svn commit: r202528 - in head/sys: kern sys
Konstantin Belousov
kib at FreeBSD.org
Sun Jan 17 21:24:28 UTC 2010
Author: kib
Date: Sun Jan 17 21:24:27 2010
New Revision: 202528
URL: http://svn.freebsd.org/changeset/base/202528
Log:
Add new function vunref(9) that decrements vnode use count (and hold
count) while vnode is exclusively locked.
The code for vput(9), vrele(9) and vunref(9) is merged.
In collaboration with: pho
Reviewed by: alc
MFC after: 3 weeks
Modified:
head/sys/kern/vfs_subr.c
head/sys/sys/vnode.h
Modified: head/sys/kern/vfs_subr.c
==============================================================================
--- head/sys/kern/vfs_subr.c Sun Jan 17 21:00:29 2010 (r202527)
+++ head/sys/kern/vfs_subr.c Sun Jan 17 21:24:27 2010 (r202528)
@@ -2149,37 +2149,44 @@ vrefcnt(struct vnode *vp)
return (usecnt);
}
+#define VPUTX_VRELE 1
+#define VPUTX_VPUT 2
+#define VPUTX_VUNREF 3
-/*
- * Vnode put/release.
- * If count drops to zero, call inactive routine and return to freelist.
- */
-void
-vrele(struct vnode *vp)
+static void
+vputx(struct vnode *vp, int func)
{
- struct thread *td = curthread; /* XXX */
+ int error;
- KASSERT(vp != NULL, ("vrele: null vp"));
+ KASSERT(vp != NULL, ("vputx: null vp"));
+ if (func == VPUTX_VUNREF)
+ ASSERT_VOP_ELOCKED(vp, "vunref");
+ else if (func == VPUTX_VPUT)
+ ASSERT_VOP_LOCKED(vp, "vput");
+ else
+ KASSERT(func == VPUTX_VRELE, ("vputx: wrong func"));
VFS_ASSERT_GIANT(vp->v_mount);
-
+ CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
VI_LOCK(vp);
/* Skip this v_writecount check if we're going to panic below. */
VNASSERT(vp->v_writecount < vp->v_usecount || vp->v_usecount < 1, vp,
- ("vrele: missed vn_close"));
- CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
+ ("vputx: missed vn_close"));
+ error = 0;
if (vp->v_usecount > 1 || ((vp->v_iflag & VI_DOINGINACT) &&
vp->v_usecount == 1)) {
+ if (func == VPUTX_VPUT)
+ VOP_UNLOCK(vp, 0);
v_decr_usecount(vp);
return;
}
+
if (vp->v_usecount != 1) {
#ifdef DIAGNOSTIC
- vprint("vrele: negative ref count", vp);
+ vprint("vputx: negative ref count", vp);
#endif
- VI_UNLOCK(vp);
- panic("vrele: negative ref cnt");
+ panic("vputx: negative ref cnt");
}
CTR2(KTR_VFS, "%s: return vnode %p to the freelist", __func__, vp);
/*
@@ -2193,22 +2200,36 @@ vrele(struct vnode *vp)
* as VI_DOINGINACT to avoid recursion.
*/
vp->v_iflag |= VI_OWEINACT;
- if (vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK) == 0) {
+ if (func == VPUTX_VRELE) {
+ error = vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK);
VI_LOCK(vp);
- if (vp->v_usecount > 0)
- vp->v_iflag &= ~VI_OWEINACT;
- if (vp->v_iflag & VI_OWEINACT)
- vinactive(vp, td);
- VOP_UNLOCK(vp, 0);
- } else {
+ } else if (func == VPUTX_VPUT && VOP_ISLOCKED(vp) != LK_EXCLUSIVE) {
+ error = VOP_LOCK(vp, LK_UPGRADE | LK_INTERLOCK | LK_NOWAIT);
VI_LOCK(vp);
- if (vp->v_usecount > 0)
- vp->v_iflag &= ~VI_OWEINACT;
+ }
+ if (vp->v_usecount > 0)
+ vp->v_iflag &= ~VI_OWEINACT;
+ if (error == 0) {
+ if (vp->v_iflag & VI_OWEINACT)
+ vinactive(vp, curthread);
+ if (func != VPUTX_VUNREF)
+ VOP_UNLOCK(vp, 0);
}
vdropl(vp);
}
/*
+ * Vnode put/release.
