[cesarb]

> crc is recalculated using corrupted bit

Why would it need to recalculate the CRC? The correct CRC (or other hash) for the data is already stored in the metadata trees; it's how it discovered that the data was corrupted in the first place. If it writes back corrupted data, it will be detected as corrupted again the next time.

[amtadt]

Because CRC is in the on-disk data structure, not in the in-ram data structure. It is stripped upon reading to ram, and created upon writing to disk.

That's how bcachefs is designed right now.

[koverstreet]

No, we carefully carry around existing checksums when moving data.

Page cache is a different story, but doesn't apply to what we're talking about here.