On 6/3/25 5:34 PM, Anuj gupta wrote: > On Wed, Jun 4, 2025 at 12:24?AM Jens Axboe <axboe@xxxxxxxxx> wrote: >> >> On 6/3/25 12:47 PM, Caleb Sander Mateos wrote: >>> blk_rq_integrity_map_user() creates the ubuf iter with ITER_DEST for >>> write-direction operations and ITER_SOURCE for read-direction ones. >>> This is backwards; writes use the user buffer as a source for metadata >>> and reads use it as a destination. Switch to the rq_data_dir() helper, >>> which maps writes to ITER_SOURCE (WRITE) and reads to ITER_DEST(READ). >> >> Was going to ask "how did this ever work without splats", but looks like >> a fairly recent change AND it's for integrity which isn't widely used. >> But it does show a gap in testing for sure. >> > > Yes, you're absolutely right. blk_rq_integrity_map_user() is currently > only used by nvme-passthru, and Keith recently added a test for that > path [1]. > > As for the user block integrity interface in general ? it?s been a bit > tricky to write generic tests so far, mostly because there's no way to > query the device's integrity capabilities from userspace. But that > should become much easier once we have support for that via an ioctl[2]. > > [1] https://lore.kernel.org/io-uring/20250416162802.3614051-1-kbusch@xxxxxxxx/ > [2] https://lore.kernel.org/all/20250527104237.2928-1-anuj20.g@xxxxxxxxxxx/ That makes sense, thanks for clarifying. -- Jens Axboe
