xref: /titanic_44/usr/src/uts/common/fs/zfs/vdev_file.c (revision 2b4a78020b9c38d1b95e2f3fefa6d6e4be382d1f)
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 | 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, 1, 0, kcred, NULL);
109 		VN_RELE(vf->vf_vnode);
110 	}
111 
112 	kmem_free(vf, sizeof (vdev_file_t));
113 	vd->vdev_tsd = NULL;
114 }
115 
116 static int
117 vdev_file_io_start(zio_t *zio)
118 {
119 	vdev_t *vd = zio->io_vd;
120 	vdev_file_t *vf = vd->vdev_tsd;
121 	ssize_t resid;
122 
123 	if (zio->io_type == ZIO_TYPE_IOCTL) {
124 		/* XXPOLICY */
125 		if (!vdev_readable(vd)) {
126 			zio->io_error = ENXIO;
127 			return (ZIO_PIPELINE_CONTINUE);
128 		}
129 
130 		switch (zio->io_cmd) {
131 		case DKIOCFLUSHWRITECACHE:
132 			zio->io_error = VOP_FSYNC(vf->vf_vnode, FSYNC | FDSYNC,
133 			    kcred, NULL);
134 			break;
135 		default:
136 			zio->io_error = ENOTSUP;
137 		}
138 
139 		return (ZIO_PIPELINE_CONTINUE);
140 	}
141 
142 	zio->io_error = vn_rdwr(zio->io_type == ZIO_TYPE_READ ?
143 	    UIO_READ : UIO_WRITE, vf->vf_vnode, zio->io_data,
144 	    zio->io_size, zio->io_offset, UIO_SYSSPACE,
145 	    0, RLIM64_INFINITY, kcred, &resid);
146 
147 	if (resid != 0 && zio->io_error == 0)
148 		zio->io_error = ENOSPC;
149 
150 	zio_interrupt(zio);
151 
152 	return (ZIO_PIPELINE_STOP);
153 }
154 
155 /* ARGSUSED */
156 static void
157 vdev_file_io_done(zio_t *zio)
158 {
159 }
160 
161 vdev_ops_t vdev_file_ops = {
162 	vdev_file_open,
163 	vdev_file_close,
164 	vdev_default_asize,
165 	vdev_file_io_start,
166 	vdev_file_io_done,
167 	NULL,
168 	VDEV_TYPE_FILE,		/* name of this vdev type */
169 	B_TRUE			/* leaf vdev */
170 };
171 
172 /*
173  * From userland we access disks just like files.
174  */
175 #ifndef _KERNEL
176 
177 vdev_ops_t vdev_disk_ops = {
178 	vdev_file_open,
179 	vdev_file_close,
180 	vdev_default_asize,
181 	vdev_file_io_start,
182 	vdev_file_io_done,
183 	NULL,
184 	VDEV_TYPE_DISK,		/* name of this vdev type */
185 	B_TRUE			/* leaf vdev */
186 };
187 
188 #endif
189