Module Name: src
Committed By: dyoung
Date: Wed Apr 29 01:03:43 UTC 2009
Modified Files:
src/sys/kern: vfs_subr.c vfs_syscalls.c
Log Message:
Extract common code from vfs_rootmountalloc(9) and mount_domount() into
a new struct mount-allocation routine, vfs_mountalloc(9). Documentation
updates will follow.
Attention: Synchronization Oversight Committee! In mount_domount(),
I postpone the call mutex_enter(&mp->mnt_updating) until right before
the VFS_MOUNT(9) call because (1) that looks to me like the earliest
possible opportunity for mp to become visible to any other LWP, because
it was just kmem_zalloc(9)'d and (2) it made extracting the common code
much easier. Tell me if my reasoning is faulty.
To generate a diff of this commit:
cvs rdiff -u -r1.375 -r1.376 src/sys/kern/vfs_subr.c
cvs rdiff -u -r1.392 -r1.393 src/sys/kern/vfs_syscalls.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/kern/vfs_subr.c
diff -u src/sys/kern/vfs_subr.c:1.375 src/sys/kern/vfs_subr.c:1.376
--- src/sys/kern/vfs_subr.c:1.375 Sat Apr 25 18:53:44 2009
+++ src/sys/kern/vfs_subr.c Wed Apr 29 01:03:43 2009
@@ -1,4 +1,4 @@
-/* $NetBSD: vfs_subr.c,v 1.375 2009/04/25 18:53:44 elad Exp $ */
+/* $NetBSD: vfs_subr.c,v 1.376 2009/04/29 01:03:43 dyoung Exp $ */
/*-
* Copyright (c) 1997, 1998, 2004, 2005, 2007, 2008 The NetBSD Foundation, Inc.
@@ -81,7 +81,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: vfs_subr.c,v 1.375 2009/04/25 18:53:44 elad Exp $");
+__KERNEL_RCSID(0, "$NetBSD: vfs_subr.c,v 1.376 2009/04/29 01:03:43 dyoung Exp $");
#include "opt_ddb.h"
#include "opt_compat_netbsd.h"
@@ -455,6 +455,30 @@
}
}
+struct mount *
+vfs_mountalloc(struct vfsops *vfsops, struct vnode *vp)
+{
+ int error;
+ struct mount *mp;
+
+ mp = kmem_zalloc(sizeof(*mp), KM_SLEEP);
+ if (mp == NULL)
+ return NULL;
+
+ mp->mnt_op = vfsops;
+ mp->mnt_refcnt = 1;
+ TAILQ_INIT(&mp->mnt_vnodelist);
+ rw_init(&mp->mnt_unmounting);
+ mutex_init(&mp->mnt_renamelock, MUTEX_DEFAULT, IPL_NONE);
+ mutex_init(&mp->mnt_updating, MUTEX_DEFAULT, IPL_NONE);
+ error = vfs_busy(mp, NULL);
+ KASSERT(error == 0);
+ mp->mnt_vnodecovered = vp;
+ mount_initspecific(mp);
+
+ return mp;
+}
+
/*
* Lookup a filesystem type, and if found allocate and initialize
* a mount structure for it.
@@ -480,18 +504,9 @@
vfsp->vfs_refcount++;
mutex_exit(&vfs_list_lock);
- mp = kmem_zalloc(sizeof(*mp), KM_SLEEP);
- if (mp == NULL)
+ if ((mp = vfs_mountalloc(vfsp, NULL)) == NULL)
return ENOMEM;
- mp->mnt_refcnt = 1;
- rw_init(&mp->mnt_unmounting);
- mutex_init(&mp->mnt_updating, MUTEX_DEFAULT, IPL_NONE);
- mutex_init(&mp->mnt_renamelock, MUTEX_DEFAULT, IPL_NONE);
- (void)vfs_busy(mp, NULL);
- TAILQ_INIT(&mp->mnt_vnodelist);
- mp->mnt_op = vfsp;
mp->mnt_flag = MNT_RDONLY;
- mp->mnt_vnodecovered = NULL;
(void)strlcpy(mp->mnt_stat.f_fstypename, vfsp->vfs_name,
sizeof(mp->mnt_stat.f_fstypename));
mp->mnt_stat.f_mntonname[0] = '/';
@@ -500,7 +515,6 @@
'\0';
(void)copystr(devname, mp->mnt_stat.f_mntfromname,
sizeof(mp->mnt_stat.f_mntfromname) - 1, 0);
- mount_initspecific(mp);
*mpp = mp;
return (0);
}
Index: src/sys/kern/vfs_syscalls.c
diff -u src/sys/kern/vfs_syscalls.c:1.392 src/sys/kern/vfs_syscalls.c:1.393
--- src/sys/kern/vfs_syscalls.c:1.392 Tue Apr 28 03:01:15 2009
+++ src/sys/kern/vfs_syscalls.c Wed Apr 29 01:03:43 2009
@@ -1,4 +1,4 @@
-/* $NetBSD: vfs_syscalls.c,v 1.392 2009/04/28 03:01:15 yamt Exp $ */
+/* $NetBSD: vfs_syscalls.c,v 1.393 2009/04/29 01:03:43 dyoung Exp $ */
/*-
* Copyright (c) 2008, 2009 The NetBSD Foundation, Inc.
@@ -66,7 +66,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: vfs_syscalls.c,v 1.392 2009/04/28 03:01:15 yamt Exp $");
+__KERNEL_RCSID(0, "$NetBSD: vfs_syscalls.c,v 1.393 2009/04/29 01:03:43 dyoung Exp $");
#ifdef _KERNEL_OPT
#include "opt_fileassoc.h"
@@ -332,24 +332,10 @@
if (vp->v_mountedhere != NULL)
return EBUSY;
- mp = kmem_zalloc(sizeof(*mp), KM_SLEEP);
- if (mp == NULL)
+ if ((mp = vfs_mountalloc(vfsops, vp)) == NULL)
return ENOMEM;
- mp->mnt_op = vfsops;
- mp->mnt_refcnt = 1;
-
- TAILQ_INIT(&mp->mnt_vnodelist);
- rw_init(&mp->mnt_unmounting);
- mutex_init(&mp->mnt_renamelock, MUTEX_DEFAULT, IPL_NONE);
- mutex_init(&mp->mnt_updating, MUTEX_DEFAULT, IPL_NONE);
- error = vfs_busy(mp, NULL);
- KASSERT(error == 0);
- mutex_enter(&mp->mnt_updating);
-
- mp->mnt_vnodecovered = vp;
mp->mnt_stat.f_owner = kauth_cred_geteuid(l->l_cred);
- mount_initspecific(mp);
/*
* The underlying file system may refuse the mount for
@@ -363,6 +349,7 @@
MNT_NOATIME | MNT_NODEVMTIME | MNT_SYMPERM | MNT_SOFTDEP |
MNT_LOG | MNT_IGNORE | MNT_RDONLY);
+ mutex_enter(&mp->mnt_updating);
error = VFS_MOUNT(mp, path, data, data_len);
mp->mnt_flag &= ~MNT_OP_FLAGS;
