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 #include <linux/fiemap.h>
  13
  14 #define BLOCKS(size) (((size) + 511) >> 9)
  15
  16 static 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
  24 int 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
  40 static 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
  65 void 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
  78 static 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
 119 static int hpfs_readpage(struct file *file, struct page *page)
 120 {
 121         return mpage_readpage(page, hpfs_get_block);
 122 }
 123
 124 static int hpfs_writepage(struct page *page, struct writeback_control *wbc)
 125 {
 126         return block_write_full_page(page, hpfs_get_block, wbc);
 127 }
 128
 129 static void hpfs_readahead(struct readahead_control *rac)
 130 {
 131         mpage_readahead(rac, 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         .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
 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         .compat_ioctl   = compat_ptr_ioctl,
 219 };
 220
 221 const struct inode_operations hpfs_file_iops =
 222 {
 223         .setattr        = hpfs_setattr,
 224         .fiemap         = hpfs_fiemap,
 225 };