From: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Date: Wed, 16 May 2007 03:53:36 +0000 (-0500)
Subject: [PATCH] JFS: Fix race waking up jfsIO kernel thread
X-Git-Tag: v2.6.20.14~25
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=cd37423cc0f2993a5f2a21d88204c4edd7b9c3e9;p=thirdparty%2Fkernel%2Fstable.git

[PATCH] JFS: Fix race waking up jfsIO kernel thread

It's possible for a journal I/O request to be added to the log_redrive
queue and the jfsIO thread to be awakened after the thread releases
log_redrive_lock but before it sets its state to TASK_INTERRUPTIBLE.

The jfsIO thread should set the state before giving up the spinlock, so
the waking thread will really wake it.

Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/fs/jfs/jfs_logmgr.c b/fs/jfs/jfs_logmgr.c
index 5065baa530b60..3760d02a2750d 100644
--- a/fs/jfs/jfs_logmgr.c
+++ b/fs/jfs/jfs_logmgr.c
@@ -2354,12 +2354,13 @@ int jfsIOWait(void *arg)
 			lbmStartIO(bp);
 			spin_lock_irq(&log_redrive_lock);
 		}
-		spin_unlock_irq(&log_redrive_lock);
 
 		if (freezing(current)) {
+			spin_unlock_irq(&log_redrive_lock);
 			refrigerator();
 		} else {
 			set_current_state(TASK_INTERRUPTIBLE);
+			spin_unlock_irq(&log_redrive_lock);
 			schedule();
 			current->state = TASK_RUNNING;
 		}