Clean ecryptfs ->get_sb() up

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/ecryptfs/main.c

@@ -281,7 +281,7 @@ static void ecryptfs_init_mount_crypt_stat(
  *
  * Returns zero on success; non-zero on error
  */
-static int ecryptfs_parse_options(struct super_block *sb, char *options)
+static int ecryptfs_parse_options(struct ecryptfs_sb_info *sbi, char *options)
 {
 	char *p;
 	int rc = 0;
@@ -293,7 +293,7 @@ static int ecryptfs_parse_options(struct super_block *sb, char *options)
 	int fn_cipher_key_bytes;
 	int fn_cipher_key_bytes_set = 0;
 	struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
-		&ecryptfs_superblock_to_private(sb)->mount_crypt_stat;
+		&sbi->mount_crypt_stat;
 	substring_t args[MAX_OPT_ARGS];
 	int token;
 	char *sig_src;
@@ -484,68 +484,6 @@ out:
 
 struct kmem_cache *ecryptfs_sb_info_cache;
 
-/**
- * ecryptfs_fill_super
- * @sb: The ecryptfs super block
- * @raw_data: The options passed to mount
- * @silent: Not used but required by function prototype
- *
- * Sets up what we can of the sb, rest is done in ecryptfs_read_super
- *
- * Returns zero on success; non-zero otherwise
- */
-static int
-ecryptfs_fill_super(struct super_block *sb, void *raw_data, int silent)
-{
-	struct ecryptfs_sb_info *esi;
-	int rc = 0;
-
-	/* Released in ecryptfs_put_super() */
-	ecryptfs_set_superblock_private(sb,
-					kmem_cache_zalloc(ecryptfs_sb_info_cache,
-							 GFP_KERNEL));
-	esi = ecryptfs_superblock_to_private(sb);
-	if (!esi) {
-		ecryptfs_printk(KERN_WARNING, "Out of memory\n");
-		rc = -ENOMEM;
-		goto out;
-	}
-
-	rc = bdi_setup_and_register(&esi->bdi, "ecryptfs", BDI_CAP_MAP_COPY);
-	if (rc)
-		goto out;
-
-	sb->s_bdi = &esi->bdi;
-	sb->s_op = &ecryptfs_sops;
-	/* Released through deactivate_super(sb) from get_sb_nodev */
-	sb->s_root = d_alloc(NULL, &(const struct qstr) {
-			     .hash = 0,.name = "/",.len = 1});
-	if (!sb->s_root) {
-		ecryptfs_printk(KERN_ERR, "d_alloc failed\n");
-		rc = -ENOMEM;
-		goto out;
-	}
-	sb->s_root->d_op = &ecryptfs_dops;
-	sb->s_root->d_sb = sb;
-	sb->s_root->d_parent = sb->s_root;
-	/* Released in d_release when dput(sb->s_root) is called */
-	/* through deactivate_super(sb) from get_sb_nodev() */
-	ecryptfs_set_dentry_private(sb->s_root,
-				    kmem_cache_zalloc(ecryptfs_dentry_info_cache,
-						     GFP_KERNEL));
-	if (!ecryptfs_dentry_to_private(sb->s_root)) {
-		ecryptfs_printk(KERN_ERR,
-				"dentry_info_cache alloc failed\n");
-		rc = -ENOMEM;
-		goto out;
-	}
-	rc = 0;
-out:
-	/* Should be able to rely on deactivate_super called from
-	 * get_sb_nodev */
-	return rc;
-}
-
 /**
  * ecryptfs_read_super
  * @sb: The ecryptfs super block
@@ -588,11 +526,8 @@ out:
  * @dev_name: The path to mount over
  * @raw_data: The options passed into the kernel
  *
- * The whole ecryptfs_get_sb process is broken into 4 functions:
+ * The whole ecryptfs_get_sb process is broken into 3 functions:
  * ecryptfs_parse_options(): handle options passed to ecryptfs, if any
- * ecryptfs_fill_super(): used by get_sb_nodev, fills out the super_block
- *                        with as much information as it can before needing
- *                        the lower filesystem.
  * ecryptfs_read_super(): this accesses the lower filesystem and uses
  *                        ecryptfs_interpose to perform most of the linking
  * ecryptfs_interpose(): links the lower filesystem into ecryptfs (inode.c)
@@ -601,30 +536,78 @@ static int ecryptfs_get_sb(struct file_system_type *fs_type, int flags,
 			const char *dev_name, void *raw_data,
 			struct vfsmount *mnt)
 {
+	struct super_block *s;
+	struct ecryptfs_sb_info *sbi;
+	struct ecryptfs_dentry_info *root_info;
+	const char *err = "Getting sb failed";
 	int rc;
-	struct super_block *sb;
 
