[PATCH 00/12] autoconvert trivial BKL users to private mutex

This is a repost of an earlier patch to remove
those users of the big kernel lock that can be
converted to a mutex using a simple script.

The only use of the BKL is in file operations
that are called without any other lock, so the
new mutex is the top-level serialization
and cannot introduce any AB-BA deadlock.

Please apply to the respective maintainer trees
if the patches look good.

Arnd Bergmann (12):
  staging: autoconvert trivial BKL users to private mutex
  isdn: autoconvert trivial BKL users to private mutex
  scsi: autoconvert trivial BKL users to private mutex
  media: autoconvert trivial BKL users to private mutex
  usb: autoconvert trivial BKL users to private mutex
  net: autoconvert trivial BKL users to private mutex
  cris: autoconvert trivial BKL users to private mutex
  sbus: autoconvert trivial BKL users to private mutex
  mtd: autoconvert trivial BKL users to private mutex
  mac: autoconvert trivial BKL users to private mutex
  ipmi: autoconvert trivial BKL users to private mutex
  drivers: autoconvert trivial BKL users to private mutex

 arch/cris/arch-v10/drivers/eeprom.c        |    2 -
 arch/cris/arch-v10/drivers/i2c.c           |    2 -
 arch/cris/arch-v32/drivers/cryptocop.c     |    2 -
 arch/cris/arch-v32/drivers/i2c.c           |   12 ++++----
 drivers/block/paride/pg.c                  |    7 ++--
 drivers/block/paride/pt.c                  |   19 ++++++------
 drivers/char/apm-emulation.c               |   11 ++++---
 drivers/char/applicom.c                    |    9 +++--
 drivers/char/ds1302.c                      |   15 +++++----
 drivers/char/ds1620.c                      |    8 ++--
 drivers/char/dsp56k.c                      |   27 +++++++++--------
 drivers/char/dtlk.c                        |    8 ++--
 drivers/char/generic_nvram.c               |    7 ++--
 drivers/char/genrtc.c                      |   13 ++++----
 drivers/char/i8k.c                         |    7 ++--
 drivers/char/ip2/ip2main.c                 |    8 ++--
 drivers/char/ipmi/ipmi_devintf.c           |   14 ++++----
 drivers/char/ipmi/ipmi_watchdog.c          |    8 ++--
 drivers/char/lp.c                          |   15 +++++----
 drivers/char/mbcs.c                        |    8 ++--
 drivers/char/mmtimer.c                     |    7 ++--
 drivers/char/mwave/mwavedd.c               |   44 ++++++++++++++--------------
 drivers/char/nvram.c                       |   11 ++++---
 drivers/char/nwflash.c                     |   12 ++++----
 drivers/char/pcmcia/cm4000_cs.c            |   11 ++++---
 drivers/char/pcmcia/cm4040_cs.c            |    7 ++--
 drivers/char/ppdev.c                       |    8 ++--
 drivers/char/rio/rio_linux.c               |    7 ++--
 drivers/char/snsc.c                        |    9 +++--
 drivers/char/toshiba.c                     |    9 +++--
 drivers/char/viotape.c                     |   11 ++++---
 drivers/char/xilinx_hwicap/xilinx_hwicap.c |    6 ++--
 drivers/hwmon/fschmd.c                     |    6 ++--
 drivers/hwmon/w83793.c                     |    6 ++--
 drivers/input/misc/hp_sdc_rtc.c            |    7 ++--
 drivers/isdn/capi/capi.c                   |    6 ++--
 drivers/isdn/divert/divert_procfs.c        |    7 ++--
 drivers/isdn/hardware/eicon/divamnt.c      |    7 ++--
 drivers/isdn/hardware/eicon/divasi.c       |    2 -
 drivers/isdn/hardware/eicon/divasmain.c    |    2 -
 drivers/isdn/hysdn/hysdn_procconf.c        |   21 +++++++------
 drivers/isdn/hysdn/hysdn_proclog.c         |   15 +++++----
 drivers/isdn/i4l/isdn_common.c             |   27 +++++++++--------
 drivers/isdn/mISDN/timerdev.c              |    7 ++--
