From f1f76f865b5f66db5b5c7f2d19874f2bb9b43b8d Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx@linutronix.de>
Date: Wed, 16 Dec 2009 21:31:33 +0000
Subject: [PATCH] devtmpfs: Convert dirlock to a mutex
devtmpfs has a rw_lock dirlock which serializes delete_path and
create_path.
This code was obviously never tested with the usual set of debugging
facilities enabled. In the dirlock held sections the code calls:
- vfs functions which take mutexes
- kmalloc(, GFP_KERNEL)
In both code pathes the might sleep warning triggers and spams dmesg.
Convert the rw_lock to a mutex. There is no reason why this needs to
be a rwlock.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
drivers/base/devtmpfs.c | 12 +++++-------
1 file changed, 5 insertions(+), 7 deletions(-)
diff --git a/drivers/base/devtmpfs.c b/drivers/base/devtmpfs.c
index 50375bb8e51d..278371c7bf5a 100644
--- a/drivers/base/devtmpfs.c
+++ b/drivers/base/devtmpfs.c
@@ -32,7 +32,7 @@ static int dev_mount = 1;
static int dev_mount;
#endif
-static rwlock_t dirlock;
+static DEFINE_MUTEX(dirlock);
static int __init mount_param(char *str)
{
@@ -93,7 +93,7 @@ static int create_path(const char *nodepath)
{
int err;
- read_lock(&dirlock);
+ mutex_lock(&dirlock);
err = dev_mkdir(nodepath, 0755);
if (err == -ENOENT) {
char *path;
@@ -117,7 +117,7 @@ static int create_path(const char *nodepath)
}
kfree(path);
}
- read_unlock(&dirlock);
+ mutex_unlock(&dirlock);
return err;
}
@@ -229,7 +229,7 @@ static int delete_path(const char *nodepath)
if (!path)
return -ENOMEM;
- write_lock(&dirlock);
+ mutex_lock(&dirlock);
for (;;) {
char *base;
@@ -241,7 +241,7 @@ static int delete_path(const char *nodepath)
if (err)
break;
}
- write_unlock(&dirlock);
+ mutex_unlock(&dirlock);
kfree(path);
return err;
@@ -352,8 +352,6 @@ int __init devtmpfs_init(void)
int err;
struct vfsmount *mnt;
- rwlock_init(&dirlock);
-
err = register_filesystem(&dev_fs_type);
if (err) {
printk(KERN_ERR "devtmpfs: unable to register devtmpfs "
--
2.34.1