/* -*- mode: c; c-basic-offset: 8; -*- * vim: noexpandtab sw=8 ts=8 sts=0: * * dlmlock.c * * underlying calls for lock creation * * 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/utsname.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 "dlmconvert.h" #define MLOG_MASK_PREFIX ML_DLM #include "cluster/masklog.h" static struct kmem_cache *dlm_lock_cache = NULL; static DEFINE_SPINLOCK(dlm_cookie_lock); static u64 dlm_next_cookie = 1; static enum dlm_status dlm_send_remote_lock_request(struct dlm_ctxt *dlm, struct dlm_lock_resource *res, struct dlm_lock *lock, int flags); static void dlm_init_lock(struct dlm_lock *newlock, int type, u8 node, u64 cookie); static void dlm_lock_release(struct kref *kref); static void dlm_lock_detach_lockres(struct dlm_lock *lock); int dlm_init_lock_cache(void) { dlm_lock_cache = kmem_cache_create("o2dlm_lock", sizeof(struct dlm_lock), 0, SLAB_HWCACHE_ALIGN, NULL); if (dlm_lock_cache == NULL) return -ENOMEM; return 0; } void dlm_destroy_lock_cache(void) { if (dlm_lock_cache) kmem_cache_destroy(dlm_lock_cache); } /* Tell us whether we can grant a new lock request. * locking: * caller needs: res->spinlock * taken: none * held on exit: none * returns: 1 if the lock can be granted, 0 otherwise. */ static int dlm_can_grant_new_lock(struct dlm_lock_resource *res, struct dlm_lock *lock) { struct list_head *iter; struct dlm_lock *tmplock; list_for_each(iter, &res->granted) { tmplock = list_entry(iter, struct dlm_lock, list); if (!dlm_lock_compatible(tmplock->ml.type, lock->ml.type)) return 0; } list_for_each(iter, &res->converting) { tmplock = list_entry(iter, struct dlm_lock, list); if (!dlm_lock_compatible(tmplock->ml.type, lock->ml.type)) return 0; } return 1; } /* performs lock creation at the lockres master site * locking: * caller needs: none * taken: takes and drops res->spinlock * held on exit: none * returns: DLM_NORMAL, DLM_NOTQUEUED */ static enum dlm_status dlmlock_master(struct dlm_ctxt *dlm, struct dlm_lock_resource *res, struct dlm_lock *lock, int flags) { int call_ast = 0, kick_thread = 0; enum dlm_status status = DLM_NORMAL; mlog_entry("type=%d\n", lock->ml.type); spin_lock(&res->spinlock); /* if called from dlm_create_lock_handler, need to * ensure it will not sleep in dlm_wait_on_lockres */ status = __dlm_lockres_state_to_status(res); if (status != DLM_NORMAL && lock->ml.node != dlm->node_num) { /* erf. state changed after lock was dropped. */ spin_unlock(&res->spinlock); dlm_error(status); return status; } __dlm_wait_on_lockres(res); __dlm_lockres_reserve_ast(res); if (dlm_can_grant_new_lock(res, lock)) { mlog(0, "I can grant this lock right away\n"); /* got it right away */ lock->lksb->status = DLM_NORMAL; status = DLM_NORMAL; dlm_lock_get(lock); list_add_tail(&lock->list, &res->granted); /* for the recovery lock, we can't allow the ast * to be queued since the dlmthread is already * frozen. but the recovery lock is always locked * with LKM_NOQUEUE so we do not need the ast in * this special case */ if (!dlm_is_recovery_lock(res->lockname.name, res->lockname.len)) { kick_thread = 1; call_ast = 1; } else { mlog(0, "%s: returning DLM_NORMAL to " "node %u for reco lock\n", dlm->name, lock->ml.node); } } else { /* for NOQUEUE request, unless we get the * lock right away, return DLM_NOTQUEUED */ if (flags & LKM_NOQUEUE) { status = DLM_NOTQUEUED; if (dlm_is_recovery_lock(res->lockname.name, res->lockname.len)) { mlog(0, "%s: returning