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, 2020 by Delphix. All rights reserved.
24  */
25 
26 #include <sys/zfs_context.h>
27 #include <sys/spa.h>
28 #include <sys/file.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 #include <sys/abd.h>
35 #include <sys/stat.h>
36 
37 /*
38  * Virtual device vector for files.
39  */
40 
41 static taskq_t *vdev_file_taskq;
42 
43 unsigned long vdev_file_logical_ashift = SPA_MINBLOCKSHIFT;
44 unsigned long vdev_file_physical_ashift = SPA_MINBLOCKSHIFT;
45 
46 void
47 vdev_file_init(void)
48 {
49 	vdev_file_taskq = taskq_create("z_vdev_file", MAX(max_ncpus, 16),
50 	    minclsyspri, max_ncpus, INT_MAX, 0);
51 }
52 
53 void
54 vdev_file_fini(void)
55 {
56 	taskq_destroy(vdev_file_taskq);
57 }
58 
59 static void
60 vdev_file_hold(vdev_t *vd)
61 {
62 	ASSERT(vd->vdev_path != NULL);
63 }
64 
65 static void
66 vdev_file_rele(vdev_t *vd)
67 {
68 	ASSERT(vd->vdev_path != NULL);
69 }
70 
71 static mode_t
72 vdev_file_open_mode(spa_mode_t spa_mode)
73 {
74 	mode_t mode = 0;
75 
76 	if ((spa_mode & SPA_MODE_READ) && (spa_mode & SPA_MODE_WRITE)) {
77 		mode = O_RDWR;
78 	} else if (spa_mode & SPA_MODE_READ) {
79 		mode = O_RDONLY;
80 	} else if (spa_mode & SPA_MODE_WRITE) {
81 		mode = O_WRONLY;
82 	}
83 
84 	return (mode | O_LARGEFILE);
85 }
86 
87 static int
88 vdev_file_open(vdev_t *vd, uint64_t *psize, uint64_t *max_psize,
89     uint64_t *logical_ashift, uint64_t *physical_ashift)
90 {
91 	vdev_file_t *vf;
92 	zfs_file_t *fp;
93 	zfs_file_attr_t zfa;
94 	int error;
95 
96 	/*
97 	 * Rotational optimizations only make sense on block devices.
98 	 */
99 	vd->vdev_nonrot = B_TRUE;
100 
101 	/*
102 	 * Allow TRIM on file based vdevs.  This may not always be supported,
103 	 * since it depends on your kernel version and underlying filesystem
104 	 * type but it is always safe to attempt.
105 	 */
106 	vd->vdev_has_trim = B_TRUE;
107 
108 	/*
109 	 * Disable secure TRIM on file based vdevs.  There is no way to
110 	 * request this behavior from the underlying filesystem.
111 	 */
112 	vd->vdev_has_securetrim = B_FALSE;
113 
114 	/*
115 	 * We must have a pathname, and it must be absolute.
116 	 */
117 	if (vd->vdev_path == NULL || vd->vdev_path[0] != '/') {
118 		vd->vdev_stat.vs_aux = VDEV_AUX_BAD_LABEL;
119 		return (SET_ERROR(EINVAL));
120 	}
121 
122 	/*
123 	 * Reopen the device if it's not currently open.  Otherwise,
124 	 * just update the physical size of the device.
125 	 */
126 	if (vd->vdev_tsd != NULL) {
127 		ASSERT(vd->vdev_reopening);
128 		vf = vd->vdev_tsd;
129 		goto skip_open;
130 	}
131 
132 	vf = vd->vdev_tsd = kmem_zalloc(sizeof (vdev_file_t), KM_SLEEP);
133 
134 	/*
135 	 * We always open the files from the root of the global zone, even if
136 	 * we're in a local zone.  If the user has gotten to this point, the
137 	 * administrator has already decided that the pool should be available
138 	 * to local zone users, so the underlying devices should be as well.
139 	 */
140 	ASSERT(vd->vdev_path != NULL && vd->vdev_path[0] == '/');
141 
142 	error = zfs_file_open(vd->vdev_path,
143 	    vdev_file_open_mode(spa_mode(vd->vdev_spa)), 0, &fp);
144 	if (error) {
145 		vd->vdev_stat.vs_aux = VDEV_AUX_OPEN_FAILED;
146 		return (error);
147 	}
148 
149 	vf->vf_file = fp;
150 
151 #ifdef _KERNEL
152 	/*
153 	 * Make sure it's a regular file.
154 	 */
155 	if (zfs_file_getattr(fp, &zfa)) {
156 		return (SET_ERROR(ENODEV));
157 	}
158 	if (!S_ISREG(zfa.zfa_mode)) {
159 		vd->vdev_stat.vs_aux = VDEV_AUX_OPEN_FAILED;
160 		return (SET_ERROR(ENODEV));
161 	}
162 #endif
163 
164 skip_open:
165 
166 	error =  zfs_file_getattr(vf->vf_file, &zfa);
167 	if (error) {
168 		vd->vdev_stat.vs_aux = VDEV_AUX_OPEN_FAILED;
169 		return (error);
170 	}
171 
172 	*max_psize = *psize = zfa.zfa_size;
173 	*logical_ashift = vdev_file_logical_ashift;
174 	*physical_ashift = vdev_file_physical_ashift;
175 
176 	return (0);
177 }
178 
179 static void
180 vdev_file_close(vdev_t *vd)
181 {
182 	vdev_file_t *vf = vd->vdev_tsd;
183 
184 	if (vd->vdev_reopening || vf == NULL)
185 		return;
186 
187 	if (vf->vf_file != NULL) {
188 		zfs_file_close(vf->vf_file);
189 	}
190 
191 	vd->vdev_delayed_close = B_FALSE;
192 	kmem_free(vf, sizeof (vdev_file_t));
193 	vd->vdev_tsd = NULL;
194 }
195 
196 /*
197  * Implements the interrupt side for file vdev types. This routine will be
198  * called when the I/O completes allowing us to transfer the I/O to the
199  * interrupt taskqs. For consistency, the code structure mimics disk vdev
200  * types.
