Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 1 | /* |
| 2 | * background writeback - scan btree for dirty data and write it to the backing |
| 3 | * device |
| 4 | * |
| 5 | * Copyright 2010, 2011 Kent Overstreet <kent.overstreet@gmail.com> |
| 6 | * Copyright 2012 Google, Inc. |
| 7 | */ |
| 8 | |
| 9 | #include "bcache.h" |
| 10 | #include "btree.h" |
| 11 | #include "debug.h" |
Kent Overstreet | 279afba | 2013-06-05 06:21:07 -0700 | [diff] [blame] | 12 | #include "writeback.h" |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 13 | |
Kent Overstreet | 5e6926d | 2013-07-24 17:50:06 -0700 | [diff] [blame] | 14 | #include <linux/delay.h> |
Kent Overstreet | 5e6926d | 2013-07-24 17:50:06 -0700 | [diff] [blame] | 15 | #include <linux/kthread.h> |
Kent Overstreet | c37511b | 2013-04-26 15:39:55 -0700 | [diff] [blame] | 16 | #include <trace/events/bcache.h> |
| 17 | |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 18 | /* Rate limiting */ |
| 19 | |
| 20 | static void __update_writeback_rate(struct cached_dev *dc) |
| 21 | { |
| 22 | struct cache_set *c = dc->disk.c; |
Tang Junhui | e40cb30 | 2017-09-06 14:25:56 +0800 | [diff] [blame] | 23 | uint64_t cache_sectors = c->nbuckets * c->sb.bucket_size - |
| 24 | bcache_flash_devs_sectors_dirty(c); |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 25 | uint64_t cache_dirty_target = |
| 26 | div_u64(cache_sectors * dc->writeback_percent, 100); |
| 27 | |
| 28 | int64_t target = div64_u64(cache_dirty_target * bdev_sectors(dc->bdev), |
| 29 | c->cached_dev_sectors); |
| 30 | |
| 31 | /* PD controller */ |
| 32 | |
Kent Overstreet | 279afba | 2013-06-05 06:21:07 -0700 | [diff] [blame] | 33 | int64_t dirty = bcache_dev_sectors_dirty(&dc->disk); |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 34 | int64_t derivative = dirty - dc->disk.sectors_dirty_last; |
Kent Overstreet | 16749c2 | 2013-11-11 13:58:34 -0800 | [diff] [blame] | 35 | int64_t proportional = dirty - target; |
| 36 | int64_t change; |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 37 | |
| 38 | dc->disk.sectors_dirty_last = dirty; |
| 39 | |
Kent Overstreet | 16749c2 | 2013-11-11 13:58:34 -0800 | [diff] [blame] | 40 | /* Scale to sectors per second */ |
| 41 | |
| 42 | proportional *= dc->writeback_rate_update_seconds; |
| 43 | proportional = div_s64(proportional, dc->writeback_rate_p_term_inverse); |
| 44 | |
| 45 | derivative = div_s64(derivative, dc->writeback_rate_update_seconds); |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 46 | |
| 47 | derivative = ewma_add(dc->disk.sectors_dirty_derivative, derivative, |
Kent Overstreet | 16749c2 | 2013-11-11 13:58:34 -0800 | [diff] [blame] | 48 | (dc->writeback_rate_d_term / |
| 49 | dc->writeback_rate_update_seconds) ?: 1, 0); |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 50 | |
Kent Overstreet | 16749c2 | 2013-11-11 13:58:34 -0800 | [diff] [blame] | 51 | derivative *= dc->writeback_rate_d_term; |
| 52 | derivative = div_s64(derivative, dc->writeback_rate_p_term_inverse); |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 53 | |
Kent Overstreet | 16749c2 | 2013-11-11 13:58:34 -0800 | [diff] [blame] | 54 | change = proportional + derivative; |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 55 | |
| 56 | /* Don't increase writeback rate if the device isn't keeping up */ |
| 57 | if (change > 0 && |
| 58 | time_after64(local_clock(), |
Kent Overstreet | 16749c2 | 2013-11-11 13:58:34 -0800 | [diff] [blame] | 59 | dc->writeback_rate.next + NSEC_PER_MSEC)) |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 60 | change = 0; |
| 61 | |
| 62 | dc->writeback_rate.rate = |
Kent Overstreet | 16749c2 | 2013-11-11 13:58:34 -0800 | [diff] [blame] | 63 | clamp_t(int64_t, (int64_t) dc->writeback_rate.rate + change, |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 64 | 1, NSEC_PER_MSEC); |
