Date:	Thu, 21 Jul 2011 11:04:03 -0500
From:	David Teigland <teigland@...hat.com>
To:	linux-kernel@...r.kernel.org
Subject: [PATCH 06/10] dlm: keep lkbs in idr

This is simpler and quicker than the hash table, and
avoids needing to search the hash list for every new
lkid to check if it's used.

Signed-off-by: David Teigland <teigland@...hat.com>
---
 fs/dlm/config.c       |    7 ---
 fs/dlm/config.h       |    1 -
 fs/dlm/dlm_internal.h |   14 ++----
 fs/dlm/lock.c         |   69 ++++++++++-------------------
 fs/dlm/lockspace.c    |  114 +++++++++++++++++++++++--------------------------
 5 files changed, 81 insertions(+), 124 deletions(-)

diff --git a/fs/dlm/config.c b/fs/dlm/config.c
index ad3b5a8..4e20f93 100644
--- a/fs/dlm/config.c
+++ b/fs/dlm/config.c
@@ -94,7 +94,6 @@ struct dlm_cluster {
 	unsigned int cl_tcp_port;
 	unsigned int cl_buffer_size;
 	unsigned int cl_rsbtbl_size;
-	unsigned int cl_lkbtbl_size;
 	unsigned int cl_dirtbl_size;
 	unsigned int cl_recover_timer;
 	unsigned int cl_toss_secs;
@@ -109,7 +108,6 @@ enum {
 	CLUSTER_ATTR_TCP_PORT = 0,
 	CLUSTER_ATTR_BUFFER_SIZE,
 	CLUSTER_ATTR_RSBTBL_SIZE,
-	CLUSTER_ATTR_LKBTBL_SIZE,
 	CLUSTER_ATTR_DIRTBL_SIZE,
 	CLUSTER_ATTR_RECOVER_TIMER,
 	CLUSTER_ATTR_TOSS_SECS,
@@ -162,7 +160,6 @@ __CONFIGFS_ATTR(name, 0644, name##_read, name##_write)
 CLUSTER_ATTR(tcp_port, 1);
 CLUSTER_ATTR(buffer_size, 1);
 CLUSTER_ATTR(rsbtbl_size, 1);
-CLUSTER_ATTR(lkbtbl_size, 1);
 CLUSTER_ATTR(dirtbl_size, 1);
 CLUSTER_ATTR(recover_timer, 1);
 CLUSTER_ATTR(toss_secs, 1);
@@ -176,7 +173,6 @@ static struct configfs_attribute *cluster_attrs[] = {
 	[CLUSTER_ATTR_TCP_PORT] = &cluster_attr_tcp_port.attr,
 	[CLUSTER_ATTR_BUFFER_SIZE] = &cluster_attr_buffer_size.attr,
 	[CLUSTER_ATTR_RSBTBL_SIZE] = &cluster_attr_rsbtbl_size.attr,
-	[CLUSTER_ATTR_LKBTBL_SIZE] = &cluster_attr_lkbtbl_size.attr,
 	[CLUSTER_ATTR_DIRTBL_SIZE] = &cluster_attr_dirtbl_size.attr,
 	[CLUSTER_ATTR_RECOVER_TIMER] = &cluster_attr_recover_timer.attr,
 	[CLUSTER_ATTR_TOSS_SECS] = &cluster_attr_toss_secs.attr,
@@ -446,7 +442,6 @@ static struct config_group *make_cluster(struct config_group *g,
 	cl->cl_tcp_port = dlm_config.ci_tcp_port;
 	cl->cl_buffer_size = dlm_config.ci_buffer_size;
 	cl->cl_rsbtbl_size = dlm_config.ci_rsbtbl_size;
-	cl->cl_lkbtbl_size = dlm_config.ci_lkbtbl_size;
 	cl->cl_dirtbl_size = dlm_config.ci_dirtbl_size;
 	cl->cl_recover_timer = dlm_config.ci_recover_timer;
 	cl->cl_toss_secs = dlm_config.ci_toss_secs;
@@ -1038,7 +1033,6 @@ int dlm_our_addr(struct sockaddr_storage *addr, int num)
 #define DEFAULT_TCP_PORT       21064
 #define DEFAULT_BUFFER_SIZE     4096
 #define DEFAULT_RSBTBL_SIZE     1024
-#define DEFAULT_LKBTBL_SIZE     1024
 #define DEFAULT_DIRTBL_SIZE     1024
 #define DEFAULT_RECOVER_TIMER      5
 #define DEFAULT_TOSS_SECS         10
@@ -1052,7 +1046,6 @@ struct dlm_config_info dlm_config = {
 	.ci_tcp_port = DEFAULT_TCP_PORT,
 	.ci_buffer_size = DEFAULT_BUFFER_SIZE,
 	.ci_rsbtbl_size = DEFAULT_RSBTBL_SIZE,
-	.ci_lkbtbl_size = DEFAULT_LKBTBL_SIZE,
 	.ci_dirtbl_size = DEFAULT_DIRTBL_SIZE,
 	.ci_recover_timer = DEFAULT_RECOVER_TIMER,
 	.ci_toss_secs = DEFAULT_TOSS_SECS,
diff --git a/fs/dlm/config.h b/fs/dlm/config.h
index dd0ce24..2605744 100644
--- a/fs/dlm/config.h
+++ b/fs/dlm/config.h
@@ -20,7 +20,6 @@ struct dlm_config_info {
 	int ci_tcp_port;
 	int ci_buffer_size;
 	int ci_rsbtbl_size;
-	int ci_lkbtbl_size;
 	int ci_dirtbl_size;
 	int ci_recover_timer;
 	int ci_toss_secs;
diff --git a/fs/dlm/dlm_internal.h b/fs/dlm/dlm_internal.h
index 0262451..23a234b 100644
--- a/fs/dlm/dlm_internal.h
+++ b/fs/dlm/dlm_internal.h
@@ -37,6 +37,7 @@
 #include <linux/jhash.h>
 #include <linux/miscdevice.h>
 #include <linux/mutex.h>
+#include <linux/idr.h>
 #include <asm/uaccess.h>
 
