dax_layout_busy_page_range() is used by file systems to scan the DAX page-cache to unmap mapping pages from user-space and to determine if any pages in the given range are busy, either due to ongoing DMA or other get_user_pages() usage. Currently it checks to see the file mapping is mapped into user-space with mapping_mapped() and returns early if not, skipping the check for DMA busy pages. This is wrong as pages may still be undergoing DMA access even if they have subsequently been unmapped from user-space. Fix this by dropping the check for mapping_mapped(). Signed-off-by: Alistair Popple <apopple@xxxxxxxxxx> Suggested-by: Dan Williams <dan.j.williams@xxxxxxxxx> --- fs/dax.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/dax.c b/fs/dax.c index c62acd2..a675eb2 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -690,7 +690,7 @@ struct page *dax_layout_busy_page_range(struct address_space *mapping, if (IS_ENABLED(CONFIG_FS_DAX_LIMITED)) return NULL; - if (!dax_mapping(mapping) || !mapping_mapped(mapping)) + if (!dax_mapping(mapping)) return NULL; /* If end == LLONG_MAX, all pages from start to till end of file */ -- git-series 0.9.1
