zcache: fix refcount leak

PATCH In review Xiao Guangrong 3 participants 14 messages Jun 26, 2012 – Jul 9, 2012 1 message not in the archive

Subsystems (2)

Memory management Staging

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A message that is not in the archive (sent off-list or not yet received): [email protected]

Xiao Guangrong

author

2012-06-26 08:49 UTC #1 lore raw

PATCH v2 1/9 zcache: fix refcount leak

In zcache_get_pool_by_id, the refcount of zcache_host is not increased, but it is always decreased in zcache_put_pool

Acked-by Seth Jennings <[email protected]>

Signed-off-by Xiao Guangrong <[email protected]>

---
 drivers/staging/zcache/zcache-main.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

drivers/staging/zcache/zcache-main.c +2 -1

index c9e08bb..55fbe3d 100644
@@ -946,8 +946,9 @@ static struct tmem_pool *zcache_get_pool_by_id(uint16_t cli_id, uint16_t poolid)
 		cli = &zcache_clients[cli_id];
 		if (cli == NULL)
 			goto out;
-		atomic_inc(&cli->refcount);
 	}
+
+	atomic_inc(&cli->refcount);
 	pool = idr_find(&cli->tmem_pools, poolid);
 	if (pool != NULL)
 		atomic_inc(&pool->refcount);

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Konrad Rzeszutek Wilk

2012-06-26 22:36 UTC #2 lore raw

Quoted 2 lines · Xiao Guangrong

In zcache_get_pool_by_id, the refcount of zcache_host is not increased, but it is always decreased in zcache_put_pool

All of the patches (1-9) look good to me, so please also affix 'Reviewed-by: Konrad Rzeszutek Wilk <[email protected]>'.

You also might want to send this patch series with Greg KH being on the To line- not just as CC -as he is the one committing the patches in the git tree.

Quoted 31 lines

Acked-by Seth Jennings <[email protected]>

Signed-off-by Xiao Guangrong <[email protected]>

---
 drivers/staging/zcache/zcache-main.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

drivers/staging/zcache/zcache-main.c +2 -1

index c9e08bb..55fbe3d 100644
@@ -946,8 +946,9 @@ static struct tmem_pool *zcache_get_pool_by_id(uint16_t cli_id, uint16_t poolid)
 		cli = &zcache_clients[cli_id];
 		if (cli == NULL)
 			goto out;
-		atomic_inc(&cli->refcount);
 	}
+
+	atomic_inc(&cli->refcount);
 	pool = idr_find(&cli->tmem_pools, poolid);
 	if (pool != NULL)
 		atomic_inc(&pool->refcount);

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Xiao Guangrong

author

2012-06-27 04:47 UTC #3 lore raw

Quoted 7 lines · Konrad Rzeszutek Wilk

Quoted 2 lines · Xiao Guangrong
In zcache_get_pool_by_id, the refcount of zcache_host is not increased, but it is always decreased in zcache_put_pool
All of the patches (1-9) look good to me, so please also affix 'Reviewed-by: Konrad Rzeszutek Wilk <[email protected]>'.

Thank you, Konrad!

Greg, need i repost this patchset with Konrad's Reviewed-by?

Quoted 3 lines

You also might want to send this patch series with Greg KH being on the To line- not just as CC -as he is the one committing the patches in the git tree.

Yes, i did it in the [PATCH 0/9], but i do not know why it was missed in mm list, the later patches replied this patch, so my mail is in the To line-. :(

Greg Kroah-Hartman

maintainer

2012-06-27 05:45 UTC #4 lore raw

Quoted 5 lines · Xiao Guangrong

Quoted 4 lines · Konrad Rzeszutek Wilk
Quoted 2 lines · Xiao Guangrong
In zcache_get_pool_by_id, the refcount of zcache_host is not increased, but it is always decreased in zcache_put_pool

Quoted 7 lines

Quoted 3 lines
All of the patches (1-9) look good to me, so please also affix 'Reviewed-by: Konrad Rzeszutek Wilk <[email protected]>'.
Thank you, Konrad!
Greg, need i repost this patchset with Konrad's Reviewed-by?

