From 32f1a95d505b99b1f01b6aeea36ec3f97245b357 Mon Sep 17 00:00:00 2001 From: "Artem B. Bityuckiy" Date: Tue, 1 Mar 2005 10:50:52 +0000 Subject: [JFFS2] Add symlink caching support. Signed-off-by: Artem B. Bityuckiy Signed-off-by: Thomas Gleixner --- fs/jffs2/symlink.c | 42 ++++++++++++++++++++++++++++++------------ 1 file changed, 30 insertions(+), 12 deletions(-) (limited to 'fs/jffs2/symlink.c') diff --git a/fs/jffs2/symlink.c b/fs/jffs2/symlink.c index 7b1820d13712..65ab6b001dca 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); -} -- cgit v1.2.3-70-g09d2