reiserfs: Replace one-element array with flexible-array member

One-element arrays are deprecated, and we are replacing them with flexible
array members instead. So, replace one-element array with flexible-array
member in direntry_uarea structure, and refactor the rest of the code,
accordingly.

Worth mentioning is that before these changes, the original implementation
was returning two-too many bytes in function direntry_create_vi():

fs/reiserfs/item_ops.c:464: int size = sizeof(struct direntry_uarea);
...
fs/reiserfs/item_ops.c-490- size += (dir_u->entry_count * sizeof(short));
...
fs/reiserfs/item_ops.c-517- return size;

Link: https://github.com/KSPP/linux/issues/79
Link: https://github.com/KSPP/linux/issues/290
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

reiserfs: delete duplicated words

Delete repeated words in fs/reiserfs/.
{from, not, we, are}

Link: https://lore.kernel.org/r/20200805024925.12281-1-rdunlap@infradead.org
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
To: linux-fsdevel@vger.kernel.org
Cc: Jan Kara <jack@suse.com>
Cc: Jeff Mahoney <jeffm@suse.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: reiserfs-devel@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>

fs/reiserfs/fix_node.c: remove set but not used variables

fs/reiserfs/fix_node.c: In function get_num_ver:
fs/reiserfs/fix_node.c:379:6: warning: variable cur_free set but not used [-Wunused-but-set-variable]
fs/reiserfs/fix_node.c: In function dc_check_balance_internal:
fs/reiserfs/fix_node.c:1737:6: warning: variable maxsize set but not used [-Wunused-but-set-variable]

Link: http://lkml.kernel.org/r/1566379929-118398-7-git-send-email-zhengbin13@huawei.com
Signed-off-by: zhengbin <zhengbin13@huawei.com>
Reported-by: Hulk Robot <hulkci@huawei.com>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

reiserfs: balance_leaf refactor, move state variables into tree_balance

This patch pushes the rest of the state variables in balance_leaf into
the tree_balance structure so we can use them when we split balance_leaf
into separate functions.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Jan Kara <jack@suse.cz>

reiserfs: cleanup, remove unnecessary parens

The reiserfs code is littered with extra parens in places where the authors
may not have been certain about precedence of & vs ->. This patch cleans them
out.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Jan Kara <jack@suse.cz>

reiserfs: cleanup, remove leading whitespace from labels

This patch moves reiserfs closer to adhering to the style rules by
removing leading whitespace from labels.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Jan Kara <jack@suse.cz>

reiserfs: cleanup, remove sb argument from journal_mark_dirty

journal_mark_dirty doesn't need a separate sb argument; It's provided
by the transaction handle.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Jan Kara <jack@suse.cz>

reiserfs: cleanup, reformat comments to normal kernel style

This patch reformats comments in the reiserfs code to fit in 80 columns and
to follow the style rules.

There is no functional change but it helps make my eyes bleed less.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Jan Kara <jack@suse.cz>

reiserfs: cleanup, rename key and item accessors to more friendly names

This patch does a quick search and replace:
B_N_PITEM_HEAD() -> item_head()
B_N_PDELIM_KEY() -> internal_key()
B_N_PKEY() -> leaf_key()
B_N_PITEM() -> item_body()

And the item_head version:
B_I_PITEM() -> ih_item_body()
I_ENTRY_COUNT() -> ih_entry_count()

And the treepath variants:
get_ih() -> tp_item_head()
PATH_PITEM_HEAD() -> tp_item_head()
get_item() -> tp_item_body()

... which makes the code much easier on the eyes.

I've also removed a few unused macros.

Checkpatch will complain about the 80 character limit for do_balan.c.
I've addressed that in a later patchset to split up balance_leaf().

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Jan Kara <jack@suse.cz>

reiserfs: locking, handle nested locks properly

The reiserfs write lock replaced the BKL and uses similar semantics.

Frederic's locking code makes a distinction between when the lock is nested
and when it's being acquired/released, but I don't think that's the right
distinction to make.

The right distinction is between the lock being released at end-of-use and
the lock being released for a schedule. The unlock should return the depth
and the lock should restore it, rather than the other way around as it is now.

This patch implements that and adds a number of places where the lock
should be dropped.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>

move private bits of reiserfs_fs.h to fs/reiserfs/reiserfs.h

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.

2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).

* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

reiserfs: fix misspelling of "journaled"

"Journaled" is misspelled "journlaled" in an output string; this patch
fixed it. No changes in functionality.

Signed-off-by: Adam Buchbinder <adam.buchbinder@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

kill-the-bkl/reiserfs: move the concurrent tree accesses checks per superblock

When do_balance() balances the tree, a trick is performed to
provide the ability for other tree writers/readers to check whether
do_balance() is executing concurrently (requires CONFIG_REISERFS_CHECK).

This is done to protect concurrent accesses to the tree. The trick
is the following:

When do_balance is called, a unique global variable called cur_tb
takes a pointer to the current tree to be rebalanced.
Once do_balance finishes its work, cur_tb takes the NULL value.

