Patch "lightnvm: pblk: prevent gc kicks when gc is not operational" has been added to the 4.14-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    lightnvm: pblk: prevent gc kicks when gc is not operational

to the 4.14-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     lightnvm-pblk-prevent-gc-kicks-when-gc-is-not-operational.patch
and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Mon Dec 18 13:29:00 CET 2017
From: Hans Holmberg <hans.holmberg@cnexlabs.com>
Date: Fri, 13 Oct 2017 14:46:34 +0200
Subject: lightnvm: pblk: prevent gc kicks when gc is not operational

From: Hans Holmberg <hans.holmberg@cnexlabs.com>


[ Upstream commit 3e3a5b8ebd5d3b1d68facc58b0674a2564653222 ]

GC can be kicked after it has been shut down when closing the last
line during exit, resulting in accesses to freed structures.

Make sure that GC is not triggered while it is not operational.
Also make sure that GC won't be re-activated during exit when
running on another processor by using timer_del_sync.

Signed-off-by: Hans Holmberg <hans.holmberg@cnexlabs.com>
Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/lightnvm/pblk-gc.c   |    9 +++++----
 drivers/lightnvm/pblk-init.c |    1 +
 2 files changed, 6 insertions(+), 4 deletions(-)

--- a/drivers/lightnvm/pblk-gc.c
+++ b/drivers/lightnvm/pblk-gc.c
@@ -486,10 +486,10 @@ void pblk_gc_should_start(struct pblk *p
 {
 	struct pblk_gc *gc = &pblk->gc;
 
-	if (gc->gc_enabled && !gc->gc_active)
+	if (gc->gc_enabled && !gc->gc_active) {
 		pblk_gc_start(pblk);
-
-	pblk_gc_kick(pblk);
+		pblk_gc_kick(pblk);
+	}
 }
 
 /*
@@ -628,7 +628,8 @@ void pblk_gc_exit(struct pblk *pblk)
 	flush_workqueue(gc->gc_reader_wq);
 	flush_workqueue(gc->gc_line_reader_wq);
 
-	del_timer(&gc->gc_timer);
+	gc->gc_enabled = 0;
+	del_timer_sync(&gc->gc_timer);
 	pblk_gc_stop(pblk, 1);
 
 	if (gc->gc_ts)
--- a/drivers/lightnvm/pblk-init.c
+++ b/drivers/lightnvm/pblk-init.c
@@ -923,6 +923,7 @@ static void *pblk_init(struct nvm_tgt_de
 	pblk->dev = dev;
 	pblk->disk = tdisk;
 	pblk->state = PBLK_STATE_RUNNING;
+	pblk->gc.gc_enabled = 0;
 
 	spin_lock_init(&pblk->trans_lock);
 	spin_lock_init(&pblk->lock);


Patches currently in stable-queue which might be from hans.holmberg@cnexlabs.com are

queue-4.14/lightnvm-pblk-prevent-gc-kicks-when-gc-is-not-operational.patch