linux/fs/affs/file.c
<<
>>
Prefs
   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 *  linux/fs/affs/file.c
   4 *
   5 *  (c) 1996  Hans-Joachim Widmaier - Rewritten
   6 *
   7 *  (C) 1993  Ray Burr - Modified for Amiga FFS filesystem.
   8 *
   9 *  (C) 1992  Eric Youngdale Modified for ISO 9660 filesystem.
  10 *
  11 *  (C) 1991  Linus Torvalds - minix filesystem
  12 *
  13 *  affs regular file handling primitives
  14 */
  15
  16#include <linux/uio.h>
  17#include <linux/blkdev.h>
  18#include <linux/mpage.h>
  19#include "affs.h"
  20
  21static struct buffer_head *affs_get_extblock_slow(struct inode *inode, u32 ext);
  22
  23static int
  24affs_file_open(struct inode *inode, struct file *filp)
  25{
  26        pr_debug("open(%lu,%d)\n",
  27                 inode->i_ino, atomic_read(&AFFS_I(inode)->i_opencnt));
  28        atomic_inc(&AFFS_I(inode)->i_opencnt);
  29        return 0;
  30}
  31
  32static int
  33affs_file_release(struct inode *inode, struct file *filp)
  34{
  35        pr_debug("release(%lu, %d)\n",
  36                 inode->i_ino, atomic_read(&AFFS_I(inode)->i_opencnt));
  37
  38        if (atomic_dec_and_test(&AFFS_I(inode)->i_opencnt)) {
  39                inode_lock(inode);
  40                if (inode->i_size != AFFS_I(inode)->mmu_private)
  41                        affs_truncate(inode);
  42                affs_free_prealloc(inode);
  43                inode_unlock(inode);
  44        }
  45
  46        return 0;
  47}
  48
  49static int
  50affs_grow_extcache(struct inode *inode, u32 lc_idx)
  51{
  52        struct super_block      *sb = inode->i_sb;
  53        struct buffer_head      *bh;
  54        u32 lc_max;
  55        int i, j, key;
  56
  57        if (!AFFS_I(inode)->i_lc) {
  58                char *ptr = (char *)get_zeroed_page(GFP_NOFS);
  59                if (!ptr)
  60                        return -ENOMEM;
  61                AFFS_I(inode)->i_lc = (u32 *)ptr;
  62                AFFS_I(inode)->i_ac = (struct affs_ext_key *)(ptr + AFFS_CACHE_SIZE / 2);
  63        }
  64
  65        lc_max = AFFS_LC_SIZE << AFFS_I(inode)->i_lc_shift;
  66
  67        if (AFFS_I(inode)->i_extcnt > lc_max) {
  68                u32 lc_shift, lc_mask, tmp, off;
  69
  70                /* need to recalculate linear cache, start from old size */
  71                lc_shift = AFFS_I(inode)->i_lc_shift;
  72                tmp = (AFFS_I(inode)->i_extcnt / AFFS_LC_SIZE) >> lc_shift;
  73                for (; tmp; tmp >>= 1)
  74                        lc_shift++;
  75                lc_mask = (1 << lc_shift) - 1;
  76
  77                /* fix idx and old size to new shift */
  78                lc_idx >>= (lc_shift - AFFS_I(inode)->i_lc_shift);
  79                AFFS_I(inode)->i_lc_size >>= (lc_shift - AFFS_I(inode)->i_lc_shift);
  80
  81                /* first shrink old cache to make more space */
  82                off = 1 << (lc_shift - AFFS_I(inode)->i_lc_shift);
  83                for (i = 1, j = off; j < AFFS_LC_SIZE; i++, j += off)
  84                        AFFS_I(inode)->i_ac[i] = AFFS_I(inode)->i_ac[j];
  85
  86                AFFS_I(inode)->i_lc_shift = lc_shift;
  87                AFFS_I(inode)->i_lc_mask = lc_mask;
  88        }
  89
  90        /* fill cache to the needed index */
  91        i = AFFS_I(inode)->i_lc_size;
  92        AFFS_I(inode)->i_lc_size = lc_idx + 1;
  93        for (; i <= lc_idx; i++) {
  94                if (!i) {
  95                        AFFS_I(inode)->i_lc[0] = inode->i_ino;
  96                        continue;
  97                }
  98                key = AFFS_I(inode)->i_lc[i - 1];
  99                j = AFFS_I(inode)->i_lc_mask + 1;
 100                // unlock cache
 101                for (; j > 0; j--) {
 102                        bh = affs_bread(sb, key);
 103                        if (!bh)
 104                                goto err;
 105                        key = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
 106                        affs_brelse(bh);
 107                }
 108                // lock cache
 109                AFFS_I(inode)->i_lc[i] = key;
 110        }
 111
 112        return 0;
 113
 114err:
 115        // lock cache
 116        return -EIO;
 117}
 118
 119static struct buffer_head *
 120affs_alloc_extblock(struct inode *inode, struct buffer_head *bh, u32 ext)
 121{
 122        struct super_block *sb = inode->i_sb;
 123        struct buffer_head *new_bh;
 124        u32 blocknr, tmp;
 125
 126        blocknr = affs_alloc_block(inode, bh->b_blocknr);
 127        if (!blocknr)
 128                return ERR_PTR(-ENOSPC);
 129
 130        new_bh = affs_getzeroblk(sb, blocknr);
 131        if (!new_bh) {
 132                affs_free_block(sb, blocknr);
 133                return ERR_PTR(-EIO);
 134        }
 135
 136        AFFS_HEAD(new_bh)->ptype = cpu_to_be32(T_LIST);
 137        AFFS_HEAD(new_bh)->key = cpu_to_be32(blocknr);
