for-6.8/io_uring-2024-01-18

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Merge tag 'for-6.8/io_uring-2024-01-18' of git://git.kernel.dk/linux

Pull io_uring fixes from Jens Axboe:
 "Nothing major in here, just a few fixes and cleanups that arrived
  after the initial merge window pull request got finalized, as well as
  a fix for a patch that got merged earlier"

* tag 'for-6.8/io_uring-2024-01-18' of git://git.kernel.dk/linux:
  io_uring: combine cq_wait_nr checks
  io_uring: clean *local_work_add var naming
  io_uring: clean up local tw add-wait sync
  io_uring: adjust defer tw counting
  io_uring/register: guard compat syscall with CONFIG_COMPAT
  io_uring/rsrc: improve code generation for fixed file assignment
  io_uring/rw: cleanup io_rw_done()
This commit is contained in:
Linus Torvalds 2024-01-18 18:17:57 -08:00
commit e9a5a78d1a
4 changed files with 86 additions and 47 deletions

View file

@ -137,6 +137,14 @@ struct io_defer_entry {
#define IO_DISARM_MASK (REQ_F_ARM_LTIMEOUT | REQ_F_LINK_TIMEOUT | REQ_F_FAIL)
#define IO_REQ_LINK_FLAGS (REQ_F_LINK | REQ_F_HARDLINK)
/*
* No waiters. It's larger than any valid value of the tw counter
* so that tests against ->cq_wait_nr would fail and skip wake_up().
*/
#define IO_CQ_WAKE_INIT (-1U)
/* Forced wake up if there is a waiter regardless of ->cq_wait_nr */
#define IO_CQ_WAKE_FORCE (IO_CQ_WAKE_INIT >> 1)
static bool io_uring_try_cancel_requests(struct io_ring_ctx *ctx,
struct task_struct *task,
bool cancel_all);
@ -303,6 +311,7 @@ static __cold struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p)
goto err;
ctx->flags = p->flags;
atomic_set(&ctx->cq_wait_nr, IO_CQ_WAKE_INIT);
init_waitqueue_head(&ctx->sqo_sq_wait);
INIT_LIST_HEAD(&ctx->sqd_list);
INIT_LIST_HEAD(&ctx->cq_overflow_list);
@ -1304,16 +1313,23 @@ static inline void io_req_local_work_add(struct io_kiocb *req, unsigned flags)
{
struct io_ring_ctx *ctx = req->ctx;
unsigned nr_wait, nr_tw, nr_tw_prev;
struct llist_node *first;
struct llist_node *head;
/* See comment above IO_CQ_WAKE_INIT */
BUILD_BUG_ON(IO_CQ_WAKE_FORCE <= IORING_MAX_CQ_ENTRIES);
/*
* We don't know how many reuqests is there in the link and whether
* they can even be queued lazily, fall back to non-lazy.
*/
if (req->flags & (REQ_F_LINK | REQ_F_HARDLINK))
flags &= ~IOU_F_TWQ_LAZY_WAKE;
first = READ_ONCE(ctx->work_llist.first);
head = READ_ONCE(ctx->work_llist.first);
do {
nr_tw_prev = 0;
if (first) {
struct io_kiocb *first_req = container_of(first,
if (head) {
struct io_kiocb *first_req = container_of(head,
struct io_kiocb,
io_task_work.node);
/*
@ -1322,17 +1338,29 @@ static inline void io_req_local_work_add(struct io_kiocb *req, unsigned flags)
*/
nr_tw_prev = READ_ONCE(first_req->nr_tw);
}
/*
* Theoretically, it can overflow, but that's fine as one of
* previous adds should've tried to wake the task.
*/
nr_tw = nr_tw_prev + 1;
/* Large enough to fail the nr_wait comparison below */
if (!(flags & IOU_F_TWQ_LAZY_WAKE))
nr_tw = -1U;
nr_tw = IO_CQ_WAKE_FORCE;
req->nr_tw = nr_tw;
req->io_task_work.node.next = first;
} while (!try_cmpxchg(&ctx->work_llist.first, &first,
req->io_task_work.node.next = head;
} while (!try_cmpxchg(&ctx->work_llist.first, &head,
&req->io_task_work.node));
if (!first) {
/*
* cmpxchg implies a full barrier, which pairs with the barrier
* in set_current_state() on the io_cqring_wait() side. It's used
* to ensure that either we see updated ->cq_wait_nr, or waiters
* going to sleep will observe the work added to the list, which
* is similar to the wait/wawke task state sync.
*/
if (!head) {
if (ctx->flags & IORING_SETUP_TASKRUN_FLAG)
atomic_or(IORING_SQ_TASKRUN, &ctx->rings->sq_flags);
if (ctx->has_evfd)
@ -1340,14 +1368,12 @@ static inline void io_req_local_work_add(struct io_kiocb *req, unsigned flags)
}
nr_wait = atomic_read(&ctx->cq_wait_nr);
/* no one is waiting */
if (!nr_wait)
/* not enough or no one is waiting */
if (nr_tw < nr_wait)
return;
/* either not enough or the previous add has already woken it up */
if (nr_wait > nr_tw || nr_tw_prev >= nr_wait)
/* the previous add has already woken it up */
if (nr_tw_prev >= nr_wait)
return;
/* pairs with set_current_state() in io_cqring_wait() */
smp_mb__after_atomic();
wake_up_state(ctx->submitter_task, TASK_INTERRUPTIBLE);
}
@ -2000,9 +2026,10 @@ inline struct file *io_file_get_fixed(struct io_kiocb *req, int fd,
goto out;
fd = array_index_nospec(fd, ctx->nr_user_files);
slot = io_fixed_file_slot(&ctx->file_table, fd);
file = io_slot_file(slot);
if (!req->rsrc_node)
__io_req_set_rsrc_node(req, ctx);
req->flags |= io_slot_flags(slot);
io_req_set_rsrc_node(req, ctx, 0);
file = io_slot_file(slot);
out:
io_ring_submit_unlock(ctx, issue_flags);
return file;
@ -2613,7 +2640,7 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events,
ret = io_cqring_wait_schedule(ctx, &iowq);
__set_current_state(TASK_RUNNING);
atomic_set(&ctx->cq_wait_nr, 0);
atomic_set(&ctx->cq_wait_nr, IO_CQ_WAKE_INIT);
/*
* Run task_work after scheduling and before io_should_wake().

