windows-freelance-deadlock-20080809

[openafs.git] / src / WINNT / afsd / cm_scache.c

diff --git a/src/WINNT/afsd/cm_scache.c b/src/WINNT/afsd/cm_scache.c
index 9e6d17c..5b7b521 100644 (file)
--- a/src/WINNT/afsd/cm_scache.c
+++ b/src/WINNT/afsd/cm_scache.c
@@ -45,21 +45,20 @@ extern osi_mutex_t cm_Freelance_Lock;
 /* must be called with cm_scacheLock write-locked! */
 void cm_AdjustScacheLRU(cm_scache_t *scp)
 {
-    if (scp == cm_data.scacheLRULastp)
-        cm_data.scacheLRULastp = (cm_scache_t *) osi_QPrev(&scp->q);
+    lock_AssertWrite(&cm_scacheLock);
     osi_QRemoveHT((osi_queue_t **) &cm_data.scacheLRUFirstp, (osi_queue_t **) &cm_data.scacheLRULastp, &scp->q);
-    osi_QAdd((osi_queue_t **) &cm_data.scacheLRUFirstp, &scp->q);
-    if (!cm_data.scacheLRULastp) 
-        cm_data.scacheLRULastp = scp;
+    osi_QAddH((osi_queue_t **) &cm_data.scacheLRUFirstp, (osi_queue_t **) &cm_data.scacheLRULastp, &scp->q);
 }
 
-/* call with scache write-locked and mutex held */
+/* call with cm_scacheLock write-locked and scp rw held */
 void cm_RemoveSCacheFromHashTable(cm_scache_t *scp)
 {
     cm_scache_t **lscpp;
     cm_scache_t *tscp;
     int i;
        
+    lock_AssertWrite(&cm_scacheLock);
+    lock_AssertWrite(&scp->rw);
     if (scp->flags & CM_SCACHEFLAG_INHASH) {
        /* hash it out first */
        i = CM_SCACHE_HASH(&scp->fid);
@@ -68,6 +67,7 @@ void cm_RemoveSCacheFromHashTable(cm_scache_t *scp)
             lscpp = &tscp->nextp, tscp = tscp->nextp) {
            if (tscp == scp) {
                *lscpp = scp->nextp;
+                scp->nextp = NULL;
                scp->flags &= ~CM_SCACHEFLAG_INHASH;
                break;
            }
@@ -93,7 +93,9 @@ long cm_RecycleSCache(cm_scache_t *scp, afs_int32 flags)
        return -1;
     }
 
+    lock_ObtainWrite(&scp->rw);
     cm_RemoveSCacheFromHashTable(scp);
+    lock_ReleaseWrite(&scp->rw);
 
 #if 0
     if (flags & CM_SCACHE_RECYCLEFLAG_DESTROY_BUFFERS) {
@@ -232,6 +234,7 @@ cm_scache_t *cm_GetNewSCache(void)
     cm_scache_t *scp;
     int retry = 0;
 
+    lock_AssertWrite(&cm_scacheLock);
 #if 0
     /* first pass - look for deleted objects */
     for ( scp = cm_data.scacheLRULastp;
@@ -701,13 +704,12 @@ long cm_GetSCache(cm_fid_t *fidp, cm_scache_t **outScpp, cm_user_t *userp,
         char mp[MOUNTPOINTLEN] = "";
         afs_uint32 fileType;
 
+        lock_ReleaseWrite(&cm_scacheLock);
         osi_Log0(afsd_logp,"cm_GetSCache Freelance and special");
 
         if (cm_getLocalMountPointChange()) {   // check for changes
             cm_clearLocalMountPointChange();    // clear the changefile
-                   lock_ReleaseWrite(&cm_scacheLock);
             cm_reInitLocalMountPoints();       // start reinit
-                       lock_ObtainWrite(&cm_scacheLock);
         }
 
         lock_ObtainMutex(&cm_Freelance_Lock);
@@ -723,7 +725,7 @@ long cm_GetSCache(cm_fid_t *fidp, cm_scache_t **outScpp, cm_user_t *userp,
 
         }
         lock_ReleaseMutex(&cm_Freelance_Lock);
-
+        lock_ObtainWrite(&cm_scacheLock);
         if (scp == NULL)
             scp = cm_GetNewSCache();
        if (scp == NULL) {
@@ -749,8 +751,8 @@ long cm_GetSCache(cm_fid_t *fidp, cm_scache_t **outScpp, cm_user_t *userp,
         scp->dotdotFid.vnode=1;
         scp->flags |= (CM_SCACHEFLAG_PURERO | CM_SCACHEFLAG_RO);
         if (!(scp->flags & CM_SCACHEFLAG_INHASH)) {
-            scp->nextp=cm_data.scacheHashTablep[hash];
-            cm_data.scacheHashTablep[hash]=scp;
+            scp->nextp = cm_data.scacheHashTablep[hash];
+            cm_data.scacheHashTablep[hash] = scp;
             scp->flags |= CM_SCACHEFLAG_INHASH;
         }
         scp->refCount = 1;
@@ -1042,6 +1044,9 @@ long cm_SyncOp(cm_scache_t *scp, cm_buf_t *bufp, cm_user_t *userp, cm_req_t *req
     afs_uint32 sleep_buf_cmflags = 0;
     afs_uint32 sleep_scp_bufs = 0;
     int wakeupCycle;
+    int getAccessRights = 1;
+
+    lock_AssertWrite(&scp->rw);
 
