diff options
| author | Javier González <javier@javigon.com> | 2018-10-09 13:12:07 +0200 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2018-10-09 08:25:08 -0600 |
| commit | 44cdbdc657b23f75736eca3e88b781f009104363 (patch) | |
| tree | db6d14e7d352ee04ff6f7ec6ea20a34fdf990d8d | |
| parent | 02a1520d56d11982ccc8eab56e4c562fd05d2c86 (diff) | |
lightnvm: pblk: fix race on sysfs line state
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>
| -rw-r--r-- | drivers/lightnvm/pblk-core.c | 5 | ||||
| -rw-r--r-- | drivers/lightnvm/pblk-sysfs.c | 8 |
2 files changed, 10 insertions, 3 deletions
diff --git a/drivers/lightnvm/pblk-core.c b/drivers/lightnvm/pblk-core.c index 4045a9b1ee74..6944aac43b01 100644 --- a/drivers/lightnvm/pblk-core.c +++ b/drivers/lightnvm/pblk-core.c @@ -1611,13 +1611,14 @@ struct pblk_line *pblk_line_replace_data(struct pblk *pblk) 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); diff --git a/drivers/lightnvm/pblk-sysfs.c b/drivers/lightnvm/pblk-sysfs.c index cba83ac43e62..2d2818155aa8 100644 --- a/drivers/lightnvm/pblk-sysfs.c +++ b/drivers/lightnvm/pblk-sysfs.c @@ -263,8 +263,14 @@ static ssize_t pblk_sysfs_lines(struct pblk *pblk, char *page) 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); |