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1a3e32e6a2
mirror_zfs/module/zfs/dnode.c
Alexander Motin 1a3e32e6a2 Cleanup DB_DNODE() macros usage 
- Use the macros in few places it was missed.
 - Reduce scope of DB_DNODE_ENTER/EXIT() and inline some DB_DNODE()
uses to make it more obvious what exactly is protected there and
make unprotected accesses by mistake more difficult.
 - Make use of zrl_owner().

Reviewed-by: Rob Wing <rob.wing@klarasystems.com
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Allan Jude <allan@klarasystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by:	Alexander Motin <mav@FreeBSD.org>
Sponsored by:	iXsystems, Inc.
Closes #16374
2024-07-29 14:47:01 -07:00

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/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or https://opensource.org/licenses/CDDL-1.0.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2012, 2020 by Delphix. All rights reserved.
* Copyright (c) 2014 Spectra Logic Corporation, All rights reserved.
*/
#include <sys/zfs_context.h>
#include <sys/dbuf.h>
#include <sys/dnode.h>
#include <sys/dmu.h>
#include <sys/dmu_impl.h>
#include <sys/dmu_tx.h>
#include <sys/dmu_objset.h>
#include <sys/dsl_dir.h>
#include <sys/dsl_dataset.h>
#include <sys/spa.h>
#include <sys/zio.h>
#include <sys/dmu_zfetch.h>
#include <sys/range_tree.h>
#include <sys/trace_zfs.h>
#include <sys/zfs_project.h>
dnode_stats_t dnode_stats = {
{ "dnode_hold_dbuf_hold", KSTAT_DATA_UINT64 },
{ "dnode_hold_dbuf_read", KSTAT_DATA_UINT64 },
{ "dnode_hold_alloc_hits", KSTAT_DATA_UINT64 },
{ "dnode_hold_alloc_misses", KSTAT_DATA_UINT64 },
{ "dnode_hold_alloc_interior", KSTAT_DATA_UINT64 },
{ "dnode_hold_alloc_lock_retry", KSTAT_DATA_UINT64 },
{ "dnode_hold_alloc_lock_misses", KSTAT_DATA_UINT64 },
{ "dnode_hold_alloc_type_none", KSTAT_DATA_UINT64 },
{ "dnode_hold_free_hits", KSTAT_DATA_UINT64 },
{ "dnode_hold_free_misses", KSTAT_DATA_UINT64 },
{ "dnode_hold_free_lock_misses", KSTAT_DATA_UINT64 },
{ "dnode_hold_free_lock_retry", KSTAT_DATA_UINT64 },
{ "dnode_hold_free_overflow", KSTAT_DATA_UINT64 },
{ "dnode_hold_free_refcount", KSTAT_DATA_UINT64 },
{ "dnode_free_interior_lock_retry", KSTAT_DATA_UINT64 },
{ "dnode_allocate", KSTAT_DATA_UINT64 },
{ "dnode_reallocate", KSTAT_DATA_UINT64 },
{ "dnode_buf_evict", KSTAT_DATA_UINT64 },
{ "dnode_alloc_next_chunk", KSTAT_DATA_UINT64 },
{ "dnode_alloc_race", KSTAT_DATA_UINT64 },
{ "dnode_alloc_next_block", KSTAT_DATA_UINT64 },
{ "dnode_move_invalid", KSTAT_DATA_UINT64 },
{ "dnode_move_recheck1", KSTAT_DATA_UINT64 },
{ "dnode_move_recheck2", KSTAT_DATA_UINT64 },
{ "dnode_move_special", KSTAT_DATA_UINT64 },
{ "dnode_move_handle", KSTAT_DATA_UINT64 },
{ "dnode_move_rwlock", KSTAT_DATA_UINT64 },
{ "dnode_move_active", KSTAT_DATA_UINT64 },
};
dnode_sums_t dnode_sums;
static kstat_t *dnode_ksp;
static kmem_cache_t *dnode_cache;
static dnode_phys_t dnode_phys_zero __maybe_unused;
int zfs_default_bs = SPA_MINBLOCKSHIFT;
int zfs_default_ibs = DN_MAX_INDBLKSHIFT;
#ifdef _KERNEL
static kmem_cbrc_t dnode_move(void *, void *, size_t, void *);
#endif /* _KERNEL */
static int
dbuf_compare(const void *x1, const void *x2)
{
const dmu_buf_impl_t *d1 = x1;
const dmu_buf_impl_t *d2 = x2;
int cmp = TREE_CMP(d1->db_level, d2->db_level);
if (likely(cmp))
return (cmp);
cmp = TREE_CMP(d1->db_blkid, d2->db_blkid);
if (likely(cmp))
return (cmp);
if (d1->db_state == DB_MARKER) {
ASSERT3S(d2->db_state, !=, DB_MARKER);
return (TREE_PCMP(d1->db_parent, d2));
} else if (d2->db_state == DB_MARKER) {
ASSERT3S(d1->db_state, !=, DB_MARKER);
return (TREE_PCMP(d1, d2->db_parent));
}
if (d1->db_state == DB_SEARCH) {
ASSERT3S(d2->db_state, !=, DB_SEARCH);
return (-1);
} else if (d2->db_state == DB_SEARCH) {
ASSERT3S(d1->db_state, !=, DB_SEARCH);
return (1);
}
return (TREE_PCMP(d1, d2));
}
static int
dnode_cons(void *arg, void *unused, int kmflag)
{
(void) unused, (void) kmflag;
dnode_t *dn = arg;
rw_init(&dn->dn_struct_rwlock, NULL, RW_NOLOCKDEP, NULL);
mutex_init(&dn->dn_mtx, NULL, MUTEX_DEFAULT, NULL);
mutex_init(&dn->dn_dbufs_mtx, NULL, MUTEX_DEFAULT, NULL);
cv_init(&dn->dn_notxholds, NULL, CV_DEFAULT, NULL);
cv_init(&dn->dn_nodnholds, NULL, CV_DEFAULT, NULL);
/*
* Every dbuf has a reference, and dropping a tracked reference is
* O(number of references), so don't track dn_holds.
*/
zfs_refcount_create_untracked(&dn->dn_holds);
zfs_refcount_create(&dn->dn_tx_holds);
list_link_init(&dn->dn_link);
memset(dn->dn_next_type, 0, sizeof (dn->dn_next_type));
memset(dn->dn_next_nblkptr, 0, sizeof (dn->dn_next_nblkptr));
memset(dn->dn_next_nlevels, 0, sizeof (dn->dn_next_nlevels));
memset(dn->dn_next_indblkshift, 0, sizeof (dn->dn_next_indblkshift));
memset(dn->dn_next_bonustype, 0, sizeof (dn->dn_next_bonustype));
memset(dn->dn_rm_spillblk, 0, sizeof (dn->dn_rm_spillblk));
memset(dn->dn_next_bonuslen, 0, sizeof (dn->dn_next_bonuslen));
memset(dn->dn_next_blksz, 0, sizeof (dn->dn_next_blksz));
memset(dn->dn_next_maxblkid, 0, sizeof (dn->dn_next_maxblkid));
for (int i = 0; i < TXG_SIZE; i++) {
multilist_link_init(&dn->dn_dirty_link[i]);
dn->dn_free_ranges[i] = NULL;
list_create(&dn->dn_dirty_records[i],
sizeof (dbuf_dirty_record_t),
offsetof(dbuf_dirty_record_t, dr_dirty_node));
}
dn->dn_allocated_txg = 0;
dn->dn_free_txg = 0;
dn->dn_assigned_txg = 0;
dn->dn_dirty_txg = 0;
dn->dn_dirtyctx = 0;
dn->dn_dirtyctx_firstset = NULL;
dn->dn_bonus = NULL;
dn->dn_have_spill = B_FALSE;
dn->dn_zio = NULL;
dn->dn_oldused = 0;
dn->dn_oldflags = 0;
dn->dn_olduid = 0;
dn->dn_oldgid = 0;
dn->dn_oldprojid = ZFS_DEFAULT_PROJID;
dn->dn_newuid = 0;
dn->dn_newgid = 0;
dn->dn_newprojid = ZFS_DEFAULT_PROJID;
dn->dn_id_flags = 0;
dn->dn_dbufs_count = 0;
avl_create(&dn->dn_dbufs, dbuf_compare, sizeof (dmu_buf_impl_t),
offsetof(dmu_buf_impl_t, db_link));
dn->dn_moved = 0;
return (0);
}
static void
dnode_dest(void *arg, void *unused)
{
(void) unused;
dnode_t *dn = arg;
rw_destroy(&dn->dn_struct_rwlock);
mutex_destroy(&dn->dn_mtx);
mutex_destroy(&dn->dn_dbufs_mtx);
cv_destroy(&dn->dn_notxholds);
cv_destroy(&dn->dn_nodnholds);
zfs_refcount_destroy(&dn->dn_holds);
zfs_refcount_destroy(&dn->dn_tx_holds);
ASSERT(!list_link_active(&dn->dn_link));
for (int i = 0; i < TXG_SIZE; i++) {
ASSERT(!multilist_link_active(&dn->dn_dirty_link[i]));
ASSERT3P(dn->dn_free_ranges[i], ==, NULL);
list_destroy(&dn->dn_dirty_records[i]);
ASSERT0(dn->dn_next_nblkptr[i]);
ASSERT0(dn->dn_next_nlevels[i]);
ASSERT0(dn->dn_next_indblkshift[i]);
ASSERT0(dn->dn_next_bonustype[i]);
ASSERT0(dn->dn_rm_spillblk[i]);
ASSERT0(dn->dn_next_bonuslen[i]);
ASSERT0(dn->dn_next_blksz[i]);
ASSERT0(dn->dn_next_maxblkid[i]);
}
ASSERT0(dn->dn_allocated_txg);
ASSERT0(dn->dn_free_txg);
ASSERT0(dn->dn_assigned_txg);
