An update to the RCU documentation calling out the
self-limiting-update-rate advantages of synchronize_rcu(), and describing
how to use call_rcu() in a way that results in self-limiting updates.
Self-limiting updates are important to avoiding RCU-induced OOM in face of
denial-of-service attacks.
Signed-off-by: NPaul E. McKenney <paulmck@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Backoff readahead size exponentially on I/O error.

Michael Tokarev <mjt@tls.msk.ru> described the problem as:

[QUOTE]
Suppose there's a CD-rom with a scratch/etc, one sector is unreadable.
In order to "fix" it, one have to read it and write to another CD-rom,
or something.. or just ignore the error (if it's just a skip in a video
stream).  Let's assume the unreadable block is number U.

But current behavior is just insane.  An application requests block
number N, which is before U. Kernel tries to read-ahead blocks N..U.
Cdrom drive tries to read it, re-read it.. for some time.  Finally,
when all the N..U-1 blocks are read, kernel returns block number N
(as requested) to an application, successefully.

Now an app requests block number N+1, and kernel tries to read
blocks N+1..U+1.  Retrying again as in previous step.

And so on, up to when an app requests block number U-1.  And when,
finally, it requests block U, it receives read error.

So, kernel currentry tries to re-read the same failing block as
many times as the current readahead value (256 (times?) by default).

This whole process already killed my cdrom drive (I posted about it
to LKML several months ago) - literally, the drive has fried, and
does not work anymore.  Ofcourse that problem was a bug in firmware
(or whatever) of the drive *too*, but.. main problem with that is
current readahead logic as described above.
[/QUOTE]

Which was confirmed by Jens Axboe <axboe@suse.de>:

[QUOTE]
For ide-cd, it tends do only end the first part of the request on a
medium error. So you may see a lot of repeats :/
[/QUOTE]

With this patch, retries are expected to be reduced from, say, 256, to 5.

[akpm@osdl.org: cleanups]
Signed-off-by: NWu Fengguang <wfg@mail.ustc.edu.cn>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

In the error case, add_msg() gets called from timer functions, so should
be using GFP_ATOMIC instead of GFP_KERNEL.

Ref: http://bugzilla.kernel.org/show_bug.cgi?id=6659.  Thanks to Christian
Werner <chw@ch-werner.de> for reporting, and for the initial fix.
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Priority: not critical.
Mark 3 functions __init.  Saves a little memory.
This makes these functions' calls to AdvWaitEEPCmd() (which is __init)
be clean (i.e., eliminates text -> init -> text call chain).

Fix multiple section mismatch warnings:
WARNING: drivers/scsi/advansys.o - Section mismatch: reference to .init.text: from .text between 'AdvSet3550EEPConfig' (at offset 0x7a22) and 'AdvSet38C0800EEPConfig'
WARNING: drivers/scsi/advansys.o - Section mismatch: reference to .init.text: from .text between 'AdvSet3550EEPConfig' (at offset 0x7a4e) and 'AdvSet38C0800EEPConfig'
WARNING: drivers/scsi/advansys.o - Section mismatch: reference to .init.text: from .text between 'AdvSet3550EEPConfig' (at offset 0x7a79) and 'AdvSet38C0800EEPConfig'
WARNING: drivers/scsi/advansys.o - Section mismatch: reference to .init.text: from .text between 'AdvSet3550EEPConfig' (at offset 0x7aa2) and 'AdvSet38C0800EEPConfig'
WARNING: drivers/scsi/advansys.o - Section mismatch: reference to .init.text: from .text between 'AdvSet3550EEPConfig' (at offset 0x7abb) and 'AdvSet38C0800EEPConfig'
WARNING: drivers/scsi/advansys.o - Section mismatch: reference to .init.text: from .text between 'AdvSet38C0800EEPConfig' (at offset 0x7ae0) and 'AdvSet38C1600EEPConfig'
WARNING: drivers/scsi/advansys.o - Section mismatch: reference to .init.text: from .text between 'AdvSet38C0800EEPConfig' (at offset 0x7b0c) and 'AdvSet38C1600EEPConfig'
WARNING: drivers/scsi/advansys.o - Section mismatch: reference to .init.text: from .text between 'AdvSet38C0800EEPConfig' (at offset 0x7b37) and 'AdvSet38C1600EEPConfig'
WARNING: drivers/scsi/advansys.o - Section mismatch: reference to .init.text: from .text between 'AdvSet38C0800EEPConfig' (at offset 0x7b60) and 'AdvSet38C1600EEPConfig'
WARNING: drivers/scsi/advansys.o - Section mismatch: reference to .init.text: from .text between 'AdvSet38C0800EEPConfig' (at offset 0x7b79) and 'AdvSet38C1600EEPConfig'
WARNING: drivers/scsi/advansys.o - Section mismatch: reference to .init.text: from .text between 'AdvSet38C1600EEPConfig' (at offset 0x7b9e) and 'AdvExeScsiQueue'
WARNING: drivers/scsi/advansys.o - Section mismatch: reference to .init.text: from .text between 'AdvSet38C1600EEPConfig' (at offset 0x7bca) and 'AdvExeScsiQueue'
WARNING: drivers/scsi/advansys.o - Section mismatch: reference to .init.text: from .text between 'AdvSet38C1600EEPConfig' (at offset 0x7bf5) and 'AdvExeScsiQueue'
WARNING: drivers/scsi/advansys.o - Section mismatch: reference to .init.text: from .text between 'AdvSet38C1600EEPConfig' (at offset 0x7c1e) and 'AdvExeScsiQueue'
WARNING: drivers/scsi/advansys.o - Section mismatch: reference to .init.text: from .text between 'AdvSet38C1600EEPConfig' (at offset 0x7c37) and 'AdvExeScsiQueue'
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Priority: tossup.
In theory some of these (previously) __init functions could be called
after init, but that problem has not been observed AFAIK.

