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-rw-r--r--sys/kern/kern_osd.c301
1 files changed, 301 insertions, 0 deletions
diff --git a/sys/kern/kern_osd.c b/sys/kern/kern_osd.c
new file mode 100644
index 0000000..d9563e6
--- /dev/null
+++ b/sys/kern/kern_osd.c
@@ -0,0 +1,301 @@
+/*-
+ * Copyright (c) 2007 Pawel Jakub Dawidek <pjd@FreeBSD.org>
+ * All rights reserved.
+ *
+ * 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 AUTHORS 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 AUTHORS 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/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+#include <sys/kernel.h>
+#include <sys/systm.h>
+#include <sys/sysctl.h>
+#include <sys/errno.h>
+#include <sys/malloc.h>
+#include <sys/lock.h>
+#include <sys/mutex.h>
+#include <sys/queue.h>
+#include <sys/proc.h>
+#include <sys/osd.h>
+
+/* OSD (Object Specific Data) */
+
+static MALLOC_DEFINE(M_OSD, "osd", "Object Specific Data");
+
+static int osd_debug = 0;
+TUNABLE_INT("debug.osd", &osd_debug);
+SYSCTL_INT(_debug, OID_AUTO, osd, CTLFLAG_RW, &osd_debug, 0, "OSD debug level");
+
+#define OSD_DEBUG(...) do { \
+ if (osd_debug) { \
+ printf("OSD (%s:%u): ", __func__, __LINE__); \
+ printf(__VA_ARGS__); \
+ printf("\n"); \
+ } \
+} while (0)
+
+/*
+ * Lists of objects with OSD.
+ */
+static LIST_HEAD(, osd) osd_list[OSD_LAST + 1];
+static osd_destructor_t *osd_destructors[OSD_LAST + 1];
+static u_int osd_nslots[OSD_LAST + 1];
+static struct mtx osd_lock[OSD_LAST + 1];
+
+static void
+osd_default_destructor(void *value __unused)
+{
+ /* Do nothing. */
+}
+
+int
+osd_register(u_int type, osd_destructor_t destructor)
+{
+ void *newptr;
+ u_int i;
+
+ KASSERT(type >= OSD_FIRST && type <= OSD_LAST, ("Invalid type."));
+
+ /*
+ * If no destructor is given, use default one. We need to use some
+ * destructor, because NULL destructor means unused slot.
+ */
+ if (destructor == NULL)
+ destructor = osd_default_destructor;
+
+ mtx_lock(&osd_lock[type]);
+ /*
+ * First, we try to find unused slot.
+ */
+ for (i = 0; i < osd_nslots[type]; i++) {
+ if (osd_destructors[type][i] == NULL) {
+ OSD_DEBUG("Unused slot found (type=%u, slot=%u).",
+ type, i);
+ break;
+ }
+ }
+ /*
+ * If no unused slot was found, allocate one.
+ */
+ if (i == osd_nslots[type]) {
+ osd_nslots[type]++;
+ newptr = realloc(osd_destructors[type],
+ sizeof(osd_destructor_t) * osd_nslots[type], M_OSD,
+ M_NOWAIT | M_ZERO);
+ if (newptr == NULL) {
+ mtx_unlock(&osd_lock[type]);
+ return (0);
+ }
+ osd_destructors[type] = newptr;
+ OSD_DEBUG("New slot allocated (type=%u, slot=%u).",
+ type, i + 1);
+ }
+ osd_destructors[type][i] = destructor;
+ mtx_unlock(&osd_lock[type]);
+ return (i + 1);
+}
+
+void
+osd_deregister(u_int type, u_int slot)
+{
+ struct osd *osd, *tosd;
+
+ KASSERT(type >= OSD_FIRST && type <= OSD_LAST, ("Invalid type."));
+ KASSERT(slot > 0, ("Invalid slot."));
+ KASSERT(osd_destructors[type][slot - 1] != NULL, ("Unused slot."));
+
+ mtx_lock(&osd_lock[type]);
+ /*
+ * Free all OSD for the given slot.
+ */
+ LIST_FOREACH_SAFE(osd, &osd_list[type], osd_next, tosd) {
+ osd_del(type, osd, slot);
+ }
+ /*
+ * Set destructor to NULL to free the slot.
+ */
+ osd_destructors[type][slot - 1] = NULL;
+ if (slot == osd_nslots[type]) {
+ osd_nslots[type]--;
+ osd_destructors[type] = realloc(osd_destructors[type],
+ sizeof(osd_destructor_t) * osd_nslots[type], M_OSD,
+ M_NOWAIT | M_ZERO);
+ /*
+ * We always reallocate to smaller size, so we assume it will
+ * always succeed.
+ */
+ KASSERT(osd_destructors[type] != NULL, ("realloc() failed"));
+ OSD_DEBUG("Deregistration of the last slot (type=%u, slot=%u).",
+ type, slot);
+ } else {
+ OSD_DEBUG("Slot deregistration (type=%u, slot=%u).",
+ type, slot);
+ }
+ mtx_unlock(&osd_lock[type]);
+}
+
+int
+osd_set(u_int type, struct osd *osd, u_int slot, void *value)
+{
+
+ KASSERT(type >= OSD_FIRST && type <= OSD_LAST, ("Invalid type."));
+ KASSERT(slot > 0, ("Invalid slot."));
+ KASSERT(osd_destructors[type][slot - 1] != NULL, ("Unused slot."));
+
+ if (osd->osd_nslots == 0) {
+ /*
+ * First OSD for this object, so we need to allocate space and
+ * put it onto the list.
