fs/nilfs2/segbuf.c

   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         u32 crc;
 209
 210         bh = list_entry(segbuf->sb_segsum_buffers.next, struct buffer_head,
 211                         b_assoc_buffers);
 212         raw_sum = (struct nilfs_segment_summary *)bh->b_data;
 213         crc = crc32_le(seed,
 214                        (unsigned char *)raw_sum + sizeof(raw_sum->ss_datasum),
 215                        bh->b_size - sizeof(raw_sum->ss_datasum));
 216
 217         list_for_each_entry_continue(bh, &segbuf->sb_segsum_buffers,
 218                                      b_assoc_buffers) {
 219                 crc = crc32_le(crc, bh->b_data, bh->b_size);
 220         }
 221         list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) {
 222                 size_t offset = offset_in_folio(bh->b_folio, bh->b_data);
 223                 unsigned char *from;
 224
 225                 /* Do not support block sizes larger than PAGE_SIZE */
 226                 from = kmap_local_folio(bh->b_folio, offset);
 227                 crc = crc32_le(crc, from, bh->b_size);
 228                 kunmap_local(from);
 229         }
 230         raw_sum->ss_datasum = cpu_to_le32(crc);
 231 }
 232
 233 static void
 234 nilfs_segbuf_fill_in_super_root_crc(struct nilfs_segment_buffer *segbuf,
 235                                     u32 seed)
 236 {
 237         struct nilfs_super_root *raw_sr;
 238         struct the_nilfs *nilfs = segbuf->sb_super->s_fs_info;
 239         unsigned int srsize;
 240         u32 crc;
 241
 242         raw_sr = (struct nilfs_super_root *)segbuf->sb_super_root->b_data;
 243         srsize = NILFS_SR_BYTES(nilfs->ns_inode_size);
 244         crc = crc32_le(seed,
 245                        (unsigned char *)raw_sr + sizeof(raw_sr->sr_sum),
 246                        srsize - sizeof(raw_sr->sr_sum));
 247         raw_sr->sr_sum = cpu_to_le32(crc);
 248 }
 249
 250 static void nilfs_release_buffers(struct list_head *list)
 251 {
 252         struct buffer_head *bh, *n;
 253
 254         list_for_each_entry_safe(bh, n, list, b_assoc_buffers) {
 255                 list_del_init(&bh->b_assoc_buffers);
 256                 brelse(bh);
 257         }
 258 }
 259
 260 static void nilfs_segbuf_clear(struct nilfs_segment_buffer *segbuf)
 261 {
 262         nilfs_release_buffers(&segbuf->sb_segsum_buffers);
 263         nilfs_release_buffers(&segbuf->sb_payload_buffers);
 264         segbuf->sb_super_root = NULL;
 265 }
 266
 267 /*
 268  * Iterators for segment buffers
 269  */
 270 void nilfs_clear_logs(struct list_head *logs)
 271 {
 272         struct nilfs_segment_buffer *segbuf;
 273
 274         list_for_each_entry(segbuf, logs, sb_list)
 275                 nilfs_segbuf_clear(segbuf);
 276 }
 277
 278 void nilfs_truncate_logs(struct list_head *logs,
 279                          struct nilfs_segment_buffer *last)
 280 {
 281         struct nilfs_segment_buffer *n, *segbuf;
 282
 283         segbuf = list_prepare_entry(last, logs, sb_list);
 284         list_for_each_entry_safe_continue(segbuf, n, logs, sb_list) {
 285                 list_del_init(&segbuf->sb_list);
 286                 nilfs_segbuf_clear(segbuf);
 287                 nilfs_segbuf_free(segbuf);
 288         }
 289 }
 290
 291 int nilfs_write_logs(struct list_head *logs, struct the_nilfs *nilfs)
 292 {
 293         struct nilfs_segment_buffer *segbuf;
 294         int ret = 0;
 295
 296         list_for_each_entry(segbuf, logs, sb_list) {
 297                 ret = nilfs_segbuf_write(segbuf, nilfs);
 298                 if (ret)
 299                         break;
 300         }
 301         return ret;
 302 }
 303
 304 int nilfs_wait_on_logs(struct list_head *logs)
 305 {
 306         struct nilfs_segment_buffer *segbuf;
 307         int err, ret = 0;
 308
 309         list_for_each_entry(segbuf, logs, sb_list) {
 310                 err = nilfs_segbuf_wait(segbuf);
 311                 if (err && !ret)
 312                         ret = err;
 313         }
 314         return ret;
 315 }
 316
 317 /**
 318  * nilfs_add_checksums_on_logs - add checksums on the logs
 319  * @logs: list of segment buffers storing target logs
 320  * @seed: checksum seed value
 321  */
 322 void nilfs_add_checksums_on_logs(struct list_head *logs, u32 seed)
 323 {
 324         struct nilfs_segment_buffer *segbuf;
 325
 326         list_for_each_entry(segbuf, logs, sb_list) {
 327                 if (segbuf->sb_super_root)
 328                         nilfs_segbuf_fill_in_super_root_crc(segbuf, seed);
 329                 nilfs_segbuf_fill_in_segsum_crc(segbuf, seed);
 330                 nilfs_segbuf_fill_in_data_crc(segbuf, seed);
 331         }
 332 }
 333
 334 /*
 335  * BIO operations
 336  */
 337 static void nilfs_end_bio_write(struct bio *bio)
 338 {
 339         struct nilfs_segment_buffer *segbuf = bio->bi_private;
 340
 341         if (bio->bi_status)
