MFC r324962 (by fsu@):

Set doreallocblks sysctl value to zero by default because of
possibility of filesystem corruption.

Fedor has found some weird behavior in his tests.

MFC r310705, r310706:
style(9) cleanups.

Just to reduce some of the issues found with indent(1).

MFC r297796:
ext2fs: replace 0 with NULL for pointers.

While here do late initialization of ebap, similar as was
done in UFS.

Found with devel/coccinelle.

MFC r297479, r297695:

Update comment: Linux does set a randomized generation number of an inode
on ext2/3/4. While here use arc4random() instead of random().

Reviewed by: pfg

MFC r294504, r294652, r294653, r294655:

ext2fs: Bring back the htree dir_index implementation.

The htree dir_index is perhaps one of the most characteristic
features of the linux ext3 implementation. It was removed
in r281670, due to repeated bug reports.

Damjan Jovanic detected and fixed three bugs and did some
stress testing by building Apache OpenOffice on top of it
so it is now in good shape to bring back.

Differential Revision: https://reviews.freebsd.org/D5007

Submitted by: Damjan Jovanovic
Reviewed by: pfg
RelNotes: yes

MFC r277340, r277349:

Remove dead code.
After the ext2 variant of the "orlov allocator" was implemented,
the case for a negative or zero dirsize disappeared.

Drop the dead code and unsign dirsize given that it can't be
negative anyways.

ext2fs: fix for uninitialized pointer read.
path.ep_bp was being used uninitialized in ext4_ext_find_extent().

CID: 1062344
CID: 1008669

MFC r262623, r262667:

ext2fs: use of tab vs spaces.

Consistently use a single tab after a #define as mentioned in style(9).
Use tabs instead of space for indenting.
Fix a typo: "hash_vesion".

No functional change.

MFC r261136:

ext2fs: Re-enable reallocblk.

The major corruption issues affecting this code have been fixed.

Tested by: Mike Ma

MFC r277340, r277349:

Remove dead code.
After the ext2 variant of the "orlov allocator" was implemented,
the case for a negative or zero dirsize disappeared.

Drop the dead code and unsign dirsize given that it can't be
negative anyways.

ext2fs: fix for uninitialized pointer read.
path.ep_bp was being used uninitialized in ext4_ext_find_extent().

CID: 1062344
CID: 1008669

MFC r262623, r262667:

ext2fs: use of tab vs spaces.

Consistently use a single tab after a #define as mentioned in style(9).
Use tabs instead of space for indenting.
Fix a typo: "hash_vesion".

No functional change.

MFC r261136:

ext2fs: Re-enable reallocblk.

The major corruption issues affecting this code have been fixed.

Tested by: Mike Ma