New ext4 features
From Ext4
Multiblock Allocation
- Primary developer: Alex Tomas
- Status: Patches available - ready to push to mainline
- Changes on-disk format: No
- Target Date: ?
- e2fsprogs changes: No
- outstanding issues: None
Delayed Allocation
- Primary developer: Alex Tomas
- Status: Patches in unstable patch series
- Changes on-disk format: No
- Target Date: (in patch queue)
- e2fsprogs changes: No
- outstanding issues: handling 1k,2k block size and default data=order mode, ENOSPC handling
Break 32000 subdirectory limit
- Primary developer: Andreas
- Status: Done
- Changes on-disk format: Yes
- Target Date: (in patch queue)
- e2fsprogs changes: done
- outstanding issues: None
directory Inodes reservation
- Primary developer: Coly
- Status: Patch available
- Changes on-disk format: No
- Target Date: Nov, 2007
- e2fsprogs changes: Needed
- outstanding issues:
nsec timestamps
- Primary developer: Andreas
- Status: Done
- Change on-disk format: Yes
- Target Date: (in patch queue)
- e2fsprogs changes: Done
- outstanding issues:
inode version on disk
- Primary developer: Jean-Noel Cordenner, Kalpak Shah
- Status: Done
- Change on-disk format: Yes
- Target Date: (in patch queue)
- e2fsprogs changes: None
- outstanding issues: None
uninitialized groups
- Primary developer: Andreas Dilger
- Status: Done
- Change on-disk format: Yes
- Target Date: (in patch queue)
- e2fsprogs changes: Done
- outstanding issues: lazy zeroing of unused inode table blocks after filesystem is first mounted
journal checksumming
- Primary developer: Andreas
- Status: Prototype available
- Change on-disk format: Yes
- Target Date: (in patch queue)
- e2fsprogs changes: Needed
- outstanding issues:
persistent preallocation
- Primary developer: Amit Arora, Suparna
- Status: Patches available and reviewed
- Change on-disk format: Yes
- Target Date: Once interface issue is resolved
- e2fsprogs changes: complete
- outstanding issues: Need consensus on what interface should be used (ioctl, fcntl..), should return value be zero or number of block allocated on success
Online Defragmentation
- Primary developer: Takashi Sato
- Status:
latest patch: v0.2 posted on Jan 10th. Previous tries: http://marc.theaimsgroup.com/?l=linux-ext4&m=116678507906760&w=2 http://marc.theaimsgroup.com/?l=linux-ext4&m=116307062907075&w=2
- Related discussions
ext3 online defrag: http://marc.theaimsgroup.com/?l=linux-fsdevel&m=116160640814410&w=2
- Dependencies: Multiple block allocation from Alex Thomas
- Change on-disk format: No
- Target Date:
- e2fsprogs changes: No
- outstanding issues:
Undelete Feature for Ext4
- Primary Developer:
- status: Idea was proposed on the mailing list, still need more thought on the feature.
- Change on-disk format:
- Target Date:
- e2fsprogs changes:
- outstanding issues: Should the kernel be involved with undelete
Large file support
- Primary Developer: Takashi Sato
- status: Increase 2Tb limit on filesize. Takashi has begun working on this.
- Change on-disk format:
- Target Date:
- e2fsprogs Changes: Needed
- outstanding issues: unknown