nilfs2: use unlocked_ioctl

Pekka Enberg suggested converting ->ioctl operations to use
->unlocked_ioctl to avoid BKL.

The conversion was verified to be safe, so I will take it on this
occasion.

Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/nilfs2/dir.c

@@ -702,7 +702,7 @@ struct file_operations nilfs_dir_operations = {
 	.llseek		= generic_file_llseek,
 	.read		= generic_read_dir,
 	.readdir	= nilfs_readdir,
-	.ioctl		= nilfs_ioctl,
+	.unlocked_ioctl	= nilfs_ioctl,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl	= nilfs_ioctl,
 #endif	/* CONFIG_COMPAT */

fs/nilfs2/file.c

@@ -140,7 +140,7 @@ struct file_operations nilfs_file_operations = {
 	.write		= do_sync_write,
 	.aio_read	= generic_file_aio_read,
 	.aio_write	= generic_file_aio_write,
-	.ioctl		= nilfs_ioctl,
+	.unlocked_ioctl	= nilfs_ioctl,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl	= nilfs_ioctl,
 #endif	/* CONFIG_COMPAT */

fs/nilfs2/ioctl.c

@@ -600,9 +600,9 @@ static int nilfs_ioctl_sync(struct inode *inode, struct file *filp,
 	return 0;
 }
 
-int nilfs_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,
-		unsigned long arg)
+long nilfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {
+	struct inode *inode = filp->f_dentry->d_inode;
 	void __user *argp = (void * __user *)arg;
 
 	switch (cmd) {

fs/nilfs2/nilfs.h

@@ -242,7 +242,7 @@ extern void nilfs_set_link(struct inode *, struct nilfs_dir_entry *,
 extern int nilfs_sync_file(struct file *, struct dentry *, int);
 
 /* ioctl.c */
-int nilfs_ioctl(struct inode *, struct file *, unsigned int, unsigned long);
+long nilfs_ioctl(struct file *, unsigned int, unsigned long);
 int nilfs_ioctl_prepare_clean_segments(struct the_nilfs *, void __user *);
 
 /* inode.c */