From: Jens Axboe <axboe@kernel.dk>
To: linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-aio@kvack.org
Cc: hch@lst.de, jmoyer@redhat.com, clm@fb.com, Jens Axboe <axboe@kernel.dk>
Subject: [PATCH 26/27] aio: add support for submission/completion rings
Date: Mon, 10 Dec 2018 17:15:48 -0700 [thread overview]
Message-ID: <20181211001549.30085-27-axboe@kernel.dk> (raw)
In-Reply-To: <20181211001549.30085-1-axboe@kernel.dk>
Experimental support for submitting and completing IO through rings
shared between the application and kernel.
The submission rings are struct iocb, like we would submit through
io_submit(), and the completion rings are struct io_event, like we
would pass in (and copy back) from io_getevents().
A new system call is added for this, io_ring_enter(). This system
call submits IO that is queued in the SQ ring, and/or completes IO
and stores the results in the CQ ring.
This could be augmented with a kernel thread that does the submission
and polling, then the application would never have to enter the
kernel to do IO.
Sample application: http://git.kernel.dk/cgit/fio/plain/t/aio-ring.c
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
arch/x86/entry/syscalls/syscall_64.tbl | 1 +
fs/aio.c | 456 +++++++++++++++++++++++--
include/linux/syscalls.h | 4 +-
include/uapi/linux/aio_abi.h | 26 ++
kernel/sys_ni.c | 1 +
5 files changed, 452 insertions(+), 36 deletions(-)
diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl
index 67c357225fb0..55a26700a637 100644
--- a/arch/x86/entry/syscalls/syscall_64.tbl
+++ b/arch/x86/entry/syscalls/syscall_64.tbl
@@ -344,6 +344,7 @@
333 common io_pgetevents __x64_sys_io_pgetevents
334 common rseq __x64_sys_rseq
335 common io_setup2 __x64_sys_io_setup2
+336 common io_ring_enter __x64_sys_io_ring_enter
#
# x32-specific system call numbers start at 512 to avoid cache impact
diff --git a/fs/aio.c b/fs/aio.c
index a69e6228fe62..f4f39a7f8f94 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -142,6 +142,11 @@ struct kioctx {
struct aio_mapped_range iocb_range;
+ /* if used, completion and submission rings */
+ struct aio_mapped_range sq_ring;
+ struct aio_mapped_range cq_ring;
+ int cq_ring_overflow;
+
struct rcu_work free_rwork; /* see free_ioctx() */
/*
@@ -297,6 +302,8 @@ static const struct address_space_operations aio_ctx_aops;
static const unsigned int iocb_page_shift =
ilog2(PAGE_SIZE / sizeof(struct iocb));
+static const unsigned int event_page_shift =
+ ilog2(PAGE_SIZE / sizeof(struct io_event));
/*
* We rely on block level unplugs to flush pending requests, if we schedule
@@ -307,6 +314,7 @@ static const bool aio_use_state_req_list = true;
static const bool aio_use_state_req_list = false;
#endif
+static void aio_scqring_unmap(struct kioctx *);
static void aio_useriocb_unmap(struct kioctx *);
static void aio_iopoll_reap_events(struct kioctx *);
static void aio_iocb_buffer_unmap(struct kioctx *);
@@ -539,6 +547,12 @@ static const struct address_space_operations aio_ctx_aops = {
#endif
};
+/* Polled IO or SQ/CQ rings don't use the old ring */
+static bool aio_ctx_old_ring(struct kioctx *ctx)
+{
+ return !(ctx->flags & (IOCTX_FLAG_IOPOLL | IOCTX_FLAG_SCQRING));
+}
+