No, I can add it when I apply them.

greg k-h

Xiao Guangrong

author

2012-07-09 05:56 UTC #5 lore raw

Quoted 10 lines · Greg Kroah-Hartman

Quoted 9 lines · Xiao Guangrong
Quoted 7 lines · Konrad Rzeszutek Wilk
Quoted 2 lines · Xiao Guangrong
In zcache_get_pool_by_id, the refcount of zcache_host is not increased, but it is always decreased in zcache_put_pool
All of the patches (1-9) look good to me, so please also affix 'Reviewed-by: Konrad Rzeszutek Wilk <[email protected]>'.

Quoted 6 lines

Quoted 3 lines
Thank you, Konrad!
Greg, need i repost this patchset with Konrad's Reviewed-by?
No, I can add it when I apply them.

Greg, sorry to trouble you but this patches stayed in the list for nearly two weeks. If it is ok, could you please apply them? :)

Greg Kroah-Hartman

maintainer

2012-07-09 14:47 UTC #6 lore raw

Quoted 13 lines · Xiao Guangrong

Quoted 12 lines · Greg Kroah-Hartman
Quoted 11 lines · Xiao Guangrong
Quoted 7 lines · Konrad Rzeszutek Wilk
Quoted 2 lines · Xiao Guangrong
In zcache_get_pool_by_id, the refcount of zcache_host is not increased, but it is always decreased in zcache_put_pool
All of the patches (1-9) look good to me, so please also affix 'Reviewed-by: Konrad Rzeszutek Wilk <[email protected]>'.
Thank you, Konrad!

Quoted 8 lines

Quoted 4 lines
Quoted 1 line
Greg, need i repost this patchset with Konrad's Reviewed-by?
No, I can add it when I apply them.
Greg, sorry to trouble you but this patches stayed in the list for nearly two weeks. If it is ok, could you please apply them? :)

I have now returned from my vacation that I was on for parts of the last two weeks and am digging out through my patch queue. I'll get to these soon, thanks for your patience.

greg k-h

Xiao Guangrong

author

2012-06-26 08:50 UTC #7 lore raw

PATCH v2 2/9 zcache: fix a compile warning

In reply to a message not in the archive

Fix:

drivers/staging/zcache/zcache-main.c: In function a??zcache_comp_opa??:
drivers/staging/zcache/zcache-main.c:112:2: warning: a??reta?? may be used uninitial

Signed-off-by Xiao Guangrong <[email protected]>

---
 drivers/staging/zcache/zcache-main.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

drivers/staging/zcache/zcache-main.c +2 -0

index 55fbe3d..58e7bd4 100644
@@ -109,6 +109,8 @@ static inline int zcache_comp_op(enum comp_op op,
 	case ZCACHE_COMPOP_DECOMPRESS:
 		ret = crypto_comp_decompress(tfm, src, slen, dst, dlen);
 		break;
+	default:
+		ret = -EINVAL;
 	}
 	put_cpu();
 	return ret;

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Xiao Guangrong

author

2012-06-26 08:50 UTC #8 lore raw

PATCH v2 3/9 zcache: remove unnecessary config option dependence

In reply to a message not in the archive

zcache is enabled only if one of CONFIG_CLEANCACHE and CONFIG_FRONTSWAP is enabled, see the Kconfig:

	depends on (CLEANCACHE || FRONTSWAP) && CRYPTO=y && X86

So, we can remove the check in the source code

Acked-by Seth Jennings <[email protected]>

Signed-off-by Xiao Guangrong <[email protected]>

---
 drivers/staging/zcache/zcache-main.c |    7 ++-----
 1 files changed, 2 insertions(+), 5 deletions(-)

drivers/staging/zcache/zcache-main.c +2 -5

index 58e7bd4..36c3b05 100644
@@ -36,9 +36,6 @@
 
 #include "../zsmalloc/zsmalloc.h"
 
-#if (!defined(CONFIG_CLEANCACHE) && !defined(CONFIG_FRONTSWAP))
-#error "zcache is useless without CONFIG_CLEANCACHE or CONFIG_FRONTSWAP"
-#endif
 #ifdef CONFIG_CLEANCACHE
 #include <linux/cleancache.h>
 #endif