-	rc = get_sb_nodev(fs_type, flags, raw_data, ecryptfs_fill_super, mnt);
+	sbi = kmem_cache_zalloc(ecryptfs_sb_info_cache, GFP_KERNEL);
-	if (rc < 0) {
+	if (!sbi) {
-		printk(KERN_ERR "Getting sb failed; rc = [%d]\n", rc);
+		rc = -ENOMEM;
 		goto out;
 	}
-	sb = mnt->mnt_sb;
+
-	rc = ecryptfs_parse_options(sb, raw_data);
+	rc = ecryptfs_parse_options(sbi, raw_data);
 	if (rc) {
-		printk(KERN_ERR "Error parsing options; rc = [%d]\n", rc);
+		err = "Error parsing options";
-		goto out_abort;
-	}
-	rc = ecryptfs_read_super(sb, dev_name);
-	if (rc) {
-		printk(KERN_ERR "Reading sb failed; rc = [%d]\n", rc);
-		goto out_abort;
-	}
 		goto out;
-out_abort:
+	}
-	dput(sb->s_root); /* aka mnt->mnt_root, as set by get_sb_nodev() */
+
-	deactivate_locked_super(sb);
+	s = sget(fs_type, NULL, set_anon_super, NULL);
+	if (IS_ERR(s)) {
+		rc = PTR_ERR(s);
+		goto out;
+	}
+
+	s->s_flags = flags;
+	rc = bdi_setup_and_register(&sbi->bdi, "ecryptfs", BDI_CAP_MAP_COPY);
+	if (rc) {
+		deactivate_locked_super(s);
+		goto out;
+	}
+
+	ecryptfs_set_superblock_private(s, sbi);
+	s->s_bdi = &sbi->bdi;
+
+	/* ->kill_sb() will take care of sbi after that point */
+	sbi = NULL;
+	s->s_op = &ecryptfs_sops;
+
+	rc = -ENOMEM;
+	s->s_root = d_alloc(NULL, &(const struct qstr) {
+			     .hash = 0,.name = "/",.len = 1});
+	if (!s->s_root) {
+		deactivate_locked_super(s);
+		goto out;
+	}
+	s->s_root->d_op = &ecryptfs_dops;
+	s->s_root->d_sb = s;
+	s->s_root->d_parent = s->s_root;
+
+	root_info = kmem_cache_zalloc(ecryptfs_dentry_info_cache, GFP_KERNEL);
+	if (!root_info) {
+		deactivate_locked_super(s);
+		goto out;
+	}
+	/* ->kill_sb() will take care of root_info */
+	ecryptfs_set_dentry_private(s->s_root, root_info);
+	s->s_flags |= MS_ACTIVE;
+	rc = ecryptfs_read_super(s, dev_name);
+	if (rc) {
+		deactivate_locked_super(s);
+		err = "Reading sb failed";
+		goto out;
+	}
+	simple_set_mnt(mnt, s);
+	return 0;
+
 out:
+	if (sbi) {
+		ecryptfs_destroy_mount_crypt_stat(&sbi->mount_crypt_stat);
+		kmem_cache_free(ecryptfs_sb_info_cache, sbi);
+	}
+	printk(KERN_ERR "%s; rc = [%d]\n", err, rc);
 	return rc;
 }