nfsd: open-code special directory-hardlink check

We allow the fh_verify caller to specify that any object *except* those
of a given type is allowed, by passing a negative type.  But only one
caller actually uses it.  Open-code that check in the one caller.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>

2 files changed, 4 insertions, 11 deletions

diff --git a/fs/nfsd/nfsfh.c b/fs/nfsd/nfsfh.c
index 90c6aa6d5e0f..8cd49b9bf085 100644
--- a/fs/nfsd/nfsfh.c
+++ b/fs/nfsd/nfsfh.c
@@ -61,7 +61,6 @@ static int nfsd_acceptable(void *expv, struct dentry *dentry)
 static inline __be32
 nfsd_mode_check(struct svc_rqst *rqstp, umode_t mode, int type)
 {
-        /* Type can be negative when creating hardlinks - not to a dir */
         if (type > 0 && (mode & S_IFMT) != type) {
                 if (rqstp->rq_vers == 4 && (mode & S_IFMT) == S_IFLNK)
                         return nfserr_symlink;
@@ -72,14 +71,6 @@ nfsd_mode_check(struct svc_rqst *rqstp, umode_t mode, int type)
                 else
                         return nfserr_inval;
         }
-        if (type < 0 && (mode & S_IFMT) == -type) {
-                if (rqstp->rq_vers == 4 && (mode & S_IFMT) == S_IFLNK)
-                        return nfserr_symlink;
-                else if (type == -S_IFDIR)
-                        return nfserr_isdir;
-                else
-                        return nfserr_notdir;
-        }
         return 0;
 }
 
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index fd0acca5370a..0c92a17d1770 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -1632,10 +1632,12 @@ nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp,
         err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_CREATE);
         if (err)
                 goto out;
-        err = fh_verify(rqstp, tfhp, -S_IFDIR, NFSD_MAY_NOP);
+        err = fh_verify(rqstp, tfhp, 0, NFSD_MAY_NOP);
         if (err)
                 goto out;
-
+        err = nfserr_isdir;
+        if (S_ISDIR(tfhp->fh_dentry->d_inode->i_mode))
+                goto out;
         err = nfserr_perm;
         if (!len)
                 goto out;