 138        AFFS_TAIL(sb, new_bh)->stype = cpu_to_be32(ST_FILE);
 139        AFFS_TAIL(sb, new_bh)->parent = cpu_to_be32(inode->i_ino);
 140        affs_fix_checksum(sb, new_bh);
 141
 142        mark_buffer_dirty_inode(new_bh, inode);
 143
 144        tmp = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
 145        if (tmp)
 146                affs_warning(sb, "alloc_ext", "previous extension set (%x)", tmp);
 147        AFFS_TAIL(sb, bh)->extension = cpu_to_be32(blocknr);
 148        affs_adjust_checksum(bh, blocknr - tmp);
 149        mark_buffer_dirty_inode(bh, inode);
 150
 151        AFFS_I(inode)->i_extcnt++;
 152        mark_inode_dirty(inode);
 153
 154        return new_bh;
 155}
 156
 157static inline struct buffer_head *
 158affs_get_extblock(struct inode *inode, u32 ext)
 159{
 160        /* inline the simplest case: same extended block as last time */
 161        struct buffer_head *bh = AFFS_I(inode)->i_ext_bh;
 162        if (ext == AFFS_I(inode)->i_ext_last)
 163                get_bh(bh);
 164        else
 165                /* we have to do more (not inlined) */
 166                bh = affs_get_extblock_slow(inode, ext);
 167
 168        return bh;
 169}
 170
 171static struct buffer_head *
 172affs_get_extblock_slow(struct inode *inode, u32 ext)
 173{
 174        struct super_block *sb = inode->i_sb;
 175        struct buffer_head *bh;
 176        u32 ext_key;
 177        u32 lc_idx, lc_off, ac_idx;
 178        u32 tmp, idx;
 179
 180        if (ext == AFFS_I(inode)->i_ext_last + 1) {
 181                /* read the next extended block from the current one */
 182                bh = AFFS_I(inode)->i_ext_bh;
 183                ext_key = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
 184                if (ext < AFFS_I(inode)->i_extcnt)
 185                        goto read_ext;
 186                BUG_ON(ext > AFFS_I(inode)->i_extcnt);
 187                bh = affs_alloc_extblock(inode, bh, ext);
 188                if (IS_ERR(bh))
 189                        return bh;
 190                goto store_ext;
 191        }
 192
 193        if (ext == 0) {
 194                /* we seek back to the file header block */
 195                ext_key = inode->i_ino;
 196                goto read_ext;
 197        }
 198
 199        if (ext >= AFFS_I(inode)->i_extcnt) {
 200                struct buffer_head *prev_bh;
 201
 202                /* allocate a new extended block */
 203                BUG_ON(ext > AFFS_I(inode)->i_extcnt);
 204
 205                /* get previous extended block */
 206                prev_bh = affs_get_extblock(inode, ext - 1);
 207                if (IS_ERR(prev_bh))
 208                        return prev_bh;
 209                bh = affs_alloc_extblock(inode, prev_bh, ext);
 210                affs_brelse(prev_bh);
 211                if (IS_ERR(bh))
 212                        return bh;
 213                goto store_ext;
 214        }
 215
 216again:
 217        /* check if there is an extended cache and whether it's large enough */
 218        lc_idx = ext >> AFFS_I(inode)->i_lc_shift;
 219        lc_off = ext & AFFS_I(inode)->i_lc_mask;
 220
 221        if (lc_idx >= AFFS_I(inode)->i_lc_size) {
 222                int err;
 223
 224                err = affs_grow_extcache(inode, lc_idx);
 225                if (err)
 226                        return ERR_PTR(err);
 227                goto again;
 228        }
 229
 230        /* every n'th key we find in the linear cache */
 231        if (!lc_off) {
 232                ext_key = AFFS_I(inode)->i_lc[lc_idx];
 233                goto read_ext;
 234        }
 235
 236        /* maybe it's still in the associative cache */
 237        ac_idx = (ext - lc_idx - 1) & AFFS_AC_MASK;
 238        if (AFFS_I(inode)->i_ac[ac_idx].ext == ext) {
 239                ext_key = AFFS_I(inode)->i_ac[ac_idx].key;
 240                goto read_ext;
 241        }
 242
 243        /* try to find one of the previous extended blocks */
 244        tmp = ext;
 245        idx = ac_idx;
 246        while (--tmp, --lc_off > 0) {
 247                idx = (idx - 1) & AFFS_AC_MASK;
 248                if (AFFS_I(inode)->i_ac[idx].ext == tmp) {
 249                        ext_key = AFFS_I(inode)->i_ac[idx].key;
 250                        goto find_ext;
 251                }
 252        }
 253
 254        /* fall back to the linear cache */
 255        ext_key = AFFS_I(inode)->i_lc[lc_idx];
 256find_ext:
 257        /* read all extended blocks until we find the one we need */
 258        //unlock cache
 259        do {
 260                bh = affs_bread(sb, ext_key);
 261                if (!bh)
 262                        goto err_bread;
 263                ext_key = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
 264                affs_brelse(bh);
 265                tmp++;
 266        } while (tmp < ext);
 267        //lock cache
 268
 269        /* store it in the associative cache */
 270        // recalculate ac_idx?
