ceph: do not use i_wrbuffer_ref as refcount for Fb cap
We increments i_wrbuffer_ref when taking the Fb cap. This breaks
the dirty page accounting and causes looping in
__ceph_do_pending_vmtruncate, and ceph client hangs.
This bug can be reproduced occasionally by running blogbench.
Add a new field i_wb_ref to inode and dedicate it to Fb reference
counting.
Signed-off-by: Henry C Chang <henry.cy.chang@gmail.com>
Signed-off-by: Sage Weil <sage@newdream.net>
diff --git a/fs/ceph/super.h b/fs/ceph/super.h
index b1f1b8b..f5cabef 100644
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -293,7 +293,7 @@
/* held references to caps */
int i_pin_ref;
- int i_rd_ref, i_rdcache_ref, i_wr_ref;
+ int i_rd_ref, i_rdcache_ref, i_wr_ref, i_wb_ref;
int i_wrbuffer_ref, i_wrbuffer_ref_head;
u32 i_shared_gen; /* increment each time we get FILE_SHARED */
u32 i_rdcache_gen; /* incremented each time we get FILE_CACHE. */