static int aio_setup_ring(struct kioctx *ctx, unsigned int nr_events)
{
struct aio_ring *ring;
@@ -553,7 +567,7 @@ static int aio_setup_ring(struct kioctx *ctx, unsigned int nr_events)
* IO polling doesn't require any io event entries
*/
size = sizeof(struct aio_ring);
- if (!(ctx->flags & IOCTX_FLAG_IOPOLL)) {
+ if (aio_ctx_old_ring(ctx)) {
nr_events += 2; /* 1 is required, 2 for good luck */
size += sizeof(struct io_event) * nr_events;
}
@@ -640,6 +654,17 @@ static int aio_setup_ring(struct kioctx *ctx, unsigned int nr_events)
return 0;
}
+/*
+ * Don't support cancel on anything that isn't regular aio
+ */
+static bool aio_ctx_supports_cancel(struct kioctx *ctx)
+{
+ int noflags = IOCTX_FLAG_USERIOCB | IOCTX_FLAG_IOPOLL |
+ IOCTX_FLAG_SCQRING;
+
+ return (ctx->flags & noflags) == 0;
+}
+
#define AIO_EVENTS_PER_PAGE (PAGE_SIZE / sizeof(struct io_event))
#define AIO_EVENTS_FIRST_PAGE ((PAGE_SIZE - sizeof(struct aio_ring)) / sizeof(struct io_event))
#define AIO_EVENTS_OFFSET (AIO_EVENTS_PER_PAGE - AIO_EVENTS_FIRST_PAGE)
@@ -650,6 +675,8 @@ void kiocb_set_cancel_fn(struct kiocb *iocb, kiocb_cancel_fn *cancel)
struct kioctx *ctx = req->ki_ctx;
unsigned long flags;
+ if (WARN_ON_ONCE(!aio_ctx_supports_cancel(ctx)))
+ return;
if (WARN_ON_ONCE(!list_empty(&req->ki_list)))
return;
@@ -673,6 +700,7 @@ static void free_ioctx(struct work_struct *work)
aio_iocb_buffer_unmap(ctx);
aio_useriocb_unmap(ctx);
+ aio_scqring_unmap(ctx);
aio_free_ring(ctx);
free_percpu(ctx->cpu);
percpu_ref_exit(&ctx->reqs);
@@ -1218,6 +1246,47 @@ static void aio_fill_event(struct io_event *ev, struct aio_kiocb *iocb,
ev->res2 = res2;
}
+static struct io_event *__aio_get_cqring_ev(struct aio_io_event_ring *ring,
+ struct aio_mapped_range *range,
+ unsigned *next_tail)
+{
+ struct io_event *ev;
+ unsigned tail;
+
+ smp_rmb();
+ tail = READ_ONCE(ring->tail);
+ *next_tail = tail + 1;
+ if (*next_tail == ring->nr_events)
+ *next_tail = 0;
+ if (*next_tail == READ_ONCE(ring->head))
+ return NULL;
+
+ /* io_event array starts offset one into the mapped range */
+ tail++;
+ ev = page_address(range->pages[tail >> event_page_shift]);
+ tail &= ((1 << event_page_shift) - 1);
+ return ev + tail;
+}
+
+static void aio_commit_cqring(struct kioctx *ctx, unsigned next_tail)
+{
+ struct aio_io_event_ring *ring;
+
+ ring = page_address(ctx->cq_ring.pages[0]);
+ if (next_tail != ring->tail) {
+ ring->tail = next_tail;
+ smp_wmb();
+ }
+}
+
+static struct io_event *aio_peek_cqring(struct kioctx *ctx, unsigned *ntail)
+{
+ struct aio_io_event_ring *ring;
+
+ ring = page_address(ctx->cq_ring.pages[0]);
+ return __aio_get_cqring_ev(ring, &ctx->cq_ring, ntail);
+}
+
static void aio_ring_complete(struct kioctx *ctx, struct aio_kiocb *iocb,
long res, long res2)
{
@@ -1279,7 +1348,36 @@ static void aio_complete(struct aio_kiocb *iocb, long res, long res2)
{
struct kioctx *ctx = iocb->ki_ctx;
- aio_ring_complete(ctx, iocb, res, res2);
+ if (ctx->flags & IOCTX_FLAG_SCQRING) {
+ unsigned long flags;
+ struct io_event *ev;
+ unsigned int tail;
+
+ /*
+ * If we can't get a cq entry, userspace overflowed the
+ * submission (by quite a lot). Flag it as an overflow
+ * condition, and next io_ring_enter(2) call will return
+ * -EOVERFLOW.
