Convert dbuf dirty record record list to a list_t

Additionally pull in state machine comments about
upcoming async cow work.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matt Ahrens <matt@delphix.com>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes #9902
This commit is contained in:
Matthew Macy 2020-02-05 11:07:19 -08:00 committed by GitHub
parent 741db5a346
commit cccbed9f98
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
6 changed files with 103 additions and 91 deletions

View File

@ -127,8 +127,8 @@ typedef struct dbuf_dirty_record {
/* pointer back to our dbuf */
struct dmu_buf_impl *dr_dbuf;
/* pointer to next dirty record */
struct dbuf_dirty_record *dr_next;
/* list link for dbuf dirty records */
list_node_t dr_dbuf_node;
/* pointer to parent dirty record */
struct dbuf_dirty_record *dr_parent;
@ -257,8 +257,8 @@ typedef struct dmu_buf_impl {
kcondvar_t db_changed;
dbuf_dirty_record_t *db_data_pending;
/* pointer to most recent dirty record for this buffer */
dbuf_dirty_record_t *db_last_dirty;
/* List of dirty records for the buffer sorted newest to oldest. */
list_t db_dirty_records;
/*
* Our link on the owner dnodes's dn_dbufs list.
@ -379,6 +379,29 @@ void dbuf_fini(void);
boolean_t dbuf_is_metadata(dmu_buf_impl_t *db);
static inline dbuf_dirty_record_t *
dbuf_find_dirty_lte(dmu_buf_impl_t *db, uint64_t txg)
{
dbuf_dirty_record_t *dr;
for (dr = list_head(&db->db_dirty_records);
dr != NULL && dr->dr_txg > txg;
dr = list_next(&db->db_dirty_records, dr))
continue;
return (dr);
}
static inline dbuf_dirty_record_t *
dbuf_find_dirty_eq(dmu_buf_impl_t *db, uint64_t txg)
{
dbuf_dirty_record_t *dr;
dr = dbuf_find_dirty_lte(db, txg);
if (dr && dr->dr_txg == txg)
return (dr);
return (NULL);
}
#define DBUF_GET_BUFC_TYPE(_db) \
(dbuf_is_metadata(_db) ? ARC_BUFC_METADATA : ARC_BUFC_DATA)

