btrfs: make btrfs_cleanup_fs_roots use the radix tree lock

The radix root is primarily protected by the fs_roots_radix_lock, so use
that to lookup and get a ref on all of our fs roots in
btrfs_cleanup_fs_roots. The tree reference is taken in the protected
section as before.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 3a6d35e1edb723cc2a3a89cb35fde1596bcfbd59..4d3eba909664fc3f4390d2a548eb8a262cfb204f 100644 (file)
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -3932,15 +3932,14 @@ int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
        int i = 0;
        int err = 0;
        unsigned int ret = 0;
-       int index;
 
        while (1) {
-               index = srcu_read_lock(&fs_info->subvol_srcu);
+               spin_lock(&fs_info->fs_roots_radix_lock);
                ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
                                             (void **)gang, root_objectid,
                                             ARRAY_SIZE(gang));
                if (!ret) {
-                       srcu_read_unlock(&fs_info->subvol_srcu, index);
+                       spin_unlock(&fs_info->fs_roots_radix_lock);
                        break;
                }
                root_objectid = gang[ret - 1]->root_key.objectid + 1;
@@ -3954,7 +3953,7 @@ int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
                        /* grab all the search result for later use */
                        gang[i] = btrfs_grab_root(gang[i]);
                }
-               srcu_read_unlock(&fs_info->subvol_srcu, index);
+               spin_unlock(&fs_info->fs_roots_radix_lock);
 
                for (i = 0; i < ret; i++) {
                        if (!gang[i])