On 9.04.2018 10:47, Qu Wenruo wrote:
> When manually patching super blocks, current validation check is pretty
> weak (limited to magic number and csum) and doesn't provide extra check
> for some obvious corruption (like invalid sectorsize).
>
> This patch will enhance dump-super by:
>
> 1) Refactor print function and add checker helper macro
> Instead of manually call printf() and takes 2 lines to just print one
> member, introduce several helper macros to print/check value.
> Most of the callers just need 1 line.
> (Although the macro and helper itself offsets the saved lines)
>
> 2) Add extra check for some members
> The following members will be checked, and if invalid the suffix
> " [INVALID]" will be pended:
> bytenr: alignment check
> sys_array_size: maximum check
> root: alignment check
> root_level: maximum check
> chunk_root: alignment check
> chunk_root_level: maximum check
> chunk_root_generation: maximum check against root generation
> log_root: alignment check
> log_root_level: maximum check
> log_root_transid: maximum check against root generation + 1
> bytes_used: alignment check
> sectorsize: power of 2 and 4K~64K range check
> nodesize: the same as sectorsize, plus minimum check
> stripesize: the same as kernel check
> cache_generation: maximum check against root generation
> uuid_tree_generation: maximum check against root generation
>
> 3) output sequence change
> Put bytenr/level/generation together for the same root (tree root,
> chunk root, and log root).
>
> 4) Minor output change
> To make dev_item macro easier, the following output is changed:
> dev_item.devid -> dev_item.id
> dev_item.dev_group -> dev_item.group
>
> Signed-off-by: Qu Wenruo <wqu@xxxxxxxx>
> ---
> cmds-inspect-dump-super.c | 168 ++++++++++++++++++++++----------------
> 1 file changed, 99 insertions(+), 69 deletions(-)
>
> diff --git a/cmds-inspect-dump-super.c b/cmds-inspect-dump-super.c
> index 24588c87cce6..8000d2ace663 100644
> --- a/cmds-inspect-dump-super.c
> +++ b/cmds-inspect-dump-super.c
> @@ -312,11 +312,42 @@ static void print_readable_super_flag(u64 flag)
> super_flags_num, BTRFS_SUPER_FLAG_SUPP);
> }
>
> +/* Helper to print member in %llu */
> +#define print_super(sb, member, spacer) \
> + printf("%s%s%llu\n", #member, spacer, (u64) btrfs_super_##member(sb));
> +
> +/* Helper to print member in %llx */
> +#define print_super_hex(sb, member, spacer) \
> + printf("%s%s%llx\n", #member, spacer, (u64) btrfs_super_##member(sb));
nit: I like the idea of the patch, however, I think the presence of the
"spacer" argument is a bit annoying. Why don't you make all the print
out to be aligned to the same level i.e hardcode \t\t\ or \t\t or whatever?
> +
> +/*
> + * Helper macro to wrap member checker
> + *
> + * Only support %llu output for member.
> + */
> +#define print_check_super(sb, member, spacer, bad_condition) \
> +({ \
> + u64 value; \
> + \
> + value = btrfs_super_##member(sb); \
> + printf("%s%s%llu", #member, spacer, (u64) value); \
> + if (bad_condition) \
> + printf(" [INVALID]"); \
> + printf("\n"); \
> +})
> +
> +/* Helper to print sb->dev_item members */
> +#define print_super_dev(sb, member, spacer) \
> + printf("dev_item.%s%s%llu\n", #member, spacer, \
> + (u64) btrfs_stack_device_##member(&sb->dev_item));
> +
> static void dump_superblock(struct btrfs_super_block *sb, int full)
> {
> int i;
> char *s, buf[BTRFS_UUID_UNPARSED_SIZE];
> + int max_level = BTRFS_MAX_LEVEL; /* to save several chars */
> u8 *p;
> + u64 super_gen;
> u32 csum_size;
> u16 csum_type;
>
> @@ -348,10 +379,16 @@ static void dump_superblock(struct btrfs_super_block *sb, int full)
> printf(" [DON'T MATCH]");
> putchar('\n');
>
> - printf("bytenr\t\t\t%llu\n",
> - (unsigned long long)btrfs_super_bytenr(sb));
> - printf("flags\t\t\t0x%llx\n",
> - (unsigned long long)btrfs_super_flags(sb));
> + /*
> + * Use btrfs minimal sector size as basic check for bytenr, since we
> + * can't trust sector size from super block.
