notmuch/test/corpora/lkml/cur/1382298770.001740:2,

From: Suresh Jayaraman <sjayaraman-l3A5Bk7waGM@public.gmane.org>
Subject: [RFC][PATCH 05/10] cifs: define superblock-level cache index objects and register them
Date: Tue, 22 Jun 2010 20:53:26 +0530
Lines: 177
Message-ID: <1277220206-3559-1-git-send-email-sjayaraman@suse.de>
References: <yes>
Cc: linux-cifs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, David Howells <dhowells-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
To: Steve French <smfrench-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
X-From: linux-cifs-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Tue Jun 22 17:45:50 2010
Return-path: <linux-cifs-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
Envelope-to: glkc-linux-cifs-1dZseelyfdZg9hUCZPvPmw@public.gmane.org
Received: from vger.kernel.org ([209.132.180.67])
	by lo.gmane.org with esmtp (Exim 4.69)
	(envelope-from <linux-cifs-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>)
	id 1OR5fZ-0000Vj-Mj
	for glkc-linux-cifs-1dZseelyfdZg9hUCZPvPmw@public.gmane.org; Tue, 22 Jun 2010 17:45:50 +0200
Received: (majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org) by vger.kernel.org via listexpand
	id S1752511Ab0FVPpJ (ORCPT <rfc822;glkc-linux-cifs@m.gmane.org>);
	Tue, 22 Jun 2010 11:45:09 -0400
Received: from victor.provo.novell.com ([137.65.250.26]:56189 "EHLO
	victor.provo.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1752441Ab0FVPoA (ORCPT
	<rfc822;groupwise-SJayaraman-Et1tbQHTxzrQT0dZR+AlfA@public.gmane.org:0:0>);
	Tue, 22 Jun 2010 11:44:00 -0400
Received: from localhost (prv-ext-foundry1int.gns.novell.com [137.65.251.240])
	by victor.provo.novell.com with ESMTP; Tue, 22 Jun 2010 09:23:29 -0600
X-Mailer: git-send-email 1.6.4.2
In-Reply-To: <yes>
Sender: linux-cifs-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Precedence: bulk
List-ID: <linux-cifs.vger.kernel.org>
X-Mailing-List: linux-cifs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Archived-At: <http://permalink.gmane.org/gmane.linux.kernel/1001766>

Define superblock-level cache index objects (managed by cifsTconInfo structs).
Each superblock object is created in a server-level index object and in itself
an index into which inode-level objects are inserted.

Currently, the superblock objects are keyed by sharename.

Signed-off-by: Suresh Jayaraman <sjayaraman-l3A5Bk7waGM@public.gmane.org>
---
 fs/cifs/cache.c    |   62 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 fs/cifs/cifsglob.h |    3 ++
 fs/cifs/connect.c  |    4 +++
 fs/cifs/fscache.c  |   17 ++++++++++++++
 fs/cifs/fscache.h  |    6 +++++
 5 files changed, 92 insertions(+)

Index: cifs-2.6/fs/cifs/cache.c
===================================================================
--- cifs-2.6.orig/fs/cifs/cache.c
+++ cifs-2.6/fs/cifs/cache.c
@@ -76,3 +76,65 @@ const struct fscache_cookie_def cifs_fsc
 	.type = FSCACHE_COOKIE_TYPE_INDEX,
 	.get_key = cifs_server_get_key,
 };
+
+static char *extract_sharename(const char *treename)
+{
+	const char *src;
+	char *delim, *dst;
+	int len;
+
+	/* skip double chars at the beginning */
+	src = treename + 2;
+
+	/* share name is always preceded by '\\' now */
+	delim = strchr(src, '\\');
+	if (!delim)
+		return ERR_PTR(-EINVAL);
+	delim++;
+	len = strlen(delim);
+
+	/* caller has to free the memory */
+	dst = kstrndup(delim, len, GFP_KERNEL);
+	if (!dst)
+		return ERR_PTR(-ENOMEM);
+
+	return dst;
+}
+
+/*
+ * Superblock object currently keyed by share name
+ */
+static uint16_t cifs_super_get_key(const void *cookie_netfs_data, void *buffer,
+				   uint16_t maxbuf)
+{
+	const struct cifsTconInfo *tcon = cookie_netfs_data;
+	char *sharename;
+	uint16_t len;
+
+	sharename = extract_sharename(tcon->treeName);
+	if (IS_ERR(sharename)) {
+		cFYI(1, "CIFS: couldn't extract sharename\n");
+		sharename = NULL;
+		return 0;
+	}
+
+	len = strlen(sharename);
+	if (len > maxbuf)
+		return 0;
+
+	memcpy(buffer, sharename, len);
+
+	kfree(sharename);
+
+	return len;
+}
+
+/*
+ * Superblock object for FS-Cache
+ */
+const struct fscache_cookie_def cifs_fscache_super_index_def = {
+	.name = "CIFS.super",
+	.type = FSCACHE_COOKIE_TYPE_INDEX,
+	.get_key = cifs_super_get_key,
+};
+
Index: cifs-2.6/fs/cifs/cifsglob.h
===================================================================
--- cifs-2.6.orig/fs/cifs/cifsglob.h
+++ cifs-2.6/fs/cifs/cifsglob.h
@@ -317,6 +317,9 @@ struct cifsTconInfo {
 	bool local_lease:1; /* check leases (only) on local system not remote */
 	bool broken_posix_open; /* e.g. Samba server versions < 3.3.2, 3.2.9 */
 	bool need_reconnect:1; /* connection reset, tid now invalid */
+#ifdef CONFIG_CIFS_FSCACHE
+	struct fscache_cookie *fscache; /* cookie for share */
+#endif
 	/* BB add field for back pointer to sb struct(s)? */
 };
 
