Theodore: Thanks for your explaining. I ignored this detail before, it is more clear to me now. Best regards. Coly 在 2007-04-09一的 11:26 -0400，Theodore Tso写道： > On Mon, Apr 09, 2007 at 10:33:13AM +0800, coly wrote: > > Theodore: > > > > Thanks for your replying. > > > > Can I understand this way: > > * Though sizeof(struct ext4_inode) is 152, the real inode size on disk > > still depends on mount options. > > Not mount options, but how the filesystem is formatted. So substitute > "mount" with "mke2fs", and that would be correct. > > > * If use old inode size, the on disk inode will be 128 bytes. > > * If use new inode size(e.g. extent option in mount), the on disk inode > > will be 256, or more bytes. > > s/mount/mke2fs/ > > And the on-disk inode size is 256, 512, or some greater power of two, > up to the filesystem blocksize. > > > * If on disk inode size is 128 bytes, only first 128 bytes of struct > > ext4_inode take effects. > > Well, there's no space to store the fields beyond the first 128, so > any features that require the extra inode fields can't be used. > > - Ted - 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
