Merge tag 'ecryptfs-3.6-rc1-fixes' of git://git.kernel.org/pub/scm/li…

…nux/kernel/git/tyhicks/ecryptfs

Pull ecryptfs fixes from Tyler Hicks:
 - Fixes a bug when the lower filesystem mount options include 'acl',
   but the eCryptfs mount options do not
 - Cleanups in the messaging code
 - Better handling of empty files in the lower filesystem to improve
   usability.  Failed file creations are now cleaned up and empty lower
   files are converted into eCryptfs during open().
 - The write-through cache changes are being reverted due to bugs that
   are not easy to fix.  Stability outweighs the performance
   enhancements here.
 - Improvement to the mount code to catch unsupported ciphers specified
   in the mount options

* tag 'ecryptfs-3.6-rc1-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tyhicks/ecryptfs:
  eCryptfs: check for eCryptfs cipher support at mount
  eCryptfs: Revert to a writethrough cache model
  eCryptfs: Initialize empty lower files when opening them
  eCryptfs: Unlink lower inode when ecryptfs_create() fails
  eCryptfs: Make all miscdev functions use daemon ptr in file private_data
  eCryptfs: Remove unused messaging declarations and function
  eCryptfs: Copy up POSIX ACL and read-only flags from lower mount

fs/ecryptfs/ecryptfs_kernel.h

@@ -385,19 +385,14 @@ struct ecryptfs_msg_ctx {
 	struct mutex mux;
 };
 
-struct ecryptfs_daemon;
-
 struct ecryptfs_daemon {
 #define ECRYPTFS_DAEMON_IN_READ      0x00000001
 #define ECRYPTFS_DAEMON_IN_POLL      0x00000002
 #define ECRYPTFS_DAEMON_ZOMBIE       0x00000004
 #define ECRYPTFS_DAEMON_MISCDEV_OPEN 0x00000008
 	u32 flags;
 	u32 num_queued_msg_ctx;
-	struct pid *pid;
-	uid_t euid;
-	struct user_namespace *user_ns;
-	struct task_struct *task;
+	struct file *file;
 	struct mutex mux;
 	struct list_head msg_ctx_out_queue;
 	wait_queue_head_t wait;
@@ -554,6 +549,8 @@ extern struct kmem_cache *ecryptfs_key_tfm_cache;
 struct inode *ecryptfs_get_inode(struct inode *lower_inode,
 				 struct super_block *sb);
 void ecryptfs_i_size_init(const char *page_virt, struct inode *inode);
+int ecryptfs_initialize_file(struct dentry *ecryptfs_dentry,
+			     struct inode *ecryptfs_inode);
 int ecryptfs_decode_and_decrypt_filename(char **decrypted_name,
 					 size_t *decrypted_name_size,
 					 struct dentry *ecryptfs_dentry,
@@ -607,13 +604,8 @@ int
 ecryptfs_setxattr(struct dentry *dentry, const char *name, const void *value,
 		  size_t size, int flags);
 int ecryptfs_read_xattr_region(char *page_virt, struct inode *ecryptfs_inode);
-int ecryptfs_process_helo(uid_t euid, struct user_namespace *user_ns,
-			  struct pid *pid);
-int ecryptfs_process_quit(uid_t euid, struct user_namespace *user_ns,
-			  struct pid *pid);
-int ecryptfs_process_response(struct ecryptfs_message *msg, uid_t euid,
-			      struct user_namespace *user_ns, struct pid *pid,
-			      u32 seq);
+int ecryptfs_process_response(struct ecryptfs_daemon *daemon,
+			      struct ecryptfs_message *msg, u32 seq);
 int ecryptfs_send_message(char *data, int data_len,
 			  struct ecryptfs_msg_ctx **msg_ctx);
 int ecryptfs_wait_for_response(struct ecryptfs_msg_ctx *msg_ctx,
@@ -658,8 +650,7 @@ int ecryptfs_read_lower_page_segment(struct page *page_for_ecryptfs,
 				     struct inode *ecryptfs_inode);
 struct page *ecryptfs_get_locked_page(struct inode *inode, loff_t index);
 int ecryptfs_exorcise_daemon(struct ecryptfs_daemon *daemon);
-int ecryptfs_find_daemon_by_euid(struct ecryptfs_daemon **daemon, uid_t euid,
-				 struct user_namespace *user_ns);
+int ecryptfs_find_daemon_by_euid(struct ecryptfs_daemon **daemon);
 int ecryptfs_parse_packet_length(unsigned char *data, size_t *size,
 				 size_t *length_size);
 int ecryptfs_write_packet_length(char *dest, size_t size,
@@ -671,8 +662,7 @@ int ecryptfs_send_miscdev(char *data, size_t data_size,
 			  u16 msg_flags, struct ecryptfs_daemon *daemon);
 void ecryptfs_msg_ctx_alloc_to_free(struct ecryptfs_msg_ctx *msg_ctx);
 int
-ecryptfs_spawn_daemon(struct ecryptfs_daemon **daemon, uid_t euid,
-		      struct user_namespace *user_ns, struct pid *pid);
+ecryptfs_spawn_daemon(struct ecryptfs_daemon **daemon, struct file *file);
 int ecryptfs_init_kthread(void);
 void ecryptfs_destroy_kthread(void);
 int ecryptfs_privileged_open(struct file **lower_file,

