Re: [patch] document ext3 a bit better

From: Randy Dunlap
Date: Fri Jan 09 2009 - 18:38:16 EST


Jiri Kosina wrote:
> 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@xxxxxxx>
>> Signed-off-by: "Theodore Ts'o" <tytso@xxxxxxx>
>>
>> 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

(probably should be Acked-by or Reviewed-by
if he isn't merging it)

> through trivial tree?

I'm so far behind on doc patches that I haven't read any of this thread
yet, so you can merge it IMO.

Thanks,
--
~Randy
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