LU-4231 llite: proper support of NFS anonymous dentries

NFS can ask to encode dentries that are not connected to the root.
The fix check for parent is NULL and encode a file handle accordingly.

Signed-off-by: Dmitry Eremin <dmitry.eremin@intel.com>
Change-Id: Idba91fd4bca4f26a37fd9bc76a340d2fbf557c9e
Reviewed-on: http://review.whamcloud.com/8347
Reviewed-by: Fan Yong <fan.yong@intel.com>
Tested-by: Jenkins
Reviewed-by: James Simmons <uja.ornl@gmail.com>
Reviewed-by: Jian Yu <jian.yu@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>

diff --git a/lustre/llite/llite_nfs.c b/lustre/llite/llite_nfs.c
index dbfdde0..2926caf 100644 (file)
--- a/lustre/llite/llite_nfs.c
+++ b/lustre/llite/llite_nfs.c
@@ -127,10 +127,11 @@ ll_iget_for_nfs(struct super_block *sb, struct lu_fid *fid, struct lu_fid *paren
         struct dentry *result;
         ENTRY;
 
-        CDEBUG(D_INFO, "Get dentry for fid: "DFID"\n", PFID(fid));
         if (!fid_is_sane(fid))
                 RETURN(ERR_PTR(-ESTALE));
 
+       CDEBUG(D_INFO, "Get dentry for fid: "DFID"\n", PFID(fid));
+
         inode = search_inode_for_lustre(sb, fid);
         if (IS_ERR(inode))
                 RETURN(ERR_PTR(PTR_ERR(inode)));
@@ -146,7 +147,7 @@ ll_iget_for_nfs(struct super_block *sb, struct lu_fid *fid, struct lu_fid *paren
          * We have to find the parent to tell MDS how to init lov objects.
          */
        if (S_ISREG(inode->i_mode) && !ll_i2info(inode)->lli_has_smd &&
-           parent != NULL) {
+           parent != NULL && !fid_is_zero(parent)) {
                struct ll_inode_info *lli = ll_i2info(inode);
 
                spin_lock(&lli->lli_lock);
@@ -163,7 +164,12 @@ ll_iget_for_nfs(struct super_block *sb, struct lu_fid *fid, struct lu_fid *paren
         RETURN(result);
 }
 
-#define LUSTRE_NFS_FID          0x97
+#ifndef FILEID_INVALID
+#define FILEID_INVALID 0xff
+#endif
+#ifndef FILEID_LUSTRE
+#define FILEID_LUSTRE  0x97
+#endif
 
 /**
  * \a connectable - is nfsd will connect himself or this should be done
@@ -185,22 +191,27 @@ static int ll_encode_fh(struct inode *inode, __u32 *fh, int *plen,
                        struct inode *parent)
 {
 #endif
+       int fileid_len = sizeof(struct lustre_nfs_fid) / 4;
        struct lustre_nfs_fid *nfs_fid = (void *)fh;
        ENTRY;
 
        CDEBUG(D_INFO, "%s: encoding for ("DFID") maxlen=%d minlen=%d\n",
               ll_get_fsname(inode->i_sb, NULL, 0),
-              PFID(ll_inode2fid(inode)), *plen,
-              (int)sizeof(struct lustre_nfs_fid));
+              PFID(ll_inode2fid(inode)), *plen, fileid_len);
 
-       if (*plen < sizeof(struct lustre_nfs_fid) / 4)
-               RETURN(255);
+       if (*plen < fileid_len) {
+               *plen = fileid_len;
+               RETURN(FILEID_INVALID);
+       }
 
        nfs_fid->lnf_child = *ll_inode2fid(inode);
-       nfs_fid->lnf_parent = *ll_inode2fid(parent);
-       *plen = sizeof(struct lustre_nfs_fid) / 4;
+       if (parent != NULL)
+               nfs_fid->lnf_parent = *ll_inode2fid(parent);
+       else
+               fid_zero(&nfs_fid->lnf_parent);
+       *plen = fileid_len;
 
-       RETURN(LUSTRE_NFS_FID);
+       RETURN(FILEID_LUSTRE);
 }
 
 static int ll_nfs_get_name_filldir(void *cookie, const char *name, int namelen,
@@ -256,8 +267,8 @@ static struct dentry *ll_fh_to_dentry(struct super_block *sb, struct fid *fid,
 {
         struct lustre_nfs_fid *nfs_fid = (struct lustre_nfs_fid *)fid;
 
-        if (fh_type != LUSTRE_NFS_FID)
-                RETURN(ERR_PTR(-EPROTO));
+       if (fh_type != FILEID_LUSTRE)
+               RETURN(ERR_PTR(-EPROTO));
 
         RETURN(ll_iget_for_nfs(sb, &nfs_fid->lnf_child, &nfs_fid->lnf_parent));
 }
@@ -267,11 +278,12 @@ static struct dentry *ll_fh_to_parent(struct super_block *sb, struct fid *fid,
 {
         struct lustre_nfs_fid *nfs_fid = (struct lustre_nfs_fid *)fid;
 
-        if (fh_type != LUSTRE_NFS_FID)
-                RETURN(ERR_PTR(-EPROTO));
+       if (fh_type != FILEID_LUSTRE)
+               RETURN(ERR_PTR(-EPROTO));
 
         RETURN(ll_iget_for_nfs(sb, &nfs_fid->lnf_parent, NULL));
 }
+
 static struct dentry *ll_get_parent(struct dentry *dchild)
 {
         struct ptlrpc_request *req = NULL;