There were 2 cases of cleanup_module() (module_exit) calling __init
functions (clear_requested_irq() & have_requested_irq()).
These are more serious, but still not observed AFAIK.

Fix sections mismatch:
WARNING: drivers/char/ip2/ip2main.o - Section mismatch: reference to .init.text: from .text between 'cleanup_module' (at offset 0x228b) and 'ip2_loadmain'
WARNING: drivers/char/ip2/ip2main.o - Section mismatch: reference to .init.text: from .text between 'cleanup_module' (at offset 0x22ae) and 'ip2_loadmain'
WARNING: drivers/char/ip2/ip2main.o - Section mismatch: reference to .init.text: from .text between 'ip2_loadmain' (at offset 0x2501) and 'set_irq'
WARNING: drivers/char/ip2/ip2main.o - Section mismatch: reference to .init.text: from .text between 'ip2_loadmain' (at offset 0x25de) and 'set_irq'
WARNING: drivers/char/ip2/ip2main.o - Section mismatch: reference to .init.text: from .text between 'ip2_loadmain' (at offset 0x2698) and 'set_irq'
WARNING: drivers/char/ip2/ip2main.o - Section mismatch: reference to .init.text: from .text between 'ip2_loadmain' (at offset 0x2922) and 'set_irq'
WARNING: drivers/char/ip2/ip2main.o - Section mismatch: reference to .init.text: from .text between 'ip2_loadmain' (at offset 0x299e) and 'set_irq'
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Priority: not critical.
Make __mcdx_init() __init and static.  Saves a little memory.

Fix section mismatch warning and make the function static while there:
WARNING: drivers/cdrom/mcdx.o - Section mismatch: reference to .init.text: from .text between 'init_module' (at offset 0x8be) and 'mcdx_transfer'
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Cc: Jens Axboe <axboe@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Priority: not critical.
Change 3 functions from __init to __devinit.
Could be an init/probe problem in theory, but not observed, so not
high priority IMO.

Fix section mismatch warnings:
WARNING: drivers/video/tridentfb.o - Section mismatch: reference to .init.text: from .text between 'trident_pci_probe' (at offset 0x1aad) and 'trident_pci_remove'
WARNING: drivers/video/tridentfb.o - Section mismatch: reference to .init.text: from .text between 'trident_pci_probe' (at offset 0x1b22) and 'trident_pci_remove'
WARNING: drivers/video/tridentfb.o - Section mismatch: reference to .init.text: from .text between 'trident_pci_probe' (at offset 0x1b31) and 'trident_pci_remove'
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

netdev->set_config can be called at any time, so these references
to __initdata would be a real problem.
However, problem has not been observed AFAIK.

