/*
* Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
* Copyright 2011 Nexenta Systems, Inc. All rights reserved.
- * Copyright (c) 2012, 2018 by Delphix. All rights reserved.
+ * Copyright (c) 2012, 2019 by Delphix. All rights reserved.
* Copyright (c) 2013 by Saso Kiselkov. All rights reserved.
* Copyright (c) 2014 Spectra Logic Corporation, All rights reserved.
*/
bzero(db, sizeof (dmu_buf_impl_t));
mutex_init(&db->db_mtx, NULL, MUTEX_DEFAULT, NULL);
+ rw_init(&db->db_rwlock, NULL, RW_DEFAULT, NULL);
cv_init(&db->db_changed, NULL, CV_DEFAULT, NULL);
multilist_link_init(&db->db_cache_link);
zfs_refcount_create(&db->db_holds);
{
dmu_buf_impl_t *db = vdb;
mutex_destroy(&db->db_mtx);
+ rw_destroy(&db->db_rwlock);
cv_destroy(&db->db_changed);
ASSERT(!multilist_link_active(&db->db_cache_link));
zfs_refcount_destroy(&db->db_holds);
db->db.db_object);
/*
* dnode_grow_indblksz() can make this fail if we don't
- * have the struct_rwlock. XXX indblksz no longer
+ * have the parent's rwlock. XXX indblksz no longer
* grows. safe to do this now?
*/
- if (RW_WRITE_HELD(&dn->dn_struct_rwlock)) {
+ if (RW_LOCK_HELD(&db->db_parent->db_rwlock)) {
ASSERT3P(db->db_blkptr, ==,
((blkptr_t *)db->db_parent->db.db_data +
db->db_blkid % epb));
}
}
+/*
+ * This function is used to lock the parent of the provided dbuf. This should be
+ * used when modifying or reading db_blkptr.
+ */
+db_lock_type_t
+dmu_buf_lock_parent(dmu_buf_impl_t *db, krw_t rw, void *tag)
+{
+ enum db_lock_type ret = DLT_NONE;
+ if (db->db_parent != NULL) {
+ rw_enter(&db->db_parent->db_rwlock, rw);
+ ret = DLT_PARENT;
+ } else if (dmu_objset_ds(db->db_objset) != NULL) {
+ rrw_enter(&dmu_objset_ds(db->db_objset)->ds_bp_rwlock, rw,
+ tag);
+ ret = DLT_OBJSET;
+ }
+ /*
+ * We only return a DLT_NONE lock when it's the top-most indirect block
+ * of the meta-dnode of the MOS.
+ */
+ return (ret);
+}
+
+/*
+ * We need to pass the lock type in because it's possible that the block will
+ * move from being the topmost indirect block in a dnode (and thus, have no
+ * parent) to not the top-most via an indirection increase. This would cause a
+ * panic if we didn't pass the lock type in.
+ */
+void
+dmu_buf_unlock_parent(dmu_buf_impl_t *db, db_lock_type_t type, void *tag)
+{
+ if (type == DLT_PARENT)
+ rw_exit(&db->db_parent->db_rwlock);
+ else if (type == DLT_OBJSET)
+ rrw_exit(&dmu_objset_ds(db->db_objset)->ds_bp_rwlock, tag);
+}
+
static void
dbuf_read_done(zio_t *zio, const zbookmark_phys_t *zb, const blkptr_t *bp,
arc_buf_t *buf, void *vdb)
return (err);
}
+/*
+ * Drops db_mtx and the parent lock specified by dblt and tag before
+ * returning.
