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* [PATCH] block_dev: Suppress bdev_cache_init() kmemleak warninig
@ 2012-01-09 22:44 Sergey Senozhatsky
  2012-01-09 23:03 ` Al Viro
  0 siblings, 1 reply; 4+ messages in thread
From: Sergey Senozhatsky @ 2012-01-09 22:44 UTC (permalink / raw)
  To: Alexander Viro; +Cc: linux-fsdevel, linux-kernel

block_dev: Suppress bdev_cache_init() kmemleak warninig

Kmemleak reports the following warning in bdev_cache_init()
[    0.003738] kmemleak: Object 0xffff880153035200 (size 256):
[    0.003823] kmemleak:   comm "swapper/0", pid 0, jiffies 4294667299
[    0.003909] kmemleak:   min_count = 1
[    0.003988] kmemleak:   count = 0
[    0.004066] kmemleak:   flags = 0x1
[    0.004144] kmemleak:   checksum = 0
[    0.004224] kmemleak:   backtrace:
[    0.004303]      [<ffffffff814755ac>] kmemleak_alloc+0x21/0x3e
[    0.004446]      [<ffffffff811100ba>] kmem_cache_alloc+0xca/0x1dc
[    0.004592]      [<ffffffff811371b1>] alloc_vfsmnt+0x1f/0x198
[    0.004736]      [<ffffffff811375c5>] vfs_kern_mount+0x36/0xd2
[    0.004879]      [<ffffffff8113929a>] kern_mount_data+0x18/0x32
[    0.005025]      [<ffffffff81ab9075>] bdev_cache_init+0x51/0x81
[    0.005169]      [<ffffffff81ab8abf>] vfs_caches_init+0x101/0x10d
[    0.005313]      [<ffffffff81a9bae3>] start_kernel+0x344/0x383
[    0.005456]      [<ffffffff81a9b2a7>] x86_64_start_reservations+0xae/0xb2
[    0.005602]      [<ffffffff81a9b3ad>] x86_64_start_kernel+0x102/0x111
[    0.005747]      [<ffffffffffffffff>] 0xffffffffffffffff
[    0.008653] kmemleak: Trying to color unknown object at 0xffff880153035220 as Grey
[    0.008754] Pid: 0, comm: swapper/0 Not tainted 3.3.0-rc0-dbg-04200-g8180888-dirty #888
[    0.008856] Call Trace:
[    0.008934]  [<ffffffff81118704>] ? find_and_get_object+0x44/0x118
[    0.009023]  [<ffffffff81118fe6>] paint_ptr+0x57/0x8f
[    0.009109]  [<ffffffff81475935>] kmemleak_not_leak+0x23/0x42
[    0.009195]  [<ffffffff81ab9096>] bdev_cache_init+0x72/0x81
[    0.009282]  [<ffffffff81ab8abf>] vfs_caches_init+0x101/0x10d
[    0.009368]  [<ffffffff81a9bae3>] start_kernel+0x344/0x383
[    0.009466]  [<ffffffff81a9b2a7>] x86_64_start_reservations+0xae/0xb2
[    0.009555]  [<ffffffff81a9b140>] ? early_idt_handlers+0x140/0x140
[    0.009643]  [<ffffffff81a9b3ad>] x86_64_start_kernel+0x102/0x111

due to attempt to mark pointer to `struct vfsmount' as a gray object, which
is embedded into `struct mount' returned from alloc_vfsmnt(). Pass actual
allocated `struct mount' pointer to kmemleak_not_leak() instead.


Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>

---

diff --git a/fs/block_dev.c b/fs/block_dev.c
index 69a5b6f..60589ef 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -29,6 +29,7 @@
 #include <linux/cleancache.h>
 #include <asm/uaccess.h>
 #include "internal.h"
+#include "mount.h"
 
 struct bdev_inode {
 	struct block_device bdev;
@@ -522,6 +523,7 @@ void __init bdev_cache_init(void)
 {
 	int err;
 	struct vfsmount *bd_mnt;
+	struct mount *mnt;
 
