Merge tag 'for-5.15-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:
 "A few more error handling fixes, stemming from code inspection, error
  injection or fuzzing"

* tag 'for-5.15-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: fix abort logic in btrfs_replace_file_extents
  btrfs: check for error when looking up inode during dir entry replay
  btrfs: unify lookup return value when dir entry is missing
  btrfs: deal with errors when adding inode reference during log replay
  btrfs: deal with errors when replaying dir entry during log replay
  btrfs: deal with errors when checking if a dir entry exists during log replay
  btrfs: update refs for any root except tree log roots
  btrfs: unlock newly allocated extent buffer after error

5 files changed, 97 insertions, 52 deletions

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index dff2c8a3e059..c0cebcf745ce 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -3030,7 +3030,7 @@ struct btrfs_dir_item *
 btrfs_lookup_dir_index_item(struct btrfs_trans_handle *trans,
 			    struct btrfs_root *root,
 			    struct btrfs_path *path, u64 dir,
-			    u64 objectid, const char *name, int name_len,
+			    u64 index, const char *name, int name_len,
 			    int mod);
 struct btrfs_dir_item *
 btrfs_search_dir_index_item(struct btrfs_root *root,
diff --git a/fs/btrfs/dir-item.c b/fs/btrfs/dir-item.c
index f1274d5c3805..7721ce0c0604 100644
--- a/fs/btrfs/dir-item.c
+++ b/fs/btrfs/dir-item.c
@@ -190,9 +190,20 @@ static struct btrfs_dir_item *btrfs_lookup_match_dir(
 }
 
 /*
- * lookup a directory item based on name.  'dir' is the objectid
- * we're searching in, and 'mod' tells us if you plan on deleting the
- * item (use mod < 0) or changing the options (use mod > 0)
+ * Lookup for a directory item by name.
+ *
+ * @trans:	The transaction handle to use. Can be NULL if @mod is 0.
+ * @root:	The root of the target tree.
+ * @path:	Path to use for the search.
+ * @dir:	The inode number (objectid) of the directory.
+ * @name:	The name associated to the directory entry we are looking for.
+ * @name_len:	The length of the name.
+ * @mod:	Used to indicate if the tree search is meant for a read only
+ *		lookup, for a modification lookup or for a deletion lookup, so
+ *		its value should be 0, 1 or -1, respectively.
+ *
+ * Returns: NULL if the dir item does not exists, an error pointer if an error
+ * happened, or a pointer to a dir item if a dir item exists for the given name.
  */
 struct btrfs_dir_item *btrfs_lookup_dir_item(struct btrfs_trans_handle *trans,
 					     struct btrfs_root *root,
@@ -273,27 +284,42 @@ out:
 }
 
 /*
- * lookup a directory item based on index.  'dir' is the objectid
- * we're searching in, and 'mod' tells us if you plan on deleting the
- * item (use mod < 0) or changing the options (use mod > 0)
+ * Lookup for a directory index item by name and index number.
  *
- * The name is used to make sure the index really points to the name you were
- * looking for.
+ * @trans:	The transaction handle to use. Can be NULL if @mod is 0.
+ * @root:	The root of the target tree.
+ * @path:	Path to use for the search.
+ * @dir:	The inode number (objectid) of the directory.
+ * @index:	The index number.
+ * @name:	The name associated to the directory entry we are looking for.
+ * @name_len:	The length of the name.
+ * @mod:	Used to indicate if the tree search is meant for a read only
+ *		lookup, for a modification lookup or for a deletion lookup, so
+ *		its value should be 0, 1 or -1, respectively.
+ *
+ * Returns: NULL if the dir index item does not exists, an error pointer if an
+ * error happened, or a pointer to a dir item if the dir index item exists and
+ * matches the criteria (name and index number).
  */
 struct btrfs_dir_item *
 btrfs_lookup_dir_index_item(struct btrfs_trans_handle *trans,
 			    struct btrfs_root *root,
 			    struct btrfs_path *path, u64 dir,
-			    u64 objectid, const char *name, int name_len,
+			    u64 index, const char *name, int name_len,
 			    int mod)
 {
+	struct btrfs_dir_item *di;
 	struct btrfs_key key;
 
 	key.objectid = dir;
 	key.type = BTRFS_DIR_INDEX_KEY;
-	key.offset = objectid;
+	key.offset = index;
 
