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>

diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index b49f12822cbcb77b1dab660f4d1aa602df5effb9..29b4485cf1cac27f019c21eaad13fe8c229c2754 100644 (file)
--- 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);