inode-item.c

  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Copyright (C) 2007 Oracle.  All rights reserved.
  4 */
  5
  6#include "ctree.h"
  7#include "fs.h"
  8#include "messages.h"
  9#include "inode-item.h"
 10#include "disk-io.h"
 11#include "transaction.h"
 12#include "space-info.h"
 13#include "accessors.h"
 14#include "extent-tree.h"
 15#include "file-item.h"
 16
 17struct btrfs_inode_ref *btrfs_find_name_in_backref(const struct extent_buffer *leaf,
 18						   int slot,
 19						   const struct fscrypt_str *name)
 20{
 21	struct btrfs_inode_ref *ref;
 22	unsigned long ptr;
 23	unsigned long name_ptr;
 24	u32 item_size;
 25	u32 cur_offset = 0;
 26	int len;
 27
 28	item_size = btrfs_item_size(leaf, slot);
 29	ptr = btrfs_item_ptr_offset(leaf, slot);
 30	while (cur_offset < item_size) {
 31		ref = (struct btrfs_inode_ref *)(ptr + cur_offset);
 32		len = btrfs_inode_ref_name_len(leaf, ref);
 33		name_ptr = (unsigned long)(ref + 1);
 34		cur_offset += len + sizeof(*ref);
 35		if (len != name->len)
 36			continue;
 37		if (memcmp_extent_buffer(leaf, name->name, name_ptr,
 38					 name->len) == 0)
 39			return ref;
 40	}
 41	return NULL;
 42}
 43
 44struct btrfs_inode_extref *btrfs_find_name_in_ext_backref(
 45		const struct extent_buffer *leaf, int slot, u64 ref_objectid,
 46		const struct fscrypt_str *name)
 47{
 48	struct btrfs_inode_extref *extref;
 49	unsigned long ptr;
 50	unsigned long name_ptr;
 51	u32 item_size;
 52	u32 cur_offset = 0;
 53	int ref_name_len;
 54
 55	item_size = btrfs_item_size(leaf, slot);
 56	ptr = btrfs_item_ptr_offset(leaf, slot);
 57
 58	/*
 59	 * Search all extended backrefs in this item. We're only
 60	 * looking through any collisions so most of the time this is
 61	 * just going to compare against one buffer. If all is well,
 62	 * we'll return success and the inode ref object.
 63	 */
 64	while (cur_offset < item_size) {
 65		extref = (struct btrfs_inode_extref *) (ptr + cur_offset);
 66		name_ptr = (unsigned long)(&extref->name);
 67		ref_name_len = btrfs_inode_extref_name_len(leaf, extref);
 68
 69		if (ref_name_len == name->len &&
 70		    btrfs_inode_extref_parent(leaf, extref) == ref_objectid &&
 71		    (memcmp_extent_buffer(leaf, name->name, name_ptr,
 72					  name->len) == 0))
 73			return extref;
 74
 75		cur_offset += ref_name_len + sizeof(*extref);
 76	}
 77	return NULL;
 78}
 79
 80/* Returns NULL if no extref found */
 81struct btrfs_inode_extref *btrfs_lookup_inode_extref(struct btrfs_root *root,
 82						     struct btrfs_path *path,
 83						     const struct fscrypt_str *name,
 84						     u64 inode_objectid, u64 ref_objectid)
 85{
 86	int ret;
 87	struct btrfs_key key;
 88
 89	key.objectid = inode_objectid;
 90	key.type = BTRFS_INODE_EXTREF_KEY;
 91	key.offset = btrfs_extref_hash(ref_objectid, name->name, name->len);
 92
 93	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
 94	if (ret < 0)
 95		return ERR_PTR(ret);
 96	if (ret > 0)
 97		return NULL;
 98	return btrfs_find_name_in_ext_backref(path->nodes[0], path->slots[0],
 99					      ref_objectid, name);
100
101}
102
103static int btrfs_del_inode_extref(struct btrfs_trans_handle *trans,
104				  struct btrfs_root *root,
105				  const struct fscrypt_str *name,
106				  u64 inode_objectid, u64 ref_objectid,
107				  u64 *index)
108{
109	BTRFS_PATH_AUTO_FREE(path);
110	struct btrfs_key key;
111	struct btrfs_inode_extref *extref;
112	struct extent_buffer *leaf;
113	int ret;
114	int del_len = name->len + sizeof(*extref);
115	unsigned long ptr;
116	unsigned long item_start;
117	u32 item_size;
118
119	key.objectid = inode_objectid;
120	key.type = BTRFS_INODE_EXTREF_KEY;
121	key.offset = btrfs_extref_hash(ref_objectid, name->name, name->len);
122
123	path = btrfs_alloc_path();
124	if (!path)
125		return -ENOMEM;
126
127	ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
128	if (ret > 0)
129		return -ENOENT;
130	if (ret < 0)
131		return ret;
132
133	/*
134	 * Sanity check - did we find the right item for this name?
