On 22/12/2020 02:10, Noah Goldstein wrote:
> On Sun, Dec 20, 2020 at 03:18:05PM +0000, Pavel Begunkov wrote:
>> On 20/12/2020 06:50, noah wrote:> From: noah <[email protected]>
>>>
>>> This patch makes it so that specify a file descriptor value of -2 will
>>> skip updating the corresponding fixed file index.
>>>
>>> This will allow for users to reduce the number of syscalls necessary
>>> to update a sparse file range when using the fixed file option.
>>
>> Answering the github thread -- it's indeed a simple change, I had it the
>> same day you posted the issue. See below it's a bit cleaner. However, I
>> want to first review "io_uring: buffer registration enhancements", and
>> if it's good, for easier merging/etc I'd rather prefer to let it go
>> first (even if partially).
Noah, want to give it a try? I've just sent a prep patch, with it you
can implement it cleaner with one continue.
>>
>> diff --git a/fs/io_uring.c b/fs/io_uring.c
>> index 941fe9b64fd9..b3ae9d5da17e 100644
>> --- a/fs/io_uring.c
>> +++ b/fs/io_uring.c
>> @@ -7847,9 +7847,8 @@ static int __io_sqe_files_update(struct io_ring_ctx *ctx,
>> if (IS_ERR(ref_node))
>> return PTR_ERR(ref_node);
>>
>> - done = 0;
>> fds = u64_to_user_ptr(up->fds);
>> - while (nr_args) {
>> + for (done = 0; done < nr_args; done++) {
>> struct fixed_file_table *table;
>> unsigned index;
>>
>> @@ -7858,7 +7857,10 @@ static int __io_sqe_files_update(struct io_ring_ctx *ctx,
>> err = -EFAULT;
>> break;
>> }
>> - i = array_index_nospec(up->offset, ctx->nr_user_files);
>> + if (fd == IORING_REGISTER_FILES_SKIP)
>> + continue;
>> +
>> + i = array_index_nospec(up->offset + done, ctx->nr_user_files);
>> table = &ctx->file_data->table[i >> IORING_FILE_TABLE_SHIFT];
>> index = i & IORING_FILE_TABLE_MASK;
>> if (table->files[index]) {
>> @@ -7896,9 +7898,6 @@ static int __io_sqe_files_update(struct io_ring_ctx *ctx,
>> break;
>> }
>> }
>> - nr_args--;
>> - done++;
>> - up->offset++;
>> }
>>
>> if (needs_switch) {
--
Pavel Begunkov
On Tue, Jan 26, 2021 at 7:29 AM Pavel Begunkov <[email protected]> wrote:
>
> On 22/12/2020 02:10, Noah Goldstein wrote:
> > On Sun, Dec 20, 2020 at 03:18:05PM +0000, Pavel Begunkov wrote:
> >> On 20/12/2020 06:50, noah wrote:> From: noah <[email protected]>
> >>>
> >>> This patch makes it so that specify a file descriptor value of -2 will
> >>> skip updating the corresponding fixed file index.
> >>>
> >>> This will allow for users to reduce the number of syscalls necessary
> >>> to update a sparse file range when using the fixed file option.
> >>
> >> Answering the github thread -- it's indeed a simple change, I had it the
> >> same day you posted the issue. See below it's a bit cleaner. However, I
> >> want to first review "io_uring: buffer registration enhancements", and
> >> if it's good, for easier merging/etc I'd rather prefer to let it go
> >> first (even if partially).
>
> Noah, want to give it a try? I've just sent a prep patch, with it you
> can implement it cleaner with one continue.
>
Absolutely. Will get on it ASAP.
> >>
> >> diff --git a/fs/io_uring.c b/fs/io_uring.c
> >> index 941fe9b64fd9..b3ae9d5da17e 100644
> >> --- a/fs/io_uring.c
> >> +++ b/fs/io_uring.c
> >> @@ -7847,9 +7847,8 @@ static int __io_sqe_files_update(struct io_ring_ctx *ctx,
> >> if (IS_ERR(ref_node))
> >> return PTR_ERR(ref_node);
> >>
> >> - done = 0;
> >> fds = u64_to_user_ptr(up->fds);
> >> - while (nr_args) {
> >> + for (done = 0; done < nr_args; done++) {
> >> struct fixed_file_table *table;
> >> unsigned index;
> >>
> >> @@ -7858,7 +7857,10 @@ static int __io_sqe_files_update(struct io_ring_ctx *ctx,
> >> err = -EFAULT;
> >> break;
> >> }
> >> - i = array_index_nospec(up->offset, ctx->nr_user_files);
> >> + if (fd == IORING_REGISTER_FILES_SKIP)
> >> + continue;
> >> +
> >> + i = array_index_nospec(up->offset + done, ctx->nr_user_files);
> >> table = &ctx->file_data->table[i >> IORING_FILE_TABLE_SHIFT];
> >> index = i & IORING_FILE_TABLE_MASK;
> >> if (table->files[index]) {
> >> @@ -7896,9 +7898,6 @@ static int __io_sqe_files_update(struct io_ring_ctx *ctx,
> >> break;
> >> }
> >> }
> >> - nr_args--;
> >> - done++;
> >> - up->offset++;
> >> }
> >>
> >> if (needs_switch) {
>
> --
> Pavel Begunkov
On 26/01/2021 17:14, Noah Goldstein wrote:
> On Tue, Jan 26, 2021 at 7:29 AM Pavel Begunkov <[email protected]> wrote:
>>
>> On 22/12/2020 02:10, Noah Goldstein wrote:
>>> On Sun, Dec 20, 2020 at 03:18:05PM +0000, Pavel Begunkov wrote:
>>>> On 20/12/2020 06:50, noah wrote:> From: noah <[email protected]>
>>>>>
>>>>> This patch makes it so that specify a file descriptor value of -2 will
>>>>> skip updating the corresponding fixed file index.
