Commit graph

105 commits

Author SHA1 Message Date
Yang Yang
3c91dda97e kernel/acct.c: use dedicated helper to access rlimit values
Use rlimit() helper instead of manually writing whole chain from
task to rlimit value. See patch "posix-cpu-timers: Use dedicated
helper to access rlimit values".

Link: https://lkml.kernel.org/r/20210728030822.524789-1-yang.yang29@zte.com.cn
Signed-off-by: Yang Yang <yang.yang29@zte.com.cn>
Reported-by: Zeal Robot <zealci@zte.com.cn>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: sh_def@163.com <sh_def@163.com>
Cc: Yang Yang <yang.yang29@zte.com.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-08 11:50:26 -07:00
Hui Su
35189b8ff1 kernel/acct.c: use #elif instead of #end and #elif
Cleanup: use #elif instead of #end and #elif.

Link: https://lkml.kernel.org/r/20201015150736.GA91603@rlk
Signed-off-by: Hui Su <sh_def@163.com>
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>
2020-12-15 22:46:15 -08:00
Randy Dunlap
b7621ebf8a kernel: acct.c: fix some kernel-doc nits
Fix kernel-doc notation to use the documented Returns: syntax and place
the function description for acct_process() on the first line where it
should be.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Link: https://lkml.kernel.org/r/b4c33e5d-98e8-0c47-77b6-ac1859f94d7f@infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-16 11:11:19 -07:00
Randy Dunlap
7b7b8a2c95 kernel/: fix repeated words in comments
Fix multiple occurrences of duplicated words in kernel/.

Fix one typo/spello on the same line as a duplicate word.  Change one
instance of "the the" to "that the".  Otherwise just drop one of the
repeated words.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: https://lkml.kernel.org/r/98202fa6-8919-ef63-9efe-c0fad5ca7af1@infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-16 11:11:19 -07:00
Michel Lespinasse
c1e8d7c6a7 mmap locking API: convert mmap_sem comments
Convert comments that reference mmap_sem to reference mmap_lock instead.

[akpm@linux-foundation.org: fix up linux-next leftovers]
[akpm@linux-foundation.org: s/lockaphore/lock/, per Vlastimil]
[akpm@linux-foundation.org: more linux-next fixups, per Michel]

Signed-off-by: Michel Lespinasse <walken@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Laurent Dufour <ldufour@linux.ibm.com>
Cc: Liam Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ying Han <yinghan@google.com>
Link: http://lkml.kernel.org/r/20200520052908.204642-13-walken@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09 09:39:14 -07:00
Michel Lespinasse
d8ed45c5dc mmap locking API: use coccinelle to convert mmap_sem rwsem call sites
This change converts the existing mmap_sem rwsem calls to use the new mmap
locking API instead.

The change is generated using coccinelle with the following rule:

// spatch --sp-file mmap_lock_api.cocci --in-place --include-headers --dir .

@@
expression mm;
@@
(
-init_rwsem
+mmap_init_lock
|
-down_write
+mmap_write_lock
|
-down_write_killable
+mmap_write_lock_killable
|
-down_write_trylock
+mmap_write_trylock
|
-up_write
+mmap_write_unlock
|
-downgrade_write
+mmap_write_downgrade
|
-down_read
+mmap_read_lock
|
-down_read_killable
+mmap_read_lock_killable
|
-down_read_trylock
+mmap_read_trylock
|
-up_read
+mmap_read_unlock
)
-(&mm->mmap_sem)
+(mm)

Signed-off-by: Michel Lespinasse <walken@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Reviewed-by: Laurent Dufour <ldufour@linux.ibm.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Liam Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ying Han <yinghan@google.com>
Link: http://lkml.kernel.org/r/20200520052908.204642-5-walken@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09 09:39:14 -07:00
Arnd Bergmann
2d602bf283 acct: stop using get_seconds()
In 'struct acct', 'struct acct_v3', and 'struct taskstats' we have
a 32-bit 'ac_btime' field containing an absolute time value, which
will overflow in year 2106.

There are two possible ways to deal with it:

a) let it overflow and have user space code deal with reconstructing
   the data based on the current time, or
b) truncate the times based on the range of the u32 type.

