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ebf46264 AK |
1 | /* |
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 | */ | |
34 | ssize_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, | |
73 | 0, offset, read_count); | |
74 | 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; | |
84 | error: | |
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 | */ | |
103 | int 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, | |
135 | 0, offset, write_count); | |
136 | 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; | |
146 | error: | |
147 | if (fid) | |
148 | retval = p9_client_clunk(fid); | |
149 | return retval; | |
150 | } | |
151 | ||
152 | ssize_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 | ||
157 | const struct xattr_handler *v9fs_xattr_handlers[] = { | |
158 | &v9fs_xattr_user_handler, | |
159 | NULL | |
160 | }; |