btrfs: avoid blocking open_ctree from cleaner_kthread
This fixes a problem introduced in commit 2f3165ecf103599f82bf0ea254039db335fb5005
"btrfs: don't force mounts to wait for cleaner_kthread to delete one or more subvolumes".
open_ctree eventually calls btrfs_replay_log which in turn calls
btrfs_commit_super which tries to lock the cleaner_mutex, causing a
recursive mutex deadlock during mount.
Instead of playing whack-a-mole trying to keep up with all the
functions that may want to lock cleaner_mutex, put all the cleaner_mutex
lockers back where they were, and attack the problem more directly:
keep cleaner_kthread asleep until the filesystem is mounted.
When filesystems are mounted read-only and later remounted read-write,
open_ctree did not set fs_info->open and neither does anything else.
Set this flag in btrfs_remount so that neither btrfs_delete_unused_bgs
nor cleaner_kthread get confused by the common case of "/" filesystem
read-only mount followed by read-write remount.
Signed-off-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index bf70d33..60e7179 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -1807,6 +1807,8 @@
}
}
sb->s_flags &= ~MS_RDONLY;
+
+ fs_info->open = 1;
}
out:
wake_up_process(fs_info->transaction_kthread);