linux-kernel - [ 01/24] CIFS use sensible file nlink values if unprovided

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Message-Id: <20130719022404.116566509@linuxfoundation.org>
Date:	Thu, 18 Jul 2013 19:24:33 -0700
From:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:	linux-kernel@...r.kernel.org
Cc:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	stable@...r.kernel.org, David Disseldorp <ddiss@...e.de>,
	Steve French <smfrench@...il.com>
Subject: [ 01/24] CIFS use sensible file nlink values if unprovided

3.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Steve French <smfrench@...il.com>

commit 6658b9f70ebca5fc0795b1d6d733996af1e2caa7 upstream.

Certain servers may not set the NumberOfLinks field in query file/path
info responses. In such a case, cifs_inode_needs_reval() assumes that
all regular files are hardlinks and triggers revalidation, leading to
excessive and unnecessary network traffic.

This change hardcodes cf_nlink (and subsequently i_nlink) when not
returned by the server, similar to what already occurs in cifs_mkdir().

Signed-off-by: David Disseldorp <ddiss@...e.de>
Signed-off-by: Steve French <smfrench@...il.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 fs/cifs/inode.c |    5 +++++
 1 file changed, 5 insertions(+)

--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -549,6 +549,11 @@ cifs_all_info_to_fattr(struct cifs_fattr
 			fattr->cf_mode &= ~(S_IWUGO);
 
 		fattr->cf_nlink = le32_to_cpu(info->NumberOfLinks);
+		if (fattr->cf_nlink < 1) {
+			cFYI(1, "replacing bogus file nlink value %u\n",
+			     fattr->cf_nlink);
+			fattr->cf_nlink = 1;
+		}
 	}
 
 	fattr->cf_uid = cifs_sb->mnt_uid;


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