fs/xfs/xfs_dfrag.c

   1 /*
   2  * Copyright (c) 2000-2002,2005 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_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_dir.h"
  28 #include "xfs_dir2.h"
  29 #include "xfs_dmapi.h"
  30 #include "xfs_mount.h"
  31 #include "xfs_bmap_btree.h"
  32 #include "xfs_alloc_btree.h"
  33 #include "xfs_ialloc_btree.h"
  34 #include "xfs_dir_sf.h"
  35 #include "xfs_dir2_sf.h"
  36 #include "xfs_attr_sf.h"
  37 #include "xfs_dinode.h"
  38 #include "xfs_inode.h"
  39 #include "xfs_inode_item.h"
  40 #include "xfs_bmap.h"
  41 #include "xfs_btree.h"
  42 #include "xfs_ialloc.h"
  43 #include "xfs_itable.h"
  44 #include "xfs_dfrag.h"
  45 #include "xfs_error.h"
  46 #include "xfs_mac.h"
  47 #include "xfs_rw.h"
  48
  49 /*
  50  * Syssgi interface for swapext
  51  */
  52 int
  53 xfs_swapext(
  54         xfs_swapext_t   __user *sxu)
  55 {
  56         xfs_swapext_t   *sxp;
  57         xfs_inode_t     *ip=NULL, *tip=NULL, *ips[2];
  58         xfs_trans_t     *tp;
  59         xfs_mount_t     *mp;
  60         xfs_bstat_t     *sbp;
  61         struct file     *fp = NULL, *tfp = NULL;
  62         vnode_t         *vp, *tvp;
  63         bhv_desc_t      *bdp, *tbdp;
  64         vn_bhv_head_t   *bhp, *tbhp;
  65         static uint     lock_flags = XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL;
  66         int             ilf_fields, tilf_fields;
  67         int             error = 0;
  68         xfs_ifork_t     *tempifp, *ifp, *tifp;
  69         __uint64_t      tmp;
  70         int             aforkblks = 0;
  71         int             taforkblks = 0;
  72         char            locked = 0;
  73
  74         sxp = kmem_alloc(sizeof(xfs_swapext_t), KM_MAYFAIL);
  75         tempifp = kmem_alloc(sizeof(xfs_ifork_t), KM_MAYFAIL);
  76         if (!sxp || !tempifp) {
  77                 error = XFS_ERROR(ENOMEM);
  78                 goto error0;
  79         }
  80
  81         if (copy_from_user(sxp, sxu, sizeof(xfs_swapext_t))) {
  82                 error = XFS_ERROR(EFAULT);
  83                 goto error0;
  84         }
  85
  86         /* Pull information for the target fd */
  87         if (((fp = fget((int)sxp->sx_fdtarget)) == NULL) ||
  88             ((vp = LINVFS_GET_VP(fp->f_dentry->d_inode)) == NULL))  {
  89                 error = XFS_ERROR(EINVAL);
  90                 goto error0;
  91         }
  92
  93         bhp = VN_BHV_HEAD(vp);
  94         bdp = vn_bhv_lookup(bhp, &xfs_vnodeops);
  95         if (bdp == NULL) {
  96                 error = XFS_ERROR(EBADF);
  97                 goto error0;
  98         } else {
  99                 ip = XFS_BHVTOI(bdp);
 100         }
 101
 102         if (((tfp = fget((int)sxp->sx_fdtmp)) == NULL) ||
 103             ((tvp = LINVFS_GET_VP(tfp->f_dentry->d_inode)) == NULL)) {
 104                 error = XFS_ERROR(EINVAL);
 105                 goto error0;
 106         }
 107
 108         tbhp = VN_BHV_HEAD(tvp);
 109         tbdp = vn_bhv_lookup(tbhp, &xfs_vnodeops);
 110         if (tbdp == NULL) {
 111                 error = XFS_ERROR(EBADF);
 112                 goto error0;
 113         } else {
 114                 tip = XFS_BHVTOI(tbdp);
 115         }
 116
 117         if (ip->i_mount != tip->i_mount) {
 118                 error =  XFS_ERROR(EINVAL);
 119                 goto error0;
 120         }
 121
 122         if (ip->i_ino == tip->i_ino) {
 123                 error =  XFS_ERROR(EINVAL);
 124                 goto error0;
 125         }
 126
 127         mp = ip->i_mount;
 128
 129         sbp = &sxp->sx_stat;
 130
 131         if (XFS_FORCED_SHUTDOWN(mp)) {
 132                 error =  XFS_ERROR(EIO);
 133                 goto error0;
 134         }
 135
 136         locked = 1;
 137
 138         /* Lock in i_ino order */
 139         if (ip->i_ino < tip->i_ino) {
 140                 ips[0] = ip;
 141                 ips[1] = tip;
