Re: Journaling patches

["Steve O'Hara-Smith" <steve@xxxxxxxxxx>]

On Thu, 25 Jan 2007 10:18:04 -0800 (PST)
Matthew Dillon <dillon@apollo.backplane.com> wrote:

> :	Hi,
> :
> :	The first attached patch (jscan_patches) makes the -D option of
> :jscan work. It includes tests that the directory actually exists. Apply
> :within /usr/src/sbin/jscan
> 
>     Ok, this one needs a little work.  You are calling chdir() on every
>     single journaling record rather then just once at the beginning
>     (e.g. up in jscan.c before the loops that call dump_mirror()).
> 
>     The bit in jscan.c should use !S_ISDIR(sb.st_mode) instead of
>     (sb.st_mode & S_IFDIR).

	The attached patch (to jscan.c only) addresses these points and
works nicely in my vkernel environment.

> :	Having the journal appears to reduce the filesystem performance
> to :about one third of it's unjournaled level however some of that is
> probably :due to the journal being on the same disc as the filesystem.
> 
>     Write performance will suffer a lot with this sort of journaling,
>     though it is buffered fairly well within the kernel.

	Indeed, I wasn't complaining just leaving some figures so that
perhaps others would not be surprised.

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