LXR linux/fs/xfs/xfs

   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_inum.h"
  23#include "xfs_trans.h"
  24#include "xfs_sb.h"
  25#include "xfs_ag.h"
  26#include "xfs_dir2.h"
  27#include "xfs_mount.h"
  28#include "xfs_da_btree.h"
  29#include "xfs_bmap_btree.h"
  30#include "xfs_dinode.h"
  31#include "xfs_inode.h"
  32#include "xfs_inode_item.h"
  33#include "xfs_bmap.h"
  34#include "xfs_error.h"
  35#include "xfs_quota.h"
  36#include "xfs_utils.h"
  37#include "xfs_trans_space.h"
  38#include "xfs_vnodeops.h"
  39#include "xfs_trace.h"
  40
  41
  42/*
  43 * Enter all inodes for a rename transaction into a sorted array.
  44 */
  45STATIC void
  46xfs_sort_for_rename(
  47        xfs_inode_t     *dp1,   /* in: old (source) directory inode */
  48        xfs_inode_t     *dp2,   /* in: new (target) directory inode */
  49        xfs_inode_t     *ip1,   /* in: inode of old entry */
  50        xfs_inode_t     *ip2,   /* in: inode of new entry, if it
  51                                   already exists, NULL otherwise. */
  52        xfs_inode_t     **i_tab,/* out: array of inode returned, sorted */
  53        int             *num_inodes)  /* out: number of inodes in array */
  54{
  55        xfs_inode_t             *temp;
  56        int                     i, j;
  57
  58        /*
  59         * i_tab contains a list of pointers to inodes.  We initialize
  60         * the table here & we'll sort it.  We will then use it to
  61         * order the acquisition of the inode locks.
  62         *
  63         * Note that the table may contain duplicates.  e.g., dp1 == dp2.
  64         */
  65        i_tab[0] = dp1;
  66        i_tab[1] = dp2;
  67        i_tab[2] = ip1;
  68        if (ip2) {
  69                *num_inodes = 4;
  70                i_tab[3] = ip2;
  71        } else {
  72                *num_inodes = 3;
  73                i_tab[3] = NULL;
  74        }
  75
  76        /*
  77         * Sort the elements via bubble sort.  (Remember, there are at
  78         * most 4 elements to sort, so this is adequate.)
  79         */
  80        for (i = 0; i < *num_inodes; i++) {
  81                for (j = 1; j < *num_inodes; j++) {
  82                        if (i_tab[j]->i_ino < i_tab[j-1]->i_ino) {
  83                                temp = i_tab[j];
  84                                i_tab[j] = i_tab[j-1];
  85                                i_tab[j-1] = temp;
  86                        }
  87                }
  88        }
  89}
  90
  91/*
  92 * xfs_rename
  93 */
  94int
  95xfs_rename(
  96        xfs_inode_t     *src_dp,
  97        struct xfs_name *src_name,
  98        xfs_inode_t     *src_ip,
  99        xfs_inode_t     *target_dp,
 100        struct xfs_name *target_name,
 101        xfs_inode_t     *target_ip)
 102{
 103        xfs_trans_t     *tp = NULL;
 104        xfs_mount_t     *mp = src_dp->i_mount;
 105        int             new_parent;             /* moving to a new dir */
 106        int             src_is_directory;       /* src_name is a directory */
 107        int             error;
 108        xfs_bmap_free_t free_list;
 109        xfs_fsblock_t   first_block;
 110        int             cancel_flags;
 111        int             committed;
 112        xfs_inode_t     *inodes[4];
 113        int             spaceres;
 114        int             num_inodes;
 115
 116        trace_xfs_rename(src_dp, target_dp, src_name, target_name);
 117
 118        new_parent = (src_dp != target_dp);
 119        src_is_directory = S_ISDIR(src_ip->i_d.di_mode);
 120
 121        if (src_is_directory) {
 122                /*
 123                 * Check for link count overflow on target_dp
 124                 */
 125                if (target_ip == NULL && new_parent &&
 126                    target_dp->i_d.di_nlink >= XFS_MAXLINK) {
 127                        error = XFS_ERROR(EMLINK);
 128                        goto std_return;
 129                }
 130        }
 131
 132        xfs_sort_for_rename(src_dp, target_dp, src_ip, target_ip,
 133                                inodes, &num_inodes);
 134
 135        xfs_bmap_init(&free_list, &first_block);
 136        tp = xfs_trans_alloc(mp, XFS_TRANS_RENAME);
 137        cancel_flags = XFS_TRANS_RELEASE_LOG_RES;
 138        spaceres = XFS_RENAME_SPACE_RES(mp, target_name->len);
 139        error = xfs_trans_reserve(tp, spaceres, XFS_RENAME_LOG_RES(mp), 0,
 140                        XFS_TRANS_PERM_LOG_RES, XFS_RENAME_LOG_COUNT);
