vfs_races-2.6-rhel5.patch

非常经典的一个分布式系统

diff -urp linux-2.6.18.rawops/fs/dcache.c linux-2.6.18.races/fs/dcache.c
--- linux-2.6.18.rawops/fs/dcache.c	2007-02-08 19:00:31.000000000 +0200
+++ linux-2.6.18.races/fs/dcache.c	2007-02-14 19:23:49.000000000 +0200
@@ -230,6 +230,13 @@ int d_invalidate(struct dentry * dentry)
 		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.
@@ -1400,13 +1407,21 @@ static void _d_rehash(struct dentry * en
  * 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)
 {
-	spin_lock(&dcache_lock);
+ 	if (lock)
+	    spin_lock(&dcache_lock);
 	spin_lock(&entry->d_lock);
 	_d_rehash(entry);
 	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 { \
@@ -1481,14 +1496,13 @@ static void switch_names(struct dentry *
  * dcache entries should not be moved in this way.
  */
 
-void d_move(struct dentry * dentry, struct dentry * target)
+void __d_move(struct dentry * dentry, struct dentry * target)
 {
 	struct hlist_head *list;
 
 	if (!dentry->d_inode)
 		printk(KERN_WARNING "VFS: moving negative dcache entry\n");
 
-	spin_lock(&dcache_lock);
 	write_seqlock(&rename_lock);
 	/*
 	 * XXXX: do we really need to take target->d_lock?
@@ -1549,6 +1563,14 @@ already_unhashed:
 	fsnotify_d_move(dentry);
 	spin_unlock(&dentry->d_lock);
 	write_sequnlock(&rename_lock);
+}
+
+EXPORT_SYMBOL(__d_move);
+
+void d_move(struct dentry *dentry, struct dentry *target)
+{
+	spin_lock(&dcache_lock);
+	__d_move(dentry, target);
 	spin_unlock(&dcache_lock);
 }
 
diff -urp linux-2.6.18.rawops/include/linux/dcache.h linux-2.6.18.races/include/linux/dcache.h
--- linux-2.6.18.rawops/include/linux/dcache.h	2007-02-14 16:52:37.000000000 +0200
+++ linux-2.6.18.races/include/linux/dcache.h	2007-02-14 19:21:14.000000000 +0200
@@ -177,6 +177,7 @@ d_iput:		no		no		no       yes
 
 #define DCACHE_REFERENCED	0x0008  /* Recently used, don't discard. */
 #define DCACHE_UNHASHED		0x0010	
+#define DCACHE_LUSTRE_INVALID	0x0040  /* Lustre invalidated */
 
 #define DCACHE_INOTIFY_PARENT_WATCHED	0x0020 /* Parent inode is watched */
 
@@ -254,6 +255,7 @@ extern int have_submounts(struct dentry 
  * This adds the entry to the hash queues.
  */
 extern void d_rehash(struct dentry *);
+extern void d_rehash_cond(struct dentry *, int lock);
 
 /**
  * d_add - add dentry to hash queues
@@ -289,6 +291,7 @@ static inline struct dentry *d_add_uniqu
 
 /* used for rename() and baskets */
 extern void d_move(struct dentry *, struct dentry *);
+extern void __d_move(struct dentry *, struct dentry *);
 
 /* appendix may either be NULL or be used for transname suffixes */
 extern struct dentry * d_lookup(struct dentry *, struct qstr *);