aboutsummaryrefslogtreecommitdiff
path: root/fs/afs/xattr.c
blob: 5552d034090af8ce985d907469261b2cc3d46d18 (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
// SPDX-License-Identifier: GPL-2.0-or-later
/* Extended attribute handling for AFS.  We use xattrs to get and set metadata
 * instead of providing pioctl().
 *
 * Copyright (C) 2017 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 */

#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/xattr.h>
#include "internal.h"

static const char afs_xattr_list[] =
	"afs.acl\0"
	"afs.cell\0"
	"afs.fid\0"
	"afs.volume\0"
	"afs.yfs.acl\0"
	"afs.yfs.acl_inherited\0"
	"afs.yfs.acl_num_cleaned\0"
	"afs.yfs.vol_acl";

/*
 * Retrieve a list of the supported xattrs.
 */
ssize_t afs_listxattr(struct dentry *dentry, char *buffer, size_t size)
{
	if (size == 0)
		return sizeof(afs_xattr_list);
	if (size < sizeof(afs_xattr_list))
		return -ERANGE;
	memcpy(buffer, afs_xattr_list, sizeof(afs_xattr_list));
	return sizeof(afs_xattr_list);
}

/*
 * Get a file's ACL.
 */
static int afs_xattr_get_acl(const struct xattr_handler *handler,
			     struct dentry *dentry,
			     struct inode *inode, const char *name,
			     void *buffer, size_t size)
{
	struct afs_fs_cursor fc;
	struct afs_status_cb *scb;
	struct afs_vnode *vnode = AFS_FS_I(inode);
	struct afs_acl *acl = NULL;
	struct key *key;
	int ret = -ENOMEM;

	scb = kzalloc(sizeof(struct afs_status_cb), GFP_NOFS);
	if (!scb)
		goto error;

	key = afs_request_key(vnode->volume->cell);
	if (IS_ERR(key)) {
		ret = PTR_ERR(key);
		goto error_scb;
	}

	ret = -ERESTARTSYS;
	if (afs_begin_vnode_operation(&fc, vnode, key, true)) {
		afs_dataversion_t data_version = vnode->status.data_version;

		while (afs_select_fileserver(&fc)) {
			fc.cb_break = afs_calc_vnode_cb_break(vnode);
			acl = afs_fs_fetch_acl(&fc, scb);
		}

		afs_check_for_remote_deletion(&fc, fc.vnode);
		afs_vnode_commit_status(&fc, vnode, fc.cb_break,
					&data_version, scb);
		ret = afs_end_vnode_operation(&fc);
	}

	if (ret == 0) {
		ret = acl->size;
		if (size > 0) {
			if (acl->size <= size)
				memcpy(buffer, acl->data, acl->size);
			else
				ret = -ERANGE;
		}
		kfree(acl);
	}

	key_put(key);
error_scb:
	kfree(scb);
error:
	return ret;
}

/*
 * Set a file's AFS3 ACL.
 */
static int afs_xattr_set_acl(const struct xattr_handler *handler,
                             struct dentry *dentry,
                             struct inode *inode, const char *name,
                             const void *buffer, size_t size, int flags)
{
	struct afs_fs_cursor fc;
	struct afs_status_cb *scb;
	struct afs_vnode *vnode = AFS_FS_I(inode);
	struct afs_acl *acl = NULL;
	struct key *key;
	int ret = -ENOMEM;

	if (flags == XATTR_CREATE)
		return -EINVAL;

	scb = kzalloc(sizeof(struct afs_status_cb), GFP_NOFS);
	if (!scb)
		goto error;

	acl = kmalloc(sizeof(*acl) + size, GFP_KERNEL);
	if (!acl)
		goto error_scb;

	key = afs_request_key(vnode->volume->cell);
	if (IS_ERR(key)) {
		ret = PTR_ERR(key);
		goto error_acl;
	}

	acl->size = size;
	memcpy(acl->data, buffer, size);

	ret = -ERESTARTSYS;
	if (afs_begin_vnode_operation(&fc, vnode, key, true)) {
		afs_dataversion_t data_version = vnode->status.data_version;

		while (afs_select_fileserver(&fc)) {
			fc.cb_break = afs_calc_vnode_cb_break(vnode);
			afs_fs_store_acl(&fc, acl, scb);
		}

		afs_check_for_remote_deletion(&fc, fc.vnode);
		afs_vnode_commit_status(&fc, vnode, fc.cb_break,
					&data_version, scb);
		ret = afs_end_vnode_operation(&fc);
	}

	key_put(key);
error_acl:
	kfree(acl);
error_scb:
	kfree(scb);
error:
	return ret;
}

static const struct xattr_handler afs_xattr_afs_acl_handler = {
	.name   = "afs.acl",
	.get    = afs_xattr_get_acl,
	.set    = afs_xattr_set_acl,
};

