[Suspend2][ 00/13] Storage manager.

[Suspend2][ 00/13] Storage manager.

[Nigel Cunningham]

The storage manager provides a way for a userspace helper to bring
up and tear down access to storage, as necessary. The helper must
not itself need external programs, but can perform actions such as
bringing up access to networked storage.

[Suspend2][ 01/13] [Suspend2] Storage.c header.

[Nigel Cunningham]

Header for the storage.c file. This file provides the interface to a
userspace helper that manages access to storage (possibly network storage,
eg).

Signed-off-by: Nigel Cunningham <nigel@suspend2.net>

 kernel/power/storage.c |   36 ++++++++++++++++++++++++++++++++++++
 1 files changed, 36 insertions(+), 0 deletions(-)

diff --git a/kernel/power/storage.c b/kernel/power/storage.c
new file mode 100644
index 0000000..91b24a6
--- /dev/null
+++ b/kernel/power/storage.c
@@ -0,0 +1,36 @@
+/*
+ * kernel/power/storage.c
+ *
+ * Copyright (C) 2005-2006 Nigel Cunningham <nigel@suspend2.net>
+ *
+ * This file is released under the GPLv2.
+ *
+ * Routines for talking to a userspace program that manages storage.
+ *
+ * The kernel side:
+ * - starts the userspace program;
+ * - sends messages telling it when to open and close the connection;
+ * - tells it when to quit;
+ *
+ * The user space side:
+ * - passes messages regarding status;
+ *
+ */
+
+#include <linux/suspend.h>
+#include <linux/freezer.h>
+ 
+#include "proc.h"
+#include "modules.h"
+#include "netlink.h"
+#include "storage.h"
+#include "ui.h"
+
+static struct user_helper_data usm_helper_data;
+static struct suspend_module_ops usm_ops;
+static int message_received = 0;
+static int activations = 0;
+static int usm_prepare_count = 0;
+static int storage_manager_last_action = 0;
+static int storage_manager_action = 0;
+       

--
Nigel Cunningham		nigel at suspend2 dot net

[Suspend2][ 02/13] [Suspend2] Receive storage manager message

[Nigel Cunningham]

Routine called when netlink messages are received.

Signed-off-by: Nigel Cunningham <nigel@suspend2.net>

 kernel/power/storage.c |   38 ++++++++++++++++++++++++++++++++++++++
 1 files changed, 38 insertions(+), 0 deletions(-)

diff --git a/kernel/power/storage.c b/kernel/power/storage.c
index 91b24a6..b66efe2 100644
--- a/kernel/power/storage.c
+++ b/kernel/power/storage.c
@@ -34,3 +34,41 @@ static int usm_prepare_count = 0;
 static int storage_manager_last_action = 0;
 static int storage_manager_action = 0;
        
+static int usm_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
+{
+	int type;
+	int *data;
+
+	type = nlh->nlmsg_type;
+
+	/* A control message: ignore them */
+	if (type < NETLINK_MSG_BASE)
+		return 0;
+
+	/* Unknown message: reply with EINVAL */
+	if (type >= USM_MSG_MAX)
+		return -EINVAL;
+
+	/* All operations require privileges, even GET */
+	if (security_netlink_recv(skb))
+		return -EPERM;
+
+	/* Only allow one task to receive NOFREEZE privileges */
+	if (type == NETLINK_MSG_NOFREEZE_ME && usm_helper_data.pid != -1)
+		return -EBUSY;
+
+	data = (int*)NLMSG_DATA(nlh);
+
+	switch (type) {
+		case USM_MSG_SUCCESS:
+		case USM_MSG_FAILED:
+			message_received = type;
+			complete(&usm_helper_data.wait_for_process);
+			break;
+		default:
+			printk("Storage manager doesn't recognise message %d.\n", type);
+	}
+
+	return 1;
+}
+

--
Nigel Cunningham		nigel at suspend2 dot net

[Suspend2][ 03/13] [Suspend2] Ask userspace to enable/disable access to our storage.

[Nigel Cunningham]

Ask userspace to do whatever it needs to do to provide us with access to
the image storage, or to tear down the access.

