aboutsummaryrefslogtreecommitdiff
path: root/fs/xfs/xfs_rename.c
blob: 02f0e8f53a94c403c19882f92f24d2f5cad52ac1 (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
/*
 * Copyright (c) 2000-2003,2005 Silicon Graphics, Inc.
 * All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU 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.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write the Free Software Foundation,
 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_types.h"
#include "xfs_log.h"
#include "xfs_inum.h"
#include "xfs_trans.h"
#include "xfs_sb.h"
#include "xfs_ag.h"
#include "xfs_dir2.h"
#include "xfs_dmapi.h"
#include "xfs_mount.h"
#include "xfs_da_btree.h"
#include "xfs_bmap_btree.h"
#include "xfs_dir2_sf.h"
#include "xfs_attr_sf.h"
#include "xfs_dinode.h"
#include "xfs_inode.h"
#include "xfs_inode_item.h"
#include "xfs_bmap.h"
#include "xfs_error.h"
#include "xfs_quota.h"
#include "xfs_utils.h"
#include "xfs_trans_space.h"
#include "xfs_vnodeops.h"


/*
 * Given an array of up to 4 inode pointers, unlock the pointed to inodes.
 * If there are fewer than 4 entries in the array, the empty entries will
 * be at the end and will have NULL pointers in them.
 */
STATIC void
xfs_rename_unlock4(
	xfs_inode_t	**i_tab,
	uint		lock_mode)
{
	int	i;

	xfs_iunlock(i_tab[0], lock_mode);
	for (i = 1; i < 4; i++) {
		if (i_tab[i] == NULL)
			break;

		/*
		 * Watch out for duplicate entries in the table.
		 */
		if (i_tab[i] != i_tab[i-1])
			xfs_iunlock(i_tab[i], lock_mode);
	}
}

/*
 * Enter all inodes for a rename transaction into a sorted array.
 */
STATIC void
xfs_sort_for_rename(
	xfs_inode_t	*dp1,	/* in: old (source) directory inode */
	xfs_inode_t	*dp2,	/* in: new (target) directory inode */
	xfs_inode_t	*ip1,	/* in: inode of old entry */
	xfs_inode_t	*ip2,	/* in: inode of new entry, if it
				   already exists, NULL otherwise. */
	xfs_inode_t	**i_tab,/* out: array of inode returned, sorted */
	int		*num_inodes)  /* out: number of inodes in array */
{
	xfs_inode_t		*temp;
	int			i, j;

	/*
	 * i_tab contains a list of pointers to inodes.  We initialize
	 * the table here & we'll sort it.  We will then use it to
	 * order the acquisition of the inode locks.
	 *
	 * Note that the table may contain duplicates.  e.g., dp1 == dp2.
	 */
	i_tab[0] = dp1;
	i_tab[1] = dp2;
	i_tab[2] = ip1;
	if (ip2) {
		*num_inodes = 4;
		i_tab[3] = ip2;
	} else {
		*num_inodes = 3;
		i_tab[3] = NULL;
	}

	/*
	 * Sort the elements via bubble sort.  (Remember, there are at
	 * most 4 elements to sort, so this is adequate.)
	 */
	for (i = 0; i < *num_inodes; i++) {
		for (j = 1; j < *num_inodes; j++) {
			if (i_tab[j]->i_ino < i_tab[j-1]->i_ino) {
				temp = i_tab[j];
				i_tab[j] = i_tab[j-1];
				i_tab[j-1] = temp;
			}
		}
	}
}

/*
 * xfs_rename
 */
int
xfs_rename(
	xfs_inode_t	*src_dp,
	struct xfs_name	*src_name,
	xfs_inode_t	*src_ip,
	xfs_inode_t	*target_dp,
	struct xfs_name	*target_name,
	xfs_inode_t	*target_ip)
{
	xfs_trans_t	*tp = NULL;
	xfs_mount_t	*mp = src_dp->i_mount;
	int		new_parent;		/* moving to a new dir */
	int		src_is_directory;	/* src_name is a directory */
	int		error;
	xfs_bmap_free_t free_list;
	xfs_fsblock_t   first_block;
	int		cancel_flags;
	int		committed;
	xfs_inode_t	*inodes[4];
	int		spaceres;
	int		num_inodes;

	xfs_itrace_entry(src_dp);
	xfs_itrace_entry(target_dp);

	if (DM_EVENT_ENABLED(src_dp, DM_EVENT_RENAME) ||
	    DM_EVENT_ENABLED(target_dp, DM_EVENT_RENAME)) {
		error = XFS_SEND_NAMESP(mp, DM_EVENT_RENAME,
					src_dp, DM_RIGHT_NULL,
					target_dp, DM_RIGHT_NULL,
					src_name->name, target_name->name,
					0, 0, 0);
		if (error)
			return error;
	}
	/* Return through std_return after this point. */

