| 1 | // SPDX-License-Identifier: GPL-2.0+ |
| 2 | /* |
| 3 | * NILFS segment buffer |
| 4 | * |
| 5 | * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation. |
| 6 | * |
| 7 | * Written by Ryusuke Konishi. |
| 8 | * |
| 9 | */ |
| 10 | |
| 11 | #include <linux/buffer_head.h> |
| 12 | #include <linux/writeback.h> |
| 13 | #include <linux/crc32.h> |
| 14 | #include <linux/backing-dev.h> |
| 15 | #include <linux/slab.h> |
| 16 | #include "page.h" |
| 17 | #include "segbuf.h" |
| 18 | |
| 19 | |
| 20 | struct nilfs_write_info { |
| 21 | struct the_nilfs *nilfs; |
| 22 | struct bio *bio; |
| 23 | int start, end; /* The region to be submitted */ |
| 24 | int rest_blocks; |
| 25 | int max_pages; |
| 26 | int nr_vecs; |
| 27 | sector_t blocknr; |
| 28 | }; |
| 29 | |
| 30 | static int nilfs_segbuf_write(struct nilfs_segment_buffer *segbuf, |
| 31 | struct the_nilfs *nilfs); |
| 32 | static int nilfs_segbuf_wait(struct nilfs_segment_buffer *segbuf); |
| 33 | |
| 34 | struct nilfs_segment_buffer *nilfs_segbuf_new(struct super_block *sb) |
| 35 | { |
| 36 | struct nilfs_segment_buffer *segbuf; |
| 37 | |
| 38 | segbuf = kmem_cache_alloc(nilfs_segbuf_cachep, GFP_NOFS); |
| 39 | if (unlikely(!segbuf)) |
| 40 | return NULL; |
| 41 | |
| 42 | segbuf->sb_super = sb; |
| 43 | INIT_LIST_HEAD(&segbuf->sb_list); |
| 44 | INIT_LIST_HEAD(&segbuf->sb_segsum_buffers); |
| 45 | INIT_LIST_HEAD(&segbuf->sb_payload_buffers); |
| 46 | segbuf->sb_super_root = NULL; |
| 47 | |
| 48 | init_completion(&segbuf->sb_bio_event); |
| 49 | atomic_set(&segbuf->sb_err, 0); |
| 50 | segbuf->sb_nbio = 0; |
| 51 | |
| 52 | return segbuf; |
| 53 | } |
| 54 | |
| 55 | void nilfs_segbuf_free(struct nilfs_segment_buffer *segbuf) |
| 56 | { |
| 57 | kmem_cache_free(nilfs_segbuf_cachep, segbuf); |
| 58 | } |
| 59 | |
| 60 | void nilfs_segbuf_map(struct nilfs_segment_buffer *segbuf, __u64 segnum, |
| 61 | unsigned long offset, struct the_nilfs *nilfs) |
| 62 | { |
| 63 | segbuf->sb_segnum = segnum; |
| 64 | nilfs_get_segment_range(nilfs, segnum, &segbuf->sb_fseg_start, |
| 65 | &segbuf->sb_fseg_end); |
| 66 | |
| 67 | segbuf->sb_pseg_start = segbuf->sb_fseg_start + offset; |
| 68 | segbuf->sb_rest_blocks = |
| 69 | segbuf->sb_fseg_end - segbuf->sb_pseg_start + 1; |
| 70 | } |
| 71 | |
| 72 | /** |
| 73 | * nilfs_segbuf_map_cont - map a new log behind a given log |
| 74 | * @segbuf: new segment buffer |
| 75 | * @prev: segment buffer containing a log to be continued |
| 76 | */ |
| 77 | void nilfs_segbuf_map_cont(struct nilfs_segment_buffer *segbuf, |
| 78 | struct nilfs_segment_buffer *prev) |
| 79 | { |
| 80 | segbuf->sb_segnum = prev->sb_segnum; |
| 81 | segbuf->sb_fseg_start = prev->sb_fseg_start; |
