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 *
 82btrfs_lookup_inode_extref(struct btrfs_trans_handle *trans,
 83			  struct btrfs_root *root,
 84			  struct btrfs_path *path,
 85			  const struct fscrypt_str *name,
 86			  u64 inode_objectid, u64 ref_objectid, int ins_len,
 87			  int cow)
 88{
 89	int ret;
 90	struct btrfs_key key;
 91
 92	key.objectid = inode_objectid;
 93	key.type = BTRFS_INODE_EXTREF_KEY;
 94	key.offset = btrfs_extref_hash(ref_objectid, name->name, name->len);
 95
 96	ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
 97	if (ret < 0)
 98		return ERR_PTR(ret);
 99	if (ret > 0)
100		return NULL;
101	return btrfs_find_name_in_ext_backref(path->nodes[0], path->slots[0],
102					      ref_objectid, name);
103
104}
105
106static int btrfs_del_inode_extref(struct btrfs_trans_handle *trans,
107				  struct btrfs_root *root,
108				  const struct fscrypt_str *name,
109				  u64 inode_objectid, u64 ref_objectid,
110				  u64 *index)
111{
112	struct btrfs_path *path;
113	struct btrfs_key key;
114	struct btrfs_inode_extref *extref;
115	struct extent_buffer *leaf;
116	int ret;
117	int del_len = name->len + sizeof(*extref);
118	unsigned long ptr;
119	unsigned long item_start;
120	u32 item_size;
121
122	key.objectid = inode_objectid;
123	key.type = BTRFS_INODE_EXTREF_KEY;
124	key.offset = btrfs_extref_hash(ref_objectid, name->name, name->len);
125
126	path = btrfs_alloc_path();
127	if (!path)
128		return -ENOMEM;
129
130	ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
131	if (ret > 0)
132		ret = -ENOENT;
133	if (ret < 0)
134		goto out;
135
136	/*
137	 * Sanity check - did we find the right item for this name?
138	 * This should always succeed so error here will make the FS
139	 * readonly.
140	 */
141	extref = btrfs_find_name_in_ext_backref(path->nodes[0], path->slots[0],
142						ref_objectid, name);
143	if (!extref) {
144		btrfs_abort_transaction(trans, -ENOENT);
145		ret = -ENOENT;
146		goto out;
147	}
148
149	leaf = path->nodes[0];
150	item_size = btrfs_item_size(leaf, path->slots[0]);
151	if (index)
152		*index = btrfs_inode_extref_index(leaf, extref);
153
154	if (del_len == item_size) {
155		/*
156		 * Common case only one ref in the item, remove the
157		 * whole item.
158		 */
159		ret = btrfs_del_item(trans, root, path);
160		goto out;
161	}
162
163	ptr = (unsigned long)extref;
164	item_start = btrfs_item_ptr_offset(leaf, path->slots[0]);
165
166	memmove_extent_buffer(leaf, ptr, ptr + del_len,
167			      item_size - (ptr + del_len - item_start));
168
169	btrfs_truncate_item(trans, path, item_size - del_len, 1);
170
171out:
172	btrfs_free_path(path);
173
174	return ret;
175}
176
177int btrfs_del_inode_ref(struct btrfs_trans_handle *trans,
178			struct btrfs_root *root, const struct fscrypt_str *name,
 
179			u64 inode_objectid, u64 ref_objectid, u64 *index)
180{
181	struct btrfs_path *path;
182	struct btrfs_key key;
183	struct btrfs_inode_ref *ref;
184	struct extent_buffer *leaf;
185	unsigned long ptr;
186	unsigned long item_start;
187	u32 item_size;
188	u32 sub_item_len;
189	int ret;
190	int search_ext_refs = 0;
191	int del_len = name->len + sizeof(*ref);
192
193	key.objectid = inode_objectid;
194	key.offset = ref_objectid;
195	key.type = BTRFS_INODE_REF_KEY;
196
197	path = btrfs_alloc_path();
198	if (!path)
199		return -ENOMEM;
200
201	ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
202	if (ret > 0) {
203		ret = -ENOENT;
204		search_ext_refs = 1;
205		goto out;
206	} else if (ret < 0) {
207		goto out;
208	}
209
210	ref = btrfs_find_name_in_backref(path->nodes[0], path->slots[0], name);
 