+ */
static int
-dbuf_read_impl(dmu_buf_impl_t *db, zio_t *zio, uint32_t flags)
+dbuf_read_impl(dmu_buf_impl_t *db, zio_t *zio, uint32_t flags,
+ db_lock_type_t dblt, void *tag)
{
dnode_t *dn;
zbookmark_phys_t zb;
DB_DNODE_ENTER(db);
dn = DB_DNODE(db);
ASSERT(!zfs_refcount_is_zero(&db->db_holds));
- /* We need the struct_rwlock to prevent db_blkptr from changing. */
- ASSERT(RW_LOCK_HELD(&dn->dn_struct_rwlock));
ASSERT(MUTEX_HELD(&db->db_mtx));
ASSERT(db->db_state == DB_UNCACHED);
ASSERT(db->db_buf == NULL);
+ ASSERT(db->db_parent == NULL ||
+ RW_LOCK_HELD(&db->db_parent->db_rwlock));
if (db->db_blkid == DMU_BONUS_BLKID) {
/*
DB_DNODE_EXIT(db);
db->db_state = DB_CACHED;
mutex_exit(&db->db_mtx);
+ dmu_buf_unlock_parent(db, dblt, tag);
return (0);
}
DB_DNODE_EXIT(db);
db->db_state = DB_CACHED;
mutex_exit(&db->db_mtx);
+ dmu_buf_unlock_parent(db, dblt, tag);
return (0);
}
"object set %llu", dmu_objset_id(db->db_objset));
DB_DNODE_EXIT(db);
mutex_exit(&db->db_mtx);
+ dmu_buf_unlock_parent(db, dblt, tag);
return (SET_ERROR(EIO));
}
err = dbuf_read_verify_dnode_crypt(db, flags);
if (err != 0) {
DB_DNODE_EXIT(db);
+ dmu_buf_unlock_parent(db, dblt, tag);
mutex_exit(&db->db_mtx);
return (err);
}
if ((flags & DB_RF_NO_DECRYPT) && BP_IS_PROTECTED(db->db_blkptr))
zio_flags |= ZIO_FLAG_RAW;
-
- err = arc_read(zio, db->db_objset->os_spa, db->db_blkptr,
+ /*
+ * The zio layer will copy the provided blkptr later, but we need to
+ * do this now so that we can release the parent's rwlock. We have to
+ * do that now so that if dbuf_read_done is called synchronously (on
+ * an l1 cache hit) we don't acquire the db_mtx while holding the
+ * parent's rwlock, which would be a lock ordering violation.
+ */
+ blkptr_t bp = *db->db_blkptr;
+ dmu_buf_unlock_parent(db, dblt, tag);
+ (void) arc_read(zio, db->db_objset->os_spa, &bp,
dbuf_read_done, db, ZIO_PRIORITY_SYNC_READ, zio_flags,
&aflags, &zb);
-
return (err);
}
DB_DNODE_ENTER(db);
dn = DB_DNODE(db);
- if ((flags & DB_RF_HAVESTRUCT) == 0)
- rw_enter(&dn->dn_struct_rwlock, RW_READER);
prefetch = db->db_level == 0 && db->db_blkid != DMU_BONUS_BLKID &&
(flags & DB_RF_NOPREFETCH) == 0 && dn != NULL &&
dbuf_set_data(db, db->db_buf);
}
mutex_exit(&db->db_mtx);
- if (err == 0 && prefetch)
- dmu_zfetch(&dn->dn_zfetch, db->db_blkid, 1, B_TRUE);
- if ((flags & DB_RF_HAVESTRUCT) == 0)
- rw_exit(&dn->dn_struct_rwlock);
+ if (err == 0 && prefetch) {
+ dmu_zfetch(&dn->dn_zfetch, db->db_blkid, 1, B_TRUE,
+ flags & DB_RF_HAVESTRUCT);
+ }
DB_DNODE_EXIT(db);
DBUF_STAT_BUMP(hash_hits);
} else if (db->db_state == DB_UNCACHED) {
spa_t *spa = dn->dn_objset->os_spa;
boolean_t need_wait = B_FALSE;
+ db_lock_type_t dblt = dmu_buf_lock_parent(db, RW_READER, FTAG);
+
if (zio == NULL &&
db->db_blkptr != NULL && !BP_IS_HOLE(db->db_blkptr)) {
zio = zio_root(spa, NULL, NULL, ZIO_FLAG_CANFAIL);
need_wait = B_TRUE;
}
- err = dbuf_read_impl(db, zio, flags);
-
- /* dbuf_read_impl has dropped db_mtx for us */
-
- if (!err && prefetch)
- dmu_zfetch(&dn->dn_zfetch, db->db_blkid, 1, B_TRUE);
+ err = dbuf_read_impl(db, zio, flags, dblt, FTAG);
+ /*
+ * dbuf_read_impl has dropped db_mtx and our parent's rwlock
+ * for us
+ */
+ if (!err && prefetch) {
+ dmu_zfetch(&dn->dn_zfetch, db->db_blkid, 1, B_TRUE,
+ flags & DB_RF_HAVESTRUCT);
+ }
- if ((flags & DB_RF_HAVESTRUCT) == 0)
- rw_exit(&dn->dn_struct_rwlock);
DB_DNODE_EXIT(db);
DBUF_STAT_BUMP(hash_misses);
* occurred and the dbuf went to UNCACHED.
