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 #include "xfs_vnodeops.h"
  46
  47 /*
  48  * Syssgi interface for swapext
  49  */
  50 int
  51 xfs_swapext(
  52         xfs_swapext_t   __user *sxu)
  53 {
  54         xfs_swapext_t   *sxp;
  55         xfs_inode_t     *ip=NULL, *tip=NULL;
  56         xfs_mount_t     *mp;
  57         struct file     *fp = NULL, *tfp = NULL;
  58         bhv_vnode_t     *vp, *tvp;
  59         int             error = 0;
  60
  61         sxp = kmem_alloc(sizeof(xfs_swapext_t), KM_MAYFAIL);
  62         if (!sxp) {
  63                 error = XFS_ERROR(ENOMEM);
  64                 goto error0;
  65         }
  66
  67         if (copy_from_user(sxp, sxu, sizeof(xfs_swapext_t))) {
  68                 error = XFS_ERROR(EFAULT);
  69                 goto error0;
  70         }
  71
  72         /* Pull information for the target fd */
  73         if (((fp = fget((int)sxp->sx_fdtarget)) == NULL) ||
  74             ((vp = vn_from_inode(fp->f_path.dentry->d_inode)) == NULL))  {
  75                 error = XFS_ERROR(EINVAL);
  76                 goto error0;
  77         }
  78
  79         ip = xfs_vtoi(vp);
  80         if (ip == NULL) {
  81                 error = XFS_ERROR(EBADF);
  82                 goto error0;
  83         }
  84
  85         if (((tfp = fget((int)sxp->sx_fdtmp)) == NULL) ||
  86             ((tvp = vn_from_inode(tfp->f_path.dentry->d_inode)) == NULL)) {
  87                 error = XFS_ERROR(EINVAL);
  88                 goto error0;
  89         }
  90
  91         tip = xfs_vtoi(tvp);
  92         if (tip == NULL) {
  93                 error = XFS_ERROR(EBADF);
  94                 goto error0;
  95         }
  96
  97         if (ip->i_mount != tip->i_mount) {
  98                 error =  XFS_ERROR(EINVAL);
  99                 goto error0;
 100         }
 101
 102         if (ip->i_ino == tip->i_ino) {
 103                 error =  XFS_ERROR(EINVAL);
 104                 goto error0;
 105         }
 106
 107         mp = ip->i_mount;
 108
 109         if (XFS_FORCED_SHUTDOWN(mp)) {
 110                 error =  XFS_ERROR(EIO);
 111                 goto error0;
 112         }
 113
 114         error = XFS_SWAP_EXTENTS(mp, &ip->i_iocore, &tip->i_iocore, sxp);
 115
 116  error0:
 117         if (fp != NULL)
 118                 fput(fp);
 119         if (tfp != NULL)
 120                 fput(tfp);
 121
 122         if (sxp != NULL)
 123                 kmem_free(sxp, sizeof(xfs_swapext_t));
 124
 125         return error;
 126 }
 127
 128 int
 129 xfs_swap_extents(
 130         xfs_inode_t     *ip,
 131         xfs_inode_t     *tip,
 132         xfs_swapext_t   *sxp)
 133 {
 134         xfs_mount_t     *mp;
 135         xfs_inode_t     *ips[2];
 136         xfs_trans_t     *tp;
 137         xfs_bstat_t     *sbp = &sxp->sx_stat;
 138         bhv_vnode_t     *vp, *tvp;
 139         xfs_ifork_t     *tempifp, *ifp, *tifp;
 140         int             ilf_fields, tilf_fields;
 141         static uint     lock_flags = XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL;
 142         int             error = 0;
 143         int             aforkblks = 0;
 144         int             taforkblks = 0;
 145         __uint64_t      tmp;
 146         char            locked = 0;
 147
 148         mp = ip->i_mount;
 149
 150         tempifp = kmem_alloc(sizeof(xfs_ifork_t), KM_MAYFAIL);
 151         if (!tempifp) {
 152                 error = XFS_ERROR(ENOMEM);
 153                 goto error0;
 154         }
 155
 156         sbp = &sxp->sx_stat;
 157         vp = XFS_ITOV(ip);
 158         tvp = XFS_ITOV(tip);
 159
 160         /* Lock in i_ino order */
 161         if (ip->i_ino < tip->i_ino) {
 162                 ips[0] = ip;
 163                 ips[1] = tip;
 164         } else {
 165                 ips[0] = tip;
 166                 ips[1] = ip;
 167         }
 168
 169         xfs_lock_inodes(ips, 2, 0, lock_flags);
