md: unplug writes to external bitmaps.

When writing to an 'external' bitmap we don't currently unplug the
device before waiting, so we can get a 3msec delay each time;
So use REQ_UNPLUG to force and unplug.

Signed-off-by: NeilBrown <neilb@suse.de>
This commit is contained in:
NeilBrown 2010-10-27 15:37:41 +11:00
parent a167f66324
commit be2a2656ee

View File

@ -343,7 +343,7 @@ static void write_page(struct bitmap *bitmap, struct page *page, int wait)
atomic_inc(&bitmap->pending_writes);
set_buffer_locked(bh);
set_buffer_mapped(bh);
submit_bh(WRITE, bh);
submit_bh(WRITE | REQ_UNPLUG | REQ_SYNC, bh);
bh = bh->b_this_page;
}