nilfs2: do not acquire rwsem in nilfs_bmap_write()

It is now clear that nilfs_bmap_write() is only used to finalize logs
written to disk. Concurrent bmap modification operations are not
performed on bmaps in this context. Additionally, this function does not
modify data used in read-only operations such as bmap lookups.

Therefore, there is no need to acquire bmap->b_sem in nilfs_bmap_write(),
so delete it.

Link: https://lkml.kernel.org/r/20240122140202.6950-10-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

nilfs2: fix infinite loop in nilfs_mdt_get_block()

If the disk image that nilfs2 mounts is corrupted and a virtual block
address obtained by block lookup for a metadata file is invalid,
nilfs_bmap_lookup_at_level() may return the same internal return code as
-ENOENT, meaning the block does not exist in the metadata file.

This duplication of return codes confuses nilfs_mdt_get_block(), causing
it to read and create a metadata block indefinitely.

In particular, if this happens to the inode metadata file, ifile,
semaphore i_rwsem can be left held, causing task hangs in lock_mount.

Fix this issue by making nilfs_bmap_lookup_at_level() treat virtual block
address translation failures with -ENOENT as metadata corruption instead
of returning the error code.

Link: https://lkml.kernel.org/r/20230430193046.6769-1-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+221d75710bde87fa0e97@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?extid=221d75710bde87fa0e97
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

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: fix some kernel-doc warnings for nilfs2

Fixes the following W=1 kernel build warning(s):

fs/nilfs2/bmap.c:378: warning: Excess function parameter 'bhp' description in 'nilfs_bmap_assign'
fs/nilfs2/cpfile.c:907: warning: Excess function parameter 'status' description in 'nilfs_cpfile_change_cpmode'
fs/nilfs2/cpfile.c:946: warning: Excess function parameter 'stat' description in 'nilfs_cpfile_get_stat'
fs/nilfs2/page.c:76: warning: Excess function parameter 'inode' description in 'nilfs_forget_buffer'
fs/nilfs2/sufile.c:563: warning: Excess function parameter 'stat' description in 'nilfs_sufile_get_stat'

Signed-off-by: Wang Hai <wanghai38@huawei.com>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: https://lkml.kernel.org/r/1601386269-2423-1-git-send-email-konishi.ryusuke@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

treewide: Use fallthrough pseudo-keyword

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.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: hide function name argument from nilfs_error()

Simplify nilfs_error(), an output function used to report critical
issues in file system. This renames the original nilfs_error() function
to __nilfs_error() and redefines it as a macro to hide its function name
argument within the macro.

Every call site of nilfs_error() is changed to strip __func__ argument
except nilfs_bmap_convert_error(); nilfs_bmap_convert_error() directly
calls __nilfs_error() because it inherits caller's function name.

Link: http://lkml.kernel.org/r/1464875891-5443-2-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: 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: do not emit extra newline on nilfs_warning() and nilfs_error()

This updates call sites of nilfs_warning() and nilfs_error() so that they
don't add a duplicate newline. These output functions are already
designed to add a trailing newline to the message.

Link: http://lkml.kernel.org/r/1462886671-3521-2-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>

mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros

PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.

This promise never materialized. And unlikely will.

We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE. And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.

Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.

Let's stop pretending that pages in page cache are special. They are
not.

The changes are pretty straight-forward:

- <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;

- <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;

- PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};

- page_cache_get() -> get_page();

- page_cache_release() -> put_page();

This patch contains automated changes generated with coccinelle using
script below. For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.

The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.

There are few places in the code where coccinelle didn't reach. I'll
fix them manually in a separate patch. Comments and documentation also
will be addressed with the separate patch.

virtual patch

@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT

@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE

@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK

@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)

@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)

@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: add bmap function to seek a valid key

Add a new bmap function, nilfs_bmap_seek_key(), which seeks a valid
entry and returns its key starting from a given key. This function
can be used to skip hole blocks efficiently.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: unify type of key arguments in bmap interface

The type of key arguments in block mapping interface varies depending
on function. For instance, nilfs_bmap_lookup_at_level() takes "__u64"
for its key argument whereas nilfs_bmap_lookup() takes "unsigned
long".

This fits them to "__u64" to eliminate the variation.

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: get rid of NILFS_I_NILFS

This replaces all references of NILFS_I_NILFS(inode)->ns_bdev with
inode->i_sb->s_bdev and unfolds remaining uses of NILFS_I_NILFS inline
function.

Before 2.6.37, referring to a nilfs object from inodes needed a
conditional judgement, and NILFS_I_NILFS was helpful to simplify it.
But now we can simply do it by going through a super block instance
like inode->i_sb->s_fs_info.

