iallocsem_consistency.patch

非常经典的一个分布式系统

Index: linux-2.6.9/fs/attr.c
===================================================================
--- linux-2.6.9/fs.orig/attr.c	2006-03-10 17:20:39.000000000 +0200
+++ linux-2.6.9/fs/attr.c	2006-04-09 01:21:44.000000000 +0300
@@ -177,6 +177,9 @@
 	if (!attr->ia_valid)
 		return 0;
 
+        if (ia_valid & ATTR_SIZE)
+                down_write(&dentry->d_inode->i_alloc_sem);
+
 	if (inode->i_op && inode->i_op->setattr) {
 		audit_notify_watch(inode, MAY_WRITE);
 		error = security_inode_setattr(dentry, attr);
@@ -194,6 +197,10 @@
 				error = inode_setattr(inode, attr);
 		}
 	}
+
+        if (ia_valid & ATTR_SIZE)
+                up_write(&dentry->d_inode->i_alloc_sem);
+
 	if (!error) {
 		unsigned long dn_mask = setattr_mask(ia_valid);
 		if (dn_mask)
Index: linux-2.6.9/fs/open.c
===================================================================
--- linux-2.6.9/fs.orig/open.c	2006-04-09 01:18:08.000000000 +0300
+++ linux-2.6.9/fs/open.c	2006-04-09 01:22:29.000000000 +0300
@@ -205,16 +205,16 @@
 	newattrs.ia_size = length;
 	newattrs.ia_valid = ATTR_SIZE | ATTR_CTIME;
 	down(&dentry->d_inode->i_sem);
-	down_write(&dentry->d_inode->i_alloc_sem);
 	if (called_from_open)
 		newattrs.ia_valid |= ATTR_FROM_OPEN;
 	if (op->setattr_raw) {
 		newattrs.ia_valid |= ATTR_RAW;
 		newattrs.ia_ctime = CURRENT_TIME;
+		down_write(&dentry->d_inode->i_alloc_sem);
 		err = op->setattr_raw(dentry->d_inode, &newattrs);
+		up_write(&dentry->d_inode->i_alloc_sem);
 	} else
 		err = notify_change(dentry, &newattrs);
-	up_write(&dentry->d_inode->i_alloc_sem);
 	up(&dentry->d_inode->i_sem);
 	return err;
 }