Hi, Tao, On 4/26/24 10:39 PM, Hou Tao wrote: > From: Hou Tao <houtao1@xxxxxxxxxx> > > 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@xxxxxxxxxxxxxxx/ > * 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@xxxxxxxxxxxxxxx/ > > [1]: https://lore.kernel.org/linux-fsdevel/20240105105305.4052672-1-houtao@xxxxxxxxxxxxxxx/ > > 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@xxxxxxxxxxxxxxx/ -- Thanks, Jingbo
