diff options
Diffstat (limited to 'fs/ocfs2/dlm/dlmunlock.c')
-rw-r--r-- | fs/ocfs2/dlm/dlmunlock.c | 713 |
1 files changed, 713 insertions, 0 deletions
diff --git a/fs/ocfs2/dlm/dlmunlock.c b/fs/ocfs2/dlm/dlmunlock.c new file mode 100644 index 000000000..c8e9b7031 --- /dev/null +++ b/fs/ocfs2/dlm/dlmunlock.c @@ -0,0 +1,713 @@ +/* -*- mode: c; c-basic-offset: 8; -*- + * vim: noexpandtab sw=8 ts=8 sts=0: + * + * dlmunlock.c + * + * underlying calls for unlocking locks + * + * 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/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" + +#define MLOG_MASK_PREFIX ML_DLM +#include "cluster/masklog.h" + +#define DLM_UNLOCK_FREE_LOCK 0x00000001 +#define DLM_UNLOCK_CALL_AST 0x00000002 +#define DLM_UNLOCK_REMOVE_LOCK 0x00000004 +#define DLM_UNLOCK_REGRANT_LOCK 0x00000008 +#define DLM_UNLOCK_CLEAR_CONVERT_TYPE 0x00000010 + + +static enum dlm_status dlm_get_cancel_actions(struct dlm_ctxt *dlm, + struct dlm_lock_resource *res, + struct dlm_lock *lock, + struct dlm_lockstatus *lksb, + int *actions); +static enum dlm_status dlm_get_unlock_actions(struct dlm_ctxt *dlm, + struct dlm_lock_resource *res, + struct dlm_lock *lock, + struct dlm_lockstatus *lksb, + int *actions); + +static enum dlm_status dlm_send_remote_unlock_request(struct dlm_ctxt *dlm, + struct dlm_lock_resource *res, + struct dlm_lock *lock, + struct dlm_lockstatus *lksb, + int flags, + u8 owner); + + +/* + * according to the spec: + * http://opendlm.sourceforge.net/cvsmirror/opendlm/docs/dlmbook_final.pdf + * + * flags & LKM_CANCEL != 0: must be converting or blocked + * flags & LKM_CANCEL == 0: must be granted + * + * So to unlock a converting lock, you must first cancel the + * convert (passing LKM_CANCEL in flags), then call the unlock + * again (with no LKM_CANCEL in flags). + */ + + +/* + * locking: + * caller needs: none + * taken: res->spinlock and lock->spinlock taken and dropped + * held on exit: none + * returns: DLM_NORMAL, DLM_NOLOCKMGR, status from network + * all callers should have taken an extra ref on lock coming in + */ +static enum dlm_status dlmunlock_common(struct dlm_ctxt *dlm, + struct dlm_lock_resource *res, + struct dlm_lock *lock, + struct dlm_lockstatus *lksb, + int flags, int *call_ast, + int master_node) +{ + enum dlm_status status; + int actions = 0; + int in_use; + u8 owner; + int recovery_wait = 0; + + mlog(0, "master_node = %d, valblk = %d\n", master_node, + flags & LKM_VALBLK); + + if (master_node) + BUG_ON(res->owner != dlm->node_num); + else + BUG_ON(res->owner == dlm->node_num); + + spin_lock(&dlm->ast_lock); + /* We want to be sure that we're not freeing a lock + * that still has AST's pending... */ + in_use = !list_empty(&lock->ast_list); + spin_unlock(&dlm->ast_lock); + if (in_use && !(flags & LKM_CANCEL)) { + mlog(ML_ERROR, "lockres %.*s: Someone is calling dlmunlock " + "while waiting for an ast!", res->lockname.len, + res->lockname.name); + return DLM_BADPARAM; + } + + spin_lock(&res->spinlock); + if (res->state & DLM_LOCK_RES_IN_PROGRESS) { + if (master_node && !(flags & LKM_CANCEL)) { + mlog(ML_ERROR, "lockres in progress!