#include <asm/kmap_types.h>
#include <asm/uaccess.h>
+#ifdef CONFIG_EPOLL
+#include <linux/poll.h>
+#include <linux/anon_inodes.h>
+#endif
+
#if DEBUG > 1
#define dprintk printk
#else
if (waitqueue_active(&ctx->wait))
wake_up(&ctx->wait);
+#ifdef CONFIG_EPOLL
+ if (ctx->file && waitqueue_active(&ctx->poll_wait))
+ wake_up(&ctx->poll_wait);
+#endif
+
spin_unlock_irqrestore(&ctx->ctx_lock, flags);
return ret;
}
/* aio_read_evt
* Pull an event off of the ioctx's event ring. Returns the number of
* events fetched (0 or 1 ;-)
+ * If ent parameter is 0, just returns the number of events that would
+ * be fetched.
* FIXME: make this use cmpxchg.
* TODO: make the ringbuffer user mmap()able (requires FIXME).
*/
head = ring->head % info->nr;
if (head != ring->tail) {
- struct io_event *evp = aio_ring_event(info, head, KM_USER1);
- *ent = *evp;
- head = (head + 1) % info->nr;
- smp_mb(); /* finish reading the event before updatng the head */
- ring->head = head;
- ret = 1;
- put_aio_ring_event(evp, KM_USER1);
+ if (ent) { /* event requested */
+ struct io_event *evp =
+ aio_ring_event(info, head, KM_USER1);
+ *ent = *evp;
+ head = (head + 1) % info->nr;
+ /* finish reading the event before updatng the head */
+ smp_mb();
+ ring->head = head;
+ ret = 1;
+ put_aio_ring_event(evp, KM_USER1);
+ } else /* only need to know availability */
+ ret = 1;
}
spin_unlock(&info->ring_lock);
aio_cancel_all(ioctx);
wait_for_all_aios(ioctx);
+#ifdef CONFIG_EPOLL
+ /* forget the poll file, but it's up to the user to close it */
+ if (ioctx->file) {
+ fput(ioctx->file);
+ ioctx->file->private_data = 0;
+ ioctx->file = 0;
+ }
+#endif
/*
* Wake up any waiters. The setting of ctx->dead must be seen
put_ioctx(ioctx); /* once for the lookup */
}
+#ifdef CONFIG_EPOLL
+
+static int aio_queue_fd_close(struct inode *inode, struct file *file)
+{
+ struct kioctx *ioctx = file->private_data;
+ if (ioctx) {
+ file->private_data = 0;
+ spin_lock_irq(&ioctx->ctx_lock);
+ ioctx->file = 0;
+ spin_unlock_irq(&ioctx->ctx_lock);
+ fput(file);
+ }
+ return 0;
+}
+
+static unsigned int aio_queue_fd_poll(struct file *file, poll_table *wait)
+{ unsigned int pollflags = 0;
+ struct kioctx *ioctx = file->private_data;
+
+ if (ioctx) {
+
+ spin_lock_irq(&ioctx->ctx_lock);
+ /* Insert inside our poll wait queue */
+ poll_wait(file, &ioctx->poll_wait, wait);
+
+ /* Check our condition */
+ if (aio_read_evt(ioctx, 0))
+ pollflags = POLLIN | POLLRDNORM;
+ spin_unlock_irq(&ioctx->ctx_lock);
+ }
+
+ return pollflags;
+}
+
+static const struct file_operations aioq_fops = {
+ .release = aio_queue_fd_close,
+ .poll = aio_queue_fd_poll
+};
+
+/* make_aio_fd:
+ * Create a file descriptor that can be used to poll the event queue.
+ * Based on the excellent epoll code.
+ */
+
+static int make_aio_fd(struct kioctx *ioctx)
+{
+ int fd;
+ struct file *file;
+
+ fd = anon_inode_getfd("[aioq]", &aioq_fops, ioctx, 0);
+ if (fd < 0)
+ return fd;
+
+ /* associate the file with the IO context */
+ file = fget(fd);
+ if (!file)
+ return -EBADF;
+ file->private_data = ioctx;
+ ioctx->file = file;
+ init_waitqueue_head(&ioctx->poll_wait);
+ return fd;
+}
+#endif
+
/* sys_io_setup:
* Create an aio_context capable of receiving at least nr_events.
* ctxp must not point to an aio_context that already exists, and
* resources are available. May fail with -EFAULT if an invalid
* pointer is passed for ctxp. Will fail with -ENOSYS if not
* implemented.
+ *
+ * To request a selectable fd, the user context has to be initialized
+ * to 1, instead of 0, and the return value is the fd.
+ * This keeps the system call compatible, since a non-zero value
+ * was not allowed so far.
*/
SYSCALL_DEFINE2(io_setup, unsigned, nr_events, aio_context_t __user *, ctxp)
{
struct kioctx *ioctx = NULL;
unsigned long ctx;
long ret;
+ int make_fd = 0;
ret = get_user(ctx, ctxp);
if (unlikely(ret))
goto out;
ret = -EINVAL;
+#ifdef CONFIG_EPOLL
+ if (ctx == 1) {
+ make_fd = 1;
+ ctx = 0;
+ }
+#endif
if (unlikely(ctx || nr_events == 0)) {
pr_debug("EINVAL: io_setup: ctx %lu nr_events %u\n",
ctx, nr_events);
ret = PTR_ERR(ioctx);
if (!IS_ERR(ioctx)) {
ret = put_user(ioctx->user_id, ctxp);
- if (!ret)
- return 0;
+#ifdef CONFIG_EPOLL
+ if (make_fd && ret >= 0)
+ ret = make_aio_fd(ioctx);
+#endif
+ if (ret >= 0)
+ return ret;
get_ioctx(ioctx); /* io_destroy() expects us to hold a ref */
io_destroy(ioctx);
projects / linux-flexiantxendom0-3.2.10.git / blobdiff