 141        if (error == ENOSPC) {
 142                spaceres = 0;
 143                error = xfs_trans_reserve(tp, 0, XFS_RENAME_LOG_RES(mp), 0,
 144                                XFS_TRANS_PERM_LOG_RES, XFS_RENAME_LOG_COUNT);
 145        }
 146        if (error) {
 147                xfs_trans_cancel(tp, 0);
 148                goto std_return;
 149        }
 150
 151        /*
 152         * Attach the dquots to the inodes
 153         */
 154        error = xfs_qm_vop_rename_dqattach(inodes);
 155        if (error) {
 156                xfs_trans_cancel(tp, cancel_flags);
 157                goto std_return;
 158        }
 159
 160        /*
 161         * Lock all the participating inodes. Depending upon whether
 162         * the target_name exists in the target directory, and
 163         * whether the target directory is the same as the source
 164         * directory, we can lock from 2 to 4 inodes.
 165         */
 166        xfs_lock_inodes(inodes, num_inodes, XFS_ILOCK_EXCL);
 167
 168        /*
 169         * Join all the inodes to the transaction. From this point on,
 170         * we can rely on either trans_commit or trans_cancel to unlock
 171         * them.
 172         */
 173        xfs_trans_ijoin(tp, src_dp, XFS_ILOCK_EXCL);
 174        if (new_parent)
 175                xfs_trans_ijoin(tp, target_dp, XFS_ILOCK_EXCL);
 176        xfs_trans_ijoin(tp, src_ip, XFS_ILOCK_EXCL);
 177        if (target_ip)
 178                xfs_trans_ijoin(tp, target_ip, XFS_ILOCK_EXCL);
 179
 180        /*
 181         * If we are using project inheritance, we only allow renames
 182         * into our tree when the project IDs are the same; else the
 183         * tree quota mechanism would be circumvented.
 184         */
 185        if (unlikely((target_dp->i_d.di_flags & XFS_DIFLAG_PROJINHERIT) &&
 186                     (xfs_get_projid(target_dp) != xfs_get_projid(src_ip)))) {
 187                error = XFS_ERROR(EXDEV);
 188                goto error_return;
 189        }
 190
 191        /*
 192         * Set up the target.
 193         */
 194        if (target_ip == NULL) {
 195                /*
 196                 * If there's no space reservation, check the entry will
 197                 * fit before actually inserting it.
 198                 */
 199                error = xfs_dir_canenter(tp, target_dp, target_name, spaceres);
 200                if (error)
 201                        goto error_return;
 202                /*
 203                 * If target does not exist and the rename crosses
 204                 * directories, adjust the target directory link count
 205                 * to account for the ".." reference from the new entry.
 206                 */
 207                error = xfs_dir_createname(tp, target_dp, target_name,
 208                                                src_ip->i_ino, &first_block,
 209                                                &free_list, spaceres);
 210                if (error == ENOSPC)
 211                        goto error_return;
 212                if (error)
 213                        goto abort_return;
 214
 215                xfs_trans_ichgtime(tp, target_dp,
 216                                        XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
 217
 218                if (new_parent && src_is_directory) {
 219                        error = xfs_bumplink(tp, target_dp);
 220                        if (error)
 221                                goto abort_return;
 222                }
 223        } else { /* target_ip != NULL */
 224                /*
 225                 * If target exists and it's a directory, check that both
 226                 * target and source are directories and that target can be
 227                 * destroyed, or that neither is a directory.
 228                 */
 229                if (S_ISDIR(target_ip->i_d.di_mode)) {
 230                        /*
 231                         * Make sure target dir is empty.
 232                         */
 233                        if (!(xfs_dir_isempty(target_ip)) ||
 234                            (target_ip->i_d.di_nlink > 2)) {
 235                                error = XFS_ERROR(EEXIST);
 236                                goto error_return;
 237                        }
 238                }
 239
 240                /*
 241                 * Link the source inode under the target name.
