fs/xfs/xfs_dfrag.c

   1 /*
   2  * Copyright (c) 2000-2006 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_bit.h"
  22 #include "xfs_log.h"
  23 #include "xfs_inum.h"
  24 #include "xfs_trans.h"
  25 #include "xfs_sb.h"
  26 #include "xfs_ag.h"
  27 #include "xfs_dir2.h"
  28 #include "xfs_dmapi.h"
  29 #include "xfs_mount.h"
  30 #include "xfs_bmap_btree.h"
  31 #include "xfs_alloc_btree.h"
  32 #include "xfs_ialloc_btree.h"
  33 #include "xfs_dir2_sf.h"
  34 #include "xfs_attr_sf.h"
  35 #include "xfs_dinode.h"
  36 #include "xfs_inode.h"
  37 #include "xfs_inode_item.h"
  38 #include "xfs_bmap.h"
  39 #include "xfs_btree.h"
  40 #include "xfs_ialloc.h"
  41 #include "xfs_itable.h"
  42 #include "xfs_dfrag.h"
  43 #include "xfs_error.h"
  44 #include "xfs_rw.h"
  45
  46 /*
  47  * Syssgi interface for swapext
  48  */
  49 int
  50 xfs_swapext(
  51         xfs_swapext_t   __user *sxu)
  52 {
  53         xfs_swapext_t   *sxp;
  54         xfs_inode_t     *ip=NULL, *tip=NULL;
  55         xfs_mount_t     *mp;
  56         struct file     *fp = NULL, *tfp = NULL;
  57         bhv_vnode_t     *vp, *tvp;
  58         int             error = 0;
  59
  60         sxp = kmem_alloc(sizeof(xfs_swapext_t), KM_MAYFAIL);
  61         if (!sxp) {
  62                 error = XFS_ERROR(ENOMEM);
  63                 goto error0;
  64         }
  65
  66         if (copy_from_user(sxp, sxu, sizeof(xfs_swapext_t))) {
  67                 error = XFS_ERROR(EFAULT);
  68                 goto error0;
  69         }
  70
  71         /* Pull information for the target fd */
  72         if (((fp = fget((int)sxp->sx_fdtarget)) == NULL) ||
  73             ((vp = vn_from_inode(fp->f_path.dentry->d_inode)) == NULL))  {
  74                 error = XFS_ERROR(EINVAL);
  75                 goto error0;
  76         }
  77
  78         ip = xfs_vtoi(vp);
  79         if (ip == NULL) {
  80                 error = XFS_ERROR(EBADF);
  81                 goto error0;
  82         }
  83
  84         if (((tfp = fget((int)sxp->sx_fdtmp)) == NULL) ||
  85             ((tvp = vn_from_inode(tfp->f_path.dentry->d_inode)) == NULL)) {
  86                 error = XFS_ERROR(EINVAL);
  87                 goto error0;
  88         }
  89
  90         tip = xfs_vtoi(tvp);
  91         if (tip == NULL) {
  92                 error = XFS_ERROR(EBADF);
  93                 goto error0;
  94         }
  95
  96         if (ip->i_mount != tip->i_mount) {
  97                 error =  XFS_ERROR(EINVAL);
  98                 goto error0;
  99         }
 100
 101         if (ip->i_ino == tip->i_ino) {
 102                 error =  XFS_ERROR(EINVAL);
 103                 goto error0;
 104         }
 105
 106         mp = ip->i_mount;
 107
 108         if (XFS_FORCED_SHUTDOWN(mp)) {
 109                 error =  XFS_ERROR(EIO);
 110                 goto error0;
 111         }
 112
 113         error = XFS_SWAP_EXTENTS(mp, &ip->i_iocore, &tip->i_iocore, sxp);
 114
 115  error0:
 116         if (fp != NULL)
 117                 fput(fp);
 118         if (tfp != NULL)
 119                 fput(tfp);
 120
 121         if (sxp != NULL)
 122                 kmem_free(sxp, sizeof(xfs_swapext_t));
 123
 124         return error;
 125 }
 126
 127 int
 128 xfs_swap_extents(
 129         xfs_inode_t     *ip,
