diff options
Diffstat (limited to 'sys/kern/kern_osd.c')
-rw-r--r-- | sys/kern/kern_osd.c | 301 |
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); |