xref: /openbmc/linux/fs/hpfs/file.c (revision ca79522c)
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 
13 static 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 
21 int 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 
37 static 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 
53 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 
66 static 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 
98 static int hpfs_writepage(struct page *page, struct writeback_control *wbc)
99 {
100 	return block_write_full_page(page,hpfs_get_block, wbc);
101 }
102 
103 static int hpfs_readpage(struct file *file, struct page *page)
104 {
105 	return block_read_full_page(page,hpfs_get_block);
106 }
107 
108 static void hpfs_write_failed(struct address_space *mapping, loff_t to)
109 {
110 	struct inode *inode = mapping->host;
111 
112 	if (to > inode->i_size) {
113 		truncate_pagecache(inode, to, inode->i_size);
114 		hpfs_truncate(inode);
115 	}
116 }
117 
118 static int hpfs_write_begin(struct file *file, struct address_space *mapping,
119 			loff_t pos, unsigned len, unsigned flags,
120 			struct page **pagep, void **fsdata)
121 {
122 	int ret;
123 
124 	*pagep = NULL;
125 	ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
126 				hpfs_get_block,
127 				&hpfs_i(mapping->host)->mmu_private);
128 	if (unlikely(ret))
129 		hpfs_write_failed(mapping, pos + len);
130 
131 	return ret;
132 }
133 
134 static int hpfs_write_end(struct file *file, struct address_space *mapping,
135 			loff_t pos, unsigned len, unsigned copied,
136 			struct page *pagep, void *fsdata)
137 {
138 	struct inode *inode = mapping->host;
139 	int err;
140 	err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata);
141 	if (err < len)
142 		hpfs_write_failed(mapping, pos + len);
143 	if (!(err < 0)) {
144 		/* make sure we write it on close, if not earlier */
145 		hpfs_lock(inode->i_sb);
146 		hpfs_i(inode)->i_dirty = 1;
147 		hpfs_unlock(inode->i_sb);
148 	}
149 	return err;
150 }
151 
152 static sector_t _hpfs_bmap(struct address_space *mapping, sector_t block)
153 {
154 	return generic_block_bmap(mapping,block,hpfs_get_block);
155 }
156 
157 const struct address_space_operations hpfs_aops = {
158 	.readpage = hpfs_readpage,
159 	.writepage = hpfs_writepage,
160 	.write_begin = hpfs_write_begin,
161 	.write_end = hpfs_write_end,
162 	.bmap = _hpfs_bmap
163 };
164 
165 const struct file_operations hpfs_file_ops =
166 {
167 	.llseek		= generic_file_llseek,
168 	.read		= do_sync_read,
169 	.aio_read	= generic_file_aio_read,
170 	.write		= do_sync_write,
171 	.aio_write	= generic_file_aio_write,
172 	.mmap		= generic_file_mmap,
173 	.release	= hpfs_file_release,
174 	.fsync		= hpfs_file_fsync,
175 	.splice_read	= generic_file_splice_read,
176 };
177 
178 const struct inode_operations hpfs_file_iops =
179 {
180 	.setattr	= hpfs_setattr,
181 };
182