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/iomap.h>
  13 #include <linux/fiemap.h>
  14
  15 #define BLOCKS(size) (((size) + 511) >> 9)
  16
  17 static int hpfs_file_release(struct inode *inode, struct file *file)
  18 {
  19         hpfs_lock(inode->i_sb);
  20         hpfs_write_if_changed(inode);
  21         hpfs_unlock(inode->i_sb);
  22         return 0;
  23 }
  24
  25 int hpfs_file_fsync(struct file *file, loff_t start, loff_t end, int datasync)
  26 {
  27         struct inode *inode = file->f_mapping->host;
  28         int ret;
  29
  30         ret = file_write_and_wait_range(file, start, end);
  31         if (ret)
  32                 return ret;
  33         return sync_blockdev(inode->i_sb->s_bdev);
  34 }
  35
  36 /*
  37  * generic_file_read often calls bmap with non-existing sector,
  38  * so we must ignore such errors.
  39  */
  40
  41 static secno hpfs_bmap(struct inode *inode, unsigned file_secno, unsigned *n_secs)
  42 {
  43         struct hpfs_inode_info *hpfs_inode = hpfs_i(inode);
  44         unsigned n, disk_secno;
  45         struct fnode *fnode;
  46         struct buffer_head *bh;
  47         if (BLOCKS(hpfs_i(inode)->mmu_private) <= file_secno) return 0;
  48         n = file_secno - hpfs_inode->i_file_sec;
  49         if (n < hpfs_inode->i_n_secs) {
  50                 *n_secs = hpfs_inode->i_n_secs - n;
  51                 return hpfs_inode->i_disk_sec + n;
  52         }
  53         if (!(fnode = hpfs_map_fnode(inode->i_sb, inode->i_ino, &bh))) return 0;
  54         disk_secno = hpfs_bplus_lookup(inode->i_sb, inode, &fnode->btree, file_secno, bh);
  55         if (disk_secno == -1) return 0;
  56         if (hpfs_chk_sectors(inode->i_sb, disk_secno, 1, "bmap")) return 0;
  57         n = file_secno - hpfs_inode->i_file_sec;
  58         if (n < hpfs_inode->i_n_secs) {
  59                 *n_secs = hpfs_inode->i_n_secs - n;
  60                 return hpfs_inode->i_disk_sec + n;
  61         }
  62         *n_secs = 1;
  63         return disk_secno;
  64 }
  65
  66 void hpfs_truncate(struct inode *i)
  67 {
  68         if (IS_IMMUTABLE(i)) return /*-EPERM*/;
  69         hpfs_lock_assert(i->i_sb);
  70
  71         hpfs_i(i)->i_n_secs = 0;
  72         i->i_blocks = 1 + ((i->i_size + 511) >> 9);
  73         hpfs_i(i)->mmu_private = i->i_size;
  74         hpfs_truncate_btree(i->i_sb, i->i_ino, 1, ((i->i_size + 511) >> 9));
  75         hpfs_write_inode(i);
  76         hpfs_i(i)->i_n_secs = 0;
  77 }
  78
  79 static int hpfs_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create)
  80 {
  81         int r;
  82         secno s;
  83         unsigned n_secs;
  84         hpfs_lock(inode->i_sb);
  85         s = hpfs_bmap(inode, iblock, &n_secs);
  86         if (s) {
  87                 if (bh_result->b_size >> 9 < n_secs)
  88                         n_secs = bh_result->b_size >> 9;
  89                 n_secs = hpfs_search_hotfix_map_for_range(inode->i_sb, s, n_secs);
  90                 if (unlikely(!n_secs)) {
  91                         s = hpfs_search_hotfix_map(inode->i_sb, s);
  92                         n_secs = 1;
  93                 }
  94                 map_bh(bh_result, inode->i_sb, s);
  95                 bh_result->b_size = n_secs << 9;
  96                 goto ret_0;
  97         }
  98         if (!create) goto ret_0;
  99         if (iblock<<9 != hpfs_i(inode)->mmu_private) {
 100                 BUG();
 101                 r = -EIO;
 102                 goto ret_r;
 103         }
 104         if ((s = hpfs_add_sector_to_btree(inode->i_sb, inode->i_ino, 1, inode->i_blocks - 1)) == -1) {
 105                 hpfs_truncate_btree(inode->i_sb, inode->i_ino, 1, inode->i_blocks - 1);
 106                 r = -ENOSPC;
 107                 goto ret_r;
 108         }
 109         inode->i_blocks++;
 110         hpfs_i(inode)->mmu_private += 512;
 111         set_buffer_new(bh_result);
 112         map_bh(bh_result, inode->i_sb, hpfs_search_hotfix_map(inode->i_sb, s));
 113         ret_0:
 114         r = 0;
 115         ret_r:
 116         hpfs_unlock(inode->i_sb);
 117         return r;
 118 }
 119
 120 static int hpfs_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
 121                 unsigned flags, struct iomap *iomap, struct iomap *srcmap)
 122 {
 123         struct super_block *sb = inode->i_sb;
 124         unsigned int blkbits = inode->i_blkbits;
 125         unsigned int n_secs;
 126         secno s;
 127
 128         if (WARN_ON_ONCE(flags & (IOMAP_WRITE | IOMAP_ZERO)))
 129                 return -EINVAL;
 130
 131         iomap->bdev = inode->i_sb->s_bdev;
 132         iomap->offset = offset;
 133
 134         hpfs_lock(sb);
 135         s = hpfs_bmap(inode, offset >> blkbits, &n_secs);
 136         if (s) {
