fs/fuse/file.c | 12 ++++++++---- fs/fuse/fuse_i.h | 3 +++ fs/fuse/virtio_fs.c | 25 ++++++++++++++++--------- 3 files changed, 27 insertions(+), 13 deletions(-)
From: Hou Tao <houtao1@huawei.com>
Hi,
The patch set aims to fix the warning related to an abnormal size
parameter of kmalloc() in virtiofs. Patch #1 fixes it by introducing
use_pages_for_kvec_io option in fuse_conn and enabling it in virtiofs.
Beside the abnormal size parameter for kmalloc, the gfp parameter is
also questionable: GFP_ATOMIC is used even when the allocation occurs
in a kworker context. Patch #2 fixes it by using GFP_NOFS when the
allocation is initiated by the kworker. For more details, please check
the individual patches.
As usual, comments are always welcome.
Change Log:
v3:
* introduce use_pages_for_kvec_io for virtiofs. When the option is
enabled, fuse will use iov_iter_extract_pages() to construct a page
array and pass the pages array instead of a pointer to virtiofs.
The benefit is twofold: the length of the data passed to virtiofs is
limited by max_pages, and there is no memory copy compared with v2.
v2: https://lore.kernel.org/linux-fsdevel/20240228144126.2864064-1-houtao@huaweicloud.com/
* limit the length of ITER_KVEC dio by max_pages instead of the
newly-introduced max_nopage_rw. Using max_pages make the ITER_KVEC
dio being consistent with other rw operations.
* replace kmalloc-allocated bounce buffer by using a bounce buffer
backed by scattered pages when the length of the bounce buffer for
KVEC_ITER dio is larger than PAG_SIZE, so even on hosts with
fragmented memory, the KVEC_ITER dio can be handled normally by
virtiofs. (Bernd Schubert)
* merge the GFP_NOFS patch [1] into this patch-set and use
memalloc_nofs_{save|restore}+GFP_KERNEL instead of GFP_NOFS
(Benjamin Coddington)
v1: https://lore.kernel.org/linux-fsdevel/20240103105929.1902658-1-houtao@huaweicloud.com/
[1]: https://lore.kernel.org/linux-fsdevel/20240105105305.4052672-1-houtao@huaweicloud.com/
Hou Tao (2):
virtiofs: use pages instead of pointer for kernel direct IO
virtiofs: use GFP_NOFS when enqueuing request through kworker
fs/fuse/file.c | 12 ++++++++----
fs/fuse/fuse_i.h | 3 +++
fs/fuse/virtio_fs.c | 25 ++++++++++++++++---------
3 files changed, 27 insertions(+), 13 deletions(-)
--
2.29.2
Hi, Tao,
On 4/26/24 10:39 PM, Hou Tao wrote:
> From: Hou Tao <houtao1@huawei.com>
>
> Hi,
>
> The patch set aims to fix the warning related to an abnormal size
> parameter of kmalloc() in virtiofs. Patch #1 fixes it by introducing
> use_pages_for_kvec_io option in fuse_conn and enabling it in virtiofs.
> Beside the abnormal size parameter for kmalloc, the gfp parameter is
> also questionable: GFP_ATOMIC is used even when the allocation occurs
> in a kworker context. Patch #2 fixes it by using GFP_NOFS when the
> allocation is initiated by the kworker. For more details, please check
> the individual patches.
>
> As usual, comments are always welcome.
>
> Change Log:
>
> v3:
> * introduce use_pages_for_kvec_io for virtiofs. When the option is
> enabled, fuse will use iov_iter_extract_pages() to construct a page
> array and pass the pages array instead of a pointer to virtiofs.
> The benefit is twofold: the length of the data passed to virtiofs is
> limited by max_pages, and there is no memory copy compared with v2.
>
> v2: https://lore.kernel.org/linux-fsdevel/20240228144126.2864064-1-houtao@huaweicloud.com/
> * limit the length of ITER_KVEC dio by max_pages instead of the
> newly-introduced max_nopage_rw. Using max_pages make the ITER_KVEC
> dio being consistent with other rw operations.