 drivers/macintosh/adb.c                    |   10 +++---
 drivers/macintosh/smu.c                    |    6 ++--
 drivers/macintosh/via-pmu.c                |   11 ++++---
 drivers/media/dvb/bt8xx/dst_ca.c           |    7 ++--
 drivers/media/video/cx88/cx88-blackbird.c  |   13 ++++----
 drivers/media/video/dabusb.c               |   18 ++++++------
 drivers/media/video/se401.c                |    9 +++--
 drivers/media/video/stradis.c              |    9 +++--
 drivers/media/video/usbvideo/vicam.c       |   14 ++++----
 drivers/message/fusion/mptctl.c            |   15 +++++----
 drivers/message/i2o/i2o_config.c           |   23 +++++++-------
 drivers/misc/phantom.c                     |   11 ++++---
 drivers/mtd/mtdchar.c                      |   15 +++++----
 drivers/net/ppp_generic.c                  |   19 ++++++------
 drivers/net/wan/cosa.c                     |   10 +++---
 drivers/pci/hotplug/cpqphp_sysfs.c         |   13 ++++----
 drivers/rtc/rtc-m41t80.c                   |   13 ++++----
 drivers/sbus/char/display7seg.c            |    8 ++--
 drivers/sbus/char/envctrl.c                |    2 -
 drivers/sbus/char/flash.c                  |   15 +++++----
 drivers/sbus/char/openprom.c               |   15 +++++----
 drivers/sbus/char/uctrl.c                  |    7 ++--
 drivers/scsi/3w-9xxx.c                     |    7 ++--
 drivers/scsi/3w-sas.c                      |    7 ++--
 drivers/scsi/3w-xxxx.c                     |    9 ++---
 drivers/scsi/aacraid/linit.c               |   15 +++++----
 drivers/scsi/ch.c                          |    8 ++--
 drivers/scsi/dpt_i2o.c                     |   18 ++++++------
 drivers/scsi/gdth.c                        |   11 ++++---
 drivers/scsi/megaraid.c                    |    8 ++--
 drivers/scsi/megaraid/megaraid_mm.c        |    8 ++--
 drivers/scsi/megaraid/megaraid_sas.c       |    2 -
 drivers/scsi/mpt2sas/mpt2sas_ctl.c         |   11 ++++---
 drivers/scsi/osst.c                        |   15 +++++----
 drivers/scsi/scsi_tgt_if.c                 |    2 -
 drivers/scsi/sg.c                          |   11 ++++---
 drivers/staging/crystalhd/crystalhd_lnx.c  |    9 +++--
 drivers/staging/dt3155/dt3155_drv.c        |    6 ++-
 drivers/staging/vme/devices/vme_user.c     |    7 ++--
 drivers/telephony/ixj.c                    |    7 ++--
 drivers/usb/gadget/printer.c               |    7 ++--
 drivers/usb/misc/iowarrior.c               |   15 +++++----
 drivers/usb/misc/rio500.c                  |   15 +++++----
 drivers/usb/misc/usblcd.c                  |   16 +++++-----
 drivers/watchdog/cpwd.c                    |   15 +++++----
 fs/hfsplus/ioctl.c                         |   11 ++++---
 net/wanrouter/wanmain.c                    |    7 ++--
 net/wanrouter/wanproc.c                    |    7 ++--
 92 files changed, 505 insertions(+), 469 deletions(-)

Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Corey Minyard <redacted>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: David Woodhouse <redacted>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: "James E.J. Bottomley" <redacted>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Karsten Keil <redacted>
Cc: Mauro Carvalho Chehab <redacted>
Cc: netdev@vger.kernel.org
Cc: openipmi-developer@lists.sourceforge.net
Cc: devel@driverdev.osuosl.org
Cc: linux-cris-kernel@axis.com
Cc: linux-media@vger.kernel.org
Cc: linux-mtd@lists.infradead.org
Cc: linuxppc-dev@ozlabs.org
Cc: linux-scsi@vger.kernel.org
Cc: linux-usb@vger.kernel.org

All these files use the big kernel lock in a trivial
way to serialize their private file operations,
typically resulting from an earlier semi-automatic
pushdown from VFS.

