/* -*- mode: c; c-basic-offset: 8; -*- * vim: noexpandtab sw=8 ts=8 sts=0: * * dlmast.c * * AST and BAST functionality for local and remote nodes * * 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 "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" static void dlm_update_lvb(struct dlm_ctxt *dlm, struct dlm_lock_resource *res, struct dlm_lock *lock); static int dlm_should_cancel_bast(struct dlm_ctxt *dlm, struct dlm_lock *lock); /* Should be called as an ast gets queued to see if the new * lock level will obsolete a pending bast. * For example, if dlm_thread queued a bast for an EX lock that * was blocking another EX, but before sending the bast the * lock owner downconverted to NL, the bast is now obsolete. * Only the ast should be sent. * This is needed because the lock and convert paths can queue * asts out-of-band (not waiting for dlm_thread) in order to * allow for LKM_NOQUEUE to get immediate responses. */ static int dlm_should_cancel_bast(struct dlm_ctxt *dlm, struct dlm_lock *lock) { assert_spin_locked(&dlm->ast_lock); assert_spin_locked(&lock->spinlock); if (lock->ml.highest_blocked == LKM_IVMODE) return 0; BUG_ON(lock->ml.highest_blocked == LKM_NLMODE); if (lock->bast_pending && list_empty(&lock->bast_list)) /* old bast already sent, ok */ return 0; if (lock->ml.type == LKM_EXMODE) /* EX blocks anything left, any bast still valid */ return 0; else if (lock->ml.type == LKM_NLMODE) /* NL blocks nothing, no reason to send any bast, cancel it */ return 1; else if (lock->ml.highest_blocked != LKM_EXMODE) /* PR only blocks EX */ return 1; return 0; } static void __dlm_queue_ast(struct dlm_ctxt *dlm, struct dlm_lock *lock) { mlog_entry_void(); BUG_ON(!dlm); BUG_ON(!lock); assert_spin_locked(&dlm->ast_lock); if (!list_empty(&lock->ast_list)) { mlog(ML_ERROR, "ast list not empty!! pending=%d, newlevel=%d\n", lock->ast_pending, lock->ml.type); BUG(); } if (lock->ast_pending) mlog(0, "lock has an ast getting flushed right now\n"); /* putting lock on list, add a ref */ dlm_lock_get(lock); spin_lock(&lock->spinlock); /* check to see if this ast obsoletes the bast */ if (dlm_should_cancel_bast(dlm, lock)) { struct dlm_lock_resource *res = lock->lockres; mlog(0, "%s: cancelling bast for %.*s\n", dlm->name, res->lockname.len, res->lockname.name); lock->bast_pending = 0; list_del_init(&lock->bast_list); lock->ml.highest_blocked = LKM_IVMODE; /* removing lock from list, remove a ref. guaranteed * this won't be the last ref because of the get above, * so res->spinlock will not be taken here */ dlm_lock_put(lock); /* free up the reserved bast that we are cancelling. * guaranteed that this will not be the last reserved * ast because *both* an ast and a bast were reserved * to get to this point. the res->spinlock will not be * taken here */ dlm_lockres_release_ast(dlm, res); } list_add_tail(&lock->ast_list, &dlm->pending_asts); lock->ast_pending = 1; spin_unlock(&lock->spinlock); } void dlm_queue_ast(struct dlm_ctxt *dlm, struct dlm_lock *lock) { mlog_entry_void(); BUG_ON(!dlm); BUG_ON(!lock); spin_lock(&dlm->ast_lock); __dlm_queue_ast(dlm, lock); spin_unlock(&dlm->ast_lock); } static void __dlm_queue_bast(struct dlm_ctxt *dlm, struct dlm_lock *lock) { mlog_entry_void(); BUG_ON(!dlm); BUG_ON(!lock); assert_spin_locked(&dlm->ast_lock); BUG_ON(!list_empty(&lock->bast_list)); if (lock->bast_pending) mlog(0, "lock has a bast getting flushed right now\n"); /* putting lock on list, add a ref */ dlm_lock_get(lock); spin_lock(&lock->spinlock); list_add_tail(&lock->bast_list, &dlm->pending_basts); lock->bast_pending = 1; spin_unlock(&lock->spinlock); } void dlm_queue_bast(struct dlm_ctxt *dlm, struct dlm_lock *lock) { mlog_entry_void(); BUG_ON(!dlm); BUG_ON(!lock); spin_lock(&dlm->ast_lock); __dlm_queue_bast(dlm, lock); spin_unlock(&dlm->ast_lock); } static void dlm_update_lvb(struct dlm_ctxt *dlm, struct dlm_lock_resource *res, struct dlm_lock *lock) { struct dlm_lockstatus *lksb = lock->lksb; BUG_ON(!lksb); /* only updates if this node masters the lockres */ if (res->owner == dlm->node_num) { spin_lock(&res->spinlock); /* check the lksb flags for the direction */ if (lksb->flags & DLM_LKSB_GET_LVB) { mlog(0, "getting lvb from lockres for %s node\n", lock->ml.node == dlm->node_num ? "master" : "remote"); memcpy(lksb->lvb, res->lvb, DLM_LVB_LEN); } /* Do nothing for lvb put requests - they should be done in * place when the lock is downconverted - otherwise we risk * racing gets and puts which could result in old lvb data * being propagated. We leave the put flag set and clear it * here. In the future we might want to clear it at the time * the put is actually done. */ spin_unlock(&res->spinlock); } /* reset any lvb flags on the lksb */ lksb->flags &= ~(DLM_LKSB_PUT_LVB|DLM_LKSB_GET_LVB); } void dlm_do_local_ast(struct dlm_ctxt *dlm, struct dlm_lock_resource *res, struct dlm_lock *lock) { dlm_astlockfunc_t *fn; struct dlm_lockstatus *lksb; mlog_entry_void(); lksb = lock->lksb; fn = lock->ast; BUG_ON(lock->ml.node != dlm->node_num); dlm_update_lvb(dlm, res, lock); (*fn)(lock->astdata); } int dlm_do_remote_ast(struct dlm_ctxt *dlm, struct dlm_lock_resource *res, struct dlm_lock *lock) { int ret; struct dlm_lockstatus *lksb; int lksbflags; mlog_entry_void(); lksb = lock->lksb; BUG_ON(lock->ml.node == dlm->node_num); lksbflags = lksb->flags; dlm_update_lvb(dlm, res, lock); /* lock request came from another node * go do the ast over there */ ret = dlm_send_proxy_ast(dlm, res, lock, lksbflags); return ret; } void dlm_do_local_bast(struct dlm_ctxt *dlm, struct dlm_lock_resource *res, struct dlm_lock *lock, int blocked_type) { dlm_bastlockfunc_t *fn = lock->bast; mlog_entry_void(); BUG_ON(lock->ml.node != dlm->node_num); (*fn)(lock->astdata, blocked_type); } int dlm_proxy_ast_handler(struct o2net_msg *msg, u32 len, void *data, void **ret_data) { int ret; unsigned int locklen; struct dlm_ctxt *dlm = data; struct dlm_lock_resource *res = NULL; struct dlm_lock *lock = NULL; struct dlm_proxy_ast *past = (struct dlm_proxy_ast *) msg->buf; char *name; struct list_head *iter, *head=NULL; u64 cookie; u32 flags; u8 node; if (!dlm_grab(dlm)) { dlm_error(DLM_REJECTED); return DLM_REJECTED; } mlog_bug_on_msg(!dlm_domain_fully_joined(dlm), "Domain %s not fully joined!\n", dlm->name); name = past->name; locklen = past->namelen; cookie = past->cookie; flags = be32_to_cpu(past->flags); node = past->node_idx; if (locklen > DLM_LOCKID_NAME_MAX) { ret = DLM_IVBUFLEN; mlog(ML_ERROR, "Invalid name length (%d) in proxy ast " "handler!\n", locklen); goto leave; } if ((flags & (LKM_PUT_LVB|LKM_GET_LVB)) == (LKM_PUT_LVB|LKM_GET_LVB)) { mlog(ML_ERROR, "Both PUT and GET lvb specified, (0x%x)\n", flags); ret = DLM_BADARGS; goto leave; } mlog(0, "lvb: %s\n", flags & LKM_PUT_LVB ? "put lvb" : (flags & LKM_GET_LVB ? "get lvb" : "none")); mlog(0, "type=%d, blocked_type=%d\n", past->type, past->blocked_type); if (past->type != DLM_AST && past->type != DLM_BAST) { mlog(ML_ERROR, "Unknown ast type! %d, cookie=%u:%llu" "name=%.*s, node=%u\n", past->type, dlm_get_lock_cookie_node(be64_to_cpu(cookie)), dlm_get_lock_cookie_seq(be64_to_cpu(cookie)), locklen, name, node); ret = DLM_IVLOCKID; goto leave; } res = dlm_lookup_lockres(dlm, name, locklen); if (!res) { mlog(0, "Got %sast for unknown lockres! cookie=%u:%llu, " "name=%.