git.sesse.net Git - bcachefs-tools-debian/blob - libbcachefs/reflink.c

   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 #include "subvolume.h"
  11
  12 #include <linux/sched/signal.h>
  13
  14 static inline unsigned bkey_type_to_indirect(const struct bkey *k)
  15 {
  16         switch (k->type) {
  17         case KEY_TYPE_extent:
  18                 return KEY_TYPE_reflink_v;
  19         case KEY_TYPE_inline_data:
  20                 return KEY_TYPE_indirect_inline_data;
  21         default:
  22                 return 0;
  23         }
  24 }
  25
  26 /* reflink pointers */
  27
  28 const char *bch2_reflink_p_invalid(const struct bch_fs *c, struct bkey_s_c k)
  29 {
  30         struct bkey_s_c_reflink_p p = bkey_s_c_to_reflink_p(k);
  31
  32         if (bkey_val_bytes(p.k) != sizeof(*p.v))
  33                 return "incorrect value size";
  34
  35         if (c->sb.version >= bcachefs_metadata_version_reflink_p_fix &&
  36             le64_to_cpu(p.v->idx) < le32_to_cpu(p.v->front_pad))
  37                 return "idx < front_pad";
  38
  39         return NULL;
  40 }
  41
  42 void bch2_reflink_p_to_text(struct printbuf *out, struct bch_fs *c,
  43                             struct bkey_s_c k)
  44 {
  45         struct bkey_s_c_reflink_p p = bkey_s_c_to_reflink_p(k);
  46
  47         pr_buf(out, "idx %llu front_pad %u back_pad %u",
  48                le64_to_cpu(p.v->idx),
  49                le32_to_cpu(p.v->front_pad),
  50                le32_to_cpu(p.v->back_pad));
  51 }
  52
  53 bool bch2_reflink_p_merge(struct bch_fs *c, struct bkey_s _l, struct bkey_s_c _r)
  54 {
  55         struct bkey_s_reflink_p l = bkey_s_to_reflink_p(_l);
  56         struct bkey_s_c_reflink_p r = bkey_s_c_to_reflink_p(_r);
  57
  58         /*
  59          * Disabled for now, the triggers code needs to be reworked for merging
  60          * of reflink pointers to work:
  61          */
  62         return false;
  63
  64         if (le64_to_cpu(l.v->idx) + l.k->size != le64_to_cpu(r.v->idx))
  65                 return false;
  66
  67         bch2_key_resize(l.k, l.k->size + r.k->size);
  68         return true;
  69 }
  70
  71 /* indirect extents */
  72
  73 const char *bch2_reflink_v_invalid(const struct bch_fs *c, struct bkey_s_c k)
  74 {
  75         struct bkey_s_c_reflink_v r = bkey_s_c_to_reflink_v(k);
  76
  77         if (bkey_val_bytes(r.k) < sizeof(*r.v))
  78                 return "incorrect value size";
  79
  80         return bch2_bkey_ptrs_invalid(c, k);
  81 }
  82
  83 void bch2_reflink_v_to_text(struct printbuf *out, struct bch_fs *c,
  84                             struct bkey_s_c k)
  85 {
  86         struct bkey_s_c_reflink_v r = bkey_s_c_to_reflink_v(k);
  87
  88         pr_buf(out, "refcount: %llu ", le64_to_cpu(r.v->refcount));
  89
  90         bch2_bkey_ptrs_to_text(out, c, k);
  91 }
  92
  93 bool bch2_reflink_v_merge(struct bch_fs *c, struct bkey_s _l, struct bkey_s_c _r)
  94 {
  95         struct bkey_s_reflink_v   l = bkey_s_to_reflink_v(_l);
  96         struct bkey_s_c_reflink_v r = bkey_s_c_to_reflink_v(_r);
  97
  98         return l.v->refcount == r.v->refcount && bch2_extent_merge(c, _l, _r);
  99 }
 100
 101 /* indirect inline data */
 102
 103 const char *bch2_indirect_inline_data_invalid(const struct bch_fs *c,
 104                                               struct bkey_s_c k)
 105 {
 106         if (bkey_val_bytes(k.k) < sizeof(struct bch_indirect_inline_data))
 107                 return "incorrect value size";
 108         return NULL;
 109 }
 110