Kent Overstreet | 16749c2 | 2013-11-11 13:58:34 -0800 | [diff] [blame] | 65 | |
| 66 | dc->writeback_rate_proportional = proportional; |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 67 | dc->writeback_rate_derivative = derivative; |
| 68 | dc->writeback_rate_change = change; |
| 69 | dc->writeback_rate_target = target; |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 70 | } |
| 71 | |
| 72 | static void update_writeback_rate(struct work_struct *work) |
| 73 | { |
| 74 | struct cached_dev *dc = container_of(to_delayed_work(work), |
| 75 | struct cached_dev, |
| 76 | writeback_rate_update); |
| 77 | |
| 78 | down_read(&dc->writeback_lock); |
| 79 | |
| 80 | if (atomic_read(&dc->has_dirty) && |
| 81 | dc->writeback_percent) |
| 82 | __update_writeback_rate(dc); |
| 83 | |
| 84 | up_read(&dc->writeback_lock); |
Kent Overstreet | 5e6926d | 2013-07-24 17:50:06 -0700 | [diff] [blame] | 85 | |
| 86 | schedule_delayed_work(&dc->writeback_rate_update, |
| 87 | dc->writeback_rate_update_seconds * HZ); |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 88 | } |
| 89 | |
| 90 | static unsigned writeback_delay(struct cached_dev *dc, unsigned sectors) |
| 91 | { |
Kent Overstreet | c4d951d | 2013-08-21 17:49:09 -0700 | [diff] [blame] | 92 | if (test_bit(BCACHE_DEV_DETACHING, &dc->disk.flags) || |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 93 | !dc->writeback_percent) |
| 94 | return 0; |
| 95 | |
Kent Overstreet | 16749c2 | 2013-11-11 13:58:34 -0800 | [diff] [blame] | 96 | return bch_next_delay(&dc->writeback_rate, sectors); |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 97 | } |
| 98 | |
Kent Overstreet | 5e6926d | 2013-07-24 17:50:06 -0700 | [diff] [blame] | 99 | struct dirty_io { |
| 100 | struct closure cl; |
| 101 | struct cached_dev *dc; |
| 102 | struct bio bio; |
| 103 | }; |
Kent Overstreet | 72c2706 | 2013-06-05 06:24:39 -0700 | [diff] [blame] | 104 | |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 105 | static void dirty_init(struct keybuf_key *w) |
| 106 | { |
| 107 | struct dirty_io *io = w->private; |
| 108 | struct bio *bio = &io->bio; |
| 109 | |
| 110 | bio_init(bio); |
| 111 | if (!io->dc->writeback_percent) |
| 112 | bio_set_prio(bio, IOPRIO_PRIO_VALUE(IOPRIO_CLASS_IDLE, 0)); |
| 113 | |
Kent Overstreet | 4f024f3 | 2013-10-11 15:44:27 -0700 | [diff] [blame] | 114 | bio->bi_iter.bi_size = KEY_SIZE(&w->key) << 9; |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 115 | bio->bi_max_vecs = DIV_ROUND_UP(KEY_SIZE(&w->key), PAGE_SECTORS); |
| 116 | bio->bi_private = w; |
| 117 | bio->bi_io_vec = bio->bi_inline_vecs; |
Kent Overstreet | 169ef1c | 2013-03-28 12:50:55 -0600 | [diff] [blame] | 118 | bch_bio_map(bio, NULL); |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 119 | } |
| 120 | |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 121 | static void dirty_io_destructor(struct closure *cl) |
| 122 | { |
| 123 | struct dirty_io *io = container_of(cl, struct dirty_io, cl); |
| 124 | kfree(io); |
| 125 | } |
| 126 | |
| 127 | static void write_dirty_finish(struct closure *cl) |
| 128 | { |
| 129 | struct dirty_io *io = container_of(cl, struct dirty_io, cl); |
| 130 | struct keybuf_key *w = io->bio.bi_private; |
| 131 | struct cached_dev *dc = io->dc; |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 132 | |
Guoqing Jiang | 491221f | 2016-09-22 03:10:01 -0400 | [diff] [blame] | 133 | bio_free_pages(&io->bio); |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 134 | |
| 135 | /* This is kind of a dumb way of signalling errors. */ |
| 136 | if (KEY_DIRTY(&w->key)) { |
Kent Overstreet | 6054c6d | 2013-07-24 18:06:22 -0700 | [diff] [blame] | 137 | int ret; |
Kent Overstreet | cc7b881 | 2013-07-24 18:07:22 -0700 | [diff] [blame] | 138 | unsigned i; |
| 139 | struct keylist keys; |