ASSERT0(dn->dn_dirty_txg);
ASSERT0(dn->dn_dirtyctx);
ASSERT3P(dn->dn_dirtyctx_firstset, ==, NULL);
ASSERT3P(dn->dn_bonus, ==, NULL);
ASSERT(!dn->dn_have_spill);
ASSERT3P(dn->dn_zio, ==, NULL);
ASSERT0(dn->dn_oldused);
ASSERT0(dn->dn_oldflags);
ASSERT0(dn->dn_olduid);
ASSERT0(dn->dn_oldgid);
ASSERT0(dn->dn_oldprojid);
ASSERT0(dn->dn_newuid);
ASSERT0(dn->dn_newgid);
ASSERT0(dn->dn_newprojid);
ASSERT0(dn->dn_id_flags);
ASSERT0(dn->dn_dbufs_count);
avl_destroy(&dn->dn_dbufs);
}
static int
dnode_kstats_update(kstat_t *ksp, int rw)
{
dnode_stats_t *ds = ksp->ks_data;
if (rw == KSTAT_WRITE)
return (EACCES);
ds->dnode_hold_dbuf_hold.value.ui64 =
wmsum_value(&dnode_sums.dnode_hold_dbuf_hold);
ds->dnode_hold_dbuf_read.value.ui64 =
wmsum_value(&dnode_sums.dnode_hold_dbuf_read);
ds->dnode_hold_alloc_hits.value.ui64 =
wmsum_value(&dnode_sums.dnode_hold_alloc_hits);
ds->dnode_hold_alloc_misses.value.ui64 =
wmsum_value(&dnode_sums.dnode_hold_alloc_misses);
ds->dnode_hold_alloc_interior.value.ui64 =
wmsum_value(&dnode_sums.dnode_hold_alloc_interior);
ds->dnode_hold_alloc_lock_retry.value.ui64 =
wmsum_value(&dnode_sums.dnode_hold_alloc_lock_retry);
ds->dnode_hold_alloc_lock_misses.value.ui64 =
wmsum_value(&dnode_sums.dnode_hold_alloc_lock_misses);
ds->dnode_hold_alloc_type_none.value.ui64 =
wmsum_value(&dnode_sums.dnode_hold_alloc_type_none);
ds->dnode_hold_free_hits.value.ui64 =
wmsum_value(&dnode_sums.dnode_hold_free_hits);
ds->dnode_hold_free_misses.value.ui64 =
wmsum_value(&dnode_sums.dnode_hold_free_misses);
ds->dnode_hold_free_lock_misses.value.ui64 =
wmsum_value(&dnode_sums.dnode_hold_free_lock_misses);
ds->dnode_hold_free_lock_retry.value.ui64 =
wmsum_value(&dnode_sums.dnode_hold_free_lock_retry);
ds->dnode_hold_free_refcount.value.ui64 =
wmsum_value(&dnode_sums.dnode_hold_free_refcount);
ds->dnode_hold_free_overflow.value.ui64 =
wmsum_value(&dnode_sums.dnode_hold_free_overflow);
ds->dnode_free_interior_lock_retry.value.ui64 =
wmsum_value(&dnode_sums.dnode_free_interior_lock_retry);
ds->dnode_allocate.value.ui64 =
wmsum_value(&dnode_sums.dnode_allocate);
ds->dnode_reallocate.value.ui64 =
wmsum_value(&dnode_sums.dnode_reallocate);
ds->dnode_buf_evict.value.ui64 =
wmsum_value(&dnode_sums.dnode_buf_evict);
ds->dnode_alloc_next_chunk.value.ui64 =
wmsum_value(&dnode_sums.dnode_alloc_next_chunk);
ds->dnode_alloc_race.value.ui64 =
wmsum_value(&dnode_sums.dnode_alloc_race);
ds->dnode_alloc_next_block.value.ui64 =
wmsum_value(&dnode_sums.dnode_alloc_next_block);
ds->dnode_move_invalid.value.ui64 =
wmsum_value(&dnode_sums.dnode_move_invalid);
ds->dnode_move_recheck1.value.ui64 =
wmsum_value(&dnode_sums.dnode_move_recheck1);
ds->dnode_move_recheck2.value.ui64 =
wmsum_value(&dnode_sums.dnode_move_recheck2);
ds->dnode_move_special.value.ui64 =
wmsum_value(&dnode_sums.dnode_move_special);
ds->dnode_move_handle.value.ui64 =
wmsum_value(&dnode_sums.dnode_move_handle);
ds->dnode_move_rwlock.value.ui64 =
wmsum_value(&dnode_sums.dnode_move_rwlock);
ds->dnode_move_active.value.ui64 =
wmsum_value(&dnode_sums.dnode_move_active);
return (0);
}
void
dnode_init(void)
{
ASSERT(dnode_cache == NULL);
dnode_cache = kmem_cache_create("dnode_t", sizeof (dnode_t),
0, dnode_cons, dnode_dest, NULL, NULL, NULL, 0);
kmem_cache_set_move(dnode_cache, dnode_move);
wmsum_init(&dnode_sums.dnode_hold_dbuf_hold, 0);
wmsum_init(&dnode_sums.dnode_hold_dbuf_read, 0);
wmsum_init(&dnode_sums.dnode_hold_alloc_hits, 0);
wmsum_init(&dnode_sums.dnode_hold_alloc_misses, 0);
wmsum_init(&dnode_sums.dnode_hold_alloc_interior, 0);
wmsum_init(&dnode_sums.dnode_hold_alloc_lock_retry, 0);
wmsum_init(&dnode_sums.dnode_hold_alloc_lock_misses, 0);
wmsum_init(&dnode_sums.dnode_hold_alloc_type_none, 0);
wmsum_init(&dnode_sums.dnode_hold_free_hits, 0);
wmsum_init(&dnode_sums.dnode_hold_free_misses, 0);
wmsum_init(&dnode_sums.dnode_hold_free_lock_misses, 0);
wmsum_init(&dnode_sums.dnode_hold_free_lock_retry, 0);
wmsum_init(&dnode_sums.dnode_hold_free_refcount, 0);
wmsum_init(&dnode_sums.dnode_hold_free_overflow, 0);
wmsum_init(&dnode_sums.dnode_free_interior_lock_retry, 0);
wmsum_init(&dnode_sums.dnode_allocate, 0);
wmsum_init(&dnode_sums.dnode_reallocate, 0);
wmsum_init(&dnode_sums.dnode_buf_evict, 0);
wmsum_init(&dnode_sums.dnode_alloc_next_chunk, 0);
wmsum_init(&dnode_sums.dnode_alloc_race, 0);
wmsum_init(&dnode_sums.dnode_alloc_next_block, 0);
wmsum_init(&dnode_sums.dnode_move_invalid, 0);
wmsum_init(&dnode_sums.dnode_move_recheck1, 0);
wmsum_init(&dnode_sums.dnode_move_recheck2, 0);
wmsum_init(&dnode_sums.dnode_move_special, 0);
wmsum_init(&dnode_sums.dnode_move_handle, 0);
wmsum_init(&dnode_sums.dnode_move_rwlock, 0);
wmsum_init(&dnode_sums.dnode_move_active, 0);
dnode_ksp = kstat_create("zfs", 0, "dnodestats", "misc",
KSTAT_TYPE_NAMED, sizeof (dnode_stats) / sizeof (kstat_named_t),
KSTAT_FLAG_VIRTUAL);
if (dnode_ksp != NULL) {
dnode_ksp->ks_data = &dnode_stats;
dnode_ksp->ks_update = dnode_kstats_update;
kstat_install(dnode_ksp);
}
}
void
dnode_fini(void)
{
if (dnode_ksp != NULL) {
kstat_delete(dnode_ksp);
dnode_ksp = NULL;
}
wmsum_fini(&dnode_sums.dnode_hold_dbuf_hold);
wmsum_fini(&dnode_sums.dnode_hold_dbuf_read);
wmsum_fini(&dnode_sums.dnode_hold_alloc_hits);
wmsum_fini(&dnode_sums.dnode_hold_alloc_misses);
wmsum_fini(&dnode_sums.dnode_hold_alloc_interior);
wmsum_fini(&dnode_sums.dnode_hold_alloc_lock_retry);
wmsum_fini(&dnode_sums.dnode_hold_alloc_lock_misses);
wmsum_fini(&dnode_sums.dnode_hold_alloc_type_none);
wmsum_fini(&dnode_sums.dnode_hold_free_hits);
wmsum_fini(&dnode_sums.dnode_hold_free_misses);
wmsum_fini(&dnode_sums.dnode_hold_free_lock_misses);
wmsum_fini(&dnode_sums.dnode_hold_free_lock_retry);
wmsum_fini(&dnode_sums.dnode_hold_free_refcount);
wmsum_fini(&dnode_sums.dnode_hold_free_overflow);
wmsum_fini(&dnode_sums.dnode_free_interior_lock_retry);
wmsum_fini(&dnode_sums.dnode_allocate);
wmsum_fini(&dnode_sums.dnode_reallocate);
wmsum_fini(&dnode_sums.dnode_buf_evict);
wmsum_fini(&dnode_sums.dnode_alloc_next_chunk);
wmsum_fini(&dnode_sums.dnode_alloc_race);
wmsum_fini(&dnode_sums.dnode_alloc_next_block);
wmsum_fini(&dnode_sums.dnode_move_invalid);
wmsum_fini(&dnode_sums.dnode_move_recheck1);
wmsum_fini(&dnode_sums.dnode_move_recheck2);
wmsum_fini(&dnode_sums.dnode_move_special);
wmsum_fini(&dnode_sums.dnode_move_handle);
wmsum_fini(&dnode_sums.dnode_move_rwlock);
wmsum_fini(&dnode_sums.dnode_move_active);
kmem_cache_destroy(dnode_cache);
dnode_cache = NULL;
}
#ifdef ZFS_DEBUG
void
dnode_verify(dnode_t *dn)
{
int drop_struct_lock = FALSE;
ASSERT(dn->dn_phys);
ASSERT(dn->dn_objset);
ASSERT(dn->dn_handle->dnh_dnode == dn);
ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type));
if (!(zfs_flags & ZFS_DEBUG_DNODE_VERIFY))
return;