None of these drivers appears to want to lock against
other code, and they all use the BKL as the top-level
lock in their file operations, meaning that there
is no lock-order inversion problem.

Consequently, we can remove the BKL completely,
replacing it with a per-file mutex in every case.
Using a scripted approach means we can avoid
typos.

file=$1
name=$2
if grep -q lock_kernel ${file} ; then
    if grep -q 'include.*linux.mutex.h' ${file} ; then
            sed -i '/include.*<linux\/smp_lock.h>/d' ${file}
    else
            sed -i 's/include.*<linux\/smp_lock.h>.*$/include <linux\/mutex.h>/g' ${file}
    fi
    sed -i ${file} \
        -e "/^#include.*linux.mutex.h/,$ {
                1,/^\(static\|int\|long\)/ {
                     /^\(static\|int\|long\)/istatic DEFINE_MUTEX(${name}_mutex);

} }"  \
    -e "s/\(un\)*lock_kernel\>[ ]*()/mutex_\1lock(\&${name}_mutex)/g" \
    -e '/[      ]*cycle_kernel_lock();/d'
else
    sed -i -e '/include.*\<smp_lock.h\>/d' ${file}  \
                -e '/cycle_kernel_lock()/d'
fi

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: linuxppc-dev@ozlabs.org
---
 drivers/macintosh/adb.c     |   10 +++++-----
 drivers/macintosh/smu.c     |    6 +++---
 drivers/macintosh/via-pmu.c |   11 ++++++-----
 3 files changed, 14 insertions(+), 13 deletions(-)

diff --git a/drivers/macintosh/adb.c b/drivers/macintosh/adb.c
index 1c4ee6e..e75e3be 100644
--- a/drivers/macintosh/adb.c
+++ b/drivers/macintosh/adb.c

@@ -24,7 +24,6 @@
 #include <linux/fs.h>
 #include <linux/mm.h>
 #include <linux/sched.h>
-#include <linux/smp_lock.h>
 #include <linux/adb.h>
 #include <linux/cuda.h>
 #include <linux/pmu.h>

@@ -55,6 +54,7 @@ extern struct adb_driver adb_iop_driver;
 extern struct adb_driver via_pmu_driver;
 extern struct adb_driver macio_adb_driver;
 
+static DEFINE_MUTEX(adb_mutex);
 static struct adb_driver *adb_driver_list[] = {
 #ifdef CONFIG_ADB_MACII
 	&via_macii_driver,

@@ -647,7 +647,7 @@ static int adb_open(struct inode *inode, struct file *file)
 	struct adbdev_state *state;
 	int ret = 0;
 
-	lock_kernel();
+	mutex_lock(&adb_mutex);
 	if (iminor(inode) > 0 || adb_controller == NULL) {
 		ret = -ENXIO;
 		goto out;

@@ -665,7 +665,7 @@ static int adb_open(struct inode *inode, struct file *file)
 	state->inuse = 1;
 
 out:
-	unlock_kernel();
+	mutex_unlock(&adb_mutex);
 	return ret;
 }
 

@@ -674,7 +674,7 @@ static int adb_release(struct inode *inode, struct file *file)
 	struct adbdev_state *state = file->private_data;
 	unsigned long flags;
 
-	lock_kernel();
+	mutex_lock(&adb_mutex);
 	if (state) {
 		file->private_data = NULL;
 		spin_lock_irqsave(&state->lock, flags);

