fs/hpfs/file.c

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