On Jan 06, 2009 12:21 -0500, Theodore Ts'o wrote: > @@ -64,6 +64,12 @@ config LSF > + The ext4 filesystem requires that this feature be enabled in > + order to support filesystems that have the huge_file feature > + enabled. Otherwise, it will refuse to mount any filesystems > + that use the huge_file feature, which is enabled by default > + by mke2fs.ext4. Wouldn't it make sense to just enable this by default if ext4 is enabled? On a related note, I wonder if we need to re-examine the use of the COMPAT flags in ext4. We went from a usage of "kernel enables flag when feature is used" (e.g. LARGE_FILE) to "admin must set flag in order to use feature" (e.g HUGE_FILE). The former system was recording the state of currently-used features in the filesystem, and maximized portability of the filesystem if the feature was NOT used. The newer system makes a filesystem somewhat less portable even if the feature is not being used at all (e.g. files > 2TB in size). I wonder if we should split the s_feature_*compat fields in the superblock to "present feature" and "allowed feature" so that e.g. HUGE_FILE count be put into "allowed feature" and would only appear in "present feature" if a file > 2TB in size arrives. That ensures the filesystem remains maximally compatible, while allowing the admin to select which features are permissible. Cheers, Andreas -- Andreas Dilger Sr. Staff Engineer, Lustre Group Sun Microsystems of Canada, Inc. -- 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
