xref: /titanic_41/usr/src/uts/common/fs/zfs/vdev_file.c (revision 68c47f65208790c466e5e484f2293d3baed71c6a)
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 2009 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 	/*
55 	 * Reopen the device if it's not currently open.  Otherwise,
56 	 * just update the physical size of the device.
57 	 */
58 	if (vd->vdev_tsd != NULL) {
59 		ASSERT(vd->vdev_reopening);
60 		vf = vd->vdev_tsd;
61 		goto skip_open;
62 	}
63 
64 	vf = vd->vdev_tsd = kmem_zalloc(sizeof (vdev_file_t), KM_SLEEP);
65 
66 	/*
67 	 * We always open the files from the root of the global zone, even if
68 	 * we're in a local zone.  If the user has gotten to this point, the
69 	 * administrator has already decided that the pool should be available
70 	 * to local zone users, so the underlying devices should be as well.
71 	 */
72 	ASSERT(vd->vdev_path != NULL && vd->vdev_path[0] == '/');
73 	error = vn_openat(vd->vdev_path + 1, UIO_SYSSPACE,
74 	    spa_mode(vd->vdev_spa) | FOFFMAX, 0, &vp, 0, 0, rootdir, -1);
75 
76 	if (error) {
77 		vd->vdev_stat.vs_aux = VDEV_AUX_OPEN_FAILED;
78 		return (error);
79 	}
80 
81 	vf->vf_vnode = vp;
82 
83 #ifdef _KERNEL
84 	/*
85 	 * Make sure it's a regular file.
86 	 */
87 	if (vp->v_type != VREG) {
88 		vd->vdev_stat.vs_aux = VDEV_AUX_OPEN_FAILED;
89 		return (ENODEV);
90 	}
91 #endif
92 
93 skip_open:
94 	/*
95 	 * Determine the physical size of the file.
96 	 */
97 	vattr.va_mask = AT_SIZE;
98 	error = VOP_GETATTR(vf->vf_vnode, &vattr, 0, kcred, NULL);
99 	if (error) {
100 		vd->vdev_stat.vs_aux = VDEV_AUX_OPEN_FAILED;
101 		return (error);
102 	}
103 
104 	*psize = vattr.va_size;
105 	*ashift = SPA_MINBLOCKSHIFT;
106 
107 	return (0);
108 }
109 
110 static void
111 vdev_file_close(vdev_t *vd)
112 {
113 	vdev_file_t *vf = vd->vdev_tsd;
114 
115 	if (vd->vdev_reopening || vf == NULL)
116 		return;
117 
118 	if (vf->vf_vnode != NULL) {
119 		(void) VOP_PUTPAGE(vf->vf_vnode, 0, 0, B_INVAL, kcred, NULL);
120 		(void) VOP_CLOSE(vf->vf_vnode, spa_mode(vd->vdev_spa), 1, 0,
121 		    kcred, NULL);
122 		VN_RELE(vf->vf_vnode);
123 	}
124 
125 	kmem_free(vf, sizeof (vdev_file_t));
126 	vd->vdev_tsd = NULL;
127 }
128 
129 static int
130 vdev_file_io_start(zio_t *zio)
131 {
132 	vdev_t *vd = zio->io_vd;
133 	vdev_file_t *vf = vd->vdev_tsd;
134 	ssize_t resid;
135 
136 	if (zio->io_type == ZIO_TYPE_IOCTL) {
137 		/* XXPOLICY */
138 		if (!vdev_readable(vd)) {
139 			zio->io_error = ENXIO;
140 			return (ZIO_PIPELINE_CONTINUE);
141 		}
142 
143 		switch (zio->io_cmd) {
144 		case DKIOCFLUSHWRITECACHE:
145 			zio->io_error = VOP_FSYNC(vf->vf_vnode, FSYNC | FDSYNC,
146 			    kcred, NULL);
147 			break;
148 		default:
149 			zio->io_error = ENOTSUP;
150 		}
151 
152 		return (ZIO_PIPELINE_CONTINUE);
153 	}
154 
155 	zio->io_error = vn_rdwr(zio->io_type == ZIO_TYPE_READ ?
156 	    UIO_READ : UIO_WRITE, vf->vf_vnode, zio->io_data,
157 	    zio->io_size, zio->io_offset, UIO_SYSSPACE,
158 	    0, RLIM64_INFINITY, kcred, &resid);
159 
160 	if (resid != 0 && zio->io_error == 0)
161 		zio->io_error = ENOSPC;
162 
163 	zio_interrupt(zio);
164 
165 	return (ZIO_PIPELINE_STOP);
166 }
167 
168 /* ARGSUSED */
169 static void
170 vdev_file_io_done(zio_t *zio)
171 {
172 }
173 
174 vdev_ops_t vdev_file_ops = {
175 	vdev_file_open,
176 	vdev_file_close,
177 	vdev_default_asize,
178 	vdev_file_io_start,
179 	vdev_file_io_done,
180 	NULL,
181 	VDEV_TYPE_FILE,		/* name of this vdev type */
182 	B_TRUE			/* leaf vdev */
183 };
184 
185 /*
186  * From userland we access disks just like files.
187  */
188 #ifndef _KERNEL
189 
190 vdev_ops_t vdev_disk_ops = {
191 	vdev_file_open,
192 	vdev_file_close,
193 	vdev_default_asize,
194 	vdev_file_io_start,
195 	vdev_file_io_done,
196 	NULL,
197 	VDEV_TYPE_DISK,		/* name of this vdev type */
198 	B_TRUE			/* leaf vdev */
199 };
200 
201 #endif
202