vfs_races-2.6.12.patch

非常经典的一个分布式系统

Index: linux-2.6.7-vanilla/fs/dcache.c
===================================================================
--- linux-2.6.7-vanilla.orig/fs/dcache.c	2004-07-01 12:09:19.000000000 +0300
+++ linux-2.6.7-vanilla/fs/dcache.c	2004-07-01 12:29:12.510193264 +0300
@@ -219,6 +219,13 @@
 		spin_unlock(&dcache_lock);
 		return 0;
 	}
+
+	/* network invalidation by Lustre */
+	if (dentry->d_flags & DCACHE_LUSTRE_INVALID) {
+		spin_unlock(&dcache_lock);
+		return 0;
+	}
+
 	/*
 	 * Check whether to do a partial shrink_dcache
 	 * to get rid of unused child entries.
@@ -1199,16 +1199,25 @@
  * Adds a dentry to the hash according to its name.
  */
  
-void d_rehash(struct dentry * entry)
+void d_rehash_cond(struct dentry * entry, int lock)
 {
 	struct hlist_head *list = d_hash(entry->d_parent, entry->d_name.hash);
 
-	spin_lock(&dcache_lock);
+	if (lock)
+		spin_lock(&dcache_lock);
 	spin_lock(&entry->d_lock);
 	__d_rehash(entry, list);
 	spin_unlock(&entry->d_lock);
-	spin_unlock(&dcache_lock);
+	if (lock)
+		spin_unlock(&dcache_lock);
 }
 
+EXPORT_SYMBOL(d_rehash_cond);
+
+void d_rehash(struct dentry * entry)
+{
+	d_rehash_cond(entry, 1);
+ }
+
 #define do_switch(x,y) do { \
 	__typeof__ (x) __tmp = x; \
 	x = y; y = __tmp; } while (0)
Index: linux-2.6.7-vanilla/include/linux/dcache.h
===================================================================
--- linux-2.6.7-vanilla.orig/include/linux/dcache.h	2004-07-01 12:24:53.602553208 +0300
+++ linux-2.6.7-vanilla/include/linux/dcache.h	2004-07-01 12:27:29.757814000 +0300
@@ -159,6 +159,8 @@
 
 #define DCACHE_REFERENCED	0x0008  /* Recently used, don't discard. */
 #define DCACHE_UNHASHED		0x0010	
+#define DCACHE_LUSTRE_INVALID     0x0020  /* Lustre invalidated */
+
 
 extern spinlock_t dcache_lock;