-	return btrfs_lookup_match_dir(trans, root, path, &key, name, name_len, mod);
+	di = btrfs_lookup_match_dir(trans, root, path, &key, name, name_len, mod);
+	if (di == ERR_PTR(-ENOENT))
+		return NULL;
+
+	return di;
 }
 
 struct btrfs_dir_item *
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index fc3da7585fb7..0ab456cb4bf8 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -4859,6 +4859,7 @@ struct extent_buffer *btrfs_alloc_tree_block(struct btrfs_trans_handle *trans,
 out_free_delayed:
 	btrfs_free_delayed_extent_op(extent_op);
 out_free_buf:
+	btrfs_tree_unlock(buf);
 	free_extent_buffer(buf);
 out_free_reserved:
 	btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset, 0);
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 7ff577005d0f..a1762363f61f 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -734,8 +734,7 @@ int btrfs_drop_extents(struct btrfs_trans_handle *trans,
 	if (args->start >= inode->disk_i_size && !args->replace_extent)
 		modify_tree = 0;
 
-	update_refs = (test_bit(BTRFS_ROOT_SHAREABLE, &root->state) ||
-		       root == fs_info->tree_root);
+	update_refs = (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID);
 	while (1) {
 		recow = 0;
 		ret = btrfs_lookup_file_extent(trans, root, path, ino,
@@ -2704,14 +2703,16 @@ int btrfs_replace_file_extents(struct btrfs_inode *inode,
 						 drop_args.bytes_found);
 		if (ret != -ENOSPC) {
 			/*
-			 * When cloning we want to avoid transaction aborts when
-			 * nothing was done and we are attempting to clone parts
-			 * of inline extents, in such cases -EOPNOTSUPP is
-			 * returned by __btrfs_drop_extents() without having
-			 * changed anything in the file.
+			 * The only time we don't want to abort is if we are
+			 * attempting to clone a partial inline extent, in which
+			 * case we'll get EOPNOTSUPP.  However if we aren't
+			 * clone we need to abort no matter what, because if we
+			 * got EOPNOTSUPP via prealloc then we messed up and
+			 * need to abort.
 			 */
-			if (extent_info && !extent_info->is_new_extent &&
-			    ret && ret != -EOPNOTSUPP)
+			if (ret &&
+			    (ret != -EOPNOTSUPP ||
+			     (extent_info && extent_info->is_new_extent)))
 				btrfs_abort_transaction(trans, ret);
 			break;
 		}
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index f7efc26aa82a..b415c5ec03ea 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -939,9 +939,11 @@ out:
 }
 
 /*
- * helper function to see if a given name and sequence number found
- * in an inode back reference are already in a directory and correctly
- * point to this inode
+ * See if a given name and sequence number found in an inode back reference are
+ * already in a directory and correctly point to this inode.
+ *
+ * Returns: < 0 on error, 0 if the directory entry does not exists and 1 if it
+ * exists.
  */
 static noinline int inode_in_dir(struct btrfs_root *root,
 				 struct btrfs_path *path,
@@ -950,29 +952,34 @@ static noinline int inode_in_dir(struct btrfs_root *root,
 {
 	struct btrfs_dir_item *di;
 	struct btrfs_key location;
-	int match = 0;
+	int ret = 0;
 
 	di = btrfs_lookup_dir_index_item(NULL, root, path, dirid,
 					 index, name, name_len, 0);
-	if (di && !IS_ERR(di)) {
+	if (IS_ERR(di)) {
+		ret = PTR_ERR(di);
+		goto out;
+	} else if (di) {
 		btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
 		if (location.objectid != objectid)
 			goto out;
-	} else
+	} else {
 		goto out;
-	btrfs_release_path(path);
+	}
 
+	btrfs_release_path(path);
 	di = btrfs_lookup_dir_item(NULL, root, path, dirid, name, name_len, 0);
-	if (di && !IS_ERR(di)) {
-		btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
-		if (location.objectid != objectid)
-			goto out;
-	} else
+	if (IS_ERR(di)) {
+		ret = PTR_ERR(di);
 		goto out;
-	match = 1;
+	} else if (di) {
+		btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
+		if (location.objectid == objectid)
+			ret = 1;
+	}
 out:
 	btrfs_release_path(path);
-	return match;
+	return ret;
 }
 
