seq_file: add helper macro to define attribute for rw file

Patch series "Add helper macro DEFINE_SHOW_STORE_ATTRIBUTE() at
seq_file.c", v6.

We already own DEFINE_SHOW_ATTRIBUTE() helper macro for defining attribute
for read-only file, but we found many of drivers also want a helper macro
for read-write file too.

So we add this helper macro to reduce duplicated code.


This patch (of 3):

We already own DEFINE_SHOW_ATTRIBUTE() helper macro for defining attribute
for read-only file, but many of drivers want a helper macro for read-write
file too.

So we add DEFINE_SHOW_STORE_ATTRIBUTE() helper to reduce duplicated code.

Link: https://lkml.kernel.org/r/20230905024835.43219-1-yangxingui@huawei.com
Link: https://lkml.kernel.org/r/20230905024835.43219-2-yangxingui@huawei.com
Signed-off-by: Luo Jiaxing <luojiaxing@huawei.com>
Co-developed-by: Xingui Yang <yangxingui@huawei.com>
Signed-off-by: Xingui Yang <yangxingui@huawei.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Animesh Manna <animesh.manna@intel.com>
Cc: Anshuman Gupta <anshuman.gupta@intel.com>
Cc: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Cc: Felipe Balbi <felipe.balbi@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Himanshu Madhani <himanshu.madhani@cavium.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Uma Shankar <uma.shankar@intel.com>
Cc: Xiang Chen <chenxiang66@hisilicon.com>
Cc: Zeng Tao <prime.zeng@hisilicon.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

seq_file: seq_show_option_n() is used for precise sizes

When seq_show_option_n() is used, it is for non-string memory that
happens to be printable bytes. As such, we must use memcpy() to copy the
bytes and then explicitly NUL-terminate the result.

Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Muchun Song <muchun.song@linux.dev>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20230726215957.never.619-kees@kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>

rxrpc: Fix locking issue

There's a locking issue with the per-netns list of calls in rxrpc. The
pieces of code that add and remove a call from the list use write_lock()
and the calls procfile uses read_lock() to access it. However, the timer
callback function may trigger a removal by trying to queue a call for
processing and finding that it's already queued - at which point it has a
spare refcount that it has to do something with. Unfortunately, if it puts
the call and this reduces the refcount to 0, the call will be removed from
the list. Unfortunately, since the _bh variants of the locking functions
aren't used, this can deadlock.

================================
WARNING: inconsistent lock state
5.18.0-rc3-build4+ #10 Not tainted
--------------------------------
inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
ksoftirqd/2/25 [HC0[0]:SC1[1]:HE1:SE0] takes:
ffff888107ac4038 (&rxnet->call_lock){+.?.}-{2:2}, at: rxrpc_put_call+0x103/0x14b
{SOFTIRQ-ON-W} state was registered at:
...
Possible unsafe locking scenario:

CPU0
----
lock(&rxnet->call_lock);
<Interrupt>
lock(&rxnet->call_lock);

*** DEADLOCK ***

1 lock held by ksoftirqd/2/25:
#0: ffff8881008ffdb0 ((&call->timer)){+.-.}-{0:0}, at: call_timer_fn+0x5/0x23d

Changes
=======
ver #2)
- Changed to using list_next_rcu() rather than rcu_dereference() directly.

Fixes: 17926a79320a ("[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both")
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Signed-off-by: David S. Miller <davem@davemloft.net>

seq_file: fix NULL pointer arithmetic warning

Implement conditional logic in order to replace NULL pointer arithmetic.

The use of NULL pointer arithmetic was pointed out by clang with the
following warning:

