xref: /linux/fs/bcachefs/reflink.c (revision fcb29877f7e18a1f27d7d6871f5f7bb6aaade575)
1 // SPDX-License-Identifier: GPL-2.0
2 #include "bcachefs.h"
3 #include "bkey_buf.h"
4 #include "btree_update.h"
5 #include "buckets.h"
6 #include "extents.h"
7 #include "inode.h"
8 #include "io_misc.h"
9 #include "io_write.h"
10 #include "rebalance.h"
11 #include "reflink.h"
12 #include "subvolume.h"
13 #include "super-io.h"
14 
15 #include <linux/sched/signal.h>
16 
17 static inline unsigned bkey_type_to_indirect(const struct bkey *k)
18 {
19 	switch (k->type) {
20 	case KEY_TYPE_extent:
21 		return KEY_TYPE_reflink_v;
22 	case KEY_TYPE_inline_data:
23 		return KEY_TYPE_indirect_inline_data;
24 	default:
25 		return 0;
26 	}
27 }
28 
29 /* reflink pointers */
30 
31 int bch2_reflink_p_invalid(struct bch_fs *c, struct bkey_s_c k,
32 			   enum bkey_invalid_flags flags,
33 			   struct printbuf *err)
34 {
35 	struct bkey_s_c_reflink_p p = bkey_s_c_to_reflink_p(k);
36 
37 	if (c->sb.version >= bcachefs_metadata_version_reflink_p_fix &&
38 	    le64_to_cpu(p.v->idx) < le32_to_cpu(p.v->front_pad)) {
39 		prt_printf(err, "idx < front_pad (%llu < %u)",
40 		       le64_to_cpu(p.v->idx), le32_to_cpu(p.v->front_pad));
41 		return -EINVAL;
42 	}
43 
44 	return 0;
45 }
46 
47 void bch2_reflink_p_to_text(struct printbuf *out, struct bch_fs *c,
48 			    struct bkey_s_c k)
49 {
50 	struct bkey_s_c_reflink_p p = bkey_s_c_to_reflink_p(k);
51 
52 	prt_printf(out, "idx %llu front_pad %u back_pad %u",
53 	       le64_to_cpu(p.v->idx),
54 	       le32_to_cpu(p.v->front_pad),
55 	       le32_to_cpu(p.v->back_pad));
56 }
57 
58 bool bch2_reflink_p_merge(struct bch_fs *c, struct bkey_s _l, struct bkey_s_c _r)
59 {
60 	struct bkey_s_reflink_p l = bkey_s_to_reflink_p(_l);
61 	struct bkey_s_c_reflink_p r = bkey_s_c_to_reflink_p(_r);
62 
63 	/*
64 	 * Disabled for now, the triggers code needs to be reworked for merging
65 	 * of reflink pointers to work:
66 	 */
67 	return false;
68 
69 	if (le64_to_cpu(l.v->idx) + l.k->size != le64_to_cpu(r.v->idx))
70 		return false;
71 
72 	bch2_key_resize(l.k, l.k->size + r.k->size);
73 	return true;
74 }
75 
76 /* indirect extents */
77 
78 int bch2_reflink_v_invalid(struct bch_fs *c, struct bkey_s_c k,
79 			   enum bkey_invalid_flags flags,
80 			   struct printbuf *err)
81 {
82 	return bch2_bkey_ptrs_invalid(c, k, flags, err);
83 }
84 
85 void bch2_reflink_v_to_text(struct printbuf *out, struct bch_fs *c,
86 			    struct bkey_s_c k)
87 {
88 	struct bkey_s_c_reflink_v r = bkey_s_c_to_reflink_v(k);
89 
90 	prt_printf(out, "refcount: %llu ", le64_to_cpu(r.v->refcount));
91 
92 	bch2_bkey_ptrs_to_text(out, c, k);
93 }
94 
95 #if 0
96 Currently disabled, needs to be debugged:
97 
98 bool bch2_reflink_v_merge(struct bch_fs *c, struct bkey_s _l, struct bkey_s_c _r)
99 {
100 	struct bkey_s_reflink_v   l = bkey_s_to_reflink_v(_l);
101 	struct bkey_s_c_reflink_v r = bkey_s_c_to_reflink_v(_r);
102 
103 	return l.v->refcount == r.v->refcount && bch2_extent_merge(c, _l, _r);
104 }
105 #endif
106 
107 static inline void check_indirect_extent_deleting(struct bkey_i *new, unsigned *flags)
108 {
