Btrfs: fix use of radix_tree for name_cache in send/receive (7e0926fe) · Commits · 戴 / test

fs/btrfs/send.c

+37 −39

Original line number	Diff line number	Diff line
		@@ -125,6 +125,15 @@ struct send_ctx {

		struct name_cache_entry {
		struct list_head list;
		/*
		* radix_tree has only 32bit entries but we need to handle 64bit inums.
		* We use the lower 32bit of the 64bit inum to store it in the tree. If
		* more then one inum would fall into the same entry, we use radix_list
		* to store the additional entries. radix_list is also used to store
		* entries where two entries have the same inum but different
		* generations.
		*/
		struct list_head radix_list;
		u64 ino;
		u64 gen;
		u64 parent_ino;
		@@ -1726,27 +1735,21 @@ static int name_cache_insert(struct send_ctx *sctx,
		struct name_cache_entry *nce)
		{
		int ret = 0;
		struct name_cache_entry **ncea;

		ncea = radix_tree_lookup(&sctx->name_cache, nce->ino);
		if (ncea) {
		if (!ncea[0])
		ncea[0] = nce;
		else if (!ncea[1])
		ncea[1] = nce;
		else
		BUG();
		} else {
		ncea = kmalloc(sizeof(void ) 2, GFP_NOFS);
		if (!ncea)
		struct list_head *nce_head;

		nce_head = radix_tree_lookup(&sctx->name_cache,
		(unsigned long)nce->ino);
		if (!nce_head) {
		nce_head = kmalloc(sizeof(*nce_head), GFP_NOFS);
		if (!nce_head)
		return -ENOMEM;
		INIT_LIST_HEAD(nce_head);

		ncea[0] = nce;
		ncea[1] = NULL;
		ret = radix_tree_insert(&sctx->name_cache, nce->ino, ncea);
		ret = radix_tree_insert(&sctx->name_cache, nce->ino, nce_head);
		if (ret < 0)
		return ret;
		}
		list_add_tail(&nce->radix_list, nce_head);
		list_add_tail(&nce->list, &sctx->name_cache_list);
		sctx->name_cache_size++;

		@@ -1756,41 +1759,36 @@ static int name_cache_insert(struct send_ctx *sctx,
		static void name_cache_delete(struct send_ctx *sctx,
		struct name_cache_entry *nce)
		{
		struct name_cache_entry **ncea;
		struct list_head *nce_head;

		ncea = radix_tree_lookup(&sctx->name_cache, nce->ino);
		BUG_ON(!ncea);

		if (ncea[0] == nce)
		ncea[0] = NULL;
		else if (ncea[1] == nce)
		ncea[1] = NULL;
		else
		BUG();

		if (!ncea[0] && !ncea[1]) {
		radix_tree_delete(&sctx->name_cache, nce->ino);
		kfree(ncea);
		}
		nce_head = radix_tree_lookup(&sctx->name_cache,
		(unsigned long)nce->ino);
		BUG_ON(!nce_head);

		list_del(&nce->radix_list);
		list_del(&nce->list);

		sctx->name_cache_size--;

		if (list_empty(nce_head)) {
		radix_tree_delete(&sctx->name_cache, (unsigned long)nce->ino);
		kfree(nce_head);
		}
		}

		static struct name_cache_entry name_cache_search(struct send_ctx sctx,
		u64 ino, u64 gen)
		{
		struct name_cache_entry **ncea;
		struct list_head *nce_head;
		struct name_cache_entry *cur;

		ncea = radix_tree_lookup(&sctx->name_cache, ino);
		if (!ncea)
		nce_head = radix_tree_lookup(&sctx->name_cache, (unsigned long)ino);
		if (!nce_head)
		return NULL;

		if (ncea[0] && ncea[0]->gen == gen)
		return ncea[0];
		else if (ncea[1] && ncea[1]->gen == gen)
		return ncea[1];
		list_for_each_entry(cur, nce_head, radix_list) {
		if (cur->ino == ino && cur->gen == gen)
		return cur;
		}
		return NULL;
		}

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