 271        AFFS_I(inode)->i_ac[ac_idx].ext = ext;
 272        AFFS_I(inode)->i_ac[ac_idx].key = ext_key;
 273
 274read_ext:
 275        /* finally read the right extended block */
 276        //unlock cache
 277        bh = affs_bread(sb, ext_key);
 278        if (!bh)
 279                goto err_bread;
 280        //lock cache
 281
 282store_ext:
 283        /* release old cached extended block and store the new one */
 284        affs_brelse(AFFS_I(inode)->i_ext_bh);
 285        AFFS_I(inode)->i_ext_last = ext;
 286        AFFS_I(inode)->i_ext_bh = bh;
 287        get_bh(bh);
 288
 289        return bh;
 290
 291err_bread:
 292        affs_brelse(bh);
 293        return ERR_PTR(-EIO);
 294}
 295
 296static int
 297affs_get_block(struct inode *inode, sector_t block, struct buffer_head *bh_result, int create)
 298{
 299        struct super_block      *sb = inode->i_sb;
 300        struct buffer_head      *ext_bh;
 301        u32                      ext;
 302
 303        pr_debug("%s(%lu, %llu)\n", __func__, inode->i_ino,
 304                 (unsigned long long)block);
 305
 306        BUG_ON(block > (sector_t)0x7fffffffUL);
 307
 308        if (block >= AFFS_I(inode)->i_blkcnt) {
 309                if (block > AFFS_I(inode)->i_blkcnt || !create)
 310                        goto err_big;
 311        } else
 312                create = 0;
 313
 314        //lock cache
 315        affs_lock_ext(inode);
 316
 317        ext = (u32)block / AFFS_SB(sb)->s_hashsize;
 318        block -= ext * AFFS_SB(sb)->s_hashsize;
 319        ext_bh = affs_get_extblock(inode, ext);
 320        if (IS_ERR(ext_bh))
 321                goto err_ext;
 322        map_bh(bh_result, sb, (sector_t)be32_to_cpu(AFFS_BLOCK(sb, ext_bh, block)));
 323
 324        if (create) {
 325                u32 blocknr = affs_alloc_block(inode, ext_bh->b_blocknr);
 326                if (!blocknr)
 327                        goto err_alloc;
 328                set_buffer_new(bh_result);
 329                AFFS_I(inode)->mmu_private += AFFS_SB(sb)->s_data_blksize;
 330                AFFS_I(inode)->i_blkcnt++;
 331
 332                /* store new block */
 333                if (bh_result->b_blocknr)
 334                        affs_warning(sb, "get_block",
 335                                     "block already set (%llx)",
 336                                     (unsigned long long)bh_result->b_blocknr);
 337                AFFS_BLOCK(sb, ext_bh, block) = cpu_to_be32(blocknr);
 338                AFFS_HEAD(ext_bh)->block_count = cpu_to_be32(block + 1);
 339                affs_adjust_checksum(ext_bh, blocknr - bh_result->b_blocknr + 1);
 340                bh_result->b_blocknr = blocknr;
 341
 342                if (!block) {
 343                        /* insert first block into header block */
 344                        u32 tmp = be32_to_cpu(AFFS_HEAD(ext_bh)->first_data);
 345                        if (tmp)
 346                                affs_warning(sb, "get_block", "first block already set (%d)", tmp);
 347                        AFFS_HEAD(ext_bh)->first_data = cpu_to_be32(blocknr);
 348                        affs_adjust_checksum(ext_bh, blocknr - tmp);
 349                }
 350        }
 351
 352        affs_brelse(ext_bh);
 353        //unlock cache
 354        affs_unlock_ext(inode);
 355        return 0;
 356
 357err_big:
 358        affs_error(inode->i_sb, "get_block", "strange block request %llu",
 359                   (unsigned long long)block);
 360        return -EIO;
 361err_ext:
 362        // unlock cache
 363        affs_unlock_ext(inode);
 364        return PTR_ERR(ext_bh);
 365err_alloc:
 366        brelse(ext_bh);
 367        clear_buffer_mapped(bh_result);
 368        bh_result->b_bdev = NULL;
 369        // unlock cache
 370        affs_unlock_ext(inode);
 371        return -ENOSPC;
 372}
 373
 374static int affs_writepages(struct address_space *mapping,
 375                           struct writeback_control *wbc)
 376{
 377        return mpage_writepages(mapping, wbc, affs_get_block);
 378}
 379
 380static int affs_read_folio(struct file *file, struct folio *folio)
 381{
 382        return block_read_full_folio(folio, affs_get_block);
 383}
 384
 385static void affs_write_failed(struct address_space *mapping, loff_t to)
 386{
 387        struct inode *inode = mapping->host;
 388
 389        if (to > inode->i_size) {
 390                truncate_pagecache(inode, inode->i_size);
 391                affs_truncate(inode);
 392        }
 393}
 394
 395static ssize_t
 396affs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
 397{
 398        struct file *file = iocb->ki_filp;
 399        struct address_space *mapping = file->f_mapping;
 400        struct inode *inode = mapping->host;
 401        size_t count = iov_iter_count(iter);
 402        loff_t offset = iocb->ki_pos;
 403        ssize_t ret;
 404
 405        if (iov_iter_rw(iter) == WRITE) {
