btrfs-progs: mkfs: check metadata redundancy

Currently BTRFS allows you to make bad choices of data and
metadata levels. For example -d raid1 -m raid0 means you can
only use half your total disk space, but will lose everything
if 1 disk fails. It should give a warning in these cases.

When making a filesystem, check that metadata mode is at least
as redundant as the data mode. For example give warning when:

	-d raid1 -m raid0

Signed-off-by: Sam Tygier <samtygier@yahoo.co.uk>
[make the check more visible in mkfs output]
Signed-off-by: David Sterba <dsterba@suse.cz>
This commit is contained in:
Sam Tygier 2015-05-30 15:54:48 +01:00 committed by David Sterba
parent 1e9a6b6984
commit fbb356632c
3 changed files with 25 additions and 0 deletions

6
mkfs.c
View file

@ -1429,6 +1429,12 @@ int main(int ac, char **av)
nodesize * i;
}
if (group_profile_max_safe_loss(metadata_profile) <
group_profile_max_safe_loss(data_profile)){
fprintf(stderr,
"WARNING: metatdata has lower redundancy than data!\n\n");
}
/*
* FS features that can be set by other means than -O
* just set the bit here

18
utils.c
View file

@ -2354,6 +2354,24 @@ int test_num_disk_vs_raid(u64 metadata_profile, u64 data_profile,
return 0;
}
int group_profile_max_safe_loss(u64 flags)
{
switch (flags & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
case 0: /* single */
case BTRFS_BLOCK_GROUP_DUP:
case BTRFS_BLOCK_GROUP_RAID0:
return 0;
case BTRFS_BLOCK_GROUP_RAID1:
case BTRFS_BLOCK_GROUP_RAID5:
case BTRFS_BLOCK_GROUP_RAID10:
return 1;
case BTRFS_BLOCK_GROUP_RAID6:
return 2;
default:
return -1;
}
}
/* Check if disk is suitable for btrfs
* returns:
* 1: something is wrong, estr provides the error

View file

@ -144,6 +144,7 @@ int test_dev_for_mkfs(char *file, int force_overwrite, char *estr);
int get_label_mounted(const char *mount_path, char *labelp);
int test_num_disk_vs_raid(u64 metadata_profile, u64 data_profile,
u64 dev_cnt, int mixed, char *estr);
int group_profile_max_safe_loss(u64 flags);
int is_vol_small(char *file);
int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
int verify);