Kent Overstreet | 0b93207 | 2013-07-24 17:26:51 -0700 | [diff] [blame] | 140 | |
Kent Overstreet | 0b93207 | 2013-07-24 17:26:51 -0700 | [diff] [blame] | 141 | bch_keylist_init(&keys); |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 142 | |
Kent Overstreet | 1b207d8 | 2013-09-10 18:52:54 -0700 | [diff] [blame] | 143 | bkey_copy(keys.top, &w->key); |
| 144 | SET_KEY_DIRTY(keys.top, false); |
| 145 | bch_keylist_push(&keys); |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 146 | |
| 147 | for (i = 0; i < KEY_PTRS(&w->key); i++) |
| 148 | atomic_inc(&PTR_BUCKET(dc->disk.c, &w->key, i)->pin); |
| 149 | |
Kent Overstreet | cc7b881 | 2013-07-24 18:07:22 -0700 | [diff] [blame] | 150 | ret = bch_btree_insert(dc->disk.c, &keys, NULL, &w->key); |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 151 | |
Kent Overstreet | 6054c6d | 2013-07-24 18:06:22 -0700 | [diff] [blame] | 152 | if (ret) |
Kent Overstreet | c37511b | 2013-04-26 15:39:55 -0700 | [diff] [blame] | 153 | trace_bcache_writeback_collision(&w->key); |
| 154 | |
Kent Overstreet | 6054c6d | 2013-07-24 18:06:22 -0700 | [diff] [blame] | 155 | atomic_long_inc(ret |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 156 | ? &dc->disk.c->writeback_keys_failed |
| 157 | : &dc->disk.c->writeback_keys_done); |
| 158 | } |
| 159 | |
| 160 | bch_keybuf_del(&dc->writeback_keys, w); |
Kent Overstreet | c2a4f31 | 2013-09-23 23:17:31 -0700 | [diff] [blame] | 161 | up(&dc->in_flight); |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 162 | |
| 163 | closure_return_with_destructor(cl, dirty_io_destructor); |
| 164 | } |
| 165 | |
Christoph Hellwig | 4246a0b | 2015-07-20 15:29:37 +0200 | [diff] [blame] | 166 | static void dirty_endio(struct bio *bio) |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 167 | { |
| 168 | struct keybuf_key *w = bio->bi_private; |
| 169 | struct dirty_io *io = w->private; |
| 170 | |
Christoph Hellwig | 4246a0b | 2015-07-20 15:29:37 +0200 | [diff] [blame] | 171 | if (bio->bi_error) |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 172 | SET_KEY_DIRTY(&w->key, false); |
| 173 | |
| 174 | closure_put(&io->cl); |
| 175 | } |
| 176 | |
| 177 | static void write_dirty(struct closure *cl) |
| 178 | { |
| 179 | struct dirty_io *io = container_of(cl, struct dirty_io, cl); |
| 180 | struct keybuf_key *w = io->bio.bi_private; |
| 181 | |
| 182 | dirty_init(w); |
Mike Christie | ad0d9e7 | 2016-06-05 14:32:05 -0500 | [diff] [blame] | 183 | bio_set_op_attrs(&io->bio, REQ_OP_WRITE, 0); |
Kent Overstreet | 4f024f3 | 2013-10-11 15:44:27 -0700 | [diff] [blame] | 184 | io->bio.bi_iter.bi_sector = KEY_START(&w->key); |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 185 | io->bio.bi_bdev = io->dc->bdev; |
| 186 | io->bio.bi_end_io = dirty_endio; |
| 187 | |
Kent Overstreet | 749b61d | 2013-11-23 23:11:25 -0800 | [diff] [blame] | 188 | closure_bio_submit(&io->bio, cl); |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 189 | |
Tang Junhui | 57aa1a69 | 2017-09-06 14:25:59 +0800 | [diff] [blame] | 190 | continue_at(cl, write_dirty_finish, io->dc->writeback_write_wq); |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 191 | } |
| 192 | |
Christoph Hellwig | 4246a0b | 2015-07-20 15:29:37 +0200 | [diff] [blame] | 193 | static void read_dirty_endio(struct bio *bio) |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 194 | { |
| 195 | struct keybuf_key *w = bio->bi_private; |
| 196 | struct dirty_io *io = w->private; |
| 197 | |
| 198 | bch_count_io_errors(PTR_CACHE(io->dc->disk.c, &w->key, 0), |
Christoph Hellwig | 4246a0b | 2015-07-20 15:29:37 +0200 | [diff] [blame] | 199 | bio->bi_error, "reading dirty data from cache"); |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 200 | |
Christoph Hellwig | 4246a0b | 2015-07-20 15:29:37 +0200 | [diff] [blame] | 201 | dirty_endio(bio); |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 202 | } |
