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@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. 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@xxxxxxxxxxxxxxx/ >