+ */
+ spin_lock_irqsave(&ctx->completion_lock, flags);
+ ev = aio_peek_cqring(ctx, &tail);
+ if (ev) {
+ aio_fill_event(ev, iocb, res, res2);
+ aio_commit_cqring(ctx, tail);
+ } else
+ ctx->cq_ring_overflow = 1;
+ spin_unlock_irqrestore(&ctx->completion_lock, flags);
+ } else {
+ aio_ring_complete(ctx, iocb, res, res2);
+
+ /*
+ * We have to order our ring_info tail store above and test
+ * of the wait list below outside the wait lock. This is
+ * like in wake_up_bit() where clearing a bit has to be
+ * ordered with the unlocked test.
+ */
+ smp_mb();
+ }
/*
* Check if the user asked us to deliver the result through an
@@ -1291,14 +1389,6 @@ static void aio_complete(struct aio_kiocb *iocb, long res, long res2)
eventfd_ctx_put(iocb->ki_eventfd);
}
- /*
- * We have to order our ring_info tail store above and test
- * of the wait list below outside the wait lock. This is
- * like in wake_up_bit() where clearing a bit has to be
- * ordered with the unlocked test.
- */
- smp_mb();
-
if (waitqueue_active(&ctx->wait))
wake_up(&ctx->wait);
iocb_put(iocb);
@@ -1421,6 +1511,9 @@ static long aio_iopoll_reap(struct kioctx *ctx, struct io_event __user *evs,
return 0;
list_for_each_entry_safe(iocb, n, &ctx->poll_completing, ki_list) {
+ struct io_event *ev = NULL;
+ unsigned int next_tail;
+
if (*nr_events == max)
break;
if (!test_bit(KIOCB_F_POLL_COMPLETED, &iocb->ki_flags))
@@ -1428,6 +1521,14 @@ static long aio_iopoll_reap(struct kioctx *ctx, struct io_event __user *evs,
if (to_free == AIO_IOPOLL_BATCH)
iocb_put_many(ctx, iocbs, &to_free);
+ /* Will only happen if the application over-commits */
+ ret = -EAGAIN;
+ if (ctx->flags & IOCTX_FLAG_SCQRING) {
+ ev = aio_peek_cqring(ctx, &next_tail);
+ if (!ev)
+ break;
+ }
+
list_del(&iocb->ki_list);
iocbs[to_free++] = iocb;
@@ -1446,8 +1547,11 @@ static long aio_iopoll_reap(struct kioctx *ctx, struct io_event __user *evs,
file_count = 1;
}
- if (evs && copy_to_user(evs + *nr_events, &iocb->ki_ev,
- sizeof(iocb->ki_ev))) {
+ if (ev) {
+ memcpy(ev, &iocb->ki_ev, sizeof(*ev));
+ aio_commit_cqring(ctx, next_tail);
+ } else if (evs && copy_to_user(evs + *nr_events, &iocb->ki_ev,
+ sizeof(iocb->ki_ev))) {
ret = -EFAULT;
break;
}
@@ -1628,15 +1732,42 @@ static long read_events(struct kioctx *ctx, long min_nr, long nr,
return ret;
}
-static struct iocb *aio_iocb_from_index(struct kioctx *ctx, int index)
+static struct iocb *__aio_sqring_from_index(struct aio_iocb_ring *ring,
+ struct aio_mapped_range *range,
+ int index)
{
struct iocb *iocb;
- iocb = page_address(ctx->iocb_range.pages[index >> iocb_page_shift]);
+ /* iocb array starts offset one into the mapped range */
+ index++;
+ iocb = page_address(range->pages[index >> iocb_page_shift]);
index &= ((1 << iocb_page_shift) - 1);
return iocb + index;
}
+static struct iocb *aio_sqring_from_index(struct kioctx *ctx, int index)
+{
+ struct aio_iocb_ring *ring;
+
+ ring = page_address(ctx->sq_ring.pages[0]);
+ return __aio_sqring_from_index(ring, &ctx->sq_ring, index);
+}
+
+static struct iocb *aio_iocb_from_index(struct kioctx *ctx, int index)
+{
+ struct iocb *iocb;
+
+ if (ctx->flags & IOCTX_FLAG_SCQRING) {