| 203 | |
| 204 | static void read_dirty_submit(struct closure *cl) |
| 205 | { |
| 206 | struct dirty_io *io = container_of(cl, struct dirty_io, cl); |
| 207 | |
Kent Overstreet | 749b61d | 2013-11-23 23:11:25 -0800 | [diff] [blame] | 208 | closure_bio_submit(&io->bio, cl); |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 209 | |
Tang Junhui | 57aa1a69 | 2017-09-06 14:25:59 +0800 | [diff] [blame] | 210 | continue_at(cl, write_dirty, io->dc->writeback_write_wq); |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 211 | } |
| 212 | |
Kent Overstreet | 5e6926d | 2013-07-24 17:50:06 -0700 | [diff] [blame] | 213 | static void read_dirty(struct cached_dev *dc) |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 214 | { |
Kent Overstreet | 5e6926d | 2013-07-24 17:50:06 -0700 | [diff] [blame] | 215 | unsigned delay = 0; |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 216 | struct keybuf_key *w; |
| 217 | struct dirty_io *io; |
Kent Overstreet | 5e6926d | 2013-07-24 17:50:06 -0700 | [diff] [blame] | 218 | struct closure cl; |
| 219 | |
| 220 | closure_init_stack(&cl); |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 221 | |
| 222 | /* |
| 223 | * XXX: if we error, background writeback just spins. Should use some |
| 224 | * mempools. |
| 225 | */ |
| 226 | |
Kent Overstreet | 5e6926d | 2013-07-24 17:50:06 -0700 | [diff] [blame] | 227 | while (!kthread_should_stop()) { |
Kent Overstreet | 5e6926d | 2013-07-24 17:50:06 -0700 | [diff] [blame] | 228 | |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 229 | w = bch_keybuf_next(&dc->writeback_keys); |
| 230 | if (!w) |
| 231 | break; |
| 232 | |
| 233 | BUG_ON(ptr_stale(dc->disk.c, &w->key, 0)); |
| 234 | |
Kent Overstreet | 5e6926d | 2013-07-24 17:50:06 -0700 | [diff] [blame] | 235 | if (KEY_START(&w->key) != dc->last_read || |
| 236 | jiffies_to_msecs(delay) > 50) |
| 237 | while (!kthread_should_stop() && delay) |
Slava Pestov | 9e5c353 | 2014-05-01 13:48:57 -0700 | [diff] [blame] | 238 | delay = schedule_timeout_interruptible(delay); |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 239 | |
| 240 | dc->last_read = KEY_OFFSET(&w->key); |
| 241 | |
| 242 | io = kzalloc(sizeof(struct dirty_io) + sizeof(struct bio_vec) |
| 243 | * DIV_ROUND_UP(KEY_SIZE(&w->key), PAGE_SECTORS), |
| 244 | GFP_KERNEL); |
| 245 | if (!io) |
| 246 | goto err; |
| 247 | |
| 248 | w->private = io; |
| 249 | io->dc = dc; |
| 250 | |
| 251 | dirty_init(w); |
Mike Christie | ad0d9e7 | 2016-06-05 14:32:05 -0500 | [diff] [blame] | 252 | bio_set_op_attrs(&io->bio, REQ_OP_READ, 0); |
Kent Overstreet | 4f024f3 | 2013-10-11 15:44:27 -0700 | [diff] [blame] | 253 | io->bio.bi_iter.bi_sector = PTR_OFFSET(&w->key, 0); |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 254 | io->bio.bi_bdev = PTR_CACHE(dc->disk.c, |
| 255 | &w->key, 0)->bdev; |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 256 | io->bio.bi_end_io = read_dirty_endio; |
| 257 | |
Kent Overstreet | 8e51e41 | 2013-06-06 18:15:57 -0700 | [diff] [blame] | 258 | if (bio_alloc_pages(&io->bio, GFP_KERNEL)) |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 259 | goto err_free; |
| 260 | |
Kent Overstreet | c37511b | 2013-04-26 15:39:55 -0700 | [diff] [blame] | 261 | trace_bcache_writeback(&w->key); |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 262 | |
Kent Overstreet | c2a4f31 | 2013-09-23 23:17:31 -0700 | [diff] [blame] | 263 | down(&dc->in_flight); |
Kent Overstreet | 5e6926d | 2013-07-24 17:50:06 -0700 | [diff] [blame] | 264 | closure_call(&io->cl, read_dirty_submit, NULL, &cl); |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 265 | |
| 266 | delay = writeback_delay(dc, KEY_SIZE(&w->key)); |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 267 | } |
| 268 | |
| 269 | if (0) { |
| 270 | err_free: |
| 271 | kfree(w->private); |
