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Merge branch 'io_uring-5.5' into for-linus

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* io_uring-5.5:
  io_uring: fix a typo in a comment
  io_uring: hook all linked requests via link_list
  io_uring: fix error handling in io_queue_link_head
  io_uring: use hash table for poll command lookups
This commit is contained in:
Jens Axboe 2019-12-05 19:09:26 -07:00
commit 8539429917
1 changed files with 68 additions and 70 deletions
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138
fs/io_uring.c
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@ -145,7 +145,7 @@ struct io_rings {
/* /*
* Number of completion events lost because the queue was full; * Number of completion events lost because the queue was full;
* this should be avoided by the application by making sure * this should be avoided by the application by making sure
* there are not more requests pending thatn there is space in * there are not more requests pending than there is space in
* the completion queue. * the completion queue.
* *
* Written by the kernel, shouldn't be modified by the * Written by the kernel, shouldn't be modified by the
@ -275,7 +275,8 @@ struct io_ring_ctx {
* manipulate the list, hence no extra locking is needed there. * manipulate the list, hence no extra locking is needed there.
*/ */
struct list_head poll_list; struct list_head poll_list;
struct rb_root cancel_tree; struct hlist_head *cancel_hash;
unsigned cancel_hash_bits;
spinlock_t inflight_lock; spinlock_t inflight_lock;
struct list_head inflight_list; struct list_head inflight_list;
@ -355,7 +356,7 @@ struct io_kiocb {
struct io_ring_ctx *ctx; struct io_ring_ctx *ctx;
union { union {
struct list_head list; struct list_head list;
struct rb_node rb_node; struct hlist_node hash_node;
}; };
struct list_head link_list; struct list_head link_list;
unsigned int flags; unsigned int flags;
@ -444,6 +445,7 @@ static void io_ring_ctx_ref_free(struct percpu_ref *ref)
static struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p) static struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p)
{ {
struct io_ring_ctx *ctx; struct io_ring_ctx *ctx;
int hash_bits;
ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
if (!ctx) if (!ctx)
@ -457,6 +459,21 @@ static struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p)
if (!ctx->completions) if (!ctx->completions)
goto err; goto err;
/*
* Use 5 bits less than the max cq entries, that should give us around
* 32 entries per hash list if totally full and uniformly spread.
*/
hash_bits = ilog2(p->cq_entries);
hash_bits -= 5;
if (hash_bits <= 0)
hash_bits = 1;
ctx->cancel_hash_bits = hash_bits;
ctx->cancel_hash = kmalloc((1U << hash_bits) * sizeof(struct hlist_head),
GFP_KERNEL);
if (!ctx->cancel_hash)
goto err;
__hash_init(ctx->cancel_hash, 1U << hash_bits);
if (percpu_ref_init(&ctx->refs, io_ring_ctx_ref_free, if (percpu_ref_init(&ctx->refs, io_ring_ctx_ref_free,
PERCPU_REF_ALLOW_REINIT, GFP_KERNEL)) PERCPU_REF_ALLOW_REINIT, GFP_KERNEL))
goto err; goto err;
@ -470,7 +487,6 @@ static struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p)
init_waitqueue_head(&ctx->wait); init_waitqueue_head(&ctx->wait);
spin_lock_init(&ctx->completion_lock); spin_lock_init(&ctx->completion_lock);
INIT_LIST_HEAD(&ctx->poll_list); INIT_LIST_HEAD(&ctx->poll_list);
ctx->cancel_tree = RB_ROOT;
INIT_LIST_HEAD(&ctx->defer_list); INIT_LIST_HEAD(&ctx->defer_list);
INIT_LIST_HEAD(&ctx->timeout_list); INIT_LIST_HEAD(&ctx->timeout_list);
init_waitqueue_head(&ctx->inflight_wait); init_waitqueue_head(&ctx->inflight_wait);
@ -481,6 +497,7 @@ err:
if (ctx->fallback_req) if (ctx->fallback_req)
kmem_cache_free(req_cachep, ctx->fallback_req); kmem_cache_free(req_cachep, ctx->fallback_req);
kfree(ctx->completions); kfree(ctx->completions);
kfree(ctx->cancel_hash);
kfree(ctx); kfree(ctx);
return NULL; return NULL;
} }
@ -899,7 +916,6 @@ static bool io_link_cancel_timeout(struct io_kiocb *req)
static void io_req_link_next(struct io_kiocb *req, struct io_kiocb **nxtptr) static void io_req_link_next(struct io_kiocb *req, struct io_kiocb **nxtptr)
{ {
struct io_ring_ctx *ctx = req->ctx; struct io_ring_ctx *ctx = req->ctx;
struct io_kiocb *nxt;
bool wake_ev = false; bool wake_ev = false;
/* Already got next link */ /* Already got next link */
@ -911,24 +927,21 @@ static void io_req_link_next(struct io_kiocb *req, struct io_kiocb **nxtptr)
* potentially happen if the chain is messed up, check to be on the * potentially happen if the chain is messed up, check to be on the
* safe side. * safe side.
