[PATCH 09/23] dax: Use dax_store_noinit() in grab_mapping_entry()
From: Jan Kara
Date: Wed Apr 22 2020 - 11:03:11 EST
Although we store NULL here, there aren't any marks set on the entry
so use xas_store_noinit() to save some time when trying to reinitialize
marks. Furthermore we actually overwrite the entry shortly afterwards
with new PTE entry anyway.
Signed-off-by: Jan Kara <jack@xxxxxxx>
---
fs/dax.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/fs/dax.c b/fs/dax.c
index f8358928549c..03c6ca693f3c 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -523,7 +523,11 @@ static void *grab_mapping_entry(struct xa_state *xas,
}
dax_disassociate_entry(entry, mapping, false);
- xas_store(xas, NULL); /* undo the PMD join */
+ /*
+ * Remove PMD entry. There should be no marks set for the entry
+ * so don't bother reinitializing them with xas_erase().
+ */
+ xas_store_noinit(xas, NULL);
dax_wake_entry(xas, entry, true);
mapping->nrexceptional--;
entry = NULL;
--
2.16.4