linux/fs/hpfs/file.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 *  linux/fs/hpfs/file.c
   4 *
   5 *  Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
   6 *
   7 *  file VFS functions
   8 */
   9
  10#include "hpfs_fn.h"
  11#include <linux/mpage.h>
  12#include <linux/fiemap.h>
  13
  14#define BLOCKS(size) (((size) + 511) >> 9)
  15
  16static int hpfs_file_release(struct inode *inode, struct file *file)
  17{
  18        hpfs_lock(inode->i_sb);
  19        hpfs_write_if_changed(inode);
  20        hpfs_unlock(inode->i_sb);
  21        return 0;
  22}
  23
  24int hpfs_file_fsync(struct file *file, loff_t start, loff_t end, int datasync)
  25{
  26        struct inode *inode = file->f_mapping->host;
  27        int ret;
  28
  29        ret = file_write_and_wait_range(file, start, end);
  30        if (ret)
  31                return ret;
  32        return sync_blockdev(inode->i_sb->s_bdev);
  33}
  34
  35/*
  36 * generic_file_read often calls bmap with non-existing sector,
  37 * so we must ignore such errors.
  38 */
  39
  40static secno hpfs_bmap(struct inode *inode, unsigned file_secno, unsigned *n_secs)
  41{
  42        struct hpfs_inode_info *hpfs_inode = hpfs_i(inode);
  43        unsigned n, disk_secno;
  44        struct fnode *fnode;
  45        struct buffer_head *bh;
  46        if (BLOCKS(hpfs_i(inode)->mmu_private) <= file_secno) return 0;
  47        n = file_secno - hpfs_inode->i_file_sec;
  48        if (n < hpfs_inode->i_n_secs) {
  49                *n_secs = hpfs_inode->i_n_secs - n;
  50                return hpfs_inode->i_disk_sec + n;
  51        }
  52        if (!(fnode = hpfs_map_fnode(inode->i_sb, inode->i_ino, &bh))) return 0;
  53        disk_secno = hpfs_bplus_lookup(inode->i_sb, inode, &fnode->btree, file_secno, bh);
  54        if (disk_secno == -1) return 0;
  55        if (hpfs_chk_sectors(inode->i_sb, disk_secno, 1, "bmap")) return 0;
  56        n = file_secno - hpfs_inode->i_file_sec;
  57        if (n < hpfs_inode->i_n_secs) {
  58                *n_secs = hpfs_inode->i_n_secs - n;
  59                return hpfs_inode->i_disk_sec + n;
  60        }
  61        *n_secs = 1;
  62        return disk_secno;
  63}
  64
  65void hpfs_truncate(struct inode *i)
  66{
  67        if (IS_IMMUTABLE(i)) return /*-EPERM*/;
  68        hpfs_lock_assert(i->i_sb);
  69
  70        hpfs_i(i)->i_n_secs = 0;
  71        i->i_blocks = 1 + ((i->i_size + 511) >> 9);
  72        hpfs_i(i)->mmu_private = i->i_size;
  73        hpfs_truncate_btree(i->i_sb, i->i_ino, 1, ((i->i_size + 511) >> 9));
  74        hpfs_write_inode(i);
  75        hpfs_i(i)->i_n_secs = 0;
  76}
  77
  78static int hpfs_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create)
  79{
  80        int r;
  81        secno s;
  82        unsigned n_secs;
  83        hpfs_lock(inode->i_sb);
  84        s = hpfs_bmap(inode, iblock, &n_secs);
  85        if (s) {
  86                if (bh_result->b_size >> 9 < n_secs)
  87                        n_secs = bh_result->b_size >> 9;
  88                n_secs = hpfs_search_hotfix_map_for_range(inode->i_sb, s, n_secs);
  89                if (unlikely(!n_secs)) {
  90                        s = hpfs_search_hotfix_map(inode->i_sb, s);
  91                        n_secs = 1;
  92                }
  93                map_bh(bh_result, inode->i_sb, s);
  94                bh_result->b_size = n_secs << 9;
  95                goto ret_0;
  96        }
  97        if (!create) goto ret_0;
  98        if (iblock<<9 != hpfs_i(inode)->mmu_private) {
  99                BUG();
 100                r = -EIO;
 101                goto ret_r;
 102        }
 103        if ((s = hpfs_add_sector_to_btree(inode->i_sb, inode->i_ino, 1, inode->i_blocks - 1)) == -1) {
 104                hpfs_truncate_btree(inode->i_sb, inode->i_ino, 1, inode->i_blocks - 1);
 105                r = -ENOSPC;
 106                goto ret_r;
 107        }
 108        inode->i_blocks++;
 109        hpfs_i(inode)->mmu_private += 512;