@@ -2028,7 +2025,7 @@ static int __init zcache_init(void)
 		goto out;
 	}
 #endif /* CONFIG_SYSFS */
-#if defined(CONFIG_CLEANCACHE) || defined(CONFIG_FRONTSWAP)
+
 	if (zcache_enabled) {
 		unsigned int cpu;

@@ -2059,7 +2056,7 @@ static int __init zcache_init(void)
 		pr_err("zcache: can't create client\n");
 		goto out;
 	}
-#endif
+
 #ifdef CONFIG_CLEANCACHE
 	if (zcache_enabled && use_cleancache) {
 		struct cleancache_ops old_ops;

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Xiao Guangrong

author

2012-06-26 08:50 UTC #9 lore raw

PATCH v2 4/9 zcache: mark zbud_init/zcache_comp_init as __init

In reply to a message not in the archive

These functions are called only when system is initializing, so mark __init for them to free memory

Acked-by Seth Jennings <[email protected]>

Signed-off-by Xiao Guangrong <[email protected]>

---
 drivers/staging/zcache/zcache-main.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

drivers/staging/zcache/zcache-main.c +2 -2

index 36c3b05..a77cacb 100644
@@ -600,7 +600,7 @@ out:
 	return;
 }
 
-static void zbud_init(void)
+static void __init zbud_init(void)
 {
 	int i;

@@ -1985,7 +1985,7 @@ static int __init enable_zcache_compressor(char *s)
 __setup("zcache=", enable_zcache_compressor);
 
 
-static int zcache_comp_init(void)
+static int __init zcache_comp_init(void)
 {
 	int ret = 0;

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Xiao Guangrong

author

2012-06-26 08:51 UTC #10 lore raw

PATCH v2 5/9 zcache: cleanup zbud_init

In reply to a message not in the archive

Need not set global parameters to 0

Acked-by Seth Jennings <[email protected]>

Signed-off-by Xiao Guangrong <[email protected]>

---
 drivers/staging/zcache/zcache-main.c |    6 ++----
 1 files changed, 2 insertions(+), 4 deletions(-)

drivers/staging/zcache/zcache-main.c +2 -4

index a77cacb..0529b46 100644
@@ -605,11 +605,9 @@ static void __init zbud_init(void)
 	int i;
 
 	INIT_LIST_HEAD(&zbud_buddied_list);
-	zcache_zbud_buddied_count = 0;
-	for (i = 0; i < NCHUNKS; i++) {
+
+	for (i = 0; i < NCHUNKS; i++)
 		INIT_LIST_HEAD(&zbud_unbuddied[i].list);
-		zbud_unbuddied[i].count = 0;
-	}
 }
 
 #ifdef CONFIG_SYSFS

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Xiao Guangrong

author

2012-06-26 08:51 UTC #11 lore raw

PATCH v2 6/9 zcache: optimize zcache_do_preload

In reply to a message not in the archive

zcache_do_preload is called in zcache_put_page where IRQ is disabled, so, need not care preempt

Acked-by Seth Jennings <[email protected]>

Signed-off-by Xiao Guangrong <[email protected]>

---
 drivers/staging/zcache/zcache-main.c |   21 +++++++++------------
 1 files changed, 9 insertions(+), 12 deletions(-)

drivers/staging/zcache/zcache-main.c +9 ~~-12~~

index 0529b46..57e25fc 100644
@@ -1031,45 +1031,43 @@ static int zcache_do_preload(struct tmem_pool *pool)
 		goto out;
 	if (unlikely(zcache_obj_cache == NULL))
 		goto out;
-	preempt_disable();
+
+	/* IRQ has already been disabled. */
 	kp = &__get_cpu_var(zcache_preloads);
 	while (kp->nr < ARRAY_SIZE(kp->objnodes)) {
-		preempt_enable_no_resched();
 		objnode = kmem_cache_alloc(zcache_objnode_cache,
 				ZCACHE_GFP_MASK);
 		if (unlikely(objnode == NULL)) {
 			zcache_failed_alloc++;
 			goto out;
 		}
-		preempt_disable();
-		kp = &__get_cpu_var(zcache_preloads);
-		if (kp->nr < ARRAY_SIZE(kp->objnodes))
-			kp->objnodes[kp->nr++] = objnode;
-		else
-			kmem_cache_free(zcache_objnode_cache, objnode);
+
+		kp->objnodes[kp->nr++] = objnode;
 	}
-	preempt_enable_no_resched();
+
 	obj = kmem_cache_alloc(zcache_obj_cache, ZCACHE_GFP_MASK);
 	if (unlikely(obj == NULL)) {
 		zcache_failed_alloc++;
 		goto out;
 	}
+
 	page = (void *)__get_free_page(ZCACHE_GFP_MASK);
 	if (unlikely(page == NULL)) {
 		zcache_failed_get_free_pages++;
 		kmem_cache_free(zcache_obj_cache, obj);
 		goto out;
 	}
-	preempt_disable();
-	kp = &__get_cpu_var(zcache_preloads);
+
 	if (kp->obj == NULL)
 		kp->obj = obj;
 	else
 		kmem_cache_free(zcache_obj_cache, obj);
+
 	if (kp->page == NULL)
 		kp->page = page;
 	else
 		free_page((unsigned long)page);
+
 	ret = 0;
 out:
 	return ret;

