From ffa6376d01fc83daeb1d703752d1b9d097a6734f Mon Sep 17 00:00:00 2001
From: Krzysztof Mazur <krzysiek@podlesie.net>
Date: Thu, 16 Dec 2010 21:04:35 +0100
Subject: [PATCH 05/84] lsbd: write partition table after modification

---
 drivers/block/lsbd.c | 60 ++++++++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 51 insertions(+), 9 deletions(-)

diff --git a/drivers/block/lsbd.c b/drivers/block/lsbd.c
index e5197ae..b7c88b9 100644
--- a/drivers/block/lsbd.c
+++ b/drivers/block/lsbd.c
@@ -81,6 +81,7 @@ struct lsbd {
 	struct list_head wqueue[LSBD_QUEUE_COUNT];
 	wait_queue_head_t wqueue_wait;
 	unsigned int wqueue_len;
+	unsigned int blocks_to_write;
 	struct semaphore req_sem;
 
 	struct lsbd_partition part[16];
@@ -97,7 +98,7 @@ struct lsbd_request {
 	int move;
 };
 
-#if 1
+#if 0
 #define lsbd_debug(c, fmt, ...)						\
 	printk(KERN_DEBUG "lsbd%d: "fmt, (c)->id, ## __VA_ARGS__)
 #else
@@ -551,6 +552,8 @@ static int lsbd_load_params(struct lsbd *p)
 				p->blocks * p->sectors_per_block
 				* (p->sector_size >> 10));
 		lsbd_sizes[p->id] = p->lsectors * (p->sector_size >> 10);
+
+		p->blocks_to_write = 0;
 		
 		lsbd_load_partitions(p, b);
 		brelse(bh);
@@ -640,6 +643,24 @@ static int lsbd_set_dev(struct lsbd *p, int major, int minor)
 
 	return lsbd_mount(p);
 }
+
+static int lsbd_write_blocks(struct lsbd *p, unsigned int num)
+{
+	unsigned long flags;
+
+	/*
+	 * increase number of block for redundancy
+	 */
+	num *= 2;
+	
+	spin_lock_irqsave(&p->wqueue_lock, flags);
+	if (p->blocks_to_write < num)
+		p->blocks_to_write = num;
+	spin_unlock_irqrestore(&p->wqueue_lock, flags);
+	wake_up_interruptible(&p->wqueue_wait);
+
+	return 0;
+}
 	
 static int lsbd_partition(struct lsbd *p, struct lsbd_part_info *part)
 {
@@ -669,6 +690,7 @@ static int lsbd_partition(struct lsbd *p, struct lsbd_part_info *part)
 			lsbd_lcache_t *l;
 			lsbd_lcache_t *ol;
 			unsigned int i;
+			unsigned int chunk;
 
 			l = vmalloc(part->size * sizeof(l[0]));
 			if (l == NULL)
@@ -678,6 +700,11 @@ static int lsbd_partition(struct lsbd *p, struct lsbd_part_info *part)
 			ol = p->lcache;
 			p->lcache = l;
 
+			p->lsectors = part->size;
+
+			chunk = (p->sector_size - 0x800) / sizeof(*l);
+			lsbd_write_blocks(p, p->lsectors / chunk);
+
 	/*
 	 * FIXME: implement lcache locking 
 	 */
@@ -701,6 +728,9 @@ static int lsbd_partition(struct lsbd *p, struct lsbd_part_info *part)
 	p->part[part->num].start = part->start;
 	p->part[part->num].size = part->size;
 	lsbd_update_part(p, part->num);
+
+	/* write partition */
+	lsbd_write_blocks(p, 1);
 	return 0;
 }
 
@@ -1156,6 +1186,9 @@ int lsbd_write_block(struct lsbd *p)
 static int lsbd_thread(void *data)
 {
 	struct lsbd *p = data;
+	int ret;
+	int want_write;
+	int want_clean;
 
 	lock_kernel();
 	daemonize();
@@ -1178,14 +1211,19 @@ static int lsbd_thread(void *data)
 	complete(p->event);
 	for (;;) {
 		DECLARE_WAITQUEUE(wait, current);
-		unsigned int len;
+	
+		want_write = 0;
+		want_clean = 0;
 
 		add_wait_queue(&p->wqueue_wait, &wait);
 		set_task_state(current, TASK_INTERRUPTIBLE);
 		spin_lock_irq(&p->wqueue_lock);
-		len = p->wqueue_len;
+
+		if (p->wqueue_len || p->blocks_to_write)
+			want_write = 1;
 		spin_unlock_irq(&p->wqueue_lock);
-		if (!len && (block_diff(p, p->clean_block, p->cur_block) >= 16))
+		want_clean = (block_diff(p, p->clean_block, p->cur_block) < 16);
+		if (!(want_write || want_clean))
 			schedule();
 		current->state = TASK_RUNNING;
 		remove_wait_queue(&p->wqueue_wait, &wait);
@@ -1201,14 +1239,18 @@ static int lsbd_thread(void *data)
 		if (p->stop)
 			break;
 
-		if (block_diff(p, p->clean_block, p->cur_block) < 16)
+		if (want_clean)
 			lsbd_clean_block(p);
 
-		while (len && (block_diff(p, p->clean_block, p->cur_block)
-					> 1)) {
-			lsbd_write_block(p);
+		while (want_write && (block_diff(p, p->clean_block,
+						p->cur_block) > 1)) {
+			ret = lsbd_write_block(p);
 			spin_lock_irq(&p->wqueue_lock);
-			len = p->wqueue_len;
+			if (!ret && p->blocks_to_write)
+				p->blocks_to_write--;
+			want_write = 0;
+			if (p->wqueue_len || p->blocks_to_write)
+				want_write = 1;
 			spin_unlock_irq(&p->wqueue_lock);
 		}
 	}
-- 
1.8.4.652.g0d6e0ce