+ iocb = aio_sqring_from_index(ctx, index);
+ } else {
+ iocb = page_address(ctx->iocb_range.pages[index >> iocb_page_shift]);
+ index &= ((1 << iocb_page_shift) - 1);
+ iocb += index;
+ }
+
+ return iocb;
+}
+
static void aio_unmap_range(struct aio_mapped_range *range)
{
int i;
@@ -1692,6 +1823,52 @@ static int aio_useriocb_map(struct kioctx *ctx, struct iocb __user *iocbs)
return aio_map_range(&ctx->iocb_range, iocbs, size, 0);
}
+static void aio_scqring_unmap(struct kioctx *ctx)
+{
+ aio_unmap_range(&ctx->sq_ring);
+ aio_unmap_range(&ctx->cq_ring);
+}
+
+static int aio_scqring_map(struct kioctx *ctx,
+ struct aio_iocb_ring __user *sq_ring,
+ struct aio_io_event_ring __user *cq_ring)
+{
+ struct aio_iocb_ring *ksq_ring;
+ struct aio_io_event_ring *kcq_ring;
+ int ret, sq_ring_size, cq_ring_size;
+ size_t size;
+
+ /*
+ * The CQ ring size is QD + 1, so we don't have to track full condition
+ * for head == tail. The SQ ring we make twice that in size, to make
+ * room for having more inflight than the QD.
+ */
+ sq_ring_size = ctx->max_reqs;
+ cq_ring_size = 2 * ctx->max_reqs;
+
+ size = sq_ring_size * sizeof(struct iocb);
+ ret = aio_map_range(&ctx->sq_ring, sq_ring,
+ sq_ring_size * sizeof(struct iocb), 0);
+ if (ret)
+ return ret;
+
+ ret = aio_map_range(&ctx->cq_ring, cq_ring,
+ cq_ring_size * sizeof(struct io_event), FOLL_WRITE);
+ if (ret) {
+ aio_unmap_range(&ctx->sq_ring);
+ return ret;
+ }
+
+ ksq_ring = page_address(ctx->sq_ring.pages[0]);
+ ksq_ring->nr_events = sq_ring_size;
+ ksq_ring->head = ksq_ring->tail = 0;
+
+ kcq_ring = page_address(ctx->cq_ring.pages[0]);
+ kcq_ring->nr_events = cq_ring_size;
+ kcq_ring->head = kcq_ring->tail = 0;
+ return 0;
+}
+
static void aio_iocb_buffer_unmap(struct kioctx *ctx)
{
int i, j;
@@ -1815,22 +1992,22 @@ static int aio_iocb_buffer_map(struct kioctx *ctx)
* *iocbs - pointer to array of struct iocb, for when
* IOCTX_FLAG_USERIOCB is set in flags.
*
- * *user1 - reserved for future use
+ * *sq_ring - pointer to the userspace SQ ring, if used.
*
- * *user2 - reserved for future use.
+ * *cq_ring - pointer to the userspace CQ ring, if used.
*/
-SYSCALL_DEFINE6(io_setup2, u32, nr_events, u32, flags, struct iocb __user *,
- iocbs, void __user *, user1, void __user *, user2,
+SYSCALL_DEFINE6(io_setup2, u32, nr_events, u32, flags,
+ struct iocb __user *, iocbs,
+ struct aio_iocb_ring __user *, sq_ring,
+ struct aio_io_event_ring __user *, cq_ring,
aio_context_t __user *, ctxp)
{
struct kioctx *ioctx;
unsigned long ctx;
long ret;
- if (user1 || user2)
- return -EINVAL;
if (flags & ~(IOCTX_FLAG_USERIOCB | IOCTX_FLAG_IOPOLL |
- IOCTX_FLAG_FIXEDBUFS))
+ IOCTX_FLAG_FIXEDBUFS | IOCTX_FLAG_SCQRING))
return -EINVAL;
ret = get_user(ctx, ctxp);
@@ -1843,18 +2020,26 @@ SYSCALL_DEFINE6(io_setup2, u32, nr_events, u32, flags, struct iocb __user *,
goto out;
if (flags & IOCTX_FLAG_USERIOCB) {
+ ret = -EINVAL;
+ if (flags & IOCTX_FLAG_SCQRING)
+ goto err;
+
ret = aio_useriocb_map(ioctx, iocbs);
if (ret)
goto err;
- if (flags & IOCTX_FLAG_FIXEDBUFS) {
- ret = aio_iocb_buffer_map(ioctx);
- if (ret)
- goto err;
- }
- } else if (flags & IOCTX_FLAG_FIXEDBUFS) {