fs/ecryptfs/file.c

@@ -138,29 +138,50 @@ static int ecryptfs_readdir(struct file *file, void *dirent, filldir_t filldir)
 	return rc;
 }
 
-static void ecryptfs_vma_close(struct vm_area_struct *vma)
-{
-	filemap_write_and_wait(vma->vm_file->f_mapping);
-}
-
-static const struct vm_operations_struct ecryptfs_file_vm_ops = {
-	.close		= ecryptfs_vma_close,
-	.fault		= filemap_fault,
-};
+struct kmem_cache *ecryptfs_file_info_cache;
 
-static int ecryptfs_file_mmap(struct file *file, struct vm_area_struct *vma)
+static int read_or_initialize_metadata(struct dentry *dentry)
 {
+	struct inode *inode = dentry->d_inode;
+	struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
+	struct ecryptfs_crypt_stat *crypt_stat;
 	int rc;
 
-	rc = generic_file_mmap(file, vma);
+	crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
+	mount_crypt_stat = &ecryptfs_superblock_to_private(
+						inode->i_sb)->mount_crypt_stat;
+	mutex_lock(&crypt_stat->cs_mutex);
+
+	if (crypt_stat->flags & ECRYPTFS_POLICY_APPLIED &&
+	    crypt_stat->flags & ECRYPTFS_KEY_VALID) {
+		rc = 0;
+		goto out;
+	}
+
+	rc = ecryptfs_read_metadata(dentry);
 	if (!rc)
-		vma->vm_ops = &ecryptfs_file_vm_ops;
+		goto out;
+
+	if (mount_crypt_stat->flags & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED) {
+		crypt_stat->flags &= ~(ECRYPTFS_I_SIZE_INITIALIZED
+				       | ECRYPTFS_ENCRYPTED);
+		rc = 0;
+		goto out;
+	}
 
+	if (!(mount_crypt_stat->flags & ECRYPTFS_XATTR_METADATA_ENABLED) &&
+	    !i_size_read(ecryptfs_inode_to_lower(inode))) {
+		rc = ecryptfs_initialize_file(dentry, inode);
+		if (!rc)
+			goto out;
+	}
+
+	rc = -EIO;
+out:
+	mutex_unlock(&crypt_stat->cs_mutex);
 	return rc;
 }
 