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

nilfs2: get rid of nilfs_sb_info structure

This directly uses sb->s_fs_info to keep a nilfs filesystem object and
fully removes the intermediate nilfs_sb_info structure. With this
change, the hierarchy of on-memory structures of nilfs will be
simplified as follows:

Before:
super_block
-> nilfs_sb_info
-> the_nilfs
-> cptree --+-> nilfs_root (current file system)
+-> nilfs_root (snapshot A)
+-> nilfs_root (snapshot B)
:
-> nilfs_sc_info (log writer structure)
After:
super_block
-> the_nilfs
-> cptree --+-> nilfs_root (current file system)
+-> nilfs_root (snapshot A)
+-> nilfs_root (snapshot B)
:
-> nilfs_sc_info (log writer structure)

The reason why we didn't design so from the beginning is because the
initial shape also differed from the above. The early hierachy was
composed of "per-mount-point" super_block -> nilfs_sb_info pairs and a
shared nilfs object. On the kernel 2.6.37, it was changed to the
current shape in order to unify super block instances into one per
device, and this cleanup became applicable as the result.

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

nilfs2: record used amount of each checkpoint in checkpoint list

This records the number of used blocks per checkpoint in each
checkpoint entry of cpfile. Even though userland tools can get the
block count via nilfs_get_cpinfo ioctl, it was not updated by the
nilfs2 kernel code. This fixes the issue and makes it available for
userland tools to calculate used amount per checkpoint.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: Jiro SEKIBA <jir@unicus.jp>

nilfs2: unfold nilfs_dat_inode function

nilfs_dat_inode function was a wrapper to switch between normal dat
inode and gcdat, a clone of the dat inode for garbage collection.

This function got obsolete when the gcdat inode was removed, and now
we can access the dat inode directly from a nilfs object. So, we will
unfold the wrapper and remove it.

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

nilfs2: call nilfs_error inside bmap routines

Some functions using nilfs bmap routines can wrongly return invalid
argument error (i.e. -EINVAL) that bmap returns as an internal code
for btree corruption.

This fixes the issue by catching and converting the internal EINVAL to
EIO and calling nilfs_error function inside bmap routines.

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

nilfs2: get rid of GCDAT inode

This applies prepared rollback function and redirect function of
metadata file to DAT file, and eliminates GCDAT inode.

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

nilfs2: add routines to save and restore bmap state

This adds routines to save and restore the state of bmap structure.
The bmap state is stored in a given nilfs_bmap_store object.

These routines will be used to roll back the state of dat inode
without using gcdat inode.

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

nilfs2: get rid of nilfs_bmap_union

This removes nilfs_bmap_union and finally unifies three structures and
the union in bmap/btree code into one.

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

nilfs2: trivial coding style fix

This is a trivial style fix patch to mend errors/warnings
reported by "checkpatch.pl --file".

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

nilfs2: move out mark_inode_dirty calls from bmap routines

Previously, nilfs_bmap_add_blocks() and nilfs_bmap_sub_blocks() called
mark_inode_dirty() after they changed the number of data blocks.

This moves these calls outside bmap outermost functions like
nilfs_bmap_insert() or nilfs_bmap_truncate().

This will mitigate overhead for truncate or delete operation since
they repeatedly remove set of blocks. Nearly 10 percent improvement
was observed for removal of a large file:

# dd if=/dev/zero of=/test/aaa bs=1M count=512
# time rm /test/aaa

real 2.968s -> 2.705s

Further optimization may be possible by eliminating these
mark_inode_dirty() uses though I avoid mixing separate changes here.

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

nilfs2: stop marking metadata inode dirty within btree operations

Since metadata file routines mark the inode dirty after they
successfully changed bmap objects, nilfs_mdt_mark_dirty() calls in
nilfs_bmap_add_blocks() and nilfs_bmap_sub_blocks() are redundant.

This removes these overlapping calls from the bmap routines.

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

nilfs2: convert nilfs_bmap_lookup to an inline function

The nilfs_bmap_lookup() is now a wrapper function of
nilfs_bmap_lookup_at_level().

This moves the nilfs_bmap_lookup() to a header file converting it to
an inline function and gives an opportunity for optimization.

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

nilfs2: allow btree code to directly call dat operations

The current btree code is written so that btree functions call dat
operations via wrapper functions in bmap.c when they allocate, free,
or modify virtual block addresses.

This abstraction requires additional function calls and causes
frequent call of nilfs_bmap_get_dat() function since it is used in the
every wrapper function.

This removes the wrapper functions and makes them available from
btree.c and direct.c, which will increase the opportunity of
compiler optimization.