 137                 n_secs = hpfs_search_hotfix_map_for_range(sb, s,
 138                                 min_t(loff_t, n_secs, length));
 139                 if (unlikely(!n_secs)) {
 140                         s = hpfs_search_hotfix_map(sb, s);
 141                         n_secs = 1;
 142                 }
 143                 iomap->type = IOMAP_MAPPED;
 144                 iomap->flags = IOMAP_F_MERGED;
 145                 iomap->addr = (u64)s << blkbits;
 146                 iomap->length = (u64)n_secs << blkbits;
 147         } else {
 148                 iomap->type = IOMAP_HOLE;
 149                 iomap->addr = IOMAP_NULL_ADDR;
 150                 iomap->length = 1 << blkbits;
 151         }
 152
 153         hpfs_unlock(sb);
 154         return 0;
 155 }
 156
 157 static const struct iomap_ops hpfs_iomap_ops = {
 158         .iomap_begin            = hpfs_iomap_begin,
 159 };
 160
 161 static int hpfs_read_folio(struct file *file, struct folio *folio)
 162 {
 163         return mpage_read_folio(folio, hpfs_get_block);
 164 }
 165
 166 static void hpfs_readahead(struct readahead_control *rac)
 167 {
 168         mpage_readahead(rac, hpfs_get_block);
 169 }
 170
 171 static int hpfs_writepages(struct address_space *mapping,
 172                            struct writeback_control *wbc)
 173 {
 174         return mpage_writepages(mapping, wbc, hpfs_get_block);
 175 }
 176
 177 static void hpfs_write_failed(struct address_space *mapping, loff_t to)
 178 {
 179         struct inode *inode = mapping->host;
 180
 181         hpfs_lock(inode->i_sb);
 182
 183         if (to > inode->i_size) {
 184                 truncate_pagecache(inode, inode->i_size);
 185                 hpfs_truncate(inode);
 186         }
 187
 188         hpfs_unlock(inode->i_sb);
 189 }
 190
 191 static int hpfs_write_begin(struct file *file, struct address_space *mapping,
 192                         loff_t pos, unsigned len,
 193                         struct page **pagep, void **fsdata)
 194 {
 195         int ret;
 196
 197         *pagep = NULL;
 198         ret = cont_write_begin(file, mapping, pos, len, pagep, fsdata,
 199                                 hpfs_get_block,
 200                                 &hpfs_i(mapping->host)->mmu_private);
 201         if (unlikely(ret))
 202                 hpfs_write_failed(mapping, pos + len);
 203
 204         return ret;
 205 }
 206
 207 static int hpfs_write_end(struct file *file, struct address_space *mapping,
 208                         loff_t pos, unsigned len, unsigned copied,
 209                         struct page *pagep, void *fsdata)
 210 {
 211         struct inode *inode = mapping->host;
 212         int err;
 213         err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata);
 214         if (err < len)
 215                 hpfs_write_failed(mapping, pos + len);
 216         if (!(err < 0)) {
 217                 /* make sure we write it on close, if not earlier */
 218                 hpfs_lock(inode->i_sb);
 219                 hpfs_i(inode)->i_dirty = 1;
 220                 hpfs_unlock(inode->i_sb);
 221         }
 222         return err;
 223 }
 224
 225 static sector_t _hpfs_bmap(struct address_space *mapping, sector_t block)
 226 {
 227         return generic_block_bmap(mapping, block, hpfs_get_block);
 228 }
 229
 230 static int hpfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, u64 start, u64 len)
 231 {
 232         int ret;
 233
 234         inode_lock(inode);
 235         len = min_t(u64, len, i_size_read(inode));
 236         ret = iomap_fiemap(inode, fieinfo, start, len, &hpfs_iomap_ops);
 237         inode_unlock(inode);
 238
 239         return ret;
 240 }
 241
 242 const struct address_space_operations hpfs_aops = {
 243         .dirty_folio    = block_dirty_folio,
 244         .invalidate_folio = block_invalidate_folio,
 245         .read_folio = hpfs_read_folio,
 246         .readahead = hpfs_readahead,
 247         .writepages = hpfs_writepages,
 248         .write_begin = hpfs_write_begin,
 249         .write_end = hpfs_write_end,
 250         .bmap = _hpfs_bmap,
 251         .migrate_folio = buffer_migrate_folio,
 252 };
 253
 254 const struct file_operations hpfs_file_ops =
 255 {
 256         .llseek         = generic_file_llseek,
 257         .read_iter      = generic_file_read_iter,
 258         .write_iter     = generic_file_write_iter,
 259         .mmap           = generic_file_mmap,
 260         .release        = hpfs_file_release,
 261         .fsync          = hpfs_file_fsync,
 262         .splice_read    = generic_file_splice_read,
 263         .unlocked_ioctl = hpfs_ioctl,
 264         .compat_ioctl   = compat_ptr_ioctl,
 265 };
 266
 267 const struct inode_operations hpfs_file_iops =
 268 {
 269         .setattr        = hpfs_setattr,
 270         .fiemap         = hpfs_fiemap,
 271 };