summaryrefslogtreecommitdiffstats
path: root/fs/orangefs/xattr.c
blob: 81ac88bb91ff9fc6d0d77dc555b8142c86a8040d (plain)
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
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
/*
 * (C) 2001 Clemson University and The University of Chicago
 *
 * See COPYING in top-level directory.
 */

/*
 *  Linux VFS extended attribute operations.
 */

#include "protocol.h"
#include "orangefs-kernel.h"
#include "orangefs-bufmap.h"
#include <linux/posix_acl_xattr.h>
#include <linux/xattr.h>


#define SYSTEM_ORANGEFS_KEY "system.pvfs2."
#define SYSTEM_ORANGEFS_KEY_LEN 13

/*
 * this function returns
 *   0 if the key corresponding to name is not meant to be printed as part
 *     of a listxattr.
 *   1 if the key corresponding to name is meant to be returned as part of
 *     a listxattr.
 * The ones that start SYSTEM_ORANGEFS_KEY are the ones to avoid printing.
 */
static int is_reserved_key(const char *key, size_t size)
{

	if (size < SYSTEM_ORANGEFS_KEY_LEN)
		return 1;

	return strncmp(key, SYSTEM_ORANGEFS_KEY, SYSTEM_ORANGEFS_KEY_LEN) ?  1 : 0;
}

static inline int convert_to_internal_xattr_flags(int setxattr_flags)
{
	int internal_flag = 0;

	if (setxattr_flags & XATTR_REPLACE) {
		/* Attribute must exist! */
		internal_flag = ORANGEFS_XATTR_REPLACE;
	} else if (setxattr_flags & XATTR_CREATE) {
		/* Attribute must not exist */
		internal_flag = ORANGEFS_XATTR_CREATE;
	}
	return internal_flag;
}


/*
 * Tries to get a specified key's attributes of a given
 * file into a user-specified buffer. Note that the getxattr
 * interface allows for the users to probe the size of an
 * extended attribute by passing in a value of 0 to size.
 * Thus our return value is always the size of the attribute
 * unless the key does not exist for the file and/or if
 * there were errors in fetching the attribute value.
 */
ssize_t orangefs_inode_getxattr(struct inode *inode, const char *name,
				void *buffer, size_t size)
{
	struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(inode);
	struct orangefs_kernel_op_s *new_op = NULL;
	ssize_t ret = -ENOMEM;
	ssize_t length = 0;
	int fsuid;
	int fsgid;

	gossip_debug(GOSSIP_XATTR_DEBUG,
		     "%s: name %s, buffer_size %zd\n",
		     __func__, name, size);

	if (S_ISLNK(inode->i_mode))
		return -EOPNOTSUPP;

	if (strlen(name) >= ORANGEFS_MAX_XATTR_NAMELEN)
		return -EINVAL;

	fsuid = from_kuid(&init_user_ns, current_fsuid());
	fsgid = from_kgid(&init_user_ns, current_fsgid());

	gossip_debug(GOSSIP_XATTR_DEBUG,
		     "getxattr on inode %pU, name %s "
		     "(uid %o, gid %o)\n",
		     get_khandle_from_ino(inode),
		     name,
		     fsuid,
		     fsgid);

	down_read(&orangefs_inode->xattr_sem);

	new_op = op_alloc(ORANGEFS_VFS_OP_GETXATTR);
	if (!new_op)
		goto out_unlock;

	new_op->upcall.req.getxattr.refn = orangefs_inode->refn;
	strcpy(new_op->upcall.req.getxattr.key, name);

	/*
	 * NOTE: Although keys are meant to be NULL terminated textual
	 * strings, I am going to explicitly pass the length just in case
	 * we change this later on...
	 */
	new_op->upcall.req.getxattr.key_sz = strlen(name) + 1;

	ret = service_operation(new_op, "orangefs_inode_getxattr",
				get_interruptible_flag(inode));
	if (ret != 0) {
		if (ret == -ENOENT) {
			ret = -ENODATA;
			gossip_debug(GOSSIP_XATTR_DEBUG,
				     "orangefs_inode_getxattr: inode %pU key %s"
				     " does not exist!\n",
				     get_khandle_from_ino(inode),
				     (char *)new_op->upcall.req.getxattr.key);
		}
		goto out_release_op;
	}

