lightnvm: pblk: fix erase counters on error fail

When block erases fail, these blocks are marked bad. The number of valid
blocks in the line was not updated, which could cause an infinite loop
on the erase path.

Fix this atomic counter and, in order to avoid taking an irq lock on the
interrupt context, make the erase counters atomic too.

Also, in the case that a significant number of blocks become bad in a
line, the result is the double shared metadata buffer (emeta) to stop
the pipeline until all metadata is flushed to the media. Increase the
number of metadata lines from 2 to 4 to avoid this case.

Fixes: a4bd217b4326 "lightnvm: physical block device (pblk) target"

Signed-off-by: Javier González <javier@cnexlabs.com>
Reviewed-by: Matias Bjørling <matias@cnexlabs.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/drivers/lightnvm/pblk-map.c b/drivers/lightnvm/pblk-map.c
index 3f8bab4c4d5c..17c16955284d 100644
--- a/drivers/lightnvm/pblk-map.c
+++ b/drivers/lightnvm/pblk-map.c
@@ -110,7 +110,7 @@ void pblk_map_erase_rq(struct pblk *pblk, struct nvm_rq *rqd,
 				continue;
 
 			set_bit(erase_lun, e_line->erase_bitmap);
-			e_line->left_eblks--;
+			atomic_dec(&e_line->left_eblks);
 			*erase_ppa = rqd->ppa_list[i];
 			erase_ppa->g.blk = e_line->id;
 
@@ -129,7 +129,7 @@ void pblk_map_erase_rq(struct pblk *pblk, struct nvm_rq *rqd,
 			return;
 
 		set_bit(i, e_line->erase_bitmap);
-		e_line->left_eblks--;
+		atomic_dec(&e_line->left_eblks);
 		*erase_ppa = pblk->luns[i].bppa; /* set ch and lun */
 		erase_ppa->g.blk = e_line->id;
 	}