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authorArnd Bergmann <arnd@arndb.de>2010-06-02 14:28:52 +0200
committerArnd Bergmann <arnd@arndb.de>2010-09-15 21:00:45 +0200
commitc45d15d24eb2b49bf734e1e5e7e103befb76b19b (patch)
treedd768c089fd3393e8fa2c4f4fb50cedb1044037d /drivers/scsi/sg.c
parent49553c2ef88749dd502687f4eb9c258bb10a4f44 (diff)
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scsi: 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> Cc: linux-scsi@vger.kernel.org Cc: "James E.J. Bottomley" <James.Bottomley@suse.de>
Diffstat (limited to 'drivers/scsi/sg.c')
-rw-r--r--drivers/scsi/sg.c12
1 files changed, 7 insertions, 5 deletions
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index 78d616315d8e..b5507d59b5a6 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -49,7 +49,7 @@ static int sg_version_num = 30534; /* 2 digits for each component */
#include <linux/blkdev.h>
#include <linux/delay.h>
#include <linux/blktrace_api.h>
-#include <linux/smp_lock.h>
+#include <linux/mutex.h>
#include "scsi.h"
#include <scsi/scsi_dbg.h>
@@ -103,6 +103,8 @@ static int scatter_elem_sz_prev = SG_SCATTER_SZ;
static int sg_add(struct device *, struct class_interface *);
static void sg_remove(struct device *, struct class_interface *);
+static DEFINE_MUTEX(sg_mutex);
+
static DEFINE_IDR(sg_index_idr);
static DEFINE_RWLOCK(sg_index_lock); /* Also used to lock
file descriptor list for device */
@@ -229,7 +231,7 @@ sg_open(struct inode *inode, struct file *filp)
int res;
int retval;
- lock_kernel();
+ mutex_lock(&sg_mutex);
nonseekable_open(inode, filp);
SCSI_LOG_TIMEOUT(3, printk("sg_open: dev=%d, flags=0x%x\n", dev, flags));
sdp = sg_get_dev(dev);
@@ -314,7 +316,7 @@ sdp_put:
sg_put:
if (sdp)
sg_put_dev(sdp);
- unlock_kernel();
+ mutex_unlock(&sg_mutex);
return retval;
}
@@ -1092,9 +1094,9 @@ sg_unlocked_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
{
int ret;
- lock_kernel();
+ mutex_lock(&sg_mutex);
ret = sg_ioctl(filp, cmd_in, arg);
- unlock_kernel();
+ mutex_unlock(&sg_mutex);
return ret;
}
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