 406                loff_t size = offset + count;
 407
 408                if (AFFS_I(inode)->mmu_private < size)
 409                        return 0;
 410        }
 411
 412        ret = blockdev_direct_IO(iocb, inode, iter, affs_get_block);
 413        if (ret < 0 && iov_iter_rw(iter) == WRITE)
 414                affs_write_failed(mapping, offset + count);
 415        return ret;
 416}
 417
 418static int affs_write_begin(struct file *file, struct address_space *mapping,
 419                        loff_t pos, unsigned len,
 420                        struct page **pagep, void **fsdata)
 421{
 422        int ret;
 423
 424        *pagep = NULL;
 425        ret = cont_write_begin(file, mapping, pos, len, pagep, fsdata,
 426                                affs_get_block,
 427                                &AFFS_I(mapping->host)->mmu_private);
 428        if (unlikely(ret))
 429                affs_write_failed(mapping, pos + len);
 430
 431        return ret;
 432}
 433
 434static int affs_write_end(struct file *file, struct address_space *mapping,
 435                          loff_t pos, unsigned int len, unsigned int copied,
 436                          struct page *page, void *fsdata)
 437{
 438        struct inode *inode = mapping->host;
 439        int ret;
 440
 441        ret = generic_write_end(file, mapping, pos, len, copied, page, fsdata);
 442
 443        /* Clear Archived bit on file writes, as AmigaOS would do */
 444        if (AFFS_I(inode)->i_protect & FIBF_ARCHIVED) {
 445                AFFS_I(inode)->i_protect &= ~FIBF_ARCHIVED;
 446                mark_inode_dirty(inode);
 447        }
 448
 449        return ret;
 450}
 451
 452static sector_t _affs_bmap(struct address_space *mapping, sector_t block)
 453{
 454        return generic_block_bmap(mapping,block,affs_get_block);
 455}
 456
 457const struct address_space_operations affs_aops = {
 458        .dirty_folio    = block_dirty_folio,
 459        .invalidate_folio = block_invalidate_folio,
 460        .read_folio = affs_read_folio,
 461        .writepages = affs_writepages,
 462        .write_begin = affs_write_begin,
 463        .write_end = affs_write_end,
 464        .direct_IO = affs_direct_IO,
 465        .migrate_folio = buffer_migrate_folio,
 466        .bmap = _affs_bmap
 467};
 468
 469static inline struct buffer_head *
 470affs_bread_ino(struct inode *inode, int block, int create)
 471{
 472        struct buffer_head *bh, tmp_bh;
 473        int err;
 474
 475        tmp_bh.b_state = 0;
 476        err = affs_get_block(inode, block, &tmp_bh, create);
 477        if (!err) {
 478                bh = affs_bread(inode->i_sb, tmp_bh.b_blocknr);
 479                if (bh) {
 480                        bh->b_state |= tmp_bh.b_state;
 481                        return bh;
 482                }
 483                err = -EIO;
 484        }
 485        return ERR_PTR(err);
 486}
 487
 488static inline struct buffer_head *
 489affs_getzeroblk_ino(struct inode *inode, int block)
 490{
 491        struct buffer_head *bh, tmp_bh;
 492        int err;
 493
 494        tmp_bh.b_state = 0;
 495        err = affs_get_block(inode, block, &tmp_bh, 1);
 496        if (!err) {
 497                bh = affs_getzeroblk(inode->i_sb, tmp_bh.b_blocknr);
 498                if (bh) {
 499                        bh->b_state |= tmp_bh.b_state;
 500                        return bh;
 501                }
 502                err = -EIO;
 503        }
 504        return ERR_PTR(err);
 505}
 506
 507static inline struct buffer_head *
 508affs_getemptyblk_ino(struct inode *inode, int block)
 509{
 510        struct buffer_head *bh, tmp_bh;
 511        int err;
 512
 513        tmp_bh.b_state = 0;
 514        err = affs_get_block(inode, block, &tmp_bh, 1);
 515        if (!err) {
 516                bh = affs_getemptyblk(inode->i_sb, tmp_bh.b_blocknr);
 517                if (bh) {
 518                        bh->b_state |= tmp_bh.b_state;
 519                        return bh;
 520                }
 521                err = -EIO;
 522        }
 523        return ERR_PTR(err);
 524}
 525
 526static int affs_do_read_folio_ofs(struct folio *folio, size_t to, int create)
 527{
 528        struct inode *inode = folio->mapping->host;
 529        struct super_block *sb = inode->i_sb;
 530        struct buffer_head *bh;
 531        size_t pos = 0;
 532        size_t bidx, boff, bsize;
 533        u32 tmp;
 534
 535        pr_debug("%s(%lu, %ld, 0, %zu)\n", __func__, inode->i_ino,
 536                 folio->index, to);
 537        BUG_ON(to > folio_size(folio));
 538        bsize = AFFS_SB(sb)->s_data_blksize;
 539        tmp = folio_pos(folio);
 540        bidx = tmp / bsize;
 541        boff = tmp % bsize;
 542
 543        while (pos < to) {
 544                bh = affs_bread_ino(inode, bidx, create);
 545                if (IS_ERR(bh))
 546                        return PTR_ERR(bh);
