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