+ * If count drops to zero, call inactive routine and return to freelist.
+ */
+void
+vrele(struct vnode *vp)
+{
+
+ vputx(vp, VPUTX_VRELE);
+}
+
+/*
* Release an already locked vnode. This give the same effects as
* unlock+vrele(), but takes less time and avoids releasing and
* re-aquiring the lock (as vrele() acquires the lock internally.)
@@ -2216,56 +2237,18 @@ vrele(struct vnode *vp)
void
vput(struct vnode *vp)
{
- struct thread *td = curthread; /* XXX */
- int error;
- KASSERT(vp != NULL, ("vput: null vp"));
- ASSERT_VOP_LOCKED(vp, "vput");
- VFS_ASSERT_GIANT(vp->v_mount);
- CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
- VI_LOCK(vp);
- /* Skip this v_writecount check if we're going to panic below. */
- VNASSERT(vp->v_writecount < vp->v_usecount || vp->v_usecount < 1, vp,
- ("vput: missed vn_close"));
- error = 0;
+ vputx(vp, VPUTX_VPUT);
+}
- if (vp->v_usecount > 1 || ((vp->v_iflag & VI_DOINGINACT) &&
- vp->v_usecount == 1)) {
- VOP_UNLOCK(vp, 0);
- v_decr_usecount(vp);
- return;
- }
+/*
+ * Release an exclusively locked vnode. Do not unlock the vnode lock.
+ */
+void
+vunref(struct vnode *vp)
+{
- if (vp->v_usecount != 1) {
-#ifdef DIAGNOSTIC
- vprint("vput: negative ref count", vp);
-#endif
- panic("vput: negative ref cnt");
- }
- CTR2(KTR_VFS, "%s: return to freelist the vnode %p", __func__, vp);
- /*
- * We want to hold the vnode until the inactive finishes to
- * prevent vgone() races. We drop the use count here and the
- * hold count below when we're done.
- */
- v_decr_useonly(vp);
- vp->v_iflag |= VI_OWEINACT;
- if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) {
- error = VOP_LOCK(vp, LK_UPGRADE|LK_INTERLOCK|LK_NOWAIT);
- VI_LOCK(vp);
- if (error) {
- if (vp->v_usecount > 0)
- vp->v_iflag &= ~VI_OWEINACT;
- goto done;
- }
- }
- if (vp->v_usecount > 0)
- vp->v_iflag &= ~VI_OWEINACT;
- if (vp->v_iflag & VI_OWEINACT)
- vinactive(vp, td);
- VOP_UNLOCK(vp, 0);
-done:
- vdropl(vp);
+ vputx(vp, VPUTX_VUNREF);
}
/*
Modified: head/sys/sys/vnode.h
==============================================================================
--- head/sys/sys/vnode.h Sun Jan 17 21:00:29 2010 (r202527)
+++ head/sys/sys/vnode.h Sun Jan 17 21:24:27 2010 (r202528)
@@ -632,6 +632,7 @@ void vholdl(struct vnode *);
int vinvalbuf(struct vnode *vp, int save, int slpflag, int slptimeo);
int vtruncbuf(struct vnode *vp, struct ucred *cred, struct thread *td,
off_t length, int blksize);
+void vunref(struct vnode *);
void vn_printf(struct vnode *vp, const char *fmt, ...) __printflike(2,3);
#define vprint(label, vp) vn_printf((vp), "%s\n", (label))
int vrecycle(struct vnode *vp, struct thread *td);
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