\n"); + spin_unlock(&res->spinlock); + return DLM_FORWARD; + } + /* ok for this to sleep if not in a network handler */ + __dlm_wait_on_lockres(res); + res->state |= DLM_LOCK_RES_IN_PROGRESS; + } + spin_lock(&lock->spinlock); + + if (res->state & DLM_LOCK_RES_RECOVERING) { + status = DLM_RECOVERING; + goto leave; + } + + if (res->state & DLM_LOCK_RES_MIGRATING) { + status = DLM_MIGRATING; + goto leave; + } + + /* see above for what the spec says about + * LKM_CANCEL and the lock queue state */ + if (flags & LKM_CANCEL) + status = dlm_get_cancel_actions(dlm, res, lock, lksb, &actions); + else + status = dlm_get_unlock_actions(dlm, res, lock, lksb, &actions); + + if (status != DLM_NORMAL && (status != DLM_CANCELGRANT || !master_node)) + goto leave; + + /* By now this has been masked out of cancel requests. */ + if (flags & LKM_VALBLK) { + /* make the final update to the lvb */ + if (master_node) + memcpy(res->lvb, lksb->lvb, DLM_LVB_LEN); + else + flags |= LKM_PUT_LVB; /* let the send function + * handle it. */ + } + + if (!master_node) { + owner = res->owner; + /* drop locks and send message */ + if (flags & LKM_CANCEL) + lock->cancel_pending = 1; + else + lock->unlock_pending = 1; + spin_unlock(&lock->spinlock); + spin_unlock(&res->spinlock); + status = dlm_send_remote_unlock_request(dlm, res, lock, lksb, + flags, owner); + spin_lock(&res->spinlock); + spin_lock(&lock->spinlock); + /* if the master told us the lock was already granted, + * let the ast handle all of these actions */ + if (status == DLM_CANCELGRANT) { + actions &= ~(DLM_UNLOCK_REMOVE_LOCK| + DLM_UNLOCK_REGRANT_LOCK| + DLM_UNLOCK_CLEAR_CONVERT_TYPE); + } else if (status == DLM_RECOVERING || + status == DLM_MIGRATING || + status == DLM_FORWARD || + status == DLM_NOLOCKMGR + ) { + /* must clear the actions because this unlock + * is about to be retried. cannot free or do + * any list manipulation. */ + mlog(0, "%s:%.*s: clearing actions, %s\n", + dlm->name, res->lockname.len, + res->lockname.name, + status==DLM_RECOVERING?"recovering": + (status==DLM_MIGRATING?"migrating": + (status == DLM_FORWARD ? "forward" : + "nolockmanager"))); + actions = 0; + } + if (flags & LKM_CANCEL) + lock->cancel_pending = 0; + else { + if (!lock->unlock_pending) + recovery_wait = 1; + else + lock->unlock_pending = 0; + } + } + + /* get an extra ref on lock. if we are just switching + * lists here, we dont want the lock to go away. */ + dlm_lock_get(lock); + + if (actions & DLM_UNLOCK_REMOVE_LOCK) { + list_del_init(&lock->list); + dlm_lock_put(lock); + } + if (actions & DLM_UNLOCK_REGRANT_LOCK) { + dlm_lock_get(lock); + list_add_tail(&lock->list, &res->granted); + } + if (actions & DLM_UNLOCK_CLEAR_CONVERT_TYPE) { + mlog(0, "clearing convert_type at %smaster node\n", + master_node ? "" : "non-"); + lock->ml.convert_type = LKM_IVMODE; + } + + /* remove the extra ref on lock */ + dlm_lock_put(lock); + +leave: + res->state &= ~DLM_LOCK_RES_IN_PROGRESS; + if (!dlm_lock_on_list(&res->converting, lock)) + BUG_ON(lock->ml.convert_type != LKM_IVMODE); + else + BUG_ON(lock->ml.convert_type == LKM_IVMODE); + spin_unlock(&lock->spinlock); + spin_unlock(&res->spinlock); + wake_up(&res->wq); + + if (recovery_wait) { + spin_lock(&res->spinlock); + /* Unlock request will directly succeed after owner dies, + * and the lock is already removed from grant list. We have to + * wait for RECOVERING done or we miss the chance to purge it + * since the removement is much faster than RECOVERING proc. + */ + __dlm_wait_on_lockres_flags(res, DLM_LOCK_RES_RECOVERING); + spin_unlock(&res->spinlock); + } + + /* let the caller's final dlm_lock_put handle the actual kfree */ + if (actions & DLM_UNLOCK_FREE_LOCK) { + /* this should always be coupled with list removal */ + BUG_ON(!(actions & DLM_UNLOCK_REMOVE_LOCK)); + mlog(0, "lock %u:%llu should be gone now! refs=%d\n", + dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)), + dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie)), + kref_read(&lock->lock_refs)-1); + dlm_lock_put(lock); + } + if (actions & DLM_UNLOCK_CALL_AST) + *call_ast = 1; + + /* if cancel or unlock succeeded, lvb work is done */ + if (status == DLM_NORMAL) + lksb->flags &= ~(DLM_LKSB_PUT_LVB|DLM_LKSB_GET_LVB); + + return status; +} + +void dlm_commit_pending_unlock(struct dlm_lock_resource *res, + struct dlm_lock *lock) +{ + /* leave DLM_LKSB_PUT_LVB on the lksb so any final + * update of the lvb will be sent to the new master */ + list_del_init(&lock->list); +} + +void dlm_commit_pending_cancel(struct dlm_lock_resource *res, + struct dlm_lock *lock) +{ + list_move_tail(&lock->list, &res->granted); + lock->ml.convert_type = LKM_IVMODE; +} + + +static inline enum dlm_status dlmunlock_master(struct dlm_ctxt *dlm, + struct dlm_lock_resource *res, + struct dlm_lock *lock, + struct dlm_lockstatus *lksb, + int flags, + int *call_ast) +{ + return dlmunlock_common(dlm, res, lock, lksb, flags, call_ast, 1); +} + +static inline enum dlm_status dlmunlock_remote(struct dlm_ctxt *dlm, + struct dlm_lock_resource *res, + struct dlm_lock *lock, + struct dlm_lockstatus *lksb, + int flags, int *call_ast) +{ + return dlmunlock_common(dlm, res, lock, lksb, flags, call_ast, 0); +} + +/* + * locking: + * caller needs: none + * taken: none + * held on exit: none + * returns: DLM_NORMAL, DLM_NOLOCKMGR, status from network + */ +static enum dlm_status dlm_send_remote_unlock_request(struct dlm_ctxt *dlm, + struct dlm_lock_resource *res, + struct dlm_lock *lock, + struct dlm_lockstatus *lksb, + int flags, + u8 owner) +{ + struct dlm_unlock_lock unlock; + int tmpret; + enum dlm_status ret; + int status = 0; + struct kvec vec[2]; + size_t veclen = 1; + + mlog(0, "%.*s\n", res->lockname.len, res->lockname.name); + + if (owner == dlm->node_num) { + /* ended up trying to contact ourself. this means + * that the lockres had been remote but became local + * via a migration. just retry it, now as local */ + mlog(0, "%s:%.