135	 * This should always succeed so error here will make the FS
136	 * readonly.
137	 */
138	extref = btrfs_find_name_in_ext_backref(path->nodes[0], path->slots[0],
139						ref_objectid, name);
140	if (unlikely(!extref)) {
141		btrfs_abort_transaction(trans, -ENOENT);
142		return -ENOENT;
143	}
144
145	leaf = path->nodes[0];
146	item_size = btrfs_item_size(leaf, path->slots[0]);
147	if (index)
148		*index = btrfs_inode_extref_index(leaf, extref);
149
150	if (del_len == item_size) {
151		/* Common case only one ref in the item, remove the whole item. */
152		return btrfs_del_item(trans, root, path);
153	}
154
155	ptr = (unsigned long)extref;
156	item_start = btrfs_item_ptr_offset(leaf, path->slots[0]);
157
158	memmove_extent_buffer(leaf, ptr, ptr + del_len,
159			      item_size - (ptr + del_len - item_start));
160
161	btrfs_truncate_item(trans, path, item_size - del_len, 1);
162
163	return ret;
164}
165
166int btrfs_del_inode_ref(struct btrfs_trans_handle *trans,
167			struct btrfs_root *root, const struct fscrypt_str *name,
168			u64 inode_objectid, u64 ref_objectid, u64 *index)
169{
170	struct btrfs_path *path;
171	struct btrfs_key key;
172	struct btrfs_inode_ref *ref;
173	struct extent_buffer *leaf;
174	unsigned long ptr;
175	unsigned long item_start;
176	u32 item_size;
177	u32 sub_item_len;
178	int ret;
179	int search_ext_refs = 0;
180	int del_len = name->len + sizeof(*ref);
181
182	key.objectid = inode_objectid;
183	key.type = BTRFS_INODE_REF_KEY;
184	key.offset = ref_objectid;
185
186	path = btrfs_alloc_path();
187	if (!path)
188		return -ENOMEM;
189
190	ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
191	if (ret > 0) {
192		ret = -ENOENT;
193		search_ext_refs = 1;
194		goto out;
195	} else if (ret < 0) {
196		goto out;
197	}
198
199	ref = btrfs_find_name_in_backref(path->nodes[0], path->slots[0], name);
200	if (!ref) {
201		ret = -ENOENT;
202		search_ext_refs = 1;
203		goto out;
204	}
205	leaf = path->nodes[0];
206	item_size = btrfs_item_size(leaf, path->slots[0]);
207
208	if (index)
209		*index = btrfs_inode_ref_index(leaf, ref);
210
211	if (del_len == item_size) {
212		ret = btrfs_del_item(trans, root, path);
213		goto out;
214	}
215	ptr = (unsigned long)ref;
216	sub_item_len = name->len + sizeof(*ref);
217	item_start = btrfs_item_ptr_offset(leaf, path->slots[0]);
218	memmove_extent_buffer(leaf, ptr, ptr + sub_item_len,
219			      item_size - (ptr + sub_item_len - item_start));
220	btrfs_truncate_item(trans, path, item_size - sub_item_len, 1);
221out:
222	btrfs_free_path(path);
223
224	if (search_ext_refs) {
225		/*
226		 * No refs were found, or we could not find the
227		 * name in our ref array. Find and remove the extended
228		 * inode ref then.
229		 */
230		return btrfs_del_inode_extref(trans, root, name,
231					      inode_objectid, ref_objectid, index);
232	}
233
234	return ret;
235}
236
237/*
238 * Insert an extended inode ref into a tree.
239 *
240 * The caller must have checked against BTRFS_LINK_MAX already.
