From 039f28fe1e04615c1d975c21bb3b30f833727b84 Mon Sep 17 00:00:00 2001 From: Alexander Motin Date: Mon, 18 Mar 2024 14:19:53 -0400 Subject: [PATCH] BRT: Fix holes cloning. - When reading L0 block pointers handle buffers without ones and without dirty records as a holes. Those appear when dnode size was increased, but the end was never written, so there are no new indirection levels to store the pointers. It makes no sense to return EAGAIN here, since sync won't create new indirection levels until there will be actual writes. - When cloning blocks set destination hole logical birth time to the current TXG. Otherwise if we are cloning over existing data, newly created holes may not be properly replicated later. Use BP_SET_BIRTH() when possible to not replicate its logic. Signed-off-by: Alexander Motin Sponsored by: iXsystems, Inc. Closes: #15994 --- module/zfs/dmu.c | 26 +++++++++++++------------- 1 file changed, 13 insertions(+), 13 deletions(-) diff --git a/module/zfs/dmu.c b/module/zfs/dmu.c index d82211e6d4c..ad248d0be86 100644 --- a/module/zfs/dmu.c +++ b/module/zfs/dmu.c @@ -2257,11 +2257,13 @@ dmu_read_l0_bps(objset_t *os, uint64_t object, uint64_t offset, uint64_t length, if (bp == NULL) { /* - * The block was created in this transaction group, - * so it has no BP yet. + * The file size was increased, but the block was never + * written, otherwise we would either have the block + * pointer or the dirty record and would not get here. + * It is effectively a hole, so report it as such. */ - error = SET_ERROR(EAGAIN); - goto out; + BP_ZERO(&bps[i]); + continue; } /* * Make sure we clone only data blocks. @@ -2353,18 +2355,16 @@ dmu_brt_clone(objset_t *os, uint64_t object, uint64_t offset, uint64_t length, ASSERT3U(dr->dr_txg, ==, tx->tx_txg); dl = &dr->dt.dl; dl->dr_overridden_by = *bp; - dl->dr_brtwrite = B_TRUE; - dl->dr_override_state = DR_OVERRIDDEN; - if (BP_IS_HOLE(bp)) { - dl->dr_overridden_by.blk_birth = 0; - dl->dr_overridden_by.blk_phys_birth = 0; - } else { - dl->dr_overridden_by.blk_birth = dr->dr_txg; + if (!BP_IS_HOLE(bp) || bp->blk_birth != 0) { if (!BP_IS_EMBEDDED(bp)) { - dl->dr_overridden_by.blk_phys_birth = - BP_PHYSICAL_BIRTH(bp); + BP_SET_BIRTH(&dl->dr_overridden_by, dr->dr_txg, + BP_PHYSICAL_BIRTH(bp)); + } else { + dl->dr_overridden_by.blk_birth = dr->dr_txg; } } + dl->dr_brtwrite = B_TRUE; + dl->dr_override_state = DR_OVERRIDDEN; mutex_exit(&db->db_mtx);