nilfs2: remove filenames from file comments

Remove filenames that are not particularly useful in file comments, and
suppress checkpatch warnings

WARNING: It's generally not useful to have the filename in the file

Link: https://lkml.kernel.org/r/1635151862-11547-3-git-send-email-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: Qing Wang <wangqing@vivo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: convert to SPDX license tags

Remove the verbose license text from NILFS2 files and replace them with
SPDX tags. This does not change the license of any of the code.

Link: http://lkml.kernel.org/r/1535624528-5982-1-git-send-email-konishi.ryusuke@lab.ntt.co.jp
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: avoid bare use of 'unsigned'

This fixes checkpatch.pl warning "WARNING: Prefer 'unsigned int' to
bare use of 'unsigned'".

Link: http://lkml.kernel.org/r/1462886671-3521-5-git-send-email-konishi.ryusuke@lab.ntt.co.jp
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: clean up old e-mail addresses

E-mail addresses of osrg.net domain are no longer available. This
removes them from authorship notices and prevents reporters from being
confused.

Link: http://lkml.kernel.org/r/1461935747-10380-5-git-send-email-konishi.ryusuke@lab.ntt.co.jp
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: remove FSF mailing address from GPL notices

This removes the extra paragraph which mentions FSF address in GPL
notices from source code of nilfs2 and avoids the checkpatch.pl error
related to it.

Link: http://lkml.kernel.org/r/1461935747-10380-4-git-send-email-konishi.ryusuke@lab.ntt.co.jp
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: free unused dat file blocks during garbage collection

As a nilfs2 volume ages, the amount of available disk space decreases
little by little due to bloat of DAT (disk address translation) metadata
file. Even if we delete all files in a file system and free their block
addresses from the DAT file through a garbage collection, empty DAT blocks
are not freed.

This fixes the issue by extending the deallocator of block addresses so
that empty data blocks and empty bitmap blocks of DAT are deleted.

The following comparison shows the effect of this patch. Each shows disk
amount information of a nilfs2 volume that we cleaned out by deleting all
files and running gc after having filled 90% of its capacity.

Before:
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/sda1 500105212 3022844 472072192 1% /test

After:
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/sda1 500105212 16380 475078656 1% /test

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: implement calculation of free inodes count

Currently, NILFS2 returns 0 as free inodes count (f_ffree) and current
used inodes count as total file nodes in file system (f_files):

df -i
Filesystem Inodes IUsed IFree IUse% Mounted on
/dev/loop0 2 2 0 100% /mnt/nilfs2

This patch implements real calculation of free inodes count. First of
all, it is calculated total file nodes in file system as
(desc_blocks_count * groups_per_desc_block * entries_per_group). Then, it
is calculated free inodes count as difference the total file nodes and
used inodes count. As a result, we have such output for NILFS2:

df -i
Filesystem Inodes IUsed IFree IUse% Mounted on
/dev/loop0 4194304 2114701 2079603 51% /mnt/nilfs2

Reported-by: Clemens Eisserer <linuxhippy@gmail.com>
Signed-off-by: Vyacheslav Dubeyko <slava@dubeyko.com>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Tested-by: Vyacheslav Dubeyko <slava@dubeyko.com>
Cc: Joern Engel <joern@logfs.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: add omitted comments for different structures in driver implementation

Add omitted comments for different structures in driver implementation.

Signed-off-by: Vyacheslav Dubeyko <slava@dubeyko.com>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: use little-endian bitops

As a preparation for removing ext2 non-atomic bit operations from
asm/bitops.h. This converts ext2 non-atomic bit operations to
little-endian bit operations.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: add kernel doc comments to persistent object allocator functions

The implementation of persistent object allocator (alloc.c) is poorly
documented. This adds kernel doc style comments on that functions.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

nilfs2: fix various typos in comments

This fixes various typos I found in comments of nilfs2.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

nilfs2: add cache framework for persistent object allocator

This adds setup and cleanup routines of the persistent object
allocator cache.

According to ftrace analyses, accessing buffers of the DAT file
suffers indispensable overhead many times. To mitigate the overhead,
This introduce cache framework for the persistent object allocator
(palloc) which the DAT file and ifile are using.

struct nilfs_palloc_cache represents the cache object per metadata
file using palloc.

The cache is initialized through nilfs_palloc_setup_cache() and
destroyed by nilfs_palloc_destroy_cache(); callers of the former
function will be added to individual allocators of DAT and ifile on
successive patches.

nilfs_palloc_destroy_cache() will be called from nilfs_mdt_destroy()
if the cache is attached to a metadata file. A companion function
nilfs_palloc_clear_cache() is provided to allow releasing buffer head
references independently with the cleanup task. This adjunctive
function will be used before invalidating pages of metadata file with
the cache.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

nilfs2: persistent object allocator

This adds common functions to allocate or deallocate entries with bitmaps
on a meta data file. This feature is used by the DAT and ifile.

Signed-off-by: Koji Sato <sato.koji@lab.ntt.co.jp>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Yoshiji Amagai <amagai.yoshiji@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>