 547                tmp = min(bsize - boff, to - pos);
 548                BUG_ON(pos + tmp > to || tmp > bsize);
 549                memcpy_to_folio(folio, pos, AFFS_DATA(bh) + boff, tmp);
 550                affs_brelse(bh);
 551                bidx++;
 552                pos += tmp;
 553                boff = 0;
 554        }
 555        return 0;
 556}
 557
 558static int
 559affs_extent_file_ofs(struct inode *inode, u32 newsize)
 560{
 561        struct super_block *sb = inode->i_sb;
 562        struct buffer_head *bh, *prev_bh;
 563        u32 bidx, boff;
 564        u32 size, bsize;
 565        u32 tmp;
 566
 567        pr_debug("%s(%lu, %d)\n", __func__, inode->i_ino, newsize);
 568        bsize = AFFS_SB(sb)->s_data_blksize;
 569        bh = NULL;
 570        size = AFFS_I(inode)->mmu_private;
 571        bidx = size / bsize;
 572        boff = size % bsize;
 573        if (boff) {
 574                bh = affs_bread_ino(inode, bidx, 0);
 575                if (IS_ERR(bh))
 576                        return PTR_ERR(bh);
 577                tmp = min(bsize - boff, newsize - size);
 578                BUG_ON(boff + tmp > bsize || tmp > bsize);
 579                memset(AFFS_DATA(bh) + boff, 0, tmp);
 580                be32_add_cpu(&AFFS_DATA_HEAD(bh)->size, tmp);
 581                affs_fix_checksum(sb, bh);
 582                mark_buffer_dirty_inode(bh, inode);
 583                size += tmp;
 584                bidx++;
 585        } else if (bidx) {
 586                bh = affs_bread_ino(inode, bidx - 1, 0);
 587                if (IS_ERR(bh))
 588                        return PTR_ERR(bh);
 589        }
 590
 591        while (size < newsize) {
 592                prev_bh = bh;
 593                bh = affs_getzeroblk_ino(inode, bidx);
 594                if (IS_ERR(bh))
 595                        goto out;
 596                tmp = min(bsize, newsize - size);
 597                BUG_ON(tmp > bsize);
 598                AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA);
 599                AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino);
 600                AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx);
 601                AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp);
 602                affs_fix_checksum(sb, bh);
 603                bh->b_state &= ~(1UL << BH_New);
 604                mark_buffer_dirty_inode(bh, inode);
 605                if (prev_bh) {
 606                        u32 tmp_next = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next);
 607
 608                        if (tmp_next)
 609                                affs_warning(sb, "extent_file_ofs",
 610                                             "next block already set for %d (%d)",
 611                                             bidx, tmp_next);
 612                        AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr);
 613                        affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp_next);
 614                        mark_buffer_dirty_inode(prev_bh, inode);
 615                        affs_brelse(prev_bh);
 616                }
 617                size += bsize;
 618                bidx++;
 619        }
 620        affs_brelse(bh);
 621        inode->i_size = AFFS_I(inode)->mmu_private = newsize;
 622        return 0;
 623
 624out:
 625        inode->i_size = AFFS_I(inode)->mmu_private = newsize;
 626        return PTR_ERR(bh);
 627}
 628
 629static int affs_read_folio_ofs(struct file *file, struct folio *folio)
 630{
 631        struct inode *inode = folio->mapping->host;
 632        size_t to;
 633        int err;
 634
 635        pr_debug("%s(%lu, %ld)\n", __func__, inode->i_ino, folio->index);
 636        to = folio_size(folio);
 637        if (folio_pos(folio) + to > inode->i_size) {
 638                to = inode->i_size - folio_pos(folio);
 639                folio_zero_segment(folio, to, folio_size(folio));
 640        }
 641
 642        err = affs_do_read_folio_ofs(folio, to, 0);
 643        if (!err)
 644                folio_mark_uptodate(folio);
 645        folio_unlock(folio);
 646        return err;
 647}
 648
 649static int affs_write_begin_ofs(struct file *file, struct address_space *mapping,
 650                                loff_t pos, unsigned len,
 651                                struct page **pagep, void **fsdata)
 652{
 653        struct inode *inode = mapping->host;
 654        struct folio *folio;
 655        pgoff_t index;
 656        int err = 0;
 657
 658        pr_debug("%s(%lu, %llu, %llu)\n", __func__, inode->i_ino, pos,
 659                 pos + len);
 660        if (pos > AFFS_I(inode)->mmu_private) {
 661                /* XXX: this probably leaves a too-big i_size in case of
 662                 * failure. Should really be updating i_size at write_end time
 663                 */
 664                err = affs_extent_file_ofs(inode, pos);
