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Commit feb7cbb0 authored by Jaegeuk Kim's avatar Jaegeuk Kim
Browse files

f2fs: avoid abnormal behavior on broken symlink 



When f2fs_symlink was triggered and checkpoint was done before syncing its
link path, f2fs can get broken symlink like "xxx -> \0\0\0".
This incurs abnormal path_walk by VFS.

Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
parent d0cae97c

fs/f2fs/namei.c

+19 −1
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ 
#include <linux/sched.h>

#include <linux/ctype.h>

#include <linux/dcache.h>

#include <linux/namei.h>



#include "f2fs.h"

#include "node.h"
@@ -295,6 +296,23 @@ static int f2fs_unlink(struct inode *dir, struct dentry *dentry) 
	return err;

}



static void *f2fs_follow_link(struct dentry *dentry, struct nameidata *nd)

{

	struct page *page;



	page = page_follow_link_light(dentry, nd);

	if (IS_ERR(page))

		return page;



	/* this is broken symlink case */

	if (*nd_get_link(nd) == 0) {

		kunmap(page);

		page_cache_release(page);

		return ERR_PTR(-ENOENT);

	}

	return page;

}



static int f2fs_symlink(struct inode *dir, struct dentry *dentry,

					const char *symname)

{
@@ -790,7 +808,7 @@ const struct inode_operations f2fs_dir_inode_operations = { 


const struct inode_operations f2fs_symlink_inode_operations = {

	.readlink       = generic_readlink,

	.follow_link    = page_follow_link_light,

	.follow_link    = f2fs_follow_link,

	.put_link       = page_put_link,

	.getattr	= f2fs_getattr,

	.setattr	= f2fs_setattr,