Ocfs2 users - Jun 2010 - debugfs.ocfs2 and Feature Incompat

Hi!

When i'm running debugfs.ocfs2 i get the following result:
debugfs.ocfs2 -R "stats" /dev/sdb
         Revision: 0.90
         Mount Count: 0   Max Mount Count: 20
         State: 0   Errors: 0
         Check Interval: 0   Last Check: Mon May 10 12:17:37 2010
         Creator OS: 0
         Feature Compat: 3 backup-super strict-journal-super
         Feature Incompat: 8016 sparse extended-slotmap inline-data 
metaecc xattr indexed-dirs refcount
         Tunefs Incomplete: 0
         Feature RO compat: 1 unwritten
         Root Blknum: 5   System Dir Blknum: 6
         First Cluster Group Blknum: 3
         Block Size Bits: 12   Cluster Size Bits: 12
         Max Node Slots: 10
         Extended Attributes Inline Size: 256
         Label: ocfs2disk
         UUID: B029D592BBB04D1ABA25111216009DD2
         Hash: 476522312 (0x1c672748)
         DX Seed[0]: 0x00000000
         DX Seed[1]: 0x00000000
         DX Seed[2]: 0x00000000
         Cluster stack: classic o2cb
         Inode: 2   Mode: 00   Generation: 2428650348 (0x90c2436c)
         FS Generation: 2428650348 (0x90c2436c)
         CRC32: 6695a25a   ECC: 01ec
         Type: Unknown   Attr: 0x0   Flags: Valid System Superblock
         Dynamic Features: (0x0)
         User: 0 (root)   Group: 0 (root)   Size: 0
         Links: 0   Clusters: 47456155
         ctime: 0x4be7dd41 -- Mon May 10 12:17:37 2010
         atime: 0x0 -- Thu Jan  1 01:00:00 1970
         mtime: 0x4be7dd41 -- Mon May 10 12:17:37 2010
         dtime: 0x0 -- Thu Jan  1 01:00:00 1970
         ctime_nsec: 0x00000000 -- 0
         atime_nsec: 0x00000000 -- 0
         mtime_nsec: 0x00000000 -- 0
         Refcount Block: 0
         Last Extblk: 0   Orphan Slot: 0
         Sub Alloc Slot: Global   Sub Alloc Bit: 65535

But why is inline-data, indexed-dirs and so on incompatible?

# debugfs.ocfs2 -V
debugfs.ocfs2 1.6.0

#uname -a
Linux server 2.6.32.12

Stefan

On 06/01/2010 04:06 AM, Stefan Priebe - allied internet ag wrote:

<snip>
>           Feature Compat: 3 backup-super strict-journal-super
>           Feature Incompat: 8016 sparse extended-slotmap inline-data
> metaecc xattr indexed-dirs refcount
>           Tunefs Incomplete: 0
>           Feature RO compat: 1 unwritten
>
<snip>
> But why is inline-data, indexed-dirs and so on incompatible?
incompat means that a version of the fs not aware of this feature
should not mount the fs. And that fsck should abort. Users encountering
this error need to mount the fs with a newer version of the fs. Or, use
tunefs.ocfs2 to disable that feature.

Similarly, ro compat features means that a version of the fs not aware
of the feature can mount fs in read-only mode only.

As to which feature is incompat/ro/compat is a function of the disk format
change involved. Changes that do not negatively affect the functioning when
mounted with an older version are "compat". Changes that will corrupt
the
fs if mounted with an older version are "incompat". "ro
compat" are changes
that will work as long as the older fs does not write to it.