| 82 | segbuf->sb_fseg_end = prev->sb_fseg_end; |
| 83 | segbuf->sb_pseg_start = prev->sb_pseg_start + prev->sb_sum.nblocks; |
| 84 | segbuf->sb_rest_blocks = |
| 85 | segbuf->sb_fseg_end - segbuf->sb_pseg_start + 1; |
| 86 | } |
| 87 | |
| 88 | void nilfs_segbuf_set_next_segnum(struct nilfs_segment_buffer *segbuf, |
| 89 | __u64 nextnum, struct the_nilfs *nilfs) |
| 90 | { |
| 91 | segbuf->sb_nextnum = nextnum; |
| 92 | segbuf->sb_sum.next = nilfs_get_segment_start_blocknr(nilfs, nextnum); |
| 93 | } |
| 94 | |
| 95 | int nilfs_segbuf_extend_segsum(struct nilfs_segment_buffer *segbuf) |
| 96 | { |
| 97 | struct buffer_head *bh; |
| 98 | |
| 99 | bh = sb_getblk(segbuf->sb_super, |
| 100 | segbuf->sb_pseg_start + segbuf->sb_sum.nsumblk); |
| 101 | if (unlikely(!bh)) |
| 102 | return -ENOMEM; |
| 103 | |
| 104 | lock_buffer(bh); |
| 105 | if (!buffer_uptodate(bh)) { |
| 106 | memset(bh->b_data, 0, bh->b_size); |
| 107 | set_buffer_uptodate(bh); |
| 108 | } |
| 109 | unlock_buffer(bh); |
| 110 | nilfs_segbuf_add_segsum_buffer(segbuf, bh); |
| 111 | return 0; |
| 112 | } |
| 113 | |
| 114 | int nilfs_segbuf_extend_payload(struct nilfs_segment_buffer *segbuf, |
| 115 | struct buffer_head **bhp) |
| 116 | { |
| 117 | struct buffer_head *bh; |
| 118 | |
| 119 | bh = sb_getblk(segbuf->sb_super, |
| 120 | segbuf->sb_pseg_start + segbuf->sb_sum.nblocks); |
| 121 | if (unlikely(!bh)) |
| 122 | return -ENOMEM; |
| 123 | |
| 124 | nilfs_segbuf_add_payload_buffer(segbuf, bh); |
| 125 | *bhp = bh; |
| 126 | return 0; |
| 127 | } |
| 128 | |
| 129 | int nilfs_segbuf_reset(struct nilfs_segment_buffer *segbuf, unsigned int flags, |
| 130 | time64_t ctime, __u64 cno) |
| 131 | { |
| 132 | int err; |
| 133 | |
| 134 | segbuf->sb_sum.nblocks = segbuf->sb_sum.nsumblk = 0; |
| 135 | err = nilfs_segbuf_extend_segsum(segbuf); |
| 136 | if (unlikely(err)) |
| 137 | return err; |
| 138 | |
| 139 | segbuf->sb_sum.flags = flags; |
| 140 | segbuf->sb_sum.sumbytes = sizeof(struct nilfs_segment_summary); |
| 141 | segbuf->sb_sum.nfinfo = segbuf->sb_sum.nfileblk = 0; |
| 142 | segbuf->sb_sum.ctime = ctime; |
| 143 | segbuf->sb_sum.cno = cno; |
| 144 | return 0; |
| 145 | } |
| 146 | |
| 147 | /* |
| 148 | * Setup segment summary |
| 149 | */ |
| 150 | void nilfs_segbuf_fill_in_segsum(struct nilfs_segment_buffer *segbuf) |
| 151 | { |
| 152 | struct nilfs_segment_summary *raw_sum; |
| 153 | struct buffer_head *bh_sum; |
| 154 | |
| 155 | bh_sum = list_entry(segbuf->sb_segsum_buffers.next, |
| 156 | struct buffer_head, b_assoc_buffers); |
| 157 | raw_sum = (struct nilfs_segment_summary *)bh_sum->b_data; |
| 158 | |
| 159 | raw_sum->ss_magic = cpu_to_le32(NILFS_SEGSUM_MAGIC); |
| 160 | raw_sum->ss_bytes = cpu_to_le16(sizeof(*raw_sum)); |