 342                 atomic_inc(&segbuf->sb_err);
 343
 344         bio_put(bio);
 345         complete(&segbuf->sb_bio_event);
 346 }
 347
 348 static int nilfs_segbuf_submit_bio(struct nilfs_segment_buffer *segbuf,
 349                                    struct nilfs_write_info *wi)
 350 {
 351         struct bio *bio = wi->bio;
 352
 353         bio->bi_end_io = nilfs_end_bio_write;
 354         bio->bi_private = segbuf;
 355         submit_bio(bio);
 356         segbuf->sb_nbio++;
 357
 358         wi->bio = NULL;
 359         wi->rest_blocks -= wi->end - wi->start;
 360         wi->nr_vecs = min(wi->max_pages, wi->rest_blocks);
 361         wi->start = wi->end;
 362         return 0;
 363 }
 364
 365 static void nilfs_segbuf_prepare_write(struct nilfs_segment_buffer *segbuf,
 366                                        struct nilfs_write_info *wi)
 367 {
 368         wi->bio = NULL;
 369         wi->rest_blocks = segbuf->sb_sum.nblocks;
 370         wi->max_pages = BIO_MAX_VECS;
 371         wi->nr_vecs = min(wi->max_pages, wi->rest_blocks);
 372         wi->start = wi->end = 0;
 373         wi->blocknr = segbuf->sb_pseg_start;
 374 }
 375
 376 static int nilfs_segbuf_submit_bh(struct nilfs_segment_buffer *segbuf,
 377                                   struct nilfs_write_info *wi,
 378                                   struct buffer_head *bh)
 379 {
 380         int err;
 381
 382         BUG_ON(wi->nr_vecs <= 0);
 383  repeat:
 384         if (!wi->bio) {
 385                 wi->bio = bio_alloc(wi->nilfs->ns_bdev, wi->nr_vecs,
 386                                     REQ_OP_WRITE, GFP_NOIO);
 387                 wi->bio->bi_iter.bi_sector = (wi->blocknr + wi->end) <<
 388                         (wi->nilfs->ns_blocksize_bits - 9);
 389         }
 390
 391         if (bio_add_folio(wi->bio, bh->b_folio, bh->b_size,
 392                           offset_in_folio(bh->b_folio, bh->b_data))) {
 393                 wi->end++;
 394                 return 0;
 395         }
 396         /* bio is FULL */
 397         err = nilfs_segbuf_submit_bio(segbuf, wi);
 398         /* never submit current bh */
 399         if (likely(!err))
 400                 goto repeat;
 401         return err;
 402 }
 403
 404 /**
 405  * nilfs_segbuf_write - submit write requests of a log
 406  * @segbuf: buffer storing a log to be written
 407  * @nilfs: nilfs object
 408  *
 409  * Return Value: On Success, 0 is returned. On Error, one of the following
 410  * negative error code is returned.
 411  *
 412  * %-EIO - I/O error
 413  *
 414  * %-ENOMEM - Insufficient memory available.
 415  */
 416 static int nilfs_segbuf_write(struct nilfs_segment_buffer *segbuf,
 417                               struct the_nilfs *nilfs)
 418 {
 419         struct nilfs_write_info wi;
 420         struct buffer_head *bh;
 421         int res = 0;
 422
 423         wi.nilfs = nilfs;
 424         nilfs_segbuf_prepare_write(segbuf, &wi);
 425
 426         list_for_each_entry(bh, &segbuf->sb_segsum_buffers, b_assoc_buffers) {
 427                 res = nilfs_segbuf_submit_bh(segbuf, &wi, bh);
 428                 if (unlikely(res))
 429                         goto failed_bio;
 430         }
 431
 432         list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) {
 433                 res = nilfs_segbuf_submit_bh(segbuf, &wi, bh);
 434                 if (unlikely(res))
 435                         goto failed_bio;
 436         }
 437
 438         if (wi.bio) {
 439                 /*
 440                  * Last BIO is always sent through the following
 441                  * submission.
 442                  */
 443                 wi.bio->bi_opf |= REQ_SYNC;
 444                 res = nilfs_segbuf_submit_bio(segbuf, &wi);
 445         }
 446
 447  failed_bio:
 448         return res;
 449 }
 450
 451 /**
 452  * nilfs_segbuf_wait - wait for completion of requested BIOs
 453  * @segbuf: segment buffer
 454  *
 455  * Return Value: On Success, 0 is returned. On Error, one of the following
 456  * negative error code is returned.
 457  *
 458  * %-EIO - I/O error
 459  */
 460 static int nilfs_segbuf_wait(struct nilfs_segment_buffer *segbuf)
 461 {
 462         int err = 0;
 463
 464         if (!segbuf->sb_nbio)
 465                 return 0;
 466
 467         do {
 468                 wait_for_completion(&segbuf->sb_bio_event);
 469         } while (--segbuf->sb_nbio > 0);
 470
 471         if (unlikely(atomic_read(&segbuf->sb_err) > 0)) {
 472                 nilfs_err(segbuf->sb_super,
 473                           "I/O error writing log (start-blocknr=%llu, block-count=%lu) in segment %llu",
 474                           (unsigned long long)segbuf->sb_pseg_start,
 475                           segbuf->sb_sum.nblocks,
 476                           (unsigned long long)segbuf->sb_segnum);
 477                 err = -EIO;
 478         }
 479         return err;
 480 }