From e5d670dcb7b336fb0c2fcff29ce87892e492e6b3 Mon Sep 17 00:00:00 2001 From: Ian Abbott Date: Fri, 8 Nov 2013 15:03:40 +0000 Subject: [PATCH] staging: comedi: use file->private_data in file operations Since the `struct comedi_device` should now be protected from being freed while an open file object is using it, use the `private_data` member of the `struct file` to point to it. Set it in `comedi_open()` and use it in the other file operation handlers instead of calling `comedi_dev_from_minor()` and checking the result. Signed-off-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/comedi_fops.c | 38 ++++++---------------------- 1 file changed, 8 insertions(+), 30 deletions(-) diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c index 37400e85c417..08aa93a1c87c 100644 --- a/drivers/staging/comedi/comedi_fops.c +++ b/drivers/staging/comedi/comedi_fops.c @@ -1828,12 +1828,9 @@ static long comedi_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { const unsigned minor = iminor(file_inode(file)); - struct comedi_device *dev = comedi_dev_from_minor(minor); + struct comedi_device *dev = file->private_data; int rc; - if (!dev) - return -ENODEV; - mutex_lock(&dev->mutex); /* Device config is special, because it must work on @@ -1964,7 +1961,7 @@ static struct vm_operations_struct comedi_vm_ops = { static int comedi_mmap(struct file *file, struct vm_area_struct *vma) { const unsigned minor = iminor(file_inode(file)); - struct comedi_device *dev = comedi_dev_from_minor(minor); + struct comedi_device *dev = file->private_data; struct comedi_subdevice *s; struct comedi_async *async; unsigned long start = vma->vm_start; @@ -1973,9 +1970,6 @@ static int comedi_mmap(struct file *file, struct vm_area_struct *vma) int i; int retval; - if (!dev) - return -ENODEV; - mutex_lock(&dev->mutex); if (!dev->attached) { @@ -2043,12 +2037,9 @@ static unsigned int comedi_poll(struct file *file, poll_table *wait) { unsigned int mask = 0; const unsigned minor = iminor(file_inode(file)); - struct comedi_device *dev = comedi_dev_from_minor(minor); + struct comedi_device *dev = file->private_data; struct comedi_subdevice *s; - if (!dev) - return -ENODEV; - mutex_lock(&dev->mutex); if (!dev->attached) { @@ -2088,14 +2079,11 @@ static ssize_t comedi_write(struct file *file, const char __user *buf, int n, m, count = 0, retval = 0; DECLARE_WAITQUEUE(wait, current); const unsigned minor = iminor(file_inode(file)); - struct comedi_device *dev = comedi_dev_from_minor(minor); + struct comedi_device *dev = file->private_data; bool on_wait_queue = false; bool attach_locked; unsigned int old_detach_count; - if (!dev) - return -ENODEV; - /* Protect against device detachment during operation. */ down_read(&dev->attach_lock); attach_locked = true; @@ -2227,14 +2215,11 @@ static ssize_t comedi_read(struct file *file, char __user *buf, size_t nbytes, int n, m, count = 0, retval = 0; DECLARE_WAITQUEUE(wait, current); const unsigned minor = iminor(file_inode(file)); - struct comedi_device *dev = comedi_dev_from_minor(minor); + struct comedi_device *dev = file->private_data; unsigned int old_detach_count; bool become_nonbusy = false; bool attach_locked; - if (!dev) - return -ENODEV; - /* Protect against device detachment during operation. */ down_read(&dev->attach_lock); attach_locked = true; @@ -2424,6 +2409,7 @@ ok: } dev->use_count++; + file->private_data = dev; rc = 0; out: @@ -2435,25 +2421,17 @@ out: static int comedi_fasync(int fd, struct file *file, int on) { - const unsigned minor = iminor(file_inode(file)); - struct comedi_device *dev = comedi_dev_from_minor(minor); - - if (!dev) - return -ENODEV; + struct comedi_device *dev = file->private_data; return fasync_helper(fd, file, on, &dev->async_queue); } static int comedi_close(struct inode *inode, struct file *file) { - const unsigned minor = iminor(inode); - struct comedi_device *dev = comedi_dev_from_minor(minor); + struct comedi_device *dev = file->private_data; struct comedi_subdevice *s = NULL; int i; - if (!dev) - return -ENODEV; - mutex_lock(&dev->mutex); if (dev->subdevices) { -- 2.20.1