file.c
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/*
* linux/fs/hpfs/file.c
*
* Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
*
* file VFS functions
*/
#include "hpfs_fn.h"
#define BLOCKS(size) (((size) + 511) >> 9)
static int hpfs_file_release(struct inode *inode, struct file *file)
{
lock_kernel();
hpfs_write_if_changed(inode);
unlock_kernel();
return 0;
}
int hpfs_file_fsync(struct file *file, struct dentry *dentry, int datasync)
{
/*return file_fsync(file, dentry);*/
return 0; /* Don't fsync :-) */
}
/*
* generic_file_read often calls bmap with non-existing sector,
* so we must ignore such errors.
*/
static secno hpfs_bmap(struct inode *inode, unsigned file_secno)
{
struct hpfs_inode_info *hpfs_inode = hpfs_i(inode);
unsigned n, disk_secno;
struct fnode *fnode;
struct buffer_head *bh;
if (BLOCKS(hpfs_i(inode)->mmu_private) <= file_secno) return 0;
n = file_secno - hpfs_inode->i_file_sec;
if (n < hpfs_inode->i_n_secs) return hpfs_inode->i_disk_sec + n;
if (!(fnode = hpfs_map_fnode(inode->i_sb, inode->i_ino, &bh))) return 0;
disk_secno = hpfs_bplus_lookup(inode->i_sb, inode, &fnode->btree, file_secno, bh);
if (disk_secno == -1) return 0;
if (hpfs_chk_sectors(inode->i_sb, disk_secno, 1, "bmap")) return 0;
return disk_secno;
}
static void hpfs_truncate(struct inode *i)
{
if (IS_IMMUTABLE(i)) return /*-EPERM*/;
lock_kernel();
hpfs_i(i)->i_n_secs = 0;
i->i_blocks = 1 + ((i->i_size + 511) >> 9);
hpfs_i(i)->mmu_private = i->i_size;
hpfs_truncate_btree(i->i_sb, i->i_ino, 1, ((i->i_size + 511) >> 9));
hpfs_write_inode(i);
hpfs_i(i)->i_n_secs = 0;
unlock_kernel();
}
static int hpfs_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create)
{
secno s;
s = hpfs_bmap(inode, iblock);
if (s) {
map_bh(bh_result, inode->i_sb, s);
return 0;
}
if (!create) return 0;
if (iblock<<9 != hpfs_i(inode)->mmu_private) {
BUG();
return -EIO;
}
if ((s = hpfs_add_sector_to_btree(inode->i_sb, inode->i_ino, 1, inode->i_blocks - 1)) == -1) {
hpfs_truncate_btree(inode->i_sb, inode->i_ino, 1, inode->i_blocks - 1);
return -ENOSPC;
}
inode->i_blocks++;
hpfs_i(inode)->mmu_private += 512;
set_buffer_new(bh_result);
map_bh(bh_result, inode->i_sb, s);
return 0;
}
static int hpfs_writepage(struct page *page, struct writeback_control *wbc)
{
return block_write_full_page(page,hpfs_get_block, wbc);
}
static int hpfs_readpage(struct file *file, struct page *page)
{
return block_read_full_page(page,hpfs_get_block);
}
static int hpfs_write_begin(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned flags,
struct page **pagep, void **fsdata)
{
*pagep = NULL;
return cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
hpfs_get_block,
&hpfs_i(mapping->host)->mmu_private);
}
static sector_t _hpfs_bmap(struct address_space *mapping, sector_t block)
{
return generic_block_bmap(mapping,block,hpfs_get_block);
}
const struct address_space_operations hpfs_aops = {
.readpage = hpfs_readpage,
.writepage = hpfs_writepage,
.sync_page = block_sync_page,
.write_begin = hpfs_write_begin,
.write_end = generic_write_end,
.bmap = _hpfs_bmap
};
static ssize_t hpfs_file_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
ssize_t retval;
retval = do_sync_write(file, buf, count, ppos);
if (retval > 0)
hpfs_i(file->f_path.dentry->d_inode)->i_dirty = 1;
return retval;
}
const struct file_operations hpfs_file_ops =
{
.llseek = generic_file_llseek,
.read = do_sync_read,
.aio_read = generic_file_aio_read,
.write = hpfs_file_write,
.aio_write = generic_file_aio_write,
.mmap = generic_file_mmap,
.release = hpfs_file_release,
.fsync = hpfs_file_fsync,
.splice_read = generic_file_splice_read,
};
const struct inode_operations hpfs_file_iops =
{
.truncate = hpfs_truncate,
.setattr = hpfs_notify_change,
};