> * replace kmalloc-allocated bounce buffer by using a bounce buffer
> backed by scattered pages when the length of the bounce buffer for
> KVEC_ITER dio is larger than PAG_SIZE, so even on hosts with
> fragmented memory, the KVEC_ITER dio can be handled normally by
> virtiofs. (Bernd Schubert)
> * merge the GFP_NOFS patch [1] into this patch-set and use
> memalloc_nofs_{save|restore}+GFP_KERNEL instead of GFP_NOFS
> (Benjamin Coddington)
>
> v1: https://lore.kernel.org/linux-fsdevel/20240103105929.1902658-1-houtao@huaweicloud.com/
>
> [1]: https://lore.kernel.org/linux-fsdevel/20240105105305.4052672-1-houtao@huaweicloud.com/
>
> Hou Tao (2):
> virtiofs: use pages instead of pointer for kernel direct IO
> virtiofs: use GFP_NOFS when enqueuing request through kworker
>
> fs/fuse/file.c | 12 ++++++++----
> fs/fuse/fuse_i.h | 3 +++
> fs/fuse/virtio_fs.c | 25 ++++++++++++++++---------
> 3 files changed, 27 insertions(+), 13 deletions(-)
>
We also encountered the same issue as [1] these days when attempting to
insmod a module with ~6MB size, which is upon a virtiofs filesystem.
It would be much helpful if this issue has a standard fix in the
upstream. I see there will be v4 when reading through the mailing
thread. Glad to know if there's any update to this series.
[1]
https://lore.kernel.org/linux-fsdevel/20240103105929.1902658-1-houtao@huaweicloud.com/
--
Thanks,
Jingbo
Hi,
On 8/14/2024 2:34 PM, Jingbo Xu wrote:
> Hi, Tao,
>
> On 4/26/24 10:39 PM, Hou Tao wrote:
>> From: Hou Tao <houtao1@huawei.com>
>>
>> Hi,
>>
>> The patch set aims to fix the warning related to an abnormal size
>> parameter of kmalloc() in virtiofs. Patch #1 fixes it by introducing
>> use_pages_for_kvec_io option in fuse_conn and enabling it in virtiofs.
>> Beside the abnormal size parameter for kmalloc, the gfp parameter is
>> also questionable: GFP_ATOMIC is used even when the allocation occurs
>> in a kworker context. Patch #2 fixes it by using GFP_NOFS when the
>> allocation is initiated by the kworker. For more details, please check
>> the individual patches.
>>
>> As usual, comments are always welcome.
>>
>> Change Log:
>>
>> v3:
>> * introduce use_pages_for_kvec_io for virtiofs. When the option is
>> enabled, fuse will use iov_iter_extract_pages() to construct a page
>> array and pass the pages array instead of a pointer to virtiofs.
>> The benefit is twofold: the length of the data passed to virtiofs is
>> limited by max_pages, and there is no memory copy compared with v2.
>>
>> v2: https://lore.kernel.org/linux-fsdevel/20240228144126.2864064-1-houtao@huaweicloud.com/
>> * limit the length of ITER_KVEC dio by max_pages instead of the
>> newly-introduced max_nopage_rw. Using max_pages make the ITER_KVEC
>> dio being consistent with other rw operations.
>> * replace kmalloc-allocated bounce buffer by using a bounce buffer
>> backed by scattered pages when the length of the bounce buffer for
>> KVEC_ITER dio is larger than PAG_SIZE, so even on hosts with
>> fragmented memory, the KVEC_ITER dio can be handled normally by
>> virtiofs. (Bernd Schubert)
>> * merge the GFP_NOFS patch [1] into this patch-set and use
>> memalloc_nofs_{save|restore}+GFP_KERNEL instead of GFP_NOFS
>> (Benjamin Coddington)
>>
>> v1: https://lore.kernel.org/linux-fsdevel/20240103105929.1902658-1-houtao@huaweicloud.com/
>>
>> [1]: https://lore.kernel.org/linux-fsdevel/20240105105305.4052672-1-houtao@huaweicloud.com/
>>
>> Hou Tao (2):
>> virtiofs: use pages instead of pointer for kernel direct IO
>> virtiofs: use GFP_NOFS when enqueuing request through kworker
>>
>> fs/fuse/file.c | 12 ++++++++----
>> fs/fuse/fuse_i.h | 3 +++
>> fs/fuse/virtio_fs.c | 25 ++++++++++++++++---------
>> 3 files changed, 27 insertions(+), 13 deletions(-)
>>
> We also encountered the same issue as [1] these days when attempting to
> insmod a module with ~6MB size, which is upon a virtiofs filesystem.