NOTQUEUED to " "node %u for reco lock\n", dlm->name, lock->ml.node); } } else { dlm_lock_get(lock); list_add_tail(&lock->list, &res->blocked); kick_thread = 1; } } /* reduce the inflight count, this may result in the lockres * being purged below during calc_usage */ if (lock->ml.node == dlm->node_num) dlm_lockres_drop_inflight_ref(dlm, res); spin_unlock(&res->spinlock); wake_up(&res->wq); /* either queue the ast or release it */ if (call_ast) dlm_queue_ast(dlm, lock); else dlm_lockres_release_ast(dlm, res); dlm_lockres_calc_usage(dlm, res); if (kick_thread) dlm_kick_thread(dlm, res); return status; } void dlm_revert_pending_lock(struct dlm_lock_resource *res, struct dlm_lock *lock) { /* remove from local queue if it failed */ list_del_init(&lock->list); lock->lksb->flags &= ~DLM_LKSB_GET_LVB; } /* * locking: * caller needs: none * taken: takes and drops res->spinlock * held on exit: none * returns: DLM_DENIED, DLM_RECOVERING, or net status */ static enum dlm_status dlmlock_remote(struct dlm_ctxt *dlm, struct dlm_lock_resource *res, struct dlm_lock *lock, int flags) { enum dlm_status status = DLM_DENIED; int lockres_changed = 1; mlog_entry("type=%d\n", lock->ml.type); mlog(0, "lockres %.*s, flags = 0x%x\n", res->lockname.len, res->lockname.name, flags); spin_lock(&res->spinlock); /* will exit this call with spinlock held */ __dlm_wait_on_lockres(res); res->state |= DLM_LOCK_RES_IN_PROGRESS; /* add lock to local (secondary) queue */ dlm_lock_get(lock); list_add_tail(&lock->list, &res->blocked); lock->lock_pending = 1; spin_unlock(&res->spinlock); /* spec seems to say that you will get DLM_NORMAL when the lock * has been queued, meaning we need to wait for a reply here. */ status = dlm_send_remote_lock_request(dlm, res, lock, flags); spin_lock(&res->spinlock); res->state &= ~DLM_LOCK_RES_IN_PROGRESS; lock->lock_pending = 0; if (status != DLM_NORMAL) { if (status == DLM_RECOVERING && dlm_is_recovery_lock(res->lockname.name, res->lockname.len)) { /* recovery lock was mastered by dead node. * we need to have calc_usage shoot down this * lockres and completely remaster it. */ mlog(0, "%s: recovery lock was owned by " "dead node %u, remaster it now.\n", dlm->name, res->owner); } else if (status != DLM_NOTQUEUED) { /* * DO NOT call calc_usage, as this would unhash * the remote lockres before we ever get to use * it. treat as if we never made any change to * the lockres. */ lockres_changed = 0; dlm_error(status); } dlm_revert_pending_lock(res, lock); dlm_lock_put(lock); } else if (dlm_is_recovery_lock(res->lockname.name, res->lockname.len)) { /* special case for the $RECOVERY lock. * there will never be an AST delivered to put * this lock on the proper secondary queue * (granted), so do it manually. */ mlog(0, "%s: $RECOVERY lock for this node (%u) is " "mastered by %u; got lock, manually granting (no ast)\n", dlm->name, dlm->node_num, res->owner); list_move_tail(&lock->list, &res->granted); } spin_unlock(&res->spinlock); if (lockres_changed) dlm_lockres_calc_usage(dlm, res); wake_up(&res->wq); return status; } /* for remote lock creation. * locking: * caller needs: none, but need res->state & DLM_LOCK_RES_IN_PROGRESS * taken: none * held on exit: none * returns: DLM_NOLOCKMGR, or net status */ static enum dlm_status dlm_send_remote_lock_request(struct dlm_ctxt *dlm, struct dlm_lock_resource *res, struct dlm_lock *lock, int flags) { struct dlm_create_lock create; int tmpret, status = 0; enum