From: Tom Keiser <tkeiser@sinenomine.net>
Date: Mon, 14 Jul 2008 14:37:58 +0000 (+0000)
Subject: dafs-avoid-assert-while-moving-volumes-20080714
X-Git-Tag: openafs-devel-1_5_61~967
X-Git-Url: https://git.michaelhowe.org/gitweb/?a=commitdiff_plain;h=5c762d3b7672a88fcf4df85e919ac11be7946d4f;p=packages%2Fo%2Fopenafs.git

dafs-avoid-assert-while-moving-volumes-20080714

LICENSE IPL10

The volume state is perfectly consistent. FSYNC_NEEDVOLUME (and the
other state in the pending_vol_op object) is perfectly normal -- it
simply means the volser has exclusive access to the volume for the
purposes of cloning. The bug is that during the DAFS development, I
changed the semantics of the VGetVolume interface without updating the
control logic in afsfileprocs accordingly:

In 1_4_x:
vp->specialstatus != 0 results in returning vp with nUsers incremented
and *ec = vp->sepcialstatus

In DAFS:
V_AttachState(vp) == VOL_STATE_UNATTACHED results in returning a NULL
vp. Since (vp->specialstatus != 0), *ec = vp->specialstatus.

The net result is we need to modify the VBUSY logic in CheckVnode().
---

diff --git a/src/viced/afsfileprocs.c b/src/viced/afsfileprocs.c
index 09385c5ac..2af9cd17e 100644
--- a/src/viced/afsfileprocs.c
+++ b/src/viced/afsfileprocs.c
@@ -559,6 +559,14 @@ CheckVnode(AFSFid * fid, Volume ** volptr, Vnode ** vptr, int lock)
 	     * must check local_errorCode because demand attach fs
 	     * can have local_errorCode == VSALVAGING, errorCode == VBUSY */
 	    else if (local_errorCode == VBUSY && lock == READ_LOCK) {
+#ifdef AFS_DEMAND_ATTACH_FS
+		/* DAFS case is complicated by the fact that local_errorCode can
+		 * be VBUSY in cases where the volume is truly offline */
+		if (!*volptr) {
+		    /* volume is in VOL_STATE_UNATTACHED */
+		    return (errorCode);
+		}
+#endif /* AFS_DEMAND_ATTACH_FS */
 		errorCode = 0;
 		break;
 	    } else if (errorCode)