btrfs: factor btrfs_read_roots() out of open_ctree()

Also, remove the two local variables create_uuid_tree
and check_uuid_tree; we can use the existence of
the uuid root and/or the RESCAN_UUID_TREE flag to
determine what action to take.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: David Sterba <dsterba@suse.cz>

1 files changed, 66 insertions, 65 deletions

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 954f0658dd0e..c7546d6512cc 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2354,6 +2354,65 @@ static int btrfs_replay_log(struct btrfs_fs_info *fs_info,
         return 0;
 }
 
+static int btrfs_read_roots(struct btrfs_fs_info *fs_info,
+                            struct btrfs_root *tree_root)
+{
+        struct btrfs_root *extent_root;
+        struct btrfs_root *dev_root;
+        struct btrfs_root *csum_root;
+        struct btrfs_root *quota_root;
+        struct btrfs_root *uuid_root;
+        struct btrfs_key location;
+        int ret;
+
+        location.objectid = BTRFS_EXTENT_TREE_OBJECTID;
+        location.type = BTRFS_ROOT_ITEM_KEY;
+        location.offset = 0;
+
+        extent_root = btrfs_read_tree_root(tree_root, &location);
+        if (IS_ERR(extent_root))
+                return PTR_ERR(extent_root);
+        set_bit(BTRFS_ROOT_TRACK_DIRTY, &extent_root->state);
+        fs_info->extent_root = extent_root;
+
+        location.objectid = BTRFS_DEV_TREE_OBJECTID;
+        dev_root = btrfs_read_tree_root(tree_root, &location);
+        if (IS_ERR(dev_root))
+                return PTR_ERR(dev_root);
+        set_bit(BTRFS_ROOT_TRACK_DIRTY, &dev_root->state);
+        fs_info->dev_root = dev_root;
+        btrfs_init_devices_late(fs_info);
+
+        location.objectid = BTRFS_CSUM_TREE_OBJECTID;
+        csum_root = btrfs_read_tree_root(tree_root, &location);
+        if (IS_ERR(csum_root))
+                return PTR_ERR(csum_root);
+        set_bit(BTRFS_ROOT_TRACK_DIRTY, &csum_root->state);
+        fs_info->csum_root = csum_root;
+
+        location.objectid = BTRFS_QUOTA_TREE_OBJECTID;
+        quota_root = btrfs_read_tree_root(tree_root, &location);
+        if (!IS_ERR(quota_root)) {
+                set_bit(BTRFS_ROOT_TRACK_DIRTY, &quota_root->state);
+                fs_info->quota_enabled = 1;
+                fs_info->pending_quota_state = 1;
+                fs_info->quota_root = quota_root;
+        }
+
+        location.objectid = BTRFS_UUID_TREE_OBJECTID;
+        uuid_root = btrfs_read_tree_root(tree_root, &location);
+        if (IS_ERR(uuid_root)) {
+                ret = PTR_ERR(uuid_root);
+                if (ret != -ENOENT)
+                        return ret;
+        } else {
+                set_bit(BTRFS_ROOT_TRACK_DIRTY, &uuid_root->state);
+                fs_info->uuid_root = uuid_root;
+        }
+
+        return 0;
+}
+
 int open_ctree(struct super_block *sb,
                struct btrfs_fs_devices *fs_devices,
                char *options)
@@ -2368,19 +2427,12 @@ int open_ctree(struct super_block *sb,
         struct btrfs_super_block *disk_super;
         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
         struct btrfs_root *tree_root;
-        struct btrfs_root *extent_root;
-        struct btrfs_root *csum_root;
         struct btrfs_root *chunk_root;
-        struct btrfs_root *dev_root;
-        struct btrfs_root *quota_root;
-        struct btrfs_root *uuid_root;
         int ret;
         int err = -EINVAL;
         int num_backups_tried = 0;
         int backup_index = 0;
         int max_active;
-        bool create_uuid_tree;
-        bool check_uuid_tree;
 
         tree_root = fs_info->tree_root = btrfs_alloc_root(fs_info);
         chunk_root = fs_info->chunk_root = btrfs_alloc_root(fs_info);
@@ -2804,61 +2856,9 @@ retry_root_backup:
         tree_root->commit_root = btrfs_root_node(tree_root);
         btrfs_set_root_refs(&tree_root->root_item, 1);
 
