diff options
Diffstat (limited to 'drivers/md/dm-ioctl.c')
| -rw-r--r-- | drivers/md/dm-ioctl.c | 49 |
1 files changed, 48 insertions, 1 deletions
diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c index 41852ae287a5..6b65a538d91d 100644 --- a/drivers/md/dm-ioctl.c +++ b/drivers/md/dm-ioctl.c @@ -23,6 +23,14 @@ #define DM_MSG_PREFIX "ioctl" #define DM_DRIVER_EMAIL "dm-devel@redhat.com" +struct dm_file { + /* + * poll will wait until the global event number is greater than + * this value. + */ + unsigned global_event_nr; +}; + /*----------------------------------------------------------------- * The ioctl interface needs to be able to look up devices by * name or uuid. @@ -1868,8 +1876,47 @@ static long dm_compat_ctl_ioctl(struct file *file, uint command, ulong u) #define dm_compat_ctl_ioctl NULL #endif +static int dm_open(struct inode *inode, struct file *filp) +{ + int r; + struct dm_file *priv; + + r = nonseekable_open(inode, filp); + if (unlikely(r)) + return r; + + priv = filp->private_data = kmalloc(sizeof(struct dm_file), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + priv->global_event_nr = atomic_read(&dm_global_event_nr); + + return 0; +} + +static int dm_release(struct inode *inode, struct file *filp) +{ + kfree(filp->private_data); + return 0; +} + +static unsigned dm_poll(struct file *filp, poll_table *wait) +{ + struct dm_file *priv = filp->private_data; + unsigned mask = 0; + + poll_wait(filp, &dm_global_eventq, wait); + + if ((int)(atomic_read(&dm_global_event_nr) - priv->global_event_nr) > 0) + mask |= POLLIN; + + return mask; +} + static const struct file_operations _ctl_fops = { - .open = nonseekable_open, + .open = dm_open, + .release = dm_release, + .poll = dm_poll, .unlocked_ioctl = dm_ctl_ioctl, .compat_ioctl = dm_compat_ctl_ioctl, .owner = THIS_MODULE, |