Messages in this thread | | | From | Andreas Dilger <> | Subject | Re: [Ext2-devel] ext2 inode size (on-disk) | Date | Thu, 19 Apr 2001 23:35:40 -0600 (MDT) |
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Al writes: > I don't think that it's needed - old kernels (up to -CURRENT ;-) will > simply refuse to mount if ->s_inode_size != 128. Old utilites may be > trickier, though...
Probably would need an incompat flag for changing the inode size anyways, so old utilities wouldn't set that anyways.
> I'm somewhat concerned about the following: last block of inode table > fragment may have less inodes than the rest. Reason: number of inodes > per group should be a multiple of 8 and with inodes bigger than 128 > bytes it may give such effect. Comments?
I don't _think_ that there is a requirement for a multiple-of-8 inodes per group. OK, looking into mke2fs (actually lib/ext2fs/initialize.c) it _does_ show that it needs to be a multiple of 8, but I'm not sure exactly what the "bitmap splicing code" mentioned in the comment is.
In the end, it doesn't really matter much - if we go with multiple-of-2 inode sizes, all it means is that we may need to have multiple-of-2 (or possibly 4 for 512-byte inodes in a 1k block filesystem) inode table blocks in each group. Not a big deal. The code already handles this.
> I would really, really like to end up with accurate description of > inode table layout somewhere in Documentation/filesystems. Heck, I > volunteer to write it down and submit into the tree ;-)
I can write a few words as well.
Cheers, Andreas -- Andreas Dilger \ "If a man ate a pound of pasta and a pound of antipasto, \ would they cancel out, leaving him still hungry?" http://www-mddsp.enel.ucalgary.ca/People/adilger/ -- Dogbert - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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