 #include <linux/dlm.h>
@@ -52,7 +53,6 @@ struct dlm_ls;
 struct dlm_lkb;
 struct dlm_rsb;
 struct dlm_member;
-struct dlm_lkbtable;
 struct dlm_rsbtable;
 struct dlm_dirtable;
 struct dlm_direntry;
@@ -108,11 +108,6 @@ struct dlm_rsbtable {
 	spinlock_t		lock;
 };
 
-struct dlm_lkbtable {
-	struct list_head	list;
-	rwlock_t		lock;
-	uint16_t		counter;
-};
 
 /*
  * Lockspace member (per node in a ls)
@@ -248,7 +243,6 @@ struct dlm_lkb {
 	int8_t			lkb_wait_count;
 	int			lkb_wait_nodeid; /* for debugging */
 
-	struct list_head	lkb_idtbl_list;	/* lockspace lkbtbl */
 	struct list_head	lkb_statequeue;	/* rsb g/c/w list */
 	struct list_head	lkb_rsb_lookup;	/* waiting for rsb lookup */
 	struct list_head	lkb_wait_reply;	/* waiting for remote reply */
@@ -465,12 +459,12 @@ struct dlm_ls {
 	unsigned long		ls_scan_time;
 	struct kobject		ls_kobj;
 
+	struct idr		ls_lkbidr;
+	spinlock_t		ls_lkbidr_spin;
+
 	struct dlm_rsbtable	*ls_rsbtbl;
 	uint32_t		ls_rsbtbl_size;
 
