Document some of the dev_t related APIs.

Submitted by: Chad David <davidc@acns.ab.ca>

8 files changed, 461 insertions, 0 deletions

diff --git a/share/man/man9/cdevsw_add.9 b/share/man/man9/cdevsw_add.9
new file mode 100644
index 0000000..375027f
--- /dev/null
+++ b/share/man/man9/cdevsw_add.9
@@ -0,0 +1,57 @@
+.\"
+.\" 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 July 9, 2001
+.Dt CDEVSW_ADD 9
+.Os
+.Sh NAME
+.Nm cdevsw_add
+.Nd "Adds a cdevsw entry"
+.Sh SYNOPSIS
+.Fd #include <sys/conf.h>
+.Ft int
+.Fo cdevsw_add
+.Fa "struct cdevsw *newentry"
+.Fc
+.Sh DESCRIPTION
+The
+.Nm
+function adds
+.Ar newentry
+to the cdevsw table if its major number is greater than or equal to zero,
+and is less than NUMCDEVSW.
+.Pp
+Its argument is: 
+.Bl -tag
+.It Ar 
+The device to add to the table.
+.Sh RETURN VALUES
+A value of 0 is returned on success; otherwise, EINVAL is returned
+indicating that the major number is not in the valid range.
+.Sh AUTHORS
+This man page was written by Chad David.
diff --git a/share/man/man9/cdevsw_remove.9 b/share/man/man9/cdevsw_remove.9
new file mode 100644
index 0000000..4d7b49e
--- /dev/null
+++ b/share/man/man9/cdevsw_remove.9
@@ -0,0 +1,57 @@
+.\"
+.\" 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 July 9, 2001
+.Dt CDEVSW_REMOVE 9
+.Os
+.Sh NAME
+.Nm cdevsw_remove
+.Nd "Removes a cdevsw entry"
+.Sh SYNOPSIS
+.Fd #include <sys/conf.h>
+.Ft int
+.Fo cdevsw_add
+.Fa "struct cdevsw *oldentry"
+.Fc
+.Sh DESCRIPTION
+The
+.Nm
+function removes
+.Ar oldentry
+from the cdevsw table if its major number is greater than or equal to zero,
+and is less than NUMCDEVSW.
+.Pp
+Its argument is: 
+.Bl -tag
+.It Ar 
+The device to remove from the table.
+.Sh RETURN VALUES
+A value of 0 is returned on success; otherwise, EINVAL is returned
+indicating that the major number is not in the valid range.
+.Sh AUTHORS
+This man page was written by Chad David.
diff --git a/share/man/man9/devsw.9 b/share/man/man9/devsw.9
new file mode 100644
index 0000000..2510f07
--- /dev/null
+++ b/share/man/man9/devsw.9
@@ -0,0 +1,57 @@
+.\"
+.\" 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 July 9, 2001
+.Dt DEVSW 9
+.Os
+.Sh NAME
+.Nm devsw
+.Nd "Checks if the vnode represents a disk"
+.Sh SYNOPSIS
+.Fd #include <sys/conf.h>
+.Ft struct cdevsw *
+.Fo devsw
+.Fa "dev_t dev"
+.Fc
+.Sh DESCRIPTION
+The
+.Nm
+function returns a pointer to the cdevsw structure associated
+with this character device id.  If dev->si_cdevsw is set it is
+returned; otherwise, the
+.Ar major(9)
+offset into the cdevsw array is returned.
+.Pp
+Its argument is: 
+.Bl -tag
+.It Ar dev
+The device whose cdevsw entry should be returned.
+.Sh RETURN VALUES
+A pointer to a cdevsw structure.
+.Sh AUTHORS
+This man page was written by Chad David.
diff --git a/share/man/man9/major.9 b/share/man/man9/major.9
new file mode 100644
index 0000000..c00a64e
--- /dev/null
+++ b/share/man/man9/major.9
@@ -0,0 +1,56 @@
+.\"
+.\" 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 July 9, 2001
+.Dt MAJOR 9
+.Os
+.Sh NAME
+.Nm major
+.Nd "Returns the major number for the device"
+.Sh SYNOPSIS
+.Fd #include <sys/systm.h>
+.Ft int
+.Fo major
+.Fa "dev_t dev"
+.Fc
+.Sh DESCRIPTION
+The
+.Nm
+function returns the major device number for the given device.
+.Pp
+Its argument is: 
+.Bl -tag
+.It Ar dev
+The device whose major device number should be returned.
+.Sh RETURN VALUES
+An integer greater than zero and less than NUMCDEVSW, or NOUDEV
+if the device is invalid.
+.Sh SEE ALSO
+.Xr minor 9
