mm: Update file times from fault path only if .page_mkwrite is not set
Filesystems wanting to properly support freezing need to have control
when file_update_time() is called. After pushing file_update_time()
to all relevant .page_mkwrite implementations we can just stop calling
file_update_time() when filesystem implements .page_mkwrite.
Tested-by: Kamal Mostafa <kamal@canonical.com>
Tested-by: Peter M. Petrakis <peter.petrakis@canonical.com>
Tested-by: Dann Frazier <dann.frazier@canonical.com>
Tested-by: Massimo Morana <massimo.morana@canonical.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/mm/memory.c b/mm/memory.c
index 2466d12..7c7fa7b 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2638,6 +2638,9 @@
if (!page_mkwrite) {
wait_on_page_locked(dirty_page);
set_page_dirty_balance(dirty_page, page_mkwrite);
+ /* file_update_time outside page_lock */
+ if (vma->vm_file)
+ file_update_time(vma->vm_file);
}
put_page(dirty_page);
if (page_mkwrite) {
@@ -2655,10 +2658,6 @@
}
}
- /* file_update_time outside page_lock */
- if (vma->vm_file)
- file_update_time(vma->vm_file);
-
return ret;
}
@@ -3327,12 +3326,13 @@
if (dirty_page) {
struct address_space *mapping = page->mapping;
+ int dirtied = 0;
if (set_page_dirty(dirty_page))
- page_mkwrite = 1;
+ dirtied = 1;
unlock_page(dirty_page);
put_page(dirty_page);
- if (page_mkwrite && mapping) {
+ if ((dirtied || page_mkwrite) && mapping) {
/*
* Some device drivers do not set page.mapping but still
* dirty their pages
@@ -3341,7 +3341,7 @@
}
/* file_update_time outside page_lock */
- if (vma->vm_file)
+ if (vma->vm_file && !page_mkwrite)
file_update_time(vma->vm_file);
} else {
unlock_page(vmf.page);