xref: /linux/fs/bcachefs/reflink.c (revision 67e0dd8f0d8b4bf09098c4692abcb43a20089dff)
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.h"
9 #include "reflink.h"
10 
11 #include <linux/sched/signal.h>
12 
13 static inline unsigned bkey_type_to_indirect(const struct bkey *k)
14 {
15 	switch (k->type) {
16 	case KEY_TYPE_extent:
17 		return KEY_TYPE_reflink_v;
18 	case KEY_TYPE_inline_data:
19 		return KEY_TYPE_indirect_inline_data;
20 	default:
21 		return 0;
22 	}
23 }
24 
25 /* reflink pointers */
26 
27 const char *bch2_reflink_p_invalid(const struct bch_fs *c, struct bkey_s_c k)
28 {
29 	struct bkey_s_c_reflink_p p = bkey_s_c_to_reflink_p(k);
30 
31 	if (bkey_val_bytes(p.k) != sizeof(*p.v))
32 		return "incorrect value size";
33 
34 	return NULL;
35 }
36 
37 void bch2_reflink_p_to_text(struct printbuf *out, struct bch_fs *c,
38 			    struct bkey_s_c k)
39 {
40 	struct bkey_s_c_reflink_p p = bkey_s_c_to_reflink_p(k);
41 
42 	pr_buf(out, "idx %llu", le64_to_cpu(p.v->idx));
43 }
44 
45 bool bch2_reflink_p_merge(struct bch_fs *c, struct bkey_s _l, struct bkey_s_c _r)
46 {
47 	struct bkey_s_reflink_p l = bkey_s_to_reflink_p(_l);
48 	struct bkey_s_c_reflink_p r = bkey_s_c_to_reflink_p(_r);
49 
50 	/*
51 	 * Disabled for now, the triggers code needs to be reworked for merging
52 	 * of reflink pointers to work:
53 	 */
54 	return false;
55 
56 	if (le64_to_cpu(l.v->idx) + l.k->size != le64_to_cpu(r.v->idx))
57 		return false;
58 
59 	bch2_key_resize(l.k, l.k->size + r.k->size);
60 	return true;
61 }
62 
63 /* indirect extents */
64 
65 const char *bch2_reflink_v_invalid(const struct bch_fs *c, struct bkey_s_c k)
66 {
67 	struct bkey_s_c_reflink_v r = bkey_s_c_to_reflink_v(k);
68 
69 	if (bkey_val_bytes(r.k) < sizeof(*r.v))
70 		return "incorrect value size";
71 
72 	return bch2_bkey_ptrs_invalid(c, k);
73 }
74 
75 void bch2_reflink_v_to_text(struct printbuf *out, struct bch_fs *c,
76 			    struct bkey_s_c k)
77 {
78 	struct bkey_s_c_reflink_v r = bkey_s_c_to_reflink_v(k);
79 
80 	pr_buf(out, "refcount: %llu ", le64_to_cpu(r.v->refcount));
81 
82 	bch2_bkey_ptrs_to_text(out, c, k);
83 }
84 
85 bool bch2_reflink_v_merge(struct bch_fs *c, struct bkey_s _l, struct bkey_s_c _r)
86 {
87 	struct bkey_s_reflink_v   l = bkey_s_to_reflink_v(_l);
88 	struct bkey_s_c_reflink_v r = bkey_s_c_to_reflink_v(_r);
89 
90 	return l.v->refcount == r.v->refcount && bch2_extent_merge(c, _l, _r);
91 }
92 
93 /* indirect inline data */
94 
95 const char *bch2_indirect_inline_data_invalid(const struct bch_fs *c,
96 					      struct bkey_s_c k)
97 {
98 	if (bkey_val_bytes(k.k) < sizeof(struct bch_indirect_inline_data))
99 		return "incorrect value size";
100 	return NULL;
101 }
102 
103 void bch2_indirect_inline_data_to_text(struct printbuf *out,
104 					struct bch_fs *c, struct bkey_s_c k)
105 {
106 	struct bkey_s_c_indirect_inline_data d = bkey_s_c_to_indirect_inline_data(k);
107 	unsigned datalen = bkey_inline_data_bytes(k.k);
108 
109 	pr_buf(out, "refcount %llu datalen %u: %*phN",
110 	       le64_to_cpu(d.v->refcount), datalen,
111 	       min(datalen, 32U), d.v->data);
112 }
113 
114 static int bch2_make_extent_indirect(struct btree_trans *trans,
115 				     struct btree_iter *extent_iter,
116 				     struct bkey_i *orig)
117 {
