btrfs: fix mount/umount race
Do *NOT* skip doomed superblocks in btrfs_test_super(); we want
sget() to wait for their shutdown to complete. Since we don't
mutilate ->s_fs_info in ->put_super() anymore (or free what it
used to point to until the superblock is past being findable
by sget()), we can just DTRT there and report a match.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index eca4862..b9fd62a 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -733,20 +733,15 @@
struct btrfs_root *test_root = data;
struct btrfs_root *root = btrfs_sb(s);
- /*
- * If this super block is going away, return false as it
- * can't match as an existing super block.
- */
- if (!atomic_read(&s->s_active))
- return 0;
return root->fs_info->fs_devices == test_root->fs_info->fs_devices;
}
static int btrfs_set_super(struct super_block *s, void *data)
{
- s->s_fs_info = data;
-
- return set_anon_super(s, data);
+ int err = set_anon_super(s, data);
+ if (!err)
+ s->s_fs_info = data;
+ return err;
}
/*
