[PATCH v7 8/8] fsdax: add exception for reflinked files
From: Shiyang Ruan <hidden>
Date: 2021-09-24 13:20:20
Also in:
linux-fsdevel, linux-xfs, lkml, nvdimm
Subsystem:
filesystem direct access (dax), filesystems (vfs and infrastructure), the rest · Maintainers:
Dan Williams, Alexander Viro, Christian Brauner, Linus Torvalds
For reflinked files, one dax page may be associated more than once with different fime mapping and index. It will report warning. Now, since we have introduced dax-RMAP for this case and also have to keep its functionality for other filesystems who are not support rmap, I add this exception here. Signed-off-by: Shiyang Ruan <redacted> --- fs/dax.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index 2536c105ec7f..1a57211b1bc9 100644
--- a/fs/dax.c
+++ b/fs/dax.c@@ -352,9 +352,10 @@ static void dax_associate_entry(void *entry, struct address_space *mapping, for_each_mapped_pfn(entry, pfn) { struct page *page = pfn_to_page(pfn); - WARN_ON_ONCE(page->mapping); - page->mapping = mapping; - page->index = index + i++; + if (!page->mapping) { + page->mapping = mapping; + page->index = index + i++; + } } }
@@ -370,9 +371,10 @@ static void dax_disassociate_entry(void *entry, struct address_space *mapping, struct page *page = pfn_to_page(pfn); WARN_ON_ONCE(trunc && page_ref_count(page) > 1); - WARN_ON_ONCE(page->mapping && page->mapping != mapping); - page->mapping = NULL; - page->index = 0; + if (page->mapping == mapping) { + page->mapping = NULL; + page->index = 0; + } } }
--
2.33.0