*s: this node became the master due to a " + "migration, re-evaluate now\n", dlm->name, + res->lockname.len, res->lockname.name); + return DLM_FORWARD; + } + + memset(&unlock, 0, sizeof(unlock)); + unlock.node_idx = dlm->node_num; + unlock.flags = cpu_to_be32(flags); + unlock.cookie = lock->ml.cookie; + unlock.namelen = res->lockname.len; + memcpy(unlock.name, res->lockname.name, unlock.namelen); + + vec[0].iov_len = sizeof(struct dlm_unlock_lock); + vec[0].iov_base = &unlock; + + if (flags & LKM_PUT_LVB) { + /* extra data to send if we are updating lvb */ + vec[1].iov_len = DLM_LVB_LEN; + vec[1].iov_base = lock->lksb->lvb; + veclen++; + } + + tmpret = o2net_send_message_vec(DLM_UNLOCK_LOCK_MSG, dlm->key, + vec, veclen, owner, &status); + if (tmpret >= 0) { + // successfully sent and received + if (status == DLM_FORWARD) + mlog(0, "master was in-progress. retry\n"); + ret = status; + } else { + mlog(ML_ERROR, "Error %d when sending message %u (key 0x%x) to " + "node %u\n", tmpret, DLM_UNLOCK_LOCK_MSG, dlm->key, owner); + if (dlm_is_host_down(tmpret)) { + /* NOTE: this seems strange, but it is what we want. + * when the master goes down during a cancel or + * unlock, the recovery code completes the operation + * as if the master had not died, then passes the + * updated state to the recovery master. this thread + * just needs to finish out the operation and call + * the unlockast. */ + if (dlm_is_node_dead(dlm, owner)) + ret = DLM_NORMAL; + else + ret = DLM_NOLOCKMGR; + } else { + /* something bad. this will BUG in ocfs2 */ + ret = dlm_err_to_dlm_status(tmpret); + } + } + + return ret; +} + +/* + * locking: + * caller needs: none + * taken: takes and drops res->spinlock + * held on exit: none + * returns: DLM_NORMAL, DLM_BADARGS, DLM_IVLOCKID, + * return value from dlmunlock_master + */ +int dlm_unlock_lock_handler(struct o2net_msg *msg, u32 len, void *data, + void **ret_data) +{ + struct dlm_ctxt *dlm = data; + struct dlm_unlock_lock *unlock = (struct dlm_unlock_lock *)msg->buf; + struct dlm_lock_resource *res = NULL; + struct dlm_lock *lock = NULL; + enum dlm_status status = DLM_NORMAL; + int found = 0, i; + struct dlm_lockstatus *lksb = NULL; + int ignore; + u32 flags; + struct list_head *queue; + + flags = be32_to_cpu(unlock->flags); + + if (flags & LKM_GET_LVB) { + mlog(ML_ERROR, "bad args! GET_LVB specified on unlock!\n"); + return DLM_BADARGS; + } + + if ((flags & (LKM_PUT_LVB|LKM_CANCEL)) == (LKM_PUT_LVB|LKM_CANCEL)) { + mlog(ML_ERROR, "bad args! cannot modify lvb on a CANCEL " + "request!\n"); + return DLM_BADARGS; + } + + if (unlock->namelen > DLM_LOCKID_NAME_MAX) { + mlog(ML_ERROR, "Invalid name length in unlock handler!\n"); + return DLM_IVBUFLEN; + } + + if (!dlm_grab(dlm)) + return DLM_FORWARD; + + mlog_bug_on_msg(!dlm_domain_fully_joined(dlm), + "Domain %s not fully joined!\n", dlm->name); + + mlog(0, "lvb: %s\n", flags & LKM_PUT_LVB ? "put lvb" : "none"); + + res = dlm_lookup_lockres(dlm, unlock->name, unlock->namelen); + if (!res) { + /* We assume here that a no lock resource simply means + * it was migrated away and destroyed before the other + * node could detect it. */ + mlog(0, "returning DLM_FORWARD -- res no longer exists\n"); + status = DLM_FORWARD; + goto not_found; + } + + queue=&res->granted; + found = 0; + spin_lock(&res->spinlock); + if (res->state & DLM_LOCK_RES_RECOVERING) { + spin_unlock(&res->spinlock); + mlog(0, "returning DLM_RECOVERING\n"); + status = DLM_RECOVERING; + goto leave; + } + + if (res->state & DLM_LOCK_RES_MIGRATING) { + spin_unlock(&res->spinlock); + mlog(0, "returning DLM_MIGRATING\n"); + status = DLM_MIGRATING; + goto leave; + } + + if (res->owner != dlm->node_num) { + spin_unlock(&res->spinlock); + mlog(0, "returning DLM_FORWARD -- not master\n"); + status = DLM_FORWARD; + goto leave; + } + + for (i=0; i<3; i++) { + list_for_each_entry(lock, queue, list) { + if (lock->ml.cookie == unlock->cookie && + lock->ml.node == unlock->node_idx) { + dlm_lock_get(lock); + found = 1; + break; + } + } + if (found) + break; + /* scan granted -> converting -> blocked queues */ + queue++; + } + spin_unlock(&res->spinlock); + if (!found) { + status = DLM_IVLOCKID; + goto not_found; + } + + /* lock was found on queue */ + lksb = lock->lksb; + if (flags & (LKM_VALBLK|LKM_PUT_LVB) && + lock->ml.type != LKM_EXMODE) + flags &= ~(LKM_VALBLK|LKM_PUT_LVB); + + /* unlockast only called on originating node */ + if (flags & LKM_PUT_LVB) { + lksb->flags |= DLM_LKSB_PUT_LVB; + memcpy(&lksb->lvb[0], &unlock->lvb[0], DLM_LVB_LEN); + } + + /* if this is in-progress, propagate the DLM_FORWARD + * all the way back out */ + status = dlmunlock_master(dlm, res, lock, lksb, flags, &ignore); + if (status == DLM_FORWARD) + mlog(0, "lockres is in progress\n"); + + if (flags & LKM_PUT_LVB) + lksb->flags &= ~DLM_LKSB_PUT_LVB; + + dlm_lockres_calc_usage(dlm, res); + dlm_kick_thread(dlm, res); + +not_found: + if (!found) + mlog(ML_ERROR, "failed to find lock to unlock! " + "cookie=%u:%llu\n", + dlm_get_lock_cookie_node(be64_to_cpu(unlock->cookie)), + dlm_get_lock_cookie_seq(be64_to_cpu(unlock->cookie))); + else + dlm_lock_put(lock); + +leave: + if (res) + dlm_lockres_put(res); + + dlm_put(dlm); + + return status; +} + + +static enum dlm_status dlm_get_cancel_actions(struct dlm_ctxt *dlm, + struct dlm_lock_resource *res, + struct dlm_lock *lock, + struct dlm_lockstatus *lksb, + int *actions) +{ + enum dlm_status status; + + if (dlm_lock_on_list(&res->blocked, lock)) { + /* cancel this outright */ + status = DLM_NORMAL; + *actions = (DLM_UNLOCK_CALL_AST | + DLM_UNLOCK_REMOVE_LOCK); + } else if (dlm_lock_on_list(&res->converting, lock)) { + /* cancel the request, put back on granted */ + status = DLM_NORMAL; + *actions = (DLM_UNLOCK_CALL_AST | + DLM_UNLOCK_REMOVE_LOCK | + DLM_UNLOCK_REGRANT_LOCK | + DLM_UNLOCK_CLEAR_CONVERT_TYPE); + } else if (dlm_lock_on_list(&res->granted, lock)) { + /* too late, already granted. */ + status = DLM_CANCELGRANT; + *actions = DLM_UNLOCK_CALL_AST; + } else { + mlog(ML_ERROR, "lock to cancel is not on any list!\n"); + status = DLM_IVLOCKID; + *actions = 0; + } + return status; +} + +static enum dlm_status dlm_get_unlock_actions(struct dlm_ctxt *dlm, + struct dlm_lock_resource *res, + struct dlm_lock *lock, + struct dlm_lockstatus *lksb, + int *actions) +{ + enum dlm_status status; + + /* unlock request */ + if (!dlm_lock_on_list(&res->granted, lock)) { + status = DLM_DENIED; + dlm_error(status); + *actions = 0; + } else { + /* unlock granted lock */ + status = DLM_NORMAL; + *actions = (DLM_UNLOCK_FREE_LOCK | + DLM_UNLOCK_CALL_AST | + DLM_UNLOCK_REMOVE_LOCK); + } + return status; +} + +/* there