- /* can only support fixed bufs with user mapped iocbs */
+ }
+ if (flags & IOCTX_FLAG_SCQRING) {
+ ret = aio_scqring_map(ioctx, sq_ring, cq_ring);
+ if (ret)
+ goto err;
+ }
+ if (flags & IOCTX_FLAG_FIXEDBUFS) {
ret = -EINVAL;
- goto err;
+ if (!(flags & (IOCTX_FLAG_USERIOCB | IOCTX_FLAG_SCQRING)))
+ goto err;
+ ret = aio_iocb_buffer_map(ioctx);
+ if (ret)
+ goto err;
}
ret = put_user(ioctx->user_id, ctxp);
@@ -2556,8 +2741,7 @@ static int __io_submit_one(struct kioctx *ctx, const struct iocb *iocb,
return -EINVAL;
}
- /* Poll IO doesn't need ring reservations */
- if (!(ctx->flags & IOCTX_FLAG_IOPOLL) && !get_reqs_available(ctx))
+ if (aio_ctx_old_ring(ctx) && !get_reqs_available(ctx))
return -EAGAIN;
ret = -EAGAIN;
@@ -2581,7 +2765,7 @@ static int __io_submit_one(struct kioctx *ctx, const struct iocb *iocb,
}
/* Don't support cancel on user mapped iocbs or polled context */
- if (!(ctx->flags & (IOCTX_FLAG_USERIOCB | IOCTX_FLAG_IOPOLL))) {
+ if (aio_ctx_supports_cancel(ctx)) {
ret = put_user(KIOCB_KEY, &user_iocb->aio_key);
if (unlikely(ret)) {
pr_debug("EFAULT: aio_key\n");
@@ -2647,7 +2831,7 @@ static int __io_submit_one(struct kioctx *ctx, const struct iocb *iocb,
eventfd_ctx_put(req->ki_eventfd);
iocb_put(req);
out_put_reqs_available:
- if (!(ctx->flags & IOCTX_FLAG_IOPOLL))
+ if (aio_ctx_old_ring(ctx))
put_reqs_available(ctx, 1);
return ret;
}
@@ -2720,6 +2904,201 @@ static void aio_submit_state_start(struct aio_submit_state *state,
#endif
}
+static struct iocb *__aio_get_sqring(struct aio_iocb_ring *ring,
+ struct aio_mapped_range *range,
+ unsigned *next_head)
+{
+ unsigned head;
+
+ smp_rmb();
+ head = READ_ONCE(ring->head);
+ if (head == READ_ONCE(ring->tail))
+ return NULL;
+
+ *next_head = head + 1;
+ if (*next_head == ring->nr_events)
+ *next_head = 0;
+
+ return __aio_sqring_from_index(ring, range, head);
+}
+
+static void aio_commit_sqring(struct kioctx *ctx, unsigned next_head)
+{
+ struct aio_iocb_ring *ring;
+
+ ring = page_address(ctx->sq_ring.pages[0]);
+ if (ring->head != next_head) {
+ ring->head = next_head;
+ smp_wmb();
+ }
+}
+
+static const struct iocb *aio_peek_sqring(struct kioctx *ctx, unsigned *nhead)
+{
+ struct aio_iocb_ring *ring;
+
+ ring = page_address(ctx->sq_ring.pages[0]);
+ return __aio_get_sqring(ring, &ctx->sq_ring, nhead);
+}
+
+static int aio_ring_submit(struct kioctx *ctx, unsigned int to_submit)
+{
+ bool kaddr = (ctx->flags & IOCTX_FLAG_FIXEDBUFS) != 0;
+ struct aio_submit_state state, *statep = NULL;
+ int i, ret = 0, submit = 0;
+
+ if (to_submit > AIO_PLUG_THRESHOLD) {
+ aio_submit_state_start(&state, ctx, to_submit);
+ statep = &state;
+ }
+
+ for (i = 0; i < to_submit; i++) {
+ const struct iocb *iocb;
+ unsigned int next_head;
+
+ iocb = aio_peek_sqring(ctx, &next_head);
+ if (!iocb)
+ break;
+
+ ret = __io_submit_one(ctx, iocb, NULL, NULL, false, kaddr);
+ if (ret)
+ break;
+
+ submit++;
+ aio_commit_sqring(ctx, next_head);
+ }
+
+ if (statep)
+ aio_submit_state_end(statep);
+
+ return submit ? submit : ret;
+}
+
+/*
+ * Wait until events become available, if we don't already have some. The
+ * application must reap them itself, as they reside on the shared cq ring.
