From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jaegeuk Kim Subject: [PATCH 2/3] f2fs: avoid abnormal behavior on broken symlink Date: Thu, 16 Apr 2015 00:30:44 -0700 Message-ID: <1429169445-18306-2-git-send-email-jaegeuk@kernel.org> References: <1429169445-18306-1-git-send-email-jaegeuk@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: Jaegeuk Kim To: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net Return-path: In-Reply-To: <1429169445-18306-1-git-send-email-jaegeuk@kernel.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net List-Id: linux-fsdevel.vger.kernel.org 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 --- 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 #include #include +#include #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 ------------------------------------------------------------------------------ BPM Camp - Free Virtual Workshop May 6th at 10am PDT/1PM EDT Develop your own process in accordance with the BPMN 2 standard Learn Process modeling best practices with Bonita BPM through live exercises http://www.bonitasoft.com/be-part-of-it/events/bpm-camp-virtual- event?utm_ source=Sourceforge_BPM_Camp_5_6_15&utm_medium=email&utm_campaign=VA_SF