linux/fs/hpfs/file.c
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   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
  13static 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
  21int 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
  37static 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
  53void 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
  66static 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
  98static int hpfs_writepage(struct page *page, struct writeback_control *wbc)
  99{
 100        return block_write_full_page(page,hpfs_get_block, wbc);
 101}
 102
 103static int hpfs_readpage(struct file *file, struct page *page)
 104{
 105        return block_read_full_page(page,hpfs_get_block);
 106}
 107
 108static 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
 118static 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
 134static sector_t _hpfs_bmap(struct address_space *mapping, sector_t block)
 135{
 136        return generic_block_bmap(mapping,block,hpfs_get_block);
 137}
 138
 139const struct address_space_operations hpfs_aops = {
 140        .readpage = hpfs_readpage,
 141        .writepage = hpfs_writepage,
 142        .write_begin = hpfs_write_begin,
 143        .write_end = generic_write_end,
 144        .bmap = _hpfs_bmap
 145};
 146
 147static ssize_t hpfs_file_write(struct file *file, const char __user *buf,
 148                        size_t count, loff_t *ppos)
 149{
 150        ssize_t retval;
 151
 152        retval = do_sync_write(file, buf, count, ppos);
 153        if (retval > 0) {
 154                hpfs_lock(file->f_path.dentry->d_sb);
 155                hpfs_i(file->f_path.dentry->d_inode)->i_dirty = 1;
 156                hpfs_unlock(file->f_path.dentry->d_sb);
 157        }
 158        return retval;
 159}
 160
 161const struct file_operations hpfs_file_ops =
 162{
 163        .llseek         = generic_file_llseek,
 164        .read           = do_sync_read,
 165        .aio_read       = generic_file_aio_read,
 166        .write          = hpfs_file_write,
 167        .aio_write      = generic_file_aio_write,
 168        .mmap           = generic_file_mmap,
 169        .release        = hpfs_file_release,
 170        .fsync          = hpfs_file_fsync,
 171        .splice_read    = generic_file_splice_read,
 172};
 173
 174const struct inode_operations hpfs_file_iops =
 175{
 176        .setattr        = hpfs_setattr,
 177};
 178
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