dlm_status ret; mlog_entry_void(); memset(&create, 0, sizeof(create)); create.node_idx = dlm->node_num; create.requested_type = lock->ml.type; create.cookie = lock->ml.cookie; create.namelen = res->lockname.len; create.flags = cpu_to_be32(flags); memcpy(create.name, res->lockname.name, create.namelen); tmpret = o2net_send_message(DLM_CREATE_LOCK_MSG, dlm->key, &create, sizeof(create), res->owner, &status); if (tmpret >= 0) { // successfully sent and received ret = status; // this is already a dlm_status if (ret == DLM_REJECTED) { mlog(ML_ERROR, "%s:%.*s: BUG. this is a stale lockres " "no longer owned by %u. that node is coming back " "up currently.\n", dlm->name, create.namelen, create.name, res->owner); dlm_print_one_lock_resource(res); BUG(); } } else { mlog_errno(tmpret); if (dlm_is_host_down(tmpret)) { ret = DLM_RECOVERING; mlog(0, "node %u died so returning DLM_RECOVERING " "from lock message!\n", res->owner); } else { ret = dlm_err_to_dlm_status(tmpret); } } return ret; } void dlm_lock_get(struct dlm_lock *lock) { kref_get(&lock->lock_refs); } void dlm_lock_put(struct dlm_lock *lock) { kref_put(&lock->lock_refs, dlm_lock_release); } static void dlm_lock_release(struct kref *kref) { struct dlm_lock *lock; lock = container_of(kref, struct dlm_lock, lock_refs); BUG_ON(!list_empty(&lock->list)); 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_lock_detach_lockres(lock); if (lock->lksb_kernel_allocated) { mlog(0, "freeing kernel-allocated lksb\n"); kfree(lock->lksb); } kmem_cache_free(dlm_lock_cache, lock); } /* associate a lock with it's lockres, getting a ref on the lockres */ void dlm_lock_attach_lockres(struct dlm_lock *lock, struct dlm_lock_resource *res) { dlm_lockres_get(res); lock->lockres = res; } /* drop ref on lockres, if there is still one associated with lock */ static void dlm_lock_detach_lockres(struct dlm_lock *lock) { struct dlm_lock_resource *res; res = lock->lockres; if (res) { lock->lockres = NULL; mlog(0, "removing lock's lockres reference\n"); dlm_lockres_put(res); } } static void dlm_init_lock(struct dlm_lock *newlock, int type, u8 node, u64 cookie) { INIT_LIST_HEAD(&newlock->list); INIT_LIST_HEAD(&newlock->ast_list); INIT_LIST_HEAD(&newlock->bast_list); spin_lock_init(&newlock->spinlock); newlock->ml.type = type; newlock->ml.convert_type = LKM_IVMODE; newlock->ml.highest_blocked = LKM_IVMODE; newlock->ml.node = node; newlock->ml.pad1 = 0; newlock->ml.list = 0; newlock->ml.flags = 0; newlock->ast = NULL; newlock->bast = NULL; newlock->astdata = NULL; newlock->ml.cookie = cpu_to_be64(cookie); newlock->ast_pending = 0; newlock->bast_pending = 0; newlock->convert_pending = 0; newlock->lock_pending = 0; newlock->unlock_pending = 0; newlock->cancel_pending = 0; newlock->lksb_kernel_allocated = 0; kref_init(&newlock->lock_refs); } struct dlm_lock * dlm_new_lock(int type, u8 node, u64 cookie, struct dlm_lockstatus *lksb) { struct dlm_lock *lock; int kernel_allocated = 0; lock = (struct dlm_lock *) kmem_cache_zalloc(dlm_lock_cache, GFP_NOFS); if (!lock) return NULL; if (!lksb) { /* zero memory only if kernel-allocated */ lksb = kzalloc(sizeof(*lksb), GFP_NOFS); if (!lksb) { kfree(lock); return NULL; } kernel_allocated = 1; } dlm_init_lock(lock, type, node, cookie); if (kernel_allocated) lock->lksb_kernel_allocated = 1; lock->lksb = lksb; lksb->lockid = lock; return lock; } /* handler for lock creation net message * locking: * caller needs: none * taken: takes and