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Commit 8787c7a3 authored by Tyler Hicks's avatar Tyler Hicks
Browse files

eCryptfs: Revert "dont call lookup_one_len to avoid NULL nameidata" 



This reverts commit 21edad32 and commit
93c3fe40, 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: default avatarAl Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: default avatarTyler Hicks <tyhicks@linux.vnet.ibm.com>
parent 85e2efbb

fs/ecryptfs/inode.c

+12 −94
Original line number Diff line number Diff line
@@ -348,75 +348,6 @@ int ecryptfs_lookup_and_interpose_lower(struct dentry *ecryptfs_dentry, 
	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;