diff options
Diffstat (limited to 'ANDROID_3.4.5/fs/ocfs2/dlm/dlmmaster.c')
-rw-r--r-- | ANDROID_3.4.5/fs/ocfs2/dlm/dlmmaster.c | 3414 |
1 files changed, 0 insertions, 3414 deletions
diff --git a/ANDROID_3.4.5/fs/ocfs2/dlm/dlmmaster.c b/ANDROID_3.4.5/fs/ocfs2/dlm/dlmmaster.c deleted file mode 100644 index 005261c3..00000000 --- a/ANDROID_3.4.5/fs/ocfs2/dlm/dlmmaster.c +++ /dev/null @@ -1,3414 +0,0 @@ -/* -*- mode: c; c-basic-offset: 8; -*- - * vim: noexpandtab sw=8 ts=8 sts=0: - * - * dlmmod.c - * - * standalone DLM module - * - * Copyright (C) 2004 Oracle. All rights reserved. - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public - * License as published by the Free Software Foundation; either - * version 2 of the License, or (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - * General Public License for more details. - * - * You should have received a copy of the GNU General Public - * License along with this program; if not, write to the - * Free Software Foundation, Inc., 59 Temple Place - Suite 330, - * Boston, MA 021110-1307, USA. - * - */ - - -#include <linux/module.h> -#include <linux/fs.h> -#include <linux/types.h> -#include <linux/slab.h> -#include <linux/highmem.h> -#include <linux/init.h> -#include <linux/sysctl.h> -#include <linux/random.h> -#include <linux/blkdev.h> -#include <linux/socket.h> -#include <linux/inet.h> -#include <linux/spinlock.h> -#include <linux/delay.h> - - -#include "cluster/heartbeat.h" -#include "cluster/nodemanager.h" -#include "cluster/tcp.h" - -#include "dlmapi.h" -#include "dlmcommon.h" -#include "dlmdomain.h" -#include "dlmdebug.h" - -#define MLOG_MASK_PREFIX (ML_DLM|ML_DLM_MASTER) -#include "cluster/masklog.h" - -static void dlm_mle_node_down(struct dlm_ctxt *dlm, - struct dlm_master_list_entry *mle, - struct o2nm_node *node, - int idx); -static void dlm_mle_node_up(struct dlm_ctxt *dlm, - struct dlm_master_list_entry *mle, - struct o2nm_node *node, - int idx); - -static void dlm_assert_master_worker(struct dlm_work_item *item, void *data); -static int dlm_do_assert_master(struct dlm_ctxt *dlm, - struct dlm_lock_resource *res, - void *nodemap, u32 flags); -static void dlm_deref_lockres_worker(struct dlm_work_item *item, void *data); - -static inline int dlm_mle_equal(struct dlm_ctxt *dlm, - struct dlm_master_list_entry *mle, - const char *name, - unsigned int namelen) -{ - if (dlm != mle->dlm) - return 0; - - if (namelen != mle->mnamelen || - memcmp(name, mle->mname, namelen) != 0) - return 0; - - return 1; -} - -static struct kmem_cache *dlm_lockres_cache = NULL; -static struct kmem_cache *dlm_lockname_cache = NULL; -static struct kmem_cache *dlm_mle_cache = NULL; - -static void dlm_mle_release(struct kref *kref); -static void dlm_init_mle(struct dlm_master_list_entry *mle, - enum dlm_mle_type type, - struct dlm_ctxt *dlm, - struct dlm_lock_resource *res, - const char *name, - unsigned int namelen); -static void dlm_put_mle(struct dlm_master_list_entry *mle); -static void __dlm_put_mle(struct dlm_master_list_entry *mle); -static int dlm_find_mle(struct dlm_ctxt *dlm, - struct dlm_master_list_entry **mle, - char *name, unsigned int namelen); - -static int dlm_do_master_request(struct dlm_lock_resource *res, - struct dlm_master_list_entry *mle, int to); - - -static int dlm_wait_for_lock_mastery(struct dlm_ctxt *dlm, - struct dlm_lock_resource *res, - struct dlm_master_list_entry *mle, - int *blocked); -static int dlm_restart_lock_mastery(struct dlm_ctxt *dlm, - struct dlm_lock_resource *res, - struct dlm_master_list_entry *mle, - int blocked); -static int dlm_add_migration_mle(struct dlm_ctxt *dlm, - struct dlm_lock_resource *res, - struct dlm_master_list_entry *mle, - struct dlm_master_list_entry **oldmle, - const char *name, unsigned int namelen, - u8 new_master, u8 master); - -static u8 dlm_pick_migration_target(struct dlm_ctxt *dlm, - struct dlm_lock_resource *res); -static void dlm_remove_nonlocal_locks(struct dlm_ctxt *dlm, - struct dlm_lock_resource *res); -static int dlm_mark_lockres_migrating(struct dlm_ctxt *dlm, - struct dlm_lock_resource *res, - u8 target); -static int dlm_pre_master_reco_lockres(struct dlm_ctxt *dlm, - struct dlm_lock_resource *res); - - -int dlm_is_host_down(int errno) -{ - switch (errno) { - case -EBADF: - case -ECONNREFUSED: - case -ENOTCONN: - case -ECONNRESET: - case -EPIPE: - case -EHOSTDOWN: - case -EHOSTUNREACH: - case -ETIMEDOUT: - case -ECONNABORTED: - case -ENETDOWN: - case -ENETUNREACH: - case -ENETRESET: - case -ESHUTDOWN: - case -ENOPROTOOPT: - case -EINVAL: /* if returned from our tcp code, - this means there is no socket */ - return 1; - } - return 0; -} - - -/* - * MASTER LIST FUNCTIONS - */ - - -/* - * regarding master list entries and heartbeat callbacks: - * - * in order to avoid sleeping and allocation that occurs in - * heartbeat, master list entries are simply attached to the - * dlm's established heartbeat callbacks. the mle is attached - * when it is created, and since the dlm->spinlock is held at - * that time, any heartbeat event will be properly discovered - * by the mle. the mle needs to be detached from the - * dlm->mle_hb_events list as soon as heartbeat events are no - * longer useful to the mle, and before the mle is freed. - * - * as a general rule, heartbeat events are no longer needed by - * the mle once an "answer" regarding the lock master has been - * received. - */ -static inline void __dlm_mle_attach_hb_events(struct dlm_ctxt *dlm, - struct dlm_master_list_entry *mle) -{ - assert_spin_locked(&dlm->spinlock); - - list_add_tail(&mle->hb_events, &dlm->mle_hb_events); -} - - -static inline void __dlm_mle_detach_hb_events(struct dlm_ctxt *dlm, - struct dlm_master_list_entry *mle) -{ - if (!list_empty(&mle->hb_events)) - list_del_init(&mle->hb_events); -} - - -static inline void dlm_mle_detach_hb_events(struct dlm_ctxt *dlm, - struct dlm_master_list_entry *mle) -{ - spin_lock(&dlm->spinlock); - __dlm_mle_detach_hb_events(dlm, mle); - spin_unlock(&dlm->spinlock); -} - -static void dlm_get_mle_inuse(struct dlm_master_list_entry *mle) -{ - struct dlm_ctxt *dlm; - dlm = mle->dlm; - - assert_spin_locked(&dlm->spinlock); - assert_spin_locked(&dlm->master_lock); - mle->inuse++; - kref_get(&mle->mle_refs); -} - -static void dlm_put_mle_inuse(struct dlm_master_list_entry *mle) -{ - struct dlm_ctxt *dlm; - dlm = mle->dlm; - - spin_lock(&dlm->spinlock); - spin_lock(&dlm->master_lock); - mle->inuse--; - __dlm_put_mle(mle); - spin_unlock(&dlm->master_lock); - spin_unlock(&dlm->spinlock); - -} - -/* remove from list and free */ -static void __dlm_put_mle(struct dlm_master_list_entry *mle) -{ - struct dlm_ctxt *dlm; - dlm = mle->dlm; - - assert_spin_locked(&dlm->spinlock); - assert_spin_locked(&dlm->master_lock); - if (!atomic_read(&mle->mle_refs.refcount)) { - /* this may or may not crash, but who cares. - * it's a BUG. */ - mlog(ML_ERROR, "bad mle: %p\n", mle); - dlm_print_one_mle(mle); - BUG(); - } else - kref_put(&mle->mle_refs, dlm_mle_release); -} - - -/* must not have any spinlocks coming in */ -static void dlm_put_mle(struct dlm_master_list_entry *mle) -{ - struct dlm_ctxt *dlm; - dlm = mle->dlm; - - spin_lock(&dlm->spinlock); - spin_lock(&dlm->master_lock); - __dlm_put_mle(mle); - spin_unlock(&dlm->master_lock); - spin_unlock(&dlm->spinlock); -} - -static inline void dlm_get_mle(struct dlm_master_list_entry *mle) -{ - kref_get(&mle->mle_refs); -} - -static void dlm_init_mle(struct dlm_master_list_entry *mle, - enum dlm_mle_type type, - struct dlm_ctxt *dlm, - struct dlm_lock_resource *res, - const char *name, - unsigned int namelen) -{ - assert_spin_locked(&dlm->spinlock); - - mle->dlm = dlm; - mle->type = type; - INIT_HLIST_NODE(&mle->master_hash_node); - INIT_LIST_HEAD(&mle->hb_events); - memset(mle->maybe_map, 0, sizeof(mle->maybe_map)); - spin_lock_init(&mle->spinlock); - init_waitqueue_head(&mle->wq); - atomic_set(&mle->woken, 0); - kref_init(&mle->mle_refs); - memset(mle->response_map, 0, sizeof(mle->response_map)); - mle->master = O2NM_MAX_NODES; - mle->new_master = O2NM_MAX_NODES; - mle->inuse = 0; - - BUG_ON(mle->type != DLM_MLE_BLOCK && - mle->type != DLM_MLE_MASTER && - mle->type != DLM_MLE_MIGRATION); - - if (mle->type == DLM_MLE_MASTER) { - BUG_ON(!res); - mle->mleres = res; - memcpy(mle->mname, res->lockname.name, res->lockname.len); - mle->mnamelen = res->lockname.len; - mle->mnamehash = res->lockname.hash; - } else { - BUG_ON(!name); - mle->mleres = NULL; - memcpy(mle->mname, name, namelen); - mle->mnamelen = namelen; - mle->mnamehash = dlm_lockid_hash(name, namelen); - } - - atomic_inc(&dlm->mle_tot_count[mle->type]); - atomic_inc(&dlm->mle_cur_count[mle->type]); - - /* copy off the node_map and register hb callbacks on our copy */ - memcpy(mle->node_map, dlm->domain_map, sizeof(mle->node_map)); - memcpy(mle->vote_map, dlm->domain_map, sizeof(mle->vote_map)); - clear_bit(dlm->node_num, mle->vote_map); - clear_bit(dlm->node_num, mle->node_map); - - /* attach the mle to the domain node up/down events */ - __dlm_mle_attach_hb_events(dlm, mle); -} - -void __dlm_unlink_mle(struct dlm_ctxt *dlm, struct dlm_master_list_entry *mle) -{ - assert_spin_locked(&dlm->spinlock); - assert_spin_locked(&dlm->master_lock); - - if (!hlist_unhashed(&mle->master_hash_node)) - hlist_del_init(&mle->master_hash_node); -} - -void __dlm_insert_mle(struct dlm_ctxt *dlm, struct dlm_master_list_entry *mle) -{ - struct hlist_head *bucket; - - assert_spin_locked(&dlm->master_lock); - - bucket = dlm_master_hash(dlm, mle->mnamehash); - hlist_add_head(&mle->master_hash_node, bucket); -} - -/* returns 1 if found, 0 if not */ -static int dlm_find_mle(struct dlm_ctxt *dlm, - struct dlm_master_list_entry **mle, - char *name, unsigned int namelen) -{ - struct dlm_master_list_entry *tmpmle; - struct hlist_head *bucket; - struct hlist_node *list; - unsigned int hash; - - assert_spin_locked(&dlm->master_lock); - - hash = dlm_lockid_hash(name, namelen); - bucket = dlm_master_hash(dlm, hash); - hlist_for_each(list, bucket) { - tmpmle = hlist_entry(list, struct dlm_master_list_entry, - master_hash_node); - if (!dlm_mle_equal(dlm, tmpmle, name, namelen)) - continue; - dlm_get_mle(tmpmle); - *mle = tmpmle; - return 1; - } - return 0; -} - -void dlm_hb_event_notify_attached(struct dlm_ctxt *dlm, int idx, int node_up) -{ - struct dlm_master_list_entry *mle; - - assert_spin_locked(&dlm->spinlock); - - list_for_each_entry(mle, &dlm->mle_hb_events, hb_events) { - if (node_up) - dlm_mle_node_up(dlm, mle, NULL, idx); - else - dlm_mle_node_down(dlm, mle, NULL, idx); - } -} - -static void dlm_mle_node_down(struct dlm_ctxt *dlm, - struct dlm_master_list_entry *mle, - struct o2nm_node *node, int idx) -{ - spin_lock(&mle->spinlock); - - if (!test_bit(idx, mle->node_map)) - mlog(0, "node %u already removed from nodemap!\n", idx); - else - clear_bit(idx, mle->node_map); - - spin_unlock(&mle->spinlock); -} - -static void dlm_mle_node_up(struct dlm_ctxt *dlm, - struct dlm_master_list_entry *mle, - struct o2nm_node *node, int idx) -{ - spin_lock(&mle->spinlock); - - if (test_bit(idx, mle->node_map)) - mlog(0, "node %u already in node map!\n", idx); - else - set_bit(idx, mle->node_map); - - spin_unlock(&mle->spinlock); -} - - -int dlm_init_mle_cache(void) -{ - dlm_mle_cache = kmem_cache_create("o2dlm_mle", - sizeof(struct dlm_master_list_entry), - 0, SLAB_HWCACHE_ALIGN, - NULL); - if (dlm_mle_cache == NULL) - return -ENOMEM; - return 0; -} - -void dlm_destroy_mle_cache(void) -{ - if (dlm_mle_cache) - kmem_cache_destroy(dlm_mle_cache); -} - -static void dlm_mle_release(struct kref *kref) -{ - struct dlm_master_list_entry *mle; - struct dlm_ctxt *dlm; - - mle = container_of(kref, struct dlm_master_list_entry, mle_refs); - dlm = mle->dlm; - - assert_spin_locked(&dlm->spinlock); - assert_spin_locked(&dlm->master_lock); - - mlog(0, "Releasing mle for %.