Patch "NFSD: Add helper to decode OPEN's openflag4 argument" has been added to the 5.10-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    NFSD: Add helper to decode OPEN's openflag4 argument

to the 5.10-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     nfsd-add-helper-to-decode-open-s-openflag4-argument.patch
and it can be found in the queue-5.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 0daee30812d7436847b4ff4c26907df029698101
Author: Chuck Lever <chuck.lever@xxxxxxxxxx>
Date:   Mon Nov 16 17:41:21 2020 -0500

    NFSD: Add helper to decode OPEN's openflag4 argument
    
    [ Upstream commit e6ec04b27bfb4869c0e35fbcf24333d379f101d5 ]
    
    Refactor for clarity.
    
    Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 62096b2a57b35..76715d1935ade 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -988,6 +988,28 @@ nfsd4_decode_createhow4(struct nfsd4_compoundargs *argp, struct nfsd4_open *open
 	return nfs_ok;
 }
 
+static __be32
+nfsd4_decode_openflag4(struct nfsd4_compoundargs *argp, struct nfsd4_open *open)
+{
+	__be32 status;
+
+	if (xdr_stream_decode_u32(argp->xdr, &open->op_create) < 0)
+		return nfserr_bad_xdr;
+	switch (open->op_create) {
+	case NFS4_OPEN_NOCREATE:
+		break;
+	case NFS4_OPEN_CREATE:
+		status = nfsd4_decode_createhow4(argp, open);
+		if (status)
+			return status;
+		break;
+	default:
+		return nfserr_bad_xdr;
+	}
+
+	return nfs_ok;
+}
+
 static __be32 nfsd4_decode_share_access(struct nfsd4_compoundargs *argp, u32 *share_access, u32 *deleg_want, u32 *deleg_when)
 {
 	__be32 *p;
@@ -1082,19 +1104,9 @@ nfsd4_decode_open(struct nfsd4_compoundargs *argp, struct nfsd4_open *open)
 	status = nfsd4_decode_opaque(argp, &open->op_owner);
 	if (status)
 		goto xdr_error;
-	READ_BUF(4);
-	open->op_create = be32_to_cpup(p++);
-	switch (open->op_create) {
-	case NFS4_OPEN_NOCREATE:
-		break;
-	case NFS4_OPEN_CREATE:
-		status = nfsd4_decode_createhow4(argp, open);
-		if (status)
-			return status;
-		break;
-	default:
-		goto xdr_error;
-	}
+	status = nfsd4_decode_openflag4(argp, open);
+	if (status)
+		return status;
 
 	/* open_claim */
 	READ_BUF(4);