From ee1435d516a31e8ec2d07ec9021bf032ac12f9cd Mon Sep 17 00:00:00 2001
From: Peter Somogyi <psomogyi@gamax.hu>
Date: Sat, 15 Oct 2005 03:32:06 +0000
Subject: [PATCH] newvcache-can-fail-now-20051014

FIXES 22260

allow newvcache to fail without ooping

sort of nasty, if you want more vcaches, say so.
---
 src/afs/VNOPS/afs_vnop_lookup.c  | 19 ++++++++++++++-----
 src/afs/VNOPS/afs_vnop_symlink.c |  6 ++++++
 src/afs/afs_vcache.c             | 28 ++++++++++++++++++++++++----
 3 files changed, 44 insertions(+), 9 deletions(-)

diff --git a/src/afs/VNOPS/afs_vnop_lookup.c b/src/afs/VNOPS/afs_vnop_lookup.c
index 057dc4373..df5f09e43 100644
--- a/src/afs/VNOPS/afs_vnop_lookup.c
+++ b/src/afs/VNOPS/afs_vnop_lookup.c
@@ -709,15 +709,24 @@ afs_DoBulkStat(struct vcache *adp, long dirCookie, struct vrequest *areqp)
 	    } while (tvcp && retry);
 	    if (!tvcp) {	/* otherwise, create manually */
 		tvcp = afs_NewVCache(&tfid, hostp);
-		ObtainWriteLock(&tvcp->lock, 505);
-		ReleaseWriteLock(&afs_xvcache);
-		afs_RemoveVCB(&tfid);
-		ReleaseWriteLock(&tvcp->lock);
+		if (tvcp)
+		{
+			ObtainWriteLock(&tvcp->lock, 505);
+			ReleaseWriteLock(&afs_xvcache);
+			afs_RemoveVCB(&tfid);
+			ReleaseWriteLock(&tvcp->lock);
+		} else {
+			ReleaseWriteLock(&afs_xvcache);
+		}
 	    } else {
 		ReleaseWriteLock(&afs_xvcache);
 	    }
 	    if (!tvcp)
-		goto done;	/* can't happen at present, more's the pity */
+	    {
+		ReleaseReadLock(&dcp->lock);
+		ReleaseReadLock(&adp->lock);
+		goto done;	/* can happen if afs_NewVCache fails */
+	    }
 
 #ifdef AFS_DARWIN80_ENV
             if (tvcp->states & CVInit) {
diff --git a/src/afs/VNOPS/afs_vnop_symlink.c b/src/afs/VNOPS/afs_vnop_symlink.c
index b273a2dd6..205e40743 100644
--- a/src/afs/VNOPS/afs_vnop_symlink.c
+++ b/src/afs/VNOPS/afs_vnop_symlink.c
@@ -191,6 +191,12 @@ int afs_symlink
      * no one can get a pointer to the new cache entry until we release 
      * the xvcache lock. */
     tvc = afs_NewVCache(&newFid, hostp);
+    if (!tvc)
+    {
+	code = -2;
+	ReleaseWriteLock(&afs_xvcache);
+	goto done;
+    }
     ObtainWriteLock(&tvc->lock, 157);
     ObtainWriteLock(&afs_xcbhash, 500);
     tvc->states |= CStatd;	/* have valid info */
diff --git a/src/afs/afs_vcache.c b/src/afs/afs_vcache.c
index 6c0bc8267..31cf9177e 100644
--- a/src/afs/afs_vcache.c
+++ b/src/afs/afs_vcache.c
@@ -695,12 +695,11 @@ restart:
 		break;
 	}
 	if (anumber == VCACHE_FREE) {
-	    printf("NewVCache: warning none freed, using %d of %d\n",
+	    printf("afs_NewVCache: warning none freed, using %d of %d\n",
 		   afs_vcount, afs_maxvcount);
 	    if (afs_vcount >= afs_maxvcount) {
-		osi_Panic("NewVCache - none freed");
-		/* XXX instead of panicing, should do afs_maxvcount++
-		 * and magic up another one */
+	    	printf("afs_NewVCache - none freed\n");
+		return NULL;
 	    }
 	}
     }
@@ -1697,6 +1696,12 @@ afs_GetVCache(register struct VenusFid *afid, struct vrequest *areq,
 	newvcache = 1;
 
 	ConvertWToSLock(&afs_xvcache);
+	if (!tvc)
+	{
+		ReleaseSharedLock(&afs_xvcache);
+		return NULL;
+	}
+
 	afs_stats_cmperf.vcacheMisses++;
     }
 
@@ -1921,6 +1926,11 @@ afs_LookupVCache(struct VenusFid *afid, struct vrequest *areq,
 	tvc = afs_NewVCache(&nfid, serverp);
 	newvcache = 1;
 	ConvertWToSLock(&afs_xvcache);
+	if (!tvc)
+	{
+		ReleaseSharedLock(&afs_xvcache);
+		return NULL;
+	}
     }
 
     ReleaseSharedLock(&afs_xvcache);
@@ -2104,6 +2114,11 @@ afs_GetRootVCache(struct VenusFid *afid, struct vrequest *areq,
 	UpgradeSToWLock(&afs_xvcache, 23);
 	/* no cache entry, better grab one */
 	tvc = afs_NewVCache(afid, NULL);
+	if (!tvc)
+	{
+		ReleaseWriteLock(&afs_xvcache);
+		return NULL;
+	}
 	newvcache = 1;
 	afs_stats_cmperf.vcacheMisses++;
     } else {
@@ -2374,6 +2389,11 @@ afs_StuffVcache(register struct VenusFid *afid,
 	tvc = afs_NewVCache(afid, NULL);
 	newvcache = 1;
 	ConvertWToSLock(&afs_xvcache);
+	if (!tvc)
+	{
+		ReleaseSharedLock(&afs_xvcache);
+		return NULL;
+	}
     }
 
     ReleaseSharedLock(&afs_xvcache);
-- 
2.39.5