211	if (!ref) {
212		ret = -ENOENT;
213		search_ext_refs = 1;
214		goto out;
215	}
216	leaf = path->nodes[0];
217	item_size = btrfs_item_size(leaf, path->slots[0]);
218
219	if (index)
220		*index = btrfs_inode_ref_index(leaf, ref);
221
222	if (del_len == item_size) {
223		ret = btrfs_del_item(trans, root, path);
224		goto out;
225	}
226	ptr = (unsigned long)ref;
227	sub_item_len = name->len + sizeof(*ref);
228	item_start = btrfs_item_ptr_offset(leaf, path->slots[0]);
229	memmove_extent_buffer(leaf, ptr, ptr + sub_item_len,
230			      item_size - (ptr + sub_item_len - item_start));
231	btrfs_truncate_item(trans, path, item_size - sub_item_len, 1);
232out:
233	btrfs_free_path(path);
234
235	if (search_ext_refs) {
236		/*
237		 * No refs were found, or we could not find the
238		 * name in our ref array. Find and remove the extended
239		 * inode ref then.
240		 */
241		return btrfs_del_inode_extref(trans, root, name,
242					      inode_objectid, ref_objectid, index);
243	}
244
245	return ret;
246}
247
248/*
249 * Insert an extended inode ref into a tree.
250 *
251 * The caller must have checked against BTRFS_LINK_MAX already.
252 */
253static int btrfs_insert_inode_extref(struct btrfs_trans_handle *trans,
254				     struct btrfs_root *root,
255				     const struct fscrypt_str *name,
256				     u64 inode_objectid, u64 ref_objectid,
257				     u64 index)
258{
259	struct btrfs_inode_extref *extref;
260	int ret;
261	int ins_len = name->len + sizeof(*extref);
262	unsigned long ptr;
263	struct btrfs_path *path;
264	struct btrfs_key key;
265	struct extent_buffer *leaf;
 
266
267	key.objectid = inode_objectid;
268	key.type = BTRFS_INODE_EXTREF_KEY;
269	key.offset = btrfs_extref_hash(ref_objectid, name->name, name->len);
270
271	path = btrfs_alloc_path();
272	if (!path)
273		return -ENOMEM;
274
275	ret = btrfs_insert_empty_item(trans, root, path, &key,
276				      ins_len);
277	if (ret == -EEXIST) {
278		if (btrfs_find_name_in_ext_backref(path->nodes[0],
279						   path->slots[0],
280						   ref_objectid,
281						   name))
282			goto out;
283
284		btrfs_extend_item(trans, path, ins_len);
285		ret = 0;
286	}
287	if (ret < 0)
288		goto out;
289
290	leaf = path->nodes[0];
 
291	ptr = (unsigned long)btrfs_item_ptr(leaf, path->slots[0], char);
292	ptr += btrfs_item_size(leaf, path->slots[0]) - ins_len;
293	extref = (struct btrfs_inode_extref *)ptr;
294
295	btrfs_set_inode_extref_name_len(path->nodes[0], extref, name->len);
296	btrfs_set_inode_extref_index(path->nodes[0], extref, index);
297	btrfs_set_inode_extref_parent(path->nodes[0], extref, ref_objectid);
298
299	ptr = (unsigned long)&extref->name;
300	write_extent_buffer(path->nodes[0], name->name, ptr, name->len);
301	btrfs_mark_buffer_dirty(trans, path->nodes[0]);
302
303out:
304	btrfs_free_path(path);
305	return ret;
306}
307
308/* Will return 0, -ENOMEM, -EMLINK, or -EEXIST or anything from the CoW path */
309int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans,
310			   struct btrfs_root *root, const struct fscrypt_str *name,
 
311			   u64 inode_objectid, u64 ref_objectid, u64 index)
312{
313	struct btrfs_fs_info *fs_info = root->fs_info;
314	struct btrfs_path *path;
315	struct btrfs_key key;
316	struct btrfs_inode_ref *ref;
317	unsigned long ptr;
318	int ret;
319	int ins_len = name->len + sizeof(*ref);
320
321	key.objectid = inode_objectid;
322	key.offset = ref_objectid;
323	key.type = BTRFS_INODE_REF_KEY;
324
325	path = btrfs_alloc_path();
326	if (!path)
327		return -ENOMEM;
328
329	path->skip_release_on_error = 1;