| 272 | err: |
| 273 | bch_keybuf_del(&dc->writeback_keys, w); |
| 274 | } |
| 275 | |
Kent Overstreet | c2a4f31 | 2013-09-23 23:17:31 -0700 | [diff] [blame] | 276 | /* |
| 277 | * Wait for outstanding writeback IOs to finish (and keybuf slots to be |
| 278 | * freed) before refilling again |
| 279 | */ |
Kent Overstreet | 5e6926d | 2013-07-24 17:50:06 -0700 | [diff] [blame] | 280 | closure_sync(&cl); |
| 281 | } |
| 282 | |
| 283 | /* Scan for dirty data */ |
| 284 | |
| 285 | void bcache_dev_sectors_dirty_add(struct cache_set *c, unsigned inode, |
| 286 | uint64_t offset, int nr_sectors) |
| 287 | { |
| 288 | struct bcache_device *d = c->devices[inode]; |
Kent Overstreet | 48a915a | 2013-10-31 15:43:22 -0700 | [diff] [blame] | 289 | unsigned stripe_offset, stripe, sectors_dirty; |
Kent Overstreet | 5e6926d | 2013-07-24 17:50:06 -0700 | [diff] [blame] | 290 | |
| 291 | if (!d) |
| 292 | return; |
| 293 | |
Kent Overstreet | 48a915a | 2013-10-31 15:43:22 -0700 | [diff] [blame] | 294 | stripe = offset_to_stripe(d, offset); |
Kent Overstreet | 5e6926d | 2013-07-24 17:50:06 -0700 | [diff] [blame] | 295 | stripe_offset = offset & (d->stripe_size - 1); |
| 296 | |
| 297 | while (nr_sectors) { |
| 298 | int s = min_t(unsigned, abs(nr_sectors), |
| 299 | d->stripe_size - stripe_offset); |
| 300 | |
| 301 | if (nr_sectors < 0) |
| 302 | s = -s; |
| 303 | |
Kent Overstreet | 48a915a | 2013-10-31 15:43:22 -0700 | [diff] [blame] | 304 | if (stripe >= d->nr_stripes) |
| 305 | return; |
| 306 | |
| 307 | sectors_dirty = atomic_add_return(s, |
| 308 | d->stripe_sectors_dirty + stripe); |
| 309 | if (sectors_dirty == d->stripe_size) |
| 310 | set_bit(stripe, d->full_dirty_stripes); |
| 311 | else |
| 312 | clear_bit(stripe, d->full_dirty_stripes); |
| 313 | |
Kent Overstreet | 5e6926d | 2013-07-24 17:50:06 -0700 | [diff] [blame] | 314 | nr_sectors -= s; |
| 315 | stripe_offset = 0; |
| 316 | stripe++; |
| 317 | } |
| 318 | } |
| 319 | |
| 320 | static bool dirty_pred(struct keybuf *buf, struct bkey *k) |
| 321 | { |
Kent Overstreet | 627ccd2 | 2015-11-29 18:47:01 -0800 | [diff] [blame] | 322 | struct cached_dev *dc = container_of(buf, struct cached_dev, writeback_keys); |
| 323 | |
| 324 | BUG_ON(KEY_INODE(k) != dc->disk.id); |
| 325 | |
Kent Overstreet | 5e6926d | 2013-07-24 17:50:06 -0700 | [diff] [blame] | 326 | return KEY_DIRTY(k); |
| 327 | } |
| 328 | |
Kent Overstreet | 48a915a | 2013-10-31 15:43:22 -0700 | [diff] [blame] | 329 | static void refill_full_stripes(struct cached_dev *dc) |
Kent Overstreet | 5e6926d | 2013-07-24 17:50:06 -0700 | [diff] [blame] | 330 | { |
Kent Overstreet | 48a915a | 2013-10-31 15:43:22 -0700 | [diff] [blame] | 331 | struct keybuf *buf = &dc->writeback_keys; |
| 332 | unsigned start_stripe, stripe, next_stripe; |
| 333 | bool wrapped = false; |
Kent Overstreet | 5e6926d | 2013-07-24 17:50:06 -0700 | [diff] [blame] | 334 | |
Kent Overstreet | 48a915a | 2013-10-31 15:43:22 -0700 | [diff] [blame] | 335 | stripe = offset_to_stripe(&dc->disk, KEY_OFFSET(&buf->last_scanned)); |
Kent Overstreet | 5e6926d | 2013-07-24 17:50:06 -0700 | [diff] [blame] | 336 | |
Kent Overstreet | 48a915a | 2013-10-31 15:43:22 -0700 | [diff] [blame] | 337 | if (stripe >= dc->disk.nr_stripes) |
| 338 | stripe = 0; |
| 339 | |
| 340 | start_stripe = stripe; |
Kent Overstreet | 5e6926d | 2013-07-24 17:50:06 -0700 | [diff] [blame] | 341 | |
| 342 | while (1) { |
Kent Overstreet | 48a915a | 2013-10-31 15:43:22 -0700 | [diff] [blame] | 343 | stripe = find_next_bit(dc->disk.full_dirty_stripes, |
| 344 | dc->disk.nr_stripes, stripe); |
Kent Overstreet | 5e6926d | 2013-07-24 17:50:06 -0700 | [diff] [blame] | 345 | |
Kent Overstreet | 48a915a | 2013-10-31 15:43:22 -0700 | [diff] [blame] | 346 | if (stripe == dc->disk.nr_stripes) |
| 347 | goto next; |
