windows-scache-recycle-20060603

A deadlock was detected when performing "fs flushall" if the file
server reports VNOVNODE.   The scp->createBufferLock is already
held by the current thread and there is no mechanism to propagate
the knowledge.  Therefore, an alternate mechanism for clearing the
cache must be developed.  A new function cm_RecycleSCache(scp,flags)
has been extracted from cm_GetNewSCache().  This function performs
the task of recycling an cm_scache_t object.  When called from
cm_GetNewSCache() with no flags the expectation is that there are
no associated buffers that are queued to be read or written.  When
called from cm_Analyze() with the CM_SCACHE_RECYCLEFLAG_DESTROY_BUFFERS
flag, any queued buffers will be de-queued and marked as if the operations
were performed so the data can be discarded.

This patch also addresses the following issues:

* CM_ERROR codes were logged as "unknown" by cm_Analyze.

* In response to VNOVNODE, the parent is only discarded if the current
  cm_scache_t is not a directory.

* In the Ioctl FlushFile and FlushVolume functions, there were no
  checks to protect against flushing the Freelance SCache entries.

* In FlushFile, the wrong cm_scache_t object was being released.

* In cm_GetNewSCache, do not allow Freelance SCache entries to be
  recycled.  Choose a new entry if cm_RecycleSCache fails.

