kclient: fix up dentry if we can take i_mutex, but avoid rehashing dentry if there...

diff --git a/src/kernel/inode.c b/src/kernel/inode.c
index 23c21d5d89baacb82a8835b354d3f8d4edc9a5f2..b4c4619597d28bf0a8dbf786a0974cc5c1edbe59 100644 (file)
--- a/src/kernel/inode.c
+++ b/src/kernel/inode.c
@@ -624,7 +624,8 @@ int ceph_dentry_lease_valid(struct dentry *dentry)
  * splice a dentry to an inode.
  * caller must hold directory i_mutex for this to be safe.
  */
-static struct dentry *splice_dentry(struct dentry *dn, struct inode *in)
+static struct dentry *splice_dentry(struct dentry *dn, struct inode *in,
+                                   bool rehash)
 {
        struct dentry *realdn;
 
@@ -645,7 +646,7 @@ static struct dentry *splice_dentry(struct dentry *dn, struct inode *in)
        } else
                dout(10, "dn %p attached to %p ino %llx\n",
                     dn, dn->d_inode, ceph_ino(dn->d_inode));
-       if (d_unhashed(dn))
+       if (rehash && d_unhashed(dn))
                d_rehash(dn);
        return dn;
 }
@@ -668,11 +669,12 @@ int ceph_fill_trace(struct super_block *sb, struct ceph_mds_request *req,
        struct qstr dname;
        struct dentry *dn = sb->s_root;
        struct dentry *parent = NULL;
+       struct dentry *existing;
        struct inode *in;
        struct ceph_mds_reply_inode *ininfo;
        int d = 0;
        u64 ino;
-       int have_icontent = 0;
+       int have_icontent = 0, have_lease = 0;
 
        if (rinfo->trace_numi == 0) {
                dout(10, "fill_trace reply has empty trace!\n");
@@ -739,21 +741,20 @@ int ceph_fill_trace(struct super_block *sb, struct ceph_mds_request *req,
                     (int)dname.len, dname.name,
                     have_icontent, rinfo->trace_dlease[d]->mask);
 
-               /* do we have a dn lease? */
-               if (!have_icontent &&
-                   rinfo->trace_dlease[d]->mask == 0) {
-                       dout(0, "fill_trace  no icontent|dentry lease\n");
-                       goto no_dentry_lease;
-               }
-
                /* try to take dir i_mutex */
                if (req->r_locked_dir != parent->d_inode &&
                    mutex_trylock(&parent->d_inode->i_mutex) == 0) {
                        dout(0, "fill_trace  FAILED to take %p i_mutex\n",
                             parent->d_inode);
-                       goto no_dentry_lease;
+                       goto no_dir_mutex;
                }
 
+               /* do we have a dn lease? */
+               have_lease = have_icontent ||
+                       (rinfo->trace_dlease[d]->mask & CEPH_LOCK_DN);
+               if (!have_lease)
+                       dout(0, "fill_trace  no icontent|dentry lease\n");
+
                dout(10, "fill_trace  took %p i_mutex\n", parent->d_inode);
 
                dname.hash = full_name_hash(dname.name, dname.len);
@@ -806,7 +807,7 @@ int ceph_fill_trace(struct super_block *sb, struct ceph_mds_request *req,
                        }
                        dout(20, "d_instantiate %p NULL\n", dn);
                        d_instantiate(dn, NULL);
-                       if (d_unhashed(dn))
+                       if (have_lease && d_unhashed(dn))
                                d_rehash(dn);
                        in = 0;
                        update_dentry_lease(dn, rinfo->trace_dlease[d],
@@ -857,12 +858,13 @@ int ceph_fill_trace(struct super_block *sb, struct ceph_mds_request *req,
                                in = NULL;
                                goto out_dir;
                        }
-                       dn = splice_dentry(dn, in);
+                       dn = splice_dentry(dn, in, have_lease);
                }
                BUG_ON(dn->d_parent != parent);
 
-               update_dentry_lease(dn, rinfo->trace_dlease[d],
-                                   session, req->r_from_time);
+               if (have_lease)
+                       update_dentry_lease(dn, rinfo->trace_dlease[d],
+                                           session, req->r_from_time);
 
                /* done with dn update */
                if (req->r_locked_dir != parent->d_inode)
@@ -897,10 +899,10 @@ int ceph_fill_trace(struct super_block *sb, struct ceph_mds_request *req,
                break;
 
 
-       no_dentry_lease:
+       no_dir_mutex:
                /*
-                * we have no lease or i_mutex for this dir, so do
-                * not update or hash a dentry.
+                * we couldn't take i_mutex for this dir, so do not
+                * lookup or relink any existing dentry.
                 */
                if (d == rinfo->trace_numd-1 && req->r_last_dentry) {
                        dn = req->r_last_dentry;
@@ -925,7 +927,7 @@ int ceph_fill_trace(struct super_block *sb, struct ceph_mds_request *req,
                        in = NULL;
                        break;
                }
-               struct dentry *existing = d_find_alias(in);
+               existing = d_find_alias(in);
                if (existing) {
                        if (dn)
                                dput(dn);
@@ -1024,7 +1026,7 @@ retry_lookup:
                                dput(dn);
                                return -ENOMEM;
                        }
-                       dn = splice_dentry(dn, in);
+                       dn = splice_dentry(dn, in, true);
                }
 
                if (ceph_fill_inode(in, &rinfo->dir_in[i], 0) < 0) {