btrfs: export find_next_inode() as btrfs_find_first_inode()

Export the relocation private helper find_next_inode() to inode.c, as this
same logic is also used at btrfs_prune_dentries() and will be used by an
upcoming change that adds an extent map shrinker. The next patch will
change btrfs_prune_dentries() to use this helper.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/btrfs_inode.h

@@ -543,6 +543,7 @@ ssize_t btrfs_dio_read(struct kiocb *iocb, struct iov_iter *iter,
 		       size_t done_before);
 struct iomap_dio *btrfs_dio_write(struct kiocb *iocb, struct iov_iter *iter,
 				  size_t done_before);
+struct btrfs_inode *btrfs_find_first_inode(struct btrfs_root *root, u64 min_ino);
 
 extern const struct dentry_operations btrfs_dentry_operations;
 

fs/btrfs/inode.c

@@ -10807,6 +10807,65 @@ void btrfs_assert_inode_range_clean(struct btrfs_inode *inode, u64 start, u64 en
 	ASSERT(ordered == NULL);
 }
 
+/*
+ * Find the first inode with a minimum number.
+ *
+ * @root:	The root to search for.
+ * @min_ino:	The minimum inode number.
+ *
+ * Find the first inode in the @root with a number >= @min_ino and return it.
+ * Returns NULL if no such inode found.
+ */
+struct btrfs_inode *btrfs_find_first_inode(struct btrfs_root *root, u64 min_ino)
+{
+	struct rb_node *node;
+	struct rb_node *prev;
+	struct btrfs_inode *inode;
+
+	spin_lock(&root->inode_lock);
+again:
+	node = root->inode_tree.rb_node;
+	prev = NULL;
+	while (node) {
+		prev = node;
+		inode = rb_entry(node, struct btrfs_inode, rb_node);
+		if (min_ino < btrfs_ino(inode))
+			node = node->rb_left;
+		else if (min_ino > btrfs_ino(inode))
+			node = node->rb_right;
+		else
+			break;
+	}
+
+	if (!node) {
+		while (prev) {
+			inode = rb_entry(prev, struct btrfs_inode, rb_node);
+			if (min_ino <= btrfs_ino(inode)) {
+				node = prev;
+				break;
+			}
+			prev = rb_next(prev);
+		}
+	}
+
+	while (node) {
+		inode = rb_entry(prev, struct btrfs_inode, rb_node);
+		if (igrab(&inode->vfs_inode)) {
+			spin_unlock(&root->inode_lock);
+			return inode;
+		}
+
+		min_ino = btrfs_ino(inode) + 1;
+		if (cond_resched_lock(&root->inode_lock))
+			goto again;
+
+		node = rb_next(node);
+	}
+	spin_unlock(&root->inode_lock);
+
+	return NULL;
+}
+
 static const struct inode_operations btrfs_dir_inode_operations = {
 	.getattr	= btrfs_getattr,
 	.lookup		= btrfs_lookup,

fs/btrfs/relocation.c

@@ -951,60 +951,6 @@ int btrfs_update_reloc_root(struct btrfs_trans_handle *trans,
 	return ret;
 }
 
-/*
- * helper to find first cached inode with inode number >= objectid
- * in a subvolume
- */
-static struct inode *find_next_inode(struct btrfs_root *root, u64 objectid)
-{
-	struct rb_node *node;
-	struct rb_node *prev;
-	struct btrfs_inode *entry;
-	struct inode *inode;
-
-	spin_lock(&root->inode_lock);
-again:
-	node = root->inode_tree.rb_node;
-	prev = NULL;
-	while (node) {
-		prev = node;
-		entry = rb_entry(node, struct btrfs_inode, rb_node);
-
-		if (objectid < btrfs_ino(entry))
-			node = node->rb_left;
-		else if (objectid > btrfs_ino(entry))
-			node = node->rb_right;
-		else
-			break;
-	}
-	if (!node) {
-		while (prev) {
-			entry = rb_entry(prev, struct btrfs_inode, rb_node);
-			if (objectid <= btrfs_ino(entry)) {
-				node = prev;
-				break;
-			}
-			prev = rb_next(prev);
-		}
-	}
-	while (node) {
-		entry = rb_entry(node, struct btrfs_inode, rb_node);
-		inode = igrab(&entry->vfs_inode);
-		if (inode) {
-			spin_unlock(&root->inode_lock);
-			return inode;
-		}
-
-		objectid = btrfs_ino(entry) + 1;
-		if (cond_resched_lock(&root->inode_lock))
-			goto again;
-
-		node = rb_next(node);
-	}
-	spin_unlock(&root->inode_lock);
-	return NULL;
-}
-
 /*
  * get new location of data
  */
@@ -1065,7 +1011,7 @@ int replace_file_extents(struct btrfs_trans_handle *trans,
 	struct btrfs_fs_info *fs_info = root->fs_info;
 	struct btrfs_key key;
 	struct btrfs_file_extent_item *fi;
-	struct inode *inode = NULL;
+	struct btrfs_inode *inode = NULL;
 	u64 parent;
 	u64 bytenr;
 	u64 new_bytenr = 0;
@@ -1112,13 +1058,13 @@ int replace_file_extents(struct btrfs_trans_handle *trans,
 		 */
 		if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
 			if (first) {
-				inode = find_next_inode(root, key.objectid);
+				inode = btrfs_find_first_inode(root, key.objectid);
 				first = 0;
-			} else if (inode && btrfs_ino(BTRFS_I(inode)) < key.objectid) {
-				btrfs_add_delayed_iput(BTRFS_I(inode));
-				inode = find_next_inode(root, key.objectid);
+			} else if (inode && btrfs_ino(inode) < key.objectid) {
+				btrfs_add_delayed_iput(inode);
+				inode = btrfs_find_first_inode(root, key.objectid);
 			}
-			if (inode && btrfs_ino(BTRFS_I(inode)) == key.objectid) {
+			if (inode && btrfs_ino(inode) == key.objectid) {
 				struct extent_state *cached_state = NULL;
 
