diff options
author | Arnd Bergmann <arnd@arndb.de> | 2010-06-02 14:28:52 +0200 |
---|---|---|
committer | Arnd Bergmann <arnd@arndb.de> | 2010-10-05 15:01:04 +0200 |
commit | 613655fa39ff6957754fa8ceb8559980920eb8ee (patch) | |
tree | ad19600cb81207b24188683d7fc4ae88013339d1 /drivers/sbus/char | |
parent | 609146fdb319cebce93be550938ab852f7bade90 (diff) | |
download | lwn-613655fa39ff6957754fa8ceb8559980920eb8ee.tar.gz lwn-613655fa39ff6957754fa8ceb8559980920eb8ee.zip |
drivers: 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.
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>
Diffstat (limited to 'drivers/sbus/char')
-rw-r--r-- | drivers/sbus/char/jsflash.c | 24 |
1 files changed, 13 insertions, 11 deletions
diff --git a/drivers/sbus/char/jsflash.c b/drivers/sbus/char/jsflash.c index 4942050dc5b6..13f48e28a1e1 100644 --- a/drivers/sbus/char/jsflash.c +++ b/drivers/sbus/char/jsflash.c @@ -27,7 +27,7 @@ */ #include <linux/module.h> -#include <linux/smp_lock.h> +#include <linux/mutex.h> #include <linux/types.h> #include <linux/errno.h> #include <linux/miscdevice.h> @@ -68,6 +68,8 @@ #define JSF_PART_BITS 2 /* 2 bits of minors to cover JSF_NPART */ #define JSF_PART_MASK 0x3 /* 2 bits mask */ +static DEFINE_MUTEX(jsf_mutex); + /* * Access functions. * We could ioremap(), but it's easier this way. @@ -225,7 +227,7 @@ static loff_t jsf_lseek(struct file * file, loff_t offset, int orig) { loff_t ret; - lock_kernel(); + mutex_lock(&jsf_mutex); switch (orig) { case 0: file->f_pos = offset; @@ -238,7 +240,7 @@ static loff_t jsf_lseek(struct file * file, loff_t offset, int orig) default: ret = -EINVAL; } - unlock_kernel(); + mutex_unlock(&jsf_mutex); return ret; } @@ -384,18 +386,18 @@ static int jsf_ioctl_program(void __user *arg) static long jsf_ioctl(struct file *f, unsigned int cmd, unsigned long arg) { - lock_kernel(); + mutex_lock(&jsf_mutex); int error = -ENOTTY; void __user *argp = (void __user *)arg; if (!capable(CAP_SYS_ADMIN)) { - unlock_kernel(); + mutex_unlock(&jsf_mutex); return -EPERM; } switch (cmd) { case JSFLASH_IDENT: if (copy_to_user(argp, &jsf0.id, JSFIDSZ)) { - unlock_kernel(); + mutex_unlock(&jsf_mutex); return -EFAULT; } break; @@ -407,7 +409,7 @@ static long jsf_ioctl(struct file *f, unsigned int cmd, unsigned long arg) break; } - unlock_kernel(); + mutex_unlock(&jsf_mutex); return error; } @@ -418,17 +420,17 @@ static int jsf_mmap(struct file * file, struct vm_area_struct * vma) static int jsf_open(struct inode * inode, struct file * filp) { - lock_kernel(); + mutex_lock(&jsf_mutex); if (jsf0.base == 0) { - unlock_kernel(); + mutex_unlock(&jsf_mutex); return -ENXIO; } if (test_and_set_bit(0, (void *)&jsf0.busy) != 0) { - unlock_kernel(); + mutex_unlock(&jsf_mutex); return -EBUSY; } - unlock_kernel(); + mutex_unlock(&jsf_mutex); return 0; /* XXX What security? */ } |