 111 void bch2_indirect_inline_data_to_text(struct printbuf *out,
 112                                         struct bch_fs *c, struct bkey_s_c k)
 113 {
 114         struct bkey_s_c_indirect_inline_data d = bkey_s_c_to_indirect_inline_data(k);
 115         unsigned datalen = bkey_inline_data_bytes(k.k);
 116
 117         pr_buf(out, "refcount %llu datalen %u: %*phN",
 118                le64_to_cpu(d.v->refcount), datalen,
 119                min(datalen, 32U), d.v->data);
 120 }
 121
 122 static int bch2_make_extent_indirect(struct btree_trans *trans,
 123                                      struct btree_iter *extent_iter,
 124                                      struct bkey_i *orig)
 125 {
 126         struct bch_fs *c = trans->c;
 127         struct btree_iter reflink_iter = { NULL };
 128         struct bkey_s_c k;
 129         struct bkey_i *r_v;
 130         struct bkey_i_reflink_p *r_p;
 131         __le64 *refcount;
 132         int ret;
 133
 134         if (orig->k.type == KEY_TYPE_inline_data)
 135                 bch2_check_set_feature(c, BCH_FEATURE_reflink_inline_data);
 136
 137         for_each_btree_key_norestart(trans, reflink_iter, BTREE_ID_reflink,
 138                            POS(0, c->reflink_hint),
 139                            BTREE_ITER_INTENT|BTREE_ITER_SLOTS, k, ret) {
 140                 if (reflink_iter.pos.inode) {
 141                         bch2_btree_iter_set_pos(&reflink_iter, POS_MIN);
 142                         continue;
 143                 }
 144
 145                 if (bkey_deleted(k.k) && orig->k.size <= k.k->size)
 146                         break;
 147         }
 148
 149         if (ret)
 150                 goto err;
 151
 152         /* rewind iter to start of hole, if necessary: */
 153         bch2_btree_iter_set_pos_to_extent_start(&reflink_iter);
 154
 155         r_v = bch2_trans_kmalloc(trans, sizeof(__le64) + bkey_bytes(&orig->k));
 156         ret = PTR_ERR_OR_ZERO(r_v);
 157         if (ret)
 158                 goto err;
 159
 160         bkey_init(&r_v->k);
 161         r_v->k.type     = bkey_type_to_indirect(&orig->k);
 162         r_v->k.p        = reflink_iter.pos;
 163         bch2_key_resize(&r_v->k, orig->k.size);
 164         r_v->k.version  = orig->k.version;
 165
 166         set_bkey_val_bytes(&r_v->k, sizeof(__le64) + bkey_val_bytes(&orig->k));
 167
 168         refcount        = bkey_refcount(r_v);
 169         *refcount       = 0;
 170         memcpy(refcount + 1, &orig->v, bkey_val_bytes(&orig->k));
 171
 172         ret = bch2_trans_update(trans, &reflink_iter, r_v, 0);
 173         if (ret)
 174                 goto err;
 175
 176         /*
 177          * orig is in a bkey_buf which statically allocates 5 64s for the val,
 178          * so we know it will be big enough:
 179          */
 180         orig->k.type = KEY_TYPE_reflink_p;
 181         r_p = bkey_i_to_reflink_p(orig);
 182         set_bkey_val_bytes(&r_p->k, sizeof(r_p->v));
 183         memset(&r_p->v, 0, sizeof(r_p->v));
 184
 185         r_p->v.idx = cpu_to_le64(bkey_start_offset(&r_v->k));
 186
 187         ret = bch2_trans_update(trans, extent_iter, &r_p->k_i, 0);
 188 err:
 189         c->reflink_hint = reflink_iter.pos.offset;
 190         bch2_trans_iter_exit(trans, &reflink_iter);
 191
 192         return ret;
 193 }
 194
 195 static struct bkey_s_c get_next_src(struct btree_iter *iter, struct bpos end)
 196 {
 197         struct bkey_s_c k;
 198         int ret;
 199
 200         for_each_btree_key_continue_norestart(*iter, 0, k, ret) {
 201                 if (bkey_cmp(iter->pos, end) >= 0)
