diff options
| -rw-r--r-- | fs/io_uring.c | 133 |
1 files changed, 52 insertions, 81 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c index 2d14a4f636d6..a0a6d13c0c16 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -600,7 +600,6 @@ enum { REQ_F_FORCE_ASYNC_BIT = IOSQE_ASYNC_BIT, REQ_F_BUFFER_SELECT_BIT = IOSQE_BUFFER_SELECT_BIT, - REQ_F_LINK_HEAD_BIT, REQ_F_FAIL_LINK_BIT, REQ_F_INFLIGHT_BIT, REQ_F_CUR_POS_BIT, @@ -632,8 +631,6 @@ enum { /* IOSQE_BUFFER_SELECT */ REQ_F_BUFFER_SELECT = BIT(REQ_F_BUFFER_SELECT_BIT), - /* head of a link */ - REQ_F_LINK_HEAD = BIT(REQ_F_LINK_HEAD_BIT), /* fail rest of links */ REQ_F_FAIL_LINK = BIT(REQ_F_FAIL_LINK_BIT), /* on inflight list */ @@ -715,7 +712,7 @@ struct io_kiocb { struct task_struct *task; u64 user_data; - struct list_head link_list; + struct io_kiocb *link; /* * 1. used with ctx->iopoll_list with reads/writes @@ -1023,6 +1020,9 @@ struct sock *io_uring_get_socket(struct file *file) } EXPORT_SYMBOL(io_uring_get_socket); +#define io_for_each_link(pos, head) \ + for (pos = (head); pos; pos = pos->link) + static inline void io_clean_op(struct io_kiocb *req) { if (req->flags & (REQ_F_NEED_CLEANUP | REQ_F_BUFFER_SELECTED | @@ -1501,10 +1501,8 @@ static void io_prep_async_link(struct io_kiocb *req) { struct io_kiocb *cur; - io_prep_async_work(req); - if (req->flags & REQ_F_LINK_HEAD) - list_for_each_entry(cur, &req->link_list, link_list) - io_prep_async_work(cur); + io_for_each_link(cur, req) + io_prep_async_work(cur); } static struct io_kiocb *__io_queue_async_work(struct io_kiocb *req) @@ -1687,20 +1685,15 @@ static inline bool __io_match_files(struct io_kiocb *req, req->work.identity->files == files; } -static bool io_match_files(struct io_kiocb *req, - struct files_struct *files) +static bool io_match_files(struct io_kiocb *head, struct files_struct *files) { - struct io_kiocb *link; + struct io_kiocb *req; if (!files) return true; - if (__io_match_files(req, files)) - return true; - if (req->flags & REQ_F_LINK_HEAD) { - list_for_each_entry(link, &req->link_list, link_list) { - if (__io_match_files(link, files)) - return true; - } + io_for_each_link(req, head) { + if (__io_match_files(req, files)) + return true; } return false; } @@ -1967,6 +1960,14 @@ static void __io_free_req(struct io_kiocb *req) percpu_ref_put(&ctx->refs); } +static inline void io_remove_next_linked(struct io_kiocb *req) +{ + struct io_kiocb *nxt = req->link; + + req->link = nxt->link; + nxt->link = NULL; +} + static void io_kill_linked_timeout(struct io_kiocb *req) { struct io_ring_ctx *ctx = req->ctx; @@ -1975,8 +1976,8 @@ static void io_kill_linked_timeout(struct io_kiocb *req) unsigned long flags; spin_lock_irqsave(&ctx->completion_lock, flags); - link = list_first_entry_or_null(&req->link_list, struct io_kiocb, - link_list); + link = req->link; + /* * Can happen if a linked timeout fired and link had been like * req -> link t-out -> link t-out [-> ...] @@ -1985,7 +1986,7 @@ static void io_kill_linked_timeout(struct io_kiocb *req) struct io_timeout_data *io = link->async_data; int ret; - list_del_init(&link->link_list); + io_remove_next_linked(req); link->timeout.head = NULL; ret = hrtimer_try_to_cancel(&io->timer); if (ret != -1) { @@ -2003,41 +2004,22 @@ static void io_kill_linked_timeout(struct io_kiocb *req) } } -static struct io_kiocb *io_req_link_next(struct io_kiocb *req) -{ - struct io_kiocb *nxt; - - /* - * The list should never be empty when we are called here. But could - * potentially happen if the chain is messed up, check to be on the - * safe side. - */ - if (unlikely(list_empty(&req->link_list))) - return NULL; - - nxt = list_first_entry(&req->link_list, struct io_kiocb, link_list); - list_del_init(&req->link_list); - if (!list_empty(&nxt->link_list)) - nxt->flags |= REQ_F_LINK_HEAD; - return nxt; -} -/* - * Called if REQ_F_LINK_HEAD is set, and we fail the head request - */ static void io_fail_links(struct io_kiocb *req) { + struct io_kiocb *link, *nxt; struct io_ring_ctx *ctx = req->ctx; unsigned long flags; spin_lock_irqsave(&ctx->completion_lock, flags); - while (!list_empty(&req->link_list)) { - struct io_kiocb *link = list_first_entry(&req->link_list, - struct io_kiocb, link_list); + link = req->link; + req->link = NULL; - list_del_init(&link->link_list); - trace_io_uring_fail_link(req, link); + while (link) { + nxt = link->link; + link->link = NULL; + trace_io_uring_fail_link(req, link); io_cqring_fill_event(link, -ECANCELED); /* @@ -2049,8 +2031,8 @@ static void io_fail_links(struct io_kiocb *req) io_put_req_deferred(link, 2); else io_double_put_req(link); + link = nxt; } - io_commit_cqring(ctx); spin_unlock_irqrestore(&ctx->completion_lock, flags); @@ -2059,7 +2041,6 @@ static void io_fail_links(struct io_kiocb *req) static struct io_kiocb *__io_req_find_next(struct io_kiocb *req) { - req->flags &= ~REQ_F_LINK_HEAD; if (req->flags & REQ_F_LINK_TIMEOUT) io_kill_linked_timeout(req); @@ -2069,15 +2050,19 @@ static struct io_kiocb *__io_req_find_next(struct io_kiocb *req) * dependencies to the next request. In case of failure, fail the rest * of the chain. */ - if (likely(!