protocol/client: cluster/afr: Support lock recovery and self heal.

Signed-off-by: Pavan Vilas Sondur <pavan@gluster.com>
Signed-off-by: Vijay Bellur <vijay@dev.gluster.com>

BUG: 865 (Add locks recovery support in GlusterFS)
URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=865

1 files changed, 450 insertions, 0 deletions

diff --git a/xlators/features/locks/src/reservelk.c b/xlators/features/locks/src/reservelk.c
new file mode 100644
index 00000000000..c36484c46cc
--- /dev/null
+++ b/xlators/features/locks/src/reservelk.c
@@ -0,0 +1,450 @@
+/*
+  Copyright (c) 2006, 2007, 2008 Gluster, Inc. <http://www.gluster.com>
+  This file is part of GlusterFS.
+
+  GlusterFS 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 3 of the License,
+  or (at your option) any later version.
+
+  GlusterFS 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, see
+  <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef _CONFIG_H
+#define _CONFIG_H
+#include "config.h"
+#endif
+
+#include "glusterfs.h"
+#include "compat.h"
+#include "xlator.h"
+#include "inode.h"
+#include "logging.h"
+#include "common-utils.h"
+#include "list.h"
+
+#include "locks.h"
+#include "common.h"
+
+void
+__delete_reserve_lock (posix_lock_t *lock)
+{
+	list_del (&lock->list);
+}
+
+void
+__destroy_reserve_lock (posix_lock_t *lock)
+{
+	FREE (lock);
+}
+
+/* Return true if the two reservelks have exactly same lock boundaries */
+int
+reservelks_equal (posix_lock_t *l1, posix_lock_t *l2)
+{
+	if ((l1->fl_start == l2->fl_start) &&
+	    (l1->fl_end == l2->fl_end))
+		return 1;
+
+	return 0;
+}
+
+/* Determine if lock is grantable or not */
+static posix_lock_t *
+__reservelk_grantable (pl_inode_t *pl_inode, posix_lock_t *lock)
+{
+        xlator_t     *this     = NULL;
+	posix_lock_t *l        = NULL;
+        posix_lock_t *ret_lock = NULL;
+
+        this = THIS;
+
+	if (list_empty (&pl_inode->reservelk_list)) {
+                gf_log (this->name, GF_LOG_TRACE,
+                        "No reservelks in list");
+		goto out;
+        }
+	list_for_each_entry (l, &pl_inode->reservelk_list, list){
+		if (reservelks_equal (lock, l)) {
+                        ret_lock = l;
+                        break;
+		}
+	}
+out:
+	return ret_lock;
+}
+
+static int
+__same_owner_reservelk (posix_lock_t *l1, posix_lock_t *l2)
+{
+        return ((l1->owner == l2->owner));
+
+}
+
+static posix_lock_t *
+__matching_reservelk (pl_inode_t *pl_inode, posix_lock_t *lock)
+{
+        posix_lock_t *l = NULL;
+
+        if (list_empty (&pl_inode->reservelk_list)) {
+            gf_log ("posix-locks", GF_LOG_TRACE,
+                    "reservelk list empty");
+            return NULL;
+        }
+
+        list_for_each_entry (l, &pl_inode->reservelk_list, list) {
+                if (reservelks_equal (l, lock)) {
+                        gf_log ("posix-locks", GF_LOG_TRACE,
+                                "equal reservelk found");
+                        break;
+                }
+        }
+
+        return l;
+}
+
+static int
+__reservelk_conflict (xlator_t *this, pl_inode_t *pl_inode,
+                      posix_lock_t *lock)
+{
+        posix_lock_t *conf = NULL;
+        int ret = 0;
+
+        conf = __matching_reservelk (pl_inode, lock);
+        if (conf) {
+                gf_log (this->name, GF_LOG_TRACE,
+                        "Matching reservelk found");
+                if (__same_owner_reservelk (lock, conf)) {
+                        list_del_init (&conf->list);
+                        gf_log (this->name, GF_LOG_TRACE,
+                                "Removing the matching reservelk for setlk to progress");
+                        FREE (conf);
+                        ret = 0;
+                } else {
+                        gf_log (this->name, GF_LOG_TRACE,
+                                "Conflicting reservelk found");
+                        ret = 1;
+                }
+
+        }
+        return ret;
+
+}
+
+int
+pl_verify_reservelk (xlator_t *this, pl_inode_t *pl_inode,
+                     posix_lock_t *lock, int can_block)
+{
+        int ret = 0;
+
+        pthread_mutex_lock (&pl_inode->mutex);
+        {
+                if (__reservelk_conflict (this, pl_inode, lock)) {
+                        gf_log (this->name, GF_LOG_TRACE,
+                                "Found conflicting reservelk. Blocking until reservelk is unlocked.");
+                        lock->blocked = can_block;
+                        list_add_tail (&lock->list, &pl_inode->blocked_calls);
+                        ret = -1;
+                        goto unlock;
+                }
+
+                gf_log (this->name, GF_LOG_TRACE,
+                        "no conflicting reservelk found. Call continuing");
+                ret = 0;
+
+        }
+unlock:
+        pthread_mutex_unlock (&pl_inode->mutex);
+
+        return ret;
+
+}
+
+
+/* Determines if lock can be granted and adds the lock. If the lock
+ * is blocking, adds it to the blocked_reservelks.