diff --git a/src/WINNT/afsd/cm_conn.c b/src/WINNT/afsd/cm_conn.c
index d9c5e42..e52d0b5 100644 (file)
--- a/src/WINNT/afsd/cm_conn.c
+++ b/src/WINNT/afsd/cm_conn.c
@@ -412,11 +412,18 @@ cm_Analyze(cm_conn_t *connp, cm_user_t *userp, cm_req_t *reqp,
            cm_scache_t * scp;
            osi_Log4(afsd_logp, "cm_Analyze passed VNOVNODE cell %u vol %u vn %u uniq %u.",
                      fidp->cell, fidp->volume, fidp->vnode, fidp->unique);
+
            scp = cm_FindSCache(fidp);
            if (scp) {
-               cm_scache_t *pscp = cm_FindSCacheParent(scp);
-               cm_CleanFile(scp, userp, reqp);
-               cm_ReleaseSCache(scp);
+               cm_scache_t *pscp = NULL;
+
+               if (scp->fileType != CM_SCACHETYPE_DIRECTORY)
+                   pscp = cm_FindSCacheParent(scp);
+
+               lock_ObtainWrite(&cm_scacheLock);
+               cm_RecycleSCache(scp, CM_SCACHE_RECYCLEFLAG_DESTROY_BUFFERS);
+               lock_ReleaseWrite(&cm_scacheLock);
+
                if (pscp) {
                    if (pscp->cbExpires > 0 && pscp->cbServerp != NULL) {
                        lock_ObtainMutex(&pscp->mx);
@@ -516,6 +523,59 @@ cm_Analyze(cm_conn_t *connp, cm_user_t *userp, cm_req_t *reqp,
            case UAEINVAL          : s = "UAEINVAL";           break;
             case EACCES            : s = "EACCES";             break;
            case UAEACCES          : s = "UAECCES";            break;
+           case ENOENT            : s = "ENOENT";             break;
+           case UAENOENT          : s = "UAENOENT";           break;
+           case CM_ERROR_NOSUCHCELL        : s = "CM_ERROR_NOSUCHCELL";         break;                         
+           case CM_ERROR_NOSUCHVOLUME      : s = "CM_ERROR_NOSUCHVOLUME";       break;                         
+           case CM_ERROR_TIMEDOUT          : s = "CM_ERROR_TIMEDOUT";           break;                 
+           case CM_ERROR_RETRY             : s = "CM_ERROR_RETRY";              break; 
+           case CM_ERROR_NOACCESS          : s = "CM_ERROR_NOACCESS";           break; 
+           case CM_ERROR_NOSUCHFILE        : s = "CM_ERROR_NOSUCHFILE";         break;                         
+           case CM_ERROR_STOPNOW           : s = "CM_ERROR_STOPNOW";            break;                         
+           case CM_ERROR_TOOBIG            : s = "CM_ERROR_TOOBIG";             break;                                 
+           case CM_ERROR_INVAL             : s = "CM_ERROR_INVAL";              break;                                 
+           case CM_ERROR_BADFD             : s = "CM_ERROR_BADFD";              break;                                 
+           case CM_ERROR_BADFDOP           : s = "CM_ERROR_BADFDOP";            break;                         
+           case CM_ERROR_EXISTS            : s = "CM_ERROR_EXISTS";             break;                                 
+           case CM_ERROR_CROSSDEVLINK      : s = "CM_ERROR_CROSSDEVLINK";       break;                         
+           case CM_ERROR_BADOP             : s = "CM_ERROR_BADOP";              break;                                 
+           case CM_ERROR_BADPASSWORD       : s = "CM_ERROR_BADPASSWORD";        break;         
+           case CM_ERROR_NOTDIR            : s = "CM_ERROR_NOTDIR";             break;                                 
+           case CM_ERROR_ISDIR             : s = "CM_ERROR_ISDIR";              break;                                 
+           case CM_ERROR_READONLY          : s = "CM_ERROR_READONLY";           break;                         
+           case CM_ERROR_WOULDBLOCK        : s = "CM_ERROR_WOULDBLOCK";         break;                         
+           case CM_ERROR_QUOTA             : s = "CM_ERROR_QUOTA";              break;                                 
+           case CM_ERROR_SPACE             : s = "CM_ERROR_SPACE";              break;                                 
+           case CM_ERROR_BADSHARENAME      : s = "CM_ERROR_BADSHARENAME";       break;                         
+           case CM_ERROR_BADTID            : s = "CM_ERROR_BADTID";             break;                                 
+           case CM_ERROR_UNKNOWN           : s = "CM_ERROR_UNKNOWN";            break;                         
+           case CM_ERROR_NOMORETOKENS      : s = "CM_ERROR_NOMORETOKENS";       break;                         
+           case CM_ERROR_NOTEMPTY          : s = "CM_ERROR_NOTEMPTY";           break;                         
+           case CM_ERROR_USESTD            : s = "CM_ERROR_USESTD";             break;                                 
+           case CM_ERROR_REMOTECONN        : s = "CM_ERROR_REMOTECONN";         break;                         
+           case CM_ERROR_ATSYS             : s = "CM_ERROR_ATSYS";              break;                                 
+           case CM_ERROR_NOSUCHPATH        : s = "CM_ERROR_NOSUCHPATH";         break;                         
+           case CM_ERROR_CLOCKSKEW         : s = "CM_ERROR_CLOCKSKEW";          break;                         
+           case CM_ERROR_BADSMB            : s = "CM_ERROR_BADSMB";             break;                                 
+           case CM_ERROR_ALLBUSY           : s = "CM_ERROR_ALLBUSY";            break;                         
+           case CM_ERROR_NOFILES           : s = "CM_ERROR_NOFILES";            break;                         
+           case CM_ERROR_PARTIALWRITE      : s = "CM_ERROR_PARTIALWRITE";       break;                         
+           case CM_ERROR_NOIPC             : s = "CM_ERROR_NOIPC";              break;                                 
+           case CM_ERROR_BADNTFILENAME     : s = "CM_ERROR_BADNTFILENAME";      break;                         
+           case CM_ERROR_BUFFERTOOSMALL    : s = "CM_ERROR_BUFFERTOOSMALL";     break;                         
+           case CM_ERROR_RENAME_IDENTICAL  : s = "CM_ERROR_RENAME_IDENTICAL";   break;                 
+           case CM_ERROR_ALLOFFLINE        : s = "CM_ERROR_ALLOFFLINE";         break;          
+           case CM_ERROR_AMBIGUOUS_FILENAME: s = "CM_ERROR_AMBIGUOUS_FILENAME"; break;  
+           case CM_ERROR_BADLOGONTYPE      : s = "CM_ERROR_BADLOGONTYPE";       break;             
+           case CM_ERROR_GSSCONTINUE       : s = "CM_ERROR_GSSCONTINUE";        break;         
+           case CM_ERROR_TIDIPC            : s = "CM_ERROR_TIDIPC";             break;              
+           case CM_ERROR_TOO_MANY_SYMLINKS : s = "CM_ERROR_TOO_MANY_SYMLINKS";  break;   
+           case CM_ERROR_PATH_NOT_COVERED  : s = "CM_ERROR_PATH_NOT_COVERED";   break;    
+           case CM_ERROR_LOCK_CONFLICT     : s = "CM_ERROR_LOCK_CONFLICT";      break;       
+           case CM_ERROR_SHARING_VIOLATION : s = "CM_ERROR_SHARING_VIOLATION";  break;   
+           case CM_ERROR_ALLDOWN           : s = "CM_ERROR_ALLDOWN";            break;             
+           case CM_ERROR_TOOFEWBUFS        : s = "CM_ERROR_TOOFEWBUFS";         break;                         
+           case CM_ERROR_TOOMANYBUFS       : s = "CM_ERROR_TOOMANYBUFS";        break;                         
             }
             osi_Log2(afsd_logp, "cm_Analyze: ignoring error code 0x%x (%s)", 
                      errorCode, s);

