More kernel vfs docco.

Xref vfs_mount(9) from vfs_mount(9)

Submitted by: Chad David <davidc@acns.ab.ca>
PR: docs/32431

1 files changed, 73 insertions, 0 deletions

diff --git a/share/man/man9/vfs_getnewfsid.9 b/share/man/man9/vfs_getnewfsid.9
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+.\"
+.\" Copyright (C) 2001 Chad David <davidc@acns.ab.ca>. All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice(s), this list of conditions and the following disclaimer as
+.\"    the first lines of this file unmodified other than the possible
+.\"    addition of one or more copyright notices.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice(s), this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY
+.\" EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+.\" WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+.\" DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE LIABLE FOR ANY
+.\" DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+.\" (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+.\" SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+.\" CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
+.\" DAMAGE.
+.\"
+.\" $FreeBSD$
+.\"
+.Dd November 21, 2001
+.Dt VFS_GETNEWFSID 9
+.Os
+.Sh NAME
+.Nm vfs_getnewfsid
+.Nd "allocate a new fsid"
+.Sh SYNOPSIS
+.In sys/param.h
+.In sys/mount.h
+.Ft void
+.Fn vfs_getnewfsid "struct mount *mp"
+.Sh DESCRIPTION
+The
+.Fn vfs_getnewfsid
+function allocates a new filesystem identifier for the mount point given.
+Filesystems typically call
+.Fn vfs_getnewfsid
+in their mount routine in order to acquire a unique id within the system
+which can later be used to uniquely identify the filesystem via calls such as
+.Fn vfs_getvfs .
+.Pp
+The actual fsid is made up of two 32 bit integers, that are stored in the statfs
+structure of
+.Fa mp .
+The first integer is unique in the set of mounted filesystems, while the second holds
+the filesystem type.
+.Bd -literal
+	typedef	struct fsid {
+		int32_t val[2];
+	} fsid_t;
+.Ed
+.Sh PSEUDOCODE
+.Bd -literal
+	xxx_mount(struct mount *mp, char *path, caddr_t data, struct nameidata *ndp, struct thread *td)
+	{
+		...
+		vfs_getnewfsid(mp);
+		...
+	}
+.Ed
+.Sh SEE ALSO
+.Xr vfs_getvfs 9
+.Sh AUTHORS
+This man page was written by
+.An Chad David Aq davidc@acns.ab.ca .