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

[ 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>

diff --git a/drivers/lightnvm/pblk-gc.c b/drivers/lightnvm/pblk-gc.c
index 6090d28f7995a51f4d5972bf965457f1388874f7..d6bae085e1d27504a6402c31be5411a2224faa38 100644 (file)
--- a/drivers/lightnvm/pblk-gc.c
+++ b/drivers/lightnvm/pblk-gc.c
@@ -486,10 +486,10 @@ void pblk_gc_should_start(struct pblk *pblk)
 {
        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)

diff --git a/drivers/lightnvm/pblk-init.c b/drivers/lightnvm/pblk-init.c
index 1b0f61233c216ac7f262ff58aee2d4a0bdc76ad6..1a01f201e9e75b932f1e53606c77b1be1a044ebc 100644 (file)
--- a/drivers/lightnvm/pblk-init.c
+++ b/drivers/lightnvm/pblk-init.c
@@ -923,6 +923,7 @@ static void *pblk_init(struct nvm_tgt_dev *dev, struct gendisk *tdisk,
        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);