From: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Date: Thu, 18 Jan 2007 03:18:35 +0000 (-0600)
Subject: JFS: call io_schedule() instead of schedule() to avoid deadlock
X-Git-Tag: v2.6.21-rc2~42^2~14^2~1
X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=4aa0d230c2cfc1ac4bcf7c5466f9943cf14233a9;p=linux-2.6-omap-h63xx.git

JFS: call io_schedule() instead of schedule() to avoid deadlock

The introduction of Jens Axboe's explicit i/o plugging patches introduced a
deadlock in jfs.  This was caused by the process initiating I/O not
unplugging the queue before waiting on the commit thread.  The commit
thread itself was waiting for that I/O to complete.  Calling io_schedule()
rather than schedule() unplugs the I/O queue avoiding the deadlock, and it
appears to be the right function to call in any case.

Signed-off-by: Dave Kleikamp <shaggy@austin.ibm.com>
---

diff --git a/fs/jfs/jfs_lock.h b/fs/jfs/jfs_lock.h
index 7d78e83d7c4..df48ece4b7a 100644
--- a/fs/jfs/jfs_lock.h
+++ b/fs/jfs/jfs_lock.h
@@ -42,7 +42,7 @@ do {							\
 		if (cond)				\
 			break;				\
 		unlock_cmd;				\
-		schedule();				\
+		io_schedule();				\
 		lock_cmd;				\
 	}						\
 	current->state = TASK_RUNNING;			\
diff --git a/fs/jfs/jfs_metapage.c b/fs/jfs/jfs_metapage.c
index ceaf03b9493..58deae00750 100644
--- a/fs/jfs/jfs_metapage.c
+++ b/fs/jfs/jfs_metapage.c
@@ -56,7 +56,7 @@ static inline void __lock_metapage(struct metapage *mp)
 		set_current_state(TASK_UNINTERRUPTIBLE);
 		if (metapage_locked(mp)) {
 			unlock_page(mp->page);
-			schedule();
+			io_schedule();
 			lock_page(mp->page);
 		}
 	} while (trylock_metapage(mp));
diff --git a/fs/jfs/jfs_txnmgr.c b/fs/jfs/jfs_txnmgr.c
index d558e51b0df..6988a1082f5 100644
--- a/fs/jfs/jfs_txnmgr.c
+++ b/fs/jfs/jfs_txnmgr.c
@@ -135,7 +135,7 @@ static inline void TXN_SLEEP_DROP_LOCK(wait_queue_head_t * event)
 	add_wait_queue(event, &wait);
 	set_current_state(TASK_UNINTERRUPTIBLE);
 	TXN_UNLOCK();
-	schedule();
+	io_schedule();
 	current->state = TASK_RUNNING;
 	remove_wait_queue(event, &wait);
 }