-struct kmem_cache *ecryptfs_file_info_cache;
-
 /**
  * ecryptfs_open
  * @inode: inode speciying file to open
@@ -236,32 +257,9 @@ static int ecryptfs_open(struct inode *inode, struct file *file)
 		rc = 0;
 		goto out;
 	}
-	mutex_lock(&crypt_stat->cs_mutex);
-	if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)
-	    || !(crypt_stat->flags & ECRYPTFS_KEY_VALID)) {
-		rc = ecryptfs_read_metadata(ecryptfs_dentry);
-		if (rc) {
-			ecryptfs_printk(KERN_DEBUG,
-					"Valid headers not found\n");
-			if (!(mount_crypt_stat->flags
-			      & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)) {
-				rc = -EIO;
-				printk(KERN_WARNING "Either the lower file "
-				       "is not in a valid eCryptfs format, "
-				       "or the key could not be retrieved. "
-				       "Plaintext passthrough mode is not "
-				       "enabled; returning -EIO\n");
-				mutex_unlock(&crypt_stat->cs_mutex);
-				goto out_put;
-			}
-			rc = 0;
-			crypt_stat->flags &= ~(ECRYPTFS_I_SIZE_INITIALIZED
-					       | ECRYPTFS_ENCRYPTED);
-			mutex_unlock(&crypt_stat->cs_mutex);
-			goto out;
-		}
-	}
-	mutex_unlock(&crypt_stat->cs_mutex);
+	rc = read_or_initialize_metadata(ecryptfs_dentry);
+	if (rc)
+		goto out_put;
 	ecryptfs_printk(KERN_DEBUG, "inode w/ addr = [0x%p], i_ino = "
 			"[0x%.16lx] size: [0x%.16llx]\n", inode, inode->i_ino,
 			(unsigned long long)i_size_read(inode));
@@ -292,15 +290,7 @@ static int ecryptfs_release(struct inode *inode, struct file *file)
 static int
 ecryptfs_fsync(struct file *file, loff_t start, loff_t end, int datasync)
 {
-	int rc = 0;
-
-	rc = generic_file_fsync(file, start, end, datasync);
-	if (rc)
-		goto out;
-	rc = vfs_fsync_range(ecryptfs_file_to_lower(file), start, end,
-			     datasync);
-out:
-	return rc;
+	return vfs_fsync(ecryptfs_file_to_lower(file), datasync);
 }
 
 static int ecryptfs_fasync(int fd, struct file *file, int flag)
@@ -369,7 +359,7 @@ const struct file_operations ecryptfs_main_fops = {
 #ifdef CONFIG_COMPAT
 	.compat_ioctl = ecryptfs_compat_ioctl,
 #endif
-	.mmap = ecryptfs_file_mmap,
+	.mmap = generic_file_mmap,
 	.open = ecryptfs_open,
 	.flush = ecryptfs_flush,
 	.release = ecryptfs_release,

fs/ecryptfs/inode.c

@@ -143,6 +143,31 @@ static int ecryptfs_interpose(struct dentry *lower_dentry,
 	return 0;
 }
 
+static int ecryptfs_do_unlink(struct inode *dir, struct dentry *dentry,
+			      struct inode *inode)
+{
+	struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
+	struct inode *lower_dir_inode = ecryptfs_inode_to_lower(dir);
+	struct dentry *lower_dir_dentry;
+	int rc;
+
+	dget(lower_dentry);
+	lower_dir_dentry = lock_parent(lower_dentry);
+	rc = vfs_unlink(lower_dir_inode, lower_dentry);
+	if (rc) {
+		printk(KERN_ERR "Error in vfs_unlink; rc = [%d]\n", rc);
+		goto out_unlock;
+	}
+	fsstack_copy_attr_times(dir, lower_dir_inode);
+	set_nlink(inode, ecryptfs_inode_to_lower(inode)->i_nlink);
+	inode->i_ctime = dir->i_ctime;
+	d_drop(dentry);
+out_unlock:
+	unlock_dir(lower_dir_dentry);
+	dput(lower_dentry);
+	return rc;
+}
+
 /**
  * ecryptfs_do_create
  * @directory_inode: inode of the new file's dentry's parent in ecryptfs
@@ -182,8 +207,10 @@ ecryptfs_do_create(struct inode *directory_inode,
 	}
 	inode = __ecryptfs_get_inode(lower_dentry->d_inode,
 				     directory_inode->i_sb);
-	if (IS_ERR(inode))
+	if (IS_ERR(inode)) {
+		vfs_unlink(lower_dir_dentry->d_inode, lower_dentry);
 		goto out_lock;
+	}
 	fsstack_copy_attr_times(directory_inode, lower_dir_dentry->d_inode);
 	fsstack_copy_inode_size(directory_inode, lower_dir_dentry->d_inode);
 out_lock:
@@ -200,8 +227,8 @@ ecryptfs_do_create(struct inode *directory_inode,
  *
  * Returns zero on success
  */
-static int ecryptfs_initialize_file(struct dentry *ecryptfs_dentry,
-				    struct inode *ecryptfs_inode)
+int ecryptfs_initialize_file(struct dentry *ecryptfs_dentry,
+			     struct inode *ecryptfs_inode)
 {
 	struct ecryptfs_crypt_stat *crypt_stat =
 		&ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat;
@@ -264,7 +291,9 @@ ecryptfs_create(struct inode *directory_inode, struct dentry *ecryptfs_dentry,
 	 * that this on disk file is prepared to be an ecryptfs file */
 	rc = ecryptfs_initialize_file(ecryptfs_dentry, ecryptfs_inode);
 	if (rc) {
-		drop_nlink(ecryptfs_inode);
+		ecryptfs_do_unlink(directory_inode, ecryptfs_dentry,
+				   ecryptfs_inode);
+		make_bad_inode(ecryptfs_inode);
 		unlock_new_inode(ecryptfs_inode);
 		iput(ecryptfs_inode);
 		goto out;
@@ -466,27 +495,7 @@ static int ecryptfs_link(struct dentry *old_dentry, struct inode *dir,
 