*/
mutex_exit(&db->db_mtx);
- if (prefetch)
- dmu_zfetch(&dn->dn_zfetch, db->db_blkid, 1, B_TRUE);
- if ((flags & DB_RF_HAVESTRUCT) == 0)
- rw_exit(&dn->dn_struct_rwlock);
+ if (prefetch) {
+ dmu_zfetch(&dn->dn_zfetch, db->db_blkid, 1, B_TRUE,
+ flags & DB_RF_HAVESTRUCT);
+ }
DB_DNODE_EXIT(db);
DBUF_STAT_BUMP(hash_misses);
if (db->db_state == DB_CACHED) {
ASSERT(db->db.db_data != NULL);
arc_release(db->db_buf, db);
+ rw_enter(&db->db_rwlock, RW_WRITER);
bzero(db->db.db_data, db->db.db_size);
+ rw_exit(&db->db_rwlock);
arc_buf_freeze(db->db_buf);
}
DB_DNODE_ENTER(db);
dn = DB_DNODE(db);
- /* XXX does *this* func really need the lock? */
- ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock));
-
- /*
- * This call to dmu_buf_will_dirty() with the dn_struct_rwlock held
- * is OK, because there can be no other references to the db
- * when we are changing its size, so no concurrent DB_FILL can
- * be happening.
- */
/*
* XXX we should be doing a dbuf_read, checking the return
* value and returning that up to our callers
dnode_t *dn;
objset_t *os;
dbuf_dirty_record_t **drp, *dr;
- int drop_struct_lock = FALSE;
int txgoff = tx->tx_txg & TXG_MASK;
+ boolean_t drop_struct_rwlock = B_FALSE;
ASSERT(tx->tx_txg != 0);
ASSERT(!zfs_refcount_is_zero(&db->db_holds));
return (dr);
}
- /*
- * The dn_struct_rwlock prevents db_blkptr from changing
- * due to a write from syncing context completing
- * while we are running, so we want to acquire it before
- * looking at db_blkptr.
- */
if (!RW_WRITE_HELD(&dn->dn_struct_rwlock)) {
rw_enter(&dn->dn_struct_rwlock, RW_READER);
- drop_struct_lock = TRUE;
+ drop_struct_rwlock = B_TRUE;
+ }
+
+ /*
+ * If we are overwriting a dedup BP, then unless it is snapshotted,
+ * when we get to syncing context we will need to decrement its
+ * refcount in the DDT. Prefetch the relevant DDT block so that
+ * syncing context won't have to wait for the i/o.
+ */
+ if (db->db_blkptr != NULL) {
+ db_lock_type_t dblt = dmu_buf_lock_parent(db, RW_READER, FTAG);
+ ddt_prefetch(os->os_spa, db->db_blkptr);
+ dmu_buf_unlock_parent(db, dblt, FTAG);
}
/*
dn->dn_next_nlevels[(tx->tx_txg-1) & TXG_MASK] > db->db_level ||
dn->dn_next_nlevels[(tx->tx_txg-2) & TXG_MASK] > db->db_level);
- /*
- * If we are overwriting a dedup BP, then unless it is snapshotted,
- * when we get to syncing context we will need to decrement its
- * refcount in the DDT. Prefetch the relevant DDT block so that
- * syncing context won't have to wait for the i/o.
