1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
|
/*
* linux/fs/hpfs/file.c
*
* Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
*
* file VFS functions
*/
#include "hpfs_fn.h"
#include <linux/mpage.h>
#define BLOCKS(size) (((size) + 511) >> 9)
static int hpfs_file_release(struct inode *inode, struct file *file)
{
hpfs_lock(inode->i_sb);
hpfs_write_if_changed(inode);
hpfs_unlock(inode->i_sb);
return 0;
}
int hpfs_file_fsync(struct file *file, loff_t start, loff_t end, int datasync)
{
struct inode *inode = file->f_mapping->host;
int ret;
ret = filemap_write_and_wait_range(file->f_mapping, start, end);
if (ret)
return ret;
return sync_blockdev(inode->i_sb->s_bdev);
}
/*
* generic_file_read often calls bmap with non-existing sector,
* so we must ignore such errors.
*/
static secno hpfs_bmap(struct inode *inode, unsigned file_secno, unsigned *n_secs)
{
struct hpfs_inode_info *hpfs_inode = hpfs_i(inode);
unsigned n, disk_secno;
struct fnode *fnode;
struct buffer_head *bh;
if (BLOCKS(hpfs_i(inode)->mmu_private) <= file_secno) return 0;
n = file_secno - hpfs_inode->i_file_sec;
if (n < hpfs_inode->i_n_secs) {
*n_secs = hpfs_inode->i_n_secs - n;
return hpfs_inode->i_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;
n = file_secno - hpfs_inode->i_file_sec;
if (n < hpfs_inode->i_n_secs) {
*n_secs = hpfs_inode->i_n_secs - n;
return hpfs_inode->i_disk_sec + n;
}
*n_secs = 1;
return disk_secno;
}
void hpfs_truncate(struct inode *i)
{
if (IS_IMMUTABLE(i)) return /*-EPERM*/;
hpfs_lock_assert(i->i_sb);
hpfs_i(i)->i_n_secs = 0;
i->i_blocks = 1 + ((i->i_size + 511) >> 9);
hpfs_i(i)->mmu_private = i->i_size;
hpfs_truncate_btree(i->i_sb, i->i_ino, 1, ((i->i_size + 511) >> 9));
hpfs_write_inode(i);
hpfs_i(i)->i_n_secs = 0;
}
static int hpfs_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create)
{
int r;
secno s;
unsigned n_secs;
hpfs_lock(inode->i_sb);
s = hpfs_bmap(inode, iblock, &n_secs);
if (s) {
if (bh_result->b_size >> 9 < n_secs)
n_secs = bh_result->b_size >> 9;
map_bh(bh_result, inode->i_sb, s);
bh_result->b_size = n_secs << 9;
goto ret_0;
}
if (!create) goto ret_0;
if (iblock<<9 != hpfs_i(inode)->mmu_private) {
BUG();
r = -EIO;
goto ret_r;
}
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);
r = -ENOSPC;
goto ret_r;
}
inode->i_blocks++;
hpfs_i(inode)->mmu_private += 512;
set_buffer_new(bh_result);
map_bh(bh_result, inode->i_sb, s);
ret_0:
r = 0;
ret_r:
hpfs_unlock(inode->i_sb);
return r;
}
static int hpfs_readpage(struct file *file, struct page *page)
{
return mpage_readpage(page, hpfs_get_block);
}
static int hpfs_writepage(struct page *page, struct writeback_control *wbc)
{
return block_write_full_page(page, hpfs_get_block, wbc);
}
static int hpfs_readpages(struct file *file, struct address_space *mapping,
struct list_head *pages, unsigned nr_pages)
{
return mpage_readpages(mapping, pages, nr_pages, hpfs_get_block);
}
static int hpfs_writepages(struct address_space *mapping,
struct writeback_control *wbc)
{
return mpage_writepages(mapping, wbc, hpfs_get_block);
}
static void hpfs_write_failed(struct address_space *mapping, loff_t to)
{
struct inode *inode = mapping->host;
hpfs_lock(inode->i_sb);
if (to > inode->i_size) {
truncate_pagecache(inode, inode->i_size);
hpfs_truncate(inode);
}
hpfs_unlock(inode->i_sb);
}
static int hpfs_write_begin(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned flags,
struct page **pagep, void **fsdata)
{
int ret;
*pagep = NULL;
ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
hpfs_get_block,
&hpfs_i(mapping->host)->mmu_private);
if (unlikely(ret))
hpfs_write_failed(mapping, pos + len);
return ret;
}
static int hpfs_write_end(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned copied,
struct page *pagep, void *fsdata)
{
struct inode *inode = mapping->host;
int err;
err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata);
if (err < len)
hpfs_write_failed(mapping, pos + len);
if (!(err < 0)) {
/* make sure we write it on close, if not earlier */
hpfs_lock(inode->i_sb);
hpfs_i(inode)->i_dirty = 1;
hpfs_unlock(inode->i_sb);
}
return err;
}
static sector_t _hpfs_bmap(struct address_space *mapping, sector_t block)
{
return generic_block_bmap(mapping,block,hpfs_get_block);
}
const struct address_space_operations hpfs_aops = {
.readpage = hpfs_readpage,
.writepage = hpfs_writepage,
.readpages = hpfs_readpages,
.writepages = hpfs_writepages,
.write_begin = hpfs_write_begin,
.write_end = hpfs_write_end,
.bmap = _hpfs_bmap
};
const struct file_operations hpfs_file_ops =
{
.llseek = generic_file_llseek,
.read = new_sync_read,
.read_iter = generic_file_read_iter,
.write = do_sync_write,
.aio_write = generic_file_aio_write,
.mmap = generic_file_mmap,
.release = hpfs_file_release,
.fsync = hpfs_file_fsync,
.splice_read = generic_file_splice_read,
};
const struct inode_operations hpfs_file_iops =
{
.setattr = hpfs_setattr,
};
|
