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) 2011, 2016 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 #include <sys/abd.h>
34 
35 /*
36  * Virtual device vector for files.
37  */
38 
39 static taskq_t *vdev_file_taskq;
40 
41 void
vdev_file_init(void)42 vdev_file_init(void)
43 {
44 	vdev_file_taskq = taskq_create("z_vdev_file", MAX(max_ncpus, 16),
45 	    minclsyspri, max_ncpus, INT_MAX, 0);
46 }
47 
48 void
vdev_file_fini(void)49 vdev_file_fini(void)
50 {
51 	taskq_destroy(vdev_file_taskq);
52 }
53 
54 static void
vdev_file_hold(vdev_t * vd)55 vdev_file_hold(vdev_t *vd)
56 {
57 	ASSERT(vd->vdev_path != NULL);
58 }
59 
60 static void
vdev_file_rele(vdev_t * vd)61 vdev_file_rele(vdev_t *vd)
62 {
63 	ASSERT(vd->vdev_path != NULL);
64 }
65 
66 static int
vdev_file_open(vdev_t * vd,uint64_t * psize,uint64_t * max_psize,uint64_t * logical_ashift,uint64_t * physical_ashift)67 vdev_file_open(vdev_t *vd, uint64_t *psize, uint64_t *max_psize,
68     uint64_t *logical_ashift, uint64_t *physical_ashift)
69 {
70 	vdev_file_t *vf;
71 	vnode_t *vp;
72 	vattr_t vattr;
73 	int error;
74 
75 	/* Rotational optimizations only make sense on block devices */
76 	vd->vdev_nonrot = B_TRUE;
77 
78 	/*
79 	 * We must have a pathname, and it must be absolute.
80 	 */
81 	if (vd->vdev_path == NULL || vd->vdev_path[0] != '/') {
82 		vd->vdev_stat.vs_aux = VDEV_AUX_BAD_LABEL;
83 		return (SET_ERROR(EINVAL));
84 	}
85 
86 	/*
87 	 * Reopen the device if it's not currently open.  Otherwise,
88 	 * just update the physical size of the device.
89 	 */
90 	if (vd->vdev_tsd != NULL) {
91 		ASSERT(vd->vdev_reopening);
92 		vf = vd->vdev_tsd;
93 		vp = vf->vf_vnode;
94 		goto skip_open;
95 	}
96 
97 	vf = vd->vdev_tsd = kmem_zalloc(sizeof (vdev_file_t), KM_SLEEP);
98 
99 	/*
100 	 * We always open the files from the root of the global zone, even if
101 	 * we're in a local zone.  If the user has gotten to this point, the
102 	 * administrator has already decided that the pool should be available
103 	 * to local zone users, so the underlying devices should be as well.
104 	 */
105 	ASSERT(vd->vdev_path != NULL && vd->vdev_path[0] == '/');
106 	error = vn_openat(vd->vdev_path + 1, UIO_SYSSPACE,
107 	    spa_mode(vd->vdev_spa) | FOFFMAX, 0, &vp, 0, 0, rootdir, -1);
108 
109 	if (error) {
110 		vd->vdev_stat.vs_aux = VDEV_AUX_OPEN_FAILED;
111 		kmem_free(vd->vdev_tsd, sizeof (vdev_file_t));
112 		vd->vdev_tsd = NULL;
113 		return (error);
114 	}
115 
116 	vf->vf_vnode = vp;
117 
118 #ifdef _KERNEL
119 	/*
120 	 * Make sure it's a regular file.
121 	 */
122 	if (vp->v_type != VREG) {
123 #ifdef __FreeBSD__
124 		(void) VOP_CLOSE(vp, spa_mode(vd->vdev_spa), 1, 0, kcred, NULL);
125 #endif
126 		vd->vdev_stat.vs_aux = VDEV_AUX_OPEN_FAILED;
127 #ifdef __FreeBSD__
128 		kmem_free(vd->vdev_tsd, sizeof (vdev_file_t));
129 		vd->vdev_tsd = NULL;
130 #endif
131 		return (SET_ERROR(ENODEV));
132 	}
133 #endif	/* _KERNEL */
134 
135 skip_open:
136 	/*
137 	 * Determine the physical size of the file.
138 	 */
139 	vattr.va_mask = AT_SIZE;
140 	vn_lock(vp, LK_SHARED | LK_RETRY);
141 	error = VOP_GETATTR(vp, &vattr, kcred);
142 	VOP_UNLOCK(vp, 0);
143 	if (error) {
144 		(void) VOP_CLOSE(vp, spa_mode(vd->vdev_spa), 1, 0, kcred, NULL);
145 		vd->vdev_stat.vs_aux = VDEV_AUX_OPEN_FAILED;
146 		kmem_free(vd->vdev_tsd, sizeof (vdev_file_t));
147 		vd->vdev_tsd = NULL;
148 		return (error);
149 	}
150 
151 	vd->vdev_notrim = B_TRUE;
152 
153 	*max_psize = *psize = vattr.va_size;
154 	*logical_ashift = SPA_MINBLOCKSHIFT;
155 	*physical_ashift = SPA_MINBLOCKSHIFT;
156 
157 	return (0);
158 }
159 
160 static void
vdev_file_close(vdev_t * vd)161 vdev_file_close(vdev_t *vd)
162 {
163 	vdev_file_t *vf = vd->vdev_tsd;
164 
165 	if (vd->vdev_reopening || vf == NULL)
166 		return;
167 
168 	if (vf->vf_vnode != NULL) {
169 		(void) VOP_CLOSE(vf->vf_vnode, spa_mode(vd->vdev_spa), 1, 0,
170 		    kcred, NULL);
171 	}
172 
173 	vd->vdev_delayed_close = B_FALSE;
174 	kmem_free(vf, sizeof (vdev_file_t));
175 	vd->vdev_tsd = NULL;
176 }
177 
178 /*
179  * Implements the interrupt side for file vdev types. This routine will be
180  * called when the I/O completes allowing us to transfer the I/O to the
181  * interrupt taskqs. For consistency, the code structure mimics disk vdev
182  * types.
