[PATCH v3 15/17] nfsd: move v0 checking out of nfsd_check_obj_isreg()

From: NeilBrown <neil-+NVA1uvv1dVBDLzU/[email protected]>

A future patch will use nfsd_check_obj_isreg() in a context where the
protocol version is not easily available.  So move the version check out
and put it at the end of do_open_lookup().

Also change to return errno error code and use nfserrno() to convert to
nfs error codes.  Use -ELOOP for nfserr_symlink, which is an error
indication a problem with symlinks.  -EFTYPE is a good match for
nfserr_wrong_type.

Signed-off-by: NeilBrown <neil-+NVA1uvv1dVBDLzU/[email protected]>
---
 fs/nfsd/nfs4proc.c | 29 ++++++++++++-----------------
 fs/nfsd/vfs.c      |  4 +++-
 2 files changed, 15 insertions(+), 18 deletions(-)

diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index 0d1bcb12ecbc..ffeda7214d66 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -168,23 +168,17 @@ do_open_permission(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfs
 	return fh_verify(rqstp, current_fh, S_IFREG, accmode);
 }
 
-static __be32 nfsd_check_obj_isreg(struct dentry *child, u32 minor_version)
+static __be32 nfsd_check_obj_isreg(struct dentry *child)
 {
 	umode_t mode = d_inode(child)->i_mode;
 
 	if (S_ISREG(mode))
-		return nfs_ok;
+		return 0;
 	if (S_ISDIR(mode))
-		return nfserr_isdir;
+		return -EISDIR;
 	if (S_ISLNK(mode))
-		return nfserr_symlink;
-
-	/* RFC 7530 - 16.16.6 */
-	if (minor_version == 0)
-		return nfserr_symlink;
-	else
-		return nfserr_wrong_type;
-
+		return -ELOOP;
+	return -EFTYPE;
 }
 
 static void nfsd4_set_open_owner_reply_cache(struct nfsd4_compound_state *cstate, struct nfsd4_open *open, struct svc_fh *resfh)
@@ -212,8 +206,6 @@ static __be32
 nfsd4_create_file(struct svc_rqst *rqstp, struct svc_fh *fhp,
 		  struct svc_fh *resfhp, struct nfsd4_open *open)
 {
-	struct nfsd4_compoundres *resp = rqstp->rq_resp;
-	struct nfsd4_compound_state *cstate = &resp->cstate;
 	struct iattr *iap = &open->op_iattr;
 	struct nfsd_attrs attrs = {
 		.na_iattr	= iap,
@@ -356,8 +348,8 @@ nfsd4_create_file(struct svc_rqst *rqstp, struct svc_fh *fhp,
 		 * op_filp and consequently a valid ->f_path.dentry.
 		 */
 
-		status = nfsd_check_obj_isreg(child, cstate->minorversion);
-		if (status == nfs_ok) {
+		status = nfserrno(nfsd_check_obj_isreg(child));
+		if (!status) {
 			open->op_filp = dentry_open(&path, oflags,
 						    current_cred());
 			if (IS_ERR(open->op_filp)) {
@@ -536,8 +528,7 @@ do_open_lookup(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, stru
 	}
 	if (status)
 		goto out;
-	status = nfsd_check_obj_isreg((*resfh)->fh_dentry,
-				      cstate->minorversion);
+	status = nfserrno(nfsd_check_obj_isreg((*resfh)->fh_dentry));
 	if (status)
 		goto out;
 
@@ -549,6 +540,10 @@ do_open_lookup(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, stru
 	status = do_open_permission(rqstp, *resfh, open, accmode);
 	set_change_info(&open->op_cinfo, current_fh);
 out:
+	if (status == nfserr_wrong_type && cstate->minorversion == 0)
+		/* RFC 7530 - 16.16.6 */
+		return nfserr_symlink;
+
 	return status;
 }
 
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 9e05c3949cc1..c0e8c87a5e00 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -61,7 +61,7 @@ u64 nfsd_io_cache_write __read_mostly = NFSD_IO_BUFFERED;
  * it's an error we don't expect, log it once and return nfserr_io.
  */
 __be32
-nfserrno (int errno)
+nfserrno(int errno)
 {
 	static struct {
 		__be32	nfserr;
@@ -105,6 +105,8 @@ nfserrno (int errno)
 		{ nfserr_perm, -ENOKEY },
 		{ nfserr_no_grace, -ENOGRACE},
 		{ nfserr_io, -EBADMSG },
+		{ nfserr_symlink, -ELOOP },
+		{ nfserr_wrong_type, -EFTYPE },
 	};
 	int	i;
 
-- 
2.50.0.107.gf914562f5916.dirty