// SPDX-License-Identifier: GPL-2.0 /* * Copyright (C) 2014 Filipe David Borba Manana <fdmanana@gmail.com> */ #include <linux/hashtable.h> #include "props.h" #include "btrfs_inode.h" #include "transaction.h" #include "ctree.h" #include "xattr.h" #include "compression.h" #define BTRFS_PROP_HANDLERS_HT_BITS 8 static DEFINE_HASHTABLE(prop_handlers_ht, BTRFS_PROP_HANDLERS_HT_BITS); struct prop_handler { struct hlist_node node; const char *xattr_name; int (*validate)(const char *value, size_t len); int (*apply)(struct inode *inode, const char *value, size_t len); const char *(*extract)(struct inode *inode); int inheritable; }; static const struct hlist_head *find_prop_handlers_by_hash(const u64 hash) { struct hlist_head *h; h = &prop_handlers_ht[hash_min(hash, BTRFS_PROP_HANDLERS_HT_BITS)]; if (hlist_empty(h)) return NULL; return h; } static const struct prop_handler * find_prop_handler(const char *name, const struct hlist_head *handlers) { struct prop_handler *h; if (!handlers) { u64 hash = btrfs_name_hash(name, strlen(name)); handlers = find_prop_handlers_by_hash(hash); if (!handlers) return NULL; } hlist_for_each_entry(h, handlers, node) if (!strcmp(h->xattr_name, name)) return h; return NULL; } int btrfs_validate_prop(const char *name, const char *value, size_t value_len) { const struct prop_handler *handler; if (strlen(name) <= XATTR_BTRFS_PREFIX_LEN) return -EINVAL; handler = find_prop_handler(name, NULL); if (!handler) return -EINVAL; if (value_len == 0) return 0; return handler->validate(value, value_len); } int btrfs_set_prop(struct btrfs_trans_handle *trans, struct inode *inode, const char *name, const char *value, size_t value_len, int flags) { const struct prop_handler *handler; int ret; handler = find_prop_handler(name, NULL); if (!handler) return -EINVAL; if (value_len == 0) { ret = btrfs_setxattr(trans, inode, handler->xattr_name, NULL, 0, flags); if (ret) return ret; ret = handler->apply(inode, NULL, 0); ASSERT(ret == 0); return ret; } ret = btrfs_setxattr(trans, inode, handler->xattr_name, value, value_len, flags); if (ret) return ret; ret = handler->apply(inode, value, value_len); if (ret) { btrfs_setxattr(trans, inode, handler->xattr_name, NULL, 0, flags); return ret; } set_bit(BTRFS_INODE_HAS_PROPS, &BTRFS_I(inode)->runtime_flags); return 0; } static int iterate_object_props(struct btrfs_root *root, struct btrfs_path *path, u64 objectid, void (*iterator)(void *, const struct prop_handler *, const char *, size_t), void *ctx) { int ret; char *name_buf = NULL; char *value_buf = NULL; int name_buf_len = 0; int value_buf_len = 0; while (1) { struct btrfs_key key; struct btrfs_dir_item *di; struct extent_buffer *leaf; u32 total_len, cur, this_len; int slot; const struct hlist_head *handlers; slot = path->slots[0]; leaf = path->nodes[0]; if (slot >= btrfs_header_nritems(leaf)) { ret = btrfs_next_leaf(root, path); if (ret < 0) goto out; else if (ret > 0) break; continue; } btrfs_item_key_to_cpu(leaf, &key, slot); if (key.objectid != objectid) break; if (key.type != BTRFS_XATTR_ITEM_KEY) break; handlers = find_prop_handlers_by_hash(key.offset); if (!handlers) goto next_slot; di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item); cur = 0; total_len = btrfs_item_size_nr(leaf, slot); while (cur < total_len) { u32 name_len = btrfs_dir_name_len(leaf, di); u32 data_len = btrfs_dir_data_len(leaf, di); unsigned long name_ptr, data_ptr; const struct prop_handler *handler; this_len = sizeof(*di) + name_len + data_len; name_ptr = (unsigned long)(di + 1); data_ptr = name_ptr + name_len; if (name_len <= XATTR_BTRFS_PREFIX_LEN || memcmp_extent_buffer(leaf, XATTR_BTRFS_PREFIX, name_ptr, XATTR_BTRFS_PREFIX_LEN)) goto next_dir_item; if (name_len >= name_buf_len) { kfree(name_buf); name_buf_len = name_len + 1; name_buf = kmalloc(name_buf_len, GFP_NOFS); if (!name_buf) { ret = -ENOMEM; goto out; } } read_extent_buffer(leaf, name_buf, name_ptr, name_len); name_buf[name_len] = '\0'; handler = find_prop_handler(name_buf, handlers); if (!handler) goto next_dir_item; if (data_len > value_buf_len) { kfree(value_buf); value_buf_len = data_len; value_buf = kmalloc(data_len, GFP_NOFS); if (!value_buf) { ret = -ENOMEM; goto out; } } read_extent_buffer(leaf, value_buf, data_ptr, data_len); iterator(ctx, handler, value_buf, data_len); next_dir_item: cur += this_len; di = (struct btrfs_dir_item *)((char *) di + this_len); } next_slot: path->slots[0]++; } ret = 0; out: btrfs_release_path(path); kfree(name_buf); kfree(value_buf); return ret; } static void inode_prop_iterator(void *ctx, const struct prop_handler *handler, const char *value, size_t len) { struct inode *inode = ctx; struct btrfs_root *root = BTRFS_I(inode)->root; int