 142         } else {
 143                 ips[0] = tip;
 144                 ips[1] = ip;
 145         }
 146
 147         xfs_lock_inodes(ips, 2, 0, lock_flags);
 148
 149         /* Check permissions */
 150         error = xfs_iaccess(ip, S_IWUSR, NULL);
 151         if (error)
 152                 goto error0;
 153
 154         error = xfs_iaccess(tip, S_IWUSR, NULL);
 155         if (error)
 156                 goto error0;
 157
 158         /* Verify that both files have the same format */
 159         if ((ip->i_d.di_mode & S_IFMT) != (tip->i_d.di_mode & S_IFMT)) {
 160                 error = XFS_ERROR(EINVAL);
 161                 goto error0;
 162         }
 163
 164         /* Verify both files are either real-time or non-realtime */
 165         if ((ip->i_d.di_flags & XFS_DIFLAG_REALTIME) !=
 166             (tip->i_d.di_flags & XFS_DIFLAG_REALTIME)) {
 167                 error = XFS_ERROR(EINVAL);
 168                 goto error0;
 169         }
 170
 171         /* Should never get a local format */
 172         if (ip->i_d.di_format == XFS_DINODE_FMT_LOCAL ||
 173             tip->i_d.di_format == XFS_DINODE_FMT_LOCAL) {
 174                 error = XFS_ERROR(EINVAL);
 175                 goto error0;
 176         }
 177
 178         if (VN_CACHED(tvp) != 0) {
 179                 xfs_inval_cached_trace(&tip->i_iocore, 0, -1, 0, -1);
 180                 VOP_FLUSHINVAL_PAGES(tvp, 0, -1, FI_REMAPF_LOCKED);
 181         }
 182
 183         /* Verify O_DIRECT for ftmp */
 184         if (VN_CACHED(tvp) != 0) {
 185                 error = XFS_ERROR(EINVAL);
 186                 goto error0;
 187         }
 188
 189         /* Verify all data are being swapped */
 190         if (sxp->sx_offset != 0 ||
 191             sxp->sx_length != ip->i_d.di_size ||
 192             sxp->sx_length != tip->i_d.di_size) {
 193                 error = XFS_ERROR(EFAULT);
 194                 goto error0;
 195         }
 196
 197         /*
 198          * If the target has extended attributes, the tmp file
 199          * must also in order to ensure the correct data fork
 200          * format.
 201          */
 202         if ( XFS_IFORK_Q(ip) != XFS_IFORK_Q(tip) ) {
 203                 error = XFS_ERROR(EINVAL);
 204                 goto error0;
 205         }
 206
 207         /*
 208          * Compare the current change & modify times with that
 209          * passed in.  If they differ, we abort this swap.
 210          * This is the mechanism used to ensure the calling
 211          * process that the file was not changed out from
 212          * under it.
 213          */
 214         if ((sbp->bs_ctime.tv_sec != ip->i_d.di_ctime.t_sec) ||
 215             (sbp->bs_ctime.tv_nsec != ip->i_d.di_ctime.t_nsec) ||
 216             (sbp->bs_mtime.tv_sec != ip->i_d.di_mtime.t_sec) ||
 217             (sbp->bs_mtime.tv_nsec != ip->i_d.di_mtime.t_nsec)) {
 218                 error = XFS_ERROR(EBUSY);
 219                 goto error0;
 220         }
 221
 222         /* We need to fail if the file is memory mapped.  Once we have tossed
 223          * all existing pages, the page fault will have no option
 224          * but to go to the filesystem for pages. By making the page fault call
 225          * VOP_READ (or write in the case of autogrow) they block on the iolock
 226          * until we have switched the extents.
 227          */
 228         if (VN_MAPPED(vp)) {
 229                 error = XFS_ERROR(EBUSY);
 230                 goto error0;
 231         }
 232
 233         xfs_iunlock(ip, XFS_ILOCK_EXCL);
 234         xfs_iunlock(tip, XFS_ILOCK_EXCL);
 235
 236         /*
 237          * There is a race condition here since we gave up the
 238          * ilock.  However, the data fork will not change since
 239          * we have the iolock (locked for truncation too) so we
 240          * are safe.  We don't really care if non-io related
 241          * fields change.
