fs/hpfs/file.c

   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
  13 #define BLOCKS(size) (((size) + 511) >> 9)
  14
  15 static int hpfs_file_release(struct inode *inode, struct file *file)
  16 {
  17         hpfs_lock(inode->i_sb);
  18         hpfs_write_if_changed(inode);
  19         hpfs_unlock(inode->i_sb);
  20         return 0;
  21 }
  22
  23 int hpfs_file_fsync(struct file *file, loff_t start, loff_t end, int datasync)
  24 {
  25         struct inode *inode = file->f_mapping->host;
  26         int ret;
  27
  28         ret = file_write_and_wait_range(file, start, end);
  29         if (ret)
  30                 return ret;
  31         return sync_blockdev(inode->i_sb->s_bdev);
  32 }
  33
  34 /*
  35  * generic_file_read often calls bmap with non-existing sector,
  36  * so we must ignore such errors.
  37  */
  38
  39 static secno hpfs_bmap(struct inode *inode, unsigned file_secno, unsigned *n_secs)
  40 {
  41         struct hpfs_inode_info *hpfs_inode = hpfs_i(inode);
  42         unsigned n, disk_secno;
  43         struct fnode *fnode;
  44         struct buffer_head *bh;
  45         if (BLOCKS(hpfs_i(inode)->mmu_private) <= file_secno) return 0;
  46         n = file_secno - hpfs_inode->i_file_sec;
  47         if (n < hpfs_inode->i_n_secs) {
  48                 *n_secs = hpfs_inode->i_n_secs - n;
  49                 return hpfs_inode->i_disk_sec + n;
  50         }
  51         if (!(fnode = hpfs_map_fnode(inode->i_sb, inode->i_ino, &bh))) return 0;
  52         disk_secno = hpfs_bplus_lookup(inode->i_sb, inode, &fnode->btree, file_secno, bh);
  53         if (disk_secno == -1) return 0;
  54         if (hpfs_chk_sectors(inode->i_sb, disk_secno, 1, "bmap")) return 0;
  55         n = file_secno - hpfs_inode->i_file_sec;
  56         if (n < hpfs_inode->i_n_secs) {
  57                 *n_secs = hpfs_inode->i_n_secs - n;
  58                 return hpfs_inode->i_disk_sec + n;
  59         }
  60         *n_secs = 1;
  61         return disk_secno;
  62 }
  63
  64 void hpfs_truncate(struct inode *i)
  65 {
  66         if (IS_IMMUTABLE(i)) return /*-EPERM*/;
  67         hpfs_lock_assert(i->i_sb);
  68
  69         hpfs_i(i)->i_n_secs = 0;
  70         i->i_blocks = 1 + ((i->i_size + 511) >> 9);
  71         hpfs_i(i)->mmu_private = i->i_size;
  72         hpfs_truncate_btree(i->i_sb, i->i_ino, 1, ((i->i_size + 511) >> 9));
  73         hpfs_write_inode(i);
  74         hpfs_i(i)->i_n_secs = 0;
  75 }
  76
  77 static int hpfs_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create)
  78 {
  79         int r;
  80         secno s;
  81         unsigned n_secs;
  82         hpfs_lock(inode->i_sb);
  83         s = hpfs_bmap(inode, iblock, &n_secs);
  84         if (s) {
  85                 if (bh_result->b_size >> 9 < n_secs)
  86                         n_secs = bh_result->b_size >> 9;
  87                 n_secs = hpfs_search_hotfix_map_for_range(inode->i_sb, s, n_secs);
  88                 if (unlikely(!n_secs)) {
  89                         s = hpfs_search_hotfix_map(inode->i_sb, s);
  90                         n_secs = 1;
  91                 }
  92                 map_bh(bh_result, inode->i_sb, s);
  93                 bh_result->b_size = n_secs << 9;
  94                 goto ret_0;
  95         }
  96         if (!create) goto ret_0;
  97         if (iblock<<9 != hpfs_i(inode)->mmu_private) {
  98                 BUG();
  99                 r = -EIO;
 100                 goto ret_r;
 101         }
 102         if ((s = hpfs_add_sector_to_btree(inode->i_sb, inode->i_ino, 1, inode->i_blocks - 1)) == -1) {
 103                 hpfs_truncate_btree(inode->i_sb, inode->i_ino, 1, inode->i_blocks - 1);
 104                 r = -ENOSPC;
 105                 goto ret_r;
 106         }
 107         inode->i_blocks++;
 108         hpfs_i(inode)->mmu_private += 512;
 109         set_buffer_new(bh_result);
 110         map_bh(bh_result, inode->i_sb, hpfs_search_hotfix_map(inode->i_sb, s));
 111         ret_0:
 112         r = 0;
 113         ret_r:
 114         hpfs_unlock(inode->i_sb);
 115         return r;
 116 }
 117
 118 static int hpfs_readpage(struct file *file, struct page *page)
 119 {
 120         return mpage_readpage(page, hpfs_get_block);
 121 }
 122
 123 static int hpfs_writepage(struct page *page, struct writeback_control *wbc)
 124 {
 125         return block_write_full_page(page, hpfs_get_block, wbc);
 126 }
 127
 128 static int hpfs_readpages(struct file *file, struct address_space *mapping,
 129                           struct list_head *pages, unsigned nr_pages)
 130 {
 131         return mpage_readpages(mapping, pages, nr_pages, hpfs_get_block);
 132 }
 133
 134 static int hpfs_writepages(struct address_space *mapping,
 135                            struct writeback_control *wbc)
 136 {
 137         return mpage_writepages(mapping, wbc, hpfs_get_block);
 138 }
 139
 140 static 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
 154 static 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
 170 static 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
 188 static sector_t _hpfs_bmap(struct address_space *mapping, sector_t block)
 189 {
 190         return generic_block_bmap(mapping, block, hpfs_get_block);
 191 }
 192
 193 static 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
 198 const struct address_space_operations hpfs_aops = {
 199         .readpage = hpfs_readpage,
 200         .writepage = hpfs_writepage,
 201         .readpages = hpfs_readpages,
 202         .writepages = hpfs_writepages,
 203         .write_begin = hpfs_write_begin,
 204         .write_end = hpfs_write_end,
 205         .bmap = _hpfs_bmap
 206 };
 207
 208 const 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 };
 219
 220 const struct inode_operations hpfs_file_iops =
 221 {
 222         .setattr        = hpfs_setattr,
 223         .fiemap         = hpfs_fiemap,
 224 };