1 /* $NetBSD: dm_pdev.c,v 1.6 2010/01/04 00:19:08 haad Exp $ */
4 * Copyright (c) 2008 The NetBSD Foundation, Inc.
7 * This code is derived from software contributed to The NetBSD Foundation
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
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.
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.
32 #include <sys/types.h>
33 #include <sys/param.h>
36 #include <sys/fcntl.h>
37 #include <sys/malloc.h>
38 #include <sys/namei.h>
39 #include <sys/vnode.h>
40 #include <sys/nlookup.h>
44 SLIST_HEAD(dm_pdevs, dm_pdev) dm_pdev_list;
46 struct lock dm_pdev_mutex;
48 static dm_pdev_t *dm_pdev_alloc(const char *);
49 static int dm_pdev_rem(dm_pdev_t *);
50 static dm_pdev_t *dm_pdev_lookup_name(const char *);
53 * Find used pdev with name == dm_pdev_name.
54 * needs to be called with the dm_pdev_mutex held.
57 dm_pdev_lookup_name(const char *dm_pdev_name)
61 KKASSERT(dm_pdev_name != NULL);
63 SLIST_FOREACH(dm_pdev, &dm_pdev_list, next_pdev) {
64 if (strcmp(dm_pdev_name, dm_pdev->name) == 0)
72 dm_dk_lookup(const char *dev_name, struct vnode **vpp)
74 struct nlookupdata nd;
77 error = nlookup_init(&nd, dev_name, UIO_SYSSPACE, NLC_FOLLOW);
81 error = vn_open(&nd, NULL, FREAD|FWRITE, 0);
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.
96 * This function adjusts the dumping offset that is passed to the next
97 * dev_ddump() so it is correct for that underlying device.
100 dm_pdev_correct_dump_offset(dm_pdev_t *pdev, off_t offset)
104 noffset = pdev->pdev_pinfo.reserved_blocks +
105 pdev->pdev_pinfo.media_offset / pdev->pdev_pinfo.media_blksize;
106 noffset *= DEV_BSIZE;
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
118 dm_pdev_insert(const char *dev_name)
123 KKASSERT(dev_name != NULL);
125 lockmgr(&dm_pdev_mutex, LK_EXCLUSIVE);
126 dmp = dm_pdev_lookup_name(dev_name);
130 aprint_debug("dmp_pdev_insert pdev %s already in tree\n", dev_name);
131 lockmgr(&dm_pdev_mutex, LK_RELEASE);
134 lockmgr(&dm_pdev_mutex, LK_RELEASE);
136 if ((dmp = dm_pdev_alloc(dev_name)) == NULL)
139 error = dm_dk_lookup(dev_name, &dmp->pdev_vnode);
141 aprint_debug("dk_lookup on device: %s failed with error %d!\n",
149 * Get us the partinfo from the underlying device, it's needed for
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);
156 lockmgr(&dm_pdev_mutex, LK_EXCLUSIVE);
157 SLIST_INSERT_HEAD(&dm_pdev_list, dmp, next_pdev);
158 lockmgr(&dm_pdev_mutex, LK_RELEASE);
163 * Initialize pdev subsystem.
168 SLIST_INIT(&dm_pdev_list); /* initialize global pdev list */
169 lockinit(&dm_pdev_mutex, "dmpdev", 0, LK_CANRECURSE);
174 * Allocat new pdev structure if is not already present and
178 dm_pdev_alloc(const char *name)
182 if ((dmp = kmalloc(sizeof(dm_pdev_t), M_DM, M_WAITOK | M_ZERO)) == NULL)
185 strlcpy(dmp->name, name, MAX_DEV_NAME);
188 dmp->pdev_vnode = NULL;
193 * Destroy allocated dm_pdev.
196 dm_pdev_rem(dm_pdev_t * dmp)
200 KKASSERT(dmp != NULL);
202 if (dmp->pdev_vnode != NULL) {
203 err = vn_close(dmp->pdev_vnode, FREAD | FWRITE);
213 * Destroy all existing pdev's in device-mapper.
216 dm_pdev_destroy(void)
220 lockmgr(&dm_pdev_mutex, LK_EXCLUSIVE);
221 while (!SLIST_EMPTY(&dm_pdev_list)) { /* List Deletion. */
223 dm_pdev = SLIST_FIRST(&dm_pdev_list);
225 SLIST_REMOVE_HEAD(&dm_pdev_list, next_pdev);
227 dm_pdev_rem(dm_pdev);
229 lockmgr(&dm_pdev_mutex, LK_RELEASE);
231 lockuninit(&dm_pdev_mutex);
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
243 * Decrement pdev reference counter if 0 remove it.
246 dm_pdev_decr(dm_pdev_t * dmp)
248 KKASSERT(dmp != NULL);
250 * If this was last reference remove dmp from
253 lockmgr(&dm_pdev_mutex, LK_EXCLUSIVE);
255 if (--dmp->ref_cnt == 0) {
256 SLIST_REMOVE(&dm_pdev_list, dmp, dm_pdev, next_pdev);
257 lockmgr(&dm_pdev_mutex, LK_RELEASE);
261 lockmgr(&dm_pdev_mutex, LK_RELEASE);