 665                if (err)
 666                        return err;
 667        }
 668
 669        index = pos >> PAGE_SHIFT;
 670        folio = __filemap_get_folio(mapping, index, FGP_WRITEBEGIN,
 671                        mapping_gfp_mask(mapping));
 672        if (IS_ERR(folio))
 673                return PTR_ERR(folio);
 674        *pagep = &folio->page;
 675
 676        if (folio_test_uptodate(folio))
 677                return 0;
 678
 679        /* XXX: inefficient but safe in the face of short writes */
 680        err = affs_do_read_folio_ofs(folio, folio_size(folio), 1);
 681        if (err) {
 682                folio_unlock(folio);
 683                folio_put(folio);
 684        }
 685        return err;
 686}
 687
 688static int affs_write_end_ofs(struct file *file, struct address_space *mapping,
 689                                loff_t pos, unsigned len, unsigned copied,
 690                                struct page *page, void *fsdata)
 691{
 692        struct folio *folio = page_folio(page);
 693        struct inode *inode = mapping->host;
 694        struct super_block *sb = inode->i_sb;
 695        struct buffer_head *bh, *prev_bh;
 696        char *data;
 697        u32 bidx, boff, bsize;
 698        unsigned from, to;
 699        u32 tmp;
 700        int written;
 701
 702        from = pos & (PAGE_SIZE - 1);
 703        to = from + len;
 704        /*
 705         * XXX: not sure if this can handle short copies (len < copied), but
 706         * we don't have to, because the folio should always be uptodate here,
 707         * due to write_begin.
 708         */
 709
 710        pr_debug("%s(%lu, %llu, %llu)\n", __func__, inode->i_ino, pos,
 711                 pos + len);
 712        bsize = AFFS_SB(sb)->s_data_blksize;
 713        data = folio_address(folio);
 714
 715        bh = NULL;
 716        written = 0;
 717        tmp = (folio->index << PAGE_SHIFT) + from;
 718        bidx = tmp / bsize;
 719        boff = tmp % bsize;
 720        if (boff) {
 721                bh = affs_bread_ino(inode, bidx, 0);
 722                if (IS_ERR(bh)) {
 723                        written = PTR_ERR(bh);
 724                        goto err_first_bh;
 725                }
 726                tmp = min(bsize - boff, to - from);
 727                BUG_ON(boff + tmp > bsize || tmp > bsize);
 728                memcpy(AFFS_DATA(bh) + boff, data + from, tmp);
 729                be32_add_cpu(&AFFS_DATA_HEAD(bh)->size, tmp);
 730                affs_fix_checksum(sb, bh);
 731                mark_buffer_dirty_inode(bh, inode);
 732                written += tmp;
 733                from += tmp;
 734                bidx++;
 735        } else if (bidx) {
 736                bh = affs_bread_ino(inode, bidx - 1, 0);
 737                if (IS_ERR(bh)) {
 738                        written = PTR_ERR(bh);
 739                        goto err_first_bh;
 740                }
 741        }
 742        while (from + bsize <= to) {
 743                prev_bh = bh;
 744                bh = affs_getemptyblk_ino(inode, bidx);
 745                if (IS_ERR(bh))
 746                        goto err_bh;
 747                memcpy(AFFS_DATA(bh), data + from, bsize);
 748                if (buffer_new(bh)) {
 749                        AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA);
 750                        AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino);
 751                        AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx);
 752                        AFFS_DATA_HEAD(bh)->size = cpu_to_be32(bsize);
 753                        AFFS_DATA_HEAD(bh)->next = 0;
 754                        bh->b_state &= ~(1UL << BH_New);
 755                        if (prev_bh) {
 756                                u32 tmp_next = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next);
 757
 758                                if (tmp_next)
 759                                        affs_warning(sb, "commit_write_ofs",
 760                                                     "next block already set for %d (%d)",
 761                                                     bidx, tmp_next);
 762                                AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr);
 763                                affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp_next);
 764                                mark_buffer_dirty_inode(prev_bh, inode);
 765                        }
 766                }
 767                affs_brelse(prev_bh);
 768                affs_fix_checksum(sb, bh);
 769                mark_buffer_dirty_inode(bh, inode);
 770                written += bsize;
 771                from += bsize;
 772                bidx++;
 773        }
 774        if (from < to) {
 775                prev_bh = bh;
 776                bh = affs_bread_ino(inode, bidx, 1);
 777                if (IS_ERR(bh))
