ceph: fix pending vmtruncate race
The locking order for pending vmtruncate is wrong, it can lead to
following race:
write wmtruncate work
------------------------ ----------------------
lock i_mutex
check i_truncate_pending check i_truncate_pending
truncate_inode_pages() lock i_mutex (blocked)
copy data to page cache
unlock i_mutex
truncate_inode_pages()
The fix is take i_mutex before calling __ceph_do_pending_vmtruncate()
Fixes: http://tracker.ceph.com/issues/5453
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: Sage Weil <sage@inktank.com>
diff --git a/fs/ceph/super.h b/fs/ceph/super.h
index dfbb729..cbded57 100644
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -692,7 +692,7 @@
extern int ceph_inode_holds_cap(struct inode *inode, int mask);
extern int ceph_inode_set_size(struct inode *inode, loff_t size);
-extern void __ceph_do_pending_vmtruncate(struct inode *inode, bool needlock);
+extern void __ceph_do_pending_vmtruncate(struct inode *inode);
extern void ceph_queue_vmtruncate(struct inode *inode);
extern void ceph_queue_invalidate(struct inode *inode);