- */
- ddt_prefetch(os->os_spa, db->db_blkptr);
if (db->db_level == 0) {
ASSERT(!db->db_objset->os_raw_receive ||
dn->dn_maxblkid >= db->db_blkid);
dnode_new_blkid(dn, db->db_blkid, tx,
- drop_struct_lock, B_FALSE);
+ drop_struct_rwlock, B_FALSE);
ASSERT(dn->dn_maxblkid >= db->db_blkid);
}
if (db->db_parent == NULL || db->db_parent == dn->dn_dbuf) {
int epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT;
-
- parent = dbuf_hold_level(dn, db->db_level+1,
+ parent = dbuf_hold_level(dn, db->db_level + 1,
db->db_blkid >> epbs, FTAG);
ASSERT(parent != NULL);
parent_held = TRUE;
}
- if (drop_struct_lock)
+ if (drop_struct_rwlock)
rw_exit(&dn->dn_struct_rwlock);
- ASSERT3U(db->db_level+1, ==, parent->db_level);
+ ASSERT3U(db->db_level + 1, ==, parent->db_level);
di = dbuf_dirty(parent, tx);
if (parent_held)
dbuf_rele(parent, FTAG);
}
mutex_exit(&db->db_mtx);
} else {
- ASSERT(db->db_level+1 == dn->dn_nlevels);
+ ASSERT(db->db_level + 1 == dn->dn_nlevels);
ASSERT(db->db_blkid < dn->dn_nblkptr);
ASSERT(db->db_parent == NULL || db->db_parent == dn->dn_dbuf);
mutex_enter(&dn->dn_mtx);
ASSERT(!list_link_active(&dr->dr_dirty_node));
list_insert_tail(&dn->dn_dirty_records[txgoff], dr);
mutex_exit(&dn->dn_mtx);
- if (drop_struct_lock)
+ if (drop_struct_rwlock)
rw_exit(&dn->dn_struct_rwlock);
}
*parentp = NULL;
return (err);
}
+ rw_enter(&(*parentp)->db_rwlock, RW_READER);
*bpp = ((blkptr_t *)(*parentp)->db.db_data) +
(blkid & ((1ULL << epbs) - 1));
if (blkid > (dn->dn_phys->dn_maxblkid >> (level * epbs)))
ASSERT(BP_IS_HOLE(*bpp));
+ rw_exit(&(*parentp)->db_rwlock);
return (0);
} else {
/* the block is referenced from the dnode */
if (blkid > dn->dn_maxblkid)
return;
- if (dnode_block_freed(dn, blkid))
+ if (level == 0 && dnode_block_freed(dn, blkid))
return;
/*
DBUF_GET_BUFC_TYPE(db), db->db.db_size));
}
+ rw_enter(&db->db_rwlock, RW_WRITER);
bcopy(data->b_data, db->db.db_data, arc_buf_size(data));
+ rw_exit(&db->db_rwlock);
}
/*
dbuf_spill_set_blksz(dmu_buf_t *db_fake, uint64_t blksz, dmu_tx_t *tx)
{
dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
- dnode_t *dn;
if (db->db_blkid != DMU_SPILL_BLKID)
return (SET_ERROR(ENOTSUP));
ASSERT3U(blksz, <=, spa_maxblocksize(dmu_objset_spa(db->db_objset)));
blksz = P2ROUNDUP(blksz, SPA_MINBLOCKSIZE);
- DB_DNODE_ENTER(db);
- dn = DB_DNODE(db);
- rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
dbuf_new_size(db, blksz, tx);
- rw_exit(&dn->dn_struct_rwlock);
- DB_DNODE_EXIT(db);
return (0);
}
mutex_exit(&db->db_mtx);
- rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
+ db_lock_type_t dblt = dmu_buf_lock_parent(db, RW_WRITER, FTAG);
*db->db_blkptr = *bp;
- rw_exit(&dn->dn_struct_rwlock);
+ dmu_buf_unlock_parent(db, dblt, FTAG);
}
/* ARGSUSED */
* anybody from reading the blocks we're about to
* zero out.
