Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus

[sfrench/cifs-2.6.git] / drivers / staging / comedi / comedi_fops.c

diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c
index aced00e5cd107ae03b7c5e4edc81f1135aa711cc..aeb2c00875cd2110117afae796edb95748134e39 100644 (file)
--- a/drivers/staging/comedi/comedi_fops.c
+++ b/drivers/staging/comedi/comedi_fops.c
@@ -83,7 +83,7 @@ static int do_subdinfo_ioctl(struct comedi_device *dev,
 static int do_chaninfo_ioctl(struct comedi_device *dev,
                             struct comedi_chaninfo __user *arg);
 static int do_bufinfo_ioctl(struct comedi_device *dev,
-                           struct comedi_bufinfo __user *arg);
+                           struct comedi_bufinfo __user *arg, void *file);
 static int do_cmd_ioctl(struct comedi_device *dev,
                        struct comedi_cmd __user *arg, void *file);
 static int do_lock_ioctl(struct comedi_device *dev, unsigned int arg,
@@ -169,7 +169,8 @@ static long comedi_unlocked_ioctl(struct file *file, unsigned int cmd,
                break;
        case COMEDI_BUFINFO:
                rc = do_bufinfo_ioctl(dev,
-                                     (struct comedi_bufinfo __user *)arg);
+                                     (struct comedi_bufinfo __user *)arg,
+                                     file);
                break;
        case COMEDI_LOCK:
                rc = do_lock_ioctl(dev, arg, file);
@@ -563,7 +564,7 @@ static int do_chaninfo_ioctl(struct comedi_device *dev,
 
   */
 static int do_bufinfo_ioctl(struct comedi_device *dev,
-                           struct comedi_bufinfo __user *arg)
+                           struct comedi_bufinfo __user *arg, void *file)
 {
        struct comedi_bufinfo bi;
        struct comedi_subdevice *s;
@@ -576,6 +577,10 @@ static int do_bufinfo_ioctl(struct comedi_device *dev,
                return -EINVAL;
 
        s = dev->subdevices + bi.subdevice;
+
+       if (s->lock && s->lock != file)
+               return -EACCES;
+
        async = s->async;
 
        if (!async) {
@@ -584,8 +589,17 @@ static int do_bufinfo_ioctl(struct comedi_device *dev,
                bi.buf_read_ptr = 0;
                bi.buf_write_count = 0;
                bi.buf_read_count = 0;
+               bi.bytes_read = 0;
+               bi.bytes_written = 0;
                goto copyback;
        }
+       if (!s->busy) {
+               bi.bytes_read = 0;
+               bi.bytes_written = 0;
+               goto copyback_position;
+       }
+       if (s->busy != file)
+               return -EACCES;
 
        if (bi.bytes_read && (s->subdev_flags & SDF_CMD_READ)) {
                bi.bytes_read = comedi_buf_read_alloc(async, bi.bytes_read);
@@ -604,6 +618,7 @@ static int do_bufinfo_ioctl(struct comedi_device *dev,
                comedi_buf_write_free(async, bi.bytes_written);
        }
 
+copyback_position:
        bi.buf_write_count = async->buf_write_count;
        bi.buf_write_ptr = async->buf_write_ptr;
        bi.buf_read_count = async->buf_read_count;
@@ -1576,6 +1591,19 @@ static ssize_t comedi_write(struct file *file, const char __user *buf,
        while (nbytes > 0 && !retval) {
                set_current_state(TASK_INTERRUPTIBLE);
 
+               if (!(comedi_get_subdevice_runflags(s) & SRF_RUNNING)) {
+                       if (count == 0) {
+                               if (comedi_get_subdevice_runflags(s) &
+                                       SRF_ERROR) {
+                                       retval = -EPIPE;
+                               } else {
+                                       retval = 0;
+                               }
+                               do_become_nonbusy(dev, s);
+                       }
+                       break;
+               }
+
                n = nbytes;
 
                m = n;
@@ -1588,16 +1616,6 @@ static ssize_t comedi_write(struct file *file, const char __user *buf,
                        n = m;
 
                if (n == 0) {
-                       if (!(comedi_get_subdevice_runflags(s) & SRF_RUNNING)) {
-                               if (comedi_get_subdevice_runflags(s) &
-                                   SRF_ERROR) {
-                                       retval = -EPIPE;
-                               } else {
-                                       retval = 0;
-                               }
-                               do_become_nonbusy(dev, s);
-                               break;
-                       }
                        if (file->f_flags & O_NONBLOCK) {
                                retval = -EAGAIN;
                                break;