diff --git a/src/WINNT/afsd/cm_ioctl.c b/src/WINNT/afsd/cm_ioctl.c
index 151350f..f8ee369 100644 (file)
--- a/src/WINNT/afsd/cm_ioctl.c
+++ b/src/WINNT/afsd/cm_ioctl.c
@@ -88,6 +88,13 @@ long cm_FlushFile(cm_scache_t *scp, cm_user_t *userp, cm_req_t *reqp)
 {
     long code;
 
+#ifdef AFS_FREELANCE_CLIENT
+    if ( scp->fid.cell == AFS_FAKE_ROOT_CELL_ID && scp->fid.volume == AFS_FAKE_ROOT_VOL_ID ) {
+       cm_noteLocalMountPointChange();
+       return 0;
+    }
+#endif
+
     lock_ObtainWrite(&scp->bufCreateLock);
     code = buf_FlushCleanPages(scp, userp, reqp);
         
@@ -110,7 +117,7 @@ long cm_FlushParent(cm_scache_t *scp, cm_user_t *userp, cm_req_t *reqp)
   
     /* now flush the file */
     code = cm_FlushFile(pscp, userp, reqp);
-    cm_ReleaseSCache(scp);
+    cm_ReleaseSCache(pscp);
 
     return code;
 }
@@ -122,6 +129,13 @@ long cm_FlushVolume(cm_user_t *userp, cm_req_t *reqp, afs_uint32 cell, afs_uint3
     cm_scache_t *scp;
     int i;
 
+#ifdef AFS_FREELANCE_CLIENT
+    if ( cell == AFS_FAKE_ROOT_CELL_ID && volume == AFS_FAKE_ROOT_VOL_ID ) {
+       cm_noteLocalMountPointChange();
+       return 0;
+    }
+#endif
+
     lock_ObtainWrite(&cm_scacheLock);
     for (i=0; i<cm_data.hashTableSize; i++) {
         for (scp = cm_data.hashTablep[i]; scp; scp = scp->nextp) {

diff --git a/src/WINNT/afsd/cm_scache.c b/src/WINNT/afsd/cm_scache.c
index 5414232..4485e17 100644 (file)
--- a/src/WINNT/afsd/cm_scache.c
+++ b/src/WINNT/afsd/cm_scache.c
@@ -52,16 +52,150 @@ void cm_AdjustLRU(cm_scache_t *scp)
         cm_data.scacheLRULastp = scp;
 }
 