+ */
+static int aio_cqring_wait(struct kioctx *ctx, int min_events)
+{
+ struct aio_io_event_ring *ring;
+ DEFINE_WAIT(wait);
+ int ret = 0;
+
+ ring = page_address(ctx->cq_ring.pages[0]);
+ smp_rmb();
+ if (ring->head != ring->tail)
+ return 0;
+
+ do {
+ prepare_to_wait(&ctx->wait, &wait, TASK_INTERRUPTIBLE);
+
+ ret = 0;
+ smp_rmb();
+ if (ring->head != ring->tail)
+ break;
+ if (!min_events)
+ break;
+
+ schedule();
+
+ ret = -EINVAL;
+ if (atomic_read(&ctx->dead))
+ break;
+ ret = -EINTR;
+ if (signal_pending(current))
+ break;
+ } while (1);
+
+ finish_wait(&ctx->wait, &wait);
+ return ret;
+}
+
+static int __io_ring_enter(struct kioctx *ctx, unsigned int to_submit,
+ unsigned int min_complete, unsigned int flags)
+{
+ int ret = 0;
+
+ if (flags & IORING_FLAG_SUBMIT) {
+ ret = aio_ring_submit(ctx, to_submit);
+ if (ret < 0)
+ return ret;
+ }
+ if (flags & IORING_FLAG_GETEVENTS) {
+ unsigned int nr_events = 0;
+ int get_ret;
+
+ if (!ret && to_submit)
+ min_complete = 0;
+
+ if (ctx->flags & IOCTX_FLAG_IOPOLL)
+ get_ret = __aio_iopoll_check(ctx, NULL, &nr_events,
+ min_complete, -1U);
+ else
+ get_ret = aio_cqring_wait(ctx, min_complete);
+
+ if (get_ret < 0 && !ret)
+ ret = get_ret;
+ }
+
+ return ret;
+}
+
+/* sys_io_ring_enter:
+ * Alternative way to both submit and complete IO, instead of using
+ * io_submit(2) and io_getevents(2). Requires the use of the SQ/CQ
+ * ring interface, hence the io_context must be setup with
+ * io_setup2() and IOCTX_FLAG_SCQRING must be specified (and the
+ * sq_ring/cq_ring passed in).
+ *
+ * Returns the number of IOs submitted, if IORING_FLAG_SUBMIT
+ * is used, otherwise returns 0 for IORING_FLAG_GETEVENTS success,
+ * but not the number of events, as those will have to be found
+ * by the application by reading the CQ ring anyway.
+ *
+ * Apart from that, the error returns are much like io_submit()
+ * and io_getevents(), since a lot of the same error conditions
+ * are shared.
