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