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Be a little closer to current reality.

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phk 1997-10-11 07:39:45 +00:00
parent 48ec947acb
commit bd3b9b08a8
1 changed files with 42 additions and 21 deletions
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63
share/man/man9/vnode.9
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@ -26,7 +26,7 @@
.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
.\"
.\" $Id: vnode.9,v 1.2 1997/03/22 22:47:31 mpp Exp $
.\" $Id: vnode.9,v 1.3 1997/04/13 14:49:11 bde Exp $
.\"
.Dd July 24, 1996
.Os
@ -104,39 +104,60 @@ struct vnode {
/*
* Vnode flags.
*/
#define VROOT 0x0001 /* root of its file system */
#define VTEXT 0x0002 /* vnode is a pure text prototype */
#define VSYSTEM 0x0004 /* vnode being used by kernel */
#define VOLOCK 0x0008 /* vnode is locked waiting for an object */
#define VOWANT 0x0010 /* a process is waiting for VOLOCK */
#define VXLOCK 0x0100 /* vnode is locked to change underlying type */
#define VXWANT 0x0200 /* process is waiting for vnode */
#define VBWAIT 0x0400 /* waiting for output to complete */
#define VALIASED 0x0800 /* vnode has an alias */
#define VDIROP 0x1000 /* LFS: vnode is involved in a directory op */
#define VVMIO 0x2000 /* VMIO flag */
#define VNINACT 0x4000 /* LFS: skip ufs_inactive() in lfs_vunref */
#define VAGE 0x8000 /* Insert vnode at head of free list */
#define VROOT 0x00001 /* root of its file system */
#define VTEXT 0x00002 /* vnode is a pure text prototype */
#define VSYSTEM 0x00004 /* vnode being used by kernel */
#define VOLOCK 0x00008 /* vnode is locked waiting for an object */
#define VOWANT 0x00010 /* a process is waiting for VOLOCK */
#define VXLOCK 0x00100 /* vnode is locked to change underlying type */
#define VXWANT 0x00200 /* process is waiting for vnode */
#define VBWAIT 0x00400 /* waiting for output to complete */
#define VALIASED 0x00800 /* vnode has an alias */
#define VDIROP 0x01000 /* LFS: vnode is involved in a directory op */
#define VVMIO 0x02000 /* VMIO flag */
#define VNINACT 0x04000 /* LFS: skip ufs_inactive() in lfs_vunref */
#define VAGE 0x08000 /* Insert vnode at head of free list */
#define VOLOCK 0x10000 /* vnode is locked waiting for an object */
#define VOWANT 0x20000 /* a process is waiting for VOLOCK */
#define VDOOMED 0x40000 /* This vnode is being recycled */
#define VFREE 0x80000 /* This vnode is on the freelist */
.Ed
.Sh DESCRIPTION
The vnode is the focus of all file activity in UNIX. There is a
unique vnode allocated for each active file, each current directory,
each mounted-on file, text file, and the root.
.Pp
Each vnode has two reference counts,
.Dv v_usecount
Each vnode has three reference counts,
.Dv v_usecount ,
.Dv v_holdcnt
and
.Dv v_writecount .
The first is the number of clients within the kernel which are
using this vnode. This count is maintained by
.Xr vref 9 ,
.Xr vrele 9 and
.Xr vrele 9
and
.Xr vput 9 .
When the
The second is the number of clients withing the kernel who veto
the recycling of this vnode. This count is
maintained by
.Xr vhold 9
and
.Xr vdrop 9 .
When both the
.Dv v_usecount
of a vnode reaches zero then the vnode may be reused for another
file, possibly in another filesystem.
The second is a count of the number of clients which are writing into
and the
.Dv v_holdcnt
of a vnode reaches zero then the vnode will be put on the freelist
and may be reused for another file, possibly in another filesystem.
The transistion to and from the freelist is handled by
.Xr getnetvnode 9 ,
.Xr vfree 9
and
.Xr vbusy 9 .
The third is a count of the number of clients which are writing into
the file. It is maintained by the
.Xr open 2
and