From 35645ac3c1853fbb54d8acd50fd12184f7905d5f Mon Sep 17 00:00:00 2001
From: Pavel Begunkov <asml.silence@gmail.com>
Date: Sun, 17 Oct 2021 00:07:09 +0100
Subject: [PATCH] io_uring: combine REQ_F_NOWAIT_{READ,WRITE} flags
Git-commit: 35645ac3c1853fbb54d8acd50fd12184f7905d5f
Patch-mainline: v5.16-rc1
References: bsc#1205205
Merge REQ_F_NOWAIT_READ and REQ_F_NOWAIT_WRITE into one flag, i.e.
REQ_F_SUPPORT_NOWAIT. First it gets rid of dependence on CONFIG_64BIT
but also simplifies the code.
One thing to consider is when we don't have ->{read,write}_iter and go
through loop_rw_iter(). Just fail it with -EAGAIN if we expect nowait
behaviour but not sure whether it supports it.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/f832a20e5186c2e79c6519280c238f559a1d2bbc.1634425438.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>
---
fs/io_uring.c | 61 ++++++++++++++++++---------------------------------
1 file changed, 21 insertions(+), 40 deletions(-)
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 8a5b20eafccf..d7bf2002ab0c 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -732,8 +732,7 @@ enum {
REQ_F_ARM_LTIMEOUT_BIT,
REQ_F_ASYNC_DATA_BIT,
/* keep async read/write and isreg together and in order */
- REQ_F_NOWAIT_READ_BIT,
- REQ_F_NOWAIT_WRITE_BIT,
+ REQ_F_SUPPORT_NOWAIT_BIT,
REQ_F_ISREG_BIT,
/* not a real bit, just to check we're not overflowing the space */
@@ -774,10 +773,8 @@ enum {
REQ_F_COMPLETE_INLINE = BIT(REQ_F_COMPLETE_INLINE_BIT),
/* caller should reissue async */
REQ_F_REISSUE = BIT(REQ_F_REISSUE_BIT),
- /* supports async reads */
- REQ_F_NOWAIT_READ = BIT(REQ_F_NOWAIT_READ_BIT),
- /* supports async writes */
- REQ_F_NOWAIT_WRITE = BIT(REQ_F_NOWAIT_WRITE_BIT),
+ /* supports async reads/writes */
+ REQ_F_SUPPORT_NOWAIT = BIT(REQ_F_SUPPORT_NOWAIT_BIT),
/* regular file */
REQ_F_ISREG = BIT(REQ_F_ISREG_BIT),
/* has creds assigned */
@@ -1390,18 +1387,13 @@ static bool req_need_defer(struct io_kiocb *req, u32 seq)
return false;
}
-#define FFS_ASYNC_READ 0x1UL
-#define FFS_ASYNC_WRITE 0x2UL
-#ifdef CONFIG_64BIT
-#define FFS_ISREG 0x4UL
-#else
-#define FFS_ISREG 0x0UL
-#endif
-#define FFS_MASK ~(FFS_ASYNC_READ|FFS_ASYNC_WRITE|FFS_ISREG)
+#define FFS_NOWAIT 0x1UL
+#define FFS_ISREG 0x2UL
+#define FFS_MASK ~(FFS_NOWAIT|FFS_ISREG)
static inline bool io_req_ffs_set(struct io_kiocb *req)
{
- return IS_ENABLED(CONFIG_64BIT) && (req->flags & REQ_F_FIXED_FILE);
+ return req->flags & REQ_F_FIXED_FILE;
}
static inline void io_req_track_inflight(struct io_kiocb *req)
@@ -2772,7 +2764,7 @@ static bool io_bdev_nowait(struct block_device *bdev)
* any file. For now, just ensure that anything potentially problematic is done
* inline.
