/* * Copyright (C) 2014 Filipe David Borba Manana <fdmanana@gmail.com> * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public * License v2 as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public * License along with this program; if not, write to the * Free Software Foundation, Inc., 59 Temple Place - Suite 330, * Boston, MA 021110-1307, USA. */ #include <linux/hashtable.h> #include "props.h" #include "btrfs_inode.h" #include "hash.h" #include "transaction.h" #include "xattr.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 int prop_compression_validate(const char *value, size_t len); static int prop_compression_apply(struct inode *inode, const char *value, size_t len); static const char *prop_compression_extract(struct inode *inode); 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 }, { .xattr_name = NULL } }; void __init btrfs_props_init(void) { struct prop_handler *p; hash_init(prop_handlers_ht); for (p = &prop_handlers[0]; p->xattr_name; p++) { u64 h = btrfs_name_hash(p->xattr_name, strlen(p->xattr_name)); hash_add(prop_handlers_ht, &p->node, h); } } 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; } static 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; if (strlen(name) <= XATTR_BTRFS_PREFIX_LEN) return -EINVAL; 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 = handler->validate(value, value_len); if (ret) 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; } int btrfs_set_prop(struct inode *inode, const char *name, const char *value, size_t value_len, int flags) { return __btrfs_set_prop(NULL, inode, name, value, value_len, flags); } 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(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(inode); int ret; ret = iterate_object_props(root, path, ino, inode_prop_iterator, inode); return ret; } static int inherit_props(struct btrfs_trans_handle *trans, struct inode *inode, struct inode *parent) { const struct prop_handler *h; struct btrfs_root *root = BTRFS_I(inode)->root; int ret; if (!test_bit(BTRFS_INODE_HAS_PROPS, &BTRFS_I(parent)->runtime_flags)) return 0; for (h = &prop_handlers[0]; h->xattr_name; h++) { const char *value; u64 num_bytes; if (!h->inheritable) continue; value = h->extract(parent); if (!value) continue; num_bytes = btrfs_calc_trans_metadata_size(root, 1); ret = btrfs_block_rsv_add(root, trans->block_rsv, num_bytes, BTRFS_RESERVE_NO_FLUSH); if (ret) goto out; ret = __btrfs_set_prop(trans, inode, h->xattr_name, value, strlen(value), 0); btrfs_block_rsv_release(root, trans->block_rsv, num_bytes); if (ret) goto out; } ret = 0; out: return ret; } 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 btrfs_key key; struct inode *parent_inode, *child_inode; int ret; key.objectid = BTRFS_FIRST_FREE_OBJECTID; key.type = BTRFS_INODE_ITEM_KEY; key.offset = 0; parent_inode = btrfs_iget(parent_root->fs_info->sb, &key, parent_root, NULL); if (IS_ERR(parent_inode)) return PTR_ERR(parent_inode); child_inode = btrfs_iget(root->fs_info->sb, &key, root, NULL); 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; } static int prop_compression_validate(const char *value, size_t len) { if (!strncmp("lzo", value, len)) return 0; else if (!strncmp("zlib", value, len)) return 0; return -EINVAL; } static int prop_compression_apply(struct inode *inode, const char *value, size_t len) { int type; if (len == 0) { BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS; BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS; BTRFS_I(inode)->force_compress = BTRFS_COMPRESS_NONE; return 0; } if (!strncmp("lzo", value, len)) type = BTRFS_COMPRESS_LZO; else if (!strncmp("zlib", value, len)) type = BTRFS_COMPRESS_ZLIB; else return -EINVAL; BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS; BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS; BTRFS_I(inode)->force_compress = type; return 0; } static const char *prop_compression_extract(struct inode *inode) { switch (BTRFS_I(inode)->force_compress) { case BTRFS_COMPRESS_ZLIB: return "zlib"; case BTRFS_COMPRESS_LZO: return "lzo"; } return NULL; }