1 // SPDX-License-Identifier: GPL-2.0
16 #include "disk-io.h"
37  * [ inode objectid, BTRFS_VERITY_DESC_ITEM_KEY, offset ]
39  * At offset 0, we store a btrfs_verity_descriptor_item which tracks the
41  * Starting at offset 1, these hold the generic fs verity descriptor.
46  * [ inode objectid, BTRFS_VERITY_MERKLE_ITEM_KEY, offset ]
48  * These also start at offset 0, and correspond to the merkle tree bytes.
49  * So when fsverity asks for page 0 of the merkle tree, we pull up one page
50  * starting at offset 0 for this key type.  These are also opaque to btrfs,
54  * linearly with the size of the file (with 4K pages/blocks and SHA-256, it's
66  * Compute the logical file offset where we cache the Merkle tree.
71  * fs-verity, it is convenient to do size computations in terms of a file
72  * offset, rather than in terms of page indices.
74  * Use 64K to be sure it's past the last page in the file, even with 64K pages.
78  * Returns the file offset on success, negative error code on failure.
82 	u64 sz = inode->i_size;  in merkle_file_pos()
85 	if (rounded > inode->i_sb->s_maxbytes)  in merkle_file_pos()
86 		return -EFBIG;  in merkle_file_pos()
106 	struct btrfs_root *root = inode->root;  in drop_verity_items()
114 		return -ENOMEM;  in drop_verity_items()
130 		key.offset = (u64)-1;  in drop_verity_items()
132 		ret = btrfs_search_slot(trans, root, &key, path, -1, 1);  in drop_verity_items()
136 			if (path->slots[0] == 0)  in drop_verity_items()
138 			path->slots[0]--;  in drop_verity_items()
144 		btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);  in drop_verity_items()
156 		ret = btrfs_del_items(trans, root, path, path->slots[0], 1);  in drop_verity_items()
197  * Insert and write inode items with a given key type and offset.
201  * @offset:    item offset to insert at
206  * The inserted items will have key (ino, key_type, offset + off) where off is
207  * consecutively increasing from 0 up to the last item ending at offset + len.
211 static int write_key_bytes(struct btrfs_inode *inode, u8 key_type, u64 offset,  in write_key_bytes()  argument
216 	struct btrfs_root *root = inode->root;  in write_key_bytes()
226 		return -ENOMEM;  in write_key_bytes()
238 		key.offset = offset;  in write_key_bytes()
252 		leaf = path->nodes[0];  in write_key_bytes()
254 		data = btrfs_item_ptr(leaf, path->slots[0], void);  in write_key_bytes()
257 		offset += copy_bytes;  in write_key_bytes()
259 		len -= copy_bytes;  in write_key_bytes()
270  * Read inode items of the given key type and offset from the btree.
274  * @offset:     item offset to read from
279  *              page and ignore dest, but it must still be non-NULL to avoid the
280  *              counting-only behavior.
282  * @dest_page:  copy into this page instead of the dest buffer
287  * reading into a provided buffer (dest) or into the page cache
291 static int read_key_bytes(struct btrfs_inode *inode, u8 key_type, u64 offset,  in read_key_bytes()  argument
292 			  char *dest, u64 len, struct page *dest_page)  in read_key_bytes()
295 	struct btrfs_root *root = inode->root;  in read_key_bytes()
310 		return -ENOMEM;  in read_key_bytes()
313 		path->reada = READA_FORWARD;  in read_key_bytes()
317 	key.offset = offset;  in read_key_bytes()
324 		if (path->slots[0] == 0)  in read_key_bytes()
326 		path->slots[0]--;  in read_key_bytes()
330 		leaf = path->nodes[0];  in read_key_bytes()
331 		btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);  in read_key_bytes()
336 		item_end = btrfs_item_size(leaf, path->slots[0]) + key.offset;  in read_key_bytes()
343 			if (key.offset != offset)  in read_key_bytes()
347 			 * Our initial offset might be in the middle of an  in read_key_bytes()
350 			if (key.offset > offset)  in read_key_bytes()
352 			if (item_end <= offset)  in read_key_bytes()
360 			copy_end = min(offset + len, item_end);  in read_key_bytes()
363 		copy_bytes = copy_end - offset;  in read_key_bytes()
365 		/* Offset from the start of item for copying */  in read_key_bytes()
366 		copy_offset = offset - key.offset;  in read_key_bytes()
372 			data = btrfs_item_ptr(leaf, path->slots[0], void);  in read_key_bytes()
381 		offset += copy_bytes;  in read_key_bytes()
383 		len -= copy_bytes;  in read_key_bytes()
386 		path->slots[0]++;  in read_key_bytes()
387 		if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {  in read_key_bytes()
422 	struct btrfs_root *root = inode->root;  in del_orphan()
432 	if (!inode->vfs_inode.i_nlink)  in del_orphan()
436 	if (ret == -ENOENT)  in del_orphan()
442  * Rollback in-progress verity if we encounter an error.