+ */
+ osd->osd_slots = malloc(sizeof(void *) * slot, M_OSD,
+ M_NOWAIT | M_ZERO);
+ if (osd->osd_slots == NULL)
+ return (ENOMEM);
+ osd->osd_nslots = slot;
+ mtx_lock(&osd_lock[type]);
+ LIST_INSERT_HEAD(&osd_list[type], osd, osd_next);
+ mtx_unlock(&osd_lock[type]);
+ OSD_DEBUG("Setting first slot (type=%u).", type);
+ } else if (slot > osd->osd_nslots) {
+ void *newptr;
+
+ /*
+ * Too few slots allocated here, needs to extend the array.
+ */
+ newptr = realloc(osd->osd_slots, sizeof(void *) * slot, M_OSD,
+ M_NOWAIT | M_ZERO);
+ if (newptr == NULL)
+ return (ENOMEM);
+ osd->osd_slots = newptr;
+ osd->osd_nslots = slot;
+ OSD_DEBUG("Growing slots array (type=%u).", type);
+ }
+ OSD_DEBUG("Setting slot value (type=%u, slot=%u, value=%p).", type,
+ slot, value);
+ osd->osd_slots[slot - 1] = value;
+ return (0);
+}
+
+void *
+osd_get(u_int type, struct osd *osd, u_int slot)
+{
+
+ KASSERT(type >= OSD_FIRST && type <= OSD_LAST, ("Invalid type."));
+ KASSERT(slot > 0, ("Invalid slot."));
+ KASSERT(osd_destructors[type][slot - 1] != NULL, ("Unused slot."));
+
+ if (slot > osd->osd_nslots) {
+ OSD_DEBUG("Slot doesn't exist (type=%u, slot=%u).", type, slot);
+ return (NULL);
+ }
+
+ OSD_DEBUG("Returning slot value (type=%u, slot=%u, value=%p).", type,
+ slot, osd->osd_slots[slot - 1]);
+ return (osd->osd_slots[slot - 1]);
+}
+
+void
+osd_del(u_int type, struct osd *osd, u_int slot)
+{
+ int i;
+
+ KASSERT(type >= OSD_FIRST && type <= OSD_LAST, ("Invalid type."));
+ KASSERT(slot > 0, ("Invalid slot."));
+ KASSERT(osd_destructors[type][slot - 1] != NULL, ("Unused slot."));
+
+ OSD_DEBUG("Deleting slot (type=%u, slot=%u).", type, slot);
+
+ if (slot > osd->osd_nslots) {
+ OSD_DEBUG("Slot doesn't exist (type=%u, slot=%u).", type, slot);
+ return;
+ }
+ osd_destructors[type][slot - 1](osd->osd_slots[slot - 1]);
+ osd->osd_slots[slot - 1] = NULL;
+ for (i = osd->osd_nslots - 1; i >= 0; i--) {
+ if (osd->osd_slots[i] != NULL) {
+ OSD_DEBUG("Slot still has a value (type=%u, slot=%u).", type, i + 1);
+ break;
+ }
+ }
+ if (i == -1) {
+ int unlock;
+
+ /* No values left for this object. */
+ OSD_DEBUG("No more slots left (type=%u).", type);
+ if ((unlock = !mtx_owned(&osd_lock[type])))
+ mtx_lock(&osd_lock[type]);
+ LIST_REMOVE(osd, osd_next);
+ if (unlock)
+ mtx_unlock(&osd_lock[type]);
+ free(osd->osd_slots, M_OSD);
+ osd->osd_slots = NULL;
+ osd->osd_nslots = 0;
+ } else if (slot == osd->osd_nslots) {
+ /* This was the last slot. */
+ osd->osd_slots = realloc(osd->osd_slots,
+ sizeof(void *) * (i + 1), M_OSD, M_NOWAIT | M_ZERO);
+ /*
+ * We always reallocate to smaller size, so we assume it will
+ * always succeed.
+ */
+ KASSERT(osd->osd_slots != NULL, ("realloc() failed"));
+ osd->osd_nslots = i + 1;
+ OSD_DEBUG("Reducing slots array to %u (type=%u).",
+ osd->osd_nslots, type);
+ }
+}
+
+void
+osd_exit(u_int type, struct osd *osd)
+{
+ u_int i;
+
+ KASSERT(type >= OSD_FIRST && type <= OSD_LAST, ("Invalid type."));
+
+ if (osd->osd_nslots == 0) {
+ KASSERT(osd->osd_slots == NULL, ("Non-null osd_slots."));
+ /* No OSD attached, just leave. */
+ return;
+ }
+
+ mtx_lock(&osd_lock[type]);
+ for (i = 1; i <= osd->osd_nslots; i++)
+ osd_del(type, osd, i);
+ mtx_unlock(&osd_lock[type]);
+ OSD_DEBUG("Object exit (type=%u).", type);
+}
+
+static void
+osd_init(void *arg __unused)
+{
+ u_int i;
+
+ for (i = OSD_FIRST; i <= OSD_LAST; i++) {
+ osd_nslots[i] = 0;
+ LIST_INIT(&osd_list[i]);
+ mtx_init(&osd_lock[i], "osd", NULL, MTX_DEF);
+ osd_destructors[i] = NULL;
+ }
+}
+SYSINIT(osd, SI_SUB_LOCK, SI_ORDER_ANY, osd_init, NULL);
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