+ */
+SYSCALL_DEFINE4(io_ring_enter, aio_context_t, ctx_id, u32, to_submit,
+ u32, min_complete, u32, flags)
+{
+ struct kioctx *ctx;
+ long ret;
+
+ BUILD_BUG_ON(sizeof(struct aio_iocb_ring) != sizeof(struct iocb));
+ BUILD_BUG_ON(sizeof(struct aio_io_event_ring) !=
+ sizeof(struct io_event));
+
+ ctx = lookup_ioctx(ctx_id);
+ if (!ctx) {
+ pr_debug("EINVAL: invalid context id\n");
+ return -EINVAL;
+ }
+
+ ret = -EBUSY;
+ if (!mutex_trylock(&ctx->getevents_lock))
+ goto err;
+
+ ret = -EOVERFLOW;
+ if (ctx->cq_ring_overflow) {
+ ctx->cq_ring_overflow = 0;
+ goto err_unlock;
+ }
+
+ ret = -EINVAL;
+ if (unlikely(atomic_read(&ctx->dead)))
+ goto err_unlock;
+
+ if (ctx->flags & IOCTX_FLAG_SCQRING)
+ ret = __io_ring_enter(ctx, to_submit, min_complete, flags);
+
+err_unlock:
+ mutex_unlock(&ctx->getevents_lock);
+err:
+ percpu_ref_put(&ctx->users);
+ return ret;
+}
+
/* sys_io_submit:
* Queue the nr iocbs pointed to by iocbpp for processing. Returns
* the number of iocbs queued. May return -EINVAL if the aio_context
@@ -2749,6 +3128,10 @@ SYSCALL_DEFINE3(io_submit, aio_context_t, ctx_id, long, nr,
return -EINVAL;
}
+ /* SCQRING must use io_ring_enter() */
+ if (ctx->flags & IOCTX_FLAG_SCQRING)
+ return -EINVAL;
+
if (nr > ctx->nr_events)
nr = ctx->nr_events;
@@ -2865,7 +3248,7 @@ SYSCALL_DEFINE3(io_cancel, aio_context_t, ctx_id, struct iocb __user *, iocb,
if (unlikely(!ctx))
return -EINVAL;
- if (ctx->flags & (IOCTX_FLAG_USERIOCB | IOCTX_FLAG_IOPOLL))
+ if (!aio_ctx_supports_cancel(ctx))
goto err;
spin_lock_irq(&ctx->ctx_lock);
@@ -2900,7 +3283,10 @@ static long do_io_getevents(aio_context_t ctx_id,
long ret = -EINVAL;
if (likely(ioctx)) {
- if (likely(min_nr <= nr && min_nr >= 0)) {
+ /* SCQRING must use io_ring_enter() */
+ if (ioctx->flags & IOCTX_FLAG_SCQRING)
+ ret = -EINVAL;
+ else if (min_nr <= nr && min_nr >= 0) {
if (ioctx->flags & IOCTX_FLAG_IOPOLL)
ret = aio_iopoll_check(ioctx, min_nr, nr, events);
else
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index a20a663d583f..576725d00020 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -288,8 +288,10 @@ static inline void addr_limit_user_check(void)
#ifndef CONFIG_ARCH_HAS_SYSCALL_WRAPPER
asmlinkage long sys_io_setup(unsigned nr_reqs, aio_context_t __user *ctx);
asmlinkage long sys_io_setup2(unsigned, unsigned, struct iocb __user *,
- void __user *, void __user *,
+ struct aio_iocb_ring __user *,
+ struct aio_io_event_ring __user *,
aio_context_t __user *);
+asmlinkage long sys_io_ring_enter(aio_context_t, unsigned, unsigned, unsigned);
asmlinkage long sys_io_destroy(aio_context_t ctx);
asmlinkage long sys_io_submit(aio_context_t, long,
struct iocb __user * __user *);
diff --git a/include/uapi/linux/aio_abi.h b/include/uapi/linux/aio_abi.h
index 05d72cf86bd3..9fb7d0ec868f 100644
--- a/include/uapi/linux/aio_abi.h
+++ b/include/uapi/linux/aio_abi.h
@@ -111,6 +111,32 @@ struct iocb {
#define IOCTX_FLAG_USERIOCB (1 << 0) /* iocbs are user mapped */
#define IOCTX_FLAG_IOPOLL (1 << 1) /* io_context is polled */
#define IOCTX_FLAG_FIXEDBUFS (1 << 2) /* IO buffers are fixed */
+#define IOCTX_FLAG_SCQRING (1 << 3) /* Use SQ/CQ rings */
+
+struct aio_iocb_ring {
+ union {
+ struct {
+ u32 head, tail;
+ u32 nr_events;