241 */
242static int btrfs_insert_inode_extref(struct btrfs_trans_handle *trans,
243				     struct btrfs_root *root,
244				     const struct fscrypt_str *name,
245				     u64 inode_objectid, u64 ref_objectid,
246				     u64 index)
247{
248	struct btrfs_inode_extref *extref;
249	int ret;
250	int ins_len = name->len + sizeof(*extref);
251	unsigned long ptr;
252	BTRFS_PATH_AUTO_FREE(path);
253	struct btrfs_key key;
254	struct extent_buffer *leaf;
255
256	key.objectid = inode_objectid;
257	key.type = BTRFS_INODE_EXTREF_KEY;
258	key.offset = btrfs_extref_hash(ref_objectid, name->name, name->len);
259
260	path = btrfs_alloc_path();
261	if (!path)
262		return -ENOMEM;
263
264	ret = btrfs_insert_empty_item(trans, root, path, &key,
265				      ins_len);
266	if (ret == -EEXIST) {
267		if (btrfs_find_name_in_ext_backref(path->nodes[0],
268						   path->slots[0],
269						   ref_objectid,
270						   name))
271			return ret;
272
273		btrfs_extend_item(trans, path, ins_len);
274		ret = 0;
275	}
276	if (ret < 0)
277		return ret;
278
279	leaf = path->nodes[0];
280	ptr = (unsigned long)btrfs_item_ptr(leaf, path->slots[0], char);
281	ptr += btrfs_item_size(leaf, path->slots[0]) - ins_len;
282	extref = (struct btrfs_inode_extref *)ptr;
283
284	btrfs_set_inode_extref_name_len(path->nodes[0], extref, name->len);
285	btrfs_set_inode_extref_index(path->nodes[0], extref, index);
286	btrfs_set_inode_extref_parent(path->nodes[0], extref, ref_objectid);
287
288	ptr = (unsigned long)&extref->name;
289	write_extent_buffer(path->nodes[0], name->name, ptr, name->len);
290
291	return 0;
292}
293
294/* Will return 0, -ENOMEM, -EMLINK, or -EEXIST or anything from the CoW path */
295int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans,
296			   struct btrfs_root *root, const struct fscrypt_str *name,
297			   u64 inode_objectid, u64 ref_objectid, u64 index)
298{
299	struct btrfs_fs_info *fs_info = root->fs_info;
300	struct btrfs_path *path;
301	struct btrfs_key key;
302	struct btrfs_inode_ref *ref;
303	unsigned long ptr;
304	int ret;
305	int ins_len = name->len + sizeof(*ref);
306
307	key.objectid = inode_objectid;
308	key.type = BTRFS_INODE_REF_KEY;
309	key.offset = ref_objectid;
310
311	path = btrfs_alloc_path();
312	if (!path)
313		return -ENOMEM;
314
315	path->skip_release_on_error = true;
316	ret = btrfs_insert_empty_item(trans, root, path, &key,
317				      ins_len);
318	if (ret == -EEXIST) {
319		u32 old_size;
320		ref = btrfs_find_name_in_backref(path->nodes[0], path->slots[0],
321						 name);
322		if (ref)
323			goto out;
324
325		old_size = btrfs_item_size(path->nodes[0], path->slots[0]);
326		btrfs_extend_item(trans, path, ins_len);
327		ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
328				     struct btrfs_inode_ref);
329		ref = (struct btrfs_inode_ref *)((unsigned long)ref + old_size);
330		btrfs_set_inode_ref_name_len(path->nodes[0], ref, name->len);
331		btrfs_set_inode_ref_index(path->nodes[0], ref, index);
332		ptr = (unsigned long)(ref + 1);
333		ret = 0;
334	} else if (ret < 0) {
335		if (ret == -EOVERFLOW) {
336			if (btrfs_find_name_in_backref(path->nodes[0],
337						       path->slots[0],
338						       name))
339				ret = -EEXIST;
340			else
341				ret = -EMLINK;
342		}
343		goto out;
344	} else {
345		ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
346				     struct btrfs_inode_ref);
347		btrfs_set_inode_ref_name_len(path->nodes[0], ref, name->len);
348		btrfs_set_inode_ref_index(path->nodes[0], ref, index);
349		ptr = (unsigned long)(ref + 1);
350	}
351	write_extent_buffer(path->nodes[0], name->name, ptr, name->len);
352out:
353	btrfs_free_path(path);
354
355	if (ret == -EMLINK) {
356		struct btrfs_super_block *disk_super = fs_info->super_copy;
357		/* We ran out of space in the ref array. Need to
358		 * add an extended ref. */
359		if (btrfs_super_incompat_flags(disk_super)
