From 73f507171cfa407b19f254aef95cbb058c8180cf Mon Sep 17 00:00:00 2001 From: "Aneesh Kumar K.V" Date: Tue, 16 Aug 2011 22:19:28 +0530 Subject: [PATCH] fs/9p: Always ask new inode in lookup for cache mode disabled This make sure we don't end up reusing the unlinked inode object. The ideal way is to use inode i_generation. But i_generation is not available in userspace always. Signed-off-by: Aneesh Kumar K.V --- fs/9p/vfs_inode.c | 28 +++++++++++++++++++++------- 1 file changed, 21 insertions(+), 7 deletions(-) diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c index 9e3ea6ce6951..e3c03db3c788 100644 --- a/fs/9p/vfs_inode.c +++ b/fs/9p/vfs_inode.c @@ -825,6 +825,7 @@ static int v9fs_vfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nameidata) { + struct dentry *res; struct super_block *sb; struct v9fs_session_info *v9ses; struct p9_fid *dfid, *fid; @@ -856,22 +857,35 @@ struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry, return ERR_PTR(result); } - - inode = v9fs_get_inode_from_fid(v9ses, fid, dir->i_sb); + /* + * Make sure we don't use a wrong inode due to parallel + * unlink. For cached mode create calls request for new + * inode. But with cache disabled, lookup should do this. + */ + if (v9ses->cache) + inode = v9fs_get_inode_from_fid(v9ses, fid, dir->i_sb); + else + inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb); if (IS_ERR(inode)) { result = PTR_ERR(inode); inode = NULL; goto error; } - result = v9fs_fid_add(dentry, fid); if (result < 0) goto error_iput; - inst_out: - d_add(dentry, inode); - return NULL; - + /* + * If we had a rename on the server and a parallel lookup + * for the new name, then make sure we instantiate with + * the new name. ie look up for a/b, while on server somebody + * moved b under k and client parallely did a lookup for + * k/b. + */ + res = d_materialise_unique(dentry, inode); + if (!IS_ERR(res)) + return res; + result = PTR_ERR(res); error_iput: iput(inode); error: -- 2.20.1