Return-Path: linux-nfs-owner@vger.kernel.org Received: from fieldses.org ([174.143.236.118]:43439 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752546AbaEVTcn (ORCPT ); Thu, 22 May 2014 15:32:43 -0400 From: "J. Bruce Fields" To: linux-nfs@vger.kernel.org Cc: Christoph Hellwig , "J. Bruce Fields" Subject: [PATCH 32/52] nfsd4: fix buflen calculation after read encoding Date: Thu, 22 May 2014 15:32:07 -0400 Message-Id: <1400787148-25941-33-git-send-email-bfields@redhat.com> In-Reply-To: <1400787148-25941-1-git-send-email-bfields@redhat.com> References: <1400787148-25941-1-git-send-email-bfields@redhat.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: From: "J. Bruce Fields" 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 91d0b9a..ad594f2 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; } -- 1.9.0