Fix section mismatch warnings:
WARNING: drivers/net/wan/sdla.o - Section mismatch: reference to .init.data: from .text between 'sdla_set_config' (at offset 0x1b8e) and 'sdla_stats'
WARNING: drivers/net/wan/sdla.o - Section mismatch: reference to .init.data: from .text between 'sdla_set_config' (at offset 0x1e76) and 'sdla_stats'
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

In the course of trying to track down a bug where a file mtime was not
being updated correctly, it was discovered that the m/ctime updates were
not quite being handled correctly for ftruncate() calls.

Quoth SUSv3:

open(2):

        If O_TRUNC is set and the file did previously exist, upon
        successful completion, open() shall mark for update the st_ctime
        and st_mtime fields of the file.

truncate(2):

        Upon successful completion, if the file size is changed, this
        function shall mark for update the st_ctime and st_mtime fields
        of the file, and the S_ISUID and S_ISGID bits of the file mode
        may be cleared.

ftruncate(2):

        Upon successful completion, if fildes refers to a regular file,
        the ftruncate() function shall mark for update the st_ctime and
        st_mtime fields of the file and the S_ISUID and S_ISGID bits of
        the file mode may be cleared. If the ftruncate() function is
        unsuccessful, the file is unaffected.

The open(O_TRUNC) and truncate cases were being handled correctly, but the
ftruncate case was being handled like the truncate case.  The semantics of
truncate and ftruncate don't quite match, so ftruncate needs to be handled
slightly differently.

The attached patch addresses this issue for ftruncate(2).

My thanx to Stephen Tweedie and Trond Myklebust for their help in
understanding the situation and semantics.
Signed-off-by: NPeter Staubach <staubach@redhat.com>
Cc: "Stephen C. Tweedie" <sct@redhat.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

I'm testing glibc on MIPS64, little-endian, N32, O32 and N64 multilibs.

Among the NPTL test failures seen are some arising from sigsuspend problems
for N32: it blocks the wrong signals, so SIGCANCEL (SIGRTMIN) is blocked
despite glibc's carefully excluding it from sets of signals to block.
Specifically, testing suggests it blocks signal N^32 instead of signal N,
so (in the example tested) blocking SIGUSR1 (17) blocks signal 49 instead.

glibc's sigset_t uses an array of unsigned long, as does the kernel.
In both cases, signal N+1 is represented as
(1UL << (N % (8 * sizeof (unsigned long)))) in word number
(N / (8 * sizeof (unsigned long))).

Thus the N32 glibc uses an array of 32-bit words and the N64 kernel uses an
array of 64-bit words.  For little-endian, the layout is the same, with
signals 1-32 in the first 4 bytes, signals 33-64 in the second, etc.; for
big-endian, userspace has that layout while in the kernel each 8 bytes have
the two halves swapped from the userspace layout.

The N32 sigsuspend syscall uses sigset_from_compat to convert the userspace
sigset to kernel format.  If __COMPAT_ENDIAN_SWAP__ is *not* set, this uses
logic of the form

  set->sig[0] = compat->sig[0] | (((long)compat->sig[1]) << 32 )

to convert the userspace sigset to a kernel one.  This looks correct to me
for both big and little endian, given that in userspace compat->sig[1] will
represent signals 33-64, and so will the high 32 bits of set->sig[0] in the
kernel.  If however __COMPAT_ENDIAN_SWAP__ *is* set, as it is for
__MIPSEL__, it uses

  set->sig[0] = compat->sig[1] | (((long)compat->sig[0]) << 32 );

which seems incorrect for both big and little endian, and would
explain the observed symptoms.

This code is the only use of __COMPAT_ENDIAN_SWAP__, so if incorrect
then that macro serves no purpose, in which case something like the
following patch would seem appropriate to remove it.
Signed-off-by: NJoseph Myers <joseph@codesourcery.com>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The variables nlen and rlen are defined/initialized but not used in
ext3_add_entry().
Signed-off-by: NJohann Lombardi <johann.lombardi@bull.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

__getname() may fail and return NULL (as pointed out by Coverity 437 &
1220).
Signed-off-by: NFlorin Malita <fmalita@gmail.com>
Acked-by: NEric Van Hensbergen <ericvh@gmail.com>
Cc: <rminnich@lanl.gov>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The table is empty, why does it still exist?
Signed-off-by: NStephen Hemminger <shemminger@osdl.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Finding "init_module" high stack usage problems is challenging when there
are over 1600 "init_module" functions in the kernel tree, so make
checkstack.pl print out the filename where the stack usage occurs.  This is
useful for code built as loadable modules.

