io_uring: change submit file state invariant

Keep submit state invariant of whether there are file refs left based on
state->nr_refs instead of (state->file==NULL), and always check against
the first one. It's easier to track and allows to remove 1 if. It also
automatically leaves struct submit_state in a consistent state after
io_submit_state_end(), that's not used yet but nice.

btw rename has_refs to file_refs for more clarity.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 6f18b5f..a83593c 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -762,7 +762,7 @@ struct io_submit_state {
         */
        struct file             *file;
        unsigned int            fd;
-       unsigned int            has_refs;
+       unsigned int            file_refs;
        unsigned int            ios_left;
 };
 
@@ -2756,16 +2756,15 @@ static void io_iopoll_req_issued(struct io_kiocb *req, bool in_async)
                wake_up(&ctx->sq_data->wait);
 }
 
-static void __io_state_file_put(struct io_submit_state *state)
+static inline void __io_state_file_put(struct io_submit_state *state)
 {
-       if (state->has_refs)
-               fput_many(state->file, state->has_refs);
-       state->file = NULL;
+       fput_many(state->file, state->file_refs);
+       state->file_refs = 0;
 }
 
 static inline void io_state_file_put(struct io_submit_state *state)
 {
-       if (state->file)
+       if (state->file_refs)
                __io_state_file_put(state);
 }
 
@@ -2779,19 +2778,19 @@ static struct file *__io_file_get(struct io_submit_state *state, int fd)
        if (!state)
                return fget(fd);
 
-       if (state->file) {
+       if (state->file_refs) {
                if (state->fd == fd) {
-                       state->has_refs--;
+                       state->file_refs--;
                        return state->file;
                }
                __io_state_file_put(state);
        }
        state->file = fget_many(fd, state->ios_left);
-       if (!state->file)
+       if (unlikely(!state->file))
                return NULL;
 
        state->fd = fd;
-       state->has_refs = state->ios_left - 1;
+       state->file_refs = state->ios_left - 1;
        return state->file;
 }
 
@@ -6601,7 +6600,7 @@ static void io_submit_state_start(struct io_submit_state *state,
        INIT_LIST_HEAD(&state->comp.list);
        state->comp.ctx = ctx;
        state->free_reqs = 0;
-       state->file = NULL;
+       state->file_refs = 0;
        state->ios_left = max_ios;
 }