Just making a note for anyone else running Raspbian 11 Bullseye: I was experiencing repeated crashes and found lots of btrfs “mmc_erase” errors in syslog. Long story short it appears there is a lowlevel issue with btrfs discard and some SD cards. The fix that appears (so far) to work is to add “nodiscard” to the btrfs options in fstab:
proc /proc proc defaults 0 0
PARTUUID=123xyzpdq-01 /boot/efi vfat defaults 0 2
PARTUUID=123xyzpdq-02 / btrfs defaults,noatime,nodiscard 0 1
Ref: [PATCH 5.10 77/79] mmc: core: Add SD card quirk for broken discard - Greg Kroah-Hartman
Ref: btrfs file corruption with pci-e sd card reader with discard mount option(likely a driver bug?) : btrfs