*s, type %d\n", mle->mnamelen, mle->mname, - mle->type); - - /* remove from list if not already */ - __dlm_unlink_mle(dlm, mle); - - /* detach the mle from the domain node up/down events */ - __dlm_mle_detach_hb_events(dlm, mle); - - atomic_dec(&dlm->mle_cur_count[mle->type]); - - /* NOTE: kfree under spinlock here. - * if this is bad, we can move this to a freelist. */ - kmem_cache_free(dlm_mle_cache, mle); -} - - -/* - * LOCK RESOURCE FUNCTIONS - */ - -int dlm_init_master_caches(void) -{ - dlm_lockres_cache = kmem_cache_create("o2dlm_lockres", - sizeof(struct dlm_lock_resource), - 0, SLAB_HWCACHE_ALIGN, NULL); - if (!dlm_lockres_cache) - goto bail; - - dlm_lockname_cache = kmem_cache_create("o2dlm_lockname", - DLM_LOCKID_NAME_MAX, 0, - SLAB_HWCACHE_ALIGN, NULL); - if (!dlm_lockname_cache) - goto bail; - - return 0; -bail: - dlm_destroy_master_caches(); - return -ENOMEM; -} - -void dlm_destroy_master_caches(void) -{ - if (dlm_lockname_cache) - kmem_cache_destroy(dlm_lockname_cache); - - if (dlm_lockres_cache) - kmem_cache_destroy(dlm_lockres_cache); -} - -static void dlm_lockres_release(struct kref *kref) -{ - struct dlm_lock_resource *res; - struct dlm_ctxt *dlm; - - res = container_of(kref, struct dlm_lock_resource, refs); - dlm = res->dlm; - - /* This should not happen -- all lockres' have a name - * associated with them at init time. */ - BUG_ON(!res->lockname.name); - - mlog(0, "destroying lockres %.*s\n", res->lockname.len, - res->lockname.name); - - spin_lock(&dlm->track_lock); - if (!list_empty(&res->tracking)) - list_del_init(&res->tracking); - else { - mlog(ML_ERROR, "Resource %.*s not on the Tracking list\n", - res->lockname.len, res->lockname.name); - dlm_print_one_lock_resource(res); - } - spin_unlock(&dlm->track_lock); - - atomic_dec(&dlm->res_cur_count); - - if (!hlist_unhashed(&res->hash_node) || - !list_empty(&res->granted) || - !list_empty(&res->converting) || - !list_empty(&res->blocked) || - !list_empty(&res->dirty) || - !list_empty(&res->recovering) || - !list_empty(&res->purge)) { - mlog(ML_ERROR, - "Going to BUG for resource %.*s." - " We're on a list! [%c%c%c%c%c%c%c]\n", - res->lockname.len, res->lockname.name, - !hlist_unhashed(&res->hash_node) ? 'H' : ' ', - !list_empty(&res->granted) ? 'G' : ' ', - !list_empty(&res->converting) ? 'C' : ' ', - !list_empty(&res->blocked) ? 'B' : ' ', - !list_empty(&res->dirty) ? 'D' : ' ', - !list_empty(&res->recovering) ? 'R' : ' ', - !list_empty(&res->purge) ? 'P' : ' '); - - dlm_print_one_lock_resource(res); - } - - /* By the time we're ready to blow this guy away, we shouldn't - * be on any lists. */ - BUG_ON(!hlist_unhashed(&res->hash_node)); - BUG_ON(!list_empty(&res->granted)); - BUG_ON(!list_empty(&res->converting)); - BUG_ON(!list_empty(&res->blocked)); - BUG_ON(!list_empty(&res->dirty)); - BUG_ON(!list_empty(&res->recovering)); - BUG_ON(!list_empty(&res->purge)); - - kmem_cache_free(dlm_lockname_cache, (void *)res->lockname.name); - - kmem_cache_free(dlm_lockres_cache, res); -} - -void dlm_lockres_put(struct dlm_lock_resource *res) -{ - kref_put(&res->refs, dlm_lockres_release); -} - -static void dlm_init_lockres(struct dlm_ctxt *dlm, - struct dlm_lock_resource *res, - const char *name, unsigned int namelen) -{ - char *qname; - - /* If we memset here, we lose our reference to the kmalloc'd - * res->lockname.name, so be sure to init every field - * correctly! */ - - qname = (char *) res->lockname.name; - memcpy(qname, name, namelen); - - res->lockname.len = namelen; - res->lockname.hash = dlm_lockid_hash(name, namelen); - - init_waitqueue_head(&res->wq); - spin_lock_init(&res->spinlock); - INIT_HLIST_NODE(&res->hash_node); - INIT_LIST_HEAD(&res->granted); - INIT_LIST_HEAD(&res->converting); - INIT_LIST_HEAD(&res->blocked); - INIT_LIST_HEAD(&res->dirty); - INIT_LIST_HEAD(&res->recovering); - INIT_LIST_HEAD(&res->purge); - INIT_LIST_HEAD(&res->tracking); - atomic_set(&res->asts_reserved, 0); - res->migration_pending = 0; - res->inflight_locks = 0; - - res->dlm = dlm; - - kref_init(&res->refs); - - atomic_inc(&dlm->res_tot_count); - atomic_inc(&dlm->res_cur_count); - - /* just for consistency */ - spin_lock(&res->spinlock); - dlm_set_lockres_owner(dlm, res, DLM_LOCK_RES_OWNER_UNKNOWN); - spin_unlock(&res->spinlock); - - res->state = DLM_LOCK_RES_IN_PROGRESS; - - res->last_used = 0; - - spin_lock(&dlm->spinlock); - list_add_tail(&res->tracking, &dlm->tracking_list); - spin_unlock(&dlm->spinlock); - - memset(res->lvb, 0, DLM_LVB_LEN); - memset(res->refmap, 0, sizeof(res->refmap)); -} - -struct dlm_lock_resource *dlm_new_lockres(struct dlm_ctxt *dlm, - const char *name, - unsigned int namelen) -{ - struct dlm_lock_resource *res = NULL; - - res = kmem_cache_zalloc(dlm_lockres_cache, GFP_NOFS); - if (!res) - goto error; - - res->lockname.name = kmem_cache_zalloc(dlm_lockname_cache, GFP_NOFS); - if (!res->lockname.name) - goto error; - - dlm_init_lockres(dlm, res, name, namelen); - return res; - -error: - if (res && res->lockname.name) - kmem_cache_free(dlm_lockname_cache, (void *)res->lockname.name); - - if (res) - kmem_cache_free(dlm_lockres_cache, res); - return NULL; -} - -void dlm_lockres_set_refmap_bit(struct dlm_ctxt *dlm, - struct dlm_lock_resource *res, int bit) -{ - assert_spin_locked(&res->spinlock); - - mlog(0, "res %.*s, set node %u, %ps()\n", res->lockname.len, - res->lockname.name, bit, __builtin_return_address(0)); - - set_bit(bit, res->refmap); -} - -void dlm_lockres_clear_refmap_bit(struct dlm_ctxt *dlm, - struct dlm_lock_resource *res, int bit) -{ - assert_spin_locked(&res->spinlock); - - mlog(0, "res %.*s, clr node %u, %ps()\n", res->lockname.len, - res->lockname.name, bit, __builtin_return_address(0)); - - clear_bit(bit, res->refmap); -} - - -void dlm_lockres_grab_inflight_ref(struct dlm_ctxt *dlm, - struct dlm_lock_resource *res) -{ - assert_spin_locked(&res->spinlock); - - res->inflight_locks++; - - mlog(0, "%s: res %.*s, inflight++: now %u, %ps()\n", dlm->name, - res->lockname.len, res->lockname.name, res->inflight_locks, - __builtin_return_address(0)); -} - -void dlm_lockres_drop_inflight_ref(struct dlm_ctxt *dlm, - struct dlm_lock_resource *res) -{ - assert_spin_locked(&res->spinlock); - - BUG_ON(res->inflight_locks == 0); - - res->inflight_locks--; - - mlog(0, "%s: res %.*s, inflight--: now %u, %ps()\n", dlm->name, - res->lockname.len, res->lockname.name, res->inflight_locks, - __builtin_return_address(0)); - - wake_up(&res->wq); -} - -/* - * lookup a lock resource by name. - * may already exist in the hashtable. - * lockid is null terminated - * - * if not, allocate enough for the lockres and for - * the temporary structure used in doing the mastering. - * - * also, do a lookup in the dlm->master_list to see - * if another node has begun mastering the same lock. - * if so, there should be a block entry in there - * for this name, and we should *not* attempt to master - * the lock here. need to wait around for that node - * to assert_master (or die). - * - */ -struct dlm_lock_resource * dlm_get_lock_resource(struct dlm_ctxt *dlm, - const char *lockid, - int namelen, - int flags) -{ - struct dlm_lock_resource *tmpres=NULL, *res=NULL; - struct dlm_master_list_entry *mle = NULL; - struct dlm_master_list_entry *alloc_mle = NULL; - int blocked = 0; - int ret, nodenum; - struct dlm_node_iter iter; - unsigned int hash; - int tries = 0; - int bit, wait_on_recovery = 0; - - BUG_ON(!lockid); - - hash = dlm_lockid_hash(lockid, namelen); - - mlog(0, "get lockres %s (len %d)\n", lockid, namelen); - -lookup: - spin_lock(&dlm->spinlock); - tmpres = __dlm_lookup_lockres_full(dlm, lockid, namelen, hash); - if (tmpres) { - spin_unlock(&dlm->spinlock); - spin_lock(&tmpres->spinlock); - /* Wait on the thread that is mastering the resource */ - if (tmpres->owner == DLM_LOCK_RES_OWNER_UNKNOWN) { - __dlm_wait_on_lockres(tmpres); - BUG_ON(tmpres->owner == DLM_LOCK_RES_OWNER_UNKNOWN); - spin_unlock(&tmpres->spinlock); - dlm_lockres_put(tmpres); - tmpres = NULL; - goto lookup; - } - - /* Wait on the resource purge to complete before continuing */ - if (tmpres->state & DLM_LOCK_RES_DROPPING_REF) { - BUG_ON(tmpres->owner == dlm->node_num); - __dlm_wait_on_lockres_flags(tmpres, - DLM_LOCK_RES_DROPPING_REF); - spin_unlock(&tmpres->spinlock); - dlm_lockres_put(tmpres); - tmpres = NULL; - goto lookup; - } - - /* Grab inflight ref to pin the resource */ - dlm_lockres_grab_inflight_ref(dlm, tmpres); - - spin_unlock(&tmpres->spinlock); - if (res) - dlm_lockres_put(res); - res = tmpres; - goto leave; - } - - if (!res) { - spin_unlock(&dlm->spinlock); - mlog(0, "allocating a new resource\n"); - /* nothing found and we need to allocate one. */ - alloc_mle = kmem_cache_alloc(dlm_mle_cache, GFP_NOFS); - if (!alloc_mle) - goto leave; - res = dlm_new_lockres(dlm, lockid, namelen); - if (!res) - goto leave; - goto lookup; - } - - mlog(0, "no lockres found, allocated our own: %p\n", res); - - if (flags & LKM_LOCAL) { - /* caller knows it's safe to assume it's not mastered elsewhere - * DONE! return right away */ - spin_lock(&res->spinlock); - dlm_change_lockres_owner(dlm, res, dlm->node_num); - __dlm_insert_lockres(dlm, res); - dlm_lockres_grab_inflight_ref(dlm, res); - spin_unlock(&res->spinlock); - spin_unlock(&dlm->spinlock); - /* lockres still marked IN_PROGRESS */ - goto wake_waiters; - } - - /* check master list to see if another node has started mastering it */ - spin_lock(&dlm->master_lock); - - /* if we found a block, wait for lock to be mastered by another node */ - blocked = dlm_find_mle(dlm, &mle, (char *)lockid, namelen); - if (blocked) { - int mig; - if (mle->type == DLM_MLE_MASTER) { - mlog(ML_ERROR, "master entry for nonexistent lock!\n"); - BUG(); - } - mig = (mle->type == DLM_MLE_MIGRATION); - /* if there is a migration in progress, let the migration - * finish before continuing. we can wait for the absence - * of the MIGRATION mle: either the migrate finished or - * one of the nodes died and the mle was cleaned up. - * if there is a BLOCK here, but it already has a master - * set, we are too late. the master does not have a ref - * for us in the refmap. detach the mle and drop it. - * either way, go back to the top and start over. */ - if (mig || mle->master != O2NM_MAX_NODES) { - BUG_ON(mig && mle->master == dlm->node_num); - /* we arrived too late. the master does not - * have a ref for us. retry. */ - mlog(0, "%s:%.*s: late on %s\n", - dlm->name, namelen, lockid, - mig ? "MIGRATION" : "BLOCK"); - spin_unlock(&dlm->master_lock); - spin_unlock(&dlm->spinlock); - - /* master is known, detach */ - if (!mig) - dlm_mle_detach_hb_events(dlm, mle); - dlm_put_mle(mle); - mle = NULL; - /* this is lame, but we can't wait on either - * the mle or lockres waitqueue here */ - if (mig) - msleep(100); - goto lookup; - } - } else { - /* go ahead and try to master lock on this node */ - mle = alloc_mle; - /* make sure this does not get freed below */ - alloc_mle = NULL; - dlm_init_mle(mle, DLM_MLE_MASTER, dlm, res, NULL, 0); - set_bit(dlm->node_num, mle->maybe_map); - __dlm_insert_mle(dlm, mle); - - /* still holding the dlm spinlock, check the recovery map - * to see if there are any nodes that still need to be - * considered. these will not appear in the mle nodemap - * but they might own this lockres. wait on them. */ - bit = find_next_bit(dlm->recovery_map, O2NM_MAX_NODES, 0); - if (bit < O2NM_MAX_NODES) { - mlog(0, "%s: res %.