1 /* $NetBSD: dm_pdev.c,v 1.6 2010/01/04 00:19:08 haad Exp $ */
2
3 /*
4 * Copyright (c) 2010-2011 Alex Hornung <alex@alexhornung.com>
5 * Copyright (c) 2008 The NetBSD Foundation, Inc.
6 * All rights reserved.
7 *
8 * This code is derived from software contributed to The NetBSD Foundation
9 * by Adam Hamsik.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30 * POSSIBILITY OF SUCH DAMAGE.
31 */
32
33 #include <sys/disk.h>
34 #include <sys/fcntl.h>
35 #include <sys/malloc.h>
36 #include <sys/nlookup.h>
37 #include <sys/proc.h>
38
39 #include <dev/disk/dm/dm.h>
40
41 static TAILQ_HEAD(, dm_pdev) dm_pdev_list;
42
43 static struct lock dm_pdev_mutex;
44
45 static dm_pdev_t *dm_pdev_alloc(const char *);
46 static int dm_pdev_free(dm_pdev_t *);
47 static dm_pdev_t *dm_pdev_lookup_name(const char *);
48
49 /*
50 * Find used pdev with name == dm_pdev_name.
51 * needs to be called with the dm_pdev_mutex held.
52 */
53 static dm_pdev_t *
dm_pdev_lookup_name(const char * dm_pdev_name)54 dm_pdev_lookup_name(const char *dm_pdev_name)
55 {
56 dm_pdev_t *dmp;
57
58 KKASSERT(dm_pdev_name != NULL);
59
60 TAILQ_FOREACH(dmp, &dm_pdev_list, next_pdev) {
61 if (strcmp(dm_pdev_name, dmp->name) == 0)
62 return dmp;
63 }
64
65 return NULL;
66 }
67
68 static int
dm_dk_lookup(const char * dev_name,struct vnode ** vpp)69 dm_dk_lookup(const char *dev_name, struct vnode **vpp)
70 {
71 struct nlookupdata nd;
72 int error;
73
74 error = nlookup_init(&nd, dev_name, UIO_SYSSPACE, NLC_FOLLOW);
75 if (error)
76 return error;
77
78 error = vn_open(&nd, NULL, FREAD|FWRITE, 0);
79 if (error) {
80 nlookup_done(&nd);
81 return error;
82 }
83
84 *vpp = nd.nl_open_vp;
85 nd.nl_open_vp = NULL;
86 nlookup_done(&nd);
87
88 return 0;
89 }
90
91 /*
92 * Since dm can have arbitrary stacking on any number of disks and any dm
93 * volume is at least stacked onto another disk, we need to adjust the
94 * dumping offset (which is a raw offset from the beginning of the lowest
95 * physical disk) taking into account the offset of the underlying device
96 * which in turn takes into account the offset below it, etc.
97 *
98 * This function adjusts the dumping offset that is passed to the next
99 * dev_ddump() so it is correct for that underlying device.
100 */
101 off_t
dm_pdev_correct_dump_offset(dm_pdev_t * pdev,off_t offset)102 dm_pdev_correct_dump_offset(dm_pdev_t *pdev, off_t offset)
103 {
104 off_t noffset;
105
106 noffset = pdev->pdev_pinfo.reserved_blocks +
107 pdev->pdev_pinfo.media_offset / pdev->pdev_pinfo.media_blksize;
108 noffset *= DEV_BSIZE;
109 noffset += offset;
110
111 return noffset;
112 }
113
114 /*
115 * Create entry for device with name dev_name and open vnode for it.
116 * If entry already exists in global TAILQ I will only increment
117 * reference counter.
118 */
119 dm_pdev_t *
dm_pdev_insert(const char * dev_name)120 dm_pdev_insert(const char *dev_name)
121 {
122 dm_pdev_t *dmp;
123 struct vattr va;
124 int error;
125
126 KKASSERT(dev_name != NULL);
127
128 lockmgr(&dm_pdev_mutex, LK_EXCLUSIVE);
129 dmp = dm_pdev_lookup_name(dev_name);
130
131 if (dmp != NULL) {
132 dmp->ref_cnt++;
133 dmdebug("pdev %s already in tree\n", dev_name);
134 lockmgr(&dm_pdev_mutex, LK_RELEASE);
135 return dmp;
136 }
137
138 if ((dmp = dm_pdev_alloc(dev_name)) == NULL) {
139 lockmgr(&dm_pdev_mutex, LK_RELEASE);
140 return NULL;
141 }
142
143 error = dm_dk_lookup(dev_name, &dmp->pdev_vnode);
144 if (error) {
145 dmdebug("Lookup on %s failed with error %d!\n",
146 dev_name, error);
147 dm_pdev_free(dmp);
148 lockmgr(&dm_pdev_mutex, LK_RELEASE);
149 return NULL;
150 }
151 dmp->ref_cnt = 1;
152
153 if (dm_pdev_get_vattr(dmp, &va) == -1) {
154 dmdebug("getattr on %s failed\n", dev_name);
155 dm_pdev_free(dmp);
156 lockmgr(&dm_pdev_mutex, LK_RELEASE);
157 return NULL;
158 }
159 ksnprintf(dmp->udev_name, sizeof(dmp->udev_name),
160 "%d:%d", va.va_rmajor, va.va_rminor);
161 dmp->udev = dm_pdev_get_udev(dmp);
162
163 /*
164 * Get us the partinfo from the underlying device, it's needed for
165 * dumps.