View File

@ -920,6 +920,7 @@ dbuf_verify(dmu_buf_impl_t *db)
{
dnode_t *dn;
dbuf_dirty_record_t *dr;
uint32_t txg_prev;
ASSERT(MUTEX_HELD(&db->db_mtx));
@ -951,11 +952,16 @@ dbuf_verify(dmu_buf_impl_t *db)
ASSERT3U(db->db.db_offset, ==, db->db_blkid * db->db.db_size);
}
for (dr = db->db_data_pending; dr != NULL; dr = dr->dr_next)
ASSERT(dr->dr_dbuf == db);
for (dr = db->db_last_dirty; dr != NULL; dr = dr->dr_next)
if ((dr = list_head(&db->db_dirty_records)) != NULL) {
ASSERT(dr->dr_dbuf == db);
txg_prev = dr->dr_txg;
for (dr = list_next(&db->db_dirty_records, dr); dr != NULL;
dr = list_next(&db->db_dirty_records, dr)) {
ASSERT(dr->dr_dbuf == db);
ASSERT(txg_prev > dr->dr_txg);
txg_prev = dr->dr_txg;
}
}
/*
* We can't assert that db_size matches dn_datablksz because it
@ -1468,7 +1474,7 @@ dbuf_read_impl(dmu_buf_impl_t *db, zio_t *zio, uint32_t flags,
static void
dbuf_fix_old_data(dmu_buf_impl_t *db, uint64_t txg)
{
dbuf_dirty_record_t *dr = db->db_last_dirty;
dbuf_dirty_record_t *dr = list_head(&db->db_dirty_records);
ASSERT(MUTEX_HELD(&db->db_mtx));
ASSERT(db->db.db_data != NULL);
@ -1791,9 +1797,10 @@ dbuf_free_range(dnode_t *dn, uint64_t start_blkid, uint64_t end_blkid,
}
/* The dbuf is referenced */
if (db->db_last_dirty != NULL) {
dbuf_dirty_record_t *dr = db->db_last_dirty;
if (!list_is_empty(&db->db_dirty_records)) {
dbuf_dirty_record_t *dr;
dr = list_head(&db->db_dirty_records);
if (dr->dr_txg == txg) {
/*
* This buffer is "in-use", re-adjust the file
@ -1835,6 +1842,7 @@ void
dbuf_new_size(dmu_buf_impl_t *db, int size, dmu_tx_t *tx)
{
arc_buf_t *buf, *obuf;
dbuf_dirty_record_t *dr;
int osize = db->db.db_size;
arc_buf_contents_t type = DBUF_GET_BUFC_TYPE(db);
dnode_t *dn;
@ -1865,12 +1873,12 @@ dbuf_new_size(dmu_buf_impl_t *db, int size, dmu_tx_t *tx)
arc_buf_destroy(obuf, db);
db->db.db_size = size;
if (db->db_level == 0) {
db->db_last_dirty->dt.dl.dr_data = buf;
}
ASSERT3U(db->db_last_dirty->dr_txg, ==, tx->tx_txg);
ASSERT3U(db->db_last_dirty->dr_accounted, ==, osize);
db->db_last_dirty->dr_accounted = size;
dr = list_head(&db->db_dirty_records);
if (db->db_level == 0)
dr->dt.dl.dr_data = buf;
ASSERT3U(dr->dr_txg, ==, tx->tx_txg);
ASSERT3U(dr->dr_accounted, ==, osize);
dr->dr_accounted = size;
mutex_exit(&db->db_mtx);
dmu_objset_willuse_space(dn->dn_objset, size - osize, tx);
@ -1921,7 +1929,7 @@ dbuf_dirty(dmu_buf_impl_t *db, dmu_tx_t *tx)
{
dnode_t *dn;
objset_t *os;
dbuf_dirty_record_t **drp, *dr;
dbuf_dirty_record_t *dr, *dr_next, *dr_head;
int txgoff = tx->tx_txg & TXG_MASK;
boolean_t drop_struct_rwlock = B_FALSE;
@ -1999,17 +2007,16 @@ dbuf_dirty(dmu_buf_impl_t *db, dmu_tx_t *tx)
/*
* If this buffer is already dirty, we're done.
*/
drp = &db->db_last_dirty;
ASSERT(*drp == NULL || (*drp)->dr_txg <= tx->tx_txg ||
dr_head = list_head(&db->db_dirty_records);
ASSERT(dr_head == NULL || dr_head->dr_txg <= tx->tx_txg ||
db->db.db_object == DMU_META_DNODE_OBJECT);
while ((dr = *drp) != NULL && dr->dr_txg > tx->tx_txg)
drp = &dr->dr_next;
if (dr && dr->dr_txg == tx->tx_txg) {
dr_next = dbuf_find_dirty_lte(db, tx->tx_txg);
if (dr_next && dr_next->dr_txg == tx->tx_txg) {
DB_DNODE_EXIT(db);
dbuf_redirty(dr);
dbuf_redirty(dr_next);
mutex_exit(&db->db_mtx);
return (dr);
return (dr_next);
}
/*
@ -2053,6 +2060,7 @@ dbuf_dirty(dmu_buf_impl_t *db, dmu_tx_t *tx)
*/
dr = kmem_zalloc(sizeof (dbuf_dirty_record_t), KM_SLEEP);
list_link_init(&dr->dr_dirty_node);
list_link_init(&dr->dr_dbuf_node);
if (db->db_level == 0) {
