Re: [PATCH v4] eventfd: convert to f_op->read_iter()

From: Jens Axboe
Date: Sun May 03 2020 - 10:42:46 EST


On 5/3/20 7:46 AM, Al Viro wrote:
> On Fri, May 01, 2020 at 05:54:09PM -0600, Jens Axboe wrote:
>> On 5/1/20 5:12 PM, Al Viro wrote:
>>> On Fri, May 01, 2020 at 01:11:09PM -0600, Jens Axboe wrote:
>>>> + flags &= EFD_SHARED_FCNTL_FLAGS;
>>>> + flags |= O_RDWR;
>>>> + fd = get_unused_fd_flags(flags);
>>>> if (fd < 0)
>>>> - eventfd_free_ctx(ctx);
>>>> + goto err;
>>>> +
>>>> + file = anon_inode_getfile("[eventfd]", &eventfd_fops, ctx, flags);
>>>> + if (IS_ERR(file)) {
>>>> + put_unused_fd(fd);
>>>> + fd = PTR_ERR(file);
>>>> + goto err;
>>>> + }
>>>>
>>>> + file->f_mode |= FMODE_NOWAIT;
>>>> + fd_install(fd, file);
>>>> + return fd;
>>>> +err:
>>>> + eventfd_free_ctx(ctx);
>>>> return fd;
>>>> }
>>>
>>> Looks sane... I can take it via vfs.git, or leave it for you if you
>>> have other stuff in the same area...
>>
>> Would be great if you can queue it up in vfs.git, thanks! Don't have
>> anything else that'd conflict with this.
>
> Applied; BTW, what happens if
> ctx->id = ida_simple_get(&eventfd_ida, 0, 0, GFP_KERNEL);
> fails? Quitely succeed with BS value (-ENOSPC/-ENOMEM) shown by
> eventfd_show_fdinfo()?

Huh yeah that's odd, not sure how I missed that when touching code
near it. Want a followup patch to fix that issue?

--
Jens Axboe