am ed2fe57c: Use single tree for multiple storage views. (5271b5ed) · Commits · e / os / android_system_core

sdcard/sdcard.c

+140 −71

Original line number	Diff line number	Diff line
		@@ -151,7 +151,6 @@ struct node {
		perm_t perm;
		userid_t userid;
		uid_t uid;
		gid_t gid;
		mode_t mode;

		struct node next; / per-dir sibling list */
		@@ -192,22 +191,13 @@ struct fuse_global {
		gid_t gid;
		bool multi_user;

		Hashmap* package_to_appid;
		};

		/* Single FUSE mount */
		struct fuse {
		struct fuse_global* global;

		char source_path[PATH_MAX];
		char dest_path[PATH_MAX];
		char obb_path[PATH_MAX];

		Hashmap* package_to_appid;

		__u64 next_generation;
		int fd;
		struct node root;
		gid_t gid;
		mode_t mask;

		/* Used to allocate unique inode numbers for fuse nodes. We use
		* a simple counter based scheme where inode numbers from deleted
		@@ -227,6 +217,22 @@ struct fuse {
		* Accesses must be guarded by \|lock\|.
		*/
		__u32 inode_ctr;

		struct fuse* fuse_default;
		struct fuse* fuse_read;
		struct fuse* fuse_write;
		};

		/* Single FUSE mount */
		struct fuse {
		struct fuse_global* global;

		char dest_path[PATH_MAX];

		int fd;

		gid_t gid;
		mode_t mask;
		};

		/* Private data used by a single FUSE handler */
		@@ -386,8 +392,8 @@ static char* find_file_within(const char* path, const char* name,
		return actual;
		}

		static void attr_from_stat(struct fuse_attr attr, const struct stat s, const struct node* node)
		{
		static void attr_from_stat(struct fuse* fuse, struct fuse_attr *attr,
		const struct stat s, const struct node node) {
		attr->ino = node->ino;
		attr->size = s->st_size;
		attr->blocks = s->st_blocks;
		@@ -401,12 +407,26 @@ static void attr_from_stat(struct fuse_attr attr, const struct stat s, const s
		attr->nlink = s->st_nlink;

		attr->uid = node->uid;
		attr->gid = node->gid;

		if (fuse->gid == AID_SDCARD_RW) {
		/* As an optimization, certain trusted system components only run
		* as owner but operate across all users. Since we're now handing
		* out the sdcard_rw GID only to trusted apps, we're okay relaxing
		* the user boundary enforcement for the default view. The UIDs
		* assigned to app directories are still multiuser aware. */
		attr->gid = AID_SDCARD_RW;
		} else {
		attr->gid = multiuser_get_uid(node->userid, fuse->gid);
		}

		/* Filter requested mode based on underlying file, and
		* pass through file type. */
		int visible_mode = node->mode;
		if (node->perm != PERM_PRE_ROOT) {
		visible_mode = visible_mode & ~fuse->mask;
		}
		int owner_mode = s->st_mode & 0700;
		int filtered_mode = node->mode & (owner_mode \| (owner_mode >> 3) \| (owner_mode >> 6));
		int filtered_mode = visible_mode & (owner_mode \| (owner_mode >> 3) \| (owner_mode >> 6));
		attr->mode = (attr->mode & S_IFMT) \| filtered_mode;
		}

		@@ -432,7 +452,6 @@ static void derive_permissions_locked(struct fuse* fuse, struct node *parent,
		node->perm = PERM_INHERIT;
		node->userid = parent->userid;
		node->uid = parent->uid;
		node->gid = parent->gid;
		node->mode = parent->mode;