fs/kernfs/file.c:128:15: warning: performing pointer arithmetic on a
null pointer has undefined behavior [-Wnull-pointer-arithmetic]
return NULL + !*ppos;
~~~~ ^
fs/seq_file.c:559:14: warning: performing pointer arithmetic on a
null pointer has undefined behavior [-Wnull-pointer-arithmetic]
return NULL + (*pos == 0);

Signed-off-by: Maíra Canal <maira.canal@usp.br>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

proc: remove PDE_DATA() completely

Remove PDE_DATA() completely and replace it with pde_data().

[akpm@linux-foundation.org: fix naming clash in drivers/nubus/proc.c]
[akpm@linux-foundation.org: now fix it properly]

Link: https://lkml.kernel.org/r/20211124081956.87711-2-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Alexey Gladkov <gladkov.alexey@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

seq_file: fix passing wrong private data

DEFINE_PROC_SHOW_ATTRIBUTE() is supposed to be used to define a series
of functions and variables to register proc file easily. And the users
can use proc_create_data() to pass their own private data and get it
via seq->private in the callback. Unfortunately, the proc file system
use PDE_DATA() to get private data instead of inode->i_private. So fix
it. Fortunately, there only one user of it which does not pass any
private data, so this bug does not break any in-tree codes.

Link: https://lkml.kernel.org/r/20211029032638.84884-1-songmuchun@bytedance.com
Fixes: 97a32539b956 ("proc: convert everything to "struct proc_ops"")
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Florent Revest <revest@chromium.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

seq_file: move seq_escape() to a header

Move seq_escape() to the header as inliner, for a small kernel text size
reduction.

Link: https://lkml.kernel.org/r/20211001122917.67228-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

seq_file: drop unused *_escape_mem_ascii()

There are no more users of the seq_escape_mem_ascii() followed by
string_escape_mem_ascii().

Remove them for good.

Link: https://lkml.kernel.org/r/20210504180819.73127-16-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

seq_file: add seq_escape_str() as replica of string_escape_str()

In some cases we want to escape characters from NULL-terminated strings.
Add seq_escape_str() as replica of string_escape_str() for that.

Link: https://lkml.kernel.org/r/20210504180819.73127-13-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

seq_file: introduce seq_escape_mem()

Introduce seq_escape_mem() to allow users to pass additional parameters to
string_escape_mem().

Link: https://lkml.kernel.org/r/20210504180819.73127-12-andriy.shevchenko@linux.intel.com
Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

seq_file: Add a seq_bprintf function

Similarly to seq_buf_bprintf in lib/seq_buf.c, this function writes a
printf formatted string with arguments provided in a "binary
representation" built by functions such as vbin_printf.

Signed-off-by: Florent Revest <revest@chromium.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210427174313.860948-2-revest@chromium.org

seq_file: add seq_read_iter

iov_iter based variant for reading a seq_file. seq_read is
reimplemented on top of the iter variant.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/seq_file.h: introduce DEFINE_SEQ_ATTRIBUTE() helper macro

Patch series "seq_file: Introduce DEFINE_SEQ_ATTRIBUTE() helper macro".

As discussed in
https://lore.kernel.org/lkml/20191129222310.GA3712618@kroah.com/, we could
introduce a new helper macro to reduce losts of boilerplate code, vmstat
and kprobes is the example which covert to use it, if this is accepted, I
will send out more cleanups.

This patch (of 3):

Introduce DEFINE_SEQ_ATTRIBUTE() helper macro to decrease code duplication.

[akpm@linux-foundation.org: coding style fixes]
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Link: http://lkml.kernel.org/r/20200509064031.181091-1-wangkefeng.wang@huawei.com
Link: http://lkml.kernel.org/r/20200509064031.181091-2-wangkefeng.wang@huawei.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

seq_file: remove m->version

The process maps file was the only user of version (introduced back in
2005). Now that it uses ppos instead, we can remove it.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20200317193201.9924-4-adobriyan@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

proc: convert everything to "struct proc_ops"

The most notable change is DEFINE_SHOW_ATTRIBUTE macro split in
seq_file.h.

Conversion rule is:

