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/string.h>
10#include <linux/sched.h>
11#include <linux/smp_lock.h>
12#include "hpfs_fn.h"
13
14#define BLOCKS(size) (((size) + 511) >> 9)
15
16/* HUH? */
17int hpfs_open(struct inode *i, struct file *f)
18{
19	lock_kernel();
20	hpfs_lock_inode(i);
21	hpfs_unlock_inode(i); /* make sure nobody is deleting the file */
22	unlock_kernel();
23	if (!i->i_nlink) return -ENOENT;
24	return 0;
25}
26
27int hpfs_file_release(struct inode *inode, struct file *file)
28{
29	lock_kernel();
30	hpfs_write_if_changed(inode);
31	unlock_kernel();
32	return 0;
33}
34
35int hpfs_file_fsync(struct file *file, struct dentry *dentry, int datasync)
36{
37	/*return file_fsync(file, dentry);*/
38	return 0; /* Don't fsync :-) */
39}
40
41/*
42 * generic_file_read often calls bmap with non-existing sector,
43 * so we must ignore such errors.
44 */
45
46secno hpfs_bmap(struct inode *inode, unsigned file_secno)
47{
48	unsigned n, disk_secno;
49	struct fnode *fnode;
50	struct buffer_head *bh;
51	if (BLOCKS(inode->u.hpfs_i.mmu_private) <= file_secno) return 0;
52	n = file_secno - inode->i_hpfs_file_sec;
53	if (n < inode->i_hpfs_n_secs) return inode->i_hpfs_disk_sec + n;
54	if (!(fnode = hpfs_map_fnode(inode->i_sb, inode->i_ino, &bh))) return 0;
55	disk_secno = hpfs_bplus_lookup(inode->i_sb, inode, &fnode->btree, file_secno, bh);
56	if (disk_secno == -1) return 0;
57	if (hpfs_chk_sectors(inode->i_sb, disk_secno, 1, "bmap")) return 0;
58	return disk_secno;
59}
60
61void hpfs_truncate(struct inode *i)
62{
63	if (IS_IMMUTABLE(i)) return /*-EPERM*/;
64	i->i_hpfs_n_secs = 0;
65	i->i_blocks = 1 + ((i->i_size + 511) >> 9);
66	i->u.hpfs_i.mmu_private = i->i_size;
67	hpfs_truncate_btree(i->i_sb, i->i_ino, 1, ((i->i_size + 511) >> 9));
68	hpfs_write_inode(i);
69}
70
71int hpfs_get_block(struct inode *inode, long iblock, struct buffer_head *bh_result, int create)
72{
73	secno s;
74	s = hpfs_bmap(inode, iblock);
75	if (s) {
76		bh_result->b_dev = inode->i_dev;
77		bh_result->b_blocknr = s;
78		bh_result->b_state |= (1UL << BH_Mapped);
79		return 0;
80	}
81	if (!create) return 0;
82	if (iblock<<9 != inode->u.hpfs_i.mmu_private) {
83		BUG();
84		return -EIO;
85	}
86	if ((s = hpfs_add_sector_to_btree(inode->i_sb, inode->i_ino, 1, inode->i_blocks - 1)) == -1) {
87		hpfs_truncate_btree(inode->i_sb, inode->i_ino, 1, inode->i_blocks - 1);
88		return -ENOSPC;
89	}
90	inode->i_blocks++;
91	inode->u.hpfs_i.mmu_private += 512;
92	bh_result->b_dev = inode->i_dev;
93	bh_result->b_blocknr = s;
94	bh_result->b_state |= (1UL << BH_Mapped) | (1UL << BH_New);
95	return 0;
96}
97
98static int hpfs_writepage(struct page *page)
99{
100	return block_write_full_page(page,hpfs_get_block);
101}
102static int hpfs_readpage(struct file *file, struct page *page)
103{
104	return block_read_full_page(page,hpfs_get_block);
105}
106static int hpfs_prepare_write(struct file *file, struct page *page, unsigned from, unsigned to)
107{
108	return cont_prepare_write(page,from,to,hpfs_get_block,
109		&page->mapping->host->u.hpfs_i.mmu_private);
110}
111static int _hpfs_bmap(struct address_space *mapping, long block)
112{
113	return generic_block_bmap(mapping,block,hpfs_get_block);
114}
115struct address_space_operations hpfs_aops = {
116	readpage: hpfs_readpage,
117	writepage: hpfs_writepage,
118	sync_page: block_sync_page,
119	prepare_write: hpfs_prepare_write,
120	commit_write: generic_commit_write,
121	bmap: _hpfs_bmap
122};
123
124ssize_t hpfs_file_write(struct file *file, const char *buf, size_t count, loff_t *ppos)
125{
126	ssize_t retval;
127
128	retval = generic_file_write(file, buf, count, ppos);
129	if (retval > 0) {
130		struct inode *inode = file->f_dentry->d_inode;
131		inode->i_mtime = CURRENT_TIME;
132		inode->i_hpfs_dirty = 1;
133	}
134	return retval;
135}
136
137