if (!RW_WRITE_HELD(&dn->dn_struct_rwlock)) {
rw_enter(&dn->dn_struct_rwlock, RW_READER);
drop_struct_lock = TRUE;
}
if (dn->dn_phys->dn_type != DMU_OT_NONE || dn->dn_allocated_txg != 0) {
int i;
int max_bonuslen = DN_SLOTS_TO_BONUSLEN(dn->dn_num_slots);
ASSERT3U(dn->dn_indblkshift, <=, SPA_MAXBLOCKSHIFT);
if (dn->dn_datablkshift) {
ASSERT3U(dn->dn_datablkshift, >=, SPA_MINBLOCKSHIFT);
ASSERT3U(dn->dn_datablkshift, <=, SPA_MAXBLOCKSHIFT);
ASSERT3U(1<<dn->dn_datablkshift, ==, dn->dn_datablksz);
}
ASSERT3U(dn->dn_nlevels, <=, 30);
ASSERT(DMU_OT_IS_VALID(dn->dn_type));
ASSERT3U(dn->dn_nblkptr, >=, 1);
ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR);
ASSERT3U(dn->dn_bonuslen, <=, max_bonuslen);
ASSERT3U(dn->dn_datablksz, ==,
dn->dn_datablkszsec << SPA_MINBLOCKSHIFT);
ASSERT3U(ISP2(dn->dn_datablksz), ==, dn->dn_datablkshift != 0);
ASSERT3U((dn->dn_nblkptr - 1) * sizeof (blkptr_t) +
dn->dn_bonuslen, <=, max_bonuslen);
for (i = 0; i < TXG_SIZE; i++) {
ASSERT3U(dn->dn_next_nlevels[i], <=, dn->dn_nlevels);
}
}
if (dn->dn_phys->dn_type != DMU_OT_NONE)
ASSERT3U(dn->dn_phys->dn_nlevels, <=, dn->dn_nlevels);
ASSERT(DMU_OBJECT_IS_SPECIAL(dn->dn_object) || dn->dn_dbuf != NULL);
if (dn->dn_dbuf != NULL) {
ASSERT3P(dn->dn_phys, ==,
(dnode_phys_t *)dn->dn_dbuf->db.db_data +
(dn->dn_object % (dn->dn_dbuf->db.db_size >> DNODE_SHIFT)));
}
if (drop_struct_lock)
rw_exit(&dn->dn_struct_rwlock);
}
#endif
void
dnode_byteswap(dnode_phys_t *dnp)
{
uint64_t *buf64 = (void*)&dnp->dn_blkptr;
int i;
if (dnp->dn_type == DMU_OT_NONE) {
memset(dnp, 0, sizeof (dnode_phys_t));
return;
}
dnp->dn_datablkszsec = BSWAP_16(dnp->dn_datablkszsec);
dnp->dn_bonuslen = BSWAP_16(dnp->dn_bonuslen);
dnp->dn_extra_slots = BSWAP_8(dnp->dn_extra_slots);
dnp->dn_maxblkid = BSWAP_64(dnp->dn_maxblkid);
dnp->dn_used = BSWAP_64(dnp->dn_used);
/*
* dn_nblkptr is only one byte, so it's OK to read it in either
* byte order. We can't read dn_bouslen.
*/
ASSERT(dnp->dn_indblkshift <= SPA_MAXBLOCKSHIFT);
ASSERT(dnp->dn_nblkptr <= DN_MAX_NBLKPTR);
for (i = 0; i < dnp->dn_nblkptr * sizeof (blkptr_t)/8; i++)
buf64[i] = BSWAP_64(buf64[i]);
/*
* OK to check dn_bonuslen for zero, because it won't matter if
* we have the wrong byte order. This is necessary because the
* dnode dnode is smaller than a regular dnode.
*/
if (dnp->dn_bonuslen != 0) {
dmu_object_byteswap_t byteswap;
ASSERT(DMU_OT_IS_VALID(dnp->dn_bonustype));
byteswap = DMU_OT_BYTESWAP(dnp->dn_bonustype);
dmu_ot_byteswap[byteswap].ob_func(DN_BONUS(dnp),
DN_MAX_BONUS_LEN(dnp));
}
/* Swap SPILL block if we have one */
if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR)
byteswap_uint64_array(DN_SPILL_BLKPTR(dnp), sizeof (blkptr_t));
}
void
dnode_buf_byteswap(void *vbuf, size_t size)
{
int i = 0;
ASSERT3U(sizeof (dnode_phys_t), ==, (1<<DNODE_SHIFT));
ASSERT((size & (sizeof (dnode_phys_t)-1)) == 0);
while (i < size) {
dnode_phys_t *dnp = (void *)(((char *)vbuf) + i);
dnode_byteswap(dnp);
i += DNODE_MIN_SIZE;
if (dnp->dn_type != DMU_OT_NONE)
i += dnp->dn_extra_slots * DNODE_MIN_SIZE;
}
}
void
dnode_setbonuslen(dnode_t *dn, int newsize, dmu_tx_t *tx)
{
ASSERT3U(zfs_refcount_count(&dn->dn_holds), >=, 1);
dnode_setdirty(dn, tx);
rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
ASSERT3U(newsize, <=, DN_SLOTS_TO_BONUSLEN(dn->dn_num_slots) -
(dn->dn_nblkptr-1) * sizeof (blkptr_t));
if (newsize < dn->dn_bonuslen) {
/* clear any data after the end of the new size */
size_t diff = dn->dn_bonuslen - newsize;
char *data_end = ((char *)dn->dn_bonus->db.db_data) + newsize;
memset(data_end, 0, diff);
}
dn->dn_bonuslen = newsize;
if (newsize == 0)
dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = DN_ZERO_BONUSLEN;
else
dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen;
rw_exit(&dn->dn_struct_rwlock);
}
void
dnode_setbonus_type(dnode_t *dn, dmu_object_type_t newtype, dmu_tx_t *tx)
{
ASSERT3U(zfs_refcount_count(&dn->dn_holds), >=, 1);
dnode_setdirty(dn, tx);
rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
dn->dn_bonustype = newtype;
dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype;
rw_exit(&dn->dn_struct_rwlock);
}
void
dnode_rm_spill(dnode_t *dn, dmu_tx_t *tx)
{
ASSERT3U(zfs_refcount_count(&dn->dn_holds), >=, 1);
ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock));
dnode_setdirty(dn, tx);
dn->dn_rm_spillblk[tx->tx_txg & TXG_MASK] = DN_KILL_SPILLBLK;
dn->dn_have_spill = B_FALSE;
}
static void
dnode_setdblksz(dnode_t *dn, int size)
{
ASSERT0(P2PHASE(size, SPA_MINBLOCKSIZE));
ASSERT3U(size, <=, SPA_MAXBLOCKSIZE);
ASSERT3U(size, >=, SPA_MINBLOCKSIZE);
ASSERT3U(size >> SPA_MINBLOCKSHIFT, <,
1<<(sizeof (dn->dn_phys->dn_datablkszsec) * 8));
dn->dn_datablksz = size;
dn->dn_datablkszsec = size >> SPA_MINBLOCKSHIFT;
dn->dn_datablkshift = ISP2(size) ? highbit64(size - 1) : 0;
}
static dnode_t *
dnode_create(objset_t *os, dnode_phys_t *dnp, dmu_buf_impl_t *db,
uint64_t object, dnode_handle_t *dnh)
{
dnode_t *dn;
dn = kmem_cache_alloc(dnode_cache, KM_SLEEP);
dn->dn_moved = 0;
/*
* Defer setting dn_objset until the dnode is ready to be a candidate
* for the dnode_move() callback.
*/
dn->dn_object = object;
dn->dn_dbuf = db;
dn->dn_handle = dnh;
dn->dn_phys = dnp;
if (dnp->dn_datablkszsec) {
dnode_setdblksz(dn, dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT);
} else {
dn->dn_datablksz = 0;
dn->dn_datablkszsec = 0;
dn->dn_datablkshift = 0;
}
dn->dn_indblkshift = dnp->dn_indblkshift;
dn->dn_nlevels = dnp->dn_nlevels;
dn->dn_type = dnp->dn_type;
dn->dn_nblkptr = dnp->dn_nblkptr;
dn->dn_checksum = dnp->dn_checksum;
dn->dn_compress = dnp->dn_compress;
dn->dn_bonustype = dnp->dn_bonustype;
dn->dn_bonuslen = dnp->dn_bonuslen;
dn->dn_num_slots = dnp->dn_extra_slots + 1;
dn->dn_maxblkid = dnp->dn_maxblkid;
dn->dn_have_spill = ((dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) != 0);
dn->dn_id_flags = 0;
dmu_zfetch_init(&dn->dn_zfetch, dn);
ASSERT(DMU_OT_IS_VALID(dn->dn_phys->dn_type));
ASSERT(zrl_is_locked(&dnh->dnh_zrlock));
ASSERT(!DN_SLOT_IS_PTR(dnh->dnh_dnode));
mutex_enter(&os->os_lock);
/*
* Exclude special dnodes from os_dnodes so an empty os_dnodes
* signifies that the special dnodes have no references from
* their children (the entries in os_dnodes). This allows
* dnode_destroy() to easily determine if the last child has
* been removed and then complete eviction of the objset.
*/
if (!DMU_OBJECT_IS_SPECIAL(object))
list_insert_head(&os->os_dnodes, dn);
membar_producer();
/*
* Everything else must be valid before assigning dn_objset
* makes the dnode eligible for dnode_move().
*/
dn->dn_objset = os;
dnh->dnh_dnode = dn;
mutex_exit(&os->os_lock);
arc_space_consume(sizeof (dnode_t), ARC_SPACE_DNODE);
return (dn);
}
/*
* Caller must be holding the dnode handle, which is released upon return.