 /*
@@ -1182,7 +1189,9 @@ next:
 	/* look for a conflicting sequence number */
 	di = btrfs_lookup_dir_index_item(trans, root, path, btrfs_ino(dir),
 					 ref_index, name, namelen, 0);
-	if (di && !IS_ERR(di)) {
+	if (IS_ERR(di)) {
+		return PTR_ERR(di);
+	} else if (di) {
 		ret = drop_one_dir_item(trans, root, path, dir, di);
 		if (ret)
 			return ret;
@@ -1192,7 +1201,9 @@ next:
 	/* look for a conflicting name */
 	di = btrfs_lookup_dir_item(trans, root, path, btrfs_ino(dir),
 				   name, namelen, 0);
-	if (di && !IS_ERR(di)) {
+	if (IS_ERR(di)) {
+		return PTR_ERR(di);
+	} else if (di) {
 		ret = drop_one_dir_item(trans, root, path, dir, di);
 		if (ret)
 			return ret;
@@ -1517,10 +1528,12 @@ static noinline int add_inode_ref(struct btrfs_trans_handle *trans,
 		if (ret)
 			goto out;
 
-		/* if we already have a perfect match, we're done */
-		if (!inode_in_dir(root, path, btrfs_ino(BTRFS_I(dir)),
-					btrfs_ino(BTRFS_I(inode)), ref_index,
-					name, namelen)) {
+		ret = inode_in_dir(root, path, btrfs_ino(BTRFS_I(dir)),
+				   btrfs_ino(BTRFS_I(inode)), ref_index,
+				   name, namelen);
+		if (ret < 0) {
+			goto out;
+		} else if (ret == 0) {
 			/*
 			 * look for a conflicting back reference in the
 			 * metadata. if we find one we have to unlink that name
@@ -1580,6 +1593,7 @@ static noinline int add_inode_ref(struct btrfs_trans_handle *trans,
 			if (ret)
 				goto out;
 		}
+		/* Else, ret == 1, we already have a perfect match, we're done. */
 
 		ref_ptr = (unsigned long)(ref_ptr + ref_struct_size) + namelen;
 		kfree(name);
@@ -1936,8 +1950,8 @@ static noinline int replay_one_name(struct btrfs_trans_handle *trans,
 	struct btrfs_key log_key;
 	struct inode *dir;
 	u8 log_type;
-	int exists;
-	int ret = 0;
+	bool exists;
+	int ret;
 	bool update_size = (key->type == BTRFS_DIR_INDEX_KEY);
 	bool name_added = false;
 
@@ -1957,12 +1971,12 @@ static noinline int replay_one_name(struct btrfs_trans_handle *trans,
 		   name_len);
 
 	btrfs_dir_item_key_to_cpu(eb, di, &log_key);
-	exists = btrfs_lookup_inode(trans, root, path, &log_key, 0);
-	if (exists == 0)
-		exists = 1;
-	else
-		exists = 0;
+	ret = btrfs_lookup_inode(trans, root, path, &log_key, 0);
 	btrfs_release_path(path);
+	if (ret < 0)
+		goto out;
+	exists = (ret == 0);
+	ret = 0;
 
 	if (key->type == BTRFS_DIR_ITEM_KEY) {
 		dst_di = btrfs_lookup_dir_item(trans, root, path, key->objectid,
@@ -1977,7 +1991,11 @@ static noinline int replay_one_name(struct btrfs_trans_handle *trans,
 		ret = -EINVAL;
 		goto out;
 	}
-	if (IS_ERR_OR_NULL(dst_di)) {
+
+	if (IS_ERR(dst_di)) {
+		ret = PTR_ERR(dst_di);
+		goto out;
+	} else if (!dst_di) {
 		/* we need a sequence number to insert, so we only
 		 * do inserts for the BTRFS_DIR_INDEX_KEY types
 		 */
@@ -2281,7 +2299,7 @@ again:
 						     dir_key->offset,
 						     name, name_len, 0);
 		}
-		if (!log_di || log_di == ERR_PTR(-ENOENT)) {
+		if (!log_di) {
 			btrfs_dir_item_key_to_cpu(eb, di, &location);
 			btrfs_release_path(path);
 			btrfs_release_path(log_path);
@@ -3540,8 +3558,7 @@ out_unlock:
 	if (err == -ENOSPC) {
 		btrfs_set_log_full_commit(trans);
 		err = 0;
-	} else if (err < 0 && err != -ENOENT) {
-		/* ENOENT can be returned if the entry hasn't been fsynced yet */
+	} else if (err < 0) {
 		btrfs_abort_transaction(trans, err);
 	}