> + * This 4K check should works fine for most architecture, and will be
> + * just a little loose for 64K page system.
> + *
> + * And such 4K check will be used for other members too.
> + */
> + print_check_super(sb, bytenr, "\t\t\t", (!IS_ALIGNED(value, SZ_4K)));
> + print_super_hex(sb, flags, "\t\t\t");
> print_readable_super_flag(btrfs_super_flags(sb));
>
> printf("magic\t\t\t");
> @@ -372,53 +409,56 @@ static void dump_superblock(struct btrfs_super_block *sb, int full)
> putchar(isprint(s[i]) ? s[i] : '.');
> putchar('\n');
>
> - printf("generation\t\t%llu\n",
> - (unsigned long long)btrfs_super_generation(sb));
> - printf("root\t\t\t%llu\n", (unsigned long long)btrfs_super_root(sb));
> - printf("sys_array_size\t\t%llu\n",
> - (unsigned long long)btrfs_super_sys_array_size(sb));
> - printf("chunk_root_generation\t%llu\n",
> - (unsigned long long)btrfs_super_chunk_root_generation(sb));
> - printf("root_level\t\t%llu\n",
> - (unsigned long long)btrfs_super_root_level(sb));
> - printf("chunk_root\t\t%llu\n",
> - (unsigned long long)btrfs_super_chunk_root(sb));
> - printf("chunk_root_level\t%llu\n",
> - (unsigned long long)btrfs_super_chunk_root_level(sb));
> - printf("log_root\t\t%llu\n",
> - (unsigned long long)btrfs_super_log_root(sb));
> - printf("log_root_transid\t%llu\n",
> - (unsigned long long)btrfs_super_log_root_transid(sb));
> - printf("log_root_level\t\t%llu\n",
> - (unsigned long long)btrfs_super_log_root_level(sb));
> - printf("total_bytes\t\t%llu\n",
> - (unsigned long long)btrfs_super_total_bytes(sb));
> - printf("bytes_used\t\t%llu\n",
> - (unsigned long long)btrfs_super_bytes_used(sb));
> - printf("sectorsize\t\t%llu\n",
> - (unsigned long long)btrfs_super_sectorsize(sb));
> - printf("nodesize\t\t%llu\n",
> - (unsigned long long)btrfs_super_nodesize(sb));
> + print_check_super(sb, sys_array_size, "\t\t",
> + (value > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE));
> +
> + super_gen = btrfs_super_generation(sb);
> + print_check_super(sb, root, "\t\t\t", (!IS_ALIGNED(value, SZ_4K)));
> + print_check_super(sb, root_level, "\t\t", (value >= max_level));
> + print_super(sb, generation, "\t\t");
> +
> + print_check_super(sb, chunk_root, "\t\t", (!IS_ALIGNED(value, SZ_4K)));
> + print_check_super(sb, chunk_root_level, "\t", (value >= max_level));
> + /*
> + * Here we trust super generation, and use it as checker for other
> + * tree roots. Applies to all other trees.
> + */
> + print_check_super(sb, chunk_root_generation, "\t", (value > super_gen));
> +
> + print_check_super(sb, log_root, "\t\t", (!IS_ALIGNED(value, SZ_4K)));
> + print_check_super(sb, log_root_level, "\t\t", (value >= max_level));
> + print_check_super(sb, log_root_transid, "\t", (value > super_gen + 1));
> +
> + /*
> + * For total bytes, it's possible that old kernel is using unaligned
> + * size, not critical so don't do 4K check here.
