Merge tag 'for-5.5/io_uring-20191121' of git://git.kernel.dk/linux-block

Pull io_uring updates from Jens Axboe:
 "A lot of stuff has been going on this cycle, with improving the
  support for networked IO (and hence unbounded request completion
  times) being one of the major themes. There's been a set of fixes done
  this week, I'll send those out as well once we're certain we're fully
  happy with them.

  This contains:

   - Unification of the "normal" submit path and the SQPOLL path (Pavel)

   - Support for sparse (and bigger) file sets, and updating of those
     file sets without needing to unregister/register again.

   - Independently sized CQ ring, instead of just making it always 2x
     the SQ ring size. This makes it more flexible for networked
     applications.

   - Support for overflowed CQ ring, never dropping events but providing
     backpressure on submits.

   - Add support for absolute timeouts, not just relative ones.

   - Support for generic cancellations. This divorces io_uring from
     workqueues as well, which additionally gets us one step closer to
     generic async system call support.

   - With cancellations, we can support grabbing the process file table
     as well, just like we do mm context. This allows support for system
     calls that create file descriptors, like accept4() support that's
     built on top of that.

   - Support for io_uring tracing (Dmitrii)

   - Support for linked timeouts. These abort an operation if it isn't
     completed by the time noted in the linke timeout.

   - Speedup tracking of poll requests

   - Various cleanups making the coder easier to follow (Jackie, Pavel,
     Bob, YueHaibing, me)

   - Update MAINTAINERS with new io_uring list"

* tag 'for-5.5/io_uring-20191121' of git://git.kernel.dk/linux-block: (64 commits)
  io_uring: make POLL_ADD/POLL_REMOVE scale better
  io-wq: remove now redundant struct io_wq_nulls_list
  io_uring: Fix getting file for non-fd opcodes
  io_uring: introduce req_need_defer()
  io_uring: clean up io_uring_cancel_files()
  io-wq: ensure free/busy list browsing see all items
  io-wq: ensure we have a stable view of ->cur_work for cancellations
  io_wq: add get/put_work handlers to io_wq_create()
  io_uring: check for validity of ->rings in teardown
  io_uring: fix potential deadlock in io_poll_wake()
  io_uring: use correct "is IO worker" helper
  io_uring: fix -ENOENT issue with linked timer with short timeout
  io_uring: don't do flush cancel under inflight_lock
  io_uring: flag SQPOLL busy condition to userspace
  io_uring: make ASYNC_CANCEL work with poll and timeout
  io_uring: provide fallback request for OOM situations
  io_uring: convert accept4() -ERESTARTSYS into -EINTR
  io_uring: fix error clear of ->file_table in io_sqe_files_register()
  io_uring: separate the io_free_req and io_free_req_find_next interface
  io_uring: keep io_put_req only responsible for release and put req
  ...

include/uapi/linux/io_uring.h

@@ -19,7 +19,10 @@ struct io_uring_sqe {
 	__u8	flags;		/* IOSQE_ flags */
 	__u16	ioprio;		/* ioprio for the request */
 	__s32	fd;		/* file descriptor to do IO on */
-	__u64	off;		/* offset into file */
+	union {
+		__u64	off;	/* offset into file */
+		__u64	addr2;
+	};
 	__u64	addr;		/* pointer to buffer or iovecs */
 	__u32	len;		/* buffer size or number of iovecs */
 	union {
@@ -29,6 +32,8 @@ struct io_uring_sqe {
 		__u32		sync_range_flags;
 		__u32		msg_flags;
 		__u32		timeout_flags;
+		__u32		accept_flags;
+		__u32		cancel_flags;
 	};
 	__u64	user_data;	/* data to be passed back at completion time */
 	union {
@@ -50,6 +55,7 @@ struct io_uring_sqe {
 #define IORING_SETUP_IOPOLL	(1U << 0)	/* io_context is polled */
 #define IORING_SETUP_SQPOLL	(1U << 1)	/* SQ poll thread */
 #define IORING_SETUP_SQ_AFF	(1U << 2)	/* sq_thread_cpu is valid */
+#define IORING_SETUP_CQSIZE	(1U << 3)	/* app defines CQ size */
 
 #define IORING_OP_NOP		0
 #define IORING_OP_READV		1
@@ -63,12 +69,21 @@ struct io_uring_sqe {
 #define IORING_OP_SENDMSG	9
 #define IORING_OP_RECVMSG	10
 #define IORING_OP_TIMEOUT	11
+#define IORING_OP_TIMEOUT_REMOVE	12
+#define IORING_OP_ACCEPT	13
+#define IORING_OP_ASYNC_CANCEL	14
+#define IORING_OP_LINK_TIMEOUT	15
 
 /*
  * sqe->fsync_flags
  */
 #define IORING_FSYNC_DATASYNC	(1U << 0)
 
+/*
+ * sqe->timeout_flags
+ */
+#define IORING_TIMEOUT_ABS	(1U << 0)
+
 /*
  * IO completion data structure (Completion Queue Entry)
  */
@@ -140,6 +155,7 @@ struct io_uring_params {
  * io_uring_params->features flags
  */
 #define IORING_FEAT_SINGLE_MMAP		(1U << 0)
+#define IORING_FEAT_NODROP		(1U << 1)
 
 /*
  * io_uring_register(2) opcodes and arguments
@@ -150,5 +166,11 @@ struct io_uring_params {
 #define IORING_UNREGISTER_FILES		3
 #define IORING_REGISTER_EVENTFD		4
 #define IORING_UNREGISTER_EVENTFD	5
+#define IORING_REGISTER_FILES_UPDATE	6
+
+struct io_uring_files_update {
+	__u32 offset;
+	__s32 *fds;
+};
 
 #endif