xref: /linux/fs/bcachefs/io_misc.c (revision 031fba65fc202abf1f193e321be7a2c274fd88ba)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * io_misc.c - fallocate, fpunch, truncate:
4  */
5 
6 #include "bcachefs.h"
7 #include "alloc_foreground.h"
8 #include "bkey_buf.h"
9 #include "btree_update.h"
10 #include "buckets.h"
11 #include "clock.h"
12 #include "error.h"
13 #include "extents.h"
14 #include "extent_update.h"
15 #include "inode.h"
16 #include "io_misc.h"
17 #include "io_write.h"
18 #include "logged_ops.h"
19 #include "subvolume.h"
20 
21 /* Overwrites whatever was present with zeroes: */
22 int bch2_extent_fallocate(struct btree_trans *trans,
23 			  subvol_inum inum,
24 			  struct btree_iter *iter,
25 			  unsigned sectors,
26 			  struct bch_io_opts opts,
27 			  s64 *i_sectors_delta,
28 			  struct write_point_specifier write_point)
29 {
30 	struct bch_fs *c = trans->c;
31 	struct disk_reservation disk_res = { 0 };
32 	struct closure cl;
33 	struct open_buckets open_buckets = { 0 };
34 	struct bkey_s_c k;
35 	struct bkey_buf old, new;
36 	unsigned sectors_allocated = 0;
37 	bool have_reservation = false;
38 	bool unwritten = opts.nocow &&
39 	    c->sb.version >= bcachefs_metadata_version_unwritten_extents;
40 	int ret;
41 
42 	bch2_bkey_buf_init(&old);
43 	bch2_bkey_buf_init(&new);
44 	closure_init_stack(&cl);
45 
46 	k = bch2_btree_iter_peek_slot(iter);
47 	ret = bkey_err(k);
48 	if (ret)
49 		return ret;
50 
51 	sectors = min_t(u64, sectors, k.k->p.offset - iter->pos.offset);
52 
53 	if (!have_reservation) {
54 		unsigned new_replicas =
55 			max(0, (int) opts.data_replicas -
56 			    (int) bch2_bkey_nr_ptrs_fully_allocated(k));
57 		/*
58 		 * Get a disk reservation before (in the nocow case) calling
59 		 * into the allocator:
60 		 */
61 		ret = bch2_disk_reservation_get(c, &disk_res, sectors, new_replicas, 0);
62 		if (unlikely(ret))
63 			goto err;
64 
65 		bch2_bkey_buf_reassemble(&old, c, k);
66 	}
67 
68 	if (have_reservation) {
69 		if (!bch2_extents_match(k, bkey_i_to_s_c(old.k)))
70 			goto err;
71 
72 		bch2_key_resize(&new.k->k, sectors);
73 	} else if (!unwritten) {
74 		struct bkey_i_reservation *reservation;
75 
76 		bch2_bkey_buf_realloc(&new, c, sizeof(*reservation) / sizeof(u64));
77 		reservation = bkey_reservation_init(new.k);
78 		reservation->k.p = iter->pos;
79 		bch2_key_resize(&reservation->k, sectors);
80 		reservation->v.nr_replicas = opts.data_replicas;
81 	} else {
82 		struct bkey_i_extent *e;
83 		struct bch_devs_list devs_have;
84 		struct write_point *wp;
85 		struct bch_extent_ptr *ptr;
86 
87 		devs_have.nr = 0;
88 
89 		bch2_bkey_buf_realloc(&new, c, BKEY_EXTENT_U64s_MAX);
90 
91 		e = bkey_extent_init(new.k);
92 		e->k.p = iter->pos;
93 
94 		ret = bch2_alloc_sectors_start_trans(trans,
95 				opts.foreground_target,
96 				false,
97 				write_point,
98 				&devs_have,
99 				opts.data_replicas,
100 				opts.data_replicas,
101 				BCH_WATERMARK_normal, 0, &cl, &wp);
102 		if (bch2_err_matches(ret, BCH_ERR_operation_blocked))
103 			ret = -BCH_ERR_transaction_restart_nested;
104 		if (ret)
105 			goto err;
106 
107 		sectors = min(sectors, wp->sectors_free);
