ceph: fix freeing inode vs removing session caps race

remove_session_caps() uses iterate_session_caps() to remove caps,
but iterate_session_caps() skips inodes that are being deleted.
So session->s_nr_caps can be non-zero after iterate_session_caps()
return.

We can fix the issue by waiting until deletions are complete.
__wait_on_freeing_inode() is designed for the job, but it is not
exported, so we use lookup inode function to access it.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/fs/ceph/super.h b/fs/ceph/super.h
index cbded572345..afcd62a6891 100644
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -677,6 +677,8 @@ extern void ceph_destroy_inode(struct inode *inode);
 
 extern struct inode *ceph_get_inode(struct super_block *sb,
 				    struct ceph_vino vino);
+extern struct inode *ceph_lookup_inode(struct super_block *sb,
+				       struct ceph_vino vino);
 extern struct inode *ceph_get_snapdir(struct inode *parent);
 extern int ceph_fill_file_size(struct inode *inode, int issued,
 			       u32 truncate_seq, u64 truncate_size, u64 size);