118 	struct bch_fs *c = trans->c;
119 	struct btree_iter reflink_iter = { NULL };
120 	struct bkey_s_c k;
121 	struct bkey_i *r_v;
122 	struct bkey_i_reflink_p *r_p;
123 	__le64 *refcount;
124 	int ret;
125 
126 	if (orig->k.type == KEY_TYPE_inline_data)
127 		bch2_check_set_feature(c, BCH_FEATURE_reflink_inline_data);
128 
129 	for_each_btree_key(trans, reflink_iter, BTREE_ID_reflink,
130 			   POS(0, c->reflink_hint),
131 			   BTREE_ITER_INTENT|BTREE_ITER_SLOTS, k, ret) {
132 		if (reflink_iter.pos.inode) {
133 			bch2_btree_iter_set_pos(&reflink_iter, POS_MIN);
134 			continue;
135 		}
136 
137 		if (bkey_deleted(k.k) && orig->k.size <= k.k->size)
138 			break;
139 	}
140 
141 	if (ret)
142 		goto err;
143 
144 	/* rewind iter to start of hole, if necessary: */
145 	bch2_btree_iter_set_pos_to_extent_start(&reflink_iter);
146 
147 	r_v = bch2_trans_kmalloc(trans, sizeof(__le64) + bkey_bytes(&orig->k));
148 	ret = PTR_ERR_OR_ZERO(r_v);
149 	if (ret)
150 		goto err;
151 
152 	bkey_init(&r_v->k);
153 	r_v->k.type	= bkey_type_to_indirect(&orig->k);
154 	r_v->k.p	= reflink_iter.pos;
155 	bch2_key_resize(&r_v->k, orig->k.size);
156 	r_v->k.version	= orig->k.version;
157 
158 	set_bkey_val_bytes(&r_v->k, sizeof(__le64) + bkey_val_bytes(&orig->k));
159 
160 	refcount	= bkey_refcount(r_v);
161 	*refcount	= 0;
162 	memcpy(refcount + 1, &orig->v, bkey_val_bytes(&orig->k));
163 
164 	ret = bch2_trans_update(trans, &reflink_iter, r_v, 0);
165 	if (ret)
166 		goto err;
167 
168 	orig->k.type = KEY_TYPE_reflink_p;
169 	r_p = bkey_i_to_reflink_p(orig);
170 	set_bkey_val_bytes(&r_p->k, sizeof(r_p->v));
171 	r_p->v.idx = cpu_to_le64(bkey_start_offset(&r_v->k));
172 
173 	ret = bch2_trans_update(trans, extent_iter, &r_p->k_i, 0);
174 err:
175 	c->reflink_hint = reflink_iter.pos.offset;
176 	bch2_trans_iter_exit(trans, &reflink_iter);
177 
178 	return ret;
179 }
180 
181 static struct bkey_s_c get_next_src(struct btree_iter *iter, struct bpos end)
182 {
183 	struct bkey_s_c k;
184 	int ret;
185 
186 	for_each_btree_key_continue(*iter, 0, k, ret) {
187 		if (bkey_cmp(iter->pos, end) >= 0)
188 			break;
189 
190 		if (bkey_extent_is_data(k.k))
191 			return k;
192 	}
193 
194 	if (bkey_cmp(iter->pos, end) >= 0)
195 		bch2_btree_iter_set_pos(iter, end);
196 	return ret ? bkey_s_c_err(ret) : bkey_s_c_null;
197 }
198 
199 s64 bch2_remap_range(struct bch_fs *c,
200 		     struct bpos dst_start, struct bpos src_start,
201 		     u64 remap_sectors, u64 *journal_seq,
202 		     u64 new_i_size, s64 *i_sectors_delta)
203 {
204 	struct btree_trans trans;
205 	struct btree_iter dst_iter, src_iter;
206 	struct bkey_s_c src_k;
207 	struct bkey_buf new_dst, new_src;
208 	struct bpos dst_end = dst_start, src_end = src_start;
209 	struct bpos src_want;
210 	u64 dst_done;
211 	int ret = 0, ret2 = 0;
212 
213 	if (!percpu_ref_tryget(&c->writes))
214 		return -EROFS;
215 
216 	bch2_check_set_feature(c, BCH_FEATURE_reflink);
217 
218 	dst_end.offset += remap_sectors;
219 	src_end.offset += remap_sectors;
220 
221 	bch2_bkey_buf_init(&new_dst);
222 	bch2_bkey_buf_init(&new_src);
223 	bch2_trans_init(&trans, c, BTREE_ITER_MAX, 4096);
224 
225 	bch2_trans_iter_init(&trans, &src_iter, BTREE_ID_extents, src_start,
226 			     BTREE_ITER_INTENT);
