Linux Kernel  3.7.1
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
xfs_rename.c
Go to the documentation of this file.
1 /*
2  * Copyright (c) 2000-2003,2005 Silicon Graphics, Inc.
3  * All Rights Reserved.
4  *
5  * This program is free software; you can redistribute it and/or
6  * modify it under the terms of the GNU General Public License as
7  * published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope that it would be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write the Free Software Foundation,
16  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
17  */
18 #include "xfs.h"
19 #include "xfs_fs.h"
20 #include "xfs_types.h"
21 #include "xfs_log.h"
22 #include "xfs_trans.h"
23 #include "xfs_sb.h"
24 #include "xfs_ag.h"
25 #include "xfs_dir2.h"
26 #include "xfs_mount.h"
27 #include "xfs_da_btree.h"
28 #include "xfs_bmap_btree.h"
29 #include "xfs_dinode.h"
30 #include "xfs_inode.h"
31 #include "xfs_inode_item.h"
32 #include "xfs_bmap.h"
33 #include "xfs_error.h"
34 #include "xfs_quota.h"
35 #include "xfs_utils.h"
36 #include "xfs_trans_space.h"
37 #include "xfs_vnodeops.h"
38 #include "xfs_trace.h"
39 
40 
41 /*
42  * Enter all inodes for a rename transaction into a sorted array.
43  */
44 STATIC void
46  xfs_inode_t *dp1, /* in: old (source) directory inode */
47  xfs_inode_t *dp2, /* in: new (target) directory inode */
48  xfs_inode_t *ip1, /* in: inode of old entry */
49  xfs_inode_t *ip2, /* in: inode of new entry, if it
50  already exists, NULL otherwise. */
51  xfs_inode_t **i_tab,/* out: array of inode returned, sorted */
52  int *num_inodes) /* out: number of inodes in array */
53 {
54  xfs_inode_t *temp;
55  int i, j;
56 
57  /*
58  * i_tab contains a list of pointers to inodes. We initialize
59  * the table here & we'll sort it. We will then use it to
60  * order the acquisition of the inode locks.
61  *
62  * Note that the table may contain duplicates. e.g., dp1 == dp2.
63  */
64  i_tab[0] = dp1;
65  i_tab[1] = dp2;
66  i_tab[2] = ip1;
67  if (ip2) {
68  *num_inodes = 4;
69  i_tab[3] = ip2;
70  } else {
71  *num_inodes = 3;
72  i_tab[3] = NULL;
73  }
74 
75  /*
76  * Sort the elements via bubble sort. (Remember, there are at
77  * most 4 elements to sort, so this is adequate.)
78  */
79  for (i = 0; i < *num_inodes; i++) {
80  for (j = 1; j < *num_inodes; j++) {
81  if (i_tab[j]->i_ino < i_tab[j-1]->i_ino) {
82  temp = i_tab[j];
83  i_tab[j] = i_tab[j-1];
84  i_tab[j-1] = temp;
85  }
86  }
87  }
88 }
89 
90 /*
91  * xfs_rename
92  */
93 int
95  xfs_inode_t *src_dp,
96  struct xfs_name *src_name,
97  xfs_inode_t *src_ip,
98  xfs_inode_t *target_dp,
99  struct xfs_name *target_name,
100  xfs_inode_t *target_ip)
101 {
102  xfs_trans_t *tp = NULL;
103  xfs_mount_t *mp = src_dp->i_mount;
104  int new_parent; /* moving to a new dir */
105  int src_is_directory; /* src_name is a directory */
106  int error;
108  xfs_fsblock_t first_block;
109  int cancel_flags;
110  int committed;
111  xfs_inode_t *inodes[4];
112  int spaceres;
113  int num_inodes;
114 
115  trace_xfs_rename(src_dp, target_dp, src_name, target_name);
116 
117  new_parent = (src_dp != target_dp);
118  src_is_directory = S_ISDIR(src_ip->i_d.di_mode);
119 
120  xfs_sort_for_rename(src_dp, target_dp, src_ip, target_ip,
121  inodes, &num_inodes);
122 
123  xfs_bmap_init(&free_list, &first_block);
125  cancel_flags = XFS_TRANS_RELEASE_LOG_RES;
126  spaceres = XFS_RENAME_SPACE_RES(mp, target_name->len);
127  error = xfs_trans_reserve(tp, spaceres, XFS_RENAME_LOG_RES(mp), 0,
129  if (error == ENOSPC) {
130  spaceres = 0;
131  error = xfs_trans_reserve(tp, 0, XFS_RENAME_LOG_RES(mp), 0,
133  }
134  if (error) {
135  xfs_trans_cancel(tp, 0);
136  goto std_return;
137  }
138 
139  /*
140  * Attach the dquots to the inodes
141  */
142  error = xfs_qm_vop_rename_dqattach(inodes);
143  if (error) {
144  xfs_trans_cancel(tp, cancel_flags);
145  goto std_return;
146  }
147 
148  /*
149  * Lock all the participating inodes. Depending upon whether
150  * the target_name exists in the target directory, and
151  * whether the target directory is the same as the source
152  * directory, we can lock from 2 to 4 inodes.
153  */
154  xfs_lock_inodes(inodes, num_inodes, XFS_ILOCK_EXCL);
155 
156  /*
157  * Join all the inodes to the transaction. From this point on,
158  * we can rely on either trans_commit or trans_cancel to unlock
159  * them.
