[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>

1 files changed, 14 insertions, 1 deletions

diff --git a/fs/fat/file.c b/fs/fat/file.c
index c672df4036e9..8707a8cfa02c 100644
--- a/fs/fat/file.c
+++ b/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;