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	hpfs_lock(inode->i_sb);
 16	hpfs_write_if_changed(inode);
 17	hpfs_unlock(inode->i_sb);
 18	return 0;
 19}
 20
 21int hpfs_file_fsync(struct file *file, loff_t start, loff_t end, int datasync)
 22{
 23	struct inode *inode = file->f_mapping->host;
 24	int ret;
 25
 26	ret = filemap_write_and_wait_range(file->f_mapping, start, end);
 27	if (ret)
 28		return ret;
 29	return sync_blockdev(inode->i_sb->s_bdev);
 30}
 31
 32/*
 33 * generic_file_read often calls bmap with non-existing sector,
 34 * so we must ignore such errors.
 35 */
 36
 37static secno hpfs_bmap(struct inode *inode, unsigned file_secno)
 38{
 39	struct hpfs_inode_info *hpfs_inode = hpfs_i(inode);
 40	unsigned n, disk_secno;
 41	struct fnode *fnode;
 42	struct buffer_head *bh;
 43	if (BLOCKS(hpfs_i(inode)->mmu_private) <= file_secno) return 0;
 44	n = file_secno - hpfs_inode->i_file_sec;
 45	if (n < hpfs_inode->i_n_secs) return hpfs_inode->i_disk_sec + n;
 46	if (!(fnode = hpfs_map_fnode(inode->i_sb, inode->i_ino, &bh))) return 0;
 47	disk_secno = hpfs_bplus_lookup(inode->i_sb, inode, &fnode->btree, file_secno, bh);
 48	if (disk_secno == -1) return 0;
 49	if (hpfs_chk_sectors(inode->i_sb, disk_secno, 1, "bmap")) return 0;
 50	return disk_secno;
 51}
 52
 53static void hpfs_truncate(struct inode *i)
 54{
 55	if (IS_IMMUTABLE(i)) return /*-EPERM*/;
 56	hpfs_lock_assert(i->i_sb);
 57
 58	hpfs_i(i)->i_n_secs = 0;
 59	i->i_blocks = 1 + ((i->i_size + 511) >> 9);
 60	hpfs_i(i)->mmu_private = i->i_size;
 61	hpfs_truncate_btree(i->i_sb, i->i_ino, 1, ((i->i_size + 511) >> 9));
 62	hpfs_write_inode(i);
 63	hpfs_i(i)->i_n_secs = 0;
 64}
 65
 66static int hpfs_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create)
 67{
 68	int r;
 69	secno s;
 70	hpfs_lock(inode->i_sb);
 71	s = hpfs_bmap(inode, iblock);
 72	if (s) {
 73		map_bh(bh_result, inode->i_sb, s);
 74		goto ret_0;
 75	}
 76	if (!create) goto ret_0;
 77	if (iblock<<9 != hpfs_i(inode)->mmu_private) {
 78		BUG();
 79		r = -EIO;
 80		goto ret_r;
 81	}
 82	if ((s = hpfs_add_sector_to_btree(inode->i_sb, inode->i_ino, 1, inode->i_blocks - 1)) == -1) {
 83		hpfs_truncate_btree(inode->i_sb, inode->i_ino, 1, inode->i_blocks - 1);
 84		r = -ENOSPC;
 85		goto ret_r;
 86	}
 87	inode->i_blocks++;
 88	hpfs_i(inode)->mmu_private += 512;
 89	set_buffer_new(bh_result);
 90	map_bh(bh_result, inode->i_sb, s);
 91	ret_0:
 92	r = 0;
 93	ret_r:
 94	hpfs_unlock(inode->i_sb);
 95	return r;
 96}
 97
 98static int hpfs_writepage(struct page *page, struct writeback_control *wbc)
 99{
100	return block_write_full_page(page,hpfs_get_block, wbc);
101}
102
103static int hpfs_readpage(struct file *file, struct page *page)
104{
105	return block_read_full_page(page,hpfs_get_block);
106}
107
108static int hpfs_write_begin(struct file *file, struct address_space *mapping,
109			loff_t pos, unsigned len, unsigned flags,
110			struct page **pagep, void **fsdata)
111{
112	int ret;
113
114	*pagep = NULL;
115	ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
116				hpfs_get_block,
117				&hpfs_i(mapping->host)->mmu_private);
118	if (unlikely(ret)) {
119		loff_t isize = mapping->host->i_size;
120		if (pos + len > isize)
121			vmtruncate(mapping->host, isize);
122	}
123
124	return ret;
125}
126
127static sector_t _hpfs_bmap(struct address_space *mapping, sector_t block)
128{
129	return generic_block_bmap(mapping,block,hpfs_get_block);
130}
131
132const struct address_space_operations hpfs_aops = {
133	.readpage = hpfs_readpage,
134	.writepage = hpfs_writepage,
135	.write_begin = hpfs_write_begin,
136	.write_end = generic_write_end,
137	.bmap = _hpfs_bmap
138};
139
140static ssize_t hpfs_file_write(struct file *file, const char __user *buf,
141			size_t count, loff_t *ppos)
142{
143	ssize_t retval;
144
145	retval = do_sync_write(file, buf, count, ppos);
146	if (retval > 0) {
147		hpfs_lock(file->f_path.dentry->d_sb);
148		hpfs_i(file->f_path.dentry->d_inode)->i_dirty = 1;
149		hpfs_unlock(file->f_path.dentry->d_sb);
150	}
151	return retval;
152}
153
154const struct file_operations hpfs_file_ops =
155{
156	.llseek		= generic_file_llseek,
157	.read		= do_sync_read,
158	.aio_read	= generic_file_aio_read,
159	.write		= hpfs_file_write,
160	.aio_write	= generic_file_aio_write,
161	.mmap		= generic_file_mmap,
162	.release	= hpfs_file_release,
163	.fsync		= hpfs_file_fsync,
164	.splice_read	= generic_file_splice_read,
165};
166
167const struct inode_operations hpfs_file_iops =
168{
169	.truncate	= hpfs_truncate,
170	.setattr	= hpfs_setattr,
171};