From 001bea73e70efdf48a9e00188cf302f6b6aed2bf Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 18 Aug 2015 14:55:11 -0700 Subject: [PATCH] blkcg: replace blkcg_policy->pd_size with ->pd_alloc/free_fn() methods A blkg (blkcg_gq) represents the relationship between a cgroup and request_queue. Each active policy has a pd (blkg_policy_data) on each blkg. The pd's were allocated by blkcg core and each policy could request to allocate extra space at the end by setting blkcg_policy->pd_size larger than the size of pd. This is a bit unusual but was done this way mostly to simplify error handling and all the existing use cases could be handled this way; however, this is becoming too restrictive now that percpu memory can be allocated without blocking. This introduces two new mandatory blkcg_policy methods - pd_alloc_fn() and pd_free_fn() - which are used to allocate and release pd for a given policy. As pd allocation is now done from policy side, it can simply allocate a larger area which embeds pd at the beginning. This change makes ->pd_size pointless. Removed. Signed-off-by: Tejun Heo Cc: Vivek Goyal Signed-off-by: Jens Axboe --- Reading git-format-patch failed