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 39db05b14398..a4871f16df13 100644
--- a/fs/btrfs/dedupe.c
+++ b/fs/btrfs/dedupe.c
@@ -20,6 +20,14 @@ 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)
{
@@ -171,3 +179,146 @@ 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;
+}
--
2.17.0
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