb)))
> goto free_and_return;
> @@ -2891,8 +2898,7 @@ int journal_init(struct super_block *sb, const char *j_dev_name,
> goto free_and_return;
> }
>
> - ret = journal_read(sb);
> - if (ret < 0) {
> + if (journal_read(sb) < 0) {
> reiserfs_warning(sb, "reiserfs-2006",
> "Replay Failure, unable to mount");
> goto free_and_return;
> @@ -2900,10 +2906,14 @@ int journal_init(struct super_block *sb, const char *j_dev_name,
>
> INIT_DELAYED_WORK(&journal->j_work, flush_async_commits);
> journal->j_work_sb = sb;
> - return 0;
> + ret = 0;
> +
> free_and_return:
> - free_journal_ram(sb);
> - return 1;
> + if (ret)
> + free_journal_ram(sb);
> +
> + down_write(&sb->s_umount);
> + return ret;
> }
>
> /*
>
> --
> 2.34.1
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
