diff options
| -rw-r--r-- | drivers/infiniband/core/uverbs_main.c | 20 |
1 files changed, 13 insertions, 7 deletions
diff --git a/drivers/infiniband/core/uverbs_main.c b/drivers/infiniband/core/uverbs_main.c index 8ede1e475ce..fdfcf7910d9 100644 --- a/drivers/infiniband/core/uverbs_main.c +++ b/drivers/infiniband/core/uverbs_main.c @@ -45,7 +45,6 @@ #include <linux/file.h> #include <linux/mount.h> #include <linux/cdev.h> -#include <linux/smp_lock.h> #include <asm/uaccess.h> @@ -611,23 +610,32 @@ static int ib_uverbs_mmap(struct file *filp, struct vm_area_struct *vma) return file->device->ib_dev->mmap(file->ucontext, vma); } +/* + * ib_uverbs_open() does not need the BKL: + * + * - dev_table[] accesses are protected by map_lock, the + * ib_uverbs_device structures are properly reference counted, and + * everything else is purely local to the file being created, so + * races against other open calls are not a problem; + * - there is no ioctl method to race against; + * - the device is added to dev_table[] as the last part of module + * initialization, the open method will either immediately run + * -ENXIO, or all required initialization will be done. + */ static int ib_uverbs_open(struct inode *inode, struct file *filp) { struct ib_uverbs_device *dev; struct ib_uverbs_file *file; int ret; - lock_kernel(); spin_lock(&map_lock); dev = dev_table[iminor(inode) - IB_UVERBS_BASE_MINOR]; if (dev) kref_get(&dev->ref); spin_unlock(&map_lock); - if (!dev) { - unlock_kernel(); + if (!dev) return -ENXIO; - } if (!try_module_get(dev->ib_dev->owner)) { ret = -ENODEV; @@ -648,7 +656,6 @@ static int ib_uverbs_open(struct inode *inode, struct file *filp) filp->private_data = file; - unlock_kernel(); return 0; err_module: @@ -656,7 +663,6 @@ err_module: err: kref_put(&dev->ref, ib_uverbs_release_dev); - unlock_kernel(); return ret; } |