>
> It would be much helpful if this issue has a standard fix in the
> upstream. I see there will be v4 when reading through the mailing
> thread. Glad to know if there's any update to this series.
Being busy with other stuff these days. I hope to send v4 before next
weekend.
>
> [1]
> https://lore.kernel.org/linux-fsdevel/20240103105929.1902658-1-houtao@huaweicloud.com/
>
On 8/14/24 3:46 PM, Hou Tao wrote:
> Hi,
>
> On 8/14/2024 2:34 PM, Jingbo Xu wrote:
>> Hi, Tao,
>>
>> On 4/26/24 10:39 PM, Hou Tao wrote:
>>> From: Hou Tao <houtao1@huawei.com>
>>>
>>> Hi,
>>>
>>> The patch set aims to fix the warning related to an abnormal size
>>> parameter of kmalloc() in virtiofs. Patch #1 fixes it by introducing
>>> use_pages_for_kvec_io option in fuse_conn and enabling it in virtiofs.
>>> Beside the abnormal size parameter for kmalloc, the gfp parameter is
>>> also questionable: GFP_ATOMIC is used even when the allocation occurs
>>> in a kworker context. Patch #2 fixes it by using GFP_NOFS when the
>>> allocation is initiated by the kworker. For more details, please check
>>> the individual patches.
>>>
>>> As usual, comments are always welcome.
>>>
>>> Change Log:
>>>
>>> v3:
>>> * introduce use_pages_for_kvec_io for virtiofs. When the option is
>>> enabled, fuse will use iov_iter_extract_pages() to construct a page
>>> array and pass the pages array instead of a pointer to virtiofs.
>>> The benefit is twofold: the length of the data passed to virtiofs is
>>> limited by max_pages, and there is no memory copy compared with v2.
>>>
>>> v2: https://lore.kernel.org/linux-fsdevel/20240228144126.2864064-1-houtao@huaweicloud.com/
>>> * limit the length of ITER_KVEC dio by max_pages instead of the
>>> newly-introduced max_nopage_rw. Using max_pages make the ITER_KVEC
>>> dio being consistent with other rw operations.
>>> * replace kmalloc-allocated bounce buffer by using a bounce buffer
>>> backed by scattered pages when the length of the bounce buffer for
>>> KVEC_ITER dio is larger than PAG_SIZE, so even on hosts with
>>> fragmented memory, the KVEC_ITER dio can be handled normally by
>>> virtiofs. (Bernd Schubert)
>>> * merge the GFP_NOFS patch [1] into this patch-set and use
>>> memalloc_nofs_{save|restore}+GFP_KERNEL instead of GFP_NOFS
>>> (Benjamin Coddington)
>>>
>>> v1: https://lore.kernel.org/linux-fsdevel/20240103105929.1902658-1-houtao@huaweicloud.com/
>>>
>>> [1]: https://lore.kernel.org/linux-fsdevel/20240105105305.4052672-1-houtao@huaweicloud.com/
>>>
>>> Hou Tao (2):
>>> virtiofs: use pages instead of pointer for kernel direct IO
>>> virtiofs: use GFP_NOFS when enqueuing request through kworker
>>>
>>> fs/fuse/file.c | 12 ++++++++----
>>> fs/fuse/fuse_i.h | 3 +++
>>> fs/fuse/virtio_fs.c | 25 ++++++++++++++++---------
>>> 3 files changed, 27 insertions(+), 13 deletions(-)
>>>
>> We also encountered the same issue as [1] these days when attempting to
>> insmod a module with ~6MB size, which is upon a virtiofs filesystem.
>>
>> It would be much helpful if this issue has a standard fix in the
>> upstream. I see there will be v4 when reading through the mailing
>> thread. Glad to know if there's any update to this series.
>
> Being busy with other stuff these days. I hope to send v4 before next
> weekend.
Many thanks, Tao.
--
Thanks,
Jingbo
© 2016 - 2025 Red Hat, Inc.