 	bdev_cachep = kmem_cache_create("bdev_cache", sizeof(struct bdev_inode),
 			0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
@@ -534,11 +536,12 @@ void __init bdev_cache_init(void)
 	if (IS_ERR(bd_mnt))
 		panic("Cannot create bdev pseudo-fs");
 	/*
-	 * This vfsmount structure is only used to obtain the
+	 * This mount structure is only used to obtain the
 	 * blockdev_superblock, so tell kmemleak not to report it.
 	 */
-	kmemleak_not_leak(bd_mnt);
-	blockdev_superblock = bd_mnt->mnt_sb;	/* For writeback */
+	mnt = container_of(bd_mnt, struct mount, mnt);
+	kmemleak_not_leak(mnt);
+	blockdev_superblock = bd_mnt->mnt_sb;   /* For writeback */
 }
 
 /*


^ permalink raw reply related	[flat|nested] 4+ messages in thread

* Re: [PATCH] block_dev: Suppress bdev_cache_init() kmemleak warninig
  2012-01-09 22:44 [PATCH] block_dev: Suppress bdev_cache_init() kmemleak warninig Sergey Senozhatsky
@ 2012-01-09 23:03 ` Al Viro
  2012-01-09 23:43   ` [PATCH] block_dev: Suppress bdev_cache_init() kmemleak warninig V2 Sergey Senozhatsky
  0 siblings, 1 reply; 4+ messages in thread
From: Al Viro @ 2012-01-09 23:03 UTC (permalink / raw)
  To: Sergey Senozhatsky; +Cc: linux-fsdevel, linux-kernel

On Tue, Jan 10, 2012 at 01:44:36AM +0300, Sergey Senozhatsky wrote:

> due to attempt to mark pointer to `struct vfsmount' as a gray object, which
> is embedded into `struct mount' returned from alloc_vfsmnt(). Pass actual
> allocated `struct mount' pointer to kmemleak_not_leak() instead.

*snort*

how about turning bd_mnt into a static instead and to hell with messing with
annotations?  It's not like one word of .bss was worth those convolutions...

^ permalink raw reply	[flat|nested] 4+ messages in thread

* [PATCH] block_dev: Suppress bdev_cache_init() kmemleak warninig V2
  2012-01-09 23:03 ` Al Viro
@ 2012-01-09 23:43   ` Sergey Senozhatsky
  2012-01-10  0:07     ` [PATCH] block_dev: Remove kmemleak header include Sergey Senozhatsky
  0 siblings, 1 reply; 4+ messages in thread
From: Sergey Senozhatsky @ 2012-01-09 23:43 UTC (permalink / raw)
  To: Al Viro; +Cc: Sergey Senozhatsky, linux-fsdevel, linux-kernel

block_dev: Suppress bdev_cache_init() kmemleak warninig

Kmemleak reports the following warning in bdev_cache_init()
[    0.003738] kmemleak: Object 0xffff880153035200 (size 256):
[    0.003823] kmemleak:   comm "swapper/0", pid 0, jiffies 4294667299
[    0.003909] kmemleak:   min_count = 1
[    0.003988] kmemleak:   count = 0
[    0.004066] kmemleak:   flags = 0x1
[    0.004144] kmemleak:   checksum = 0
[    0.004224] kmemleak:   backtrace:
[    0.004303]      [<ffffffff814755ac>] kmemleak_alloc+0x21/0x3e
[    0.004446]      [<ffffffff811100ba>] kmem_cache_alloc+0xca/0x1dc
[    0.004592]      [<ffffffff811371b1>] alloc_vfsmnt+0x1f/0x198
[    0.004736]      [<ffffffff811375c5>] vfs_kern_mount+0x36/0xd2
[    0.004879]      [<ffffffff8113929a>] kern_mount_data+0x18/0x32
[    0.005025]      [<ffffffff81ab9075>] bdev_cache_init+0x51/0x81
[    0.005169]      [<ffffffff81ab8abf>] vfs_caches_init+0x101/0x10d
[    0.005313]      [<ffffffff81a9bae3>] start_kernel+0x344/0x383
[    0.005456]      [<ffffffff81a9b2a7>] x86_64_start_reservations+0xae/0xb2
[    0.005602]      [<ffffffff81a9b3ad>] x86_64_start_kernel+0x102/0x111
[    0.005747]      [<ffffffffffffffff>] 0xffffffffffffffff
[    0.008653] kmemleak: Trying to color unknown object at 0xffff880153035220 as Grey
[    0.008754] Pid: 0, comm: swapper/0 Not tainted 3.3.0-rc0-dbg-04200-g8180888-dirty #888
[    0.008856] Call Trace:
[    0.008934]  [<ffffffff81118704>] ? find_and_get_object+0x44/0x118
[    0.009023]  [<ffffffff81118fe6>] paint_ptr+0x57/0x8f
[    0.009109]  [<ffffffff81475935>] kmemleak_not_leak+0x23/0x42
[    0.009195]  [<ffffffff81ab9096>] bdev_cache_init+0x72/0x81
[    0.009282]  [<ffffffff81ab8abf>] vfs_caches_init+0x101/0x10d
[    0.009368]  [<ffffffff81a9bae3>] start_kernel+0x344/0x383
[    0.009466]  [<ffffffff81a9b2a7>] x86_64_start_reservations+0xae/0xb2
[    0.009555]  [<ffffffff81a9b140>] ? early_idt_handlers+0x140/0x140
[    0.009643]  [<ffffffff81a9b3ad>] x86_64_start_kernel+0x102/0x111