+ */
+static int
+__lock_reservelk (xlator_t *this, pl_inode_t *pl_inode, posix_lock_t *lock,
+                  int can_block)
+{
+	posix_lock_t *conf = NULL;
+	int ret = -EINVAL;
+
+	conf = __reservelk_grantable (pl_inode, lock);
+	if (conf){
+		ret = -EAGAIN;
+		if (can_block == 0)
+			goto out;
+
+		list_add_tail (&lock->list, &pl_inode->blocked_reservelks);
+
+                gf_log (this->name, GF_LOG_TRACE,
+                        "%s (pid=%d) lk-owner:%"PRIu64" %"PRId64" - %"PRId64" => Blocked",
+                        lock->fl_type == F_UNLCK ? "Unlock" : "Lock",
+                        lock->client_pid,
+                        lock->owner,
+                        lock->user_flock.l_start,
+                        lock->user_flock.l_len);
+
+
+		goto out;
+	}
+
+	list_add (&lock->list, &pl_inode->reservelk_list);
+
+	ret = 0;
+
+out:
+	return ret;
+}
+
+static posix_lock_t *
+find_matching_reservelk (posix_lock_t *lock, pl_inode_t *pl_inode)
+{
+	posix_lock_t *l = NULL;
+	list_for_each_entry (l, &pl_inode->reservelk_list, list) {
+		if (reservelks_equal (l, lock))
+			return l;
+	}
+	return NULL;
+}
+
+/* Set F_UNLCK removes a lock which has the exact same lock boundaries
+ * as the UNLCK lock specifies. If such a lock is not found, returns invalid
+ */
+static posix_lock_t *
+__reserve_unlock_lock (xlator_t *this, posix_lock_t *lock, pl_inode_t *pl_inode)
+{
+
+	posix_lock_t *conf = NULL;
+
+	conf = find_matching_reservelk (lock, pl_inode);
+	if (!conf) {
+                gf_log (this->name, GF_LOG_DEBUG,
+                        " Matching lock not found for unlock");
+		goto out;
+        }
+	__delete_reserve_lock (conf);
+        gf_log (this->name, GF_LOG_DEBUG,
+                " Matching lock found for unlock");
+
+out:
+	return conf;
+
+
+}
+
+static void
+__grant_blocked_reserve_locks (xlator_t *this, pl_inode_t *pl_inode,
+                               struct list_head *granted)
+{
+	int	      bl_ret = 0;
+	posix_lock_t *bl = NULL;
+	posix_lock_t *tmp = NULL;
+
+        struct list_head blocked_list;
+
+        INIT_LIST_HEAD (&blocked_list);
+        list_splice_init (&pl_inode->blocked_reservelks, &blocked_list);
+
+	list_for_each_entry_safe (bl, tmp, &blocked_list, list) {
+
+		list_del_init (&bl->list);
+
+		bl_ret = __lock_reservelk (this, pl_inode, bl, 1);
+
+		if (bl_ret == 0) {
+			list_add (&bl->list, granted);
+                }
+        }
+	return;
+}
+
+/* Grant all reservelks blocked on lock(s) */
+void
+grant_blocked_reserve_locks (xlator_t *this, pl_inode_t *pl_inode)
+{
+	struct list_head granted;
+	posix_lock_t *lock = NULL;
+	posix_lock_t *tmp = NULL;
+
+	INIT_LIST_HEAD (&granted);
+
+        if (list_empty (&pl_inode->blocked_reservelks)) {
+                gf_log (this->name, GF_LOG_TRACE,
+                        "No blocked locks to be granted");
+                return;
+        }
+
+        pthread_mutex_lock (&pl_inode->mutex);
+	{
+		__grant_blocked_reserve_locks (this, pl_inode, &granted);
+	}
+        pthread_mutex_unlock (&pl_inode->mutex);
+
+	list_for_each_entry_safe (lock, tmp, &granted, list) {
+                gf_log (this->name, GF_LOG_TRACE,
+			"%s (pid=%d) (lk-owner=%"PRIu64") %"PRId64" - %"PRId64" => Granted",
+			lock->fl_type == F_UNLCK ? "Unlock" : "Lock",
+			lock->client_pid,
+			lock->owner,
+			lock->user_flock.l_start,
+			lock->user_flock.l_len);
+
+		STACK_UNWIND_STRICT (lk, lock->frame, 0, 0, &lock->user_flock);
+	}
+
+}
+
+static void
+__grant_blocked_lock_calls (xlator_t *this, pl_inode_t *pl_inode,
+                            struct list_head *granted)
+{
+	int	      bl_ret = 0;
+	posix_lock_t *bl = NULL;
+	posix_lock_t *tmp = NULL;
+
+        struct list_head blocked_list;
+
+        INIT_LIST_HEAD (&blocked_list);
+        list_splice_init (&pl_inode->blocked_reservelks, &blocked_list);
+
+	list_for_each_entry_safe (bl, tmp, &blocked_list, list) {
+
+		list_del_init (&bl->list);
+
+		bl_ret = pl_verify_reservelk (this, pl_inode, bl, bl->blocked);
+
+		if (bl_ret == 0) {
