From: NeilBrown Date: Wed, 20 May 2015 05:05:09 +0000 (+1000) Subject: md/bitmap: remove rcu annotation from pointer arithmetic. X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=8532e3439087de69bb1b71fd6be2baa6fc196a55;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git md/bitmap: remove rcu annotation from pointer arithmetic. Evaluating "&mddev->disks" is simple pointer arithmetic, so it does not need 'rcu' annotations - no dereferencing is happening. Also enhance the comment to explain that 'rdev' in that case is not actually a pointer to an rdev. Reported-by: Patrick Marlier Signed-off-by: NeilBrown --- diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c index 2bc56e2a3526..135a0907e9de 100644 --- a/drivers/md/bitmap.c +++ b/drivers/md/bitmap.c @@ -177,11 +177,16 @@ static struct md_rdev *next_active_rdev(struct md_rdev *rdev, struct mddev *mdde * nr_pending is 0 and In_sync is clear, the entries we return will * still be in the same position on the list when we re-enter * list_for_each_entry_continue_rcu. + * + * Note that if entered with 'rdev == NULL' to start at the + * beginning, we temporarily assign 'rdev' to an address which + * isn't really an rdev, but which can be used by + * list_for_each_entry_continue_rcu() to find the first entry. */ rcu_read_lock(); if (rdev == NULL) /* start at the beginning */ - rdev = list_entry_rcu(&mddev->disks, struct md_rdev, same_set); + rdev = list_entry(&mddev->disks, struct md_rdev, same_set); else { /* release the previous rdev and start from there. */ rdev_dec_pending(rdev, mddev);