Merge tag 'for-5.7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs updates from David Sterba:
 "A number of core changes that make things work better in general, code
  is simpler and cleaner.

  Core changes:

   - per-inode file extent tree, for in memory tracking of contiguous
     extent ranges to make sure i_size adjustments are accurate

   - tree root structures are protected by reference counts, replacing
     SRCU that did not cover some cases

   - leak detector for tree root structures

   - per-transaction pinned extent tracking

   - buffer heads are replaced by bios for super block access

   - speedup of extent back reference resolution, on an example test
     scenario the runtime of send went down from a hour to minutes

   - factor out locking scheme used for subvolume writer and NOCOW
     exclusion, abstracted as DREW lock, double reader-writer exclusion
     (allow either readers or writers)

   - cleanup and abstract extent allocation policies, preparation for
     zoned device support

   - make reflink/clone_range work on inline extents

   - add more cancellation point for relocation, improves long response
     from 'balance cancel'

   - add page migration callback for data pages

   - switch to guid for uuids, with additional cleanups of the interface

   - make ranged full fsyncs more efficient

   - removal of obsolete ioctl flag BTRFS_SUBVOL_CREATE_ASYNC

   - remove b-tree readahead from delayed refs paths, avoiding seek and
     read unnecessary blocks

  Features:

   - v2 of ioctl to delete subvolumes, allowing to delete by id and more
     future extensions

  Fixes:

   - fix qgroup rescan worker that could block umount

   - fix crash during unmount due to race with delayed inode workers

   - fix dellaloc flushing logic that could create unnecessary chunks
     under heavy load

   - fix missing file extent item for hole after ranged fsync

   - several fixes in relocation error handling

  Other:

   - more documentation of relocation, device replace, space
     reservations

   - many random cleanups"

* tag 'for-5.7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (210 commits)
  btrfs: fix missing semaphore unlock in btrfs_sync_file
  btrfs: use nofs allocations for running delayed items
  btrfs: sysfs: Use scnprintf() instead of snprintf()
  btrfs: do not resolve backrefs for roots that are being deleted
  btrfs: track reloc roots based on their commit root bytenr
  btrfs: restart relocate_tree_blocks properly
  btrfs: reloc: reorder reservation before root selection
  btrfs: do not readahead in build_backref_tree
  btrfs: do not use readahead for running delayed refs
  btrfs: Remove async_transid from btrfs_mksubvol/create_subvol/create_snapshot
  btrfs: Remove transid argument from btrfs_ioctl_snap_create_transid
  btrfs: Remove BTRFS_SUBVOL_CREATE_ASYNC support
  btrfs: kill the subvol_srcu
  btrfs: make btrfs_cleanup_fs_roots use the radix tree lock
  btrfs: don't take an extra root ref at allocation time
  btrfs: hold a ref on the root on the dead roots list
  btrfs: make inodes hold a ref on their roots
  btrfs: move the root freeing stuff into btrfs_put_root
  btrfs: move ino_cache_inode dropping out of btrfs_free_fs_root
  btrfs: make the extent buffer leak check per fs info
  ...

1 files changed, 5 insertions, 38 deletions

diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c
index 612411c74550..668f22844017 100644
--- a/fs/btrfs/root-tree.c
+++ b/fs/btrfs/root-tree.c
@@ -22,7 +22,6 @@
 static void btrfs_read_root_item(struct extent_buffer *eb, int slot,
 				struct btrfs_root_item *item)
 {
-	uuid_le uuid;
 	u32 len;
 	int need_reset = 0;
 
@@ -44,8 +43,7 @@ static void btrfs_read_root_item(struct extent_buffer *eb, int slot,
 			sizeof(*item) - offsetof(struct btrfs_root_item,
 					generation_v2));
 
-		uuid_le_gen(&uuid);
-		memcpy(item->uuid, uuid.b, BTRFS_UUID_SIZE);
+		generate_random_guid(item->uuid);
 	}
 }
 
@@ -255,25 +253,7 @@ int btrfs_find_orphan_roots(struct btrfs_fs_info *fs_info)
 		root_key.objectid = key.offset;
 		key.offset++;
 
-		/*
-		 * The root might have been inserted already, as before we look
-		 * for orphan roots, log replay might have happened, which
-		 * triggers a transaction commit and qgroup accounting, which
-		 * in turn reads and inserts fs roots while doing backref
-		 * walking.
-		 */
-		root = btrfs_lookup_fs_root(fs_info, root_key.objectid);
-		if (root) {
-			WARN_ON(!test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED,
-					  &root->state));
-			if (btrfs_root_refs(&root->root_item) == 0) {
-				set_bit(BTRFS_ROOT_DEAD_TREE, &root->state);
-				btrfs_add_dead_root(root);
-			}
-			continue;
-		}
-
-		root = btrfs_read_fs_root(tree_root, &root_key);
+		root = btrfs_get_fs_root(fs_info, &root_key, false);
 		err = PTR_ERR_OR_ZERO(root);
 		if (err && err != -ENOENT) {
 			break;
@@ -300,25 +280,12 @@ int btrfs_find_orphan_roots(struct btrfs_fs_info *fs_info)
 			continue;
 		}
 
-		err = btrfs_init_fs_root(root);
-		if (err) {
-			btrfs_free_fs_root(root);
-			break;
-		}
-
-		set_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state);
-
-		err = btrfs_insert_fs_root(fs_info, root);
-		if (err) {
-			BUG_ON(err == -EEXIST);
-			btrfs_free_fs_root(root);
-			break;
-		}
-
+		WARN_ON(!test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state));
 		if (btrfs_root_refs(&root->root_item) == 0) {
 			set_bit(BTRFS_ROOT_DEAD_TREE, &root->state);
 			btrfs_add_dead_root(root);
 		}
+		btrfs_put_root(root);
 	}
 
 	btrfs_free_path(path);
@@ -553,5 +520,5 @@ int btrfs_subvolume_reserve_metadata(struct btrfs_root *root,
 void btrfs_subvolume_release_metadata(struct btrfs_fs_info *fs_info,
 				      struct btrfs_block_rsv *rsv)
 {
-	btrfs_block_rsv_release(fs_info, rsv, (u64)-1);
+	btrfs_block_rsv_release(fs_info, rsv, (u64)-1, NULL);
 }