Then, concurrent tree readers/writers just have to check the value
of cur_tb to ensure do_balance isn't executing concurrently.
If it is, then it proves that schedule() occured on do_balance(),
which then relaxed the bkl that protected the tree.

Now that the bkl has be turned into a mutex, this check is still
fine even though do_balance() becomes preemptible: the write lock
will not be automatically released on schedule(), so the tree is
still protected.

But this is only fine if we have a single reiserfs mountpoint.
Indeed, because the bkl is a global lock, it didn't allowed
concurrent executions between a tree reader/writer in a mount point
and a do_balance() on another tree from another mountpoint.

So assuming all these readers/writers weren't supposed to be
reentrant, the current check now sometimes detect false positives with
the current per-superblock mutex which allows this reentrancy.

This patch keeps the concurrent tree accesses check but moves it
per superblock, so that only trees from a same mount point are
checked to be not accessed concurrently.

[ Impact: fix spurious panic while running several reiserfs mount-points ]

Cc: Jeff Mahoney <jeffm@suse.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Alexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>

kill-the-BKL/reiserfs: release the write lock inside get_neighbors()

get_neighbors() is used to get the left and/or right blocks
against a given one in order to balance a tree.

sb_bread() is used to read the buffer of these neighors blocks and
while it waits for this operation, it might sleep.

The bkl was released at this point, and then we can also release
the write lock before calling sb_bread().

This is safe because if the filesystem is changed after this
lock release, the function returns REPEAT_SEARCH (aka SCHEDULE_OCCURRED
in the function header comments) in order to repeat the neighbhor
research.

[ Impact: release the reiserfs write lock when it is not needed ]

Cc: Jeff Mahoney <jeffm@suse.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Alexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>

reiserfs: kill-the-BKL

This patch is an attempt to remove the Bkl based locking scheme from
reiserfs and is intended.

It is a bit inspired from an old attempt by Peter Zijlstra:

http://lkml.indiana.edu/hypermail/linux/kernel/0704.2/2174.html

The bkl is heavily used in this filesystem to prevent from
concurrent write accesses on the filesystem.

Reiserfs makes a deep use of the specific properties of the Bkl:

- It can be acqquired recursively by a same task
- It is released on the schedule() calls and reacquired when schedule() returns

The two properties above are a roadmap for the reiserfs write locking so it's
very hard to simply replace it with a common mutex.

- We need a recursive-able locking unless we want to restructure several blocks
of the code.
- We need to identify the sites where the bkl was implictly relaxed
(schedule, wait, sync, etc...) so that we can in turn release and
reacquire our new lock explicitly.
Such implicit releases of the lock are often required to let other
resources producer/consumer do their job or we can suffer unexpected
starvations or deadlocks.

So the new lock that replaces the bkl here is a per superblock mutex with a
specific property: it can be acquired recursively by a same task, like the
bkl.

For such purpose, we integrate a lock owner and a lock depth field on the
superblock information structure.

The first axis on this patch is to turn reiserfs_write_(un)lock() function
into a wrapper to manage this mutex. Also some explicit calls to
lock_kernel() have been converted to reiserfs_write_lock() helpers.

The second axis is to find the important blocking sites (schedule...(),
wait_on_buffer(), sync_dirty_buffer(), etc...) and then apply an explicit
release of the write lock on these locations before blocking. Then we can
safely wait for those who can give us resources or those who need some.
Typically this is a fight between the current writer, the reiserfs workqueue
(aka the async commiter) and the pdflush threads.

The third axis is a consequence of the second. The write lock is usually
on top of a lock dependency chain which can include the journal lock, the
flush lock or the commit lock. So it's dangerous to release and trying to
reacquire the write lock while we still hold other locks.

This is fine with the bkl:

T1 T2

lock_kernel()
mutex_lock(A)
unlock_kernel()
// do something
lock_kernel()
mutex_lock(A) -> already locked by T1
schedule() (and then unlock_kernel())
lock_kernel()
mutex_unlock(A)
....

This is not fine with a mutex:

T1 T2

mutex_lock(write)
mutex_lock(A)
mutex_unlock(write)
// do something
mutex_lock(write)
mutex_lock(A) -> already locked by T1
schedule()

mutex_lock(write) -> already locked by T2
deadlock

The solution in this patch is to provide a helper which releases the write
lock and sleep a bit if we can't lock a mutex that depend on it. It's another
simulation of the bkl behaviour.

The last axis is to locate the fs callbacks that are called with the bkl held,
according to Documentation/filesystem/Locking.

Those are:

- reiserfs_remount
- reiserfs_fill_super
- reiserfs_put_super

Reiserfs didn't need to explicitly lock because of the context of these callbacks.
But now we must take care of that with the new locking.