/*
 * Get a file's YFS ACL.
 */
static int afs_xattr_get_yfs(const struct xattr_handler *handler,
			     struct dentry *dentry,
			     struct inode *inode, const char *name,
			     void *buffer, size_t size)
{
	struct afs_fs_cursor fc;
	struct afs_status_cb *scb;
	struct afs_vnode *vnode = AFS_FS_I(inode);
	struct yfs_acl *yacl = NULL;
	struct key *key;
	char buf[16], *data;
	int which = 0, dsize, ret = -ENOMEM;

	if (strcmp(name, "acl") == 0)
		which = 0;
	else if (strcmp(name, "acl_inherited") == 0)
		which = 1;
	else if (strcmp(name, "acl_num_cleaned") == 0)
		which = 2;
	else if (strcmp(name, "vol_acl") == 0)
		which = 3;
	else
		return -EOPNOTSUPP;

	yacl = kzalloc(sizeof(struct yfs_acl), GFP_KERNEL);
	if (!yacl)
		goto error;

	if (which == 0)
		yacl->flags |= YFS_ACL_WANT_ACL;
	else if (which == 3)
		yacl->flags |= YFS_ACL_WANT_VOL_ACL;

	scb = kzalloc(sizeof(struct afs_status_cb), GFP_NOFS);
	if (!scb)
		goto error_yacl;

	key = afs_request_key(vnode->volume->cell);
	if (IS_ERR(key)) {
		ret = PTR_ERR(key);
		goto error_scb;
	}

	ret = -ERESTARTSYS;
	if (afs_begin_vnode_operation(&fc, vnode, key, true)) {
		afs_dataversion_t data_version = vnode->status.data_version;

		while (afs_select_fileserver(&fc)) {
			fc.cb_break = afs_calc_vnode_cb_break(vnode);
			yfs_fs_fetch_opaque_acl(&fc, yacl, scb);
		}

		afs_check_for_remote_deletion(&fc, fc.vnode);
		afs_vnode_commit_status(&fc, vnode, fc.cb_break,
					&data_version, scb);
		ret = afs_end_vnode_operation(&fc);
	}

	if (ret < 0)
		goto error_key;

	switch (which) {
	case 0:
		data = yacl->acl->data;
		dsize = yacl->acl->size;
		break;
	case 1:
		data = buf;
		dsize = snprintf(buf, sizeof(buf), "%u", yacl->inherit_flag);
		break;
	case 2:
		data = buf;
		dsize = snprintf(buf, sizeof(buf), "%u", yacl->num_cleaned);
		break;
	case 3:
		data = yacl->vol_acl->data;
		dsize = yacl->vol_acl->size;
		break;
	default:
		ret = -EOPNOTSUPP;
		goto error_key;
	}

	ret = dsize;
	if (size > 0) {
		if (dsize > size) {
			ret = -ERANGE;
			goto error_key;
		}
		memcpy(buffer, data, dsize);
	}

error_key:
	key_put(key);
error_scb:
	kfree(scb);
error_yacl:
	yfs_free_opaque_acl(yacl);
error:
	return ret;
}

/*
 * Set a file's YFS ACL.
 */
static int afs_xattr_set_yfs(const struct xattr_handler *handler,
                             struct dentry *dentry,
                             struct inode *inode, const char *name,
                             const void *buffer, size_t size, int flags)
{
	struct afs_fs_cursor fc;
	struct afs_status_cb *scb;
	struct afs_vnode *vnode = AFS_FS_I(inode);
	struct afs_acl *acl = NULL;
	struct key *key;
	int ret = -ENOMEM;

	if (flags == XATTR_CREATE ||
	    strcmp(name, "acl") != 0)
		return -EINVAL;

	scb = kzalloc(sizeof(struct afs_status_cb), GFP_NOFS);
	if (!scb)
		goto error;