 242                 * If the source inode is a directory and we are moving
 243                 * it across directories, its ".." entry will be
 244                 * inconsistent until we replace that down below.
 245                 *
 246                 * In case there is already an entry with the same
 247                 * name at the destination directory, remove it first.
 248                 */
 249                error = xfs_dir_replace(tp, target_dp, target_name,
 250                                        src_ip->i_ino,
 251                                        &first_block, &free_list, spaceres);
 252                if (error)
 253                        goto abort_return;
 254
 255                xfs_trans_ichgtime(tp, target_dp,
 256                                        XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
 257
 258                /*
 259                 * Decrement the link count on the target since the target
 260                 * dir no longer points to it.
 261                 */
 262                error = xfs_droplink(tp, target_ip);
 263                if (error)
 264                        goto abort_return;
 265
 266                if (src_is_directory) {
 267                        /*
 268                         * Drop the link from the old "." entry.
 269                         */
 270                        error = xfs_droplink(tp, target_ip);
 271                        if (error)
 272                                goto abort_return;
 273                }
 274        } /* target_ip != NULL */
 275
 276        /*
 277         * Remove the source.
 278         */
 279        if (new_parent && src_is_directory) {
 280                /*
 281                 * Rewrite the ".." entry to point to the new
 282                 * directory.
 283                 */
 284                error = xfs_dir_replace(tp, src_ip, &xfs_name_dotdot,
 285                                        target_dp->i_ino,
 286                                        &first_block, &free_list, spaceres);
 287                ASSERT(error != EEXIST);
 288                if (error)
 289                        goto abort_return;
 290        }
 291
 292        /*
 293         * We always want to hit the ctime on the source inode.
 294         *
 295         * This isn't strictly required by the standards since the source
 296         * inode isn't really being changed, but old unix file systems did
 297         * it and some incremental backup programs won't work without it.
 298         */
 299        xfs_trans_ichgtime(tp, src_ip, XFS_ICHGTIME_CHG);
 300        xfs_trans_log_inode(tp, src_ip, XFS_ILOG_CORE);
 301
 302        /*
 303         * Adjust the link count on src_dp.  This is necessary when
 304         * renaming a directory, either within one parent when
 305         * the target existed, or across two parent directories.
 306         */
 307        if (src_is_directory && (new_parent || target_ip != NULL)) {
 308
 309                /*
 310                 * Decrement link count on src_directory since the
 311                 * entry that's moved no longer points to it.
 312                 */
 313                error = xfs_droplink(tp, src_dp);
 314                if (error)
 315                        goto abort_return;
 316        }
 317
 318        error = xfs_dir_removename(tp, src_dp, src_name, src_ip->i_ino,
 319                                        &first_block, &free_list, spaceres);
 320        if (error)
 321                goto abort_return;
 322
 323        xfs_trans_ichgtime(tp, src_dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
 324        xfs_trans_log_inode(tp, src_dp, XFS_ILOG_CORE);
 325        if (new_parent)
 326                xfs_trans_log_inode(tp, target_dp, XFS_ILOG_CORE);
 327
 328        /*
 329         * If this is a synchronous mount, make sure that the
 330         * rename transaction goes to disk before returning to
 331         * the user.
 332         */
 333        if (mp->m_flags & (XFS_MOUNT_WSYNC|XFS_MOUNT_DIRSYNC)) {
 334                xfs_trans_set_sync(tp);
 335        }
 336
 337        error = xfs_bmap_finish(&tp, &free_list, &committed);
 338        if (error) {
 339                xfs_bmap_cancel(&free_list);
 340                xfs_trans_cancel(tp, (XFS_TRANS_RELEASE_LOG_RES |
 341                                 XFS_TRANS_ABORT));
 342                goto std_return;
 343        }
 344
 345        /*
 346         * trans_commit will unlock src_ip, target_ip & decrement
 347         * the vnode references.
 348         */
 349        return xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
 350
 351 abort_return:
 352        cancel_flags |= XFS_TRANS_ABORT;
 353 error_return:
 354        xfs_bmap_cancel(&free_list);
 355        xfs_trans_cancel(tp, cancel_flags);
 356 std_return:
 357        return error;
 358}
 359