module/zfs/vdev_file.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
  23  */
  24
  25 #include <sys/zfs_context.h>
  26 #include <sys/spa.h>
  27 #include <sys/vdev_file.h>
  28 #include <sys/vdev_impl.h>
  29 #include <sys/zio.h>
  30 #include <sys/fs/zfs.h>
  31 #include <sys/fm/fs/zfs.h>
  32
  33 /*
  34  * Virtual device vector for files.
  35  */
  36
  37 static void
  38 vdev_file_hold(vdev_t *vd)
  39 {
  40         ASSERT(vd->vdev_path != NULL);
  41 }
  42
  43 static void
  44 vdev_file_rele(vdev_t *vd)
  45 {
  46         ASSERT(vd->vdev_path != NULL);
  47 }
  48
  49 static int
  50 vdev_file_open(vdev_t *vd, uint64_t *psize, uint64_t *ashift)
  51 {
  52         vdev_file_t *vf;
  53         vnode_t *vp;
  54         vattr_t vattr;
  55         int error;
  56
  57         /*
  58          * We must have a pathname, and it must be absolute.
  59          */
  60         if (vd->vdev_path == NULL || vd->vdev_path[0] != '/') {
  61                 vd->vdev_stat.vs_aux = VDEV_AUX_BAD_LABEL;
  62                 return (EINVAL);
  63         }
  64
  65         /*
  66          * Reopen the device if it's not currently open.  Otherwise,
  67          * just update the physical size of the device.
  68          */
  69         if (vd->vdev_tsd != NULL) {
  70                 ASSERT(vd->vdev_reopening);
  71                 vf = vd->vdev_tsd;
  72                 goto skip_open;
  73         }
  74
  75         vf = vd->vdev_tsd = kmem_zalloc(sizeof (vdev_file_t), KM_SLEEP);
  76
  77         /*
  78          * We always open the files from the root of the global zone, even if
  79          * we're in a local zone.  If the user has gotten to this point, the
  80          * administrator has already decided that the pool should be available
  81          * to local zone users, so the underlying devices should be as well.
  82          */
  83         ASSERT(vd->vdev_path != NULL && vd->vdev_path[0] == '/');
  84         error = vn_openat(vd->vdev_path + 1, UIO_SYSSPACE,
  85             spa_mode(vd->vdev_spa) | FOFFMAX, 0, &vp, 0, 0, rootdir, -1);
  86
  87         if (error) {
  88                 vd->vdev_stat.vs_aux = VDEV_AUX_OPEN_FAILED;
  89                 return (error);
  90         }
  91
  92         vf->vf_vnode = vp;
  93
  94 #ifdef _KERNEL
  95         /*
  96          * Make sure it's a regular file.
  97          */
  98         if (vp->v_type != VREG) {
  99                 vd->vdev_stat.vs_aux = VDEV_AUX_OPEN_FAILED;
 100                 return (ENODEV);
 101         }
 102 #endif
 103
 104 skip_open:
 105         /*
 106          * Determine the physical size of the file.
 107          */
 108         vattr.va_mask = AT_SIZE;
 109         error = VOP_GETATTR(vf->vf_vnode, &vattr, 0, kcred, NULL);
 110         if (error) {
 111                 vd->vdev_stat.vs_aux = VDEV_AUX_OPEN_FAILED;
 112                 return (error);
 113         }
 114
 115         *psize = vattr.va_size;
 116         *ashift = SPA_MINBLOCKSHIFT;
 117
 118         return (0);
 119 }
 120
 121 static void
 122 vdev_file_close(vdev_t *vd)
 123 {
 124         vdev_file_t *vf = vd->vdev_tsd;
 125
 126         if (vd->vdev_reopening || vf == NULL)
 127                 return;
 128
 129         if (vf->vf_vnode != NULL) {
 130                 (void) VOP_PUTPAGE(vf->vf_vnode, 0, 0, B_INVAL, kcred, NULL);
 131                 (void) VOP_CLOSE(vf->vf_vnode, spa_mode(vd->vdev_spa), 1, 0,
 132                     kcred, NULL);
 133                 VN_RELE(vf->vf_vnode);
 134         }
 135
 136         vd->vdev_delayed_close = B_FALSE;
 137         kmem_free(vf, sizeof (vdev_file_t));
 138         vd->vdev_tsd = NULL;
 139 }
 140
 141 static int
 142 vdev_file_io_start(zio_t *zio)
 143 {
 144         vdev_t *vd = zio->io_vd;
 145         vdev_file_t *vf = vd->vdev_tsd;
 146         ssize_t resid;
 147
 148         if (zio->io_type == ZIO_TYPE_IOCTL) {
 149                 /* XXPOLICY */
 150                 if (!vdev_readable(vd)) {
 151                         zio->io_error = ENXIO;
 152                         return (ZIO_PIPELINE_CONTINUE);
 153                 }
 154
 155                 switch (zio->io_cmd) {
 156                 case DKIOCFLUSHWRITECACHE:
 157                         zio->io_error = VOP_FSYNC(vf->vf_vnode, FSYNC | FDSYNC,
 158                             kcred, NULL);
 159                         break;
 160                 default:
 161                         zio->io_error = ENOTSUP;
 162                 }
 163
 164                 return (ZIO_PIPELINE_CONTINUE);
 165         }
 166
 167         zio->io_error = vn_rdwr(zio->io_type == ZIO_TYPE_READ ?
 168             UIO_READ : UIO_WRITE, vf->vf_vnode, zio->io_data,
 169             zio->io_size, zio->io_offset, UIO_SYSSPACE,
 170             0, RLIM64_INFINITY, kcred, &resid);
 171
 172         if (resid != 0 && zio->io_error == 0)
 173                 zio->io_error = ENOSPC;
 174
 175         zio_interrupt(zio);
 176
 177         return (ZIO_PIPELINE_STOP);
 178 }
 179
 180 /* ARGSUSED */
 181 static void
 182 vdev_file_io_done(zio_t *zio)
 183 {
 184 }
 185
 186 vdev_ops_t vdev_file_ops = {
 187         vdev_file_open,
 188         vdev_file_close,
 189         vdev_default_asize,
 190         vdev_file_io_start,
 191         vdev_file_io_done,
 192         NULL,
 193         vdev_file_hold,
 194         vdev_file_rele,
 195         VDEV_TYPE_FILE,         /* name of this vdev type */
 196         B_TRUE                  /* leaf vdev */
 197 };
 198
 199 /*
 200  * From userland we access disks just like files.
 201  */
 202 #ifndef _KERNEL
 203
 204 vdev_ops_t vdev_disk_ops = {
 205         vdev_file_open,
 206         vdev_file_close,
 207         vdev_default_asize,
 208         vdev_file_io_start,
 209         vdev_file_io_done,
 210         NULL,
 211         vdev_file_hold,
 212         vdev_file_rele,
 213         VDEV_TYPE_DISK,         /* name of this vdev type */
 214         B_TRUE                  /* leaf vdev */
 215 };
 216
 217 #endif