		/* Derive custom permissions based on parent and current node */
		@@ -444,16 +463,6 @@ static void derive_permissions_locked(struct fuse* fuse, struct node *parent,
		/* Legacy internal layout places users at top level */
		node->perm = PERM_ROOT;
		node->userid = strtoul(node->name, NULL, 10);
		if (fuse->gid == AID_SDCARD_RW) {
		/* As an optimization, certain trusted system components only run
		* as owner but operate across all users. Since we're now handing
		* out the sdcard_rw GID only to trusted apps, we're okay relaxing
		* the user boundary enforcement for the default view. The UIDs
		* assigned to app directories are still multiuser aware. */
		node->gid = fuse->gid;
		} else {
		node->gid = multiuser_get_uid(node->userid, fuse->gid);
		}
		node->mode = 0771;
		break;
		case PERM_ROOT:
		@@ -475,8 +484,8 @@ static void derive_permissions_locked(struct fuse* fuse, struct node *parent,
		node->perm = PERM_ANDROID_OBB;
		node->mode = 0771;
		/* Single OBB directory is always shared */
		node->graft_path = fuse->obb_path;
		node->graft_pathlen = strlen(fuse->obb_path);
		node->graft_path = fuse->global->obb_path;
		node->graft_pathlen = strlen(fuse->global->obb_path);
		} else if (!strcasecmp(node->name, "media")) {
		/* App-specific directories inside; let anyone traverse */
		node->perm = PERM_ANDROID_MEDIA;
		@@ -493,8 +502,6 @@ static void derive_permissions_locked(struct fuse* fuse, struct node *parent,
		node->mode = 0770;
		break;
		}

		node->mode = node->mode & ~fuse->mask;
		}

		/* Kernel has already enforced everything we returned through
		@@ -535,7 +542,7 @@ struct node create_node_locked(struct fuse fuse,

		// Detect overflows in the inode counter. "4 billion nodes should be enough
		// for everybody".
		if (fuse->inode_ctr == 0) {
		if (fuse->global->inode_ctr == 0) {
		ERROR("No more inode numbers available");
		return NULL;
		}
		@@ -561,8 +568,8 @@ struct node create_node_locked(struct fuse fuse,
		}
		node->namelen = namelen;
		node->nid = ptr_to_id(node);
		node->ino = fuse->inode_ctr++;
		node->gen = fuse->next_generation++;
		node->ino = fuse->global->inode_ctr++;
		node->gen = fuse->global->next_generation++;

		node->deleted = false;

		@@ -616,7 +623,7 @@ static int rename_node_locked(struct node node, const char name,
		static struct node lookup_node_by_id_locked(struct fuse fuse, __u64 nid)
		{
		if (nid == FUSE_ROOT_ID) {
		return &fuse->root;
		return &fuse->global->root;
		} else {
		return id_to_ptr(nid);
		}
		@@ -708,7 +715,7 @@ static int fuse_reply_entry(struct fuse* fuse, __u64 unique,
		return -ENOMEM;
		}
		memset(&out, 0, sizeof(out));
		attr_from_stat(&out.attr, &s, node);
		attr_from_stat(fuse, &out.attr, &s, node);
		out.attr_valid = 10;
		out.entry_valid = 10;
		out.nodeid = node->nid;
		@@ -728,12 +735,43 @@ static int fuse_reply_attr(struct fuse* fuse, __u64 unique, const struct node* n
		return -errno;
		}
		memset(&out, 0, sizeof(out));
		attr_from_stat(&out.attr, &s, node);
		attr_from_stat(fuse, &out.attr, &s, node);
		out.attr_valid = 10;
		fuse_reply(fuse, unique, &out, sizeof(out));
		return NO_STATUS;
		}

		static void fuse_notify_delete(struct fuse* fuse, const __u64 parent,
		const __u64 child, const char* name) {
		struct fuse_out_header hdr;
		struct fuse_notify_delete_out data;
		struct iovec vec[3];
		size_t namelen = strlen(name);
		int res;

		hdr.len = sizeof(hdr) + sizeof(data) + namelen + 1;
		hdr.error = FUSE_NOTIFY_DELETE;
		hdr.unique = 0;

		data.parent = parent;
		data.child = child;
		data.namelen = namelen;
		data.padding = 0;

		vec[0].iov_base = &hdr;
		vec[0].iov_len = sizeof(hdr);
		vec[1].iov_base = &data;
		vec[1].iov_len = sizeof(data);
		vec[2].iov_base = (void*) name;
		vec[2].iov_len = namelen + 1;