@@ -687,7 +687,7 @@ static int adb_release(struct inode *inode, struct file *file)
 			spin_unlock_irqrestore(&state->lock, flags);
 		}
 	}
-	unlock_kernel();
+	mutex_unlock(&adb_mutex);
 	return 0;
 }
 

diff --git a/drivers/macintosh/smu.c b/drivers/macintosh/smu.c
index 2506c95..8775dd4 100644
--- a/drivers/macintosh/smu.c
+++ b/drivers/macintosh/smu.c

@@ -19,7 +19,6 @@
  *    the userland interface
  */
 
-#include <linux/smp_lock.h>
 #include <linux/types.h>
 #include <linux/kernel.h>
 #include <linux/device.h>

@@ -97,6 +96,7 @@ struct smu_device {
  * I don't think there will ever be more than one SMU, so
  * for now, just hard code that
  */
+static DEFINE_MUTEX(smu_mutex);
 static struct smu_device	*smu;
 static DEFINE_MUTEX(smu_part_access);
 static int smu_irq_inited;

@@ -1095,12 +1095,12 @@ static int smu_open(struct inode *inode, struct file *file)
 	pp->mode = smu_file_commands;
 	init_waitqueue_head(&pp->wait);
 
-	lock_kernel();
+	mutex_lock(&smu_mutex);
 	spin_lock_irqsave(&smu_clist_lock, flags);
 	list_add(&pp->list, &smu_clist);
 	spin_unlock_irqrestore(&smu_clist_lock, flags);
 	file->private_data = pp;
-	unlock_kernel();
+	mutex_unlock(&smu_mutex);
 
 	return 0;
 }

diff --git a/drivers/macintosh/via-pmu.c b/drivers/macintosh/via-pmu.c
index 3d4fc0f..28e4822 100644
--- a/drivers/macintosh/via-pmu.c
+++ b/drivers/macintosh/via-pmu.c

@@ -18,7 +18,7 @@
  *
  */
 #include <stdarg.h>
-#include <linux/smp_lock.h>
+#include <linux/mutex.h>
 #include <linux/types.h>
 #include <linux/errno.h>
 #include <linux/kernel.h>

@@ -72,6 +72,7 @@
 /* How many iterations between battery polls */
 #define BATTERY_POLLING_COUNT	2
 
+static DEFINE_MUTEX(pmu_info_proc_mutex);
 static volatile unsigned char __iomem *via;
 
 /* VIA registers - spaced 0x200 bytes apart */

@@ -2076,7 +2077,7 @@ pmu_open(struct inode *inode, struct file *file)
 	pp->rb_get = pp->rb_put = 0;
 	spin_lock_init(&pp->lock);
 	init_waitqueue_head(&pp->wait);
-	lock_kernel();
+	mutex_lock(&pmu_info_proc_mutex);
 	spin_lock_irqsave(&all_pvt_lock, flags);
 #if defined(CONFIG_INPUT_ADBHID) && defined(CONFIG_PMAC_BACKLIGHT)
 	pp->backlight_locker = 0;

@@ -2084,7 +2085,7 @@ pmu_open(struct inode *inode, struct file *file)
 	list_add(&pp->list, &all_pmu_pvt);
 	spin_unlock_irqrestore(&all_pvt_lock, flags);
 	file->private_data = pp;
-	unlock_kernel();
+	mutex_unlock(&pmu_info_proc_mutex);
 	return 0;
 }
 

@@ -2341,9 +2342,9 @@ static long pmu_unlocked_ioctl(struct file *filp,
 {
 	int ret;
 
-	lock_kernel();
+	mutex_lock(&pmu_info_proc_mutex);
 	ret = pmu_ioctl(filp, cmd, arg);
-	unlock_kernel();
+	mutex_unlock(&pmu_info_proc_mutex);
 
 	return ret;
 }

-- 
1.7.1