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
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
|
/*
* File operations for Coda.
* Original version: (C) 1996 Peter Braam
* Rewritten for Linux 2.1: (C) 1997 Carnegie Mellon University
*
* Carnegie Mellon encourages users of this code to contribute improvements
* to the Coda project. Contact Peter Braam <coda@cs.cmu.edu>.
*/
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/time.h>
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/stat.h>
#include <linux/cred.h>
#include <linux/errno.h>
#include <linux/spinlock.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/coda.h>
#include <linux/coda_psdev.h>
#include "coda_linux.h"
#include "coda_int.h"
static ssize_t
coda_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
{
struct file *coda_file = iocb->ki_filp;
struct coda_file_info *cfi = CODA_FTOC(coda_file);
BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
return vfs_iter_read(cfi->cfi_container, to, &iocb->ki_pos);
}
static ssize_t
coda_file_splice_read(struct file *coda_file, loff_t *ppos,
struct pipe_inode_info *pipe, size_t count,
unsigned int flags)
{
ssize_t (*splice_read)(struct file *, loff_t *,
struct pipe_inode_info *, size_t, unsigned int);
struct coda_file_info *cfi;
struct file *host_file;
cfi = CODA_FTOC(coda_file);
BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
host_file = cfi->cfi_container;
splice_read = host_file->f_op->splice_read;
if (!splice_read)
splice_read = default_file_splice_read;
return splice_read(host_file, ppos, pipe, count, flags);
}
static ssize_t
coda_file_write_iter(struct kiocb *iocb, struct iov_iter *to)
{
struct file *coda_file = iocb->ki_filp;
struct inode *coda_inode = file_inode(coda_file);
struct coda_file_info *cfi = CODA_FTOC(coda_file);
struct file *host_file;
ssize_t ret;
BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
host_file = cfi->cfi_container;
file_start_write(host_file);
inode_lock(coda_inode);
ret = vfs_iter_write(cfi->cfi_container, to, &iocb->ki_pos);
coda_inode->i_size = file_inode(host_file)->i_size;
coda_inode->i_blocks = (coda_inode->i_size + 511) >> 9;
coda_inode->i_mtime = coda_inode->i_ctime = current_time(coda_inode);
inode_unlock(coda_inode);
file_end_write(host_file);
return ret;
}
static int
coda_file_mmap(struct file *coda_file, struct vm_area_struct *vma)
{
struct coda_file_info *cfi;
struct coda_inode_info *cii;
struct file *host_file;
struct inode *coda_inode, *host_inode;
cfi = CODA_FTOC(coda_file);
BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
host_file = cfi->cfi_container;
if (!host_file->f_op->mmap)
return -ENODEV;
coda_inode = file_inode(coda_file);
host_inode = file_inode(host_file);
cii = ITOC(coda_inode);
spin_lock(&cii->c_lock);
coda_file->f_mapping = host_file->f_mapping;
if (coda_inode->i_mapping == &coda_inode->i_data)
coda_inode->i_mapping = host_inode->i_mapping;
/* only allow additional mmaps as long as userspace isn't changing
* the container file on us! */
else if (coda_inode->i_mapping != host_inode->i_mapping) {
spin_unlock(&cii->c_lock);
return -EBUSY;
}
/* keep track of how often the coda_inode/host_file has been mmapped */
cii->c_mapcount++;
cfi->cfi_mapcount++;
spin_unlock(&cii->c_lock);
return host_file->f_op->mmap(host_file, vma);
}
int coda_open(struct inode *coda_inode, struct file *coda_file)
{
struct file *host_file = NULL;
int error;
unsigned short flags = coda_file->f_flags & (~O_EXCL);
unsigned short coda_flags = coda_flags_to_cflags(flags);
struct coda_file_info *cfi;
cfi = kmalloc(sizeof(struct coda_file_info), GFP_KERNEL);
if (!cfi)
return -ENOMEM;
error = venus_open(coda_inode->i_sb, coda_i2f(coda_inode), coda_flags,
&host_file);
if (!host_file)
error = -EIO;
if (error) {
kfree(cfi);
return error;
}
host_file->f_flags |= coda_file->f_flags & (O_APPEND | O_SYNC);
cfi->cfi_magic = CODA_MAGIC;
cfi->cfi_mapcount = 0;
cfi->cfi_container = host_file;
BUG_ON(coda_file->private_data != NULL);
coda_file->private_data = cfi;
return 0;
}
int coda_release(struct inode *coda_inode, struct file *coda_file)
{
unsigned short flags = (coda_file->f_flags) & (~O_EXCL);
unsigned short coda_flags = coda_flags_to_cflags(flags);
struct coda_file_info *cfi;
struct coda_inode_info *cii;
struct inode *host_inode;
int err;
cfi = CODA_FTOC(coda_file);
BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
err = venus_close(coda_inode->i_sb, coda_i2f(coda_inode),
coda_flags, coda_file->f_cred->fsuid);
host_inode = file_inode(cfi->cfi_container);
cii = ITOC(coda_inode);
/* did we mmap this file? */
spin_lock(&cii->c_lock);
if (coda_inode->i_mapping == &host_inode->i_data) {
cii->c_mapcount -= cfi->cfi_mapcount;
if (!cii->c_mapcount)
coda_inode->i_mapping = &coda_inode->i_data;
}
spin_unlock(&cii->c_lock);
fput(cfi->cfi_container);
kfree(coda_file->private_data);
coda_file->private_data = NULL;
/* VFS fput ignores the return value from file_operations->release, so
* there is no use returning an error here */
return 0;
}
int coda_fsync(struct file *coda_file, loff_t start, loff_t end, int datasync)
{
struct file *host_file;
struct inode *coda_inode = file_inode(coda_file);
struct coda_file_info *cfi;
int err;
if (!(S_ISREG(coda_inode->i_mode) || S_ISDIR(coda_inode->i_mode) ||
S_ISLNK(coda_inode->i_mode)))
return -EINVAL;
err = filemap_write_and_wait_range(coda_inode->i_mapping, start, end);
if (err)
return err;
inode_lock(coda_inode);
cfi = CODA_FTOC(coda_file);
BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
host_file = cfi->cfi_container;
err = vfs_fsync(host_file, datasync);
if (!err && !datasync)
err = venus_fsync(coda_inode->i_sb, coda_i2f(coda_inode));
inode_unlock(coda_inode);
return err;
}
const struct file_operations coda_file_operations = {
.llseek = generic_file_llseek,
.read_iter = coda_file_read_iter,
.write_iter = coda_file_write_iter,
.mmap = coda_file_mmap,
.open = coda_open,
.release = coda_release,
.fsync = coda_fsync,
.splice_read = coda_file_splice_read,
};
|
