fs/xfs/xfs_rename.c

   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
  45 xfs_sort_for_rename(
  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
  94 xfs_rename(
  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;
 107         xfs_bmap_free_t free_list;
 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);
 124         tp = xfs_trans_alloc(mp, XFS_TRANS_RENAME);
 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,
 128                         XFS_TRANS_PERM_LOG_RES, XFS_RENAME_LOG_COUNT);
 129         if (error == ENOSPC) {
 130                 spaceres = 0;
 131                 error = xfs_trans_reserve(tp, 0, XFS_RENAME_LOG_RES(mp), 0,
 132                                 XFS_TRANS_PERM_LOG_RES, XFS_RENAME_LOG_COUNT);
 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,
 204                                         XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
 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,
 244                                         XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
 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          */
 287         xfs_trans_ichgtime(tp, src_ip, XFS_ICHGTIME_CHG);
 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
 311         xfs_trans_ichgtime(tp, src_dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
 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);
 328                 xfs_trans_cancel(tp, (XFS_TRANS_RELEASE_LOG_RES |
 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          */
 337         return xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
 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 }