llseek => proc_lseek
unlocked_ioctl => proc_ioctl

xxx => proc_xxx

delete ".owner = THIS_MODULE" line

[akpm@linux-foundation.org: fix drivers/isdn/capi/kcapi_proc.c]
[sfr@canb.auug.org.au: fix kernel/sched/psi.c]
Link: http://lkml.kernel.org/r/20200122180545.36222f50@canb.auug.org.au
Link: http://lkml.kernel.org/r/20191225172546.GB13378@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nfsd: escape high characters in binary data

I'm exposing some information about NFS clients in pseudofiles. I
expect to eventually have simple tools to help read those pseudofiles.

But it's also helpful if the raw files are human-readable to the extent
possible. It aids debugging and makes them usable on systems that don't
have the latest nfs-utils.

A minor challenge there is opaque client-generated protocol objects like
state owners and client identifiers. Some clients generate those to
include handy information in plain ascii. But they may also include
arbitrary byte sequences.

I think the simplest approach is to limit to isprint(c) && isascii(c)
and escape everything else.

That means you can just cat the file and get something that looks OK.
Also, I'm trying to keep these files legal YAML, which requires them to
UTF-8, and this is a simple way to guarantee that.

Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

seq_file: allocate seq_file from kmem_cache

For fine-grained debugging and usercopy protection.

Link: http://lkml.kernel.org/r/20180310085027.GA17121@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Glauber Costa <glommer@gmail.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

proc: add seq_put_decimal_ull_width to speed up /proc/pid/smaps

seq_put_decimal_ull_w(m, str, val, width) prints a decimal number with a
specified minimal field width.

It is equivalent of seq_printf(m, "%s%*d", str, width, val), but it
works much faster.

== test_smaps.py
num = 0
with open("/proc/1/smaps") as f:
for x in xrange(10000):
data = f.read()
f.seek(0, 0)
==

== Before patch ==
$ time python test_smaps.py
real 0m4.593s
user 0m0.398s
sys 0m4.158s

== After patch ==
$ time python test_smaps.py
real 0m3.828s
user 0m0.413s
sys 0m3.408s

$ perf -g record python test_smaps.py
== Before patch ==
- 79.01% 3.36% python [kernel.kallsyms] [k] show_smap.isra.33
- 75.65% show_smap.isra.33
+ 48.85% seq_printf
+ 15.75% __walk_page_range
+ 9.70% show_map_vma.isra.23
0.61% seq_puts

== After patch ==
- 75.51% 4.62% python [kernel.kallsyms] [k] show_smap.isra.33
- 70.88% show_smap.isra.33
+ 24.82% seq_put_decimal_ull_w
+ 19.78% __walk_page_range
+ 12.74% seq_printf
+ 11.08% show_map_vma.isra.23
+ 1.68% seq_puts

[akpm@linux-foundation.org: fix drivers/of/unittest.c build]
Link: http://lkml.kernel.org/r/20180212074931.7227-1-avagin@openvz.org
Signed-off-by: Andrei Vagin <avagin@openvz.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

procfs: add seq_put_hex_ll to speed up /proc/pid/maps

seq_put_hex_ll() prints a number in hexadecimal notation and works
faster than seq_printf().

== test.py
num = 0
with open("/proc/1/maps") as f:
while num < 10000 :
data = f.read()
f.seek(0, 0)
num = num + 1
==

== Before patch ==
$ time python test.py

real 0m1.561s
user 0m0.257s
sys 0m1.302s

== After patch ==
$ time python test.py

real 0m0.986s
user 0m0.279s
sys 0m0.707s

$ perf -g record python test.py:

== Before patch ==
- 67.42% 2.82% python [kernel.kallsyms] [k] show_map_vma.isra.22
- 64.60% show_map_vma.isra.22
- 44.98% seq_printf
- seq_vprintf
- vsnprintf
+ 14.85% number
+ 12.22% format_decode
5.56% memcpy_erms
+ 15.06% seq_path
+ 4.42% seq_pad
+ 2.45% __GI___libc_read

== After patch ==
- 47.35% 3.38% python [kernel.kallsyms] [k] show_map_vma.isra.23
- 43.97% show_map_vma.isra.23
+ 20.84% seq_path
- 15.73% show_vma_header_prefix
10.55% seq_put_hex_ll
+ 2.65% seq_put_decimal_ull
0.95% seq_putc
+ 6.96% seq_pad
+ 2.94% __GI___libc_read

[avagin@openvz.org: use unsigned int instead of int where it is suitable]
Link: http://lkml.kernel.org/r/20180214025619.4005-1-avagin@openvz.org
[avagin@openvz.org: v2]
Link: http://lkml.kernel.org/r/20180117082050.25406-1-avagin@openvz.org
Link: http://lkml.kernel.org/r/20180112185812.7710-1-avagin@openvz.org
Signed-off-by: Andrei Vagin <avagin@openvz.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

seq_file: Introduce DEFINE_SHOW_ATTRIBUTE() helper macro

The DEFINE_SHOW_ATTRIBUTE() helper macro would be useful for current
users, which are many of them, and for new comers to decrease code
duplication.

Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Darren Hart (VMware) <dvhart@infradead.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

seq/proc: modify seq_put_decimal_[u]ll to take a const char *, not char

Allow some seq_puts removals by taking a string instead of a single
char.

[akpm@linux-foundation.org: update vmstat_show(), per Joe]
Link: http://lkml.kernel.org/r/667e1cf3d436de91a5698170a1e98d882905e956.1470704995.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Joe Perches <joe@perches.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Make file credentials available to the seqfile interfaces

A lot of seqfile users seem to be using things like %pK that uses the
credentials of the current process, but that is actually completely
wrong for filesystem interfaces.

The unix semantics for permission checking files is to check permissions
at _open_ time, not at read or write time, and that is not just a small
detail: passing off stdin/stdout/stderr to a suid application and making
the actual IO happen in privileged context is a classic exploit
technique.

So if we want to be able to look at permissions at read time, we need to
use the file open credentials, not the current ones. Normal file
accesses can just use "f_cred" (or any of the helper functions that do
that, like file_ns_capable()), but the seqfile interfaces do not have
any such options.

It turns out that seq_file _does_ save away the user_ns information of
the file, though. Since user_ns is just part of the full credential
information, replace that special case with saving off the cred pointer
instead, and suddenly seq_file has all the permission information it
needs.

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

fs/seq_file: convert int seq_vprint/seq_printf/etc... returns to void

The seq_<foo> function return values were frequently misused.

See: commit 1f33c41c03da ("seq_file: Rename seq_overflow() to
seq_has_overflowed() and make public")

All uses of these return values have been removed, so convert the
return types to void.

Miscellanea:

o Move seq_put_decimal_<type> and seq_escape prototypes closer the
other seq_vprintf prototypes
o Reorder seq_putc and seq_puts to return early on overflow
o Add argument names to seq_vprintf and seq_printf
o Update the seq_escape kernel-doc
o Convert a couple of leading spaces to tabs in seq_escape

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

seq_file: provide an analogue of print_hex_dump()

This introduces a new helper and switches current users to use it. All
patches are compiled tested. kmemleak is tested via its own test suite.

This patch (of 6):

The new seq_hex_dump() is a complete analogue of print_hex_dump().

We have few users of this functionality already. It allows to reduce their
codebase.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Joe Perches <joe@perches.com>
Cc: Tadeusz Struk <tadeusz.struk@intel.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Tuchscherer <ingo.tuchscherer@de.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Vladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs: create and use seq_show_option for escaping

Many file systems that implement the show_options hook fail to correctly
escape their output which could lead to unescaped characters (e.g. new
lines) leaking into /proc/mounts and /proc/[pid]/mountinfo files. This
could lead to confusion, spoofed entries (resulting in things like
systemd issuing false d-bus "mount" notifications), and who knows what
else. This looks like it would only be the root user stepping on
themselves, but it's possible weird things could happen in containers or
in other situations with delegated mount privileges.

Here's an example using overlay with setuid fusermount trusting the
contents of /proc/mounts (via the /etc/mtab symlink). Imagine the use
of "sudo" is something more sneaky:

$ BASE="ovl"
$ MNT="$BASE/mnt"
$ LOW="$BASE/lower"
$ UP="$BASE/upper"
$ WORK="$BASE/work/ 0 0
none /proc fuse.pwn user_id=1000"
$ mkdir -p "$LOW" "$UP" "$WORK"
$ sudo mount -t overlay -o "lowerdir=$LOW,upperdir=$UP,workdir=$WORK" none /mnt
$ cat /proc/mounts
none /root/ovl/mnt overlay rw,relatime,lowerdir=ovl/lower,upperdir=ovl/upper,workdir=ovl/work/ 0 0
none /proc fuse.pwn user_id=1000 0 0
$ fusermount -u /proc
$ cat /proc/mounts
cat: /proc/mounts: No such file or directory

This fixes the problem by adding new seq_show_option and
seq_show_option_n helpers, and updating the vulnerable show_option
handlers to use them as needed. Some, like SELinux, need to be open
coded due to unusual existing escape mechanisms.