+/* called with cm_scacheLock write-locked; recycles an existing scp. */
+long cm_RecycleSCache(cm_scache_t *scp, afs_int32 flags)
+{
+    cm_scache_t **lscpp;
+    cm_scache_t *tscp;
+    int i;
+
+#ifdef AFS_FREELANCE_CLIENT
+    /* Do not recycle Freelance cache entries */
+    if ( cm_freelanceEnabled && 
+         scp->fid.cell==AFS_FAKE_ROOT_CELL_ID &&
+         scp->fid.volume==AFS_FAKE_ROOT_VOL_ID )
+       return -1;
+#endif /* AFS_FREELANCE_CLIENT */
+
+
+    if (scp->flags & CM_SCACHEFLAG_INHASH) {
+       /* hash it out first */
+       i = CM_SCACHE_HASH(&scp->fid);
+       for (lscpp = &cm_data.hashTablep[i], tscp = cm_data.hashTablep[i];
+             tscp;
+             lscpp = &tscp->nextp, tscp = tscp->nextp) {
+           if (tscp == scp) {
+               *lscpp = scp->nextp;
+               scp->flags &= ~CM_SCACHEFLAG_INHASH;
+               break;
+           }
+       }
+       osi_assertx(tscp, "afsd: scache hash screwup");
+    }
+
+    if (flags & CM_SCACHE_RECYCLEFLAG_DESTROY_BUFFERS) {
+       osi_queueData_t *qdp;
+       cm_buf_t *bufp;
+
+       while(qdp = scp->bufWritesp) {
+            bufp = osi_GetQData(qdp);
+           osi_QRemove((osi_queue_t **) &scp->bufWritesp, &qdp->q);
+           osi_QDFree(qdp);
+           if (bufp) {
+               lock_ObtainMutex(&bufp->mx);
+               bufp->cmFlags &= ~CM_BUF_CMSTORING;
+               bufp->flags &= ~CM_BUF_DIRTY;
+               bufp->dataVersion = -1; /* bad */
+               bufp->dirtyCounter++;
+               if (bufp->flags & CM_BUF_WAITING) {
+                   osi_Log2(afsd_logp, "CM RecycleSCache Waking [scp 0x%x] bufp 0x%x", scp, bufp);
+                   osi_Wakeup((long) &bufp);
+               }
+               lock_ReleaseMutex(&bufp->mx);
+               buf_Release(bufp);
+           }
+        }
+       while(qdp = scp->bufReadsp) {
+            bufp = osi_GetQData(qdp);
+           osi_QRemove((osi_queue_t **) &scp->bufReadsp, &qdp->q);
+           osi_QDFree(qdp);
+           if (bufp) {
+               lock_ObtainMutex(&bufp->mx);
+               bufp->cmFlags &= ~CM_BUF_CMFETCHING;
+               bufp->flags &= ~CM_BUF_DIRTY;
+               bufp->dataVersion = -1; /* bad */
+               bufp->dirtyCounter++;
+               if (bufp->flags & CM_BUF_WAITING) {
+                   osi_Log2(afsd_logp, "CM RecycleSCache Waking [scp 0x%x] bufp 0x%x", scp, bufp);
+                   osi_Wakeup((long) &bufp);
+               }
+               lock_ReleaseMutex(&bufp->mx);
+               buf_Release(bufp);
+           }
+        }
+    } else {
+       /* look for things that shouldn't still be set */
+       osi_assert(scp->bufWritesp == NULL);
+       osi_assert(scp->bufReadsp == NULL);
+    }
+
+    /* invalidate so next merge works fine;
+     * also initialize some flags */
+    scp->flags &= ~(CM_SCACHEFLAG_STATD
+                    | CM_SCACHEFLAG_RO
+                    | CM_SCACHEFLAG_PURERO
+                    | CM_SCACHEFLAG_OVERQUOTA
+                    | CM_SCACHEFLAG_OUTOFSPACE);
+    scp->serverModTime = 0;
+    scp->dataVersion = 0;
+    scp->bulkStatProgress = hzero;
+    scp->waitCount = 0;
+
+    scp->fid.vnode = 0;
+    scp->fid.volume = 0;
+    scp->fid.unique = 0;
+    scp->fid.cell = 0;
+
+    /* discard callback */
+    if (scp->cbServerp) {
+       cm_PutServer(scp->cbServerp);
+       scp->cbServerp = NULL;
+    }
+    scp->cbExpires = 0;
+
+    /* remove from dnlc */
+    cm_dnlcPurgedp(scp);
+    cm_dnlcPurgevp(scp);
+
+    /* discard cached status; if non-zero, Close
+     * tried to store this to server but failed */
+    scp->mask = 0;
+
+    /* drop held volume ref */
+    if (scp->volp) {
+       cm_PutVolume(scp->volp);
+       scp->volp = NULL;
+    }
+
+    /* discard symlink info */
+    scp->mountPointStringp[0] = 0;
+    memset(&scp->mountRootFid, 0, sizeof(cm_fid_t));
+    memset(&scp->dotdotFid, 0, sizeof(cm_fid_t));
+
+    /* reset locking info */
+    scp->fileLocksH = NULL;
+    scp->fileLocksT = NULL;
+    scp->serverLock = (-1);
+    scp->exclusiveLocks = 0;
+    scp->sharedLocks = 0;
+
+    /* not locked, but there can be no references to this guy
+     * while we hold the global refcount lock.
+     */
+    cm_FreeAllACLEnts(scp);
+
+    return 0;
+}
+
+
 /* called with cm_scacheLock write-locked; find a vnode to recycle.
  * Can allocate a new one if desperate, or if below quota (cm_data.maxSCaches).
  */
 cm_scache_t *cm_GetNewSCache(void)
 {
     cm_scache_t *scp;
-    int i;
-    cm_scache_t **lscpp;
-    cm_scache_t *tscp;
 
