ceph: use LOOKUPINO to make unconnected nfs fh more reliable

If we are unable to locate an inode by ino, ask the MDS using the new
LOOKUPINO command.

Signed-off-by: Sage Weil <sage@newdream.net>

2 files changed, 18 insertions, 2 deletions

diff --git a/fs/ceph/export.c b/fs/ceph/export.c
index e41056174bf8..f1828af09912 100644
--- a/fs/ceph/export.c
+++ b/fs/ceph/export.c
@@ -86,6 +86,7 @@ static int ceph_encode_fh(struct dentry *dentry, u32 *rawfh, int *max_len,
 static struct dentry *__fh_to_dentry(struct super_block *sb,
                                      struct ceph_nfs_fh *fh)
 {
+        struct ceph_mds_client *mdsc = ceph_sb_to_client(sb)->mdsc;
         struct inode *inode;
         struct dentry *dentry;
         struct ceph_vino vino;
@@ -95,8 +96,22 @@ static struct dentry *__fh_to_dentry(struct super_block *sb,
         vino.ino = fh->ino;
         vino.snap = CEPH_NOSNAP;
         inode = ceph_find_inode(sb, vino);
-        if (!inode)
-                return ERR_PTR(-ESTALE);
+        if (!inode) {
+                struct ceph_mds_request *req;
+
+                req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPINO,
+                                               USE_ANY_MDS);
+                if (IS_ERR(req))
+                        return ERR_CAST(req);
+
+                req->r_ino1 = vino;
+                req->r_num_caps = 1;
+                err = ceph_mdsc_do_request(mdsc, NULL, req);
+                ceph_mdsc_put_request(req);
+                inode = ceph_find_inode(sb, vino);
+                if (!inode)
+                        return ERR_PTR(-ESTALE);
+        }
 
         dentry = d_obtain_alias(inode);
         if (IS_ERR(dentry)) {
diff --git a/include/linux/ceph/ceph_fs.h b/include/linux/ceph/ceph_fs.h
index b8e995fbd867..b8c60694b2b0 100644
--- a/include/linux/ceph/ceph_fs.h
+++ b/include/linux/ceph/ceph_fs.h
@@ -313,6 +313,7 @@ enum {
         CEPH_MDS_OP_GETATTR    = 0x00101,
         CEPH_MDS_OP_LOOKUPHASH = 0x00102,
         CEPH_MDS_OP_LOOKUPPARENT = 0x00103,
+        CEPH_MDS_OP_LOOKUPINO  = 0x00104,
 
         CEPH_MDS_OP_SETXATTR   = 0x01105,
         CEPH_MDS_OP_RMXATTR    = 0x01106,