360		    & BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF)
361			ret = btrfs_insert_inode_extref(trans, root, name,
362							inode_objectid,
363							ref_objectid, index);
364	}
365
366	return ret;
367}
368
369int btrfs_insert_empty_inode(struct btrfs_trans_handle *trans,
370			     struct btrfs_root *root,
371			     struct btrfs_path *path, u64 objectid)
372{
373	struct btrfs_key key;
374	int ret;
375	key.objectid = objectid;
376	key.type = BTRFS_INODE_ITEM_KEY;
377	key.offset = 0;
378
379	ret = btrfs_insert_empty_item(trans, root, path, &key,
380				      sizeof(struct btrfs_inode_item));
381	return ret;
382}
383
384int btrfs_lookup_inode(struct btrfs_trans_handle *trans, struct btrfs_root
385		       *root, struct btrfs_path *path,
386		       struct btrfs_key *location, int mod)
387{
388	int ins_len = mod < 0 ? -1 : 0;
389	int cow = mod != 0;
390	int ret;
391	int slot;
392	struct extent_buffer *leaf;
393	struct btrfs_key found_key;
394
395	ret = btrfs_search_slot(trans, root, location, path, ins_len, cow);
396	if (ret > 0 && location->type == BTRFS_ROOT_ITEM_KEY &&
397	    location->offset == (u64)-1 && path->slots[0] != 0) {
398		slot = path->slots[0] - 1;
399		leaf = path->nodes[0];
400		btrfs_item_key_to_cpu(leaf, &found_key, slot);
401		if (found_key.objectid == location->objectid &&
402		    found_key.type == location->type) {
403			path->slots[0]--;
404			return 0;
405		}
406	}
407	return ret;
408}
409
410static inline void btrfs_trace_truncate(const struct btrfs_inode *inode,
411					const struct extent_buffer *leaf,
412					const struct btrfs_file_extent_item *fi,
413					u64 offset, int extent_type, int slot)
414{
415	if (!inode)
416		return;
417	if (extent_type == BTRFS_FILE_EXTENT_INLINE)
418		trace_btrfs_truncate_show_fi_inline(inode, leaf, fi, slot,
419						    offset);
420	else
421		trace_btrfs_truncate_show_fi_regular(inode, leaf, fi, offset);
422}
423
424/*
425 * Remove inode items from a given root.
426 *
427 * @trans:		A transaction handle.
428 * @root:		The root from which to remove items.
429 * @inode:		The inode whose items we want to remove.
430 * @control:		The btrfs_truncate_control to control how and what we
431 *			are truncating.
432 *
433 * Remove all keys associated with the inode from the given root that have a key
434 * with a type greater than or equals to @min_type. When @min_type has a value of
435 * BTRFS_EXTENT_DATA_KEY, only remove file extent items that have an offset value
436 * greater than or equals to @new_size. If a file extent item that starts before
437 * @new_size and ends after it is found, its length is adjusted.
438 *
439 * Returns: 0 on success, < 0 on error and NEED_TRUNCATE_BLOCK when @min_type is
440 * BTRFS_EXTENT_DATA_KEY and the caller must truncate the last block.
441 */
442int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
443			       struct btrfs_root *root,
444			       struct btrfs_truncate_control *control)
445{
446	struct btrfs_fs_info *fs_info = root->fs_info;
447	BTRFS_PATH_AUTO_FREE(path);
448	struct extent_buffer *leaf;
449	struct btrfs_file_extent_item *fi;
450	struct btrfs_key key;
451	struct btrfs_key found_key;
452	u64 new_size = control->new_size;
453	u64 extent_num_bytes = 0;
454	u64 extent_offset = 0;
455	u64 item_end = 0;
456	u32 found_type = (u8)-1;
457	int del_item;
458	int pending_del_nr = 0;
459	int pending_del_slot = 0;
460	int extent_type = -1;
461	int ret;
462	u64 bytes_deleted = 0;
463	bool be_nice = false;
464
465	ASSERT(control->inode || !control->clear_extent_range);
466	ASSERT(new_size == 0 || control->min_type == BTRFS_EXTENT_DATA_KEY);
467
468	control->last_size = new_size;
469	control->sub_bytes = 0;
470
471	/*
472	 * For shareable roots we want to back off from time to time, this turns
473	 * out to be subvolume roots, reloc roots, and data reloc roots.
