Re: [PATCH 1/2] block: Read max write zeroes once for __blkdev_issue_write_zeroes()

On 15/08/2024 16:26, Christoph Hellwig wrote:

quoted

quoted

quoted

+/*
+ * Pass bio_write_zeroes_limit() return value in @limit, as the return
+ * value may change after a REQ_OP_WRITE_ZEROES is issued.
+ */

I don't think that really helps all that much to explain the issue,
which is about SCSI not having an ahead of time flag that reliably
works for write same support, which makes it clear the limit to 0 on
the first I/O completion.  Maybe you can actually spell this out?

Please just tell me what you would like to see, and I will copy verbatim.

Probably just what I just wrote.  Unless Martin can come up with
better language.

/*
  * SCSI does not have a reliable ahead of time flag that reliably
  * works for write same support; instead, the limit is set to zero for
  * the first failed I/O completion. As such, only read the limit prior
  * to submission, as it may later change.
  */

ok?