due to attempt to mark pointer to `struct vfsmount' as a gray object, which
is embedded into `struct mount' returned from alloc_vfsmnt(). 

Make `bd_mnt' static, avoiding need to tell kmemleak to mark it gray, as
suggested by Al Viro.

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>

---

diff --git a/fs/block_dev.c b/fs/block_dev.c
index 69a5b6f..de3913b 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -521,7 +521,7 @@ static struct super_block *blockdev_superblock __read_mostly;
 void __init bdev_cache_init(void)
 {
 	int err;
-	struct vfsmount *bd_mnt;
+	static struct vfsmount *bd_mnt;
 
 	bdev_cachep = kmem_cache_create("bdev_cache", sizeof(struct bdev_inode),
 			0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
@@ -533,12 +533,7 @@ void __init bdev_cache_init(void)
 	bd_mnt = kern_mount(&bd_type);
 	if (IS_ERR(bd_mnt))
 		panic("Cannot create bdev pseudo-fs");
-	/*
-	 * This vfsmount structure is only used to obtain the
-	 * blockdev_superblock, so tell kmemleak not to report it.
-	 */
-	kmemleak_not_leak(bd_mnt);
-	blockdev_superblock = bd_mnt->mnt_sb;	/* For writeback */
+	blockdev_superblock = bd_mnt->mnt_sb;   /* For writeback */
 }
 
 /*



^ permalink raw reply related	[flat|nested] 4+ messages in thread

* [PATCH] block_dev: Remove kmemleak header include
  2012-01-09 23:43   ` [PATCH] block_dev: Suppress bdev_cache_init() kmemleak warninig V2 Sergey Senozhatsky
@ 2012-01-10  0:07     ` Sergey Senozhatsky
  0 siblings, 0 replies; 4+ messages in thread
From: Sergey Senozhatsky @ 2012-01-10  0:07 UTC (permalink / raw)
  To: Al Viro; +Cc: linux-fsdevel, linux-kernel

block_dev: Remove kmemleak header include

No need to include kmemleak.h header, since the only kmemleak
function call has been deleted from bdev_cache_init().

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>

---

diff --git a/fs/block_dev.c b/fs/block_dev.c
index 69a5b6f..ce87d2a 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -25,7 +25,6 @@
 #include <linux/uio.h>
 #include <linux/namei.h>
 #include <linux/log2.h>
-#include <linux/kmemleak.h>
 #include <linux/cleancache.h>
 #include <asm/uaccess.h>
 #include "internal.h"

^ permalink raw reply related	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2012-01-10  0:12 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2012-01-09 22:44 [PATCH] block_dev: Suppress bdev_cache_init() kmemleak warninig Sergey Senozhatsky
2012-01-09 23:03 ` Al Viro
2012-01-09 23:43   ` [PATCH] block_dev: Suppress bdev_cache_init() kmemleak warninig V2 Sergey Senozhatsky
2012-01-10  0:07     ` [PATCH] block_dev: Remove kmemleak header include Sergey Senozhatsky

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