dax: use pfn_mkwrite to update c/mtime + freeze protection
From: Yigal Korman <yigal@plexistor.com>
[v1]
Without this patch, c/mtime is not updated correctly when mmap'ed page is
first read from and then written to.
A new xfstest is submitted for testing this (generic/080)
[v2]
Jan Kara has pointed out that if we add the
sb_start/end_pagefault pair in the new pfn_mkwrite we
are then fixing another bug where: A user could start
writing to the page while filesystem is frozen.
Signed-off-by: Yigal Korman <yigal@plexistor.com>
Signed-off-by: Boaz Harrosh <boaz@plexistor.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Matthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 598abbb..aa78c70 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -206,6 +206,7 @@
static const struct vm_operations_struct ext4_dax_vm_ops = {
.fault = ext4_dax_fault,
.page_mkwrite = ext4_dax_mkwrite,
+ .pfn_mkwrite = dax_pfn_mkwrite,
};
#else
#define ext4_dax_vm_ops ext4_file_vm_ops