-	struct dlm_lkbtable	*ls_lkbtbl;
-	uint32_t		ls_lkbtbl_size;
-
 	struct dlm_dirtable	*ls_dirtbl;
 	uint32_t		ls_dirtbl_size;
 
diff --git a/fs/dlm/lock.c b/fs/dlm/lock.c
index 3c72348..784cde4 100644
--- a/fs/dlm/lock.c
+++ b/fs/dlm/lock.c
@@ -580,9 +580,8 @@ static void detach_lkb(struct dlm_lkb *lkb)
 
 static int create_lkb(struct dlm_ls *ls, struct dlm_lkb **lkb_ret)
 {
-	struct dlm_lkb *lkb, *tmp;
-	uint32_t lkid = 0;
-	uint16_t bucket;
+	struct dlm_lkb *lkb;
+	int rv, id;
 
 	lkb = dlm_allocate_lkb(ls);
 	if (!lkb)
@@ -596,58 +595,38 @@ static int create_lkb(struct dlm_ls *ls, struct dlm_lkb **lkb_ret)
 	INIT_LIST_HEAD(&lkb->lkb_time_list);
 	INIT_LIST_HEAD(&lkb->lkb_astqueue);
 
-	get_random_bytes(&bucket, sizeof(bucket));
-	bucket &= (ls->ls_lkbtbl_size - 1);
-
-	write_lock(&ls->ls_lkbtbl[bucket].lock);
+ retry:
+	rv = idr_pre_get(&ls->ls_lkbidr, GFP_NOFS);
+	if (!rv)
+		return -ENOMEM;
 
-	/* counter can roll over so we must verify lkid is not in use */
+	spin_lock(&ls->ls_lkbidr_spin);
+	rv = idr_get_new_above(&ls->ls_lkbidr, lkb, 1, &id);
+	if (!rv)
+		lkb->lkb_id = id;
+	spin_unlock(&ls->ls_lkbidr_spin);
 
-	while (lkid == 0) {
-		lkid = (bucket << 16) | ls->ls_lkbtbl[bucket].counter++;
+	if (rv == -EAGAIN)
+		goto retry;
 
-		list_for_each_entry(tmp, &ls->ls_lkbtbl[bucket].list,
-				    lkb_idtbl_list) {
-			if (tmp->lkb_id != lkid)
-				continue;
-			lkid = 0;
-			break;
-		}
+	if (rv < 0) {
+		log_error(ls, "create_lkb idr error %d", rv);
+		return rv;
 	}
 
-	lkb->lkb_id = lkid;
-	list_add(&lkb->lkb_idtbl_list, &ls->ls_lkbtbl[bucket].list);
-	write_unlock(&ls->ls_lkbtbl[bucket].lock);
-
 	*lkb_ret = lkb;
 	return 0;
 }
 
-static struct dlm_lkb *__find_lkb(struct dlm_ls *ls, uint32_t lkid)
-{
-	struct dlm_lkb *lkb;
-	uint16_t bucket = (lkid >> 16);
-
-	list_for_each_entry(lkb, &ls->ls_lkbtbl[bucket].list, lkb_idtbl_list) {
-		if (lkb->lkb_id == lkid)
-			return lkb;
-	}
-	return NULL;
-}
-
 static int find_lkb(struct dlm_ls *ls, uint32_t lkid, struct dlm_lkb **lkb_ret)
 {
 	struct dlm_lkb *lkb;
-	uint16_t bucket = (lkid >> 16);
-
-	if (bucket >= ls->ls_lkbtbl_size)
-		return -EBADSLT;
 
-	read_lock(&ls->ls_lkbtbl[bucket].lock);
-	lkb = __find_lkb(ls, lkid);
+	spin_lock(&ls->ls_lkbidr_spin);
+	lkb = idr_find(&ls->ls_lkbidr, lkid);
 	if (lkb)
 		kref_get(&lkb->lkb_ref);
-	read_unlock(&ls->ls_lkbtbl[bucket].lock);
+	spin_unlock(&ls->ls_lkbidr_spin);
 