For built-in code, it just prints the kernel image file name, like
"vmlinux".  Examples:

(before patch:)
0x0000000d callback:					1928
0xffffffff81678c09 huft_build:				1560
0x0018 init_module:					1512

(after patch:)
0x0000000d callback [divacapi]:				1928
0xffffffff81678c09 huft_build [vmlinux]:		1560
0x0018 init_module [hdaps]:				1512

Also change one if-series to use elsif to cut down on unneeded tests.
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Acked-by: NJoern Engel <joern@wh.fh-wedel.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Add an RTC driver for the Dallas DS1742 RTC chip.

[akpm@osdl.org: cleanups, compile fix]
Signed-off-by: NAtsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Add an RTC driver for the Dallas DS1553 RTC chip.

[akpm@osdl.org: cleanups, compile fix]
Signed-off-by: NAtsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

- whitespace fixes (80-col display)

- one unneeded cast of void*

Cc: Andrew Victor <andrew@sanpeople.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Adds support for the RTC integrated in the Atmel AT91RM9200 SoC.

Driver was originally written for 2.4 by Rick Bronson.  Then converted to
2.6 ARM RTC API by Steven Scholz.  Now converted to the RTC class model.
Signed-off-by: NAndrew Victor <andrew@sanpeople.com>
Signed-off-by: NAlessandro Zummo <a.zummo@towertech.it>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

RTC: Add exported function rtc_year_days() to calculate the tm_yday value.
Signed-off-by: NAndrew Victor <andrew@sanpeople.com>
Signed-off-by: NAlessandro Zummo <a.zummo@towertech.it>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch adds support for the v3020 RTC from EM Microelectronic.

The v3020 RTC is designed to be connected on a bus using only one data bit.
 Since any data bit may be used, it is necessary to specify this to the
driver by passing a struct v3020_platform_data pointer (see
include/linux/rtc-v3020.h) to the driver.

Part of the following code comes from the kernel patchs produced by
Compulab for their products.  The original file (available here:
http://raph.people.8d.com/misc/emv3020.c) was released under the terms of
the GPL license.

[akpm@osdl.org: cleanups]
Signed-off-by: NRaphael Assenat <raph@raphnet.net>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Rtc driver documentation update

* Mention the max-user-freq control file.
* Add missing header in example code.
Signed-off-by: NJean Delvare <khali@linux-fr.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Add support for the MAX6902 SPI RTC chip.  Tested on a pxa2xx cpu.

The compulab code comes from the kernel patch the produce for their
cn-x255 board. (inside a zip file on the
http://www.compulab.co.il/x255/html/x255-developer.htm)

The original file (drivers/char/max6902.c) was GPL, which is of course
an appropriate licence:

/*
 * max6902.c
 *
 * Driver for MAX6902 RTC
 *
 * Copyright (C) 2004 Compulab Ltd.
 *
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 *
 */

For reference, you can get the original file here:
http://raph.people.8d.com/misc/max6902.c

[akpm@osdl.org: cleanups]
Signed-off-by: NRaphael Assenat <raph@raphnet.net>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Centralize CAP_SYS_XXX checks to avoid duplicate code and missing checks in
the drivers.
Signed-off-by: NAlessandro Zummo <a.zummo@towertech.it>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Remove commented capability checks and add some others.
Signed-off-by: NAlessandro Zummo <a.zummo@towertech.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

A port of the driver for the pcf8583 i2c rtc controller to the generic RTC
framework by Alessandro Zummo.  Based on
drivers/acorn/char/{pcf8583.[hc],i2c.c}.  Hopefully, acorn can be converted
too to use this driver in the future.
Signed-off-by: NG. Liakhovetski <gl@dsa-ac.de>
Signed-off-by: NAlessandro Zummo <a.zummo@towertech.it>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Jean Delvare <khali@linux-fr.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Import genrtc's RTC UIE emulation (CONFIG_GEN_RTC_X) to rtc-dev driver with
slight adjustments/refinements.  This makes UIE-less rtc drivers work
better with programs doing read/poll on /dev/rtc, such as hwclock.  This
emulation should not harm rtc drivers with UIE support, since
rtc_dev_ioctl() calls underlaying rtc driver's ioctl() first.
Signed-off-by: NAtsushi Nemoto <anemo@mba.ocn.ne.jp>
Acked-by: NAlessandro Zummo <a.zummo@towertech.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This is an "RTC-framework" driver for DS1307 and similar RTC chips,

It should be a full replacement for the existing ds1337.c driver (using the
older RTC glue), giving a net increase in the number of RTC chips that work
out-of-the-box.  There's a whole cluster of RTCs that are very similar, but
the 1337 driver was a bit too picky to work with most of them.

