diff options
Diffstat (limited to 'fs/ocfs2/dlm/dlmlock.c')
| -rw-r--r-- | fs/ocfs2/dlm/dlmlock.c | 676 |
1 files changed, 676 insertions, 0 deletions
diff --git a/fs/ocfs2/dlm/dlmlock.c b/fs/ocfs2/dlm/dlmlock.c new file mode 100644 index 00000000000..d1a0038557a --- /dev/null +++ b/fs/ocfs2/dlm/dlmlock.c @@ -0,0 +1,676 @@ +/* -*- 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 spinlock_t dlm_cookie_lock = SPIN_LOCK_UNLOCKED; +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); + +/* 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 { + /* for NOQUEUE request, unless we get the + * lock right away, return DLM_NOTQUEUED */ + if (flags & LKM_NOQUEUE) + status = DLM_NOTQUEUED; + else { + dlm_lock_get(lock); + list_add_tail(&lock->list, &res->blocked); + kick_thread = 1; + } + } + + 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; + + 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_NOTQUEUED) + dlm_error(status); + dlm_revert_pending_lock(res, lock); + dlm_lock_put(lock); + } + spin_unlock(&res->spinlock); + + 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 + } 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); + } + kfree(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 = kcalloc(1, sizeof(*lock), GFP_KERNEL); + if (!lock) + return NULL; + + if (!lksb) { + /* zero memory only if kernel-allocated */ + lksb = kcalloc(1, sizeof(*lksb), GFP_KERNEL); + 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) +{ + 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; + + mlog_bug_on_msg(!dlm_domain_fully_joined(dlm), + "Domain %s not fully joined!\n", dlm->name); + + name = create->name; + namelen = create->namelen; + + 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, 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, strlen(name)) || 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 (strlen(name) > DLM_LOCKID_NAME_MAX || strlen(name) < 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, 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); + 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); |