ceph: move ceph_find_inode() outside the s_mutex

ceph_find_inode() may wait on freeing inode, using it inside the s_mutex
may cause deadlock. (the freeing inode is waiting for OSD read reply, but
dispatch thread is blocked by the s_mutex)

Signed-off-by: Yan, Zheng <zyan@redhat.com>
Reviewed-by: Sage Weil <sage@redhat.com>

diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index 6d1cd45..b3b0a91 100644 (file)
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -3045,6 +3045,12 @@ void ceph_handle_caps(struct ceph_mds_session *session,
                }
        }
 
+       /* lookup ino */
+       inode = ceph_find_inode(sb, vino);
+       ci = ceph_inode(inode);
+       dout(" op %s ino %llx.%llx inode %p\n", ceph_cap_op_name(op), vino.ino,
+            vino.snap, inode);
+
        mutex_lock(&session->s_mutex);
        session->s_seq++;
        dout(" mds%d seq %lld cap seq %u\n", session->s_mds, session->s_seq,
@@ -3053,11 +3059,6 @@ void ceph_handle_caps(struct ceph_mds_session *session,
        if (op == CEPH_CAP_OP_IMPORT)
                ceph_add_cap_releases(mdsc, session);
 
-       /* lookup ino */
-       inode = ceph_find_inode(sb, vino);
-       ci = ceph_inode(inode);
-       dout(" op %s ino %llx.%llx inode %p\n", ceph_cap_op_name(op), vino.ino,
-            vino.snap, inode);
        if (!inode) {
                dout(" i don't have ino %llx\n", vino.ino);
 

diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index a17fc49..5edf206 100644 (file)
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -2944,14 +2944,15 @@ static void handle_lease(struct ceph_mds_client *mdsc,
        if (dname.len != get_unaligned_le32(h+1))
                goto bad;
 
-       mutex_lock(&session->s_mutex);
-       session->s_seq++;
-
        /* lookup inode */
        inode = ceph_find_inode(sb, vino);
        dout("handle_lease %s, ino %llx %p %.*s\n",
             ceph_lease_op_name(h->action), vino.ino, inode,
             dname.len, dname.name);
+
+       mutex_lock(&session->s_mutex);
+       session->s_seq++;
+
        if (inode == NULL) {
                dout("handle_lease no inode %llx\n", vino.ino);
                goto release;