lkml.org 
[lkml]   [2015]   [Apr]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 2/3] f2fs: avoid abnormal behavior on broken symlink
Date
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: Jaegeuk Kim <jaegeuk@kernel.org>
---
fs/f2fs/namei.c | 20 +++++++++++++++++++-
1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c
index 5d990d8..6cfd954 100644
--- a/fs/f2fs/namei.c
+++ b/fs/f2fs/namei.c
@@ -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 @@ fail:
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,
--
2.1.1


\
 
 \ /
  Last update: 2015-04-16 10:01    [W:0.056 / U:0.320 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site