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_atomic(bh->b_page); 224 crc = crc32_le(crc, kaddr + bh_offset(bh), bh->b_size); 225 kunmap_atomic(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 } 478