1 files changed, 762 insertions, 0 deletions

diff --git a/xlators/features/locks/src/internal.c b/xlators/features/locks/src/internal.c
new file mode 100644
index 00000000000..7f454a78e22
--- /dev/null
+++ b/xlators/features/locks/src/internal.c
@@ -0,0 +1,762 @@
+/*
+  Copyright (c) 2006, 2007, 2008 Z RESEARCH, Inc. <http://www.zresearch.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"
+
+
+
+static int
+delete_locks_of_transport (pl_inode_t *pinode, transport_t *trans)
+{
+	posix_lock_t *tmp = NULL;
+	posix_lock_t *l = NULL;
+
+	list_for_each_entry_safe (l, tmp, &pinode->dir_list, list) {
+		if (l->transport == trans) {
+			__delete_lock (pinode, tmp);
+			__destroy_lock (tmp);
+		}
+	}
+
+	return 0;
+}
+
+
+static posix_lock_t *
+__find_exact_matching_lock (pl_inode_t *pinode, posix_lock_t *lock)
+{
+	posix_lock_t *l     = NULL;
+	posix_lock_t *match = NULL;
+
+	list_for_each_entry (l, DOMAIN_HEAD (pinode, GF_LOCK_INTERNAL), list) {
+		if (same_owner (l, lock)
+		    && (l->fl_start == lock->fl_start)
+		    && (l->fl_end   == lock->fl_end)) {
+			match = l;
+			break;
+		}
+	}
+
+	return match;
+}
+
+/**
+ * pl_inodelk: 
+ *
+ * This fop provides fcntl-style locking on files for internal
+ * purposes. Locks held through this fop reside in a domain different
+ * from those held by applications. This fop is for the use of AFR.
+ */
+
+
+static int
+pl_inodelk_common (call_frame_t *frame, xlator_t *this,
+		   inode_t *inode, int32_t cmd, struct flock *flock)
+{
+	int32_t op_ret   = -1;
+	int32_t op_errno = 0;
+	int     can_block = 0;
+
+	posix_locks_private_t * priv       = NULL;
+	transport_t *           transport  = NULL;
+	pid_t                   client_pid = -1;
+	pl_inode_t *            pinode     = NULL;
+	
+	posix_lock_t *          reqlock    = NULL;
+	posix_lock_t *          matchlock  = NULL;  /* steady, fire! */
+
+	VALIDATE_OR_GOTO (frame, unwind);
+	VALIDATE_OR_GOTO (inode, unwind);
+	VALIDATE_OR_GOTO (flock, unwind);
+	
+	if ((flock->l_start < 0) || (flock->l_len < 0)) {
+		op_errno = EINVAL;
+		goto unwind;
+	}
+
+	transport  = frame->root->trans;
+	client_pid = frame->root->pid;
+
+	priv = (posix_locks_private_t *) this->private;
+
+	VALIDATE_OR_GOTO (priv, unwind);
+
+	pinode = pl_inode_get (this, inode);
+	if (!pinode) {
+		gf_log (this->name, GF_LOG_ERROR,
+			"out of memory :(");
+		op_errno = ENOMEM;
+		goto unwind;
+	}
+
+	if (client_pid == 0) {
+		/* 
+		   special case: this means release all locks 
+		   from this transport
+		*/
+
+		gf_log (this->name, GF_LOG_DEBUG,
+			"releasing all locks from transport %p", transport);
+
+		delete_locks_of_transport (pinode, transport);
+		goto unwind;
+	}
+
+	reqlock = new_posix_lock (flock, transport, client_pid);
+	if (!reqlock) {
+		gf_log (this->name, GF_LOG_ERROR,
+			"out of memory :(");
+		op_ret = -1;
+		op_errno = ENOMEM;
+		goto unwind;
+	}
+
+	pthread_mutex_lock (&pinode->mutex);
+	{
+		switch (cmd) {
+		case F_SETLKW:
+			can_block = 1;
+			reqlock->frame = frame;
+			reqlock->this  = this;
+			
+			/* fall through */
+			
+		case F_SETLK:
+			memcpy (&reqlock->user_flock, flock, sizeof (struct flock));
+			
+			switch (flock->l_type) {
+				