Neither of them solves the actual problem. Pick the second
one to best document what the issue is, and have someone
fix it in a future version.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2019-12-18 18:07:31 +01:00
Al Viro
9419a3191d acct_on(): don't mess with freeze protection
What happens there is that we are replacing file->path.mnt of
a file we'd just opened with a clone and we need the write
count contribution to be transferred from original mount to
new one.  That's it.  We do *NOT* want any kind of freeze
protection for the duration of switchover.

IOW, we should just use __mnt_{want,drop}_write() for that
switchover; no need to bother with mnt_{want,drop}_write()
there.

Tested-by: Amir Goldstein <amir73il@gmail.com>
Reported-by: syzbot+2a73a6ea9507b7112141@syzkaller.appspotmail.com
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-04-04 21:04:13 -04:00
Oleg Nesterov
4d9570158b kernel/acct.c: fix the acct->needcheck check in check_free_space()
As Tsukada explains, the time_is_before_jiffies(acct->needcheck) check
is very wrong, we need time_is_after_jiffies() to make sys_acct() work.

Ignoring the overflows, the code should "goto out" if needcheck >
jiffies, while currently it checks "needcheck < jiffies" and thus in the
likely case check_free_space() does nothing until jiffies overflow.

In particular this means that sys_acct() is simply broken, acct_on()
sets acct->needcheck = jiffies and expects that check_free_space()
should set acct->active = 1 after the free-space check, but this won't
happen if jiffies increments in between.

This was broken by commit 32dc730860 ("get rid of timer in
kern/acct.c") in 2011, then another (correct) commit 795a2f22a8
("acct() should honour the limits from the very beginning") made the
problem more visible.

Link: http://lkml.kernel.org/r/20171213133940.GA6554@redhat.com
Fixes: 32dc730860 ("get rid of timer in kern/acct.c")
Reported-by: TSUKADA Koutaro <tsukada@ascade.co.jp>
Suggested-by: TSUKADA Koutaro <tsukada@ascade.co.jp>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-01-04 16:45:09 -08:00
Ingo Molnar
8c5db92a70 Merge branch 'linus' into locking/core, to resolve conflicts
Conflicts:
	include/linux/compiler-clang.h
	include/linux/compiler-gcc.h
	include/linux/compiler-intel.h
	include/uapi/linux/stddef.h

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-11-07 10:32:44 +01:00
Greg Kroah-Hartman
b24413180f 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>
2017-11-02 11:10:55 +01:00
Mark Rutland
6aa7de0591 locking/atomics: COCCINELLE/treewide: Convert trivial ACCESS_ONCE() patterns to READ_ONCE()/WRITE_ONCE()
Please do not apply this to mainline directly, instead please re-run the
coccinelle script shown below and apply its output.

For several reasons, it is desirable to use {READ,WRITE}_ONCE() in
preference to ACCESS_ONCE(), and new code is expected to use one of the
former. So far, there's been no reason to change most existing uses of
ACCESS_ONCE(), as these aren't harmful, and changing them results in
churn.

However, for some features, the read/write distinction is critical to
correct operation. To distinguish these cases, separate read/write
accessors must be used. This patch migrates (most) remaining
ACCESS_ONCE() instances to {READ,WRITE}_ONCE(), using the following
coccinelle script:

----
// Convert trivial ACCESS_ONCE() uses to equivalent READ_ONCE() and
// WRITE_ONCE()

// $ make coccicheck COCCI=/home/mark/once.cocci SPFLAGS="--include-headers" MODE=patch

virtual patch

@ depends on patch @
expression E1, E2;
@@

- ACCESS_ONCE(E1) = E2
+ WRITE_ONCE(E1, E2)

@ depends on patch @
expression E;
@@

- ACCESS_ONCE(E)
+ READ_ONCE(E)
----

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: davem@davemloft.net
Cc: linux-arch@vger.kernel.org
Cc: mpe@ellerman.id.au
Cc: shuah@kernel.org
Cc: snitzer@redhat.com
Cc: thor.thayer@linux.intel.com
Cc: tj@kernel.org
Cc: viro@zeniv.linux.org.uk
Cc: will.deacon@arm.com
Link: http://lkml.kernel.org/r/1508792849-3115-19-git-send-email-paulmck@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-25 11:01:08 +02:00
Christoph Hellwig
73e18f7c0b fs: make the buf argument to __kernel_write a void pointer
This matches kernel_read and kernel_write and avoids any need for casts in
the callers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-09-04 19:05:15 -04:00
Ingo Molnar
32ef5517c2 sched/headers: Prepare to move cputime functionality from <linux/sched.h> into <linux/sched/cputime.h>
Introduce a trivial, mostly empty <linux/sched/cputime.h> header
to prepare for the moving of cputime functionality out of sched.h.