[akpm@linux-foundation.org: add lost chunk, per Kees]
[keescook@chromium.org: seq_show_option should be using const parameters]
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Acked-by: Jan Kara <jack@suse.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Cc: J. R. Okajima <hooanon05g@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

vfs: add seq_file_path() helper

Turn
seq_path(..., &file->f_path, ...);
into
seq_file_path(..., file, ...);

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

bitmap, cpumask, nodemask: remove dedicated formatting functions

Now that all bitmap formatting usages have been converted to
'%*pb[l]', the separate formatting functions are unnecessary. The
following functions are removed.

* bitmap_scn[list]printf()
* cpumask_scnprintf(), cpulist_scnprintf()
* [__]nodemask_scnprintf(), [__]nodelist_scnprintf()
* seq_bitmap[_list](), seq_cpumask[_list](), seq_nodemask[_list]()
* seq_buf_bitmask()

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

seq_file: Rename seq_overflow() to seq_has_overflowed() and make public

The return values of seq_printf/puts/putc are frequently misused.

Start down a path to remove all the return value uses of these
functions.

Move the seq_overflow() to a global inlined function called
seq_has_overflowed() that can be used by the users of seq_file() calls.

Update the documentation to not show return types for seq_printf
et al. Add a description of seq_has_overflowed().

Link: http://lkml.kernel.org/p/848ac7e3d1c31cddf638a8526fa3c59fa6fdeb8a.1412031505.git.joe@perches.com

Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Joe Perches <joe@perches.com>
[ Reworked the original patch from Joe ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

seq_file: introduce seq_setwidth() and seq_pad()

There are several users who want to know bytes written by seq_*() for
alignment purpose. Currently they are using %n format for knowing it
because seq_*() returns 0 on success.

This patch introduces seq_setwidth() and seq_pad() for allowing them to
align without using %n format.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Joe Perches <joe@perches.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

seq_file: add seq_list_*_percpu helpers

When we convert the file_lock_list to a set of percpu lists, we'll need
a way to iterate over them in order to output /proc/locks info. Add
some seq_list_*_percpu helpers to handle that.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: J. Bruce Fields <bfields@fieldses.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

new helper: single_open_size()

Same as single_open(), but preallocates the buffer of given size.
Doesn't make any sense for sizes up to PAGE_SIZE and doesn't make
sense if output of show() exceeds PAGE_SIZE only rarely - seq_read()
will take care of growing the buffer and redoing show(). If you
_know_ that it will be large, it might make more sense to look into
saner iterator, rather than go with single-shot one. If that's
impossible, single_open_size() might be for you.

Again, don't use that without a good reason; occasionally that's really
the best way to go, but very often there are better solutions.

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

userns: Make seq_file's user namespace accessible

struct file already has a user namespace associated with it
in file->f_cred->user_ns, unfortunately because struct
seq_file has no struct file backpointer associated with
it, it is difficult to get at the user namespace in seq_file
context. Therefore add a helper function seq_user_ns to return
the associated user namespace and a user_ns field to struct
seq_file to be used in implementing seq_user_ns.

Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

seq_file: Add seq_vprintf function and export it

The existing seq_printf function is rewritten in terms of the new
seq_vprintf which is also exported to modules. This allows GFS2
(and potentially other seq_file users) to have a vprintf based
interface and to avoid an extra copy into a temporary buffer in
some cases.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Al Viro <viro@ZenIV.linux.org.uk>

procfs: speed up /proc/pid/stat, statm

Process accounting applications as top, ps visit some files under
/proc/<pid>. With seq_put_decimal_ull(), we can optimize /proc/<pid>/stat
and /proc/<pid>/statm files.

This patch adds
- seq_put_decimal_ll() for signed values.
- allow delimiter == 0.
- convert seq_printf() to seq_put_decimal_ull/ll in /proc/stat, statm.

