VREF (9)

Leading comments

Copyright (c) 1996 Doug Rabson

All rights reserved.

This program is free software.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
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1. Redistributions of source code must retain the above copyright
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2. Redistributions in binary form must reproduce the above copyright
   notice, this list of conditions and the following disclaimer in...

(The comments found at the beginning of the groff file "man9/VREF.9freebsd".)

NAME

vref - increment the use count for a vnode

SYNOPSIS

In sys/param.h In sys/vnode.h Ft void Fn vref struct vnode *vp

DESCRIPTION

Increment the v_usecount field of a vnode.

Fa vp

the vnode to increment

Each vnode maintains a reference count of how many parts of the system are using the vnode. This allows the system to detect when a vnode is no longer being used and can be safely recycled for a different file.

Any code in the system which is using a vnode (e.g. during the operation of some algorithm or to store in a data structure) should call Fn vref .

SEE ALSO

vget(9), vnode(9), vput(9), vrefcnt(9), vrele(9)

AUTHORS

This manual page was written by An Doug Rabson .