160  */
161  xfs_trans_ijoin(tp, src_dp, XFS_ILOCK_EXCL);
162  if (new_parent)
163  xfs_trans_ijoin(tp, target_dp, XFS_ILOCK_EXCL);
164  xfs_trans_ijoin(tp, src_ip, XFS_ILOCK_EXCL);
165  if (target_ip)
166  xfs_trans_ijoin(tp, target_ip, XFS_ILOCK_EXCL);
167 
168  /*
169  * If we are using project inheritance, we only allow renames
170  * into our tree when the project IDs are the same; else the
171  * tree quota mechanism would be circumvented.
172  */
173  if (unlikely((target_dp->i_d.di_flags & XFS_DIFLAG_PROJINHERIT) &&
174  (xfs_get_projid(target_dp) != xfs_get_projid(src_ip)))) {
175  error = XFS_ERROR(EXDEV);
176  goto error_return;
177  }
178 
179  /*
180  * Set up the target.
181  */
182  if (target_ip == NULL) {
183  /*
184  * If there's no space reservation, check the entry will
185  * fit before actually inserting it.
186  */
187  error = xfs_dir_canenter(tp, target_dp, target_name, spaceres);
188  if (error)
189  goto error_return;
190  /*
191  * If target does not exist and the rename crosses
192  * directories, adjust the target directory link count
193  * to account for the ".." reference from the new entry.
194  */
195  error = xfs_dir_createname(tp, target_dp, target_name,
196  src_ip->i_ino, &first_block,
197  &free_list, spaceres);
198  if (error == ENOSPC)
199  goto error_return;
200  if (error)
201  goto abort_return;
202 
203  xfs_trans_ichgtime(tp, target_dp,
205 
206  if (new_parent && src_is_directory) {
207  error = xfs_bumplink(tp, target_dp);
208  if (error)
209  goto abort_return;
210  }
211  } else { /* target_ip != NULL */
212  /*
213  * If target exists and it's a directory, check that both
214  * target and source are directories and that target can be
215  * destroyed, or that neither is a directory.
216  */
217  if (S_ISDIR(target_ip->i_d.di_mode)) {
218  /*
219  * Make sure target dir is empty.
220  */
221  if (!(xfs_dir_isempty(target_ip)) ||
222  (target_ip->i_d.di_nlink > 2)) {
223  error = XFS_ERROR(EEXIST);
224  goto error_return;
225  }
226  }
227 
228  /*
229  * Link the source inode under the target name.
230  * If the source inode is a directory and we are moving
231  * it across directories, its ".." entry will be
232  * inconsistent until we replace that down below.
233  *
234  * In case there is already an entry with the same
235  * name at the destination directory, remove it first.
236  */
237  error = xfs_dir_replace(tp, target_dp, target_name,
238  src_ip->i_ino,
239  &first_block, &free_list, spaceres);
240  if (error)
241  goto abort_return;
242 
243  xfs_trans_ichgtime(tp, target_dp,
245 
246  /*
247  * Decrement the link count on the target since the target
248  * dir no longer points to it.
249  */
250  error = xfs_droplink(tp, target_ip);
251  if (error)
252  goto abort_return;
253 
254  if (src_is_directory) {
255  /*
256  * Drop the link from the old "." entry.
257  */
258  error = xfs_droplink(tp, target_ip);
259  if (error)
260  goto abort_return;
261  }
262  } /* target_ip != NULL */
263 
264  /*
265  * Remove the source.
266  */
267  if (new_parent && src_is_directory) {
268  /*
269  * Rewrite the ".." entry to point to the new
270  * directory.
271  */
272  error = xfs_dir_replace(tp, src_ip, &xfs_name_dotdot,
273  target_dp->i_ino,
274  &first_block, &free_list, spaceres);
275  ASSERT(error != EEXIST);
276  if (error)
277  goto abort_return;
278  }
279 
280  /*
281  * We always want to hit the ctime on the source inode.
282  *
283  * This isn't strictly required by the standards since the source
284  * inode isn't really being changed, but old unix file systems did
285  * it and some incremental backup programs won't work without it.
286  */
288  xfs_trans_log_inode(tp, src_ip, XFS_ILOG_CORE);
289 
290  /*
291  * Adjust the link count on src_dp. This is necessary when
292  * renaming a directory, either within one parent when
293  * the target existed, or across two parent directories.
294  */
295  if (src_is_directory && (new_parent || target_ip != NULL)) {
296 
297  /*
298  * Decrement link count on src_directory since the
299  * entry that's moved no longer points to it.
300  */
301  error = xfs_droplink(tp, src_dp);
302  if (error)
303  goto abort_return;
304  }
305 
306  error = xfs_dir_removename(tp, src_dp, src_name, src_ip->i_ino,
307  &first_block, &free_list, spaceres);
308  if (error)
309  goto abort_return;
310 
312  xfs_trans_log_inode(tp, src_dp, XFS_ILOG_CORE);
313  if (new_parent)
314  xfs_trans_log_inode(tp, target_dp, XFS_ILOG_CORE);
315 
316  /*
317  * If this is a synchronous mount, make sure that the
318  * rename transaction goes to disk before returning to
319  * the user.
320  */
321  if (mp->m_flags & (XFS_MOUNT_WSYNC|XFS_MOUNT_DIRSYNC)) {
322  xfs_trans_set_sync(tp);
323  }
324 
325  error = xfs_bmap_finish(&tp, &free_list, &committed);
326  if (error) {
327  xfs_bmap_cancel(&free_list);
329  XFS_TRANS_ABORT));
330  goto std_return;
331  }
332 
333  /*
334  * trans_commit will unlock src_ip, target_ip & decrement
335  * the vnode references.
336  */
338 
339  abort_return:
340  cancel_flags |= XFS_TRANS_ABORT;
341  error_return:
342  xfs_bmap_cancel(&free_list);
343  xfs_trans_cancel(tp, cancel_flags);
344  std_return:
345  return error;
346 }