tree 54a5b937d4acd579f43b9dc062afd41ecaa33d82
parent 90db6919f5f1614d1b7a92052445506bc6c564d2
author Nicholas Swenson <nks@daterainc.com> 1389312184 -0800
committer Kent Overstreet <kmo@daterainc.com> 1395170553 -0700

bcache: Fix moving_gc deadlocking with a foreground write

Deadlock happened because a foreground write slept, waiting for a bucket
to be allocated. Normally the gc would mark buckets available for invalidation.
But the moving_gc was stuck waiting for outstanding writes to complete.
These writes used the bcache_wq, the same queue foreground writes used.

This fix gives moving_gc its own work queue, so it was still finish moving
even if foreground writes are stuck waiting for allocation. It also makes
work queue a parameter to the data_insert path, so moving_gc can use its
workqueue for writes.

Signed-off-by: Nicholas Swenson <nks@daterainc.com>
Signed-off-by: Kent Overstreet <kmo@daterainc.com>