ret; ret = handler->apply(inode, value, len); if (unlikely(ret)) btrfs_warn(root->fs_info, "error applying prop %s to ino %llu (root %llu): %d", handler->xattr_name, btrfs_ino(BTRFS_I(inode)), root->root_key.objectid, ret); else set_bit(BTRFS_INODE_HAS_PROPS, &BTRFS_I(inode)->runtime_flags); } int btrfs_load_inode_props(struct inode *inode, struct btrfs_path *path) { struct btrfs_root *root = BTRFS_I(inode)->root; u64 ino = btrfs_ino(BTRFS_I(inode)); int ret; ret = iterate_object_props(root, path, ino, inode_prop_iterator, inode); return ret; } static int prop_compression_validate(const char *value, size_t len) { if (!value) return 0; if (btrfs_compress_is_valid_type(value, len)) return 0; return -EINVAL; } static int prop_compression_apply(struct inode *inode, const char *value, size_t len) { struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); int type; if (len == 0) { BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS; BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS; BTRFS_I(inode)->prop_compress = BTRFS_COMPRESS_NONE; return 0; } if (!strncmp("lzo", value, 3)) { type = BTRFS_COMPRESS_LZO; btrfs_set_fs_incompat(fs_info, COMPRESS_LZO); } else if (!strncmp("zlib", value, 4)) { type = BTRFS_COMPRESS_ZLIB; } else if (!strncmp("zstd", value, 4)) { type = BTRFS_COMPRESS_ZSTD; btrfs_set_fs_incompat(fs_info, COMPRESS_ZSTD); } else { return -EINVAL; } BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS; BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS; BTRFS_I(inode)->prop_compress = type; return 0; } static const char *prop_compression_extract(struct inode *inode) { switch (BTRFS_I(inode)->prop_compress) { case BTRFS_COMPRESS_ZLIB: case BTRFS_COMPRESS_LZO: case BTRFS_COMPRESS_ZSTD: return btrfs_compress_type2str(BTRFS_I(inode)->prop_compress); default: break; } return NULL; } static struct prop_handler prop_handlers[] = { { .xattr_name = XATTR_BTRFS_PREFIX "compression", .validate = prop_compression_validate, .apply = prop_compression_apply, .extract = prop_compression_extract, .inheritable = 1 }, }; static int inherit_props(struct btrfs_trans_handle *trans, struct inode *inode, struct inode *parent) { struct btrfs_root *root = BTRFS_I(inode)->root; struct btrfs_fs_info *fs_info = root->fs_info; int ret; int i; bool need_reserve = false; if (!test_bit(BTRFS_INODE_HAS_PROPS, &BTRFS_I(parent)->runtime_flags)) return 0; for (i = 0; i < ARRAY_SIZE(prop_handlers); i++) { const struct prop_handler *h = &prop_handlers[i]; const char *value; u64 num_bytes = 0; if (!h->inheritable) continue; value = h->extract(parent); if (!value) continue; /* * This is not strictly necessary as the property should be * valid, but in case it isn't, don't propagate it futher. */ ret = h->validate(value, strlen(value)); if (ret) continue; /* * Currently callers should be reserving 1 item for properties, * since we only have 1 property that we currently support. If * we add more in the future we need to try and reserve more * space for them. But we should also revisit how we do space * reservations if we do add more properties in the future. */ if (need_reserve) { num_bytes = btrfs_calc_insert_metadata_size(fs_info, 1); ret = btrfs_block_rsv_add(root, trans->block_rsv, num_bytes, BTRFS_RESERVE_NO_FLUSH); if (ret) return ret; } ret = btrfs_setxattr(trans, inode, h->xattr_name, value, strlen(value), 0); if (!ret) { ret = h->apply(inode, value, strlen(value)); if (ret) btrfs_setxattr(trans, inode, h->xattr_name, NULL, 0, 0); else set_bit(BTRFS_INODE_HAS_PROPS, &BTRFS_I(inode)->runtime_flags); } if (need_reserve) { btrfs_block_rsv_release(fs_info, trans->block_rsv, num_bytes, NULL); if (ret) return ret; } need_reserve = true; } return 0; } int btrfs_inode_inherit_props(struct btrfs_trans_handle *trans, struct inode *inode, struct inode *dir) { if (!dir) return 0; return inherit_props(trans, inode, dir); } int btrfs_subvol_inherit_props(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_root *parent_root) { struct super_block *sb = root->fs_info->sb; struct inode *parent_inode, *child_inode; int ret; parent_inode = btrfs_iget(sb, BTRFS_FIRST_FREE_OBJECTID, parent_root); if (IS_ERR(parent_inode)) return PTR_ERR(parent_inode); child_inode = btrfs_iget(sb, BTRFS_FIRST_FREE_OBJECTID, root); if (IS_ERR(child_inode)) { iput(parent_inode); return PTR_ERR(child_inode); } ret = inherit_props(trans, child_inode, parent_inode); iput(child_inode); iput(parent_inode); return ret; } void __init btrfs_props_init(void) { int i; for (i = 0; i < ARRAY_SIZE(prop_handlers); i++) { struct prop_handler *p = &prop_handlers[i]; u64 h = btrfs_name_hash(p->xattr_name, strlen(p->xattr_name)); hash_add(prop_handlers_ht, &p->node, h); } }