-        location.objectid = BTRFS_EXTENT_TREE_OBJECTID;
-        location.type = BTRFS_ROOT_ITEM_KEY;
-        location.offset = 0;
-
-        extent_root = btrfs_read_tree_root(tree_root, &location);
-        if (IS_ERR(extent_root)) {
-                ret = PTR_ERR(extent_root);
-                goto recovery_tree_root;
-        }
-        set_bit(BTRFS_ROOT_TRACK_DIRTY, &extent_root->state);
-        fs_info->extent_root = extent_root;
-
-        location.objectid = BTRFS_DEV_TREE_OBJECTID;
-        dev_root = btrfs_read_tree_root(tree_root, &location);
-        if (IS_ERR(dev_root)) {
-                ret = PTR_ERR(dev_root);
-                goto recovery_tree_root;
-        }
-        set_bit(BTRFS_ROOT_TRACK_DIRTY, &dev_root->state);
-        fs_info->dev_root = dev_root;
-        btrfs_init_devices_late(fs_info);
-
-        location.objectid = BTRFS_CSUM_TREE_OBJECTID;
-        csum_root = btrfs_read_tree_root(tree_root, &location);
-        if (IS_ERR(csum_root)) {
-                ret = PTR_ERR(csum_root);
+        ret = btrfs_read_roots(fs_info, tree_root);
+        if (ret)
                 goto recovery_tree_root;
-        }
-        set_bit(BTRFS_ROOT_TRACK_DIRTY, &csum_root->state);
-        fs_info->csum_root = csum_root;
-
-        location.objectid = BTRFS_QUOTA_TREE_OBJECTID;
-        quota_root = btrfs_read_tree_root(tree_root, &location);
-        if (!IS_ERR(quota_root)) {
-                set_bit(BTRFS_ROOT_TRACK_DIRTY, &quota_root->state);
-                fs_info->quota_enabled = 1;
-                fs_info->pending_quota_state = 1;
-                fs_info->quota_root = quota_root;
-        }
-
-        location.objectid = BTRFS_UUID_TREE_OBJECTID;
-        uuid_root = btrfs_read_tree_root(tree_root, &location);
-        if (IS_ERR(uuid_root)) {
-                ret = PTR_ERR(uuid_root);
-                if (ret != -ENOENT)
-                        goto recovery_tree_root;
-                create_uuid_tree = true;
-                check_uuid_tree = false;
-        } else {
-                set_bit(BTRFS_ROOT_TRACK_DIRTY, &uuid_root->state);
-                fs_info->uuid_root = uuid_root;
-                create_uuid_tree = false;
-                check_uuid_tree =
-                    generation != btrfs_super_uuid_tree_generation(disk_super);
-        }
 
         fs_info->generation = generation;
         fs_info->last_trans_committed = generation;
@@ -2896,7 +2896,7 @@ retry_root_backup:
                 goto fail_sysfs;
         }
 
-        ret = btrfs_read_block_groups(extent_root);
+        ret = btrfs_read_block_groups(fs_info->extent_root);
         if (ret) {
                 printk(KERN_ERR "BTRFS: Failed to read block groups: %d\n", ret);
                 goto fail_sysfs;
@@ -3019,7 +3019,7 @@ retry_root_backup:
 
         btrfs_qgroup_rescan_resume(fs_info);
 
-        if (create_uuid_tree) {
+        if (!fs_info->uuid_root) {
                 pr_info("BTRFS: creating UUID tree\n");
                 ret = btrfs_create_uuid_tree(fs_info);
                 if (ret) {
@@ -3028,8 +3028,9 @@ retry_root_backup:
                         close_ctree(tree_root);
                         return ret;
                 }
-        } else if (check_uuid_tree ||
-                   btrfs_test_opt(tree_root, RESCAN_UUID_TREE)) {
+        } else if (btrfs_test_opt(tree_root, RESCAN_UUID_TREE) ||
+                   fs_info->generation !=
+                                btrfs_super_uuid_tree_generation(disk_super)) {
                 pr_info("BTRFS: checking UUID tree\n");
                 ret = btrfs_check_uuid_tree(fs_info);
                 if (ret) {