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
|
/*
* Copyright IBM Corporation, 2010
* Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of version 2.1 of the GNU Lesser General Public License
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it would be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
*
*/
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/sched.h>
#include <net/9p/9p.h>
#include <net/9p/client.h>
#include "fid.h"
#include "xattr.h"
ssize_t v9fs_fid_xattr_get(struct p9_fid *fid, const char *name,
void *buffer, size_t buffer_size)
{
ssize_t retval;
int msize, read_count;
u64 offset = 0, attr_size;
struct p9_fid *attr_fid;
attr_fid = p9_client_xattrwalk(fid, name, &attr_size);
if (IS_ERR(attr_fid)) {
retval = PTR_ERR(attr_fid);
P9_DPRINTK(P9_DEBUG_VFS,
"p9_client_attrwalk failed %zd\n", retval);
attr_fid = NULL;
goto error;
}
if (!buffer_size) {
/* request to get the attr_size */
retval = attr_size;
goto error;
}
if (attr_size > buffer_size) {
retval = -ERANGE;
goto error;
}
msize = attr_fid->clnt->msize;
while (attr_size) {
if (attr_size > (msize - P9_IOHDRSZ))
read_count = msize - P9_IOHDRSZ;
else
read_count = attr_size;
read_count = p9_client_read(attr_fid, ((char *)buffer)+offset,
NULL, offset, read_count);
if (read_count < 0) {
/* error in xattr read */
retval = read_count;
goto error;
}
offset += read_count;
attr_size -= read_count;
}
/* Total read xattr bytes */
retval = offset;
error:
if (attr_fid)
p9_client_clunk(attr_fid);
return retval;
}
/*
* v9fs_xattr_get()
*
* Copy an extended attribute into the buffer
* provided, or compute the buffer size required.
* Buffer is NULL to compute the size of the buffer required.
*
* Returns a negative error number on failure, or the number of bytes
* used / required on success.
*/
ssize_t v9fs_xattr_get(struct dentry *dentry, const char *name,
void *buffer, size_t buffer_size)
{
struct p9_fid *fid;
P9_DPRINTK(P9_DEBUG_VFS, "%s: name = %s value_len = %zu\n",
__func__, name, buffer_size);
fid = v9fs_fid_lookup(dentry);
if (IS_ERR(fid))
return PTR_ERR(fid);
return v9fs_fid_xattr_get(fid, name, buffer, buffer_size);
}
/*
* v9fs_xattr_set()
*
* Create, replace or remove an extended attribute for this inode. Buffer
* is NULL to remove an existing extended attribute, and non-NULL to
* either replace an existing extended attribute, or create a new extended
* attribute. The flags XATTR_REPLACE and XATTR_CREATE
* specify that an extended attribute must exist and must not exist
* previous to the call, respectively.
*
* Returns 0, or a negative error number on failure.
*/
int v9fs_xattr_set(struct dentry *dentry, const char *name,
const void *value, size_t value_len, int flags)
{
u64 offset = 0;
int retval, msize, write_count;
struct p9_fid *fid = NULL;
P9_DPRINTK(P9_DEBUG_VFS, "%s: name = %s value_len = %zu flags = %d\n",
__func__, name, value_len, flags);
fid = v9fs_fid_clone(dentry);
if (IS_ERR(fid)) {
retval = PTR_ERR(fid);
fid = NULL;
goto error;
}
/*
* On success fid points to xattr
*/
retval = p9_client_xattrcreate(fid, name, value_len, flags);
if (retval < 0) {
P9_DPRINTK(P9_DEBUG_VFS,
"p9_client_xattrcreate failed %d\n", retval);
goto error;
}
msize = fid->clnt->msize;
while (value_len) {
if (value_len > (msize - P9_IOHDRSZ))
write_count = msize - P9_IOHDRSZ;
else
write_count = value_len;
write_count = p9_client_write(fid, ((char *)value)+offset,
NULL, offset, write_count);
if (write_count < 0) {
/* error in xattr write */
retval = write_count;
goto error;
}
offset += write_count;
value_len -= write_count;
}
/* Total read xattr bytes */
retval = offset;
error:
if (fid)
retval = p9_client_clunk(fid);
return retval;
}
ssize_t v9fs_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size)
{
return v9fs_xattr_get(dentry, NULL, buffer, buffer_size);
}
const struct xattr_handler *v9fs_xattr_handlers[] = {
&v9fs_xattr_user_handler,
#ifdef CONFIG_9P_FS_POSIX_ACL
&v9fs_xattr_acl_access_handler,
&v9fs_xattr_acl_default_handler,
#endif
NULL
};
|
