Loading...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 | // SPDX-License-Identifier: GPL-2.0 #include "bcachefs.h" #include "btree_key_cache.h" #include "btree_update.h" #include "errcode.h" #include "error.h" #include "fs.h" #include "snapshot.h" #include "subvolume.h" #include <linux/random.h> static int bch2_subvolume_delete(struct btree_trans *, u32); static int check_subvol(struct btree_trans *trans, struct btree_iter *iter, struct bkey_s_c k) { struct bch_fs *c = trans->c; struct bkey_s_c_subvolume subvol; struct bch_snapshot snapshot; unsigned snapid; int ret = 0; if (k.k->type != KEY_TYPE_subvolume) return 0; subvol = bkey_s_c_to_subvolume(k); snapid = le32_to_cpu(subvol.v->snapshot); ret = bch2_snapshot_lookup(trans, snapid, &snapshot); if (bch2_err_matches(ret, ENOENT)) bch_err(c, "subvolume %llu points to nonexistent snapshot %u", k.k->p.offset, snapid); if (ret) return ret; if (BCH_SUBVOLUME_UNLINKED(subvol.v)) { ret = bch2_subvolume_delete(trans, iter->pos.offset); bch_err_msg(c, ret, "deleting subvolume %llu", iter->pos.offset); return ret ?: -BCH_ERR_transaction_restart_nested; } if (!BCH_SUBVOLUME_SNAP(subvol.v)) { u32 snapshot_root = bch2_snapshot_root(c, le32_to_cpu(subvol.v->snapshot)); u32 snapshot_tree; struct bch_snapshot_tree st; rcu_read_lock(); snapshot_tree = snapshot_t(c, snapshot_root)->tree; rcu_read_unlock(); ret = bch2_snapshot_tree_lookup(trans, snapshot_tree, &st); bch2_fs_inconsistent_on(bch2_err_matches(ret, ENOENT), c, "%s: snapshot tree %u not found", __func__, snapshot_tree); if (ret) return ret; if (fsck_err_on(le32_to_cpu(st.master_subvol) != subvol.k->p.offset, c, subvol_not_master_and_not_snapshot, "subvolume %llu is not set as snapshot but is not master subvolume", k.k->p.offset)) { struct bkey_i_subvolume *s = bch2_bkey_make_mut_typed(trans, iter, &subvol.s_c, 0, subvolume); ret = PTR_ERR_OR_ZERO(s); if (ret) return ret; SET_BCH_SUBVOLUME_SNAP(&s->v, true); } } fsck_err: return ret; } int bch2_check_subvols(struct bch_fs *c) { int ret = bch2_trans_run(c, for_each_btree_key_commit(trans, iter, BTREE_ID_subvolumes, POS_MIN, BTREE_ITER_PREFETCH, k, NULL, NULL, BCH_TRANS_COMMIT_no_enospc, check_subvol(trans, &iter, k))); bch_err_fn(c, ret); return ret; } /* Subvolumes: */ int bch2_subvolume_invalid(struct bch_fs *c, struct bkey_s_c k, enum bkey_invalid_flags flags, struct printbuf *err) { int ret = 0; bkey_fsck_err_on(bkey_lt(k.k->p, SUBVOL_POS_MIN) || bkey_gt(k.k->p, SUBVOL_POS_MAX), c, err, subvol_pos_bad, "invalid pos"); fsck_err: return ret; } void bch2_subvolume_to_text(struct printbuf *out, struct bch_fs *c, struct bkey_s_c k) { struct bkey_s_c_subvolume s = bkey_s_c_to_subvolume(k); prt_printf(out, "root %llu snapshot id %u", le64_to_cpu(s.v->inode), le32_to_cpu(s.v->snapshot)); if (bkey_val_bytes(s.k) > offsetof(struct bch_subvolume, parent)) prt_printf(out, " parent %u", le32_to_cpu(s.v->parent)); } static __always_inline int bch2_subvolume_get_inlined(struct btree_trans *trans, unsigned subvol, bool inconsistent_if_not_found, int iter_flags, struct bch_subvolume *s) { int ret = bch2_bkey_get_val_typed(trans, BTREE_ID_subvolumes, POS(0, subvol), iter_flags, subvolume, s); bch2_fs_inconsistent_on(bch2_err_matches(ret, ENOENT) && inconsistent_if_not_found, trans->c, "missing subvolume %u", subvol); return ret; } int bch2_subvolume_get(struct btree_trans *trans, unsigned subvol, bool inconsistent_if_not_found, int iter_flags, struct bch_subvolume *s) { return bch2_subvolume_get_inlined(trans, subvol, inconsistent_if_not_found, iter_flags, s); } int bch2_subvol_is_ro_trans(struct btree_trans *trans, u32 subvol) { struct bch_subvolume s; int ret = bch2_subvolume_get_inlined(trans, subvol, true, 0, &s); if (ret) return ret; if (BCH_SUBVOLUME_RO(&s)) return -EROFS; return 0; } int