+  start:
     if (cm_data.currentSCaches >= cm_data.maxSCaches) {
         for (scp = cm_data.scacheLRULastp;
               scp;
@@ -72,88 +206,21 @@ cm_scache_t *cm_GetNewSCache(void)
                 
         if (scp) {
             osi_assert(scp >= cm_data.scacheBaseAddress && scp < (cm_scache_t *)cm_data.hashTablep);
-            /* we found an entry, so return it */
-            if (scp->flags & CM_SCACHEFLAG_INHASH) {
-                /* hash it out first */
-                i = CM_SCACHE_HASH(&scp->fid);
-                for (lscpp = &cm_data.hashTablep[i], tscp = cm_data.hashTablep[i];
-                      tscp;
-                      lscpp = &tscp->nextp, tscp = tscp->nextp) {
-                    if (tscp == scp) {
-                        *lscpp = scp->nextp;
-                        scp->flags &= ~CM_SCACHEFLAG_INHASH;
-                        break;
-                    }
-                }
-                osi_assertx(tscp, "afsd: scache hash screwup");
-            }
 
-            /* look for things that shouldn't still be set */
-            osi_assert(scp->bufWritesp == NULL);
-            osi_assert(scp->bufReadsp == NULL);
-
-            /* invalidate so next merge works fine;
-            * also initialize some flags */
-            scp->flags &= ~(CM_SCACHEFLAG_STATD
-                             | CM_SCACHEFLAG_RO
-                             | CM_SCACHEFLAG_PURERO
-                             | CM_SCACHEFLAG_OVERQUOTA
-                             | CM_SCACHEFLAG_OUTOFSPACE);
-            scp->serverModTime = 0;
-            scp->dataVersion = 0;
-            scp->bulkStatProgress = hzero;
-            scp->waitCount = 0;
-
-            scp->fid.vnode = 0;
-            scp->fid.volume = 0;
-            scp->fid.unique = 0;
-            scp->fid.cell = 0;
-
-            /* discard callback */
-            if (scp->cbServerp) {
-                cm_PutServer(scp->cbServerp);
-                scp->cbServerp = NULL;
-            }
-            scp->cbExpires = 0;
-
-            /* remove from dnlc */
-            cm_dnlcPurgedp(scp);
-            cm_dnlcPurgevp(scp);
-
-            /* discard cached status; if non-zero, Close
-             * tried to store this to server but failed */
-            scp->mask = 0;
-
-            /* drop held volume ref */
-            if (scp->volp) {
-                cm_PutVolume(scp->volp);
-                scp->volp = NULL;
-            }
-
-            /* discard symlink info */
-            scp->mountPointStringp[0] = 0;
-            memset(&scp->mountRootFid, 0, sizeof(cm_fid_t));
-            memset(&scp->dotdotFid, 0, sizeof(cm_fid_t));
-
-            /* reset locking info */
-            scp->fileLocksH = NULL;
-            scp->fileLocksT = NULL;
-            scp->serverLock = (-1);
-            scp->exclusiveLocks = 0;
-            scp->sharedLocks = 0;
-
-            /* not locked, but there can be no references to this guy
-             * while we hold the global refcount lock.
-             */
-            cm_FreeAllACLEnts(scp);
-
-            /* now remove from the LRU queue and put it back at the
-             * head of the LRU queue.
-             */
-            cm_AdjustLRU(scp);
-
-            /* and we're done */
-            return scp;
+           if (!cm_RecycleSCache(scp, 0)) {
+           
+               /* we found an entry, so return it */
+               /* now remove from the LRU queue and put it back at the
+                * head of the LRU queue.
+                */
+               cm_AdjustLRU(scp);
+
+               /* and we're done */
+               return scp;
+           } else {
+               /* We don't like this entry, choose another one. */
+               goto start;
+           }
         }
     }
         