 170         locked = 1;
 171
 172         /* Check permissions */
 173         error = xfs_iaccess(ip, S_IWUSR, NULL);
 174         if (error)
 175                 goto error0;
 176
 177         error = xfs_iaccess(tip, S_IWUSR, NULL);
 178         if (error)
 179                 goto error0;
 180
 181         /* Verify that both files have the same format */
 182         if ((ip->i_d.di_mode & S_IFMT) != (tip->i_d.di_mode & S_IFMT)) {
 183                 error = XFS_ERROR(EINVAL);
 184                 goto error0;
 185         }
 186
 187         /* Verify both files are either real-time or non-realtime */
 188         if ((ip->i_d.di_flags & XFS_DIFLAG_REALTIME) !=
 189             (tip->i_d.di_flags & XFS_DIFLAG_REALTIME)) {
 190                 error = XFS_ERROR(EINVAL);
 191                 goto error0;
 192         }
 193
 194         /* Should never get a local format */
 195         if (ip->i_d.di_format == XFS_DINODE_FMT_LOCAL ||
 196             tip->i_d.di_format == XFS_DINODE_FMT_LOCAL) {
 197                 error = XFS_ERROR(EINVAL);
 198                 goto error0;
 199         }
 200
 201         if (VN_CACHED(tvp) != 0) {
 202                 xfs_inval_cached_trace(&tip->i_iocore, 0, -1, 0, -1);
 203                 error = xfs_flushinval_pages(tip, 0, -1,
 204                                 FI_REMAPF_LOCKED);
 205                 if (error)
 206                         goto error0;
 207         }
 208
 209         /* Verify O_DIRECT for ftmp */
 210         if (VN_CACHED(tvp) != 0) {
 211                 error = XFS_ERROR(EINVAL);
 212                 goto error0;
 213         }
 214
 215         /* Verify all data are being swapped */
 216         if (sxp->sx_offset != 0 ||
 217             sxp->sx_length != ip->i_d.di_size ||
 218             sxp->sx_length != tip->i_d.di_size) {
 219                 error = XFS_ERROR(EFAULT);
 220                 goto error0;
 221         }
 222
 223         /*
 224          * If the target has extended attributes, the tmp file
 225          * must also in order to ensure the correct data fork
 226          * format.
 227          */
 228         if ( XFS_IFORK_Q(ip) != XFS_IFORK_Q(tip) ) {
 229                 error = XFS_ERROR(EINVAL);
 230                 goto error0;
 231         }
 232
 233         /*
 234          * Compare the current change & modify times with that
 235          * passed in.  If they differ, we abort this swap.
 236          * This is the mechanism used to ensure the calling
 237          * process that the file was not changed out from
 238          * under it.
 239          */
 240         if ((sbp->bs_ctime.tv_sec != ip->i_d.di_ctime.t_sec) ||
 241             (sbp->bs_ctime.tv_nsec != ip->i_d.di_ctime.t_nsec) ||
 242             (sbp->bs_mtime.tv_sec != ip->i_d.di_mtime.t_sec) ||
 243             (sbp->bs_mtime.tv_nsec != ip->i_d.di_mtime.t_nsec)) {
 244                 error = XFS_ERROR(EBUSY);
 245                 goto error0;
 246         }
 247
 248         /* We need to fail if the file is memory mapped.  Once we have tossed
 249          * all existing pages, the page fault will have no option
 250          * but to go to the filesystem for pages. By making the page fault call
 251          * vop_read (or write in the case of autogrow) they block on the iolock
 252          * until we have switched the extents.
 253          */
 254         if (VN_MAPPED(vp)) {
 255                 error = XFS_ERROR(EBUSY);
 256                 goto error0;
 257         }
 258
 259         xfs_iunlock(ip, XFS_ILOCK_EXCL);
 260         xfs_iunlock(tip, XFS_ILOCK_EXCL);
 261
 262         /*
 263          * There is a race condition here since we gave up the
 264          * ilock.  However, the data fork will not change since
 265          * we have the iolock (locked for truncation too) so we
 266          * are safe.  We don't really care if non-io related
 267          * fields change.