474	 */
475	if (test_bit(BTRFS_ROOT_SHAREABLE, &root->state))
476		be_nice = true;
477
478	path = btrfs_alloc_path();
479	if (!path)
480		return -ENOMEM;
481	path->reada = READA_BACK;
482
483	key.objectid = control->ino;
484	key.type = (u8)-1;
485	key.offset = (u64)-1;
486
487search_again:
488	/*
489	 * With a 16K leaf size and 128MiB extents, you can actually queue up a
490	 * huge file in a single leaf.  Most of the time that bytes_deleted is
491	 * > 0, it will be huge by the time we get here
492	 */
493	if (be_nice && bytes_deleted > SZ_32M &&
494	    btrfs_should_end_transaction(trans)) {
495		ret = -EAGAIN;
496		goto out;
497	}
498
499	ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
500	if (ret < 0)
501		goto out;
502
503	if (ret > 0) {
504		ret = 0;
505		/* There are no items in the tree for us to truncate, we're done */
506		if (path->slots[0] == 0)
507			goto out;
508		path->slots[0]--;
509	}
510
511	while (1) {
512		u64 clear_start = 0, clear_len = 0, extent_start = 0;
513		bool refill_delayed_refs_rsv = false;
514
515		fi = NULL;
516		leaf = path->nodes[0];
517		btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
518		found_type = found_key.type;
519
520		if (found_key.objectid != control->ino)
521			break;
522
523		if (found_type < control->min_type)
524			break;
525
526		item_end = found_key.offset;
527		if (found_type == BTRFS_EXTENT_DATA_KEY) {
528			fi = btrfs_item_ptr(leaf, path->slots[0],
529					    struct btrfs_file_extent_item);
530			extent_type = btrfs_file_extent_type(leaf, fi);
531			if (extent_type != BTRFS_FILE_EXTENT_INLINE)
532				item_end +=
533				    btrfs_file_extent_num_bytes(leaf, fi);
534			else if (extent_type == BTRFS_FILE_EXTENT_INLINE)
535				item_end += btrfs_file_extent_ram_bytes(leaf, fi);
536
537			btrfs_trace_truncate(control->inode, leaf, fi,
538					     found_key.offset, extent_type,
539					     path->slots[0]);
540			item_end--;
541		}
542		if (found_type > control->min_type) {
543			del_item = 1;
544		} else {
545			if (item_end < new_size)
546				break;
547			if (found_key.offset >= new_size)
548				del_item = 1;
549			else
550				del_item = 0;
551		}
552
553		/* FIXME, shrink the extent if the ref count is only 1 */
554		if (found_type != BTRFS_EXTENT_DATA_KEY)
555			goto delete;
556
557		control->extents_found++;
558
559		if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
560			u64 num_dec;
561
562			clear_start = found_key.offset;
563			extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
564			if (!del_item) {
565				u64 orig_num_bytes =
566					btrfs_file_extent_num_bytes(leaf, fi);
567				extent_num_bytes = ALIGN(new_size -
568						found_key.offset,
569						fs_info->sectorsize);
570				clear_start = ALIGN(new_size, fs_info->sectorsize);
571
572				btrfs_set_file_extent_num_bytes(leaf, fi,
573							 extent_num_bytes);
574				num_dec = (orig_num_bytes - extent_num_bytes);
575				if (extent_start != 0)
576					control->sub_bytes += num_dec;
577			} else {
578				extent_num_bytes =
579					btrfs_file_extent_disk_num_bytes(leaf, fi);
580				extent_offset = found_key.offset -
581					btrfs_file_extent_offset(leaf, fi);
582
583				/* FIXME blocksize != 4096 */
584				num_dec = btrfs_file_extent_num_bytes(leaf, fi);
585				if (extent_start != 0)
586					control->sub_bytes += num_dec;
587			}
588			clear_len = num_dec;
589		} else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
590			/*
591			 * We can't truncate inline items that have had
592			 * special encodings
593			 */
594			if (!del_item &&
595			    btrfs_file_extent_encryption(leaf, fi) == 0 &&
596			    btrfs_file_extent_other_encoding(leaf, fi) == 0 &&
597			    btrfs_file_extent_compression(leaf, fi) == 0) {
598				u32 size = (u32)(new_size - found_key.offset);
599
600				btrfs_set_file_extent_ram_bytes(leaf, fi, size);
601				size = btrfs_file_extent_calc_inline_size(size);
602				btrfs_truncate_item(trans, path, size, 1);
603			} else if (!del_item) {
604				/*
605				 * We have to bail so the last_size is set to
606				 * just before this extent.