*/
-static bool __io_file_supports_nowait(struct file *file, int rw)
+static bool __io_file_supports_nowait(struct file *file)
{
umode_t mode = file_inode(file)->i_mode;
@@ -2795,24 +2787,14 @@ static bool __io_file_supports_nowait(struct file *file, int rw)
/* any ->read/write should understand O_NONBLOCK */
if (file->f_flags & O_NONBLOCK)
return true;
-
- if (!(file->f_mode & FMODE_NOWAIT))
- return false;
-
- if (rw == READ)
- return file->f_op->read_iter != NULL;
-
- return file->f_op->write_iter != NULL;
+ return file->f_mode & FMODE_NOWAIT;
}
-static bool io_file_supports_nowait(struct io_kiocb *req, int rw)
+static inline bool io_file_supports_nowait(struct io_kiocb *req)
{
- if (rw == READ && (req->flags & REQ_F_NOWAIT_READ))
+ if (likely(req->flags & REQ_F_SUPPORT_NOWAIT))
return true;
- else if (rw == WRITE && (req->flags & REQ_F_NOWAIT_WRITE))
- return true;
-
- return __io_file_supports_nowait(req->file, rw);
+ return __io_file_supports_nowait(req->file);
}
static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe,
@@ -2844,7 +2826,7 @@ static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe,
* reliably. If not, or it IOCB_NOWAIT is set, don't retry.
*/
if ((kiocb->ki_flags & IOCB_NOWAIT) ||
- ((file->f_flags & O_NONBLOCK) && !io_file_supports_nowait(req, rw)))
+ ((file->f_flags & O_NONBLOCK) && !io_file_supports_nowait(req)))
req->flags |= REQ_F_NOWAIT;
ioprio = READ_ONCE(sqe->ioprio);
@@ -3235,7 +3217,8 @@ static ssize_t loop_rw_iter(int rw, struct io_kiocb *req, struct iov_iter *iter)
*/
if (kiocb->ki_flags & IOCB_HIPRI)
return -EOPNOTSUPP;
- if (kiocb->ki_flags & IOCB_NOWAIT)
+ if ((kiocb->ki_flags & IOCB_NOWAIT) &&
+ !(kiocb->ki_filp->f_flags & O_NONBLOCK))
return -EAGAIN;
while (iov_iter_count(iter)) {
@@ -3475,7 +3458,7 @@ static int io_read(struct io_kiocb *req, unsigned int issue_flags)
if (force_nonblock) {
/* If the file doesn't support async, just async punt */
- if (unlikely(!io_file_supports_nowait(req, READ))) {
+ if (unlikely(!io_file_supports_nowait(req))) {
ret = io_setup_async_rw(req, iovec, s, true);
return ret ?: -EAGAIN;
}
@@ -3599,7 +3582,7 @@ static int io_write(struct io_kiocb *req, unsigned int issue_flags)
if (force_nonblock) {
/* If the file doesn't support async, just async punt */
- if (unlikely(!io_file_supports_nowait(req, WRITE)))
+ if (unlikely(!io_file_supports_nowait(req)))
goto copy_iov;
/* file path doesn't support NOWAIT for non-direct_IO */
@@ -3631,7 +3614,7 @@ static int io_write(struct io_kiocb *req, unsigned int issue_flags)
}
kiocb->ki_flags |= IOCB_WRITE;
- if (req->file->f_op->write_iter)
+ if (likely(req->file->f_op->write_iter))
ret2 = call_write_iter(req->file, kiocb, &s->iter);
else if (req->file->f_op->write)
ret2 = loop_rw_iter(WRITE, req, &s->iter);
@@ -6778,10 +6761,8 @@ static void io_fixed_file_set(struct io_fixed_file *file_slot, struct file *file
{
unsigned long file_ptr = (unsigned long) file;
- if (__io_file_supports_nowait(file, READ))
- file_ptr |= FFS_ASYNC_READ;
- if (__io_file_supports_nowait(file, WRITE))
- file_ptr |= FFS_ASYNC_WRITE;
+ if (__io_file_supports_nowait(file))
+ file_ptr |= FFS_NOWAIT;
if (S_ISREG(file_inode(file)->i_mode))
file_ptr |= FFS_ISREG;
file_slot->file_ptr = file_ptr;
@@ -6800,7 +6781,7 @@ static inline struct file *io_file_get_fixed(struct io_ring_ctx *ctx,
file = (struct file *) (file_ptr & FFS_MASK);
file_ptr &= ~FFS_MASK;
/* mask in overlapping REQ_F and FFS bits */
- req->flags |= (file_ptr << REQ_F_NOWAIT_READ_BIT);
+ req->flags |= (file_ptr << REQ_F_SUPPORT_NOWAIT_BIT);
io_req_set_rsrc_node(req, ctx);
return file;
}
--
2.35.3