*/
- rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
+ rw_enter(&db->db_rwlock, RW_WRITER);
bzero(db->db.db_data, db->db.db_size);
- rw_exit(&dn->dn_struct_rwlock);
+ rw_exit(&db->db_rwlock);
}
DB_DNODE_EXIT(db);
}
}
static void
-dbuf_remap_impl(dnode_t *dn, blkptr_t *bp, dmu_tx_t *tx)
+dbuf_remap_impl(dnode_t *dn, blkptr_t *bp, krwlock_t *rw, dmu_tx_t *tx)
{
blkptr_t bp_copy = *bp;
spa_t *spa = dmu_objset_spa(dn->dn_objset);
if (spa_remap_blkptr(spa, &bp_copy, dbuf_remap_impl_callback,
&drica)) {
/*
- * The struct_rwlock prevents dbuf_read_impl() from
+ * The db_rwlock prevents dbuf_read_impl() from
* dereferencing the BP while we are changing it. To
* avoid lock contention, only grab it when we are actually
* changing the BP.
*/
- rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
+ if (rw != NULL)
+ rw_enter(rw, RW_WRITER);
*bp = bp_copy;
- rw_exit(&dn->dn_struct_rwlock);
+ if (rw != NULL)
+ rw_exit(rw);
}
}
if (db->db_level > 0) {
blkptr_t *bp = db->db.db_data;
for (int i = 0; i < db->db.db_size >> SPA_BLKPTRSHIFT; i++) {
- dbuf_remap_impl(dn, &bp[i], tx);
+ dbuf_remap_impl(dn, &bp[i], &db->db_rwlock, tx);
}
} else if (db->db.db_object == DMU_META_DNODE_OBJECT) {
dnode_phys_t *dnp = db->db.db_data;
for (int i = 0; i < db->db.db_size >> DNODE_SHIFT;
i += dnp[i].dn_extra_slots + 1) {
for (int j = 0; j < dnp[i].dn_nblkptr; j++) {
- dbuf_remap_impl(dn, &dnp[i].dn_blkptr[j], tx);
+ krwlock_t *lock = (dn->dn_dbuf == NULL ? NULL :
+ &dn->dn_dbuf->db_rwlock);
+ dbuf_remap_impl(dn, &dnp[i].dn_blkptr[j], lock,
+ tx);
}
}
}
}
blk = dbuf_whichblock(mdn, 0, object * sizeof (dnode_phys_t));
-
db = dbuf_hold(mdn, blk, FTAG);
if (drop_struct_lock)
rw_exit(&mdn->dn_struct_rwlock);
/* resize the old block */
err = dbuf_hold_impl(dn, 0, 0, TRUE, FALSE, FTAG, &db);
- if (err == 0)
+ if (err == 0) {
dbuf_new_size(db, size, tx);
- else if (err != ENOENT)
+ } else if (err != ENOENT) {
goto fail;
+ }
dnode_setdblksz(dn, size);
dnode_setdirty(dn, tx);
int trunc = FALSE;
int epbs;
- rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
blksz = dn->dn_datablksz;
blkshift = dn->dn_datablkshift;
epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT;
head = P2NPHASE(off, blksz);
blkoff = P2PHASE(off, blksz);
if ((off >> blkshift) > dn->dn_maxblkid)
- goto out;
+ return;
} else {
ASSERT(dn->dn_maxblkid == 0);
if (off == 0 && len >= blksz) {
*/
blkid = 0;
nblks = 1;
- if (dn->dn_nlevels > 1)
+ if (dn->dn_nlevels > 1) {
+ rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
dnode_dirty_l1(dn, 0, tx);
+ rw_exit(&dn->dn_struct_rwlock);
+ }
goto done;
} else if (off >= blksz) {
/* Freeing past end-of-data */
- goto out;
+ return;
} else {
/* Freeing part of the block. */
head = blksz - off;
}
/* zero out any partial block data at the start of the range */
if (head) {
+ int res;
ASSERT3U(blkoff + head, ==, blksz);
if (len < head)
head = len;
- if (dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, 0, off),
- TRUE, FALSE, FTAG, &db) == 0) {
+ rw_enter(&dn->dn_struct_rwlock, RW_READER);
+ res = dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, 0, off),
+ TRUE, FALSE, FTAG, &db);
+ rw_exit(&dn->dn_struct_rwlock);
+ if (res == 0) {
caddr_t data;
+ boolean_t dirty;
+ 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 */
- if (db->db_last_dirty ||
- (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr))) {