drops res->spinlock * held on exit: none * returns: DLM_NORMAL, DLM_SYSERR, DLM_IVLOCKID, DLM_NOTQUEUED */ int dlm_create_lock_handler(struct o2net_msg *msg, u32 len, void *data, void **ret_data) { struct dlm_ctxt *dlm = data; struct dlm_create_lock *create = (struct dlm_create_lock *)msg->buf; struct dlm_lock_resource *res = NULL; struct dlm_lock *newlock = NULL; struct dlm_lockstatus *lksb = NULL; enum dlm_status status = DLM_NORMAL; char *name; unsigned int namelen; BUG_ON(!dlm); mlog_entry_void(); if (!dlm_grab(dlm)) return DLM_REJECTED; name = create->name; namelen = create->namelen; status = DLM_REJECTED; if (!dlm_domain_fully_joined(dlm)) { mlog(ML_ERROR, "Domain %s not fully joined, but node %u is " "sending a create_lock message for lock %.*s!\n", dlm->name, create->node_idx, namelen, name); dlm_error(status); goto leave; } status = DLM_IVBUFLEN; if (namelen > DLM_LOCKID_NAME_MAX) { dlm_error(status); goto leave; } status = DLM_SYSERR; newlock = dlm_new_lock(create->requested_type, create->node_idx, be64_to_cpu(create->cookie), NULL); if (!newlock) { dlm_error(status); goto leave; } lksb = newlock->lksb; if (be32_to_cpu(create->flags) & LKM_GET_LVB) { lksb->flags |= DLM_LKSB_GET_LVB; mlog(0, "set DLM_LKSB_GET_LVB flag\n"); } status = DLM_IVLOCKID; res = dlm_lookup_lockres(dlm, name, namelen); if (!res) { dlm_error(status); goto leave; } spin_lock(&res->spinlock); status = __dlm_lockres_state_to_status(res); spin_unlock(&res->spinlock); if (status != DLM_NORMAL) { mlog(0, "lockres recovering/migrating/in-progress\n"); goto leave; } dlm_lock_attach_lockres(newlock, res); status = dlmlock_master(dlm, res, newlock, be32_to_cpu(create->flags)); leave: if (status != DLM_NORMAL) if (newlock) dlm_lock_put(newlock); if (res) dlm_lockres_put(res); dlm_put(dlm); return status; } /* fetch next node-local (u8 nodenum + u56 cookie) into u64 */ static inline void dlm_get_next_cookie(u8 node_num, u64 *cookie) { u64 tmpnode = node_num; /* shift single byte of node num into top 8 bits */ tmpnode <<= 56; spin_lock(&dlm_cookie_lock); *cookie = (dlm_next_cookie | tmpnode); if (++dlm_next_cookie & 0xff00000000000000ull) { mlog(0, "This node's cookie will now wrap!\n"); dlm_next_cookie = 1; } spin_unlock(&dlm_cookie_lock); } enum dlm_status dlmlock(struct dlm_ctxt *dlm, int mode, struct dlm_lockstatus *lksb, int flags, const char *name, int namelen, dlm_astlockfunc_t *ast, void *data, dlm_bastlockfunc_t *bast) { enum dlm_status status; struct dlm_lock_resource *res = NULL; struct dlm_lock *lock = NULL; int convert = 0, recovery = 0; /* yes this function is a mess. * TODO: clean this up. lots of common code in the * lock and convert paths, especially in the retry blocks */ if (!lksb) { dlm_error(DLM_BADARGS); return DLM_BADARGS; } status = DLM_BADPARAM; if (mode != LKM_EXMODE && mode != LKM_PRMODE && mode != LKM_NLMODE) { dlm_error(status); goto error; } if (flags & ~LKM_VALID_FLAGS) { dlm_error(status); goto error; } convert = (flags & LKM_CONVERT); recovery = (flags & LKM_RECOVERY); if (recovery && (!dlm_is_recovery_lock(name, namelen) || convert) ) { dlm_error(status); goto error; } if (convert && (flags & LKM_LOCAL)) { mlog(ML_ERROR, "strange LOCAL convert request!