On 2018-08-21 23:57, Duncan wrote:
Austin S. Hemmelgarn posted on Tue, 21 Aug 2018 13:01:00 -0400 as
excerpted:
Otherwise, the only option for people who want it set is to patch the
kernel to get noatime as the default (instead of relatime). I would
look at pushing such a patch upstream myself actually, if it weren't for
the fact that I'm fairly certain that it would be immediately NACK'ed by
at least Linus, and probably a couple of other people too.
What about making default-noatime a kconfig option, presumably set to
default-relatime by default? That seems to be the way many legacy-
incompatible changes work. Then for most it's up to the distro, which in
fact it is already, only if the distro set noatime-default they'd at
least be using an upstream option instead of patching it themselves,
making it upstream code that could be accounted for instead of downstream
code that... who knows?
That's probably a lot more likely to make it upstream, but it's a bit
beyond my skills when it comes to stuff like this.
Meanwhile, I'd be interested in seeing your local patch. I'm local-
patching noatime-default here too, but not being a dev, I'm not entirely
sure I'm doing it "correctly", tho AFAICT it does seem to work. FWIW,
here's what I'm doing (posting inline so may be white-space damaged, and
IIRC I just recently manually updated the line numbers so they don't
reflect the code at the 2014 date any more, but as I'm not sure of the
"correctness" it's not intended to be applied in any case):
--- fs/namespace.c.orig 2014-04-18 23:54:42.167666098 -0700
+++ fs/namespace.c 2014-04-19 00:19:08.622741946 -0700
@@ -2823,8 +2823,9 @@ long do_mount(const char *dev_name, cons
goto dput_out;
/* Default to relatime unless overriden */
- if (!(flags & MS_NOATIME))
- mnt_flags |= MNT_RELATIME;
+ /* JED: Make that noatime */
+ if (!(flags & MS_RELATIME))
+ mnt_flags |= MNT_NOATIME;
/* Separate the per-mountpoint flags */
if (flags & MS_NOSUID)
@@ -2837,6 +2837,8 @@ long do_mount(const char *dev_name, cons
mnt_flags |= MNT_NOATIME;
if (flags & MS_NODIRATIME)
mnt_flags |= MNT_NODIRATIME;
+ if (flags & MS_RELATIME)
+ mnt_flags |= MNT_RELATIME;
if (flags & MS_STRICTATIME)
mnt_flags &= ~(MNT_RELATIME | MNT_NOATIME);
if (flags & MS_RDONLY)
Sane, or am I "doing it wrong!"(TM), or perhaps doing it correctly, but
missing a chunk that should be applied elsewhere?
Mine only has the first part, not the second, which seems to cover
making sure it's noatime by default. I never use relatime though, so
that may be broken with my patch because of me not having the second part.
Meanwhile, since broken rootflags requiring an initr* came up let me take
the opportunity to ask once again, does btrfs-raid1 root still require an
initr*? It'd be /so/ nice to be able to supply the appropriate
rootflags=device=...,device=... and actually have it work so I didn't
need the initr* any longer!
Last I knew, specifying appropriate `device=` options in rootflags works
correctly without an initrd.
