1 files changed, 60 insertions, 39 deletions

diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
index e486e49b31ed..442f7ef873fc 100644
--- a/fs/ext4/ioctl.c
+++ b/fs/ext4/ioctl.c
@@ -269,6 +269,29 @@ static int uuid_is_zero(__u8 u[16])
 }
 #endif
 
+/*
+ * If immutable is set and we are not clearing it, we're not allowed to change
+ * anything else in the inode.  Don't error out if we're only trying to set
+ * immutable on an immutable file.
+ */
+static int ext4_ioctl_check_immutable(struct inode *inode, __u32 new_projid,
+				      unsigned int flags)
+{
+	struct ext4_inode_info *ei = EXT4_I(inode);
+	unsigned int oldflags = ei->i_flags;
+
+	if (!(oldflags & EXT4_IMMUTABLE_FL) || !(flags & EXT4_IMMUTABLE_FL))
+		return 0;
+
+	if ((oldflags & ~EXT4_IMMUTABLE_FL) != (flags & ~EXT4_IMMUTABLE_FL))
+		return -EPERM;
+	if (ext4_has_feature_project(inode->i_sb) &&
+	    __kprojid_val(ei->i_projid) != new_projid)
+		return -EPERM;
+
+	return 0;
+}
+
 static int ext4_ioctl_setflags(struct inode *inode,
 			       unsigned int flags)
 {
@@ -289,16 +312,9 @@ static int ext4_ioctl_setflags(struct inode *inode,
 	/* The JOURNAL_DATA flag is modifiable only by root */
 	jflag = flags & EXT4_JOURNAL_DATA_FL;
 
-	/*
-	 * The IMMUTABLE and APPEND_ONLY flags can only be changed by
-	 * the relevant capability.
-	 *
-	 * This test looks nicer. Thanks to Pauline Middelink
-	 */
-	if ((flags ^ oldflags) & (EXT4_APPEND_FL | EXT4_IMMUTABLE_FL)) {
-		if (!capable(CAP_LINUX_IMMUTABLE))
-			goto flags_out;
-	}
+	err = vfs_ioc_setflags_prepare(inode, oldflags, flags);
+	if (err)
+		goto flags_out;
 
 	/*
 	 * The JOURNAL_DATA flag can only be changed by
@@ -340,6 +356,20 @@ static int ext4_ioctl_setflags(struct inode *inode,
 		}
 	}
 
+	/*
+	 * Wait for all pending directio and then flush all the dirty pages
+	 * for this file.  The flush marks all the pages readonly, so any
+	 * subsequent attempt to write to the file (particularly mmap pages)
+	 * will come through the filesystem and fail.
+	 */
+	if (S_ISREG(inode->i_mode) && !IS_IMMUTABLE(inode) &&
+	    (flags & EXT4_IMMUTABLE_FL)) {
+		inode_dio_wait(inode);
+		err = filemap_write_and_wait(inode->i_mapping);
+		if (err)
+			goto flags_out;
+	}
+
 	handle = ext4_journal_start(inode, EXT4_HT_INODE, 1);
 	if (IS_ERR(handle)) {
 		err = PTR_ERR(handle);
@@ -704,28 +734,15 @@ group_add_out:
 	return err;
 }
 
-static int ext4_ioctl_check_project(struct inode *inode, struct fsxattr *fa)
+static void ext4_fill_fsxattr(struct inode *inode, struct fsxattr *fa)
 {
-	/*
-	 * Project Quota ID state is only allowed to change from within the init
-	 * namespace. Enforce that restriction only if we are trying to change
-	 * the quota ID state. Everything else is allowed in user namespaces.
-	 */
-	if (current_user_ns() == &init_user_ns)
-		return 0;
-
-	if (__kprojid_val(EXT4_I(inode)->i_projid) != fa->fsx_projid)
-		return -EINVAL;
+	struct ext4_inode_info *ei = EXT4_I(inode);
 
-	if (ext4_test_inode_flag(inode, EXT4_INODE_PROJINHERIT)) {
-		if (!(fa->fsx_xflags & FS_XFLAG_PROJINHERIT))
-			return -EINVAL;
-	} else {
-		if (fa->fsx_xflags & FS_XFLAG_PROJINHERIT)
-			return -EINVAL;
-	}
+	simple_fill_fsxattr(fa, ext4_iflags_to_xflags(ei->i_flags &
+						      EXT4_FL_USER_VISIBLE));
 
-	return 0;
+	if (ext4_has_feature_project(inode->i_sb))
+		fa->fsx_projid = from_kprojid(&init_user_ns, ei->i_projid);
 }
 
 long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
@@ -742,6 +759,8 @@ long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 		return ext4_ioc_getfsmap(sb, (void __user *)arg);
 	case EXT4_IOC_GETFLAGS:
 		flags = ei->i_flags & EXT4_FL_USER_VISIBLE;
+		if (S_ISREG(inode->i_mode))
+			flags &= ~EXT4_PROJINHERIT_FL;
 		return put_user(flags, (int __user *) arg);
 	case EXT4_IOC_SETFLAGS: {
 		int err;
@@ -769,7 +788,11 @@ long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 			return err;
 
 		inode_lock(inode);
-		err = ext4_ioctl_setflags(inode, flags);
+		err = ext4_ioctl_check_immutable(inode,
+				from_kprojid(&init_user_ns, ei->i_projid),
+				flags);
+		if (!err)
+			err = ext4_ioctl_setflags(inode, flags);
 		inode_unlock(inode);
 		mnt_drop_write_file(filp);
 		return err;
@@ -1096,13 +1119,7 @@ resizefs_out:
 	{
 		struct fsxattr fa;
 
-		memset(&fa, 0, sizeof(struct fsxattr));
-		fa.fsx_xflags = ext4_iflags_to_xflags(ei->i_flags & EXT4_FL_USER_VISIBLE);
-
-		if (ext4_has_feature_project(inode->i_sb)) {
-			fa.fsx_projid = (__u32)from_kprojid(&init_user_ns,
-				EXT4_I(inode)->i_projid);
-		}
+		ext4_fill_fsxattr(inode, &fa);
 
 		if (copy_to_user((struct fsxattr __user *)arg,
 				 &fa, sizeof(fa)))
@@ -1111,7 +1128,7 @@ resizefs_out:
 	}
 	case EXT4_IOC_FSSETXATTR:
 	{
-		struct fsxattr fa;
+		struct fsxattr fa, old_fa;
 		int err;
 
 		if (copy_from_user(&fa, (struct fsxattr __user *)arg,
@@ -1134,11 +1151,15 @@ resizefs_out:
 			return err;
 
 		inode_lock(inode);
-		err = ext4_ioctl_check_project(inode, &fa);
+		ext4_fill_fsxattr(inode, &old_fa);
+		err = vfs_ioc_fssetxattr_check(inode, &old_fa, &fa);
 		if (err)
 			goto out;
 		flags = (ei->i_flags & ~EXT4_FL_XFLAG_VISIBLE) |
 			 (flags & EXT4_FL_XFLAG_VISIBLE);
+		err = ext4_ioctl_check_immutable(inode, fa.fsx_projid, flags);
+		if (err)
+			goto out;
 		err = ext4_ioctl_setflags(inode, flags);
 		if (err)
 			goto out;