On 3/26/13 10:23 AM, Bernd Schubert wrote: > Sorry for my late reply, I had been rather busy. > > On 02/14/2013 01:05 AM, Anand Avati wrote: >> On Wed, Feb 13, 2013 at 3:44 PM, Theodore Ts'o <tytso@xxxxxxx> wrote: >>> >>> I suspect this would seriously screw over Gluster, though, and this >>> wouldn't be a solution for NFSv3, since NFS needs long-lived directory >>> cookies, and not the short-lived cookies which is all POSIX/SuSv3 >>> guarantees. >>> >> >> Actually this would work just fine with Gluster. Except in the case of > > Would it really work perfectly? What about a server reboot in the middle of a readdir of a client? > >> gluster-NFS, the native client is only acting like a router/proxy of >> syscalls to the backend system. A directory opened by an application will >> have a matching directory fd opened on ext4, and readdir from an app will >> be translated into readdir on the matching fd on ext4. So the >> app-on-glusterfs and glusterfsd-on-ext4 are essentially "moving in tandem". >> As long as the offs^H^H^H^H cookies do not overflow in the transformation, >> Gluster would not have a problem. >> >> However Gluster-NFS (and NFS in general, too) will break, as we >> opendir/closedir potentially on every request. > > We don't have reached a conclusion so far, do we? What about the > ioctl approach, but a bit differently? Would it work to specify the > allowed upper bits for ext4 (for example 16 additional bit) and the > remaining part for gluster? One of the mails had the calculation > formula: I did throw together an ioctl patch last week, but I think Anand has a new approach he's trying out which won't require ext4 code changes. I'll let him reply when he has a moment. :) -Eric > final_d_off = (ext4_d_off * MAX_SERVERS) + server_idx > > But what is the value of MAX_SERVERS? > > > Cheers, > Bernd > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-ext4" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
