On 3/8/12 9:37 AM, Ben Myers wrote: > On Wed, Mar 07, 2012 at 08:05:12PM -0600, Eric Sandeen wrote: >> On 3/7/12 7:34 PM, Dave Chinner wrote: >>> On Wed, Mar 07, 2012 at 11:20:57AM -0600, Eric Sandeen wrote: >>>> From: Dave Chinner <dchinner@xxxxxxxxxx> >>>> >>>> Default to allowing 64-bit inodes on the filesystem. >>>> >>>> Add a feature bit to the the superblock to record whether 64 bit inodes have >>>> been allocated on the filesystem or not. This allows us to reject mounting the >>>> filesytem with inode32 if 64 bit inodes are present. >>>> >>>> Once a 64 bitinode is allocated, the inode64 superblock feature bit will be set. >>>> Once the superblock feature bit is set, the filesystem will default to 64 bit >>>> inodes regardless of whether inode64 is specified as a mount option. >>>> >>>> To ensure only 32 bit inodes are created, the inode32 mount option must be >>>> used. If there are already 64 bit inodes as flagged by the superblock feature >>>> bit, then the inode32 mount will be refused. >>>> >>>> Signed-off-by: Dave Chinner <dchinner@xxxxxxxxxx> >>>> --- >>>> >>>> Passing this along to revive the old discussion ... >>> >>> I have no objections to do this. However, the kernel patch is just >>> the tip of the iceberg when it comes to implementing this. >>> >>> Were there patches for userspace support of the feature bit? I don't >>> recall if there were. I'm thinking that xfs_info needs to output >>> whether this is set, which means the flag needs to be added to the >>> xfs geometry ioctls in the kernel. >> >> Nope, you just put this patch out as a suggestion, and pointed out >> that userspace needed updates too. >> >> If people are in agreement about this then we can proceed with the rest... > > Please do. I too have been burned by mounting a filesystem with big > inos without the correct mount option. This is a great idea. So, after thinking about this (and talking on irc) some more, I'm not convinced that a feature flag is the way to go. If we set a feature flag, suddenly old filesystems with 64-bit inodes will grow a new feature, and this will force a userspace upgrade - but there is no real new feature. This seems like a bad idea. My original patch (which Dave responded to with this one) simply made inode64 default, with no feature flags. Unless someone has a really compelling argument for the flag, I'm thinking this is the wrong approach after all. Perhaps I should resend the just-make-it-default patch. Comments? -Eric > -Ben > _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