		res = writev(fuse->fd, vec, 3);
		/* Ignore ENOENT, since other views may not have seen the entry */
		if (res < 0 && errno != ENOENT) {
		ERROR("* NOTIFY FAILED * %d\n", errno);
		}
		}

		static int handle_lookup(struct fuse* fuse, struct fuse_handler* handler,
		const struct fuse_in_header hdr, const char name)
		{
		@@ -931,7 +969,7 @@ static int handle_mkdir(struct fuse* fuse, struct fuse_handler* handler,
		}
		if (parent_node->perm == PERM_ANDROID && !strcasecmp(name, "obb")) {
		char nomedia[PATH_MAX];
		snprintf(nomedia, PATH_MAX, "%s/.nomedia", fuse->obb_path);
		snprintf(nomedia, PATH_MAX, "%s/.nomedia", fuse->global->obb_path);
		if (touch(nomedia, 0664) != 0) {
		ERROR("Failed to touch(%s): %s\n", nomedia, strerror(errno));
		return -ENOENT;
		@@ -972,6 +1010,20 @@ static int handle_unlink(struct fuse* fuse, struct fuse_handler* handler,
		child_node->deleted = true;
		}
		pthread_mutex_unlock(&fuse->global->lock);
		if (parent_node && child_node) {
		/* Tell all other views that node is gone */
		TRACE("[%d] fuse_notify_delete parent=%"PRIx64", child=%"PRIx64", name=%s\n",
		handler->token, (uint64_t) parent_node->nid, (uint64_t) child_node->nid, name);
		if (fuse != fuse->global->fuse_default) {
		fuse_notify_delete(fuse->global->fuse_default, parent_node->nid, child_node->nid, name);
		}
		if (fuse != fuse->global->fuse_read) {
		fuse_notify_delete(fuse->global->fuse_read, parent_node->nid, child_node->nid, name);
		}
		if (fuse != fuse->global->fuse_write) {
		fuse_notify_delete(fuse->global->fuse_write, parent_node->nid, child_node->nid, name);
		}
		}
		return 0;
		}

		@@ -1006,6 +1058,20 @@ static int handle_rmdir(struct fuse* fuse, struct fuse_handler* handler,
		child_node->deleted = true;
		}
		pthread_mutex_unlock(&fuse->global->lock);
		if (parent_node && child_node) {
		/* Tell all other views that node is gone */
		TRACE("[%d] fuse_notify_delete parent=%"PRIx64", child=%"PRIx64", name=%s\n",
		handler->token, (uint64_t) parent_node->nid, (uint64_t) child_node->nid, name);
		if (fuse != fuse->global->fuse_default) {
		fuse_notify_delete(fuse->global->fuse_default, parent_node->nid, child_node->nid, name);
		}
		if (fuse != fuse->global->fuse_read) {
		fuse_notify_delete(fuse->global->fuse_read, parent_node->nid, child_node->nid, name);
		}
		if (fuse != fuse->global->fuse_write) {
		fuse_notify_delete(fuse->global->fuse_write, parent_node->nid, child_node->nid, name);
		}
		}
		return 0;
		}

		@@ -1201,12 +1267,12 @@ static int handle_statfs(struct fuse* fuse, struct fuse_handler* handler,

		pthread_mutex_lock(&fuse->global->lock);
		TRACE("[%d] STATFS\n", handler->token);
		res = get_node_path_locked(&fuse->root, path, sizeof(path));
		res = get_node_path_locked(&fuse->global->root, path, sizeof(path));
		pthread_mutex_unlock(&fuse->global->lock);
		if (res < 0) {
		return -ENOENT;
		}
		if (statfs(fuse->root.name, &stat) < 0) {
		if (statfs(fuse->global->root.name, &stat) < 0) {
		return -errno;
		}
		memset(&out, 0, sizeof(out));
		@@ -1690,30 +1756,9 @@ static int fuse_setup(struct fuse* fuse, gid_t gid, mode_t mask) {
		return -1;
		}

