xref: /titanic_41/usr/src/uts/common/fs/zfs/vdev_file.c (revision b2510a409d954c73416522e09c354f1d6dbdb0b0)
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  * Copyright (c) 2012 by Delphix. All rights reserved.
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 void
39 vdev_file_hold(vdev_t *vd)
40 {
41 	ASSERT(vd->vdev_path != NULL);
42 }
43 
44 static void
45 vdev_file_rele(vdev_t *vd)
46 {
47 	ASSERT(vd->vdev_path != NULL);
48 }
49 
50 static int
51 vdev_file_open(vdev_t *vd, uint64_t *psize, uint64_t *max_psize,
52     uint64_t *ashift)
53 {
54 	vdev_file_t *vf;
55 	vnode_t *vp;
56 	vattr_t vattr;
57 	int error;
58 
59 	/*
60 	 * We must have a pathname, and it must be absolute.
61 	 */
62 	if (vd->vdev_path == NULL || vd->vdev_path[0] != '/') {
63 		vd->vdev_stat.vs_aux = VDEV_AUX_BAD_LABEL;
64 		return (EINVAL);
65 	}
66 
67 	/*
68 	 * Reopen the device if it's not currently open.  Otherwise,
69 	 * just update the physical size of the device.
70 	 */
71 	if (vd->vdev_tsd != NULL) {
72 		ASSERT(vd->vdev_reopening);
73 		vf = vd->vdev_tsd;
74 		goto skip_open;
75 	}
76 
77 	vf = vd->vdev_tsd = kmem_zalloc(sizeof (vdev_file_t), KM_SLEEP);
78 
79 	/*
80 	 * We always open the files from the root of the global zone, even if
81 	 * we're in a local zone.  If the user has gotten to this point, the
82 	 * administrator has already decided that the pool should be available
83 	 * to local zone users, so the underlying devices should be as well.
84 	 */
85 	ASSERT(vd->vdev_path != NULL && vd->vdev_path[0] == '/');
86 	error = vn_openat(vd->vdev_path + 1, UIO_SYSSPACE,
87 	    spa_mode(vd->vdev_spa) | FOFFMAX, 0, &vp, 0, 0, rootdir, -1);
88 
89 	if (error) {
90 		vd->vdev_stat.vs_aux = VDEV_AUX_OPEN_FAILED;
91 		return (error);
92 	}
93 
94 	vf->vf_vnode = vp;
95 
96 #ifdef _KERNEL
97 	/*
98 	 * Make sure it's a regular file.
99 	 */
100 	if (vp->v_type != VREG) {
101 		vd->vdev_stat.vs_aux = VDEV_AUX_OPEN_FAILED;
102 		return (ENODEV);
103 	}
104 #endif
105 
106 skip_open:
107 	/*
108 	 * Determine the physical size of the file.
109 	 */
110 	vattr.va_mask = AT_SIZE;
111 	error = VOP_GETATTR(vf->vf_vnode, &vattr, 0, kcred, NULL);
112 	if (error) {
113 		vd->vdev_stat.vs_aux = VDEV_AUX_OPEN_FAILED;
114 		return (error);
115 	}
116 
117 	*max_psize = *psize = vattr.va_size;
118 	*ashift = SPA_MINBLOCKSHIFT;
119 
120 	return (0);
121 }
122 
123 static void
124 vdev_file_close(vdev_t *vd)
125 {
126 	vdev_file_t *vf = vd->vdev_tsd;
127 
128 	if (vd->vdev_reopening || vf == NULL)
129 		return;
130 
131 	if (vf->vf_vnode != NULL) {
132 		(void) VOP_PUTPAGE(vf->vf_vnode, 0, 0, B_INVAL, kcred, NULL);
133 		(void) VOP_CLOSE(vf->vf_vnode, spa_mode(vd->vdev_spa), 1, 0,
134 		    kcred, NULL);
135 		VN_RELE(vf->vf_vnode);
136 	}
137 
138 	vd->vdev_delayed_close = B_FALSE;
139 	kmem_free(vf, sizeof (vdev_file_t));
140 	vd->vdev_tsd = NULL;
141 }
142 
143 static int
144 vdev_file_io_start(zio_t *zio)
145 {
146 	vdev_t *vd = zio->io_vd;
147 	vdev_file_t *vf = vd->vdev_tsd;
148 	ssize_t resid;
149 
150 	if (zio->io_type == ZIO_TYPE_IOCTL) {
151 		/* XXPOLICY */
152 		if (!vdev_readable(vd)) {
153 			zio->io_error = ENXIO;
154 			return (ZIO_PIPELINE_CONTINUE);
155 		}
156 
157 		switch (zio->io_cmd) {
158 		case DKIOCFLUSHWRITECACHE:
159 			zio->io_error = VOP_FSYNC(vf->vf_vnode, FSYNC | FDSYNC,
160 			    kcred, NULL);
161 			break;
162 		default:
163 			zio->io_error = ENOTSUP;
164 		}
165 
166 		return (ZIO_PIPELINE_CONTINUE);
167 	}
168 
169 	zio->io_error = vn_rdwr(zio->io_type == ZIO_TYPE_READ ?
170 	    UIO_READ : UIO_WRITE, vf->vf_vnode, zio->io_data,
171 	    zio->io_size, zio->io_offset, UIO_SYSSPACE,
172 	    0, RLIM64_INFINITY, kcred, &resid);
173 
174 	if (resid != 0 && zio->io_error == 0)
175 		zio->io_error = ENOSPC;
176 
177 	zio_interrupt(zio);
178 
179 	return (ZIO_PIPELINE_STOP);
180 }
181 
182 /* ARGSUSED */
183 static void
184 vdev_file_io_done(zio_t *zio)
185 {
186 }
187 
188 vdev_ops_t vdev_file_ops = {
189 	vdev_file_open,
190 	vdev_file_close,
191 	vdev_default_asize,
192 	vdev_file_io_start,
193 	vdev_file_io_done,
194 	NULL,
195 	vdev_file_hold,
196 	vdev_file_rele,
197 	VDEV_TYPE_FILE,		/* name of this vdev type */
198 	B_TRUE			/* leaf vdev */
199 };
200 
201 /*
202  * From userland we access disks just like files.
203  */
204 #ifndef _KERNEL
205 
206 vdev_ops_t vdev_disk_ops = {
207 	vdev_file_open,
208 	vdev_file_close,
209 	vdev_default_asize,
210 	vdev_file_io_start,
211 	vdev_file_io_done,
212 	NULL,
213 	vdev_file_hold,
214 	vdev_file_rele,
215 	VDEV_TYPE_DISK,		/* name of this vdev type */
216 	B_TRUE			/* leaf vdev */
217 };
218 
219 #endif
220