Merge branch 'devel'
[cascardo/linux.git] / fs / ceph / export.c
index fbb2a64..8e1b60e 100644 (file)
@@ -40,38 +40,49 @@ struct ceph_nfs_confh {
        u32 parent_name_hash;
 } __attribute__ ((packed));
 
-static int ceph_encode_fh(struct dentry *dentry, u32 *rawfh, int *max_len,
-                         int connectable)
+/*
+ * The presence of @parent_inode here tells us whether NFS wants a
+ * connectable file handle.  However, we want to make a connectionable
+ * file handle unconditionally so that the MDS gets as much of a hint
+ * as possible.  That means we only use @parent_dentry to indicate
+ * whether nfsd wants a connectable fh, and whether we should indicate
+ * failure from a too-small @max_len.
+ */
+static int ceph_encode_fh(struct inode *inode, u32 *rawfh, int *max_len,
+                         struct inode *parent_inode)
 {
        int type;
        struct ceph_nfs_fh *fh = (void *)rawfh;
        struct ceph_nfs_confh *cfh = (void *)rawfh;
-       struct dentry *parent;
-       struct inode *inode = dentry->d_inode;
        int connected_handle_length = sizeof(*cfh)/4;
        int handle_length = sizeof(*fh)/4;
+       struct dentry *dentry = d_find_alias(inode);
+       struct dentry *parent;
 
        /* don't re-export snaps */
        if (ceph_snap(inode) != CEPH_NOSNAP)
                return -EINVAL;
 
-       spin_lock(&dentry->d_lock);
-       parent = dentry->d_parent;
-       if (*max_len >= connected_handle_length) {
+       /* if we found an alias, generate a connectable fh */
+       if (*max_len >= connected_handle_length && dentry) {
                dout("encode_fh %p connectable\n", dentry);
-               cfh->ino = ceph_ino(dentry->d_inode);
+               spin_lock(&dentry->d_lock);
+               parent = dentry->d_parent;
+               cfh->ino = ceph_ino(inode);
                cfh->parent_ino = ceph_ino(parent->d_inode);
                cfh->parent_name_hash = ceph_dentry_hash(parent->d_inode,
                                                         dentry);
                *max_len = connected_handle_length;
                type = 2;
+               spin_unlock(&dentry->d_lock);
        } else if (*max_len >= handle_length) {
-               if (connectable) {
+               if (parent_inode) {
+                       /* nfsd wants connectable */
                        *max_len = connected_handle_length;
                        type = 255;
                } else {
                        dout("encode_fh %p\n", dentry);
-                       fh->ino = ceph_ino(dentry->d_inode);
+                       fh->ino = ceph_ino(inode);
                        *max_len = handle_length;
                        type = 1;
                }
@@ -79,7 +90,6 @@ static int ceph_encode_fh(struct dentry *dentry, u32 *rawfh, int *max_len,
                *max_len = handle_length;
                type = 255;
        }
-       spin_unlock(&dentry->d_lock);
        return type;
 }