01/01: [NTOSKRNL] Don't keep the spin lock hold too long when we lost the BCB race

[Pierre Schweitzer]

https://git.reactos.org/?p=reactos.git;a=commitdiff;h=1acb5a9fab662f65a3be4…

commit 1acb5a9fab662f65a3be4fd319832edfe98cff6e
Author:     Pierre Schweitzer <pierre(a)reactos.org>
AuthorDate: Fri Oct 12 08:20:32 2018 +0200
Commit:     Pierre Schweitzer <pierre(a)reactos.org>
CommitDate: Fri Oct 12 08:20:32 2018 +0200

    [NTOSKRNL] Don't keep the spin lock hold too long when we lost the BCB race
    
    This will avoid a deadlock on unpin.
---
 ntoskrnl/cc/pin.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/ntoskrnl/cc/pin.c b/ntoskrnl/cc/pin.c
index bba87960c3..b3906a9321 100644
--- a/ntoskrnl/cc/pin.c
+++ b/ntoskrnl/cc/pin.c
@@ -385,6 +385,8 @@ CcPinRead (
         iBcb = CcpFindBcb(SharedCacheMap, FileOffset, Length, TRUE);
         if (iBcb != NULL)
         {
+            KeReleaseSpinLock(&SharedCacheMap->BcbSpinLock, OldIrql);
+
             /* Free our now unused BCB */
             CcUnpinData(*Bcb);
 
@@ -414,8 +416,8 @@ CcPinRead (
 
             /* Insert ourselves in the linked list */
             InsertTailList(&SharedCacheMap->BcbList, &iBcb->BcbEntry);
+            KeReleaseSpinLock(&SharedCacheMap->BcbSpinLock, OldIrql);
         }
-        KeReleaseSpinLock(&SharedCacheMap->BcbSpinLock, OldIrql);
     }
     /* We found a BCB, lock it and return it */
     else