linux-ext4 - [PATCH] ext4: Don't overwrite allocation_context ac

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Message-Id: <1228914463-12716-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com>
Date:	Wed, 10 Dec 2008 18:37:43 +0530
From:	"Aneesh Kumar K.V" <aneesh.kumar@...ux.vnet.ibm.com>
To:	cmm@...ibm.com, tytso@....edu, sandeen@...hat.com
Cc:	linux-ext4@...r.kernel.org,
	"Aneesh Kumar K.V" <aneesh.kumar@...ux.vnet.ibm.com>
Subject: [PATCH] ext4: Don't overwrite allocation_context ac_status

We can call ext4_mb_check_limits even after successfull
allocation. Make sure we don't overwrite ac_status.
This fix the below lockdep warning

=============================================
[ INFO: possible recursive locking detected ]
2.6.28-rc6-autokern1 #1
---------------------------------------------
fsstress/11948 is trying to acquire lock:
 (&meta_group_info[i]->alloc_sem){----}, at: [<c04d9a49>] ext4_mb_load_buddy+0x9f/0x278
.....

stack backtrace:
.....
 [<c04db974>] ext4_mb_regular_allocator+0xbb5/0xd44
.....

but task is already holding lock:
 (&meta_group_info[i]->alloc_sem){----}, at: [<c04d9a49>] ext4_mb_load_buddy+0x9f/0x278

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@...ux.vnet.ibm.com>
---
 fs/ext4/mballoc.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 22d31c3..8ce2f19 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -1403,6 +1403,8 @@ static void ext4_mb_check_limits(struct ext4_allocation_context *ac,
 	struct ext4_free_extent ex;
 	int max;
 
+	if (ac->ac_status == AC_STATUS_FOUND)
+		return;
 	/*
 	 * We don't want to scan for a whole year
 	 */
-- 
1.6.1.rc1.56.g2dd62

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