On 25.03.19 г. 10:22 ч., Qu Wenruo wrote:
> 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)
> +{
How about renaming this function to reset_imode/set_imode:
reset_imode and make it take a u32 parameter for the imode.
> + 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);
And calling it here with the correct parameter based on whether ino is
BTRFS_ROOT_TREE_DIR_OBJECTID. Also move the asserts from reset_imode to
this function.
Otherwise you are separating the checks/asserts across 2 function and
this is somewhat cumbersome to follow.
> + 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) &&
>