 268          */
 269
 270         xfs_tosspages(ip, 0, -1, FI_REMAPF);
 271
 272         tp = xfs_trans_alloc(mp, XFS_TRANS_SWAPEXT);
 273         if ((error = xfs_trans_reserve(tp, 0,
 274                                      XFS_ICHANGE_LOG_RES(mp), 0,
 275                                      0, 0))) {
 276                 xfs_iunlock(ip,  XFS_IOLOCK_EXCL);
 277                 xfs_iunlock(tip, XFS_IOLOCK_EXCL);
 278                 xfs_trans_cancel(tp, 0);
 279                 locked = 0;
 280                 goto error0;
 281         }
 282         xfs_lock_inodes(ips, 2, 0, XFS_ILOCK_EXCL);
 283
 284         /*
 285          * Count the number of extended attribute blocks
 286          */
 287         if ( ((XFS_IFORK_Q(ip) != 0) && (ip->i_d.di_anextents > 0)) &&
 288              (ip->i_d.di_aformat != XFS_DINODE_FMT_LOCAL)) {
 289                 error = xfs_bmap_count_blocks(tp, ip, XFS_ATTR_FORK, &aforkblks);
 290                 if (error) {
 291                         xfs_trans_cancel(tp, 0);
 292                         goto error0;
 293                 }
 294         }
 295         if ( ((XFS_IFORK_Q(tip) != 0) && (tip->i_d.di_anextents > 0)) &&
 296              (tip->i_d.di_aformat != XFS_DINODE_FMT_LOCAL)) {
 297                 error = xfs_bmap_count_blocks(tp, tip, XFS_ATTR_FORK,
 298                         &taforkblks);
 299                 if (error) {
 300                         xfs_trans_cancel(tp, 0);
 301                         goto error0;
 302                 }
 303         }
 304
 305         /*
 306          * Swap the data forks of the inodes
 307          */
 308         ifp = &ip->i_df;
 309         tifp = &tip->i_df;
 310         *tempifp = *ifp;        /* struct copy */
 311         *ifp = *tifp;           /* struct copy */
 312         *tifp = *tempifp;       /* struct copy */
 313
 314         /*
 315          * Fix the on-disk inode values
 316          */
 317         tmp = (__uint64_t)ip->i_d.di_nblocks;
 318         ip->i_d.di_nblocks = tip->i_d.di_nblocks - taforkblks + aforkblks;
 319         tip->i_d.di_nblocks = tmp + taforkblks - aforkblks;
 320
 321         tmp = (__uint64_t) ip->i_d.di_nextents;
 322         ip->i_d.di_nextents = tip->i_d.di_nextents;
 323         tip->i_d.di_nextents = tmp;
 324
 325         tmp = (__uint64_t) ip->i_d.di_format;
 326         ip->i_d.di_format = tip->i_d.di_format;
 327         tip->i_d.di_format = tmp;
 328
 329         ilf_fields = XFS_ILOG_CORE;
 330
 331         switch(ip->i_d.di_format) {
 332         case XFS_DINODE_FMT_EXTENTS:
 333                 /* If the extents fit in the inode, fix the
 334                  * pointer.  Otherwise it's already NULL or
 335                  * pointing to the extent.
 336                  */
 337                 if (ip->i_d.di_nextents <= XFS_INLINE_EXTS) {
 338                         ifp->if_u1.if_extents =
 339                                 ifp->if_u2.if_inline_ext;
 340                 }
 341                 ilf_fields |= XFS_ILOG_DEXT;
 342                 break;
 343         case XFS_DINODE_FMT_BTREE:
 344                 ilf_fields |= XFS_ILOG_DBROOT;
 345                 break;
 346         }
 347
 348         tilf_fields = XFS_ILOG_CORE;
 349
 350         switch(tip->i_d.di_format) {
 351         case XFS_DINODE_FMT_EXTENTS:
 352                 /* If the extents fit in the inode, fix the
 353                  * pointer.  Otherwise it's already NULL or
 354                  * pointing to the extent.
 355                  */
 356                 if (tip->i_d.di_nextents <= XFS_INLINE_EXTS) {
 357                         tifp->if_u1.if_extents =
 358                                 tifp->if_u2.if_inline_ext;
 359                 }
 360                 tilf_fields |= XFS_ILOG_DEXT;
 361                 break;
 362         case XFS_DINODE_FMT_BTREE:
 363                 tilf_fields |= XFS_ILOG_DBROOT;
 364                 break;
 365         }
 366
 367         /*
 368          * Increment vnode ref counts since xfs_trans_commit &
 369          * xfs_trans_cancel will both unlock the inodes and
 370          * decrement the associated ref counts.
 371          */
 372         VN_HOLD(vp);
 373         VN_HOLD(tvp);
 374
 375         xfs_trans_ijoin(tp, ip, lock_flags);
 376         xfs_trans_ijoin(tp, tip, lock_flags);
 377
 378         xfs_trans_log_inode(tp, ip,  ilf_fields);
 379         xfs_trans_log_inode(tp, tip, tilf_fields);
 380
 381         /*
 382          * If this is a synchronous mount, make sure that the
 383          * transaction goes to disk before returning to the user.
 384          */
 385         if (mp->m_flags & XFS_MOUNT_WSYNC) {
 386                 xfs_trans_set_sync(tp);
 387         }
 388
 389         error = xfs_trans_commit(tp, XFS_TRANS_SWAPEXT);
 390         locked = 0;
 391
 392  error0:
 393         if (locked) {
 394                 xfs_iunlock(ip,  lock_flags);
 395                 xfs_iunlock(tip, lock_flags);
 396         }
 397         if (tempifp != NULL)
 398                 kmem_free(tempifp, sizeof(xfs_ifork_t));
 399         return error;
 400 }