Re: [PULL REQUEST] md bug fixes and minor improvements
From: Dan Williams <hidden>
Date: 2008-08-01 17:35:00
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Subsystem:
the rest · Maintainer:
Linus Torvalds
On Fri, 2008-08-01 at 19:22 +0200, Jens Axboe wrote:
quoted hunk ↗ jump to hunk
It is a bit asymmetrical, largely due to the fact that the ->unplug_fn() itself grabs the lock. The below patch should fix it, since Neil has added a proper queue lock to the md queues. If someone can confirm that this fixes it, I'll queue up a patch with proper descriptions.quoted
I guess Jens is gone too..I'm back, just been busy this week :-)diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c index 621a272..f19b52f 100644 --- a/drivers/md/bitmap.c +++ b/drivers/md/bitmap.c@@ -1234,7 +1234,9 @@ int bitmap_startwrite(struct bitmap *bitmap, sector_t offset, unsigned long sect case 0: bitmap_file_set_bit(bitmap, offset); bitmap_count_page(bitmap,offset, 1); + spin_lock_irq(&bitmap->mddev->queue->queue_lock); blk_plug_device(bitmap->mddev->queue); + spin_unlock_irq(&bitmap->mddev->queue->queue_lock); /* fall through */ case 1: *bmc = 2;
We also need to protect the blk_plug_device call a few lines down (and an obvious compile fix).
diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
index 621a272..c1b07e7 100644
--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c@@ -1224,7 +1224,9 @@ int bitmap_startwrite(struct bitmap *bitmap, sector_t offset, unsigned long sect prepare_to_wait(&bitmap->overflow_wait, &__wait, TASK_UNINTERRUPTIBLE); spin_unlock_irq(&bitmap->lock); + spin_lock_irq(bitmap->mddev->queue->queue_lock); blk_unplug(bitmap->mddev->queue); + spin_unlock_irq(bitmap->mddev->queue->queue_lock); schedule(); finish_wait(&bitmap->overflow_wait, &__wait); continue;
@@ -1234,7 +1236,9 @@ int bitmap_startwrite(struct bitmap *bitmap, sector_t offset, unsigned long sect case 0: bitmap_file_set_bit(bitmap, offset); bitmap_count_page(bitmap,offset, 1); + spin_lock_irq(bitmap->mddev->queue->queue_lock); blk_plug_device(bitmap->mddev->queue); + spin_unlock_irq(bitmap->mddev->queue->queue_lock); /* fall through */ case 1: *bmc = 2;