Signed-off-by: Nigel Cunningham <nigel@suspend2.net>

 kernel/power/storage.c |   58 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 58 insertions(+), 0 deletions(-)

diff --git a/kernel/power/storage.c b/kernel/power/storage.c
index b66efe2..71b8c02 100644
--- a/kernel/power/storage.c
+++ b/kernel/power/storage.c
@@ -72,3 +72,61 @@ static int usm_user_rcv_msg(struct sk_bu
 	return 1;
 }
 
+int suspend_activate_storage(int force)
+{
+	int tries = 1;
+
+	if (usm_helper_data.pid == -1 || usm_ops.disabled)
+		return 0;
+
+	message_received = 0;
+	activations++;
+
+	if (activations > 1 && !force)
+		return 0;
+
+	while ((!message_received || message_received == USM_MSG_FAILED) && tries < 2) {
+		suspend_prepare_status(DONT_CLEAR_BAR, "Activate storage attempt %d.\n", tries);
+
+		init_completion(&usm_helper_data.wait_for_process);
+
+		suspend_send_netlink_message(&usm_helper_data,
+			USM_MSG_CONNECT,
+			NULL, 0);
+
+		/* Wait 2 seconds for the userspace process to make contact */
+		wait_for_completion_timeout(&usm_helper_data.wait_for_process, 2*HZ);
+
+		tries++;
+	}
+
+	return 0;
+}
+
+int suspend_deactivate_storage(int force)
+{
+	if (usm_helper_data.pid == -1 || usm_ops.disabled)
+		return 0;
+	
+	message_received = 0;
+	activations--;
+
+	if (activations && !force)
+		return 0;
+
+	init_completion(&usm_helper_data.wait_for_process);
+
+	suspend_send_netlink_message(&usm_helper_data,
+			USM_MSG_DISCONNECT,
+			NULL, 0);
+
+	wait_for_completion_timeout(&usm_helper_data.wait_for_process, 2*HZ);
+
+	if (!message_received || message_received == USM_MSG_FAILED) {
+		printk("Returning failure disconnecting storage.\n");
+		return 1;
+	}
+
+	return 0;
+}
+

--
Nigel Cunningham		nigel at suspend2 dot net

[Suspend2][ 04/13] [Suspend2] Utility function for testing storage managers.

[Nigel Cunningham]

Provide a means whereby a developer (via a proc entry) can test a storage
manager. Invoke the prepare, activate, deactivate and cleanup routines in
that order.

Signed-off-by: Nigel Cunningham <nigel@suspend2.net>

 kernel/power/storage.c |   18 ++++++++++++++++++
 1 files changed, 18 insertions(+), 0 deletions(-)

diff --git a/kernel/power/storage.c b/kernel/power/storage.c
index 71b8c02..c007a8e 100644
--- a/kernel/power/storage.c
+++ b/kernel/power/storage.c
@@ -130,3 +130,21 @@ int suspend_deactivate_storage(int force
 	return 0;
 }
 
+#ifdef CONFIG_PM_DEBUG
+static void storage_manager_simulate(void)
+{
+	printk("--- Storage manager simulate ---\n");
+	suspend_prepare_usm();
+	schedule();
+	printk("--- Activate storage 1 ---\n");
+	suspend_activate_storage(1);
+	schedule();
+	printk("--- Deactivate storage 1 ---\n");
+	suspend_deactivate_storage(1);
+	schedule();
+	printk("--- Cleanup usm ---\n");
+	suspend_cleanup_usm();
+	schedule();
+	printk("--- Storage manager simulate ends ---\n");
+}
+#endif

--
Nigel Cunningham		nigel at suspend2 dot net

[Suspend2][ 05/13] [Suspend2] Get storage manager space needed in image header.

[Nigel Cunningham]

Get the amount of space in the image header needed by the storage manager.

Signed-off-by: Nigel Cunningham <nigel@suspend2.net>

 kernel/power/storage.c |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)

diff --git a/kernel/power/storage.c b/kernel/power/storage.c
index c007a8e..5fdcadd 100644
--- a/kernel/power/storage.c
+++ b/kernel/power/storage.c
@@ -148,3 +148,9 @@ static void storage_manager_simulate(voi
 	printk("--- Storage manager simulate ends ---\n");
 }
 #endif
+
+static unsigned long usm_storage_needed(void)
+{
+	return strlen(usm_helper_data.program);
+}
+

--
Nigel Cunningham		nigel at suspend2 dot net

[Suspend2][ 06/13] [Suspend2] Serialise storage manager config in an image header.