+			case F_WRLCK:
+				if (!pl_is_lock_grantable (pinode, reqlock, GF_LOCK_INTERNAL)) {
+					if (can_block) {
+						gf_log (this->name, GF_LOG_DEBUG,
+							"%s (pid=%d) %"PRId64" - %"PRId64" => blocked",
+							reqlock->fl_type == F_UNLCK ? "unlock" : "lock",
+							reqlock->client_pid,
+							reqlock->user_flock.l_start,
+							reqlock->user_flock.l_len);
+						pl_insert_lock (pinode, reqlock, GF_LOCK_INTERNAL);
+						
+						goto unlock;
+					}
+					
+					__destroy_lock (reqlock);
+					
+					
+					gf_log (this->name, GF_LOG_DEBUG,
+						"%s (pid=%d) %"PRId64" - %"PRId64" => NOK",
+						reqlock->fl_type == F_UNLCK ? "unlock" : "lock",
+						reqlock->client_pid, reqlock->user_flock.l_start,
+						reqlock->user_flock.l_len);
+					op_errno = EAGAIN;
+					
+					goto unlock;
+				}
+				
+				gf_log (this->name, GF_LOG_DEBUG,
+					"%s (pid=%d) %"PRId64" - %"PRId64" => OK",
+					reqlock->fl_type == F_UNLCK ? "unlock" : "lock",
+					reqlock->client_pid,
+					reqlock->user_flock.l_start,
+					reqlock->user_flock.l_len);
+				pl_insert_lock (pinode, reqlock, GF_LOCK_INTERNAL);
+				
+				break;
+				
+			case F_UNLCK:
+				matchlock = __find_exact_matching_lock (pinode, reqlock);
+
+				__destroy_lock (reqlock);
+				if (!matchlock) {
+					op_errno = EINVAL;
+					goto unlock;
+				}
+				
+				__delete_lock (pinode, matchlock);
+				__destroy_lock (matchlock);
+				
+				break;
+				
+			default:
+				op_errno = ENOTSUP;
+				gf_log (this->name, GF_LOG_ERROR,
+					"lock type %d not supported for [F]INODELK",
+					flock->l_type);
+				goto unlock;
+			}
+			
+			
+			break;
+			
+		default:
+			op_errno = ENOTSUP;
+			gf_log (this->name, GF_LOG_ERROR,
+				"lock command F_GETLK not supported for [F]INODELK (cmd=%d)", 
+				cmd);
+			goto unlock;
+		}
+		
+		op_ret = 0;
+		
+	unlock:
+		if (pinode)
+			pthread_mutex_unlock (&pinode->mutex);
+	}
+
+unwind:
+	STACK_UNWIND (frame, op_ret, op_errno);
+	return 0;
+}
+
+
+int
+pl_inodelk (call_frame_t *frame, xlator_t *this,
+	    loc_t *loc, int32_t cmd, struct flock *flock)
+{
+	return pl_inodelk_common (frame, this, loc->inode, cmd, flock);
+}
+
+
+int
+pl_finodelk (call_frame_t *frame, xlator_t *this,
+	     fd_t *fd, int32_t cmd, struct flock *flock)
+{
+	return pl_inodelk_common (frame, this, fd->inode, cmd, flock);
+}
+
+
+/**
+ * types_conflict - do two types of lock conflict?
+ * @t1: type
+ * @t2: type
+ *
+ * two read locks do not conflict
+ * any other case conflicts
+ */
+
+static int
+types_conflict (entrylk_type t1, entrylk_type t2)
+{
+	return !((t1 == ENTRYLK_RDLCK) && (t2 == ENTRYLK_RDLCK));
+}
+
+/**
+ * all_names - does a basename represent all names?
+ * @basename: name to check
+ */
+
+#define all_names(basename) ((basename == NULL) ? 1 : 0)
+
+/**
+ * names_conflict - do two names conflict?
+ * @n1: name
+ * @n2: name
+ */
+
+static int 
+names_conflict (const char *n1, const char *n2)
+{
+	return all_names (n1) || all_names (n2) || !strcmp (n1, n2);
+}
+
+
+static int 
+names_equal (const char *n1, const char *n2)
+{
+	return (n1 == NULL && n2 == NULL) || (n1 && n2 && !strcmp (n1, n2));
+}
+
+/**
+ * lock_grantable - is this lock grantable?
