pblk exposes a sysfs interface that represents its internal state. Part
of this state is the map bitmap for the current open line, which should
be protected by the line lock to avoid a race when freeing the line
metadata. Currently, it is not.
This patch makes sure that the line state is consistent and NULL
bitmap pointers are not dereferenced.
Signed-off-by: Javier González <javier@cnexlabs.com>
Signed-off-by: Matias Bjørling <mb@lightnvm.io>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
struct pblk_line *cur, *new = NULL;
unsigned int left_seblks;
- cur = l_mg->data_line;
new = l_mg->data_next;
if (!new)
goto out;
- l_mg->data_line = new;
spin_lock(&l_mg->free_lock);
+ cur = l_mg->data_line;
+ l_mg->data_line = new;
+
pblk_line_setup_metadata(new, l_mg, &pblk->lm);
spin_unlock(&l_mg->free_lock);
sec_in_line = l_mg->data_line->sec_in_line;
meta_weight = bitmap_weight(&l_mg->meta_bitmap,
PBLK_DATA_LINES);
- map_weight = bitmap_weight(l_mg->data_line->map_bitmap,
+
+ spin_lock(&l_mg->data_line->lock);
+ if (l_mg->data_line->map_bitmap)
+ map_weight = bitmap_weight(l_mg->data_line->map_bitmap,
lm->sec_per_line);
+ else
+ map_weight = 0;
+ spin_unlock(&l_mg->data_line->lock);
}
spin_unlock(&l_mg->free_lock);