*s, At least one node (%d) " - "to recover before lock mastery can begin\n", - dlm->name, namelen, (char *)lockid, bit); - wait_on_recovery = 1; - } - } - - /* at this point there is either a DLM_MLE_BLOCK or a - * DLM_MLE_MASTER on the master list, so it's safe to add the - * lockres to the hashtable. anyone who finds the lock will - * still have to wait on the IN_PROGRESS. */ - - /* finally add the lockres to its hash bucket */ - __dlm_insert_lockres(dlm, res); - - /* Grab inflight ref to pin the resource */ - spin_lock(&res->spinlock); - dlm_lockres_grab_inflight_ref(dlm, res); - spin_unlock(&res->spinlock); - - /* get an extra ref on the mle in case this is a BLOCK - * if so, the creator of the BLOCK may try to put the last - * ref at this time in the assert master handler, so we - * need an extra one to keep from a bad ptr deref. */ - dlm_get_mle_inuse(mle); - spin_unlock(&dlm->master_lock); - spin_unlock(&dlm->spinlock); - -redo_request: - while (wait_on_recovery) { - /* any cluster changes that occurred after dropping the - * dlm spinlock would be detectable be a change on the mle, - * so we only need to clear out the recovery map once. */ - if (dlm_is_recovery_lock(lockid, namelen)) { - mlog(0, "%s: Recovery map is not empty, but must " - "master $RECOVERY lock now\n", dlm->name); - if (!dlm_pre_master_reco_lockres(dlm, res)) - wait_on_recovery = 0; - else { - mlog(0, "%s: waiting 500ms for heartbeat state " - "change\n", dlm->name); - msleep(500); - } - continue; - } - - dlm_kick_recovery_thread(dlm); - msleep(1000); - dlm_wait_for_recovery(dlm); - - spin_lock(&dlm->spinlock); - bit = find_next_bit(dlm->recovery_map, O2NM_MAX_NODES, 0); - if (bit < O2NM_MAX_NODES) { - mlog(0, "%s: res %.*s, At least one node (%d) " - "to recover before lock mastery can begin\n", - dlm->name, namelen, (char *)lockid, bit); - wait_on_recovery = 1; - } else - wait_on_recovery = 0; - spin_unlock(&dlm->spinlock); - - if (wait_on_recovery) - dlm_wait_for_node_recovery(dlm, bit, 10000); - } - - /* must wait for lock to be mastered elsewhere */ - if (blocked) - goto wait; - - ret = -EINVAL; - dlm_node_iter_init(mle->vote_map, &iter); - while ((nodenum = dlm_node_iter_next(&iter)) >= 0) { - ret = dlm_do_master_request(res, mle, nodenum); - if (ret < 0) - mlog_errno(ret); - if (mle->master != O2NM_MAX_NODES) { - /* found a master ! */ - if (mle->master <= nodenum) - break; - /* if our master request has not reached the master - * yet, keep going until it does. this is how the - * master will know that asserts are needed back to - * the lower nodes. */ - mlog(0, "%s: res %.*s, Requests only up to %u but " - "master is %u, keep going\n", dlm->name, namelen, - lockid, nodenum, mle->master); - } - } - -wait: - /* keep going until the response map includes all nodes */ - ret = dlm_wait_for_lock_mastery(dlm, res, mle, &blocked); - if (ret < 0) { - wait_on_recovery = 1; - mlog(0, "%s: res %.*s, Node map changed, redo the master " - "request now, blocked=%d\n", dlm->name, res->lockname.len, - res->lockname.name, blocked); - if (++tries > 20) { - mlog(ML_ERROR, "%s: res %.*s, Spinning on " - "dlm_wait_for_lock_mastery, blocked = %d\n", - dlm->name, res->lockname.len, - res->lockname.name, blocked); - dlm_print_one_lock_resource(res); - dlm_print_one_mle(mle); - tries = 0; - } - goto redo_request; - } - - mlog(0, "%s: res %.*s, Mastered by %u\n", dlm->name, res->lockname.len, - res->lockname.name, res->owner); - /* make sure we never continue without this */ - BUG_ON(res->owner == O2NM_MAX_NODES); - - /* master is known, detach if not already detached */ - dlm_mle_detach_hb_events(dlm, mle); - dlm_put_mle(mle); - /* put the extra ref */ - dlm_put_mle_inuse(mle); - -wake_waiters: - spin_lock(&res->spinlock); - res->state &= ~DLM_LOCK_RES_IN_PROGRESS; - spin_unlock(&res->spinlock); - wake_up(&res->wq); - -leave: - /* need to free the unused mle */ - if (alloc_mle) - kmem_cache_free(dlm_mle_cache, alloc_mle); - - return res; -} - - -#define DLM_MASTERY_TIMEOUT_MS 5000 - -static int dlm_wait_for_lock_mastery(struct dlm_ctxt *dlm, - struct dlm_lock_resource *res, - struct dlm_master_list_entry *mle, - int *blocked) -{ - u8 m; - int ret, bit; - int map_changed, voting_done; - int assert, sleep; - -recheck: - ret = 0; - assert = 0; - - /* check if another node has already become the owner */ - spin_lock(&res->spinlock); - if (res->owner != DLM_LOCK_RES_OWNER_UNKNOWN) { - mlog(0, "%s:%.*s: owner is suddenly %u\n", dlm->name, - res->lockname.len, res->lockname.name, res->owner); - spin_unlock(&res->spinlock); - /* this will cause the master to re-assert across - * the whole cluster, freeing up mles */ - if (res->owner != dlm->node_num) { - ret = dlm_do_master_request(res, mle, res->owner); - if (ret < 0) { - /* give recovery a chance to run */ - mlog(ML_ERROR, "link to %u went down?: %d\n", res->owner, ret); - msleep(500); - goto recheck; - } - } - ret = 0; - goto leave; - } - spin_unlock(&res->spinlock); - - spin_lock(&mle->spinlock); - m = mle->master; - map_changed = (memcmp(mle->vote_map, mle->node_map, - sizeof(mle->vote_map)) != 0); - voting_done = (memcmp(mle->vote_map, mle->response_map, - sizeof(mle->vote_map)) == 0); - - /* restart if we hit any errors */ - if (map_changed) { - int b; - mlog(0, "%s: %.*s: node map changed, restarting\n", - dlm->name, res->lockname.len, res->lockname.name); - ret = dlm_restart_lock_mastery(dlm, res, mle, *blocked); - b = (mle->type == DLM_MLE_BLOCK); - if ((*blocked && !b) || (!*blocked && b)) { - mlog(0, "%s:%.*s: status change: old=%d new=%d\n", - dlm->name, res->lockname.len, res->lockname.name, - *blocked, b); - *blocked = b; - } - spin_unlock(&mle->spinlock); - if (ret < 0) { - mlog_errno(ret); - goto leave; - } - mlog(0, "%s:%.*s: restart lock mastery succeeded, " - "rechecking now\n", dlm->name, res->lockname.len, - res->lockname.name); - goto recheck; - } else { - if (!voting_done) { - mlog(0, "map not changed and voting not done " - "for %s:%.*s\n", dlm->name, res->lockname.len, - res->lockname.name); - } - } - - if (m != O2NM_MAX_NODES) { - /* another node has done an assert! - * all done! */ - sleep = 0; - } else { - sleep = 1; - /* have all nodes responded? */ - if (voting_done && !*blocked) { - bit = find_next_bit(mle->maybe_map, O2NM_MAX_NODES, 0); - if (dlm->node_num <= bit) { - /* my node number is lowest. - * now tell other nodes that I am - * mastering this. */ - mle->master = dlm->node_num; - /* ref was grabbed in get_lock_resource - * will be dropped in dlmlock_master */ - assert = 1; - sleep = 0; - } - /* if voting is done, but we have not received - * an assert master yet, we must sleep */ - } - } - - spin_unlock(&mle->spinlock); - - /* sleep if we haven't finished voting yet */ - if (sleep) { - unsigned long timeo = msecs_to_jiffies(DLM_MASTERY_TIMEOUT_MS); - - /* - if (atomic_read(&mle->mle_refs.refcount) < 2) - mlog(ML_ERROR, "mle (%p) refs=%d, name=%.*s\n", mle, - atomic_read(&mle->mle_refs.refcount), - res->lockname.len, res->lockname.name); - */ - atomic_set(&mle->woken, 0); - (void)wait_event_timeout(mle->wq, - (atomic_read(&mle->woken) == 1), - timeo); - if (res->owner == O2NM_MAX_NODES) { - mlog(0, "%s:%.*s: waiting again\n", dlm->name, - res->lockname.len, res->lockname.name); - goto recheck; - } - mlog(0, "done waiting, master is %u\n", res->owner); - ret = 0; - goto leave; - } - - ret = 0; /* done */ - if (assert) { - m = dlm->node_num; - mlog(0, "about to master %.*s here, this=%u\n", - res->lockname.len, res->lockname.name, m); - ret = dlm_do_assert_master(dlm, res, mle->vote_map, 0); - if (ret) { - /* This is a failure in the network path, - * not in the response to the assert_master - * (any nonzero response is a BUG on this node). - * Most likely a socket just got disconnected - * due to node death. */ - mlog_errno(ret); - } - /* no longer need to restart lock mastery. - * all living nodes have been contacted. */ - ret = 0; - } - - /* set the lockres owner */ - spin_lock(&res->spinlock); - /* mastery reference obtained either during - * assert_master_handler or in get_lock_resource */ - dlm_change_lockres_owner(dlm, res, m); - spin_unlock(&res->spinlock); - -leave: - return ret; -} - -struct dlm_bitmap_diff_iter -{ - int curnode; - unsigned long *orig_bm; - unsigned long *cur_bm; - unsigned long diff_bm[BITS_TO_LONGS(O2NM_MAX_NODES)]; -}; - -enum dlm_node_state_change -{ - NODE_DOWN = -1, - NODE_NO_CHANGE = 0, - NODE_UP -}; - -static void dlm_bitmap_diff_iter_init(struct dlm_bitmap_diff_iter *iter, - unsigned long *orig_bm, - unsigned long *cur_bm) -{ - unsigned long p1, p2; - int i; - - iter->curnode = -1; - iter->orig_bm = orig_bm; - iter->cur_bm = cur_bm; - - for (i = 0; i < BITS_TO_LONGS(O2NM_MAX_NODES); i++) { - p1 = *(iter->orig_bm + i); - p2 = *(iter->cur_bm + i); - iter->diff_bm[i] = (p1 & ~p2) | (p2 & ~p1); - } -} - -static int dlm_bitmap_diff_iter_next(struct dlm_bitmap_diff_iter *iter, - enum dlm_node_state_change *state) -{ - int bit; - - if (iter->curnode >= O2NM_MAX_NODES) - return -ENOENT; - - bit = find_next_bit(iter->diff_bm, O2NM_MAX_NODES, - iter->curnode+1); - if (bit >= O2NM_MAX_NODES) { - iter->curnode = O2NM_MAX_NODES; - return -ENOENT; - } - - /* if it was there in the original then this node died */ - if (test_bit(bit, iter->orig_bm)) - *state = NODE_DOWN; - else - *state = NODE_UP; - - iter->curnode = bit; - return bit; -} - - -static int dlm_restart_lock_mastery(struct dlm_ctxt *dlm, - struct dlm_lock_resource *res, - struct dlm_master_list_entry *mle, - int blocked) -{ - struct dlm_bitmap_diff_iter bdi; - enum dlm_node_state_change sc; - int node; - int ret = 0; - - mlog(0, "something happened such that the " - "master process may need to be restarted!\n"); - - assert_spin_locked(&mle->spinlock); - - dlm_bitmap_diff_iter_init(&bdi, mle->vote_map, mle->node_map); - node = dlm_bitmap_diff_iter_next(&bdi, &sc); - while (node >= 0) { - if (sc == NODE_UP) { - /* a node came up. clear any old vote from - * the response map and set it in the vote map - * then restart the mastery. */ - mlog(ML_NOTICE, "node %d up while restarting\n", node); - - /* redo the master request, but only for the new node */ - mlog(0, "sending request to new node\n"); - clear_bit(node, mle->response_map); - set_bit(node, mle->vote_map); - } else { - mlog(ML_ERROR, "node down! %d\n", node); - if (blocked) { - int lowest = find_next_bit(mle->maybe_map, - O2NM_MAX_NODES, 0); - - /* act like it was never there */ - clear_bit(node, mle->maybe_map); - - if (node == lowest) { - mlog(0, "expected master %u died" - " while this node was blocked " - "waiting on it!\n", node); - lowest = find_next_bit(mle->maybe_map, - O2NM_MAX_NODES, - lowest+1); - if (lowest < O2NM_MAX_NODES) { - mlog(0, "%s:%.*s:still " - "blocked. waiting on %u " - "now\n", dlm->name, - res->lockname.len, - res->lockname.name, - lowest); - } else { - /* mle is an MLE_BLOCK, but - * there is now nothing left to - * block on. we need to return - * all the way back out and try - * again with an MLE_MASTER. - * dlm_do_local_recovery_cleanup - * has already run, so the mle - * refcount is ok */ - mlog(0, "%s:%.*s: no " - "longer blocking. try to " - "master this here\n", - dlm->name, - res->lockname.len, - res->lockname.name); - mle->type = DLM_MLE_MASTER; - mle->mleres = res; - } - } - } - - /* now blank out everything, as if we had never - * contacted anyone */ - memset(mle->maybe_map, 0, sizeof(mle->maybe_map)); - memset(mle->response_map, 0, sizeof(mle->response_map)); - /* reset the vote_map to the current node_map */ - memcpy(mle->vote_map, mle->node_map, - sizeof(mle->node_map)); - /* put myself into the maybe map */ - if (mle->type != DLM_MLE_BLOCK) - set_bit(dlm->node_num, mle->maybe_map); - } - ret = -EAGAIN; - node = dlm_bitmap_diff_iter_next(&bdi, &sc); - } - return ret; -} - - -/* - * DLM_MASTER_REQUEST_MSG - * - * returns: 0 on success, - * -errno on a network error - * - * on error, the caller should assume the target node is "dead" - * - */ - -static int dlm_do_master_request(struct dlm_lock_resource *res, - struct dlm_master_list_entry *mle, int to) -{ - struct dlm_ctxt *dlm = mle->dlm; - struct dlm_master_request request; - int ret, response=0, resend; - - memset(&request, 0, sizeof(request)); - request.node_idx = dlm->node_num; - - BUG_ON(mle->type == DLM_MLE_MIGRATION); - - request.namelen = (u8)mle->mnamelen; - memcpy(request.name, mle->mname, request.namelen); - -again: - ret = o2net_send_message(DLM_MASTER_REQUEST_MSG, dlm->key, &request, - sizeof(request), to, &response); - if (ret < 0) { - if (ret == -ESRCH) { - /* should never happen */ - mlog(ML_ERROR, "TCP stack not ready!