On Fri, 2015-06-26 at 15:13 +0800, Dongsheng Yang wrote: > On 06/26/2015 03:01 PM, Artem Bityutskiy wrote: > > On Fri, 2015-06-26 at 09:17 +0800, Dongsheng Yang wrote: > ... > > > This means that if a file-system (e.g., UBIFS or JFFS2) never supported > > atime, it is harder to add atime support without breaking the old > > behavior. > > > > What if we push the two "set NOATIME flag" lines of code down to > > individual file-systems, instead of having it at the VFS level? > > TO be sure I understand it correctly, do you mean pushing the flags > parsing work to individual file-systems? Then we can set the default > behavior in file-system itself. No, I mean removing these 2 lines from do_mount() /* Default to relatime */ mnt_flags |= MNT_RELATIME; and add them to the struct file_system_type->mount() of every individual file-system (e.g., ext4_mount()). > But there is another problem I called as problem 2 in my last mail. > That we can not distinguish: > -o - default behavior (*no atime*) > -o atime - atime support -o atime does not mean anything from the kernel POW, it is only user-space tools which may translate it to something meaningful for the kernel. No file-systems can distinguish these two anyway. So I would say this is not a problem, people have to use 'strictatime' instead. What do you think about this as the alternative to the UBIFS_ATIME_SUPPORT configuration switch, which will introduce additional churn? -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html