void *data_old = db->db_buf;
@ -2087,8 +2095,7 @@ dbuf_dirty(dmu_buf_impl_t *db, dmu_tx_t *tx)
dr->dr_accounted = db->db.db_size;
dr->dr_dbuf = db;
dr->dr_txg = tx->tx_txg;
dr->dr_next = *drp;
*drp = dr;
list_insert_before(&db->db_dirty_records, dr_next, dr);
/*
* We could have been freed_in_flight between the dbuf_noread
@ -2186,7 +2193,7 @@ dbuf_dirty(dmu_buf_impl_t *db, dmu_tx_t *tx)
* Since we've dropped the mutex, it's possible that
* dbuf_undirty() might have changed this out from under us.
*/
if (db->db_last_dirty == dr ||
if (list_head(&db->db_dirty_records) == dr ||
dn->dn_object == DMU_META_DNODE_OBJECT) {
mutex_enter(&di->dt.di.dr_mtx);
ASSERT3U(di->dr_txg, ==, tx->tx_txg);
@ -2222,7 +2229,7 @@ dbuf_undirty(dmu_buf_impl_t *db, dmu_tx_t *tx)
{
dnode_t *dn;
uint64_t txg = tx->tx_txg;
dbuf_dirty_record_t *dr, **drp;
dbuf_dirty_record_t *dr;
ASSERT(txg != 0);
@ -2242,12 +2249,9 @@ dbuf_undirty(dmu_buf_impl_t *db, dmu_tx_t *tx)
/*
* If this buffer is not dirty, we're done.
*/
for (drp = &db->db_last_dirty; (dr = *drp) != NULL; drp = &dr->dr_next)
if (dr->dr_txg <= txg)
break;
if (dr == NULL || dr->dr_txg < txg)
dr = dbuf_find_dirty_eq(db, txg);
if (dr == NULL)
return (B_FALSE);
ASSERT(dr->dr_txg == txg);
ASSERT(dr->dr_dbuf == db);
DB_DNODE_ENTER(db);
@ -2260,7 +2264,7 @@ dbuf_undirty(dmu_buf_impl_t *db, dmu_tx_t *tx)
dsl_pool_undirty_space(dmu_objset_pool(dn->dn_objset),
dr->dr_accounted, txg);
*drp = dr->dr_next;
list_remove(&db->db_dirty_records, dr);
/*
* Note that there are three places in dbuf_dirty()
@ -2320,15 +2324,14 @@ dmu_buf_will_dirty_impl(dmu_buf_t *db_fake, int flags, dmu_tx_t *tx)
*/
mutex_enter(&db->db_mtx);
dbuf_dirty_record_t *dr;
for (dr = db->db_last_dirty;
dr != NULL && dr->dr_txg >= tx->tx_txg; dr = dr->dr_next) {
if (db->db_state == DB_CACHED) {
dbuf_dirty_record_t *dr = dbuf_find_dirty_eq(db, tx->tx_txg);
/*
* It's possible that it is already dirty but not cached,
* because there are some calls to dbuf_dirty() that don't
* go through dmu_buf_will_dirty().
*/
if (dr->dr_txg == tx->tx_txg && db->db_state == DB_CACHED) {
if (dr != NULL) {
/* This dbuf is already dirty and cached. */
dbuf_redirty(dr);
mutex_exit(&db->db_mtx);
@ -2356,17 +2359,12 @@ boolean_t
dmu_buf_is_dirty(dmu_buf_t *db_fake, dmu_tx_t *tx)
{
dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
dbuf_dirty_record_t *dr;
mutex_enter(&db->db_mtx);
for (dbuf_dirty_record_t *dr = db->db_last_dirty;
dr != NULL && dr->dr_txg >= tx->tx_txg; dr = dr->dr_next) {
if (dr->dr_txg == tx->tx_txg) {
mutex_exit(&db->db_mtx);
return (B_TRUE);
}
}
dr = dbuf_find_dirty_eq(db, tx->tx_txg);
mutex_exit(&db->db_mtx);
return (B_FALSE);
return (dr != NULL);
}
void
@ -2421,12 +2419,9 @@ dmu_buf_set_crypt_params(dmu_buf_t *db_fake, boolean_t byteorder,
dmu_buf_will_dirty_impl(db_fake,
DB_RF_MUST_SUCCEED | DB_RF_NOPREFETCH | DB_RF_NO_DECRYPT, tx);
dr = db->db_last_dirty;
while (dr != NULL && dr->dr_txg > tx->tx_txg)
dr = dr->dr_next;
dr = dbuf_find_dirty_eq(db, tx->tx_txg);
ASSERT3P(dr, !=, NULL);
ASSERT3U(dr->dr_txg, ==, tx->tx_txg);
dr->dt.dl.dr_has_raw_params = B_TRUE;
dr->dt.dl.dr_byteorder = byteorder;
@ -2439,12 +2434,14 @@ static void
dbuf_override_impl(dmu_buf_impl_t *db, const blkptr_t *bp, dmu_tx_t *tx)
{
struct dirty_leaf *dl;
dbuf_dirty_record_t *dr;
ASSERT3U(db->db_last_dirty->dr_txg, ==, tx->tx_txg);
dl = &db->db_last_dirty->dt.dl;
dr = list_head(&db->db_dirty_records);
ASSERT3U(dr->dr_txg, ==, tx->tx_txg);
dl = &dr->dt.dl;
