dm - undo my pointless moving of dm.h
[dragonfly.git] / sys / dev / disk / dm / dm_pdev.c
CommitLineData
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1/* $NetBSD: dm_pdev.c,v 1.6 2010/01/04 00:19:08 haad Exp $ */
2
3/*
4 * Copyright (c) 2008 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Adam Hamsik.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32#include <sys/types.h>
33#include <sys/param.h>
34
35#include <sys/disk.h>
36#include <sys/fcntl.h>
5b279a20 37#include <sys/malloc.h>
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38#include <sys/namei.h>
39#include <sys/vnode.h>
5b279a20 40#include <sys/nlookup.h>
ff56536e 41
a84e173e 42#include <dev/disk/dm/dm.h>
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43
44SLIST_HEAD(dm_pdevs, dm_pdev) dm_pdev_list;
45
add6c27f 46struct lock dm_pdev_mutex;
ff56536e 47
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48static dm_pdev_t *dm_pdev_alloc(const char *);
49static int dm_pdev_rem(dm_pdev_t *);
50static dm_pdev_t *dm_pdev_lookup_name(const char *);
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51
52/*
53 * Find used pdev with name == dm_pdev_name.
add6c27f 54 * needs to be called with the dm_pdev_mutex held.
ff56536e 55 */
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56static dm_pdev_t *
57dm_pdev_lookup_name(const char *dm_pdev_name)
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58{
59 dm_pdev_t *dm_pdev;
ff56536e 60
5b279a20 61 KKASSERT(dm_pdev_name != NULL);
ff56536e 62
ff56536e 63 SLIST_FOREACH(dm_pdev, &dm_pdev_list, next_pdev) {
add6c27f 64 if (strcmp(dm_pdev_name, dm_pdev->name) == 0)
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65 return dm_pdev;
66 }
67
68 return NULL;
69}
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70
71static int
72dm_dk_lookup(const char *dev_name, struct vnode **vpp)
73{
74 struct nlookupdata nd;
75 int error;
76
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77 error = nlookup_init(&nd, dev_name, UIO_SYSSPACE, NLC_FOLLOW);
78 if (error)
79 return error;
80
81 error = vn_open(&nd, NULL, FREAD|FWRITE, 0);
82 *vpp = nd.nl_open_vp;
83 nd.nl_open_vp = NULL;
84 nlookup_done(&nd);
85
86 return 0;
87}
88
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89/*
90 * Since dm can have arbitrary stacking on any number of disks and any dm
91 * volume is at least stacked onto another disk, we need to adjust the
92 * dumping offset (which is a raw offset from the beginning of the lowest
93 * physical disk) taking into account the offset of the underlying device
94 * which in turn takes into account the offset below it, etc.
95 *
96 * This function adjusts the dumping offset that is passed to the next
97 * dev_ddump() so it is correct for that underlying device.
98 */
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99off_t
100dm_pdev_correct_dump_offset(dm_pdev_t *pdev, off_t offset)
101{
102 off_t noffset;
103
104 noffset = pdev->pdev_pinfo.reserved_blocks +
105 pdev->pdev_pinfo.media_offset / pdev->pdev_pinfo.media_blksize;
106 noffset *= DEV_BSIZE;
107 noffset += offset;
108
109 return noffset;
110}
111
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112/*
113 * Create entry for device with name dev_name and open vnode for it.
114 * If entry already exists in global SLIST I will only increment
115 * reference counter.
116 */
117dm_pdev_t *
118dm_pdev_insert(const char *dev_name)
119{
120 dm_pdev_t *dmp;
121 int error;
122
5b279a20 123 KKASSERT(dev_name != NULL);
ff56536e 124
5b279a20 125 lockmgr(&dm_pdev_mutex, LK_EXCLUSIVE);
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126 dmp = dm_pdev_lookup_name(dev_name);
127
128 if (dmp != NULL) {
129 dmp->ref_cnt++;
130 aprint_debug("dmp_pdev_insert pdev %s already in tree\n", dev_name);
5b279a20 131 lockmgr(&dm_pdev_mutex, LK_RELEASE);
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132 return dmp;
133 }
5b279a20 134 lockmgr(&dm_pdev_mutex, LK_RELEASE);
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135
136 if ((dmp = dm_pdev_alloc(dev_name)) == NULL)
137 return NULL;
138
5b279a20 139 error = dm_dk_lookup(dev_name, &dmp->pdev_vnode);
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140 if (error) {
141 aprint_debug("dk_lookup on device: %s failed with error %d!\n",
142 dev_name, error);
5b279a20 143 kfree(dmp, M_DM);
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144 return NULL;
145 }
146 dmp->ref_cnt = 1;
147
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148 /*
149 * Get us the partinfo from the underlying device, it's needed for
150 * dumps.