330	ret = btrfs_insert_empty_item(trans, root, path, &key,
331				      ins_len);
332	if (ret == -EEXIST) {
333		u32 old_size;
334		ref = btrfs_find_name_in_backref(path->nodes[0], path->slots[0],
335						 name);
336		if (ref)
337			goto out;
338
339		old_size = btrfs_item_size(path->nodes[0], path->slots[0]);
340		btrfs_extend_item(trans, path, ins_len);
341		ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
342				     struct btrfs_inode_ref);
343		ref = (struct btrfs_inode_ref *)((unsigned long)ref + old_size);
344		btrfs_set_inode_ref_name_len(path->nodes[0], ref, name->len);
345		btrfs_set_inode_ref_index(path->nodes[0], ref, index);
346		ptr = (unsigned long)(ref + 1);
347		ret = 0;
348	} else if (ret < 0) {
349		if (ret == -EOVERFLOW) {
350			if (btrfs_find_name_in_backref(path->nodes[0],
351						       path->slots[0],
352						       name))
353				ret = -EEXIST;
354			else
355				ret = -EMLINK;
356		}
357		goto out;
358	} else {
359		ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
360				     struct btrfs_inode_ref);
361		btrfs_set_inode_ref_name_len(path->nodes[0], ref, name->len);
362		btrfs_set_inode_ref_index(path->nodes[0], ref, index);
363		ptr = (unsigned long)(ref + 1);
364	}
365	write_extent_buffer(path->nodes[0], name->name, ptr, name->len);
366	btrfs_mark_buffer_dirty(trans, path->nodes[0]);
367
368out:
369	btrfs_free_path(path);
370
371	if (ret == -EMLINK) {
372		struct btrfs_super_block *disk_super = fs_info->super_copy;
373		/* We ran out of space in the ref array. Need to
374		 * add an extended ref. */
375		if (btrfs_super_incompat_flags(disk_super)
376		    & BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF)
377			ret = btrfs_insert_inode_extref(trans, root, name,
 
378							inode_objectid,
379							ref_objectid, index);
380	}
381
382	return ret;
383}
384
385int btrfs_insert_empty_inode(struct btrfs_trans_handle *trans,
386			     struct btrfs_root *root,
387			     struct btrfs_path *path, u64 objectid)
388{
389	struct btrfs_key key;
390	int ret;
391	key.objectid = objectid;
392	key.type = BTRFS_INODE_ITEM_KEY;
393	key.offset = 0;
394
395	ret = btrfs_insert_empty_item(trans, root, path, &key,
396				      sizeof(struct btrfs_inode_item));
397	return ret;
398}
399
400int btrfs_lookup_inode(struct btrfs_trans_handle *trans, struct btrfs_root
401		       *root, struct btrfs_path *path,
402		       struct btrfs_key *location, int mod)
403{
404	int ins_len = mod < 0 ? -1 : 0;
405	int cow = mod != 0;
406	int ret;
407	int slot;
408	struct extent_buffer *leaf;
409	struct btrfs_key found_key;
410
411	ret = btrfs_search_slot(trans, root, location, path, ins_len, cow);
412	if (ret > 0 && location->type == BTRFS_ROOT_ITEM_KEY &&
413	    location->offset == (u64)-1 && path->slots[0] != 0) {
414		slot = path->slots[0] - 1;
415		leaf = path->nodes[0];
416		btrfs_item_key_to_cpu(leaf, &found_key, slot);
417		if (found_key.objectid == location->objectid &&
418		    found_key.type == location->type) {
419			path->slots[0]--;
420			return 0;
421		}
422	}
423	return ret;
424}
425
426static inline void btrfs_trace_truncate(const struct btrfs_inode *inode,
427					const struct extent_buffer *leaf,
428					const struct btrfs_file_extent_item *fi,
429					u64 offset, int extent_type, int slot)
430{
431	if (!inode)
432		return;
433	if (extent_type == BTRFS_FILE_EXTENT_INLINE)
434		trace_btrfs_truncate_show_fi_inline(inode, leaf, fi, slot,
435						    offset);
436	else
437		trace_btrfs_truncate_show_fi_regular(inode, leaf, fi, offset);
438}
439
440/*
441 * Remove inode items from a given root.
