1 // SPDX-License-Identifier: GPL-2.0 2 3 #include "bcachefs.h" 4 #include "alloc_background.h" 5 #include "alloc_foreground.h" 6 #include "btree_iter.h" 7 #include "btree_update.h" 8 #include "btree_write_buffer.h" 9 #include "buckets.h" 10 #include "clock.h" 11 #include "compress.h" 12 #include "disk_groups.h" 13 #include "errcode.h" 14 #include "error.h" 15 #include "inode.h" 16 #include "io_write.h" 17 #include "move.h" 18 #include "rebalance.h" 19 #include "subvolume.h" 20 #include "super-io.h" 21 #include "trace.h" 22 23 #include <linux/freezer.h> 24 #include <linux/kthread.h> 25 #include <linux/sched/cputime.h> 26 27 #define REBALANCE_WORK_SCAN_OFFSET (U64_MAX - 1) 28 29 static const char * const bch2_rebalance_state_strs[] = { 30 #define x(t) #t, 31 BCH_REBALANCE_STATES() 32 NULL 33 #undef x 34 }; 35 36 static int __bch2_set_rebalance_needs_scan(struct btree_trans *trans, u64 inum) 37 { 38 struct btree_iter iter; 39 struct bkey_s_c k; 40 struct bkey_i_cookie *cookie; 41 u64 v; 42 int ret; 43 44 bch2_trans_iter_init(trans, &iter, BTREE_ID_rebalance_work, 45 SPOS(inum, REBALANCE_WORK_SCAN_OFFSET, U32_MAX), 46 BTREE_ITER_intent); 47 k = bch2_btree_iter_peek_slot(&iter); 48 ret = bkey_err(k); 49 if (ret) 50 goto err; 51 52 v = k.k->type == KEY_TYPE_cookie 53 ? le64_to_cpu(bkey_s_c_to_cookie(k).v->cookie) 54 : 0; 55 56 cookie = bch2_trans_kmalloc(trans, sizeof(*cookie)); 57 ret = PTR_ERR_OR_ZERO(cookie); 58 if (ret) 59 goto err; 60 61 bkey_cookie_init(&cookie->k_i); 62 cookie->k.p = iter.pos; 63 cookie->v.cookie = cpu_to_le64(v + 1); 64 65 ret = bch2_trans_update(trans, &iter, &cookie->k_i, 0); 66 err: 67 bch2_trans_iter_exit(trans, &iter); 68 return ret; 69 } 70 71 int bch2_set_rebalance_needs_scan(struct bch_fs *c, u64 inum) 72 { 73 int ret = bch2_trans_commit_do(c, NULL, NULL, 74 BCH_TRANS_COMMIT_no_enospc| 75 BCH_TRANS_COMMIT_lazy_rw, 76 __bch2_set_rebalance_needs_scan(trans, inum)); 77 rebalance_wakeup(c); 78 return ret; 79 } 80 81 int bch2_set_fs_needs_rebalance(struct bch_fs *c) 82 { 83 return bch2_set_rebalance_needs_scan(c, 0); 84 } 85 86 static int bch2_clear_rebalance_needs_scan(struct btree_trans *trans, u64 inum, u64 cookie) 87 { 88 struct btree_iter iter; 89 struct bkey_s_c k; 90 u64 v; 91 int ret; 92 93 bch2_trans_iter_init(trans, &iter, BTREE_ID_rebalance_work, 94 SPOS(inum, REBALANCE_WORK_SCAN_OFFSET, U32_MAX), 95 BTREE_ITER_intent); 96 k = bch2_btree_iter_peek_slot(&iter); 97 ret = bkey_err(k); 98 if (ret) 99 goto err; 100 101 v = k.k->type == KEY_TYPE_cookie 102 ? le64_to_cpu(bkey_s_c_to_cookie(k).v->cookie) 103 : 0; 104 105 if (v == cookie) 106 ret = bch2_btree_delete_at(trans, &iter, 0); 107 err: 108 bch2_trans_iter_exit(trans, &iter); 109 return ret; 110 } 111 112 static struct bkey_s_c next_rebalance_entry(struct btree_trans *trans, 113 struct btree_iter *work_iter) 114 { 115 return !kthread_should_stop() 116 ? bch2_btree_iter_peek(work_iter) 117 : bkey_s_c_null; 118 } 119 120 static int bch2_bkey_clear_needs_rebalance(struct btree_trans *trans, 121 struct btree_iter *iter, 122 struct bkey_s_c k) 123 { 124 struct bkey_i *n = bch2_bkey_make_mut(trans, iter, &k, 0); 125 int ret = PTR_ERR_OR_ZERO(n); 126 if (ret) 127 return ret; 128 129 extent_entry_drop(bkey_i_to_s(n), 130 (void *) bch2_bkey_rebalance_opts(bkey_i_to_s_c(n))); 131 return