I’m new to a lot of this, just trying to use a NAS at home, single usb external disk, not RAID. Was working great for a few months, I’m not sure what changed today when it stopped mounting. Any advice appreciated.

Dmesg log attached


uname -a
Linux rock64 4.4.190-1233-rockchip-ayufan-gd3f1be0ed310 #1 SMP Wed Aug 28 08:59:34 UTC 2019 aarch64 GNU/Linux



btrfs --version
btrfs-progs v4.7.3



btrfs fi show
Label: '3TBRock64'  uuid: 71eda2e3-384c-4868-b5d4-683f222865e6
	Total devices 1 FS bytes used 2.48TiB
	devid    1 size 2.73TiB used 2.59TiB path /dev/mapper/sda-crypt


btrfs fi df /dev/mapper/sda-crypt
ERROR: not a btrfs filesystem: /dev/mapper/sda-crypt


btrfs inspect-internal dump-super /dev/mapper/sda-crypt 
superblock: bytenr=65536, device=/dev/mapper/sda-crypt
---------------------------------------------------------
csum_type		0 (crc32c)
csum_size		4
csum			0x9e8b0c33 [match]
bytenr			65536
flags			0x1
			( WRITTEN )
magic			_BHRfS_M [match]
fsid			71eda2e3-384c-4868-b5d4-683f222865e6
label			3TBRock64
generation		395886
root			2638934654976
sys_array_size		129
chunk_root_generation	377485
root_level		1
chunk_root		20971520
chunk_root_level	1
log_root		2638952366080
log_root_transid	0
log_root_level		0
total_bytes		3000556847104
bytes_used		2729422221312
sectorsize		4096
nodesize		16384
leafsize		16384
stripesize		4096
root_dir		6
num_devices		1
compat_flags		0x0
compat_ro_flags		0x0
incompat_flags		0x161
			( MIXED_BACKREF |
			  BIG_METADATA |
			  EXTENDED_IREF |
			  SKINNY_METADATA )
cache_generation	395886
uuid_tree_generation	395886
dev_item.uuid		b7f4386a-18e0-437b-9588-6064ff483fd5
dev_item.fsid		71eda2e3-384c-4868-b5d4-683f222865e6 [match]
dev_item.type		0
dev_item.total_bytes	3000556847104
dev_item.bytes_used	2843293515776
dev_item.io_align	4096
dev_item.io_width	4096
dev_item.sector_size	4096
dev_item.devid		1
dev_item.dev_group	0
dev_item.seek_speed	0
dev_item.bandwidth	0


dev_item.generation	0