Module Name: src
Committed By: riastradh
Date: Mon Apr 20 14:03:10 UTC 2015
Modified Files:
src/share/man/man9: vnode.9
Log Message:
Document current state of vget.
To generate a diff of this commit:
cvs rdiff -u -r1.61 -r1.62 src/share/man/man9/vnode.9
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/share/man/man9/vnode.9
diff -u src/share/man/man9/vnode.9:1.61 src/share/man/man9/vnode.9:1.62
--- src/share/man/man9/vnode.9:1.61 Mon Mar 24 13:42:40 2014
+++ src/share/man/man9/vnode.9 Mon Apr 20 14:03:10 2015
@@ -1,4 +1,4 @@
-.\" $NetBSD: vnode.9,v 1.61 2014/03/24 13:42:40 hannken Exp $
+.\" $NetBSD: vnode.9,v 1.62 2015/04/20 14:03:10 riastradh Exp $
.\"
.\" Copyright (c) 2001, 2005, 2006 The NetBSD Foundation, Inc.
.\" All rights reserved.
@@ -27,7 +27,7 @@
.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
.\" POSSIBILITY OF SUCH DAMAGE.
.\"
-.Dd March 24, 2014
+.Dd April 20, 2015
.Dt VNODE 9
.Os
.Sh NAME
@@ -67,7 +67,7 @@
.Ft void
.Fn vrele_async "struct vnode *vp"
.Ft int
-.Fn vget "struct vnode *vp" "int lockflag"
+.Fn vget "struct vnode *vp" "int lockflag" "int wait"
.Ft void
.Fn vput "struct vnode *vp"
.Ft void
@@ -527,27 +527,60 @@ are zero, the vnode is placed on the fre
.It Fn vrele_async "vp"
Will asychronously release the vnode in different context than the caller,
sometime after the call.
-.It Fn vget "vp" "lockflags"
+.It Fn vget "vp" "lockflags" "wait"
Reclaim vnode
.Fa vp
-from the freelist, increment its reference count and lock it.
-The argument
+from the freelist and increment its reference count.
+.Pp
+The vnode
+.Fa vp
+may be changing state: another thread may be initializing it from disk,
+or revoking it with
+.Xr revoke 2 ,
+or reclaiming it with
+.Xr VOP_RECLAIM 9 .
+In that case,
+.Fn vget
+will wait until the state has changed, if
.Fa lockflags
-specifies the
-.Xr rwlock 9
-flags used to lock the vnode.
-If the
-.Dv VI_XLOCK
-flag is set in
-.Fa vp Ns 's
-.Em v_flag ,
-vnode
-.Fa vp
-is being recycled in
-.Fn vgone
-and the calling thread sleeps until the transition is complete.
-When it is awakened, an error is returned to indicate that the vnode is
-no longer usable.
+is
+.Li 0
+and
+.Fa wait
+is
+.Li true ;
+or will return
+.Dv EBUSY
+if
+.Fa lockflags
+is
+.Dv LK_NOWAIT
+and
+.Fa wait
+is
+.Li false .
+.Pp
+(The extra argument enables the compiler to detect old code which
+additionally used
+.Fn vget
+to lock the vnode.)
+.Pp
+Returns
+.Bl -tag -offset abcd -width ENOENT -compact
+.It Li EBUSY
+if
+.Fa vp
+was changing state and
+.Fa wait
+is false,
+.It Li ENOENT
+if the system was reclaiming
+.Fa vp
+with
+.Xr VOP_RECLAIM 9 .
+.It Li 0
+on success.
+.El
.It Fn vput "vp"
Unlock vnode
.Fa vp
