Re: [patch] document ext3 a bit better

Jiri Kosina
2009-01-09T23:25:32Z

On Tue, 6 Jan 2009, Pavel Machek wrote:

> On Mon 2009-01-05 09:57:13, Theodore Tso wrote:
> > On Sun, Jan 04, 2009 at 11:34:33PM +0100, Pavel Machek wrote:
> > > @@ -14,6 +14,11 @@ Options
> > > When mounting an ext3 filesystem, the following option are accepted:
> > > (*) == default
> > >
> > > +ro Mount filesystem read only. Note that ext3 will replay
> > > + the journal (and thus write to the partition) even when
> > > + mounted "read only". "ro, noload" can be used to prevent
> > > + writes to the filesystem.
> >
> > I'd sugest "ro,noload" since the spaces screw up the mount options
> > parsing both on the command-line and in /etc/fstab. So how about:
> >
> > Using the mount options "ro,noload" can be used....
>
> Too many "using", but yes, fixed, thanks.
>
> > > @@ -95,6 +102,8 @@ debug Extra debugging information is s
> > > errors=remount-ro(*) Remount the filesystem read-only on an error.
> > > errors=continue Keep going on a filesystem error.
> > > errors=panic Panic and halt the machine if an error occurs.
> > > + (Note that default is overriden by superblock
> > > + setting on most systems).
> >
> > The default is always specified by the superblock setting. So users
> > will probably find it easier to understand if we remove the "(*)" and
> > to add the explanatory comment:
> >
> > (These mount options override the errors behavior
> > specified in the superblock, which can be configured
> > using tune2fs)
> >
> > Pavel, thanks for working on improving the documentation; with these
> > fixes,
>
> Thanks!
>
> ---
>
> ext3 has quite unexpected semantics or "ro" and defaults are
> not what they are documented to be, due to mkfs override.
>
> Signed-off-by: Pavel Machek <pavel@suse.cz>
> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
>
> diff --git a/Documentation/filesystems/ext3.txt b/Documentation/filesystems/ext3.txt
> index 9dd2a3b..49c08bf 100644
> --- a/Documentation/filesystems/ext3.txt
> +++ b/Documentation/filesystems/ext3.txt
> @@ -14,6 +14,11 @@ Options
> When mounting an ext3 filesystem, the following option are accepted:
> (*) == default
>
> +ro Mount filesystem read only. Note that ext3 will replay
> + the journal (and thus write to the partition) even when
> + mounted "read only". Mount options "ro,noload" can be
> + used to prevent writes to the filesystem.
> +
> journal=update Update the ext3 file system's journal to the current
> format.
>
> @@ -27,7 +32,9 @@ journal_dev=devnum When the external jou
> identified through its new major/minor numbers encoded
> in devnum.
>
> -noload Don't load the journal on mounting.
> +noload Don't load the journal on mounting. Note that this forces
> + mount of inconsistent filesystem, which can lead to
> + various problems.
>
> data=journal All data are committed into the journal prior to being
> written into the main file system.
> @@ -92,9 +99,12 @@ nocheck
>
> debug Extra debugging information is sent to syslog.
>
> -errors=remount-ro(*) Remount the filesystem read-only on an error.
> +errors=remount-ro Remount the filesystem read-only on an error.
> errors=continue Keep going on a filesystem error.
> errors=panic Panic and halt the machine if an error occurs.
> + (These mount options override the errors behavior
> + specified in the superblock, which can be
> + configured using tune2fs.)
>
> data_err=ignore(*) Just print an error message if an error occurs
> in a file data buffer in ordered mode.
>

So, documentation guys, are you going to take this patch through the
Documentation tree (tytso already Signed off on that), or should I take it
through trivial tree?

Thanks,

--
Jiri Kosina
SUSE Labs