Merge branch 'ro-bind.b6' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6

* 'ro-bind.b6' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (24 commits)
  [PATCH] r/o bind mounts: debugging for missed calls
  [PATCH] r/o bind mounts: honor mount writer counts at remount
  [PATCH] r/o bind mounts: track numbers of writers to mounts
  [PATCH] r/o bind mounts: check mnt instead of superblock directly
  [PATCH] r/o bind mounts: elevate count for xfs timestamp updates
  [PATCH] r/o bind mounts: make access() use new r/o helper
  [PATCH] r/o bind mounts: write counts for truncate()
  [PATCH] r/o bind mounts: elevate write count for chmod/chown callers
  [PATCH] r/o bind mounts: elevate write count for open()s
  [PATCH] r/o bind mounts: elevate write count for ioctls()
  [PATCH] r/o bind mounts: write count for file_update_time()
  [PATCH] r/o bind mounts: elevate write count for do_utimes()
  [PATCH] r/o bind mounts: write counts for touch_atime()
  [PATCH] r/o bind mounts: elevate write count for ncp_ioctl()
  [PATCH] r/o bind mounts: elevate write count for xattr_permission() callers
  [PATCH] r/o bind mounts: get write access for vfs_rename() callers
  [PATCH] r/o bind mounts: write counts for link/symlink
  [PATCH] r/o bind mounts: get callers of vfs_mknod/create/mkdir()
  [PATCH] r/o bind mounts: elevate write count for rmdir and unlink.
  [PATCH] r/o bind mounts: drop write during emergency remount
  ...

1 files changed, 25 insertions, 26 deletions

diff --git a/fs/inode.c b/fs/inode.c
index 53245ffcf93..27ee1af50d0 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -1199,42 +1199,37 @@ void touch_atime(struct vfsmount *mnt, struct dentry *dentry)
 	struct inode *inode = dentry->d_inode;
 	struct timespec now;
 
-	if (inode->i_flags & S_NOATIME)
+	if (mnt_want_write(mnt))
 		return;
+	if (inode->i_flags & S_NOATIME)
+		goto out;
 	if (IS_NOATIME(inode))
-		return;
+		goto out;
 	if ((inode->i_sb->s_flags & MS_NODIRATIME) && S_ISDIR(inode->i_mode))
-		return;
+		goto out;
 
-	/*
-	 * We may have a NULL vfsmount when coming from NFSD
-	 */
-	if (mnt) {
-		if (mnt->mnt_flags & MNT_NOATIME)
-			return;
-		if ((mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode))
-			return;
-
-		if (mnt->mnt_flags & MNT_RELATIME) {
-			/*
-			 * With relative atime, only update atime if the
-			 * previous atime is earlier than either the ctime or
-			 * mtime.
-			 */
-			if (timespec_compare(&inode->i_mtime,
-						&inode->i_atime) < 0 &&
-			    timespec_compare(&inode->i_ctime,
-						&inode->i_atime) < 0)
-				return;
-		}
+	if (mnt->mnt_flags & MNT_NOATIME)
+		goto out;
+	if ((mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode))
+		goto out;
+	if (mnt->mnt_flags & MNT_RELATIME) {
+		/*
+		 * With relative atime, only update atime if the previous
+		 * atime is earlier than either the ctime or mtime.
+		 */
+		if (timespec_compare(&inode->i_mtime, &inode->i_atime) < 0 &&
+		    timespec_compare(&inode->i_ctime, &inode->i_atime) < 0)
+			goto out;
 	}
 
 	now = current_fs_time(inode->i_sb);
 	if (timespec_equal(&inode->i_atime, &now))
-		return;
+		goto out;
 
 	inode->i_atime = now;
 	mark_inode_dirty_sync(inode);
+out:
+	mnt_drop_write(mnt);
 }
 EXPORT_SYMBOL(touch_atime);
 
@@ -1255,10 +1250,13 @@ void file_update_time(struct file *file)
 	struct inode *inode = file->f_path.dentry->d_inode;
 	struct timespec now;
 	int sync_it = 0;
+	int err;
 
 	if (IS_NOCMTIME(inode))
 		return;
-	if (IS_RDONLY(inode))
+
+	err = mnt_want_write(file->f_path.mnt);
+	if (err)
 		return;
 
 	now = current_fs_time(inode->i_sb);
@@ -1279,6 +1277,7 @@ void file_update_time(struct file *file)
 
 	if (sync_it)
 		mark_inode_dirty_sync(inode);
+	mnt_drop_write(file->f_path.mnt);
 }
 
 EXPORT_SYMBOL(file_update_time);