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 <linux/smp_lock.h>
  10 #include "hpfs_fn.h"
  11
  12 #define BLOCKS(size) (((size) + 511) >> 9)
  13
  14 static int hpfs_file_release(struct inode *inode, struct file *file)
  15 {
  16         lock_kernel();
  17         hpfs_write_if_changed(inode);
  18         unlock_kernel();
  19         return 0;
  20 }
  21
  22 int hpfs_file_fsync(struct file *file, int datasync)
  23 {
  24         /*return file_fsync(file, datasync);*/
  25         return 0; /* Don't fsync :-) */
  26 }
  27
  28 /*
  29  * generic_file_read often calls bmap with non-existing sector,
  30  * so we must ignore such errors.
  31  */
  32
  33 static secno hpfs_bmap(struct inode *inode, unsigned file_secno)
  34 {
  35         struct hpfs_inode_info *hpfs_inode = hpfs_i(inode);
  36         unsigned n, disk_secno;
  37         struct fnode *fnode;
  38         struct buffer_head *bh;
  39         if (BLOCKS(hpfs_i(inode)->mmu_private) <= file_secno) return 0;
  40         n = file_secno - hpfs_inode->i_file_sec;
  41         if (n < hpfs_inode->i_n_secs) return hpfs_inode->i_disk_sec + n;
  42         if (!(fnode = hpfs_map_fnode(inode->i_sb, inode->i_ino, &bh))) return 0;
  43         disk_secno = hpfs_bplus_lookup(inode->i_sb, inode, &fnode->btree, file_secno, bh);
  44         if (disk_secno == -1) return 0;
  45         if (hpfs_chk_sectors(inode->i_sb, disk_secno, 1, "bmap")) return 0;
  46         return disk_secno;
  47 }
  48
  49 static void hpfs_truncate(struct inode *i)
  50 {
  51         if (IS_IMMUTABLE(i)) return /*-EPERM*/;
  52         lock_kernel();
  53         hpfs_i(i)->i_n_secs = 0;
  54         i->i_blocks = 1 + ((i->i_size + 511) >> 9);
  55         hpfs_i(i)->mmu_private = i->i_size;
  56         hpfs_truncate_btree(i->i_sb, i->i_ino, 1, ((i->i_size + 511) >> 9));
  57         hpfs_write_inode(i);
  58         hpfs_i(i)->i_n_secs = 0;
  59         unlock_kernel();
  60 }
  61
  62 static int hpfs_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create)
  63 {
  64         secno s;
  65         s = hpfs_bmap(inode, iblock);
  66         if (s) {
  67                 map_bh(bh_result, inode->i_sb, s);
  68                 return 0;
  69         }
  70         if (!create) return 0;
  71         if (iblock<<9 != hpfs_i(inode)->mmu_private) {
  72                 BUG();
  73                 return -EIO;
  74         }
  75         if ((s = hpfs_add_sector_to_btree(inode->i_sb, inode->i_ino, 1, inode->i_blocks - 1)) == -1) {
  76                 hpfs_truncate_btree(inode->i_sb, inode->i_ino, 1, inode->i_blocks - 1);
  77                 return -ENOSPC;
  78         }
  79         inode->i_blocks++;
  80         hpfs_i(inode)->mmu_private += 512;
  81         set_buffer_new(bh_result);
  82         map_bh(bh_result, inode->i_sb, s);
  83         return 0;
  84 }
  85
  86 static int hpfs_writepage(struct page *page, struct writeback_control *wbc)
  87 {
  88         return block_write_full_page(page,hpfs_get_block, wbc);
  89 }
  90
  91 static int hpfs_readpage(struct file *file, struct page *page)
  92 {
  93         return block_read_full_page(page,hpfs_get_block);
  94 }
  95
  96 static int hpfs_write_begin(struct file *file, struct address_space *mapping,
  97                         loff_t pos, unsigned len, unsigned flags,
  98                         struct page **pagep, void **fsdata)
  99 {
 100         int ret;
 101
 102         *pagep = NULL;
 103         ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
 104                                 hpfs_get_block,
 105                                 &hpfs_i(mapping->host)->mmu_private);
 106         if (unlikely(ret)) {
 107                 loff_t isize = mapping->host->i_size;
 108                 if (pos + len > isize)
 109                         vmtruncate(mapping->host, isize);
 110         }
 111
 112         return ret;
 113 }
 114
 115 static sector_t _hpfs_bmap(struct address_space *mapping, sector_t block)
 116 {
 117         return generic_block_bmap(mapping,block,hpfs_get_block);
 118 }
 119
 120 const struct address_space_operations hpfs_aops = {
 121         .readpage = hpfs_readpage,
 122         .writepage = hpfs_writepage,
 123         .sync_page = block_sync_page,
 124         .write_begin = hpfs_write_begin,
 125         .write_end = generic_write_end,
 126         .bmap = _hpfs_bmap
 127 };
 128
 129 static ssize_t hpfs_file_write(struct file *file, const char __user *buf,
 130                         size_t count, loff_t *ppos)
 131 {
 132         ssize_t retval;
 133
 134         retval = do_sync_write(file, buf, count, ppos);
 135         if (retval > 0)
 136                 hpfs_i(file->f_path.dentry->d_inode)->i_dirty = 1;
 137         return retval;
 138 }
 139
 140 const struct file_operations hpfs_file_ops =
 141 {
 142         .llseek         = generic_file_llseek,
 143         .read           = do_sync_read,
 144         .aio_read       = generic_file_aio_read,
 145         .write          = hpfs_file_write,
 146         .aio_write      = generic_file_aio_write,
 147         .mmap           = generic_file_mmap,
 148         .release        = hpfs_file_release,
 149         .fsync          = hpfs_file_fsync,
 150         .splice_read    = generic_file_splice_read,
 151 };
 152
 153 const struct inode_operations hpfs_file_iops =
 154 {
 155         .truncate       = hpfs_truncate,
 156         .setattr        = hpfs_setattr,
 157 };