Orange Pi5 kernel

// 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);
<------>}
}