+.Sh AUTHORS
+This man page was written by Chad David.
diff --git a/share/man/man9/minor.9 b/share/man/man9/minor.9
new file mode 100644
index 0000000..5f4fc8e
--- /dev/null
+++ b/share/man/man9/minor.9
@@ -0,0 +1,55 @@
+.\"
+.\" 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 July 9, 2001
+.Dt MINOR 9
+.Os
+.Sh NAME
+.Nm minor
+.Nd "Returns the minor number for the device"
+.Sh SYNOPSIS
+.Fd #include <sys/systm.h>
+.Ft int
+.Fo minor
+.Fa "dev_t dev"
+.Fc
+.Sh DESCRIPTION
+The
+.Nm
+function returns the minor device number for the given device.
+.Pp
+Its argument is: 
+.Bl -tag
+.It Ar dev
+The device whose minor device number should be returned.
+.Sh RETURN VALUES
+An integer greater than zero, or NOUDEV if the device is invalid.
+.Sh SEE ALSO
+.Xr major 9
+.Sh AUTHORS
+This man page was written by Chad David.
diff --git a/share/man/man9/umajor.9 b/share/man/man9/umajor.9
new file mode 100644
index 0000000..56f10f6
--- /dev/null
+++ b/share/man/man9/umajor.9
@@ -0,0 +1,58 @@
+.\"
+.\" 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 July 9, 2001
+.Dt UMAJOR 9
+.Os
+.Sh NAME
+.Nm umajor
+.Nd "Returns the major number from the raw device number"
+.Sh SYNOPSIS
+.Fd #include <sys/systm.h>
+.Ft int
+.Fo umajor
+.Fa "udev_t dev"
+.Fc
+.Sh DESCRIPTION
+The
+.Nm
+function returns the major device number form the given raw device
+number.
+.Pp
+Its argument is: 
+.Bl -tag
+.It Ar dev
+The device number whose major id should be calculated and returned.
+.Sh RETURN VALUES
+An integer greater than or equal to zero.
+.Sh SEE ALSO
+.Xr uminor 9
+.Xr minor 9
+.Xr major 9
+.Sh AUTHORS
+This man page was written by Chad David.
diff --git a/share/man/man9/uminor.9 b/share/man/man9/uminor.9
new file mode 100644
index 0000000..afdeb4b
--- /dev/null
+++ b/share/man/man9/uminor.9
@@ -0,0 +1,58 @@
+.\"
+.\" 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 July 9, 2001
+.Dt UMINOR 9
+.Os
+.Sh NAME
+.Nm uminor
+.Nd "Returns the minor number from the raw device number"
+.Sh SYNOPSIS
+.Fd #include <sys/systm.h>
+.Ft int
+.Fo uminor
+.Fa "udev_t dev"
+.Fc
+.Sh DESCRIPTION
+The
+.Nm
+function returns the minor device number from the raw device number.
+.Pp
+Its argument is: 
+.Bl -tag
+.It Ar dev
+The raw device number from which the minor device number should be
+calculated.
+.Sh RETURN VALUES
+An integer greater than or equal to zero.
+.Sh SEE ALSO
+.Xr umajor 9
+.Xr major 9
+.Xr minor 9
+.Sh AUTHORS
+This man page was written by Chad David.
diff --git a/share/man/man9/vn_isdisk.9 b/share/man/man9/vn_isdisk.9
new file mode 100644
index 0000000..c0953cc
--- /dev/null
+++ b/share/man/man9/vn_isdisk.9
@@ -0,0 +1,63 @@
+.\"
+.\" 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 July 9, 2001
+.Dt VN_ISDISK 9
+.Os
+.Sh NAME
+.Nm vn_isdisk
+.Nd "Checks if the vnode represents a disk"
+.Sh SYNOPSIS
+.Fd #include <sys/vnode.h>
+.Ft int
+.Fo vn_isdisk
+.Fa "struct vnode *vp"
+.Fa "int *errp"
+.Fc
+.Sh DESCRIPTION
+The
+.Nm
+function checks to see if the vnode represents a disk.
+In order for the vnode to be a disk it must be a character
+device, v_rdev must be valid, and the cdevsw entrys flags
+must have D_DISK set.
+.Pp
+Its arguments are:
+.Bl -tag errp
+.It Ar vp
+The vnode to check.
+.It Ar errp
+A integer pointer to store the error number in if the call fails. 
+.El
+.Sh RETURN VALUES
+If the vnode represents a disk one is returned; otherwise, zero
+is returned and
+.Ar errp
+will contain the error number.
+.Sh AUTHORS
+This man page was written by Chad David.