From: trondmy@kernel.org
To: linux-nfs@vger.kernel.org
Subject: [PATCH 2/3] NFS: Avoid copy of xdr padding in readlink, layoutget and getxattr
Date: Wed, 18 Nov 2020 17:19:38 -0500 [thread overview]
Message-ID: <20201118221939.20715-2-trondmy@kernel.org> (raw)
In-Reply-To: <20201118221939.20715-1-trondmy@kernel.org>
From: Trond Myklebust <trond.myklebust@hammerspace.com>
When doing a readlink, layoutget or getxattr call into an array of
pages, we don't care if the XDR padding ends up in the last page
when the data length is not 32-bit aligned.
Avoid an unnecessary copy by just leaving that padding in place.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
fs/nfs/nfs2xdr.c | 2 +-
fs/nfs/nfs3xdr.c | 2 +-
fs/nfs/nfs42xdr.c | 2 +-
fs/nfs/nfs4xdr.c | 4 ++--
4 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/fs/nfs/nfs2xdr.c b/fs/nfs/nfs2xdr.c
index f6676af37d5d..db9c265ad9e1 100644
--- a/fs/nfs/nfs2xdr.c
+++ b/fs/nfs/nfs2xdr.c
@@ -437,7 +437,7 @@ static int decode_path(struct xdr_stream *xdr)
length = be32_to_cpup(p);
if (unlikely(length >= xdr->buf->page_len || length > NFS_MAXPATHLEN))
goto out_size;
- recvd = xdr_read_pages(xdr, length);
+ recvd = xdr_read_pages(xdr, xdr_align_size(length));
if (unlikely(length > recvd))
goto out_cheating;
xdr_terminate_string(xdr->buf, length);
diff --git a/fs/nfs/nfs3xdr.c b/fs/nfs/nfs3xdr.c
index 69971f6c840d..d3e1726d538b 100644
--- a/fs/nfs/nfs3xdr.c
+++ b/fs/nfs/nfs3xdr.c
@@ -234,7 +234,7 @@ static int decode_nfspath3(struct xdr_stream *xdr)
count = be32_to_cpup(p);
if (unlikely(count >= xdr->buf->page_len || count > NFS3_MAXPATHLEN))
goto out_nametoolong;
- recvd = xdr_read_pages(xdr, count);
+ recvd = xdr_read_pages(xdr, xdr_align_size(count));
if (unlikely(count > recvd))
goto out_cheating;
xdr_terminate_string(xdr->buf, count);
diff --git a/fs/nfs/nfs42xdr.c b/fs/nfs/nfs42xdr.c
index 6e060a88f98c..e58bfe208ae8 100644
--- a/fs/nfs/nfs42xdr.c
+++ b/fs/nfs/nfs42xdr.c
@@ -495,7 +495,7 @@ static int decode_getxattr(struct xdr_stream *xdr,
res->xattr_len = len;
if (len > 0) {
- rdlen = xdr_read_pages(xdr, len);
+ rdlen = xdr_read_pages(xdr, xdr_align_size(len));
if (rdlen < len)
return -EIO;
}
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index c8714381d511..755b556e85c3 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -5250,7 +5250,7 @@ static int decode_readlink(struct xdr_stream *xdr, struct rpc_rqst *req)
dprintk("nfs: server returned giant symlink!\n");
return -ENAMETOOLONG;
}
- recvd = xdr_read_pages(xdr, len);
+ recvd = xdr_read_pages(xdr, xdr_align_size(len));
if (recvd < len) {
dprintk("NFS: server cheating in readlink reply: "
"count %u > recvd %u\n", len, recvd);
@@ -5925,7 +5925,7 @@ static int decode_layoutget(struct xdr_stream *xdr, struct rpc_rqst *req,
res->type,
res->layoutp->len);
- recvd = xdr_read_pages(xdr, res->layoutp->len);
+ recvd = xdr_read_pages(xdr, xdr_align_size(res->layoutp->len));
if (res->layoutp->len > recvd) {
dprintk("NFS: server cheating in layoutget reply: "
"layout len %u > recvd %u\n",
--
2.28.0
next prev parent reply other threads:[~2020-11-18 22:19 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-18 22:19 [PATCH 1/3] NFSv4: Fix the alignment of page data in the getdeviceinfo reply trondmy
2020-11-18 22:19 ` trondmy [this message]
2020-11-18 22:19 ` [PATCH 3/3] NFS: Avoid copy of xdr padding in read() trondmy
2020-11-19 14:17 ` Chuck Lever
2020-11-19 14:30 ` Trond Myklebust
2020-11-19 14:31 ` Chuck Lever
2020-11-19 14:34 ` Trond Myklebust
2020-11-19 22:58 ` Chuck Lever
2020-11-20 0:58 ` Trond Myklebust
2020-11-20 14:52 ` Chuck Lever
2020-11-20 17:14 ` Trond Myklebust
2020-11-20 17:51 ` Chuck Lever
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