442 *
443 * @trans:		A transaction handle.
444 * @root:		The root from which to remove items.
445 * @inode:		The inode whose items we want to remove.
446 * @control:		The btrfs_truncate_control to control how and what we
447 *			are truncating.
448 *
449 * Remove all keys associated with the inode from the given root that have a key
450 * with a type greater than or equals to @min_type. When @min_type has a value of
451 * BTRFS_EXTENT_DATA_KEY, only remove file extent items that have an offset value
452 * greater than or equals to @new_size. If a file extent item that starts before
453 * @new_size and ends after it is found, its length is adjusted.
454 *
455 * Returns: 0 on success, < 0 on error and NEED_TRUNCATE_BLOCK when @min_type is
456 * BTRFS_EXTENT_DATA_KEY and the caller must truncate the last block.
457 */
458int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
459			       struct btrfs_root *root,
460			       struct btrfs_truncate_control *control)
461{
462	struct btrfs_fs_info *fs_info = root->fs_info;
463	struct btrfs_path *path;
464	struct extent_buffer *leaf;
465	struct btrfs_file_extent_item *fi;
466	struct btrfs_key key;
467	struct btrfs_key found_key;
468	u64 new_size = control->new_size;
469	u64 extent_num_bytes = 0;
470	u64 extent_offset = 0;
471	u64 item_end = 0;
472	u32 found_type = (u8)-1;
473	int del_item;
474	int pending_del_nr = 0;
475	int pending_del_slot = 0;
476	int extent_type = -1;
477	int ret;
478	u64 bytes_deleted = 0;
479	bool be_nice = false;
480
481	ASSERT(control->inode || !control->clear_extent_range);
482	ASSERT(new_size == 0 || control->min_type == BTRFS_EXTENT_DATA_KEY);
483
484	control->last_size = new_size;
485	control->sub_bytes = 0;
486
487	/*
488	 * For shareable roots we want to back off from time to time, this turns
489	 * out to be subvolume roots, reloc roots, and data reloc roots.