Kent Overstreet | 5e6926d | 2013-07-24 17:50:06 -0700 | [diff] [blame] | 348 | |
Kent Overstreet | 48a915a | 2013-10-31 15:43:22 -0700 | [diff] [blame] | 349 | next_stripe = find_next_zero_bit(dc->disk.full_dirty_stripes, |
| 350 | dc->disk.nr_stripes, stripe); |
| 351 | |
| 352 | buf->last_scanned = KEY(dc->disk.id, |
| 353 | stripe * dc->disk.stripe_size, 0); |
| 354 | |
| 355 | bch_refill_keybuf(dc->disk.c, buf, |
| 356 | &KEY(dc->disk.id, |
| 357 | next_stripe * dc->disk.stripe_size, 0), |
| 358 | dirty_pred); |
| 359 | |
| 360 | if (array_freelist_empty(&buf->freelist)) |
| 361 | return; |
| 362 | |
| 363 | stripe = next_stripe; |
| 364 | next: |
| 365 | if (wrapped && stripe > start_stripe) |
| 366 | return; |
| 367 | |
| 368 | if (stripe == dc->disk.nr_stripes) { |
| 369 | stripe = 0; |
| 370 | wrapped = true; |
| 371 | } |
Kent Overstreet | 5e6926d | 2013-07-24 17:50:06 -0700 | [diff] [blame] | 372 | } |
| 373 | } |
| 374 | |
Kent Overstreet | 627ccd2 | 2015-11-29 18:47:01 -0800 | [diff] [blame] | 375 | /* |
| 376 | * Returns true if we scanned the entire disk |
| 377 | */ |
Kent Overstreet | 5e6926d | 2013-07-24 17:50:06 -0700 | [diff] [blame] | 378 | static bool refill_dirty(struct cached_dev *dc) |
| 379 | { |
| 380 | struct keybuf *buf = &dc->writeback_keys; |
Kent Overstreet | 627ccd2 | 2015-11-29 18:47:01 -0800 | [diff] [blame] | 381 | struct bkey start = KEY(dc->disk.id, 0, 0); |
Kent Overstreet | 5e6926d | 2013-07-24 17:50:06 -0700 | [diff] [blame] | 382 | struct bkey end = KEY(dc->disk.id, MAX_KEY_OFFSET, 0); |
Kent Overstreet | 627ccd2 | 2015-11-29 18:47:01 -0800 | [diff] [blame] | 383 | struct bkey start_pos; |
| 384 | |
| 385 | /* |
| 386 | * make sure keybuf pos is inside the range for this disk - at bringup |
| 387 | * we might not be attached yet so this disk's inode nr isn't |
| 388 | * initialized then |
| 389 | */ |
| 390 | if (bkey_cmp(&buf->last_scanned, &start) < 0 || |
| 391 | bkey_cmp(&buf->last_scanned, &end) > 0) |
| 392 | buf->last_scanned = start; |
Kent Overstreet | 48a915a | 2013-10-31 15:43:22 -0700 | [diff] [blame] | 393 | |
| 394 | if (dc->partial_stripes_expensive) { |
| 395 | refill_full_stripes(dc); |
| 396 | if (array_freelist_empty(&buf->freelist)) |
| 397 | return false; |
| 398 | } |
Kent Overstreet | 5e6926d | 2013-07-24 17:50:06 -0700 | [diff] [blame] | 399 | |
Kent Overstreet | 627ccd2 | 2015-11-29 18:47:01 -0800 | [diff] [blame] | 400 | start_pos = buf->last_scanned; |
Kent Overstreet | 48a915a | 2013-10-31 15:43:22 -0700 | [diff] [blame] | 401 | bch_refill_keybuf(dc->disk.c, buf, &end, dirty_pred); |
Kent Overstreet | 5e6926d | 2013-07-24 17:50:06 -0700 | [diff] [blame] | 402 | |
Kent Overstreet | 627ccd2 | 2015-11-29 18:47:01 -0800 | [diff] [blame] | 403 | if (bkey_cmp(&buf->last_scanned, &end) < 0) |
| 404 | return false; |
| 405 | |
| 406 | /* |
| 407 | * If we get to the end start scanning again from the beginning, and |
| 408 | * only scan up to where we initially started scanning from: |
| 409 | */ |
| 410 | buf->last_scanned = start; |
| 411 | bch_refill_keybuf(dc->disk.c, buf, &start_pos, dirty_pred); |
| 412 | |
| 413 | return bkey_cmp(&buf->last_scanned, &start_pos) >= 0; |
Kent Overstreet | 5e6926d | 2013-07-24 17:50:06 -0700 | [diff] [blame] | 414 | } |
| 415 | |
| 416 | static int bch_writeback_thread(void *arg) |
| 417 | { |
| 418 | struct cached_dev *dc = arg; |
| 419 | bool searched_full_index; |
| 420 | |
| 421 | while (!kthread_should_stop()) { |
| 422 | down_write(&dc->writeback_lock); |
Coly Li | ee6fcd8 | 2018-02-07 11:41:41 -0800 | [diff] [blame] | 423 | set_current_state(TASK_INTERRUPTIBLE); |
Coly Li | fe45138 | 2018-03-18 17:36:15 -0700 | [diff] [blame] | 424 | /* |
| 425 | * If the bache device is detaching, skip here and continue |
| 426 | * to perform writeback. Otherwise, if no dirty data on cache, |
