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>
This commit is contained in:
Thomas Gleixner
2009-12-16 21:31:33 +00:00
committed by Matt Sealey
parent 7e7842a806
commit ccd366ff9f

View File

@@ -30,7 +30,7 @@ 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)
{
@@ -91,7 +91,7 @@ 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;
@@ -115,7 +115,7 @@ static int create_path(const char *nodepath)
}
kfree(path);
}
read_unlock(&dirlock);
mutex_unlock(&dirlock);
return err;
}
@@ -225,7 +225,7 @@ static int delete_path(const char *nodepath)
if (!path)
return -ENOMEM;
write_lock(&dirlock);
mutex_lock(&dirlock);
for (;;) {
char *base;
@@ -237,7 +237,7 @@ static int delete_path(const char *nodepath)
if (err)
break;
}
write_unlock(&dirlock);
mutex_unlock(&dirlock);
kfree(path);
return err;
@@ -348,8 +348,6 @@ 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 "