diff --git a/src/WINNT/afsd/cm_scache.h b/src/WINNT/afsd/cm_scache.h
index 389baac..b8abbaf 100644 (file)
--- a/src/WINNT/afsd/cm_scache.h
+++ b/src/WINNT/afsd/cm_scache.h
@@ -279,6 +279,9 @@ typedef struct cm_scache {
 #define CM_SCACHESYNC_NOWAIT           0x100000/* don't wait for the state,
                                                 * just fail */
 
+/* flags for cm_RecycleSCache  */
+#define CM_SCACHE_RECYCLEFLAG_DESTROY_BUFFERS  0x1
+
 /* flags for cm_MergeStatus */
 #define CM_MERGEFLAG_FORCE             1       /* check mtime before merging;
                                                 * used to see if we're merging
@@ -347,4 +350,6 @@ extern long cm_ValidateSCache(void);
 
 extern long cm_ShutdownSCache(void);
 
+extern long cm_RecycleSCache(cm_scache_t *scp, afs_int32 flags);
+
 #endif /*  __CM_SCACHE_H_ENV__ */

diff --git a/src/WINNT/afsd/cm_utils.c b/src/WINNT/afsd/cm_utils.c
index afefb57..8d73014 100644 (file)
--- a/src/WINNT/afsd/cm_utils.c
+++ b/src/WINNT/afsd/cm_utils.c
@@ -246,7 +246,7 @@ long cm_MapRPCError(long error, cm_req_t *reqp)
         error = CM_ERROR_EXISTS;
     else if (error == 20) 
         error = CM_ERROR_NOTDIR;
-    else if (error == 2) 
+    else if (error == 2)       /* ENOENT */
         error = CM_ERROR_NOSUCHFILE;
     else if (error == 11        /* EAGAIN, most servers */
              || error == 35)   /* EAGAIN, Digital UNIX */

diff --git a/src/WINNT/afsd/cm_vnodeops.c b/src/WINNT/afsd/cm_vnodeops.c
index 4969b4f..44b79f8 100644 (file)
--- a/src/WINNT/afsd/cm_vnodeops.c
+++ b/src/WINNT/afsd/cm_vnodeops.c
@@ -1344,6 +1344,13 @@ long cm_Unlink(cm_scache_t *dscp, char *namep, cm_user_t *userp, cm_req_t *reqp)
     cm_SyncOpDone(dscp, NULL, sflags);
     if (code == 0) 
         cm_MergeStatus(dscp, &newDirStatus, &volSync, userp, 0);
+       else if (code == CM_ERROR_NOSUCHFILE) {
+               /* windows would not have allowed the request to delete the file 
+                * if it did not believe the file existed.  therefore, we must 
+                * have an inconsistent view of the world.
+                */
+               dscp->cbServerp = NULL;
+       }
     lock_ReleaseMutex(&dscp->mx);
 
     return code;