X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=include%2Flinux%2Fvs_cowbl.h;fp=include%2Flinux%2Fvs_cowbl.h;h=b4fff2de38303a472c41fe440f14916f6782852a;hb=76828883507a47dae78837ab5dec5a5b4513c667;hp=0000000000000000000000000000000000000000;hpb=64ba3f394c830ec48a1c31b53dcae312c56f1604;p=linux-2.6.git

diff --git a/include/linux/vs_cowbl.h b/include/linux/vs_cowbl.h
new file mode 100644
index 000000000..b4fff2de3
--- /dev/null
+++ b/include/linux/vs_cowbl.h
@@ -0,0 +1,44 @@
+#ifndef _VS_COWBL_H
+#define _VS_COWBL_H
+
+#include <linux/fs.h>
+#include <linux/dcache.h>
+#include <linux/namei.h>
+
+extern struct dentry *cow_break_link(const char *pathname);
+
+static inline int cow_check_and_break(struct nameidata *nd)
+{
+	struct inode *inode = nd->dentry->d_inode;
+	int error = 0;
+	if (IS_RDONLY(inode) || MNT_IS_RDONLY(nd->mnt))
+		return -EROFS;
+	if (IS_COW(inode)) {
+		if (IS_COW_LINK(inode)) {
+			struct dentry *new_dentry, *old_dentry = nd->dentry;
+			char *path, *buf;
+
+			buf = kmalloc(PATH_MAX, GFP_KERNEL);
+			if (!buf) {
+				return -ENOMEM;
+			}
+			path = d_path(nd->dentry, nd->mnt, buf, PATH_MAX);
+			new_dentry = cow_break_link(path);
+			kfree(buf);
+			if (!IS_ERR(new_dentry)) {
+				nd->dentry = new_dentry;
+				dput(old_dentry);
+			} else
+				error = PTR_ERR(new_dentry);
+		} else {
+			inode->i_flags &= ~(S_IUNLINK|S_IMMUTABLE);
+			inode->i_ctime = CURRENT_TIME;
+			mark_inode_dirty(inode);
+		}
+	}
+	return error;
+}
+
+#else
+#warning duplicate inclusion
+#endif