>>>>>
>>>>> This will allow for users to reduce the number of syscalls necessary
>>>>> to update a sparse file range when using the fixed file option.
>>>>
>>>> Answering the github thread -- it's indeed a simple change, I had it the
>>>> same day you posted the issue. See below it's a bit cleaner. However, I
>>>> want to first review "io_uring: buffer registration enhancements", and
>>>> if it's good, for easier merging/etc I'd rather prefer to let it go
>>>> first (even if partially).
>>
>> Noah, want to give it a try? I've just sent a prep patch, with it you
>> can implement it cleaner with one continue.
>
> Absolutely. Will get on it ASAP.
Perfect. Even better if you add a liburing test
--
Pavel Begunkov
On Tue, Jan 26, 2021 at 12:24 PM Pavel Begunkov <[email protected]> wrote:
>
> On 26/01/2021 17:14, Noah Goldstein wrote:
> > On Tue, Jan 26, 2021 at 7:29 AM Pavel Begunkov <[email protected]> wrote:
> >>
> >> On 22/12/2020 02:10, Noah Goldstein wrote:
> >>> On Sun, Dec 20, 2020 at 03:18:05PM +0000, Pavel Begunkov wrote:
> >>>> On 20/12/2020 06:50, noah wrote:> From: noah <[email protected]>
> >>>>>
> >>>>> This patch makes it so that specify a file descriptor value of -2 will
> >>>>> skip updating the corresponding fixed file index.
> >>>>>
> >>>>> This will allow for users to reduce the number of syscalls necessary
> >>>>> to update a sparse file range when using the fixed file option.
> >>>>
> >>>> Answering the github thread -- it's indeed a simple change, I had it the
> >>>> same day you posted the issue. See below it's a bit cleaner. However, I
> >>>> want to first review "io_uring: buffer registration enhancements", and
> >>>> if it's good, for easier merging/etc I'd rather prefer to let it go
> >>>> first (even if partially).
> >>
> >> Noah, want to give it a try? I've just sent a prep patch, with it you
> >> can implement it cleaner with one continue.
> >
> > Absolutely. Will get on it ASAP.
>
> Perfect. Even better if you add a liburing test
>
> --
> Pavel Begunkov
Do you think the return value should not include files skipped?
i.e register fds[1, 2, 3, -1] with no errors returns 4. should fds[1,
2, -2, -1] return 3 or 4 do you think?
Personally think the latter makes more sense. Thoughts?
On 26/01/2021 18:43, Noah Goldstein wrote:
> On Tue, Jan 26, 2021 at 12:24 PM Pavel Begunkov <[email protected]> wrote:
>>
>> On 26/01/2021 17:14, Noah Goldstein wrote:
>>> On Tue, Jan 26, 2021 at 7:29 AM Pavel Begunkov <[email protected]> wrote:
>>>>
>>>> On 22/12/2020 02:10, Noah Goldstein wrote:
>>>>> On Sun, Dec 20, 2020 at 03:18:05PM +0000, Pavel Begunkov wrote:
>>>>>> On 20/12/2020 06:50, noah wrote:> From: noah <[email protected]>
>>>>>>>
>>>>>>> This patch makes it so that specify a file descriptor value of -2 will
>>>>>>> skip updating the corresponding fixed file index.
>>>>>>>
>>>>>>> This will allow for users to reduce the number of syscalls necessary
>>>>>>> to update a sparse file range when using the fixed file option.
>>>>>>
>>>>>> Answering the github thread -- it's indeed a simple change, I had it the
>>>>>> same day you posted the issue. See below it's a bit cleaner. However, I
>>>>>> want to first review "io_uring: buffer registration enhancements", and
>>>>>> if it's good, for easier merging/etc I'd rather prefer to let it go
>>>>>> first (even if partially).
>>>>
>>>> Noah, want to give it a try? I've just sent a prep patch, with it you
>>>> can implement it cleaner with one continue.
>>>
>>> Absolutely. Will get on it ASAP.
>>
>> Perfect. Even better if you add a liburing test
>
> Do you think the return value should not include files skipped?
>
> i.e register fds[1, 2, 3, -1] with no errors returns 4. should fds[1,
> 2, -2, -1] return 3 or 4 do you think?
>
> Personally think the latter makes more sense. Thoughts?
Let's just return @done, 4 in your case. Because otherwise locating which
index has failed would be hell. And it's consistent with delete (i.e. -1).
--
Pavel Begunkov