[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 5065baa530b601d2d4ee28a5247ff7bc23e09b60..3760d02a2750def90956bdf2ae9ed23252324b75 100644 (file)
--- 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;
                }