fs: Add freezing handling to mnt_want_write() / mnt_drop_write()

Most of places where we want freeze protection coincides with the places where
we also have remount-ro protection. So make mnt_want_write() and
mnt_drop_write() (and their _file alternative) prevent freezing as well.
For the few cases that are really interested only in remount-ro protection
provide new function variants.

BugLink: https://bugs.launchpad.net/bugs/897421
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>

1 files changed, 1 insertions, 1 deletions

diff --git a/fs/file_table.c b/fs/file_table.c
index b54bf7fd0b15..701985e4ccda 100644
--- a/fs/file_table.c
+++ b/fs/file_table.c
@@ -217,7 +217,7 @@ static void drop_file_write_access(struct file *file)
                 return;
         if (file_check_writeable(file) != 0)
                 return;
-        mnt_drop_write(mnt);
+        __mnt_drop_write(mnt);
         file_release_write(file);
 }