xref: /illumos-gate/usr/src/uts/common/fs/zfs/vdev_file.c (revision 8119dad84d6416f13557b0ba8e2aaf9064cbcfd3)
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  * Copyright 2019 Joyent, Inc.
25  */
26 
27 #include <sys/zfs_context.h>
28 #include <sys/spa.h>
29 #include <sys/spa_impl.h>
30 #include <sys/vdev_file.h>
31 #include <sys/vdev_impl.h>
32 #include <sys/vdev_trim.h>
33 #include <sys/zio.h>
34 #include <sys/fs/zfs.h>
35 #include <sys/fm/fs/zfs.h>
36 #include <sys/abd.h>
37 #include <sys/fcntl.h>
38 #include <sys/vnode.h>
39 
40 /*
41  * Virtual device vector for files.
42  */
43 
44 static void
45 vdev_file_hold(vdev_t *vd)
46 {
47 	ASSERT(vd->vdev_path != NULL);
48 }
49 
50 static void
51 vdev_file_rele(vdev_t *vd)
52 {
53 	ASSERT(vd->vdev_path != NULL);
54 }
55 
56 static int
57 vdev_file_open(vdev_t *vd, uint64_t *psize, uint64_t *max_psize,
58     uint64_t *ashift)
59 {
60 	vdev_file_t *vf;
61 	vnode_t *vp;
62 	vattr_t vattr;
63 	int error;
64 
65 	/*
66 	 * Rotational optimizations only make sense on block devices.
67 	 */
68 	vd->vdev_nonrot = B_TRUE;
69 
70 	/*
71 	 * Allow TRIM on file based vdevs.  This may not always be supported,
72 	 * since it depends on your kernel version and underlying filesystem
73 	 * type but it is always safe to attempt.
74 	 */
75 	vd->vdev_has_trim = B_TRUE;
76 
77 	/*
78 	 * Disable secure TRIM on file based vdevs.  There is no way to
79 	 * request this behavior from the underlying filesystem.
80 	 */
81 	vd->vdev_has_securetrim = B_FALSE;
82 
83 	/*
84 	 * We must have a pathname, and it must be absolute.
85 	 */
86 	if (vd->vdev_path == NULL || vd->vdev_path[0] != '/') {
87 		vd->vdev_stat.vs_aux = VDEV_AUX_BAD_LABEL;
88 		return (SET_ERROR(EINVAL));
89 	}
90 
91 	/*
92 	 * Reopen the device if it's not currently open.  Otherwise,
93 	 * just update the physical size of the device.
94 	 */
95 	if (vd->vdev_tsd != NULL) {
96 		ASSERT(vd->vdev_reopening);
97 		vf = vd->vdev_tsd;
98 		goto skip_open;
99 	}
100 
101 	vf = vd->vdev_tsd = kmem_zalloc(sizeof (vdev_file_t), KM_SLEEP);
102 
103 	/*
104 	 * We always open the files from the root of the global zone, even if
105 	 * we're in a local zone.  If the user has gotten to this point, the
106 	 * administrator has already decided that the pool should be available
107 	 * to local zone users, so the underlying devices should be as well.
108 	 */
109 	ASSERT(vd->vdev_path != NULL && vd->vdev_path[0] == '/');
110 	error = vn_openat(vd->vdev_path + 1, UIO_SYSSPACE,
111 	    spa_mode(vd->vdev_spa) | FOFFMAX, 0, &vp, 0, 0, rootdir, -1);
112 
113 	if (error) {
114 		vd->vdev_stat.vs_aux = VDEV_AUX_OPEN_FAILED;
115 		return (error);
116 	}
117 
118 	vf->vf_vnode = vp;
119 
120 #ifdef _KERNEL
121 	/*
122 	 * Make sure it's a regular file.
123 	 */
124 	if (vp->v_type != VREG) {
125 		vd->vdev_stat.vs_aux = VDEV_AUX_OPEN_FAILED;
126 		return (SET_ERROR(ENODEV));
127 	}
128 #endif
129 
130 skip_open:
131 	/*
132 	 * Determine the physical size of the file.
