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authorChristoph Hellwig <hch@lst.de>2018-11-19 23:57:42 +0100
committerJens Axboe <axboe@kernel.dk>2018-12-18 16:29:58 +0100
commit432c79978c33ecef91b1b04cea6936c20810da29 (patch)
tree63b7dd99d723848d5559e13779cabd5805184ad0 /fs/aio.c
parentaio: use assigned completion handler (diff)
downloadlinux-432c79978c33ecef91b1b04cea6936c20810da29.tar.xz
linux-432c79978c33ecef91b1b04cea6936c20810da29.zip
aio: separate out ring reservation from req allocation
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>
Diffstat (limited to '')
-rw-r--r--fs/aio.c30
1 files changed, 17 insertions, 13 deletions
diff --git a/fs/aio.c b/fs/aio.c
index 6f32d30d7f45..7556709b9b8d 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -902,7 +902,7 @@ 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;
@@ -994,6 +994,14 @@ 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.
@@ -1002,24 +1010,15 @@ 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)
@@ -1807,9 +1806,13 @@ 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) {
/*
@@ -1872,11 +1875,12 @@ 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;
}