Update all code that relies on these facilities.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-02 08:42:39 +01:00
Frederic Weisbecker
d4bc42af73 acct: Convert obsolete cputime type to nsecs
Use the new nsec based cputime accessors as part of the whole cputime
conversion from cputime_t to nsecs.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Wanpeng Li <wanpeng.li@hotmail.com>
Link: http://lkml.kernel.org/r/1485832191-26889-13-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-02-01 09:13:51 +01:00
Frederic Weisbecker
a1cecf2ba7 sched/cputime: Introduce special task_cputime_t() API to return old-typed cputime
This API returns a task's cputime in cputime_t in order to ease the
conversion of cputime internals to use nsecs units instead. Blindly
converting all cputime readers to use this API now will later let us
convert more smoothly and step by step all these places to use the
new nsec based cputime.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Wanpeng Li <wanpeng.li@hotmail.com>
Link: http://lkml.kernel.org/r/1485832191-26889-7-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-02-01 09:13:48 +01:00
Al Viro
d0f88f8d5d acct: check FMODE_CAN_WRITE
it's not calling ->write() directly anymore.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-11 22:27:55 -04:00
Al Viro
59eda0e07f new fs_pin killing logics
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-01-25 23:17:28 -05:00
Al Viro
3b994d98a8 get rid of the second argument of acct_kill()
Replace the old ns->bacct only with NULL and only if it still points
to acct.  And assign the new value to it *before* calling acct_kill()
in acct_on().  That way we don't need to pass the new acct to acct_kill().

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-01-25 23:17:27 -05:00
Al Viro
34cece2e8a take count and rcu_head out of fs_pin
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-01-25 23:17:27 -05:00
Al Viro
32426f6653 pull bumping refcount into ->kill()
there will be one more change of ->kill() calling conventions; this
isn't final.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-01-25 23:16:29 -05:00
Al Viro
9e251d0204 kill pin_put()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-01-25 23:16:28 -05:00
Ying Xue
067b722faf acct: eliminate compile warning
If ACCT_VERSION is not defined to 3, below warning appears:
  CC      kernel/acct.o
  kernel/acct.c: In function `do_acct_process':
  kernel/acct.c:475:24: warning: unused variable `ns' [-Wunused-variable]

[akpm@linux-foundation.org: retain the local for code size improvements
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:26:04 -04:00
Ionut Alexa
2577d92ebd kernel/acct.c: fix coding style warnings and errors
Signed-off-by: Ionut Alexa <ionut.m.alexa@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-07 14:40:09 -04:00
Al Viro
3064c3563b death to mnt_pinned
Rather than playing silly buggers with vfsmount refcounts, just have
acct_on() ask fs/namespace.c for internal clone of file->f_path.mnt
and replace it with said clone.  Then attach the pin to original
vfsmount.  Voila - the clone will be alive until the file gets closed,
making sure that underlying superblock remains active, etc., and
we can drop the original vfsmount, so that it's not kept busy.
If the file lives until the final mntput of the original vfsmount,
we'll notice that there's an fs_pin (one in bsd_acct_struct that
holds that file) and mnt_pin_kill() will take it out.  Since
->kill() is synchronous, we won't proceed past that point until
these files are closed (and private clones of our vfsmount are
gone), so we get the same ordering warranties we used to get.

mnt_pin()/mnt_unpin()/->mnt_pinned is gone now, and good riddance -
it never became usable outside of kernel/acct.c (and racy wrt
umount even there).

