From 4b2be9588b87feecd0124cec9014b4a9b3c6933a Mon Sep 17 00:00:00 2001
From: Chas Williams <chas@cmf.nrl.navy.mil>
Date: Tue, 30 Jul 2002 20:34:32 +0000
Subject: [PATCH] Enable afs_DoPartialWrite() and afs_PrefetchChunk() in
 afs_UFSRead and afs_UFSWrite for Linux; fixes deadlock condition for small
 cache sizes.

---
 src/afs/VNOPS/afs_vnop_read.c  |  6 +++---
 src/afs/VNOPS/afs_vnop_write.c | 16 ++++++----------
 2 files changed, 9 insertions(+), 13 deletions(-)

diff --git a/src/afs/VNOPS/afs_vnop_read.c b/src/afs/VNOPS/afs_vnop_read.c
index bbbe2f3a2d..55d4160f89 100644
--- a/src/afs/VNOPS/afs_vnop_read.c
+++ b/src/afs/VNOPS/afs_vnop_read.c
@@ -330,7 +330,7 @@ tagain:
      */
     if (tdc) {
 	ReleaseReadLock(&tdc->lock);
-#ifndef	AFS_VM_RDWR_ENV
+#if !defined(AFS_VM_RDWR_ENV) || defined(AFS_LINUX22_ENV)
 	/* try to queue prefetch, if needed */
 	if (!noLock) {
 	    afs_PrefetchChunk(avc, tdc, acred, &treq);
@@ -559,7 +559,7 @@ afs_UFSReadFast(avc, auio, acred, albn, abpp, noLock)
 
 	    if (!noLock) {
 		ReleaseReadLock(&avc->lock);
-#ifndef	AFS_VM_RDWR_ENV
+#if !defined(AFS_VM_RDWR_ENV) || defined(AFS_LINUX22_ENV)
 		if (!(code = afs_InitReq(&treq, acred))) {
 		    if (!(tdc->mflags & DFNextStarted))
 			afs_PrefetchChunk(avc, tdc, acred, &treq);
@@ -982,7 +982,7 @@ tagain:
      */
     if (tdc) {
 	ReleaseReadLock(&tdc->lock);
-#ifndef	AFS_VM_RDWR_ENV
+#if !defined(AFS_VM_RDWR_ENV) || defined(AFS_LINUX22_ENV)
 	/* try to queue prefetch, if needed */
 	if (!noLock) {
 	    if (!(tdc->mflags & DFNextStarted))
diff --git a/src/afs/VNOPS/afs_vnop_write.c b/src/afs/VNOPS/afs_vnop_write.c
index 53a0d4013d..b19b244af5 100644
--- a/src/afs/VNOPS/afs_vnop_write.c
+++ b/src/afs/VNOPS/afs_vnop_write.c
@@ -297,7 +297,9 @@ afs_MemWrite(avc, auio, aio, acred, noLock)
 	    avc->m.Length = filePos;
 	}
 #endif
-#ifndef AFS_VM_RDWR_ENV
+	ReleaseWriteLock(&tdc->lock);
+	afs_PutDCache(tdc);
+#if !defined(AFS_VM_RDWR_ENV) || defined(AFS_LINUX22_ENV)
 	/*
 	 * If write is implemented via VM, afs_DoPartialWrite() is called from
 	 * the high-level write op.
@@ -306,14 +308,10 @@ afs_MemWrite(avc, auio, aio, acred, noLock)
 	    code = afs_DoPartialWrite(avc, &treq);
 	    if (code) {
 		error = code;
-		ReleaseWriteLock(&tdc->lock);
-		afs_PutDCache(tdc);
 		break;
 	    }
 	}
 #endif
-	ReleaseWriteLock(&tdc->lock);
-	afs_PutDCache(tdc);
     }
 #ifndef	AFS_VM_RDWR_ENV
     afs_FakeClose(avc, acred);
@@ -618,7 +616,9 @@ afs_UFSWrite(avc, auio, aio, acred, noLock)
 	}
 #endif
 	osi_UFSClose(tfile);
-#ifndef	AFS_VM_RDWR_ENV
+	ReleaseWriteLock(&tdc->lock);
+	afs_PutDCache(tdc);
+#if !defined(AFS_VM_RDWR_ENV) || defined(AFS_LINUX22_ENV)
 	/*
 	 * If write is implemented via VM, afs_DoPartialWrite() is called from
 	 * the high-level write op.
@@ -627,14 +627,10 @@ afs_UFSWrite(avc, auio, aio, acred, noLock)
 	    code = afs_DoPartialWrite(avc, &treq);
 	    if (code) {
 		error = code;
-		ReleaseWriteLock(&tdc->lock);
-		afs_PutDCache(tdc);
 		break;
 	    }
 	}
 #endif
-	ReleaseWriteLock(&tdc->lock);
-	afs_PutDCache(tdc);
     }
 #ifndef	AFS_VM_RDWR_ENV
     afs_FakeClose(avc, acred);