From 751a2cd05bfeb7d1948f912446187a063b251c19 Mon Sep 17 00:00:00 2001
From: Poul-Henning Kamp <phk@FreeBSD.org>
Date: Mon, 5 Nov 2001 10:33:45 +0000
Subject: [PATCH] Define a new mount flag "MNT_JAILDEVFS"

Collect the magic combination of flags which can be updated into
a macro in sys/mount.h rather than inlining them (twice!) in
vfs_syscalls.c
---
 sys/kern/vfs_extattr.c  | 10 ++--------
 sys/kern/vfs_syscalls.c | 10 ++--------
 sys/sys/mount.h         | 13 +++++++++++--
 3 files changed, 15 insertions(+), 18 deletions(-)

diff --git a/sys/kern/vfs_extattr.c b/sys/kern/vfs_extattr.c
index cb82b083935..696c92e37c5 100644
--- a/sys/kern/vfs_extattr.c
+++ b/sys/kern/vfs_extattr.c
@@ -365,14 +365,8 @@ update:
 		mp->mnt_flag |= MNT_RDONLY;
 	else if (mp->mnt_flag & MNT_RDONLY)
 		mp->mnt_kern_flag |= MNTK_WANTRDWR;
-	mp->mnt_flag &=~ (MNT_NOSUID | MNT_NOEXEC | MNT_NODEV |
-	    MNT_SYNCHRONOUS | MNT_UNION | MNT_ASYNC | MNT_NOATIME |
-	    MNT_NOSYMFOLLOW | MNT_IGNORE |
-	    MNT_NOCLUSTERR | MNT_NOCLUSTERW | MNT_SUIDDIR);
-	mp->mnt_flag |= fsflags & (MNT_NOSUID | MNT_NOEXEC |
-	    MNT_NODEV | MNT_SYNCHRONOUS | MNT_UNION | MNT_ASYNC | MNT_FORCE |
-	    MNT_NOSYMFOLLOW | MNT_IGNORE |
-	    MNT_NOATIME | MNT_NOCLUSTERR | MNT_NOCLUSTERW | MNT_SUIDDIR);
+	mp->mnt_flag &=~ MNT_UPDATEMASK;
+	mp->mnt_flag |= fsflags & (MNT_UPDATEMASK | MNT_FORCE);
 	/*
 	 * Mount the filesystem.
 	 * XXX The final recipients of VFS_MOUNT just overwrite the ndp they
diff --git a/sys/kern/vfs_syscalls.c b/sys/kern/vfs_syscalls.c
index cb82b083935..696c92e37c5 100644
--- a/sys/kern/vfs_syscalls.c
+++ b/sys/kern/vfs_syscalls.c
@@ -365,14 +365,8 @@ update:
 		mp->mnt_flag |= MNT_RDONLY;
 	else if (mp->mnt_flag & MNT_RDONLY)
 		mp->mnt_kern_flag |= MNTK_WANTRDWR;
-	mp->mnt_flag &=~ (MNT_NOSUID | MNT_NOEXEC | MNT_NODEV |
-	    MNT_SYNCHRONOUS | MNT_UNION | MNT_ASYNC | MNT_NOATIME |
-	    MNT_NOSYMFOLLOW | MNT_IGNORE |
-	    MNT_NOCLUSTERR | MNT_NOCLUSTERW | MNT_SUIDDIR);
-	mp->mnt_flag |= fsflags & (MNT_NOSUID | MNT_NOEXEC |
-	    MNT_NODEV | MNT_SYNCHRONOUS | MNT_UNION | MNT_ASYNC | MNT_FORCE |
-	    MNT_NOSYMFOLLOW | MNT_IGNORE |
-	    MNT_NOATIME | MNT_NOCLUSTERR | MNT_NOCLUSTERW | MNT_SUIDDIR);
+	mp->mnt_flag &=~ MNT_UPDATEMASK;
+	mp->mnt_flag |= fsflags & (MNT_UPDATEMASK | MNT_FORCE);
 	/*
 	 * Mount the filesystem.
 	 * XXX The final recipients of VFS_MOUNT just overwrite the ndp they
diff --git a/sys/sys/mount.h b/sys/sys/mount.h
index 8b0d0120078..e2b856157c0 100644
--- a/sys/sys/mount.h
+++ b/sys/sys/mount.h
@@ -153,6 +153,7 @@ struct mount {
 #define	MNT_SUIDDIR	0x00100000	/* special handling of SUID on dirs */
 #define	MNT_SOFTDEP	0x00200000	/* soft updates being done */
 #define	MNT_NOSYMFOLLOW	0x00400000	/* do not follow symlinks */
+#define	MNT_JAILDEVFS	0x02000000	/* Jail friendly DEVFS behaviour */
 #define	MNT_NOATIME	0x10000000	/* disable update of file access time */
 #define	MNT_NOCLUSTERR	0x40000000	/* disable cluster read */
 #define	MNT_NOCLUSTERW	0x80000000	/* disable cluster write */
@@ -190,7 +191,16 @@ struct mount {
 			MNT_LOCAL	| MNT_USER	| MNT_QUOTA	| \
 			MNT_ROOTFS	| MNT_NOATIME	| MNT_NOCLUSTERR| \
 			MNT_NOCLUSTERW	| MNT_SUIDDIR	| MNT_SOFTDEP	| \
-			MNT_IGNORE	| MNT_EXPUBLIC	| MNT_NOSYMFOLLOW)
+			MNT_IGNORE	| MNT_EXPUBLIC	| MNT_NOSYMFOLLOW | \
+			MNT_JAILDEVFS)
+
+/* Mask of flags that can be updated */
+#define MNT_UPDATEMASK (MNT_NOSUID	| MNT_NOEXEC	| MNT_NODEV	| \
+			MNT_SYNCHRONOUS	| MNT_UNION	| MNT_ASYNC	| \
+			MNT_NOATIME | \
+			MNT_NOSYMFOLLOW	| MNT_IGNORE	| MNT_JAILDEVFS	| \
+			MNT_NOCLUSTERR	| MNT_NOCLUSTERW | MNT_SUIDDIR)
+  
 /*
  * External filesystem command modifier flags.
  * Unmount can use the MNT_FORCE flag.
@@ -206,7 +216,6 @@ struct mount {
 /*
  * Still available
  */
-#define	MNT_SPARE1	0x02000000
 #define	MNT_SPARE2	0x04000000
 #define	MNT_SPARE3	0x08000000
 /*