108 		sectors_allocated = sectors;
109 
110 		bch2_key_resize(&e->k, sectors);
111 
112 		bch2_open_bucket_get(c, wp, &open_buckets);
113 		bch2_alloc_sectors_append_ptrs(c, wp, &e->k_i, sectors, false);
114 		bch2_alloc_sectors_done(c, wp);
115 
116 		extent_for_each_ptr(extent_i_to_s(e), ptr)
117 			ptr->unwritten = true;
118 	}
119 
120 	have_reservation = true;
121 
122 	ret = bch2_extent_update(trans, inum, iter, new.k, &disk_res,
123 				 0, i_sectors_delta, true);
124 err:
125 	if (!ret && sectors_allocated)
126 		bch2_increment_clock(c, sectors_allocated, WRITE);
127 
128 	bch2_open_buckets_put(c, &open_buckets);
129 	bch2_disk_reservation_put(c, &disk_res);
130 	bch2_bkey_buf_exit(&new, c);
131 	bch2_bkey_buf_exit(&old, c);
132 
133 	if (closure_nr_remaining(&cl) != 1) {
134 		bch2_trans_unlock(trans);
135 		closure_sync(&cl);
136 	}
137 
138 	return ret;
139 }
140 
141 /*
142  * Returns -BCH_ERR_transacton_restart if we had to drop locks:
143  */
144 int bch2_fpunch_at(struct btree_trans *trans, struct btree_iter *iter,
145 		   subvol_inum inum, u64 end,
146 		   s64 *i_sectors_delta)
147 {
148 	struct bch_fs *c	= trans->c;
149 	unsigned max_sectors	= KEY_SIZE_MAX & (~0 << c->block_bits);
150 	struct bpos end_pos = POS(inum.inum, end);
151 	struct bkey_s_c k;
152 	int ret = 0, ret2 = 0;
153 	u32 snapshot;
154 
155 	while (!ret ||
156 	       bch2_err_matches(ret, BCH_ERR_transaction_restart)) {
157 		struct disk_reservation disk_res =
158 			bch2_disk_reservation_init(c, 0);
159 		struct bkey_i delete;
160 
161 		if (ret)
162 			ret2 = ret;
163 
164 		bch2_trans_begin(trans);
165 
166 		ret = bch2_subvolume_get_snapshot(trans, inum.subvol, &snapshot);
167 		if (ret)
168 			continue;
169 
170 		bch2_btree_iter_set_snapshot(iter, snapshot);
171 
172 		/*
173 		 * peek_upto() doesn't have ideal semantics for extents:
174 		 */
175 		k = bch2_btree_iter_peek_upto(iter, end_pos);
176 		if (!k.k)
177 			break;
178 
179 		ret = bkey_err(k);
180 		if (ret)
181 			continue;
182 
183 		bkey_init(&delete.k);
184 		delete.k.p = iter->pos;
185 
186 		/* create the biggest key we can */
187 		bch2_key_resize(&delete.k, max_sectors);
188 		bch2_cut_back(end_pos, &delete);
189 
190 		ret = bch2_extent_update(trans, inum, iter, &delete,
191 				&disk_res, 0, i_sectors_delta, false);
192 		bch2_disk_reservation_put(c, &disk_res);
193 	}
194 
195 	return ret ?: ret2;
196 }
197 
198 int bch2_fpunch(struct bch_fs *c, subvol_inum inum, u64 start, u64 end,
199 		s64 *i_sectors_delta)
200 {
201 	struct btree_trans *trans = bch2_trans_get(c);
202 	struct btree_iter iter;
203 	int ret;
204 
205 	bch2_trans_iter_init(trans, &iter, BTREE_ID_extents,
206 			     POS(inum.inum, start),
207 			     BTREE_ITER_INTENT);
208 
209 	ret = bch2_fpunch_at(trans, &iter, inum, end, i_sectors_delta);
210 
211 	bch2_trans_iter_exit(trans, &iter);
212 	bch2_trans_put(trans);
213 
214 	if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
215 		ret = 0;
216 
217 	return ret;
218 }
219 
220 /* truncate: */
221 
222 void bch2_logged_op_truncate_to_text(struct printbuf *out, struct bch_fs *c, struct bkey_s_c k)
223 {
224 	struct bkey_s_c_logged_op_truncate op = bkey_s_c_to_logged_op_truncate(k);
