ceph: only release unused caps with mds requests

We were releasing used caps (e.g. FILE_CACHE) from encode_inode_release
with MDS requests (e.g. setattr).  We don't carry refs on most caps, so
this code worked most of the time, but for setattr (utimes) we try to
drop Fscr.

This causes cap state to get slightly out of sync with reality, and may
result in subsequent mds revoke messages getting ignored.

Fix by only releasing unused caps.

Signed-off-by: Sage Weil <sage@newdream.net>

diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index d9e860ff9f3a177021dfc4ee9effae7a05a20d61..7d0a0d0adc18f882e88e31f91650dab7b168014c 100644 (file)
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -2836,11 +2836,18 @@ int ceph_encode_inode_release(void **p, struct inode *inode,
        struct ceph_cap *cap;
        struct ceph_mds_request_release *rel = *p;
        int ret = 0;
-
-       dout("encode_inode_release %p mds%d drop %s unless %s\n", inode,
-            mds, ceph_cap_string(drop), ceph_cap_string(unless));
+       int used = 0;
 
        spin_lock(&inode->i_lock);
+       used = __ceph_caps_used(ci);
+
+       dout("encode_inode_release %p mds%d used %s drop %s unless %s\n", inode,
+            mds, ceph_cap_string(used), ceph_cap_string(drop),
+            ceph_cap_string(unless));
+
+       /* only drop unused caps */
+       drop &= ~used;
+
        cap = __get_cap_for_mds(ci, mds);
        if (cap && __cap_is_valid(cap)) {
                if (force ||