In root tree, we only have 2 types of inodes:
- ROOT_TREE_DIR inode
Its mode is fixed to 40755
- free space cache inodes
Its mode is fixed to 100600
This patch will add the ability to repair such inodes to lowmem mode.
For fs/subvolume tree error, at least we haven't see such corruption
yet, so we don't need to rush to fix corruption in fs trees yet.
The repair function, repair_imode() can be reused by later original mode
patch, so it's placed in check/mode-common.c.
Signed-off-by: Qu Wenruo <wqu@xxxxxxxx>
---
check/mode-common.c | 48 +++++++++++++++++++++++++++++++++++++++++++
check/mode-common.h | 2 ++
check/mode-lowmem.c | 50 ++++++++++++++++++++++++++++++++++++++++++++-
3 files changed, 99 insertions(+), 1 deletion(-)
diff --git a/check/mode-common.c b/check/mode-common.c
index fed102b0ce7a..1c150a3d5a7c 100644
--- a/check/mode-common.c
+++ b/check/mode-common.c
@@ -795,3 +795,51 @@ out:
btrfs_release_path(&path);
return ret;
}
+
+/*
+ * Reset inode mode with invalid mode to its known correct value.
+ *
+ * Only support free space cache inode and root tree dir inode of root tree.
+ * Caller should ensure such condition.
+ *
+ * Return 0 if repair is done, @path will point to the correct inode item.
+ * Return <0 for errors.
+ */
+int repair_imode(struct btrfs_trans_handle *trans, struct btrfs_root *root,
+ struct btrfs_path *path, u64 ino)
+{
+ struct btrfs_inode_item *iitem;
+ struct extent_buffer *leaf;
+ struct btrfs_key key;
+ u32 correct_mode;
+ int slot;
+ int ret;
+
+ ASSERT(root->root_key.objectid == BTRFS_ROOT_TREE_OBJECTID);
+ ASSERT(ino == BTRFS_ROOT_TREE_DIR_OBJECTID || is_fstree(ino));
+
+ if (ino == BTRFS_ROOT_TREE_DIR_OBJECTID)
+ correct_mode = 040755; /* Directory, 0755 */
+ else
+ correct_mode = 0100600; /* Regular file, 0600 */
+
+ key.objectid = ino;
+ key.type = BTRFS_INODE_ITEM_KEY;
+ key.offset = 0;
+
+ ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
+ if (ret > 0)
+ ret = -ENOENT;
+ if (ret < 0) {
+ errno = -ret;
+ error("failed to search tree %llu: %m",
+ root->root_key.objectid);
+ return ret;
+ }
+ leaf = path->nodes[0];
+ slot = path->slots[0];
+ iitem = btrfs_item_ptr(leaf, slot, struct btrfs_inode_item);
+ btrfs_set_inode_mode(leaf, iitem, correct_mode);
+ btrfs_mark_buffer_dirty(leaf);
+ return ret;
+}
diff --git a/check/mode-common.h b/check/mode-common.h
index 4c88365abbcc..8895747adf1d 100644
--- a/check/mode-common.h
+++ b/check/mode-common.h
@@ -125,6 +125,8 @@ int delete_corrupted_dir_item(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_key *di_key, char *namebuf,
u32 namelen);
+int repair_imode(struct btrfs_trans_handle *trans, struct btrfs_root *root,
+ struct btrfs_path *path, u64 ino);
/*
* Check if the inode mode @imode is valid
diff --git a/check/mode-lowmem.c b/check/mode-lowmem.c
index 1553a4a5d2c1..f37c3b42e6b6 100644
--- a/check/mode-lowmem.c
+++ b/check/mode-lowmem.c
@@ -2396,6 +2396,48 @@ static bool has_orphan_item(struct btrfs_root *root, u64 ino)
return false;
}
+static int repair_imode_lowmem(struct btrfs_root *root,
+ struct btrfs_path *path)
+{
+ struct btrfs_trans_handle *trans;
+ struct btrfs_key key;
+ int ret;
+
+ if (root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID) {
+ error(
+ "repair inode mode outside of root tree is not supported yet");
+ return -ENOTTY;
+ }
+ btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
+ ASSERT(key.type == BTRFS_INODE_ITEM_KEY);
+ if (key.objectid != BTRFS_ROOT_TREE_DIR_OBJECTID &&
+ !is_fstree(key.objectid)) {
+ error("unsupported ino %llu", key.objectid);
+ return -ENOTTY;
+ }
+
+ trans = btrfs_start_transaction(root, 1);
+ if (IS_ERR(trans)) {
+ ret = PTR_ERR(trans);
+ errno = -ret;
+ error("failed to start transaction: %m");
+ return ret;
+ }
+ btrfs_release_path(path);
+
+ ret = repair_imode(trans, root, path, key.objectid);
+ if (ret < 0)
+ goto abort;
+ ret = btrfs_commit_transaction(trans, root);
+ if (!ret)
+ printf("reset mode for inode %llu root %llu\n",
+ key.objectid, root->root_key.objectid);
+ return ret;
+abort:
+ btrfs_abort_transaction(trans, ret);
+ return ret;
+}
+
/*
* Check INODE_ITEM and related ITEMs (the same inode number)
* 1. check link count
@@ -2454,7 +2496,13 @@ static int check_inode_item(struct btrfs_root *root, struct btrfs_path *path)
if (!is_valid_imode(mode)) {
error("invalid imode mode bits: 0%o", mode);
- err |= INODE_MODE_ERROR;
+ if (repair) {
+ ret = repair_imode_lowmem(root, path);
+ if (ret < 0)
+ err |= INODE_MODE_ERROR;
+ } else {
+ err |= INODE_MODE_ERROR;
+ }
}
if (S_ISLNK(mode) &&
--
2.21.0