		fuse->next_generation = 0;
		fuse->inode_ctr = 1;
		fuse->gid = gid;
		fuse->mask = mask;

		memset(&fuse->root, 0, sizeof(fuse->root));
		fuse->root.nid = FUSE_ROOT_ID; /* 1 */
		fuse->root.refcount = 2;
		fuse->root.namelen = strlen(fuse->source_path);
		fuse->root.name = strdup(fuse->source_path);
		fuse->root.userid = 0;
		fuse->root.uid = AID_ROOT;
		fuse->root.gid = fuse->gid;

		if (fuse->global->multi_user) {
		fuse->root.perm = PERM_PRE_ROOT;
		fuse->root.mode = 0711;
		snprintf(fuse->obb_path, sizeof(fuse->obb_path), "%s/obb", fuse->source_path);
		} else {
		fuse->root.perm = PERM_ROOT;
		fuse->root.mode = 0771 & ~mask;
		snprintf(fuse->obb_path, sizeof(fuse->obb_path), "%s/Android/obb", fuse->source_path);
		}

		return 0;
		}

		@@ -1743,23 +1788,49 @@ static void run(const char* source_path, const char* label, uid_t uid,
		global.uid = uid;
		global.gid = gid;
		global.multi_user = multi_user;
		global.next_generation = 0;
		global.inode_ctr = 1;

		fuse_default.global = &global;
		strcpy(fuse_default.source_path, source_path);
		snprintf(fuse_default.dest_path, PATH_MAX, "/mnt/runtime_default/%s", label);
		memset(&global.root, 0, sizeof(global.root));
		global.root.nid = FUSE_ROOT_ID; /* 1 */
		global.root.refcount = 2;
		global.root.namelen = strlen(source_path);
		global.root.name = strdup(source_path);
		global.root.userid = 0;
		global.root.uid = AID_ROOT;

		fuse_read.global = &global;
		strcpy(fuse_read.source_path, source_path);
		snprintf(fuse_read.dest_path, PATH_MAX, "/mnt/runtime_read/%s", label);
		strcpy(global.source_path, source_path);

		if (multi_user) {
		global.root.perm = PERM_PRE_ROOT;
		global.root.mode = 0711;
		snprintf(global.obb_path, sizeof(global.obb_path), "%s/obb", source_path);
		} else {
		global.root.perm = PERM_ROOT;
		global.root.mode = 0771;
		snprintf(global.obb_path, sizeof(global.obb_path), "%s/Android/obb", source_path);
		}

		fuse_default.global = &global;
		fuse_read.global = &global;
		fuse_write.global = &global;
		strcpy(fuse_write.source_path, source_path);

		global.fuse_default = &fuse_default;
		global.fuse_read = &fuse_read;
		global.fuse_write = &fuse_write;

		snprintf(fuse_default.dest_path, PATH_MAX, "/mnt/runtime_default/%s", label);
		snprintf(fuse_read.dest_path, PATH_MAX, "/mnt/runtime_read/%s", label);
		snprintf(fuse_write.dest_path, PATH_MAX, "/mnt/runtime_write/%s", label);

		handler_default.fuse = &fuse_default;
		handler_read.fuse = &fuse_read;
		handler_write.fuse = &fuse_write;

		handler_default.token = 0;
		handler_read.token = 1;
		handler_write.token = 2;

		umask(0);

		if (fuse_setup(&fuse_default, AID_SDCARD_RW, 0006)
		@@ -1784,9 +1855,7 @@ static void run(const char* source_path, const char* label, uid_t uid,
		}

		if (multi_user) {
		fs_prepare_dir(fuse_default.obb_path, 0775, uid, gid);
		fs_prepare_dir(fuse_read.obb_path, 0775, uid, gid);
		fs_prepare_dir(fuse_write.obb_path, 0775, uid, gid);
		fs_prepare_dir(global.obb_path, 0775, uid, gid);
		}

		if (pthread_create(&thread_default, NULL, start_handler, &handler_default)