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 "move.h" 17 #include "rebalance.h" 18 #include "subvolume.h" 19 #include "super-io.h" 20 #include "trace.h" 21 22 #include <linux/freezer.h> 23 #include <linux/kthread.h> 24 #include <linux/sched/cputime.h> 25 26 #define REBALANCE_WORK_SCAN_OFFSET (U64_MAX - 1) 27 28 static const char * const bch2_rebalance_state_strs[] = { 29 #define x(t) #t, 30 BCH_REBALANCE_STATES() 31 NULL 32 #undef x 33 }; 34 35 static int __bch2_set_rebalance_needs_scan(struct btree_trans *trans, u64 inum) 36 { 37 struct btree_iter iter; 38 struct bkey_s_c k; 39 struct bkey_i_cookie *cookie; 40 u64 v; 41 int ret; 42 43 bch2_trans_iter_init(trans, &iter, BTREE_ID_rebalance_work, 44 SPOS(inum, REBALANCE_WORK_SCAN_OFFSET, U32_MAX), 45 BTREE_ITER_INTENT); 46 k = bch2_btree_iter_peek_slot(&iter); 47 ret = bkey_err(k); 48 if (ret) 49 goto err; 50 51 v = k.k->type == KEY_TYPE_cookie 52 ? le64_to_cpu(bkey_s_c_to_cookie(k).v->cookie) 53 : 0; 54 55 cookie = bch2_trans_kmalloc(trans, sizeof(*cookie)); 56 ret = PTR_ERR_OR_ZERO(cookie); 57 if (ret) 58 goto err; 59 60 bkey_cookie_init(&cookie->k_i); 61 cookie->k.p = iter.pos; 62 cookie->v.cookie = cpu_to_le64(v + 1); 63 64 ret = bch2_trans_update(trans, &iter, &cookie->k_i, 0); 65 err: 66 bch2_trans_iter_exit(trans, &iter); 67 return ret; 68 } 69 70 int bch2_set_rebalance_needs_scan(struct bch_fs *c, u64 inum) 71 { 72 int ret = bch2_trans_do(c, NULL, NULL, BCH_TRANS_COMMIT_no_enospc|BCH_TRANS_COMMIT_lazy_rw, 73 __bch2_set_rebalance_needs_scan(trans, inum)); 74 rebalance_wakeup(c); 75 return ret; 76 } 77 78 int bch2_set_fs_needs_rebalance(struct bch_fs *c) 79 { 80 return bch2_set_rebalance_needs_scan(c, 0); 81 } 82 83 static int bch2_clear_rebalance_needs_scan(struct btree_trans *trans, u64 inum, u64 cookie) 84 { 85 struct btree_iter iter; 86 struct bkey_s_c k; 87 u64 v; 88 int ret; 89 90 bch2_trans_iter_init(trans, &iter, BTREE_ID_rebalance_work, 91 SPOS(inum, REBALANCE_WORK_SCAN_OFFSET, U32_MAX), 92 BTREE_ITER_INTENT); 93 k = bch2_btree_iter_peek_slot(&iter); 94 ret = bkey_err(k); 95 if (ret) 96 goto err; 97 98 v = k.k->type == KEY_TYPE_cookie 99 ? le64_to_cpu(bkey_s_c_to_cookie(k).v->cookie) 100 : 0; 101 102 if (v == cookie) 103 ret = bch2_btree_delete_at(trans, &iter, 0); 104 err: 105 bch2_trans_iter_exit(trans, &iter); 106 return ret; 107 } 108 109 static struct bkey_s_c next_rebalance_entry(struct btree_trans *trans, 110 struct btree_iter *work_iter) 111 { 112 return !kthread_should_stop() 113 ? bch2_btree_iter_peek(work_iter) 114 : bkey_s_c_null; 115 } 116 117 static int bch2_bkey_clear_needs_rebalance(struct btree_trans *trans, 118 struct btree_iter *iter, 119 struct bkey_s_c k) 120 { 121 struct bkey_i *n = bch2_bkey_make_mut(trans, iter, &k, 0); 122 int ret = PTR_ERR_OR_ZERO(n); 123 if (ret) 124 return ret; 125 126 extent_entry_drop(bkey_i_to_s(n), 127 (void *) bch2_bkey_rebalance_opts(bkey_i_to_s_c(n))); 128 return bch2_trans_commit(trans, NULL, NULL, BCH_TRANS_COMMIT_no_enospc); 129 } 130 131 static struct bkey_s_c next_rebalance_extent(struct btree_trans *trans, 132 struct bpos work_pos, 133 struct btree_iter *extent_iter, 134 struct data_update_opts *data_opts) 135 { 136 struct bch_fs *c = trans->c; 137 struct bkey_s_c k; 138 139 bch2_trans_iter_exit(trans, extent_iter); 140 bch2_trans_iter_init(trans, extent_iter, 141 work_pos.inode ? BTREE_ID_extents : BTREE_ID_reflink, 142 work_pos, 143 BTREE_ITER_ALL_SNAPSHOTS); 144 k = bch2_btree_iter_peek_slot(extent_iter); 145 if (bkey_err(k)) 146 return k; 147 148 const struct bch_extent_rebalance *r = k.k ? bch2_bkey_rebalance_opts(k) : NULL; 149 if (!r) { 150 /* raced due to btree write buffer, nothing to do */ 151 return bkey_s_c_null; 152 } 153 154 memset(data_opts, 0, sizeof(*data_opts)); 155 156 data_opts->rewrite_ptrs = 157 bch2_bkey_ptrs_need_rebalance(c, k, r->target, r->compression); 158 data_opts->target = r->target; 159 160 if (!data_opts->rewrite_ptrs) { 161 /* 162 * device we would want to write to offline? devices in target 163 * changed? 164 * 165 * We'll now need a full scan before this extent is picked up 166 * again: 167 */ 168 int ret = bch2_bkey_clear_needs_rebalance(trans, extent_iter, k); 169 if (ret) 170 return bkey_s_c_err(ret); 171 return bkey_s_c_null; 172 } 173 174 if (trace_rebalance_extent_enabled()) { 175 struct printbuf buf = PRINTBUF; 176 177 prt_str(&buf, "target="); 178 bch2_target_to_text(&buf, c, r->target); 179 prt_str(&buf, " compression="); 180 bch2_compression_opt_to_text(&buf, r->compression); 181 prt_str(&buf, " "); 182 bch2_bkey_val_to_text(&buf, c, k); 183 184 trace_rebalance_extent(c, buf.buf); 185 printbuf_exit(&buf); 186 } 187 188 return k; 189 } 190 191 noinline_for_stack 192 static int do_rebalance_extent(struct moving_context *ctxt, 193 struct bpos work_pos, 194 struct btree_iter *extent_iter) 195 { 196 struct btree_trans *trans = ctxt->trans; 197 struct bch_fs *c = trans->c; 198 struct bch_fs_rebalance *r = &trans->c->rebalance; 199 struct data_update_opts data_opts; 200 struct bch_io_opts io_opts; 201 struct bkey_s_c k; 202 struct bkey_buf sk; 203 int ret; 204 205 ctxt->stats = &r->work_stats; 206 r->state = BCH_REBALANCE_working; 207 208 bch2_bkey_buf_init(&sk); 209 210 ret = bkey_err(k = next_rebalance_extent(trans, work_pos, 211 extent_iter, &data_opts)); 212 if (ret || !k.k) 213 goto out; 214 215 ret = bch2_move_get_io_opts_one(trans, &io_opts, k); 216 if (ret) 217 goto out; 218 219 atomic64_add(k.k->size, &ctxt->stats->sectors_seen); 220 221 /* 222 * The iterator gets unlocked by __bch2_read_extent - need to 223 * save a copy of @k elsewhere: 224 */ 225 bch2_bkey_buf_reassemble(&sk, c, k); 226 k = bkey_i_to_s_c(sk.k); 227 228 ret = bch2_move_extent(ctxt, NULL, extent_iter, k, io_opts, data_opts); 229 if (ret) { 230 if (bch2_err_matches(ret, ENOMEM)) { 231 /* memory allocation failure, wait for some IO to finish */ 232 bch2_move_ctxt_wait_for_io(ctxt); 233 ret = -BCH_ERR_transaction_restart_nested; 234 } 235 236 if (bch2_err_matches(ret, BCH_ERR_transaction_restart)) 237 goto out; 238 239 /* skip it and continue, XXX signal failure */ 240 ret = 0; 241 } 242 out: 243 bch2_bkey_buf_exit(&sk, c); 244 return ret; 245 } 246 247 static bool rebalance_pred(struct bch_fs *c, void *arg, 248 struct bkey_s_c k, 249 struct bch_io_opts *io_opts, 250 struct data_update_opts *data_opts) 251 { 252 unsigned target, compression; 253 254 if (k.k->p.inode) { 