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

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>

diff --git a/drivers/lightnvm/pblk-gc.c b/drivers/lightnvm/pblk-gc.c
index 7b103bce58bf73cee510913ac35811107b3a1f8b..81efac18ff571fb33c373112e35e42d621eeac3b 100644 (file)
--- a/drivers/lightnvm/pblk-gc.c
+++ b/drivers/lightnvm/pblk-gc.c
@@ -478,10 +478,10 @@ 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);
+       }
 }
 
 /*
@@ -620,7 +620,8 @@ 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 2e599738372dd5668a55f28f0cf8a91466427dad..27eb430958ff67b616447e68246172844ca2047e 100644 (file)
--- a/drivers/lightnvm/pblk-init.c
+++ b/drivers/lightnvm/pblk-init.c
@@ -931,6 +931,7 @@ 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);