kclient: handle potential splice_dentry failure

diff --git a/src/kernel/inode.c b/src/kernel/inode.c
index b4c4619597d28bf0a8dbf786a0974cc5c1edbe59..f69e1ef0d7db7412c97a015972fcda8bf756de8e 100644 (file)
--- a/src/kernel/inode.c
+++ b/src/kernel/inode.c
@@ -625,7 +625,7 @@ int ceph_dentry_lease_valid(struct dentry *dentry)
  * caller must hold directory i_mutex for this to be safe.
  */
 static struct dentry *splice_dentry(struct dentry *dn, struct inode *in,
-                                   bool rehash)
+                                   bool *prehash)
 {
        struct dentry *realdn;
 
@@ -633,7 +633,17 @@ static struct dentry *splice_dentry(struct dentry *dn, struct inode *in,
        if (!d_unhashed(dn))
                d_drop(dn);
        realdn = d_materialise_unique(dn, in);
-       if (realdn && !IS_ERR(realdn)) {
+       if (IS_ERR(realdn)) {
+               derr(0, "error splicing %p (%d) with %p (%d) "
+                    "inode %p ino %llx\n",
+                    dn, atomic_read(&dn->d_count),
+                    realdn, atomic_read(&realdn->d_count),
+                    realdn->d_inode,
+                    ceph_ino(realdn->d_inode));
+               if (prehash)
+                       *prehash = false; /* don't rehash on error */
+               goto out;
+       } else if (realdn) {
                dout(10, "dn %p (%d) spliced with %p (%d) "
                     "inode %p ino %llx\n",
                     dn, atomic_read(&dn->d_count),
@@ -646,8 +656,9 @@ 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 (rehash && d_unhashed(dn))
+       if ((!prehash || *prehash) && d_unhashed(dn))
                d_rehash(dn);
+out:
        return dn;
 }
 
@@ -674,7 +685,8 @@ int ceph_fill_trace(struct super_block *sb, struct ceph_mds_request *req,
        struct ceph_mds_reply_inode *ininfo;
        int d = 0;
        u64 ino;
-       int have_icontent = 0, have_lease = 0;
+       int have_icontent = 0;
+       bool have_lease = 0;
 
        if (rinfo->trace_numi == 0) {
                dout(10, "fill_trace reply has empty trace!\n");
@@ -858,9 +870,8 @@ int ceph_fill_trace(struct super_block *sb, struct ceph_mds_request *req,
                                in = NULL;
                                goto out_dir;
                        }
-                       dn = splice_dentry(dn, in, have_lease);
+                       dn = splice_dentry(dn, in, &have_lease);
                }
-               BUG_ON(dn->d_parent != parent);
 
                if (have_lease)
                        update_dentry_lease(dn, rinfo->trace_dlease[d],
@@ -1026,7 +1037,7 @@ retry_lookup:
                                dput(dn);
                                return -ENOMEM;
                        }
-                       dn = splice_dentry(dn, in, true);
+                       dn = splice_dentry(dn, in, NULL);
                }
 
                if (ceph_fill_inode(in, &rinfo->dir_in[i], 0) < 0) {