DAFS: Do not VDeregisterVolOp_r while exclusive

We should wait for a volume to transition out of an exclusive state
before calling VDeregisterVolOp_r on a volume, since some code may be
examining the vol op outside of VOL_LOCK in an exclusive state. We
should be doing this anyway before performing volume state checks,
since we may be trying to e.g. attach the volume at the same time.

Change-Id: I3a5b78b7c0033887a973ce941ced592df8c4bf3d
Reviewed-on: http://gerrit.openafs.org/4287
Tested-by: Andrew Deason <adeason@sinenomine.net>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@dementia.org>

diff --git a/src/vol/fssync-server.c b/src/vol/fssync-server.c
index bec018dcae0b3aeaf1c9d9a2be45850cd7e1b894..4126afd8c522d8e5ca3a634ad26cffa8dc2808d8 100644 (file)
--- a/src/vol/fssync-server.c
+++ b/src/vol/fssync-server.c
@@ -727,6 +727,10 @@ FSYNC_com_VolOn(FSSYNC_VolOp_command * vcom, SYNC_response * res)
     if (vcom->hdr->command == FSYNC_VOL_LEAVE_OFF) {
        /* nothing much to do if we're leaving the volume offline */
 #ifdef AFS_DEMAND_ATTACH_FS
+       if (vp) {
+           VCreateReservation_r(vp);
+           VWaitExclusiveState_r(vp);
+       }
        if (vp && V_attachState(vp) != VOL_STATE_DELETED) {
            if (FSYNC_partMatch(vcom, vp, 1)) {
                if ((V_attachState(vp) == VOL_STATE_UNATTACHED) ||
@@ -745,6 +749,11 @@ FSYNC_com_VolOn(FSSYNC_VolOp_command * vcom, SYNC_response * res)
            code = SYNC_FAILED;
            res->hdr.reason = FSYNC_UNKNOWN_VOLID;
        }
+
+       if (vp) {
+           VCancelReservation_r(vp);
+           vp = NULL;
+       }
 #endif
        goto done;
     }
@@ -755,7 +764,11 @@ FSYNC_com_VolOn(FSSYNC_VolOp_command * vcom, SYNC_response * res)
                                vcom->vop->partName,
                                vcom->vop->volume);
     if (vp) {
+       VCreateReservation_r(vp);
+       VWaitExclusiveState_r(vp);
        VDeregisterVolOp_r(vp);
+       VCancelReservation_r(vp);
+       vp = NULL;
     }
 #else /* !AFS_DEMAND_ATTACH_FS */
     tvolName[0] = OS_DIRSEPC;
@@ -1059,15 +1072,18 @@ FSYNC_com_VolOff(FSSYNC_VolOp_command * vcom, SYNC_response * res)
            }
 
 #ifdef AFS_DEMAND_ATTACH_FS
+           VCreateReservation_r(vp);
             VOfflineForVolOp_r(&error, vp, "A volume utility is running.");
             if (error==0) {
                 osi_Assert(vp->nUsers==0);
                 vp->pending_vol_op->vol_op_state = FSSYNC_VolOpRunningOffline;
             }
             else {
+               VWaitExclusiveState_r(vp);
                VDeregisterVolOp_r(vp);
                 code = SYNC_DENIED;
             }
+           VCancelReservation_r(vp);
 #else
            VOffline_r(vp, "A volume utility is running.");
 #endif
@@ -1218,6 +1234,9 @@ FSYNC_com_VolDone(FSSYNC_VolOp_command * vcom, SYNC_response * res)
     if (vp) {
        if (FSYNC_partMatch(vcom, vp, 1)) {
 #ifdef AFS_DEMAND_ATTACH_FS
+           VCreateReservation_r(vp);
+           VWaitExclusiveState_r(vp);
+
            if ((V_attachState(vp) == VOL_STATE_UNATTACHED) ||
                (V_attachState(vp) == VOL_STATE_PREATTACHED) ||
                VIsErrorState(V_attachState(vp))) {
@@ -1239,6 +1258,9 @@ FSYNC_com_VolDone(FSSYNC_VolOp_command * vcom, SYNC_response * res)
                code = SYNC_DENIED;
                res->hdr.reason = FSYNC_BAD_STATE;
            }
+
+           VCancelReservation_r(vp);
+           vp = NULL;
 #else /* AFS_DEMAND_ATTACH_FS */
            if (!vp->specialStatus) {
                vp->specialStatus = VNOVOL;
@@ -1317,6 +1339,9 @@ FSYNC_com_VolError(FSSYNC_VolOp_command * vcom, SYNC_response * res)
        if (FSYNC_partMatch(vcom, vp, 0)) {
            /* null out salvsync control state, as it's no longer relevant */
            memset(&vp->salvage, 0, sizeof(vp->salvage));
+
+           VCreateReservation_r(vp);
+           VWaitExclusiveState_r(vp);
             VDeregisterVolOp_r(vp);
 
             if (vcom->hdr->reason == FSYNC_SALVAGE) {
@@ -1325,6 +1350,9 @@ FSYNC_com_VolError(FSSYNC_VolOp_command * vcom, SYNC_response * res)
                VChangeState_r(vp, VOL_STATE_ERROR);
             }
 
+           VCancelReservation_r(vp);
+           vp = NULL;
+
            code = SYNC_OK;
        } else {
            res->hdr.reason = FSYNC_WRONG_PART;