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

nilfs2: add update functions of virtual block address to dat

This is a preparation for the successive cleanup ("nilfs2: allow btree
to directly call dat operations").

This adds functions bundling a few operations to change an entry of
virtual block address on the dat file.

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

nilfs2: fix lockdep warning between regular file and inode file

This will fix the following false positive of recursive locking which
lockdep has detected:

=============================================
[ INFO: possible recursive locking detected ]
2.6.30-nilfs #42
---------------------------------------------
nilfs_cleanerd/10607 is trying to acquire lock:
(&bmap->b_sem){++++-.}, at: [<e0d025b7>] nilfs_bmap_lookup_at_level+0x1a/0x74 [nilfs2]

but task is already holding lock:
(&bmap->b_sem){++++-.}, at: [<e0d024e0>] nilfs_bmap_truncate+0x19/0x6a [nilfs2]
other info that might help us debug this:
2 locks held by nilfs_cleanerd/10607:
#0: (&nilfs->ns_segctor_sem){++++.+}, at: [<e0d0d75a>] nilfs_transaction_begin+0xb6/0x10c [nilfs2]
#1: (&bmap->b_sem){++++-.}, at: [<e0d024e0>] nilfs_bmap_truncate+0x19/0x6a [nilfs2]

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

nilfs2: support contiguous lookup of blocks

Although get_block() callback function can return extent of contiguous
blocks with bh->b_size, nilfs_get_block() function did not support
this feature.

This adds contiguous lookup feature to the block mapping codes of
nilfs, and allows the nilfs_get_blocks() function to return the extent
information by applying the feature.

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

nilfs2: remove bmap pointer operations

Previously, the bmap codes of nilfs used three types of function
tables. The abuse of indirect function calls decreased source
readability and suffered many indirect jumps which would confuse
branch prediction of processors.

This eliminates one type of the function tables,
nilfs_bmap_ptr_operations, which was used to dispatch low level
pointer operations of the nilfs bmap.

This adds a new integer variable "b_ptr_type" to nilfs_bmap struct,
and uses the value to select the pointer operations.

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

nilfs2: remove useless b_low and b_high fields from nilfs_bmap struct

This will cut off 16 bytes from the nilfs_bmap struct which is
embedded in the on-memory inode of nilfs.

The b_high field was never used, and the b_low field stores a constant
value which can be determined by whether the inode uses btree for
block mapping or not.

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

nilfs2: move get block functions in bmap.c into btree codes

Two get block function for btree nodes, nilfs_bmap_get_block() and
nilfs_bmap_get_new_block(), are called only from the btree codes.
This relocation will increase opportunities of compiler optimization.

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

nilfs2: remove nilfs_bmap_delete_block

nilfs_bmap_delete_block() is a wrapper function calling
nilfs_btnode_delete(). This removes it for simplicity.

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

nilfs2: remove nilfs_bmap_put_block

nilfs_bmap_put_block() is a wrapper function calling brelse(). This
eliminates the wrapper for simplicity.

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

nilfs2: unify bmap operations starting use of indirect block address

This simplifies some low level functions of bmap.

Three bmap pointer operations, nilfs_bmap_start_v(),
nilfs_bmap_commit_v(), and nilfs_bmap_abort_v(), are unified into one
nilfs_bmap_start_v() function. And the related indirect function calls
are replaced with it.

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

nilfs2: fix lockdep recursive locking warning on bmap

The bmap semaphore of DAT file can be held while a bmap of other files
is locked. This has caused the following false detection of lockdep
check:

mount.nilfs2/4667 is trying to acquire lock:
(&bmap->b_sem){..--}, at: [<d0c6c4b4>] nilfs_bmap_lookup_at_level+0x1a/0x74 [nilfs2]

but task is already holding lock:
(&bmap->b_sem){..--}, at: [<d0c6c4b4>] nilfs_bmap_lookup_at_level+0x1a/0x74 [nilfs2]

This will fix the false detection by distinguishing semaphores of the
DAT and other files.

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

nilfs2: clean up indirect function calling conventions

This cleans up the strange indirect function calling convention used in
nilfs to follow the normal kernel coding style.

Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
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: integrated block mapping

This adds structures and operations for the block mapping (bmap for
short). NILFS2 uses direct mappings for short files or B-tree based
mappings for longer files.

Every on-disk data block is held with inodes and managed through this
block mapping. The nilfs_bmap structure and a set of functions here
provide this capability to the NILFS2 inode.

[penberg@cs.helsinki.fi: remove a bunch of bmap wrapper macros]
[akpm@linux-foundation.org: coding-style fixes]
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: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>