\n"); - BUG(); - } else if (ret == -EINVAL) { - mlog(ML_ERROR, "bad args passed to o2net!\n"); - BUG(); - } else if (ret == -ENOMEM) { - mlog(ML_ERROR, "out of memory while trying to send " - "network message! retrying\n"); - /* this is totally crude */ - msleep(50); - goto again; - } else if (!dlm_is_host_down(ret)) { - /* not a network error. bad. */ - mlog_errno(ret); - mlog(ML_ERROR, "unhandled error!"); - BUG(); - } - /* all other errors should be network errors, - * and likely indicate node death */ - mlog(ML_ERROR, "link to %d went down!\n", to); - goto out; - } - - ret = 0; - resend = 0; - spin_lock(&mle->spinlock); - switch (response) { - case DLM_MASTER_RESP_YES: - set_bit(to, mle->response_map); - mlog(0, "node %u is the master, response=YES\n", to); - mlog(0, "%s:%.*s: master node %u now knows I have a " - "reference\n", dlm->name, res->lockname.len, - res->lockname.name, to); - mle->master = to; - break; - case DLM_MASTER_RESP_NO: - mlog(0, "node %u not master, response=NO\n", to); - set_bit(to, mle->response_map); - break; - case DLM_MASTER_RESP_MAYBE: - mlog(0, "node %u not master, response=MAYBE\n", to); - set_bit(to, mle->response_map); - set_bit(to, mle->maybe_map); - break; - case DLM_MASTER_RESP_ERROR: - mlog(0, "node %u hit an error, resending\n", to); - resend = 1; - response = 0; - break; - default: - mlog(ML_ERROR, "bad response! %u\n", response); - BUG(); - } - spin_unlock(&mle->spinlock); - if (resend) { - /* this is also totally crude */ - msleep(50); - goto again; - } - -out: - return ret; -} - -/* - * locks that can be taken here: - * dlm->spinlock - * res->spinlock - * mle->spinlock - * dlm->master_list - * - * if possible, TRIM THIS DOWN!!! - */ -int dlm_master_request_handler(struct o2net_msg *msg, u32 len, void *data, - void **ret_data) -{ - u8 response = DLM_MASTER_RESP_MAYBE; - struct dlm_ctxt *dlm = data; - struct dlm_lock_resource *res = NULL; - struct dlm_master_request *request = (struct dlm_master_request *) msg->buf; - struct dlm_master_list_entry *mle = NULL, *tmpmle = NULL; - char *name; - unsigned int namelen, hash; - int found, ret; - int set_maybe; - int dispatch_assert = 0; - - if (!dlm_grab(dlm)) - return DLM_MASTER_RESP_NO; - - if (!dlm_domain_fully_joined(dlm)) { - response = DLM_MASTER_RESP_NO; - goto send_response; - } - - name = request->name; - namelen = request->namelen; - hash = dlm_lockid_hash(name, namelen); - - if (namelen > DLM_LOCKID_NAME_MAX) { - response = DLM_IVBUFLEN; - goto send_response; - } - -way_up_top: - spin_lock(&dlm->spinlock); - res = __dlm_lookup_lockres(dlm, name, namelen, hash); - if (res) { - spin_unlock(&dlm->spinlock); - - /* take care of the easy cases up front */ - spin_lock(&res->spinlock); - if (res->state & (DLM_LOCK_RES_RECOVERING| - DLM_LOCK_RES_MIGRATING)) { - spin_unlock(&res->spinlock); - mlog(0, "returning DLM_MASTER_RESP_ERROR since res is " - "being recovered/migrated\n"); - response = DLM_MASTER_RESP_ERROR; - if (mle) - kmem_cache_free(dlm_mle_cache, mle); - goto send_response; - } - - if (res->owner == dlm->node_num) { - dlm_lockres_set_refmap_bit(dlm, res, request->node_idx); - spin_unlock(&res->spinlock); - response = DLM_MASTER_RESP_YES; - if (mle) - kmem_cache_free(dlm_mle_cache, mle); - - /* this node is the owner. - * there is some extra work that needs to - * happen now. the requesting node has - * caused all nodes up to this one to - * create mles. this node now needs to - * go back and clean those up. */ - dispatch_assert = 1; - goto send_response; - } else if (res->owner != DLM_LOCK_RES_OWNER_UNKNOWN) { - spin_unlock(&res->spinlock); - // mlog(0, "node %u is the master\n", res->owner); - response = DLM_MASTER_RESP_NO; - if (mle) - kmem_cache_free(dlm_mle_cache, mle); - goto send_response; - } - - /* ok, there is no owner. either this node is - * being blocked, or it is actively trying to - * master this lock. */ - if (!(res->state & DLM_LOCK_RES_IN_PROGRESS)) { - mlog(ML_ERROR, "lock with no owner should be " - "in-progress!\n"); - BUG(); - } - - // mlog(0, "lockres is in progress...\n"); - spin_lock(&dlm->master_lock); - found = dlm_find_mle(dlm, &tmpmle, name, namelen); - if (!found) { - mlog(ML_ERROR, "no mle found for this lock!\n"); - BUG(); - } - set_maybe = 1; - spin_lock(&tmpmle->spinlock); - if (tmpmle->type == DLM_MLE_BLOCK) { - // mlog(0, "this node is waiting for " - // "lockres to be mastered\n"); - response = DLM_MASTER_RESP_NO; - } else if (tmpmle->type == DLM_MLE_MIGRATION) { - mlog(0, "node %u is master, but trying to migrate to " - "node %u.\n", tmpmle->master, tmpmle->new_master); - if (tmpmle->master == dlm->node_num) { - mlog(ML_ERROR, "no owner on lockres, but this " - "node is trying to migrate it to %u?!\n", - tmpmle->new_master); - BUG(); - } else { - /* the real master can respond on its own */ - response = DLM_MASTER_RESP_NO; - } - } else if (tmpmle->master != DLM_LOCK_RES_OWNER_UNKNOWN) { - set_maybe = 0; - if (tmpmle->master == dlm->node_num) { - response = DLM_MASTER_RESP_YES; - /* this node will be the owner. - * go back and clean the mles on any - * other nodes */ - dispatch_assert = 1; - dlm_lockres_set_refmap_bit(dlm, res, - request->node_idx); - } else - response = DLM_MASTER_RESP_NO; - } else { - // mlog(0, "this node is attempting to " - // "master lockres\n"); - response = DLM_MASTER_RESP_MAYBE; - } - if (set_maybe) - set_bit(request->node_idx, tmpmle->maybe_map); - spin_unlock(&tmpmle->spinlock); - - spin_unlock(&dlm->master_lock); - spin_unlock(&res->spinlock); - - /* keep the mle attached to heartbeat events */ - dlm_put_mle(tmpmle); - if (mle) - kmem_cache_free(dlm_mle_cache, mle); - goto send_response; - } - - /* - * lockres doesn't exist on this node - * if there is an MLE_BLOCK, return NO - * if there is an MLE_MASTER, return MAYBE - * otherwise, add an MLE_BLOCK, return NO - */ - spin_lock(&dlm->master_lock); - found = dlm_find_mle(dlm, &tmpmle, name, namelen); - if (!found) { - /* this lockid has never been seen on this node yet */ - // mlog(0, "no mle found\n"); - if (!mle) { - spin_unlock(&dlm->master_lock); - spin_unlock(&dlm->spinlock); - - mle = kmem_cache_alloc(dlm_mle_cache, GFP_NOFS); - if (!mle) { - response = DLM_MASTER_RESP_ERROR; - mlog_errno(-ENOMEM); - goto send_response; - } - goto way_up_top; - } - - // mlog(0, "this is second time thru, already allocated, " - // "add the block.\n"); - dlm_init_mle(mle, DLM_MLE_BLOCK, dlm, NULL, name, namelen); - set_bit(request->node_idx, mle->maybe_map); - __dlm_insert_mle(dlm, mle); - response = DLM_MASTER_RESP_NO; - } else { - // mlog(0, "mle was found\n"); - set_maybe = 1; - spin_lock(&tmpmle->spinlock); - if (tmpmle->master == dlm->node_num) { - mlog(ML_ERROR, "no lockres, but an mle with this node as master!\n"); - BUG(); - } - if (tmpmle->type == DLM_MLE_BLOCK) - response = DLM_MASTER_RESP_NO; - else if (tmpmle->type == DLM_MLE_MIGRATION) { - mlog(0, "migration mle was found (%u->%u)\n", - tmpmle->master, tmpmle->new_master); - /* real master can respond on its own */ - response = DLM_MASTER_RESP_NO; - } else - response = DLM_MASTER_RESP_MAYBE; - if (set_maybe) - set_bit(request->node_idx, tmpmle->maybe_map); - spin_unlock(&tmpmle->spinlock); - } - spin_unlock(&dlm->master_lock); - spin_unlock(&dlm->spinlock); - - if (found) { - /* keep the mle attached to heartbeat events */ - dlm_put_mle(tmpmle); - } -send_response: - /* - * __dlm_lookup_lockres() grabbed a reference to this lockres. - * The reference is released by dlm_assert_master_worker() under - * the call to dlm_dispatch_assert_master(). If - * dlm_assert_master_worker() isn't called, we drop it here. - */ - if (dispatch_assert) { - if (response != DLM_MASTER_RESP_YES) - mlog(ML_ERROR, "invalid response %d\n", response); - if (!res) { - mlog(ML_ERROR, "bad lockres while trying to assert!\n"); - BUG(); - } - mlog(0, "%u is the owner of %.*s, cleaning everyone else\n", - dlm->node_num, res->lockname.len, res->lockname.name); - ret = dlm_dispatch_assert_master(dlm, res, 0, request->node_idx, - DLM_ASSERT_MASTER_MLE_CLEANUP); - if (ret < 0) { - mlog(ML_ERROR, "failed to dispatch assert master work\n"); - response = DLM_MASTER_RESP_ERROR; - dlm_lockres_put(res); - } - } else { - if (res) - dlm_lockres_put(res); - } - - dlm_put(dlm); - return response; -} - -/* - * DLM_ASSERT_MASTER_MSG - */ - - -/* - * NOTE: this can be used for debugging - * can periodically run all locks owned by this node - * and re-assert across the cluster... - */ -static int dlm_do_assert_master(struct dlm_ctxt *dlm, - struct dlm_lock_resource *res, - void *nodemap, u32 flags) -{ - struct dlm_assert_master assert; - int to, tmpret; - struct dlm_node_iter iter; - int ret = 0; - int reassert; - const char *lockname = res->lockname.name; - unsigned int namelen = res->lockname.len; - - BUG_ON(namelen > O2NM_MAX_NAME_LEN); - - spin_lock(&res->spinlock); - res->state |= DLM_LOCK_RES_SETREF_INPROG; - spin_unlock(&res->spinlock); - -again: - reassert = 0; - - /* note that if this nodemap is empty, it returns 0 */ - dlm_node_iter_init(nodemap, &iter); - while ((to = dlm_node_iter_next(&iter)) >= 0) { - int r = 0; - struct dlm_master_list_entry *mle = NULL; - - mlog(0, "sending assert master to %d (%.*s)\n", to, - namelen, lockname); - memset(&assert, 0, sizeof(assert)); - assert.node_idx = dlm->node_num; - assert.namelen = namelen; - memcpy(assert.name, lockname, namelen); - assert.flags = cpu_to_be32(flags); - - tmpret = o2net_send_message(DLM_ASSERT_MASTER_MSG, dlm->key, - &assert, sizeof(assert), to, &r); - if (tmpret < 0) { - mlog(ML_ERROR, "Error %d when sending message %u (key " - "0x%x) to node %u\n", tmpret, - DLM_ASSERT_MASTER_MSG, dlm->key, to); - if (!dlm_is_host_down(tmpret)) { - mlog(ML_ERROR, "unhandled error=%d!\n", tmpret); - BUG(); - } - /* a node died. finish out the rest of the nodes. */ - mlog(0, "link to %d went down!\n", to); - /* any nonzero status return will do */ - ret = tmpret; - r = 0; - } else if (r < 0) { - /* ok, something horribly messed. kill thyself. */ - mlog(ML_ERROR,"during assert master of %.*s to %u, " - "got %d.\n", namelen, lockname, to, r); - spin_lock(&dlm->spinlock); - spin_lock(&dlm->master_lock); - if (dlm_find_mle(dlm, &mle, (char *)lockname, - namelen)) { - dlm_print_one_mle(mle); - __dlm_put_mle(mle); - } - spin_unlock(&dlm->master_lock); - spin_unlock(&dlm->spinlock); - BUG(); - } - - if (r & DLM_ASSERT_RESPONSE_REASSERT && - !(r & DLM_ASSERT_RESPONSE_MASTERY_REF)) { - mlog(ML_ERROR, "%.*s: very strange, " - "master MLE but no lockres on %u\n", - namelen, lockname, to); - } - - if (r & DLM_ASSERT_RESPONSE_REASSERT) { - mlog(0, "%.*s: node %u create mles on other " - "nodes and requests a re-assert\n", - namelen, lockname, to); - reassert = 1; - } - if (r & DLM_ASSERT_RESPONSE_MASTERY_REF) { - mlog(0, "%.*s: node %u has a reference to this " - "lockres, set the bit in the refmap\n", - namelen, lockname, to); - spin_lock(&res->spinlock); - dlm_lockres_set_refmap_bit(dlm, res, to); - spin_unlock(&res->spinlock); - } - } - - if (reassert) - goto again; - - spin_lock(&res->spinlock); - res->state &= ~DLM_LOCK_RES_SETREF_INPROG; - spin_unlock(&res->spinlock); - wake_up(&res->wq); - - return ret; -} - -/* - * locks that can be taken here: - * dlm->spinlock - * res->spinlock - * mle->spinlock - * dlm->master_list - * - * if possible, TRIM THIS DOWN!!! - */ -int dlm_assert_master_handler(struct o2net_msg *msg, u32 len, void *data, - void **ret_data) -{ - struct dlm_ctxt *dlm = data; - struct dlm_master_list_entry *mle = NULL; - struct dlm_assert_master *assert = (struct dlm_assert_master *)msg->buf; - struct dlm_lock_resource *res = NULL; - char *name; - unsigned int namelen, hash; - u32 flags; - int master_request = 0, have_lockres_ref = 0; - int ret = 0; - - if (!dlm_grab(dlm)) - return 0; - - name = assert->name; - namelen = assert->namelen; - hash = dlm_lockid_hash(name, namelen); - flags = be32_to_cpu(assert->flags); - - if (namelen > DLM_LOCKID_NAME_MAX) { - mlog(ML_ERROR, "Invalid name length!"); - goto done; - } - - spin_lock(&dlm->spinlock); - - if (flags) - mlog(0, "assert_master with flags: %u\n", flags); - - /* find the MLE */ - spin_lock(&dlm->master_lock); - if (!dlm_find_mle(dlm, &mle, name, namelen)) { - /* not an error, could be master just re-asserting */ - mlog(0, "just got an assert_master from %u, but no " - "MLE for it! (%.