 242          */
 243
 244         VOP_TOSS_PAGES(vp, 0, -1, FI_REMAPF);
 245
 246         tp = xfs_trans_alloc(mp, XFS_TRANS_SWAPEXT);
 247         if ((error = xfs_trans_reserve(tp, 0,
 248                                      XFS_ICHANGE_LOG_RES(mp), 0,
 249                                      0, 0))) {
 250                 xfs_iunlock(ip,  XFS_IOLOCK_EXCL);
 251                 xfs_iunlock(tip, XFS_IOLOCK_EXCL);
 252                 xfs_trans_cancel(tp, 0);
 253                 locked = 0;
 254                 goto error0;
 255         }
 256         xfs_lock_inodes(ips, 2, 0, XFS_ILOCK_EXCL);
 257
 258         /*
 259          * Count the number of extended attribute blocks
 260          */
 261         if ( ((XFS_IFORK_Q(ip) != 0) && (ip->i_d.di_anextents > 0)) &&
 262              (ip->i_d.di_aformat != XFS_DINODE_FMT_LOCAL)) {
 263                 error = xfs_bmap_count_blocks(tp, ip, XFS_ATTR_FORK, &aforkblks);
 264                 if (error) {
 265                         xfs_trans_cancel(tp, 0);
 266                         goto error0;
 267                 }
 268         }
 269         if ( ((XFS_IFORK_Q(tip) != 0) && (tip->i_d.di_anextents > 0)) &&
 270              (tip->i_d.di_aformat != XFS_DINODE_FMT_LOCAL)) {
 271                 error = xfs_bmap_count_blocks(tp, tip, XFS_ATTR_FORK,
 272                         &taforkblks);
 273                 if (error) {
 274                         xfs_trans_cancel(tp, 0);
 275                         goto error0;
 276                 }
 277         }
 278
 279         /*
 280          * Swap the data forks of the inodes
 281          */
 282         ifp = &ip->i_df;
 283         tifp = &tip->i_df;
 284         *tempifp = *ifp;        /* struct copy */
 285         *ifp = *tifp;           /* struct copy */
 286         *tifp = *tempifp;       /* struct copy */
 287
 288         /*
 289          * Fix the on-disk inode values
 290          */
 291         tmp = (__uint64_t)ip->i_d.di_nblocks;
 292         ip->i_d.di_nblocks = tip->i_d.di_nblocks - taforkblks + aforkblks;
 293         tip->i_d.di_nblocks = tmp + taforkblks - aforkblks;
 294
 295         tmp = (__uint64_t) ip->i_d.di_nextents;
 296         ip->i_d.di_nextents = tip->i_d.di_nextents;
 297         tip->i_d.di_nextents = tmp;
 298
 299         tmp = (__uint64_t) ip->i_d.di_format;
 300         ip->i_d.di_format = tip->i_d.di_format;
 301         tip->i_d.di_format = tmp;
 302
 303         ilf_fields = XFS_ILOG_CORE;
 304
 305         switch(ip->i_d.di_format) {
 306         case XFS_DINODE_FMT_EXTENTS:
 307                 /* If the extents fit in the inode, fix the
 308                  * pointer.  Otherwise it's already NULL or
 309                  * pointing to the extent.
 310                  */
 311                 if (ip->i_d.di_nextents <= XFS_INLINE_EXTS) {
 312                         ifp->if_u1.if_extents =
 313                                 ifp->if_u2.if_inline_ext;
 314                 }
 315                 ilf_fields |= XFS_ILOG_DEXT;
 316                 break;
 317         case XFS_DINODE_FMT_BTREE:
 318                 ilf_fields |= XFS_ILOG_DBROOT;
 319                 break;
 320         }
 321
 322         tilf_fields = XFS_ILOG_CORE;
 323
 324         switch(tip->i_d.di_format) {
 325         case XFS_DINODE_FMT_EXTENTS:
 326                 /* If the extents fit in the inode, fix the
 327                  * pointer.  Otherwise it's already NULL or
 328                  * pointing to the extent.
 329                  */
 330                 if (tip->i_d.di_nextents <= XFS_INLINE_EXTS) {
 331                         tifp->if_u1.if_extents =
 332                                 tifp->if_u2.if_inline_ext;
 333                 }
 334                 tilf_fields |= XFS_ILOG_DEXT;
 335                 break;
 336         case XFS_DINODE_FMT_BTREE:
 337                 tilf_fields |= XFS_ILOG_DBROOT;
 338                 break;
 339         }
 340
 341         /*
 342          * Increment vnode ref counts since xfs_trans_commit &
 343          * xfs_trans_cancel will both unlock the inodes and
 344          * decrement the associated ref counts.
 345          */
 346         VN_HOLD(vp);
 347         VN_HOLD(tvp);
 348
 349         xfs_trans_ijoin(tp, ip, lock_flags);
 350         xfs_trans_ijoin(tp, tip, lock_flags);
 351
 352         xfs_trans_log_inode(tp, ip,  ilf_fields);
 353         xfs_trans_log_inode(tp, tip, tilf_fields);
 354
 355         /*
 356          * If this is a synchronous mount, make sure that the
 357          * transaction goes to disk before returning to the user.
 358          */
 359         if (mp->m_flags & XFS_MOUNT_WSYNC) {
 360                 xfs_trans_set_sync(tp);
 361         }
 362
 363         error = xfs_trans_commit(tp, XFS_TRANS_SWAPEXT, NULL);
 364         locked = 0;
 365
 366  error0:
 367         if (locked) {
 368                 xfs_iunlock(ip,  lock_flags);
 369                 xfs_iunlock(tip, lock_flags);
 370         }
 371
 372         if (fp != NULL)
 373                 fput(fp);
 374         if (tfp != NULL)
 375                 fput(tfp);
 376
 377         if (sxp != NULL)
 378                 kmem_free(sxp, sizeof(xfs_swapext_t));
 379         if (tempifp != NULL)
 380                 kmem_free(tempifp, sizeof(xfs_ifork_t));
 381
 382         return error;
 383 }