| 427 | * or there is dirty data on cache but writeback is disabled, |
| 428 | * the writeback thread should sleep here and wait for others |
| 429 | * to wake up it. |
| 430 | */ |
| 431 | if (!test_bit(BCACHE_DEV_DETACHING, &dc->disk.flags) && |
| 432 | (!atomic_read(&dc->has_dirty) || !dc->writeback_running)) { |
Kent Overstreet | 5e6926d | 2013-07-24 17:50:06 -0700 | [diff] [blame] | 433 | up_write(&dc->writeback_lock); |
Kent Overstreet | 5e6926d | 2013-07-24 17:50:06 -0700 | [diff] [blame] | 434 | |
Coly Li | ee6fcd8 | 2018-02-07 11:41:41 -0800 | [diff] [blame] | 435 | if (kthread_should_stop()) { |
| 436 | set_current_state(TASK_RUNNING); |
Kent Overstreet | 5e6926d | 2013-07-24 17:50:06 -0700 | [diff] [blame] | 437 | return 0; |
Coly Li | ee6fcd8 | 2018-02-07 11:41:41 -0800 | [diff] [blame] | 438 | } |
Kent Overstreet | 5e6926d | 2013-07-24 17:50:06 -0700 | [diff] [blame] | 439 | |
Kent Overstreet | 5e6926d | 2013-07-24 17:50:06 -0700 | [diff] [blame] | 440 | schedule(); |
| 441 | continue; |
| 442 | } |
Coly Li | ee6fcd8 | 2018-02-07 11:41:41 -0800 | [diff] [blame] | 443 | set_current_state(TASK_RUNNING); |
Kent Overstreet | 5e6926d | 2013-07-24 17:50:06 -0700 | [diff] [blame] | 444 | |
| 445 | searched_full_index = refill_dirty(dc); |
| 446 | |
| 447 | if (searched_full_index && |
| 448 | RB_EMPTY_ROOT(&dc->writeback_keys.keys)) { |
| 449 | atomic_set(&dc->has_dirty, 0); |
| 450 | cached_dev_put(dc); |
| 451 | SET_BDEV_STATE(&dc->sb, BDEV_STATE_CLEAN); |
| 452 | bch_write_bdev_super(dc, NULL); |
Coly Li | fe45138 | 2018-03-18 17:36:15 -0700 | [diff] [blame] | 453 | /* |
| 454 | * If bcache device is detaching via sysfs interface, |
| 455 | * writeback thread should stop after there is no dirty |
| 456 | * data on cache. BCACHE_DEV_DETACHING flag is set in |
| 457 | * bch_cached_dev_detach(). |
| 458 | */ |
| 459 | if (test_bit(BCACHE_DEV_DETACHING, &dc->disk.flags)) |
| 460 | break; |
Kent Overstreet | 5e6926d | 2013-07-24 17:50:06 -0700 | [diff] [blame] | 461 | } |
| 462 | |
| 463 | up_write(&dc->writeback_lock); |
| 464 | |
| 465 | bch_ratelimit_reset(&dc->writeback_rate); |
| 466 | read_dirty(dc); |
| 467 | |
| 468 | if (searched_full_index) { |
| 469 | unsigned delay = dc->writeback_delay * HZ; |
| 470 | |
| 471 | while (delay && |
| 472 | !kthread_should_stop() && |
Kent Overstreet | c4d951d | 2013-08-21 17:49:09 -0700 | [diff] [blame] | 473 | !test_bit(BCACHE_DEV_DETACHING, &dc->disk.flags)) |
Slava Pestov | 9e5c353 | 2014-05-01 13:48:57 -0700 | [diff] [blame] | 474 | delay = schedule_timeout_interruptible(delay); |
Kent Overstreet | 5e6926d | 2013-07-24 17:50:06 -0700 | [diff] [blame] | 475 | } |
| 476 | } |
| 477 | |
| 478 | return 0; |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 479 | } |
| 480 | |
Kent Overstreet | 444fc0b | 2013-05-11 17:07:26 -0700 | [diff] [blame] | 481 | /* Init */ |
| 482 | |
Kent Overstreet | c18536a | 2013-07-24 17:44:17 -0700 | [diff] [blame] | 483 | struct sectors_dirty_init { |
| 484 | struct btree_op op; |
| 485 | unsigned inode; |
| 486 | }; |
| 487 | |
| 488 | static int sectors_dirty_init_fn(struct btree_op *_op, struct btree *b, |
Kent Overstreet | 48dad8b | 2013-09-10 18:48:51 -0700 | [diff] [blame] | 489 | struct bkey *k) |
Kent Overstreet | 444fc0b | 2013-05-11 17:07:26 -0700 | [diff] [blame] | 490 | { |
Kent Overstreet | c18536a | 2013-07-24 17:44:17 -0700 | [diff] [blame] | 491 | struct sectors_dirty_init *op = container_of(_op, |
| 492 | struct sectors_dirty_init, op); |
Kent Overstreet | 48dad8b | 2013-09-10 18:48:51 -0700 | [diff] [blame] | 493 | if (KEY_INODE(k) > op->inode) |
| 494 | return MAP_DONE; |
Kent Overstreet | 444fc0b | 2013-05-11 17:07:26 -0700 | [diff] [blame] | 495 | |
Kent Overstreet | 48dad8b | 2013-09-10 18:48:51 -0700 | [diff] [blame] | 496 | if (KEY_DIRTY(k)) |
| 497 | bcache_dev_sectors_dirty_add(b->c, KEY_INODE(k), |