@@ -1580,7 +1578,6 @@ static int zcache_put_page(int cli_id, int pool_id, struct tmem_oid *oidp,
 				zcache_failed_pers_puts++;
 		}
 		zcache_put_pool(pool);
-		preempt_enable_no_resched();
 	} else {
 		zcache_put_to_flush++;
 		if (atomic_read(&pool->obj_count) > 0)

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Xiao Guangrong

author

2012-06-26 08:52 UTC #12 lore raw

PATCH v2 7/9 zcache: cleanup zcache_do_preload and zcache_put_page

In reply to a message not in the archive

Cleanup the code for zcache_do_preload and zcache_put_page

Acked-by Seth Jennings <[email protected]>

Signed-off-by Xiao Guangrong <[email protected]>

---
 drivers/staging/zcache/zcache-main.c |   37 ++++++++++++++-------------------
 1 files changed, 16 insertions(+), 21 deletions(-)

drivers/staging/zcache/zcache-main.c +16 ~~-21~~

index 57e25fc..fbd9bcf 100644
@@ -1045,29 +1045,24 @@ static int zcache_do_preload(struct tmem_pool *pool)
 		kp->objnodes[kp->nr++] = objnode;
 	}
 
-	obj = kmem_cache_alloc(zcache_obj_cache, ZCACHE_GFP_MASK);
-	if (unlikely(obj == NULL)) {
-		zcache_failed_alloc++;
-		goto out;
+	if (!kp->obj) {
+		obj = kmem_cache_alloc(zcache_obj_cache, ZCACHE_GFP_MASK);
+		if (unlikely(obj == NULL)) {
+			zcache_failed_alloc++;
+			goto out;
+		}
+		kp->obj = obj;
 	}
 
-	page = (void *)__get_free_page(ZCACHE_GFP_MASK);
-	if (unlikely(page == NULL)) {
-		zcache_failed_get_free_pages++;
-		kmem_cache_free(zcache_obj_cache, obj);
-		goto out;
+	if (!kp->page) {
+		page = (void *)__get_free_page(ZCACHE_GFP_MASK);
+		if (unlikely(page == NULL)) {
+			zcache_failed_get_free_pages++;
+			goto out;
+		}
+		kp->page =  page;
 	}
 
-	if (kp->obj == NULL)
-		kp->obj = obj;
-	else
-		kmem_cache_free(zcache_obj_cache, obj);
-
-	if (kp->page == NULL)
-		kp->page = page;
-	else
-		free_page((unsigned long)page);
-
 	ret = 0;
 out:
 	return ret;

@@ -1577,14 +1572,14 @@ static int zcache_put_page(int cli_id, int pool_id, struct tmem_oid *oidp,
 			else
 				zcache_failed_pers_puts++;
 		}
-		zcache_put_pool(pool);
 	} else {
 		zcache_put_to_flush++;
 		if (atomic_read(&pool->obj_count) > 0)
 			/* the put fails whether the flush succeeds or not */
 			(void)tmem_flush_page(pool, oidp, index);
-		zcache_put_pool(pool);
 	}
+
+	zcache_put_pool(pool);
 out:
 	return ret;
 }