bch2_subvol_is_ro(struct bch_fs *c, u32 subvol) { return bch2_trans_do(c, NULL, NULL, 0, bch2_subvol_is_ro_trans(trans, subvol)); } int bch2_snapshot_get_subvol(struct btree_trans *trans, u32 snapshot, struct bch_subvolume *subvol) { struct bch_snapshot snap; return bch2_snapshot_lookup(trans, snapshot, &snap) ?: bch2_subvolume_get(trans, le32_to_cpu(snap.subvol), true, 0, subvol); } int bch2_subvolume_get_snapshot(struct btree_trans *trans, u32 subvolid, u32 *snapid) { struct btree_iter iter; struct bkey_s_c_subvolume subvol; int ret; subvol = bch2_bkey_get_iter_typed(trans, &iter, BTREE_ID_subvolumes, POS(0, subvolid), BTREE_ITER_CACHED|BTREE_ITER_WITH_UPDATES, subvolume); ret = bkey_err(subvol); bch2_fs_inconsistent_on(bch2_err_matches(ret, ENOENT), trans->c, "missing subvolume %u", subvolid); if (likely(!ret)) *snapid = le32_to_cpu(subvol.v->snapshot); bch2_trans_iter_exit(trans, &iter); return ret; } static int bch2_subvolume_reparent(struct btree_trans *trans, struct btree_iter *iter, struct bkey_s_c k, u32 old_parent, u32 new_parent) { struct bkey_i_subvolume *s; int ret; if (k.k->type != KEY_TYPE_subvolume) return 0; if (bkey_val_bytes(k.k) > offsetof(struct bch_subvolume, parent) && le32_to_cpu(bkey_s_c_to_subvolume(k).v->parent) != old_parent) return 0; s = bch2_bkey_make_mut_typed(trans, iter, &k, 0, subvolume); ret = PTR_ERR_OR_ZERO(s); if (ret) return ret; s->v.parent = cpu_to_le32(new_parent); return 0; } /* * Separate from the snapshot tree in the snapshots btree, we record the tree * structure of how snapshot subvolumes were created - the parent subvolume of * each snapshot subvolume. * * When a subvolume is deleted, we scan for child subvolumes and reparant them, * to avoid dangling references: */ static int bch2_subvolumes_reparent(struct btree_trans *trans, u32 subvolid_to_delete) { struct bch_subvolume s; return lockrestart_do(trans, bch2_subvolume_get(trans, subvolid_to_delete, true, BTREE_ITER_CACHED, &s)) ?: for_each_btree_key_commit(trans, iter, BTREE_ID_subvolumes, POS_MIN, BTREE_ITER_PREFETCH, k, NULL, NULL, BCH_TRANS_COMMIT_no_enospc, bch2_subvolume_reparent(trans, &iter, k, subvolid_to_delete, le32_to_cpu(s.parent))); } /* * Delete subvolume, mark snapshot ID as deleted, queue up snapshot * deletion/cleanup: */ static int __bch2_subvolume_delete(struct btree_trans *trans, u32 subvolid) { struct btree_iter iter; struct bkey_s_c_subvolume subvol; u32 snapid; int ret = 0; subvol = bch2_bkey_get_iter_typed(trans, &iter, BTREE_ID_subvolumes, POS(0, subvolid), BTREE_ITER_CACHED|BTREE_ITER_INTENT, subvolume); ret = bkey_err(subvol); bch2_fs_inconsistent_on(bch2_err_matches(ret, ENOENT), trans->c, "missing subvolume %u", subvolid); if (ret) return ret; snapid = le32_to_cpu(subvol.v->snapshot); ret = bch2_btree_delete_at(trans, &iter, 0) ?: bch2_snapshot_node_set_deleted(trans, snapid); bch2_trans_iter_exit(trans, &iter); return ret; } static int bch2_subvolume_delete(struct btree_trans *trans, u32 subvolid) { return bch2_subvolumes_reparent(trans, subvolid) ?: commit_do(trans, NULL, NULL, BCH_TRANS_COMMIT_no_enospc, __bch2_subvolume_delete(trans, subvolid)); } static void bch2_subvolume_wait_for_pagecache_and_delete(struct work_struct *work) { struct bch_fs *c = container_of(work, struct bch_fs, snapshot_wait_for_pagecache_and_delete_work); snapshot_id_list s; u32 *id; int ret = 0; while (!ret) { mutex_lock(&c->snapshots_unlinked_lock); s = c->snapshots_unlinked; darray_init(&c->snapshots_unlinked); mutex_unlock(&c->snapshots_unlinked_lock); if (!s.nr) break; bch2_evict_subvolume_inodes(c, &s); for (id = s.data; id < s.data + s.nr; id++) { ret = bch2_trans_run(c, bch2_subvolume_delete(trans, *id)); bch_err_msg(c, ret, "deleting subvolume %u", *id); if (ret) break; } darray_exit(&s); } bch2_write_ref_put(c, BCH_WRITE_REF_snapshot_delete_pagecache); } struct