JFS: call io_schedule() instead of schedule() to avoid deadlock (4aa0d230) · Commits · 戴 / test

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>

fs/jfs/jfs_lock.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -42,7 +42,7 @@ do { \
		if (cond) \
		break; \
		unlock_cmd; \
		schedule(); \
		io_schedule(); \
		lock_cmd; \
		} \
		current->state = TASK_RUNNING; \

fs/jfs/jfs_metapage.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -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));

fs/jfs/jfs_txnmgr.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -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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