[Nigel Cunningham]

Routines to read and write the storage manager configuration.

Signed-off-by: Nigel Cunningham <nigel@suspend2.net>

 kernel/power/storage.c |   16 ++++++++++++++++
 1 files changed, 16 insertions(+), 0 deletions(-)

diff --git a/kernel/power/storage.c b/kernel/power/storage.c
index 5fdcadd..714e95e 100644
--- a/kernel/power/storage.c
+++ b/kernel/power/storage.c
@@ -154,3 +154,19 @@ static unsigned long usm_storage_needed(
 	return strlen(usm_helper_data.program);
 }
 
+static int usm_save_config_info(char *buf)
+{
+	int len = strlen(usm_helper_data.program);
+	memcpy(buf, usm_helper_data.program, len);
+	return len;
+}
+
+static void usm_load_config_info(char *buf, int size)
+{
+	/* Don't load the saved path if one has already been set */
+	if (usm_helper_data.program[0])
+		return;
+
+	memcpy(usm_helper_data.program, buf, size);
+}
+

--
Nigel Cunningham		nigel at suspend2 dot net

[Suspend2][ 07/13] [Suspend2] Get the amount of memory needed by the storage manager.

[Nigel Cunningham]

Get the amount of memory needed by the storage manager. Note that this is
just the storage needed while running, not the grand total.

Signed-off-by: Nigel Cunningham <nigel@suspend2.net>

 kernel/power/storage.c |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)

diff --git a/kernel/power/storage.c b/kernel/power/storage.c
index 714e95e..e31623a 100644
--- a/kernel/power/storage.c
+++ b/kernel/power/storage.c
@@ -170,3 +170,9 @@ static void usm_load_config_info(char *b
 	memcpy(usm_helper_data.program, buf, size);
 }
 
+static unsigned long usm_memory_needed(void)
+{
+	/* ball park figure of 32 pages */
+	return (32 * PAGE_SIZE);
+}
+

--
Nigel Cunningham		nigel at suspend2 dot net

[Suspend2][ 08/13] [Suspend2] Prepare and cleanup the storage manager.

[Nigel Cunningham]

Start the storage manager at the beginning of a suspend/resume, and clean
it up at the end of a resume or cancelled suspend.

Signed-off-by: Nigel Cunningham <nigel@suspend2.net>

 kernel/power/storage.c |   47 +++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 47 insertions(+), 0 deletions(-)

diff --git a/kernel/power/storage.c b/kernel/power/storage.c
index e31623a..fea9276 100644
--- a/kernel/power/storage.c
+++ b/kernel/power/storage.c
@@ -176,3 +176,50 @@ static unsigned long usm_memory_needed(v
 	return (32 * PAGE_SIZE);
 }
 
+/* suspend_prepare_usm
+ */
+int suspend_prepare_usm(void)
+{
+	usm_prepare_count++;
+
+	if (usm_prepare_count > 1 || usm_ops.disabled)
+		return 0;
+	
+	usm_helper_data.pid = -1;
+
+	if (!*usm_helper_data.program)
+		return 0;
+
+	suspend_netlink_setup(&usm_helper_data);
+
+	if (usm_helper_data.pid == -1)
+		printk("Suspend2 Storage Manager wanted, but couldn't start it.\n");
+
+	suspend_activate_storage(0);
+
+	return (usm_helper_data.pid != -1);
+}
+
+void suspend_cleanup_usm(void)
+{
+	usm_prepare_count--;
+
+	if (usm_helper_data.pid > -1 && !usm_prepare_count) {
+		struct task_struct *t;
+
+		suspend_deactivate_storage(0);
+
+		suspend_send_netlink_message(&usm_helper_data,
+				NETLINK_MSG_CLEANUP, NULL, 0);
+
+		read_lock(&tasklist_lock);
+		if ((t = find_task_by_pid(usm_helper_data.pid)))
+			t->flags &= ~PF_NOFREEZE;
+		read_unlock(&tasklist_lock);
+
+		suspend_netlink_close(&usm_helper_data);
+
+		usm_helper_data.pid = -1;
+	}
+}
+

--
Nigel Cunningham		nigel at suspend2 dot net

[Suspend2][ 09/13] [Suspend2] Manually activate/deactivate the storage manager.