\n"); goto error; } if (convert) { /* CONVERT request */ /* if converting, must pass in a valid dlm_lock */ lock = lksb->lockid; if (!lock) { mlog(ML_ERROR, "NULL lock pointer in convert " "request\n"); goto error; } res = lock->lockres; if (!res) { mlog(ML_ERROR, "NULL lockres pointer in convert " "request\n"); goto error; } dlm_lockres_get(res); /* XXX: for ocfs2 purposes, the ast/bast/astdata/lksb are * static after the original lock call. convert requests will * ensure that everything is the same, or return DLM_BADARGS. * this means that DLM_DENIED_NOASTS will never be returned. */ if (lock->lksb != lksb || lock->ast != ast || lock->bast != bast || lock->astdata != data) { status = DLM_BADARGS; mlog(ML_ERROR, "new args: lksb=%p, ast=%p, bast=%p, " "astdata=%p\n", lksb, ast, bast, data); mlog(ML_ERROR, "orig args: lksb=%p, ast=%p, bast=%p, " "astdata=%p\n", lock->lksb, lock->ast, lock->bast, lock->astdata); goto error; } retry_convert: dlm_wait_for_recovery(dlm); if (res->owner == dlm->node_num) status = dlmconvert_master(dlm, res, lock, flags, mode); else status = dlmconvert_remote(dlm, res, lock, flags, mode); if (status == DLM_RECOVERING || status == DLM_MIGRATING || status == DLM_FORWARD) { /* for now, see how this works without sleeping * and just retry right away. I suspect the reco * or migration will complete fast enough that * no waiting will be necessary */ mlog(0, "retrying convert with migration/recovery/" "in-progress\n"); msleep(100); goto retry_convert; } } else { u64 tmpcookie; /* LOCK request */ status = DLM_BADARGS; if (!name) { dlm_error(status); goto error; } status = DLM_IVBUFLEN; if (namelen > DLM_LOCKID_NAME_MAX || namelen < 1) { dlm_error(status); goto error; } dlm_get_next_cookie(dlm->node_num, &tmpcookie); lock = dlm_new_lock(mode, dlm->node_num, tmpcookie, lksb); if (!lock) { dlm_error(status); goto error; } if (!recovery) dlm_wait_for_recovery(dlm); /* find or create the lock resource */ res = dlm_get_lock_resource(dlm, name, namelen, flags); if (!res) { status = DLM_IVLOCKID; dlm_error(status); goto error; } mlog(0, "type=%d, flags = 0x%x\n", mode, flags); mlog(0, "creating lock: lock=%p res=%p\n", lock, res); dlm_lock_attach_lockres(lock, res); lock->ast = ast; lock->bast = bast; lock->astdata = data; retry_lock: if (flags & LKM_VALBLK) { mlog(0, "LKM_VALBLK passed by caller\n"); /* LVB requests for non PR, PW or EX locks are * ignored. */ if (mode < LKM_PRMODE) flags &= ~LKM_VALBLK; else { flags |= LKM_GET_LVB; lock->lksb->flags |= DLM_LKSB_GET_LVB; } } if (res->owner == dlm->node_num) status = dlmlock_master(dlm, res, lock, flags); else status = dlmlock_remote(dlm, res, lock, flags); if (status == DLM_RECOVERING || status == DLM_MIGRATING || status == DLM_FORWARD) { mlog(0, "retrying lock with migration/" "recovery/in progress\n"); msleep(100); /* no waiting for dlm_reco_thread */ if (recovery) { if (status != DLM_RECOVERING) goto retry_lock; mlog(0, "%s: got RECOVERING " "for $RECOVERY lock, master " "was %u\n", dlm->name, res->owner); /* wait to see the node go down, then * drop down and allow the lockres to * get cleaned up. need to remaster. */ dlm_wait_for_node_death(dlm, res->owner, DLM_NODE_DEATH_WAIT_MAX); } else { dlm_wait_for_recovery(dlm); goto retry_lock; } } if (status != DLM_NORMAL) { lock->lksb->flags &= ~DLM_LKSB_GET_LVB; if (status != DLM_NOTQUEUED) dlm_error(status); goto error; } } error: if (status != DLM_NORMAL) { if (lock && !convert) dlm_lock_put(lock); // this is kind of unnecessary lksb->status = status; } /* put lockres ref from the convert path * or from dlm_get_lock_resource */ if (res) dlm_lockres_put(res); return status; } EXPORT_SYMBOL_GPL(dlmlock);