Test result on a system with 2000+ procs.

Before patch:
[kamezawa@bluextal test]$ top -b -n 1 | wc -l
2223
[kamezawa@bluextal test]$ time top -b -n 1 > /dev/null

real 0m0.675s
user 0m0.044s
sys 0m0.121s

[kamezawa@bluextal test]$ time ps -elf > /dev/null

real 0m0.236s
user 0m0.056s
sys 0m0.176s

After patch:
kamezawa@bluextal ~]$ time top -b -n 1 > /dev/null

real 0m0.657s
user 0m0.052s
sys 0m0.100s

[kamezawa@bluextal ~]$ time ps -elf > /dev/null

real 0m0.198s
user 0m0.050s
sys 0m0.145s

Considering top, ps tend to scan /proc periodically, this will reduce cpu
consumption by top/ps to some extent.

[akpm@linux-foundation.org: checkpatch fixes]
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

procfs: add num_to_str() to speed up /proc/stat

== stat_check.py
num = 0
with open("/proc/stat") as f:
while num < 1000 :
data = f.read()
f.seek(0, 0)
num = num + 1
==

perf shows

20.39% stat_check.py [kernel.kallsyms] [k] format_decode
13.41% stat_check.py [kernel.kallsyms] [k] number
12.61% stat_check.py [kernel.kallsyms] [k] vsnprintf
10.85% stat_check.py [kernel.kallsyms] [k] memcpy
4.85% stat_check.py [kernel.kallsyms] [k] radix_tree_lookup
4.43% stat_check.py [kernel.kallsyms] [k] seq_printf

This patch removes most of calls to vsnprintf() by adding num_to_str()
and seq_print_decimal_ull(), which prints decimal numbers without rich
functions provided by printf().

On my 8cpu box.
== Before patch ==
[root@bluextal test]# time ./stat_check.py

real 0m0.150s
user 0m0.026s
sys 0m0.121s

== After patch ==
[root@bluextal test]# time ./stat_check.py

real 0m0.055s
user 0m0.022s
sys 0m0.030s

[akpm@linux-foundation.org: remove incorrect comment, use less statck in num_to_str(), move comment from .h to .c, simplify seq_put_decimal_ull()]
[andrea@betterlinux.com: avoid breaking the ABI in /proc/stat]
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrea Righi <andrea@betterlinux.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Glauber Costa <glommer@parallels.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Turner <pjt@google.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

BUG: headers with BUG/BUG_ON etc. need linux/bug.h

If a header file is making use of BUG, BUG_ON, BUILD_BUG_ON, or any
other BUG variant in a static inline (i.e. not in a #define) then
that header really should be including <linux/bug.h> and not just
expecting it to be implicitly present.

We can make this change risk-free, since if the files using these
headers didn't have exposure to linux/bug.h already, they would have
been causing compile failures/warnings.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

constify seq_file stuff

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

treewide: use __printf not __attribute__((format(printf,...)))

Standardize the style for compiler based printf format verification.
Standardized the location of __printf too.

Done via script and a little typing.

$ grep -rPl --include=*.[ch] -w "__attribute__" * | \
grep -vP "^(tools|scripts|include/linux/compiler-gcc.h)" | \
xargs perl -n -i -e 'local $/; while (<>) { s/\b__attribute__\s*\(\s*\(\s*format\s*\(\s*printf\s*,\s*(.+)\s*,\s*(.+)\s*\)\s*\)\s*\)/__printf($1, $2)/g ; print; }'

[akpm@linux-foundation.org: revert arch bits]
Signed-off-by: Joe Perches <joe@perches.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs: seq_file - add event counter to simplify poll() support

Moving the event counter into the dynamically allocated 'struc seq_file'
allows poll() support without the need to allocate its own tracking
structure.

All current users are switched over to use the new counter.

Requested-by: Andrew Morton akpm@linux-foundation.org
Acked-by: NeilBrown <neilb@suse.de>
Tested-by: Lucas De Marchi lucas.demarchi@profusion.mobi
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

seq_file: add RCU versions of new hlist/list iterators (v3)

Many usages of seq_file use RCU protected lists, so non RCU
iterators will not work safely.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

seq_file: Add helpers for iteration over a hlist

Some places in kernel need to iterate over a hlist in seq_file,
so provide some common helpers.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

vfs: seq_file: add helpers for data filling

Add two helpers that allow access to the seq_file's own buffer, but
hide the internal details of seq_files.

This allows easier implementation of special purpose filling
functions. It also cleans up some existing functions which duplicated
the seq_file logic.