 130         xfs_inode_t     *tip,
 131         xfs_swapext_t   *sxp)
 132 {
 133         xfs_mount_t     *mp;
 134         xfs_inode_t     *ips[2];
 135         xfs_trans_t     *tp;
 136         xfs_bstat_t     *sbp = &sxp->sx_stat;
 137         bhv_vnode_t     *vp, *tvp;
 138         xfs_ifork_t     *tempifp, *ifp, *tifp;
 139         int             ilf_fields, tilf_fields;
 140         static uint     lock_flags = XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL;
 141         int             error = 0;
 142         int             aforkblks = 0;
 143         int             taforkblks = 0;
 144         __uint64_t      tmp;
 145         char            locked = 0;
 146
 147         mp = ip->i_mount;
 148
 149         tempifp = kmem_alloc(sizeof(xfs_ifork_t), KM_MAYFAIL);
 150         if (!tempifp) {
 151                 error = XFS_ERROR(ENOMEM);
 152                 goto error0;
 153         }
 154
 155         sbp = &sxp->sx_stat;
 156         vp = XFS_ITOV(ip);
 157         tvp = XFS_ITOV(tip);
 158
 159         /* Lock in i_ino order */
 160         if (ip->i_ino < tip->i_ino) {
 161                 ips[0] = ip;
 162                 ips[1] = tip;
 163         } else {
 164                 ips[0] = tip;
 165                 ips[1] = ip;
 166         }
 167
 168         xfs_lock_inodes(ips, 2, 0, lock_flags);
 169         locked = 1;
 170
 171         /* Check permissions */
 172         error = xfs_iaccess(ip, S_IWUSR, NULL);
 173         if (error)
 174                 goto error0;
 175
 176         error = xfs_iaccess(tip, S_IWUSR, NULL);
 177         if (error)
 178                 goto error0;
 179
 180         /* Verify that both files have the same format */
 181         if ((ip->i_d.di_mode & S_IFMT) != (tip->i_d.di_mode & S_IFMT)) {
 182                 error = XFS_ERROR(EINVAL);
 183                 goto error0;
 184         }
 185
 186         /* Verify both files are either real-time or non-realtime */
 187         if ((ip->i_d.di_flags & XFS_DIFLAG_REALTIME) !=
 188             (tip->i_d.di_flags & XFS_DIFLAG_REALTIME)) {
 189                 error = XFS_ERROR(EINVAL);
 190                 goto error0;
 191         }
 192
 193         /* Should never get a local format */
 194         if (ip->i_d.di_format == XFS_DINODE_FMT_LOCAL ||
 195             tip->i_d.di_format == XFS_DINODE_FMT_LOCAL) {
 196                 error = XFS_ERROR(EINVAL);
 197                 goto error0;
 198         }
 199
 200         if (VN_CACHED(tvp) != 0) {
 201                 xfs_inval_cached_trace(&tip->i_iocore, 0, -1, 0, -1);
 202                 bhv_vop_flushinval_pages(tvp, 0, -1, FI_REMAPF_LOCKED);
 203         }
 204
 205         /* Verify O_DIRECT for ftmp */
 206         if (VN_CACHED(tvp) != 0) {
 207                 error = XFS_ERROR(EINVAL);
 208                 goto error0;
 209         }
 210
 211         /* Verify all data are being swapped */
 212         if (sxp->sx_offset != 0 ||
 213             sxp->sx_length != ip->i_d.di_size ||
 214             sxp->sx_length != tip->i_d.di_size) {
 215                 error = XFS_ERROR(EFAULT);
 216                 goto error0;
 217         }
 218
 219         /*
 220          * If the target has extended attributes, the tmp file
 221          * must also in order to ensure the correct data fork
 222          * format.
