f2fs: enhance alloc_nid and build_free_nids flows (55008d84) · Commits · 戴 / test

fs/f2fs/f2fs.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -190,7 +190,6 @@ static inline void set_raw_extent(struct extent_info *ext,
		struct f2fs_nm_info {
		block_t nat_blkaddr; /* base disk address of NAT */
		nid_t max_nid; /* maximum possible node ids */
		nid_t init_scan_nid; /* the first nid to be scanned */
		nid_t next_scan_nid; /* the next nid to be scanned */

		/* NAT cache management */
		@@ -360,6 +359,7 @@ struct f2fs_sb_info {
		struct mutex writepages; /* mutex for writepages() */
		unsigned char next_lock_num; /* round-robin global locks */
		int por_doing; /* recovery is doing or not */
		int on_build_free_nids; /* build_free_nids is doing */

		/* for orphan inode management */
		struct list_head orphan_inode_list; /* orphan inode list */

fs/f2fs/node.c

+36 −46

Original line number	Diff line number	Diff line
		@@ -1309,14 +1309,14 @@ static void build_free_nids(struct f2fs_sb_info *sbi)
		struct f2fs_nm_info *nm_i = NM_I(sbi);
		struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA);
		struct f2fs_summary_block *sum = curseg->sum_blk;
		nid_t nid = 0;
		bool is_cycled = false;
		int fcnt = 0;
		int i;
		int fcnt = 0, i = 0;
		nid_t nid = nm_i->next_scan_nid;

		nid = nm_i->next_scan_nid;
		nm_i->init_scan_nid = nid;
		/* Enough entries */
		if (nm_i->fcnt > NAT_ENTRY_PER_BLOCK)
		return;

		/* readahead nat pages to be scanned */
		ra_nat_pages(sbi, nid);

		while (1) {
		@@ -1326,19 +1326,15 @@ static void build_free_nids(struct f2fs_sb_info *sbi)
		f2fs_put_page(page, 1);

		nid += (NAT_ENTRY_PER_BLOCK - (nid % NAT_ENTRY_PER_BLOCK));

		if (nid >= nm_i->max_nid) {
		if (nid >= nm_i->max_nid)
		nid = 0;
		is_cycled = true;
		}
		if (fcnt > MAX_FREE_NIDS)
		break;
		if (is_cycled && nm_i->init_scan_nid <= nid)

		if (i++ == FREE_NID_PAGES)
		break;
		}

		/* go to the next nat page in order to reuse free nids first */
		nm_i->next_scan_nid = nm_i->init_scan_nid + NAT_ENTRY_PER_BLOCK;
		/* go to the next free nat pages to find free nids abundantly */
		nm_i->next_scan_nid = nid;

		/* find free nids from current sum_pages */
		mutex_lock(&curseg->curseg_mutex);
		@@ -1375,28 +1371,13 @@ bool alloc_nid(struct f2fs_sb_info sbi, nid_t nid)
		struct free_nid *i = NULL;
		struct list_head *this;
		retry:
		mutex_lock(&nm_i->build_lock);
		if (!nm_i->fcnt) {
		/* scan NAT in order to build free nid list */
		build_free_nids(sbi);
		if (!nm_i->fcnt) {
		mutex_unlock(&nm_i->build_lock);
		if (sbi->total_valid_node_count + 1 >= nm_i->max_nid)
		return false;
		}
		}
		mutex_unlock(&nm_i->build_lock);

		/*
		* We check fcnt again since previous check is racy as
		* we didn't hold free_nid_list_lock. So other thread
		* could consume all of free nids.
		*/
		spin_lock(&nm_i->free_nid_list_lock);
		if (!nm_i->fcnt) {
		spin_unlock(&nm_i->free_nid_list_lock);
		goto retry;
		}

		/* We should not use stale free nids created by build_free_nids */
		if (nm_i->fcnt && !sbi->on_build_free_nids) {
		BUG_ON(list_empty(&nm_i->free_nid_list));
		list_for_each(this, &nm_i->free_nid_list) {
		i = list_entry(this, struct free_nid, list);
		@@ -1411,6 +1392,16 @@ retry:
		spin_unlock(&nm_i->free_nid_list_lock);
		return true;
		}
		spin_unlock(&nm_i->free_nid_list_lock);

		/* Let's scan nat pages and its caches to get free nids */
		mutex_lock(&nm_i->build_lock);
		sbi->on_build_free_nids = 1;
		build_free_nids(sbi);
		sbi->on_build_free_nids = 0;
		mutex_unlock(&nm_i->build_lock);
		goto retry;
		}

		/*
		* alloc_nid() should be called prior to this function.
		@@ -1696,7 +1687,6 @@ static int init_node_manager(struct f2fs_sb_info *sbi)
		spin_lock_init(&nm_i->free_nid_list_lock);
		rwlock_init(&nm_i->nat_tree_lock);

		nm_i->init_scan_nid = le32_to_cpu(sbi->ckpt->next_free_nid);
		nm_i->next_scan_nid = le32_to_cpu(sbi->ckpt->next_free_nid);
		nm_i->bitmap_size = __bitmap_size(sbi, NAT_BITMAP);
		version_bitmap = __bitmap_ptr(sbi, NAT_BITMAP);

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