109 	if ((*flags & BTREE_TRIGGER_INSERT) && !*bkey_refcount(new)) {
110 		new->k.type = KEY_TYPE_deleted;
111 		new->k.size = 0;
112 		set_bkey_val_u64s(&new->k, 0);;
113 		*flags &= ~BTREE_TRIGGER_INSERT;
114 	}
115 }
116 
117 int bch2_trans_mark_reflink_v(struct btree_trans *trans,
118 			      enum btree_id btree_id, unsigned level,
119 			      struct bkey_s_c old, struct bkey_i *new,
120 			      unsigned flags)
121 {
122 	check_indirect_extent_deleting(new, &flags);
123 
124 	if (old.k->type == KEY_TYPE_reflink_v &&
125 	    new->k.type == KEY_TYPE_reflink_v &&
126 	    old.k->u64s == new->k.u64s &&
127 	    !memcmp(bkey_s_c_to_reflink_v(old).v->start,
128 		    bkey_i_to_reflink_v(new)->v.start,
129 		    bkey_val_bytes(&new->k) - 8))
130 		return 0;
131 
132 	return bch2_trans_mark_extent(trans, btree_id, level, old, new, flags);
133 }
134 
135 /* indirect inline data */
136 
137 int bch2_indirect_inline_data_invalid(struct bch_fs *c, struct bkey_s_c k,
138 				      enum bkey_invalid_flags flags,
139 				      struct printbuf *err)
140 {
141 	return 0;
142 }
143 
144 void bch2_indirect_inline_data_to_text(struct printbuf *out,
145 				       struct bch_fs *c, struct bkey_s_c k)
146 {
147 	struct bkey_s_c_indirect_inline_data d = bkey_s_c_to_indirect_inline_data(k);
148 	unsigned datalen = bkey_inline_data_bytes(k.k);
149 
150 	prt_printf(out, "refcount %llu datalen %u: %*phN",
151 	       le64_to_cpu(d.v->refcount), datalen,
152 	       min(datalen, 32U), d.v->data);
153 }
154 
155 int bch2_trans_mark_indirect_inline_data(struct btree_trans *trans,
156 			      enum btree_id btree_id, unsigned level,
157 			      struct bkey_s_c old, struct bkey_i *new,
158 			      unsigned flags)
159 {
160 	check_indirect_extent_deleting(new, &flags);
161 
162 	return 0;
163 }
164 
165 static int bch2_make_extent_indirect(struct btree_trans *trans,
166 				     struct btree_iter *extent_iter,
167 				     struct bkey_i *orig)
168 {
169 	struct bch_fs *c = trans->c;
170 	struct btree_iter reflink_iter = { NULL };
171 	struct bkey_s_c k;
172 	struct bkey_i *r_v;
173 	struct bkey_i_reflink_p *r_p;
174 	__le64 *refcount;
175 	int ret;
176 
177 	if (orig->k.type == KEY_TYPE_inline_data)
178 		bch2_check_set_feature(c, BCH_FEATURE_reflink_inline_data);
179 
180 	bch2_trans_iter_init(trans, &reflink_iter, BTREE_ID_reflink, POS_MAX,
181 			     BTREE_ITER_INTENT);
182 	k = bch2_btree_iter_peek_prev(&reflink_iter);
183 	ret = bkey_err(k);
184 	if (ret)
185 		goto err;
186 
187 	r_v = bch2_trans_kmalloc(trans, sizeof(__le64) + bkey_bytes(&orig->k));
188 	ret = PTR_ERR_OR_ZERO(r_v);
189 	if (ret)
190 		goto err;
191 
192 	bkey_init(&r_v->k);
193 	r_v->k.type	= bkey_type_to_indirect(&orig->k);
194 	r_v->k.p	= reflink_iter.pos;
195 	bch2_key_resize(&r_v->k, orig->k.size);
196 	r_v->k.version	= orig->k.version;
197 
198 	set_bkey_val_bytes(&r_v->k, sizeof(__le64) + bkey_val_bytes(&orig->k));
199 
200 	refcount	= bkey_refcount(r_v);
201 	*refcount	= 0;
202 	memcpy(refcount + 1, &orig->v, bkey_val_bytes(&orig->k));
203 
204 	ret = bch2_trans_update(trans, &reflink_iter, r_v, 0);
205 	if (ret)
206 		goto err;
207 
208 	/*
209 	 * orig is in a bkey_buf which statically allocates 5 64s for the val,
