Merge branch 'work.ecryptfs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull exryptfs updates from Al Viro:
 "The interesting part here is (ecryptfs) lock_parent() fixes - its
  treatment of ->d_parent had been very wrong.

  The rest is trivial cleanups"

* 'work.ecryptfs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  ecryptfs: ecryptfs_dentry_info->crypt_stat is never used
  ecryptfs: get rid of unused accessors
  ecryptfs: saner API for lock_parent()
  ecryptfs: get rid of pointless dget/dput in ->symlink() and ->link()

2 files changed, 75 insertions, 105 deletions

diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h
index e6ac78c62ca4..495fb4514d09 100644
--- a/fs/ecryptfs/ecryptfs_kernel.h
+++ b/fs/ecryptfs/ecryptfs_kernel.h
@@ -262,10 +262,7 @@ struct ecryptfs_inode_info {
  * vfsmount too. */
 struct ecryptfs_dentry_info {
 	struct path lower_path;
-	union {
-		struct ecryptfs_crypt_stat *crypt_stat;
-		struct rcu_head rcu;
-	};
+	struct rcu_head rcu;
 };
 
 /**
@@ -496,12 +493,6 @@ ecryptfs_set_superblock_lower(struct super_block *sb,
 	((struct ecryptfs_sb_info *)sb->s_fs_info)->wsi_sb = lower_sb;
 }
 
-static inline struct ecryptfs_dentry_info *
-ecryptfs_dentry_to_private(struct dentry *dentry)
-{
-	return (struct ecryptfs_dentry_info *)dentry->d_fsdata;
-}
-
 static inline void
 ecryptfs_set_dentry_private(struct dentry *dentry,
 			    struct ecryptfs_dentry_info *dentry_info)
@@ -515,12 +506,6 @@ ecryptfs_dentry_to_lower(struct dentry *dentry)
 	return ((struct ecryptfs_dentry_info *)dentry->d_fsdata)->lower_path.dentry;
 }
 
-static inline struct vfsmount *
-ecryptfs_dentry_to_lower_mnt(struct dentry *dentry)
-{
-	return ((struct ecryptfs_dentry_info *)dentry->d_fsdata)->lower_path.mnt;
-}
-
 static inline struct path *
 ecryptfs_dentry_to_lower_path(struct dentry *dentry)
 {
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index 7169ea873347..0a1ab1db1450 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -22,19 +22,18 @@
 #include <asm/unaligned.h>
 #include "ecryptfs_kernel.h"
 
-static struct dentry *lock_parent(struct dentry *dentry)
+static int lock_parent(struct dentry *dentry,
+		       struct dentry **lower_dentry,
+		       struct inode **lower_dir)
 {
-	struct dentry *dir;
+	struct dentry *lower_dir_dentry;
 
-	dir = dget_parent(dentry);
-	inode_lock_nested(d_inode(dir), I_MUTEX_PARENT);
-	return dir;
-}
+	lower_dir_dentry = ecryptfs_dentry_to_lower(dentry->d_parent);
+	*lower_dir = d_inode(lower_dir_dentry);
+	*lower_dentry = ecryptfs_dentry_to_lower(dentry);
 
-static void unlock_dir(struct dentry *dir)
-{
-	inode_unlock(d_inode(dir));
-	dput(dir);
+	inode_lock_nested(*lower_dir, I_MUTEX_PARENT);
+	return (*lower_dentry)->d_parent == lower_dir_dentry ? 0 : -EINVAL;
 }
 
 static int ecryptfs_inode_test(struct inode *inode, void *lower_inode)
@@ -128,32 +127,29 @@ static int ecryptfs_interpose(struct dentry *lower_dentry,
 static int ecryptfs_do_unlink(struct inode *dir, struct dentry *dentry,
 			      struct inode *inode)
 {
-	struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
-	struct dentry *lower_dir_dentry;
-	struct inode *lower_dir_inode;
+	struct dentry *lower_dentry;
+	struct inode *lower_dir;
 	int rc;
 