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Xiao Guangrong

author

2012-06-26 08:52 UTC #13 lore raw

PATCH v2 8/9 zcache: introduce get_zcache_client

In reply to a message not in the archive

Introduce get_zcache_client to remove the common code

Acked-by Seth Jennings <[email protected]>

Signed-off-by Xiao Guangrong <[email protected]>

---
 drivers/staging/zcache/zcache-main.c |   46 +++++++++++++++++-----------------
 1 files changed, 23 insertions(+), 23 deletions(-)

drivers/staging/zcache/zcache-main.c +23 ~~-23~~

index fbd9bcf..2b5c73c 100644
@@ -74,6 +74,17 @@ static inline uint16_t get_client_id_from_client(struct zcache_client *cli)
 	return cli - &zcache_clients[0];
 }
 
+static struct zcache_client *get_zcache_client(uint16_t cli_id)
+{
+	if (cli_id == LOCAL_CLIENT)
+		return &zcache_host;
+
+	if ((unsigned int)cli_id < MAX_CLIENTS)
+		return &zcache_clients[cli_id];
+
+	return NULL;
+}
+
 static inline bool is_local_client(struct zcache_client *cli)
 {
 	return cli == &zcache_host;

@@ -935,15 +946,9 @@ static struct tmem_pool *zcache_get_pool_by_id(uint16_t cli_id, uint16_t poolid)
 	struct tmem_pool *pool = NULL;
 	struct zcache_client *cli = NULL;
 
-	if (cli_id == LOCAL_CLIENT)
-		cli = &zcache_host;
-	else {
-		if (cli_id >= MAX_CLIENTS)
-			goto out;
-		cli = &zcache_clients[cli_id];
-		if (cli == NULL)
-			goto out;
-	}
+	cli = get_zcache_client(cli_id);
+	if (!cli)
+		goto out;
 
 	atomic_inc(&cli->refcount);
 	pool = idr_find(&cli->tmem_pools, poolid);

@@ -966,13 +971,11 @@ static void zcache_put_pool(struct tmem_pool *pool)
 
 int zcache_new_client(uint16_t cli_id)
 {
-	struct zcache_client *cli = NULL;
+	struct zcache_client *cli;
 	int ret = -1;
 
-	if (cli_id == LOCAL_CLIENT)
-		cli = &zcache_host;
-	else if ((unsigned int)cli_id < MAX_CLIENTS)
-		cli = &zcache_clients[cli_id];
+	cli = get_zcache_client(cli_id);
+
 	if (cli == NULL)
 		goto out;
 	if (cli->allocated)

@@ -1649,17 +1652,16 @@ static int zcache_flush_object(int cli_id, int pool_id,
 static int zcache_destroy_pool(int cli_id, int pool_id)
 {
 	struct tmem_pool *pool = NULL;
-	struct zcache_client *cli = NULL;
+	struct zcache_client *cli;
 	int ret = -1;
 
 	if (pool_id < 0)
 		goto out;
-	if (cli_id == LOCAL_CLIENT)
-		cli = &zcache_host;
-	else if ((unsigned int)cli_id < MAX_CLIENTS)
-		cli = &zcache_clients[cli_id];
+
+	cli = get_zcache_client(cli_id);
 	if (cli == NULL)
 		goto out;
+
 	atomic_inc(&cli->refcount);
 	pool = idr_find(&cli->tmem_pools, pool_id);
 	if (pool == NULL)

@@ -1686,12 +1688,10 @@ static int zcache_new_pool(uint16_t cli_id, uint32_t flags)
 	struct zcache_client *cli = NULL;
 	int r;
 
-	if (cli_id == LOCAL_CLIENT)
-		cli = &zcache_host;
-	else if ((unsigned int)cli_id < MAX_CLIENTS)
-		cli = &zcache_clients[cli_id];
+	cli = get_zcache_client(cli_id);
 	if (cli == NULL)
 		goto out;
+
 	atomic_inc(&cli->refcount);
 	pool = kmalloc(sizeof(struct tmem_pool), GFP_ATOMIC);
 	if (pool == NULL) {

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Xiao Guangrong

author

2012-06-26 08:52 UTC #14 lore raw

PATCH v2 9/9 zcache: cleanup the code between tmem_obj_init and tmem_obj_find

In reply to a message not in the archive

tmem_obj_find and insertion tmem-obj have the some logic, we can integrate the code