	/*
	 * Length returned includes null terminator.
	 */
	length = new_op->downcall.resp.getxattr.val_sz;

	/*
	 * Just return the length of the queried attribute.
	 */
	if (size == 0) {
		ret = length;
		goto out_release_op;
	}

	/*
	 * Check to see if key length is > provided buffer size.
	 */
	if (length > size) {
		ret = -ERANGE;
		goto out_release_op;
	}

	memcpy(buffer, new_op->downcall.resp.getxattr.val, length);
	memset(buffer + length, 0, size - length);
	gossip_debug(GOSSIP_XATTR_DEBUG,
	     "orangefs_inode_getxattr: inode %pU "
	     "key %s key_sz %d, val_len %d\n",
	     get_khandle_from_ino(inode),
	     (char *)new_op->
		upcall.req.getxattr.key,
		     (int)new_op->
		upcall.req.getxattr.key_sz,
	     (int)ret);

	ret = length;

out_release_op:
	op_release(new_op);
out_unlock:
	up_read(&orangefs_inode->xattr_sem);
	return ret;
}

static int orangefs_inode_removexattr(struct inode *inode, const char *name,
				      int flags)
{
	struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(inode);
	struct orangefs_kernel_op_s *new_op = NULL;
	int ret = -ENOMEM;

	if (strlen(name) >= ORANGEFS_MAX_XATTR_NAMELEN)
		return -EINVAL;

	down_write(&orangefs_inode->xattr_sem);
	new_op = op_alloc(ORANGEFS_VFS_OP_REMOVEXATTR);
	if (!new_op)
		goto out_unlock;

	new_op->upcall.req.removexattr.refn = orangefs_inode->refn;
	/*
	 * NOTE: Although keys are meant to be NULL terminated
	 * textual strings, I am going to explicitly pass the
	 * length just in case we change this later on...
	 */
	strcpy(new_op->upcall.req.removexattr.key, name);
	new_op->upcall.req.removexattr.key_sz = strlen(name) + 1;

	gossip_debug(GOSSIP_XATTR_DEBUG,
		     "orangefs_inode_removexattr: key %s, key_sz %d\n",
		     (char *)new_op->upcall.req.removexattr.key,
		     (int)new_op->upcall.req.removexattr.key_sz);

	ret = service_operation(new_op,
				"orangefs_inode_removexattr",
				get_interruptible_flag(inode));
	if (ret == -ENOENT) {
		/*
		 * Request to replace a non-existent attribute is an error.
		 */
		if (flags & XATTR_REPLACE)
			ret = -ENODATA;
		else
			ret = 0;
	}

	gossip_debug(GOSSIP_XATTR_DEBUG,
		     "orangefs_inode_removexattr: returning %d\n", ret);

	op_release(new_op);
out_unlock:
	up_write(&orangefs_inode->xattr_sem);
	return ret;
}

/*
 * Tries to set an attribute for a given key on a file.
 *
 * Returns a -ve number on error and 0 on success.  Key is text, but value
 * can be binary!
 */
int orangefs_inode_setxattr(struct inode *inode, const char *name,
			    const void *value, size_t size, int flags)
{
	struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(inode);
	struct orangefs_kernel_op_s *new_op;
	int internal_flag = 0;
	int ret = -ENOMEM;

	gossip_debug(GOSSIP_XATTR_DEBUG,
		     "%s: name %s, buffer_size %zd\n",
		     __func__, name, size);

	if (size > ORANGEFS_MAX_XATTR_VALUELEN)
		return -EINVAL;
	if (strlen(name) >= ORANGEFS_MAX_XATTR_NAMELEN)
		return -EINVAL;

	internal_flag = convert_to_internal_xattr_flags(flags);

