67 строки
1.8 KiB
C
67 строки
1.8 KiB
C
/*
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* JFFS2 -- Journalling Flash File System, Version 2.
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*
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* Copyright © 2001-2007 Red Hat, Inc.
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*
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* Created by David Woodhouse <dwmw2@infradead.org>
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*
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* For licensing information, see the file 'LICENCE' in this directory.
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*
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/kernel.h>
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#include <linux/fs.h>
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#include <linux/namei.h>
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#include "nodelist.h"
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static void *jffs2_follow_link(struct dentry *dentry, struct nameidata *nd);
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const struct inode_operations jffs2_symlink_inode_operations =
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{
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.readlink = generic_readlink,
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.follow_link = jffs2_follow_link,
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.setattr = jffs2_setattr,
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.setxattr = jffs2_setxattr,
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.getxattr = jffs2_getxattr,
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.listxattr = jffs2_listxattr,
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.removexattr = jffs2_removexattr
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};
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static void *jffs2_follow_link(struct dentry *dentry, struct nameidata *nd)
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{
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struct jffs2_inode_info *f = JFFS2_INODE_INFO(d_inode(dentry));
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char *p = (char *)f->target;
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/*
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* We don't acquire the f->sem mutex here since the only data we
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* use is f->target.
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*
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* 1. If we are here the inode has already built and f->target has
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* to point to the target path.
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* 2. Nobody uses f->target (if the inode is symlink's inode). The
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* exception is inode freeing function which frees f->target. But
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* it can't be called while we are here and before VFS has
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* stopped using our f->target string which we provide by means of
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* nd_set_link() call.
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*/
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if (!p) {
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pr_err("%s(): can't find symlink target\n", __func__);
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p = ERR_PTR(-EIO);
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}
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jffs2_dbg(1, "%s(): target path is '%s'\n",
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__func__, (char *)f->target);
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nd_set_link(nd, p);
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/*
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* We will unlock the f->sem mutex but VFS will use the f->target string. This is safe
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* since the only way that may cause f->target to be changed is iput() operation.
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* But VFS will not use f->target after iput() has been called.
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*/
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return NULL;
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}
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