From 8787c7a3e0e3f1aa21856d6b6cd6880cc93497e9 Mon Sep 17 00:00:00 2001 From: Tyler Hicks Date: Thu, 17 Feb 2011 18:51:24 -0600 Subject: [PATCH] eCryptfs: Revert "dont call lookup_one_len to avoid NULL nameidata" This reverts commit 21edad32205e97dc7ccb81a85234c77e760364c8 and commit 93c3fe40c279f002906ad14584c30671097d4394, which fixed a regression by the former. Al Viro pointed out bypassed dcache lookups in ecryptfs_new_lower_dentry(), misuse of vfs_path_lookup() in ecryptfs_lookup_one_lower() and a dislike of passing nameidata to the lower filesystem. Reported-by: Al Viro Signed-off-by: Tyler Hicks --- fs/ecryptfs/inode.c | 106 +++++--------------------------------------- 1 file changed, 12 insertions(+), 94 deletions(-) diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c index bd33f87a1907..fc44823fea3a 100644 --- a/fs/ecryptfs/inode.c +++ b/fs/ecryptfs/inode.c @@ -348,75 +348,6 @@ out: return rc; } -/** - * ecryptfs_new_lower_dentry - * @name: The name of the new dentry. - * @lower_dir_dentry: Parent directory of the new dentry. - * @nd: nameidata from last lookup. - * - * Create a new dentry or get it from lower parent dir. - */ -static struct dentry * -ecryptfs_new_lower_dentry(struct qstr *name, struct dentry *lower_dir_dentry, - struct nameidata *nd) -{ - struct dentry *new_dentry; - struct dentry *tmp; - struct inode *lower_dir_inode; - - lower_dir_inode = lower_dir_dentry->d_inode; - - tmp = d_alloc(lower_dir_dentry, name); - if (!tmp) - return ERR_PTR(-ENOMEM); - - mutex_lock(&lower_dir_inode->i_mutex); - new_dentry = lower_dir_inode->i_op->lookup(lower_dir_inode, tmp, nd); - mutex_unlock(&lower_dir_inode->i_mutex); - - if (!new_dentry) - new_dentry = tmp; - else - dput(tmp); - - return new_dentry; -} - - -/** - * ecryptfs_lookup_one_lower - * @ecryptfs_dentry: The eCryptfs dentry that we are looking up - * @lower_dir_dentry: lower parent directory - * @name: lower file name - * - * Get the lower dentry from vfs. If lower dentry does not exist yet, - * create it. - */ -static struct dentry * -ecryptfs_lookup_one_lower(struct dentry *ecryptfs_dentry, - struct dentry *lower_dir_dentry, struct qstr *name) -{ - struct nameidata nd; - struct vfsmount *lower_mnt; - int err; - - lower_mnt = mntget(ecryptfs_dentry_to_lower_mnt( - ecryptfs_dentry->d_parent)); - err = vfs_path_lookup(lower_dir_dentry, lower_mnt, name->name , 0, &nd); - mntput(lower_mnt); - - if (!err) { - /* we dont need the mount */ - mntput(nd.path.mnt); - return nd.path.dentry; - } - if (err != -ENOENT) - return ERR_PTR(err); - - /* create a new lower dentry */ - return ecryptfs_new_lower_dentry(name, lower_dir_dentry, &nd); -} - /** * ecryptfs_lookup * @ecryptfs_dir_inode: The eCryptfs directory inode @@ -434,7 +365,6 @@ static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode, size_t encrypted_and_encoded_name_size; struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL; struct dentry *lower_dir_dentry, *lower_dentry; - struct qstr lower_name; int rc = 0; if ((ecryptfs_dentry->d_name.len == 1 @@ -444,20 +374,14 @@ static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode, goto out_d_drop; } lower_dir_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry->d_parent); - lower_name.name = ecryptfs_dentry->d_name.name; - lower_name.len = ecryptfs_dentry->d_name.len; - lower_name.hash = ecryptfs_dentry->d_name.hash; - if (lower_dir_dentry->d_op && lower_dir_dentry->d_op->d_hash) { - rc = lower_dir_dentry->d_op->d_hash(lower_dir_dentry, - lower_dir_dentry->d_inode, &lower_name); - if (rc < 0) - goto out_d_drop; - } - lower_dentry = ecryptfs_lookup_one_lower(ecryptfs_dentry, - lower_dir_dentry, &lower_name); + mutex_lock(&lower_dir_dentry->d_inode->i_mutex); + lower_dentry = lookup_one_len(ecryptfs_dentry->d_name.name, + lower_dir_dentry, + ecryptfs_dentry->d_name.len); + mutex_unlock(&lower_dir_dentry->d_inode->i_mutex); if (IS_ERR(lower_dentry)) { rc = PTR_ERR(lower_dentry); - ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_lower() returned " + ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_len() returned " "[%d] on lower_dentry = [%s]\n", __func__, rc, encrypted_and_encoded_name); goto out_d_drop; @@ -479,20 +403,14 @@ static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode, "filename; rc = [%d]\n", __func__, rc); goto out_d_drop; } - lower_name.name = encrypted_and_encoded_name; - lower_name.len = encrypted_and_encoded_name_size; - lower_name.hash = full_name_hash(lower_name.name, lower_name.len); - if (lower_dir_dentry->d_op && lower_dir_dentry->d_op->d_hash) { - rc = lower_dir_dentry->d_op->d_hash(lower_dir_dentry, - lower_dir_dentry->d_inode, &lower_name); - if (rc < 0) - goto out_d_drop; - } - lower_dentry = ecryptfs_lookup_one_lower(ecryptfs_dentry, - lower_dir_dentry, &lower_name); + mutex_lock(&lower_dir_dentry->d_inode->i_mutex); + lower_dentry = lookup_one_len(encrypted_and_encoded_name, + lower_dir_dentry, + encrypted_and_encoded_name_size); + mutex_unlock(&lower_dir_dentry->d_inode->i_mutex); if (IS_ERR(lower_dentry)) { rc = PTR_ERR(lower_dentry); - ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_lower() returned " + ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_len() returned " "[%d] on lower_dentry = [%s]\n", __func__, rc, encrypted_and_encoded_name); goto out_d_drop; -- 2.20.1