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Commit d33b6fba authored by Matthew Wilcox's avatar Matthew Wilcox Committed by Greg Kroah-Hartman
Browse files

Resources: insert identical resources above existing resources 



If you have two resources which aree exactly the same size,
insert_resource() currently inserts the new one below the existing one. 
This is wrong because there's no way to insert a resource of the same size
above an existing one.

I took this opportunity to rewrite the initial loop to be a for-loop
instead of a goto-loop and fix the documentation.

Signed-off-by: default avatarMatthew Wilcox <matthew@wil.cx>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent b2782408

kernel/resource.c

+16 −16
Original line number Diff line number Diff line
@@ -344,12 +344,11 @@ EXPORT_SYMBOL(allocate_resource); 
 *

 * Returns 0 on success, -EBUSY if the resource can't be inserted.

 *

 * This function is equivalent of request_resource when no conflict

 * This function is equivalent to request_resource when no conflict

 * happens. If a conflict happens, and the conflicting resources

 * entirely fit within the range of the new resource, then the new

 * resource is inserted and the conflicting resources become childs of

 * the new resource.  Otherwise the new resource becomes the child of

 * the conflicting resource

 * resource is inserted and the conflicting resources become children of

 * the new resource.

 */

int insert_resource(struct resource *parent, struct resource *new)

{
@@ -357,7 +356,8 @@ int insert_resource(struct resource *parent, struct resource *new) 
	struct resource *first, *next;



	write_lock(&resource_lock);

 begin:



	for (;; parent = first) {

	 	result = 0;

		first = __request_resource(parent, new);

		if (!first)
@@ -367,10 +367,10 @@ int insert_resource(struct resource *parent, struct resource *new) 
		if (first == parent)

			goto out;



	/* Resource fully contained by the clashing resource? Recurse into it */

	if (first->start <= new->start && first->end >= new->end) {

		parent = first;

		goto begin;

		if ((first->start > new->start) || (first->end < new->end))

			break;

		if ((first->start == new->start) && (first->end == new->end))

			break;

	}



	for (next = first; ; next = next->sibling) {