490	 */
491	if (test_bit(BTRFS_ROOT_SHAREABLE, &root->state))
492		be_nice = true;
493
494	path = btrfs_alloc_path();
495	if (!path)
496		return -ENOMEM;
497	path->reada = READA_BACK;
498
499	key.objectid = control->ino;
500	key.offset = (u64)-1;
501	key.type = (u8)-1;
502
503search_again:
504	/*
505	 * With a 16K leaf size and 128MiB extents, you can actually queue up a
506	 * huge file in a single leaf.  Most of the time that bytes_deleted is
507	 * > 0, it will be huge by the time we get here
508	 */
509	if (be_nice && bytes_deleted > SZ_32M &&
510	    btrfs_should_end_transaction(trans)) {
511		ret = -EAGAIN;
512		goto out;
513	}
514
515	ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
516	if (ret < 0)
517		goto out;
518
519	if (ret > 0) {
520		ret = 0;
521		/* There are no items in the tree for us to truncate, we're done */
522		if (path->slots[0] == 0)
523			goto out;
524		path->slots[0]--;
525	}
526
527	while (1) {
528		u64 clear_start = 0, clear_len = 0, extent_start = 0;
529		bool refill_delayed_refs_rsv = false;
530
531		fi = NULL;
532		leaf = path->nodes[0];
533		btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
534		found_type = found_key.type;
535
536		if (found_key.objectid != control->ino)
537			break;
538
539		if (found_type < control->min_type)
540			break;
541
542		item_end = found_key.offset;
543		if (found_type == BTRFS_EXTENT_DATA_KEY) {
544			fi = btrfs_item_ptr(leaf, path->slots[0],
545					    struct btrfs_file_extent_item);
546			extent_type = btrfs_file_extent_type(leaf, fi);
547			if (extent_type != BTRFS_FILE_EXTENT_INLINE)
548				item_end +=
549				    btrfs_file_extent_num_bytes(leaf, fi);
550			else if (extent_type == BTRFS_FILE_EXTENT_INLINE)
551				item_end += btrfs_file_extent_ram_bytes(leaf, fi);
552
553			btrfs_trace_truncate(control->inode, leaf, fi,
554					     found_key.offset, extent_type,
555					     path->slots[0]);
556			item_end--;
557		}
558		if (found_type > control->min_type) {
559			del_item = 1;
560		} else {
561			if (item_end < new_size)
562				break;
563			if (found_key.offset >= new_size)
564				del_item = 1;
565			else
566				del_item = 0;
567		}
568
569		/* FIXME, shrink the extent if the ref count is only 1 */
570		if (found_type != BTRFS_EXTENT_DATA_KEY)
571			goto delete;
572
573		control->extents_found++;
574
575		if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
576			u64 num_dec;
577
578			clear_start = found_key.offset;
579			extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
580			if (!del_item) {
581				u64 orig_num_bytes =
582					btrfs_file_extent_num_bytes(leaf, fi);
583				extent_num_bytes = ALIGN(new_size -
584						found_key.offset,
585						fs_info->sectorsize);
586				clear_start = ALIGN(new_size, fs_info->sectorsize);
587
588				btrfs_set_file_extent_num_bytes(leaf, fi,
589							 extent_num_bytes);
590				num_dec = (orig_num_bytes - extent_num_bytes);
591				if (extent_start != 0)
592					control->sub_bytes += num_dec;
593				btrfs_mark_buffer_dirty(trans, leaf);
594			} else {
595				extent_num_bytes =
596					btrfs_file_extent_disk_num_bytes(leaf, fi);
597				extent_offset = found_key.offset -
598					btrfs_file_extent_offset(leaf, fi);
599
600				/* FIXME blocksize != 4096 */
601				num_dec = btrfs_file_extent_num_bytes(leaf, fi);
602				if (extent_start != 0)
603					control->sub_bytes += num_dec;
604			}
605			clear_len = num_dec;
606		} else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
607			/*
608			 * We can't truncate inline items that have had
609			 * special encodings
610			 */
611			if (!del_item &&
612			    btrfs_file_extent_encryption(leaf, fi) == 0 &&
613			    btrfs_file_extent_other_encoding(leaf, fi) == 0 &&
614			    btrfs_file_extent_compression(leaf, fi) == 0) {
615				u32 size = (u32)(new_size - found_key.offset);
616
617				btrfs_set_file_extent_ram_bytes(leaf, fi, size);
618				size = btrfs_file_extent_calc_inline_size(size);
619				btrfs_truncate_item(trans, path, size, 1);
620			} else if (!del_item) {
621				/*
622				 * We have to bail so the last_size is set to
623				 * just before this extent.
624				 */
625				ret = BTRFS_NEED_TRUNCATE_BLOCK;
626				break;
627			} else {
628				/*
629				 * Inline extents are special, we just treat
630				 * them as a full sector worth in the file
631				 * extent tree just for simplicity sake.