	/* This is equivalent to a removexattr */
	if (size == 0 && !value) {
		gossip_debug(GOSSIP_XATTR_DEBUG,
			     "removing xattr (%s)\n",
			     name);
		return orangefs_inode_removexattr(inode, name, flags);
	}

	gossip_debug(GOSSIP_XATTR_DEBUG,
		     "setxattr on inode %pU, name %s\n",
		     get_khandle_from_ino(inode),
		     name);

	down_write(&orangefs_inode->xattr_sem);
	new_op = op_alloc(ORANGEFS_VFS_OP_SETXATTR);
	if (!new_op)
		goto out_unlock;


	new_op->upcall.req.setxattr.refn = orangefs_inode->refn;
	new_op->upcall.req.setxattr.flags = internal_flag;
	/*
	 * NOTE: Although keys are meant to be NULL terminated textual
	 * strings, I am going to explicitly pass the length just in
	 * case we change this later on...
	 */
	strcpy(new_op->upcall.req.setxattr.keyval.key, name);
	new_op->upcall.req.setxattr.keyval.key_sz = strlen(name) + 1;
	memcpy(new_op->upcall.req.setxattr.keyval.val, value, size);
	new_op->upcall.req.setxattr.keyval.val_sz = size;

	gossip_debug(GOSSIP_XATTR_DEBUG,
		     "orangefs_inode_setxattr: key %s, key_sz %d "
		     " value size %zd\n",
		     (char *)new_op->upcall.req.setxattr.keyval.key,
		     (int)new_op->upcall.req.setxattr.keyval.key_sz,
		     size);

	ret = service_operation(new_op,
				"orangefs_inode_setxattr",
				get_interruptible_flag(inode));

	gossip_debug(GOSSIP_XATTR_DEBUG,
		     "orangefs_inode_setxattr: returning %d\n",
		     ret);

	/* when request is serviced properly, free req op struct */
	op_release(new_op);
out_unlock:
	up_write(&orangefs_inode->xattr_sem);
	return ret;
}

/*
 * Tries to get a specified object's keys into a user-specified buffer of a
 * given size.  Note that like the previous instances of xattr routines, this
 * also allows you to pass in a NULL pointer and 0 size to probe the size for
 * subsequent memory allocations. Thus our return value is always the size of
 * all the keys unless there were errors in fetching the keys!
 */
ssize_t orangefs_listxattr(struct dentry *dentry, char *buffer, size_t size)
{
	struct inode *inode = dentry->d_inode;
	struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(inode);
	struct orangefs_kernel_op_s *new_op;
	__u64 token = ORANGEFS_ITERATE_START;
	ssize_t ret = -ENOMEM;
	ssize_t total = 0;
	int count_keys = 0;
	int key_size;
	int i = 0;
	int returned_count = 0;

	if (size > 0 && !buffer) {
		gossip_err("%s: bogus NULL pointers\n", __func__);
		return -EINVAL;
	}

	down_read(&orangefs_inode->xattr_sem);
	new_op = op_alloc(ORANGEFS_VFS_OP_LISTXATTR);
	if (!new_op)
		goto out_unlock;

	if (buffer && size > 0)
		memset(buffer, 0, size);

try_again:
	key_size = 0;
	new_op->upcall.req.listxattr.refn = orangefs_inode->refn;
	new_op->upcall.req.listxattr.token = token;
	new_op->upcall.req.listxattr.requested_count =
	    (size == 0) ? 0 : ORANGEFS_MAX_XATTR_LISTLEN;
	ret = service_operation(new_op, __func__,
				get_interruptible_flag(inode));
	if (ret != 0)
		goto done;

	if (size == 0) {
		/*
		 * This is a bit of a big upper limit, but I did not want to
		 * spend too much time getting this correct, since users end
		 * up allocating memory rather than us...
		 */
		total = new_op->downcall.resp.listxattr.returned_count *
			ORANGEFS_MAX_XATTR_NAMELEN;
		goto done;
	}

	returned_count = new_op->downcall.resp.listxattr.returned_count;
	if (returned_count < 0 ||
	    returned_count > ORANGEFS_MAX_XATTR_LISTLEN) {
		gossip_err("%s: impossible value for returned_count:%d:\n",
		__func__,
		returned_count);
		ret = -EIO;
		goto done;
	}