 	*lkb_ret = lkb;
 	return lkb ? 0 : -ENOENT;
@@ -668,12 +647,12 @@ static void kill_lkb(struct kref *kref)
 
 static int __put_lkb(struct dlm_ls *ls, struct dlm_lkb *lkb)
 {
-	uint16_t bucket = (lkb->lkb_id >> 16);
+	uint32_t lkid = lkb->lkb_id;
 
-	write_lock(&ls->ls_lkbtbl[bucket].lock);
+	spin_lock(&ls->ls_lkbidr_spin);
 	if (kref_put(&lkb->lkb_ref, kill_lkb)) {
-		list_del(&lkb->lkb_idtbl_list);
-		write_unlock(&ls->ls_lkbtbl[bucket].lock);
+		idr_remove(&ls->ls_lkbidr, lkid);
+		spin_unlock(&ls->ls_lkbidr_spin);
 
 		detach_lkb(lkb);
 
@@ -683,7 +662,7 @@ static int __put_lkb(struct dlm_ls *ls, struct dlm_lkb *lkb)
 		dlm_free_lkb(lkb);
 		return 1;
 	} else {
-		write_unlock(&ls->ls_lkbtbl[bucket].lock);
+		spin_unlock(&ls->ls_lkbidr_spin);
 		return 0;
 	}
 }
diff --git a/fs/dlm/lockspace.c b/fs/dlm/lockspace.c
index 493d1e7..871fe6d 100644
--- a/fs/dlm/lockspace.c
+++ b/fs/dlm/lockspace.c
@@ -472,17 +472,8 @@ static int new_lockspace(const char *name, int namelen, void **lockspace,
 		spin_lock_init(&ls->ls_rsbtbl[i].lock);
 	}
 
-	size = dlm_config.ci_lkbtbl_size;
-	ls->ls_lkbtbl_size = size;
-
-	ls->ls_lkbtbl = vmalloc(sizeof(struct dlm_lkbtable) * size);
-	if (!ls->ls_lkbtbl)
-		goto out_rsbfree;
-	for (i = 0; i < size; i++) {
-		INIT_LIST_HEAD(&ls->ls_lkbtbl[i].list);
-		rwlock_init(&ls->ls_lkbtbl[i].lock);
-		ls->ls_lkbtbl[i].counter = 1;
-	}
+	idr_init(&ls->ls_lkbidr);
+	spin_lock_init(&ls->ls_lkbidr_spin);
 
 	size = dlm_config.ci_dirtbl_size;
 	ls->ls_dirtbl_size = size;
@@ -605,8 +596,7 @@ static int new_lockspace(const char *name, int namelen, void **lockspace,
  out_dirfree:
 	vfree(ls->ls_dirtbl);
  out_lkbfree:
-	vfree(ls->ls_lkbtbl);
- out_rsbfree:
+	idr_destroy(&ls->ls_lkbidr);
 	vfree(ls->ls_rsbtbl);
  out_lsfree:
 	if (do_unreg)
@@ -641,50 +631,66 @@ int dlm_new_lockspace(const char *name, int namelen, void **lockspace,
 	return error;
 }
 
