resources: fix call to alignf() in allocate_resource()
Dominik Brodowski [Sun, 20 Dec 2009 09:50:02 +0000 (10:50 +0100)]
The second parameter to alignf() in allocate_resource() must
reflect what new resource is attempted to be allocated, else
functions like pcibios_align_resource() (at least on x86) or
pcmcia_align() can't work correctly.

Commit 1e5ad9679016275d422e36b12a98b0927d76f556 broke this by
setting the "new" resource until we're about to return success.
To keep the resource untouched when allocate_resource() fails,
a "tmp" resource is introduced.

Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Acked-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/resource.c

index dc15686..af96c1e 100644 (file)
@@ -308,37 +308,37 @@ static int find_resource(struct resource *root, struct resource *new,
                         void *alignf_data)
 {
        struct resource *this = root->child;
-       resource_size_t start, end;
+       struct resource tmp = *new;
 
-       start = root->start;
+       tmp.start = root->start;
        /*
         * Skip past an allocated resource that starts at 0, since the assignment
-        * of this->start - 1 to new->end below would cause an underflow.
+        * of this->start - 1 to tmp->end below would cause an underflow.
         */
        if (this && this->start == 0) {
-               start = this->end + 1;
+               tmp.start = this->end + 1;
                this = this->sibling;
        }
        for(;;) {
                if (this)
-                       end = this->start - 1;
+                       tmp.end = this->start - 1;
                else
-                       end = root->end;
-               if (start < min)
-                       start = min;
-               if (end > max)
-                       end = max;
-               start = ALIGN(start, align);
+                       tmp.end = root->end;
+               if (tmp.start < min)
+                       tmp.start = min;
+               if (tmp.end > max)
+                       tmp.end = max;
+               tmp.start = ALIGN(tmp.start, align);
                if (alignf)
-                       alignf(alignf_data, new, size, align);
-               if (start < end && end - start >= size - 1) {
-                       new->start = start;
-                       new->end = start + size - 1;
+                       alignf(alignf_data, &tmp, size, align);
+               if (tmp.start < tmp.end && tmp.end - tmp.start >= size - 1) {
+                       new->start = tmp.start;
+                       new->end = tmp.start + size - 1;
                        return 0;
                }
                if (!this)
                        break;
-               start = this->end + 1;
+               tmp.start = this->end + 1;
                this = this->sibling;
        }
        return -EBUSY;