On Thu, Jun 29, 2023 at 05:18:17PM -0400, Sidhartha Kumar wrote: > commit fd4aed8d985a3236d0877ff6d0c80ad39d4ce81a upstream > > Ackerley Tng reported an issue with hugetlbfs fallocate as noted in the > Closes tag. The issue showed up after the conversion of hugetlb page > cache lookup code to use page_cache_next_miss. User visible effects are: > > - hugetlbfs fallocate incorrectly returns -EEXIST if pages are presnet > in the file. > - hugetlb pages will not be included in core dumps if they need to be > brought in via GUP. > - userfaultfd UFFDIO_COPY will not notice pages already present in the > cache. It may try to allocate a new page and potentially return > ENOMEM as opposed to EEXIST. > > Revert the use page_cache_next_miss() in hugetlb code. > > The upstream fix[2] cannot be used used directly as the return value for > filemap_get_folio() has been changed between 6.3 and upstream. > > Closes: https://lore.kernel.org/linux-mm/cover.1683069252.git.ackerleytng@xxxxxxxxxx > Fixes: d0ce0e47b323 ("mm/hugetlb: convert hugetlb fault paths to use alloc_hugetlb_folio()") > Cc: <stable@xxxxxxxxxxxxxxx> #v6.3 > Reported-by: Ackerley Tng <ackerleytng@xxxxxxxxxx> > Signed-off-by: Sidhartha Kumar <sidhartha.kumar@xxxxxxxxxx> > > [1] https://lore.kernel.org/linux-mm/cover.1683069252.git.ackerleytng@xxxxxxxxxx/ > [2] https://lore.kernel.org/lkml/20230621230255.GD4155@monkey/ > --- > > fs/hugetlbfs/inode.c | 8 +++----- > mm/hugetlb.c | 11 +++++------ > 2 files changed, 8 insertions(+), 11 deletions(-) Now queued up, thanks. greg k-h
