Ocfs2 devel - Dec 2015 - [PATCH v2 0/4] Add online file check feature

On Wed, Dec 02, 2015 at 07:05:27PM -0700, Gang He wrote:
> Hello Pavel,
> 
> 
> 
> >>> 
> > On Wed 2015-10-28 14:25:57, Gang He wrote:
> >> When there are errors in the ocfs2 filesystem,
> >> they are usually accompanied by the inode number which caused the
error.
> >> This inode number would be the input to fixing the file.
> >> One of these options could be considered:
> >> A file in the sys filesytem which would accept inode numbers.
> >> This could be used to communication back what has to be fixed or
is fixed.
> >> You could write:
> >> $# echo "CHECK <inode>" >
/sys/fs/ocfs2/devname/filecheck
> >> or
> >> $# echo "FIX <inode>" >
/sys/fs/ocfs2/devname/filecheck
> >> 
> > 
> > Are you sure this is reasonable interface? I mean.... sysfs is
> > supposed to be one value per file. And I don't think its suitable
for
> > running commands.
> Usually, the corrupted file (inode) should be rarely encountered for OCFS2
file system, then
> lots of commands are executed via this interface with high performance is
not expected by us.
> Second, after online file check is added, we also plan to add a mount
option "error=fix", that means
> the file system can fix these errors automatically without a manual command
triggering.
It's not a "performance" issue, it's a "sysfs files only
have one value"
type thing.  Have two files, "inode_fix" and "inode_check"
and then just
write the inode into them, no need to have a "verb <inode>" type
parser.

thanks,

greg k-h

Hi Greg,

>>> 
> On Wed, Dec 02, 2015 at 07:05:27PM -0700, Gang He wrote:
>> Hello Pavel,
>> 
>> 
>> 
>> >>> 
>> > On Wed 2015-10-28 14:25:57, Gang He wrote:
>> >> When there are errors in the ocfs2 filesystem,
>> >> they are usually accompanied by the inode number which caused
the error.
>> >> This inode number would be the input to fixing the file.
>> >> One of these options could be considered:
>> >> A file in the sys filesytem which would accept inode numbers.
>> >> This could be used to communication back what has to be fixed
or is fixed.
>> >> You could write:
>> >> $# echo "CHECK <inode>" >
/sys/fs/ocfs2/devname/filecheck
>> >> or
>> >> $# echo "FIX <inode>" >
/sys/fs/ocfs2/devname/filecheck
>> >> 
>> > 
>> > Are you sure this is reasonable interface? I mean.... sysfs is
>> > supposed to be one value per file. And I don't think its
suitable for
>> > running commands.
>> Usually, the corrupted file (inode) should be rarely encountered for
OCFS2
> file system, then
>> lots of commands are executed via this interface with high performance
is
> not expected by us.
>> Second, after online file check is added, we also plan to add a mount
option
> "error=fix", that means
>> the file system can fix these errors automatically without a manual
command
> triggering.
> 
> It's not a "performance" issue, it's a "sysfs files
only have one value"
> type thing.  Have two files, "inode_fix" and
"inode_check" and then just
> write the inode into them, no need to have a "verb <inode>"
type parser.
Current, we have three functional items "check, fix and set", in the
future, maybe we can add more item.
Then, for each functional item, we need to create a sys file and add related
code (actual some code is duplicated),
I prefer to one sys file to handle multiple sub-commands.

Thanks
Gang
> 
> thanks,
> 
> greg k-h