 778                        goto err_bh;
 779                tmp = min(bsize, to - from);
 780                BUG_ON(tmp > bsize);
 781                memcpy(AFFS_DATA(bh), data + from, tmp);
 782                if (buffer_new(bh)) {
 783                        AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA);
 784                        AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino);
 785                        AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx);
 786                        AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp);
 787                        AFFS_DATA_HEAD(bh)->next = 0;
 788                        bh->b_state &= ~(1UL << BH_New);
 789                        if (prev_bh) {
 790                                u32 tmp_next = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next);
 791
 792                                if (tmp_next)
 793                                        affs_warning(sb, "commit_write_ofs",
 794                                                     "next block already set for %d (%d)",
 795                                                     bidx, tmp_next);
 796                                AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr);
 797                                affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp_next);
 798                                mark_buffer_dirty_inode(prev_bh, inode);
 799                        }
 800                } else if (be32_to_cpu(AFFS_DATA_HEAD(bh)->size) < tmp)
 801                        AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp);
 802                affs_brelse(prev_bh);
 803                affs_fix_checksum(sb, bh);
 804                mark_buffer_dirty_inode(bh, inode);
 805                written += tmp;
 806                from += tmp;
 807                bidx++;
 808        }
 809        folio_mark_uptodate(folio);
 810
 811done:
 812        affs_brelse(bh);
 813        tmp = (folio->index << PAGE_SHIFT) + from;
 814        if (tmp > inode->i_size)
 815                inode->i_size = AFFS_I(inode)->mmu_private = tmp;
 816
 817        /* Clear Archived bit on file writes, as AmigaOS would do */
 818        if (AFFS_I(inode)->i_protect & FIBF_ARCHIVED) {
 819                AFFS_I(inode)->i_protect &= ~FIBF_ARCHIVED;
 820                mark_inode_dirty(inode);
 821        }
 822
 823err_first_bh:
 824        folio_unlock(folio);
 825        folio_put(folio);
 826
 827        return written;
 828
 829err_bh:
 830        bh = prev_bh;
 831        if (!written)
 832                written = PTR_ERR(bh);
 833        goto done;
 834}
 835
 836const struct address_space_operations affs_aops_ofs = {
 837        .dirty_folio    = block_dirty_folio,
 838        .invalidate_folio = block_invalidate_folio,
 839        .read_folio = affs_read_folio_ofs,
 840        //.writepages = affs_writepages_ofs,
 841        .write_begin = affs_write_begin_ofs,
 842        .write_end = affs_write_end_ofs,
 843        .migrate_folio = filemap_migrate_folio,
 844};
 845
 846/* Free any preallocated blocks. */
 847
 848void
 849affs_free_prealloc(struct inode *inode)
 850{
 851        struct super_block *sb = inode->i_sb;
 852
 853        pr_debug("free_prealloc(ino=%lu)\n", inode->i_ino);
 854
 855        while (AFFS_I(inode)->i_pa_cnt) {
 856                AFFS_I(inode)->i_pa_cnt--;
 857                affs_free_block(sb, ++AFFS_I(inode)->i_lastalloc);
 858        }
 859}
 860
 861/* Truncate (or enlarge) a file to the requested size. */
 862
 863void
 864affs_truncate(struct inode *inode)
 865{
 866        struct super_block *sb = inode->i_sb;
 867        u32 ext, ext_key;
 868        u32 last_blk, blkcnt, blk;
 869        u32 size;
 870        struct buffer_head *ext_bh;
 871        int i;
 872
 873        pr_debug("truncate(inode=%lu, oldsize=%llu, newsize=%llu)\n",
 874                 inode->i_ino, AFFS_I(inode)->mmu_private, inode->i_size);
 875
 876        last_blk = 0;
 877        ext = 0;
 878        if (inode->i_size) {
 879                last_blk = ((u32)inode->i_size - 1) / AFFS_SB(sb)->s_data_blksize;
 880                ext = last_blk / AFFS_SB(sb)->s_hashsize;
 881        }
 882
 883        if (inode->i_size > AFFS_I(inode)->mmu_private) {
 884                struct address_space *mapping = inode->i_mapping;
 885                struct page *page;
 886                void *fsdata = NULL;
 887                loff_t isize = inode->i_size;
 888                int res;
 889
 890                res = mapping->a_ops->write_begin(NULL, mapping, isize, 0, &page, &fsdata);
 891                if (!res)
 892                        res = mapping->a_ops->write_end(NULL, mapping, isize, 0, 0, page, fsdata);
 893                else
 894                        inode->i_size = AFFS_I(inode)->mmu_private;
 895                mark_inode_dirty(inode);
 896                return;
