Commit 82cfb90b authored Sep 18, 2014 by Lai Jiangshan Committed by Jens Axboe Sep 18, 2014

drbd: compute the end before rb_insert_augmented()



Commit 98683650 "Merge branch 'drbd-8.4_ed6' into
for-3.8-drivers-drbd-8.4_ed6" switches to the new augment API, but the
new API requires that the tree is augmented before rb_insert_augmented()
is called, which is missing.

So we add the augment-code to drbd_insert_interval() when it travels the
tree up to down before rb_insert_augmented().  See the example in
include/linux/interval_tree_generic.h or Documentation/rbtree.txt.

drbd_insert_interval() may cancel the insertion when traveling, in this
case, the just added augment-code does nothing before cancel since the
@this node is already in the subtrees in this case.

CC: Michel Lespinasse <walken@google.com>
CC: stable@kernel.org # v3.10+
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Andreas Gruenbacher <agruen@linbit.com>
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

parent 590001c2

drivers/block/drbd/drbd_interval.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -79,6 +79,7 @@ bool
		drbd_insert_interval(struct rb_root root, struct drbd_interval this)
		{
		struct rb_node *new = &root->rb_node, parent = NULL;
		sector_t this_end = this->sector + (this->size >> 9);

		BUG_ON(!IS_ALIGNED(this->size, 512));

		@@ -87,6 +88,8 @@ drbd_insert_interval(struct rb_root root, struct drbd_interval this)
		rb_entry(*new, struct drbd_interval, rb);

		parent = *new;
		if (here->end < this_end)
		here->end = this_end;
		if (this->sector < here->sector)
		new = &(*new)->rb_left;
		else if (this->sector > here->sector)
		@@ -99,6 +102,7 @@ drbd_insert_interval(struct rb_root root, struct drbd_interval this)
		return false;
		}

		this->end = this_end;
		rb_link_node(&this->rb, parent, new);
		rb_insert_augmented(&this->rb, root, &augment_callbacks);
		return true;