From: Wang Xiaoguang <wangxg.f...@cn.fujitsu.com> Introduce static function inmem_add() to add hash into in-memory tree. And now we can implement the btrfs_dedupe_add() interface.
Signed-off-by: Qu Wenruo <quwen...@cn.fujitsu.com> Signed-off-by: Wang Xiaoguang <wangxg.f...@cn.fujitsu.com> Reviewed-by: Josef Bacik <jba...@fb.com> --- fs/btrfs/dedupe.c | 151 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 151 insertions(+) diff --git a/fs/btrfs/dedupe.c b/fs/btrfs/dedupe.c index b14166a..e51412b 100644 --- a/fs/btrfs/dedupe.c +++ b/fs/btrfs/dedupe.c @@ -32,6 +32,14 @@ struct inmem_hash { u8 hash[]; }; +static inline struct inmem_hash *inmem_alloc_hash(u16 algo) +{ + if (WARN_ON(algo >= ARRAY_SIZE(btrfs_hash_sizes))) + return NULL; + return kzalloc(sizeof(struct inmem_hash) + btrfs_hash_sizes[algo], + GFP_NOFS); +} + static int init_dedupe_info(struct btrfs_dedupe_info **ret_info, struct btrfs_ioctl_dedupe_args *dargs) { @@ -183,3 +191,146 @@ int btrfs_dedupe_disable(struct btrfs_fs_info *fs_info) /* Place holder for bisect, will be implemented in later patches */ return 0; } + +static int inmem_insert_hash(struct rb_root *root, + struct inmem_hash *hash, int hash_len) +{ + struct rb_node **p = &root->rb_node; + struct rb_node *parent = NULL; + struct inmem_hash *entry = NULL; + + while (*p) { + parent = *p; + entry = rb_entry(parent, struct inmem_hash, hash_node); + if (memcmp(hash->hash, entry->hash, hash_len) < 0) + p = &(*p)->rb_left; + else if (memcmp(hash->hash, entry->hash, hash_len) > 0) + p = &(*p)->rb_right; + else + return 1; + } + rb_link_node(&hash->hash_node, parent, p); + rb_insert_color(&hash->hash_node, root); + return 0; +} + +static int inmem_insert_bytenr(struct rb_root *root, + struct inmem_hash *hash) +{ + struct rb_node **p = &root->rb_node; + struct rb_node *parent = NULL; + struct inmem_hash *entry = NULL; + + while (*p) { + parent = *p; + entry = rb_entry(parent, struct inmem_hash, bytenr_node); + if (hash->bytenr < entry->bytenr) + p = &(*p)->rb_left; + else if (hash->bytenr > entry->bytenr) + p = &(*p)->rb_right; + else + return 1; + } + rb_link_node(&hash->bytenr_node, parent, p); + rb_insert_color(&hash->bytenr_node, root); + return 0; +} + +static void __inmem_del(struct btrfs_dedupe_info *dedupe_info, + struct inmem_hash *hash) +{ + list_del(&hash->lru_list); + rb_erase(&hash->hash_node, &dedupe_info->hash_root); + rb_erase(&hash->bytenr_node, &dedupe_info->bytenr_root); + + if (!WARN_ON(dedupe_info->current_nr == 0)) + dedupe_info->current_nr--; + + kfree(hash); +} + +/* + * Insert a hash into in-memory dedupe tree + * Will remove exceeding last recent use hash. + * + * If the hash mathced with existing one, we won't insert it, to + * save memory + */ +static int inmem_add(struct btrfs_dedupe_info *dedupe_info, + struct btrfs_dedupe_hash *hash) +{ + int ret = 0; + u16 algo = dedupe_info->hash_algo; + struct inmem_hash *ihash; + + ihash = inmem_alloc_hash(algo); + + if (!ihash) + return -ENOMEM; + + /* Copy the data out */ + ihash->bytenr = hash->bytenr; + ihash->num_bytes = hash->num_bytes; + memcpy(ihash->hash, hash->hash, btrfs_hash_sizes[algo]); + + mutex_lock(&dedupe_info->lock); + + ret = inmem_insert_bytenr(&dedupe_info->bytenr_root, ihash); + if (ret > 0) { + kfree(ihash); + ret = 0; + goto out; + } + + ret = inmem_insert_hash(&dedupe_info->hash_root, ihash, + btrfs_hash_sizes[algo]); + if (ret > 0) { + /* + * We only keep one hash in tree to save memory, so if + * hash conflicts, free the one to insert. + */ + rb_erase(&ihash->bytenr_node, &dedupe_info->bytenr_root); + kfree(ihash); + ret = 0; + goto out; + } + + list_add(&ihash->lru_list, &dedupe_info->lru_list); + dedupe_info->current_nr++; + + /* Remove the last dedupe hash if we exceed limit */ + while (dedupe_info->current_nr > dedupe_info->limit_nr) { + struct inmem_hash *last; + + last = list_entry(dedupe_info->lru_list.prev, + struct inmem_hash, lru_list); + __inmem_del(dedupe_info, last); + } +out: + mutex_unlock(&dedupe_info->lock); + return 0; +} + +int btrfs_dedupe_add(struct btrfs_trans_handle *trans, + struct btrfs_fs_info *fs_info, + struct btrfs_dedupe_hash *hash) +{ + struct btrfs_dedupe_info *dedupe_info = fs_info->dedupe_info; + + if (!fs_info->dedupe_enabled || !hash) + return 0; + + if (WARN_ON(dedupe_info == NULL)) + return -EINVAL; + + if (WARN_ON(!btrfs_dedupe_hash_hit(hash))) + return -EINVAL; + + /* ignore old hash */ + if (dedupe_info->blocksize != hash->num_bytes) + return 0; + + if (dedupe_info->backend == BTRFS_DEDUPE_BACKEND_INMEMORY) + return inmem_add(dedupe_info, hash); + return -EINVAL; +} -- 2.9.3 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html