vfs: add the RWF_HIPRI flag for preadv2/pwritev2
This adds a flag that tells the file system that this is a high priority
request for which it's worth to poll the hardware. The flag is purely
advisory and can be ignored if not supported.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Stephen Bates <stephen.bates@pmcs.com>
Tested-by: Stephen Bates <stephen.bates@pmcs.com>
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/include/uapi/linux/fs.h b/include/uapi/linux/fs.h
index 41e0433..847c656 100644
--- a/include/uapi/linux/fs.h
+++ b/include/uapi/linux/fs.h
@@ -305,4 +305,7 @@
#define SYNC_FILE_RANGE_WRITE 2
#define SYNC_FILE_RANGE_WAIT_AFTER 4
+/* flags for preadv2/pwritev2: */
+#define RWF_HIPRI 0x00000001 /* high priority request, poll if possible */
+
#endif /* _UAPI_LINUX_FS_H */