 				end = key.offset +
@@ -1128,21 +1074,19 @@ int replace_file_extents(struct btrfs_trans_handle *trans,
 				WARN_ON(!IS_ALIGNED(end, fs_info->sectorsize));
 				end--;
 				/* Take mmap lock to serialize with reflinks. */
-				if (!down_read_trylock(&BTRFS_I(inode)->i_mmap_lock))
+				if (!down_read_trylock(&inode->i_mmap_lock))
 					continue;
-				ret = try_lock_extent(&BTRFS_I(inode)->io_tree,
-						      key.offset, end,
-						      &cached_state);
+				ret = try_lock_extent(&inode->io_tree, key.offset,
+						      end, &cached_state);
 				if (!ret) {
-					up_read(&BTRFS_I(inode)->i_mmap_lock);
+					up_read(&inode->i_mmap_lock);
 					continue;
 				}
 
-				btrfs_drop_extent_map_range(BTRFS_I(inode),
-							    key.offset, end, true);
-				unlock_extent(&BTRFS_I(inode)->io_tree,
-					      key.offset, end, &cached_state);
-				up_read(&BTRFS_I(inode)->i_mmap_lock);
+				btrfs_drop_extent_map_range(inode, key.offset, end, true);
+				unlock_extent(&inode->io_tree, key.offset, end,
+					      &cached_state);
+				up_read(&inode->i_mmap_lock);
 			}
 		}
 
@@ -1185,7 +1129,7 @@ int replace_file_extents(struct btrfs_trans_handle *trans,
 	if (dirty)
 		btrfs_mark_buffer_dirty(trans, leaf);
 	if (inode)
-		btrfs_add_delayed_iput(BTRFS_I(inode));
+		btrfs_add_delayed_iput(inode);
 	return ret;
 }
 
@@ -1527,7 +1471,7 @@ static int invalidate_extent_cache(struct btrfs_root *root,
 				   const struct btrfs_key *max_key)
 {
 	struct btrfs_fs_info *fs_info = root->fs_info;
-	struct inode *inode = NULL;
+	struct btrfs_inode *inode = NULL;
 	u64 objectid;
 	u64 start, end;
 	u64 ino;
@@ -1537,23 +1481,24 @@ static int invalidate_extent_cache(struct btrfs_root *root,
 		struct extent_state *cached_state = NULL;
 
 		cond_resched();
-		iput(inode);
+		if (inode)
+			iput(&inode->vfs_inode);
 
 		if (objectid > max_key->objectid)
 			break;
 
-		inode = find_next_inode(root, objectid);
+		inode = btrfs_find_first_inode(root, objectid);
 		if (!inode)
 			break;
-		ino = btrfs_ino(BTRFS_I(inode));
+		ino = btrfs_ino(inode);
 
 		if (ino > max_key->objectid) {
-			iput(inode);
+			iput(&inode->vfs_inode);
 			break;
 		}
 
 		objectid = ino + 1;
-		if (!S_ISREG(inode->i_mode))
+		if (!S_ISREG(inode->vfs_inode.i_mode))
 			continue;
 
 		if (unlikely(min_key->objectid == ino)) {
@@ -1586,9 +1531,9 @@ static int invalidate_extent_cache(struct btrfs_root *root,
 		}
 
 		/* the lock_extent waits for read_folio to complete */
-		lock_extent(&BTRFS_I(inode)->io_tree, start, end, &cached_state);
-		btrfs_drop_extent_map_range(BTRFS_I(inode), start, end, true);
-		unlock_extent(&BTRFS_I(inode)->io_tree, start, end, &cached_state);
+		lock_extent(&inode->io_tree, start, end, &cached_state);
+		btrfs_drop_extent_map_range(inode, start, end, true);
+		unlock_extent(&inode->io_tree, start, end, &cached_state);
 	}
 	return 0;
 }