patch-2.4.10 linux/drivers/block/genhd.c

• Lines: 146
• Date: Sun Sep 9 12:00:55 2001
• Orig file: v2.4.9/linux/drivers/block/genhd.c
• Orig date: Wed Jul 25 17:10:19 2001

diff -u --recursive --new-file v2.4.9/linux/drivers/block/genhd.c linux/drivers/block/genhd.c
@@ -10,12 +10,137 @@
  *  (linux@arm.uk.linux.org)
  */
 
+/*
+ * TODO:  rip out the remaining init crap from this file  --hch
+ */
+
 #include <linux/config.h>
+#include <linux/module.h>
 #include <linux/fs.h>
 #include <linux/genhd.h>
 #include <linux/kernel.h>
 #include <linux/blk.h>
 #include <linux/init.h>
+#include <linux/spinlock.h>
+
+
+static rwlock_t gendisk_lock;
+
+/*
+ * Global kernel list of partitioning information.
+ *
+ * XXX: you should _never_ access this directly.
+ *	the only reason this is exported is source compatiblity.
+ */
+/*static*/ struct gendisk *gendisk_head;
+
+EXPORT_SYMBOL(gendisk_head);
+
+
+/**
+ * add_gendisk - add partitioning information to kernel list
+ * @gp: per-device partitioning information
+ *
+ * This function registers the partitioning information in @gp
+ * with the kernel.
+ */
+void
+add_gendisk(struct gendisk *gp)
+{
+	write_lock(&gendisk_lock);
+	gp->next = gendisk_head;
+	gendisk_head = gp;
+	write_unlock(&gendisk_lock);
+}
+
+EXPORT_SYMBOL(add_gendisk);
+
+
+/**
+ * del_gendisk - remove partitioning information from kernel list
+ * @gp: per-device partitioning information
+ *
+ * This function unregisters the partitioning information in @gp
+ * with the kernel.
+ */
+void
+del_gendisk(struct gendisk *gp)
+{
+	struct gendisk **gpp;
+
+	write_lock(&gendisk_lock);
+	for (gpp = &gendisk_head; *gpp; gpp = &((*gpp)->next))
+		if (*gpp == gp)
+			break;
+	if (*gpp)
+		*gpp = (*gpp)->next;
+	write_unlock(&gendisk_lock);
+}
+
+EXPORT_SYMBOL(del_gendisk);
+
+
+/**
+ * get_gendisk - get partitioning information for a given device
+ * @dev: device to get partitioning information for
+ *
+ * This function gets the structure containing partitioning
+ * information for the given device @dev.
+ */
+struct gendisk *
+get_gendisk(kdev_t dev)
+{
+	struct gendisk *gp = NULL;
+	int maj = MAJOR(dev);
+
+	read_lock(&gendisk_lock);
+	for (gp = gendisk_head; gp; gp = gp->next)
+		if (gp->major == maj)
+			break;
+	read_unlock(&gendisk_lock);
+
+	return gp;
+}
+
+EXPORT_SYMBOL(get_gendisk);
+
+
+#ifdef CONFIG_PROC_FS
+int
+get_partition_list(char *page, char **start, off_t offset, int count)
+{
+	struct gendisk *gp;
+	char buf[64];
+	int len, n;
+
+	len = sprintf(page, "major minor  #blocks  name\n\n");
+	read_lock(&gendisk_lock);
+	for (gp = gendisk_head; gp; gp = gp->next) {
+		for (n = 0; n < (gp->nr_real << gp->minor_shift); n++) {
+			if (gp->part[n].nr_sects == 0)
+				continue;
+
+			len += snprintf(page + len, 63,
+					"%4d  %4d %10d %s\n",
+					gp->major, n, gp->sizes[n],
+					disk_name(gp, n, buf));
+			if (len < offset)
+				offset -= len, len = 0;
+			else if (len >= offset + count)
+				goto out;
+		}
+	}
+
+out:
+	read_unlock(&gendisk_lock);
+	*start = page + offset;
+	len -= offset;
+	if (len < 0)
+		len = 0;
+	return len > count ? count : len;
+}
+#endif
+
 
 extern int blk_dev_init(void);
 #ifdef CONFIG_BLK_DEV_DAC960
@@ -33,6 +158,7 @@
 
 int __init device_init(void)
 {
+	rwlock_init(&gendisk_lock);
 	blk_dev_init();
 	sti();
 #ifdef CONFIG_I2O