(req->flags & REQ_F_FAIL_LINK))) - return io_req_link_next(req); + if (likely(!(req->flags & REQ_F_FAIL_LINK))) { + struct io_kiocb *nxt = req->link; + + req->link = NULL; + return nxt; + } io_fail_links(req); return NULL; } -static struct io_kiocb *io_req_find_next(struct io_kiocb *req) +static inline struct io_kiocb *io_req_find_next(struct io_kiocb *req) { - if (likely(!(req->flags & REQ_F_LINK_HEAD))) + if (likely(!(req->link) && !(req->flags & REQ_F_LINK_TIMEOUT))) return NULL; return __io_req_find_next(req); } @@ -2173,7 +2158,7 @@ static void io_req_task_queue(struct io_kiocb *req) } } -static void io_queue_next(struct io_kiocb *req) +static inline void io_queue_next(struct io_kiocb *req) { struct io_kiocb *nxt = io_req_find_next(req); @@ -2230,8 +2215,7 @@ static void io_req_free_batch(struct req_batch *rb, struct io_kiocb *req) io_free_req(req); return; } - if (req->flags & REQ_F_LINK_HEAD) - io_queue_next(req); + io_queue_next(req); if (req->task != rb->task) { if (rb->task) { @@ -6015,11 +5999,10 @@ static u32 io_get_sequence(struct io_kiocb *req) { struct io_kiocb *pos; struct io_ring_ctx *ctx = req->ctx; - u32 total_submitted, nr_reqs = 1; + u32 total_submitted, nr_reqs = 0; - if (req->flags & REQ_F_LINK_HEAD) - list_for_each_entry(pos, &req->link_list, link_list) - nr_reqs++; + io_for_each_link(pos, req) + nr_reqs++; total_submitted = ctx->cached_sq_head - ctx->cached_sq_dropped; return total_submitted - nr_reqs; @@ -6374,7 +6357,7 @@ static enum hrtimer_restart io_link_timeout_fn(struct hrtimer *timer) * race with the completion of the linked work. */ if (prev && refcount_inc_not_zero(&prev->refs)) - list_del_init(&req->link_list); + io_remove_next_linked(prev); else prev = NULL; spin_unlock_irqrestore(&ctx->completion_lock, flags); @@ -6392,8 +6375,8 @@ static enum hrtimer_restart io_link_timeout_fn(struct hrtimer *timer) static void __io_queue_linked_timeout(struct io_kiocb *req) { /* - * If the list is now empty, then our linked request finished before - * we got a chance to setup the timer + * If the back reference is NULL, then our linked request finished + * before we got a chance to setup the timer */ if (req->timeout.head) { struct io_timeout_data *data = req->async_data; @@ -6418,16 +6401,10 @@ static void io_queue_linked_timeout(struct io_kiocb *req) static struct io_kiocb *io_prep_linked_timeout(struct io_kiocb *req) { - struct io_kiocb *nxt; - - if (!(req->flags & REQ_F_LINK_HEAD)) - return NULL; - if (req->flags & REQ_F_LINK_TIMEOUT) - return NULL; + struct io_kiocb *nxt = req->link; - nxt = list_first_entry_or_null(&req->link_list, struct io_kiocb, - link_list); - if (!nxt || nxt->opcode != IORING_OP_LINK_TIMEOUT) + if (!nxt || (req->flags & REQ_F_LINK_TIMEOUT) || + nxt->opcode != IORING_OP_LINK_TIMEOUT) return NULL; nxt->timeout.head = req; @@ -6575,7 +6552,7 @@ static int io_submit_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe, return ret; } trace_io_uring_link(ctx, req, head); - list_add_tail(&req->link_list, &head->link_list); + link->last->link = req; link->last = req; /* last request of a link, enqueue the link */ @@ -6589,9 +6566,6 @@ static int io_submit_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe, ctx->drain_next = 0; } if (req->flags & (REQ_F_LINK | REQ_F_HARDLINK)) { - req->flags |= REQ_F_LINK_HEAD; - INIT_LIST_HEAD(&req->link_list); - ret = io_req_defer_prep(req, sqe); if (unlikely(ret)) req->flags |= REQ_F_FAIL_LINK; @@ -6724,6 +6698,7 @@ static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req, req->file = NULL; req->ctx = ctx; req->flags = 0; + req->link = NULL; /* one is dropped after submission, the other at completion */ refcount_set(&req->refs, 2); req->task = current; @@ -8682,14 +8657,10 @@ static bool io_match_link(struct io_kiocb *preq, struct io_kiocb *req) { struct io_kiocb *link; - if (!(preq->flags & REQ_F_LINK_HEAD)) - return false; - - list_for_each_entry(link, &preq->link_list, link_list) { + io_for_each_link(link, preq->link) { if (link == req) return true; } - return false; } |