632				 */
633				clear_len = fs_info->sectorsize;
634			}
635
636			control->sub_bytes += item_end + 1 - new_size;
637		}
638delete:
639		/*
640		 * We only want to clear the file extent range if we're
641		 * modifying the actual inode's mapping, which is just the
642		 * normal truncate path.
643		 */
644		if (control->clear_extent_range) {
645			ret = btrfs_inode_clear_file_extent_range(control->inode,
646						  clear_start, clear_len);
647			if (ret) {
648				btrfs_abort_transaction(trans, ret);
649				break;
650			}
651		}
652
653		if (del_item) {
654			ASSERT(!pending_del_nr ||
655			       ((path->slots[0] + 1) == pending_del_slot));
656
657			control->last_size = found_key.offset;
658			if (!pending_del_nr) {
659				/* No pending yet, add ourselves */
660				pending_del_slot = path->slots[0];
661				pending_del_nr = 1;
662			} else if (path->slots[0] + 1 == pending_del_slot) {
663				/* Hop on the pending chunk */
664				pending_del_nr++;
665				pending_del_slot = path->slots[0];
666			}
667		} else {
668			control->last_size = new_size;
669			break;
670		}
671
672		if (del_item && extent_start != 0 && !control->skip_ref_updates) {
673			struct btrfs_ref ref = {
674				.action = BTRFS_DROP_DELAYED_REF,
675				.bytenr = extent_start,
676				.num_bytes = extent_num_bytes,
677				.owning_root = btrfs_root_id(root),
678				.ref_root = btrfs_header_owner(leaf),
679			};
680
681			bytes_deleted += extent_num_bytes;
682
683			btrfs_init_data_ref(&ref, control->ino, extent_offset,
684					    btrfs_root_id(root), false);
685			ret = btrfs_free_extent(trans, &ref);
686			if (ret) {
687				btrfs_abort_transaction(trans, ret);
688				break;
689			}
690			if (be_nice && btrfs_check_space_for_delayed_refs(fs_info))
691				refill_delayed_refs_rsv = true;
692		}
693
694		if (found_type == BTRFS_INODE_ITEM_KEY)
695			break;
696
697		if (path->slots[0] == 0 ||
698		    path->slots[0] != pending_del_slot ||
699		    refill_delayed_refs_rsv) {
700			if (pending_del_nr) {
701				ret = btrfs_del_items(trans, root, path,
702						pending_del_slot,
703						pending_del_nr);
704				if (ret) {
705					btrfs_abort_transaction(trans, ret);
706					break;
707				}
708				pending_del_nr = 0;
709			}
710			btrfs_release_path(path);
711
712			/*
713			 * We can generate a lot of delayed refs, so we need to
714			 * throttle every once and a while and make sure we're
715			 * adding enough space to keep up with the work we are
716			 * generating.  Since we hold a transaction here we
717			 * can't flush, and we don't want to FLUSH_LIMIT because
718			 * we could have generated too many delayed refs to
719			 * actually allocate, so just bail if we're short and
720			 * let the normal reservation dance happen higher up.
721			 */
722			if (refill_delayed_refs_rsv) {
723				ret = btrfs_delayed_refs_rsv_refill(fs_info,
724							BTRFS_RESERVE_NO_FLUSH);
725				if (ret) {
726					ret = -EAGAIN;
727					break;
728				}
729			}
730			goto search_again;
731		} else {
732			path->slots[0]--;
733		}
734	}
735out:
736	if (ret >= 0 && pending_del_nr) {
737		int err;
738
739		err = btrfs_del_items(trans, root, path, pending_del_slot,
740				      pending_del_nr);
741		if (err) {
742			btrfs_abort_transaction(trans, err);
743			ret = err;
744		}
745	}
746
747	ASSERT(control->last_size >= new_size);
748	if (!ret && control->last_size > new_size)
749		control->last_size = new_size;
750
751	btrfs_free_path(path);
752	return ret;
753}