*s, node=%u\n", (past->type == DLM_AST ? "" : "b"), dlm_get_lock_cookie_node(be64_to_cpu(cookie)), dlm_get_lock_cookie_seq(be64_to_cpu(cookie)), locklen, name, node); ret = DLM_IVLOCKID; goto leave; } /* cannot get a proxy ast message if this node owns it */ BUG_ON(res->owner == dlm->node_num); mlog(0, "lockres %.*s\n", res->lockname.len, res->lockname.name); spin_lock(&res->spinlock); if (res->state & DLM_LOCK_RES_RECOVERING) { mlog(0, "Responding with DLM_RECOVERING!\n"); ret = DLM_RECOVERING; goto unlock_out; } if (res->state & DLM_LOCK_RES_MIGRATING) { mlog(0, "Responding with DLM_MIGRATING!\n"); ret = DLM_MIGRATING; goto unlock_out; } /* try convert queue for both ast/bast */ head = &res->converting; lock = NULL; list_for_each(iter, head) { lock = list_entry (iter, struct dlm_lock, list); if (lock->ml.cookie == cookie) goto do_ast; } /* if not on convert, try blocked for ast, granted for bast */ if (past->type == DLM_AST) head = &res->blocked; else head = &res->granted; list_for_each(iter, head) { lock = list_entry (iter, struct dlm_lock, list); if (lock->ml.cookie == cookie) goto do_ast; } mlog(0, "Got %sast for unknown lock! cookie=%u:%llu, name=%.*s, " "node=%u\n", past->type == DLM_AST ? "" : "b", dlm_get_lock_cookie_node(be64_to_cpu(cookie)), dlm_get_lock_cookie_seq(be64_to_cpu(cookie)), locklen, name, node); ret = DLM_NORMAL; unlock_out: spin_unlock(&res->spinlock); goto leave; do_ast: ret = DLM_NORMAL; if (past->type == DLM_AST) { /* do not alter lock refcount. switching lists. */ list_move_tail(&lock->list, &res->granted); mlog(0, "ast: Adding to granted list... type=%d, " "convert_type=%d\n", lock->ml.type, lock->ml.convert_type); if (lock->ml.convert_type != LKM_IVMODE) { lock->ml.type = lock->ml.convert_type; lock->ml.convert_type = LKM_IVMODE; } else { // should already be there.... } lock->lksb->status = DLM_NORMAL; /* if we requested the lvb, fetch it into our lksb now */ if (flags & LKM_GET_LVB) { BUG_ON(!(lock->lksb->flags & DLM_LKSB_GET_LVB)); memcpy(lock->lksb->lvb, past->lvb, DLM_LVB_LEN); } } spin_unlock(&res->spinlock); if (past->type == DLM_AST) dlm_do_local_ast(dlm, res, lock); else dlm_do_local_bast(dlm, res, lock, past->blocked_type); leave: if (res) dlm_lockres_put(res); dlm_put(dlm); return ret; } int dlm_send_proxy_ast_msg(struct dlm_ctxt *dlm, struct dlm_lock_resource *res, struct dlm_lock *lock, int msg_type, int blocked_type, int flags) { int ret = 0; struct dlm_proxy_ast past; struct kvec vec[2]; size_t veclen = 1; int status; mlog_entry("res %.*s, to=%u, type=%d, blocked_type=%d\n", res->lockname.len, res->lockname.name, lock->ml.node, msg_type, blocked_type); memset(&past, 0, sizeof(struct dlm_proxy_ast)); past.node_idx = dlm->node_num; past.type = msg_type; past.blocked_type = blocked_type; past.namelen = res->lockname.len; memcpy(past.name, res->lockname.name, past.namelen); past.cookie = lock->ml.cookie; vec[0].iov_len = sizeof(struct dlm_proxy_ast); vec[0].iov_base = &past; if (flags & DLM_LKSB_GET_LVB) { mlog(0, "returning requested LVB data\n"); be32_add_cpu(&past.flags, LKM_GET_LVB); vec[1].iov_len = DLM_LVB_LEN; vec[1].iov_base = lock->lksb->lvb; veclen++; } ret = o2net_send_message_vec(DLM_PROXY_AST_MSG, dlm->key, vec, veclen, lock->ml.node, &status); if (ret < 0) mlog_errno(ret); else { if (status == DLM_RECOVERING) { mlog(ML_ERROR, "sent AST to node %u, it thinks this " "node is dead!\n", lock->ml.node); BUG(); } else if (status == DLM_MIGRATING) { mlog(ML_ERROR, "sent AST to node %u, it returned " "DLM_MIGRATING!\n", lock->ml.node); BUG(); } else if (status != DLM_NORMAL && status != DLM_IVLOCKID) { mlog(ML_ERROR, "AST to node %u returned %d!\n", lock->ml.node, status); /* ignore it */ } ret = 0; } return ret; }