*/
static void
dnode_destroy(dnode_t *dn)
{
objset_t *os = dn->dn_objset;
boolean_t complete_os_eviction = B_FALSE;
ASSERT((dn->dn_id_flags & DN_ID_NEW_EXIST) == 0);
mutex_enter(&os->os_lock);
POINTER_INVALIDATE(&dn->dn_objset);
if (!DMU_OBJECT_IS_SPECIAL(dn->dn_object)) {
list_remove(&os->os_dnodes, dn);
complete_os_eviction =
list_is_empty(&os->os_dnodes) &&
list_link_active(&os->os_evicting_node);
}
mutex_exit(&os->os_lock);
/* the dnode can no longer move, so we can release the handle */
if (!zrl_is_locked(&dn->dn_handle->dnh_zrlock))
zrl_remove(&dn->dn_handle->dnh_zrlock);
dn->dn_allocated_txg = 0;
dn->dn_free_txg = 0;
dn->dn_assigned_txg = 0;
dn->dn_dirty_txg = 0;
dn->dn_dirtyctx = 0;
dn->dn_dirtyctx_firstset = NULL;
if (dn->dn_bonus != NULL) {
mutex_enter(&dn->dn_bonus->db_mtx);
dbuf_destroy(dn->dn_bonus);
dn->dn_bonus = NULL;
}
dn->dn_zio = NULL;
dn->dn_have_spill = B_FALSE;
dn->dn_oldused = 0;
dn->dn_oldflags = 0;
dn->dn_olduid = 0;
dn->dn_oldgid = 0;
dn->dn_oldprojid = ZFS_DEFAULT_PROJID;
dn->dn_newuid = 0;
dn->dn_newgid = 0;
dn->dn_newprojid = ZFS_DEFAULT_PROJID;
dn->dn_id_flags = 0;
dmu_zfetch_fini(&dn->dn_zfetch);
kmem_cache_free(dnode_cache, dn);
arc_space_return(sizeof (dnode_t), ARC_SPACE_DNODE);
if (complete_os_eviction)
dmu_objset_evict_done(os);
}
void
dnode_allocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, int ibs,
dmu_object_type_t bonustype, int bonuslen, int dn_slots, dmu_tx_t *tx)
{
int i;
ASSERT3U(dn_slots, >, 0);
ASSERT3U(dn_slots << DNODE_SHIFT, <=,
spa_maxdnodesize(dmu_objset_spa(dn->dn_objset)));
ASSERT3U(blocksize, <=,
spa_maxblocksize(dmu_objset_spa(dn->dn_objset)));
if (blocksize == 0)
blocksize = 1 << zfs_default_bs;
else
blocksize = P2ROUNDUP(blocksize, SPA_MINBLOCKSIZE);
if (ibs == 0)
ibs = zfs_default_ibs;
ibs = MIN(MAX(ibs, DN_MIN_INDBLKSHIFT), DN_MAX_INDBLKSHIFT);
dprintf("os=%p obj=%llu txg=%llu blocksize=%d ibs=%d dn_slots=%d\n",
dn->dn_objset, (u_longlong_t)dn->dn_object,
(u_longlong_t)tx->tx_txg, blocksize, ibs, dn_slots);
DNODE_STAT_BUMP(dnode_allocate);
ASSERT(dn->dn_type == DMU_OT_NONE);
ASSERT0(memcmp(dn->dn_phys, &dnode_phys_zero, sizeof (dnode_phys_t)));
ASSERT(dn->dn_phys->dn_type == DMU_OT_NONE);
ASSERT(ot != DMU_OT_NONE);
ASSERT(DMU_OT_IS_VALID(ot));
ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) ||
(bonustype == DMU_OT_SA && bonuslen == 0) ||
(bonustype == DMU_OTN_UINT64_METADATA && bonuslen == 0) ||
(bonustype != DMU_OT_NONE && bonuslen != 0));
ASSERT(DMU_OT_IS_VALID(bonustype));
ASSERT3U(bonuslen, <=, DN_SLOTS_TO_BONUSLEN(dn_slots));
ASSERT(dn->dn_type == DMU_OT_NONE);
ASSERT0(dn->dn_maxblkid);
ASSERT0(dn->dn_allocated_txg);
ASSERT0(dn->dn_assigned_txg);
ASSERT(zfs_refcount_is_zero(&dn->dn_tx_holds));
ASSERT3U(zfs_refcount_count(&dn->dn_holds), <=, 1);
ASSERT(avl_is_empty(&dn->dn_dbufs));
for (i = 0; i < TXG_SIZE; i++) {
ASSERT0(dn->dn_next_nblkptr[i]);
ASSERT0(dn->dn_next_nlevels[i]);
ASSERT0(dn->dn_next_indblkshift[i]);
ASSERT0(dn->dn_next_bonuslen[i]);
ASSERT0(dn->dn_next_bonustype[i]);
ASSERT0(dn->dn_rm_spillblk[i]);
ASSERT0(dn->dn_next_blksz[i]);
ASSERT0(dn->dn_next_maxblkid[i]);
ASSERT(!multilist_link_active(&dn->dn_dirty_link[i]));
ASSERT3P(list_head(&dn->dn_dirty_records[i]), ==, NULL);
ASSERT3P(dn->dn_free_ranges[i], ==, NULL);
}
dn->dn_type = ot;
dnode_setdblksz(dn, blocksize);
dn->dn_indblkshift = ibs;
dn->dn_nlevels = 1;
dn->dn_num_slots = dn_slots;
if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */
dn->dn_nblkptr = 1;
else {
dn->dn_nblkptr = MIN(DN_MAX_NBLKPTR,
1 + ((DN_SLOTS_TO_BONUSLEN(dn_slots) - bonuslen) >>
SPA_BLKPTRSHIFT));
}
dn->dn_bonustype = bonustype;
dn->dn_bonuslen = bonuslen;
dn->dn_checksum = ZIO_CHECKSUM_INHERIT;
dn->dn_compress = ZIO_COMPRESS_INHERIT;
dn->dn_dirtyctx = 0;
dn->dn_free_txg = 0;
dn->dn_dirtyctx_firstset = NULL;
dn->dn_dirty_txg = 0;
dn->dn_allocated_txg = tx->tx_txg;
dn->dn_id_flags = 0;
dnode_setdirty(dn, tx);
dn->dn_next_indblkshift[tx->tx_txg & TXG_MASK] = ibs;
dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = dn->dn_bonuslen;
dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = dn->dn_bonustype;
dn->dn_next_blksz[tx->tx_txg & TXG_MASK] = dn->dn_datablksz;
}
void
dnode_reallocate(dnode_t *dn, dmu_object_type_t ot, int blocksize,
dmu_object_type_t bonustype, int bonuslen, int dn_slots,
boolean_t keep_spill, dmu_tx_t *tx)
{
int nblkptr;
ASSERT3U(blocksize, >=, SPA_MINBLOCKSIZE);
ASSERT3U(blocksize, <=,
spa_maxblocksize(dmu_objset_spa(dn->dn_objset)));
ASSERT0(blocksize % SPA_MINBLOCKSIZE);
ASSERT(dn->dn_object != DMU_META_DNODE_OBJECT || dmu_tx_private_ok(tx));
ASSERT(tx->tx_txg != 0);
ASSERT((bonustype == DMU_OT_NONE && bonuslen == 0) ||
(bonustype != DMU_OT_NONE && bonuslen != 0) ||
(bonustype == DMU_OT_SA && bonuslen == 0));
ASSERT(DMU_OT_IS_VALID(bonustype));
ASSERT3U(bonuslen, <=,
DN_BONUS_SIZE(spa_maxdnodesize(dmu_objset_spa(dn->dn_objset))));
ASSERT3U(bonuslen, <=, DN_BONUS_SIZE(dn_slots << DNODE_SHIFT));
dnode_free_interior_slots(dn);
DNODE_STAT_BUMP(dnode_reallocate);
/* clean up any unreferenced dbufs */
dnode_evict_dbufs(dn);
dn->dn_id_flags = 0;
rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
dnode_setdirty(dn, tx);
if (dn->dn_datablksz != blocksize) {
/* change blocksize */
ASSERT0(dn->dn_maxblkid);
ASSERT(BP_IS_HOLE(&dn->dn_phys->dn_blkptr[0]) ||
dnode_block_freed(dn, 0));
dnode_setdblksz(dn, blocksize);
dn->dn_next_blksz[tx->tx_txg & TXG_MASK] = blocksize;
}
if (dn->dn_bonuslen != bonuslen)
dn->dn_next_bonuslen[tx->tx_txg & TXG_MASK] = bonuslen;
if (bonustype == DMU_OT_SA) /* Maximize bonus space for SA */
nblkptr = 1;
else
nblkptr = MIN(DN_MAX_NBLKPTR,
1 + ((DN_SLOTS_TO_BONUSLEN(dn_slots) - bonuslen) >>
SPA_BLKPTRSHIFT));
if (dn->dn_bonustype != bonustype)
dn->dn_next_bonustype[tx->tx_txg & TXG_MASK] = bonustype;
if (dn->dn_nblkptr != nblkptr)
dn->dn_next_nblkptr[tx->tx_txg & TXG_MASK] = nblkptr;
if (dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR && !keep_spill) {
dbuf_rm_spill(dn, tx);
dnode_rm_spill(dn, tx);
}
rw_exit(&dn->dn_struct_rwlock);
/* change type */
dn->dn_type = ot;
/* change bonus size and type */
mutex_enter(&dn->dn_mtx);
dn->dn_bonustype = bonustype;
dn->dn_bonuslen = bonuslen;
dn->dn_num_slots = dn_slots;
dn->dn_nblkptr = nblkptr;
dn->dn_checksum = ZIO_CHECKSUM_INHERIT;
dn->dn_compress = ZIO_COMPRESS_INHERIT;
ASSERT3U(dn->dn_nblkptr, <=, DN_MAX_NBLKPTR);
/* fix up the bonus db_size */
if (dn->dn_bonus) {
dn->dn_bonus->db.db_size =
DN_SLOTS_TO_BONUSLEN(dn->dn_num_slots) -
(dn->dn_nblkptr-1) * sizeof (blkptr_t);
ASSERT(dn->dn_bonuslen <= dn->dn_bonus->db.db_size);
}
dn->dn_allocated_txg = tx->tx_txg;
mutex_exit(&dn->dn_mtx);
}
#ifdef _KERNEL
static void
dnode_move_impl(dnode_t *odn, dnode_t *ndn)
{
