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.

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>
(cherry picked from commit d4ebebd0c3f89b65e93f0da6d53665271e6d2a61)

Change-Id: I55f07806a4e089577252ddb527a86142b10f797d
Reviewed-on: http://gerrit.openafs.org/4306
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 edd0910be2f62c540a188abf46f546f76bca6840..ac09b565ff91fd1664d1bdd3753b89d95827d00d 100644 (file)
--- a/src/vol/fssync-server.c
+++ b/src/vol/fssync-server.c
@@ -728,6 +728,10 @@ 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) ||
@@ -746,6 +750,11 @@ 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;
     }
@@ -756,7 +765,11 @@ 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;
@@ -1060,15 +1073,18 @@ 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
@@ -1219,6 +1235,9 @@ 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))) {
@@ -1240,6 +1259,9 @@ 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;
@@ -1318,6 +1340,9 @@ 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) {
@@ -1326,6 +1351,9 @@ 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;