[PATCH 1/2] JFS: call io_schedule() instead of schedule() to avoid deadlock

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 <[email protected]>

---
commit 4aa0d230c2cfc1ac4bcf7c5466f9943cf14233a9
tree b873dce6146f4880c6c48ab53c0079566f52a60b
parent 82d5b9a7c63054a9a2cd838ffd177697f86e7e34
author Dave Kleikamp <[email protected]> Wed, 17 Jan 2007 21:18:35 -0600
committer Dave Kleikamp <[email protected]> Wed, 17 Jan 2007 21:18:35 -0600

 fs/jfs/jfs_lock.h     |    2 +-
 fs/jfs/jfs_metapage.c |    2 +-
 fs/jfs/jfs_txnmgr.c   |    2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/fs/jfs/jfs_lock.h b/fs/jfs/jfs_lock.h
index 7d78e83..df48ece 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 ceaf03b..58deae0 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 d558e51..6988a10 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);
 }

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