455 	struct btrfs_root *root = inode->root;  in rollback_verity()
458 	ASSERT(inode_is_locked(&inode->vfs_inode));  in rollback_verity()
459 	truncate_inode_pages(inode->vfs_inode.i_mapping, inode->vfs_inode.i_size);  in rollback_verity()
460 	clear_bit(BTRFS_INODE_VERITY_IN_PROGRESS, &inode->runtime_flags);  in rollback_verity()
463 		btrfs_handle_fs_error(root->fs_info, ret,  in rollback_verity()
465 				(u64)inode->vfs_inode.i_ino);  in rollback_verity()
477 		btrfs_handle_fs_error(root->fs_info, ret,  in rollback_verity()
479 			(u64)inode->vfs_inode.i_ino);  in rollback_verity()
482 	inode->ro_flags &= ~BTRFS_INODE_RO_VERITY;  in rollback_verity()
483 	btrfs_sync_inode_flags_to_i_flags(&inode->vfs_inode);  in rollback_verity()
510  * - write out the descriptor items
511  * - mark the inode with the verity flag
512  * - delete the orphan item
513  * - mark the ro compat bit
514  * - clear the in progress bit
522 	struct btrfs_root *root = inode->root;  in finish_verity()
549 	inode->ro_flags |= BTRFS_INODE_RO_VERITY;  in finish_verity()
550 	btrfs_sync_inode_flags_to_i_flags(&inode->vfs_inode);  in finish_verity()
557 	clear_bit(BTRFS_INODE_VERITY_IN_PROGRESS, &inode->runtime_flags);  in finish_verity()
558 	btrfs_set_fs_compat_ro(root->fs_info, VERITY);  in finish_verity()
579 	struct btrfs_root *root = inode->root;  in btrfs_begin_enable_verity()
585 	if (test_bit(BTRFS_INODE_VERITY_IN_PROGRESS, &inode->runtime_flags))  in btrfs_begin_enable_verity()
586 		return -EBUSY;  in btrfs_begin_enable_verity()
605 		set_bit(BTRFS_INODE_VERITY_IN_PROGRESS, &inode->runtime_flags);  in btrfs_begin_enable_verity()
644 		btrfs_err(inode->root->fs_info,  in btrfs_end_enable_verity()
675 		return -EUCLEAN;  in btrfs_get_verity_descriptor()
679 		return -EUCLEAN;  in btrfs_get_verity_descriptor()
684 		return -ERANGE;  in btrfs_get_verity_descriptor()
691 		return -EIO;  in btrfs_get_verity_descriptor()
697  * fsverity op that reads and caches a merkle tree page.
699  * @inode:         inode to read a merkle tree page for
700  * @index:         page index relative to the start of the merkle tree
706  * Returns the page we read, or an ERR_PTR on error.
708 static struct page *btrfs_read_merkle_tree_page(struct inode *inode,  in btrfs_read_merkle_tree_page()
712 	struct page *page;  in btrfs_read_merkle_tree_page()  local
719 	if (merkle_pos > inode->i_sb->s_maxbytes - off - PAGE_SIZE)  in btrfs_read_merkle_tree_page()
720 		return ERR_PTR(-EFBIG);  in btrfs_read_merkle_tree_page()
723 	page = find_get_page_flags(inode->i_mapping, index, FGP_ACCESSED);  in btrfs_read_merkle_tree_page()
724 	if (page) {  in btrfs_read_merkle_tree_page()
725 		if (PageUptodate(page))  in btrfs_read_merkle_tree_page()
726 			return page;  in btrfs_read_merkle_tree_page()
728 		lock_page(page);  in btrfs_read_merkle_tree_page()
733 		if (!PageUptodate(page)) {  in btrfs_read_merkle_tree_page()
734 			unlock_page(page);  in btrfs_read_merkle_tree_page()
735 			put_page(page);  in btrfs_read_merkle_tree_page()
736 			return ERR_PTR(-EIO);  in btrfs_read_merkle_tree_page()
738 		unlock_page(page);  in btrfs_read_merkle_tree_page()
739 		return page;  in btrfs_read_merkle_tree_page()
742 	page = __page_cache_alloc(mapping_gfp_constraint(inode->i_mapping, ~__GFP_FS));  in btrfs_read_merkle_tree_page()
743 	if (!page)  in btrfs_read_merkle_tree_page()
744 		return ERR_PTR(-ENOMEM);  in btrfs_read_merkle_tree_page()
750 	 * [ inode objectid, BTRFS_MERKLE_ITEM_KEY, offset in bytes ]  in btrfs_read_merkle_tree_page()
753 			     page_address(page), PAGE_SIZE, page);  in btrfs_read_merkle_tree_page()
755 		put_page(page);  in btrfs_read_merkle_tree_page()
759 		memzero_page(page, ret, PAGE_SIZE - ret);  in btrfs_read_merkle_tree_page()
761 	SetPageUptodate(page);  in btrfs_read_merkle_tree_page()
762 	ret = add_to_page_cache_lru(page, inode->i_mapping, index, GFP_NOFS);  in btrfs_read_merkle_tree_page()
766 		unlock_page(page);  in btrfs_read_merkle_tree_page()
768 		put_page(page);  in btrfs_read_merkle_tree_page()
769 		/* Did someone race us into inserting this page? */  in btrfs_read_merkle_tree_page()
770 		if (ret == -EEXIST)  in btrfs_read_merkle_tree_page()
772 		page = ERR_PTR(ret);  in btrfs_read_merkle_tree_page()
774 	return page;  in btrfs_read_merkle_tree_page()
785  * Note that the block size could be different from the page size, so it is not
786  * safe to assume that index is a page index.
799 	if (merkle_pos > inode->i_sb->s_maxbytes - off - len)  in btrfs_write_merkle_tree_block()
800 		return -EFBIG;  in btrfs_write_merkle_tree_block()