From: Wei Yang <richard.weiyang@xxxxxxxxxxxxxxxxx> Subject: mm/mmap: check on file instead of the rb_root_cached of its address_space In __vma_adjust(), we do the check on *root* to decide whether to adjust the address_space. It seems to be more meaningful to do the check on *file* itself. This means we are adjusting some data because it is a file backed vma. Since we seem to assume the address_space is valid if it is a file backed vma, let's just replace *root* with *file* here. Link: https://lkml.kernel.org/r/20200913133631.37781-2-richard.weiyang@xxxxxxxxxxxxxxxxx Signed-off-by: Wei Yang <richard.weiyang@xxxxxxxxxxxxxxxxx> Reviewed-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/mmap.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) --- a/mm/mmap.c~mm-mmap-check-on-file-instead-of-the-rb_root_cached-of-its-address_space +++ a/mm/mmap.c @@ -823,7 +823,7 @@ again: anon_vma_interval_tree_pre_update_vma(next); } - if (root) { + if (file) { flush_dcache_mmap_lock(mapping); vma_interval_tree_remove(vma, root); if (adjust_next) @@ -844,7 +844,7 @@ again: next->vm_pgoff += adjust_next >> PAGE_SHIFT; } - if (root) { + if (file) { if (adjust_next) vma_interval_tree_insert(next, root); vma_interval_tree_insert(vma, root); @@ -896,7 +896,7 @@ again: anon_vma_unlock_write(anon_vma); } - if (root) { + if (file) { i_mmap_unlock_write(mapping); uprobe_mmap(vma); _