ASSERT(!RW_LOCK_HELD(&odn->dn_struct_rwlock));
ASSERT(MUTEX_NOT_HELD(&odn->dn_mtx));
ASSERT(MUTEX_NOT_HELD(&odn->dn_dbufs_mtx));
/* Copy fields. */
ndn->dn_objset = odn->dn_objset;
ndn->dn_object = odn->dn_object;
ndn->dn_dbuf = odn->dn_dbuf;
ndn->dn_handle = odn->dn_handle;
ndn->dn_phys = odn->dn_phys;
ndn->dn_type = odn->dn_type;
ndn->dn_bonuslen = odn->dn_bonuslen;
ndn->dn_bonustype = odn->dn_bonustype;
ndn->dn_nblkptr = odn->dn_nblkptr;
ndn->dn_checksum = odn->dn_checksum;
ndn->dn_compress = odn->dn_compress;
ndn->dn_nlevels = odn->dn_nlevels;
ndn->dn_indblkshift = odn->dn_indblkshift;
ndn->dn_datablkshift = odn->dn_datablkshift;
ndn->dn_datablkszsec = odn->dn_datablkszsec;
ndn->dn_datablksz = odn->dn_datablksz;
ndn->dn_maxblkid = odn->dn_maxblkid;
ndn->dn_num_slots = odn->dn_num_slots;
memcpy(ndn->dn_next_type, odn->dn_next_type,
sizeof (odn->dn_next_type));
memcpy(ndn->dn_next_nblkptr, odn->dn_next_nblkptr,
sizeof (odn->dn_next_nblkptr));
memcpy(ndn->dn_next_nlevels, odn->dn_next_nlevels,
sizeof (odn->dn_next_nlevels));
memcpy(ndn->dn_next_indblkshift, odn->dn_next_indblkshift,
sizeof (odn->dn_next_indblkshift));
memcpy(ndn->dn_next_bonustype, odn->dn_next_bonustype,
sizeof (odn->dn_next_bonustype));
memcpy(ndn->dn_rm_spillblk, odn->dn_rm_spillblk,
sizeof (odn->dn_rm_spillblk));
memcpy(ndn->dn_next_bonuslen, odn->dn_next_bonuslen,
sizeof (odn->dn_next_bonuslen));
memcpy(ndn->dn_next_blksz, odn->dn_next_blksz,
sizeof (odn->dn_next_blksz));
memcpy(ndn->dn_next_maxblkid, odn->dn_next_maxblkid,
sizeof (odn->dn_next_maxblkid));
for (int i = 0; i < TXG_SIZE; i++) {
list_move_tail(&ndn->dn_dirty_records[i],
&odn->dn_dirty_records[i]);
}
memcpy(ndn->dn_free_ranges, odn->dn_free_ranges,
sizeof (odn->dn_free_ranges));
ndn->dn_allocated_txg = odn->dn_allocated_txg;
ndn->dn_free_txg = odn->dn_free_txg;
ndn->dn_assigned_txg = odn->dn_assigned_txg;
ndn->dn_dirty_txg = odn->dn_dirty_txg;
ndn->dn_dirtyctx = odn->dn_dirtyctx;
ndn->dn_dirtyctx_firstset = odn->dn_dirtyctx_firstset;
ASSERT(zfs_refcount_count(&odn->dn_tx_holds) == 0);
zfs_refcount_transfer(&ndn->dn_holds, &odn->dn_holds);
ASSERT(avl_is_empty(&ndn->dn_dbufs));
avl_swap(&ndn->dn_dbufs, &odn->dn_dbufs);
ndn->dn_dbufs_count = odn->dn_dbufs_count;
ndn->dn_bonus = odn->dn_bonus;
ndn->dn_have_spill = odn->dn_have_spill;
ndn->dn_zio = odn->dn_zio;
ndn->dn_oldused = odn->dn_oldused;
ndn->dn_oldflags = odn->dn_oldflags;
ndn->dn_olduid = odn->dn_olduid;
ndn->dn_oldgid = odn->dn_oldgid;
ndn->dn_oldprojid = odn->dn_oldprojid;
ndn->dn_newuid = odn->dn_newuid;
ndn->dn_newgid = odn->dn_newgid;
ndn->dn_newprojid = odn->dn_newprojid;
ndn->dn_id_flags = odn->dn_id_flags;
dmu_zfetch_init(&ndn->dn_zfetch, ndn);
/*
* Update back pointers. Updating the handle fixes the back pointer of
* every descendant dbuf as well as the bonus dbuf.
*/
ASSERT(ndn->dn_handle->dnh_dnode == odn);
ndn->dn_handle->dnh_dnode = ndn;
/*
* Invalidate the original dnode by clearing all of its back pointers.
*/
odn->dn_dbuf = NULL;
odn->dn_handle = NULL;
avl_create(&odn->dn_dbufs, dbuf_compare, sizeof (dmu_buf_impl_t),
offsetof(dmu_buf_impl_t, db_link));
odn->dn_dbufs_count = 0;
odn->dn_bonus = NULL;
dmu_zfetch_fini(&odn->dn_zfetch);
/*
* Set the low bit of the objset pointer to ensure that dnode_move()
* recognizes the dnode as invalid in any subsequent callback.
*/
POINTER_INVALIDATE(&odn->dn_objset);
/*
* Satisfy the destructor.
*/
for (int i = 0; i < TXG_SIZE; i++) {
list_create(&odn->dn_dirty_records[i],
sizeof (dbuf_dirty_record_t),
offsetof(dbuf_dirty_record_t, dr_dirty_node));
odn->dn_free_ranges[i] = NULL;
odn->dn_next_nlevels[i] = 0;
odn->dn_next_indblkshift[i] = 0;
odn->dn_next_bonustype[i] = 0;
odn->dn_rm_spillblk[i] = 0;
odn->dn_next_bonuslen[i] = 0;
odn->dn_next_blksz[i] = 0;
}
odn->dn_allocated_txg = 0;
odn->dn_free_txg = 0;
odn->dn_assigned_txg = 0;
odn->dn_dirty_txg = 0;
odn->dn_dirtyctx = 0;
odn->dn_dirtyctx_firstset = NULL;
odn->dn_have_spill = B_FALSE;
odn->dn_zio = NULL;
odn->dn_oldused = 0;
odn->dn_oldflags = 0;
odn->dn_olduid = 0;
odn->dn_oldgid = 0;
odn->dn_oldprojid = ZFS_DEFAULT_PROJID;
odn->dn_newuid = 0;
odn->dn_newgid = 0;
odn->dn_newprojid = ZFS_DEFAULT_PROJID;
odn->dn_id_flags = 0;
/*
* Mark the dnode.
*/
ndn->dn_moved = 1;
odn->dn_moved = (uint8_t)-1;
}
static kmem_cbrc_t
dnode_move(void *buf, void *newbuf, size_t size, void *arg)
{
dnode_t *odn = buf, *ndn = newbuf;
objset_t *os;
int64_t refcount;
uint32_t dbufs;
/*
* The dnode is on the objset's list of known dnodes if the objset
* pointer is valid. We set the low bit of the objset pointer when
* freeing the dnode to invalidate it, and the memory patterns written
* by kmem (baddcafe and deadbeef) set at least one of the two low bits.
* A newly created dnode sets the objset pointer last of all to indicate
* that the dnode is known and in a valid state to be moved by this
* function.
*/
os = odn->dn_objset;
if (!POINTER_IS_VALID(os)) {
DNODE_STAT_BUMP(dnode_move_invalid);
return (KMEM_CBRC_DONT_KNOW);
}
/*
* Ensure that the objset does not go away during the move.
*/
rw_enter(&os_lock, RW_WRITER);
if (os != odn->dn_objset) {
rw_exit(&os_lock);
DNODE_STAT_BUMP(dnode_move_recheck1);
return (KMEM_CBRC_DONT_KNOW);
}
/*
* If the dnode is still valid, then so is the objset. We know that no
* valid objset can be freed while we hold os_lock, so we can safely
* ensure that the objset remains in use.
*/
mutex_enter(&os->os_lock);
/*
* Recheck the objset pointer in case the dnode was removed just before
* acquiring the lock.
*/
if (os != odn->dn_objset) {
mutex_exit(&os->os_lock);
rw_exit(&os_lock);
DNODE_STAT_BUMP(dnode_move_recheck2);
return (KMEM_CBRC_DONT_KNOW);
}
/*
* At this point we know that as long as we hold os->os_lock, the dnode
* cannot be freed and fields within the dnode can be safely accessed.
* The objset listing this dnode cannot go away as long as this dnode is
* on its list.
*/
rw_exit(&os_lock);
if (DMU_OBJECT_IS_SPECIAL(odn->dn_object)) {
mutex_exit(&os->os_lock);
DNODE_STAT_BUMP(dnode_move_special);
return (KMEM_CBRC_NO);
}
ASSERT(odn->dn_dbuf != NULL); /* only "special" dnodes have no parent */
/*
* Lock the dnode handle to prevent the dnode from obtaining any new
* holds. This also prevents the descendant dbufs and the bonus dbuf
* from accessing the dnode, so that we can discount their holds. The
* handle is safe to access because we know that while the dnode cannot
* go away, neither can its handle. Once we hold dnh_zrlock, we can
* safely move any dnode referenced only by dbufs.
*/
if (!zrl_tryenter(&odn->dn_handle->dnh_zrlock)) {
mutex_exit(&os->os_lock);
DNODE_STAT_BUMP(dnode_move_handle);
return (KMEM_CBRC_LATER);
}
/*
* Ensure a consistent view of the dnode's holds and the dnode's dbufs.
