Patch "nfsd/blocklayout: accept any minlength" has been added to the 4.2-stable tree

Patch "nfsd/blocklayout: accept any minlength" has been added to the 4.2-stable tree

[gregkh]

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

    nfsd/blocklayout: accept any minlength

to the 4.2-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-blocklayout-accept-any-minlength.patch
and it can be found in the queue-4.2 subdirectory.

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


>From 8c3ad9cb7343dc5f61b8cf3cdbe1016c5e7c2c8b Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@lst.de>
Date: Fri, 9 Oct 2015 15:03:26 +0200
Subject: nfsd/blocklayout: accept any minlength

From: Christoph Hellwig <hch@lst.de>

commit 8c3ad9cb7343dc5f61b8cf3cdbe1016c5e7c2c8b upstream.

Recent Linux clients have started to send GETLAYOUT requests with
minlength less than blocksize.

Servers aren't really allowed to impose this kind of restriction on
layouts; see RFC 5661 section 18.43.3 for details.

This has been observed to cause indefinite hangs on fsx runs on some
clients.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 fs/nfsd/blocklayout.c |    8 --------
 1 file changed, 8 deletions(-)

--- a/fs/nfsd/blocklayout.c
+++ b/fs/nfsd/blocklayout.c
@@ -56,14 +56,6 @@ nfsd4_block_proc_layoutget(struct inode
 	u32 device_generation = 0;
 	int error;
 
-	/*
-	 * We do not attempt to support I/O smaller than the fs block size,
-	 * or not aligned to it.
-	 */
-	if (args->lg_minlength < block_size) {
-		dprintk("pnfsd: I/O too small\n");
-		goto out_layoutunavailable;
-	}
 	if (seg->offset & (block_size - 1)) {
 		dprintk("pnfsd: I/O misaligned\n");
 		goto out_layoutunavailable;


Patches currently in stable-queue which might be from hch@lst.de are

queue-4.2/nfsd-blocklayout-accept-any-minlength.patch