subvolume_unlink_hook { struct btree_trans_commit_hook h; u32 subvol; }; static int bch2_subvolume_wait_for_pagecache_and_delete_hook(struct btree_trans *trans, struct btree_trans_commit_hook *_h) { struct subvolume_unlink_hook *h = container_of(_h, struct subvolume_unlink_hook, h); struct bch_fs *c = trans->c; int ret = 0; mutex_lock(&c->snapshots_unlinked_lock); if (!snapshot_list_has_id(&c->snapshots_unlinked, h->subvol)) ret = snapshot_list_add(c, &c->snapshots_unlinked, h->subvol); mutex_unlock(&c->snapshots_unlinked_lock); if (ret) return ret; if (!bch2_write_ref_tryget(c, BCH_WRITE_REF_snapshot_delete_pagecache)) return -EROFS; if (!queue_work(c->write_ref_wq, &c->snapshot_wait_for_pagecache_and_delete_work)) bch2_write_ref_put(c, BCH_WRITE_REF_snapshot_delete_pagecache); return 0; } int bch2_subvolume_unlink(struct btree_trans *trans, u32 subvolid) { struct btree_iter iter; struct bkey_i_subvolume *n; struct subvolume_unlink_hook *h; int ret = 0; h = bch2_trans_kmalloc(trans, sizeof(*h)); ret = PTR_ERR_OR_ZERO(h); if (ret) return ret; h->h.fn = bch2_subvolume_wait_for_pagecache_and_delete_hook; h->subvol = subvolid; bch2_trans_commit_hook(trans, &h->h); n = bch2_bkey_get_mut_typed(trans, &iter, BTREE_ID_subvolumes, POS(0, subvolid), BTREE_ITER_CACHED, subvolume); ret = PTR_ERR_OR_ZERO(n); if (unlikely(ret)) { bch2_fs_inconsistent_on(bch2_err_matches(ret, ENOENT), trans->c, "missing subvolume %u", subvolid); return ret; } SET_BCH_SUBVOLUME_UNLINKED(&n->v, true); bch2_trans_iter_exit(trans, &iter); return ret; } int bch2_subvolume_create(struct btree_trans *trans, u64 inode, u32 src_subvolid, u32 *new_subvolid, u32 *new_snapshotid, bool ro) { struct bch_fs *c = trans->c; struct btree_iter dst_iter, src_iter = (struct btree_iter) { NULL }; struct bkey_i_subvolume *new_subvol = NULL; struct bkey_i_subvolume *src_subvol = NULL; u32 parent = 0, new_nodes[2], snapshot_subvols[2]; int ret = 0; ret = bch2_bkey_get_empty_slot(trans, &dst_iter, BTREE_ID_subvolumes, POS(0, U32_MAX)); if (ret == -BCH_ERR_ENOSPC_btree_slot) ret = -BCH_ERR_ENOSPC_subvolume_create; if (ret) return ret; snapshot_subvols[0] = dst_iter.pos.offset; snapshot_subvols[1] = src_subvolid; if (src_subvolid) { /* Creating a snapshot: */ src_subvol = bch2_bkey_get_mut_typed(trans, &src_iter, BTREE_ID_subvolumes, POS(0, src_subvolid), BTREE_ITER_CACHED, subvolume); ret = PTR_ERR_OR_ZERO(src_subvol); if (unlikely(ret)) { bch2_fs_inconsistent_on(bch2_err_matches(ret, ENOENT), c, "subvolume %u not found", src_subvolid); goto err; } parent = le32_to_cpu(src_subvol->v.snapshot); } ret = bch2_snapshot_node_create(trans, parent, new_nodes, snapshot_subvols, src_subvolid ? 2 : 1); if (ret) goto err; if (src_subvolid) { src_subvol->v.snapshot = cpu_to_le32(new_nodes[1]); ret = bch2_trans_update(trans, &src_iter, &src_subvol->k_i, 0); if (ret) goto err; } new_subvol = bch2_bkey_alloc(trans, &dst_iter, 0, subvolume); ret = PTR_ERR_OR_ZERO(new_subvol); if (ret) goto err; new_subvol->v.flags = 0; new_subvol->v.snapshot = cpu_to_le32(new_nodes[0]); new_subvol->v.inode = cpu_to_le64(inode); new_subvol->v.parent = cpu_to_le32(src_subvolid); new_subvol->v.otime.lo = cpu_to_le64(bch2_current_time(c)); new_subvol->v.otime.hi = 0; SET_BCH_SUBVOLUME_RO(&new_subvol->v, ro); SET_BCH_SUBVOLUME_SNAP(&new_subvol->v, src_subvolid != 0); *new_subvolid = new_subvol->k.p.offset; *new_snapshotid = new_nodes[0]; err: bch2_trans_iter_exit(trans, &src_iter); bch2_trans_iter_exit(trans, &dst_iter); return ret; } int bch2_fs_subvolumes_init(struct bch_fs *c) { INIT_WORK(&c->snapshot_delete_work, bch2_delete_dead_snapshots_work); INIT_WORK(&c->snapshot_wait_for_pagecache_and_delete_work, bch2_subvolume_wait_for_pagecache_and_delete); mutex_init(&c->snapshots_unlinked_lock); return 0; } |