-/* Return 1 if the lockspace still has active remote locks,
- *        2 if the lockspace still has active local locks.
- */
-static int lockspace_busy(struct dlm_ls *ls)
-{
-	int i, lkb_found = 0;
-	struct dlm_lkb *lkb;
-
-	/* NOTE: We check the lockidtbl here rather than the resource table.
-	   This is because there may be LKBs queued as ASTs that have been
-	   unlinked from their RSBs and are pending deletion once the AST has
-	   been delivered */
-
-	for (i = 0; i < ls->ls_lkbtbl_size; i++) {
-		read_lock(&ls->ls_lkbtbl[i].lock);
-		if (!list_empty(&ls->ls_lkbtbl[i].list)) {
-			lkb_found = 1;
-			list_for_each_entry(lkb, &ls->ls_lkbtbl[i].list,
-					    lkb_idtbl_list) {
-				if (!lkb->lkb_nodeid) {
-					read_unlock(&ls->ls_lkbtbl[i].lock);
-					return 2;
-				}
-			}
-		}
-		read_unlock(&ls->ls_lkbtbl[i].lock);
+static int lkb_idr_is_local(int id, void *p, void *data)
+{
+	struct dlm_lkb *lkb = p;
+
+	if (!lkb->lkb_nodeid)
+		return 1;
+	return 0;
+}
+
+static int lkb_idr_is_any(int id, void *p, void *data)
+{
+	return 1;
+}
+
+static int lkb_idr_free(int id, void *p, void *data)
+{
+	struct dlm_lkb *lkb = p;
+
+	dlm_del_ast(lkb);
+
+	if (lkb->lkb_lvbptr && lkb->lkb_flags & DLM_IFL_MSTCPY)
+		dlm_free_lvb(lkb->lkb_lvbptr);
+
+	dlm_free_lkb(lkb);
+	return 0;
+}
+
+/* NOTE: We check the lkbidr here rather than the resource table.
+   This is because there may be LKBs queued as ASTs that have been unlinked
+   from their RSBs and are pending deletion once the AST has been delivered */
+
+static int lockspace_busy(struct dlm_ls *ls, int force)
+{
+	int rv;
+
+	spin_lock(&ls->ls_lkbidr_spin);
+	if (force == 0) {
+		rv = idr_for_each(&ls->ls_lkbidr, lkb_idr_is_any, ls);
+	} else if (force == 1) {
+		rv = idr_for_each(&ls->ls_lkbidr, lkb_idr_is_local, ls);
+	} else {
+		rv = 0;
 	}
-	return lkb_found;
+	spin_unlock(&ls->ls_lkbidr_spin);
+	return rv;
 }
 
 static int release_lockspace(struct dlm_ls *ls, int force)
 {
-	struct dlm_lkb *lkb;
 	struct dlm_rsb *rsb;
 	struct list_head *head;
 	int i, busy, rv;
 
-	busy = lockspace_busy(ls);
+	busy = lockspace_busy(ls, force);
 
 	spin_lock(&lslist_lock);
 	if (ls->ls_create_count == 1) {
-		if (busy > force)
+		if (busy) {
 			rv = -EBUSY;
-		else {
+		} else {
 			/* remove_lockspace takes ls off lslist */
 			ls->ls_create_count = 0;
 			rv = 0;
@@ -724,29 +730,15 @@ static int release_lockspace(struct dlm_ls *ls, int force)
 	vfree(ls->ls_dirtbl);
 
 	/*
-	 * Free all lkb's on lkbtbl[] lists.
+	 * Free all lkb's in idr
 	 */
 
-	for (i = 0; i < ls->ls_lkbtbl_size; i++) {
-		head = &ls->ls_lkbtbl[i].list;
-		while (!list_empty(head)) {
-			lkb = list_entry(head->next, struct dlm_lkb,
-					 lkb_idtbl_list);
-
-			list_del(&lkb->lkb_idtbl_list);
-
-			dlm_del_ast(lkb);
+	idr_for_each(&ls->ls_lkbidr, lkb_idr_free, ls);
+	idr_remove_all(&ls->ls_lkbidr);
+	idr_destroy(&ls->ls_lkbidr);
 
-			if (lkb->lkb_lvbptr && lkb->lkb_flags & DLM_IFL_MSTCPY)
-				dlm_free_lvb(lkb->lkb_lvbptr);
-
-			dlm_free_lkb(lkb);
-		}
-	}
 	dlm_astd_resume();
 
-	vfree(ls->ls_lkbtbl);
-
 	/*
 	 * Free all rsb's on rsbtbl[] lists
 	 */
-- 
1.7.6

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