SIGIO-driven I/O with inotify queues

Add SIGIO-driven I/O for descriptors returned by inotify_init().  The thing
may be enabled by convenient fcntl (fd, F_SETFL, O_ASYNC) call.

Signed-off-by: Dmitry Antipov <antipov@dev.rtsoft.ru>
Cc: Robert Love <rlove@google.com>
Cc: John McCutchan <ttb@tentacle.dhs.org>
Cc: Michael Kerrisk <mtk-manpages@gmx.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Dmitry Antipov 2008-02-06 01:36:19 -08:00 committed by Linus Torvalds
parent 14e11e106b
commit bcfbf84d40
1 changed files with 14 additions and 0 deletions

View File

@ -79,6 +79,7 @@ struct inotify_device {
atomic_t count; /* reference count */
struct user_struct *user; /* user who opened this dev */
struct inotify_handle *ih; /* inotify handle */
struct fasync_struct *fa; /* async notification */
unsigned int queue_size; /* size of the queue (bytes) */
unsigned int event_count; /* number of pending events */
unsigned int max_events; /* maximum number of events */
@ -315,6 +316,7 @@ static void inotify_dev_queue_event(struct inotify_watch *w, u32 wd, u32 mask,
dev->queue_size += sizeof(struct inotify_event) + kevent->event.len;
list_add_tail(&kevent->list, &dev->events);
wake_up_interruptible(&dev->wq);
kill_fasync(&dev->fa, SIGIO, POLL_IN);
out:
mutex_unlock(&dev->ev_mutex);
@ -503,6 +505,13 @@ static ssize_t inotify_read(struct file *file, char __user *buf,
return ret;
}
static int inotify_fasync(int fd, struct file *file, int on)
{
struct inotify_device *dev = file->private_data;
return fasync_helper(fd, file, on, &dev->fa) >= 0 ? 0 : -EIO;
}
static int inotify_release(struct inode *ignored, struct file *file)
{
struct inotify_device *dev = file->private_data;
@ -515,6 +524,9 @@ static int inotify_release(struct inode *ignored, struct file *file)
inotify_dev_event_dequeue(dev);
mutex_unlock(&dev->ev_mutex);
if (file->f_flags & FASYNC)
inotify_fasync(-1, file, 0);
/* free this device: the put matching the get in inotify_init() */
put_inotify_dev(dev);
@ -543,6 +555,7 @@ static long inotify_ioctl(struct file *file, unsigned int cmd,
static const struct file_operations inotify_fops = {
.poll = inotify_poll,
.read = inotify_read,
.fasync = inotify_fasync,
.release = inotify_release,
.unlocked_ioctl = inotify_ioctl,
.compat_ioctl = inotify_ioctl,
@ -590,6 +603,7 @@ asmlinkage long sys_inotify_init(void)
goto out_free_dev;
}
dev->ih = ih;
dev->fa = NULL;
filp->f_op = &inotify_fops;
filp->f_path.mnt = mntget(inotify_mnt);