[PATCH 2/3] io_uring: add interface for getting files

Pavel Begunkov
2020-01-22T00:06:25Z

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>
---
fs/io_uring.c | 66 ++++++++++++++++++++++++++++++++-------------------
1 file changed, 41 insertions(+), 25 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 8f7846cb1ebf..e9e4aee0fb99 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -1161,6 +1161,15 @@ static struct io_kiocb *io_get_req(struct io_ring_ctx *ctx,
return NULL;
}

+static inline void io_put_file(struct io_ring_ctx *ctx, struct file *file,
+ bool fixed)
+{
+ if (fixed)
+ percpu_ref_put(&ctx->file_data->refs);
+ else
+ fput(file);
+}
+
static void __io_req_do_free(struct io_kiocb *req)
{
if (likely(!io_is_fallback_req(req)))
@@ -1174,12 +1183,8 @@ static void __io_req_aux_free(struct io_kiocb *req)
struct io_ring_ctx *ctx = req->ctx;

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(ctx, req->file, (req->flags & REQ_F_FIXED_FILE));
}

static void __io_free_req(struct io_kiocb *req)
@@ -4355,41 +4360,52 @@ 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_get_file(struct io_submit_state *state, struct io_ring_ctx *ctx,
+ 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)
+{
+ struct io_ring_ctx *ctx = req->ctx;
+ 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_get_file(state, ctx, fd, &req->file, fixed);
+}
+
static int io_grab_files(struct io_kiocb *req)
{
int ret = -EBADF;
--
2.24.0