xref: /titanic_52/usr/src/uts/common/fs/zfs/vdev_file.c (revision 35b6f0471a5d938b98734483be3c5a258e319010)
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) 2013 by Delphix. All rights reserved.
24  */
25 
26 #include <sys/zfs_context.h>
27 #include <sys/spa.h>
28 #include <sys/spa_impl.h>
29 #include <sys/vdev_file.h>
30 #include <sys/vdev_impl.h>
31 #include <sys/zio.h>
32 #include <sys/fs/zfs.h>
33 #include <sys/fm/fs/zfs.h>
34 
35 /*
36  * Virtual device vector for files.
37  */
38 
39 static void
40 vdev_file_hold(vdev_t *vd)
41 {
42 	ASSERT(vd->vdev_path != NULL);
43 }
44 
45 static void
46 vdev_file_rele(vdev_t *vd)
47 {
48 	ASSERT(vd->vdev_path != NULL);
49 }
50 
51 static int
52 vdev_file_open(vdev_t *vd, uint64_t *psize, uint64_t *max_psize,
53     uint64_t *ashift)
54 {
55 	vdev_file_t *vf;
56 	vnode_t *vp;
57 	vattr_t vattr;
58 	int error;
59 
60 	/*
61 	 * We must have a pathname, and it must be absolute.
62 	 */
63 	if (vd->vdev_path == NULL || vd->vdev_path[0] != '/') {
64 		vd->vdev_stat.vs_aux = VDEV_AUX_BAD_LABEL;
65 		return (SET_ERROR(EINVAL));
66 	}
67 
68 	/*
69 	 * Reopen the device if it's not currently open.  Otherwise,
70 	 * just update the physical size of the device.
71 	 */
72 	if (vd->vdev_tsd != NULL) {
73 		ASSERT(vd->vdev_reopening);
74 		vf = vd->vdev_tsd;
75 		goto skip_open;
76 	}
77 
78 	vf = vd->vdev_tsd = kmem_zalloc(sizeof (vdev_file_t), KM_SLEEP);
79 
80 	/*
81 	 * We always open the files from the root of the global zone, even if
82 	 * we're in a local zone.  If the user has gotten to this point, the
83 	 * administrator has already decided that the pool should be available
84 	 * to local zone users, so the underlying devices should be as well.
85 	 */
86 	ASSERT(vd->vdev_path != NULL && vd->vdev_path[0] == '/');
87 	error = vn_openat(vd->vdev_path + 1, UIO_SYSSPACE,
88 	    spa_mode(vd->vdev_spa) | FOFFMAX, 0, &vp, 0, 0, rootdir, -1);
89 
90 	if (error) {
91 		vd->vdev_stat.vs_aux = VDEV_AUX_OPEN_FAILED;
92 		return (error);
93 	}
94 
95 	vf->vf_vnode = vp;
96 
97 #ifdef _KERNEL
98 	/*
99 	 * Make sure it's a regular file.
100 	 */
101 	if (vp->v_type != VREG) {
102 		vd->vdev_stat.vs_aux = VDEV_AUX_OPEN_FAILED;
103 		return (SET_ERROR(ENODEV));
104 	}
105 #endif
106 
107 skip_open:
108 	/*
109 	 * Determine the physical size of the file.
110 	 */
111 	vattr.va_mask = AT_SIZE;
112 	error = VOP_GETATTR(vf->vf_vnode, &vattr, 0, kcred, NULL);
113 	if (error) {
114 		vd->vdev_stat.vs_aux = VDEV_AUX_OPEN_FAILED;
115 		return (error);
116 	}
117 
118 	*max_psize = *psize = vattr.va_size;
119 	*ashift = SPA_MINBLOCKSHIFT;
120 
121 	return (0);
122 }
123 
124 static void
125 vdev_file_close(vdev_t *vd)
126 {
127 	vdev_file_t *vf = vd->vdev_tsd;
128 
129 	if (vd->vdev_reopening || vf == NULL)
130 		return;
131 
132 	if (vf->vf_vnode != NULL) {
133 		(void) VOP_PUTPAGE(vf->vf_vnode, 0, 0, B_INVAL, kcred, NULL);
134 		(void) VOP_CLOSE(vf->vf_vnode, spa_mode(vd->vdev_spa), 1, 0,
135 		    kcred, NULL);
136 		VN_RELE(vf->vf_vnode);
137 	}
138 
139 	vd->vdev_delayed_close = B_FALSE;
140 	kmem_free(vf, sizeof (vdev_file_t));
141 	vd->vdev_tsd = NULL;
142 }
143 
144 /*
145  * Implements the interrupt side for file vdev types. This routine will be
146  * called when the I/O completes allowing us to transfer the I/O to the
147  * interrupt taskqs. For consistency, the code structure mimics disk vdev
148  * types.
