io_uring: add interface for getting files

Preparation without functional changes. Adds io_get_file(), that allows
to grab files not only into req->file.

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 5f2c0af..1a3de73 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -1253,6 +1253,15 @@ fallback:
        return NULL;
 }
 
+static inline void io_put_file(struct io_kiocb *req, struct file *file,
+                         bool fixed)
+{
+       if (fixed)
+               percpu_ref_put(&req->ctx->file_data->refs);
+       else
+               fput(file);
+}
+
 static void __io_req_do_free(struct io_kiocb *req)
 {
        if (likely(!io_is_fallback_req(req)))
@@ -1263,18 +1272,12 @@ static void __io_req_do_free(struct io_kiocb *req)
 
 static void __io_req_aux_free(struct io_kiocb *req)
 {
-       struct io_ring_ctx *ctx = req->ctx;
-
        if (req->flags & REQ_F_NEED_CLEANUP)
                io_cleanup_req(req);
 
        kfree(req->io);
-       if (req->file) {
-               if (req->flags & REQ_F_FIXED_FILE)
-                       percpu_ref_put(&ctx->file_data->refs);
-               else
-                       fput(req->file);
-       }
+       if (req->file)
+               io_put_file(req, req->file, (req->flags & REQ_F_FIXED_FILE));
 
        io_req_work_drop_env(req);
 }
@@ -1848,7 +1851,7 @@ static void io_file_put(struct io_submit_state *state)
  * assuming most submissions are for one file, or at least that each file
  * has more than one submission.
  */
-static struct file *io_file_get(struct io_submit_state *state, int fd)
+static struct file *__io_file_get(struct io_submit_state *state, int fd)
 {
        if (!state)
                return fget(fd);
@@ -4578,41 +4581,52 @@ static inline struct file *io_file_from_index(struct io_ring_ctx *ctx,
        return table->files[index & IORING_FILE_TABLE_MASK];;
 }
 
-static int io_req_set_file(struct io_submit_state *state, struct io_kiocb *req,
-                          const struct io_uring_sqe *sqe)
+static int io_file_get(struct io_submit_state *state, struct io_kiocb *req,
+                       int fd, struct file **out_file, bool fixed)
 {
        struct io_ring_ctx *ctx = req->ctx;
-       unsigned flags;
-       int fd;
-
-       flags = READ_ONCE(sqe->flags);
-       fd = READ_ONCE(sqe->fd);
-
-       if (!io_req_needs_file(req, fd))
-               return 0;
+       struct file *file;
 
-       if (flags & IOSQE_FIXED_FILE) {
+       if (fixed) {
                if (unlikely(!ctx->file_data ||
                    (unsigned) fd >= ctx->nr_user_files))
                        return -EBADF;
                fd = array_index_nospec(fd, ctx->nr_user_files);
-               req->file = io_file_from_index(ctx, fd);
-               if (!req->file)
+               file = io_file_from_index(ctx, fd);
+               if (!file)
                        return -EBADF;
-               req->flags |= REQ_F_FIXED_FILE;
                percpu_ref_get(&ctx->file_data->refs);
        } else {
-               if (req->needs_fixed_file)
-                       return -EBADF;
                trace_io_uring_file_get(ctx, fd);
-               req->file = io_file_get(state, fd);
-               if (unlikely(!req->file))
+               file = __io_file_get(state, fd);
+               if (unlikely(!file))
                        return -EBADF;
        }
 
+       *out_file = file;
        return 0;
 }
 
+static int io_req_set_file(struct io_submit_state *state, struct io_kiocb *req,
+                          const struct io_uring_sqe *sqe)
+{
+       unsigned flags;
+       int fd;
+       bool fixed;
+
+       flags = READ_ONCE(sqe->flags);
+       fd = READ_ONCE(sqe->fd);
+
+       if (!io_req_needs_file(req, fd))
+               return 0;
+
+       fixed = (flags & IOSQE_FIXED_FILE);
+       if (unlikely(!fixed && req->needs_fixed_file))
+               return -EBADF;
+
+       return io_file_get(state, req, fd, &req->file, fixed);
+}
+
 static int io_grab_files(struct io_kiocb *req)
 {
        int ret = -EBADF;
@@ -4857,8 +4871,8 @@ static bool io_submit_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe,
        }
 
        /* same numerical values with corresponding REQ_F_*, safe to copy */
-       req->flags |= sqe_flags & (IOSQE_IO_DRAIN|IOSQE_IO_HARDLINK|
-                                       IOSQE_ASYNC);
+       req->flags |= sqe_flags & (IOSQE_IO_DRAIN | IOSQE_IO_HARDLINK |
+                                       IOSQE_ASYNC | IOSQE_FIXED_FILE);
 
        ret = io_req_set_file(state, req, sqe);
        if (unlikely(ret)) {