| 161 | raw_sum->ss_flags = cpu_to_le16(segbuf->sb_sum.flags); |
| 162 | raw_sum->ss_seq = cpu_to_le64(segbuf->sb_sum.seg_seq); |
| 163 | raw_sum->ss_create = cpu_to_le64(segbuf->sb_sum.ctime); |
| 164 | raw_sum->ss_next = cpu_to_le64(segbuf->sb_sum.next); |
| 165 | raw_sum->ss_nblocks = cpu_to_le32(segbuf->sb_sum.nblocks); |
| 166 | raw_sum->ss_nfinfo = cpu_to_le32(segbuf->sb_sum.nfinfo); |
| 167 | raw_sum->ss_sumbytes = cpu_to_le32(segbuf->sb_sum.sumbytes); |
| 168 | raw_sum->ss_pad = 0; |
| 169 | raw_sum->ss_cno = cpu_to_le64(segbuf->sb_sum.cno); |
| 170 | } |
| 171 | |
| 172 | /* |
| 173 | * CRC calculation routines |
| 174 | */ |
| 175 | static void |
| 176 | nilfs_segbuf_fill_in_segsum_crc(struct nilfs_segment_buffer *segbuf, u32 seed) |
| 177 | { |
| 178 | struct buffer_head *bh; |
| 179 | struct nilfs_segment_summary *raw_sum; |
| 180 | unsigned long size, bytes = segbuf->sb_sum.sumbytes; |
| 181 | u32 crc; |
| 182 | |
| 183 | bh = list_entry(segbuf->sb_segsum_buffers.next, struct buffer_head, |
| 184 | b_assoc_buffers); |
| 185 | |
| 186 | raw_sum = (struct nilfs_segment_summary *)bh->b_data; |
| 187 | size = min_t(unsigned long, bytes, bh->b_size); |
| 188 | crc = crc32_le(seed, |
| 189 | (unsigned char *)raw_sum + |
| 190 | sizeof(raw_sum->ss_datasum) + sizeof(raw_sum->ss_sumsum), |
| 191 | size - (sizeof(raw_sum->ss_datasum) + |
| 192 | sizeof(raw_sum->ss_sumsum))); |
| 193 | |
| 194 | list_for_each_entry_continue(bh, &segbuf->sb_segsum_buffers, |
| 195 | b_assoc_buffers) { |
| 196 | bytes -= size; |
| 197 | size = min_t(unsigned long, bytes, bh->b_size); |
| 198 | crc = crc32_le(crc, bh->b_data, size); |
| 199 | } |
| 200 | raw_sum->ss_sumsum = cpu_to_le32(crc); |
| 201 | } |
| 202 | |
| 203 | static void nilfs_segbuf_fill_in_data_crc(struct nilfs_segment_buffer *segbuf, |
| 204 | u32 seed) |
| 205 | { |
| 206 | struct buffer_head *bh; |
| 207 | struct nilfs_segment_summary *raw_sum; |
| 208 | void *kaddr; |
| 209 | u32 crc; |
| 210 | |
| 211 | bh = list_entry(segbuf->sb_segsum_buffers.next, struct buffer_head, |
| 212 | b_assoc_buffers); |
| 213 | raw_sum = (struct nilfs_segment_summary *)bh->b_data; |
| 214 | crc = crc32_le(seed, |
| 215 | (unsigned char *)raw_sum + sizeof(raw_sum->ss_datasum), |
| 216 | bh->b_size - sizeof(raw_sum->ss_datasum)); |
| 217 | |
| 218 | list_for_each_entry_continue(bh, &segbuf->sb_segsum_buffers, |
| 219 | b_assoc_buffers) { |
| 220 | crc = crc32_le(crc, bh->b_data, bh->b_size); |
| 221 | } |
| 222 | list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) { |
| 223 | kaddr = kmap_local_page(bh->b_page); |
| 224 | crc = crc32_le(crc, kaddr + bh_offset(bh), bh->b_size); |
| 225 | kunmap_local(kaddr); |
