@@ -1541,11 +1541,16 @@ static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
ssize_t ret;
/* enforce forwards compatibility on users */
- if (unlikely(iocb->aio_reserved1 || iocb->aio_reserved2)) {
+ if (unlikely(iocb->aio_reserved2)) {
pr_debug("EINVAL: reserve field set\n");
return -EINVAL;
}
+ if (unlikely(iocb->aio_rw_flags & ~IOCB_RW_FLAG_NOWAIT)) {
+ pr_debug("EINVAL: aio_rw_flags set with incompatible flags\n");
+ return -EINVAL;
+ }
+
/* prevent overflows */
if (unlikely(
(iocb->aio_buf != (unsigned long)iocb->aio_buf) ||
@@ -1586,6 +1591,9 @@ static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
req->common.ki_flags |= IOCB_EVENTFD;
}
+ if (iocb->aio_rw_flags & IOCB_RW_FLAG_NOWAIT)
+ req->common.ki_flags |= IOCB_NOWAIT;
+
ret = put_user(KIOCB_KEY, &user_iocb->aio_key);
if (unlikely(ret)) {
pr_debug("EFAULT: aio_key\n");
@@ -270,6 +270,7 @@ struct writeback_control;
#define IOCB_DSYNC (1 << 4)
#define IOCB_SYNC (1 << 5)
#define IOCB_WRITE (1 << 6)
+#define IOCB_NOWAIT (1 << 7)
struct kiocb {
struct file *ki_filp;
@@ -54,6 +54,13 @@ enum {
*/
#define IOCB_FLAG_RESFD (1 << 0)
+/*
+ * Flags for aio_rw_flags member of "struct iocb".
+ * IOCB_RW_FLAG_NOWAIT - Set if the user wants the iocb to fail if it
+ * would block for operations such as disk allocation.
+ */
+#define IOCB_RW_FLAG_NOWAIT (1 << 1)
+
/* read() from /dev/aio returns these structures. */
struct io_event {
__u64 data; /* the data field from the iocb */
@@ -79,7 +86,7 @@ struct io_event {
struct iocb {
/* these are internal to the kernel/libc. */
__u64 aio_data; /* data to be returned in event's data */
- __u32 PADDED(aio_key, aio_reserved1);
+ __u32 PADDED(aio_key, aio_rw_flags);
/* the kernel sets aio_key to the req # */
/* common fields */