On Sun, 13 Sep 2015, Julia Lawall wrote: > Remove unneeded NULL test. > > The semantic patch that makes this change is as follows: > (http://coccinelle.lip6.fr/) > > // <smpl> > @@ expression x; @@ > -if (x != NULL) > \(kmem_cache_destroy\|mempool_destroy\|dma_pool_destroy\)(x); > // </smpl> > > Signed-off-by: Julia Lawall <Julia.Lawall@xxxxxxx> > > --- > drivers/md/dm-bufio.c | 3 +-- > drivers/md/dm-cache-target.c | 3 +-- > drivers/md/dm-crypt.c | 6 ++---- > drivers/md/dm-io.c | 3 +-- > drivers/md/dm-log-userspace-base.c | 3 +-- > drivers/md/dm-region-hash.c | 4 +--- > drivers/md/dm.c | 13 ++++--------- > 7 files changed, 11 insertions(+), 24 deletions(-) > > diff --git a/drivers/md/dm-bufio.c b/drivers/md/dm-bufio.c > index 83cc52e..8ad39b6 100644 > --- a/drivers/md/dm-bufio.c > +++ b/drivers/md/dm-bufio.c > @@ -1864,8 +1864,7 @@ static void __exit dm_bufio_exit(void) > for (i = 0; i < ARRAY_SIZE(dm_bufio_caches); i++) { > struct kmem_cache *kc = dm_bufio_caches[i]; > > - if (kc) > - kmem_cache_destroy(kc); > + kmem_cache_destroy(kc); > } The variable here can be NULL. I don't know how did you conclude that it cannot. It seems that you didn't test the patch, if you did, you'd hit NULL pointer dereference here. > for (i = 0; i < ARRAY_SIZE(dm_bufio_cache_names); i++) > diff --git a/drivers/md/dm.c b/drivers/md/dm.c > index 6264781..163de31 100644 > --- a/drivers/md/dm.c > +++ b/drivers/md/dm.c > @@ -2220,10 +2220,8 @@ static void cleanup_mapped_device(struct mapped_device *md) > destroy_workqueue(md->wq); > if (md->kworker_task) > kthread_stop(md->kworker_task); > - if (md->io_pool) > - mempool_destroy(md->io_pool); > - if (md->rq_pool) > - mempool_destroy(md->rq_pool); > + mempool_destroy(md->io_pool); > + mempool_destroy(md->rq_pool); Likewise, these variables can be NULL. > if (md->bs) > bioset_free(md->bs); > > @@ -3508,11 +3506,8 @@ void dm_free_md_mempools(struct dm_md_mempools *pools) > if (!pools) > return; > > - if (pools->io_pool) > - mempool_destroy(pools->io_pool); > - > - if (pools->rq_pool) > - mempool_destroy(pools->rq_pool); > + mempool_destroy(pools->io_pool); > + mempool_destroy(pools->rq_pool); > > if (pools->bs) > bioset_free(pools->bs); Likewise, it can be NULL, see for example this code path: pools->io_pool = mempool_create_slab_pool(pool_size, cachep); if (!pools->io_pool) goto out; out: dm_free_md_mempools(pools); dm_free_md_mempools: if (pools->io_pool) mempool_destroy(pools->io_pool); It seems that you set up the cocinelle tool incorrectly, so that it produces many bogus suggestions. Mikulas > diff --git a/drivers/md/dm-log-userspace-base.c b/drivers/md/dm-log-userspace-base.c > index 058256d..53b7b06 100644 > --- a/drivers/md/dm-log-userspace-base.c > +++ b/drivers/md/dm-log-userspace-base.c > @@ -313,8 +313,7 @@ static int userspace_ctr(struct dm_dirty_log *log, struct dm_target *ti, > out: > kfree(devices_rdata); > if (r) { > - if (lc->flush_entry_pool) > - mempool_destroy(lc->flush_entry_pool); > + mempool_destroy(lc->flush_entry_pool); > kfree(lc); > kfree(ctr_str); > } else { > diff --git a/drivers/md/dm-io.c b/drivers/md/dm-io.c > index 6f8e83b..81c5e1a 100644 > --- a/drivers/md/dm-io.c > +++ b/drivers/md/dm-io.c > @@ -65,8 +65,7 @@ struct dm_io_client *dm_io_client_create(void) > return client; > > bad: > - if (client->pool) > - mempool_destroy(client->pool); > + mempool_destroy(client->pool); > kfree(client); > return ERR_PTR(-ENOMEM); > } > diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c > index dd90d12..2fd4c82 100644 > --- a/drivers/md/dm-cache-target.c > +++ b/drivers/md/dm-cache-target.c > @@ -2309,8 +2309,7 @@ static void destroy(struct cache *cache) > { > unsigned i; > > - if (cache->migration_pool) > - mempool_destroy(cache->migration_pool); > + mempool_destroy(cache->migration_pool); > > if (cache->all_io_ds) > dm_deferred_set_destroy(cache->all_io_ds); > diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c > index d60c88d..cf91a96 100644 > --- a/drivers/md/dm-crypt.c > +++ b/drivers/md/dm-crypt.c > @@ -1543,10 +1543,8 @@ static void crypt_dtr(struct dm_target *ti) > if (cc->bs) > bioset_free(cc->bs); > > - if (cc->page_pool) > - mempool_destroy(cc->page_pool); > - if (cc->req_pool) > - mempool_destroy(cc->req_pool); > + mempool_destroy(cc->page_pool); > + mempool_destroy(cc->req_pool); > > if (cc->iv_gen_ops && cc->iv_gen_ops->dtr) > cc->iv_gen_ops->dtr(cc); > diff --git a/drivers/md/dm-region-hash.c b/drivers/md/dm-region-hash.c > index b929fd5..f3d608b 100644 > --- a/drivers/md/dm-region-hash.c > +++ b/drivers/md/dm-region-hash.c > @@ -249,9 +249,7 @@ void dm_region_hash_destroy(struct dm_region_hash *rh) > if (rh->log) > dm_dirty_log_destroy(rh->log); > > - if (rh->region_pool) > - mempool_destroy(rh->region_pool); > - > + mempool_destroy(rh->region_pool); > vfree(rh->buckets); > kfree(rh); > } > > -- > dm-devel mailing list > dm-devel@xxxxxxxxxx > https://www.redhat.com/mailman/listinfo/dm-devel > -- To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