255 target = io_opts->background_target; 256 compression = background_compression(*io_opts); 257 } else { 258 const struct bch_extent_rebalance *r = bch2_bkey_rebalance_opts(k); 259 260 target = r ? r->target : io_opts->background_target; 261 compression = r ? r->compression : background_compression(*io_opts); 262 } 263 264 data_opts->rewrite_ptrs = bch2_bkey_ptrs_need_rebalance(c, k, target, compression); 265 data_opts->target = target; 266 return data_opts->rewrite_ptrs != 0; 267 } 268 269 static int do_rebalance_scan(struct moving_context *ctxt, u64 inum, u64 cookie) 270 { 271 struct btree_trans *trans = ctxt->trans; 272 struct bch_fs_rebalance *r = &trans->c->rebalance; 273 int ret; 274 275 bch2_move_stats_init(&r->scan_stats, "rebalance_scan"); 276 ctxt->stats = &r->scan_stats; 277 278 if (!inum) { 279 r->scan_start = BBPOS_MIN; 280 r->scan_end = BBPOS_MAX; 281 } else { 282 r->scan_start = BBPOS(BTREE_ID_extents, POS(inum, 0)); 283 r->scan_end = BBPOS(BTREE_ID_extents, POS(inum, U64_MAX)); 284 } 285 286 r->state = BCH_REBALANCE_scanning; 287 288 ret = __bch2_move_data(ctxt, r->scan_start, r->scan_end, rebalance_pred, NULL) ?: 289 commit_do(trans, NULL, NULL, BCH_TRANS_COMMIT_no_enospc, 290 bch2_clear_rebalance_needs_scan(trans, inum, cookie)); 291 292 bch2_move_stats_exit(&r->scan_stats, trans->c); 293 return ret; 294 } 295 296 static void rebalance_wait(struct bch_fs *c) 297 { 298 struct bch_fs_rebalance *r = &c->rebalance; 299 struct io_clock *clock = &c->io_clock[WRITE]; 300 u64 now = atomic64_read(&clock->now); 301 u64 min_member_capacity = bch2_min_rw_member_capacity(c); 302 303 if (min_member_capacity == U64_MAX) 304 min_member_capacity = 128 * 2048; 305 306 r->wait_iotime_end = now + (min_member_capacity >> 6); 307 308 if (r->state != BCH_REBALANCE_waiting) { 309 r->wait_iotime_start = now; 310 r->wait_wallclock_start = ktime_get_real_ns(); 311 r->state = BCH_REBALANCE_waiting; 312 } 313 314 bch2_kthread_io_clock_wait(clock, r->wait_iotime_end, MAX_SCHEDULE_TIMEOUT); 315 } 316 317 static int do_rebalance(struct moving_context *ctxt) 318 { 319 struct btree_trans *trans = ctxt->trans; 320 struct bch_fs *c = trans->c; 321 struct bch_fs_rebalance *r = &c->rebalance; 322 struct btree_iter rebalance_work_iter, extent_iter = { NULL }; 323 struct bkey_s_c k; 324 int ret = 0; 325 326 bch2_move_stats_init(&r->work_stats, "rebalance_work"); 327 bch2_move_stats_init(&r->scan_stats, "rebalance_scan"); 328 329 bch2_trans_iter_init(trans, &rebalance_work_iter, 330 BTREE_ID_rebalance_work, POS_MIN, 331 BTREE_ITER_ALL_SNAPSHOTS); 332 333 while (!bch2_move_ratelimit(ctxt)) { 334 if (!r->enabled) { 335 bch2_moving_ctxt_flush_all(ctxt); 336 kthread_wait_freezable(r->enabled || 337 kthread_should_stop()); 338 } 339 340 if (kthread_should_stop()) 341 break; 342 343 bch2_trans_begin(trans); 344 345 ret = bkey_err(k = next_rebalance_entry(trans, &rebalance_work_iter)); 346 if (bch2_err_matches(ret, BCH_ERR_transaction_restart)) 347 continue; 348 if (ret || !k.k) 349 break; 350 351 ret = k.k->type == KEY_TYPE_cookie 352 ? do_rebalance_scan(ctxt, k.k->p.inode, 353 le64_to_cpu(bkey_s_c_to_cookie(k).v->cookie)) 354 : do_rebalance_extent(ctxt, k.k->p, &extent_iter); 355 