* We need to guarantee that there is a hold for every dbuf in order to
* determine whether the dnode is actively referenced. Falsely matching
* a dbuf to an active hold would lead to an unsafe move. It's possible
* that a thread already having an active dnode hold is about to add a
* dbuf, and we can't compare hold and dbuf counts while the add is in
* progress.
*/
if (!rw_tryenter(&odn->dn_struct_rwlock, RW_WRITER)) {
zrl_exit(&odn->dn_handle->dnh_zrlock);
mutex_exit(&os->os_lock);
DNODE_STAT_BUMP(dnode_move_rwlock);
return (KMEM_CBRC_LATER);
}
/*
* A dbuf may be removed (evicted) without an active dnode hold. In that
* case, the dbuf count is decremented under the handle lock before the
* dbuf's hold is released. This order ensures that if we count the hold
* after the dbuf is removed but before its hold is released, we will
* treat the unmatched hold as active and exit safely. If we count the
* hold before the dbuf is removed, the hold is discounted, and the
* removal is blocked until the move completes.
*/
refcount = zfs_refcount_count(&odn->dn_holds);
ASSERT(refcount >= 0);
dbufs = DN_DBUFS_COUNT(odn);
/* We can't have more dbufs than dnode holds. */
ASSERT3U(dbufs, <=, refcount);
DTRACE_PROBE3(dnode__move, dnode_t *, odn, int64_t, refcount,
uint32_t, dbufs);
if (refcount > dbufs) {
rw_exit(&odn->dn_struct_rwlock);
zrl_exit(&odn->dn_handle->dnh_zrlock);
mutex_exit(&os->os_lock);
DNODE_STAT_BUMP(dnode_move_active);
return (KMEM_CBRC_LATER);
}
rw_exit(&odn->dn_struct_rwlock);
/*
* At this point we know that anyone with a hold on the dnode is not
* actively referencing it. The dnode is known and in a valid state to
* move. We're holding the locks needed to execute the critical section.
*/
dnode_move_impl(odn, ndn);
list_link_replace(&odn->dn_link, &ndn->dn_link);
/* If the dnode was safe to move, the refcount cannot have changed. */
ASSERT(refcount == zfs_refcount_count(&ndn->dn_holds));
ASSERT(dbufs == DN_DBUFS_COUNT(ndn));
zrl_exit(&ndn->dn_handle->dnh_zrlock); /* handle has moved */
mutex_exit(&os->os_lock);
return (KMEM_CBRC_YES);
}
#endif /* _KERNEL */
static void
dnode_slots_hold(dnode_children_t *children, int idx, int slots)
{
ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK);
for (int i = idx; i < idx + slots; i++) {
dnode_handle_t *dnh = &children->dnc_children[i];
zrl_add(&dnh->dnh_zrlock);
}
}
static void
dnode_slots_rele(dnode_children_t *children, int idx, int slots)
{
ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK);
for (int i = idx; i < idx + slots; i++) {
dnode_handle_t *dnh = &children->dnc_children[i];
if (zrl_is_locked(&dnh->dnh_zrlock))
zrl_exit(&dnh->dnh_zrlock);
else
zrl_remove(&dnh->dnh_zrlock);
}
}
static int
dnode_slots_tryenter(dnode_children_t *children, int idx, int slots)
{
ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK);
for (int i = idx; i < idx + slots; i++) {
dnode_handle_t *dnh = &children->dnc_children[i];
if (!zrl_tryenter(&dnh->dnh_zrlock)) {
for (int j = idx; j < i; j++) {
dnh = &children->dnc_children[j];
zrl_exit(&dnh->dnh_zrlock);
}
return (0);
}
}
return (1);
}
static void
dnode_set_slots(dnode_children_t *children, int idx, int slots, void *ptr)
{
ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK);
for (int i = idx; i < idx + slots; i++) {
dnode_handle_t *dnh = &children->dnc_children[i];
dnh->dnh_dnode = ptr;
}
}
static boolean_t
dnode_check_slots_free(dnode_children_t *children, int idx, int slots)
{
ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK);
/*
* If all dnode slots are either already free or
* evictable return B_TRUE.
*/
for (int i = idx; i < idx + slots; i++) {
dnode_handle_t *dnh = &children->dnc_children[i];
dnode_t *dn = dnh->dnh_dnode;
if (dn == DN_SLOT_FREE) {
continue;
} else if (DN_SLOT_IS_PTR(dn)) {
mutex_enter(&dn->dn_mtx);
boolean_t can_free = (dn->dn_type == DMU_OT_NONE &&
zfs_refcount_is_zero(&dn->dn_holds) &&
!DNODE_IS_DIRTY(dn));
mutex_exit(&dn->dn_mtx);
if (!can_free)
return (B_FALSE);
else
continue;
} else {
return (B_FALSE);
}
}
return (B_TRUE);
}
static uint_t
dnode_reclaim_slots(dnode_children_t *children, int idx, int slots)
{
uint_t reclaimed = 0;
ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK);
for (int i = idx; i < idx + slots; i++) {
dnode_handle_t *dnh = &children->dnc_children[i];
ASSERT(zrl_is_locked(&dnh->dnh_zrlock));
if (DN_SLOT_IS_PTR(dnh->dnh_dnode)) {
ASSERT3S(dnh->dnh_dnode->dn_type, ==, DMU_OT_NONE);
dnode_destroy(dnh->dnh_dnode);
dnh->dnh_dnode = DN_SLOT_FREE;
reclaimed++;
}
}
return (reclaimed);
}
void
dnode_free_interior_slots(dnode_t *dn)
{
dnode_children_t *children = dmu_buf_get_user(&dn->dn_dbuf->db);
int epb = dn->dn_dbuf->db.db_size >> DNODE_SHIFT;
int idx = (dn->dn_object & (epb - 1)) + 1;
int slots = dn->dn_num_slots - 1;
if (slots == 0)
return;
ASSERT3S(idx + slots, <=, DNODES_PER_BLOCK);
while (!dnode_slots_tryenter(children, idx, slots)) {
DNODE_STAT_BUMP(dnode_free_interior_lock_retry);
kpreempt(KPREEMPT_SYNC);
}
dnode_set_slots(children, idx, slots, DN_SLOT_FREE);
dnode_slots_rele(children, idx, slots);
}
void
dnode_special_close(dnode_handle_t *dnh)
{
dnode_t *dn = dnh->dnh_dnode;
/*
* Ensure dnode_rele_and_unlock() has released dn_mtx, after final
* zfs_refcount_remove()
*/
mutex_enter(&dn->dn_mtx);
if (zfs_refcount_count(&dn->dn_holds) > 0)
cv_wait(&dn->dn_nodnholds, &dn->dn_mtx);
mutex_exit(&dn->dn_mtx);
ASSERT3U(zfs_refcount_count(&dn->dn_holds), ==, 0);
ASSERT(dn->dn_dbuf == NULL ||
dmu_buf_get_user(&dn->dn_dbuf->db) == NULL);
zrl_add(&dnh->dnh_zrlock);
dnode_destroy(dn); /* implicit zrl_remove() */
zrl_destroy(&dnh->dnh_zrlock);
dnh->dnh_dnode = NULL;
}
void
dnode_special_open(objset_t *os, dnode_phys_t *dnp, uint64_t object,
dnode_handle_t *dnh)
{
dnode_t *dn;
zrl_init(&dnh->dnh_zrlock);
VERIFY3U(1, ==, zrl_tryenter(&dnh->dnh_zrlock));
dn = dnode_create(os, dnp, NULL, object, dnh);
DNODE_VERIFY(dn);
zrl_exit(&dnh->dnh_zrlock);
}
static void
dnode_buf_evict_async(void *dbu)
{
dnode_children_t *dnc = dbu;
DNODE_STAT_BUMP(dnode_buf_evict);
for (int i = 0; i < dnc->dnc_count; i++) {
dnode_handle_t *dnh = &dnc->dnc_children[i];
dnode_t *dn;
/*
* The dnode handle lock guards against the dnode moving to
* another valid address, so there is no need here to guard
* against changes to or from NULL.
*/
if (!DN_SLOT_IS_PTR(dnh->dnh_dnode)) {
zrl_destroy(&dnh->dnh_zrlock);
dnh->dnh_dnode = DN_SLOT_UNINIT;
continue;
}
zrl_add(&dnh->dnh_zrlock);
dn = dnh->dnh_dnode;
/*
* If there are holds on this dnode, then there should
* be holds on the dnode's containing dbuf as well; thus
* it wouldn't be eligible for eviction and this function
* would not have been called.
*/
ASSERT(zfs_refcount_is_zero(&dn->dn_holds));
ASSERT(zfs_refcount_is_zero(&dn->dn_tx_holds));
dnode_destroy(dn); /* implicit zrl_remove() for first slot */
zrl_destroy(&dnh->dnh_zrlock);
dnh->dnh_dnode = DN_SLOT_UNINIT;
}
kmem_free(dnc, sizeof (dnode_children_t) +
dnc->dnc_count * sizeof (dnode_handle_t));
}
/*
* When the DNODE_MUST_BE_FREE flag is set, the "slots" parameter is used
* to ensure the hole at the specified object offset is large enough to
* hold the dnode being created. The slots parameter is also used to ensure
* a dnode does not span multiple dnode blocks. In both of these cases, if
* a failure occurs, ENOSPC is returned. Keep in mind, these failure cases
* are only possible when using DNODE_MUST_BE_FREE.
*
* If the DNODE_MUST_BE_ALLOCATED flag is set, "slots" must be 0.
* dnode_hold_impl() will check if the requested dnode is already consumed
* as an extra dnode slot by an large dnode, in which case it returns
* ENOENT.
*
* If the DNODE_DRY_RUN flag is set, we don't actually hold the dnode, just
* return whether the hold would succeed or not. tag and dnp should set to
* NULL in this case.
*
* errors:
* EINVAL - Invalid object number or flags.