225 
226 	prt_printf(out, "subvol=%u", le32_to_cpu(op.v->subvol));
227 	prt_printf(out, " inum=%llu", le64_to_cpu(op.v->inum));
228 	prt_printf(out, " new_i_size=%llu", le64_to_cpu(op.v->new_i_size));
229 }
230 
231 static int truncate_set_isize(struct btree_trans *trans,
232 			      subvol_inum inum,
233 			      u64 new_i_size)
234 {
235 	struct btree_iter iter = { NULL };
236 	struct bch_inode_unpacked inode_u;
237 	int ret;
238 
239 	ret   = bch2_inode_peek(trans, &iter, &inode_u, inum, BTREE_ITER_INTENT) ?:
240 		(inode_u.bi_size = new_i_size, 0) ?:
241 		bch2_inode_write(trans, &iter, &inode_u);
242 
243 	bch2_trans_iter_exit(trans, &iter);
244 	return ret;
245 }
246 
247 static int __bch2_resume_logged_op_truncate(struct btree_trans *trans,
248 					    struct bkey_i *op_k,
249 					    u64 *i_sectors_delta)
250 {
251 	struct bch_fs *c = trans->c;
252 	struct btree_iter fpunch_iter;
253 	struct bkey_i_logged_op_truncate *op = bkey_i_to_logged_op_truncate(op_k);
254 	subvol_inum inum = { le32_to_cpu(op->v.subvol), le64_to_cpu(op->v.inum) };
255 	u64 new_i_size = le64_to_cpu(op->v.new_i_size);
256 	int ret;
257 
258 	ret = commit_do(trans, NULL, NULL, BTREE_INSERT_NOFAIL,
259 			truncate_set_isize(trans, inum, new_i_size));
260 	if (ret)
261 		goto err;
262 
263 	bch2_trans_iter_init(trans, &fpunch_iter, BTREE_ID_extents,
264 			     POS(inum.inum, round_up(new_i_size, block_bytes(c)) >> 9),
265 			     BTREE_ITER_INTENT);
266 	ret = bch2_fpunch_at(trans, &fpunch_iter, inum, U64_MAX, i_sectors_delta);
267 	bch2_trans_iter_exit(trans, &fpunch_iter);
268 
269 	if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
270 		ret = 0;
271 err:
272 	bch2_logged_op_finish(trans, op_k);
273 	return ret;
274 }
275 
276 int bch2_resume_logged_op_truncate(struct btree_trans *trans, struct bkey_i *op_k)
277 {
278 	return __bch2_resume_logged_op_truncate(trans, op_k, NULL);
279 }
280 
281 int bch2_truncate(struct bch_fs *c, subvol_inum inum, u64 new_i_size, u64 *i_sectors_delta)
282 {
283 	struct bkey_i_logged_op_truncate op;
284 
285 	bkey_logged_op_truncate_init(&op.k_i);
286 	op.v.subvol	= cpu_to_le32(inum.subvol);
287 	op.v.inum	= cpu_to_le64(inum.inum);
288 	op.v.new_i_size	= cpu_to_le64(new_i_size);
289 
290 	/*
291 	 * Logged ops aren't atomic w.r.t. snapshot creation: creating a
292 	 * snapshot while they're in progress, then crashing, will result in the
293 	 * resume only proceeding in one of the snapshots
294 	 */
295 	down_read(&c->snapshot_create_lock);
296 	int ret = bch2_trans_run(c,
297 		bch2_logged_op_start(trans, &op.k_i) ?:
298 		__bch2_resume_logged_op_truncate(trans, &op.k_i, i_sectors_delta));
299 	up_read(&c->snapshot_create_lock);
300 
301 	return ret;
302 }
303 
304 /* finsert/fcollapse: */
305 
306 void bch2_logged_op_finsert_to_text(struct printbuf *out, struct bch_fs *c, struct bkey_s_c k)
307 {
308 	struct bkey_s_c_logged_op_finsert op = bkey_s_c_to_logged_op_finsert(k);
309 
310 	prt_printf(out, "subvol=%u",		le32_to_cpu(op.v->subvol));
311 	prt_printf(out, " inum=%llu",		le64_to_cpu(op.v->inum));
312 	prt_printf(out, " dst_offset=%lli",	le64_to_cpu(op.v->dst_offset));