133 	 */
134 	vattr.va_mask = AT_SIZE;
135 	error = VOP_GETATTR(vf->vf_vnode, &vattr, 0, kcred, NULL);
136 	if (error) {
137 		vd->vdev_stat.vs_aux = VDEV_AUX_OPEN_FAILED;
138 		return (error);
139 	}
140 
141 	*max_psize = *psize = vattr.va_size;
142 	*ashift = SPA_MINBLOCKSHIFT;
143 
144 	return (0);
145 }
146 
147 static void
148 vdev_file_close(vdev_t *vd)
149 {
150 	vdev_file_t *vf = vd->vdev_tsd;
151 
152 	if (vd->vdev_reopening || vf == NULL)
153 		return;
154 
155 	if (vf->vf_vnode != NULL) {
156 		(void) VOP_PUTPAGE(vf->vf_vnode, 0, 0, B_INVAL, kcred, NULL);
157 		(void) VOP_CLOSE(vf->vf_vnode, spa_mode(vd->vdev_spa), 1, 0,
158 		    kcred, NULL);
159 		VN_RELE(vf->vf_vnode);
160 	}
161 
162 	vd->vdev_delayed_close = B_FALSE;
163 	kmem_free(vf, sizeof (vdev_file_t));
164 	vd->vdev_tsd = NULL;
165 }
166 
167 /*
168  * Implements the interrupt side for file vdev types. This routine will be
169  * called when the I/O completes allowing us to transfer the I/O to the
170  * interrupt taskqs. For consistency, the code structure mimics disk vdev
171  * types.
172  */
173 static int
174 vdev_file_io_intr(buf_t *bp)
175 {
176 	vdev_buf_t *vb = (vdev_buf_t *)bp;
177 	zio_t *zio = vb->vb_io;
178 
179 	zio->io_error = (geterror(bp) != 0 ? EIO : 0);
180 	if (zio->io_error == 0 && bp->b_resid != 0)
181 		zio->io_error = SET_ERROR(ENOSPC);
182 
183 	if (zio->io_type == ZIO_TYPE_READ) {
184 		abd_return_buf_copy(zio->io_abd, bp->b_un.b_addr, zio->io_size);
185 	} else {
186 		abd_return_buf(zio->io_abd, bp->b_un.b_addr, zio->io_size);
187 	}
188 
189 	kmem_free(vb, sizeof (vdev_buf_t));
190 	zio_delay_interrupt(zio);
191 	return (0);
192 }
193 
194 static void
195 vdev_file_io_strategy(void *arg)
196 {
197 	buf_t *bp = arg;
198 	vnode_t *vp = bp->b_private;
199 	ssize_t resid;
200 	int error;
201 
202 	error = vn_rdwr((bp->b_flags & B_READ) ? UIO_READ : UIO_WRITE,
203 	    vp, bp->b_un.b_addr, bp->b_bcount, ldbtob(bp->b_lblkno),
204 	    UIO_SYSSPACE, 0, RLIM64_INFINITY, kcred, &resid);
205 
206 	if (error == 0) {
207 		bp->b_resid = resid;
208 		biodone(bp);
209 	} else {
210 		bioerror(bp, error);
211 		biodone(bp);
212 	}
213 }
214 
215 static void
216 vdev_file_io_start(zio_t *zio)
217 {
218 	vdev_t *vd = zio->io_vd;
219 	vdev_file_t *vf = vd->vdev_tsd;
220 	vdev_buf_t *vb;
221 	buf_t *bp;
222 
223 	if (zio->io_type == ZIO_TYPE_IOCTL) {
224 		/* XXPOLICY */
225 		if (!vdev_readable(vd)) {
226 			zio->io_error = SET_ERROR(ENXIO);
227 			zio_interrupt(zio);
228 			return;
229 		}
230 
231 		switch (zio->io_cmd) {
232 		case DKIOCFLUSHWRITECACHE:
233 			zio->io_error = VOP_FSYNC(vf->vf_vnode, FSYNC | FDSYNC,
234 			    kcred, NULL);
235 			break;
236 		default:
237 			zio->io_error = SET_ERROR(ENOTSUP);
238 		}
239 
