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-rw-r--r--sys/dev/dm/dm_pdev.c246
1 files changed, 246 insertions, 0 deletions
diff --git a/sys/dev/dm/dm_pdev.c b/sys/dev/dm/dm_pdev.c
new file mode 100644
index 00000000000..b04d2cd7b14
--- /dev/null
+++ b/sys/dev/dm/dm_pdev.c
@@ -0,0 +1,246 @@
+/* $NetBSD: dm_pdev.c,v 1.2 2008/12/19 15:24:03 haad Exp $ */
+
+/*
+ * Copyright (c) 2008 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by Adam Hamsik.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/types.h>
+#include <sys/param.h>
+
+#include <sys/disk.h>
+#include <sys/fcntl.h>
+#include <sys/kmem.h>
+#include <sys/namei.h>
+#include <sys/vnode.h>
+
+#include <dev/dkvar.h>
+
+#include "dm.h"
+
+SLIST_HEAD(dm_pdevs, dm_pdev) dm_pdev_list;
+
+kmutex_t dm_pdev_mutex;
+
+static dm_pdev_t *dm_pdev_alloc(const char *);
+static int dm_pdev_rem(dm_pdev_t *);
+static dm_pdev_t* dm_pdev_lookup_name(const char *);
+
+/*
+ * Find used pdev with name == dm_pdev_name.
+ */
+dm_pdev_t*
+dm_pdev_lookup_name(const char *dm_pdev_name)
+{
+ dm_pdev_t *dm_pdev;
+ int dlen; int slen;
+
+ KASSERT(dm_pdev_name != NULL);
+
+ slen = strlen(dm_pdev_name);
+
+ SLIST_FOREACH(dm_pdev, &dm_pdev_list, next_pdev) {
+ dlen = strlen(dm_pdev->name);
+
+ if (slen != dlen)
+ continue;
+
+ if (strncmp(dm_pdev_name, dm_pdev->name, slen) == 0)
+ return dm_pdev;
+ }
+
+ return NULL;
+}
+
+/*
+ * Create entry for device with name dev_name and open vnode for it.
+ * If entry already exists in global SLIST I will only increment
+ * reference counter.
+ */
+dm_pdev_t*
+dm_pdev_insert(const char *dev_name)
+{
+ dm_pdev_t *dmp;
+ int error;
+
+ KASSERT(dev_name != NULL);
+
+ mutex_enter(&dm_pdev_mutex);
+ dmp = dm_pdev_lookup_name(dev_name);
+
+ if (dmp != NULL) {
+ dmp->ref_cnt++;
+ aprint_verbose("dmp_pdev_insert pdev %s already in tree\n",dev_name);
+ mutex_exit(&dm_pdev_mutex);
+ return dmp;
+ }
+ mutex_exit(&dm_pdev_mutex);
+
+ if ((dmp = dm_pdev_alloc(dev_name)) == NULL)
+ return NULL;
+
+ error = dk_lookup(dev_name, curlwp, &dmp->pdev_vnode, UIO_SYSSPACE);
+ if (error) {
+ aprint_verbose("dk_lookup on device: %s failed with error %d!\n",
+ dev_name, error);
+ kmem_free(dmp, sizeof(dm_pdev_t));
+ return NULL;
+ }
+
+ dmp->ref_cnt = 1;
+
+ mutex_enter(&dm_pdev_mutex);
+ SLIST_INSERT_HEAD(&dm_pdev_list, dmp, next_pdev);
+ mutex_exit(&dm_pdev_mutex);
+
+ return dmp;
+}
+
+/*
+ * Initialize pdev subsystem.
+ */
+int
+dm_pdev_init(void)
+{
+ SLIST_INIT(&dm_pdev_list); /* initialize global pdev list */
+ mutex_init(&dm_pdev_mutex, MUTEX_DEFAULT, IPL_NONE);
+
+ return 0;
+}
+
+/*
+ * Allocat new pdev structure if is not already present and
+ * set name.
+ */
+static dm_pdev_t*
+dm_pdev_alloc(const char *name)
+{
+ dm_pdev_t *dmp;
+
+ if ((dmp = kmem_zalloc(sizeof(dm_pdev_t), KM_NOSLEEP)) == NULL)
+ return NULL;
+
+ strlcpy(dmp->name, name, MAX_DEV_NAME);
+
+ dmp->ref_cnt = 0;
+ dmp->pdev_vnode = NULL;
+
+ return dmp;
+}
+
+/*
+ * Destroy allocated dm_pdev.
+ */
+static int
+dm_pdev_rem(dm_pdev_t *dmp)
+{
+ int err;
+
+ KASSERT(dmp != NULL);
+
+ if (dmp->pdev_vnode != NULL) {
+ err = vn_close(dmp->pdev_vnode, FREAD | FWRITE, FSCRED);
+ if (err != 0)
+ return err;
+ }
+
+ kmem_free(dmp, sizeof(*dmp));
+ dmp = NULL;
+
+ return 0;
+}
+
+/*
+ * Destroy all existing pdev's in device-mapper.
+ */
+int
+dm_pdev_destroy(void)
+{
+ dm_pdev_t *dm_pdev;
+
+ mutex_enter(&dm_pdev_mutex);
+ while (!SLIST_EMPTY(&dm_pdev_list)) { /* List Deletion. */
+
+ dm_pdev = SLIST_FIRST(&dm_pdev_list);
+
+ SLIST_REMOVE_HEAD(&dm_pdev_list, next_pdev);
+
+ dm_pdev_rem(dm_pdev);
+ }
+ mutex_exit(&dm_pdev_mutex);
+
+ mutex_destroy(&dm_pdev_mutex);
+ return 0;
+}
+
+/*
+ * This funcion is called from dm_dev_remove_ioctl.
+ * When I'm removing device from list, I have to decrement
+ * reference counter. If reference counter is 0 I will remove
+ * dmp from global list and from device list to. And I will CLOSE
+ * dmp vnode too.
+ */
+
+/*
+ * Decrement pdev reference counter if 0 remove it.
+ */
+int
+dm_pdev_decr(dm_pdev_t *dmp)
+{
+ KASSERT(dmp != NULL);
+ /*
+ * If this was last reference remove dmp from
+ * global list also.
+ */
+ mutex_enter(&dm_pdev_mutex);
+
+ if (--dmp->ref_cnt == 0) {
+ SLIST_REMOVE(&dm_pdev_list, dmp, dm_pdev, next_pdev);
+ mutex_exit(&dm_pdev_mutex);
+ dm_pdev_rem(dmp);
+ return 0;
+ }
+
+ mutex_exit(&dm_pdev_mutex);
+ return 0;
+}
+
+/*static int
+ dm_pdev_dump_list()
+ {
+ dm_pdev_t *dmp;
+
+ aprint_verbose("Dumping dm_pdev_list \n");
+
+ SLIST_FOREACH(dmp, &dm_pdev_list, next_pdev) {
+ aprint_verbose("dm_pdev_name %s ref_cnt %d list_rf_cnt %d\n",
+ dmp->name, dmp->ref_cnt, dmp->list_ref_cnt);
+ }
+
+ return 0;
+
+ }*/