blob: f88e5c2dc8730bce3548c9c550b1d8480bcfbeb6 [file] [log] [blame]
Aneesh Kumar K.Vebf46262010-05-31 13:22:56 +05301/*
2 * Copyright IBM Corporation, 2010
3 * Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of version 2.1 of the GNU Lesser General Public License
7 * as published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it would be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
12 *
13 */
14
15#include <linux/module.h>
16#include <linux/fs.h>
17#include <linux/sched.h>
18#include <net/9p/9p.h>
19#include <net/9p/client.h>
20
21#include "fid.h"
22#include "xattr.h"
23
24/*
25 * v9fs_xattr_get()
26 *
27 * Copy an extended attribute into the buffer
28 * provided, or compute the buffer size required.
29 * Buffer is NULL to compute the size of the buffer required.
30 *
31 * Returns a negative error number on failure, or the number of bytes
32 * used / required on success.
33 */
34ssize_t v9fs_xattr_get(struct dentry *dentry, const char *name,
35 void *buffer, size_t buffer_size)
36{
37 ssize_t retval;
38 int msize, read_count;
39 u64 offset = 0, attr_size;
40 struct p9_fid *fid, *attr_fid;
41
42 P9_DPRINTK(P9_DEBUG_VFS, "%s: name = %s value_len = %zu\n",
43 __func__, name, buffer_size);
44
45 fid = v9fs_fid_lookup(dentry);
46 if (IS_ERR(fid))
47 return PTR_ERR(fid);
48
49 attr_fid = p9_client_xattrwalk(fid, name, &attr_size);
50 if (IS_ERR(attr_fid)) {
51 retval = PTR_ERR(attr_fid);
52 P9_DPRINTK(P9_DEBUG_VFS,
53 "p9_client_attrwalk failed %zd\n", retval);
54 attr_fid = NULL;
55 goto error;
56 }
57 if (!buffer_size) {
58 /* request to get the attr_size */
59 retval = attr_size;
60 goto error;
61 }
62 if (attr_size > buffer_size) {
63 retval = -ERANGE;
64 goto error;
65 }
66 msize = attr_fid->clnt->msize;
67 while (attr_size) {
68 if (attr_size > (msize - P9_IOHDRSZ))
69 read_count = msize - P9_IOHDRSZ;
70 else
71 read_count = attr_size;
72 read_count = p9_client_read(attr_fid, ((char *)buffer)+offset,
Eric Van Hensbergen327aec02010-08-02 11:36:18 -050073 NULL, offset, read_count);
Aneesh Kumar K.Vebf46262010-05-31 13:22:56 +053074 if (read_count < 0) {
75 /* error in xattr read */
76 retval = read_count;
77 goto error;
78 }
79 offset += read_count;
80 attr_size -= read_count;
81 }
82 /* Total read xattr bytes */
83 retval = offset;
84error:
85 if (attr_fid)
86 p9_client_clunk(attr_fid);
87 return retval;
88
89}
90
91/*
92 * v9fs_xattr_set()
93 *
94 * Create, replace or remove an extended attribute for this inode. Buffer
95 * is NULL to remove an existing extended attribute, and non-NULL to
96 * either replace an existing extended attribute, or create a new extended
97 * attribute. The flags XATTR_REPLACE and XATTR_CREATE
98 * specify that an extended attribute must exist and must not exist
99 * previous to the call, respectively.
100 *
101 * Returns 0, or a negative error number on failure.
102 */
103int v9fs_xattr_set(struct dentry *dentry, const char *name,
104 const void *value, size_t value_len, int flags)
105{
106 u64 offset = 0;
107 int retval, msize, write_count;
108 struct p9_fid *fid = NULL;
109
110 P9_DPRINTK(P9_DEBUG_VFS, "%s: name = %s value_len = %zu flags = %d\n",
111 __func__, name, value_len, flags);
112
113 fid = v9fs_fid_clone(dentry);
114 if (IS_ERR(fid)) {
115 retval = PTR_ERR(fid);
116 fid = NULL;
117 goto error;
118 }
119 /*
120 * On success fid points to xattr
121 */
122 retval = p9_client_xattrcreate(fid, name, value_len, flags);
123 if (retval < 0) {
124 P9_DPRINTK(P9_DEBUG_VFS,
125 "p9_client_xattrcreate failed %d\n", retval);
126 goto error;
127 }
128 msize = fid->clnt->msize;;
129 while (value_len) {
130 if (value_len > (msize - P9_IOHDRSZ))
131 write_count = msize - P9_IOHDRSZ;
132 else
133 write_count = value_len;
134 write_count = p9_client_write(fid, ((char *)value)+offset,
Eric Van Hensbergen327aec02010-08-02 11:36:18 -0500135 NULL, offset, write_count);
Aneesh Kumar K.Vebf46262010-05-31 13:22:56 +0530136 if (write_count < 0) {
137 /* error in xattr write */
138 retval = write_count;
139 goto error;
140 }
141 offset += write_count;
142 value_len -= write_count;
143 }
144 /* Total read xattr bytes */
145 retval = offset;
146error:
147 if (fid)
148 retval = p9_client_clunk(fid);
149 return retval;
150}
151
152ssize_t v9fs_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size)
153{
154 return v9fs_xattr_get(dentry, NULL, buffer, buffer_size);
155}
156
157const struct xattr_handler *v9fs_xattr_handlers[] = {
158 &v9fs_xattr_user_handler,
159 NULL
160};