| 226 | } |
| 227 | raw_sum->ss_datasum = cpu_to_le32(crc); |
| 228 | } |
| 229 | |
| 230 | static void |
| 231 | nilfs_segbuf_fill_in_super_root_crc(struct nilfs_segment_buffer *segbuf, |
| 232 | u32 seed) |
| 233 | { |
| 234 | struct nilfs_super_root *raw_sr; |
| 235 | struct the_nilfs *nilfs = segbuf->sb_super->s_fs_info; |
| 236 | unsigned int srsize; |
| 237 | u32 crc; |
| 238 | |
| 239 | raw_sr = (struct nilfs_super_root *)segbuf->sb_super_root->b_data; |
| 240 | srsize = NILFS_SR_BYTES(nilfs->ns_inode_size); |
| 241 | crc = crc32_le(seed, |
| 242 | (unsigned char *)raw_sr + sizeof(raw_sr->sr_sum), |
| 243 | srsize - sizeof(raw_sr->sr_sum)); |
| 244 | raw_sr->sr_sum = cpu_to_le32(crc); |
| 245 | } |
| 246 | |
| 247 | static void nilfs_release_buffers(struct list_head *list) |
| 248 | { |
| 249 | struct buffer_head *bh, *n; |
| 250 | |
| 251 | list_for_each_entry_safe(bh, n, list, b_assoc_buffers) { |
| 252 | list_del_init(&bh->b_assoc_buffers); |
| 253 | brelse(bh); |
| 254 | } |
| 255 | } |
| 256 | |
| 257 | static void nilfs_segbuf_clear(struct nilfs_segment_buffer *segbuf) |
| 258 | { |
| 259 | nilfs_release_buffers(&segbuf->sb_segsum_buffers); |
| 260 | nilfs_release_buffers(&segbuf->sb_payload_buffers); |
| 261 | segbuf->sb_super_root = NULL; |
| 262 | } |
| 263 | |
| 264 | /* |
| 265 | * Iterators for segment buffers |
| 266 | */ |
| 267 | void nilfs_clear_logs(struct list_head *logs) |
| 268 | { |
| 269 | struct nilfs_segment_buffer *segbuf; |
| 270 | |
| 271 | list_for_each_entry(segbuf, logs, sb_list) |
| 272 | nilfs_segbuf_clear(segbuf); |
| 273 | } |
| 274 | |
| 275 | void nilfs_truncate_logs(struct list_head *logs, |
| 276 | struct nilfs_segment_buffer *last) |
| 277 | { |
| 278 | struct nilfs_segment_buffer *n, *segbuf; |
| 279 | |
| 280 | segbuf = list_prepare_entry(last, logs, sb_list); |
| 281 | list_for_each_entry_safe_continue(segbuf, n, logs, sb_list) { |
| 282 | list_del_init(&segbuf->sb_list); |
| 283 | nilfs_segbuf_clear(segbuf); |
| 284 | nilfs_segbuf_free(segbuf); |
| 285 | } |
| 286 | } |
| 287 | |
| 288 | int nilfs_write_logs(struct list_head *logs, struct the_nilfs *nilfs) |
| 289 | { |
| 290 | struct nilfs_segment_buffer *segbuf; |
| 291 | int ret = 0; |
| 292 | |
| 293 | list_for_each_entry(segbuf, logs, sb_list) { |
| 294 | ret = nilfs_segbuf_write(segbuf, nilfs); |
| 295 | if (ret) |
| 296 | break; |
| 297 | } |
| 298 | return ret; |
| 299 | } |
| 300 | |
| 301 | int nilfs_wait_on_logs(struct list_head *logs) |
| 302 | { |
| 303 | struct nilfs_segment_buffer *segbuf; |
| 304 | int err, ret = 0; |
| 305 | |
| 306 | list_for_each_entry(segbuf, logs, sb_list) { |
| 307 | err = nilfs_segbuf_wait(segbuf); |
| 308 | if (err && !ret) |