151 */
152 bzero(&dmp->pdev_pinfo, sizeof(dmp->pdev_pinfo));
153 error = dev_dioctl(dmp->pdev_vnode->v_rdev, DIOCGPART,
154 (void *)&dmp->pdev_pinfo, 0, proc0.p_ucred, NULL);
155
5b279a20 156 lockmgr(&dm_pdev_mutex, LK_EXCLUSIVE);
ff56536e 157 SLIST_INSERT_HEAD(&dm_pdev_list, dmp, next_pdev);
5b279a20 158 lockmgr(&dm_pdev_mutex, LK_RELEASE);
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159
160 return dmp;
161}
162/*
163 * Initialize pdev subsystem.
164 */
165int
166dm_pdev_init(void)
167{
168 SLIST_INIT(&dm_pdev_list); /* initialize global pdev list */
5b279a20 169 lockinit(&dm_pdev_mutex, "dmpdev", 0, LK_CANRECURSE);
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170
171 return 0;
172}
173/*
174 * Allocat new pdev structure if is not already present and
175 * set name.
176 */
177static dm_pdev_t *
178dm_pdev_alloc(const char *name)
179{
180 dm_pdev_t *dmp;
181
5b279a20 182 if ((dmp = kmalloc(sizeof(dm_pdev_t), M_DM, M_WAITOK | M_ZERO)) == NULL)
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183 return NULL;
184
185 strlcpy(dmp->name, name, MAX_DEV_NAME);
186
187 dmp->ref_cnt = 0;
188 dmp->pdev_vnode = NULL;
189
190 return dmp;
191}
192/*
193 * Destroy allocated dm_pdev.
194 */
195static int
196dm_pdev_rem(dm_pdev_t * dmp)
197{
198 int err;
199
5b279a20 200 KKASSERT(dmp != NULL);
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201
202 if (dmp->pdev_vnode != NULL) {
5b279a20 203 err = vn_close(dmp->pdev_vnode, FREAD | FWRITE);
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204 if (err != 0)
205 return err;
206 }
5b279a20 207 kfree(dmp, M_DM);
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208 dmp = NULL;
209
210 return 0;
211}
212/*
213 * Destroy all existing pdev's in device-mapper.
214 */
215int
216dm_pdev_destroy(void)
217{
218 dm_pdev_t *dm_pdev;
219
5b279a20 220 lockmgr(&dm_pdev_mutex, LK_EXCLUSIVE);
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221 while (!SLIST_EMPTY(&dm_pdev_list)) { /* List Deletion. */
222
223 dm_pdev = SLIST_FIRST(&dm_pdev_list);
224
225 SLIST_REMOVE_HEAD(&dm_pdev_list, next_pdev);
226
227 dm_pdev_rem(dm_pdev);
228 }
5b279a20 229 lockmgr(&dm_pdev_mutex, LK_RELEASE);
ff56536e 230
5b279a20 231 lockuninit(&dm_pdev_mutex);
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232 return 0;
233}
234/*
235 * This funcion is called from dm_dev_remove_ioctl.
236 * When I'm removing device from list, I have to decrement
237 * reference counter. If reference counter is 0 I will remove
238 * dmp from global list and from device list to. And I will CLOSE
239 * dmp vnode too.
240 */
241
242/*
243 * Decrement pdev reference counter if 0 remove it.
244 */
245int
246dm_pdev_decr(dm_pdev_t * dmp)
247{
5b279a20 248 KKASSERT(dmp != NULL);
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249 /*
250 * If this was last reference remove dmp from
251 * global list also.
252 */
5b279a20 253 lockmgr(&dm_pdev_mutex, LK_EXCLUSIVE);
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254
255 if (--dmp->ref_cnt == 0) {
256 SLIST_REMOVE(&dm_pdev_list, dmp, dm_pdev, next_pdev);
5b279a20 257 lockmgr(&dm_pdev_mutex, LK_RELEASE);
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258 dm_pdev_rem(dmp);
259 return 0;
260 }
5b279a20 261 lockmgr(&dm_pdev_mutex, LK_RELEASE);
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262 return 0;
263}