Messages in this thread | | | Date | Fri, 6 Oct 2023 10:22:08 -0700 | Subject | Re: [PATCH 10/21] block: Add fops atomic write support | From | Bart Van Assche <> |
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On 10/5/23 21:31, Dave Chinner wrote: > Then I don't see what your concern is. > > Single sector writes are guaranteed atomic and have been for as long > as I've worked in this game. OTOH, multi-sector writes are not > guaranteed to be atomic - they can get torn on sector boundaries, but > the individual sectors within that write are guaranteed to be > all-or-nothing. > > Any hardware device that does not guarantee single sector write > atomicity (i.e. tears in the middle of a sector) is, by definition, > broken. And we all know that broken hardware means nothing in the > storage stack works as it should, so I just don't see what point you > are trying to make...
Do you agree that the above implies that it is not useful in patch 01/21 of this series to track atomic_write_unit_min_bytes in the block layer nor to export this information to user space? The above implies that this parameter will always be equal to the logical block size. Writes to a single physical block happen atomically. If there are multiple logical blocks per physical block, the block device must serialize read/modify/write cycles internally.
Thanks,
Bart.
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