| 309 | ret = err; |
| 310 | } |
| 311 | return ret; |
| 312 | } |
| 313 | |
| 314 | /** |
| 315 | * nilfs_add_checksums_on_logs - add checksums on the logs |
| 316 | * @logs: list of segment buffers storing target logs |
| 317 | * @seed: checksum seed value |
| 318 | */ |
| 319 | void nilfs_add_checksums_on_logs(struct list_head *logs, u32 seed) |
| 320 | { |
| 321 | struct nilfs_segment_buffer *segbuf; |
| 322 | |
| 323 | list_for_each_entry(segbuf, logs, sb_list) { |
| 324 | if (segbuf->sb_super_root) |
| 325 | nilfs_segbuf_fill_in_super_root_crc(segbuf, seed); |
| 326 | nilfs_segbuf_fill_in_segsum_crc(segbuf, seed); |
| 327 | nilfs_segbuf_fill_in_data_crc(segbuf, seed); |
| 328 | } |
| 329 | } |
| 330 | |
| 331 | /* |
| 332 | * BIO operations |
| 333 | */ |
| 334 | static void nilfs_end_bio_write(struct bio *bio) |
| 335 | { |
| 336 | struct nilfs_segment_buffer *segbuf = bio->bi_private; |
| 337 | |
| 338 | if (bio->bi_status) |
| 339 | atomic_inc(&segbuf->sb_err); |
| 340 | |
| 341 | bio_put(bio); |
| 342 | complete(&segbuf->sb_bio_event); |
| 343 | } |
| 344 | |
| 345 | static int nilfs_segbuf_submit_bio(struct nilfs_segment_buffer *segbuf, |
| 346 | struct nilfs_write_info *wi) |
| 347 | { |
| 348 | struct bio *bio = wi->bio; |
| 349 | |
| 350 | bio->bi_end_io = nilfs_end_bio_write; |
| 351 | bio->bi_private = segbuf; |
| 352 | submit_bio(bio); |
| 353 | segbuf->sb_nbio++; |
| 354 | |
| 355 | wi->bio = NULL; |
| 356 | wi->rest_blocks -= wi->end - wi->start; |
| 357 | wi->nr_vecs = min(wi->max_pages, wi->rest_blocks); |
| 358 | wi->start = wi->end; |
| 359 | return 0; |
| 360 | } |
| 361 | |
| 362 | static void nilfs_segbuf_prepare_write(struct nilfs_segment_buffer *segbuf, |
| 363 | struct nilfs_write_info *wi) |
| 364 | { |
| 365 | wi->bio = NULL; |
| 366 | wi->rest_blocks = segbuf->sb_sum.nblocks; |
| 367 | wi->max_pages = BIO_MAX_VECS; |
| 368 | wi->nr_vecs = min(wi->max_pages, wi->rest_blocks); |
| 369 | wi->start = wi->end = 0; |
| 370 | wi->blocknr = segbuf->sb_pseg_start; |
| 371 | } |
| 372 | |
| 373 | static int nilfs_segbuf_submit_bh(struct nilfs_segment_buffer *segbuf, |
| 374 | struct nilfs_write_info *wi, |
| 375 | struct buffer_head *bh) |
| 376 | { |
| 377 | int len, err; |
| 378 | |
| 379 | BUG_ON(wi->nr_vecs <= 0); |
| 380 | repeat: |
| 381 | if (!wi->bio) { |
| 382 | wi->bio = bio_alloc(wi->nilfs->ns_bdev, wi->nr_vecs, |
| 383 | REQ_OP_WRITE, GFP_NOIO); |
| 384 | wi->bio->bi_iter.bi_sector = (wi->blocknr + wi->end) << |
| 385 | (wi->nilfs->ns_blocksize_bits - 9); |
| 386 | } |
| 387 | |
| 388 | len = bio_add_page(wi->bio, bh->b_page, bh->b_size, bh_offset(bh)); |
| 389 | if (len == bh->b_size) { |
| 390 | wi->end++; |
| 391 | return 0; |