After this patch, reiserfs suffers from a slight performance regression (for now).
On UP, a high volume write with dd reports an average of 27 MB/s instead
of 30 MB/s without the patch applied.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
Cc: Jeff Mahoney <jeffm@suse.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Bron Gondwana <brong@fastmail.fm>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
LKML-Reference: <1239070789-13354-1-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

reiserfs: rename [cn]_* variables

This patch renames n_, c_, etc variables to something more sane. This
is the sixth in a series of patches to rip out some of the awful
variable naming in reiserfs.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

reiserfs: rename p_._ variables

This patch is a simple s/p_._//g to the reiserfs code. This is the
fifth in a series of patches to rip out some of the awful variable
naming in reiserfs.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

reiserfs: rename p_s_tb to tb

This patch is a simple s/p_s_tb/tb/g to the reiserfs code. This is the
fourth in a series of patches to rip out some of the awful variable
naming in reiserfs.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

reiserfs: rename p_s_bh to bh

This patch is a simple s/p_s_bh/bh/g to the reiserfs code. This is the
second in a series of patches to rip out some of the awful variable
naming in reiserfs.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

reiserfs: rename p_s_sb to sb

This patch is a simple s/p_s_sb/sb/g to the reiserfs code. This is the
first in a series of patches to rip out some of the awful variable
naming in reiserfs.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

reiserfs: strip trailing whitespace

This patch strips trailing whitespace from the reiserfs code.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

reiserfs: cleanup path functions

This patch cleans up some redundancies in the reiserfs tree path code.

decrement_bcount() is essentially the same function as brelse(), so we use
that instead.

decrement_counters_in_path() is exactly the same function as pathrelse(), so
we kill that and use pathrelse() instead.

There's also a bit of cleanup that makes the code a bit more readable.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

reiserfs: rework reiserfs_panic

ReiserFS panics can be somewhat inconsistent.
In some cases:
* a unique identifier may be associated with it
* the function name may be included
* the device may be printed separately

This patch aims to make warnings more consistent. reiserfs_warning() prints
the device name, so printing it a second time is not required. The function
name for a warning is always helpful in debugging, so it is now automatically
inserted into the output. Hans has stated that every warning should have
a unique identifier. Some cases lack them, others really shouldn't have them.
reiserfs_warning() now expects an id associated with each message. In the
rare case where one isn't needed, "" will suffice.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

reiserfs: rework reiserfs_warning

ReiserFS warnings can be somewhat inconsistent.
In some cases:
* a unique identifier may be associated with it
* the function name may be included
* the device may be printed separately

This patch aims to make warnings more consistent. reiserfs_warning() prints
the device name, so printing it a second time is not required. The function
name for a warning is always helpful in debugging, so it is now automatically
inserted into the output. Hans has stated that every warning should have
a unique identifier. Some cases lack them, others really shouldn't have them.
reiserfs_warning() now expects an id associated with each message. In the
rare case where one isn't needed, "" will suffice.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

NULL noise: fs/*, mm/*, kernel/*

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

[PATCH] struct path: rename Reiserfs's struct path

Rename Reiserfs's struct path to struct treepath to prevent name collision
between it and struct path from fs/namei.c.

Signed-off-by: Josef "Jeff" Sipek <jsipek@cs.sunysb.edu>
Cc: <reiserfs-dev@namesys.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Remove obsolete #include <linux/config.h>

Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>

[PATCH] reiserfs: cleanups

Clean up several places where gcc issues warnings when -W is specified.
Thanks to Neil for finding that.

Signed-off-by: Vladimir V. Saveliev <vs@namesys.com>
Cc: Neil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: Hans Reiser <reiser@namesys.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] reiserfs: remove kmalloc wrapper

Remove kmalloc() wrapper from fs/reiserfs/. Please note that a reiserfs
/proc entry format is changed because kmalloc statistics is removed.

Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] gfp_t: fs/*

- ->releasepage() annotated (s/int/gfp_t), instances updated
- missing gfp_t in fs/* added
- fixed misannotation from the original sweep caught by bitwise checks:
XFS used __nocast both for gfp_t and for flags used by XFS allocator.
The latter left with unsigned int __nocast; we might want to add a
different type for those but for now let's leave them alone. That,
BTW, is a case when __nocast use had been actively confusing - it had
been used in the same code for two different and similar types, with
no way to catch misuses. Switch of gfp_t to bitwise had caught that
immediately...

One tricky bit is left alone to be dealt with later - mapping->flags is
a mix of gfp_t and error indications. Left alone for now.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

reiserfs: run scripts/Lindent on reiserfs code

This was a pure indentation change, using:

scripts/Lindent fs/reiserfs/*.c include/linux/reiserfs_*.h

to make reiserfs match the regular Linux indentation style. As Jeff
Mahoney <jeffm@suse.com> writes:

The ReiserFS code is a mix of a number of different coding styles, sometimes
different even from line-to-line. Since the code has been relatively stable
for quite some time and there are few outstanding patches to be applied, it
is time to reformat the code to conform to the Linux style standard outlined
in Documentation/CodingStyle.

This patch contains the result of running scripts/Lindent against
fs/reiserfs/*.c and include/linux/reiserfs_*.h. There are places where the
code can be made to look better, but I'd rather keep those patches separate
so that there isn't a subtle by-hand hand accident in the middle of a huge
patch. To be clear: This patch is reformatting *only*.

A number of patches may follow that continue to make the code more consistent
with the Linux coding style.

Hans wasn't particularly enthusiastic about these patches, but said he
wouldn't really oppose them either.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!