fs: Skip atime update on frozen filesystem
It is unexpected to block reading of frozen filesystem because of atime update.
Also handling blocking on frozen filesystem because of atime update would make
locking more complex than it already is. So just skip atime update when
filesystem is frozen like we skip it when filesystem is remounted read-only.
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>
diff --git a/fs/inode.c b/fs/inode.c
index 006c85c..74d7c20 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -1542,9 +1542,11 @@
if (timespec_equal(&inode->i_atime, &now))
return;
- if (mnt_want_write(mnt))
+ if (!sb_start_write_trylock(inode->i_sb))
return;
+ if (__mnt_want_write(mnt))
+ goto skip_update;
/*
* File systems can error out when updating inodes if they need to
* allocate new space to modify an inode (such is the case for
@@ -1553,7 +1555,9 @@
* so just ignore the return value.
*/
update_time(inode, &now, S_ATIME);
- mnt_drop_write(mnt);
+ __mnt_drop_write(mnt);
+skip_update:
+ sb_end_write(inode->i_sb);
}
EXPORT_SYMBOL(touch_atime);