[PATCH] nbd: some trivial improvements

[Amerigo Wang <amwang@redhat.com>]

This patch 1) uses task_pid_nr(current) to get the pid of current process,
 2) replaces sysfs_create_file() with device_create_file(), 3) lower
the loglevel of an error message.

Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Paul Clements <Paul.Clements@steeleye.com>
Signed-off-by: WANG Cong <amwang@redhat.com>

---
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index f533f33..07cad4b 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -405,10 +405,10 @@ static int nbd_do_it(struct nbd_device *lo)
 
 	BUG_ON(lo->magic != LO_MAGIC);
 
-	lo->pid = current->pid;
-	ret = sysfs_create_file(&disk_to_dev(lo->disk)->kobj, &pid_attr.attr);
+	lo->pid = task_pid_nr(current);
+	ret = device_create_file(disk_to_dev(lo->disk), &pid_attr);
 	if (ret) {
-		printk(KERN_ERR "nbd: sysfs_create_file failed!");
+		printk(KERN_ERR "nbd: device_create_file failed!");
 		lo->pid = 0;
 		return ret;
 	}
@@ -416,7 +416,7 @@ static int nbd_do_it(struct nbd_device *lo)
 	while ((req = nbd_read_stat(lo)) != NULL)
 		nbd_end_request(req);
 
-	sysfs_remove_file(&disk_to_dev(lo->disk)->kobj, &pid_attr.attr);
+	device_remove_file(disk_to_dev(lo->disk), &pid_attr);
 	lo->pid = 0;
 	return 0;
 }
@@ -745,7 +745,7 @@ static int __init nbd_init(void)
 	BUILD_BUG_ON(sizeof(struct nbd_request) != 28);
 
 	if (max_part < 0) {
-		printk(KERN_CRIT "nbd: max_part must be >= 0\n");
+		printk(KERN_ERR "nbd: max_part must be >= 0\n");
 		return -EINVAL;
 	}