[MTD][MTDPART] Seperate main loop from per-partition code in add_mtd_partition

add_mtd_partition was a 150+ line monster consisting mostly of a single
loop.  Seperate the loop from most of the body.  Now it should be
obvious which variables are carried around from iteration to iteration.
Signed-off-by: Jörn Engel <joern@logfs.org>
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

drivers/mtd/mtdpart.c

@@ -313,45 +313,32 @@ int del_mtd_partitions(struct mtd_info *master)
 	return 0;
 }
 
-/*
- * This function, given a master MTD object and a partition table, creates
- * and registers slave MTD objects which are bound to the master according to
- * the partition definitions.
- * (Q: should we register the master MTD object as well?)
- */
-
-int add_mtd_partitions(struct mtd_info *master,
-		       const struct mtd_partition *parts,
-		       int nbparts)
+static struct mtd_part *add_one_partition(struct mtd_info *master,
+		const struct mtd_partition *part, int partno,
+		u_int32_t cur_offset)
 {
 	struct mtd_part *slave;
-	u_int32_t cur_offset = 0;
-	int i;
-
-	printk (KERN_NOTICE "Creating %d MTD partitions on \"%s\":\n", nbparts, master->name);
-
-	for (i = 0; i < nbparts; i++) {
 
 	/* allocate the partition structure */
 	slave = kzalloc (sizeof(*slave), GFP_KERNEL);
 	if (!slave) {
-			printk ("memory allocation error while creating partitions for \"%s\"\n",
+		printk("memory allocation error while creating partitions for \"%s\"\n",
 			master->name);
 		del_mtd_partitions(master);
-			return -ENOMEM;
+		return NULL;
 	}
 	list_add(&slave->list, &mtd_partitions);
 
 	/* set up the MTD object for this partition */
 	slave->mtd.type = master->type;
-		slave->mtd.flags = master->flags & ~parts[i].mask_flags;
-		slave->mtd.size = parts[i].size;
+	slave->mtd.flags = master->flags & ~part->mask_flags;
+	slave->mtd.size = part->size;
 	slave->mtd.writesize = master->writesize;
 	slave->mtd.oobsize = master->oobsize;
 	slave->mtd.oobavail = master->oobavail;
 	slave->mtd.subpage_sft = master->subpage_sft;
 
-		slave->mtd.name = parts[i].name;
+	slave->mtd.name = part->name;
 	slave->mtd.owner = master->owner;
 
 	slave->mtd.read = part_read;
@@ -383,7 +370,7 @@ int add_mtd_partitions(struct mtd_info *master,
 		slave->mtd.get_fact_prot_info = part_get_fact_prot_info;
 	if (master->sync)
 		slave->mtd.sync = part_sync;
-		if (!i && master->suspend && master->resume) {
+	if (!partno && master->suspend && master->resume) {
 			slave->mtd.suspend = part_suspend;
 			slave->mtd.resume = part_resume;
 	}
@@ -399,8 +386,8 @@ int add_mtd_partitions(struct mtd_info *master,
 		slave->mtd.block_markbad = part_block_markbad;
 	slave->mtd.erase = part_erase;
 	slave->master = master;
-		slave->offset = parts[i].offset;
-		slave->index = i;
+	slave->offset = part->offset;
+	slave->index = partno;
 
 	if (slave->offset == MTDPART_OFS_APPEND)
 		slave->offset = cur_offset;
@@ -410,13 +397,12 @@ int add_mtd_partitions(struct mtd_info *master,
 			/* Round up to next erasesize */
 			slave->offset = ((cur_offset / master->erasesize) + 1) * master->erasesize;
 			printk(KERN_NOTICE "Moving partition %d: "
-				       "0x%08x -> 0x%08x\n", i,
+			       "0x%08x -> 0x%08x\n", partno,
 			       cur_offset, slave->offset);
 		}
 	}
 	if (slave->mtd.size == MTDPART_SIZ_FULL)
 		slave->mtd.size = master->size - slave->offset;
-		cur_offset = slave->offset + slave->mtd.size;
 
