ce68cdbed297d927e993b3ea7b8b1cee545da Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Wed, 10 Aug 2016 17:10:28 +0200 Subject: dax: Avoid page invalidation races and unnecessary radix tree traversals Currently dax_iomap_rw() takes care of invalidating page tables and evicting hole pages from the radix tree when write(2) to the file happens. This invalidation is only necessary when there is some block allocation resulting from write(2). Furthermore in current place the invalidation is racy wrt page fault instantiating a hole page just after we have invalidated it. So perform the page invalidation inside dax_iomap_actor() where we can do it only when really necessary and after blocks have been allocated so nobody will be instantiating new hole pages anymore. Reviewed-by: Christoph Hellwig Reviewed-by: Ross Zwisler Signed-off-by: Jan Kara Signed-off-by: Dan Williams --- fs/dax.c | 28 +++++++++++----------------- 1 file changed, 11 insertions(+), 17 deletions(-) (limited to 'fs/dax.c')