	/*
	 * Check to see how much can be fit in the buffer. Fit only whole keys.
	 */
	for (i = 0; i < returned_count; i++) {
		if (new_op->downcall.resp.listxattr.lengths[i] < 0 ||
		    new_op->downcall.resp.listxattr.lengths[i] >
		    ORANGEFS_MAX_XATTR_NAMELEN) {
			gossip_err("%s: impossible value for lengths[%d]\n",
			    __func__,
			    new_op->downcall.resp.listxattr.lengths[i]);
			ret = -EIO;
			goto done;
		}
		if (total + new_op->downcall.resp.listxattr.lengths[i] > size)
			goto done;

		/*
		 * Since many dumb programs try to setxattr() on our reserved
		 * xattrs this is a feeble attempt at defeating those by not
		 * listing them in the output of listxattr.. sigh
		 */
		if (is_reserved_key(new_op->downcall.resp.listxattr.key +
				    key_size,
				    new_op->downcall.resp.
					listxattr.lengths[i])) {
			gossip_debug(GOSSIP_XATTR_DEBUG, "Copying key %d -> %s\n",
					i, new_op->downcall.resp.listxattr.key +
						key_size);
			memcpy(buffer + total,
				new_op->downcall.resp.listxattr.key + key_size,
				new_op->downcall.resp.listxattr.lengths[i]);
			total += new_op->downcall.resp.listxattr.lengths[i];
			count_keys++;
		} else {
			gossip_debug(GOSSIP_XATTR_DEBUG, "[RESERVED] key %d -> %s\n",
					i, new_op->downcall.resp.listxattr.key +
						key_size);
		}
		key_size += new_op->downcall.resp.listxattr.lengths[i];
	}

	/*
	 * Since the buffer was large enough, we might have to continue
	 * fetching more keys!
	 */
	token = new_op->downcall.resp.listxattr.token;
	if (token != ORANGEFS_ITERATE_END)
		goto try_again;

done:
	gossip_debug(GOSSIP_XATTR_DEBUG, "%s: returning %d"
		     " [size of buffer %ld] (filled in %d keys)\n",
		     __func__,
		     ret ? (int)ret : (int)total,
		     (long)size,
		     count_keys);
	op_release(new_op);
	if (ret == 0)
		ret = total;
out_unlock:
	up_read(&orangefs_inode->xattr_sem);
	return ret;
}

static int orangefs_xattr_set_default(const struct xattr_handler *handler,
				      struct dentry *unused,
				      struct inode *inode,
				      const char *name,
				      const void *buffer,
				      size_t size,
				      int flags)
{
	return orangefs_inode_setxattr(inode, name, buffer, size, flags);
}

static int orangefs_xattr_get_default(const struct xattr_handler *handler,
				      struct dentry *unused,
				      struct inode *inode,
				      const char *name,
				      void *buffer,
				      size_t size)
{
	return orangefs_inode_getxattr(inode, name, buffer, size);

}

static const struct xattr_handler orangefs_xattr_default_handler = {
	.prefix = "",  /* match any name => handlers called with full name */
	.get = orangefs_xattr_get_default,
	.set = orangefs_xattr_set_default,
};

const struct xattr_handler *orangefs_xattr_handlers[] = {
	&posix_acl_access_xattr_handler,
	&posix_acl_default_xattr_handler,
	&orangefs_xattr_default_handler,
	NULL
};