diff options
author | Arnd Bergmann <arnd@arndb.de> | 2010-07-11 23:18:56 +0200 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-08-10 14:35:39 -0700 |
commit | 925ce689bb31960c839804c19ef38d676f1939b9 (patch) | |
tree | 620c9b0f054a613d86aaa62901f93019856de0f9 /drivers/usb/gadget/printer.c | |
parent | 7c7e2d00435bd8129c4bacb73fe4a2d4db4e7d7c (diff) |
USB: autoconvert trivial BKL users to private mutex
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/usb/gadget/printer.c')
-rw-r--r-- | drivers/usb/gadget/printer.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/drivers/usb/gadget/printer.c b/drivers/usb/gadget/printer.c index 88f05996aa02..cf241c371a71 100644 --- a/drivers/usb/gadget/printer.c +++ b/drivers/usb/gadget/printer.c @@ -25,7 +25,7 @@ #include <linux/ioport.h> #include <linux/sched.h> #include <linux/slab.h> -#include <linux/smp_lock.h> +#include <linux/mutex.h> #include <linux/errno.h> #include <linux/init.h> #include <linux/timer.h> @@ -70,6 +70,7 @@ #define DRIVER_DESC "Printer Gadget" #define DRIVER_VERSION "2007 OCT 06" +static DEFINE_MUTEX(printer_mutex); static const char shortname [] = "printer"; static const char driver_desc [] = DRIVER_DESC; @@ -476,7 +477,7 @@ printer_open(struct inode *inode, struct file *fd) unsigned long flags; int ret = -EBUSY; - lock_kernel(); + mutex_lock(&printer_mutex); dev = container_of(inode->i_cdev, struct printer_dev, printer_cdev); spin_lock_irqsave(&dev->lock, flags); @@ -492,7 +493,7 @@ printer_open(struct inode *inode, struct file *fd) spin_unlock_irqrestore(&dev->lock, flags); DBG(dev, "printer_open returned %x\n", ret); - unlock_kernel(); + mutex_unlock(&printer_mutex); return ret; } |