* ENOSPC - Hole too small to fulfill "slots" request (DNODE_MUST_BE_FREE)
* EEXIST - Refers to an allocated dnode (DNODE_MUST_BE_FREE)
* - Refers to a freeing dnode (DNODE_MUST_BE_FREE)
* - Refers to an interior dnode slot (DNODE_MUST_BE_ALLOCATED)
* ENOENT - The requested dnode is not allocated (DNODE_MUST_BE_ALLOCATED)
* - The requested dnode is being freed (DNODE_MUST_BE_ALLOCATED)
* EIO - I/O error when reading the meta dnode dbuf.
*
* succeeds even for free dnodes.
*/
int
dnode_hold_impl(objset_t *os, uint64_t object, int flag, int slots,
const void *tag, dnode_t **dnp)
{
int epb, idx, err;
int drop_struct_lock = FALSE;
int type;
uint64_t blk;
dnode_t *mdn, *dn;
dmu_buf_impl_t *db;
dnode_children_t *dnc;
dnode_phys_t *dn_block;
dnode_handle_t *dnh;
ASSERT(!(flag & DNODE_MUST_BE_ALLOCATED) || (slots == 0));
ASSERT(!(flag & DNODE_MUST_BE_FREE) || (slots > 0));
IMPLY(flag & DNODE_DRY_RUN, (tag == NULL) && (dnp == NULL));
/*
* If you are holding the spa config lock as writer, you shouldn't
* be asking the DMU to do *anything* unless it's the root pool
* which may require us to read from the root filesystem while
* holding some (not all) of the locks as writer.
*/
ASSERT(spa_config_held(os->os_spa, SCL_ALL, RW_WRITER) == 0 ||
(spa_is_root(os->os_spa) &&
spa_config_held(os->os_spa, SCL_STATE, RW_WRITER)));
ASSERT((flag & DNODE_MUST_BE_ALLOCATED) || (flag & DNODE_MUST_BE_FREE));
if (object == DMU_USERUSED_OBJECT || object == DMU_GROUPUSED_OBJECT ||
object == DMU_PROJECTUSED_OBJECT) {
if (object == DMU_USERUSED_OBJECT)
dn = DMU_USERUSED_DNODE(os);
else if (object == DMU_GROUPUSED_OBJECT)
dn = DMU_GROUPUSED_DNODE(os);
else
dn = DMU_PROJECTUSED_DNODE(os);
if (dn == NULL)
return (SET_ERROR(ENOENT));
type = dn->dn_type;
if ((flag & DNODE_MUST_BE_ALLOCATED) && type == DMU_OT_NONE)
return (SET_ERROR(ENOENT));
if ((flag & DNODE_MUST_BE_FREE) && type != DMU_OT_NONE)
return (SET_ERROR(EEXIST));
DNODE_VERIFY(dn);
/* Don't actually hold if dry run, just return 0 */
if (!(flag & DNODE_DRY_RUN)) {
(void) zfs_refcount_add(&dn->dn_holds, tag);
*dnp = dn;
}
return (0);
}
if (object == 0 || object >= DN_MAX_OBJECT)
return (SET_ERROR(EINVAL));
mdn = DMU_META_DNODE(os);
ASSERT(mdn->dn_object == DMU_META_DNODE_OBJECT);
DNODE_VERIFY(mdn);
if (!RW_WRITE_HELD(&mdn->dn_struct_rwlock)) {
rw_enter(&mdn->dn_struct_rwlock, RW_READER);
drop_struct_lock = TRUE;
}
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);
if (db == NULL) {
DNODE_STAT_BUMP(dnode_hold_dbuf_hold);
return (SET_ERROR(EIO));
}
/*
* We do not need to decrypt to read the dnode so it doesn't matter
* if we get the encrypted or decrypted version.
*/
err = dbuf_read(db, NULL, DB_RF_CANFAIL |
DB_RF_NO_DECRYPT | DB_RF_NOPREFETCH);
if (err) {
DNODE_STAT_BUMP(dnode_hold_dbuf_read);
dbuf_rele(db, FTAG);
return (err);
}
ASSERT3U(db->db.db_size, >=, 1<<DNODE_SHIFT);
epb = db->db.db_size >> DNODE_SHIFT;
idx = object & (epb - 1);
dn_block = (dnode_phys_t *)db->db.db_data;
ASSERT(DB_DNODE(db)->dn_type == DMU_OT_DNODE);
dnc = dmu_buf_get_user(&db->db);
dnh = NULL;
if (dnc == NULL) {
dnode_children_t *winner;
int skip = 0;
dnc = kmem_zalloc(sizeof (dnode_children_t) +
epb * sizeof (dnode_handle_t), KM_SLEEP);
dnc->dnc_count = epb;
dnh = &dnc->dnc_children[0];
/* Initialize dnode slot status from dnode_phys_t */
for (int i = 0; i < epb; i++) {
zrl_init(&dnh[i].dnh_zrlock);
if (skip) {
skip--;
continue;
}
if (dn_block[i].dn_type != DMU_OT_NONE) {
int interior = dn_block[i].dn_extra_slots;
dnode_set_slots(dnc, i, 1, DN_SLOT_ALLOCATED);
dnode_set_slots(dnc, i + 1, interior,
DN_SLOT_INTERIOR);
skip = interior;
} else {
dnh[i].dnh_dnode = DN_SLOT_FREE;
skip = 0;
}
}
dmu_buf_init_user(&dnc->dnc_dbu, NULL,
dnode_buf_evict_async, NULL);
winner = dmu_buf_set_user(&db->db, &dnc->dnc_dbu);
if (winner != NULL) {
for (int i = 0; i < epb; i++)
zrl_destroy(&dnh[i].dnh_zrlock);
kmem_free(dnc, sizeof (dnode_children_t) +
epb * sizeof (dnode_handle_t));
dnc = winner;
}
}
ASSERT(dnc->dnc_count == epb);
if (flag & DNODE_MUST_BE_ALLOCATED) {
slots = 1;
dnode_slots_hold(dnc, idx, slots);
dnh = &dnc->dnc_children[idx];
if (DN_SLOT_IS_PTR(dnh->dnh_dnode)) {
dn = dnh->dnh_dnode;
} else if (dnh->dnh_dnode == DN_SLOT_INTERIOR) {
DNODE_STAT_BUMP(dnode_hold_alloc_interior);
dnode_slots_rele(dnc, idx, slots);
dbuf_rele(db, FTAG);
return (SET_ERROR(EEXIST));
} else if (dnh->dnh_dnode != DN_SLOT_ALLOCATED) {
DNODE_STAT_BUMP(dnode_hold_alloc_misses);
dnode_slots_rele(dnc, idx, slots);
dbuf_rele(db, FTAG);
return (SET_ERROR(ENOENT));
} else {
dnode_slots_rele(dnc, idx, slots);
while (!dnode_slots_tryenter(dnc, idx, slots)) {
DNODE_STAT_BUMP(dnode_hold_alloc_lock_retry);
kpreempt(KPREEMPT_SYNC);
}
/*
* Someone else won the race and called dnode_create()
* after we checked DN_SLOT_IS_PTR() above but before
* we acquired the lock.
*/
if (DN_SLOT_IS_PTR(dnh->dnh_dnode)) {
DNODE_STAT_BUMP(dnode_hold_alloc_lock_misses);
dn = dnh->dnh_dnode;
} else {
dn = dnode_create(os, dn_block + idx, db,
object, dnh);
dmu_buf_add_user_size(&db->db,
sizeof (dnode_t));
}
}
mutex_enter(&dn->dn_mtx);
if (dn->dn_type == DMU_OT_NONE || dn->dn_free_txg != 0) {
DNODE_STAT_BUMP(dnode_hold_alloc_type_none);
mutex_exit(&dn->dn_mtx);
dnode_slots_rele(dnc, idx, slots);
dbuf_rele(db, FTAG);
return (SET_ERROR(ENOENT));
}
/* Don't actually hold if dry run, just return 0 */
if (flag & DNODE_DRY_RUN) {
mutex_exit(&dn->dn_mtx);
dnode_slots_rele(dnc, idx, slots);
dbuf_rele(db, FTAG);
return (0);
}
DNODE_STAT_BUMP(dnode_hold_alloc_hits);
} else if (flag & DNODE_MUST_BE_FREE) {
if (idx + slots - 1 >= DNODES_PER_BLOCK) {
DNODE_STAT_BUMP(dnode_hold_free_overflow);
dbuf_rele(db, FTAG);
return (SET_ERROR(ENOSPC));
}
dnode_slots_hold(dnc, idx, slots);
if (!dnode_check_slots_free(dnc, idx, slots)) {
DNODE_STAT_BUMP(dnode_hold_free_misses);
dnode_slots_rele(dnc, idx, slots);
dbuf_rele(db, FTAG);
return (SET_ERROR(ENOSPC));
}
dnode_slots_rele(dnc, idx, slots);
while (!dnode_slots_tryenter(dnc, idx, slots)) {
DNODE_STAT_BUMP(dnode_hold_free_lock_retry);
kpreempt(KPREEMPT_SYNC);
}
if (!dnode_check_slots_free(dnc, idx, slots)) {
DNODE_STAT_BUMP(dnode_hold_free_lock_misses);
dnode_slots_rele(dnc, idx, slots);
dbuf_rele(db, FTAG);
return (SET_ERROR(ENOSPC));
}
/*
* Allocated but otherwise free dnodes which would
* be in the interior of a multi-slot dnodes need
* to be freed. Single slot dnodes can be safely
* re-purposed as a performance optimization.
