treewide: remove editor modelines and cruft

The section "19) Editor modelines and other cruft" in
Documentation/process/coding-style.rst clearly says, "Do not include any
of these in source files."

I recently receive a patch to explicitly add a new one.

Let's do treewide cleanups, otherwise some people follow the existing code
and attempt to upstream their favoriate editor setups.

It is even nicer if scripts/checkpatch.pl can check it.

If we like to impose coding style in an editor-independent manner, I think
editorconfig (patch [1]) is a saner solution.

[1] https://lore.kernel.org/lkml/20200703073143.423557-1-danny@kdrag0n.dev/

Link: https://lkml.kernel.org/r/20210324054457.1477489-1-masahiroy@kernel.org
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Miguel Ojeda <ojeda@kernel.org> [auxdisplay]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 174

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation this program is
distributed in the hope that it will be useful but without any
warranty without even the implied warranty of merchantability or
fitness for a particular purpose see the gnu general public license
for more details

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 655 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070034.575739538@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

ocfs2: remove ocfs2_reflink_remap_range

Since ocfs2_remap_file_range is a thin shell around
ocfs2_remap_remap_range, move everything from the latter into the
former.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

ocfs2: support partial clone range and dedupe range

Change the ocfs2 remap code to allow for returning partial results.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

vfs: make remap_file_range functions take and return bytes completed

Change the remap_file_range functions to take a number of bytes to
operate upon and return the number of bytes they operated on. This is a
requirement for allowing fs implementations to return short clone/dedupe
results to the user, which will enable us to obey resource limits in a
graceful manner.

A subsequent patch will enable copy_file_range to signal to the
->clone_file_range implementation that it can handle a short length,
which will be returned in the function's return value. For now the
short return is not implemented anywhere so the behavior won't change --
either copy_file_range manages to clone the entire range or it tries an
alternative.

Neither clone ioctl can take advantage of this, alas.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

vfs: pass remap flags to generic_remap_file_range_prep

Plumb the remap flags through the filesystem from the vfs function
dispatcher all the way to the prep function to prepare for behavior
changes in subsequent patches.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>

ocfs2: implement the VFS clone_range, copy_range, and dedupe_range features

Connect the new VFS clone_range, copy_range, and dedupe_range features
to the existing reflink capability of ocfs2. Compared to the existing
ocfs2 reflink ioctl We have to do things a little differently to support
the VFS semantics (we can clone subranges of a file but we don't clone
xattrs), but the VFS ioctls are more broadly supported.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
v2: Convert inline data files to extents files before reflinking,
and fix i_blocks so that stat(2) output is correct.
v3: Make zero-length dedupe consistent with btrfs behavior.
v4: Use VFS double-inode lock routines and remove MAX_DEDUPE_LEN.

ocfs2: fix NULL pointer dereference in ocfs2_duplicate_clusters_by_page

Since ocfs2_cow_file_pos will invoke ocfs2_refcount_icow with a NULL as
the struct file pointer, it finally result in a null pointer dereference
in ocfs2_duplicate_clusters_by_page.

This patch replace file pointer with inode pointer in
cow_duplicate_clusters to fix this issue.

[jeff.liu@oracle.com: rebased patch against linux-next tree]
Signed-off-by: Tiger Yang <tiger.yang@oracle.com>
Signed-off-by: Jie Liu <jeff.liu@oracle.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Acked-by: Tao Ma <tm@tao.ma>
Tested-by: David Weber <wb@munzinger.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Ocfs2/refcounttree: Publicize couple of funcs from refcounttree.c

The original goal of commonizing these funcs is to benefit defraging/extent_moving
codes in the future, based on the fact that reflink and defragmentation having
the same Copy-On-Wrtie mechanism.

Signed-off-by: Tristan Ye <tristan.ye@oracle.com>

Reorganize data elements to reduce struct sizes

Thanks for the comments. I have incorportated them all.

CONFIG_OCFS2_FS_STATS is enabled and CONFIG_DEBUG_LOCK_ALLOC is disabled.
Statistics now look like -
ocfs2_write_ctxt: 2144 - 2136 = 8
ocfs2_inode_info: 1960 - 1848 = 112
ocfs2_journal: 168 - 160 = 8
ocfs2_lock_res: 336 - 304 = 32
ocfs2_refcount_tree: 512 - 472 = 40

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.de>
Signed-off-by: Joel Becker <joel.becker@oracle.com>

ocfs2: Add struct file to ocfs2_refcount_cow.

Add a new parameter 'struct file *' to ocfs2_refcount_cow
so that we can add readahead support later.

Signed-off-by: Tao Ma <tao.ma@oracle.com>

Ocfs2: Optimize ocfs2 truncate to use ocfs2_remove_btree_range() instead.

Truncate is just a special case of punching holes(from new i_size to
end), we therefore could take advantage of the existing
ocfs2_remove_btree_range() to reduce the comlexity and redundancy in
alloc.c. The goal here is to make truncate more generic and
straightforward.