| 498 | KEY_START(k), KEY_SIZE(k)); |
Kent Overstreet | 444fc0b | 2013-05-11 17:07:26 -0700 | [diff] [blame] | 499 | |
Kent Overstreet | 48dad8b | 2013-09-10 18:48:51 -0700 | [diff] [blame] | 500 | return MAP_CONTINUE; |
Kent Overstreet | 444fc0b | 2013-05-11 17:07:26 -0700 | [diff] [blame] | 501 | } |
| 502 | |
Tang Junhui | 2a9b557 | 2017-09-07 01:28:53 +0800 | [diff] [blame] | 503 | void bch_sectors_dirty_init(struct bcache_device *d) |
Kent Overstreet | 444fc0b | 2013-05-11 17:07:26 -0700 | [diff] [blame] | 504 | { |
Kent Overstreet | c18536a | 2013-07-24 17:44:17 -0700 | [diff] [blame] | 505 | struct sectors_dirty_init op; |
Kent Overstreet | 444fc0b | 2013-05-11 17:07:26 -0700 | [diff] [blame] | 506 | |
Kent Overstreet | b54d693 | 2013-07-24 18:04:18 -0700 | [diff] [blame] | 507 | bch_btree_op_init(&op.op, -1); |
Tang Junhui | 2a9b557 | 2017-09-07 01:28:53 +0800 | [diff] [blame] | 508 | op.inode = d->id; |
Kent Overstreet | 48dad8b | 2013-09-10 18:48:51 -0700 | [diff] [blame] | 509 | |
Tang Junhui | 2a9b557 | 2017-09-07 01:28:53 +0800 | [diff] [blame] | 510 | bch_btree_map_keys(&op.op, d->c, &KEY(op.inode, 0, 0), |
Kent Overstreet | 48dad8b | 2013-09-10 18:48:51 -0700 | [diff] [blame] | 511 | sectors_dirty_init_fn, 0); |
Kent Overstreet | 16749c2 | 2013-11-11 13:58:34 -0800 | [diff] [blame] | 512 | |
Tang Junhui | 2a9b557 | 2017-09-07 01:28:53 +0800 | [diff] [blame] | 513 | d->sectors_dirty_last = bcache_dev_sectors_dirty(d); |
Kent Overstreet | 444fc0b | 2013-05-11 17:07:26 -0700 | [diff] [blame] | 514 | } |
| 515 | |
Slava Pestov | 9e5c353 | 2014-05-01 13:48:57 -0700 | [diff] [blame] | 516 | void bch_cached_dev_writeback_init(struct cached_dev *dc) |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 517 | { |
Kent Overstreet | c2a4f31 | 2013-09-23 23:17:31 -0700 | [diff] [blame] | 518 | sema_init(&dc->in_flight, 64); |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 519 | init_rwsem(&dc->writeback_lock); |
Kent Overstreet | 72c2706 | 2013-06-05 06:24:39 -0700 | [diff] [blame] | 520 | bch_keybuf_init(&dc->writeback_keys); |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 521 | |
| 522 | dc->writeback_metadata = true; |
| 523 | dc->writeback_running = true; |
| 524 | dc->writeback_percent = 10; |
| 525 | dc->writeback_delay = 30; |
| 526 | dc->writeback_rate.rate = 1024; |
| 527 | |
Kent Overstreet | 16749c2 | 2013-11-11 13:58:34 -0800 | [diff] [blame] | 528 | dc->writeback_rate_update_seconds = 5; |
| 529 | dc->writeback_rate_d_term = 30; |
| 530 | dc->writeback_rate_p_term_inverse = 6000; |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 531 | |
Slava Pestov | 9e5c353 | 2014-05-01 13:48:57 -0700 | [diff] [blame] | 532 | INIT_DELAYED_WORK(&dc->writeback_rate_update, update_writeback_rate); |
| 533 | } |
| 534 | |
| 535 | int bch_cached_dev_writeback_start(struct cached_dev *dc) |
| 536 | { |
Tang Junhui | 57aa1a69 | 2017-09-06 14:25:59 +0800 | [diff] [blame] | 537 | dc->writeback_write_wq = alloc_workqueue("bcache_writeback_wq", |
| 538 | WQ_MEM_RECLAIM, 0); |
| 539 | if (!dc->writeback_write_wq) |
| 540 | return -ENOMEM; |
| 541 | |
Kent Overstreet | 5e6926d | 2013-07-24 17:50:06 -0700 | [diff] [blame] | 542 | dc->writeback_thread = kthread_create(bch_writeback_thread, dc, |
| 543 | "bcache_writeback"); |
| 544 | if (IS_ERR(dc->writeback_thread)) |
| 545 | return PTR_ERR(dc->writeback_thread); |
| 546 | |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 547 | schedule_delayed_work(&dc->writeback_rate_update, |
| 548 | dc->writeback_rate_update_seconds * HZ); |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 549 | |
Slava Pestov | 9e5c353 | 2014-05-01 13:48:57 -0700 | [diff] [blame] | 550 | bch_writeback_queue(dc); |
| 551 | |
Kent Overstreet | cafe563 | 2013-03-23 16:11:31 -0700 | [diff] [blame] | 552 | return 0; |
| 553 | } |