xref: /linux/fs/btrfs/inode-item.c (revision 906fd46a65383cd639e5eec72a047efc33045d86)
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 
17 struct btrfs_inode_ref *btrfs_find_name_in_backref(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 
44 struct btrfs_inode_extref *btrfs_find_name_in_ext_backref(
45 		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 */
81 struct btrfs_inode_extref *
82 btrfs_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 
106 static 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_handle_fs_error(root->fs_info, -ENOENT, NULL);
145 		ret = -EROFS;
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 
171 out:
172 	btrfs_free_path(path);
173 
174 	return ret;
175 }
176 
177 int 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);
232 out:
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  */
253 static 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 
303 out:
304 	btrfs_free_path(path);
305 	return ret;
306 }
307 
308 /* Will return 0, -ENOMEM, -EMLINK, or -EEXIST or anything from the CoW path */
309 int 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 
368 out:
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 
385 int 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 
400 int 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 
426 static inline void btrfs_trace_truncate(struct btrfs_inode *inode,
427 					struct extent_buffer *leaf,
428 					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  */
458 int 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 
503 search_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 		}
638 delete:
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 	}
735 out:
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 }
754