166 */
167 bzero(&dmp->pdev_pinfo, sizeof(dmp->pdev_pinfo));
168 error = dev_dioctl(dmp->pdev_vnode->v_rdev, DIOCGPART,
169 (void *)&dmp->pdev_pinfo, 0, proc0.p_ucred, NULL, NULL);
170 if (!error) {
171 struct partinfo *dpart = &dmp->pdev_pinfo;
172 dmdebug("DIOCGPART offset=%ju size=%ju blocks=%ju blksize=%d\n",
173 dpart->media_offset,
174 dpart->media_size,
175 dpart->media_blocks,
176 dpart->media_blksize);
177 } else {
178 kprintf("dmp_pdev_insert DIOCGPART failed %d\n", error);
179 }
180
181 TAILQ_INSERT_TAIL(&dm_pdev_list, dmp, next_pdev);
182 lockmgr(&dm_pdev_mutex, LK_RELEASE);
183
184 dmdebug("pdev %s %s 0x%016jx\n",
185 dmp->name, dmp->udev_name, (uintmax_t)dmp->udev);
186
187 return dmp;
188 }
189
190 /*
191 * Allocat new pdev structure if is not already present and
192 * set name.
193 */
194 static dm_pdev_t *
dm_pdev_alloc(const char * name)195 dm_pdev_alloc(const char *name)
196 {
197 dm_pdev_t *dmp;
198
199 dmp = kmalloc(sizeof(*dmp), M_DM, M_WAITOK | M_ZERO);
200 if (dmp == NULL)
201 return NULL;
202
203 if (name)
204 strlcpy(dmp->name, name, DM_MAX_DEV_NAME);
205
206 return dmp;
207 }
208
209 /*
210 * Destroy allocated dm_pdev.
211 */
212 static int
dm_pdev_free(dm_pdev_t * dmp)213 dm_pdev_free(dm_pdev_t *dmp)
214 {
215 int err;
216
217 KKASSERT(dmp != NULL);
218
219 if (dmp->pdev_vnode != NULL) {
220 err = vn_close(dmp->pdev_vnode, FREAD | FWRITE, NULL);
221 if (err != 0) {
222 kfree(dmp, M_DM);
223 return err;
224 }
225 }
226 kfree(dmp, M_DM);
227
228 return 0;
229 }
230
231 /*
232 * This funcion is called from targets' destroy() handler.
233 * When I'm removing device from list, I have to decrement
234 * reference counter. If reference counter is 0 I will remove
235 * dmp from global list and from device list to. And I will CLOSE
236 * dmp vnode too.
237 */
238 /*
239 * Decrement pdev reference counter if 0 remove it.
240 */
241 int
dm_pdev_decr(dm_pdev_t * dmp)242 dm_pdev_decr(dm_pdev_t *dmp)
243 {
244 KKASSERT(dmp != NULL);
245 /*
246 * If this was last reference remove dmp from
247 * global list also.
248 */
249 lockmgr(&dm_pdev_mutex, LK_EXCLUSIVE);
250
251 if (--dmp->ref_cnt == 0) {
252 TAILQ_REMOVE(&dm_pdev_list, dmp, next_pdev);
253 lockmgr(&dm_pdev_mutex, LK_RELEASE);
254 dm_pdev_free(dmp);
255 return 0;
256 }
257 lockmgr(&dm_pdev_mutex, LK_RELEASE);
258 return 0;
259 }
260
261 uint64_t
dm_pdev_get_udev(dm_pdev_t * dmp)262 dm_pdev_get_udev(dm_pdev_t *dmp)
263 {
264 struct vattr va;
265 int ret;
266
267 if (dmp->pdev_vnode == NULL)
268 return (uint64_t)-1;
269
270 ret = dm_pdev_get_vattr(dmp, &va);
271 if (ret)
272 return (uint64_t)-1;
273
274 ret = makeudev(va.va_rmajor, va.va_rminor);
275
276 return ret;
277 }
278
279 int
dm_pdev_get_vattr(dm_pdev_t * dmp,struct vattr * vap)280 dm_pdev_get_vattr(dm_pdev_t *dmp, struct vattr *vap)
281 {
282 int ret;
283
284 if (dmp->pdev_vnode == NULL)
285 return -1;
286
287 KKASSERT(vap);
288 ret = VOP_GETATTR(dmp->pdev_vnode, vap);
289 if (ret)
290 return -1;
291
292 return 0;
293 }
294
295 /*
296 * Initialize pdev subsystem.
297 */
298 int
dm_pdev_init(void)299 dm_pdev_init(void)
300 {
301 TAILQ_INIT(&dm_pdev_list); /* initialize global pdev list */
302 lockinit(&dm_pdev_mutex, "dmpdev", 0, LK_CANRECURSE);
303
304 return 0;
305 }
306
307 /*
308 * Destroy all existing pdev's in device-mapper.
309 */
310 int
dm_pdev_uninit(void)311 dm_pdev_uninit(void)
312 {
313 dm_pdev_t *dmp;
314
315 lockmgr(&dm_pdev_mutex, LK_EXCLUSIVE);
316
317 while ((dmp = TAILQ_FIRST(&dm_pdev_list)) != NULL) {
318 TAILQ_REMOVE(&dm_pdev_list, dmp, next_pdev);
319 dm_pdev_free(dmp);
320 }
321 KKASSERT(TAILQ_EMPTY(&dm_pdev_list));
322
323 lockmgr(&dm_pdev_mutex, LK_RELEASE);
324
325 lockuninit(&dm_pdev_mutex);
326 return 0;
327 }
328