201  */
202 static void
203 vdev_file_io_intr(zio_t *zio)
204 {
205 	zio_delay_interrupt(zio);
206 }
207 
208 static void
209 vdev_file_io_strategy(void *arg)
210 {
211 	zio_t *zio = arg;
212 	vdev_t *vd = zio->io_vd;
213 	vdev_file_t *vf;
214 	void *buf;
215 	ssize_t resid;
216 	loff_t off;
217 	ssize_t size;
218 	int err;
219 
220 	off = zio->io_offset;
221 	size = zio->io_size;
222 	resid = 0;
223 
224 	vf = vd->vdev_tsd;
225 
226 	ASSERT(zio->io_type == ZIO_TYPE_READ || zio->io_type == ZIO_TYPE_WRITE);
227 	if (zio->io_type == ZIO_TYPE_READ) {
228 		buf = abd_borrow_buf(zio->io_abd, zio->io_size);
229 		err = zfs_file_pread(vf->vf_file, buf, size, off, &resid);
230 		abd_return_buf_copy(zio->io_abd, buf, size);
231 	} else {
232 		buf = abd_borrow_buf_copy(zio->io_abd, zio->io_size);
233 		err = zfs_file_pwrite(vf->vf_file, buf, size, off, &resid);
234 		abd_return_buf(zio->io_abd, buf, size);
235 	}
236 	if (resid != 0 && zio->io_error == 0)
237 		zio->io_error = ENOSPC;
238 
239 	vdev_file_io_intr(zio);
240 }
241 
242 static void
243 vdev_file_io_start(zio_t *zio)
244 {
245 	vdev_t *vd = zio->io_vd;
246 	vdev_file_t *vf = vd->vdev_tsd;
247 
248 	if (zio->io_type == ZIO_TYPE_IOCTL) {
249 		/* XXPOLICY */
250 		if (!vdev_readable(vd)) {
251 			zio->io_error = SET_ERROR(ENXIO);
252 			zio_interrupt(zio);
253 			return;
254 		}
255 
256 		switch (zio->io_cmd) {
257 		case DKIOCFLUSHWRITECACHE:
258 			zio->io_error = zfs_file_fsync(vf->vf_file,
259 			    O_SYNC|O_DSYNC);
260 			break;
261 		default:
262 			zio->io_error = SET_ERROR(ENOTSUP);
263 		}
264 
265 		zio_execute(zio);
266 		return;
267 	} else if (zio->io_type == ZIO_TYPE_TRIM) {
268 #ifdef notyet
269 		int mode = 0;
270 
271 		ASSERT3U(zio->io_size, !=, 0);
272 
273 		/* XXX FreeBSD has no fallocate routine in file ops */
274 		zio->io_error = zfs_file_fallocate(vf->vf_file,
275 		    mode, zio->io_offset, zio->io_size);
276 #endif
277 		zio->io_error = SET_ERROR(ENOTSUP);
278 		zio_execute(zio);
279 		return;
280 	}
281 	ASSERT(zio->io_type == ZIO_TYPE_READ || zio->io_type == ZIO_TYPE_WRITE);
282 	zio->io_target_timestamp = zio_handle_io_delay(zio);
283 
284 	VERIFY3U(taskq_dispatch(vdev_file_taskq, vdev_file_io_strategy, zio,
285 	    TQ_SLEEP), !=, 0);
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_file_open,
296 	vdev_file_close,
297 	vdev_default_asize,
298 	vdev_file_io_start,
299 	vdev_file_io_done,
300 	NULL,
301 	NULL,
302 	vdev_file_hold,
303 	vdev_file_rele,
304 	NULL,
305 	vdev_default_xlate,
306 	VDEV_TYPE_FILE,		/* name of this vdev type */
307 	B_TRUE			/* leaf vdev */
308 };
309 
310 /*
311  * From userland we access disks just like files.
312  */
313 #ifndef _KERNEL
314 
315 vdev_ops_t vdev_disk_ops = {
316 	vdev_file_open,
317 	vdev_file_close,
318 	vdev_default_asize,
319 	vdev_file_io_start,
320 	vdev_file_io_done,
321 	NULL,
322 	NULL,
323 	vdev_file_hold,
324 	vdev_file_rele,
325 	NULL,
326 	vdev_default_xlate,
327 	VDEV_TYPE_DISK,		/* name of this vdev type */
328 	B_TRUE			/* leaf vdev */
329 };
330 
331 #endif
332 
333 ZFS_MODULE_PARAM(zfs_vdev_file, vdev_file_, logical_ashift, ULONG, ZMOD_RW,
334 	"Logical ashift for file-based devices");
335 ZFS_MODULE_PARAM(zfs_vdev_file, vdev_file_, physical_ashift, ULONG, ZMOD_RW,
336 	"Physical ashift for file-based devices");
337