 202                         break;
 203
 204                 if (bkey_extent_is_data(k.k))
 205                         return k;
 206         }
 207
 208         if (bkey_cmp(iter->pos, end) >= 0)
 209                 bch2_btree_iter_set_pos(iter, end);
 210         return ret ? bkey_s_c_err(ret) : bkey_s_c_null;
 211 }
 212
 213 s64 bch2_remap_range(struct bch_fs *c,
 214                      subvol_inum dst_inum, u64 dst_offset,
 215                      subvol_inum src_inum, u64 src_offset,
 216                      u64 remap_sectors,
 217                      u64 new_i_size, s64 *i_sectors_delta)
 218 {
 219         struct btree_trans trans;
 220         struct btree_iter dst_iter, src_iter;
 221         struct bkey_s_c src_k;
 222         struct bkey_buf new_dst, new_src;
 223         struct bpos dst_start = POS(dst_inum.inum, dst_offset);
 224         struct bpos src_start = POS(src_inum.inum, src_offset);
 225         struct bpos dst_end = dst_start, src_end = src_start;
 226         struct bpos src_want;
 227         u64 dst_done;
 228         u32 dst_snapshot, src_snapshot;
 229         int ret = 0, ret2 = 0;
 230
 231         if (!percpu_ref_tryget(&c->writes))
 232                 return -EROFS;
 233
 234         bch2_check_set_feature(c, BCH_FEATURE_reflink);
 235
 236         dst_end.offset += remap_sectors;
 237         src_end.offset += remap_sectors;
 238
 239         bch2_bkey_buf_init(&new_dst);
 240         bch2_bkey_buf_init(&new_src);
 241         bch2_trans_init(&trans, c, BTREE_ITER_MAX, 4096);
 242
 243         bch2_trans_iter_init(&trans, &src_iter, BTREE_ID_extents, src_start,
 244                              BTREE_ITER_INTENT);
 245         bch2_trans_iter_init(&trans, &dst_iter, BTREE_ID_extents, dst_start,
 246                              BTREE_ITER_INTENT);
 247
 248         while ((ret == 0 || ret == -EINTR) &&
 249                bkey_cmp(dst_iter.pos, dst_end) < 0) {
 250                 struct disk_reservation disk_res = { 0 };
 251
 252                 bch2_trans_begin(&trans);
 253
 254                 if (fatal_signal_pending(current)) {
 255                         ret = -EINTR;
 256                         break;
 257                 }
 258
 259                 ret = bch2_subvolume_get_snapshot(&trans, src_inum.subvol,
 260                                                   &src_snapshot);
 261                 if (ret)
 262                         continue;
 263
 264                 bch2_btree_iter_set_snapshot(&src_iter, src_snapshot);
 265
 266                 ret = bch2_subvolume_get_snapshot(&trans, dst_inum.subvol,
 267                                                   &dst_snapshot);
 268                 if (ret)
 269                         continue;
 270
 271                 bch2_btree_iter_set_snapshot(&dst_iter, dst_snapshot);
 272
 273                 dst_done = dst_iter.pos.offset - dst_start.offset;
 274                 src_want = POS(src_start.inode, src_start.offset + dst_done);
 275                 bch2_btree_iter_set_pos(&src_iter, src_want);
 276
 277                 src_k = get_next_src(&src_iter, src_end);
 278                 ret = bkey_err(src_k);
 279                 if (ret)
 280                         continue;
 281
 282                 if (bkey_cmp(src_want, src_iter.pos) < 0) {
 283                         ret = bch2_fpunch_at(&trans, &dst_iter, dst_inum,
 284                                         min(dst_end.offset,
 285                                             dst_iter.pos.offset +
 286                                             src_iter.pos.offset - src_want.offset),
