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drivers: autoconvert trivial BKL users to private mutex

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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.

These drivers do not seem to be under active
maintainance from my brief investigation. Apologies
to those maintainers that I have missed.

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>
This commit is contained in:
Arnd Bergmann
2010-06-02 14:28:52 +02:00
parent 609146fdb3
commit 613655fa39
35 changed files with 216 additions and 190 deletions
Download Patch File Download Diff File Expand all files Collapse all files

9
drivers/char/applicom.c
View File

@ -26,7 +26,7 @@
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/smp_lock.h>
#include <linux/mutex.h>
#include <linux/miscdevice.h>
#include <linux/pci.h>
#include <linux/wait.h>
@ -60,6 +60,7 @@
#define PCI_DEVICE_ID_APPLICOM_PCI2000PFB 0x0003
#endif
static DEFINE_MUTEX(ac_mutex);
static char *applicom_pci_devnames[] = {
"PCI board",
"PCI2000IBS / PCI2000CAN",
@ -707,7 +708,7 @@ static long ac_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
if (IS_ERR(adgl))
return PTR_ERR(adgl);
lock_kernel();
mutex_lock(&ac_mutex);
IndexCard = adgl->num_card-1;
if(cmd != 6 && ((IndexCard >= MAX_BOARD) || !apbs[IndexCard].RamIO)) {
@ -717,7 +718,7 @@ static long ac_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
warncount--;
}
kfree(adgl);
unlock_kernel();
mutex_unlock(&ac_mutex);
return -EINVAL;
}
@ -835,7 +836,7 @@ static long ac_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
}
Dummy = readb(apbs[IndexCard].RamIO + VERS);
kfree(adgl);
unlock_kernel();
mutex_unlock(&ac_mutex);
return 0;
}