- rw_exit(&dn->dn_struct_rwlock);
+ dirty = db->db_last_dirty ||
+ (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr));
+ dmu_buf_unlock_parent(db, dblt, FTAG);
+ if (dirty) {
dmu_buf_will_dirty(&db->db, tx);
- rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
data = db->db.db_data;
bzero(data + blkoff, head);
}
/* If the range was less than one block, we're done */
if (len == 0)
- goto out;
+ return;
/* If the remaining range is past end of file, we're done */
if ((off >> blkshift) > dn->dn_maxblkid)
- goto out;
+ return;
ASSERT(ISP2(blksz));
if (trunc)
ASSERT0(P2PHASE(off, blksz));
/* zero out any partial block data at the end of the range */
if (tail) {
+ int res;
if (len < tail)
tail = len;
- if (dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, 0, off+len),
- TRUE, FALSE, FTAG, &db) == 0) {
+ rw_enter(&dn->dn_struct_rwlock, RW_READER);
+ res = dbuf_hold_impl(dn, 0, dbuf_whichblock(dn, 0, off+len),
+ TRUE, FALSE, FTAG, &db);
+ rw_exit(&dn->dn_struct_rwlock);
+ if (res == 0) {
+ boolean_t dirty;
/* don't dirty if not on disk and not dirty */
- if (db->db_last_dirty ||
- (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr))) {
- rw_exit(&dn->dn_struct_rwlock);
+ db_lock_type_t type = dmu_buf_lock_parent(db, RW_READER,
+ FTAG);
+ dirty = db->db_last_dirty ||
+ (db->db_blkptr && !BP_IS_HOLE(db->db_blkptr));
+ dmu_buf_unlock_parent(db, type, FTAG);
+ if (dirty) {
dmu_buf_will_dirty(&db->db, tx);
- rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
bzero(db->db.db_data, tail);
}
dbuf_rele(db, FTAG);
/* If the range did not include a full block, we are done */
if (len == 0)
- goto out;
+ return;
ASSERT(IS_P2ALIGNED(off, blksz));
ASSERT(trunc || IS_P2ALIGNED(len, blksz));
* amount of space if we copy the freed BPs into deadlists.
*/
if (dn->dn_nlevels > 1) {
+ rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
uint64_t first, last;
first = blkid >> epbs;
dnode_dirty_l1(dn, i, tx);
}
+ rw_exit(&dn->dn_struct_rwlock);
}
done:
dbuf_free_range(dn, blkid, blkid + nblks - 1, tx);
dnode_setdirty(dn, tx);
-out:
-
- rw_exit(&dn->dn_struct_rwlock);
}
static boolean_t
boolean_t hole;
int i, inc, error, span;
+ ASSERT(RW_LOCK_HELD(&dn->dn_struct_rwlock));
+
hole = ((flags & DNODE_FIND_HOLE) != 0);
inc = (flags & DNODE_FIND_BACKWARDS) ? -1 : 1;
ASSERT(txg == 0 || !hole);
return (error);
}
data = db->db.db_data;
+ rw_enter(&db->db_rwlock, RW_READER);
}
-
if (db != NULL && txg != 0 && (db->db_blkptr == NULL ||
db->db_blkptr->blk_birth <= txg ||
BP_IS_HOLE(db->db_blkptr))) {
error = SET_ERROR(ESRCH);
}
- if (db)
+ if (db != NULL) {
+ rw_exit(&db->db_rwlock);
dbuf_rele(db, FTAG);
+ }
return (error);
}
/* this dnode can't be paged out because it's dirty */
ASSERT(dn->dn_phys->dn_type != DMU_OT_NONE);
- ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock));
ASSERT(new_level > 1 && dn->dn_phys->dn_nlevels > 0);
db = dbuf_hold_level(dn, dn->dn_phys->dn_nlevels, 0, FTAG);
dprintf("os=%p obj=%llu, increase to %d\n", dn->dn_objset,
dn->dn_object, dn->dn_phys->dn_nlevels);
+ /*
+ * Lock ordering requires that we hold the children's db_mutexes (by
+ * calling dbuf_find()) before holding the parent's db_rwlock. The lock
+ * order is imposed by dbuf_read's steps of "grab the lock to protect
+ * db_parent, get db_parent, hold db_parent's db_rwlock".
