diff options
author | Kurt Hackel <kurt.hackel@oracle.com> | 2005-12-15 23:31:23 +0100 |
---|---|---|
committer | Joel Becker <joel.becker@oracle.com> | 2006-01-03 20:45:47 +0100 |
commit | 6714d8e86bf443f6f7af50f9d432025649f091f5 (patch) | |
tree | 2c484bd1894a90cad7020869c7054f192d3bf34d /fs/ocfs2/dlm/dlmunlock.c | |
parent | [PATCH] OCFS2: The Second Oracle Cluster Filesystem (diff) | |
download | linux-6714d8e86bf443f6f7af50f9d432025649f091f5.tar.xz linux-6714d8e86bf443f6f7af50f9d432025649f091f5.zip |
[PATCH] OCFS2: The Second Oracle Cluster Filesystem
A distributed lock manager built with the cluster file system use case
in mind. The OCFS2 dlm exposes a VMS style API, though things have
been simplified internally. The only lock levels implemented currently
are NLMODE, PRMODE and EXMODE.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Signed-off-by: Kurt Hackel <kurt.hackel@oracle.com>
Diffstat (limited to 'fs/ocfs2/dlm/dlmunlock.c')
-rw-r--r-- | fs/ocfs2/dlm/dlmunlock.c | 672 |
1 files changed, 672 insertions, 0 deletions
diff --git a/fs/ocfs2/dlm/dlmunlock.c b/fs/ocfs2/dlm/dlmunlock.c new file mode 100644 index 000000000000..cec2ce1cd318 --- /dev/null +++ b/fs/ocfs2/dlm/dlmunlock.c @@ -0,0 +1,672 @@ +/* -*- 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/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" + +#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; + + 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->spinlock); + /* 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->spinlock); + if (in_use) { + 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) { + 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; + } + + + /* 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) + 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_NORMAL && + lksb->status == DLM_CANCELGRANT) { + actions &= ~(DLM_UNLOCK_REMOVE_LOCK| + DLM_UNLOCK_REGRANT_LOCK| + DLM_UNLOCK_CLEAR_CONVERT_TYPE); + } + if (flags & LKM_CANCEL) + lock->cancel_pending = 0; + 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); + + /* 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 %"MLFu64" should be gone now! refs=%d\n", + lock->ml.cookie, atomic_read(&lock->lock_refs.refcount)-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_del_init(&lock->list); + list_add_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_entry("%.*s\n", res->lockname.len, res->lockname.name); + + 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_CANCELGRANT) + ret = DLM_NORMAL; + else if (status == DLM_FORWARD) { + mlog(0, "master was in-progress. retry\n"); + ret = DLM_FORWARD; + } else + ret = status; + lksb->status = status; + } else { + mlog_errno(tmpret); + 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. */ + ret = DLM_NORMAL; + } else { + /* something bad. this will BUG in ocfs2 */ + ret = dlm_err_to_dlm_status(tmpret); + } + lksb->status = ret; + } + + 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) +{ + struct dlm_ctxt *dlm = data; + struct dlm_unlock_lock *unlock = (struct dlm_unlock_lock *)msg->buf; + struct dlm_lock_resource *res = NULL; + struct list_head *iter; + 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_REJECTED; + + 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(iter, queue) { + lock = list_entry(iter, struct dlm_lock, 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; + /* 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=%"MLFu64"\n", + unlock->cookie); + else { + /* send the lksb->status back to the other node */ + status = lksb->status; + 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 */ + lksb->status = DLM_NORMAL; + 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 */ + lksb->status = DLM_NORMAL; + 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. DLM_CANCELGRANT */ + lksb->status = DLM_CANCELGRANT; + status = DLM_NORMAL; + *actions = DLM_UNLOCK_CALL_AST; + } else { + mlog(ML_ERROR, "lock to cancel is not on any list!\n"); + lksb->status = DLM_IVLOCKID; + 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)) { + lksb->status = DLM_DENIED; + status = DLM_DENIED; + dlm_error(status); + *actions = 0; + } else { + /* unlock granted lock */ + lksb->status = DLM_NORMAL; + 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; + + mlog_entry_void(); + + 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); + 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) { + /* 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\n"); + goto retry; + } + + if (call_ast) { + mlog(0, "calling unlockast(%p, %d)\n", data, lksb->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, lksb->status); + } + + 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); + |