Signed-off-by Xiao Guangrong <[email protected]>

---
 drivers/staging/zcache/tmem.c |   63 +++++++++++++++++++++-------------------
 1 files changed, 33 insertions(+), 30 deletions(-)

drivers/staging/zcache/tmem.c +33 ~~-30~~

index 1ca66ea..eaa9021 100644
@@ -72,33 +72,49 @@ void tmem_register_pamops(struct tmem_pamops *m)
  * the hashbucket lock must be held.
  */
 
-/* searches for object==oid in pool, returns locked object if found */
-static struct tmem_obj *tmem_obj_find(struct tmem_hashbucket *hb,
-					struct tmem_oid *oidp)
+static struct tmem_obj
+*__tmem_obj_find(struct tmem_hashbucket*hb, struct tmem_oid *oidp,
+		 struct rb_node **parent, struct rb_node ***link)
 {
-	struct rb_node *rbnode;
-	struct tmem_obj *obj;
-
-	rbnode = hb->obj_rb_root.rb_node;
-	while (rbnode) {
-		BUG_ON(RB_EMPTY_NODE(rbnode));
-		obj = rb_entry(rbnode, struct tmem_obj, rb_tree_node);
+	struct rb_node *_parent = NULL, **rbnode;
+	struct tmem_obj *obj = NULL;
+
+	rbnode = &hb->obj_rb_root.rb_node;
+	while (*rbnode) {
+		BUG_ON(RB_EMPTY_NODE(*rbnode));
+		_parent = *rbnode;
+		obj = rb_entry(*rbnode, struct tmem_obj,
+			       rb_tree_node);
 		switch (tmem_oid_compare(oidp, &obj->oid)) {
 		case 0: /* equal */
 			goto out;
 		case -1:
-			rbnode = rbnode->rb_left;
+			rbnode = &(*rbnode)->rb_left;
 			break;
 		case 1:
-			rbnode = rbnode->rb_right;
+			rbnode = &(*rbnode)->rb_right;
 			break;
 		}
 	}
+
+	if (parent)
+		*parent = _parent;
+	if (link)
+		*link = rbnode;
+
 	obj = NULL;
 out:
 	return obj;
 }
 
+
+/* searches for object==oid in pool, returns locked object if found */
+static struct tmem_obj *tmem_obj_find(struct tmem_hashbucket *hb,
+					struct tmem_oid *oidp)
+{
+	return __tmem_obj_find(hb, oidp, NULL, NULL);
+}
+
 static void tmem_pampd_destroy_all_in_obj(struct tmem_obj *);
 
 /* free an object that has no more pampds in it */

@@ -131,8 +147,7 @@ static void tmem_obj_init(struct tmem_obj *obj, struct tmem_hashbucket *hb,
 					struct tmem_oid *oidp)
 {
 	struct rb_root *root = &hb->obj_rb_root;
-	struct rb_node **new = &(root->rb_node), *parent = NULL;
-	struct tmem_obj *this;
+	struct rb_node **new = NULL, *parent = NULL;
 
 	BUG_ON(pool == NULL);
 	atomic_inc(&pool->obj_count);

@@ -144,22 +159,10 @@ static void tmem_obj_init(struct tmem_obj *obj, struct tmem_hashbucket *hb,
 	obj->pampd_count = 0;
 	(*tmem_pamops.new_obj)(obj);
 	SET_SENTINEL(obj, OBJ);
-	while (*new) {
-		BUG_ON(RB_EMPTY_NODE(*new));
-		this = rb_entry(*new, struct tmem_obj, rb_tree_node);
-		parent = *new;
-		switch (tmem_oid_compare(oidp, &this->oid)) {
-		case 0:
-			BUG(); /* already present; should never happen! */
-			break;
-		case -1:
-			new = &(*new)->rb_left;
-			break;
-		case 1:
-			new = &(*new)->rb_right;
-			break;
-		}
-	}
+
+	if (__tmem_obj_find(hb, oidp, &parent, &new))
+		BUG();
+
 	rb_link_node(&obj->rb_tree_node, parent, new);
 	rb_insert_color(&obj->rb_tree_node, root);
 }

Signature · 7 lines

1.7.7.6

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