From: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Date: Sat, 5 May 2007 19:24:05 +0000 (-0500)
Subject: JFS: Fix race waking up jfsIO kernel thread
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=05ec9e26be1f668ccba4ca54d9a4966c6208c611;p=linux-beck.git

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@austin.ibm.com>
---

diff --git a/fs/jfs/jfs_logmgr.c b/fs/jfs/jfs_logmgr.c
index ff7f1beec30d..16c62680fcd6 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();
 			__set_current_state(TASK_RUNNING);
 		}