On Sat, Oct 12, 2024 at 02:54:01PM -0400, Kent Overstreet wrote:
On Sat, Oct 12, 2024 at 07:29:42AM GMT, Sasha Levin wrote:
From: Kent Overstreet kent.overstreet@linux.dev
[ Upstream commit b2f11c6f3e1fc60742673b8675c95b78447f3dae ]
If we need to increase the tree depth, allocate a new node, and then race with another thread that increased the tree depth before us, we'll still have a preallocated node that might be used later.
If we then use that node for a new non-root node, it'll still have a pointer to the old root instead of being zeroed - fix this by zeroing it in the cmpxchg failure path.
Signed-off-by: Kent Overstreet kent.overstreet@linux.dev Signed-off-by: Sasha Levin sashal@kernel.org
there wasn't any need to backport this, bcachefs is the only thing that uses genradix in multithreaded mode
Will do, thanks!