 static int ecryptfs_unlink(struct inode *dir, struct dentry *dentry)
 {
-	int rc = 0;
-	struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
-	struct inode *lower_dir_inode = ecryptfs_inode_to_lower(dir);
-	struct dentry *lower_dir_dentry;
-
-	dget(lower_dentry);
-	lower_dir_dentry = lock_parent(lower_dentry);
-	rc = vfs_unlink(lower_dir_inode, lower_dentry);
-	if (rc) {
-		printk(KERN_ERR "Error in vfs_unlink; rc = [%d]\n", rc);
-		goto out_unlock;
-	}
-	fsstack_copy_attr_times(dir, lower_dir_inode);
-	set_nlink(dentry->d_inode,
-		  ecryptfs_inode_to_lower(dentry->d_inode)->i_nlink);
-	dentry->d_inode->i_ctime = dir->i_ctime;
-	d_drop(dentry);
-out_unlock:
-	unlock_dir(lower_dir_dentry);
-	dput(lower_dentry);
-	return rc;
+	return ecryptfs_do_unlink(dir, dentry, dentry->d_inode);
 }
 
 static int ecryptfs_symlink(struct inode *dir, struct dentry *dentry,
@@ -961,12 +970,6 @@ static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
 			goto out;
 	}
 
-	if (S_ISREG(inode->i_mode)) {
-		rc = filemap_write_and_wait(inode->i_mapping);
-		if (rc)
-			goto out;
-		fsstack_copy_attr_all(inode, lower_inode);
-	}
 	memcpy(&lower_ia, ia, sizeof(lower_ia));
 	if (ia->ia_valid & ATTR_FILE)
 		lower_ia.ia_file = ecryptfs_file_to_lower(ia->ia_file);

fs/ecryptfs/main.c

@@ -279,6 +279,7 @@ static int ecryptfs_parse_options(struct ecryptfs_sb_info *sbi, char *options,
 	char *fnek_src;
 	char *cipher_key_bytes_src;
 	char *fn_cipher_key_bytes_src;
+	u8 cipher_code;
 
 	*check_ruid = 0;
 
@@ -420,6 +421,18 @@ static int ecryptfs_parse_options(struct ecryptfs_sb_info *sbi, char *options,
 	    && !fn_cipher_key_bytes_set)
 		mount_crypt_stat->global_default_fn_cipher_key_bytes =
 			mount_crypt_stat->global_default_cipher_key_size;
+
+	cipher_code = ecryptfs_code_for_cipher_string(
+		mount_crypt_stat->global_default_cipher_name,
+		mount_crypt_stat->global_default_cipher_key_size);
+	if (!cipher_code) {
+		ecryptfs_printk(KERN_ERR,
+				"eCryptfs doesn't support cipher: %s",
+				mount_crypt_stat->global_default_cipher_name);
+		rc = -EINVAL;
+		goto out;
+	}
+
 	mutex_lock(&key_tfm_list_mutex);
 	if (!ecryptfs_tfm_exists(mount_crypt_stat->global_default_cipher_name,
 				 NULL)) {
@@ -540,6 +553,15 @@ static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags
 	}
 
 	ecryptfs_set_superblock_lower(s, path.dentry->d_sb);
+
+	/**
+	 * Set the POSIX ACL flag based on whether they're enabled in the lower
+	 * mount. Force a read-only eCryptfs mount if the lower mount is ro.
+	 * Allow a ro eCryptfs mount even when the lower mount is rw.
+	 */
+	s->s_flags = flags & ~MS_POSIXACL;
+	s->s_flags |= path.dentry->d_sb->s_flags & (MS_RDONLY | MS_POSIXACL);
+
 	s->s_maxbytes = path.dentry->d_sb->s_maxbytes;
 	s->s_blocksize = path.dentry->d_sb->s_blocksize;
 	s->s_magic = ECRYPTFS_SUPER_MAGIC;