The branch main has been updated by imp: URL: https://cgit.FreeBSD.org/src/commit/?id=d3eb9d3db3aa36df13f96c48bff8acdf626464c5
commit d3eb9d3db3aa36df13f96c48bff8acdf626464c5 Author: santhoshkumar-mani <[email protected]> AuthorDate: 2023-07-01 17:11:57 +0000 Commit: Warner Losh <[email protected]> CommitDate: 2023-07-01 17:14:49 +0000 bios: Don't keep sending BIO_FLUSH after first ENOTSUPP. When a storage device reports that it does not support cache flush, the GEOM disk layer by default returns ENOTSUPP in response to a BIO_FLUSH command. On AWS, local volumes do not advertise themselves as having write-cache enabled. When they are selected for L3 on all HDD nodes, the L3 subsystem may inadvertently kick these L3 devices if a BIO_FLUSH command fails with an ENOTSUPP return code. The fix is to make GEOM disk return success (0) when this condition occurs and add a sysctl to make this error handling config-driven Reviewed by: imp Pull Request: https://github.com/freebsd/freebsd-src/pull/710 --- sys/geom/geom_disk.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/sys/geom/geom_disk.c b/sys/geom/geom_disk.c index 90fe0216dd8b..a000dfe6c4f2 100644 --- a/sys/geom/geom_disk.c +++ b/sys/geom/geom_disk.c @@ -71,6 +71,7 @@ struct g_disk_softc { char led[64]; uint32_t state; struct mtx done_mtx; + bool flush_notsup_succeed; }; static g_access_t g_disk_access; @@ -539,7 +540,7 @@ g_disk_start(struct bio *bp) g_trace(G_T_BIO, "g_disk_flushcache(%s)", bp->bio_to->name); if (!(dp->d_flags & DISKFLAG_CANFLUSHCACHE)) { - error = EOPNOTSUPP; + error = (sc->flush_notsup_succeed) ? 0 : EOPNOTSUPP; break; } /*FALLTHROUGH*/ @@ -760,6 +761,10 @@ g_disk_create(void *arg, int flag) SYSCTL_CHILDREN(sc->sysctl_tree), OID_AUTO, "flags", CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, dp, 0, g_disk_sysctl_flags, "A", "Report disk flags"); + SYSCTL_ADD_BOOL(&sc->sysctl_ctx, + SYSCTL_CHILDREN(sc->sysctl_tree), OID_AUTO, "flush_notsup_succeed", + CTLFLAG_RWTUN, &sc->flush_notsup_succeed, sizeof(sc->flush_notsup_succeed), + "Do not return EOPNOTSUPP if there is no cache to flush"); } pp->private = sc; dp->d_geom = gp;