607				 */
608				ret = BTRFS_NEED_TRUNCATE_BLOCK;
609				break;
610			} else {
611				/*
612				 * Inline extents are special, we just treat
613				 * them as a full sector worth in the file
614				 * extent tree just for simplicity sake.
615				 */
616				clear_len = fs_info->sectorsize;
617			}
618
619			control->sub_bytes += item_end + 1 - new_size;
620		}
621delete:
622		/*
623		 * We only want to clear the file extent range if we're
624		 * modifying the actual inode's mapping, which is just the
625		 * normal truncate path.
626		 */
627		if (control->clear_extent_range) {
628			ret = btrfs_inode_clear_file_extent_range(control->inode,
629						  clear_start, clear_len);
630			if (unlikely(ret)) {
631				btrfs_abort_transaction(trans, ret);
632				break;
633			}
634		}
635
636		if (del_item) {
637			ASSERT(!pending_del_nr ||
638			       ((path->slots[0] + 1) == pending_del_slot));
639
640			control->last_size = found_key.offset;
641			if (!pending_del_nr) {
642				/* No pending yet, add ourselves */
643				pending_del_slot = path->slots[0];
644				pending_del_nr = 1;
645			} else if (path->slots[0] + 1 == pending_del_slot) {
646				/* Hop on the pending chunk */
647				pending_del_nr++;
648				pending_del_slot = path->slots[0];
649			}
650		} else {
651			control->last_size = new_size;
652			break;
653		}
654
655		if (del_item && extent_start != 0 && !control->skip_ref_updates) {
656			struct btrfs_ref ref = {
657				.action = BTRFS_DROP_DELAYED_REF,
658				.bytenr = extent_start,
659				.num_bytes = extent_num_bytes,
660				.owning_root = btrfs_root_id(root),
661				.ref_root = btrfs_header_owner(leaf),
662			};
663
664			bytes_deleted += extent_num_bytes;
665
666			btrfs_init_data_ref(&ref, control->ino, extent_offset,
667					    btrfs_root_id(root), false);
668			ret = btrfs_free_extent(trans, &ref);
669			if (unlikely(ret)) {
670				btrfs_abort_transaction(trans, ret);
671				break;
672			}
673			if (be_nice && btrfs_check_space_for_delayed_refs(fs_info))
674				refill_delayed_refs_rsv = true;
675		}
676
677		if (found_type == BTRFS_INODE_ITEM_KEY)
678			break;
679
680		if (path->slots[0] == 0 ||
681		    path->slots[0] != pending_del_slot ||
682		    refill_delayed_refs_rsv) {
683			if (pending_del_nr) {
684				ret = btrfs_del_items(trans, root, path,
685						pending_del_slot,
686						pending_del_nr);
687				if (unlikely(ret)) {
688					btrfs_abort_transaction(trans, ret);
689					break;
690				}
691				pending_del_nr = 0;
692			}
693			btrfs_release_path(path);
694
695			/*
696			 * We can generate a lot of delayed refs, so we need to
697			 * throttle every once and a while and make sure we're
698			 * adding enough space to keep up with the work we are
699			 * generating.  Since we hold a transaction here we
700			 * can't flush, and we don't want to FLUSH_LIMIT because
701			 * we could have generated too many delayed refs to
702			 * actually allocate, so just bail if we're short and
703			 * let the normal reservation dance happen higher up.
704			 */
705			if (refill_delayed_refs_rsv) {
706				ret = btrfs_delayed_refs_rsv_refill(fs_info,
707							BTRFS_RESERVE_NO_FLUSH);
708				if (ret) {
709					ret = -EAGAIN;
710					break;
711				}
712			}
713			goto search_again;
714		} else {
715			path->slots[0]--;
716		}
717	}
718out:
719	if (ret >= 0 && pending_del_nr) {
720		int ret2;
721
722		ret2 = btrfs_del_items(trans, root, path, pending_del_slot, pending_del_nr);
723		if (unlikely(ret2)) {
724			btrfs_abort_transaction(trans, ret2);
725			ret = ret2;
726		}
727	}
728
729	ASSERT(control->last_size >= new_size);
730	if (!ret && control->last_size > new_size)
731		control->last_size = new_size;
732
733	return ret;
734}