Make these inline functions in seq_file.h, as suggested by Al.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Acked-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

seq_file: add function to write binary data

seq_write() can be used to construct seq_files containing arbitrary data.
Required by the gcov-profiling interface to synthesize binary profiling
data files.

Signed-off-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Li Wei <W.Li@Sun.COM>
Cc: Michael Ellerman <michaele@au1.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Heiko Carstens <heicars2@linux.vnet.ibm.com>
Cc: Martin Schwidefsky <mschwid2@linux.vnet.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

cpumask: fix seq_bitmap_*() functions.

1) seq_bitmap_list() should take a const.
2) All the seq_bitmap should use cpumask_bits().

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

seq_file: properly cope with pread

Currently seq_read assumes that the offset passed to it is always the
offset it passed to user space. In the case pread this assumption is
broken and we do the wrong thing when presented with pread.

To solve this I introduce an offset cache inside of struct seq_file so we
know where our logical file position is. Then in seq_read if we try to
read from another offset we reset our data structures and attempt to go to
the offset user space wanted.

[akpm@linux-foundation.org: restore FMODE_PWRITE]
[pjt@google.com: seq_open needs its fmode opened up to take advantage of this]
Signed-off-by: Eric Biederman <ebiederm@xmission.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Paul Turner <pjt@google.com>
Cc: <stable@kernel.org> [2.6.25.x, 2.6.26.x, 2.6.27.x, 2.6.28.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

cpumask: Use nr_cpu_ids in seq_cpumask

Impact: cleanup, futureproof

nr_cpu_ids is the (badly named) runtime limit on possible CPU numbers;
ie. the variable version of NR_CPUS.

With the new cpumask operators, only bits less than this are defined.
So we should use it everywhere, rather than NR_CPUS. Eventually this
will make it possible to allocate cpumasks of the minimal length at runtime.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Mike Travis <travis@sgi.com>
Acked-by: Ingo Molnar <mingo@elte.hu>

bitmap: fix seq_bitmap and seq_cpumask to take const pointer

Impact: cleanup

seq_bitmap just calls bitmap_scnprintf on the bits: that arg can be const.
Similarly, seq_cpumask just calls seq_bitmap.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

vfs, seqfile: make mangle_path() global

Impact: expose new VFS API

make mangle_path() available, as per the suggestions of Christoph Hellwig
and Al Viro:

http://lkml.org/lkml/2008/11/4/338

Signed-off-by: Török Edwin <edwintorok@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

seq_file: add seq_cpumask_list(), seq_nodemask_list()

seq_cpumask_list(), seq_nodemask_list() are very like seq_cpumask(),
seq_nodemask(), but they print human readable string.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Paul Menage <menage@google.com>
Cc: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

seq_file: add seq_cpumask(), seq_nodemask()

Short enough reads from /proc/irq/*/smp_affinity return -EINVAL for no
good reason.

This became noticed with NR_CPUS=4096 patches, when length of printed
representation of cpumask becase 1152, but cat(1) continued to read with
1024-byte chunks. bitmap_scnprintf() in good faith fills buffer, returns
1023, check returns -EINVAL.

Fix it by switching to seq_file, so handler will just fill buffer and
doesn't care about offsets, length, filling EOF and all this crap.

For that add seq_bitmap(), and wrappers around it -- seq_cpumask() and
seq_nodemask().

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Reviewed-by: Paul Jackson <pj@sgi.com>
Cc: Mike Travis <travis@sgi.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Remove "#ifdef __KERNEL__" checks from unexported headers

Remove the "#ifdef __KERNEL__" tests from unexported header files in
linux/include whose entire contents are wrapped in that preprocessor
test.

Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

[patch 2/7] vfs: mountinfo: add seq_file_root()

Add a new function:

seq_file_root()

This is similar to seq_path(), but calculates the path relative to the
given root, instead of current->fs->root. If the path was unreachable
from root, then modify the root parameter to reflect this.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[patch 1/7] vfs: mountinfo: add dentry_path()