227 	bch2_trans_iter_init(&trans, &dst_iter, BTREE_ID_extents, dst_start,
228 			     BTREE_ITER_INTENT);
229 
230 	while ((ret == 0 || ret == -EINTR) &&
231 	       bkey_cmp(dst_iter.pos, dst_end) < 0) {
232 		struct disk_reservation disk_res = { 0 };
233 
234 		bch2_trans_begin(&trans);
235 
236 		if (fatal_signal_pending(current)) {
237 			ret = -EINTR;
238 			break;
239 		}
240 
241 		dst_done = dst_iter.pos.offset - dst_start.offset;
242 		src_want = POS(src_start.inode, src_start.offset + dst_done);
243 		bch2_btree_iter_set_pos(&src_iter, src_want);
244 
245 		src_k = get_next_src(&src_iter, src_end);
246 		ret = bkey_err(src_k);
247 		if (ret)
248 			continue;
249 
250 		if (bkey_cmp(src_want, src_iter.pos) < 0) {
251 			ret = bch2_fpunch_at(&trans, &dst_iter,
252 					bpos_min(dst_end,
253 						 POS(dst_iter.pos.inode, dst_iter.pos.offset +
254 						     src_iter.pos.offset - src_want.offset)),
255 						 journal_seq, i_sectors_delta);
256 			continue;
257 		}
258 
259 		if (src_k.k->type != KEY_TYPE_reflink_p) {
260 			bch2_btree_iter_set_pos_to_extent_start(&src_iter);
261 
262 			bch2_bkey_buf_reassemble(&new_src, c, src_k);
263 			src_k = bkey_i_to_s_c(new_src.k);
264 
265 			ret = bch2_make_extent_indirect(&trans, &src_iter,
266 						new_src.k);
267 			if (ret)
268 				continue;
269 
270 			BUG_ON(src_k.k->type != KEY_TYPE_reflink_p);
271 		}
272 
273 		if (src_k.k->type == KEY_TYPE_reflink_p) {
274 			struct bkey_s_c_reflink_p src_p =
275 				bkey_s_c_to_reflink_p(src_k);
276 			struct bkey_i_reflink_p *dst_p =
277 				bkey_reflink_p_init(new_dst.k);
278 
279 			u64 offset = le64_to_cpu(src_p.v->idx) +
280 				(src_want.offset -
281 				 bkey_start_offset(src_k.k));
282 
283 			dst_p->v.idx = cpu_to_le64(offset);
284 		} else {
285 			BUG();
286 		}
287 
288 		new_dst.k->k.p = dst_iter.pos;
289 		bch2_key_resize(&new_dst.k->k,
290 				min(src_k.k->p.offset - src_want.offset,
291 				    dst_end.offset - dst_iter.pos.offset));
292 		ret = bch2_extent_update(&trans, &dst_iter, new_dst.k,
293 					 &disk_res, journal_seq,
294 					 new_i_size, i_sectors_delta,
295 					 true);
296 		bch2_disk_reservation_put(c, &disk_res);
297 	}
298 	bch2_trans_iter_exit(&trans, &dst_iter);
299 	bch2_trans_iter_exit(&trans, &src_iter);
300 
301 	BUG_ON(!ret && bkey_cmp(dst_iter.pos, dst_end));
302 	BUG_ON(bkey_cmp(dst_iter.pos, dst_end) > 0);
303 
304 	dst_done = dst_iter.pos.offset - dst_start.offset;
305 	new_i_size = min(dst_iter.pos.offset << 9, new_i_size);
306 
307 	do {
308 		struct bch_inode_unpacked inode_u;
309 		struct btree_iter inode_iter = { NULL };
310 
311 		bch2_trans_begin(&trans);
312 
313 		ret2 = bch2_inode_peek(&trans, &inode_iter, &inode_u,
314 				dst_start.inode, BTREE_ITER_INTENT);
315 
316 		if (!ret2 &&
317 		    inode_u.bi_size < new_i_size) {
318 			inode_u.bi_size = new_i_size;
319 			ret2  = bch2_inode_write(&trans, &inode_iter, &inode_u) ?:
320 				bch2_trans_commit(&trans, NULL, journal_seq, 0);
321 		}
322 
323 		bch2_trans_iter_exit(&trans, &inode_iter);
324 	} while (ret2 == -EINTR);
325 
326 	ret = bch2_trans_exit(&trans) ?: ret;
327 	bch2_bkey_buf_exit(&new_src, c);
328 	bch2_bkey_buf_exit(&new_dst, c);
329 
330 	percpu_ref_put(&c->writes);
331 
332 	return dst_done ?: ret ?: ret2;
333 }
334