diff options
| author |   Jason Gunthorpe <jgg@nvidia.com> | 2021-06-25 12:56:04 -0300 |
|---|---|---|
| committer |   Alex Williamson <alex.williamson@redhat.com> | 2021-06-28 08:52:15 -0600 |
| commit | 0dd1b7fc3e7d30802d5839f6bf8957023b437ad4 (patch) | |
| tree | 7ec72043a722cd983d6aba3b8586c7eb9370a8df /samples | |
| parent | vfio: use the new pci_dev_trylock() helper to simplify try lock (diff) | |
| download | linux-dev-0dd1b7fc3e7d30802d5839f6bf8957023b437ad4.tar.xz linux-dev-0dd1b7fc3e7d30802d5839f6bf8957023b437ad4.zip | |
vfio/mtty: Delete mdev_devices_list
Dan points out that an error case left things on this list. It is also
missing locking in available_instances_show().
Further study shows the list isn't needed at all, just store the total
ports in use in an atomic and delete the whole thing.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Fixes: 09177ac91921 ("vfio/mtty: Convert to use vfio_register_group_dev()")
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/0-v1-0bc56b362ca7+62-mtty_used_ports_jgg@nvidia.com
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Diffstat (limited to 'samples')
| -rw-r--r-- | samples/vfio-mdev/mtty.c | 24 |
1 files changed, 6 insertions, 18 deletions
diff --git a/samples/vfio-mdev/mtty.c b/samples/vfio-mdev/mtty.c index faf9b8e8873a..ffbaf07a17ea 100644 --- a/samples/vfio-mdev/mtty.c +++ b/samples/vfio-mdev/mtty.c @@ -144,8 +144,7 @@ struct mdev_state { int nr_ports; }; -static struct mutex mdev_list_lock; -static struct list_head mdev_devices_list; +static atomic_t mdev_used_ports; static const struct file_operations vd_fops = { .owner = THIS_MODULE, @@ -733,15 +732,13 @@ static int mtty_probe(struct mdev_device *mdev) mtty_create_config_space(mdev_state); - mutex_lock(&mdev_list_lock); - list_add(&mdev_state->next, &mdev_devices_list); - mutex_unlock(&mdev_list_lock); - ret = vfio_register_group_dev(&mdev_state->vdev); if (ret) { kfree(mdev_state); return ret; } + atomic_add(mdev_state->nr_ports, &mdev_used_ports); + dev_set_drvdata(&mdev->dev, mdev_state); return 0; } @@ -750,10 +747,8 @@ static void mtty_remove(struct mdev_device *mdev) { struct mdev_state *mdev_state = dev_get_drvdata(&mdev->dev); + atomic_sub(mdev_state->nr_ports, &mdev_used_ports); vfio_unregister_group_dev(&mdev_state->vdev); - mutex_lock(&mdev_list_lock); - list_del(&mdev_state->next); - mutex_unlock(&mdev_list_lock); kfree(mdev_state->vconfig); kfree(mdev_state); @@ -1274,14 +1269,10 @@ static ssize_t available_instances_show(struct mdev_type *mtype, struct mdev_type_attribute *attr, char *buf) { - struct mdev_state *mds; unsigned int ports = mtype_get_type_group_id(mtype) + 1; - int used = 0; - list_for_each_entry(mds, &mdev_devices_list, next) - used += mds->nr_ports; - - return sprintf(buf, "%d\n", (MAX_MTTYS - used)/ports); + return sprintf(buf, "%d\n", + (MAX_MTTYS - atomic_read(&mdev_used_ports)) / ports); } static MDEV_TYPE_ATTR_RO(available_instances); @@ -1395,9 +1386,6 @@ static int __init mtty_dev_init(void) ret = mdev_register_device(&mtty_dev.dev, &mdev_fops); if (ret) goto err_device; - - mutex_init(&mdev_list_lock); - INIT_LIST_HEAD(&mdev_devices_list); return 0; err_device: |