dl->dr_overridden_by = *bp;
dl->dr_override_state = DR_OVERRIDDEN;
dl->dr_overridden_by.blk_birth = db->db_last_dirty->dr_txg;
dl->dr_overridden_by.blk_birth = dr->dr_txg;
}
/* ARGSUSED */
@ -2478,6 +2475,7 @@ dmu_buf_write_embedded(dmu_buf_t *dbuf, void *data,
dmu_buf_impl_t *db = (dmu_buf_impl_t *)dbuf;
struct dirty_leaf *dl;
dmu_object_type_t type;
dbuf_dirty_record_t *dr;
if (etype == BP_EMBEDDED_TYPE_DATA) {
ASSERT(spa_feature_is_active(dmu_objset_spa(db->db_objset),
@ -2493,8 +2491,9 @@ dmu_buf_write_embedded(dmu_buf_t *dbuf, void *data,
dmu_buf_will_not_fill(dbuf, tx);
ASSERT3U(db->db_last_dirty->dr_txg, ==, tx->tx_txg);
dl = &db->db_last_dirty->dt.dl;
dr = list_head(&db->db_dirty_records);
ASSERT3U(dr->dr_txg, ==, tx->tx_txg);
dl = &dr->dt.dl;
encode_embedded_bp_compressed(&dl->dr_overridden_by,
data, comp, uncompressed_size, compressed_size);
BPE_SET_ETYPE(&dl->dr_overridden_by, etype);
@ -2503,7 +2502,7 @@ dmu_buf_write_embedded(dmu_buf_t *dbuf, void *data,
BP_SET_BYTEORDER(&dl->dr_overridden_by, byteorder);
dl->dr_override_state = DR_OVERRIDDEN;
dl->dr_overridden_by.blk_birth = db->db_last_dirty->dr_txg;
dl->dr_overridden_by.blk_birth = dr->dr_txg;
}
void
@ -2575,7 +2574,7 @@ dbuf_assign_arcbuf(dmu_buf_impl_t *db, arc_buf_t *buf, dmu_tx_t *tx)
xuio_stat_wbuf_nocopy();
if (db->db_state == DB_CACHED) {
dbuf_dirty_record_t *dr = db->db_last_dirty;
dbuf_dirty_record_t *dr = list_head(&db->db_dirty_records);
ASSERT(db->db_buf != NULL);
if (dr != NULL && dr->dr_txg == tx->tx_txg) {
@ -2827,11 +2826,13 @@ dbuf_create(dnode_t *dn, uint8_t level, uint64_t blkid,
db = kmem_cache_alloc(dbuf_kmem_cache, KM_SLEEP);
list_create(&db->db_dirty_records, sizeof (dbuf_dirty_record_t),
offsetof(dbuf_dirty_record_t, dr_dbuf_node));
db->db_objset = os;
db->db.db_object = dn->dn_object;
db->db_level = level;
db->db_blkid = blkid;
db->db_last_dirty = NULL;
db->db_dirtycnt = 0;
db->db_dnode_handle = dn->dn_handle;
db->db_parent = parent;
@ -3953,8 +3954,6 @@ dbuf_sync_leaf(dbuf_dirty_record_t *dr, dmu_tx_t *tx)
* be called).
*/
if (db->db_blkid == DMU_BONUS_BLKID) {
dbuf_dirty_record_t **drp;
ASSERT(*datap != NULL);
ASSERT0(db->db_level);
ASSERT3U(DN_MAX_BONUS_LEN(dn->dn_phys), <=,
@ -3974,12 +3973,9 @@ dbuf_sync_leaf(dbuf_dirty_record_t *dr, dmu_tx_t *tx)
arc_space_return(bonuslen, ARC_SPACE_BONUS);
}
db->db_data_pending = NULL;
drp = &db->db_last_dirty;
while (*drp != dr)
drp = &(*drp)->dr_next;
ASSERT(dr->dr_next == NULL);
ASSERT(list_next(&db->db_dirty_records, dr) == NULL);
ASSERT(dr->dr_dbuf == db);
*drp = dr->dr_next;
list_remove(&db->db_dirty_records, dr);
if (dr->dr_dbuf->db_level != 0) {
mutex_destroy(&dr->dt.di.dr_mtx);
list_destroy(&dr->dt.di.dr_children);
@ -4287,7 +4283,7 @@ dbuf_write_done(zio_t *zio, arc_buf_t *buf, void *vdb)
blkptr_t *bp = db->db_blkptr;
objset_t *os = db->db_objset;
dmu_tx_t *tx = os->os_synctx;
dbuf_dirty_record_t **drp, *dr;
dbuf_dirty_record_t *dr;
ASSERT0(zio->io_error);
ASSERT(db->db_blkptr == bp);
@ -4308,13 +4304,11 @@ dbuf_write_done(zio_t *zio, arc_buf_t *buf, void *vdb)
DBUF_VERIFY(db);
drp = &db->db_last_dirty;
while ((dr = *drp) != db->db_data_pending)
drp = &dr->dr_next;
dr = db->db_data_pending;
ASSERT(!list_link_active(&dr->dr_dirty_node));
ASSERT(dr->dr_dbuf == db);
ASSERT(dr->dr_next == NULL);
*drp = dr->dr_next;
ASSERT(list_next(&db->db_dirty_records, dr) == NULL);
list_remove(&db->db_dirty_records, dr);
#ifdef ZFS_DEBUG
if (db->db_blkid == DMU_SPILL_BLKID) {