+ };
+ struct iocb pad_iocb;
+ };
+ struct iocb iocbs[0];
+};
+
+struct aio_io_event_ring {
+ union {
+ struct {
+ u32 head, tail;
+ u32 nr_events;
+ };
+ struct io_event pad_event;
+ };
+ struct io_event events[0];
+};
+
+#define IORING_FLAG_SUBMIT (1 << 0)
+#define IORING_FLAG_GETEVENTS (1 << 1)
#undef IFBIG
#undef IFLITTLE
diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c
index 17c8b4393669..a32b7ea93838 100644
--- a/kernel/sys_ni.c
+++ b/kernel/sys_ni.c
@@ -38,6 +38,7 @@ asmlinkage long sys_ni_syscall(void)
COND_SYSCALL(io_setup);
COND_SYSCALL(io_setup2);
+COND_SYSCALL(io_ring_enter);
COND_SYSCALL_COMPAT(io_setup);
COND_SYSCALL(io_destroy);
COND_SYSCALL(io_submit);
--
2.17.1
next prev parent reply other threads:[~2018-12-11 0:16 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-11 0:15 [PATCHSET v7] Support for polled and buffed aio (and more) Jens Axboe
2018-12-11 0:15 ` [PATCH 01/27] fs: add an iopoll method to struct file_operations Jens Axboe
2018-12-11 0:15 ` [PATCH 02/27] block: add REQ_HIPRI_ASYNC Jens Axboe
2018-12-11 0:15 ` [PATCH 03/27] block: wire up block device iopoll method Jens Axboe
2018-12-11 0:15 ` [PATCH 04/27] block: use REQ_HIPRI_ASYNC for non-sync polled IO Jens Axboe
2018-12-11 0:15 ` [PATCH 05/27] iomap: wire up the iopoll method Jens Axboe
2018-12-11 0:15 ` [PATCH 06/27] aio: use assigned completion handler Jens Axboe
2018-12-11 0:15 ` [PATCH 07/27] aio: separate out ring reservation from req allocation Jens Axboe
2018-12-11 0:15 ` [PATCH 08/27] aio: don't zero entire aio_kiocb aio_get_req() Jens Axboe
2018-12-11 0:15 ` [PATCH 09/27] aio: only use blk plugs for > 2 depth submissions Jens Axboe
2018-12-11 0:15 ` [PATCH 10/27] aio: use iocb_put() instead of open coding it Jens Axboe
2018-12-11 0:15 ` [PATCH 11/27] aio: split out iocb copy from io_submit_one() Jens Axboe
2018-12-11 0:15 ` [PATCH 12/27] aio: abstract out io_event filler helper Jens Axboe
2018-12-11 0:15 ` [PATCH 13/27] aio: add io_setup2() system call Jens Axboe
2018-12-11 0:15 ` [PATCH 14/27] aio: add support for having user mapped iocbs Jens Axboe
2018-12-11 0:15 ` [PATCH 15/27] aio: support for IO polling Jens Axboe
2018-12-11 0:15 ` [PATCH 16/27] aio: add submission side request cache Jens Axboe
2018-12-11 0:15 ` [PATCH 17/27] fs: add fget_many() and fput_many() Jens Axboe
2018-12-11 0:15 ` [PATCH 18/27] aio: use fget/fput_many() for file references Jens Axboe
2018-12-11 0:15 ` [PATCH 19/27] aio: split iocb init from allocation Jens Axboe
2018-12-11 0:15 ` [PATCH 20/27] aio: batch aio_kiocb allocation Jens Axboe
2018-12-11 0:15 ` [PATCH 21/27] block: add BIO_HOLD_PAGES flag Jens Axboe
2018-12-11 0:15 ` [PATCH 22/27] block: implement bio helper to add iter bvec pages to bio Jens Axboe
2018-12-11 0:15 ` [PATCH 23/27] fs: add support for mapping an ITER_BVEC for O_DIRECT Jens Axboe
2018-12-11 0:15 ` [PATCH 24/27] aio: add support for pre-mapped user IO buffers Jens Axboe
2018-12-11 0:15 ` [PATCH 25/27] aio: split old ring complete out from aio_complete() Jens Axboe
2018-12-11 0:15 ` Jens Axboe [this message]
2018-12-11 0:15 ` [PATCH 27/27] aio: support kernel side submission for aio with SCQRING Jens Axboe
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