	new_parent = (src_dp != target_dp);
	src_is_directory = ((src_ip->i_d.di_mode & S_IFMT) == S_IFDIR);

	if (src_is_directory) {
		/*
		 * Check for link count overflow on target_dp
		 */
		if (target_ip == NULL && new_parent &&
		    target_dp->i_d.di_nlink >= XFS_MAXLINK) {
			error = XFS_ERROR(EMLINK);
			goto std_return;
		}
	}

	xfs_sort_for_rename(src_dp, target_dp, src_ip, target_ip,
				inodes, &num_inodes);

	XFS_BMAP_INIT(&free_list, &first_block);
	tp = xfs_trans_alloc(mp, XFS_TRANS_RENAME);
	cancel_flags = XFS_TRANS_RELEASE_LOG_RES;
	spaceres = XFS_RENAME_SPACE_RES(mp, target_name->len);
	error = xfs_trans_reserve(tp, spaceres, XFS_RENAME_LOG_RES(mp), 0,
			XFS_TRANS_PERM_LOG_RES, XFS_RENAME_LOG_COUNT);
	if (error == ENOSPC) {
		spaceres = 0;
		error = xfs_trans_reserve(tp, 0, XFS_RENAME_LOG_RES(mp), 0,
				XFS_TRANS_PERM_LOG_RES, XFS_RENAME_LOG_COUNT);
	}
	if (error) {
		xfs_trans_cancel(tp, 0);
		goto std_return;
	}

	/*
	 * Attach the dquots to the inodes
	 */
	if ((error = XFS_QM_DQVOPRENAME(mp, inodes))) {
		xfs_trans_cancel(tp, cancel_flags);
		goto std_return;
	}

	/*
	 * Lock all the participating inodes. Depending upon whether
	 * the target_name exists in the target directory, and
	 * whether the target directory is the same as the source
	 * directory, we can lock from 2 to 4 inodes.
	 */
	xfs_lock_inodes(inodes, num_inodes, XFS_ILOCK_EXCL);

	/*
	 * If we are using project inheritance, we only allow renames
	 * into our tree when the project IDs are the same; else the
	 * tree quota mechanism would be circumvented.
	 */
	if (unlikely((target_dp->i_d.di_flags & XFS_DIFLAG_PROJINHERIT) &&
		     (target_dp->i_d.di_projid != src_ip->i_d.di_projid))) {
		error = XFS_ERROR(EXDEV);
		xfs_rename_unlock4(inodes, XFS_ILOCK_SHARED);
		xfs_trans_cancel(tp, cancel_flags);
		goto std_return;
	}

	/*
	 * Join all the inodes to the transaction. From this point on,
	 * we can rely on either trans_commit or trans_cancel to unlock
	 * them.  Note that we need to add a vnode reference to the
	 * directories since trans_commit & trans_cancel will decrement
	 * them when they unlock the inodes.  Also, we need to be careful
	 * not to add an inode to the transaction more than once.
	 */
	IHOLD(src_dp);
	xfs_trans_ijoin(tp, src_dp, XFS_ILOCK_EXCL);

	if (new_parent) {
		IHOLD(target_dp);
		xfs_trans_ijoin(tp, target_dp, XFS_ILOCK_EXCL);
	}

	IHOLD(src_ip);
	xfs_trans_ijoin(tp, src_ip, XFS_ILOCK_EXCL);

	if (target_ip) {
		IHOLD(target_ip);
		xfs_trans_ijoin(tp, target_ip, XFS_ILOCK_EXCL);
	}

	/*
	 * Set up the target.
	 */
	if (target_ip == NULL) {
		/*
		 * If there's no space reservation, check the entry will
		 * fit before actually inserting it.
		 */
		error = xfs_dir_canenter(tp, target_dp, target_name, spaceres);
		if (error)
			goto error_return;
		/*
		 * If target does not exist and the rename crosses
		 * directories, adjust the target directory link count
		 * to account for the ".." reference from the new entry.
		 */
		error = xfs_dir_createname(tp, target_dp, target_name,
						src_ip->i_ino, &first_block,
						&free_list, spaceres);
		if (error == ENOSPC)
			goto error_return;
		if (error)
			goto abort_return;
		xfs_ichgtime(target_dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);

		if (new_parent && src_is_directory) {
			error = xfs_bumplink(tp, target_dp);
			if (error)
				goto abort_return;
		}
	} else { /* target_ip != NULL */
		/*
		 * If target exists and it's a directory, check that both
		 * target and source are directories and that target can be
		 * destroyed, or that neither is a directory.
		 */
		if ((target_ip->i_d.di_mode & S_IFMT) == S_IFDIR) {
			/*
			 * Make sure target dir is empty.
			 */
			if (!(xfs_dir_isempty(target_ip)) ||
			    (target_ip->i_d.di_nlink > 2)) {
				error = XFS_ERROR(EEXIST);
				goto error_return;
			}
		}