View File

@ -1876,7 +1876,7 @@ dmu_sync(zio_t *pio, uint64_t txg, dmu_sync_cb_t *done, zgd_t *zgd)
dmu_buf_impl_t *db = (dmu_buf_impl_t *)zgd->zgd_db;
objset_t *os = db->db_objset;
dsl_dataset_t *ds = os->os_dsl_dataset;
dbuf_dirty_record_t *dr;
dbuf_dirty_record_t *dr, *dr_next;
dmu_sync_arg_t *dsa;
zbookmark_phys_t zb;
zio_prop_t zp;
@ -1924,9 +1924,7 @@ dmu_sync(zio_t *pio, uint64_t txg, dmu_sync_cb_t *done, zgd_t *zgd)
return (dmu_sync_late_arrival(pio, os, done, zgd, &zp, &zb));
}
dr = db->db_last_dirty;
while (dr && dr->dr_txg != txg)
dr = dr->dr_next;
dr = dbuf_find_dirty_eq(db, txg);
if (dr == NULL) {
/*
@ -1937,7 +1935,8 @@ dmu_sync(zio_t *pio, uint64_t txg, dmu_sync_cb_t *done, zgd_t *zgd)
return (SET_ERROR(ENOENT));
}
ASSERT(dr->dr_next == NULL || dr->dr_next->dr_txg < txg);
dr_next = list_next(&db->db_dirty_records, dr);
ASSERT(dr_next == NULL || dr_next->dr_txg < txg);
if (db->db_blkptr != NULL) {
/*
@ -1978,7 +1977,7 @@ dmu_sync(zio_t *pio, uint64_t txg, dmu_sync_cb_t *done, zgd_t *zgd)
*/
DB_DNODE_ENTER(db);
dn = DB_DNODE(db);
if (dr->dr_next != NULL || dnode_block_freed(dn, db->db_blkid))
if (dr_next != NULL || dnode_block_freed(dn, db->db_blkid))
zp.zp_nopwrite = B_FALSE;
DB_DNODE_EXIT(db);