 223          */
 224         if ( XFS_IFORK_Q(ip) != XFS_IFORK_Q(tip) ) {
 225                 error = XFS_ERROR(EINVAL);
 226                 goto error0;
 227         }
 228
 229         /*
 230          * Compare the current change & modify times with that
 231          * passed in.  If they differ, we abort this swap.
 232          * This is the mechanism used to ensure the calling
 233          * process that the file was not changed out from
 234          * under it.
 235          */
 236         if ((sbp->bs_ctime.tv_sec != ip->i_d.di_ctime.t_sec) ||
 237             (sbp->bs_ctime.tv_nsec != ip->i_d.di_ctime.t_nsec) ||
 238             (sbp->bs_mtime.tv_sec != ip->i_d.di_mtime.t_sec) ||
 239             (sbp->bs_mtime.tv_nsec != ip->i_d.di_mtime.t_nsec)) {
 240                 error = XFS_ERROR(EBUSY);
 241                 goto error0;
 242         }
 243
 244         /* We need to fail if the file is memory mapped.  Once we have tossed
 245          * all existing pages, the page fault will have no option
 246          * but to go to the filesystem for pages. By making the page fault call
 247          * vop_read (or write in the case of autogrow) they block on the iolock
 248          * until we have switched the extents.
 249          */
 250         if (VN_MAPPED(vp)) {
 251                 error = XFS_ERROR(EBUSY);
 252                 goto error0;
 253         }
 254
 255         xfs_iunlock(ip, XFS_ILOCK_EXCL);
 256         xfs_iunlock(tip, XFS_ILOCK_EXCL);
 257
 258         /*
 259          * There is a race condition here since we gave up the
 260          * ilock.  However, the data fork will not change since
 261          * we have the iolock (locked for truncation too) so we
 262          * are safe.  We don't really care if non-io related
 263          * fields change.
 264          */
 265
 266         bhv_vop_toss_pages(vp, 0, -1, FI_REMAPF);
 267
 268         tp = xfs_trans_alloc(mp, XFS_TRANS_SWAPEXT);
 269         if ((error = xfs_trans_reserve(tp, 0,
 270                                      XFS_ICHANGE_LOG_RES(mp), 0,
 271                                      0, 0))) {
 272                 xfs_iunlock(ip,  XFS_IOLOCK_EXCL);
 273                 xfs_iunlock(tip, XFS_IOLOCK_EXCL);
 274                 xfs_trans_cancel(tp, 0);
 275                 locked = 0;
 276                 goto error0;
 277         }
 278         xfs_lock_inodes(ips, 2, 0, XFS_ILOCK_EXCL);
 279
 280         /*
 281          * Count the number of extended attribute blocks
 282          */
 283         if ( ((XFS_IFORK_Q(ip) != 0) && (ip->i_d.di_anextents > 0)) &&
 284              (ip->i_d.di_aformat != XFS_DINODE_FMT_LOCAL)) {
 285                 error = xfs_bmap_count_blocks(tp, ip, XFS_ATTR_FORK, &aforkblks);
 286                 if (error) {
 287                         xfs_trans_cancel(tp, 0);
 288                         goto error0;
 289                 }
 290         }
 291         if ( ((XFS_IFORK_Q(tip) != 0) && (tip->i_d.di_anextents > 0)) &&
 292              (tip->i_d.di_aformat != XFS_DINODE_FMT_LOCAL)) {
 293                 error = xfs_bmap_count_blocks(tp, tip, XFS_ATTR_FORK,
 294                         &taforkblks);
 295                 if (error) {
 296                         xfs_trans_cancel(tp, 0);
 297                         goto error0;
 298                 }
 299         }
 300
 301         /*
 302          * Swap the data forks of the inodes
 303          */
 304         ifp = &ip->i_df;
