diff options
| -rw-r--r-- | drivers/s390/cio/chsc_sch.c | 20 |
1 files changed, 19 insertions, 1 deletions
diff --git a/drivers/s390/cio/chsc_sch.c b/drivers/s390/cio/chsc_sch.c index 190fc844d814..5fe9f8c4b4fb 100644 --- a/drivers/s390/cio/chsc_sch.c +++ b/drivers/s390/cio/chsc_sch.c @@ -847,9 +847,27 @@ static long chsc_ioctl(struct file *filp, unsigned int cmd, } } +static atomic_t chsc_ready_for_use = ATOMIC_INIT(1); + +static int chsc_open(struct inode *inode, struct file *file) +{ + if (!atomic_dec_and_test(&chsc_ready_for_use)) { + atomic_inc(&chsc_ready_for_use); + return -EBUSY; + } + return nonseekable_open(inode, file); +} + +static int chsc_release(struct inode *inode, struct file *filp) +{ + atomic_inc(&chsc_ready_for_use); + return 0; +} + static const struct file_operations chsc_fops = { .owner = THIS_MODULE, - .open = nonseekable_open, + .open = chsc_open, + .release = chsc_release, .unlocked_ioctl = chsc_ioctl, .compat_ioctl = chsc_ioctl, .llseek = no_llseek, |