313 	prt_printf(out, " src_offset=%llu",	le64_to_cpu(op.v->src_offset));
314 }
315 
316 static int adjust_i_size(struct btree_trans *trans, subvol_inum inum, u64 offset, s64 len)
317 {
318 	struct btree_iter iter;
319 	struct bch_inode_unpacked inode_u;
320 	int ret;
321 
322 	offset	<<= 9;
323 	len	<<= 9;
324 
325 	ret = bch2_inode_peek(trans, &iter, &inode_u, inum, BTREE_ITER_INTENT);
326 	if (ret)
327 		return ret;
328 
329 	if (len > 0) {
330 		if (MAX_LFS_FILESIZE - inode_u.bi_size < len) {
331 			ret = -EFBIG;
332 			goto err;
333 		}
334 
335 		if (offset >= inode_u.bi_size) {
336 			ret = -EINVAL;
337 			goto err;
338 		}
339 	}
340 
341 	inode_u.bi_size += len;
342 	inode_u.bi_mtime = inode_u.bi_ctime = bch2_current_time(trans->c);
343 
344 	ret = bch2_inode_write(trans, &iter, &inode_u);
345 err:
346 	bch2_trans_iter_exit(trans, &iter);
347 	return ret;
348 }
349 
350 static int __bch2_resume_logged_op_finsert(struct btree_trans *trans,
351 					   struct bkey_i *op_k,
352 					   u64 *i_sectors_delta)
353 {
354 	struct bch_fs *c = trans->c;
355 	struct btree_iter iter;
356 	struct bkey_i_logged_op_finsert *op = bkey_i_to_logged_op_finsert(op_k);
357 	subvol_inum inum = { le32_to_cpu(op->v.subvol), le64_to_cpu(op->v.inum) };
358 	u64 dst_offset = le64_to_cpu(op->v.dst_offset);
359 	u64 src_offset = le64_to_cpu(op->v.src_offset);
360 	s64 shift = dst_offset - src_offset;
361 	u64 len = abs(shift);
362 	u64 pos = le64_to_cpu(op->v.pos);
363 	bool insert = shift > 0;
364 	int ret = 0;
365 
366 	bch2_trans_iter_init(trans, &iter, BTREE_ID_extents,
367 			     POS(inum.inum, 0),
368 			     BTREE_ITER_INTENT);
369 
370 	switch (op->v.state) {
371 case LOGGED_OP_FINSERT_start:
372 	op->v.state = LOGGED_OP_FINSERT_shift_extents;
373 
374 	if (insert) {
375 		ret = commit_do(trans, NULL, NULL, BTREE_INSERT_NOFAIL,
376 				adjust_i_size(trans, inum, src_offset, len) ?:
377 				bch2_logged_op_update(trans, &op->k_i));
378 		if (ret)
379 			goto err;
380 	} else {
381 		bch2_btree_iter_set_pos(&iter, POS(inum.inum, src_offset));
382 
383 		ret = bch2_fpunch_at(trans, &iter, inum, src_offset + len, i_sectors_delta);
384 		if (ret && !bch2_err_matches(ret, BCH_ERR_transaction_restart))
385 			goto err;
386 
387 		ret = commit_do(trans, NULL, NULL, BTREE_INSERT_NOFAIL,
388 				bch2_logged_op_update(trans, &op->k_i));
389 	}
390 
391 	fallthrough;
392 case LOGGED_OP_FINSERT_shift_extents:
393 	while (1) {
394 		struct disk_reservation disk_res =
395 			bch2_disk_reservation_init(c, 0);
396 		struct bkey_i delete, *copy;
397 		struct bkey_s_c k;
398 		struct bpos src_pos = POS(inum.inum, src_offset);
399 		u32 snapshot;
400 
401 		bch2_trans_begin(trans);
402 
403 		ret = bch2_subvolume_get_snapshot(trans, inum.subvol, &snapshot);
404 		if (ret)
405 			goto btree_err;
406 
407 		bch2_btree_iter_set_snapshot(&iter, snapshot);
408 		bch2_btree_iter_set_pos(&iter, SPOS(inum.inum, pos, snapshot));
409 
410 		k = insert
411 			? bch2_btree_iter_peek_prev(&iter)
412 			: bch2_btree_iter_peek_upto(&iter, POS(inum.inum, U64_MAX));
413 		if ((ret = bkey_err(k)))
414 			goto btree_err;
415 
416 		if (!k.k ||
417 		    k.k->p.inode != inum.inum ||
