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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 07/27] aio: separate out ring reservation from req allocation
Date: Mon, 10 Dec 2018 17:15:29 -0700	[thread overview]
Message-ID: <20181211001549.30085-8-axboe@kernel.dk> (raw)
In-Reply-To: <20181211001549.30085-1-axboe@kernel.dk>

From: Christoph Hellwig <hch@lst.de>

This is in preparation for certain types of IO not needing a ring
reserveration.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 fs/aio.c | 30 +++++++++++++++++-------------
 1 file changed, 17 insertions(+), 13 deletions(-)

diff --git a/fs/aio.c b/fs/aio.c
index cf0de61743e8..eaceb40e6cf5 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -901,7 +901,7 @@ static void put_reqs_available(struct kioctx *ctx, unsigned nr)
 	local_irq_restore(flags);
 }
 
-static bool get_reqs_available(struct kioctx *ctx)
+static bool __get_reqs_available(struct kioctx *ctx)
 {
 	struct kioctx_cpu *kcpu;
 	bool ret = false;
@@ -993,6 +993,14 @@ static void user_refill_reqs_available(struct kioctx *ctx)
 	spin_unlock_irq(&ctx->completion_lock);
 }
 
+static bool get_reqs_available(struct kioctx *ctx)
+{
+	if (__get_reqs_available(ctx))
+		return true;
+	user_refill_reqs_available(ctx);
+	return __get_reqs_available(ctx);
+}
+
 /* aio_get_req
  *	Allocate a slot for an aio request.
  * Returns NULL if no requests are free.
@@ -1001,24 +1009,15 @@ static inline struct aio_kiocb *aio_get_req(struct kioctx *ctx)
 {
 	struct aio_kiocb *req;
 
-	if (!get_reqs_available(ctx)) {
-		user_refill_reqs_available(ctx);
-		if (!get_reqs_available(ctx))
-			return NULL;
-	}
-
 	req = kmem_cache_alloc(kiocb_cachep, GFP_KERNEL|__GFP_ZERO);
 	if (unlikely(!req))
-		goto out_put;
+		return NULL;
 
 	percpu_ref_get(&ctx->reqs);
 	INIT_LIST_HEAD(&req->ki_list);
 	refcount_set(&req->ki_refcnt, 0);
 	req->ki_ctx = ctx;
 	return req;
-out_put:
-	put_reqs_available(ctx, 1);
-	return NULL;
 }
 
 static struct kioctx *lookup_ioctx(unsigned long ctx_id)
@@ -1805,9 +1804,13 @@ static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
 		return -EINVAL;
 	}
 
+	if (!get_reqs_available(ctx))
+		return -EAGAIN;
+
+	ret = -EAGAIN;
 	req = aio_get_req(ctx);
 	if (unlikely(!req))
-		return -EAGAIN;
+		goto out_put_reqs_available;
 
 	if (iocb.aio_flags & IOCB_FLAG_RESFD) {
 		/*
@@ -1870,11 +1873,12 @@ static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
 		goto out_put_req;
 	return 0;
 out_put_req:
-	put_reqs_available(ctx, 1);
 	percpu_ref_put(&ctx->reqs);
 	if (req->ki_eventfd)
 		eventfd_ctx_put(req->ki_eventfd);
 	kmem_cache_free(kiocb_cachep, req);
+out_put_reqs_available:
+	put_reqs_available(ctx, 1);
 	return ret;
 }
 
-- 
2.17.1


  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 ` Jens Axboe [this message]
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 ` [PATCH 26/27] aio: add support for submission/completion rings Jens Axboe
2018-12-11  0:15 ` [PATCH 27/27] aio: support kernel side submission for aio with SCQRING Jens Axboe

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