Still no support for RTC alarm IRQs (on chips that support them).
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NJames Chapman <jchapman@katalix.com>
Signed-off-by: NAlessandro Zummo <a.zummo@towertech.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

sysrq SAK is described as being something you should mistake for SAK from
c2 compliant systems - whoops.  What's meant is that it should *not* be
mistaken as such.
Signed-off-by: NJesper Juhl <jesper.juhl@gmail.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Currently, enabling/disabling printk timestamps is only possible through
reboot (bootparam) or recompile.  I normally do not run with timestamps
(since syslog handles that in a good manner), but for measuring small
kernel delays (e.g.  irq probing - see parport thread) I needed subsecond
precision, but then again, just for some minutes rather than all kernel
messages to come.  The following patch adds a module_param() with which the
timestamps can be en-/disabled in a live system through
/sys/modules/printk/parameters/printk_time.
Signed-off-by: NJan Engelhardt <jengelh@gmx.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

In radix_tree_tag_get(), return normalized value of 0/1, as indicated
by its comment.
Signed-off-by: NWu Fengguang <wfg@mail.ustc.edu.cn>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

A few days ago Arjan signaled a lockdep red flag on epoll locks, and
precisely between the epoll's device structure lock (->lock) and the wait
queue head lock (->lock).

Like I explained in another email, and directly to Arjan, this can't happen
in reality because of the explicit check at eventpoll.c:592, that does not
allow to drop an epoll fd inside the same epoll fd.  Since lockdep is
working on per-structure locks, it will never be able to know of policies
enforced in other parts of the code.

It was decided time ago of having the ability to drop epoll fds inside
other epoll fds, that triggers a very trick wakeup operations (due to
possibly reentrant callback-driven wakeups) handled by the
ep_poll_safewake() function.  While looking again at the code though, I
noticed that all the operations done on the epoll's main structure wait
queue head (->wq) are already protected by the epoll lock (->lock), so that
locked-style functions can be used to manipulate the ->wq member.  This
makes both a lock-acquire save, and lockdep happy.

Running totalmess on my dual opteron for a while did not reveal any problem
so far:

http://www.xmailserver.org/totalmess.cSigned-off-by: NDavide Libenzi <davidel@xmailserver.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Cc: Paul Clements <Paul.Clements@steeleye.com>
Cc: Jens Axboe <axboe@suse.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch makes EXT2_DEBUG work again.  Due to lack of proper include
file, EXT2_DEBUG was undefined in bitmap.c and ext2_count_free() is left
out.  Moved to balloc.c and removed bitmap.c entirely.

Second, debug versions of ext2_count_free_{inodes/blocks} reacquires
superblock lock.  Moved lock into callers.
Signed-off-by: NVal Henson <val_henson@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Why is it marked unused when in fact it's used?
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

On UP, this:

       cpumask_t mask = node_to_cpumask(numa_node_id());

       for_each_cpu_mask(cpu, mask)

does this:

mm/readahead.c: In function `node_readahead_aging':
mm/readahead.c:850: warning: unused variable `mask'

which is unpleasantly fixed by this:
Acked-by: NPaul Jackson <pj@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Make makes sysctl non-optional unless EMBEDDED is set.  There are a number
of interfaces exposed via sysctl, enough that it has to be considered core
kernel functionality at this point.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Add WARN_ON_ONCE(cond) to print once-per-bootup messages.

[rostedt@goodmis.org: improve code generation]
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Make procfs non-optional unless EMBEDDED is set, just like sysfs.  procfs
is already de facto required for a large subset of Linux functionality.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Put short function description for read_cache_pages() on one line as needed
by kernel-doc.
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Convert the ext3 in-kernel filesystem blocks to ext3_fsblk_t.  Convert the
rest of all unsigned long type in-kernel filesystem blocks to ext3_fsblk_t,
and replace the printk format string respondingly.
Signed-off-by: NMingming Cao <cmm@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>