vdev_file.c revision 185029 
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
38static int
39vdev_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 | 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	vn_lock(vp, LK_SHARED | LK_RETRY);
87	error = VOP_GETATTR(vp, &vattr, kcred);
88	VOP_UNLOCK(vp, 0);
89	if (error) {
90		vd->vdev_stat.vs_aux = VDEV_AUX_OPEN_FAILED;
91		return (error);
92	}
93
94	*psize = vattr.va_size;
95	*ashift = SPA_MINBLOCKSHIFT;
96
97	return (0);
98}
99
100static void
101vdev_file_close(vdev_t *vd)
102{
103	vdev_file_t *vf = vd->vdev_tsd;
104	int vfslocked;
105
106	if (vf == NULL)
107		return;
108
109	if (vf->vf_vnode != NULL) {
110		vfslocked = VFS_LOCK_GIANT(vf->vf_vnode->v_mount);
111		(void)vn_close(vf->vf_vnode, spa_mode, kcred, curthread);
112		VN_RELE(vf->vf_vnode);
113		VFS_UNLOCK_GIANT(vfslocked);
114	}
115
116	kmem_free(vf, sizeof (vdev_file_t));
117	vd->vdev_tsd = NULL;
118}
119
120static int
121vdev_file_io_start(zio_t *zio)
122{
123	vdev_t *vd = zio->io_vd;
124	vdev_file_t *vf = vd->vdev_tsd;
125	ssize_t resid;
126
127	if (zio->io_type == ZIO_TYPE_IOCTL) {
128		/* XXPOLICY */
129		if (!vdev_readable(vd)) {
130			zio->io_error = ENXIO;
131			return (ZIO_PIPELINE_CONTINUE);
132		}
133
134		switch (zio->io_cmd) {
135		case DKIOCFLUSHWRITECACHE:
136			zio->io_error = VOP_FSYNC(vf->vf_vnode, FSYNC | FDSYNC,
137			    kcred, NULL);
138			break;
139		default:
140			zio->io_error = ENOTSUP;
141		}
142
143		return (ZIO_PIPELINE_CONTINUE);
144	}
145
146	zio->io_error = vn_rdwr(zio->io_type == ZIO_TYPE_READ ?
147	    UIO_READ : UIO_WRITE, vf->vf_vnode, zio->io_data,
148	    zio->io_size, zio->io_offset, UIO_SYSSPACE,
149	    0, RLIM64_INFINITY, kcred, &resid);
150
151	if (resid != 0 && zio->io_error == 0)
152		zio->io_error = ENOSPC;
153
154	zio_interrupt(zio);
155
156	return (ZIO_PIPELINE_STOP);
157}
158
159/* ARGSUSED */
160static void
161vdev_file_io_done(zio_t *zio)
162{
163}
164
165vdev_ops_t vdev_file_ops = {
166	vdev_file_open,
167	vdev_file_close,
168	vdev_default_asize,
169	vdev_file_io_start,
170	vdev_file_io_done,
171	NULL,
172	VDEV_TYPE_FILE,		/* name of this vdev type */
173	B_TRUE			/* leaf vdev */
174};
175
176/*
177 * From userland we access disks just like files.
178 */
179#ifndef _KERNEL
180
181vdev_ops_t vdev_disk_ops = {
182	vdev_file_open,
183	vdev_file_close,
184	vdev_default_asize,
185	vdev_file_io_start,
186	vdev_file_io_done,
187	NULL,
188	VDEV_TYPE_DISK,		/* name of this vdev type */
189	B_TRUE			/* leaf vdev */
190};
191
192#endif
193