ceph: fix lease revocation when seq doesn't match

If the client revokes a lease with a higher seq than what we have, keep
the mds's seq, so that it honors our release.  Otherwise, we can hang
indefinitely.

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

1 files changed, 8 insertions, 4 deletions

diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index b49f12822cbc..29b4485cf1ca 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -2433,6 +2433,7 @@ static void handle_lease(struct ceph_mds_client *mdsc,
         struct ceph_dentry_info *di;
         int mds = session->s_mds;
         struct ceph_mds_lease *h = msg->front.iov_base;
+        u32 seq;
         struct ceph_vino vino;
         int mask;
         struct qstr dname;
@@ -2446,6 +2447,7 @@ static void handle_lease(struct ceph_mds_client *mdsc,
         vino.ino = le64_to_cpu(h->ino);
         vino.snap = CEPH_NOSNAP;
         mask = le16_to_cpu(h->mask);
+        seq = le32_to_cpu(h->seq);
         dname.name = (void *)h + sizeof(*h) + sizeof(u32);
         dname.len = msg->front.iov_len - sizeof(*h) - sizeof(u32);
         if (dname.len != get_unaligned_le32(h+1))
@@ -2456,8 +2458,9 @@ static void handle_lease(struct ceph_mds_client *mdsc,
 
         /* lookup inode */
         inode = ceph_find_inode(sb, vino);
-        dout("handle_lease '%s', mask %d, ino %llx %p\n",
-             ceph_lease_op_name(h->action), mask, vino.ino, inode);
+        dout("handle_lease %s, mask %d, ino %llx %p %.*s\n",
+             ceph_lease_op_name(h->action), mask, vino.ino, inode,
+             dname.len, dname.name);
         if (inode == NULL) {
                 dout("handle_lease no inode %llx\n", vino.ino);
                 goto release;
@@ -2482,7 +2485,8 @@ static void handle_lease(struct ceph_mds_client *mdsc,
         switch (h->action) {
         case CEPH_MDS_LEASE_REVOKE:
                 if (di && di->lease_session == session) {
-                        h->seq = cpu_to_le32(di->lease_seq);
+                        if (ceph_seq_cmp(di->lease_seq, seq) > 0)
+                                h->seq = cpu_to_le32(di->lease_seq);
                         __ceph_mdsc_drop_dentry_lease(dentry);
                 }
                 release = 1;
@@ -2496,7 +2500,7 @@ static void handle_lease(struct ceph_mds_client *mdsc,
                         unsigned long duration =
                                 le32_to_cpu(h->duration_ms) * HZ / 1000;
 
-                        di->lease_seq = le32_to_cpu(h->seq);
+                        di->lease_seq = seq;
                         dentry->d_time = di->lease_renew_from + duration;
                         di->lease_renew_after = di->lease_renew_from +
                                 (duration >> 1);