Index: cifs-2.6/fs/cifs/connect.c
===================================================================
--- cifs-2.6.orig/fs/cifs/connect.c
+++ cifs-2.6/fs/cifs/connect.c
@@ -1773,6 +1773,8 @@ cifs_put_tcon(struct cifsTconInfo *tcon)
 	list_del_init(&tcon->tcon_list);
 	write_unlock(&cifs_tcp_ses_lock);
 
+	cifs_fscache_release_super_cookie(tcon);
+
 	xid = GetXid();
 	CIFSSMBTDis(xid, tcon);
 	_FreeXid(xid);
@@ -1843,6 +1845,8 @@ cifs_get_tcon(struct cifsSesInfo *ses, s
 	tcon->nocase = volume_info->nocase;
 	tcon->local_lease = volume_info->local_lease;
 
+	cifs_fscache_get_super_cookie(tcon);
+
 	write_lock(&cifs_tcp_ses_lock);
 	list_add(&tcon->tcon_list, &ses->tcon_list);
 	write_unlock(&cifs_tcp_ses_lock);
Index: cifs-2.6/fs/cifs/fscache.c
===================================================================
--- cifs-2.6.orig/fs/cifs/fscache.c
+++ cifs-2.6/fs/cifs/fscache.c
@@ -45,3 +45,20 @@ void cifs_fscache_release_client_cookie(
 	server->fscache = NULL;
 }
 
+void cifs_fscache_get_super_cookie(struct cifsTconInfo *tcon)
+{
+	tcon->fscache =
+		fscache_acquire_cookie(tcon->ses->server->fscache,
+				&cifs_fscache_super_index_def, tcon);
+	cFYI(1, "CIFS: get superblock cookie (0x%p/0x%p)\n",
+				tcon, tcon->fscache);
+}
+
+void cifs_fscache_release_super_cookie(struct cifsTconInfo *tcon)
+{
+	cFYI(1, "CIFS: releasing superblock cookie (0x%p/0x%p)\n",
+			tcon, tcon->fscache);
+	fscache_relinquish_cookie(tcon->fscache, 0);
+	tcon->fscache = NULL;
+}
+
Index: cifs-2.6/fs/cifs/fscache.h
===================================================================
--- cifs-2.6.orig/fs/cifs/fscache.h
+++ cifs-2.6/fs/cifs/fscache.h
@@ -28,6 +28,7 @@
 
 extern struct fscache_netfs cifs_fscache_netfs;
 extern const struct fscache_cookie_def cifs_fscache_server_index_def;
+extern const struct fscache_cookie_def cifs_fscache_super_index_def;
 
 extern int cifs_fscache_register(void);
 extern void cifs_fscache_unregister(void);
@@ -37,6 +38,8 @@ extern void cifs_fscache_unregister(void
  */
 extern void cifs_fscache_get_client_cookie(struct TCP_Server_Info *);
 extern void cifs_fscache_release_client_cookie(struct TCP_Server_Info *);
+extern void cifs_fscache_get_super_cookie(struct cifsTconInfo *);
+extern void cifs_fscache_release_super_cookie(struct cifsTconInfo *);
 
 #else /* CONFIG_CIFS_FSCACHE */
 static inline int cifs_fscache_register(void) { return 0; }
@@ -46,6 +49,9 @@ static inline void
 cifs_fscache_get_client_cookie(struct TCP_Server_Info *server) {}
 static inline void
 cifs_fscache_get_client_cookie(struct TCP_Server_Info *server); {}
+static inline void cifs_fscache_get_super_cookie(struct cifsTconInfo *tcon) {}
+static inline void
+cifs_fscache_release_super_cookie(struct cifsTconInfo *tcon) {}
 
 #endif /* CONFIG_CIFS_FSCACHE */