+                        list_add_tail (&bl->list, granted);
+                }
+        }
+	return;
+}
+
+void
+grant_blocked_lock_calls (xlator_t *this, pl_inode_t *pl_inode)
+{
+	struct list_head granted;
+	posix_lock_t *lock = NULL;
+	posix_lock_t *tmp = NULL;
+        fd_t         *fd  = NULL;
+
+        int can_block = 0;
+        int32_t cmd = 0;
+        int ret = 0;
+
+        if (list_empty (&pl_inode->blocked_calls)) {
+                gf_log (this->name, GF_LOG_TRACE,
+                        "No blocked lock calls to be granted");
+                return;
+        }
+
+        pthread_mutex_lock (&pl_inode->mutex);
+	{
+		__grant_blocked_lock_calls (this, pl_inode, &granted);
+	}
+        pthread_mutex_unlock (&pl_inode->mutex);
+
+        list_for_each_entry_safe (lock, tmp, &granted, list) {
+                fd = fd_from_fdnum (lock);
+
+                if (lock->blocked) {
+                        can_block = 1;
+                        cmd = F_SETLKW;
+                }
+                else
+                        cmd = F_SETLK;
+
+                lock->blocked = 0;
+                ret = pl_setlk (this, pl_inode, lock, can_block);
+                if (ret == -1) {
+                        if (can_block) {
+                                pl_trace_block (this, lock->frame, fd, NULL,
+                                                cmd, &lock->user_flock, NULL);
+                                continue;
+                        } else {
+                                gf_log (this->name, GF_LOG_DEBUG, "returning EAGAIN");
+                                pl_trace_out (this, lock->frame, fd, NULL, cmd,
+                                              &lock->user_flock, -1, EAGAIN, NULL);
+                                pl_update_refkeeper (this, fd->inode);
+                                STACK_UNWIND_STRICT (lk, lock->frame, -1, EAGAIN, &lock->user_flock);
+                                __destroy_lock (lock);
+                        }
+                }
+
+        }
+
+}
+
+
+int
+pl_reserve_unlock (xlator_t *this, pl_inode_t *pl_inode, posix_lock_t *lock)
+{
+        posix_lock_t *retlock = NULL;
+        int ret = -1;
+
+        pthread_mutex_lock (&pl_inode->mutex);
+	{
+		retlock = __reserve_unlock_lock (this, lock, pl_inode);
+		if (!retlock) {
+			gf_log (this->name, GF_LOG_DEBUG,
+				"Bad Unlock issued on Inode lock");
+                        ret = -EINVAL;
+                        goto out;
+                }
+
+                gf_log (this->name, GF_LOG_TRACE,
+                        "Reservelk Unlock successful");
+		__destroy_reserve_lock (retlock);
+                ret = 0;
+        }
+out:
+        pthread_mutex_unlock (&pl_inode->mutex);
+
+        grant_blocked_reserve_locks (this, pl_inode);
+        grant_blocked_lock_calls (this, pl_inode);
+
+        return ret;
+
+}
+
+int
+pl_reserve_setlk (xlator_t *this, pl_inode_t *pl_inode, posix_lock_t *lock,
+                  int can_block)
+{
+	int ret = -EINVAL;
+
+	pthread_mutex_lock (&pl_inode->mutex);
+	{
+
+			ret = __lock_reservelk (this, pl_inode, lock, can_block);
+                        if (ret < 0)
+				gf_log (this->name, GF_LOG_TRACE,
+                                        "%s (pid=%d) (lk-owner=%"PRIu64") %"PRId64" - %"PRId64" => NOK",
+					lock->fl_type == F_UNLCK ? "Unlock" : "Lock",
+					lock->client_pid,
+                                        lock->owner,
+					lock->user_flock.l_start,
+					lock->user_flock.l_len);
+                        else
+				gf_log (this->name, GF_LOG_TRACE,
+                                        "%s (pid=%d) (lk-owner=%"PRIu64") %"PRId64" - %"PRId64" => OK",
+                                        lock->fl_type == F_UNLCK ? "Unlock" : "Lock",
+                                        lock->client_pid,
+                                        lock->owner,
+                                        lock->fl_start,
+                                        lock->fl_end);
+
+	}
+	pthread_mutex_unlock (&pl_inode->mutex);
+        return ret;
+}