+ * @inode: inode in which to look
+ * @basename: name we're trying to lock
+ * @type: type of lock
+ */
+
+static pl_entry_lock_t *
+__lock_grantable (pl_inode_t *pinode, const char *basename, entrylk_type type)
+{
+	pl_entry_lock_t *lock = NULL;
+
+	if (list_empty (&pinode->dir_list))
+		return NULL;
+
+	list_for_each_entry (lock, &pinode->dir_list, inode_list) {
+		if (names_conflict (lock->basename, basename) &&
+		    types_conflict (lock->type, type))
+			return lock;
+	}
+
+	return NULL;
+}
+
+/**
+ * find_most_matching_lock - find the lock struct which most matches in order of:
+ *                           lock on the exact basename ||
+ *                           an all_names lock
+ *                      
+ *
+ * @inode: inode in which to look
+ * @basename: name to search for
+ */
+
+static pl_entry_lock_t * 
+__find_most_matching_lock (pl_inode_t *pinode, const char *basename)
+{
+	pl_entry_lock_t *lock;
+	pl_entry_lock_t *all = NULL;
+	pl_entry_lock_t *exact = NULL;
+
+	if (list_empty (&pinode->dir_list)) 
+		return NULL;
+
+	list_for_each_entry (lock, &pinode->dir_list, inode_list) {
+		if (all_names (lock->basename))
+			all = lock;
+		else if (names_equal (lock->basename, basename))
+			exact = lock;
+	}
+
+	return (exact ? exact : all);
+}
+
+
+/**
+ * insert_new_lock - insert a new dir lock into the inode with the given parameters
+ * @pinode: inode to insert into
+ * @basename: basename for the lock
+ * @type: type of the lock
+ */
+
+static pl_entry_lock_t *
+new_entrylk_lock (pl_inode_t *pinode, const char *basename, entrylk_type type,
+		  transport_t *trans)
+{
+	pl_entry_lock_t *newlock = NULL;
+
+	newlock = CALLOC (sizeof (pl_entry_lock_t), 1);
+	if (!newlock) {
+		goto out;
+	}
+
+	newlock->basename = basename ? strdup (basename) : NULL;
+	newlock->type     = type;
+	newlock->trans    = trans;
+
+	if (type == ENTRYLK_RDLCK)
+		newlock->read_count = 1;
+
+	INIT_LIST_HEAD (&newlock->inode_list);
+	INIT_LIST_HEAD (&newlock->blocked_locks);
+
+out:
+	return newlock;
+}
+
+/**
+ * lock_name - lock a name in a directory
+ * @inode: inode for the directory in which to lock
+ * @basename: name of the entry to lock
+ *            if null, lock the entire directory
+ *            
+ * the entire directory being locked is represented as: a single
+ * pl_entry_lock_t present in the entrylk_locks list with its
+ * basename = NULL
+ */
+
+int
+__lock_name (pl_inode_t *pinode, const char *basename, entrylk_type type,
+	     call_frame_t *frame, xlator_t *this, int nonblock)
+{
+	pl_entry_lock_t *lock    = NULL;
+	pl_entry_lock_t *conf    = NULL;
+
+	transport_t *trans = NULL;
+
+	int ret = -EINVAL;
+
+	trans = frame->root->trans;
+
+	conf = __lock_grantable (pinode, basename, type);
+	if (conf) {
+		ret = -EAGAIN;
+		if (nonblock)
+			goto out;
+
+		lock = new_entrylk_lock (pinode, basename, type, trans);
+
+		if (!lock) {
+			ret = -ENOMEM;
+			goto out;
+		}
+
+		gf_log (this->name, GF_LOG_DEBUG,
+			"blocking lock: {pinode=%p, basename=%s}",
+			pinode, basename);
+
+		lock->frame   = frame;
+		lock->this    = this;
+		lock->blocked = 1;
+
+		list_add (&lock->blocked_locks, &conf->blocked_locks);
+
+
+		goto out;
+	}
+		
+	switch (type) {
+	case ENTRYLK_RDLCK:
+		lock = __find_most_matching_lock (pinode, basename);
+
