From ebf29e39c333cf47bd18af288ce0b6cd6c72a31a Mon Sep 17 00:00:00 2001 From: Qu Wenruo Date: Mon, 12 Aug 2019 14:34:20 +0800 Subject: [PATCH] btrfs-progs: check/lowmem: Check and repair root generation Since kernel is going to reject any root item which is newer than super block generation, we need to provide a way to fix such problem in btrfs-check. This patch addes the ability to report and repair root generation in lowmem mode. This is done by cowing the root node, so we will update the root generation along with the root node generation at commit transaction time. Reviewed-by: Nikolay Borisov Signed-off-by: Qu Wenruo Signed-off-by: David Sterba --- check/main.c | 36 ------------------------------------ check/mode-common.c | 36 ++++++++++++++++++++++++++++++++++++ check/mode-common.h | 1 + check/mode-lowmem.c | 17 +++++++++++++++++ check/mode-lowmem.h | 1 + 5 files changed, 55 insertions(+), 36 deletions(-) diff --git a/check/main.c b/check/main.c index 866da8dc..263a377d 100644 --- a/check/main.c +++ b/check/main.c @@ -9024,42 +9024,6 @@ again: return ret; } -static int recow_extent_buffer(struct btrfs_root *root, struct extent_buffer *eb) -{ - struct btrfs_path path; - struct btrfs_trans_handle *trans; - struct btrfs_key key; - int ret; - - printf("Recowing metadata block %llu\n", eb->start); - key.objectid = btrfs_header_owner(eb); - key.type = BTRFS_ROOT_ITEM_KEY; - key.offset = (u64)-1; - - root = btrfs_read_fs_root(root->fs_info, &key); - if (IS_ERR(root)) { - fprintf(stderr, "Couldn't find owner root %llu\n", - key.objectid); - return PTR_ERR(root); - } - - trans = btrfs_start_transaction(root, 1); - if (IS_ERR(trans)) - return PTR_ERR(trans); - - btrfs_init_path(&path); - path.lowest_level = btrfs_header_level(eb); - if (path.lowest_level) - btrfs_node_key_to_cpu(eb, &key, 0); - else - btrfs_item_key_to_cpu(eb, &key, 0); - - ret = btrfs_search_slot(trans, root, &key, &path, 0, 1); - btrfs_commit_transaction(trans, root); - btrfs_release_path(&path); - return ret; -} - static int delete_bad_item(struct btrfs_root *root, struct bad_item *bad) { struct btrfs_path path; diff --git a/check/mode-common.c b/check/mode-common.c index d5f6c8ef..195b6efa 100644 --- a/check/mode-common.c +++ b/check/mode-common.c @@ -924,3 +924,39 @@ int check_repair_free_space_inode(struct btrfs_fs_info *fs_info, } return ret; } + +int recow_extent_buffer(struct btrfs_root *root, struct extent_buffer *eb) +{ + struct btrfs_path path; + struct btrfs_trans_handle *trans; + struct btrfs_key key; + int ret; + + printf("Recowing metadata block %llu\n", eb->start); + key.objectid = btrfs_header_owner(eb); + key.type = BTRFS_ROOT_ITEM_KEY; + key.offset = (u64)-1; + + root = btrfs_read_fs_root(root->fs_info, &key); + if (IS_ERR(root)) { + fprintf(stderr, "Couldn't find owner root %llu\n", + key.objectid); + return PTR_ERR(root); + } + + trans = btrfs_start_transaction(root, 1); + if (IS_ERR(trans)) + return PTR_ERR(trans); + + btrfs_init_path(&path); + path.lowest_level = btrfs_header_level(eb); + if (path.lowest_level) + btrfs_node_key_to_cpu(eb, &key, 0); + else + btrfs_item_key_to_cpu(eb, &key, 0); + + ret = btrfs_search_slot(trans, root, &key, &path, 0, 1); + btrfs_commit_transaction(trans, root); + btrfs_release_path(&path); + return ret; +} diff --git a/check/mode-common.h b/check/mode-common.h index 4c169c6e..161b84a8 100644 --- a/check/mode-common.h +++ b/check/mode-common.h @@ -155,4 +155,5 @@ static inline bool is_valid_imode(u32 imode) return true; } +int recow_extent_buffer(struct btrfs_root *root, struct extent_buffer *eb); #endif diff --git a/check/mode-lowmem.c b/check/mode-lowmem.c index a2be0e6d..da6b6fd8 100644 --- a/check/mode-lowmem.c +++ b/check/mode-lowmem.c @@ -4957,6 +4957,7 @@ static int check_btrfs_root(struct btrfs_root *root, int check_all) struct btrfs_path path; struct node_refs nrefs; struct btrfs_root_item *root_item = &root->root_item; + u64 super_generation = btrfs_super_generation(root->fs_info->super_copy); int ret; int level; int err = 0; @@ -4978,6 +4979,22 @@ static int check_btrfs_root(struct btrfs_root *root, int check_all) level = btrfs_header_level(root->node); btrfs_init_path(&path); + if (btrfs_root_generation(root_item) > super_generation + 1) { + error( + "invalid root generation for root %llu, have %llu expect (0, %llu)", + root->root_key.objectid, btrfs_root_generation(root_item), + super_generation + 1); + err |= INVALID_GENERATION; + if (repair) { + root->node->flags |= EXTENT_BAD_TRANSID; + ret = recow_extent_buffer(root, root->node); + if (!ret) { + printf("Reset generation for root %llu\n", + root->root_key.objectid); + err &= ~INVALID_GENERATION; + } + } + } if (btrfs_root_refs(root_item) > 0 || btrfs_disk_key_objectid(&root_item->drop_progress) == 0) { path.nodes[level] = root->node; diff --git a/check/mode-lowmem.h b/check/mode-lowmem.h index d2983fd1..0361fb33 100644 --- a/check/mode-lowmem.h +++ b/check/mode-lowmem.h @@ -47,6 +47,7 @@ #define INODE_FLAGS_ERROR (1<<23) /* Invalid inode flags */ #define DIR_ITEM_HASH_MISMATCH (1<<24) /* Dir item hash mismatch */ #define INODE_MODE_ERROR (1<<25) /* Bad inode mode */ +#define INVALID_GENERATION (1<<26) /* Generation is too new */ /* * Error bit for low memory mode check.