210 	 * so we know it will be big enough:
211 	 */
212 	orig->k.type = KEY_TYPE_reflink_p;
213 	r_p = bkey_i_to_reflink_p(orig);
214 	set_bkey_val_bytes(&r_p->k, sizeof(r_p->v));
215 
216 	/* FORTIFY_SOURCE is broken here, and doesn't provide unsafe_memset() */
217 #if !defined(__NO_FORTIFY) && defined(__OPTIMIZE__) && defined(CONFIG_FORTIFY_SOURCE)
218 	__underlying_memset(&r_p->v, 0, sizeof(r_p->v));
219 #else
220 	memset(&r_p->v, 0, sizeof(r_p->v));
221 #endif
222 
223 	r_p->v.idx = cpu_to_le64(bkey_start_offset(&r_v->k));
224 
225 	ret = bch2_trans_update(trans, extent_iter, &r_p->k_i,
226 				BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE);
227 err:
228 	bch2_trans_iter_exit(trans, &reflink_iter);
229 
230 	return ret;
231 }
232 
233 static struct bkey_s_c get_next_src(struct btree_iter *iter, struct bpos end)
234 {
235 	struct bkey_s_c k;
236 	int ret;
237 
238 	for_each_btree_key_upto_continue_norestart(*iter, end, 0, k, ret) {
239 		if (bkey_extent_is_unwritten(k))
240 			continue;
241 
242 		if (bkey_extent_is_data(k.k))
243 			return k;
244 	}
245 
246 	if (bkey_ge(iter->pos, end))
247 		bch2_btree_iter_set_pos(iter, end);
248 	return ret ? bkey_s_c_err(ret) : bkey_s_c_null;
249 }
250 
251 s64 bch2_remap_range(struct bch_fs *c,
252 		     subvol_inum dst_inum, u64 dst_offset,
253 		     subvol_inum src_inum, u64 src_offset,
254 		     u64 remap_sectors,
255 		     u64 new_i_size, s64 *i_sectors_delta)
256 {
257 	struct btree_trans *trans;
258 	struct btree_iter dst_iter, src_iter;
259 	struct bkey_s_c src_k;
260 	struct bkey_buf new_dst, new_src;
261 	struct bpos dst_start = POS(dst_inum.inum, dst_offset);
262 	struct bpos src_start = POS(src_inum.inum, src_offset);
263 	struct bpos dst_end = dst_start, src_end = src_start;
264 	struct bch_io_opts opts;
265 	struct bpos src_want;
266 	u64 dst_done = 0;
267 	u32 dst_snapshot, src_snapshot;
268 	int ret = 0, ret2 = 0;
269 
270 	if (!bch2_write_ref_tryget(c, BCH_WRITE_REF_reflink))
271 		return -BCH_ERR_erofs_no_writes;
272 
273 	bch2_check_set_feature(c, BCH_FEATURE_reflink);
274 
275 	dst_end.offset += remap_sectors;
276 	src_end.offset += remap_sectors;
277 
278 	bch2_bkey_buf_init(&new_dst);
279 	bch2_bkey_buf_init(&new_src);
280 	trans = bch2_trans_get(c);
281 
282 	ret = bch2_inum_opts_get(trans, src_inum, &opts);
283 	if (ret)
284 		goto err;
285 
286 	bch2_trans_iter_init(trans, &src_iter, BTREE_ID_extents, src_start,
287 			     BTREE_ITER_INTENT);
288 	bch2_trans_iter_init(trans, &dst_iter, BTREE_ID_extents, dst_start,
289 			     BTREE_ITER_INTENT);
290 
291 	while ((ret == 0 ||
292 		bch2_err_matches(ret, BCH_ERR_transaction_restart)) &&
293 	       bkey_lt(dst_iter.pos, dst_end)) {
294 		struct disk_reservation disk_res = { 0 };
295 
296 		bch2_trans_begin(trans);
297 
298 		if (fatal_signal_pending(current)) {
299 			ret = -EINTR;
300 			break;
301 		}
302 
303 		ret = bch2_subvolume_get_snapshot(trans, src_inum.subvol,
304 						  &src_snapshot);
305 		if (ret)
306 			continue;
307 
308 		bch2_btree_iter_set_snapshot(&src_iter, src_snapshot);
309 
310 		ret = bch2_subvolume_get_snapshot(trans, dst_inum.subvol,