Several functions only used by ocfs2_commit_truncate() will smiply be
removed.

ocfs2_remove_btree_range() was originally used by the hole punching
code, which didn't take refcount trees into account (definitely a bug).
We therefore need to change that func a bit to handle refcount trees.
It must take the refcount lock, calculate and reserve blocks for
refcount tree changes, and decrease refcounts at the end. We replace
ocfs2_lock_allocators() here by adding a new func
ocfs2_reserve_blocks_for_rec_trunc() which accepts some extra blocks to
reserve. This will not hurt any other code using
ocfs2_remove_btree_range() (such as dir truncate and hole punching).

I merged the following steps into one patch since they may be
logically doing one thing, though I know it looks a little bit fat
to review.

1). Remove redundant code used by ocfs2_commit_truncate(), since we're
moving to ocfs2_remove_btree_range anyway.

2). Add a new func ocfs2_reserve_blocks_for_rec_trunc() for purpose of
accepting some extra blocks to reserve.

3). Change ocfs2_prepare_refcount_change_for_del() a bit to fit our
needs. It's safe to do this since it's only being called by
truncate.

4). Change ocfs2_remove_btree_range() a bit to take refcount case into
account.

5). Finally, we change ocfs2_commit_truncate() to call
ocfs2_remove_btree_range() in a proper way.

The patch has been tested normally for sanity check, stress tests
with heavier workload will be expected.

Based on this patch, fixing the punching holes bug will be fairly easy.

Signed-off-by: Tristan Ye <tristan.ye@oracle.com>
Acked-by: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>

ocfs2: Add ioctl for reflink.

The ioctl will take 3 parameters: old_path, new_path and
preserve and call vfs_reflink. It is useful when we backport
reflink features to old kernels.

Signed-off-by: Tao Ma <tao.ma@oracle.com>

ocfs2: Add reflink support for xattr.

Signed-off-by: Tao Ma <tao.ma@oracle.com>

ocfs2: Call refcount tree remove process properly.

Now with xattr refcount support, we need to check whether
we have xattr refcounted before we remove the refcount tree.

Now the mechanism is:
1) Check whether i_clusters == 0, if no, exit.
2) check whether we have i_xattr_loc in dinode. if yes, exit.
2) Check whether we have inline xattr stored outside, if yes, exit.
4) Remove the tree.

Signed-off-by: Tao Ma <tao.ma@oracle.com>

ocfs2: Attach xattr clusters to refcount tree.

In ocfs2, when xattr's value is larger than OCFS2_XATTR_INLINE_SIZE,
it will be kept outside of the blocks we store xattr entry. And they
are stored in a b-tree also. So this patch try to attach all these
clusters to refcount tree also.

Signed-off-by: Tao Ma <tao.ma@oracle.com>

ocfs2: Add CoW support for xattr.

In order to make 2 transcation(xattr and cow) independent with each other,
we CoW the whole xattr out in case we are setting them.

Signed-off-by: Tao Ma <tao.ma@oracle.com>

ocfs2: CoW a reflinked cluster when it is truncated.

When we truncate a file to a specific size which resides in a reflinked
cluster, we need to CoW it since ocfs2_zero_range_for_truncate will
zero the space after the size(just another type of write).

So we add a "max_cpos" in ocfs2_refcount_cow so that it will stop when
it hit the max cluster offset.

Signed-off-by: Tao Ma <tao.ma@oracle.com>

ocfs2: CoW refcount tree improvement.

During CoW, if the old extent record is refcounted, we allocate
som new clusters and do CoW. Actually we can have some improvement
here. If the old extent has refcount=1, that means now it is only
used by this file. So we don't need to allocate new clusters, just
remove the refcounted flag and it is OK. We also have to remove
it from the refcount tree while not deleting it.

Signed-off-by: Tao Ma <tao.ma@oracle.com>

ocfs2: Add CoW support.

This patch try CoW support for a refcounted record.

the whole process will be:
1. Calculate how many clusters we need to CoW and where we start.
Extents that are not completely encompassed by the write will
be broken on 1MB boundaries.
2. Do CoW for the clusters with the help of page cache.
3. Change the b-tree structure with the new allocated clusters.

Signed-off-by: Tao Ma <tao.ma@oracle.com>

ocfs2: Decrement refcount when truncating refcounted extents.

Add 'Decrement refcount for delete' in to the normal truncate
process. So for a refcounted extent record, call refcount rec
decrementation instead of cluster free.

Signed-off-by: Tao Ma <tao.ma@oracle.com>

ocfs2: Add support of decrementing refcount for delete.

Given a physical cpos and length, decrement the refcount
in the tree. If the refcount for any portion of the extent goes
to zero, that portion is queued for freeing.

Signed-off-by: Tao Ma <tao.ma@oracle.com>

ocfs2: Add refcount tree lock mechanism.

Implement locking around struct ocfs2_refcount_tree. This protects
all read/write operations on refcount trees. ocfs2_refcount_tree
has its own lock and its own caching_info, protecting buffers among
multiple nodes.

User must call ocfs2_lock_refcount_tree before his operation on
the tree and unlock it after that.

ocfs2_refcount_trees are referenced by the block number of the
refcount tree root block, So we create an rb-tree on the ocfs2_super
to look them up.

Signed-off-by: Tao Ma <tao.ma@oracle.com>

ocfs2: Add new refcount tree lock resource in dlmglue.

refcount tree lock resource is used to protect refcount
tree read/write among multiple nodes.

Signed-off-by: Tao Ma <tao.ma@oracle.com>