View file

@ -14,6 +14,7 @@
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/nospec.h>
#include <linux/compat.h>
#include <linux/io_uring.h>
#include <linux/io_uring_types.h>
@ -278,13 +279,14 @@ static __cold int io_register_iowq_aff(struct io_ring_ctx *ctx,
if (len > cpumask_size())
len = cpumask_size();
if (in_compat_syscall()) {
#ifdef CONFIG_COMPAT
if (in_compat_syscall())
ret = compat_get_bitmap(cpumask_bits(new_mask),
(const compat_ulong_t __user *)arg,
len * 8 /* CHAR_BIT */);
} else {
else
#endif
ret = copy_from_user(new_mask, arg, len);
}
if (ret) {
free_cpumask_var(new_mask);

View file

@ -102,17 +102,21 @@ static inline void io_charge_rsrc_node(struct io_ring_ctx *ctx,
node->refs++;
}
static inline void __io_req_set_rsrc_node(struct io_kiocb *req,
struct io_ring_ctx *ctx)
{
lockdep_assert_held(&ctx->uring_lock);
req->rsrc_node = ctx->rsrc_node;
io_charge_rsrc_node(ctx, ctx->rsrc_node);
}
static inline void io_req_set_rsrc_node(struct io_kiocb *req,
struct io_ring_ctx *ctx,
unsigned int issue_flags)
{
if (!req->rsrc_node) {
io_ring_submit_lock(ctx, issue_flags);
lockdep_assert_held(&ctx->uring_lock);
req->rsrc_node = ctx->rsrc_node;
io_charge_rsrc_node(ctx, ctx->rsrc_node);
__io_req_set_rsrc_node(req, ctx);
io_ring_submit_unlock(ctx, issue_flags);
}
}

View file

@ -168,27 +168,6 @@ void io_readv_writev_cleanup(struct io_kiocb *req)
kfree(io->free_iovec);
}
static inline void io_rw_done(struct kiocb *kiocb, ssize_t ret)
{
switch (ret) {
case -EIOCBQUEUED:
break;
case -ERESTARTSYS:
case -ERESTARTNOINTR:
case -ERESTARTNOHAND:
case -ERESTART_RESTARTBLOCK:
/*
* We can't just restart the syscall, since previously
* submitted sqes may already be in progress. Just fail this
* IO with EINTR.
*/
ret = -EINTR;
fallthrough;
default:
kiocb->ki_complete(kiocb, ret);
}
}
static inline loff_t *io_kiocb_update_pos(struct io_kiocb *req)
{
struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw);
@ -371,6 +350,33 @@ static void io_complete_rw_iopoll(struct kiocb *kiocb, long res)
smp_store_release(&req->iopoll_completed, 1);
}
static inline void io_rw_done(struct kiocb *kiocb, ssize_t ret)
{
/* IO was queued async, completion will happen later */
if (ret == -EIOCBQUEUED)
return;
/* transform internal restart error codes */
if (unlikely(ret < 0)) {
switch (ret) {
case -ERESTARTSYS:
case -ERESTARTNOINTR:
case -ERESTARTNOHAND:
case -ERESTART_RESTARTBLOCK:
/*
* We can't just restart the syscall, since previously
* submitted sqes may already be in progress. Just fail
* this IO with EINTR.
*/
ret = -EINTR;
break;
}
}
INDIRECT_CALL_2(kiocb->ki_complete, io_complete_rw_iopoll,
io_complete_rw, kiocb, ret);
}
static int kiocb_done(struct io_kiocb *req, ssize_t ret,
unsigned int issue_flags)
{