*s)\n", assert->node_idx, - namelen, name); - } else { - int bit = find_next_bit (mle->maybe_map, O2NM_MAX_NODES, 0); - if (bit >= O2NM_MAX_NODES) { - /* not necessarily an error, though less likely. - * could be master just re-asserting. */ - mlog(0, "no bits set in the maybe_map, but %u " - "is asserting! (%.*s)\n", assert->node_idx, - namelen, name); - } else if (bit != assert->node_idx) { - if (flags & DLM_ASSERT_MASTER_MLE_CLEANUP) { - mlog(0, "master %u was found, %u should " - "back off\n", assert->node_idx, bit); - } else { - /* with the fix for bug 569, a higher node - * number winning the mastery will respond - * YES to mastery requests, but this node - * had no way of knowing. let it pass. */ - mlog(0, "%u is the lowest node, " - "%u is asserting. (%.*s) %u must " - "have begun after %u won.\n", bit, - assert->node_idx, namelen, name, bit, - assert->node_idx); - } - } - if (mle->type == DLM_MLE_MIGRATION) { - if (flags & DLM_ASSERT_MASTER_MLE_CLEANUP) { - mlog(0, "%s:%.*s: got cleanup assert" - " from %u for migration\n", - dlm->name, namelen, name, - assert->node_idx); - } else if (!(flags & DLM_ASSERT_MASTER_FINISH_MIGRATION)) { - mlog(0, "%s:%.*s: got unrelated assert" - " from %u for migration, ignoring\n", - dlm->name, namelen, name, - assert->node_idx); - __dlm_put_mle(mle); - spin_unlock(&dlm->master_lock); - spin_unlock(&dlm->spinlock); - goto done; - } - } - } - spin_unlock(&dlm->master_lock); - - /* ok everything checks out with the MLE - * now check to see if there is a lockres */ - res = __dlm_lookup_lockres(dlm, name, namelen, hash); - if (res) { - spin_lock(&res->spinlock); - if (res->state & DLM_LOCK_RES_RECOVERING) { - mlog(ML_ERROR, "%u asserting but %.*s is " - "RECOVERING!\n", assert->node_idx, namelen, name); - goto kill; - } - if (!mle) { - if (res->owner != DLM_LOCK_RES_OWNER_UNKNOWN && - res->owner != assert->node_idx) { - mlog(ML_ERROR, "DIE! Mastery assert from %u, " - "but current owner is %u! (%.*s)\n", - assert->node_idx, res->owner, namelen, - name); - __dlm_print_one_lock_resource(res); - BUG(); - } - } else if (mle->type != DLM_MLE_MIGRATION) { - if (res->owner != DLM_LOCK_RES_OWNER_UNKNOWN) { - /* owner is just re-asserting */ - if (res->owner == assert->node_idx) { - mlog(0, "owner %u re-asserting on " - "lock %.*s\n", assert->node_idx, - namelen, name); - goto ok; - } - mlog(ML_ERROR, "got assert_master from " - "node %u, but %u is the owner! " - "(%.*s)\n", assert->node_idx, - res->owner, namelen, name); - goto kill; - } - if (!(res->state & DLM_LOCK_RES_IN_PROGRESS)) { - mlog(ML_ERROR, "got assert from %u, but lock " - "with no owner should be " - "in-progress! (%.*s)\n", - assert->node_idx, - namelen, name); - goto kill; - } - } else /* mle->type == DLM_MLE_MIGRATION */ { - /* should only be getting an assert from new master */ - if (assert->node_idx != mle->new_master) { - mlog(ML_ERROR, "got assert from %u, but " - "new master is %u, and old master " - "was %u (%.*s)\n", - assert->node_idx, mle->new_master, - mle->master, namelen, name); - goto kill; - } - - } -ok: - spin_unlock(&res->spinlock); - } - - // mlog(0, "woo! got an assert_master from node %u!\n", - // assert->node_idx); - if (mle) { - int extra_ref = 0; - int nn = -1; - int rr, err = 0; - - spin_lock(&mle->spinlock); - if (mle->type == DLM_MLE_BLOCK || mle->type == DLM_MLE_MIGRATION) - extra_ref = 1; - else { - /* MASTER mle: if any bits set in the response map - * then the calling node needs to re-assert to clear - * up nodes that this node contacted */ - while ((nn = find_next_bit (mle->response_map, O2NM_MAX_NODES, - nn+1)) < O2NM_MAX_NODES) { - if (nn != dlm->node_num && nn != assert->node_idx) - master_request = 1; - } - } - mle->master = assert->node_idx; - atomic_set(&mle->woken, 1); - wake_up(&mle->wq); - spin_unlock(&mle->spinlock); - - if (res) { - int wake = 0; - spin_lock(&res->spinlock); - if (mle->type == DLM_MLE_MIGRATION) { - mlog(0, "finishing off migration of lockres %.*s, " - "from %u to %u\n", - res->lockname.len, res->lockname.name, - dlm->node_num, mle->new_master); - res->state &= ~DLM_LOCK_RES_MIGRATING; - wake = 1; - dlm_change_lockres_owner(dlm, res, mle->new_master); - BUG_ON(res->state & DLM_LOCK_RES_DIRTY); - } else { - dlm_change_lockres_owner(dlm, res, mle->master); - } - spin_unlock(&res->spinlock); - have_lockres_ref = 1; - if (wake) - wake_up(&res->wq); - } - - /* master is known, detach if not already detached. - * ensures that only one assert_master call will happen - * on this mle. */ - spin_lock(&dlm->master_lock); - - rr = atomic_read(&mle->mle_refs.refcount); - if (mle->inuse > 0) { - if (extra_ref && rr < 3) - err = 1; - else if (!extra_ref && rr < 2) - err = 1; - } else { - if (extra_ref && rr < 2) - err = 1; - else if (!extra_ref && rr < 1) - err = 1; - } - if (err) { - mlog(ML_ERROR, "%s:%.*s: got assert master from %u " - "that will mess up this node, refs=%d, extra=%d, " - "inuse=%d\n", dlm->name, namelen, name, - assert->node_idx, rr, extra_ref, mle->inuse); - dlm_print_one_mle(mle); - } - __dlm_unlink_mle(dlm, mle); - __dlm_mle_detach_hb_events(dlm, mle); - __dlm_put_mle(mle); - if (extra_ref) { - /* the assert master message now balances the extra - * ref given by the master / migration request message. - * if this is the last put, it will be removed - * from the list. */ - __dlm_put_mle(mle); - } - spin_unlock(&dlm->master_lock); - } else if (res) { - if (res->owner != assert->node_idx) { - mlog(0, "assert_master from %u, but current " - "owner is %u (%.*s), no mle\n", assert->node_idx, - res->owner, namelen, name); - } - } - spin_unlock(&dlm->spinlock); - -done: - ret = 0; - if (res) { - spin_lock(&res->spinlock); - res->state |= DLM_LOCK_RES_SETREF_INPROG; - spin_unlock(&res->spinlock); - *ret_data = (void *)res; - } - dlm_put(dlm); - if (master_request) { - mlog(0, "need to tell master to reassert\n"); - /* positive. negative would shoot down the node. */ - ret |= DLM_ASSERT_RESPONSE_REASSERT; - if (!have_lockres_ref) { - mlog(ML_ERROR, "strange, got assert from %u, MASTER " - "mle present here for %s:%.*s, but no lockres!\n", - assert->node_idx, dlm->name, namelen, name); - } - } - if (have_lockres_ref) { - /* let the master know we have a reference to the lockres */ - ret |= DLM_ASSERT_RESPONSE_MASTERY_REF; - mlog(0, "%s:%.*s: got assert from %u, need a ref\n", - dlm->name, namelen, name, assert->node_idx); - } - return ret; - -kill: - /* kill the caller! */ - mlog(ML_ERROR, "Bad message received from another node. Dumping state " - "and killing the other node now! This node is OK and can continue.\n"); - __dlm_print_one_lock_resource(res); - spin_unlock(&res->spinlock); - spin_unlock(&dlm->spinlock); - *ret_data = (void *)res; - dlm_put(dlm); - return -EINVAL; -} - -void dlm_assert_master_post_handler(int status, void *data, void *ret_data) -{ - struct dlm_lock_resource *res = (struct dlm_lock_resource *)ret_data; - - if (ret_data) { - spin_lock(&res->spinlock); - res->state &= ~DLM_LOCK_RES_SETREF_INPROG; - spin_unlock(&res->spinlock); - wake_up(&res->wq); - dlm_lockres_put(res); - } - return; -} - -int dlm_dispatch_assert_master(struct dlm_ctxt *dlm, - struct dlm_lock_resource *res, - int ignore_higher, u8 request_from, u32 flags) -{ - struct dlm_work_item *item; - item = kzalloc(sizeof(*item), GFP_NOFS); - if (!item) - return -ENOMEM; - - - /* queue up work for dlm_assert_master_worker */ - dlm_grab(dlm); /* get an extra ref for the work item */ - dlm_init_work_item(dlm, item, dlm_assert_master_worker, NULL); - item->u.am.lockres = res; /* already have a ref */ - /* can optionally ignore node numbers higher than this node */ - item->u.am.ignore_higher = ignore_higher; - item->u.am.request_from = request_from; - item->u.am.flags = flags; - - if (ignore_higher) - mlog(0, "IGNORE HIGHER: %.*s\n", res->lockname.len, - res->lockname.name); - - spin_lock(&dlm->work_lock); - list_add_tail(&item->list, &dlm->work_list); - spin_unlock(&dlm->work_lock); - - queue_work(dlm->dlm_worker, &dlm->dispatched_work); - return 0; -} - -static void dlm_assert_master_worker(struct dlm_work_item *item, void *data) -{ - struct dlm_ctxt *dlm = data; - int ret = 0; - struct dlm_lock_resource *res; - unsigned long nodemap[BITS_TO_LONGS(O2NM_MAX_NODES)]; - int ignore_higher; - int bit; - u8 request_from; - u32 flags; - - dlm = item->dlm; - res = item->u.am.lockres; - ignore_higher = item->u.am.ignore_higher; - request_from = item->u.am.request_from; - flags = item->u.am.flags; - - spin_lock(&dlm->spinlock); - memcpy(nodemap, dlm->domain_map, sizeof(nodemap)); - spin_unlock(&dlm->spinlock); - - clear_bit(dlm->node_num, nodemap); - if (ignore_higher) { - /* if is this just to clear up mles for nodes below - * this node, do not send the message to the original - * caller or any node number higher than this */ - clear_bit(request_from, nodemap); - bit = dlm->node_num; - while (1) { - bit = find_next_bit(nodemap, O2NM_MAX_NODES, - bit+1); - if (bit >= O2NM_MAX_NODES) - break; - clear_bit(bit, nodemap); - } - } - - /* - * If we're migrating this lock to someone else, we are no - * longer allowed to assert out own mastery. OTOH, we need to - * prevent migration from starting while we're still asserting - * our dominance. The reserved ast delays migration. - */ - spin_lock(&res->spinlock); - if (res->state & DLM_LOCK_RES_MIGRATING) { - mlog(0, "Someone asked us to assert mastery, but we're " - "in the middle of migration. Skipping assert, " - "the new master will handle that.\n"); - spin_unlock(&res->spinlock); - goto put; - } else - __dlm_lockres_reserve_ast(res); - spin_unlock(&res->spinlock); - - /* this call now finishes out the nodemap - * even if one or more nodes die */ - mlog(0, "worker about to master %.*s here, this=%u\n", - res->lockname.len, res->lockname.name, dlm->node_num); - ret = dlm_do_assert_master(dlm, res, nodemap, flags); - if (ret < 0) { - /* no need to restart, we are done */ - if (!dlm_is_host_down(ret)) - mlog_errno(ret); - } - - /* Ok, we've asserted ourselves. Let's let migration start. */ - dlm_lockres_release_ast(dlm, res); - -put: - dlm_lockres_put(res); - - mlog(0, "finished with dlm_assert_master_worker\n"); -} - -/* SPECIAL CASE for the $RECOVERY lock used by the recovery thread. - * We cannot wait for node recovery to complete to begin mastering this - * lockres because this lockres is used to kick off recovery! ;-) - * So, do a pre-check on all living nodes to see if any of those nodes - * think that $RECOVERY is currently mastered by a dead node. If so, - * we wait a short time to allow that node to get notified by its own - * heartbeat stack, then check again. All $RECOVERY lock resources - * mastered by dead nodes are purged when the hearbeat callback is - * fired, so we can know for sure that it is safe to continue once - * the node returns a live node or no node. */ -static int dlm_pre_master_reco_lockres(struct dlm_ctxt *dlm, - struct dlm_lock_resource *res) -{ - struct dlm_node_iter iter; - int nodenum; - int ret = 0; - u8 master = DLM_LOCK_RES_OWNER_UNKNOWN; - - spin_lock(&dlm->spinlock); - dlm_node_iter_init(dlm->domain_map, &iter); - spin_unlock(&dlm->spinlock); - - while ((nodenum = dlm_node_iter_next(&iter)) >= 0) { - /* do not send to self */ - if (nodenum == dlm->node_num) - continue; - ret = dlm_do_master_requery(dlm, res, nodenum, &master); - if (ret < 0) { - mlog_errno(ret); - if (!dlm_is_host_down(ret)) - BUG(); - /* host is down, so answer for that node would be - * DLM_LOCK_RES_OWNER_UNKNOWN. continue. */ - ret = 0; - } - - if (master != DLM_LOCK_RES_OWNER_UNKNOWN) { - /* check to see if this master is in the recovery map */ - spin_lock(&dlm->spinlock); - if (test_bit(master, dlm->recovery_map)) { - mlog(ML_NOTICE, "%s: node %u has not seen " - "node %u go down yet, and thinks the " - "dead node is mastering the recovery " - "lock. must wait.