311 						  &dst_snapshot);
312 		if (ret)
313 			continue;
314 
315 		bch2_btree_iter_set_snapshot(&dst_iter, dst_snapshot);
316 
317 		dst_done = dst_iter.pos.offset - dst_start.offset;
318 		src_want = POS(src_start.inode, src_start.offset + dst_done);
319 		bch2_btree_iter_set_pos(&src_iter, src_want);
320 
321 		src_k = get_next_src(&src_iter, src_end);
322 		ret = bkey_err(src_k);
323 		if (ret)
324 			continue;
325 
326 		if (bkey_lt(src_want, src_iter.pos)) {
327 			ret = bch2_fpunch_at(trans, &dst_iter, dst_inum,
328 					min(dst_end.offset,
329 					    dst_iter.pos.offset +
330 					    src_iter.pos.offset - src_want.offset),
331 					i_sectors_delta);
332 			continue;
333 		}
334 
335 		if (src_k.k->type != KEY_TYPE_reflink_p) {
336 			bch2_btree_iter_set_pos_to_extent_start(&src_iter);
337 
338 			bch2_bkey_buf_reassemble(&new_src, c, src_k);
339 			src_k = bkey_i_to_s_c(new_src.k);
340 
341 			ret = bch2_make_extent_indirect(trans, &src_iter,
342 						new_src.k);
343 			if (ret)
344 				continue;
345 
346 			BUG_ON(src_k.k->type != KEY_TYPE_reflink_p);
347 		}
348 
349 		if (src_k.k->type == KEY_TYPE_reflink_p) {
350 			struct bkey_s_c_reflink_p src_p =
351 				bkey_s_c_to_reflink_p(src_k);
352 			struct bkey_i_reflink_p *dst_p =
353 				bkey_reflink_p_init(new_dst.k);
354 
355 			u64 offset = le64_to_cpu(src_p.v->idx) +
356 				(src_want.offset -
357 				 bkey_start_offset(src_k.k));
358 
359 			dst_p->v.idx = cpu_to_le64(offset);
360 		} else {
361 			BUG();
362 		}
363 
364 		new_dst.k->k.p = dst_iter.pos;
365 		bch2_key_resize(&new_dst.k->k,
366 				min(src_k.k->p.offset - src_want.offset,
367 				    dst_end.offset - dst_iter.pos.offset));
368 
369 		ret =   bch2_bkey_set_needs_rebalance(c, new_dst.k,
370 					opts.background_target,
371 					opts.background_compression) ?:
372 			bch2_extent_update(trans, dst_inum, &dst_iter,
373 					new_dst.k, &disk_res,
374 					new_i_size, i_sectors_delta,
375 					true);
376 		bch2_disk_reservation_put(c, &disk_res);
377 	}
378 	bch2_trans_iter_exit(trans, &dst_iter);
379 	bch2_trans_iter_exit(trans, &src_iter);
380 
381 	BUG_ON(!ret && !bkey_eq(dst_iter.pos, dst_end));
382 	BUG_ON(bkey_gt(dst_iter.pos, dst_end));
383 
384 	dst_done = dst_iter.pos.offset - dst_start.offset;
385 	new_i_size = min(dst_iter.pos.offset << 9, new_i_size);
386 
387 	do {
388 		struct bch_inode_unpacked inode_u;
389 		struct btree_iter inode_iter = { NULL };
390 
391 		bch2_trans_begin(trans);
392 
393 		ret2 = bch2_inode_peek(trans, &inode_iter, &inode_u,
394 				       dst_inum, BTREE_ITER_INTENT);
395 
396 		if (!ret2 &&
397 		    inode_u.bi_size < new_i_size) {
398 			inode_u.bi_size = new_i_size;
399 			ret2  = bch2_inode_write(trans, &inode_iter, &inode_u) ?:
400 				bch2_trans_commit(trans, NULL, NULL,
401 						  BTREE_INSERT_NOFAIL);
402 		}
403 
404 		bch2_trans_iter_exit(trans, &inode_iter);
405 	} while (bch2_err_matches(ret2, BCH_ERR_transaction_restart));
406 err:
407 	bch2_trans_put(trans);
408 	bch2_bkey_buf_exit(&new_src, c);
409 	bch2_bkey_buf_exit(&new_dst, c);
410 
411 	bch2_write_ref_put(c, BCH_WRITE_REF_reflink);
412 
413 	return dst_done ?: ret ?: ret2;
414 }
415