 	printk (KERN_NOTICE "0x%08x-0x%08x : \"%s\"\n", slave->offset,
 		slave->offset + slave->mtd.size, slave->mtd.name);
@@ -427,12 +413,12 @@ int add_mtd_partitions(struct mtd_info *master,
 		slave->offset = 0;
 		slave->mtd.size = 0;
 		printk ("mtd: partition \"%s\" is out of reach -- disabled\n",
-				parts[i].name);
+			part->name);
 	}
 	if (slave->offset + slave->mtd.size > master->size) {
 		slave->mtd.size = master->size - slave->offset;
 		printk ("mtd: partition \"%s\" extends beyond the end of device \"%s\" -- size truncated to %#x\n",
-				parts[i].name, master->name, slave->mtd.size);
+			part->name, master->name, slave->mtd.size);
 	}
 	if (master->numeraseregions>1) {
 		/* Deal with variable erase size stuff */
@@ -440,10 +426,10 @@ int add_mtd_partitions(struct mtd_info *master,
 		struct mtd_erase_region_info *regions = master->eraseregions;
 
 		/* Find the first erase regions which is part of this partition. */
-			for (i=0; i < master->numeraseregions && slave->offset >= regions[i].offset; i++)
+		for (i=0; i < master->numeraseregions && regions[i].offset <= slave->offset; i++)
 			;
 
-			for (i--; i < master->numeraseregions && slave->offset + slave->mtd.size > regions[i].offset; i++) {
+		for (i--; i < master->numeraseregions && regions[i].offset < slave->offset + slave->mtd.size; i++) {
 			if (slave->mtd.erasesize < regions[i].erasesize) {
 				slave->mtd.erasesize = regions[i].erasesize;
 			}
@@ -459,13 +445,13 @@ int add_mtd_partitions(struct mtd_info *master,
 		/* FIXME: Let it be writable if it is on a boundary of _minor_ erase size though */
 		slave->mtd.flags &= ~MTD_WRITEABLE;
 		printk ("mtd: partition \"%s\" doesn't start on an erase block boundary -- force read-only\n",
-				parts[i].name);
+			part->name);
 	}
 	if ((slave->mtd.flags & MTD_WRITEABLE) &&
 	    (slave->mtd.size % slave->mtd.erasesize)) {
 		slave->mtd.flags &= ~MTD_WRITEABLE;
 		printk ("mtd: partition \"%s\" doesn't end on an erase block -- force read-only\n",
-				parts[i].name);
+			part->name);
 	}
 
 	slave->mtd.ecclayout = master->ecclayout;
@@ -480,17 +466,39 @@ int add_mtd_partitions(struct mtd_info *master,
 		}
 	}
 
-		if(parts[i].mtdp)
-		{	/* store the object pointer (caller may or may not register it */
-			*parts[i].mtdp = &slave->mtd;
+	if(part->mtdp) {	/* store the object pointer (caller may or may not register it */
+		*part->mtdp = &slave->mtd;
 		slave->registered = 0;
-		}
-		else
-		{
+	} else {
 		/* register our partition */
 		add_mtd_device(&slave->mtd);
 		slave->registered = 1;
 	}
+	return slave;
+}
+
+/*
+ * This function, given a master MTD object and a partition table, creates
+ * and registers slave MTD objects which are bound to the master according to
+ * the partition definitions.
+ * (Q: should we register the master MTD object as well?)
+ */
+
+int add_mtd_partitions(struct mtd_info *master,
+		       const struct mtd_partition *parts,
+		       int nbparts)
+{
+	struct mtd_part *slave;
+	u_int32_t cur_offset = 0;
+	int i;
+
+	printk (KERN_NOTICE "Creating %d MTD partitions on \"%s\":\n", nbparts, master->name);
+
+	for (i = 0; i < nbparts; i++) {
+		slave = add_one_partition(master, parts + i, i, cur_offset);
+		if (!slave)
+			return -ENOMEM;
+		cur_offset = slave->offset + slave->mtd.size;
 	}
 
 	return 0;