149  */
150 static void
151 vdev_file_io_intr(buf_t *bp)
152 {
153 	vdev_buf_t *vb = (vdev_buf_t *)bp;
154 	zio_t *zio = vb->vb_io;
155 
156 	zio->io_error = (geterror(bp) != 0 ? EIO : 0);
157 	if (zio->io_error == 0 && bp->b_resid != 0)
158 		zio->io_error = SET_ERROR(ENOSPC);
159 
160 	kmem_free(vb, sizeof (vdev_buf_t));
161 	zio_interrupt(zio);
162 }
163 
164 static void
165 vdev_file_io_strategy(void *arg)
166 {
167 	buf_t *bp = arg;
168 	vnode_t *vp = bp->b_private;
169 	ssize_t resid;
170 	int error;
171 
172 	error = vn_rdwr((bp->b_flags & B_READ) ? UIO_READ : UIO_WRITE,
173 	    vp, bp->b_un.b_addr, bp->b_bcount, ldbtob(bp->b_lblkno),
174 	    UIO_SYSSPACE, 0, RLIM64_INFINITY, kcred, &resid);
175 
176 	if (error == 0) {
177 		bp->b_resid = resid;
178 		biodone(bp);
179 	} else {
180 		bioerror(bp, error);
181 		biodone(bp);
182 	}
183 }
184 
185 static int
186 vdev_file_io_start(zio_t *zio)
187 {
188 	vdev_t *vd = zio->io_vd;
189 	vdev_file_t *vf = vd->vdev_tsd;
190 	vdev_buf_t *vb;
191 	buf_t *bp;
192 
193 	if (zio->io_type == ZIO_TYPE_IOCTL) {
194 		/* XXPOLICY */
195 		if (!vdev_readable(vd)) {
196 			zio->io_error = SET_ERROR(ENXIO);
197 			return (ZIO_PIPELINE_CONTINUE);
198 		}
199 
200 		switch (zio->io_cmd) {
201 		case DKIOCFLUSHWRITECACHE:
202 			zio->io_error = VOP_FSYNC(vf->vf_vnode, FSYNC | FDSYNC,
203 			    kcred, NULL);
204 			break;
205 		default:
206 			zio->io_error = SET_ERROR(ENOTSUP);
207 		}
208 
209 		return (ZIO_PIPELINE_CONTINUE);
210 	}
211 
212 	vb = kmem_alloc(sizeof (vdev_buf_t), KM_SLEEP);
213 
214 	vb->vb_io = zio;
215 	bp = &vb->vb_buf;
216 
217 	bioinit(bp);
218 	bp->b_flags = (zio->io_type == ZIO_TYPE_READ ? B_READ : B_WRITE);
219 	bp->b_bcount = zio->io_size;
220 	bp->b_un.b_addr = zio->io_data;
221 	bp->b_lblkno = lbtodb(zio->io_offset);
222 	bp->b_bufsize = zio->io_size;
223 	bp->b_private = vf->vf_vnode;
224 	bp->b_iodone = (int (*)())vdev_file_io_intr;
225 
226 	VERIFY3U(taskq_dispatch(system_taskq, vdev_file_io_strategy, bp,
227 	    TQ_SLEEP), !=, 0);
228 
229 	return (ZIO_PIPELINE_STOP);
230 }
231 
232 /* ARGSUSED */
233 static void
234 vdev_file_io_done(zio_t *zio)
235 {
236 }
237 
238 vdev_ops_t vdev_file_ops = {
239 	vdev_file_open,
240 	vdev_file_close,
241 	vdev_default_asize,
242 	vdev_file_io_start,
243 	vdev_file_io_done,
244 	NULL,
245 	vdev_file_hold,
246 	vdev_file_rele,
247 	VDEV_TYPE_FILE,		/* name of this vdev type */
248 	B_TRUE			/* leaf vdev */
249 };
250 
251 /*
252  * From userland we access disks just like files.
253  */
254 #ifndef _KERNEL
255 
256 vdev_ops_t vdev_disk_ops = {
257 	vdev_file_open,
258 	vdev_file_close,
259 	vdev_default_asize,
260 	vdev_file_io_start,
261 	vdev_file_io_done,
262 	NULL,
263 	vdev_file_hold,
264 	vdev_file_rele,
265 	VDEV_TYPE_DISK,		/* name of this vdev type */
266 	B_TRUE			/* leaf vdev */
267 };
268 
269 #endif
270