Patch "NFSv4: fix getacl ERANGE for some ACL buffer sizes" has been added to the 4.10-stable tree

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

NFSv4: fix getacl ERANGE for some ACL buffer sizes

to the 4.10-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:
nfsv4-fix-getacl-erange-for-some-acl-buffer-sizes.patch
and it can be found in the queue-4.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Weston Andros Adamson <[email protected]>
Date: Thu, 23 Feb 2017 14:54:21 -0500
Subject: NFSv4: fix getacl ERANGE for some ACL buffer sizes

From: Weston Andros Adamson <[email protected]>

commit ed92d8c137b7794c2c2aa14479298b9885967607 upstream.

We're not taking into account that the space needed for the (variable length) attr bitmap, with the result that we'd sometimes get a spurious ERANGE when the ACL data got close to the end of a page.

Just add in an extra page to make sure.

---
 fs/nfs/nfs4proc.c |    8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

@@ -5065,7 +5065,7 @@ out:
  */
 static ssize_t __nfs4_get_acl_uncached(struct inode *inode, void *buf, size_t buflen)
 {
-	struct page *pages[NFS4ACL_MAXPAGES] = {NULL, };
+	struct page *pages[NFS4ACL_MAXPAGES + 1] = {NULL, };
 	struct nfs_getaclargs args = {
 		.fh = NFS_FH(inode),
 		.acl_pages = pages,

@@ -5079,13 +5079,9 @@ static ssize_t __nfs4_get_acl_uncached(s
 		.rpc_argp = &args,
 		.rpc_resp = &res,
 	};
-	unsigned int npages = DIV_ROUND_UP(buflen, PAGE_SIZE);
+	unsigned int npages = DIV_ROUND_UP(buflen, PAGE_SIZE) + 1;
 	int ret = -ENOMEM, i;
 
-	/* As long as we're doing a round trip to the server anyway,
-	 * let's be prepared for a page of acl data. */
-	if (npages == 0)
-		npages = 1;
 	if (npages > ARRAY_SIZE(pages))
 		return -ERANGE;
 

Patches currently in stable-queue which might be from [email protected] are

queue-4.10/nfsv4-fix-getacl-erange-for-some-acl-buffer-sizes.patch