\n", dlm->name, - nodenum, master); - ret = -EAGAIN; - } - spin_unlock(&dlm->spinlock); - mlog(0, "%s: reco lock master is %u\n", dlm->name, - master); - break; - } - } - return ret; -} - -/* - * DLM_DEREF_LOCKRES_MSG - */ - -int dlm_drop_lockres_ref(struct dlm_ctxt *dlm, struct dlm_lock_resource *res) -{ - struct dlm_deref_lockres deref; - int ret = 0, r; - const char *lockname; - unsigned int namelen; - - lockname = res->lockname.name; - namelen = res->lockname.len; - BUG_ON(namelen > O2NM_MAX_NAME_LEN); - - memset(&deref, 0, sizeof(deref)); - deref.node_idx = dlm->node_num; - deref.namelen = namelen; - memcpy(deref.name, lockname, namelen); - - ret = o2net_send_message(DLM_DEREF_LOCKRES_MSG, dlm->key, - &deref, sizeof(deref), res->owner, &r); - if (ret < 0) - mlog(ML_ERROR, "%s: res %.*s, error %d send DEREF to node %u\n", - dlm->name, namelen, lockname, ret, res->owner); - else if (r < 0) { - /* BAD. other node says I did not have a ref. */ - mlog(ML_ERROR, "%s: res %.*s, DEREF to node %u got %d\n", - dlm->name, namelen, lockname, res->owner, r); - dlm_print_one_lock_resource(res); - BUG(); - } - return ret; -} - -int dlm_deref_lockres_handler(struct o2net_msg *msg, u32 len, void *data, - void **ret_data) -{ - struct dlm_ctxt *dlm = data; - struct dlm_deref_lockres *deref = (struct dlm_deref_lockres *)msg->buf; - struct dlm_lock_resource *res = NULL; - char *name; - unsigned int namelen; - int ret = -EINVAL; - u8 node; - unsigned int hash; - struct dlm_work_item *item; - int cleared = 0; - int dispatch = 0; - - if (!dlm_grab(dlm)) - return 0; - - name = deref->name; - namelen = deref->namelen; - node = deref->node_idx; - - if (namelen > DLM_LOCKID_NAME_MAX) { - mlog(ML_ERROR, "Invalid name length!"); - goto done; - } - if (deref->node_idx >= O2NM_MAX_NODES) { - mlog(ML_ERROR, "Invalid node number: %u\n", node); - goto done; - } - - hash = dlm_lockid_hash(name, namelen); - - spin_lock(&dlm->spinlock); - res = __dlm_lookup_lockres_full(dlm, name, namelen, hash); - if (!res) { - spin_unlock(&dlm->spinlock); - mlog(ML_ERROR, "%s:%.*s: bad lockres name\n", - dlm->name, namelen, name); - goto done; - } - spin_unlock(&dlm->spinlock); - - spin_lock(&res->spinlock); - if (res->state & DLM_LOCK_RES_SETREF_INPROG) - dispatch = 1; - else { - BUG_ON(res->state & DLM_LOCK_RES_DROPPING_REF); - if (test_bit(node, res->refmap)) { - dlm_lockres_clear_refmap_bit(dlm, res, node); - cleared = 1; - } - } - spin_unlock(&res->spinlock); - - if (!dispatch) { - if (cleared) - dlm_lockres_calc_usage(dlm, res); - else { - mlog(ML_ERROR, "%s:%.*s: node %u trying to drop ref " - "but it is already dropped!\n", dlm->name, - res->lockname.len, res->lockname.name, node); - dlm_print_one_lock_resource(res); - } - ret = 0; - goto done; - } - - item = kzalloc(sizeof(*item), GFP_NOFS); - if (!item) { - ret = -ENOMEM; - mlog_errno(ret); - goto done; - } - - dlm_init_work_item(dlm, item, dlm_deref_lockres_worker, NULL); - item->u.dl.deref_res = res; - item->u.dl.deref_node = node; - - spin_lock(&dlm->work_lock); - list_add_tail(&item->list, &dlm->work_list); - spin_unlock(&dlm->work_lock); - - queue_work(dlm->dlm_worker, &dlm->dispatched_work); - return 0; - -done: - if (res) - dlm_lockres_put(res); - dlm_put(dlm); - - return ret; -} - -static void dlm_deref_lockres_worker(struct dlm_work_item *item, void *data) -{ - struct dlm_ctxt *dlm; - struct dlm_lock_resource *res; - u8 node; - u8 cleared = 0; - - dlm = item->dlm; - res = item->u.dl.deref_res; - node = item->u.dl.deref_node; - - spin_lock(&res->spinlock); - BUG_ON(res->state & DLM_LOCK_RES_DROPPING_REF); - if (test_bit(node, res->refmap)) { - __dlm_wait_on_lockres_flags(res, DLM_LOCK_RES_SETREF_INPROG); - dlm_lockres_clear_refmap_bit(dlm, res, node); - cleared = 1; - } - spin_unlock(&res->spinlock); - - if (cleared) { - mlog(0, "%s:%.*s node %u ref dropped in dispatch\n", - dlm->name, res->lockname.len, res->lockname.name, node); - dlm_lockres_calc_usage(dlm, res); - } else { - mlog(ML_ERROR, "%s:%.*s: node %u trying to drop ref " - "but it is already dropped!\n", dlm->name, - res->lockname.len, res->lockname.name, node); - dlm_print_one_lock_resource(res); - } - - dlm_lockres_put(res); -} - -/* - * A migrateable resource is one that is : - * 1. locally mastered, and, - * 2. zero local locks, and, - * 3. one or more non-local locks, or, one or more references - * Returns 1 if yes, 0 if not. - */ -static int dlm_is_lockres_migrateable(struct dlm_ctxt *dlm, - struct dlm_lock_resource *res) -{ - enum dlm_lockres_list idx; - int nonlocal = 0, node_ref; - struct list_head *queue; - struct dlm_lock *lock; - u64 cookie; - - assert_spin_locked(&res->spinlock); - - if (res->owner != dlm->node_num) - return 0; - - for (idx = DLM_GRANTED_LIST; idx <= DLM_BLOCKED_LIST; idx++) { - queue = dlm_list_idx_to_ptr(res, idx); - list_for_each_entry(lock, queue, list) { - if (lock->ml.node != dlm->node_num) { - nonlocal++; - continue; - } - cookie = be64_to_cpu(lock->ml.cookie); - mlog(0, "%s: Not migrateable res %.*s, lock %u:%llu on " - "%s list\n", dlm->name, res->lockname.len, - res->lockname.name, - dlm_get_lock_cookie_node(cookie), - dlm_get_lock_cookie_seq(cookie), - dlm_list_in_text(idx)); - return 0; - } - } - - if (!nonlocal) { - node_ref = find_next_bit(res->refmap, O2NM_MAX_NODES, 0); - if (node_ref >= O2NM_MAX_NODES) - return 0; - } - - mlog(0, "%s: res %.*s, Migrateable\n", dlm->name, res->lockname.len, - res->lockname.name); - - return 1; -} - -/* - * DLM_MIGRATE_LOCKRES - */ - - -static int dlm_migrate_lockres(struct dlm_ctxt *dlm, - struct dlm_lock_resource *res, u8 target) -{ - struct dlm_master_list_entry *mle = NULL; - struct dlm_master_list_entry *oldmle = NULL; - struct dlm_migratable_lockres *mres = NULL; - int ret = 0; - const char *name; - unsigned int namelen; - int mle_added = 0; - int wake = 0; - - if (!dlm_grab(dlm)) - return -EINVAL; - - BUG_ON(target == O2NM_MAX_NODES); - - name = res->lockname.name; - namelen = res->lockname.len; - - mlog(0, "%s: Migrating %.*s to node %u\n", dlm->name, namelen, name, - target); - - /* preallocate up front. if this fails, abort */ - ret = -ENOMEM; - mres = (struct dlm_migratable_lockres *) __get_free_page(GFP_NOFS); - if (!mres) { - mlog_errno(ret); - goto leave; - } - - mle = kmem_cache_alloc(dlm_mle_cache, GFP_NOFS); - if (!mle) { - mlog_errno(ret); - goto leave; - } - ret = 0; - - /* - * clear any existing master requests and - * add the migration mle to the list - */ - spin_lock(&dlm->spinlock); - spin_lock(&dlm->master_lock); - ret = dlm_add_migration_mle(dlm, res, mle, &oldmle, name, - namelen, target, dlm->node_num); - spin_unlock(&dlm->master_lock); - spin_unlock(&dlm->spinlock); - - if (ret == -EEXIST) { - mlog(0, "another process is already migrating it\n"); - goto fail; - } - mle_added = 1; - - /* - * set the MIGRATING flag and flush asts - * if we fail after this we need to re-dirty the lockres - */ - if (dlm_mark_lockres_migrating(dlm, res, target) < 0) { - mlog(ML_ERROR, "tried to migrate %.*s to %u, but " - "the target went down.\n", res->lockname.len, - res->lockname.name, target); - spin_lock(&res->spinlock); - res->state &= ~DLM_LOCK_RES_MIGRATING; - wake = 1; - spin_unlock(&res->spinlock); - ret = -EINVAL; - } - -fail: - if (oldmle) { - /* master is known, detach if not already detached */ - dlm_mle_detach_hb_events(dlm, oldmle); - dlm_put_mle(oldmle); - } - - if (ret < 0) { - if (mle_added) { - dlm_mle_detach_hb_events(dlm, mle); - dlm_put_mle(mle); - } else if (mle) { - kmem_cache_free(dlm_mle_cache, mle); - mle = NULL; - } - goto leave; - } - - /* - * at this point, we have a migration target, an mle - * in the master list, and the MIGRATING flag set on - * the lockres - */ - - /* now that remote nodes are spinning on the MIGRATING flag, - * ensure that all assert_master work is flushed. */ - flush_workqueue(dlm->dlm_worker); - - /* get an extra reference on the mle. - * otherwise the assert_master from the new - * master will destroy this. - * also, make sure that all callers of dlm_get_mle - * take both dlm->spinlock and dlm->master_lock */ - spin_lock(&dlm->spinlock); - spin_lock(&dlm->master_lock); - dlm_get_mle_inuse(mle); - spin_unlock(&dlm->master_lock); - spin_unlock(&dlm->spinlock); - - /* notify new node and send all lock state */ - /* call send_one_lockres with migration flag. - * this serves as notice to the target node that a - * migration is starting. */ - ret = dlm_send_one_lockres(dlm, res, mres, target, - DLM_MRES_MIGRATION); - - if (ret < 0) { - mlog(0, "migration to node %u failed with %d\n", - target, ret); - /* migration failed, detach and clean up mle */ - dlm_mle_detach_hb_events(dlm, mle); - dlm_put_mle(mle); - dlm_put_mle_inuse(mle); - spin_lock(&res->spinlock); - res->state &= ~DLM_LOCK_RES_MIGRATING; - wake = 1; - spin_unlock(&res->spinlock); - if (dlm_is_host_down(ret)) - dlm_wait_for_node_death(dlm, target, - DLM_NODE_DEATH_WAIT_MAX); - goto leave; - } - - /* at this point, the target sends a message to all nodes, - * (using dlm_do_migrate_request). this node is skipped since - * we had to put an mle in the list to begin the process. this - * node now waits for target to do an assert master. this node - * will be the last one notified, ensuring that the migration - * is complete everywhere. if the target dies while this is - * going on, some nodes could potentially see the target as the - * master, so it is important that my recovery finds the migration - * mle and sets the master to UNKNOWN. */ - - - /* wait for new node to assert master */ - while (1) { - ret = wait_event_interruptible_timeout(mle->wq, - (atomic_read(&mle->woken) == 1), - msecs_to_jiffies(5000)); - - if (ret >= 0) { - if (atomic_read(&mle->woken) == 1 || - res->owner == target) - break; - - mlog(0, "%s:%.*s: timed out during migration\n", - dlm->name, res->lockname.len, res->lockname.name); - /* avoid hang during shutdown when migrating lockres - * to a node which also goes down */ - if (dlm_is_node_dead(dlm, target)) { - mlog(0, "%s:%.*s: expected migration " - "target %u is no longer up, restarting\n", - dlm->name, res->lockname.len, - res->lockname.name, target); - ret = -EINVAL; - /* migration failed, detach and clean up mle */ - dlm_mle_detach_hb_events(dlm, mle); - dlm_put_mle(mle); - dlm_put_mle_inuse(mle); - spin_lock(&res->spinlock); - res->state &= ~DLM_LOCK_RES_MIGRATING; - wake = 1; - spin_unlock(&res->spinlock); - goto leave; - } - } else - mlog(0, "%s:%.*s: caught signal during migration\n", - dlm->name, res->lockname.len, res->lockname.name); - } - - /* all done, set the owner, clear the flag */ - spin_lock(&res->spinlock); - dlm_set_lockres_owner(dlm, res, target); - res->state &= ~DLM_LOCK_RES_MIGRATING; - dlm_remove_nonlocal_locks(dlm, res); - spin_unlock(&res->spinlock); - wake_up(&res->wq); - - /* master is known, detach if not already detached */ - dlm_mle_detach_hb_events(dlm, mle); - dlm_put_mle_inuse(mle); - ret = 0; - - dlm_lockres_calc_usage(dlm, res); - -leave: - /* re-dirty the lockres if we failed */ - if (ret < 0) - dlm_kick_thread(dlm, res); - - /* wake up waiters if the MIGRATING flag got set - * but migration failed */ - if (wake) - wake_up(&res->wq); - - if (mres) - free_page((unsigned long)mres); - - dlm_put(dlm); - - mlog(0, "%s: Migrating %.