[patch 3/4] fat: dont call notify_change

The FAT_IOCTL_SET_ATTRIBUTES ioctl() calls notify_change() to change
the file mode before changing the inode attributes.  Replace with
explicit calls to security_inode_setattr(), fat_setattr() and
fsnotify_change().

This is equivalent to the original.  The reason it is needed, is that
later in the series we move the immutable check into notify_change().
That would break the FAT_IOCTL_SET_ATTRIBUTES ioctl, as it needs to
perform the mode change regardless of the immutability of the file.

[Fix error if fat is built as a module.  Thanks to OGAWA Hirofumi for
noticing.]

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/fat/file.c

@@ -15,6 +15,8 @@
 #include <linux/writeback.h>
 #include <linux/backing-dev.h>
 #include <linux/blkdev.h>
+#include <linux/fsnotify.h>
+#include <linux/security.h>
 
 int fat_generic_ioctl(struct inode *inode, struct file *filp,
 		      unsigned int cmd, unsigned long arg)
@@ -64,6 +66,7 @@ int fat_generic_ioctl(struct inode *inode, struct file *filp,
 
 		/* Equivalent to a chmod() */
 		ia.ia_valid = ATTR_MODE | ATTR_CTIME;
+		ia.ia_ctime = current_fs_time(inode->i_sb);
 		if (is_dir) {
 			ia.ia_mode = MSDOS_MKMODE(attr,
 				S_IRWXUGO & ~sbi->options.fs_dmask)
@@ -90,11 +93,21 @@ int fat_generic_ioctl(struct inode *inode, struct file *filp,
 			}
 		}
 
+		/*
+		 * The security check is questionable...  We single
+		 * out the RO attribute for checking by the security
+		 * module, just because it maps to a file mode.
+		 */
+		err = security_inode_setattr(filp->f_path.dentry, &ia);
+		if (err)
+			goto up;
+
 		/* This MUST be done before doing anything irreversible... */
-		err = notify_change(filp->f_path.dentry, &ia);
+		err = fat_setattr(filp->f_path.dentry, &ia);
 		if (err)
 			goto up;
 
+		fsnotify_change(filp->f_path.dentry, ia.ia_valid);
 		if (sbi->options.sys_immutable) {
 			if (attr & ATTR_SYS)
 				inode->i_flags |= S_IMMUTABLE;

security/security.c

@@ -442,6 +442,7 @@ int security_inode_setattr(struct dentry *dentry, struct iattr *attr)
 		return 0;
 	return security_ops->inode_setattr(dentry, attr);
 }
+EXPORT_SYMBOL_GPL(security_inode_setattr);
 
 int security_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
 {