| 392 | } |
| 393 | /* bio is FULL */ |
| 394 | err = nilfs_segbuf_submit_bio(segbuf, wi); |
| 395 | /* never submit current bh */ |
| 396 | if (likely(!err)) |
| 397 | goto repeat; |
| 398 | return err; |
| 399 | } |
| 400 | |
| 401 | /** |
| 402 | * nilfs_segbuf_write - submit write requests of a log |
| 403 | * @segbuf: buffer storing a log to be written |
| 404 | * @nilfs: nilfs object |
| 405 | * |
| 406 | * Return Value: On Success, 0 is returned. On Error, one of the following |
| 407 | * negative error code is returned. |
| 408 | * |
| 409 | * %-EIO - I/O error |
| 410 | * |
| 411 | * %-ENOMEM - Insufficient memory available. |
| 412 | */ |
| 413 | static int nilfs_segbuf_write(struct nilfs_segment_buffer *segbuf, |
| 414 | struct the_nilfs *nilfs) |
| 415 | { |
| 416 | struct nilfs_write_info wi; |
| 417 | struct buffer_head *bh; |
| 418 | int res = 0; |
| 419 | |
| 420 | wi.nilfs = nilfs; |
| 421 | nilfs_segbuf_prepare_write(segbuf, &wi); |
| 422 | |
| 423 | list_for_each_entry(bh, &segbuf->sb_segsum_buffers, b_assoc_buffers) { |
| 424 | res = nilfs_segbuf_submit_bh(segbuf, &wi, bh); |
| 425 | if (unlikely(res)) |
| 426 | goto failed_bio; |
| 427 | } |
| 428 | |
| 429 | list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) { |
| 430 | res = nilfs_segbuf_submit_bh(segbuf, &wi, bh); |
| 431 | if (unlikely(res)) |
| 432 | goto failed_bio; |
| 433 | } |
| 434 | |
| 435 | if (wi.bio) { |
| 436 | /* |
| 437 | * Last BIO is always sent through the following |
| 438 | * submission. |
| 439 | */ |
| 440 | wi.bio->bi_opf |= REQ_SYNC; |
| 441 | res = nilfs_segbuf_submit_bio(segbuf, &wi); |
| 442 | } |
| 443 | |
| 444 | failed_bio: |
| 445 | return res; |
| 446 | } |
| 447 | |
| 448 | /** |
| 449 | * nilfs_segbuf_wait - wait for completion of requested BIOs |
| 450 | * @segbuf: segment buffer |
| 451 | * |
| 452 | * Return Value: On Success, 0 is returned. On Error, one of the following |
| 453 | * negative error code is returned. |
| 454 | * |
| 455 | * %-EIO - I/O error |
| 456 | */ |
| 457 | static int nilfs_segbuf_wait(struct nilfs_segment_buffer *segbuf) |
| 458 | { |
| 459 | int err = 0; |
| 460 | |
| 461 | if (!segbuf->sb_nbio) |
| 462 | return 0; |
| 463 | |
| 464 | do { |
| 465 | wait_for_completion(&segbuf->sb_bio_event); |
| 466 | } while (--segbuf->sb_nbio > 0); |
| 467 | |
| 468 | if (unlikely(atomic_read(&segbuf->sb_err) > 0)) { |
| 469 | nilfs_err(segbuf->sb_super, |
| 470 | "I/O error writing log (start-blocknr=%llu, block-count=%lu) in segment %llu", |
| 471 | (unsigned long long)segbuf->sb_pseg_start, |
| 472 | segbuf->sb_sum.nblocks, |
| 473 | (unsigned long long)segbuf->sb_segnum); |
| 474 | err = -EIO; |
| 475 | } |
| 476 | return err; |
| 477 | } |