*s to %u, returns %d\n", dlm->name, namelen, - name, target, ret); - return ret; -} - -#define DLM_MIGRATION_RETRY_MS 100 - -/* - * Should be called only after beginning the domain leave process. - * There should not be any remaining locks on nonlocal lock resources, - * and there should be no local locks left on locally mastered resources. - * - * Called with the dlm spinlock held, may drop it to do migration, but - * will re-acquire before exit. - * - * Returns: 1 if dlm->spinlock was dropped/retaken, 0 if never dropped - */ -int dlm_empty_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *res) -{ - int ret; - int lock_dropped = 0; - u8 target = O2NM_MAX_NODES; - - assert_spin_locked(&dlm->spinlock); - - spin_lock(&res->spinlock); - if (dlm_is_lockres_migrateable(dlm, res)) - target = dlm_pick_migration_target(dlm, res); - spin_unlock(&res->spinlock); - - if (target == O2NM_MAX_NODES) - goto leave; - - /* Wheee! Migrate lockres here! Will sleep so drop spinlock. */ - spin_unlock(&dlm->spinlock); - lock_dropped = 1; - ret = dlm_migrate_lockres(dlm, res, target); - if (ret) - mlog(0, "%s: res %.*s, Migrate to node %u failed with %d\n", - dlm->name, res->lockname.len, res->lockname.name, - target, ret); - spin_lock(&dlm->spinlock); -leave: - return lock_dropped; -} - -int dlm_lock_basts_flushed(struct dlm_ctxt *dlm, struct dlm_lock *lock) -{ - int ret; - spin_lock(&dlm->ast_lock); - spin_lock(&lock->spinlock); - ret = (list_empty(&lock->bast_list) && !lock->bast_pending); - spin_unlock(&lock->spinlock); - spin_unlock(&dlm->ast_lock); - return ret; -} - -static int dlm_migration_can_proceed(struct dlm_ctxt *dlm, - struct dlm_lock_resource *res, - u8 mig_target) -{ - int can_proceed; - spin_lock(&res->spinlock); - can_proceed = !!(res->state & DLM_LOCK_RES_MIGRATING); - spin_unlock(&res->spinlock); - - /* target has died, so make the caller break out of the - * wait_event, but caller must recheck the domain_map */ - spin_lock(&dlm->spinlock); - if (!test_bit(mig_target, dlm->domain_map)) - can_proceed = 1; - spin_unlock(&dlm->spinlock); - return can_proceed; -} - -static int dlm_lockres_is_dirty(struct dlm_ctxt *dlm, - struct dlm_lock_resource *res) -{ - int ret; - spin_lock(&res->spinlock); - ret = !!(res->state & DLM_LOCK_RES_DIRTY); - spin_unlock(&res->spinlock); - return ret; -} - - -static int dlm_mark_lockres_migrating(struct dlm_ctxt *dlm, - struct dlm_lock_resource *res, - u8 target) -{ - int ret = 0; - - mlog(0, "dlm_mark_lockres_migrating: %.*s, from %u to %u\n", - res->lockname.len, res->lockname.name, dlm->node_num, - target); - /* need to set MIGRATING flag on lockres. this is done by - * ensuring that all asts have been flushed for this lockres. */ - spin_lock(&res->spinlock); - BUG_ON(res->migration_pending); - res->migration_pending = 1; - /* strategy is to reserve an extra ast then release - * it below, letting the release do all of the work */ - __dlm_lockres_reserve_ast(res); - spin_unlock(&res->spinlock); - - /* now flush all the pending asts */ - dlm_kick_thread(dlm, res); - /* before waiting on DIRTY, block processes which may - * try to dirty the lockres before MIGRATING is set */ - spin_lock(&res->spinlock); - BUG_ON(res->state & DLM_LOCK_RES_BLOCK_DIRTY); - res->state |= DLM_LOCK_RES_BLOCK_DIRTY; - spin_unlock(&res->spinlock); - /* now wait on any pending asts and the DIRTY state */ - wait_event(dlm->ast_wq, !dlm_lockres_is_dirty(dlm, res)); - dlm_lockres_release_ast(dlm, res); - - mlog(0, "about to wait on migration_wq, dirty=%s\n", - res->state & DLM_LOCK_RES_DIRTY ? "yes" : "no"); - /* if the extra ref we just put was the final one, this - * will pass thru immediately. otherwise, we need to wait - * for the last ast to finish. */ -again: - ret = wait_event_interruptible_timeout(dlm->migration_wq, - dlm_migration_can_proceed(dlm, res, target), - msecs_to_jiffies(1000)); - if (ret < 0) { - mlog(0, "woken again: migrating? %s, dead? %s\n", - res->state & DLM_LOCK_RES_MIGRATING ? "yes":"no", - test_bit(target, dlm->domain_map) ? "no":"yes"); - } else { - mlog(0, "all is well: migrating? %s, dead? %s\n", - res->state & DLM_LOCK_RES_MIGRATING ? "yes":"no", - test_bit(target, dlm->domain_map) ? "no":"yes"); - } - if (!dlm_migration_can_proceed(dlm, res, target)) { - mlog(0, "trying again...\n"); - goto again; - } - - ret = 0; - /* did the target go down or die? */ - spin_lock(&dlm->spinlock); - if (!test_bit(target, dlm->domain_map)) { - mlog(ML_ERROR, "aha. migration target %u just went down\n", - target); - ret = -EHOSTDOWN; - } - spin_unlock(&dlm->spinlock); - - /* - * if target is down, we need to clear DLM_LOCK_RES_BLOCK_DIRTY for - * another try; otherwise, we are sure the MIGRATING state is there, - * drop the unneded state which blocked threads trying to DIRTY - */ - spin_lock(&res->spinlock); - BUG_ON(!(res->state & DLM_LOCK_RES_BLOCK_DIRTY)); - res->state &= ~DLM_LOCK_RES_BLOCK_DIRTY; - if (!ret) - BUG_ON(!(res->state & DLM_LOCK_RES_MIGRATING)); - spin_unlock(&res->spinlock); - - /* - * at this point: - * - * o the DLM_LOCK_RES_MIGRATING flag is set if target not down - * o there are no pending asts on this lockres - * o all processes trying to reserve an ast on this - * lockres must wait for the MIGRATING flag to clear - */ - return ret; -} - -/* last step in the migration process. - * original master calls this to free all of the dlm_lock - * structures that used to be for other nodes. */ -static void dlm_remove_nonlocal_locks(struct dlm_ctxt *dlm, - struct dlm_lock_resource *res) -{ - struct list_head *queue = &res->granted; - int i, bit; - struct dlm_lock *lock, *next; - - assert_spin_locked(&res->spinlock); - - BUG_ON(res->owner == dlm->node_num); - - for (i=0; i<3; i++) { - list_for_each_entry_safe(lock, next, queue, list) { - if (lock->ml.node != dlm->node_num) { - mlog(0, "putting lock for node %u\n", - lock->ml.node); - /* be extra careful */ - BUG_ON(!list_empty(&lock->ast_list)); - BUG_ON(!list_empty(&lock->bast_list)); - BUG_ON(lock->ast_pending); - BUG_ON(lock->bast_pending); - dlm_lockres_clear_refmap_bit(dlm, res, - lock->ml.node); - list_del_init(&lock->list); - dlm_lock_put(lock); - /* In a normal unlock, we would have added a - * DLM_UNLOCK_FREE_LOCK action. Force it. */ - dlm_lock_put(lock); - } - } - queue++; - } - bit = 0; - while (1) { - bit = find_next_bit(res->refmap, O2NM_MAX_NODES, bit); - if (bit >= O2NM_MAX_NODES) - break; - /* do not clear the local node reference, if there is a - * process holding this, let it drop the ref itself */ - if (bit != dlm->node_num) { - mlog(0, "%s:%.*s: node %u had a ref to this " - "migrating lockres, clearing\n", dlm->name, - res->lockname.len, res->lockname.name, bit); - dlm_lockres_clear_refmap_bit(dlm, res, bit); - } - bit++; - } -} - -/* - * Pick a node to migrate the lock resource to. This function selects a - * potential target based first on the locks and then on refmap. It skips - * nodes that are in the process of exiting the domain. - */ -static u8 dlm_pick_migration_target(struct dlm_ctxt *dlm, - struct dlm_lock_resource *res) -{ - enum dlm_lockres_list idx; - struct list_head *queue = &res->granted; - struct dlm_lock *lock; - int noderef; - u8 nodenum = O2NM_MAX_NODES; - - assert_spin_locked(&dlm->spinlock); - assert_spin_locked(&res->spinlock); - - /* Go through all the locks */ - for (idx = DLM_GRANTED_LIST; idx <= DLM_BLOCKED_LIST; idx++) { - queue = dlm_list_idx_to_ptr(res, idx); - list_for_each_entry(lock, queue, list) { - if (lock->ml.node == dlm->node_num) - continue; - if (test_bit(lock->ml.node, dlm->exit_domain_map)) - continue; - nodenum = lock->ml.node; - goto bail; - } - } - - /* Go thru the refmap */ - noderef = -1; - while (1) { - noderef = find_next_bit(res->refmap, O2NM_MAX_NODES, - noderef + 1); - if (noderef >= O2NM_MAX_NODES) - break; - if (noderef == dlm->node_num) - continue; - if (test_bit(noderef, dlm->exit_domain_map)) - continue; - nodenum = noderef; - goto bail; - } - -bail: - return nodenum; -} - -/* this is called by the new master once all lockres - * data has been received */ -static int dlm_do_migrate_request(struct dlm_ctxt *dlm, - struct dlm_lock_resource *res, - u8 master, u8 new_master, - struct dlm_node_iter *iter) -{ - struct dlm_migrate_request migrate; - int ret, skip, status = 0; - int nodenum; - - memset(&migrate, 0, sizeof(migrate)); - migrate.namelen = res->lockname.len; - memcpy(migrate.name, res->lockname.name, migrate.namelen); - migrate.new_master = new_master; - migrate.master = master; - - ret = 0; - - /* send message to all nodes, except the master and myself */ - while ((nodenum = dlm_node_iter_next(iter)) >= 0) { - if (nodenum == master || - nodenum == new_master) - continue; - - /* We could race exit domain. If exited, skip. */ - spin_lock(&dlm->spinlock); - skip = (!test_bit(nodenum, dlm->domain_map)); - spin_unlock(&dlm->spinlock); - if (skip) { - clear_bit(nodenum, iter->node_map); - continue; - } - - ret = o2net_send_message(DLM_MIGRATE_REQUEST_MSG, dlm->key, - &migrate, sizeof(migrate), nodenum, - &status); - if (ret < 0) { - mlog(ML_ERROR, "%s: res %.*s, Error %d send " - "MIGRATE_REQUEST to node %u\n", dlm->name, - migrate.namelen, migrate.name, ret, nodenum); - if (!dlm_is_host_down(ret)) { - mlog(ML_ERROR, "unhandled error=%d!\n", ret); - BUG(); - } - clear_bit(nodenum, iter->node_map); - ret = 0; - } else if (status < 0) { - mlog(0, "migrate request (node %u) returned %d!\n", - nodenum, status); - ret = status; - } else if (status == DLM_MIGRATE_RESPONSE_MASTERY_REF) { - /* during the migration request we short-circuited - * the mastery of the lockres. make sure we have - * a mastery ref for nodenum */ - mlog(0, "%s:%.*s: need ref for node %u\n", - dlm->name, res->lockname.len, res->lockname.name, - nodenum); - spin_lock(&res->spinlock); - dlm_lockres_set_refmap_bit(dlm, res, nodenum); - spin_unlock(&res->spinlock); - } - } - - if (ret < 0) - mlog_errno(ret); - - mlog(0, "returning ret=%d\n", ret); - return ret; -} - - -/* if there is an existing mle for this lockres, we now know who the master is. - * (the one who sent us *this* message) we can clear it up right away. - * since the process that put the mle on the list still has a reference to it, - * we can unhash it now, set the master and wake the process. as a result, - * we will have no mle in the list to start with. now we can add an mle for - * the migration and this should be the only one found for those scanning the - * list. */ -int dlm_migrate_request_handler(struct o2net_msg *msg, u32 len, void *data, - void **ret_data) -{ - struct dlm_ctxt *dlm = data; - struct dlm_lock_resource *res = NULL; - struct dlm_migrate_request *migrate = (struct dlm_migrate_request *) msg->buf; - struct dlm_master_list_entry *mle = NULL, *oldmle = NULL; - const char *name; - unsigned int namelen, hash; - int ret = 0; - - if (!dlm_grab(dlm)) - return -EINVAL; - - name = migrate->name; - namelen = migrate->namelen; - hash = dlm_lockid_hash(name, namelen); - - /* preallocate.. if this fails, abort */ - mle = kmem_cache_alloc(dlm_mle_cache, GFP_NOFS); - - if (!mle) { - ret = -ENOMEM; - goto leave; - } - - /* check for pre-existing lock */ - spin_lock(&dlm->spinlock); - res = __dlm_lookup_lockres(dlm, name, namelen, hash); - if (res) { - spin_lock(&res->spinlock); - if (res->state & DLM_LOCK_RES_RECOVERING) { - /* if all is working ok, this can only mean that we got - * a migrate request from a node that we now see as - * dead. what can we do here? drop it to the floor? */ - spin_unlock(&res->spinlock); - mlog(ML_ERROR, "Got a migrate request, but the " - "lockres is marked as recovering!"); - kmem_cache_free(dlm_mle_cache, mle); - ret = -EINVAL; /* need a better solution */ - goto unlock; - } - res->state |= DLM_LOCK_RES_MIGRATING; - spin_unlock(&res->spinlock); - } - - spin_lock(&dlm->master_lock); - /* ignore status. only nonzero status would BUG. */ - ret = dlm_add_migration_mle(dlm, res, mle, &oldmle, - name, namelen, - migrate->new_master, - migrate->master); - - spin_unlock(&dlm->master_lock); -unlock: - spin_unlock(&dlm->spinlock); - - if (oldmle) { - /* master is known, detach if not already detached */ - dlm_mle_detach_hb_events(dlm, oldmle); - dlm_put_mle(oldmle); - } - - if (res) - dlm_lockres_put(res); -leave: - dlm_put(dlm); - return ret; -} - -/* must be holding dlm->spinlock and dlm->master_lock - * when adding a migration mle, we can clear any other mles - * in the master list because we know with certainty that - * the master is "master". so we remove any old mle from - * the list after setting it's master field, and then add - * the new migration mle. this way we can hold with the rule - * of having only one mle for a given lock name at all times. */ -static int dlm_add_migration_mle(struct dlm_ctxt *dlm, - struct dlm_lock_resource *res, - struct dlm_master_list_entry *mle, - struct dlm_master_list_entry **oldmle, - const char *name, unsigned int namelen, - u8 new_master, u8 master) -{ - int found; - int ret = 0; - - *oldmle = NULL; - - assert_spin_locked(&dlm->spinlock); - assert_spin_locked(&dlm->master_lock); - - /* caller is responsible for any ref taken here on oldmle */ - found = dlm_find_mle(dlm, oldmle, (char *)name, namelen); - if (found) { - struct dlm_master_list_entry *tmp = *oldmle; - spin_lock(&tmp->spinlock); - if (tmp->type == DLM_MLE_MIGRATION) { - if (master == dlm->node_num) { - /* ah another process raced me to it */ - mlog(0, "tried to migrate %.