View File

@ -2064,15 +2064,13 @@ dmu_objset_do_userquota_updates(objset_t *os, dmu_tx_t *tx)
static void *
dmu_objset_userquota_find_data(dmu_buf_impl_t *db, dmu_tx_t *tx)
{
dbuf_dirty_record_t *dr, **drp;
dbuf_dirty_record_t *dr;
void *data;
if (db->db_dirtycnt == 0)
return (db->db.db_data); /* Nothing is changing */
for (drp = &db->db_last_dirty; (dr = *drp) != NULL; drp = &dr->dr_next)
if (dr->dr_txg == tx->tx_txg)
break;
dr = dbuf_find_dirty_eq(db, tx->tx_txg);
if (dr == NULL) {
data = NULL;

View File

@ -2074,7 +2074,7 @@ dnode_free_range(dnode_t *dn, uint64_t off, uint64_t len, dmu_tx_t *tx)
db_lock_type_t dblt = dmu_buf_lock_parent(db, RW_READER,
FTAG);
/* don't dirty if it isn't on disk and isn't dirty */
dirty = db->db_last_dirty ||
dirty = !list_is_empty(&db->db_dirty_records) ||
(db->db_blkptr && !BP_IS_HOLE(db->db_blkptr));
dmu_buf_unlock_parent(db, dblt, FTAG);
if (dirty) {
@ -2117,7 +2117,7 @@ dnode_free_range(dnode_t *dn, uint64_t off, uint64_t len, dmu_tx_t *tx)
/* don't dirty if not on disk and not dirty */
db_lock_type_t type = dmu_buf_lock_parent(db, RW_READER,
FTAG);
dirty = db->db_last_dirty ||
dirty = !list_is_empty(&db->db_dirty_records) ||
(db->db_blkptr && !BP_IS_HOLE(db->db_blkptr));
dmu_buf_unlock_parent(db, type, FTAG);
if (dirty) {

View File

@ -207,10 +207,7 @@ free_verify(dmu_buf_impl_t *db, uint64_t start, uint64_t end, dmu_tx_t *tx)
continue;
ASSERT(err == 0);
ASSERT(child->db_level == 0);
dr = child->db_last_dirty;
while (dr && dr->dr_txg > txg)
dr = dr->dr_next;
ASSERT(dr == NULL || dr->dr_txg == txg);
dr = dbuf_find_dirty_eq(child, txg);
/* data_old better be zeroed */
if (dr) {
@ -231,7 +228,7 @@ free_verify(dmu_buf_impl_t *db, uint64_t start, uint64_t end, dmu_tx_t *tx)
mutex_enter(&child->db_mtx);
buf = child->db.db_data;
if (buf != NULL && child->db_state != DB_FILL &&
child->db_last_dirty == NULL) {
list_is_empty(&child->db_dirty_records)) {
for (j = 0; j < child->db.db_size >> 3; j++) {
if (buf[j] != 0) {
panic("freed data not zero: "
@ -541,8 +538,9 @@ dnode_undirty_dbufs(list_t *list)
mutex_enter(&db->db_mtx);
/* XXX - use dbuf_undirty()? */
list_remove(list, dr);
ASSERT(db->db_last_dirty == dr);
db->db_last_dirty = NULL;
ASSERT(list_head(&db->db_dirty_records) == dr);
list_remove_head(&db->db_dirty_records);
ASSERT(list_is_empty(&db->db_dirty_records));
db->db_dirtycnt -= 1;
if (db->db_level == 0) {
ASSERT(db->db_blkid == DMU_BONUS_BLKID ||