*/ */
nxt = list_first_entry_or_null(&req->link_list, struct io_kiocb, list); while (!list_empty(&req->link_list)) {
while (nxt) { struct io_kiocb *nxt = list_first_entry(&req->link_list,
list_del_init(&nxt->list); struct io_kiocb, link_list);
if ((req->flags & REQ_F_LINK_TIMEOUT) && if (unlikely((req->flags & REQ_F_LINK_TIMEOUT) &&
(nxt->flags & REQ_F_TIMEOUT)) { (nxt->flags & REQ_F_TIMEOUT))) {
list_del_init(&nxt->link_list);
wake_ev |= io_link_cancel_timeout(nxt); wake_ev |= io_link_cancel_timeout(nxt);
nxt = list_first_entry_or_null(&req->link_list,
struct io_kiocb, list);
req->flags &= ~REQ_F_LINK_TIMEOUT; req->flags &= ~REQ_F_LINK_TIMEOUT;
continue; continue;
} }
if (!list_empty(&req->link_list)) {
INIT_LIST_HEAD(&nxt->link_list);
list_splice(&req->link_list, &nxt->link_list);
nxt->flags |= REQ_F_LINK;
}
list_del_init(&req->link_list);
if (!list_empty(&nxt->link_list))
nxt->flags |= REQ_F_LINK;
*nxtptr = nxt; *nxtptr = nxt;
break; break;
} }
@ -944,15 +957,15 @@ static void io_req_link_next(struct io_kiocb *req, struct io_kiocb **nxtptr)
static void io_fail_links(struct io_kiocb *req) static void io_fail_links(struct io_kiocb *req)
{ {
struct io_ring_ctx *ctx = req->ctx; struct io_ring_ctx *ctx = req->ctx;
struct io_kiocb *link;
unsigned long flags; unsigned long flags;
spin_lock_irqsave(&ctx->completion_lock, flags); spin_lock_irqsave(&ctx->completion_lock, flags);
while (!list_empty(&req->link_list)) { while (!list_empty(&req->link_list)) {
link = list_first_entry(&req->link_list, struct io_kiocb, list); struct io_kiocb *link = list_first_entry(&req->link_list,
list_del_init(&link->list); struct io_kiocb, link_list);
list_del_init(&link->link_list);
trace_io_uring_fail_link(req, link); trace_io_uring_fail_link(req, link);
if ((req->flags & REQ_F_LINK_TIMEOUT) && if ((req->flags & REQ_F_LINK_TIMEOUT) &&
@ -2260,14 +2273,6 @@ out:
#endif #endif
} }
static inline void io_poll_remove_req(struct io_kiocb *req)
{
if (!RB_EMPTY_NODE(&req->rb_node)) {
rb_erase(&req->rb_node, &req->ctx->cancel_tree);
RB_CLEAR_NODE(&req->rb_node);
}
}
static void io_poll_remove_one(struct io_kiocb *req) static void io_poll_remove_one(struct io_kiocb *req)
{ {
struct io_poll_iocb *poll = &req->poll; struct io_poll_iocb *poll = &req->poll;
@ -2279,36 +2284,34 @@ static void io_poll_remove_one(struct io_kiocb *req)
io_queue_async_work(req); io_queue_async_work(req);
} }
spin_unlock(&poll->head->lock); spin_unlock(&poll->head->lock);
io_poll_remove_req(req); hash_del(&req->hash_node);
} }
static void io_poll_remove_all(struct io_ring_ctx *ctx) static void io_poll_remove_all(struct io_ring_ctx *ctx)
{ {
struct rb_node *node; struct hlist_node *tmp;
struct io_kiocb *req; struct io_kiocb *req;
int i;
spin_lock_irq(&ctx->completion_lock); spin_lock_irq(&ctx->completion_lock);
while ((node = rb_first(&ctx->cancel_tree)) != NULL) { for (i = 0; i < (1U << ctx->cancel_hash_bits); i++) {
req = rb_entry(node, struct io_kiocb, rb_node); struct hlist_head *list;
io_poll_remove_one(req);
list = &ctx->cancel_hash[i];
hlist_for_each_entry_safe(req, tmp, list, hash_node)
io_poll_remove_one(req);
} }
spin_unlock_irq(&ctx->completion_lock); spin_unlock_irq(&ctx->completion_lock);
} }
static int io_poll_cancel(struct io_ring_ctx *ctx, __u64 sqe_addr) static int io_poll_cancel(struct io_ring_ctx *ctx, __u64 sqe_addr)
