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/*
* linux/fs/hpfs/file.c
*
* Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
*
* file VFS functions
*/
#include <linux/string.h>
#include "hpfs_fn.h"
int hpfs_open(struct inode *i, struct file *f)
{
hpfs_lock_inode(i);
hpfs_unlock_inode(i); /* make sure nobody is deleting the file */
if (!i->i_nlink) return -ENOENT;
return 0;
}
int hpfs_file_release(struct inode *inode, struct file *file)
{
hpfs_write_if_changed(inode);
return 0;
}
int hpfs_file_fsync(struct file *file, struct dentry *dentry)
{
/*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.
*/
secno hpfs_bmap(struct inode *inode, unsigned file_secno)
{
unsigned n, disk_secno;
struct fnode *fnode;
struct buffer_head *bh;
if (((inode->i_size + 511) >> 9) <= file_secno) return 0;
n = file_secno - inode->i_hpfs_file_sec;
if (n < inode->i_hpfs_n_secs) return inode->i_hpfs_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;
}
void hpfs_truncate(struct inode *i)
{
if (IS_IMMUTABLE(i)) return /*-EPERM*/;
i->i_hpfs_n_secs = 0;
i->i_blocks = 1 + ((i->i_size + 511) >> 9);
hpfs_truncate_btree(i->i_sb, i->i_ino, 1, ((i->i_size + 511) >> 9));
hpfs_write_inode(i);
}
int hpfs_get_block(struct inode *inode, long iblock, struct buffer_head *bh_result, int create)
{
secno s;
if (iblock < inode->i_blocks - 1) {
s = hpfs_bmap(inode, iblock);
bh_result->b_dev = inode->i_dev;
bh_result->b_blocknr = s;
bh_result->b_state |= (1UL << BH_Mapped);
return 0;
}
if (!create) return 0;
if (iblock > inode->i_blocks - 1) {
//hpfs_error(inode->i_sb, "hpfs_get_block beyond file end (requested %08x, inode size %08x", (int)iblock, (int)inode->i_blocks - 1);
printk("HPFS: could not write beyond file end. This is known bug.\n");
return -EFSERROR;
}
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++;
bh_result->b_dev = inode->i_dev;
bh_result->b_blocknr = s;
bh_result->b_state |= (1UL << BH_Mapped) | (1UL << BH_New);
return 0;
}
static int hpfs_write_partial_page(struct file *file, struct page *page, unsigned long offset, unsigned long bytes, const char * buf)
{
struct dentry *dentry = file->f_dentry;
struct inode *inode = dentry->d_inode;
struct page *new_page;
unsigned long pgpos;
long status;
pgpos = ((inode->i_blocks - 1) * 512) >> PAGE_CACHE_SHIFT;
while (pgpos < page->index) {
status = -ENOMEM;
new_page = grab_cache_page(&inode->i_data, pgpos);
if (!new_page)
goto out;
status = block_write_cont_page(file, new_page, PAGE_SIZE, 0, NULL);
UnlockPage(new_page);
page_cache_release(new_page);
if (status < 0)
goto out;
pgpos = ((inode->i_blocks - 1) * 512) >> PAGE_CACHE_SHIFT;
}
status = block_write_cont_page(file, page, offset, bytes, buf);
out:
return status;
}
ssize_t hpfs_file_write(struct file *file, const char *buf, size_t count, loff_t *ppos)
{
ssize_t retval;
retval = generic_file_write(file, buf, count,
ppos, hpfs_write_partial_page);
if (retval > 0) {
struct inode *inode = file->f_dentry->d_inode;
inode->i_mtime = CURRENT_TIME;
inode->i_hpfs_dirty = 1;
}
return retval;
}
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