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, BTREE_INSERT_NOFAIL|BTREE_INSERT_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, BTREE_INSERT_NOFAIL); 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 return k; 175 } 176 177 noinline_for_stack 178 static int do_rebalance_extent(struct moving_context *ctxt, 179 struct bpos work_pos, 180 struct btree_iter *extent_iter) 181 { 182 struct btree_trans *trans = ctxt->trans; 183 struct bch_fs *c = trans->c; 184 struct bch_fs_rebalance *r = &trans->c->rebalance; 185 struct data_update_opts data_opts; 186 struct bch_io_opts io_opts; 187 struct bkey_s_c k; 188 struct bkey_buf sk; 189 int ret; 190 191 ctxt->stats = &r->work_stats; 192 r->state = BCH_REBALANCE_working; 193 194 bch2_bkey_buf_init(&sk); 195 196 ret = bkey_err(k = next_rebalance_extent(trans, work_pos, 197 extent_iter, &data_opts)); 198 if (ret || !k.k) 199 goto out; 200 201 ret = bch2_move_get_io_opts_one(trans, &io_opts, k); 202 if (ret) 203 goto out; 204 205 atomic64_add(k.k->size, &ctxt->stats->sectors_seen); 206 207 /* 208 * The iterator gets unlocked by __bch2_read_extent - need to 209 * save a copy of @k elsewhere: 210 */ 211 bch2_bkey_buf_reassemble(&sk, c, k); 212 k = bkey_i_to_s_c(sk.k); 213 214 ret = bch2_move_extent(ctxt, NULL, extent_iter, k, io_opts, data_opts); 215 if (ret) { 216 if (bch2_err_matches(ret, ENOMEM)) { 217 /* memory allocation failure, wait for some IO to finish */ 218 bch2_move_ctxt_wait_for_io(ctxt); 219 ret = -BCH_ERR_transaction_restart_nested; 220 } 221 222 if (bch2_err_matches(ret, BCH_ERR_transaction_restart)) 223 goto out; 224 225 /* skip it and continue, XXX signal failure */ 226 ret = 0; 227 } 228 out: 229 bch2_bkey_buf_exit(&sk, c); 230 return ret; 231 } 232 233 static bool rebalance_pred(struct bch_fs *c, void *arg, 234 struct bkey_s_c k, 235 struct bch_io_opts *io_opts, 236 struct data_update_opts *data_opts) 237 { 238 unsigned target, compression; 239 240 if (k.k->p.inode) { 241 target = io_opts->background_target; 242 compression = io_opts->background_compression ?: io_opts->compression; 243 } else { 244 const struct bch_extent_rebalance *r = bch2_bkey_rebalance_opts(k); 245 246 target = r ? r->target : io_opts->background_target; 247 compression = r ? r->compression : 248 (io_opts->background_compression ?: io_opts->compression); 249 } 250 251 data_opts->rewrite_ptrs = bch2_bkey_ptrs_need_rebalance(c, k, target, compression); 252 data_opts->target = target; 253 return data_opts->rewrite_ptrs != 0; 254 } 255 256 static int do_rebalance_scan(struct moving_context *ctxt, u64 inum, u64 cookie) 257 { 258 struct btree_trans *trans = ctxt->trans; 259 struct bch_fs_rebalance *r = &trans->c->rebalance; 260 int ret; 261 262 bch2_move_stats_init(&r->scan_stats, "rebalance_scan"); 263 ctxt->stats = &r->scan_stats; 264 265 if (!inum) { 266 r->scan_start = BBPOS_MIN; 267 r->scan_end = BBPOS_MAX; 268 } else { 269 r->scan_start = BBPOS(BTREE_ID_extents, POS(inum, 0)); 270 r->scan_end = BBPOS(BTREE_ID_extents, POS(inum, U64_MAX)); 271 } 272 273 r->state = BCH_REBALANCE_scanning; 274 275 ret = __bch2_move_data(ctxt, r->scan_start, r->scan_end, rebalance_pred, NULL) ?: 276 commit_do(trans, NULL, NULL, BTREE_INSERT_NOFAIL, 277 bch2_clear_rebalance_needs_scan(trans, inum, cookie)); 278 279 bch2_move_stats_exit(&r->scan_stats, trans->c); 280 return ret; 281 } 282 283 static void rebalance_wait(struct bch_fs *c) 284 { 285 struct bch_fs_rebalance *r = &c->rebalance; 286 struct io_clock *clock = &c->io_clock[WRITE]; 287 u64 now = atomic64_read(&clock->now); 288 u64 min_member_capacity = bch2_min_rw_member_capacity(c); 289 290 if (min_member_capacity == U64_MAX) 291 min_member_capacity = 128 * 2048; 292 293 r->wait_iotime_end = now + (min_member_capacity >> 6); 294 295 if (r->state != BCH_REBALANCE_waiting) { 296 r->wait_iotime_start = now; 297 r->wait_wallclock_start = ktime_get_real_ns(); 298 r->state = BCH_REBALANCE_waiting; 299 } 300 301 bch2_kthread_io_clock_wait(clock, r->wait_iotime_end, MAX_SCHEDULE_TIMEOUT); 302 } 303 304 static int do_rebalance(struct moving_context *ctxt) 305 { 306 struct btree_trans *trans = ctxt->trans; 307 struct bch_fs *c = trans->c; 308 struct bch_fs_rebalance *r = &c->rebalance; 309 struct btree_iter rebalance_work_iter, extent_iter = { NULL }; 310 struct bkey_s_c k; 311 int ret = 0; 312 313 bch2_move_stats_init(&r->work_stats, "rebalance_work"); 314 bch2_move_stats_init(&r->scan_stats, "rebalance_scan"); 315 316 bch2_trans_iter_init(trans, &rebalance_work_iter, 317 BTREE_ID_rebalance_work, POS_MIN, 318 BTREE_ITER_ALL_SNAPSHOTS); 319 320 while (!bch2_move_ratelimit(ctxt) && 321 !kthread_wait_freezable(r->enabled)) { 322 bch2_trans_begin(trans); 323 324 ret = bkey_err(k = next_rebalance_entry(trans, &rebalance_work_iter)); 325 if (bch2_err_matches(ret, BCH_ERR_transaction_restart)) 326 continue; 327 if (ret || !k.k) 328 break; 329 330 ret = k.k->type == KEY_TYPE_cookie 331 ? do_rebalance_scan(ctxt, k.k->p.inode, 332 le64_to_cpu(bkey_s_c_to_cookie(k).v->cookie)) 333 : do_rebalance_extent(ctxt, k.k->p, &extent_iter); 334 335 if (bch2_err_matches(ret, BCH_ERR_transaction_restart)) 336 continue; 337 if (ret) 338 break; 339 340 bch2_btree_iter_advance(&rebalance_work_iter); 341 } 342 343 bch2_trans_iter_exit(trans, &extent_iter); 344 bch2_trans_iter_exit(trans, &rebalance_work_iter); 345 bch2_move_stats_exit(&r->scan_stats, c); 346 347 if (!ret && 348 !kthread_should_stop() && 349 !atomic64_read(&r->work_stats.sectors_seen) && 350 !atomic64_read(&r->scan_stats.sectors_seen)) { 351 bch2_trans_unlock_long(trans); 352 rebalance_wait(c); 353 } 354 355 if (!bch2_err_matches(ret, EROFS)) 356 bch_err_fn(c, ret); 357 return ret; 358 } 359 360 static int bch2_rebalance_thread(void *arg) 361 { 362 struct bch_fs *c = arg; 363 struct bch_fs_rebalance *r = &c->rebalance; 364 struct moving_context ctxt; 365 int ret; 366 367 set_freezable(); 368 369 bch2_moving_ctxt_init(&ctxt, c, NULL, &r->work_stats, 370 writepoint_ptr(&c->rebalance_write_point), 371 true); 372 373 while (!kthread_should_stop() && 374 !(ret = do_rebalance(&ctxt))) 375 ; 376 377 bch2_moving_ctxt_exit(&ctxt); 378 379 return 0; 380 } 381 382 void bch2_rebalance_status_to_text(struct printbuf *out, struct bch_fs *c) 383 { 384 struct bch_fs_rebalance *r = &c->rebalance; 385 386 prt_str(out, bch2_rebalance_state_strs[r->state]); 387 prt_newline(out); 388 printbuf_indent_add(out, 2); 389 390 switch (r->state) { 391 case BCH_REBALANCE_waiting: { 392 u64 now = atomic64_read(&c->io_clock[WRITE].now); 393 394 prt_str(out, "io wait duration: "); 395 bch2_prt_human_readable_s64(out, r->wait_iotime_end - r->wait_iotime_start); 396 prt_newline(out); 397 398 prt_str(out, "io wait remaining: "); 399 bch2_prt_human_readable_s64(out, r->wait_iotime_end - now); 400 prt_newline(out); 401 402 prt_str(out, "duration waited: "); 403 bch2_pr_time_units(out, ktime_get_real_ns() - r->wait_wallclock_start); 404 prt_newline(out); 405 break; 406 } 407 case BCH_REBALANCE_working: 408 bch2_move_stats_to_text(out, &r->work_stats); 409 break; 410 case BCH_REBALANCE_scanning: 411 bch2_move_stats_to_text(out, &r->scan_stats); 412 break; 413 } 414 prt_newline(out); 415 printbuf_indent_sub(out, 2); 416 } 417 418 void bch2_rebalance_stop(struct bch_fs *c) 419 { 420 struct task_struct *p; 421 422 c->rebalance.pd.rate.rate = UINT_MAX; 423 bch2_ratelimit_reset(&c->rebalance.pd.rate); 424 425 p = rcu_dereference_protected(c->rebalance.thread, 1); 426 c->rebalance.thread = NULL; 427 428 if (p) { 429 /* for sychronizing with rebalance_wakeup() */ 430 synchronize_rcu(); 431 432 kthread_stop(p); 433 put_task_struct(p); 434 } 435 } 436 437 int bch2_rebalance_start(struct bch_fs *c) 438 { 439 struct task_struct *p; 440 int ret; 441 442 if (c->rebalance.thread) 443 return 0; 444 445 if (c->opts.nochanges) 446 return 0; 447 448 p = kthread_create(bch2_rebalance_thread, c, "bch-rebalance/%s", c->name); 449 ret = PTR_ERR_OR_ZERO(p); 450 if (ret) { 451 bch_err_msg(c, ret, "creating rebalance thread"); 452 return ret; 453 } 454 455 get_task_struct(p); 456 rcu_assign_pointer(c->rebalance.thread, p); 457 wake_up_process(p); 458 return 0; 459 } 460 461 void bch2_fs_rebalance_init(struct bch_fs *c) 462 { 463 bch2_pd_controller_init(&c->rebalance.pd); 464 } 465