[JFFS2] Add symlink caching support.
Signed-off-by: Artem B. Bityuckiy <dedekind@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/fs/jffs2/symlink.c b/fs/jffs2/symlink.c
index 7b1820d..65ab6b0 100644
--- a/fs/jffs2/symlink.c
+++ b/fs/jffs2/symlink.c
@@ -7,7 +7,7 @@
*
* For licensing information, see the file 'LICENCE' in this directory.
*
- * $Id: symlink.c,v 1.14 2004/11/16 20:36:12 dwmw2 Exp $
+ * $Id: symlink.c,v 1.16 2005/03/01 10:50:48 dedekind Exp $
*
*/
@@ -19,27 +19,45 @@
#include "nodelist.h"
static int jffs2_follow_link(struct dentry *dentry, struct nameidata *nd);
-static void jffs2_put_link(struct dentry *dentry, struct nameidata *nd);
struct inode_operations jffs2_symlink_inode_operations =
{
.readlink = generic_readlink,
.follow_link = jffs2_follow_link,
- .put_link = jffs2_put_link,
.setattr = jffs2_setattr
};
static int jffs2_follow_link(struct dentry *dentry, struct nameidata *nd)
{
- unsigned char *buf;
- buf = jffs2_getlink(JFFS2_SB_INFO(dentry->d_inode->i_sb), JFFS2_INODE_INFO(dentry->d_inode));
- nd_set_link(nd, buf);
+ struct jffs2_inode_info *f = JFFS2_INODE_INFO(dentry->d_inode);
+
+ /*
+ * We don't acquire the f->sem mutex here since the only data we
+ * use is f->dents which in case of the symlink inode points to the
+ * symlink's target path.
+ *
+ * 1. If we are here the inode has already built and f->dents has
+ * to point to the target path.
+ * 2. Nobody uses f->dents (if the inode is symlink's inode). The
+ * exception is inode freeing function which frees f->dents. But
+ * it can't be called while we are here and before VFS has
+ * stopped using our f->dents string which we provide by means of
+ * nd_set_link() call.
+ */
+
+ if (!f->dents) {
+ printk(KERN_ERR "jffs2_follow_link(): can't find symlink taerget\n");
+ return -EIO;
+ }
+ D1(printk(KERN_DEBUG "jffs2_follow_link(): target path is '%s'\n", (char *) f->dents));
+
+ nd_set_link(nd, (char *)f->dents);
+
+ /*
+ * We unlock the f->sem mutex but VFS will use the f->dents string. This is safe
+ * since the only way that may cause f->dents to be changed is iput() operation.
+ * But VFS will not use f->dents after iput() has been called.
+ */
return 0;
}
-static void jffs2_put_link(struct dentry *dentry, struct nameidata *nd)
-{
- char *s = nd_get_link(nd);
- if (!IS_ERR(s))
- kfree(s);
-}