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aio: simplify KIOCB_KEY handling 

No need to pass the key field to lookup_iocb to compare it with KIOCB_KEY,
as we can do that right after retrieving it from userspace.  Also move the
KIOCB_KEY definition to aio.c as it is an internal value not used by any
other place in the kernel.

Signed-off-by: Christoph Hellwig <hch@lst.de>
hifive-unleashed-5.1
Christoph Hellwig 2018-03-30 11:19:25 +02:00
parent 3deb642f0d
commit f3a2752a43
2 changed files with 7 additions and 9 deletions
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14
fs/aio.c
View File

@ -46,6 +46,8 @@
#include "internal.h"
#define KIOCB_KEY 0
#define AIO_RING_MAGIC 0xa10a10a1
#define AIO_RING_COMPAT_FEATURES 1
#define AIO_RING_INCOMPAT_FEATURES 0
@ -1811,15 +1813,12 @@ COMPAT_SYSCALL_DEFINE3(io_submit, compat_aio_context_t, ctx_id,
* Finds a given iocb for cancellation.
*/
static struct aio_kiocb *
lookup_kiocb(struct kioctx *ctx, struct iocb __user *iocb, u32 key)
lookup_kiocb(struct kioctx *ctx, struct iocb __user *iocb)
{
struct aio_kiocb *kiocb;
assert_spin_locked(&ctx->ctx_lock);
if (key != KIOCB_KEY)
return NULL;
/* TODO: use a hash or array, this sucks. */
list_for_each_entry(kiocb, &ctx->active_reqs, ki_list) {
if (kiocb->ki_user_iocb == iocb)
@ -1846,9 +1845,10 @@ SYSCALL_DEFINE3(io_cancel, aio_context_t, ctx_id, struct iocb __user *, iocb,
u32 key;
int ret;
ret = get_user(key, &iocb->aio_key);
if (unlikely(ret))
if (unlikely(get_user(key, &iocb->aio_key)))
return -EFAULT;
if (unlikely(key != KIOCB_KEY))
return -EINVAL;
ctx = lookup_ioctx(ctx_id);
if (unlikely(!ctx))
@ -1856,7 +1856,7 @@ SYSCALL_DEFINE3(io_cancel, aio_context_t, ctx_id, struct iocb __user *, iocb,
spin_lock_irq(&ctx->ctx_lock);
kiocb = lookup_kiocb(ctx, iocb, key);
kiocb = lookup_kiocb(ctx, iocb);
if (kiocb)
ret = kiocb_cancel(kiocb);
else

2
include/linux/aio.h
View File

@ -8,8 +8,6 @@ struct kioctx;
struct kiocb;
struct mm_struct;
#define KIOCB_KEY 0
typedef int (kiocb_cancel_fn)(struct kiocb *);
/* prototypes */