Edit: I fixed it, I think :)

I believe I incorrectly turned my PC off yesterday, possibly resulting in some kind of corruption of my btrfs partition on my boot drive. I managed to boot into a USB with a live image of EndeavourOS I had, then used:
sudo btrfs rescue super-recover /dev/nvme0n1p3 and
sudo btrfs rescue zero-log /dev/nvme0n1p3

This instantly allowed me to mount my boot drive and btrfs partition and access my files. Rebooted, PC came up fine. This has certainly been an experience in patience and Linux in general. Now I can’t stop saying btrfs.

Original Post:

Hey gang, hope you’re well. I desperately need some Linux help. I was using my desktop (Bazzite w KDE Plasma) just fine, attempting to open some HTML files in Dolphin. It freezes, I physically turn off my desktop and it boots me into a terminal window with the following:

Failed to connect to system scope bus via local transport: No such file or directory  
[363.200643] BTRFS: error (device nvme0n1p3) in btrfs_replay_log:2100: errno=-5 IO failure (Failed to recover log tree)  

Generating "/run/initramfs/rdsosreport.txt"  

Entering emergency mode. Exit the shell to continue.  
Type "journalctl" to view system logs.  
You might want to save "/run/initramfs/rdsosreport.txt" to a USB stick or /boot after mounting them and attach it to a bug report.  

Press enter for maintenance (or press Control-D to continue)  

Admittedly my knowledge of Linux is incredibly limited. I have a feeling it has something to do with being unable find my M.2 drive? But the rest may be foreign to me. I figured out how to output ‘rdsosreport.txt’ and it spat out about a thousand lines that I couldn’t scroll up to see. Pressing ‘enter’ just prompts the terminal as :/var/roothome#, waiting for commands. ‘Control-D’ just brings me back to that initial message.

There is a line in journalctl that may give us some clues:

BTRFS error (device nvme0n1p3 state E): open_ctree failed: -5  
sysroot.mount: Mount process exited, code=exited, status=32/n/a  
sysroot.mount: Failed with result 'exit-code'  
Failed to mount sysroot.mount - /sysroot.  

Further down there’s:
BTRFS: error (device nvme0n1p3) in btrfs_replay_log:2100: error=-5 IO failure (Failed to recover log tree)

I greatly appreciate any time and help you smart folks can offer!

Update: I have Bazzite on a flash drive, and I have the install wizard pulled up on my desktop. Interestingly, and perhaps worryingly, it’s taking an abnormally long time to probe my drives. I have two m.2 drives in my desktop, the primary (Samsung EVO 990 2Tb) where Bazzite is installed, and the secondary (WD, I think, 1Tb split into two partitions). The installer has the “install destination” option grayed out, still attempting to locate the drives. It’s been about 10 minutes… Could both of the drives be bad? I sincerely hope not…