		/*
		 * Link the source inode under the target name.
		 * If the source inode is a directory and we are moving
		 * it across directories, its ".." entry will be
		 * inconsistent until we replace that down below.
		 *
		 * In case there is already an entry with the same
		 * name at the destination directory, remove it first.
		 */
		error = xfs_dir_replace(tp, target_dp, target_name,
					src_ip->i_ino,
					&first_block, &free_list, spaceres);
		if (error)
			goto abort_return;
		xfs_ichgtime(target_dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);

		/*
		 * Decrement the link count on the target since the target
		 * dir no longer points to it.
		 */
		error = xfs_droplink(tp, target_ip);
		if (error)
			goto abort_return;

		if (src_is_directory) {
			/*
			 * Drop the link from the old "." entry.
			 */
			error = xfs_droplink(tp, target_ip);
			if (error)
				goto abort_return;
		}
	} /* target_ip != NULL */

	/*
	 * Remove the source.
	 */
	if (new_parent && src_is_directory) {
		/*
		 * Rewrite the ".." entry to point to the new
		 * directory.
		 */
		error = xfs_dir_replace(tp, src_ip, &xfs_name_dotdot,
					target_dp->i_ino,
					&first_block, &free_list, spaceres);
		ASSERT(error != EEXIST);
		if (error)
			goto abort_return;
	}

	/*
	 * We always want to hit the ctime on the source inode.
	 *
	 * This isn't strictly required by the standards since the source
	 * inode isn't really being changed, but old unix file systems did
	 * it and some incremental backup programs won't work without it.
	 */
	xfs_ichgtime(src_ip, XFS_ICHGTIME_CHG);

	/*
	 * Adjust the link count on src_dp.  This is necessary when
	 * renaming a directory, either within one parent when
	 * the target existed, or across two parent directories.
	 */
	if (src_is_directory && (new_parent || target_ip != NULL)) {

		/*
		 * Decrement link count on src_directory since the
		 * entry that's moved no longer points to it.
		 */
		error = xfs_droplink(tp, src_dp);
		if (error)
			goto abort_return;
	}

	error = xfs_dir_removename(tp, src_dp, src_name, src_ip->i_ino,
					&first_block, &free_list, spaceres);
	if (error)
		goto abort_return;

	xfs_ichgtime(src_dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
	xfs_trans_log_inode(tp, src_dp, XFS_ILOG_CORE);
	if (new_parent)
		xfs_trans_log_inode(tp, target_dp, XFS_ILOG_CORE);

	/*
	 * If this is a synchronous mount, make sure that the
	 * rename transaction goes to disk before returning to
	 * the user.
	 */
	if (mp->m_flags & (XFS_MOUNT_WSYNC|XFS_MOUNT_DIRSYNC)) {
		xfs_trans_set_sync(tp);
	}

	error = xfs_bmap_finish(&tp, &free_list, &committed);
	if (error) {
		xfs_bmap_cancel(&free_list);
		xfs_trans_cancel(tp, (XFS_TRANS_RELEASE_LOG_RES |
				 XFS_TRANS_ABORT));
		goto std_return;
	}

	/*
	 * trans_commit will unlock src_ip, target_ip & decrement
	 * the vnode references.
	 */
	error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);

	/* Fall through to std_return with error = 0 or errno from
	 * xfs_trans_commit	 */
std_return:
	if (DM_EVENT_ENABLED(src_dp, DM_EVENT_POSTRENAME) ||
	    DM_EVENT_ENABLED(target_dp, DM_EVENT_POSTRENAME)) {
		(void) XFS_SEND_NAMESP (mp, DM_EVENT_POSTRENAME,
					src_dp, DM_RIGHT_NULL,
					target_dp, DM_RIGHT_NULL,
					src_name->name, target_name->name,
					0, error, 0);
	}
	return error;

 abort_return:
	cancel_flags |= XFS_TRANS_ABORT;
	/* FALLTHROUGH */
 error_return:
	xfs_bmap_cancel(&free_list);
	xfs_trans_cancel(tp, cancel_flags);
	goto std_return;
}