On Sun, 5 Jan 2020, Clodoaldo Neto wrote:
> I'm struggling to mount an encrypted backing device. The backing
> device is a RAID 1 array at /dev/md127 and the cache device is
> /dev/sdb1.
>
> # lsblk
> NAME MAJ:MIN RM SIZE RO
> TYPE MOUNTPOINT
> sda 8:0 0 223.6G 0 disk
> ├─sda1 8:1 0 700M 0 part /boot
> ├─sda2 8:2 0 700M 0
> part /boot/efi
> ├─sda3 8:3 0 26G 0 part
> │ └─luks-9793c78f-723c-4218-865f-83dbc4659192 253:1 0 26G 0 crypt [SWAP]
> └─sda4 8:4 0 162G 0 part
> └─luks-569b1153-2fab-4984-b1b6-c4a02ee206ef 253:0 0 162G 0 crypt /
> sdb 8:16 0 111.8G 0 disk
> ├─sdb1 8:17 0 40G 0 part
> └─sdb2 8:18 0 71.8G 0 part
> sdc 8:32 0 1.8T 0 disk
> └─sdc1 8:33 0 1.8T 0 part
> └─md127 9:127 0 1.8T 0 raid1
> sdd 8:48 0 1.8T 0 disk
> └─sdd1 8:49 0 1.8T 0 part
> └─md127 9:127 0 1.8T 0 raid1
> sde 8:64 1 58.9G 0 disk
> ├─sde1 8:65 1 20G 0 part
> └─sde2 8:66 1 38.9G 0 part
> sr0 11:0 1 1024M 0 rom
>
> # blkid | grep -E "md127|sdb1"
> /dev/sdb1: UUID="535bfa2d-4c6e-4c19-91b2-d292872a1877" TYPE="bcache"
> PARTLABEL="Linux filesystem"
> PARTUUID="505789f1-0523-4c62-bdb1-81bc0cc7bff1"
> /dev/md127: UUID="b17ceaac-27ec-44d8-8bbb-235cfaa0c4a4" TYPE="bcache"
>
> It was working right when I installed Fedora 31 yesterday but then I
> resized the caching partition and I can't make it work again.
>
> This is what I tried
>
> # wipefs -a /dev/sdb1
> /dev/sdb1: 16 bytes were erased at offset 0x00001018 (bcache): c6 85
> 73 f6 4e 1a 45 ca 82 65 f5 7f 48 ba 6d 81
>
> # make-bcache -C --writeback /dev/sdb1
> UUID: eb7d8e72-f24c-48ee-bad0-771afccca876
> Set UUID: 50e33260-4623-4374-9a61-c78b7d75280e
> version: 0
> nbuckets: 81920
> block_size: 1
> bucket_size: 1024
> nr_in_set: 1
> nr_this_dev: 0
> first_bucket: 1
>
> # ll /sys/fs/bcache/
> total 0
> drwxr-xr-x. 7 root root 0 Jan 5 18:34 50e33260-4623-4374-9a61-c78b7d75280e
> --w-------. 1 root root 4096 Jan 5 17:39 pendings_cleanup
> --w-------. 1 root root 4096 Jan 5 18:03 register
> --w-------. 1 root root 4096 Jan 5 17:39 register_quiet
>
> # bcache-super-show /dev/sdb1
> sb.magic ok
> sb.first_sector 8 [match]
> sb.csum C4CB62916B7825CE [match]
> sb.version 3 [cache device]
>
> dev.label (empty)
> dev.uuid eb7d8e72-f24c-48ee-bad0-771afccca876
> dev.sectors_per_block 1
> dev.sectors_per_bucket 1024
> dev.cache.first_sector 1024
> dev.cache.cache_sectors 83885056
> dev.cache.total_sectors 83886080
> dev.cache.ordered yes
> dev.cache.discard no
> dev.cache.pos 0
> dev.cache.replacement 0 [lru]
>
> cset.uuid 50e33260-4623-4374-9a61-c78b7d75280e
>
> # echo /dev/md127 > /sys/fs/bcache/register
> # echo 50e33260-4623-4374-9a61-c78b7d75280e > /sys/block/md127/bcache/attach
> # blkid | grep bcache0
> /dev/bcache0: UUID="7e2c0b40-8dec-4b13-8d00-b53b55160775" TYPE="crypto_LUKS"
>
> # bcache-status
> --- bcache ---
> UUID 50e33260-4623-4374-9a61-c78b7d75280e
> Block Size 512 B
> Bucket Size 512.00 KiB
> Congested? False
> Read Congestion 2.0ms
> Write Congestion 20.0ms
> Total Cache Size 40 GiB
> Total Cache Used 409.6 MiB (1%)
> Total Cache Unused 40 GiB (99%)
> Evictable Cache 40 GiB (100%)
> Replacement Policy [lru] fifo random
> Cache Mode writethrough [writeback] writearound none
> Total Hits 9 (64%)
> Total Misses 5
> Total Bypass Hits 13 (16%)
> Total Bypass Misses 64
> Total Bypassed 308.00 KiB
>
> # lsblk
> NAME MAJ:MIN RM SIZE RO
> TYPE MOUNTPOINT
> sda 8:0 0 223.6G 0 disk
> ├─sda1 8:1 0 700M 0 part /boot
> ├─sda2 8:2 0 700M 0
> part /boot/efi
> ├─sda3 8:3 0 26G 0 part
> │ └─luks-9793c78f-723c-4218-865f-83dbc4659192 253:1 0 26G 0 crypt [SWAP]
> └─sda4 8:4 0 162G 0 part
> └─luks-569b1153-2fab-4984-b1b6-c4a02ee206ef 253:0 0 162G 0 crypt /
> sdb 8:16 0 111.8G 0 disk
> ├─sdb1 8:17 0 40G 0 part
> │ └─bcache0 252:0 0 1.8T 0 disk
> └─sdb2 8:18 0 71.8G 0 part
> sdc 8:32 0 1.8T 0 disk
> └─sdc1 8:33 0 1.8T 0 part
> └─md127 9:127 0 1.8T 0 raid1
> └─bcache0 252:0 0 1.8T 0 disk
> sdd 8:48 0 1.8T 0 disk
> └─sdd1 8:49 0 1.8T 0 part
> └─md127 9:127 0 1.8T 0 raid1
> └─bcache0 252:0 0 1.8T 0 disk
> sde 8:64 1 58.9G 0 disk
> ├─sde1 8:65 1 20G 0 part
> └─sde2 8:66 1 38.9G 0 part
> sr0 11:0 1 1024M 0 rom
>
> # mount /dev/bcache0 /r
> mount: /r: unknown filesystem type 'crypto_LUKS'.
>
> # cryptsetup open /dev/bcache0 backing-device
> Enter passphrase for /dev/bcache0:
>
> # mount /dev/mapper/backing-device /r
> mount: /r: unknown filesystem type 'bcache'.
I'm guessing that make-bcache was run upon /dev/mapper/backing-device at
some point in time. Hopefully it wasn't clobbered.
Try
mount -t ext2 /dev/mapper/backing-device /r
^^^^ or whatever your original FS really was.
--
Eric Wheeler
>
> What am I missing?
>
> Regards, Clodoaldo
>
