From 0cb1ef60ae26d855e8f4a959fff66a7693766ea3 Mon Sep 17 00:00:00 2001 From: Rob Norris Date: Fri, 9 Jun 2023 10:14:42 +1000 Subject: [PATCH] ddt: compare keys, not entries We're about to have different kinds of things that we'll compare on key, so generalise this function to support that. (It actually worked fine because of the way the casts work out, but it requires the key to be at the start of the object so the cast through ddt_entry_t works, and even then it reads strangely for anything that's not a ddt_entry_t). Reviewed-by: Brian Behlendorf Signed-off-by: Rob Norris Sponsored-by: Klara, Inc. Sponsored-by: iXsystems, Inc. Closes #15887 --- cmd/zdb/zdb.c | 3 ++- include/sys/ddt.h | 3 ++- module/zfs/ddt.c | 24 ++++++++++++------------ 3 files changed, 16 insertions(+), 14 deletions(-) diff --git a/cmd/zdb/zdb.c b/cmd/zdb/zdb.c index b857e61bd0..35d71012f7 100644 --- a/cmd/zdb/zdb.c +++ b/cmd/zdb/zdb.c @@ -7121,6 +7121,7 @@ dump_block_stats(spa_t *spa) } typedef struct zdb_ddt_entry { + /* key must be first for ddt_key_compare */ ddt_key_t zdde_key; uint64_t zdde_ref_blocks; uint64_t zdde_ref_lsize; @@ -7181,7 +7182,7 @@ dump_simulated_ddt(spa_t *spa) ddt_histogram_t ddh_total = {{{0}}}; ddt_stat_t dds_total = {0}; - avl_create(&t, ddt_entry_compare, + avl_create(&t, ddt_key_compare, sizeof (zdb_ddt_entry_t), offsetof(zdb_ddt_entry_t, zdde_node)); spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER); diff --git a/include/sys/ddt.h b/include/sys/ddt.h index 2f9ff84b28..e6bbaa10e9 100644 --- a/include/sys/ddt.h +++ b/include/sys/ddt.h @@ -114,6 +114,7 @@ enum ddt_phys_type { * In-core ddt entry */ struct ddt_entry { + /* key must be first for ddt_key_compare */ ddt_key_t dde_key; ddt_phys_t dde_phys[DDT_PHYS_TYPES]; zio_t *dde_lead_zio[DDT_PHYS_TYPES]; @@ -230,7 +231,7 @@ extern boolean_t ddt_class_contains(spa_t *spa, enum ddt_class max_class, extern ddt_entry_t *ddt_repair_start(ddt_t *ddt, const blkptr_t *bp); extern void ddt_repair_done(ddt_t *ddt, ddt_entry_t *dde); -extern int ddt_entry_compare(const void *x1, const void *x2); +extern int ddt_key_compare(const void *x1, const void *x2); extern void ddt_create(spa_t *spa); extern int ddt_load(spa_t *spa); diff --git a/module/zfs/ddt.c b/module/zfs/ddt.c index 221e964138..f54a51842e 100644 --- a/module/zfs/ddt.c +++ b/module/zfs/ddt.c @@ -628,7 +628,8 @@ ddt_remove(ddt_t *ddt, ddt_entry_t *dde) ddt_entry_t * ddt_lookup(ddt_t *ddt, const blkptr_t *bp, boolean_t add) { - ddt_entry_t *dde, dde_search; + ddt_key_t search; + ddt_entry_t *dde; enum ddt_type type; enum ddt_class class; avl_index_t where; @@ -636,13 +637,13 @@ ddt_lookup(ddt_t *ddt, const blkptr_t *bp, boolean_t add) ASSERT(MUTEX_HELD(&ddt->ddt_lock)); - ddt_key_fill(&dde_search.dde_key, bp); + ddt_key_fill(&search, bp); - dde = avl_find(&ddt->ddt_tree, &dde_search, &where); + dde = avl_find(&ddt->ddt_tree, &search, &where); if (dde == NULL) { if (!add) return (NULL); - dde = ddt_alloc(&dde_search.dde_key); + dde = ddt_alloc(&search); avl_insert(&ddt->ddt_tree, dde, where); } @@ -713,7 +714,8 @@ ddt_prefetch(spa_t *spa, const blkptr_t *bp) } /* - * Opaque struct used for ddt_key comparison + * Key comparison. Any struct wanting to make use of this function must have + * the key as the first element. */ #define DDT_KEY_CMP_LEN (sizeof (ddt_key_t) / sizeof (uint16_t)) @@ -722,12 +724,10 @@ typedef struct ddt_key_cmp { } ddt_key_cmp_t; int -ddt_entry_compare(const void *x1, const void *x2) +ddt_key_compare(const void *x1, const void *x2) { - const ddt_entry_t *dde1 = x1; - const ddt_entry_t *dde2 = x2; - const ddt_key_cmp_t *k1 = (const ddt_key_cmp_t *)&dde1->dde_key; - const ddt_key_cmp_t *k2 = (const ddt_key_cmp_t *)&dde2->dde_key; + const ddt_key_cmp_t *k1 = (const ddt_key_cmp_t *)x1; + const ddt_key_cmp_t *k2 = (const ddt_key_cmp_t *)x2; int32_t cmp = 0; for (int i = 0; i < DDT_KEY_CMP_LEN; i++) { @@ -748,9 +748,9 @@ ddt_table_alloc(spa_t *spa, enum zio_checksum c) memset(ddt, 0, sizeof (ddt_t)); mutex_init(&ddt->ddt_lock, NULL, MUTEX_DEFAULT, NULL); - avl_create(&ddt->ddt_tree, ddt_entry_compare, + avl_create(&ddt->ddt_tree, ddt_key_compare, sizeof (ddt_entry_t), offsetof(ddt_entry_t, dde_node)); - avl_create(&ddt->ddt_repair_tree, ddt_entry_compare, + avl_create(&ddt->ddt_repair_tree, ddt_key_compare, sizeof (ddt_entry_t), offsetof(ddt_entry_t, dde_node)); ddt->ddt_checksum = c; ddt->ddt_spa = spa;