seems to be no point in doing this async + * since (even for the remote case) there is really + * no work to queue up... so just do it and fire the + * unlockast by hand when done... */ +enum dlm_status dlmunlock(struct dlm_ctxt *dlm, struct dlm_lockstatus *lksb, + int flags, dlm_astunlockfunc_t *unlockast, void *data) +{ + enum dlm_status status; + struct dlm_lock_resource *res; + struct dlm_lock *lock = NULL; + int call_ast, is_master; + + if (!lksb) { + dlm_error(DLM_BADARGS); + return DLM_BADARGS; + } + + if (flags & ~(LKM_CANCEL | LKM_VALBLK | LKM_INVVALBLK)) { + dlm_error(DLM_BADPARAM); + return DLM_BADPARAM; + } + + if ((flags & (LKM_VALBLK | LKM_CANCEL)) == (LKM_VALBLK | LKM_CANCEL)) { + mlog(0, "VALBLK given with CANCEL: ignoring VALBLK\n"); + flags &= ~LKM_VALBLK; + } + + if (!lksb->lockid || !lksb->lockid->lockres) { + dlm_error(DLM_BADPARAM); + return DLM_BADPARAM; + } + + lock = lksb->lockid; + BUG_ON(!lock); + dlm_lock_get(lock); + + res = lock->lockres; + BUG_ON(!res); + dlm_lockres_get(res); +retry: + call_ast = 0; + /* need to retry up here because owner may have changed */ + mlog(0, "lock=%p res=%p\n", lock, res); + + spin_lock(&res->spinlock); + is_master = (res->owner == dlm->node_num); + if (flags & LKM_VALBLK && lock->ml.type != LKM_EXMODE) + flags &= ~LKM_VALBLK; + spin_unlock(&res->spinlock); + + if (is_master) { + status = dlmunlock_master(dlm, res, lock, lksb, flags, + &call_ast); + mlog(0, "done calling dlmunlock_master: returned %d, " + "call_ast is %d\n", status, call_ast); + } else { + status = dlmunlock_remote(dlm, res, lock, lksb, flags, + &call_ast); + mlog(0, "done calling dlmunlock_remote: returned %d, " + "call_ast is %d\n", status, call_ast); + } + + if (status == DLM_RECOVERING || + status == DLM_MIGRATING || + status == DLM_FORWARD || + status == DLM_NOLOCKMGR) { + + /* We want to go away for a tiny bit to allow recovery + * / migration to complete on this resource. I don't + * know of any wait queue we could sleep on as this + * may be happening on another node. Perhaps the + * proper solution is to queue up requests on the + * other end? */ + + /* do we want to yield(); ?? */ + msleep(50); + + mlog(0, "retrying unlock due to pending recovery/" + "migration/in-progress/reconnect\n"); + goto retry; + } + + if (call_ast) { + mlog(0, "calling unlockast(%p, %d)\n", data, status); + if (is_master) { + /* it is possible that there is one last bast + * pending. make sure it is flushed, then + * call the unlockast. + * not an issue if this is a mastered remotely, + * since this lock has been removed from the + * lockres queues and cannot be found. */ + dlm_kick_thread(dlm, NULL); + wait_event(dlm->ast_wq, + dlm_lock_basts_flushed(dlm, lock)); + } + (*unlockast)(data, status); + } + + if (status == DLM_CANCELGRANT) + status = DLM_NORMAL; + + if (status == DLM_NORMAL) { + mlog(0, "kicking the thread\n"); + dlm_kick_thread(dlm, res); + } else + dlm_error(status); + + dlm_lockres_calc_usage(dlm, res); + dlm_lockres_put(res); + dlm_lock_put(lock); + + mlog(0, "returning status=%d!\n", status); + return status; +} +EXPORT_SYMBOL_GPL(dlmunlock); + |