+		if (lock && names_equal (lock->basename, basename)) {
+			lock->read_count++;
+
+			FREE (lock->basename);
+			FREE (lock);
+
+			lock = NULL;
+		} else {
+			lock = new_entrylk_lock (pinode, basename, type, trans);
+
+			if (!lock) {
+				ret = -ENOMEM;
+				goto out;
+			}
+
+			list_add (&lock->inode_list, &pinode->dir_list);
+		}
+		break;
+
+	case ENTRYLK_WRLCK:
+		lock = new_entrylk_lock (pinode, basename, type, trans);
+			
+		if (!lock) {
+			ret = -ENOMEM;
+			goto out;
+		}
+
+		list_add (&lock->inode_list, &pinode->dir_list);
+		break;
+	}
+
+	ret = 0;
+out:
+	return ret;
+}
+
+
+/**
+ * unlock_name - unlock a name in a directory
+ * @inode: inode for the directory to unlock in
+ * @basename: name of the entry to unlock
+ *            if null, unlock the entire directory
+ */
+
+pl_entry_lock_t *
+__unlock_name (pl_inode_t *pinode, const char *basename, entrylk_type type)
+{
+	pl_entry_lock_t *lock = NULL;
+	pl_entry_lock_t *ret_lock = NULL;
+
+	lock = __find_most_matching_lock (pinode, basename);
+	
+	if (!lock) {
+		gf_log ("locks", GF_LOG_DEBUG,
+			"unlock on %s (type=%s) attempted but no matching lock found",
+			basename, type == ENTRYLK_RDLCK ? "ENTRYLK_RDLCK" : 
+			"ENTRYLK_WRLCK");
+		goto out;
+	}
+	
+	if (names_equal (lock->basename, basename)
+	    && lock->type == type) {
+		if (type == ENTRYLK_RDLCK) {
+			lock->read_count--;
+		}
+		if (type == ENTRYLK_WRLCK || lock->read_count == 0) {
+			list_del (&lock->inode_list);
+			ret_lock = lock;
+		}
+	} else {
+		gf_log ("locks", GF_LOG_ERROR,
+			"unlock for a non-existing lock!");
+		goto out;
+	}
+
+out:
+	return ret_lock;
+}
+
+
+void
+__grant_blocked_entry_locks (xlator_t *this, pl_inode_t *pl_inode,
+			     pl_entry_lock_t *lock,
+			     struct list_head *granted)
+{
+	int              bl_ret = 0;
+	pl_entry_lock_t *bl   = NULL;
+	pl_entry_lock_t *tmp  = NULL;
+
+	list_for_each_entry_safe (bl, tmp, &lock->blocked_locks, 
+				  blocked_locks) {
+		list_del_init (&bl->blocked_locks);
+
+		/* TODO: error checking */
+
+		gf_log ("locks", GF_LOG_DEBUG,
+			"trying to unblock: {pinode=%p, basename=%s}",
+			pl_inode, bl->basename);
+					
+		bl_ret = __lock_name (pl_inode, bl->basename, bl->type,
+				      bl->frame, bl->this, 0);
+
+		if (bl_ret == 0) {
+			list_add (&bl->blocked_locks, granted);
+		} else {
+			if (bl->basename)
+				FREE (bl->basename);
+			FREE (bl);
+		}
+	}	
+	return;
+}
+
+
+void
+grant_blocked_entry_locks (xlator_t *this, pl_inode_t *pl_inode,
+			   pl_entry_lock_t *unlocked)
+{
+	struct list_head  granted_list;
+	pl_entry_lock_t  *tmp = NULL;
+	pl_entry_lock_t  *lock = NULL;
+
+	INIT_LIST_HEAD (&granted_list);
+
+	pthread_mutex_lock (&pl_inode->mutex);
+	{
+		__grant_blocked_entry_locks (this, pl_inode, unlocked,
+					     &granted_list);
+	}
+	pthread_mutex_unlock (&pl_inode->mutex);
+
+	list_for_each_entry_safe (lock, tmp, &granted_list, blocked_locks) {
+		list_del_init (&lock->blocked_locks);
+
+		STACK_UNWIND (lock->frame, 0, 0);
+
+		FREE (lock->basename);
+		FREE (lock);
+	}
+
+	FREE (unlocked->basename);
+	FREE (unlocked);
+
+	return;
+}
+
+
+/**
+ * release_entry_locks_for_transport: release all entry locks from this
+ * transport for this loc_t
+ */
+
+static int
+release_entry_locks_for_transport (xlator_t *this, pl_inode_t *pinode,
