Oleg Nesterov <[email protected]> writes:

> atomic_read(&ctx->dead) in aio_ring_remap() looks confusing.
> kill_ioctx() sets ctx->dead and removes ctx from ->ioctx_table
> "atomically" under mm->ioctx_lock, so aio_ring_remap() can never
> see a dead ctx.
>
> If we really want this check, we should put it under WARN_ON()
> and it should not depend on aio_ring_file == file.

Just get rid of the check, it doesn't make any sense.

-Jeff

>
> Signed-off-by: Oleg Nesterov <[email protected]>
> ---
>  fs/aio.c |   16 ++++++++--------
>  1 files changed, 8 insertions(+), 8 deletions(-)
>
> diff --git a/fs/aio.c b/fs/aio.c
> index 480440f..0693333 100644
> --- a/fs/aio.c
> +++ b/fs/aio.c
> @@ -325,14 +325,14 @@ static int aio_ring_remap(struct file *file, struct 
> vm_area_struct *vma)
>       rcu_read_lock();
>       table = rcu_dereference(mm->ioctx_table);
>       for (i = 0; i < table->nr; i++) {
> -             struct kioctx *ctx;
> -
> -             ctx = table->table[i];
> -             if (ctx && ctx->aio_ring_file == file) {
> -                     if (!atomic_read(&ctx->dead)) {
> -                             ctx->user_id = ctx->mmap_base = vma->vm_start;
> -                             res = 0;
> -                     }
> +             struct kioctx *ctx = table->table[i];
> +
> +             if (!ctx || WARN_ON(atomic_read(&ctx->dead)))
> +                     continue;
> +
> +             if (ctx->aio_ring_file == file) {
> +                     ctx->user_id = ctx->mmap_base = vma->vm_start;
> +                     res = 0;
>                       break;
>               }
>       }
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to