fuse: implement poll support
Implement poll support. Polled files are indexed using kh in a RB
tree rooted at fuse_conn->polled_files.
Client should send FUSE_NOTIFY_POLL notification once after processing
FUSE_POLL which has FUSE_POLL_SCHEDULE_NOTIFY set. Sending
notification unconditionally after the latest poll or everytime file
content might have changed is inefficient but won't cause malfunction.
fuse_file_poll() can sleep and requires patches from the following
thread which allows f_op->poll() to sleep.
http://thread.gmane.org/gmane.linux.kernel/726176
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
diff --git a/include/linux/fuse.h b/include/linux/fuse.h
index abde994..5650cf0 100644
--- a/include/linux/fuse.h
+++ b/include/linux/fuse.h
@@ -163,6 +163,13 @@
#define FUSE_IOCTL_MAX_IOV 256
+/**
+ * Poll flags
+ *
+ * FUSE_POLL_SCHEDULE_NOTIFY: request poll notify
+ */
+#define FUSE_POLL_SCHEDULE_NOTIFY (1 << 0)
+
enum fuse_opcode {
FUSE_LOOKUP = 1,
FUSE_FORGET = 2, /* no reply */
@@ -201,9 +208,11 @@
FUSE_BMAP = 37,
FUSE_DESTROY = 38,
FUSE_IOCTL = 39,
+ FUSE_POLL = 40,
};
enum fuse_notify_code {
+ FUSE_NOTIFY_POLL = 1,
FUSE_NOTIFY_CODE_MAX,
};
@@ -421,6 +430,22 @@
__u32 out_iovs;
};
+struct fuse_poll_in {
+ __u64 fh;
+ __u64 kh;
+ __u32 flags;
+ __u32 padding;
+};
+
+struct fuse_poll_out {
+ __u32 revents;
+ __u32 padding;
+};
+
+struct fuse_notify_poll_wakeup_out {
+ __u64 kh;
+};
+
struct fuse_in_header {
__u32 len;
__u32 opcode;