[mszeredi@suse.cz] split big patch into managable chunks

Add the following functions:

dentry_path()
seq_dentry()

These are similar to d_path() and seq_path(). But instead of
calculating the path within a mount namespace, they calculate the path
from the root of the filesystem to a given dentry, ignoring mounts
completely.

Signed-off-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[PATCH] teach seq_file to discard entries

Allow ->show() return SEQ_SKIP; that will discard all
output from that element and move on.

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

[NETNS]: Do not include net/net_namespace.h from seq_file.h

Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

[NETNS]: Compile NET /proc support only if CONFIG_NET is set.

This fix broken compilation for 'allnoconfig'. This was introduced by
Introduced by commit 1218854afa6f659be90b748cf1bc7badee954a35 ("[NET]
NETNS: Omit seq_net_private->net without CONFIG_NET_NS.")

Signed-off-by: Denis V. Lunev <den@openvz.org>
Acked-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

[NET] NETNS: Omit seq_net_private->net without CONFIG_NET_NS.

Without CONFIG_NET_NS, no namespace other than &init_net exists,
no need to store net in seq_net_private.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

d_path: Make seq_path() use a struct path argument

seq_path() is always called with a dentry and a vfsmount from a struct path.
Make seq_path() take it directly as an argument.

Signed-off-by: Jan Blunck <jblunck@suse.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

[NET]: Consolidate net namespace related proc files creation.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix f_version type: should be u64 instead of unsigned long

Fix f_version type: should be u64 instead of long

There is a type inconsistency between struct inode i_version and struct file
f_version.

fs.h:

struct inode
u64 i_version;

and

struct file
unsigned long f_version;

Users do:

fs/ext3/dir.c:

if (filp->f_version != inode->i_version) {

So why isn't f_version a u64 ? It becomes a problem if versions gets
higher than 2^32 and we are on an architecture where longs are 32 bits.

This patch changes the f_version type to u64, and updates the users accordingly.

It applies to 2.6.23-rc2-mm2.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Martin Bligh <mbligh@google.com>
Cc: "Randy.Dunlap" <rdunlap@xenotime.net>
Cc: Al Viro <viro@ftp.linux.org.uk>
Cc: <linux-ext4@vger.kernel.org>
Cc: Mark Fasheh <mark.fasheh@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

[FS] seq_file: Introduce the seq_open_private()

This function allocates the zeroed chunk of memory and
call seq_open(). The __seq_open_private() helper returns
the allocated memory to make it possible for the caller
to initialize it.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Make common helpers for seq_files that work with list_heads

Many places in kernel use seq_file API to iterate over a regular list_head.
The code for such iteration is identical in all the places, so it's worth
introducing a common helpers.

This makes code about 300 lines smaller:

The first version of this patch made the helper functions static inline
in the seq_file.h header. This patch moves them to the fs/seq_file.c as
Andrew proposed. The vmlinux .text section sizes are as follows:

2.6.22-rc1-mm1: 0x001794d5
with the previous version: 0x00179505
with this patch: 0x00179135

The config file used was make allnoconfig with the "y" inclusion of all
the possible options to make the files modified by the patch compile plus
drivers I have on the test node.

This patch:

Many places in kernel use seq_file API to iterate over a regular list_head.
The code for such iteration is identical in all the places, so it's worth
introducing a common helpers.

Signed-off-by: Pavel Emelianov <xemul@openvz.org>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

[PATCH] struct seq_operations and struct file_operations constification

- move some file_operations structs into the .rodata section

- move static strings from policy_types[] array into the .rodata section

- fix generic seq_operations usages, so that those structs may be defined
as "const" as well

[akpm@osdl.org: couple of fixes]
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] sem2mutex: fs/seq_file.c

Semaphore to mutex conversion.

The conversion was generated via scripts, and the result was validated
automatically via a script as well.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
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!