 897        } else if (inode->i_size == AFFS_I(inode)->mmu_private)
 898                return;
 899
 900        // lock cache
 901        ext_bh = affs_get_extblock(inode, ext);
 902        if (IS_ERR(ext_bh)) {
 903                affs_warning(sb, "truncate",
 904                             "unexpected read error for ext block %u (%ld)",
 905                             ext, PTR_ERR(ext_bh));
 906                return;
 907        }
 908        if (AFFS_I(inode)->i_lc) {
 909                /* clear linear cache */
 910                i = (ext + 1) >> AFFS_I(inode)->i_lc_shift;
 911                if (AFFS_I(inode)->i_lc_size > i) {
 912                        AFFS_I(inode)->i_lc_size = i;
 913                        for (; i < AFFS_LC_SIZE; i++)
 914                                AFFS_I(inode)->i_lc[i] = 0;
 915                }
 916                /* clear associative cache */
 917                for (i = 0; i < AFFS_AC_SIZE; i++)
 918                        if (AFFS_I(inode)->i_ac[i].ext >= ext)
 919                                AFFS_I(inode)->i_ac[i].ext = 0;
 920        }
 921        ext_key = be32_to_cpu(AFFS_TAIL(sb, ext_bh)->extension);
 922
 923        blkcnt = AFFS_I(inode)->i_blkcnt;
 924        i = 0;
 925        blk = last_blk;
 926        if (inode->i_size) {
 927                i = last_blk % AFFS_SB(sb)->s_hashsize + 1;
 928                blk++;
 929        } else
 930                AFFS_HEAD(ext_bh)->first_data = 0;
 931        AFFS_HEAD(ext_bh)->block_count = cpu_to_be32(i);
 932        size = AFFS_SB(sb)->s_hashsize;
 933        if (size > blkcnt - blk + i)
 934                size = blkcnt - blk + i;
 935        for (; i < size; i++, blk++) {
 936                affs_free_block(sb, be32_to_cpu(AFFS_BLOCK(sb, ext_bh, i)));
 937                AFFS_BLOCK(sb, ext_bh, i) = 0;
 938        }
 939        AFFS_TAIL(sb, ext_bh)->extension = 0;
 940        affs_fix_checksum(sb, ext_bh);
 941        mark_buffer_dirty_inode(ext_bh, inode);
 942        affs_brelse(ext_bh);
 943
 944        if (inode->i_size) {
 945                AFFS_I(inode)->i_blkcnt = last_blk + 1;
 946                AFFS_I(inode)->i_extcnt = ext + 1;
 947                if (affs_test_opt(AFFS_SB(sb)->s_flags, SF_OFS)) {
 948                        struct buffer_head *bh = affs_bread_ino(inode, last_blk, 0);
 949                        u32 tmp;
 950                        if (IS_ERR(bh)) {
 951                                affs_warning(sb, "truncate",
 952                                             "unexpected read error for last block %u (%ld)",
 953                                             ext, PTR_ERR(bh));
 954                                return;
 955                        }
 956                        tmp = be32_to_cpu(AFFS_DATA_HEAD(bh)->next);
 957                        AFFS_DATA_HEAD(bh)->next = 0;
 958                        affs_adjust_checksum(bh, -tmp);
 959                        affs_brelse(bh);
 960                }
 961        } else {
 962                AFFS_I(inode)->i_blkcnt = 0;
 963                AFFS_I(inode)->i_extcnt = 1;
 964        }
 965        AFFS_I(inode)->mmu_private = inode->i_size;
 966        // unlock cache
 967
 968        while (ext_key) {
 969                ext_bh = affs_bread(sb, ext_key);
 970                size = AFFS_SB(sb)->s_hashsize;
 971                if (size > blkcnt - blk)
 972                        size = blkcnt - blk;
 973                for (i = 0; i < size; i++, blk++)
 974                        affs_free_block(sb, be32_to_cpu(AFFS_BLOCK(sb, ext_bh, i)));
 975                affs_free_block(sb, ext_key);
 976                ext_key = be32_to_cpu(AFFS_TAIL(sb, ext_bh)->extension);
 977                affs_brelse(ext_bh);
 978        }
 979        affs_free_prealloc(inode);
 980}
 981
 982int affs_file_fsync(struct file *filp, loff_t start, loff_t end, int datasync)
 983{
 984        struct inode *inode = filp->f_mapping->host;
 985        int ret, err;
 986
 987        err = file_write_and_wait_range(filp, start, end);
 988        if (err)
 989                return err;
 990
 991        inode_lock(inode);
 992        ret = write_inode_now(inode, 0);
 993        err = sync_blockdev(inode->i_sb->s_bdev);
 994        if (!ret)
 995                ret = err;
 996        inode_unlock(inode);
 997        return ret;
 998}
 999const struct file_operations affs_file_operations = {
1000        .llseek         = generic_file_llseek,
1001        .read_iter      = generic_file_read_iter,
1002        .write_iter     = generic_file_write_iter,
1003        .mmap           = generic_file_mmap,
1004        .open           = affs_file_open,
1005        .release        = affs_file_release,
1006        .fsync          = affs_file_fsync,
1007        .splice_read    = filemap_splice_read,
1008};
1009
1010const struct inode_operations affs_file_inode_operations = {
1011        .setattr        = affs_notify_change,
1012};
1013