From 30596768b31069a3ae08fc305f394efb8c42b473 Mon Sep 17 00:00:00 2001 From: "J. Bruce Fields" Date: Mon, 19 May 2014 16:18:23 -0400 Subject: [PATCH] nfsd4: fix buflen calculation after read encoding We don't necessarily want to assume that the buflen is the same as the number of bytes available in the pages. We may have some reason to set it to something less (for example, later patches will use a smaller buflen to enforce session limits). So, calculate the buflen relative to the previous buflen instead of recalculating it from scratch. Signed-off-by: J. Bruce Fields --- fs/nfsd/nfs4xdr.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c index 0eeba2199c8c..1278d98a923c 100644 --- a/fs/nfsd/nfs4xdr.c +++ b/fs/nfsd/nfs4xdr.c @@ -3053,6 +3053,7 @@ nfsd4_encode_read(struct nfsd4_compoundres *resp, __be32 nfserr, unsigned long maxcount; struct xdr_stream *xdr = &resp->xdr; int starting_len = xdr->buf->len; + int space_left; long len; __be32 *p; @@ -3117,7 +3118,6 @@ nfsd4_encode_read(struct nfsd4_compoundres *resp, __be32 nfserr, resp->xdr.buf->page_len = maxcount; xdr->buf->len += maxcount; xdr->page_ptr += v; - xdr->buf->buflen = maxcount + PAGE_SIZE - 2 * RPC_MAX_AUTH_SIZE; xdr->iov = xdr->buf->tail; /* Use rest of head for padding and remaining ops: */ @@ -3130,6 +3130,12 @@ nfsd4_encode_read(struct nfsd4_compoundres *resp, __be32 nfserr, resp->xdr.buf->tail[0].iov_len = 4 - (maxcount&3); xdr->buf->len -= (maxcount&3); } + + space_left = min_t(int, (void *)xdr->end - (void *)xdr->p, + xdr->buf->buflen - xdr->buf->len); + xdr->buf->buflen = xdr->buf->len + space_left; + xdr->end = (__be32 *)((void *)xdr->end + space_left); + return 0; } -- 2.11.0