[PATCH v2 4/6] btrfs-progs: check/lowmem: Repair bad imode early

Qu Wenruo
2019-09-05T07:58:19Z

For lowmem mode, if we hit a bad inode mode, normally it is reported
when we checking the DIR_INDEX/DIR_ITEM of the parent inode.

If we didn't repair at that timing, the error will be recorded even we
fixed it later.

So this patch will check for INODE_ITEM_MISMATCH error type, and if it's
really caused by invalid imode, repair it and clear the error.

Signed-off-by: Qu Wenruo <wqu@suse.com>
---
check/mode-lowmem.c | 39 +++++++++++++++++++++++++++++++++++++++
1 file changed, 39 insertions(+)

diff --git a/check/mode-lowmem.c b/check/mode-lowmem.c
index 5f7f101daab1..5d0c520217fa 100644
--- a/check/mode-lowmem.c
+++ b/check/mode-lowmem.c
@@ -1550,6 +1550,35 @@ static int lowmem_delete_corrupted_dir_item(struct btrfs_root *root,
return ret;
}

+static int try_repair_imode(struct btrfs_root *root, u64 ino)
+{
+ struct btrfs_inode_item *iitem;
+ struct btrfs_path path;
+ struct btrfs_key key;
+ int ret;
+
+ key.objectid = ino;
+ key.type = BTRFS_INODE_ITEM_KEY;
+ key.offset = 0;
+ btrfs_init_path(&path);
+
+ ret = btrfs_search_slot(NULL, root, &key, &path, 0, 0);
+ if (ret > 0)
+ ret = -ENOENT;
+ if (ret < 0)
+ goto out;
+ iitem = btrfs_item_ptr(path.nodes[0], path.slots[0],
+ struct btrfs_inode_item);
+ if (!is_valid_imode(btrfs_inode_mode(path.nodes[0], iitem))) {
+ ret = repair_imode_common(root, &path);
+ } else {
+ ret = -ENOTTY;
+ }
+out:
+ btrfs_release_path(&path);
+ return ret;
+}
+
/*
* Call repair_inode_item_missing and repair_ternary_lowmem to repair
*
@@ -1574,6 +1603,16 @@ static int repair_dir_item(struct btrfs_root *root, struct btrfs_key *di_key,
err &= ~(INODE_ITEM_MISMATCH | INODE_ITEM_MISSING);
}

+ if (err & INODE_ITEM_MISMATCH) {
+ /*
+ * INODE_ITEM mismatch can be caused by bad imode,
+ * so check if it's a bad imode, then repair if possible.
+ */
+ ret = try_repair_imode(root, ino);
+ if (!ret)
+ err &= ~INODE_ITEM_MISMATCH;
+ }
+
if (err & ~(INODE_ITEM_MISMATCH | INODE_ITEM_MISSING)) {
ret = repair_ternary_lowmem(root, dirid, ino, index, namebuf,
name_len, filetype, err);
--
2.23.0