From ce366bfa821ec81dd45bde547ee31e659306cc61 Mon Sep 17 00:00:00 2001 From: Chao Yu Date: Mon, 24 Aug 2026 21:17:29 +0800 Subject: [PATCH] f2fs: fix to avoid potential deadloop in f2fs_fsync_node_pages() There is potential deadloop in race condition: Thread A Thread B - fsync - f2fs_do_sync_file - f2fs_fsync_node_pages - last_fsync_dnode - folio_get(last_folio) - f2fs_setattr - f2fs_truncate - f2fs_truncate_blocks - f2fs_do_truncate_blocks - f2fs_truncate_inode_blocks - truncate_dnode - truncate_node - invalidate_mapping_pages - folio->mapping = NULL - is_node_folio alwasy return false - atomic && !marked is always true, then goto retry Cc: stable@kernel.org Fixes: 608514deba38 ("f2fs: set fsync mark only for the last dnode") Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim --- fs/f2fs/node.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c index 968e5ed38816..86c2e67e43b6 100644 --- a/fs/f2fs/node.c +++ b/fs/f2fs/node.c @@ -2016,6 +2016,11 @@ int f2fs_fsync_node_pages(struct f2fs_sb_info *sbi, struct inode *inode, f2fs_debug(sbi, "Retry to write fsync mark: ino=%u, idx=%lx", ino, last_folio->index); folio_lock(last_folio); + if (unlikely(!is_node_folio(last_folio))) { + f2fs_folio_put(last_folio, true); + ret = -EAGAIN; + goto out; + } f2fs_folio_wait_writeback(last_folio, NODE, true, true); folio_mark_dirty(last_folio); folio_unlock(last_folio);