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-07 14:40:09 -04:00
Al Viro
efb170c228 take fs_pin stuff to fs/*
Add a new field to fs_pin - kill(pin).  That's what umount and r/o remount
will be calling for all pins attached to vfsmount and superblock resp.
Called after bumping the refcount, so it won't go away under us.  Dropping
the refcount is responsibility of the instance.  All generic stuff moved to
fs/fs_pin.c; the next step will rip all the knowledge of kernel/acct.c from
fs/super.c and fs/namespace.c.  After that - death to mnt_pin(); it was
intended to be usable as generic mechanism for code that wants to attach
objects to vfsmount, so that they would not make the sucker busy and
would get killed on umount.  Never got it right; it remained acct.c-specific
all along.  Now it's very close to being killable.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-07 14:40:08 -04:00
Al Viro
1629d0eb3e start carving bsd_acct_struct up
pull generic parts into struct fs_pin.  Eventually we want those
to replace mnt_pin()/mnt_unpin() mess; that stuff will move to
fs/*.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-07 14:40:08 -04:00
Al Viro
215748e67d acct: move mnt_pin() upwards.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-07 14:40:08 -04:00
Al Viro
17c0a5aaff make acct_kill() wait for file closing.
Do actual closing of file via schedule_work().  And use
__fput_sync() there.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-07 14:40:08 -04:00
Al Viro
2798d4ce61 acct: get rid of acct_lock for acct->count
* make acct->count atomic and acct freeing - rcu-delayed.
* instead of grabbing acct_lock around the places where we take a reference,
do that under rcu_read_lock() with atomic_long_inc_not_zero().
* have the new acct locked before making ns->bacct point to it

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-07 14:40:08 -04:00
Al Viro
215752fce3 acct: get rid of acct_list
Put these suckers on per-vfsmount and per-superblock lists instead.
Note: right now it's still acct_lock for everything, but that's
going to change.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-07 14:40:08 -04:00
Al Viro
54a4d58a64 acct: simplify check_free_space()
a) file can't be NULL
b) file can't be changed under us
c) all writes are serialized by acct->lock; no need to mess with
spinlock there.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-07 14:40:08 -04:00
Al Viro
b8f00e6be4 acct: new lifetime rules
Do not reuse bsd_acct_struct after closing the damn thing.
Structure lifetime is controlled by refcount now.  We also
have a mutex in there, held over closing and writing (the
file is O_APPEND, so we are not losing any concurrency).

As the result, we do not need to bother with get_file()/fput()
on log write anymore.  Moreover, do_acct_process() only needs
acct itself; file and pidns are picked from it.

Killed instances are distinguished by having NULL ->ns.
Refcount is protected by acct_lock; anybody taking the
mutex needs to grab a reference first.

The things will get a lot simpler in the next commits - this
is just the minimal chunk switching to the new lifetime rules.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-07 14:40:08 -04:00
Al Viro
9df7fa16ee acct: serialize acct_on()
brute-force - on a global mutex that isn't nested into anything.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-07 14:40:08 -04:00
Al Viro
795a2f22a8 acct() should honour the limits from the very beginning
We need to check free space on the first write to freshly opened log.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-07 14:40:07 -04:00
Al Viro
e25ff11ff1 split the slow path in acct_process() off
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-07 14:40:07 -04:00
Al Viro
cdd37e2309 separate namespace-independent parts of filling acct_t
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-07 14:40:07 -04:00
Al Viro
ed44724b79 acct: switch to __kernel_write()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-07 14:40:07 -04:00
Al Viro
ecfdb33d1f acct: encode_comp_t(0) is 0, fortunately...
There was an amusing bogosity in ac_rw calculation - it tried to
do encode_comp_t(encode_comp_t(0) / 1024).  Seeing that comp_t is
a 3-bit exponent + 13-bit mantissa... it's a good thing that 0 is
represented by all-bits-clear.

The history of that one is interesting - it was introduced in
2.1.68pre1, when acct.c had been reworked and moved to separate
file.  Two months later (2.1.86) somebody has noticed that the
sucker won't compile - there was no task_struct::io_usage.
At which point the ac_io calculation had changed from
encode_comp_t(current->io_usage) to encode_comp_t(0) and the
bug in the next line (absolutely real back then, had it ever
managed to compile) become a harmless bogosity.  Looks like
nobody has ever noticed until now.

Anyway, let's bury that idiocy now that it got noticed.  17 years
is long enough...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-07 14:40:07 -04:00
Thomas Gleixner
ccbf62d8a2 sched: Make task->start_time nanoseconds based
Simplify the timespec to nsec/usec conversions.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-07-23 10:18:05 -07:00
Thomas Gleixner
22001821d9 acct: Use ktime_get_ts()
do_posix_clock_monotonic_gettime() is a leftover from the initial
posix timer implementation which maps to ktime_get_ts()

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140611234606.764810535@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-06-12 16:18:44 +02:00
Paul McQuade
46c0a8ca3e ipc, kernel: clear whitespace
trailing whitespace

Signed-off-by: Paul McQuade <paulmcquad@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-06 16:08:14 -07:00
Paul McQuade
7153e40273 ipc, kernel: use Linux headers
Use #include <linux/uaccess.h> instead of <asm/uaccess.h>
Use #include <linux/types.h> instead of <asm/types.h>

Signed-off-by: Paul McQuade <paulmcquad@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-06 16:08:14 -07:00
Jan Kara
5ae98f1589 fs: Fix hang with BSD accounting on frozen filesystem
When BSD process accounting is enabled and logs information to a
filesystem which gets frozen, system easily becomes unusable because
each attempt to account process information blocks. Thus e.g. every task
gets blocked in exit.