 110        set_buffer_new(bh_result);
 111        map_bh(bh_result, inode->i_sb, hpfs_search_hotfix_map(inode->i_sb, s));
 112        ret_0:
 113        r = 0;
 114        ret_r:
 115        hpfs_unlock(inode->i_sb);
 116        return r;
 117}
 118
 119static int hpfs_readpage(struct file *file, struct page *page)
 120{
 121        return mpage_readpage(page, hpfs_get_block);
 122}
 123
 124static int hpfs_writepage(struct page *page, struct writeback_control *wbc)
 125{
 126        return block_write_full_page(page, hpfs_get_block, wbc);
 127}
 128
 129static void hpfs_readahead(struct readahead_control *rac)
 130{
 131        mpage_readahead(rac, hpfs_get_block);
 132}
 133
 134static int hpfs_writepages(struct address_space *mapping,
 135                           struct writeback_control *wbc)
 136{
 137        return mpage_writepages(mapping, wbc, hpfs_get_block);
 138}
 139
 140static void hpfs_write_failed(struct address_space *mapping, loff_t to)
 141{
 142        struct inode *inode = mapping->host;
 143
 144        hpfs_lock(inode->i_sb);
 145
 146        if (to > inode->i_size) {
 147                truncate_pagecache(inode, inode->i_size);
 148                hpfs_truncate(inode);
 149        }
 150
 151        hpfs_unlock(inode->i_sb);
 152}
 153
 154static int hpfs_write_begin(struct file *file, struct address_space *mapping,
 155                        loff_t pos, unsigned len, unsigned flags,
 156                        struct page **pagep, void **fsdata)
 157{
 158        int ret;
 159
 160        *pagep = NULL;
 161        ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
 162                                hpfs_get_block,
 163                                &hpfs_i(mapping->host)->mmu_private);
 164        if (unlikely(ret))
 165                hpfs_write_failed(mapping, pos + len);
 166
 167        return ret;
 168}
 169
 170static int hpfs_write_end(struct file *file, struct address_space *mapping,
 171                        loff_t pos, unsigned len, unsigned copied,
 172                        struct page *pagep, void *fsdata)
 173{
 174        struct inode *inode = mapping->host;
 175        int err;
 176        err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata);
 177        if (err < len)
 178                hpfs_write_failed(mapping, pos + len);
 179        if (!(err < 0)) {
 180                /* make sure we write it on close, if not earlier */
 181                hpfs_lock(inode->i_sb);
 182                hpfs_i(inode)->i_dirty = 1;
 183                hpfs_unlock(inode->i_sb);
 184        }
 185        return err;
 186}
 187
 188static sector_t _hpfs_bmap(struct address_space *mapping, sector_t block)
 189{
 190        return generic_block_bmap(mapping, block, hpfs_get_block);
 191}
 192
 193static int hpfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, u64 start, u64 len)
 194{
 195        return generic_block_fiemap(inode, fieinfo, start, len, hpfs_get_block);
 196}
 197
 198const struct address_space_operations hpfs_aops = {
 199        .readpage = hpfs_readpage,
 200        .writepage = hpfs_writepage,
 201        .readahead = hpfs_readahead,
 202        .writepages = hpfs_writepages,
 203        .write_begin = hpfs_write_begin,
 204        .write_end = hpfs_write_end,
 205        .bmap = _hpfs_bmap
 206};
 207
 208const struct file_operations hpfs_file_ops =
 209{
 210        .llseek         = generic_file_llseek,
 211        .read_iter      = generic_file_read_iter,
 212        .write_iter     = generic_file_write_iter,
 213        .mmap           = generic_file_mmap,
 214        .release        = hpfs_file_release,
 215        .fsync          = hpfs_file_fsync,
 216        .splice_read    = generic_file_splice_read,
 217        .unlocked_ioctl = hpfs_ioctl,
 218        .compat_ioctl   = compat_ptr_ioctl,
 219};
 220
 221const struct inode_operations hpfs_file_iops =
 222{
 223        .setattr        = hpfs_setattr,
 224        .fiemap         = hpfs_fiemap,
 225};
 226