+				   transport_t *trans)
+{
+	pl_entry_lock_t  *lock;
+	pl_entry_lock_t  *tmp;
+	struct list_head  granted;
+
+	INIT_LIST_HEAD (&granted);
+
+	pthread_mutex_lock (&pinode->mutex);
+	{
+		if (list_empty (&pinode->dir_list)) {
+			goto unlock;
+		}
+
+		list_for_each_entry_safe (lock, tmp, &pinode->dir_list,
+					  inode_list) {
+			if (lock->trans != trans)
+				continue;
+
+			list_del_init (&lock->inode_list);
+			__grant_blocked_entry_locks (this, pinode, lock,
+						     &granted);
+
+			FREE (lock->basename);
+			FREE (lock);
+		}
+	}
+unlock:
+	pthread_mutex_unlock (&pinode->mutex);
+
+	list_for_each_entry_safe (lock, tmp, &granted, blocked_locks) {
+		list_del_init (&lock->blocked_locks);
+
+		STACK_UNWIND (lock->frame, 0, 0);
+
+		FREE (lock->basename);
+		FREE (lock);
+	}
+
+	return 0;
+}
+
+
+/**
+ * pl_entrylk:
+ * 
+ * Locking on names (directory entries)
+ */
+
+int
+pl_entrylk_common (call_frame_t *frame, xlator_t *this,
+		   inode_t *inode, const char *basename, 
+		   entrylk_cmd cmd, entrylk_type type)
+{
+	int32_t op_ret   = -1;
+	int32_t op_errno = 0;
+
+	transport_t * transport = NULL;
+	pid_t pid = -1;
+
+	pl_inode_t *       pinode = NULL; 
+	int                ret    = -1;
+	pl_entry_lock_t   *unlocked = NULL;
+	char               unwind = 1;
+
+	pinode = pl_inode_get (this, inode);
+	if (!pinode) {
+		gf_log (this->name, GF_LOG_ERROR,
+			"out of memory :(");
+		op_errno = ENOMEM;
+		goto out;
+	}
+
+	pid       = frame->root->pid;
+	transport = frame->root->trans;
+
+	if (pid == 0) {
+		/* 
+		   this is a special case that means release
+		   all locks from this transport 
+		*/
+
+		gf_log (this->name, GF_LOG_DEBUG,
+			"releasing locks for transport %p", transport);
+
+		release_entry_locks_for_transport (this, pinode, transport);
+		op_ret = 0;
+
+		goto out;
+	}
+
+	switch (cmd) {
+	case ENTRYLK_LOCK:
+		pthread_mutex_lock (&pinode->mutex);
+		{
+			ret = __lock_name (pinode, basename, type,
+					   frame, this, 0);
+		}
+		pthread_mutex_unlock (&pinode->mutex);
+
+		if (ret < 0) {
+			if (ret == -EAGAIN)
+				unwind = 0;
+			op_errno = -ret;
+			goto out;
+		}
+
+		break;
+
+	case ENTRYLK_LOCK_NB:
+		pthread_mutex_lock (&pinode->mutex);
+		{
+			ret = __lock_name (pinode, basename, type,
+					   frame, this, 1);
+		}
+		pthread_mutex_unlock (&pinode->mutex);
+
+		if (ret < 0) {
+			op_errno = -ret;
+			goto out;
+		}
+
+		break;
+
+	case ENTRYLK_UNLOCK:
+		pthread_mutex_lock (&pinode->mutex);
+		{
+			unlocked = __unlock_name (pinode, basename, type);
+		}
+		pthread_mutex_unlock (&pinode->mutex);
+
+		if (unlocked)
+			grant_blocked_entry_locks (this, pinode, unlocked);
+
+		break;
+
+	default:
+		gf_log (this->name, GF_LOG_ERROR,
+			"unexpected case!");
+		goto out;
+	}
+
+	op_ret = 0;
+out:
+	if (unwind) {
+		STACK_UNWIND (frame, op_ret, op_errno);
+	}
+	
+	return 0;
+}
+
+
+int
+pl_entrylk (call_frame_t *frame, xlator_t *this,
+	    loc_t *loc, const char *basename, 
+	    entrylk_cmd cmd, entrylk_type type)
+{
+	return pl_entrylk_common (frame, this, loc->inode, basename, cmd, type);
+}
+
+
+int
+pl_fentrylk (call_frame_t *frame, xlator_t *this,
+	     fd_t *fd, const char *basename, 
+	     entrylk_cmd cmd, entrylk_type type)
+{
+	return pl_entrylk_common (frame, this, fd->inode, basename, cmd, type);	
+}