-	lower_dir_dentry = ecryptfs_dentry_to_lower(dentry->d_parent);
-	lower_dir_inode = d_inode(lower_dir_dentry);
-	inode_lock_nested(lower_dir_inode, I_MUTEX_PARENT);
+	rc = lock_parent(dentry, &lower_dentry, &lower_dir);
 	dget(lower_dentry);	// don't even try to make the lower negative
-	if (lower_dentry->d_parent != lower_dir_dentry)
-		rc = -EINVAL;
-	else if (d_unhashed(lower_dentry))
-		rc = -EINVAL;
-	else
-		rc = vfs_unlink(&init_user_ns, lower_dir_inode, lower_dentry,
-				NULL);
+	if (!rc) {
+		if (d_unhashed(lower_dentry))
+			rc = -EINVAL;
+		else
+			rc = vfs_unlink(&init_user_ns, lower_dir, lower_dentry,
+					NULL);
+	}
 	if (rc) {
 		printk(KERN_ERR "Error in vfs_unlink; rc = [%d]\n", rc);
 		goto out_unlock;
 	}
-	fsstack_copy_attr_times(dir, lower_dir_inode);
+	fsstack_copy_attr_times(dir, lower_dir);
 	set_nlink(inode, ecryptfs_inode_to_lower(inode)->i_nlink);
 	inode->i_ctime = dir->i_ctime;
 out_unlock:
 	dput(lower_dentry);
-	inode_unlock(lower_dir_inode);
+	inode_unlock(lower_dir);
 	if (!rc)
 		d_drop(dentry);
 	return rc;
@@ -177,13 +173,13 @@ ecryptfs_do_create(struct inode *directory_inode,
 {
 	int rc;
 	struct dentry *lower_dentry;
-	struct dentry *lower_dir_dentry;
+	struct inode *lower_dir;
 	struct inode *inode;
 
-	lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
-	lower_dir_dentry = lock_parent(lower_dentry);
-	rc = vfs_create(&init_user_ns, d_inode(lower_dir_dentry), lower_dentry,
-			mode, true);
+	rc = lock_parent(ecryptfs_dentry, &lower_dentry, &lower_dir);
+	if (!rc)
+		rc = vfs_create(&init_user_ns, lower_dir,
+				lower_dentry, mode, true);
 	if (rc) {
 		printk(KERN_ERR "%s: Failure to create dentry in lower fs; "
 		       "rc = [%d]\n", __func__, rc);
@@ -193,14 +189,13 @@ ecryptfs_do_create(struct inode *directory_inode,
 	inode = __ecryptfs_get_inode(d_inode(lower_dentry),
 				     directory_inode->i_sb);
 	if (IS_ERR(inode)) {
-		vfs_unlink(&init_user_ns, d_inode(lower_dir_dentry),
-			   lower_dentry, NULL);
+		vfs_unlink(&init_user_ns, lower_dir, lower_dentry, NULL);
 		goto out_lock;
 	}
-	fsstack_copy_attr_times(directory_inode, d_inode(lower_dir_dentry));
-	fsstack_copy_inode_size(directory_inode, d_inode(lower_dir_dentry));
+	fsstack_copy_attr_times(directory_inode, lower_dir);
+	fsstack_copy_inode_size(directory_inode, lower_dir);
 out_lock:
-	unlock_dir(lower_dir_dentry);
+	inode_unlock(lower_dir);
 	return inode;
 }
 
@@ -431,32 +426,28 @@ static int ecryptfs_link(struct dentry *old_dentry, struct inode *dir,
 {
 	struct dentry *lower_old_dentry;
 	struct dentry *lower_new_dentry;
-	struct dentry *lower_dir_dentry;
+	struct inode *lower_dir;
 	u64 file_size_save;
 	int rc;
 
