Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933520AbcKNL0O (ORCPT ); Mon, 14 Nov 2016 06:26:14 -0500 Received: from szxga02-in.huawei.com ([119.145.14.65]:43547 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752583AbcKNL0M (ORCPT ); Mon, 14 Nov 2016 06:26:12 -0500 From: Chao Yu To: CC: , , , Chao Yu Subject: [PATCH] f2fs: fix to account total free nid correctly Date: Mon, 14 Nov 2016 19:24:56 +0800 Message-ID: <20161114112456.113074-1-yuchao0@huawei.com> X-Mailer: git-send-email 2.8.2.311.gee88674 MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.120.216.130] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3546 Lines: 110 Thread A Thread B Thread C - f2fs_create - f2fs_new_inode - f2fs_lock_op - alloc_nid alloc last nid - f2fs_unlock_op - f2fs_create - f2fs_new_inode - f2fs_lock_op - alloc_nid as node count still not be increased, we will loop in alloc_nid - f2fs_write_node_pages - f2fs_balance_fs_bg - f2fs_sync_fs - write_checkpoint - block_operations - f2fs_lock_all - f2fs_lock_op While creating new inode, we do not allocate and account nid atomically, so that when there is almost no free nids left, we may encounter deadloop like above stack. In order to avoid that, add nm_i::free_nid_cnt for accounting free nids and do nid allocation atomically during node creation. Signed-off-by: Chao Yu --- fs/f2fs/f2fs.h | 1 + fs/f2fs/node.c | 19 +++++++++++++++---- 2 files changed, 16 insertions(+), 4 deletions(-) diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index 6de1fbf..9de6f20 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -551,6 +551,7 @@ struct f2fs_nm_info { struct radix_tree_root free_nid_root;/* root of the free_nid cache */ struct list_head nid_list[MAX_NID_LIST];/* lists for free nids */ unsigned int nid_cnt[MAX_NID_LIST]; /* the number of free node id */ + unsigned int free_nid_cnt; /* the number of total free nid */ spinlock_t nid_list_lock; /* protect nid lists ops */ struct mutex build_lock; /* lock for build free nids */ diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c index d58438f..e412d0e 100644 --- a/fs/f2fs/node.c +++ b/fs/f2fs/node.c @@ -1885,11 +1885,13 @@ bool alloc_nid(struct f2fs_sb_info *sbi, nid_t *nid) return false; } #endif - if (unlikely(sbi->total_valid_node_count + 1 > nm_i->available_nids)) - return false; - spin_lock(&nm_i->nid_list_lock); + if (unlikely(nm_i->free_nid_cnt == 0)) { + spin_unlock(&nm_i->nid_list_lock); + return false; + } + /* We should not use stale free nids created by build_free_nids */ if (nm_i->nid_cnt[FREE_NID_LIST] && !on_build_free_nids(nm_i)) { f2fs_bug_on(sbi, list_empty(&nm_i->nid_list[FREE_NID_LIST])); @@ -1900,6 +1902,7 @@ bool alloc_nid(struct f2fs_sb_info *sbi, nid_t *nid) __remove_nid_from_list(sbi, i, FREE_NID_LIST, true); i->state = NID_ALLOC; __insert_nid_to_list(sbi, i, ALLOC_NID_LIST, false); + nm_i->free_nid_cnt--; spin_unlock(&nm_i->nid_list_lock); return true; } @@ -1951,6 +1954,9 @@ void alloc_nid_failed(struct f2fs_sb_info *sbi, nid_t nid) i->state = NID_NEW; __insert_nid_to_list(sbi, i, FREE_NID_LIST, false); } + + nm_i->free_nid_cnt++; + spin_unlock(&nm_i->nid_list_lock); if (need_free) @@ -2222,8 +2228,12 @@ static void __flush_nat_entry_set(struct f2fs_sb_info *sbi, raw_nat_from_node_info(raw_ne, &ne->ni); nat_reset_flag(ne); __clear_nat_cache_dirty(NM_I(sbi), ne); - if (nat_get_blkaddr(ne) == NULL_ADDR) + if (nat_get_blkaddr(ne) == NULL_ADDR) { add_free_nid(sbi, nid, false); + spin_lock(&NM_I(sbi)->nid_list_lock); + NM_I(sbi)->free_nid_cnt++; + spin_unlock(&NM_I(sbi)->nid_list_lock); + } } if (to_journal) @@ -2302,6 +2312,7 @@ static int init_node_manager(struct f2fs_sb_info *sbi) nm_i->nid_cnt[FREE_NID_LIST] = 0; nm_i->nid_cnt[ALLOC_NID_LIST] = 0; nm_i->nat_cnt = 0; + nm_i->free_nid_cnt = nm_i->available_nids - sbi->total_valid_node_count; nm_i->ram_thresh = DEF_RAM_THRESHOLD; nm_i->ra_nid_pages = DEF_RA_NID_PAGES; nm_i->dirty_nats_ratio = DEF_DIRTY_NAT_RATIO_THRESHOLD; -- 2.8.2.311.gee88674