{ {
struct rb_node *p, *parent = NULL; struct hlist_head *list;
struct io_kiocb *req; struct io_kiocb *req;
p = ctx->cancel_tree.rb_node; list = &ctx->cancel_hash[hash_long(sqe_addr, ctx->cancel_hash_bits)];
while (p) { hlist_for_each_entry(req, list, hash_node) {
parent = p; if (sqe_addr == req->user_data) {
req = rb_entry(parent, struct io_kiocb, rb_node);
if (sqe_addr < req->user_data) {
p = p->rb_left;
} else if (sqe_addr > req->user_data) {
p = p->rb_right;
} else {
io_poll_remove_one(req); io_poll_remove_one(req);
return 0; return 0;
} }
@ -2390,7 +2393,7 @@ static void io_poll_complete_work(struct io_wq_work **workptr)
spin_unlock_irq(&ctx->completion_lock); spin_unlock_irq(&ctx->completion_lock);
return; return;
} }
io_poll_remove_req(req); hash_del(&req->hash_node);
io_poll_complete(req, mask, ret); io_poll_complete(req, mask, ret);
spin_unlock_irq(&ctx->completion_lock); spin_unlock_irq(&ctx->completion_lock);
@ -2425,7 +2428,7 @@ static int io_poll_wake(struct wait_queue_entry *wait, unsigned mode, int sync,
* for finalizing the request, mark us as having grabbed that already. * for finalizing the request, mark us as having grabbed that already.
*/ */
if (mask && spin_trylock_irqsave(&ctx->completion_lock, flags)) { if (mask && spin_trylock_irqsave(&ctx->completion_lock, flags)) {
io_poll_remove_req(req); hash_del(&req->hash_node);
io_poll_complete(req, mask, 0); io_poll_complete(req, mask, 0);
req->flags |= REQ_F_COMP_LOCKED; req->flags |= REQ_F_COMP_LOCKED;
io_put_req(req); io_put_req(req);
@ -2463,20 +2466,10 @@ static void io_poll_queue_proc(struct file *file, struct wait_queue_head *head,
static void io_poll_req_insert(struct io_kiocb *req) static void io_poll_req_insert(struct io_kiocb *req)
{ {
struct io_ring_ctx *ctx = req->ctx; struct io_ring_ctx *ctx = req->ctx;
struct rb_node **p = &ctx->cancel_tree.rb_node; struct hlist_head *list;
struct rb_node *parent = NULL;
struct io_kiocb *tmp;
while (*p) { list = &ctx->cancel_hash[hash_long(req->user_data, ctx->cancel_hash_bits)];
parent = *p; hlist_add_head(&req->hash_node, list);
tmp = rb_entry(parent, struct io_kiocb, rb_node);
if (req->user_data < tmp->user_data)
p = &(*p)->rb_left;
else
p = &(*p)->rb_right;
}
rb_link_node(&req->rb_node, parent, p);
rb_insert_color(&req->rb_node, &ctx->cancel_tree);
} }
static int io_poll_add(struct io_kiocb *req, const struct io_uring_sqe *sqe, static int io_poll_add(struct io_kiocb *req, const struct io_uring_sqe *sqe,
@ -2504,7 +2497,7 @@ static int io_poll_add(struct io_kiocb *req, const struct io_uring_sqe *sqe,
INIT_IO_WORK(&req->work, io_poll_complete_work); INIT_IO_WORK(&req->work, io_poll_complete_work);
events = READ_ONCE(sqe->poll_events); events = READ_ONCE(sqe->poll_events);
poll->events = demangle_poll(events) | EPOLLERR | EPOLLHUP; poll->events = demangle_poll(events) | EPOLLERR | EPOLLHUP;
RB_CLEAR_NODE(&req->rb_node); INIT_HLIST_NODE(&req->hash_node);
poll->head = NULL; poll->head = NULL;
poll->done = false; poll->done = false;
@ -3173,10 +3166,11 @@ static enum hrtimer_restart io_link_timeout_fn(struct hrtimer *timer)
* We don't expect the list to be empty, that will only happen if we * We don't expect the list to be empty, that will only happen if we
* race with the completion of the linked work. * race with the completion of the linked work.