240 		zio_execute(zio);
241 		return;
242 	} else if (zio->io_type == ZIO_TYPE_TRIM) {
243 		struct flock64 flck;
244 
245 		ASSERT3U(zio->io_size, !=, 0);
246 		bzero(&flck, sizeof (flck));
247 		flck.l_type = F_FREESP;
248 		flck.l_start = zio->io_offset;
249 		flck.l_len = zio->io_size;
250 		flck.l_whence = 0;
251 
252 		zio->io_error = VOP_SPACE(vf->vf_vnode, F_FREESP, &flck,
253 		    0, 0, kcred, NULL);
254 
255 		zio_execute(zio);
256 		return;
257 	}
258 
259 	ASSERT(zio->io_type == ZIO_TYPE_READ || zio->io_type == ZIO_TYPE_WRITE);
260 	zio->io_target_timestamp = zio_handle_io_delay(zio);
261 
262 	vb = kmem_alloc(sizeof (vdev_buf_t), KM_SLEEP);
263 
264 	vb->vb_io = zio;
265 	bp = &vb->vb_buf;
266 
267 	bioinit(bp);
268 	bp->b_flags = (zio->io_type == ZIO_TYPE_READ ? B_READ : B_WRITE);
269 	bp->b_bcount = zio->io_size;
270 
271 	if (zio->io_type == ZIO_TYPE_READ) {
272 		bp->b_un.b_addr =
273 		    abd_borrow_buf(zio->io_abd, zio->io_size);
274 	} else {
275 		bp->b_un.b_addr =
276 		    abd_borrow_buf_copy(zio->io_abd, zio->io_size);
277 	}
278 
279 	bp->b_lblkno = lbtodb(zio->io_offset);
280 	bp->b_bufsize = zio->io_size;
281 	bp->b_private = vf->vf_vnode;
282 	bp->b_iodone = vdev_file_io_intr;
283 
284 	VERIFY3U(taskq_dispatch(system_taskq, vdev_file_io_strategy, bp,
285 	    TQ_SLEEP), !=, TASKQID_INVALID);
286 }
287 
288 /* ARGSUSED */
289 static void
290 vdev_file_io_done(zio_t *zio)
291 {
292 }
293 
294 vdev_ops_t vdev_file_ops = {
295 	.vdev_op_open = vdev_file_open,
296 	.vdev_op_close = vdev_file_close,
297 	.vdev_op_asize = vdev_default_asize,
298 	.vdev_op_io_start = vdev_file_io_start,
299 	.vdev_op_io_done = vdev_file_io_done,
300 	.vdev_op_state_change = NULL,
301 	.vdev_op_need_resilver = NULL,
302 	.vdev_op_hold = vdev_file_hold,
303 	.vdev_op_rele = vdev_file_rele,
304 	.vdev_op_remap = NULL,
305 	.vdev_op_xlate = vdev_default_xlate,
306 	.vdev_op_dumpio = NULL,
307 	.vdev_op_type = VDEV_TYPE_FILE,		/* name of this vdev type */
308 	.vdev_op_leaf = B_TRUE			/* leaf vdev */
309 };
310 
311 /*
312  * From userland we access disks just like files.
313  */
314 #ifndef _KERNEL
315 
316 vdev_ops_t vdev_disk_ops = {
317 	.vdev_op_open = vdev_file_open,
318 	.vdev_op_close = vdev_file_close,
319 	.vdev_op_asize = vdev_default_asize,
320 	.vdev_op_io_start = vdev_file_io_start,
321 	.vdev_op_io_done = vdev_file_io_done,
322 	.vdev_op_state_change = NULL,
323 	.vdev_op_need_resilver = NULL,
324 	.vdev_op_hold = vdev_file_hold,
325 	.vdev_op_rele = vdev_file_rele,
326 	.vdev_op_remap = NULL,
327 	.vdev_op_xlate = vdev_default_xlate,
328 	.vdev_op_dumpio = NULL,
329 	.vdev_op_type = VDEV_TYPE_DISK,		/* name of this vdev type */
330 	.vdev_op_leaf = B_TRUE			/* leaf vdev */
331 };
332 
333 #endif
334