On Wed, May 07, 2025 at 06:24:34PM +0200, Ahmad Fatoum wrote: > blk_ioctl_zeroout > blkdev_issue_zeroout(..., BLKDEV_ZERO_NOUNMAP) > __blkdev_issue_write_zeroes(..., BLKDEV_ZERO_NOUNMAP) > submit_bio_wait(bio->bi_opf = REQ_NOUNMAP) > > __REQ_NOUNMAP has comment saying 'do not free blocks when zeroing', > but as shown above, TRIM allows the card to unmap the indicated region. __REQ_NOUNMAP is a hint. All the storage specs are a mess in this area as they usually get the polarity wrong and/or just have very vague semantics. Also actually writing zeroes and not unmapping is totally pointless on flash storage as it just increases PE cycles for no good reason.
