linux-kernel - [PATCH 32/37] NFS: Add read context retention for FS-Cache to call back with

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20080220160849.4715.2979.stgit@warthog.procyon.org.uk>
Date:	Wed, 20 Feb 2008 16:08:50 +0000
From:	David Howells <dhowells@...hat.com>
To:	Trond.Myklebust@...app.com, chuck.lever@...cle.com,
	casey@...aufler-ca.com
Cc:	nfsv4@...ux-nfs.org, linux-kernel@...r.kernel.org,
	linux-fsdevel@...r.kernel.org, selinux@...ho.nsa.gov,
	linux-security-module@...r.kernel.org, dhowells@...hat.com
Subject: [PATCH 32/37] NFS: Add read context retention for FS-Cache to call
	back with

Add read context retention so that FS-Cache can call back into NFS when a read
operation on the cache fails EIO rather than reading data.  This permits NFS to
then fetch the data from the server instead using the appropriate security
context.

Signed-off-by: David Howells <dhowells@...hat.com>
---

 fs/nfs/fscache-index.c |   26 ++++++++++++++++++++++++++
 1 files changed, 26 insertions(+), 0 deletions(-)


diff --git a/fs/nfs/fscache-index.c b/fs/nfs/fscache-index.c
index eec8e7e..af9f06b 100644
--- a/fs/nfs/fscache-index.c
+++ b/fs/nfs/fscache-index.c
@@ -285,6 +285,30 @@ static void nfs_cache_inode_now_uncached(void *cookie_netfs_data)
 }
 
 /*
+ * Get an extra reference on a read context.
+ * - This function can be absent if the completion function doesn't require a
+ *   context.
+ * - The read context is passed back to NFS in the event that a data read on the
+ *   cache fails with EIO - in which case the server must be contacted to
+ *   retrieve the data, which requires the read context for security.
+ */
+static void nfs_fh_get_context(void *cookie_netfs_data, void *context)
+{
+	get_nfs_open_context(context);
+}
+
+/*
+ * Release an extra reference on a read context.
+ * - This function can be absent if the completion function doesn't require a
+ *   context.
+ */
+static void nfs_fh_put_context(void *cookie_netfs_data, void *context)
+{
+	if (context)
+		put_nfs_open_context(context);
+}
+
+/*
  * Define the inode object for FS-Cache.  This is used to describe an inode
  * object to fscache_acquire_cookie().  It is keyed by the NFS file handle for
  * an inode.
@@ -301,4 +325,6 @@ const struct fscache_cookie_def nfs_cache_inode_object_def = {
 	.get_aux	= nfs_cache_inode_get_aux,
 	.check_aux	= nfs_cache_inode_check_aux,
 	.now_uncached	= nfs_cache_inode_now_uncached,
+	.get_context	= nfs_fh_get_context,
+	.put_context	= nfs_fh_put_context,
 };

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/