From 8f98479170b3ccd684baa7cd8f1abcd08605a123 Mon Sep 17 00:00:00 2001
From: Derrick Brashear <shadow@dementia.org>
Date: Sat, 8 Dec 2007 17:59:06 +0000
Subject: [PATCH] DEVEL15-writedcache-enforce-xdcache-writelock-20071208

LICENSE IPL10
FIXES 59136

in order that the writes to CacheItems not be addled, we need to *actually*
hold a *write* lock when we write. not even just read as the comment says.

and certainly not none as was happening in the dir package.


(cherry picked from commit c0a04c21cf36e4c8e25be9703f715f30d1bf55a6)
---
 src/afs/VNOPS/afs_vnop_create.c  | 2 ++
 src/afs/VNOPS/afs_vnop_dirops.c  | 2 ++
 src/afs/VNOPS/afs_vnop_link.c    | 2 ++
 src/afs/VNOPS/afs_vnop_rename.c  | 2 ++
 src/afs/VNOPS/afs_vnop_symlink.c | 2 ++
 src/afs/afs_dcache.c             | 1 +
 6 files changed, 11 insertions(+)

diff --git a/src/afs/VNOPS/afs_vnop_create.c b/src/afs/VNOPS/afs_vnop_create.c
index fbb33fc273..bdf35a9b43 100644
--- a/src/afs/VNOPS/afs_vnop_create.c
+++ b/src/afs/VNOPS/afs_vnop_create.c
@@ -353,7 +353,9 @@ afs_create(OSI_VC_DECL(adp), char *aname, struct vattr *attrs,
 	UpgradeSToWLock(&tdc->lock, 631);
     if (afs_LocalHero(adp, tdc, &OutDirStatus, 1)) {
 	/* we can do it locally */
+	ObtainWriteLock(&afs_xdcache, 291);
 	code = afs_dir_Create(tdc, aname, &newFid.Fid);
+	ReleaseWriteLock(&afs_xdcache);
 	if (code) {
 	    ZapDCE(tdc);
 	    DZap(tdc);
diff --git a/src/afs/VNOPS/afs_vnop_dirops.c b/src/afs/VNOPS/afs_vnop_dirops.c
index 0079acfe74..5e73dd0d64 100644
--- a/src/afs/VNOPS/afs_vnop_dirops.c
+++ b/src/afs/VNOPS/afs_vnop_dirops.c
@@ -132,7 +132,9 @@ afs_mkdir(OSI_VC_DECL(adp), char *aname, struct vattr *attrs,
 	ObtainWriteLock(&tdc->lock, 632);
     if (afs_LocalHero(adp, tdc, &OutDirStatus, 1)) {
 	/* we can do it locally */
+	ObtainWriteLock(&afs_xdcache, 294);
 	code = afs_dir_Create(tdc, aname, &newFid.Fid);
+	ReleaseWriteLock(&afs_xdcache);
 	if (code) {
 	    ZapDCE(tdc);	/* surprise error -- use invalid value */
 	    DZap(tdc);
diff --git a/src/afs/VNOPS/afs_vnop_link.c b/src/afs/VNOPS/afs_vnop_link.c
index cbd59aabf4..04c08a6dc4 100644
--- a/src/afs/VNOPS/afs_vnop_link.c
+++ b/src/afs/VNOPS/afs_vnop_link.c
@@ -127,7 +127,9 @@ afs_link(avc, OSI_VC_ARG(adp), aname, acred)
 	ObtainWriteLock(&tdc->lock, 635);
     if (afs_LocalHero(adp, tdc, &OutDirStatus, 1)) {
 	/* we can do it locally */
+	ObtainWriteLock(&afs_xdcache, 290);
 	code = afs_dir_Create(tdc, aname, &avc->fid.Fid);
+	ReleaseWriteLock(&afs_xdcache);
 	if (code) {
 	    ZapDCE(tdc);	/* surprise error -- invalid value */
 	    DZap(tdc);
diff --git a/src/afs/VNOPS/afs_vnop_rename.c b/src/afs/VNOPS/afs_vnop_rename.c
index 1af38a21c4..02c67f99c0 100644
--- a/src/afs/VNOPS/afs_vnop_rename.c
+++ b/src/afs/VNOPS/afs_vnop_rename.c
@@ -227,7 +227,9 @@ afsrename(struct vcache *aodp, char *aname1, struct vcache *andp,
 		code = afs_dir_Delete(tdc2, aname2);
 	    }
 	    if (code == 0) {
+		ObtainWriteLock(&afs_xdcache, 292);
 		code = afs_dir_Create(tdc2, aname2, &fileFid.Fid);
+		ReleaseWriteLock(&afs_xdcache);
 	    }
 	    if (code != 0) {
 		ZapDCE(tdc1);
diff --git a/src/afs/VNOPS/afs_vnop_symlink.c b/src/afs/VNOPS/afs_vnop_symlink.c
index fa5a8f4b98..22aa636abc 100644
--- a/src/afs/VNOPS/afs_vnop_symlink.c
+++ b/src/afs/VNOPS/afs_vnop_symlink.c
@@ -177,7 +177,9 @@ int afs_symlink
     /* otherwise, we should see if we can make the change to the dir locally */
     if (afs_LocalHero(adp, tdc, &OutDirStatus, 1)) {
 	/* we can do it locally */
+	ObtainWriteLock(&afs_xdcache, 293);
 	code = afs_dir_Create(tdc, aname, &newFid.Fid);
+	ReleaseWriteLock(&afs_xdcache);
 	if (code) {
 	    ZapDCE(tdc);	/* surprise error -- use invalid value */
 	    DZap(tdc);
diff --git a/src/afs/afs_dcache.c b/src/afs/afs_dcache.c
index 1e645a1b43..3801328af6 100644
--- a/src/afs/afs_dcache.c
+++ b/src/afs/afs_dcache.c
@@ -3073,6 +3073,7 @@ afs_WriteDCache(register struct dcache *adc, int atime)
     if (cacheDiskType == AFS_FCACHE_TYPE_MEM)
 	return 0;
     AFS_STATCNT(afs_WriteDCache);
+    osi_Assert(WriteLocked(&afs_xdcache));
     if (atime)
 	adc->f.modTime = osi_Time();
     /*