418 		    bkey_le(k.k->p, POS(inum.inum, src_offset)))
419 			break;
420 
421 		copy = bch2_bkey_make_mut_noupdate(trans, k);
422 		if ((ret = PTR_ERR_OR_ZERO(copy)))
423 			goto btree_err;
424 
425 		if (insert &&
426 		    bkey_lt(bkey_start_pos(k.k), src_pos)) {
427 			bch2_cut_front(src_pos, copy);
428 
429 			/* Splitting compressed extent? */
430 			bch2_disk_reservation_add(c, &disk_res,
431 					copy->k.size *
432 					bch2_bkey_nr_ptrs_allocated(bkey_i_to_s_c(copy)),
433 					BCH_DISK_RESERVATION_NOFAIL);
434 		}
435 
436 		bkey_init(&delete.k);
437 		delete.k.p = copy->k.p;
438 		delete.k.p.snapshot = snapshot;
439 		delete.k.size = copy->k.size;
440 
441 		copy->k.p.offset += shift;
442 		copy->k.p.snapshot = snapshot;
443 
444 		op->v.pos = cpu_to_le64(insert ? bkey_start_offset(&delete.k) : delete.k.p.offset);
445 
446 		ret =   bch2_btree_insert_trans(trans, BTREE_ID_extents, &delete, 0) ?:
447 			bch2_btree_insert_trans(trans, BTREE_ID_extents, copy, 0) ?:
448 			bch2_logged_op_update(trans, &op->k_i) ?:
449 			bch2_trans_commit(trans, &disk_res, NULL, BTREE_INSERT_NOFAIL);
450 btree_err:
451 		bch2_disk_reservation_put(c, &disk_res);
452 
453 		if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
454 			continue;
455 		if (ret)
456 			goto err;
457 
458 		pos = le64_to_cpu(op->v.pos);
459 	}
460 
461 	op->v.state = LOGGED_OP_FINSERT_finish;
462 
463 	if (!insert) {
464 		ret = commit_do(trans, NULL, NULL, BTREE_INSERT_NOFAIL,
465 				adjust_i_size(trans, inum, src_offset, shift) ?:
466 				bch2_logged_op_update(trans, &op->k_i));
467 	} else {
468 		/* We need an inode update to update bi_journal_seq for fsync: */
469 		ret = commit_do(trans, NULL, NULL, BTREE_INSERT_NOFAIL,
470 				adjust_i_size(trans, inum, 0, 0) ?:
471 				bch2_logged_op_update(trans, &op->k_i));
472 	}
473 
474 	break;
475 case LOGGED_OP_FINSERT_finish:
476 	break;
477 	}
478 err:
479 	bch2_logged_op_finish(trans, op_k);
480 	bch2_trans_iter_exit(trans, &iter);
481 	return ret;
482 }
483 
484 int bch2_resume_logged_op_finsert(struct btree_trans *trans, struct bkey_i *op_k)
485 {
486 	return __bch2_resume_logged_op_finsert(trans, op_k, NULL);
487 }
488 
489 int bch2_fcollapse_finsert(struct bch_fs *c, subvol_inum inum,
490 			   u64 offset, u64 len, bool insert,
491 			   s64 *i_sectors_delta)
492 {
493 	struct bkey_i_logged_op_finsert op;
494 	s64 shift = insert ? len : -len;
495 
496 	bkey_logged_op_finsert_init(&op.k_i);
497 	op.v.subvol	= cpu_to_le32(inum.subvol);
498 	op.v.inum	= cpu_to_le64(inum.inum);
499 	op.v.dst_offset	= cpu_to_le64(offset + shift);
500 	op.v.src_offset	= cpu_to_le64(offset);
501 	op.v.pos	= cpu_to_le64(insert ? U64_MAX : offset);
502 
503 	/*
504 	 * Logged ops aren't atomic w.r.t. snapshot creation: creating a
505 	 * snapshot while they're in progress, then crashing, will result in the
506 	 * resume only proceeding in one of the snapshots
507 	 */
508 	down_read(&c->snapshot_create_lock);
509 	int ret = bch2_trans_run(c,
510 		bch2_logged_op_start(trans, &op.k_i) ?:
511 		__bch2_resume_logged_op_finsert(trans, &op.k_i, i_sectors_delta));
512 	up_read(&c->snapshot_create_lock);
513 
514 	return ret;
515 }
516