From 2f593593b2abd38e4cd95c64ade33f3e9e91ffdc Mon Sep 17 00:00:00 2001
From: Krzysztof Mazur <krzysiek@podlesie.net>
Date: Tue, 17 May 2011 22:00:06 +0200
Subject: [PATCH 28/84] lsbd: add support for bootup autodetection

This patch adds LSBD autodetection during startup - like Linux
Software RAID. The partition must have 0xfa type.
---
 drivers/block/lsbd.c  | 43 ++++++++++++++++++++++++++++++++++++++++++-
 fs/partitions/msdos.c | 15 +++++++++++++++
 include/linux/genhd.h |  1 +
 init/main.c           |  8 ++++++++
 4 files changed, 66 insertions(+), 1 deletion(-)

diff --git a/drivers/block/lsbd.c b/drivers/block/lsbd.c
index 57de7fe..e0f091e 100644
--- a/drivers/block/lsbd.c
+++ b/drivers/block/lsbd.c
@@ -2089,6 +2089,7 @@ int __init lsbd_init_module(void)
 {
 	unsigned int i;
 
+	printk(KERN_NOTICE "lsbd: initializing module\n");
 	for (i = 0; i < LSBD_MAX; i++) {
 		struct lsbd *p = &lsbd_dev[i];
 		unsigned int j;
@@ -2170,7 +2171,47 @@ void lsbd_cleanup_module(void)
 		printk(KERN_WARNING "lsbd: cannot unregister blkdev\n");
 }
 
-#if MODULE
+#ifndef MODULE
+
+/*
+ * Searches all registered partitions for autorun LSBD at boot time.
+ */
+static kdev_t detected_devices[128];
+static int dev_cnt;
+
+void lsbd_autodetect_dev(kdev_t dev)
+{
+	if (dev_cnt >= 0 && dev_cnt < 127)
+		detected_devices[dev_cnt++] = dev;
+}
+
+void lsbd_autodetect(void)
+{
+	struct lsbd *p;
+	unsigned int i, j;
+	kdev_t dev;
+
+	printk(KERN_INFO "lsbd: autodetecting LSBD devices...\n");
+	for (j = 0; j < dev_cnt; j++) {
+		dev = detected_devices[j];
+		for (i = 0; i < LSBD_MAX; i++) {
+			p = &lsbd_dev[i];
+
+			if (!down_interruptible(&p->mutex)) {
+				if (p->tsk == NULL) {
+					lsbd_set_dev(p, MAJOR(dev), MINOR(dev));
+					return;
+				}
+				up(&p->mutex);
+			}
+		}
+	}
+}
+
+__initcall(lsbd_init_module);
+
+#else
+
 module_init(lsbd_init_module);
 module_exit(lsbd_cleanup_module);
 
diff --git a/fs/partitions/msdos.c b/fs/partitions/msdos.c
index 1ef6a8f..0b61d3f 100644
--- a/fs/partitions/msdos.c
+++ b/fs/partitions/msdos.c
@@ -45,6 +45,9 @@ EXPORT_SYMBOL(ide_xlate_1024_hook);
 #if CONFIG_BLK_DEV_MD
 extern void md_autodetect_dev(kdev_t dev);
 #endif
+#if CONFIG_BLK_DEV_LSBD
+extern void lsbd_autodetect_dev(kdev_t dev);
+#endif
 
 /*
  * Many architectures don't like unaligned accesses, which is
@@ -175,6 +178,12 @@ static void extended_partition(struct gendisk *hd, struct block_device *bdev,
 			    md_autodetect_dev(MKDEV(hd->major,*current_minor));
 			}
 #endif
+#if CONFIG_BLK_DEV_LSBD
+			if (SYS_IND(p) == LINUX_LSBD_PARTITION) {
+				lsbd_autodetect_dev(MKDEV(hd->major,
+							*current_minor));
+			}
+#endif
 
 			(*current_minor)++;
 			loopct = 0;
@@ -605,6 +614,12 @@ int msdos_partition(struct gendisk *hd, struct block_device *bdev,
 			md_autodetect_dev(MKDEV(hd->major,minor));
 		}
 #endif
+#if CONFIG_BLK_DEV_LSBD
+		if (SYS_IND(p) == LINUX_LSBD_PARTITION) {
+			lsbd_autodetect_dev(MKDEV(hd->major,
+						minor));
+		}
+#endif
 		if (is_extended_partition(p)) {
 			unsigned long size = hd->part[minor].nr_sects;
 			printk(" <");
diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index 40ab37d..7115846 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -21,6 +21,7 @@ enum {
 	WIN98_EXTENDED_PARTITION = 0x0f,
 
 	LINUX_SWAP_PARTITION = 0x82,
+	LINUX_LSBD_PARTITION = 0xfa,	/* autodetect LSBD partition */
 	LINUX_RAID_PARTITION = 0xfd,	/* autodetect RAID partition */
 
 	SOLARIS_X86_PARTITION =	LINUX_SWAP_PARTITION,
diff --git a/init/main.c b/init/main.c
index a1d0841..68bf6ef 100644
--- a/init/main.c
+++ b/init/main.c
@@ -559,6 +559,10 @@ static void run_init_process(char *init_filename)
 
 extern void prepare_namespace(void);
 
+#if CONFIG_BLK_DEV_LSBD
+extern void lsbd_autodetect(void);
+#endif
+
 static int init(void * unused)
 {
 	struct files_struct *files;
@@ -567,6 +571,10 @@ static int init(void * unused)
 
 	prepare_namespace();
 
+#if CONFIG_BLK_DEV_LSBD
+	lsbd_autodetect();
+#endif
+
 	/*
 	 * Ok, we have completed the initial bootup, and
 	 * we're essentially up and running. Get rid of the
-- 
1.8.4.652.g0d6e0ce