Commit c3d6dda6 authored by Mark Harmstone's avatar Mark Harmstone Committed by David Sterba
Browse files

btrfs: allow remapped chunks to have zero stripes 



When a chunk has been fully remapped, we are going to set its
num_stripes to 0, as it will no longer represent a physical location on
disk.

Change tree-checker to allow for this, and fix read_one_chunk() to avoid
a divide by zero.

Reviewed-by: default avatarBoris Burkov <boris@bur.io>
Signed-off-by: default avatarMark Harmstone <mark@harmstone.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 0b4d29fa

fs/btrfs/tree-checker.c

+35 −20
Original line number Diff line number Diff line
@@ -816,6 +816,32 @@ static void chunk_err(const struct btrfs_fs_info *fs_info, 
	va_end(args);

}



static bool valid_stripe_count(u64 profile, u16 num_stripes, u16 sub_stripes)

{

	switch (profile) {

	case BTRFS_BLOCK_GROUP_RAID0:

		return true;

	case BTRFS_BLOCK_GROUP_RAID10:

		return sub_stripes == btrfs_raid_array[BTRFS_RAID_RAID10].sub_stripes;

	case BTRFS_BLOCK_GROUP_RAID1:

		return num_stripes == btrfs_raid_array[BTRFS_RAID_RAID1].devs_min;

	case BTRFS_BLOCK_GROUP_RAID1C3:

		return num_stripes == btrfs_raid_array[BTRFS_RAID_RAID1C3].devs_min;

	case BTRFS_BLOCK_GROUP_RAID1C4:

		return num_stripes == btrfs_raid_array[BTRFS_RAID_RAID1C4].devs_min;

	case BTRFS_BLOCK_GROUP_RAID5:

		return num_stripes >= btrfs_raid_array[BTRFS_RAID_RAID5].devs_min;

	case BTRFS_BLOCK_GROUP_RAID6:

		return num_stripes >= btrfs_raid_array[BTRFS_RAID_RAID6].devs_min;

	case BTRFS_BLOCK_GROUP_DUP:

		return num_stripes == btrfs_raid_array[BTRFS_RAID_DUP].dev_stripes;

	case 0: /* SINGLE */

		return num_stripes == btrfs_raid_array[BTRFS_RAID_SINGLE].dev_stripes;

	default:

		BUG();

	}

}



/*

 * The common chunk check which could also work on super block sys chunk array.

 *
@@ -839,6 +865,7 @@ int btrfs_check_chunk_valid(const struct btrfs_fs_info *fs_info, 
	u64 features;

	u32 chunk_sector_size;

	bool mixed = false;

	bool remapped;

	int raid_index;

	int nparity;

	int ncopies;
@@ -861,13 +888,14 @@ int btrfs_check_chunk_valid(const struct btrfs_fs_info *fs_info, 
	raid_index = btrfs_bg_flags_to_raid_index(type);

	ncopies = btrfs_raid_array[raid_index].ncopies;

	nparity = btrfs_raid_array[raid_index].nparity;

	remapped = (type & BTRFS_BLOCK_GROUP_REMAPPED);



	if (unlikely(!num_stripes)) {

	if (unlikely(!remapped && !num_stripes)) {

		chunk_err(fs_info, leaf, chunk, logical,

			  "invalid chunk num_stripes, have %u", num_stripes);

		return -EUCLEAN;

	}

	if (unlikely(num_stripes < ncopies)) {

	if (unlikely(num_stripes != 0 && num_stripes < ncopies)) {

		chunk_err(fs_info, leaf, chunk, logical,

			  "invalid chunk num_stripes < ncopies, have %u < %d",

			  num_stripes, ncopies);
@@ -965,22 +993,9 @@ int btrfs_check_chunk_valid(const struct btrfs_fs_info *fs_info, 
		}

	}



	if (unlikely((type & BTRFS_BLOCK_GROUP_RAID10 &&

		      sub_stripes != btrfs_raid_array[BTRFS_RAID_RAID10].sub_stripes) ||

		     (type & BTRFS_BLOCK_GROUP_RAID1 &&

		      num_stripes != btrfs_raid_array[BTRFS_RAID_RAID1].devs_min) ||

		     (type & BTRFS_BLOCK_GROUP_RAID1C3 &&

		      num_stripes != btrfs_raid_array[BTRFS_RAID_RAID1C3].devs_min) ||

		     (type & BTRFS_BLOCK_GROUP_RAID1C4 &&

		      num_stripes != btrfs_raid_array[BTRFS_RAID_RAID1C4].devs_min) ||

		     (type & BTRFS_BLOCK_GROUP_RAID5 &&

		      num_stripes < btrfs_raid_array[BTRFS_RAID_RAID5].devs_min) ||

		     (type & BTRFS_BLOCK_GROUP_RAID6 &&

		      num_stripes < btrfs_raid_array[BTRFS_RAID_RAID6].devs_min) ||

		     (type & BTRFS_BLOCK_GROUP_DUP &&

		      num_stripes != btrfs_raid_array[BTRFS_RAID_DUP].dev_stripes) ||

		     ((type & BTRFS_BLOCK_GROUP_PROFILE_MASK) == 0 &&

		      num_stripes != btrfs_raid_array[BTRFS_RAID_SINGLE].dev_stripes))) {

	if (!remapped &&

	    !valid_stripe_count(type & BTRFS_BLOCK_GROUP_PROFILE_MASK,

				num_stripes, sub_stripes)) {

		chunk_err(fs_info, leaf, chunk, logical,

			"invalid num_stripes:sub_stripes %u:%u for profile %llu",

			num_stripes, sub_stripes,
@@ -1004,11 +1019,11 @@ static int check_leaf_chunk_item(struct extent_buffer *leaf, 
	struct btrfs_fs_info *fs_info = leaf->fs_info;

	int num_stripes;



	if (unlikely(btrfs_item_size(leaf, slot) < sizeof(struct btrfs_chunk))) {

	if (unlikely(btrfs_item_size(leaf, slot) < offsetof(struct btrfs_chunk, stripe))) {

		chunk_err(fs_info, leaf, chunk, key->offset,

			"invalid chunk item size: have %u expect [%zu, %u)",

			btrfs_item_size(leaf, slot),

			sizeof(struct btrfs_chunk),

			offsetof(struct btrfs_chunk, stripe),

			BTRFS_LEAF_DATA_SIZE(fs_info));

		return -EUCLEAN;

	}

fs/btrfs/volumes.c

+6 −1
Original line number Diff line number Diff line
@@ -7047,7 +7047,12 @@ static int read_one_chunk(struct btrfs_key *key, struct extent_buffer *leaf, 
	 */

	map->sub_stripes = btrfs_raid_array[index].sub_stripes;

	map->verified_stripes = 0;



	if (num_stripes > 0)

		map->stripe_size = btrfs_calc_stripe_length(map);

	else

		map->stripe_size = 0;



	for (i = 0; i < num_stripes; i++) {

		map->stripes[i].physical =

			btrfs_stripe_offset_nr(leaf, chunk, i);