[Nigel Cunningham]

Provide (via a proc entry) a means whereby the user can manually activate
and deactivate the storage manager for test and configuration purposes.

Signed-off-by: Nigel Cunningham <nigel@suspend2.net>

 kernel/power/storage.c |   13 +++++++++++++
 1 files changed, 13 insertions(+), 0 deletions(-)

diff --git a/kernel/power/storage.c b/kernel/power/storage.c
index fea9276..aa140ea 100644
--- a/kernel/power/storage.c
+++ b/kernel/power/storage.c
@@ -223,3 +223,16 @@ void suspend_cleanup_usm(void)
 	}
 }
 
+static void storage_manager_activate(void)
+{
+	if (storage_manager_action == storage_manager_last_action)
+		return;
+
+	if (storage_manager_action)
+		suspend_prepare_usm();
+	else
+		suspend_cleanup_usm();
+
+	storage_manager_last_action = storage_manager_action;
+}
+

--
Nigel Cunningham		nigel at suspend2 dot net

[Suspend2][ 10/13] [Suspend2] Storage manager proc entries.

[Nigel Cunningham]

Define the proc entries for the storage manager - there are entries for
disabling the manager, setting the program, manually activating and
simulating an atomic copy.

Signed-off-by: Nigel Cunningham <nigel@suspend2.net>

 kernel/power/storage.c |   48 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 48 insertions(+), 0 deletions(-)

diff --git a/kernel/power/storage.c b/kernel/power/storage.c
index aa140ea..c8f85db 100644
--- a/kernel/power/storage.c
+++ b/kernel/power/storage.c
@@ -236,3 +236,51 @@ static void storage_manager_activate(voi
 	storage_manager_last_action = storage_manager_action;
 }
 
+/*
+ * User interface specific /proc/suspend entries.
+ */
+
+static struct suspend_proc_data proc_params[] = {
+	{ .filename			= "disable_storage_manager",
+	  .permissions			= PROC_RW,
+	  .type				= SUSPEND_PROC_DATA_INTEGER,
+	  .data = {
+		.integer = {
+			.variable	= &usm_ops.disabled,
+			.minimum	= 0,
+			.maximum	= 1,
+		}
+	  }
+	},
+	{ .filename			= "storage_manager",
+	  .permissions			= PROC_RW,
+	  .type				= SUSPEND_PROC_DATA_STRING,
+	  .data = {
+		.string = {
+			.variable	= usm_helper_data.program,
+			.max_length	= 254,
+		}
+	  }
+	},
+	{ .filename			= "activate_storage",
+	  .permissions			= PROC_RW,
+	  .type				= SUSPEND_PROC_DATA_INTEGER,
+	  .data = {
+		.integer = {
+			.variable	= &storage_manager_action,
+			.minimum	= 0,
+			.maximum	= 1,
+		}
+	  },
+	  .write_proc 			= storage_manager_activate,
+	},
+
+#ifdef CONFIG_PM_DEBUG
+	{ .filename			= "simulate_atomic_copy",
+	  .permissions			= PROC_RW,
+	  .type				= SUSPEND_PROC_DATA_NONE,
+	  .write_proc 			= storage_manager_simulate,
+	}
+#endif
+};
+

--
Nigel Cunningham		nigel at suspend2 dot net

[Suspend2][ 11/13] [Suspend2] Storage manager module ops.

[Nigel Cunningham]

Define the operations that the core can use to access storage manager
functionality and data.