 305         tifp = &tip->i_df;
 306         *tempifp = *ifp;        /* struct copy */
 307         *ifp = *tifp;           /* struct copy */
 308         *tifp = *tempifp;       /* struct copy */
 309
 310         /*
 311          * Fix the on-disk inode values
 312          */
 313         tmp = (__uint64_t)ip->i_d.di_nblocks;
 314         ip->i_d.di_nblocks = tip->i_d.di_nblocks - taforkblks + aforkblks;
 315         tip->i_d.di_nblocks = tmp + taforkblks - aforkblks;
 316
 317         tmp = (__uint64_t) ip->i_d.di_nextents;
 318         ip->i_d.di_nextents = tip->i_d.di_nextents;
 319         tip->i_d.di_nextents = tmp;
 320
 321         tmp = (__uint64_t) ip->i_d.di_format;
 322         ip->i_d.di_format = tip->i_d.di_format;
 323         tip->i_d.di_format = tmp;
 324
 325         ilf_fields = XFS_ILOG_CORE;
 326
 327         switch(ip->i_d.di_format) {
 328         case XFS_DINODE_FMT_EXTENTS:
 329                 /* If the extents fit in the inode, fix the
 330                  * pointer.  Otherwise it's already NULL or
 331                  * pointing to the extent.
 332                  */
 333                 if (ip->i_d.di_nextents <= XFS_INLINE_EXTS) {
 334                         ifp->if_u1.if_extents =
 335                                 ifp->if_u2.if_inline_ext;
 336                 }
 337                 ilf_fields |= XFS_ILOG_DEXT;
 338                 break;
 339         case XFS_DINODE_FMT_BTREE:
 340                 ilf_fields |= XFS_ILOG_DBROOT;
 341                 break;
 342         }
 343
 344         tilf_fields = XFS_ILOG_CORE;
 345
 346         switch(tip->i_d.di_format) {
 347         case XFS_DINODE_FMT_EXTENTS:
 348                 /* If the extents fit in the inode, fix the
 349                  * pointer.  Otherwise it's already NULL or
 350                  * pointing to the extent.
 351                  */
 352                 if (tip->i_d.di_nextents <= XFS_INLINE_EXTS) {
 353                         tifp->if_u1.if_extents =
 354                                 tifp->if_u2.if_inline_ext;
 355                 }
 356                 tilf_fields |= XFS_ILOG_DEXT;
 357                 break;
 358         case XFS_DINODE_FMT_BTREE:
 359                 tilf_fields |= XFS_ILOG_DBROOT;
 360                 break;
 361         }
 362
 363         /*
 364          * Increment vnode ref counts since xfs_trans_commit &
 365          * xfs_trans_cancel will both unlock the inodes and
 366          * decrement the associated ref counts.
 367          */
 368         VN_HOLD(vp);
 369         VN_HOLD(tvp);
 370
 371         xfs_trans_ijoin(tp, ip, lock_flags);
 372         xfs_trans_ijoin(tp, tip, lock_flags);
 373
 374         xfs_trans_log_inode(tp, ip,  ilf_fields);
 375         xfs_trans_log_inode(tp, tip, tilf_fields);
 376
 377         /*
 378          * If this is a synchronous mount, make sure that the
 379          * transaction goes to disk before returning to the user.
 380          */
 381         if (mp->m_flags & XFS_MOUNT_WSYNC) {
 382                 xfs_trans_set_sync(tp);
 383         }
 384
 385         error = xfs_trans_commit(tp, XFS_TRANS_SWAPEXT, NULL);
 386         locked = 0;
 387
 388  error0:
 389         if (locked) {
 390                 xfs_iunlock(ip,  lock_flags);
 391                 xfs_iunlock(tip, lock_flags);
 392         }
 393         if (tempifp != NULL)
 394                 kmem_free(tempifp, sizeof(xfs_ifork_t));
 395         return error;
 396 }