 	file_size_save = i_size_read(d_inode(old_dentry));
 	lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
-	lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
-	dget(lower_old_dentry);
-	dget(lower_new_dentry);
-	lower_dir_dentry = lock_parent(lower_new_dentry);
-	rc = vfs_link(lower_old_dentry, &init_user_ns,
-		      d_inode(lower_dir_dentry), lower_new_dentry, NULL);
+	rc = lock_parent(new_dentry, &lower_new_dentry, &lower_dir);
+	if (!rc)
+		rc = vfs_link(lower_old_dentry, &init_user_ns, lower_dir,
+			      lower_new_dentry, NULL);
 	if (rc || d_really_is_negative(lower_new_dentry))
 		goto out_lock;
 	rc = ecryptfs_interpose(lower_new_dentry, new_dentry, dir->i_sb);
 	if (rc)
 		goto out_lock;
-	fsstack_copy_attr_times(dir, d_inode(lower_dir_dentry));
-	fsstack_copy_inode_size(dir, d_inode(lower_dir_dentry));
+	fsstack_copy_attr_times(dir, lower_dir);
+	fsstack_copy_inode_size(dir, lower_dir);
 	set_nlink(d_inode(old_dentry),
 		  ecryptfs_inode_to_lower(d_inode(old_dentry))->i_nlink);
 	i_size_write(d_inode(new_dentry), file_size_save);
 out_lock:
-	unlock_dir(lower_dir_dentry);
-	dput(lower_new_dentry);
-	dput(lower_old_dentry);
+	inode_unlock(lower_dir);
 	return rc;
 }
 
@@ -471,14 +462,14 @@ static int ecryptfs_symlink(struct user_namespace *mnt_userns,
 {
 	int rc;
 	struct dentry *lower_dentry;
-	struct dentry *lower_dir_dentry;
+	struct inode *lower_dir;
 	char *encoded_symname;
 	size_t encoded_symlen;
 	struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL;
 
-	lower_dentry = ecryptfs_dentry_to_lower(dentry);
-	dget(lower_dentry);
-	lower_dir_dentry = lock_parent(lower_dentry);
+	rc = lock_parent(dentry, &lower_dentry, &lower_dir);
+	if (rc)
+		goto out_lock;
 	mount_crypt_stat = &ecryptfs_superblock_to_private(
 		dir->i_sb)->mount_crypt_stat;
 	rc = ecryptfs_encrypt_and_encode_filename(&encoded_symname,
@@ -487,7 +478,7 @@ static int ecryptfs_symlink(struct user_namespace *mnt_userns,
 						  strlen(symname));
 	if (rc)
 		goto out_lock;
-	rc = vfs_symlink(&init_user_ns, d_inode(lower_dir_dentry), lower_dentry,
+	rc = vfs_symlink(&init_user_ns, lower_dir, lower_dentry,
 			 encoded_symname);
 	kfree(encoded_symname);
 	if (rc || d_really_is_negative(lower_dentry))
@@ -495,11 +486,10 @@ static int ecryptfs_symlink(struct user_namespace *mnt_userns,
 	rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
 	if (rc)
 		goto out_lock;
-	fsstack_copy_attr_times(dir, d_inode(lower_dir_dentry));
-	fsstack_copy_inode_size(dir, d_inode(lower_dir_dentry));
+	fsstack_copy_attr_times(dir, lower_dir);
+	fsstack_copy_inode_size(dir, lower_dir);
 out_lock:
-	unlock_dir(lower_dir_dentry);
-	dput(lower_dentry);
+	inode_unlock(lower_dir);
 	if (d_really_is_negative(dentry))
 		d_drop(dentry);
 	return rc;
@@ -510,22 +500,22 @@ static int ecryptfs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
 {
 	int rc;
 	struct dentry *lower_dentry;
-	struct dentry *lower_dir_dentry;
+	struct inode *lower_dir;
 
