[src/trunk]: src/sys/netsmb clarify locking requirements for smb_{share, vc, co...

[jdolecek <jdolecek%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/39307d93d496
branches:  trunk
changeset: 543392:39307d93d496
user:      jdolecek <jdolecek%NetBSD.org@localhost>
date:      Mon Feb 24 09:55:37 2003 +0000

description:
clarify locking requirements for smb_{share,vc,co}_{rele,put}() - the lock
must be held on entry
drain the lock in smb_co_gone(), so that it's done always
turn some SMBERROR()s to #ifdef DIAGNOSTIC/DEBUG panics

diffstat:

 sys/netsmb/smb_conn.c |  49 ++++++++++++++++++++++++-------------------------
 sys/netsmb/smb_dev.c  |  10 +++++++---
 2 files changed, 31 insertions(+), 28 deletions(-)

diffs (159 lines):

diff -r 1543e793f842 -r 39307d93d496 sys/netsmb/smb_conn.c
--- a/sys/netsmb/smb_conn.c     Mon Feb 24 09:30:42 2003 +0000
+++ b/sys/netsmb/smb_conn.c     Mon Feb 24 09:55:37 2003 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: smb_conn.c,v 1.5 2003/02/18 10:16:49 jdolecek Exp $    */
+/*     $NetBSD: smb_conn.c,v 1.6 2003/02/24 09:55:37 jdolecek Exp $    */
 
 /*
  * Copyright (c) 2000-2001 Boris Popov
@@ -35,7 +35,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: smb_conn.c,v 1.5 2003/02/18 10:16:49 jdolecek Exp $");
+__KERNEL_RCSID(0, "$NetBSD: smb_conn.c,v 1.6 2003/02/24 09:55:37 jdolecek Exp $");
 
 /*
  * Connection engine.
@@ -67,7 +67,7 @@
 
 MALLOC_DEFINE(M_SMBCONN, "SMB conn", "SMB connection");
 
-static void smb_co_init(struct smb_connobj *cp, int level, char *objname);
+static void smb_co_init(struct smb_connobj *cp, int level, const char *objname);
 static void smb_co_done(struct smb_connobj *cp);
 static int  smb_co_lockstatus(struct smb_connobj *cp);
 
@@ -98,10 +98,10 @@
 {
 
        /* XXX: hold the mutex */
-       if (smb_vclist.co_usecount > 1) {
-               SMBERROR("%d connections still active\n", smb_vclist.co_usecount - 1);
-               return EBUSY;
-       }
+#ifdef DIAGNOSTIC
+       if (smb_vclist.co_usecount > 1)
+               panic("%d connections still active\n", smb_vclist.co_usecount - 1);
+#endif
        smb_co_done(&smb_vclist);
        return 0;
 }
@@ -226,7 +226,7 @@
  * Common code for connection object
  */
 static void
-smb_co_init(struct smb_connobj *cp, int level, char *objname)
+smb_co_init(struct smb_connobj *cp, int level, const char *objname)
 {
        SLIST_INIT(&cp->co_children);
        smb_sl_init(&cp->co_interlock, objname);
@@ -240,7 +240,9 @@
 smb_co_done(struct smb_connobj *cp)
 {
        smb_sl_destroy(&cp->co_interlock);
-#ifndef __NetBSD__
+#ifdef __NetBSD__
+       lockmgr(&cp->co_lock, LK_DRAIN, NULL);
+#else
        lockdestroy(&cp->co_lock);
 #endif
 }
@@ -275,20 +277,19 @@
 smb_co_rele(struct smb_connobj *cp, struct smb_cred *scred)
 {
        SMB_CO_LOCK(cp);
+       lockmgr(&cp->co_lock, LK_RELEASE | LK_INTERLOCK, &cp->co_interlock);
        if (cp->co_usecount > 1) {
                cp->co_usecount--;
                SMB_CO_UNLOCK(cp);
                return;
        }
-       if (cp->co_usecount == 0) {
-               SMBERROR("negative use_count for object %d", cp->co_level);
-               SMB_CO_UNLOCK(cp);
-               return;
-       }
+#ifdef DIAGNOSTIC
+       if (cp->co_usecount == 0)
+               panic("negative use_count for object %d", cp->co_level);
+#endif
        cp->co_usecount--;
        cp->co_flags |= SMBO_GONE;
 
-       lockmgr(&cp->co_lock, LK_DRAIN | LK_INTERLOCK, &cp->co_interlock);
        smb_co_gone(cp, scred);
 }
 
@@ -313,23 +314,21 @@
 void
 smb_co_put(struct smb_connobj *cp, struct smb_cred *scred)
 {
-       int flags;
 
-       flags = LK_RELEASE;
        SMB_CO_LOCK(cp);
        if (cp->co_usecount > 1) {
                cp->co_usecount--;
        } else if (cp->co_usecount == 1) {
                cp->co_usecount--;
                cp->co_flags |= SMBO_GONE;
-               flags = LK_DRAIN;
-       } else {
-               SMBERROR("negative usecount");
        }
+#ifdef DIAGNOSTIC
+       else
+               panic("smb_co_put: negative usecount");
+#endif
        lockmgr(&cp->co_lock, LK_RELEASE | LK_INTERLOCK, &cp->co_interlock);
        if ((cp->co_flags & SMBO_GONE) == 0)
                return;
-       lockmgr(&cp->co_lock, LK_DRAIN, NULL);
        smb_co_gone(cp, scred);
 }
 
@@ -347,11 +346,11 @@
                return EINVAL;
        if ((flags & LK_TYPE_MASK) == 0)
                flags |= LK_EXCLUSIVE;
+#ifdef DEBUG
        if (smb_co_lockstatus(cp) == LK_EXCLUSIVE && 
-           (flags & LK_CANRECURSE) == 0) {
-               SMBERROR("recursive lock for object %d\n", cp->co_level);
-               return 0;
-       }
+           (flags & LK_CANRECURSE) == 0)
+               panic("recursive lock for object %d\n", cp->co_level);
+#endif
        return lockmgr(&cp->co_lock, flags, &cp->co_interlock);
 }
 
diff -r 1543e793f842 -r 39307d93d496 sys/netsmb/smb_dev.c
--- a/sys/netsmb/smb_dev.c      Mon Feb 24 09:30:42 2003 +0000
+++ b/sys/netsmb/smb_dev.c      Mon Feb 24 09:55:37 2003 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: smb_dev.c,v 1.11 2003/02/18 12:18:29 jdolecek Exp $    */
+/*     $NetBSD: smb_dev.c,v 1.12 2003/02/24 09:55:38 jdolecek Exp $    */
 
 /*
  * Copyright (c) 2000-2001 Boris Popov
@@ -231,11 +231,15 @@
        }
        smb_makescred(&scred, p, NULL);
        ssp = sdp->sd_share;
-       if (ssp != NULL)
+       if (ssp != NULL) {
+               smb_share_lock(ssp, 0);
                smb_share_rele(ssp, &scred);
+       }
        vcp = sdp->sd_vc;
-       if (vcp != NULL)
+       if (vcp != NULL) {
+               smb_vc_lock(vcp, 0);
                smb_vc_rele(vcp, &scred);
+       }
 /*
        smb_flushq(&sdp->sd_rqlist);
        smb_flushq(&sdp->sd_rplist);