+ */
+ dmu_buf_impl_t *children[DN_MAX_NBLKPTR];
+ ASSERT3U(nblkptr, <=, DN_MAX_NBLKPTR);
+ for (i = 0; i < nblkptr; i++) {
+ children[i] =
+ dbuf_find(dn->dn_objset, dn->dn_object, old_toplvl, i);
+ }
+
/* transfer dnode's block pointers to new indirect block */
(void) dbuf_read(db, NULL, DB_RF_MUST_SUCCEED|DB_RF_HAVESTRUCT);
+ if (dn->dn_dbuf != NULL)
+ rw_enter(&dn->dn_dbuf->db_rwlock, RW_WRITER);
+ rw_enter(&db->db_rwlock, RW_WRITER);
ASSERT(db->db.db_data);
ASSERT(arc_released(db->db_buf));
ASSERT3U(sizeof (blkptr_t) * nblkptr, <=, db->db.db_size);
/* set dbuf's parent pointers to new indirect buf */
for (i = 0; i < nblkptr; i++) {
- dmu_buf_impl_t *child =
- dbuf_find(dn->dn_objset, dn->dn_object, old_toplvl, i);
+ dmu_buf_impl_t *child = children[i];
if (child == NULL)
continue;
bzero(dn->dn_phys->dn_blkptr, sizeof (blkptr_t) * nblkptr);
+ rw_exit(&db->db_rwlock);
+ if (dn->dn_dbuf != NULL)
+ rw_exit(&dn->dn_dbuf->db_rwlock);
+
dbuf_rele(db, FTAG);
rw_exit(&dn->dn_struct_rwlock);
ASSERT(db->db_level == 1);
rw_enter(&dn->dn_struct_rwlock, RW_READER);
- err = dbuf_hold_impl(dn, db->db_level-1,
+ err = dbuf_hold_impl(dn, db->db_level - 1,
(db->db_blkid << epbs) + i, TRUE, FALSE, FTAG, &child);
rw_exit(&dn->dn_struct_rwlock);
if (err == ENOENT)
* ancestor of the first or last block to be freed. The first and
* last L1 indirect blocks are always dirtied by dnode_free_range().
*/
+ db_lock_type_t dblt = dmu_buf_lock_parent(db, RW_READER, FTAG);
VERIFY(BP_GET_FILL(db->db_blkptr) == 0 || db->db_dirtycnt > 0);
+ dmu_buf_unlock_parent(db, dblt, FTAG);
dbuf_release_bp(db);
bp = db->db.db_data;
if (db->db_level == 1) {
FREE_VERIFY(db, start, end, tx);
- free_blocks(dn, bp, end-start+1, tx);
+ rw_enter(&db->db_rwlock, RW_WRITER);
+ free_blocks(dn, bp, end - start + 1, tx);
+ rw_exit(&db->db_rwlock);
} else {
for (uint64_t id = start; id <= end; id++, bp++) {
if (BP_IS_HOLE(bp))
}
if (free_indirects) {
+ rw_enter(&db->db_rwlock, RW_WRITER);
for (i = 0, bp = db->db.db_data; i < 1 << epbs; i++, bp++)
ASSERT(BP_IS_HOLE(bp));
bzero(db->db.db_data, db->db.db_size);
free_blocks(dn, db->db_blkptr, 1, tx);
+ rw_exit(&db->db_rwlock);
}
DB_DNODE_EXIT(db);
VERIFY0(dbuf_hold_impl(dn, dnlevel - 1, i,
TRUE, FALSE, FTAG, &db));
rw_exit(&dn->dn_struct_rwlock);
-
free_children(db, blkid, nblks, free_indirects, tx);
dbuf_rele(db, FTAG);
}
projects / mirror_zfs.git / commitdiff