On 29/03/2016 22:18, Alexander Motin wrote: > Author: mav > Date: Tue Mar 29 19:18:34 2016 > New Revision: 297396 > URL: https://svnweb.freebsd.org/changeset/base/297396 > > Log: > Modify "4958 zdb trips assert on pools with ashift >= 0xe". > > Unlike Illumos FreeBSD has concept of logical ashift, that specifies > really minimal vdev block size that can be accessed. This knowledge > allows properly pad physical I/O and correctly assert its alignment. > > This change fixes L2ARC write errors when device has logical sector > size above 512 bytes. > > MFC after: 1 month > > Modified: > head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zio.c > > Modified: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zio.c > ============================================================================== > --- head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zio.c Tue Mar 29 > 19:11:04 2016 (r297395) > +++ head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zio.c Tue Mar 29 > 19:18:34 2016 (r297396) > @@ -2775,10 +2775,19 @@ zio_vdev_io_start(zio_t *zio) > (void) atomic_cas_64(&spa->spa_last_io, old, new); > } > > +#ifdef illumos > align = 1ULL << vd->vdev_top->vdev_ashift; > > if (!(zio->io_flags & ZIO_FLAG_PHYSICAL) && > P2PHASE(zio->io_size, align) != 0) { > +#else > + if (zio->io_flags & ZIO_FLAG_PHYSICAL) > + align = 1ULL << vd->vdev_top->vdev_logical_ashift;
Alexander, I believe that this is wrong. We must not modify any parameters of a physical zio including its size. Otherwise we are going to overwrite something that an originator of the I/O did not intend to overwrite. Here we should have a check (or just the assertion) that the zio conforms to disk characteristics. It's the code that creates physical zio-s that should be made aware of the alignment requirements. Please see my work in this direction: https://reviews.freebsd.org/D2789 (BTW, I added you as a reviewer there). > + else > + align = 1ULL << vd->vdev_top->vdev_ashift; > + > + if (P2PHASE(zio->io_size, align) != 0) { > +#endif > /* Transform logical writes to be a full physical block size. */ > uint64_t asize = P2ROUNDUP(zio->io_size, align); > char *abuf = NULL; > @@ -2794,6 +2803,7 @@ zio_vdev_io_start(zio_t *zio) > zio_subblock); > } > > +#ifdef illumos > /* > * If this is not a physical io, make sure that it is properly aligned > * before proceeding. > @@ -2809,6 +2819,10 @@ zio_vdev_io_start(zio_t *zio) > ASSERT0(P2PHASE(zio->io_offset, SPA_MINBLOCKSIZE)); > ASSERT0(P2PHASE(zio->io_size, SPA_MINBLOCKSIZE)); > } > +#else > + ASSERT0(P2PHASE(zio->io_offset, align)); > + ASSERT0(P2PHASE(zio->io_size, align)); > +#endif > > VERIFY(zio->io_type == ZIO_TYPE_READ || spa_writeable(spa)); > > -- Andriy Gapon _______________________________________________ svn-src-all@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
