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 2008 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  24  */
  25
  26 #include <sys/zfs_context.h>
  27 #include <sys/spa.h>
  28 #include <sys/vdev_file.h>
  29 #include <sys/vdev_impl.h>
  30 #include <sys/zio.h>
  31 #include <sys/fs/zfs.h>
  32 #include <sys/fm/fs/zfs.h>
  33
  34 /*
  35  * Virtual device vector for files.
  36  */
  37
  38 static int
  39 vdev_file_open(vdev_t *vd, uint64_t *psize, uint64_t *ashift)
  40 {
  41         vdev_file_t *vf;
  42         vnode_t *vp;
  43         vattr_t vattr;
  44         int error;
  45
  46         /*
  47          * We must have a pathname, and it must be absolute.
  48          */
  49         if (vd->vdev_path == NULL || vd->vdev_path[0] != '/') {
  50                 vd->vdev_stat.vs_aux = VDEV_AUX_BAD_LABEL;
  51                 return (EINVAL);
  52         }
  53
  54         vf = vd->vdev_tsd = kmem_zalloc(sizeof (vdev_file_t), KM_SLEEP);
  55
  56         /*
  57          * We always open the files from the root of the global zone, even if
  58          * we're in a local zone.  If the user has gotten to this point, the
  59          * administrator has already decided that the pool should be available
  60          * to local zone users, so the underlying devices should be as well.
  61          */
  62         ASSERT(vd->vdev_path != NULL && vd->vdev_path[0] == '/');
  63         error = vn_openat(vd->vdev_path + 1, UIO_SYSSPACE,
  64             spa_mode(vd->vdev_spa) | FOFFMAX, 0, &vp, 0, 0, rootdir, -1);
  65
  66         if (error) {
  67                 vd->vdev_stat.vs_aux = VDEV_AUX_OPEN_FAILED;
  68                 return (error);
  69         }
  70
  71         vf->vf_vnode = vp;
  72
  73 #ifdef _KERNEL
  74         /*
  75          * Make sure it's a regular file.
  76          */
  77         if (vp->v_type != VREG) {
  78                 vd->vdev_stat.vs_aux = VDEV_AUX_OPEN_FAILED;
  79                 return (ENODEV);
  80         }
  81 #endif
  82         /*
  83          * Determine the physical size of the file.
  84          */
  85         vattr.va_mask = AT_SIZE;
  86         error = VOP_GETATTR(vf->vf_vnode, &vattr, 0, kcred, NULL);
  87         if (error) {
  88                 vd->vdev_stat.vs_aux = VDEV_AUX_OPEN_FAILED;
  89                 return (error);
  90         }
  91
  92         *psize = vattr.va_size;
  93         *ashift = SPA_MINBLOCKSHIFT;
  94
  95         return (0);
  96 }
  97
  98 static void
  99 vdev_file_close(vdev_t *vd)
 100 {
 101         vdev_file_t *vf = vd->vdev_tsd;
 102
 103         if (vf == NULL)
 104                 return;
 105
 106         if (vf->vf_vnode != NULL) {
 107                 (void) VOP_PUTPAGE(vf->vf_vnode, 0, 0, B_INVAL, kcred, NULL);
 108                 (void) VOP_CLOSE(vf->vf_vnode, spa_mode(vd->vdev_spa), 1, 0,
 109                     kcred, NULL);
 110                 VN_RELE(vf->vf_vnode);
 111         }
 112
 113         kmem_free(vf, sizeof (vdev_file_t));
 114         vd->vdev_tsd = NULL;
 115 }
 116
 117 static int
 118 vdev_file_io_start(zio_t *zio)
 119 {
 120         vdev_t *vd = zio->io_vd;
 121         vdev_file_t *vf = vd->vdev_tsd;
 122         ssize_t resid;
 123
 124         if (zio->io_type == ZIO_TYPE_IOCTL) {
 125                 /* XXPOLICY */
 126                 if (!vdev_readable(vd)) {
 127                         zio->io_error = ENXIO;
 128                         return (ZIO_PIPELINE_CONTINUE);
 129                 }
 130
 131                 switch (zio->io_cmd) {
 132                 case DKIOCFLUSHWRITECACHE:
 133                         zio->io_error = VOP_FSYNC(vf->vf_vnode, FSYNC | FDSYNC,
 134                             kcred, NULL);
 135                         break;
 136                 default:
 137                         zio->io_error = ENOTSUP;
 138                 }
 139
 140                 return (ZIO_PIPELINE_CONTINUE);
 141         }
 142
 143         zio->io_error = vn_rdwr(zio->io_type == ZIO_TYPE_READ ?
 144             UIO_READ : UIO_WRITE, vf->vf_vnode, zio->io_data,
 145             zio->io_size, zio->io_offset, UIO_SYSSPACE,
 146             0, RLIM64_INFINITY, kcred, &resid);
 147
 148         if (resid != 0 && zio->io_error == 0)
 149                 zio->io_error = ENOSPC;
 150
 151         zio_interrupt(zio);
 152
 153         return (ZIO_PIPELINE_STOP);
 154 }
 155
 156 /* ARGSUSED */
 157 static void
 158 vdev_file_io_done(zio_t *zio)
 159 {
 160 }
 161
 162 vdev_ops_t vdev_file_ops = {
 163         vdev_file_open,
 164         vdev_file_close,
 165         vdev_default_asize,
 166         vdev_file_io_start,
 167         vdev_file_io_done,
 168         NULL,
 169         VDEV_TYPE_FILE,         /* name of this vdev type */
 170         B_TRUE                  /* leaf vdev */
 171 };
 172
 173 /*
 174  * From userland we access disks just like files.
 175  */
 176 #ifndef _KERNEL
 177
 178 vdev_ops_t vdev_disk_ops = {
 179         vdev_file_open,
 180         vdev_file_close,
 181         vdev_default_asize,
 182         vdev_file_io_start,
 183         vdev_file_io_done,
 184         NULL,
 185         VDEV_TYPE_DISK,         /* name of this vdev type */
 186         B_TRUE                  /* leaf vdev */
 187 };
 188
 189 #endif