NFSD: De-duplicate nfsd4_decode_bitmap4()

Commit Message

Chuck Lever Dec. 13, 2021, 4:58 p.m. UTC

Clean up. Trond points out that xdr_stream_decode_uint32_array()
does the same thing as nfsd4_decode_bitmap4().

Suggested-by: Trond Myklebust <[e-mail]>
Signed-off-by: Chuck Lever <[e-mail]>
---
 fs/nfsd/nfs4xdr.c |   17 +++--------------
 1 file changed, 3 insertions(+), 14 deletions(-)

This patch replaces "NFSD: Replace nfsd4_decode_bitmap4()". Changes
since that version:

- My copy of pynfs was out of date. I've updated to the latest
- I reproduced Bruce's BADXDR report with the latest pynfs
- I tested this version likewise and could not reproduce the issue
- The nice documenting comment is preserved

Patch

diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 5a93a5db4fb0..df5a4c7ea8ec 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -277,21 +277,10 @@  nfsd4_decode_verifier4(struct nfsd4_compoundargs *argp, nfs4_verifier *verf)
 static __be32
 nfsd4_decode_bitmap4(struct nfsd4_compoundargs *argp, u32 *bmval, u32 bmlen)
 {
-	u32 i, count;
-	__be32 *p;
-
-	if (xdr_stream_decode_u32(argp->xdr, &count) < 0)
-		return nfserr_bad_xdr;
-	/* request sanity */
-	if (count > 1000)
-		return nfserr_bad_xdr;
-	p = xdr_inline_decode(argp->xdr, count << 2);
-	if (!p)
-		return nfserr_bad_xdr;
-	for (i = 0; i < bmlen; i++)
-		bmval[i] = (i < count) ? be32_to_cpup(p++) : 0;
+	ssize_t status;
 
-	return nfs_ok;
+	status = xdr_stream_decode_uint32_array(argp->xdr, bmval, bmlen);
+	return status == -EBADMSG ? nfserr_bad_xdr : nfs_ok;
 }
 
 static __be32