 287                                         i_sectors_delta);
 288                         continue;
 289                 }
 290
 291                 if (src_k.k->type != KEY_TYPE_reflink_p) {
 292                         bch2_btree_iter_set_pos_to_extent_start(&src_iter);
 293
 294                         bch2_bkey_buf_reassemble(&new_src, c, src_k);
 295                         src_k = bkey_i_to_s_c(new_src.k);
 296
 297                         ret = bch2_make_extent_indirect(&trans, &src_iter,
 298                                                 new_src.k);
 299                         if (ret)
 300                                 continue;
 301
 302                         BUG_ON(src_k.k->type != KEY_TYPE_reflink_p);
 303                 }
 304
 305                 if (src_k.k->type == KEY_TYPE_reflink_p) {
 306                         struct bkey_s_c_reflink_p src_p =
 307                                 bkey_s_c_to_reflink_p(src_k);
 308                         struct bkey_i_reflink_p *dst_p =
 309                                 bkey_reflink_p_init(new_dst.k);
 310
 311                         u64 offset = le64_to_cpu(src_p.v->idx) +
 312                                 (src_want.offset -
 313                                  bkey_start_offset(src_k.k));
 314
 315                         dst_p->v.idx = cpu_to_le64(offset);
 316                 } else {
 317                         BUG();
 318                 }
 319
 320                 new_dst.k->k.p = dst_iter.pos;
 321                 bch2_key_resize(&new_dst.k->k,
 322                                 min(src_k.k->p.offset - src_want.offset,
 323                                     dst_end.offset - dst_iter.pos.offset));
 324
 325                 ret = bch2_extent_update(&trans, dst_inum, &dst_iter,
 326                                          new_dst.k, &disk_res, NULL,
 327                                          new_i_size, i_sectors_delta,
 328                                          true);
 329                 bch2_disk_reservation_put(c, &disk_res);
 330         }
 331         bch2_trans_iter_exit(&trans, &dst_iter);
 332         bch2_trans_iter_exit(&trans, &src_iter);
 333
 334         BUG_ON(!ret && bkey_cmp(dst_iter.pos, dst_end));
 335         BUG_ON(bkey_cmp(dst_iter.pos, dst_end) > 0);
 336
 337         dst_done = dst_iter.pos.offset - dst_start.offset;
 338         new_i_size = min(dst_iter.pos.offset << 9, new_i_size);
 339
 340         do {
 341                 struct bch_inode_unpacked inode_u;
 342                 struct btree_iter inode_iter = { NULL };
 343
 344                 bch2_trans_begin(&trans);
 345
 346                 ret2 = bch2_inode_peek(&trans, &inode_iter, &inode_u,
 347                                        dst_inum, BTREE_ITER_INTENT);
 348
 349                 if (!ret2 &&
 350                     inode_u.bi_size < new_i_size) {
 351                         inode_u.bi_size = new_i_size;
 352                         ret2  = bch2_inode_write(&trans, &inode_iter, &inode_u) ?:
 353                                 bch2_trans_commit(&trans, NULL, NULL,
 354                                                   BTREE_INSERT_NOFAIL);
 355                 }
 356
 357                 bch2_trans_iter_exit(&trans, &inode_iter);
 358         } while (ret2 == -EINTR);
 359
 360         bch2_trans_exit(&trans);
 361         bch2_bkey_buf_exit(&new_src, c);
 362         bch2_bkey_buf_exit(&new_dst, c);
 363
 364         percpu_ref_put(&c->writes);
 365
 366         return dst_done ?: ret ?: ret2;
 367 }