Add definitions for e2fs_daddr_t, e4fs_daddr_t in addition
to the already existing e2fs_lbn_t and adjust them for ext4.
Other than making the code more readable these changes should
fix problems related to big filesystems.
Setting the proper types can be tricky so the process was
helped by looking at UFS. In our implementation, logical block
numbers can be negative and the code depends on it. In ext2,
block numbers are unsigned so it is convenient to keep
e2fs_daddr_t unsigned and use the complete 32 bits. In the
case of e4fs_daddr_t, while the value should be unsigned, for
ext4 we only need to support 48 bits so preserving an extra
bit from the sign is not an issue.
While here also drop the ext2_setblock() prototype that was
never used.
Discussed with: mckusick, bde
MFC after: 3 weeks
Basic support for extents was implemented by Zheng Liu as part
of his Google Summer of Code in 2010. This support is read-only
at this time.
In addition to extents we also support the huge_file extension
for read-only purposes. This works nicely with the additional
support for birthtime/nanosec timestamps and dir_index that
have been added lately.
The implementation may not work for all ext4 filesystems as
it doesn't support some features that are being enabled by
default on recent linux like flex_bg. Nevertheless, the feature
should be very useful for migration or simple access in
filesystems that have been converted from ext2/3 or don't use
incompatible features.
Special thanks to Zheng Liu for his dedication and continued
work to support ext2 in FreeBSD.
Submitted by: Zheng Liu (lz@)
Reviewed by: Mike Ma, Christoph Mallon (previous version)
Sponsored by: Google Inc.
MFC after: 3 weeks
In line to what is done in UFS, define an internal type
e2fs_lbn_t for the logical block numbers.
This change is basically a no-op as the new type is unchanged
(int32_t) but it may be useful as bumping this may be required
for ext4fs.
Also, as pointed out by Bruce Evans:
-Use daddr_t for daddr in ext2_bmaparray(). This seems to
improve reliability with the reallocblks option.
- Add a cast to the fsbtodb() macro as in UFS.
Reviewed by: bde
MFC after: 3 days
The feature has been standard for a while in UFS as a means to reduce
fragmentation, therefore maintaining consistent performance with
filesystem aging. This is also very similar to what ext4 calls
"delayed allocation".
In his 2010 GSoC, Zheng Liu ported and benchmarked the missing
FANCY_REALLOC code to find more consistent performance improvements than
with the preallocation approach.
PR: 159233
Author: Zheng Liu <gnehzuil AT SPAMFREE gmail DOT com>
Sponsored by: Google Inc.
Approved by: jhb (mentor)
MFC after: 2 weeks
Eliminate the i_devvp field from the incore inodes, we can get the same
value from ip->i_ump->um_devvp.
Submitted by: Pedro F. Giffuni giffunip at yahoo
MFC after: 1 week
of Code 2009:
- BSDL block and inode allocation policies for ext2fs. This involves the use
FFS1 style block and inode allocation for ext2fs. Preallocation was removed
since it was GPL'd.
- Make ext2fs MPSAFE by introducing locks to per-mount datastructures.
- Fixes for kern/122047 PR.
- Various small bugfixes.
- Move out of gnu/ directory.
Sponsored by: Google Inc.
Submitted by: Aditya Sarawgi <sarawgi.aditya AT SPAMFREE gmail DOT com>
