> -----Original Message----- > From: Steve Dickson [mailto:SteveD@xxxxxxxxxx] > Sent: Thursday, March 19, 2009 9:18 AM > To: linux NFS Mailing list > Subject: The next step: nfsvers=4 > > As I see it, the next step to seamlessly move to V4 as the > default is to make 'mount -o nfsvers=4' actually do a v4 mount... > > There are two obvious place we can make this change. > In the kernel and/or in the mount command... > > Looking at the kernel, since v3 and v4 truly two different > file systems its seems a bit late for the nfs_get_sb() to all > of sudden have to change file system type. Meaning when > nfs_get_sb() sees the "nfsvers=4" somehow it would have to > back out and call nfs4_get_sb(), which obviously is a bit hacky.... > > Now I guess we could have one nfs_get_sb() for both v3 and v4. > Where the nfs_get_sb() could peek into the options data to > see which version is needed. This would also mean the mount > command would always have to set a version so when the "nfsvers=" > options is not set, the kernel would know which version to use. > Again, this feels a bit hacky as well but doable... > > At least to me, what seems like the best option is to have > the mount.nfs binary early on intercept "nfsvers=4" option > and then change the fs_type to "nfs4", which would allow > everything to "trickle down" as it does today... Again to me, > that seem like the least intrusive way to do it... > > Comments? Is there other ways? Whichever way it's done, if v4 becomes the default, don't forget to also make the default behavior be that the system will fall back and try a v3 mount if v4 isn't available. Otherwise you'll break a huge percentage of your user base. Of course then you also have to deal with the semantics of how to specifify "only v4" vs. "try v4 first and fall back". > > steved. > > > -- > To unsubscribe from this list: send the line "unsubscribe > linux-nfs" 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-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
