From: Andreas Gruenbacher agruenba@redhat.com
commit d3c51c55cb9274dd43c156f1f26b5eb4d5f2d58c upstream.
On filesystems with a block size smaller than PAGE_SIZE and non-empty files smaller then PAGE_SIZE, gfs2_page_mkwrite could end up allocating excess blocks beyond the end of the file, similar to fallocate. This doesn't make sense; fix it.
Reported-by: Bob Peterson rpeterso@redhat.com Fixes: 184b4e60853d ("gfs2: Fix end-of-file handling in gfs2_page_mkwrite") Cc: stable@vger.kernel.org # v5.5+ Signed-off-by: Andreas Gruenbacher agruenba@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- fs/gfs2/file.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/fs/gfs2/file.c +++ b/fs/gfs2/file.c @@ -474,8 +474,8 @@ static vm_fault_t gfs2_page_mkwrite(stru file_update_time(vmf->vma->vm_file);
/* page is wholly or partially inside EOF */ - if (offset > size - PAGE_SIZE) - length = offset_in_page(size); + if (size - offset < PAGE_SIZE) + length = size - offset; else length = PAGE_SIZE;