From 29ffb32ccd01b7397676c8c4f8883be5dc83be71 Mon Sep 17 00:00:00 2001
From: Konstantin Belousov <kib@FreeBSD.org>
Date: Wed, 3 Aug 2016 08:57:15 +0000
Subject: [PATCH] Remove Giant asserts.  Update comment.

Owning Giant in the init/uninit is accidental due to the moment where
VFS modules initialization is performed, and is not enforced by the
VFS interface.  The Giant lock does not prevent a parallel execution
of the code, it is VFS which implements the proper protocol.

Approved by:	des (pseudofs maintainer)
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
---
 sys/fs/pseudofs/pseudofs.c         | 4 ----
 sys/fs/pseudofs/pseudofs.h         | 6 +++---
 sys/fs/pseudofs/pseudofs_fileno.c  | 2 --
 sys/fs/pseudofs/pseudofs_vncache.c | 2 --
 4 files changed, 3 insertions(+), 11 deletions(-)

diff --git a/sys/fs/pseudofs/pseudofs.c b/sys/fs/pseudofs/pseudofs.c
index f9a6adf7309a..b2ae67fd7767 100644
--- a/sys/fs/pseudofs/pseudofs.c
+++ b/sys/fs/pseudofs/pseudofs.c
@@ -383,8 +383,6 @@ pfs_init(struct pfs_info *pi, struct vfsconf *vfc)
 	struct pfs_node *root;
 	int error;
 
-	mtx_assert(&Giant, MA_OWNED);
-
 	pfs_fileno_init(pi);
 
 	/* set up the root directory */
@@ -414,8 +412,6 @@ pfs_uninit(struct pfs_info *pi, struct vfsconf *vfc)
 {
 	int error;
 
-	mtx_assert(&Giant, MA_OWNED);
-
 	pfs_destroy(pi->pi_root);
 	pi->pi_root = NULL;
 	pfs_fileno_uninit(pi);
diff --git a/sys/fs/pseudofs/pseudofs.h b/sys/fs/pseudofs/pseudofs.h
index 9887880d1252..cc9b841cd042 100644
--- a/sys/fs/pseudofs/pseudofs.h
+++ b/sys/fs/pseudofs/pseudofs.h
@@ -189,9 +189,9 @@ typedef int (*pfs_destroy_t)(PFS_DESTROY_ARGS);
 /*
  * pfs_info: describes a pseudofs instance
  *
- * The pi_mutex is only used to avoid using the global subr_unit lock for
- * unrhdr.  The rest of struct pfs_info is only modified while Giant is
- * held (during vfs_init() and vfs_uninit()).
+ * The pi_mutex is only used to avoid using the global subr_unit lock
+ * for unrhdr.  The rest of struct pfs_info is only modified during
+ * vfs_init() and vfs_uninit() of the consumer filesystem.
  */
 struct pfs_info {
 	char			 pi_name[PFS_FSNAMELEN];
diff --git a/sys/fs/pseudofs/pseudofs_fileno.c b/sys/fs/pseudofs/pseudofs_fileno.c
index a8c034f06dbc..f57731c29b27 100644
--- a/sys/fs/pseudofs/pseudofs_fileno.c
+++ b/sys/fs/pseudofs/pseudofs_fileno.c
@@ -52,7 +52,6 @@ void
 pfs_fileno_init(struct pfs_info *pi)
 {
 
-	mtx_assert(&Giant, MA_OWNED);
 	mtx_init(&pi->pi_mutex, "pfs_fileno", NULL, MTX_DEF);
 	pi->pi_unrhdr = new_unrhdr(3, INT_MAX / NO_PID, &pi->pi_mutex);
 }
@@ -64,7 +63,6 @@ void
 pfs_fileno_uninit(struct pfs_info *pi)
 {
 
-	mtx_assert(&Giant, MA_OWNED);
 	delete_unrhdr(pi->pi_unrhdr);
 	pi->pi_unrhdr = NULL;
 	mtx_destroy(&pi->pi_mutex);
diff --git a/sys/fs/pseudofs/pseudofs_vncache.c b/sys/fs/pseudofs/pseudofs_vncache.c
index 1f9c04327bfb..1bec5a4c885c 100644
--- a/sys/fs/pseudofs/pseudofs_vncache.c
+++ b/sys/fs/pseudofs/pseudofs_vncache.c
@@ -84,7 +84,6 @@ void
 pfs_vncache_load(void)
 {
 
-	mtx_assert(&Giant, MA_OWNED);
 	mtx_init(&pfs_vncache_mutex, "pfs_vncache", NULL, MTX_DEF);
 	pfs_exit_tag = EVENTHANDLER_REGISTER(process_exit, pfs_exit, NULL,
 	    EVENTHANDLER_PRI_ANY);
@@ -97,7 +96,6 @@ void
 pfs_vncache_unload(void)
 {
 
-	mtx_assert(&Giant, MA_OWNED);
 	EVENTHANDLER_DEREGISTER(process_exit, pfs_exit_tag);
 	KASSERT(pfs_vncache_entries == 0,
 	    ("%d vncache entries remaining", pfs_vncache_entries));