     /* lookup this first */
     bufLocked = flags & CM_SCACHESYNC_BUFLOCKED;
@@ -1241,10 +1246,10 @@ long cm_SyncOp(cm_scache_t *scp, cm_buf_t *bufp, cm_user_t *userp, cm_req_t *req
             /* can't check access rights without a callback */
             osi_assertx(flags & CM_SCACHESYNC_NEEDCALLBACK, "!CM_SCACHESYNC_NEEDCALLBACK");
 
-            if ((rights & PRSFS_WRITE) && (scp->flags & CM_SCACHEFLAG_RO))
+            if ((rights & (PRSFS_WRITE|PRSFS_DELETE)) && (scp->flags & CM_SCACHEFLAG_RO))
                 return CM_ERROR_READONLY;
 
-            if (cm_HaveAccessRights(scp, userp, rights, &outRights)) {
+            if (cm_HaveAccessRights(scp, userp, rights, &outRights) || !getAccessRights) {
                 if (~outRights & rights) 
                    return CM_ERROR_NOACCESS;
             }
@@ -1259,6 +1264,7 @@ long cm_SyncOp(cm_scache_t *scp, cm_buf_t *bufp, cm_user_t *userp, cm_req_t *req
                 }
                 if (code) 
                     return code;
+                getAccessRights = 0;    /* do not repeat */
                 continue;
             }
         }
@@ -1722,6 +1728,13 @@ void cm_MergeStatus(cm_scache_t *dscp,
         scp->bufDataVersionLow = dataVersion;
     
     scp->dataVersion = dataVersion;
+
+    /* 
+     * If someone is waiting for status information, we can wake them up
+     * now even though the entity that issued the FetchStatus may not 
+     * have completed yet.
+     */
+    cm_SyncOpDone(scp, NULL, CM_SCACHESYNC_FETCHSTATUS);
 }
 
 /* note that our stat cache info is incorrect, so force us eventually
@@ -1801,8 +1814,12 @@ void cm_ReleaseSCacheNoLock(cm_scache_t *scp)
 #endif
 {
     afs_int32 refCount;
+    long      lockstate;
+
     osi_assertx(scp != NULL, "null cm_scache_t");
     lock_AssertAny(&cm_scacheLock);
+
+    lockstate = lock_GetRWLockState(&cm_scacheLock);
     refCount = InterlockedDecrement(&scp->refCount);
 #ifdef DEBUG_REFCOUNT
     if (refCount < 0)
@@ -1813,6 +1830,20 @@ void cm_ReleaseSCacheNoLock(cm_scache_t *scp)
     osi_Log2(afsd_logp,"cm_ReleaseSCacheNoLock scp 0x%p ref %d",scp, refCount);
     afsi_log("%s:%d cm_ReleaseSCacheNoLock scp 0x%p ref %d", file, line, scp, refCount);
 #endif
+
+    if (refCount == 0 && (scp->flags & CM_SCACHEFLAG_DELETED)) {
+        int deleted = 0;
+        if (lockstate != OSI_RWLOCK_WRITEHELD) 
+            lock_ConvertRToW(&cm_scacheLock);
+        lock_ObtainWrite(&scp->rw);
+        if (scp->flags & CM_SCACHEFLAG_DELETED)
+            deleted = 1;
+        lock_ReleaseWrite(&scp->rw);
+        if (refCount == 0 && deleted)
+            cm_RecycleSCache(scp, 0);
+        if (lockstate != OSI_RWLOCK_WRITEHELD) 
+            lock_ConvertWToR(&cm_scacheLock);
+    }
 }
 
 #ifdef DEBUG_REFCOUNT
@@ -1835,6 +1866,20 @@ void cm_ReleaseSCache(cm_scache_t *scp)
     osi_Log2(afsd_logp,"cm_ReleaseSCache scp 0x%p ref %d",scp, refCount);
     afsi_log("%s:%d cm_ReleaseSCache scp 0x%p ref %d", file, line, scp, refCount);
 #endif
+
+    if (scp->flags & CM_SCACHEFLAG_DELETED) {
+        int deleted = 0;
+        lock_ObtainWrite(&scp->rw);
+        if (scp->flags & CM_SCACHEFLAG_DELETED)
+            deleted = 1;
+        lock_ReleaseWrite(&scp->rw);
+        if (deleted) {
+            lock_ConvertRToW(&cm_scacheLock);
+            cm_RecycleSCache(scp, 0);
+            lock_ConvertWToR(&cm_scacheLock);
+        }
+    }
+
     lock_ReleaseRead(&cm_scacheLock);
 }