-	lower_dentry = ecryptfs_dentry_to_lower(dentry);
-	lower_dir_dentry = lock_parent(lower_dentry);
-	rc = vfs_mkdir(&init_user_ns, d_inode(lower_dir_dentry), lower_dentry,
-		       mode);
+	rc = lock_parent(dentry, &lower_dentry, &lower_dir);
+	if (!rc)
+		rc = vfs_mkdir(&init_user_ns, lower_dir,
+			       lower_dentry, mode);
 	if (rc || d_really_is_negative(lower_dentry))
 		goto out;
 	rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
 	if (rc)
 		goto out;
-	fsstack_copy_attr_times(dir, d_inode(lower_dir_dentry));
-	fsstack_copy_inode_size(dir, d_inode(lower_dir_dentry));
-	set_nlink(dir, d_inode(lower_dir_dentry)->i_nlink);
+	fsstack_copy_attr_times(dir, lower_dir);
+	fsstack_copy_inode_size(dir, lower_dir);
+	set_nlink(dir, lower_dir->i_nlink);
 out:
-	unlock_dir(lower_dir_dentry);
+	inode_unlock(lower_dir);
 	if (d_really_is_negative(dentry))
 		d_drop(dentry);
 	return rc;
@@ -534,29 +524,24 @@ out:
 static int ecryptfs_rmdir(struct inode *dir, struct dentry *dentry)
 {
 	struct dentry *lower_dentry;
-	struct dentry *lower_dir_dentry;
-	struct inode *lower_dir_inode;
+	struct inode *lower_dir;
 	int rc;
 
-	lower_dentry = ecryptfs_dentry_to_lower(dentry);
-	lower_dir_dentry = ecryptfs_dentry_to_lower(dentry->d_parent);
-	lower_dir_inode = d_inode(lower_dir_dentry);
-
-	inode_lock_nested(lower_dir_inode, I_MUTEX_PARENT);
+	rc = lock_parent(dentry, &lower_dentry, &lower_dir);
 	dget(lower_dentry);	// don't even try to make the lower negative
-	if (lower_dentry->d_parent != lower_dir_dentry)
-		rc = -EINVAL;
-	else if (d_unhashed(lower_dentry))
-		rc = -EINVAL;
-	else
-		rc = vfs_rmdir(&init_user_ns, lower_dir_inode, lower_dentry);
+	if (!rc) {
+		if (d_unhashed(lower_dentry))
+			rc = -EINVAL;
+		else
+			rc = vfs_rmdir(&init_user_ns, lower_dir, lower_dentry);
+	}
 	if (!rc) {
 		clear_nlink(d_inode(dentry));
-		fsstack_copy_attr_times(dir, lower_dir_inode);
-		set_nlink(dir, lower_dir_inode->i_nlink);
+		fsstack_copy_attr_times(dir, lower_dir);
+		set_nlink(dir, lower_dir->i_nlink);
 	}
 	dput(lower_dentry);
-	inode_unlock(lower_dir_inode);
+	inode_unlock(lower_dir);
 	if (!rc)
 		d_drop(dentry);
 	return rc;
@@ -568,21 +553,21 @@ ecryptfs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
 {
 	int rc;
 	struct dentry *lower_dentry;
-	struct dentry *lower_dir_dentry;
+	struct inode *lower_dir;
 
-	lower_dentry = ecryptfs_dentry_to_lower(dentry);
-	lower_dir_dentry = lock_parent(lower_dentry);
-	rc = vfs_mknod(&init_user_ns, d_inode(lower_dir_dentry), lower_dentry,
-		       mode, dev);
+	rc = lock_parent(dentry, &lower_dentry, &lower_dir);
+	if (!rc)
+		rc = vfs_mknod(&init_user_ns, lower_dir,
+			       lower_dentry, mode, dev);
 	if (rc || d_really_is_negative(lower_dentry))
 		goto out;
 	rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
 	if (rc)
 		goto out;
-	fsstack_copy_attr_times(dir, d_inode(lower_dir_dentry));
-	fsstack_copy_inode_size(dir, d_inode(lower_dir_dentry));
+	fsstack_copy_attr_times(dir, lower_dir);
+	fsstack_copy_inode_size(dir, lower_dir);
 out:
-	unlock_dir(lower_dir_dentry);
+	inode_unlock(lower_dir);
 	if (d_really_is_negative(dentry))
 		d_drop(dentry);
 	return rc;