bch2_trans_commit(trans, NULL, NULL, BCH_TRANS_COMMIT_no_enospc); 132 } 133 134 static struct bkey_s_c next_rebalance_extent(struct btree_trans *trans, 135 struct bpos work_pos, 136 struct btree_iter *extent_iter, 137 struct data_update_opts *data_opts) 138 { 139 struct bch_fs *c = trans->c; 140 struct bkey_s_c k; 141 142 bch2_trans_iter_exit(trans, extent_iter); 143 bch2_trans_iter_init(trans, extent_iter, 144 work_pos.inode ? BTREE_ID_extents : BTREE_ID_reflink, 145 work_pos, 146 BTREE_ITER_all_snapshots); 147 k = bch2_btree_iter_peek_slot(extent_iter); 148 if (bkey_err(k)) 149 return k; 150 151 const struct bch_extent_rebalance *r = k.k ? bch2_bkey_rebalance_opts(k) : NULL; 152 if (!r) { 153 /* raced due to btree write buffer, nothing to do */ 154 return bkey_s_c_null; 155 } 156 157 memset(data_opts, 0, sizeof(*data_opts)); 158 159 data_opts->rewrite_ptrs = 160 bch2_bkey_ptrs_need_rebalance(c, k, r->target, r->compression); 161 data_opts->target = r->target; 162 data_opts->write_flags |= BCH_WRITE_ONLY_SPECIFIED_DEVS; 163 164 if (!data_opts->rewrite_ptrs) { 165 /* 166 * device we would want to write to offline? devices in target 167 * changed? 168 * 169 * We'll now need a full scan before this extent is picked up 170 * again: 171 */ 172 int ret = bch2_bkey_clear_needs_rebalance(trans, extent_iter, k); 173 if (ret) 174 return bkey_s_c_err(ret); 175 return bkey_s_c_null; 176 } 177 178 if (trace_rebalance_extent_enabled()) { 179 struct printbuf buf = PRINTBUF; 180 181 prt_str(&buf, "target="); 182 bch2_target_to_text(&buf, c, r->target); 183 prt_str(&buf, " compression="); 184 bch2_compression_opt_to_text(&buf, r->compression); 185 prt_str(&buf, " "); 186 bch2_bkey_val_to_text(&buf, c, k); 187 188 trace_rebalance_extent(c, buf.buf); 189 printbuf_exit(&buf); 190 } 191 192 return k; 193 } 194 195 noinline_for_stack 196 static int do_rebalance_extent(struct moving_context *ctxt, 197 struct bpos work_pos, 198 struct btree_iter *extent_iter) 199 { 200 struct btree_trans *trans = ctxt->trans; 201 struct bch_fs *c = trans->c; 202 struct bch_fs_rebalance *r = &trans->c->rebalance; 203 struct data_update_opts data_opts; 204 struct bch_io_opts io_opts; 205 struct bkey_s_c k; 206 struct bkey_buf sk; 207 int ret; 208 209 ctxt->stats = &r->work_stats; 210 r->state = BCH_REBALANCE_working; 211 212 bch2_bkey_buf_init(&sk); 213 214 ret = bkey_err(k = next_rebalance_extent(trans, work_pos, 215 extent_iter, &data_opts)); 216 if (ret || !k.k) 217 goto out; 218 219 ret = bch2_move_get_io_opts_one(trans, &io_opts, k); 220 if (ret) 221 goto out; 222 223 atomic64_add(k.k->size, &ctxt->stats->sectors_seen); 224 225 /* 226 * The iterator gets unlocked by __bch2_read_extent - need to 227 * save a copy of @k elsewhere: 228 */ 229 bch2_bkey_buf_reassemble(&sk, c, k); 230 k = bkey_i_to_s_c(sk.k); 231 232 ret = bch2_move_extent(ctxt, NULL, extent_iter, k, io_opts, data_opts); 233 if (ret) { 234 if (bch2_err_matches(ret, ENOMEM)) { 235 /* memory allocation failure, wait for some IO to finish */ 236 bch2_move_ctxt_wait_for_io(ctxt); 237 ret = -BCH_ERR_transaction_restart_nested; 238 } 239 240 if (bch2_err_matches(ret, BCH_ERR_transaction_restart)) 241 goto out; 242 243 /* skip it and continue, XXX signal failure */ 244 ret = 0; 245 } 246 out: 247 bch2_bkey_buf_exit(&sk, c); 248 return ret; 249 } 250 251 static bool rebalance_pred(struct bch_fs *c, void *arg, 252 struct bkey_s_c k, 253 struct bch_io_opts *io_opts, 254 struct data_update_opts *data_opts) 255 { 256 unsigned target, compression; 257 258 if (k.k->p.inode) { 259 target = io_opts->background_target; 260 compression = background_compression(*io_opts); 261 } else { 262 const struct bch_extent_rebalance *r = bch2_bkey_rebalance_opts(k); 263 264 target = r ? r->target : io_opts->background_target; 265 compression = r ? r->compression : background_compression(*io_opts); 266 } 267 268 data_opts->rewrite_ptrs = bch2_bkey_ptrs_need_rebalance(c, k, target, compression); 269 data_opts->target = target; 270 data_opts->write_flags |= BCH_WRITE_ONLY_SPECIFIED_DEVS; 271 return data_opts->rewrite_ptrs != 0; 272 } 273 274 static int do_rebalance_scan(struct moving_context *ctxt, u64 inum, u64 cookie) 275 { 276 struct btree_trans *trans = ctxt->trans; 277 struct bch_fs_rebalance *r = &trans->c->rebalance; 278 int ret; 279 280 bch2_move_stats_init(&r->scan_stats, "rebalance_scan"); 281 ctxt->stats = &r->scan_stats; 282 283 if (!inum) { 284 r->scan_start = BBPOS_MIN; 285 r->scan_end = BBPOS_MAX; 286 } else { 287 r->scan_start = BBPOS(BTREE_ID_extents, POS(inum, 0)); 288 r->scan_end = BBPOS(BTREE_ID_extents, POS(inum, U64_MAX)); 289 } 290 291 r->state = BCH_REBALANCE_scanning; 292 293 ret = __bch2_move_data(ctxt, r->scan_start, r->scan_end, rebalance_pred, NULL) ?: 294 commit_do(trans, NULL, NULL, BCH_TRANS_COMMIT_no_enospc, 295 bch2_clear_rebalance_needs_scan(trans, inum, cookie)); 296 297 bch2_move_stats_exit(&r->scan_stats, trans->c); 298 return ret; 299 } 300 301 static void rebalance_wait(struct bch_fs *c) 302 { 303 struct bch_fs_rebalance *r = &c->rebalance; 304 struct io_clock *clock = &c->io_clock[WRITE]; 305 u64 now = atomic64_read(&clock->now); 306 u64 min_member_capacity = bch2_min_rw_member_capacity(c); 307 308 if (min_member_capacity == U64_MAX) 309 min_member_capacity = 128 * 2048; 310 311 r->wait_iotime_end = now + (min_member_capacity >> 6); 312 313 if (r->state != BCH_REBALANCE_waiting) { 314 r->wait_iotime_start = now; 315 r->wait_wallclock_start = ktime_get_real_ns(); 316 r->state = BCH_REBALANCE_waiting; 317 } 318 319 bch2_kthread_io_clock_wait(clock, r->wait_iotime_end, MAX_SCHEDULE_TIMEOUT); 320 } 321 322 static int do_rebalance(struct moving_context *ctxt) 323 { 324 struct btree_trans *trans = ctxt->trans; 325 struct bch_fs *c = trans->c; 326 struct bch_fs_rebalance *r = &c->rebalance; 327 struct btree_iter rebalance_work_iter, extent_iter = { NULL }; 328 struct bkey_s_c k; 329 int ret = 0; 330 331 bch2_trans_begin(trans); 332 333 bch2_move_stats_init(&r->work_stats, "rebalance_work"); 334 bch2_move_stats_init(&r->scan_stats, "rebalance_scan"); 335 336 bch2_trans_iter_init(trans, &rebalance_work_iter, 337 BTREE_ID_rebalance_work, POS_MIN, 338 BTREE_ITER_all_snapshots); 339 340 while (!bch2_move_ratelimit(ctxt)) { 341 if (!r->enabled) { 342 bch2_moving_ctxt_flush_all(ctxt); 343 kthread_wait_freezable(r->enabled || 344 kthread_should_stop()); 345 } 346 347 if (kthread_should_stop()) 348 break; 349 350 bch2_trans_begin(trans); 351 352 ret = bkey_err(k = next_rebalance_entry(trans, &rebalance_work_iter)); 353 if (bch2_err_matches(ret, BCH_ERR_transaction_restart)) 354 continue; 355 if (ret || !k.k) 356 break; 357 358 ret = k.k->type == KEY_TYPE_cookie 359 ? do_rebalance_scan(ctxt, k.k->p.inode, 360 le64_to_cpu(bkey_s_c_to_cookie(k).v->cookie)) 361 : do_rebalance_extent(ctxt, k.k->p, &extent_iter); 362 363 if (bch2_err_matches(ret, BCH_ERR_transaction_restart)) 364 continue; 365 if (ret) 366 break; 367 368 bch2_btree_iter_advance(&rebalance_work_iter); 369 } 370 371 bch2_trans_iter_exit(trans, &extent_iter); 372 bch2_trans_iter_exit(trans, &rebalance_work_iter); 373 bch2_move_stats_exit(&r->scan_stats, c); 374 375 if (!ret && 376 !kthread_should_stop() && 377 !atomic64_read(&r->work_stats.sectors_seen) && 378 !atomic64_read(&r->scan_stats.sectors_seen)) { 379 bch2_moving_ctxt_flush_all(ctxt); 380 bch2_trans_unlock_long(trans); 381 rebalance_wait(c); 382 } 383 384 if (!bch2_err_matches(ret, EROFS)) 385 bch_err_fn(c, ret); 386 return ret; 387 } 388 389 static int bch2_rebalance_thread(void *arg) 390 { 391 struct bch_fs *c = arg; 392 struct bch_fs_rebalance *r = &c->rebalance; 393 struct moving_context ctxt; 394 395 set_freezable(); 396 397 bch2_moving_ctxt_init(&ctxt, c, NULL, &r->work_stats, 398 writepoint_ptr(&c->rebalance_write_point), 399 true); 400 401 while (!kthread_should_stop() && !do_rebalance(&ctxt)) 402 ; 403 404 bch2_moving_ctxt_exit(&ctxt); 405 406 return 0; 407 } 408 409 void bch2_rebalance_status_to_text(struct printbuf *out, struct bch_fs *c) 410 { 411 struct bch_fs_rebalance *r = &c->rebalance; 412 413 prt_str(out, bch2_rebalance_state_strs[r->state]); 414 prt_newline(out); 415 printbuf_indent_add(out, 2); 416 417 switch (r->state) { 418 case BCH_REBALANCE_waiting: { 419 u64 now = atomic64_read(&c->io_clock[WRITE].now); 420 421 prt_str(out, "io wait duration: "); 422 bch2_prt_human_readable_s64(out, (r->wait_iotime_end - r->wait_iotime_start) << 9); 423 prt_newline(out); 424 425 prt_str(out, "io wait remaining: "); 426 bch2_prt_human_readable_s64(out, (r->wait_iotime_end - now) << 9); 427 prt_newline(out); 428 429 prt_str(out, "duration waited: "); 430 bch2_pr_time_units(out, ktime_get_real_ns() - r->wait_wallclock_start); 431 prt_newline(out); 432 break; 433 } 434 case BCH_REBALANCE_working: 435 bch2_move_stats_to_text(out, &r->work_stats); 436 break; 437 case BCH_REBALANCE_scanning: 438 bch2_move_stats_to_text(out, &r->scan_stats); 439 break; 440 } 441 prt_newline(out); 442 printbuf_indent_sub(out, 2); 443 } 444 445 void bch2_rebalance_stop(struct bch_fs *c) 446 { 447 struct task_struct *p; 448 449 c->rebalance.pd.rate.rate = UINT_MAX; 450 bch2_ratelimit_reset(&c->rebalance.pd.rate); 451 452 p = rcu_dereference_protected(c->rebalance.thread, 1); 453 c->rebalance.thread = NULL; 454 455 if (p) { 456 /* for sychronizing with rebalance_wakeup() */ 457 synchronize_rcu(); 458 459 kthread_stop(p); 460 put_task_struct(p); 461 } 462 } 463 464 int bch2_rebalance_start(struct bch_fs *c) 465 { 466 struct task_struct *p; 467 int ret; 468 469 if (c->rebalance.thread) 470 return 0; 471 472 if (c->opts.nochanges) 473 return 0; 474 475 p = kthread_create(bch2_rebalance_thread, c, "bch-rebalance/%s", c->name); 476 ret = PTR_ERR_OR_ZERO(p); 477 bch_err_msg(c, ret, "creating rebalance thread"); 478 if (ret) 479 return ret; 480 481 get_task_struct(p); 482 rcu_assign_pointer(c->rebalance.thread, p); 483 wake_up_process(p); 484 return 0; 485 } 486 487 void bch2_fs_rebalance_init(struct bch_fs *c) 488 { 489 bch2_pd_controller_init(&c->rebalance.pd); 490 } 491