*s, but some " - "process beat me to it\n", - namelen, name); - ret = -EEXIST; - } else { - /* bad. 2 NODES are trying to migrate! */ - mlog(ML_ERROR, "migration error mle: " - "master=%u new_master=%u // request: " - "master=%u new_master=%u // " - "lockres=%.*s\n", - tmp->master, tmp->new_master, - master, new_master, - namelen, name); - BUG(); - } - } else { - /* this is essentially what assert_master does */ - tmp->master = master; - atomic_set(&tmp->woken, 1); - wake_up(&tmp->wq); - /* remove it so that only one mle will be found */ - __dlm_unlink_mle(dlm, tmp); - __dlm_mle_detach_hb_events(dlm, tmp); - ret = DLM_MIGRATE_RESPONSE_MASTERY_REF; - mlog(0, "%s:%.*s: master=%u, newmaster=%u, " - "telling master to get ref for cleared out mle " - "during migration\n", dlm->name, namelen, name, - master, new_master); - } - spin_unlock(&tmp->spinlock); - } - - /* now add a migration mle to the tail of the list */ - dlm_init_mle(mle, DLM_MLE_MIGRATION, dlm, res, name, namelen); - mle->new_master = new_master; - /* the new master will be sending an assert master for this. - * at that point we will get the refmap reference */ - mle->master = master; - /* do this for consistency with other mle types */ - set_bit(new_master, mle->maybe_map); - __dlm_insert_mle(dlm, mle); - - return ret; -} - -/* - * Sets the owner of the lockres, associated to the mle, to UNKNOWN - */ -static struct dlm_lock_resource *dlm_reset_mleres_owner(struct dlm_ctxt *dlm, - struct dlm_master_list_entry *mle) -{ - struct dlm_lock_resource *res; - - /* Find the lockres associated to the mle and set its owner to UNK */ - res = __dlm_lookup_lockres(dlm, mle->mname, mle->mnamelen, - mle->mnamehash); - if (res) { - spin_unlock(&dlm->master_lock); - - /* move lockres onto recovery list */ - spin_lock(&res->spinlock); - dlm_set_lockres_owner(dlm, res, DLM_LOCK_RES_OWNER_UNKNOWN); - dlm_move_lockres_to_recovery_list(dlm, res); - spin_unlock(&res->spinlock); - dlm_lockres_put(res); - - /* about to get rid of mle, detach from heartbeat */ - __dlm_mle_detach_hb_events(dlm, mle); - - /* dump the mle */ - spin_lock(&dlm->master_lock); - __dlm_put_mle(mle); - spin_unlock(&dlm->master_lock); - } - - return res; -} - -static void dlm_clean_migration_mle(struct dlm_ctxt *dlm, - struct dlm_master_list_entry *mle) -{ - __dlm_mle_detach_hb_events(dlm, mle); - - spin_lock(&mle->spinlock); - __dlm_unlink_mle(dlm, mle); - atomic_set(&mle->woken, 1); - spin_unlock(&mle->spinlock); - - wake_up(&mle->wq); -} - -static void dlm_clean_block_mle(struct dlm_ctxt *dlm, - struct dlm_master_list_entry *mle, u8 dead_node) -{ - int bit; - - BUG_ON(mle->type != DLM_MLE_BLOCK); - - spin_lock(&mle->spinlock); - bit = find_next_bit(mle->maybe_map, O2NM_MAX_NODES, 0); - if (bit != dead_node) { - mlog(0, "mle found, but dead node %u would not have been " - "master\n", dead_node); - spin_unlock(&mle->spinlock); - } else { - /* Must drop the refcount by one since the assert_master will - * never arrive. This may result in the mle being unlinked and - * freed, but there may still be a process waiting in the - * dlmlock path which is fine. */ - mlog(0, "node %u was expected master\n", dead_node); - atomic_set(&mle->woken, 1); - spin_unlock(&mle->spinlock); - wake_up(&mle->wq); - - /* Do not need events any longer, so detach from heartbeat */ - __dlm_mle_detach_hb_events(dlm, mle); - __dlm_put_mle(mle); - } -} - -void dlm_clean_master_list(struct dlm_ctxt *dlm, u8 dead_node) -{ - struct dlm_master_list_entry *mle; - struct dlm_lock_resource *res; - struct hlist_head *bucket; - struct hlist_node *list; - unsigned int i; - - mlog(0, "dlm=%s, dead node=%u\n", dlm->name, dead_node); -top: - assert_spin_locked(&dlm->spinlock); - - /* clean the master list */ - spin_lock(&dlm->master_lock); - for (i = 0; i < DLM_HASH_BUCKETS; i++) { - bucket = dlm_master_hash(dlm, i); - hlist_for_each(list, bucket) { - mle = hlist_entry(list, struct dlm_master_list_entry, - master_hash_node); - - BUG_ON(mle->type != DLM_MLE_BLOCK && - mle->type != DLM_MLE_MASTER && - mle->type != DLM_MLE_MIGRATION); - - /* MASTER mles are initiated locally. The waiting - * process will notice the node map change shortly. - * Let that happen as normal. */ - if (mle->type == DLM_MLE_MASTER) - continue; - - /* BLOCK mles are initiated by other nodes. Need to - * clean up if the dead node would have been the - * master. */ - if (mle->type == DLM_MLE_BLOCK) { - dlm_clean_block_mle(dlm, mle, dead_node); - continue; - } - - /* Everything else is a MIGRATION mle */ - - /* The rule for MIGRATION mles is that the master - * becomes UNKNOWN if *either* the original or the new - * master dies. All UNKNOWN lockres' are sent to - * whichever node becomes the recovery master. The new - * master is responsible for determining if there is - * still a master for this lockres, or if he needs to - * take over mastery. Either way, this node should - * expect another message to resolve this. */ - - if (mle->master != dead_node && - mle->new_master != dead_node) - continue; - - /* If we have reached this point, this mle needs to be - * removed from the list and freed. */ - dlm_clean_migration_mle(dlm, mle); - - mlog(0, "%s: node %u died during migration from " - "%u to %u!\n", dlm->name, dead_node, mle->master, - mle->new_master); - - /* If we find a lockres associated with the mle, we've - * hit this rare case that messes up our lock ordering. - * If so, we need to drop the master lock so that we can - * take the lockres lock, meaning that we will have to - * restart from the head of list. */ - res = dlm_reset_mleres_owner(dlm, mle); - if (res) - /* restart */ - goto top; - - /* This may be the last reference */ - __dlm_put_mle(mle); - } - } - spin_unlock(&dlm->master_lock); -} - -int dlm_finish_migration(struct dlm_ctxt *dlm, struct dlm_lock_resource *res, - u8 old_master) -{ - struct dlm_node_iter iter; - int ret = 0; - - spin_lock(&dlm->spinlock); - dlm_node_iter_init(dlm->domain_map, &iter); - clear_bit(old_master, iter.node_map); - clear_bit(dlm->node_num, iter.node_map); - spin_unlock(&dlm->spinlock); - - /* ownership of the lockres is changing. account for the - * mastery reference here since old_master will briefly have - * a reference after the migration completes */ - spin_lock(&res->spinlock); - dlm_lockres_set_refmap_bit(dlm, res, old_master); - spin_unlock(&res->spinlock); - - mlog(0, "now time to do a migrate request to other nodes\n"); - ret = dlm_do_migrate_request(dlm, res, old_master, - dlm->node_num, &iter); - if (ret < 0) { - mlog_errno(ret); - goto leave; - } - - mlog(0, "doing assert master of %.*s to all except the original node\n", - res->lockname.len, res->lockname.name); - /* this call now finishes out the nodemap - * even if one or more nodes die */ - ret = dlm_do_assert_master(dlm, res, iter.node_map, - DLM_ASSERT_MASTER_FINISH_MIGRATION); - if (ret < 0) { - /* no longer need to retry. all living nodes contacted. */ - mlog_errno(ret); - ret = 0; - } - - memset(iter.node_map, 0, sizeof(iter.node_map)); - set_bit(old_master, iter.node_map); - mlog(0, "doing assert master of %.*s back to %u\n", - res->lockname.len, res->lockname.name, old_master); - ret = dlm_do_assert_master(dlm, res, iter.node_map, - DLM_ASSERT_MASTER_FINISH_MIGRATION); - if (ret < 0) { - mlog(0, "assert master to original master failed " - "with %d.\n", ret); - /* the only nonzero status here would be because of - * a dead original node. we're done. */ - ret = 0; - } - - /* all done, set the owner, clear the flag */ - spin_lock(&res->spinlock); - dlm_set_lockres_owner(dlm, res, dlm->node_num); - res->state &= ~DLM_LOCK_RES_MIGRATING; - spin_unlock(&res->spinlock); - /* re-dirty it on the new master */ - dlm_kick_thread(dlm, res); - wake_up(&res->wq); -leave: - return ret; -} - -/* - * LOCKRES AST REFCOUNT - * this is integral to migration - */ - -/* for future intent to call an ast, reserve one ahead of time. - * this should be called only after waiting on the lockres - * with dlm_wait_on_lockres, and while still holding the - * spinlock after the call. */ -void __dlm_lockres_reserve_ast(struct dlm_lock_resource *res) -{ - assert_spin_locked(&res->spinlock); - if (res->state & DLM_LOCK_RES_MIGRATING) { - __dlm_print_one_lock_resource(res); - } - BUG_ON(res->state & DLM_LOCK_RES_MIGRATING); - - atomic_inc(&res->asts_reserved); -} - -/* - * used to drop the reserved ast, either because it went unused, - * or because the ast/bast was actually called. - * - * also, if there is a pending migration on this lockres, - * and this was the last pending ast on the lockres, - * atomically set the MIGRATING flag before we drop the lock. - * this is how we ensure that migration can proceed with no - * asts in progress. note that it is ok if the state of the - * queues is such that a lock should be granted in the future - * or that a bast should be fired, because the new master will - * shuffle the lists on this lockres as soon as it is migrated. - */ -void dlm_lockres_release_ast(struct dlm_ctxt *dlm, - struct dlm_lock_resource *res) -{ - if (!atomic_dec_and_lock(&res->asts_reserved, &res->spinlock)) - return; - - if (!res->migration_pending) { - spin_unlock(&res->spinlock); - return; - } - - BUG_ON(res->state & DLM_LOCK_RES_MIGRATING); - res->migration_pending = 0; - res->state |= DLM_LOCK_RES_MIGRATING; - spin_unlock(&res->spinlock); - wake_up(&res->wq); - wake_up(&dlm->migration_wq); -} - -void dlm_force_free_mles(struct dlm_ctxt *dlm) -{ - int i; - struct hlist_head *bucket; - struct dlm_master_list_entry *mle; - struct hlist_node *tmp, *list; - - /* - * We notified all other nodes that we are exiting the domain and - * marked the dlm state to DLM_CTXT_LEAVING. If any mles are still - * around we force free them and wake any processes that are waiting - * on the mles - */ - spin_lock(&dlm->spinlock); - spin_lock(&dlm->master_lock); - - BUG_ON(dlm->dlm_state != DLM_CTXT_LEAVING); - BUG_ON((find_next_bit(dlm->domain_map, O2NM_MAX_NODES, 0) < O2NM_MAX_NODES)); - - for (i = 0; i < DLM_HASH_BUCKETS; i++) { - bucket = dlm_master_hash(dlm, i); - hlist_for_each_safe(list, tmp, bucket) { - mle = hlist_entry(list, struct dlm_master_list_entry, - master_hash_node); - if (mle->type != DLM_MLE_BLOCK) { - mlog(ML_ERROR, "bad mle: %p\n", mle); - dlm_print_one_mle(mle); - } - atomic_set(&mle->woken, 1); - wake_up(&mle->wq); - - __dlm_unlink_mle(dlm, mle); - __dlm_mle_detach_hb_events(dlm, mle); - __dlm_put_mle(mle); - } - } - spin_unlock(&dlm->master_lock); - spin_unlock(&dlm->spinlock); -} |