From b73d67f20aa9bbb8aecc02f5725b1db193e87b48 Mon Sep 17 00:00:00 2001 From: Qu Wenruo Date: Wed, 18 Jan 2017 13:21:07 +0800 Subject: [PATCH] btrfs-progs: check: fix false alert on dropped leaf in lowmem mode For btrfs-progs test case 021-partially-dropped-snapshot-case, if the first leaf is already dropped, btrfs check low-memory mode will report false alert: checking fs roots checksum verify failed on 29917184 found E4E3BDB6 wanted 00000000 checksum verify failed on 29917184 found E4E3BDB6 wanted 00000000 checksum verify failed on 29917184 found E4E3BDB6 wanted 00000000 checksum verify failed on 29917184 found E4E3BDB6 wanted 00000000 This is caused by we are calling check_fs_first_inode() function, unlike the rest part of check_fs_root_v2(), it doesn't have enough check on dropping progress, and caused the false alert. Fix it by checking dropping progress before searching slot. Signed-off-by: Qu Wenruo Signed-off-by: David Sterba --- cmds-check.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/cmds-check.c b/cmds-check.c index a55d00d9..37e5ff18 100644 --- a/cmds-check.c +++ b/cmds-check.c @@ -4947,11 +4947,18 @@ static int check_fs_first_inode(struct btrfs_root *root, unsigned int ext_ref) int err = 0; int ret; - btrfs_init_path(&path); key.objectid = BTRFS_FIRST_FREE_OBJECTID; key.type = BTRFS_INODE_ITEM_KEY; key.offset = 0; + /* For root being dropped, we don't need to check first inode */ + if (btrfs_root_refs(&root->root_item) == 0 && + btrfs_disk_key_objectid(&root->root_item.drop_progress) >= + key.objectid) + return 0; + + btrfs_init_path(&path); + ret = btrfs_search_slot(NULL, root, &key, &path, 0, 0); if (ret < 0) goto out;