356 if (bch2_err_matches(ret, BCH_ERR_transaction_restart)) 357 continue; 358 if (ret) 359 break; 360 361 bch2_btree_iter_advance(&rebalance_work_iter); 362 } 363 364 bch2_trans_iter_exit(trans, &extent_iter); 365 bch2_trans_iter_exit(trans, &rebalance_work_iter); 366 bch2_move_stats_exit(&r->scan_stats, c); 367 368 if (!ret && 369 !kthread_should_stop() && 370 !atomic64_read(&r->work_stats.sectors_seen) && 371 !atomic64_read(&r->scan_stats.sectors_seen)) { 372 bch2_moving_ctxt_flush_all(ctxt); 373 bch2_trans_unlock_long(trans); 374 rebalance_wait(c); 375 } 376 377 if (!bch2_err_matches(ret, EROFS)) 378 bch_err_fn(c, ret); 379 return ret; 380 } 381 382 static int bch2_rebalance_thread(void *arg) 383 { 384 struct bch_fs *c = arg; 385 struct bch_fs_rebalance *r = &c->rebalance; 386 struct moving_context ctxt; 387 388 set_freezable(); 389 390 bch2_moving_ctxt_init(&ctxt, c, NULL, &r->work_stats, 391 writepoint_ptr(&c->rebalance_write_point), 392 true); 393 394 while (!kthread_should_stop() && !do_rebalance(&ctxt)) 395 ; 396 397 bch2_moving_ctxt_exit(&ctxt); 398 399 return 0; 400 } 401 402 void bch2_rebalance_status_to_text(struct printbuf *out, struct bch_fs *c) 403 { 404 struct bch_fs_rebalance *r = &c->rebalance; 405 406 prt_str(out, bch2_rebalance_state_strs[r->state]); 407 prt_newline(out); 408 printbuf_indent_add(out, 2); 409 410 switch (r->state) { 411 case BCH_REBALANCE_waiting: { 412 u64 now = atomic64_read(&c->io_clock[WRITE].now); 413 414 prt_str(out, "io wait duration: "); 415 bch2_prt_human_readable_s64(out, (r->wait_iotime_end - r->wait_iotime_start) << 9); 416 prt_newline(out); 417 418 prt_str(out, "io wait remaining: "); 419 bch2_prt_human_readable_s64(out, (r->wait_iotime_end - now) << 9); 420 prt_newline(out); 421 422 prt_str(out, "duration waited: "); 423 bch2_pr_time_units(out, ktime_get_real_ns() - r->wait_wallclock_start); 424 prt_newline(out); 425 break; 426 } 427 case BCH_REBALANCE_working: 428 bch2_move_stats_to_text(out, &r->work_stats); 429 break; 430 case BCH_REBALANCE_scanning: 431 bch2_move_stats_to_text(out, &r->scan_stats); 432 break; 433 } 434 prt_newline(out); 435 printbuf_indent_sub(out, 2); 436 } 437 438 void bch2_rebalance_stop(struct bch_fs *c) 439 { 440 struct task_struct *p; 441 442 c->rebalance.pd.rate.rate = UINT_MAX; 443 bch2_ratelimit_reset(&c->rebalance.pd.rate); 444 445 p = rcu_dereference_protected(c->rebalance.thread, 1); 446 c->rebalance.thread = NULL; 447 448 if (p) { 449 /* for sychronizing with rebalance_wakeup() */ 450 synchronize_rcu(); 451 452 kthread_stop(p); 453 put_task_struct(p); 454 } 455 } 456 457 int bch2_rebalance_start(struct bch_fs *c) 458 { 459 struct task_struct *p; 460 int ret; 461 462 if (c->rebalance.thread) 463 return 0; 464 465 if (c->opts.nochanges) 466 return 0; 467 468 p = kthread_create(bch2_rebalance_thread, c, "bch-rebalance/%s", c->name); 469 ret = PTR_ERR_OR_ZERO(p); 470 bch_err_msg(c, ret, "creating rebalance thread"); 471 if (ret) 472 return ret; 473 474 get_task_struct(p); 475 rcu_assign_pointer(c->rebalance.thread, p); 476 wake_up_process(p); 477 return 0; 478 } 479 480 void bch2_fs_rebalance_init(struct bch_fs *c) 481 { 482 bch2_pd_controller_init(&c->rebalance.pd); 483 } 484