102 lines
2.8 KiB
Diff
102 lines
2.8 KiB
Diff
From: Christoph Hellwig <hch@lst.de>
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Date: Mon, 19 Nov 2018 15:57:42 -0700
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Subject: [03/14] aio: separate out ring reservation from req allocation
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Origin: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git/commit?id=730198c889d85db78058cfb57c1b41c65f55c94e
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commit 432c79978c33ecef91b1b04cea6936c20810da29 upstream.
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This is in preparation for certain types of IO not needing a ring
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reserveration.
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Signed-off-by: Christoph Hellwig <hch@lst.de>
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Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Cc: Guenter Roeck <linux@roeck-us.net>
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Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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---
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fs/aio.c | 30 +++++++++++++++++-------------
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1 file changed, 17 insertions(+), 13 deletions(-)
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diff --git a/fs/aio.c b/fs/aio.c
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index 3df3fb0678e5..b9e0df08277b 100644
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--- a/fs/aio.c
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+++ b/fs/aio.c
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@@ -902,7 +902,7 @@ static void put_reqs_available(struct kioctx *ctx, unsigned nr)
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local_irq_restore(flags);
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}
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-static bool get_reqs_available(struct kioctx *ctx)
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+static bool __get_reqs_available(struct kioctx *ctx)
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{
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struct kioctx_cpu *kcpu;
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bool ret = false;
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@@ -994,6 +994,14 @@ static void user_refill_reqs_available(struct kioctx *ctx)
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spin_unlock_irq(&ctx->completion_lock);
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}
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+static bool get_reqs_available(struct kioctx *ctx)
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+{
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+ if (__get_reqs_available(ctx))
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+ return true;
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+ user_refill_reqs_available(ctx);
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+ return __get_reqs_available(ctx);
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+}
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+
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/* aio_get_req
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* Allocate a slot for an aio request.
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* Returns NULL if no requests are free.
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@@ -1002,24 +1010,15 @@ static inline struct aio_kiocb *aio_get_req(struct kioctx *ctx)
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{
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struct aio_kiocb *req;
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- if (!get_reqs_available(ctx)) {
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- user_refill_reqs_available(ctx);
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- if (!get_reqs_available(ctx))
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- return NULL;
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- }
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-
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req = kmem_cache_alloc(kiocb_cachep, GFP_KERNEL|__GFP_ZERO);
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if (unlikely(!req))
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- goto out_put;
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+ return NULL;
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percpu_ref_get(&ctx->reqs);
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INIT_LIST_HEAD(&req->ki_list);
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refcount_set(&req->ki_refcnt, 0);
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req->ki_ctx = ctx;
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return req;
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-out_put:
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- put_reqs_available(ctx, 1);
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- return NULL;
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}
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static struct kioctx *lookup_ioctx(unsigned long ctx_id)
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@@ -1813,9 +1812,13 @@ static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
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return -EINVAL;
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}
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+ if (!get_reqs_available(ctx))
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+ return -EAGAIN;
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+
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+ ret = -EAGAIN;
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req = aio_get_req(ctx);
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if (unlikely(!req))
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- return -EAGAIN;
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+ goto out_put_reqs_available;
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if (iocb.aio_flags & IOCB_FLAG_RESFD) {
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/*
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@@ -1878,11 +1881,12 @@ static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
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goto out_put_req;
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return 0;
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out_put_req:
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- put_reqs_available(ctx, 1);
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percpu_ref_put(&ctx->reqs);
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if (req->ki_eventfd)
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eventfd_ctx_put(req->ki_eventfd);
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kmem_cache_free(kiocb_cachep, req);
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+out_put_reqs_available:
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+ put_reqs_available(ctx, 1);
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return ret;
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}
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