From: Jens Axboe <axboe@kernel.dk>
To: io-uring@vger.kernel.org
Cc: jlayton@kernel.org, josh@joshtriplett.org, Jens Axboe <axboe@kernel.dk>
Subject: [PATCH 4/6] io_uring: support deferred retrival of file from fd
Date: Wed, 4 Mar 2020 11:00:14 -0700 [thread overview]
Message-ID: <20200304180016.28212-5-axboe@kernel.dk> (raw)
In-Reply-To: <20200304180016.28212-1-axboe@kernel.dk>
We might not be able to grab the file we need at prep time, if the fd
needed is dependent on completion of another request. Support deferred
fd lookup.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
fs/io_uring.c | 21 +++++++++++++++++++--
1 file changed, 19 insertions(+), 2 deletions(-)
diff --git a/fs/io_uring.c b/fs/io_uring.c
index ed70ac09ca18..a1fc0d2acf91 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -511,6 +511,7 @@ enum {
REQ_F_OVERFLOW_BIT,
REQ_F_POLLED_BIT,
REQ_F_BUFFER_SELECTED_BIT,
+ REQ_F_DEFERRED_FD_BIT,
/* not a real bit, just to check we're not overflowing the space */
__REQ_F_LAST_BIT,
@@ -562,6 +563,8 @@ enum {
REQ_F_POLLED = BIT(REQ_F_POLLED_BIT),
/* buffer already selected */
REQ_F_BUFFER_SELECTED = BIT(REQ_F_BUFFER_SELECTED_BIT),
+ /* file assignment has been deferred */
+ REQ_F_DEFERRED_FD = BIT(REQ_F_DEFERRED_FD_BIT),
};
struct async_poll {
@@ -599,6 +602,7 @@ struct io_kiocb {
struct io_async_ctx *io;
bool needs_fixed_file;
u8 opcode;
+ int deferred_fd;
struct io_ring_ctx *ctx;
struct list_head list;
@@ -5002,6 +5006,12 @@ static int io_issue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe,
struct io_ring_ctx *ctx = req->ctx;
int ret;
+ if (req->flags & REQ_F_DEFERRED_FD) {
+ ret = io_file_get(NULL, req, req->deferred_fd, &req->file, false);
+ if (ret)
+ return ret;
+ }
+
switch (req->opcode) {
case IORING_OP_NOP:
ret = io_nop(req);
@@ -5328,7 +5338,7 @@ 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;
+ int fd, ret;
bool fixed;
flags = READ_ONCE(sqe->flags);
@@ -5341,7 +5351,14 @@ static int io_req_set_file(struct io_submit_state *state, struct io_kiocb *req,
if (unlikely(!fixed && req->needs_fixed_file))
return -EBADF;
- return io_file_get(state, req, fd, &req->file, fixed);
+ ret = io_file_get(state, req, fd, &req->file, fixed);
+ if (ret) {
+ if (fixed)
+ return ret;
+ req->deferred_fd = fd;
+ req->flags |= REQ_F_DEFERRED_FD;
+ }
+ return 0;
}
static int io_grab_files(struct io_kiocb *req)
--
2.25.1
next prev parent reply other threads:[~2020-03-04 18:00 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-04 18:00 [PATCHSET v2 0/6] Support selectable file descriptors Jens Axboe
2020-03-04 18:00 ` [PATCH 1/6] fs: openat2: Extend open_how to allow userspace-selected fds Jens Axboe
2020-03-04 18:00 ` [PATCH 2/6] io_uring: move CLOSE req->file checking into handler Jens Axboe
2020-03-04 18:00 ` [PATCH 3/6] io_uring: move read/write side file based prep into op handler Jens Axboe
2020-03-04 18:00 ` Jens Axboe [this message]
2020-03-04 18:00 ` [PATCH 5/6] net: allow specific fd selection for __sys_accept4_file() Jens Axboe
2020-03-04 18:00 ` [PATCH 6/6] io_uring: allow specific fd for IORING_OP_ACCEPT Jens Axboe
2020-03-04 19:02 ` Josh Triplett
2020-03-04 19:09 ` Jens Axboe
2020-03-04 19:51 ` Josh Triplett
2020-03-04 19:03 ` [PATCHSET v2 0/6] Support selectable file descriptors Josh Triplett
2020-03-04 19:10 ` Jens Axboe
2020-03-04 19:28 ` Jeff Layton
2020-03-04 19:50 ` Jens Axboe
2020-03-04 19:56 ` Josh Triplett
2020-03-04 20:00 ` Jens Axboe
2020-03-04 20:09 ` Josh Triplett
2020-03-04 20:14 ` Jens Axboe
2020-03-09 20:33 ` Stefan Metzmacher
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