It seems better to drop accounting information (which can already happen
when filesystem is running out of space) instead of locking system up.
So we just skip the write if the filesystem is frozen.

Reported-by: Nikola Ciprich <nikola.ciprich@linuxbox.cz>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-05-04 14:57:58 -04:00
Al Viro
03d95eb2f2 lift sb_start_write() out of ->write()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-04-09 14:12:56 -04:00
Linus Torvalds
d895cb1af1 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs pile (part one) from Al Viro:
 "Assorted stuff - cleaning namei.c up a bit, fixing ->d_name/->d_parent
  locking violations, etc.

  The most visible changes here are death of FS_REVAL_DOT (replaced with
  "has ->d_weak_revalidate()") and a new helper getting from struct file
  to inode.  Some bits of preparation to xattr method interface changes.

  Misc patches by various people sent this cycle *and* ocfs2 fixes from
  several cycles ago that should've been upstream right then.

  PS: the next vfs pile will be xattr stuff."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (46 commits)
  saner proc_get_inode() calling conventions
  proc: avoid extra pde_put() in proc_fill_super()
  fs: change return values from -EACCES to -EPERM
  fs/exec.c: make bprm_mm_init() static
  ocfs2/dlm: use GFP_ATOMIC inside a spin_lock
  ocfs2: fix possible use-after-free with AIO
  ocfs2: Fix oops in ocfs2_fast_symlink_readpage() code path
  get_empty_filp()/alloc_file() leave both ->f_pos and ->f_version zero
  target: writev() on single-element vector is pointless
  export kernel_write(), convert open-coded instances
  fs: encode_fh: return FILEID_INVALID if invalid fid_type
  kill f_vfsmnt
  vfs: kill FS_REVAL_DOT by adding a d_weak_revalidate dentry op
  nfsd: handle vfs_getattr errors in acl protocol
  switch vfs_getattr() to struct path
  default SET_PERSONALITY() in linux/elf.h
  ceph: prepopulate inodes only when request is aborted
  d_hash_and_lookup(): export, switch open-coded instances
  9p: switch v9fs_set_create_acl() to inode+fid, do it before d_instantiate()
  9p: split dropping the acls from v9fs_set_create_acl()
  ...
2013-02-26 20:16:07 -08:00
Al Viro
496ad9aa8e new helper: file_inode(file)
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-22 23:31:31 -05:00
Frederic Weisbecker
6fac4829ce cputime: Use accessors to read task cputime stats
This is in preparation for the full dynticks feature. While
remotely reading the cputime of a task running in a full
dynticks CPU, we'll need to do some extra-computation. This
way we can account the time it spent tickless in userspace
since its last cputime snapshot.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
2013-01-27 19:23:31 +01:00
Jeff Layton
669abf4e55 vfs: make path_openat take a struct filename pointer
...and fix up the callers. For do_file_open_root, just declare a
struct filename on the stack and fill out the .name field. For
do_filp_open, make it also take a struct filename pointer, and fix up its
callers to call it appropriately.

For filp_open, add a variant that takes a struct filename pointer and turn
filp_open into a wrapper around it.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-12 20:15:09 -04:00
Jeff Layton
91a27b2a75 vfs: define struct filename and have getname() return it
getname() is intended to copy pathname strings from userspace into a
kernel buffer. The result is just a string in kernel space. It would
however be quite helpful to be able to attach some ancillary info to
the string.

For instance, we could attach some audit-related info to reduce the
amount of audit-related processing needed. When auditing is enabled,
we could also call getname() on the string more than once and not
need to recopy it from userspace.

This patchset converts the getname()/putname() interfaces to return
a struct instead of a string. For now, the struct just tracks the
string in kernel space and the original userland pointer for it.

Later, we'll add other information to the struct as it becomes
convenient.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-12 20:14:55 -04:00