	acl = kmalloc(sizeof(*acl) + size, GFP_KERNEL);
	if (!acl)
		goto error_scb;

	acl->size = size;
	memcpy(acl->data, buffer, size);

	key = afs_request_key(vnode->volume->cell);
	if (IS_ERR(key)) {
		ret = PTR_ERR(key);
		goto error_acl;
	}

	ret = -ERESTARTSYS;
	if (afs_begin_vnode_operation(&fc, vnode, key, true)) {
		afs_dataversion_t data_version = vnode->status.data_version;

		while (afs_select_fileserver(&fc)) {
			fc.cb_break = afs_calc_vnode_cb_break(vnode);
			yfs_fs_store_opaque_acl2(&fc, acl, scb);
		}

		afs_check_for_remote_deletion(&fc, fc.vnode);
		afs_vnode_commit_status(&fc, vnode, fc.cb_break,
					&data_version, scb);
		ret = afs_end_vnode_operation(&fc);
	}

error_acl:
	kfree(acl);
	key_put(key);
error_scb:
	kfree(scb);
error:
	return ret;
}

static const struct xattr_handler afs_xattr_yfs_handler = {
	.prefix	= "afs.yfs.",
	.get	= afs_xattr_get_yfs,
	.set	= afs_xattr_set_yfs,
};

/*
 * Get the name of the cell on which a file resides.
 */
static int afs_xattr_get_cell(const struct xattr_handler *handler,
			      struct dentry *dentry,
			      struct inode *inode, const char *name,
			      void *buffer, size_t size)
{
	struct afs_vnode *vnode = AFS_FS_I(inode);
	struct afs_cell *cell = vnode->volume->cell;
	size_t namelen;

	namelen = cell->name_len;
	if (size == 0)
		return namelen;
	if (namelen > size)
		return -ERANGE;
	memcpy(buffer, cell->name, namelen);
	return namelen;
}

static const struct xattr_handler afs_xattr_afs_cell_handler = {
	.name	= "afs.cell",
	.get	= afs_xattr_get_cell,
};

/*
 * Get the volume ID, vnode ID and vnode uniquifier of a file as a sequence of
 * hex numbers separated by colons.
 */
static int afs_xattr_get_fid(const struct xattr_handler *handler,
			     struct dentry *dentry,
			     struct inode *inode, const char *name,
			     void *buffer, size_t size)
{
	struct afs_vnode *vnode = AFS_FS_I(inode);
	char text[16 + 1 + 24 + 1 + 8 + 1];
	size_t len;

	/* The volume ID is 64-bit, the vnode ID is 96-bit and the
	 * uniquifier is 32-bit.
	 */
	len = sprintf(text, "%llx:", vnode->fid.vid);
	if (vnode->fid.vnode_hi)
		len += sprintf(text + len, "%x%016llx",
			       vnode->fid.vnode_hi, vnode->fid.vnode);
	else
		len += sprintf(text + len, "%llx", vnode->fid.vnode);
	len += sprintf(text + len, ":%x", vnode->fid.unique);

	if (size == 0)
		return len;
	if (len > size)
		return -ERANGE;
	memcpy(buffer, text, len);
	return len;
}

static const struct xattr_handler afs_xattr_afs_fid_handler = {
	.name	= "afs.fid",
	.get	= afs_xattr_get_fid,
};

/*
 * Get the name of the volume on which a file resides.
 */
static int afs_xattr_get_volume(const struct xattr_handler *handler,
			      struct dentry *dentry,
			      struct inode *inode, const char *name,
			      void *buffer, size_t size)
{
	struct afs_vnode *vnode = AFS_FS_I(inode);
	const char *volname = vnode->volume->name;
	size_t namelen;

	namelen = strlen(volname);
	if (size == 0)
		return namelen;
	if (namelen > size)
		return -ERANGE;
	memcpy(buffer, volname, namelen);
	return namelen;
}

static const struct xattr_handler afs_xattr_afs_volume_handler = {
	.name	= "afs.volume",
	.get	= afs_xattr_get_volume,
};

const struct xattr_handler *afs_xattr_handlers[] = {
	&afs_xattr_afs_acl_handler,
	&afs_xattr_afs_cell_handler,
	&afs_xattr_afs_fid_handler,
	&afs_xattr_afs_volume_handler,
	&afs_xattr_yfs_handler,		/* afs.yfs. prefix */
	NULL
};