Signed-off-by: Nigel Cunningham <nigel@suspend2.net>

 kernel/power/storage.c |   10 ++++++++++
 1 files changed, 10 insertions(+), 0 deletions(-)

diff --git a/kernel/power/storage.c b/kernel/power/storage.c
index c8f85db..885501b 100644
--- a/kernel/power/storage.c
+++ b/kernel/power/storage.c
@@ -284,3 +284,13 @@ static struct suspend_proc_data proc_par
 #endif
 };
 
+static struct suspend_module_ops usm_ops = {
+	.type				= MISC_MODULE,
+	.name				= "Userspace Storage Manager",
+	.module				= THIS_MODULE,
+	.storage_needed			= usm_storage_needed,
+	.save_config_info		= usm_save_config_info,
+	.load_config_info		= usm_load_config_info,
+	.memory_needed			= usm_memory_needed,
+};
+       

--
Nigel Cunningham		nigel at suspend2 dot net

[Suspend2][ 12/13] [Suspend2] Initialisation of the storage manager on load.

[Nigel Cunningham]

Register the proc entries for the storage manager and set up the netlink
data structure when loaded.

Signed-off-by: Nigel Cunningham <nigel@suspend2.net>

 kernel/power/storage.c |   27 +++++++++++++++++++++++++++
 1 files changed, 27 insertions(+), 0 deletions(-)

diff --git a/kernel/power/storage.c b/kernel/power/storage.c
index 885501b..bdb2993 100644
--- a/kernel/power/storage.c
+++ b/kernel/power/storage.c
@@ -294,3 +294,30 @@ static struct suspend_module_ops usm_ops
 	.memory_needed			= usm_memory_needed,
 };
        
+/* suspend_usm_proc_init
+ * Description: Boot time initialisation for user interface.
+ */
+static __init int suspend_usm_proc_init(void)
+{
+	int result, i, numfiles = sizeof(proc_params) / sizeof(struct suspend_proc_data);
+
+	if (!(result = suspend_register_module(&usm_ops)))
+		for (i=0; i< numfiles; i++)
+			suspend_register_procfile(&proc_params[i]);
+
+	usm_helper_data.nl = NULL;
+	usm_helper_data.program[0] = '\0';
+	usm_helper_data.pid = -1;
+	usm_helper_data.skb_size = 0;
+	usm_helper_data.pool_limit = 6;
+	usm_helper_data.netlink_id = NETLINK_SUSPEND2_USM;
+	usm_helper_data.name = "userspace storage manager";
+	usm_helper_data.rcv_msg = usm_user_rcv_msg;
+	usm_helper_data.interface_version = 1;
+	usm_helper_data.must_init = 0;
+	init_completion(&usm_helper_data.wait_for_process);
+
+	return result;
+}
+
+late_initcall(suspend_usm_proc_init);

--
Nigel Cunningham		nigel at suspend2 dot net

[Suspend2][ 13/13] [Suspend2] Storage manager header file.

[Nigel Cunningham]

The header file for the storage manager, which defines the message numbers
used by it, and the functions accessible via proc entries.

Signed-off-by: Nigel Cunningham <nigel@suspend2.net>

 kernel/power/storage.h |   37 +++++++++++++++++++++++++++++++++++++
 1 files changed, 37 insertions(+), 0 deletions(-)

diff --git a/kernel/power/storage.h b/kernel/power/storage.h
new file mode 100644
index 0000000..9039dcc
--- /dev/null
+++ b/kernel/power/storage.h
@@ -0,0 +1,37 @@
+/*
+ * kernel/power/storage.h
+ *
+ * Copyright (C) 2005-2006 Nigel Cunningham <nigel@suspend2.net>
+ *
+ * This file is released under the GPLv2.
+ */
+
+int suspend_prepare_usm(void);
+void suspend_cleanup_usm(void);
+
+#ifdef CONFIG_NET
+int suspend_activate_storage(int force);
+int suspend_deactivate_storage(int force);
+#else
+static inline int suspend_activate_storage(int force)
+{
+	return 0;
+}
+
+static inline int suspend_deactivate_storage(int force)
+{
+	return 0;
+}
+#endif
+
+enum {
+	USM_MSG_BASE = 0x10,
+
+	/* Kernel -> Userspace */
+	USM_MSG_CONNECT = 0x30,
+	USM_MSG_DISCONNECT = 0x31,
+	USM_MSG_SUCCESS = 0x40,
+	USM_MSG_FAILED = 0x41,
+
+	USM_MSG_MAX,
+};

--
Nigel Cunningham		nigel at suspend2 dot net