183  */
184 static void
vdev_file_io_intr(zio_t * zio)185 vdev_file_io_intr(zio_t *zio)
186 {
187 	zio_delay_interrupt(zio);
188 }
189 
190 static void
vdev_file_io_strategy(void * arg)191 vdev_file_io_strategy(void *arg)
192 {
193 	zio_t *zio = arg;
194 	vdev_t *vd = zio->io_vd;
195 	vdev_file_t *vf;
196 	vnode_t *vp;
197 	void *addr;
198 	ssize_t resid;
199 
200 	vf = vd->vdev_tsd;
201 	vp = vf->vf_vnode;
202 
203 	ASSERT(zio->io_type == ZIO_TYPE_READ || zio->io_type == ZIO_TYPE_WRITE);
204 	if (zio->io_type == ZIO_TYPE_READ) {
205 		addr = abd_borrow_buf(zio->io_abd, zio->io_size);
206 	} else {
207 		addr = abd_borrow_buf_copy(zio->io_abd, zio->io_size);
208 	}
209 
210 	zio->io_error = vn_rdwr(zio->io_type == ZIO_TYPE_READ ?
211 	    UIO_READ : UIO_WRITE, vp, addr, zio->io_size,
212 	    zio->io_offset, UIO_SYSSPACE, 0, RLIM64_INFINITY, kcred, &resid);
213 
214 	if (zio->io_type == ZIO_TYPE_READ) {
215 		abd_return_buf_copy(zio->io_abd, addr, zio->io_size);
216 	} else {
217 		abd_return_buf(zio->io_abd, addr, zio->io_size);
218 	}
219 
220 	if (resid != 0 && zio->io_error == 0)
221 		zio->io_error = ENOSPC;
222 
223 	vdev_file_io_intr(zio);
224 }
225 
226 static void
vdev_file_io_start(zio_t * zio)227 vdev_file_io_start(zio_t *zio)
228 {
229 	vdev_t *vd = zio->io_vd;
230 	vdev_file_t *vf = vd->vdev_tsd;
231 
232 	if (zio->io_type == ZIO_TYPE_IOCTL) {
233 		/* XXPOLICY */
234 		if (!vdev_readable(vd)) {
235 			zio->io_error = SET_ERROR(ENXIO);
236 			zio_interrupt(zio);
237 			return;
238 		}
239 
240 		switch (zio->io_cmd) {
241 		case DKIOCFLUSHWRITECACHE:
242 
243 			if (zfs_nocacheflush)
244 				break;
245 
246 			zio->io_error = VOP_FSYNC(vf->vf_vnode, FSYNC | FDSYNC,
247 			    kcred, NULL);
248 			break;
249 		default:
250 			zio->io_error = SET_ERROR(ENOTSUP);
251 		}
252 
253 		zio_execute(zio);
254 		return;
255 	}
256 
257 	ASSERT(zio->io_type == ZIO_TYPE_READ || zio->io_type == ZIO_TYPE_WRITE);
258 	zio->io_target_timestamp = zio_handle_io_delay(zio);
259 
260 	VERIFY3U(taskq_dispatch(vdev_file_taskq, vdev_file_io_strategy, zio,
261 	    TQ_SLEEP), !=, 0);
262 }
263 
264 /* ARGSUSED */
265 static void
vdev_file_io_done(zio_t * zio)266 vdev_file_io_done(zio_t *zio)
267 {
268 }
269 
270 vdev_ops_t vdev_file_ops = {
271 	vdev_file_open,
272 	vdev_file_close,
273 	vdev_default_asize,
274 	vdev_file_io_start,
275 	vdev_file_io_done,
276 	NULL,
277 	NULL,
278 	vdev_file_hold,
279 	vdev_file_rele,
280 	NULL,
281 	vdev_default_xlate,
282 	VDEV_TYPE_FILE,		/* name of this vdev type */
283 	B_TRUE			/* leaf vdev */
284 };
285 
286 /*
287  * From userland we access disks just like files.
288  */
289 #ifndef _KERNEL
290 
291 vdev_ops_t vdev_disk_ops = {
292 	vdev_file_open,
293 	vdev_file_close,
294 	vdev_default_asize,
295 	vdev_file_io_start,
296 	vdev_file_io_done,
297 	NULL,
298 	NULL,
299 	vdev_file_hold,
300 	vdev_file_rele,
301 	NULL,
302 	vdev_default_xlate,
303 	VDEV_TYPE_DISK,		/* name of this vdev type */
304 	B_TRUE			/* leaf vdev */
305 };
306 
307 #endif
308