> + */
> + print_super(sb, total_bytes, "\t\t");
> +
> + /* Used bytes must be aligned to 4K */
> + print_check_super(sb, bytes_used, "\t\t", (!IS_ALIGNED(value, SZ_4K)));
> + print_check_super(sb, sectorsize, "\t\t",
> + (!(is_power_of_2(value) && value >= SZ_4K &&
> + value <= SZ_64K)));
> + print_check_super(sb, nodesize, "\t\t",
> + (!(is_power_of_2(value) && value >= SZ_4K &&
> + value <= SZ_64K &&
> + value > btrfs_super_sectorsize(sb))));
> printf("leafsize (deprecated)\t%u\n",
> le32_to_cpu(sb->__unused_leafsize));
> - printf("stripesize\t\t%llu\n",
> - (unsigned long long)btrfs_super_stripesize(sb));
> - printf("root_dir\t\t%llu\n",
> - (unsigned long long)btrfs_super_root_dir(sb));
> - printf("num_devices\t\t%llu\n",
> - (unsigned long long)btrfs_super_num_devices(sb));
> - printf("compat_flags\t\t0x%llx\n",
> - (unsigned long long)btrfs_super_compat_flags(sb));
> - printf("compat_ro_flags\t\t0x%llx\n",
> - (unsigned long long)btrfs_super_compat_ro_flags(sb));
> +
> + /* Not really used, just check it the same way as kernel */
> + print_check_super(sb, stripesize, "\t\t", (!is_power_of_2(value)));
> + print_super(sb, root_dir, "\t\t");
> + print_super(sb, num_devices, "\t\t");
> + print_super_hex(sb, compat_flags, "\t\t");
> + print_super_hex(sb, compat_ro_flags, "\t\t");
> print_readable_compat_ro_flag(btrfs_super_compat_ro_flags(sb));
> - printf("incompat_flags\t\t0x%llx\n",
> - (unsigned long long)btrfs_super_incompat_flags(sb));
> + print_super_hex(sb, incompat_flags, "\t\t");
> print_readable_incompat_flag(btrfs_super_incompat_flags(sb));
> - printf("cache_generation\t%llu\n",
> - (unsigned long long)btrfs_super_cache_generation(sb));
> - printf("uuid_tree_generation\t%llu\n",
> - (unsigned long long)btrfs_super_uuid_tree_generation(sb));
> + print_check_super(sb, cache_generation, "\t",
> + (value > super_gen && value != (u64)-1));
> + print_check_super(sb, uuid_tree_generation, "\t", (value > super_gen));
>
> uuid_unparse(sb->dev_item.uuid, buf);
> printf("dev_item.uuid\t\t%s\n", buf);
> @@ -428,28 +468,18 @@ static void dump_superblock(struct btrfs_super_block *sb, int full)
> !memcmp(sb->dev_item.fsid, sb->fsid, BTRFS_FSID_SIZE) ?
> "[match]" : "[DON'T MATCH]");
>
> - printf("dev_item.type\t\t%llu\n", (unsigned long long)
> - btrfs_stack_device_type(&sb->dev_item));
> - printf("dev_item.total_bytes\t%llu\n", (unsigned long long)
> - btrfs_stack_device_total_bytes(&sb->dev_item));
> - printf("dev_item.bytes_used\t%llu\n", (unsigned long long)
> - btrfs_stack_device_bytes_used(&sb->dev_item));
> - printf("dev_item.io_align\t%u\n", (unsigned int)
> - btrfs_stack_device_io_align(&sb->dev_item));
> - printf("dev_item.io_width\t%u\n", (unsigned int)
> - btrfs_stack_device_io_width(&sb->dev_item));
> - printf("dev_item.sector_size\t%u\n", (unsigned int)
> - btrfs_stack_device_sector_size(&sb->dev_item));
> - printf("dev_item.devid\t\t%llu\n",
> - btrfs_stack_device_id(&sb->dev_item));
> - printf("dev_item.dev_group\t%u\n", (unsigned int)
> - btrfs_stack_device_group(&sb->dev_item));
> - printf("dev_item.seek_speed\t%u\n", (unsigned int)
> - btrfs_stack_device_seek_speed(&sb->dev_item));
> - printf("dev_item.bandwidth\t%u\n", (unsigned int)
> - btrfs_stack_device_bandwidth(&sb->dev_item));
> - printf("dev_item.generation\t%llu\n", (unsigned long long)
> - btrfs_stack_device_generation(&sb->dev_item));
> + /* For embedded device item, don't do extra check, just like kernel */
> + print_super_dev(sb, type, "\t\t");
> + print_super_dev(sb, total_bytes, "\t");
> + print_super_dev(sb, bytes_used, "\t");
> + print_super_dev(sb, io_align, "\t");
> + print_super_dev(sb, io_width, "\t");
> + print_super_dev(sb, sector_size, "\t");
> + print_super_dev(sb, id, "\t");
> + print_super_dev(sb, group, "\t");
> + print_super_dev(sb, seek_speed, "\t");
> + print_super_dev(sb, bandwidth, "\t");
> + print_super_dev(sb, generation, "\t");
> if (full) {
> printf("sys_chunk_array[%d]:\n", BTRFS_SYSTEM_CHUNK_ARRAY_SIZE);
> print_sys_chunk_array(sb);
>
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