*/ */
if (!list_empty(&req->list)) { if (!list_empty(&req->link_list)) {
prev = list_entry(req->list.prev, struct io_kiocb, link_list); prev = list_entry(req->link_list.prev, struct io_kiocb,
link_list);
if (refcount_inc_not_zero(&prev->refs)) { if (refcount_inc_not_zero(&prev->refs)) {
list_del_init(&req->list); list_del_init(&req->link_list);
prev->flags &= ~REQ_F_LINK_TIMEOUT; prev->flags &= ~REQ_F_LINK_TIMEOUT;
} else } else
prev = NULL; prev = NULL;
@ -3206,7 +3200,7 @@ static void io_queue_linked_timeout(struct io_kiocb *req)
* we got a chance to setup the timer * we got a chance to setup the timer
*/ */
spin_lock_irq(&ctx->completion_lock); spin_lock_irq(&ctx->completion_lock);
if (!list_empty(&req->list)) { if (!list_empty(&req->link_list)) {
struct io_timeout_data *data = &req->io->timeout; struct io_timeout_data *data = &req->io->timeout;
data->timer.function = io_link_timeout_fn; data->timer.function = io_link_timeout_fn;
@ -3226,7 +3220,8 @@ static struct io_kiocb *io_prep_linked_timeout(struct io_kiocb *req)
if (!(req->flags & REQ_F_LINK)) if (!(req->flags & REQ_F_LINK))
return NULL; return NULL;
nxt = list_first_entry_or_null(&req->link_list, struct io_kiocb, list); nxt = list_first_entry_or_null(&req->link_list, struct io_kiocb,
link_list);
if (!nxt || nxt->sqe->opcode != IORING_OP_LINK_TIMEOUT) if (!nxt || nxt->sqe->opcode != IORING_OP_LINK_TIMEOUT)
return NULL; return NULL;
@ -3318,7 +3313,7 @@ static inline void io_queue_link_head(struct io_kiocb *req)
#define SQE_VALID_FLAGS (IOSQE_FIXED_FILE|IOSQE_IO_DRAIN|IOSQE_IO_LINK) #define SQE_VALID_FLAGS (IOSQE_FIXED_FILE|IOSQE_IO_DRAIN|IOSQE_IO_LINK)
static void io_submit_sqe(struct io_kiocb *req, struct io_submit_state *state, static bool io_submit_sqe(struct io_kiocb *req, struct io_submit_state *state,
struct io_kiocb **link) struct io_kiocb **link)
{ {
struct io_ring_ctx *ctx = req->ctx; struct io_ring_ctx *ctx = req->ctx;
@ -3337,7 +3332,7 @@ static void io_submit_sqe(struct io_kiocb *req, struct io_submit_state *state,
err_req: err_req:
io_cqring_add_event(req, ret); io_cqring_add_event(req, ret);
io_double_put_req(req); io_double_put_req(req);
return; return false;
} }
/* /*
@ -3367,7 +3362,7 @@ err_req:
goto err_req; goto err_req;
} }
trace_io_uring_link(ctx, req, prev); trace_io_uring_link(ctx, req, prev);
list_add_tail(&req->list, &prev->link_list); list_add_tail(&req->link_list, &prev->link_list);
} else if (req->sqe->flags & IOSQE_IO_LINK) { } else if (req->sqe->flags & IOSQE_IO_LINK) {
req->flags |= REQ_F_LINK; req->flags |= REQ_F_LINK;
@ -3376,6 +3371,8 @@ err_req:
} else { } else {
io_queue_sqe(req); io_queue_sqe(req);
} }
return true;
} }
/* /*
@ -3505,6 +3502,7 @@ static int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr,
} }
} }
submitted++;
sqe_flags = req->sqe->flags; sqe_flags = req->sqe->flags;
req->ring_file = ring_file; req->ring_file = ring_file;
@ -3514,9 +3512,8 @@ static int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr,
req->needs_fixed_file = async; req->needs_fixed_file = async;
trace_io_uring_submit_sqe(ctx, req->sqe->user_data, trace_io_uring_submit_sqe(ctx, req->sqe->user_data,
true, async); true, async);
io_submit_sqe(req, statep, &link); if (!io_submit_sqe(req, statep, &link))
submitted++; break;
/* /*
* If previous wasn't linked and we have a linked command, * If previous wasn't linked and we have a linked command,
* that's the end of the chain. Submit the previous link. * that's the end of the chain. Submit the previous link.
@ -4644,6 +4641,7 @@ static void io_ring_ctx_free(struct io_ring_ctx *ctx)
free_uid(ctx->user); free_uid(ctx->user);
put_cred(ctx->creds); put_cred(ctx->creds);
kfree(ctx->completions); kfree(ctx->completions);
kfree(ctx->cancel_hash);
kmem_cache_free(req_cachep, ctx->fallback_req); kmem_cache_free(req_cachep, ctx->fallback_req);
kfree(ctx); kfree(ctx);
} }