*/
if (slots > 1) {
uint_t reclaimed =
dnode_reclaim_slots(dnc, idx + 1, slots - 1);
if (reclaimed > 0)
dmu_buf_sub_user_size(&db->db,
reclaimed * sizeof (dnode_t));
}
dnh = &dnc->dnc_children[idx];
if (DN_SLOT_IS_PTR(dnh->dnh_dnode)) {
dn = dnh->dnh_dnode;
} else {
dn = dnode_create(os, dn_block + idx, db,
object, dnh);
dmu_buf_add_user_size(&db->db, sizeof (dnode_t));
}
mutex_enter(&dn->dn_mtx);
if (!zfs_refcount_is_zero(&dn->dn_holds) || dn->dn_free_txg) {
DNODE_STAT_BUMP(dnode_hold_free_refcount);
mutex_exit(&dn->dn_mtx);
dnode_slots_rele(dnc, idx, slots);
dbuf_rele(db, FTAG);
return (SET_ERROR(EEXIST));
}
/* Don't actually hold if dry run, just return 0 */
if (flag & DNODE_DRY_RUN) {
mutex_exit(&dn->dn_mtx);
dnode_slots_rele(dnc, idx, slots);
dbuf_rele(db, FTAG);
return (0);
}
dnode_set_slots(dnc, idx + 1, slots - 1, DN_SLOT_INTERIOR);
DNODE_STAT_BUMP(dnode_hold_free_hits);
} else {
dbuf_rele(db, FTAG);
return (SET_ERROR(EINVAL));
}
ASSERT0(dn->dn_free_txg);
if (zfs_refcount_add(&dn->dn_holds, tag) == 1)
dbuf_add_ref(db, dnh);
mutex_exit(&dn->dn_mtx);
/* Now we can rely on the hold to prevent the dnode from moving. */
dnode_slots_rele(dnc, idx, slots);
DNODE_VERIFY(dn);
ASSERT3P(dnp, !=, NULL);
ASSERT3P(dn->dn_dbuf, ==, db);
ASSERT3U(dn->dn_object, ==, object);
dbuf_rele(db, FTAG);
*dnp = dn;
return (0);
}
/*
* Return held dnode if the object is allocated, NULL if not.
*/
int
dnode_hold(objset_t *os, uint64_t object, const void *tag, dnode_t **dnp)
{
return (dnode_hold_impl(os, object, DNODE_MUST_BE_ALLOCATED, 0, tag,
dnp));
}
/*
* Can only add a reference if there is already at least one
* reference on the dnode. Returns FALSE if unable to add a
* new reference.
*/
boolean_t
dnode_add_ref(dnode_t *dn, const void *tag)
{
mutex_enter(&dn->dn_mtx);
if (zfs_refcount_is_zero(&dn->dn_holds)) {
mutex_exit(&dn->dn_mtx);
return (FALSE);
}
VERIFY(1 < zfs_refcount_add(&dn->dn_holds, tag));
mutex_exit(&dn->dn_mtx);
return (TRUE);
}
void
dnode_rele(dnode_t *dn, const void *tag)
{
mutex_enter(&dn->dn_mtx);
dnode_rele_and_unlock(dn, tag, B_FALSE);
}
void
dnode_rele_and_unlock(dnode_t *dn, const void *tag, boolean_t evicting)
{
uint64_t refs;
/* Get while the hold prevents the dnode from moving. */
dmu_buf_impl_t *db = dn->dn_dbuf;
dnode_handle_t *dnh = dn->dn_handle;
refs = zfs_refcount_remove(&dn->dn_holds, tag);
if (refs == 0)
cv_broadcast(&dn->dn_nodnholds);
mutex_exit(&dn->dn_mtx);
/* dnode could get destroyed at this point, so don't use it anymore */
/*
* It's unsafe to release the last hold on a dnode by dnode_rele() or
* indirectly by dbuf_rele() while relying on the dnode handle to
* prevent the dnode from moving, since releasing the last hold could
* result in the dnode's parent dbuf evicting its dnode handles. For
* that reason anyone calling dnode_rele() or dbuf_rele() without some
* other direct or indirect hold on the dnode must first drop the dnode
* handle.
*/
#ifdef ZFS_DEBUG
ASSERT(refs > 0 || zrl_owner(&dnh->dnh_zrlock) != curthread);
#endif
/* NOTE: the DNODE_DNODE does not have a dn_dbuf */
if (refs == 0 && db != NULL) {
/*
* Another thread could add a hold to the dnode handle in
* dnode_hold_impl() while holding the parent dbuf. Since the
* hold on the parent dbuf prevents the handle from being
* destroyed, the hold on the handle is OK. We can't yet assert
* that the handle has zero references, but that will be
* asserted anyway when the handle gets destroyed.
*/
mutex_enter(&db->db_mtx);
dbuf_rele_and_unlock(db, dnh, evicting);
}
}
/*
* Test whether we can create a dnode at the specified location.
*/
int
dnode_try_claim(objset_t *os, uint64_t object, int slots)
{
return (dnode_hold_impl(os, object, DNODE_MUST_BE_FREE | DNODE_DRY_RUN,
slots, NULL, NULL));
}
/*
* Checks if the dnode itself is dirty, or is carrying any uncommitted records.
* It is important to check both conditions, as some operations (eg appending
* to a file) can dirty both as a single logical unit, but they are not synced
* out atomically, so checking one and not the other can result in an object
* appearing to be clean mid-way through a commit.
*
* Do not change this lightly! If you get it wrong, dmu_offset_next() can
* detect a hole where there is really data, leading to silent corruption.
*/
boolean_t
dnode_is_dirty(dnode_t *dn)
{
mutex_enter(&dn->dn_mtx);
for (int i = 0; i < TXG_SIZE; i++) {
if (multilist_link_active(&dn->dn_dirty_link[i]) ||
!list_is_empty(&dn->dn_dirty_records[i])) {
mutex_exit(&dn->dn_mtx);
return (B_TRUE);
}
}
mutex_exit(&dn->dn_mtx);
return (B_FALSE);
}
void
dnode_setdirty(dnode_t *dn, dmu_tx_t *tx)
{
objset_t *os = dn->dn_objset;
uint64_t txg = tx->tx_txg;
if (DMU_OBJECT_IS_SPECIAL(dn->dn_object)) {
dsl_dataset_dirty(os->os_dsl_dataset, tx);
return;
}
DNODE_VERIFY(dn);
#ifdef ZFS_DEBUG
mutex_enter(&dn->dn_mtx);
ASSERT(dn->dn_phys->dn_type || dn->dn_allocated_txg);
ASSERT(dn->dn_free_txg == 0 || dn->dn_free_txg >= txg);
mutex_exit(&dn->dn_mtx);
#endif
/*
* Determine old uid/gid when necessary
*/
dmu_objset_userquota_get_ids(dn, B_TRUE, tx);
multilist_t *dirtylist = &os->os_dirty_dnodes[txg & TXG_MASK];
multilist_sublist_t *mls = multilist_sublist_lock_obj(dirtylist, dn);
/*
* If we are already marked dirty, we're done.
*/
if (multilist_link_active(&dn->dn_dirty_link[txg & TXG_MASK])) {
multilist_sublist_unlock(mls);
return;
}
ASSERT(!zfs_refcount_is_zero(&dn->dn_holds) ||
!avl_is_empty(&dn->dn_dbufs));
ASSERT(dn->dn_datablksz != 0);
ASSERT0(dn->dn_next_bonuslen[txg & TXG_MASK]);
ASSERT0(dn->dn_next_blksz[txg & TXG_MASK]);
ASSERT0(dn->dn_next_bonustype[txg & TXG_MASK]);
dprintf_ds(os->os_dsl_dataset, "obj=%llu txg=%llu\n",
(u_longlong_t)dn->dn_object, (u_longlong_t)txg);
multilist_sublist_insert_head(mls, dn);
multilist_sublist_unlock(mls);
/*
* The dnode maintains a hold on its containing dbuf as
* long as there are holds on it. Each instantiated child
* dbuf maintains a hold on the dnode. When the last child
* drops its hold, the dnode will drop its hold on the
* containing dbuf. We add a "dirty hold" here so that the
* dnode will hang around after we finish processing its
* children.
*/
VERIFY(dnode_add_ref(dn, (void *)(uintptr_t)tx->tx_txg));
(void) dbuf_dirty(dn->dn_dbuf, tx);
dsl_dataset_dirty(os->os_dsl_dataset, tx);
}
void
dnode_free(dnode_t *dn, dmu_tx_t *tx)
{
mutex_enter(&dn->dn_mtx);
if (dn->dn_type == DMU_OT_NONE || dn->dn_free_txg) {
mutex_exit(&dn->dn_mtx);
return;
}
dn->dn_free_txg = tx->tx_txg;
mutex_exit(&dn->dn_mtx);
dnode_setdirty(dn, tx);
}
/*
* Try to change the block size for the indicated dnode. This can only
* succeed if there are no blocks allocated or dirty beyond first block
*/
int
dnode_set_blksz(dnode_t *dn, uint64_t size, int ibs, dmu_tx_t *tx)
{
dmu_buf_impl_t *db;
int err;
ASSERT3U(size, <=, spa_maxblocksize(dmu_objset_spa(dn->dn_objset)));
if (size == 0)
size = SPA_MINBLOCKSIZE;
else
size = P2ROUNDUP(size, SPA_MINBLOCKSIZE);
if (ibs == dn->dn_indblkshift)
ibs = 0;
if (size == dn->dn_datablksz && ibs == 0)
return (0);
rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
/* Check for any allocated blocks beyond the first */
if (dn->dn_maxblkid != 0)
goto fail;
mutex_enter(&dn->dn_dbufs_mtx);
for (db = avl_first(&dn->dn_dbufs); db != NULL;
db = AVL_NEXT(&dn->dn_dbufs, db)) {
if (db->db_blkid != 0 && db->db_blkid != DMU_BONUS_BLKID &&
db->db_blkid != DMU_SPILL_BLKID) {
mutex_exit(&dn->dn_dbufs_mtx);
goto fail;
}
}
mutex_exit(&dn->dn_dbufs_mtx);
if (ibs && dn->dn_nlevels != 1)
goto fail;
dnode_setdirty(dn, tx);
if (size != dn->dn_datablksz) {
/* resize the old block */
err = dbuf_hold_impl(dn, 0, 0, TRUE, FALSE, FTAG, &db);
if (err == 0) {
dbuf_new_size(db, size, tx);
} else if (err != ENOENT) {
goto fail;
}
dnode_setdblksz(dn, size);
dn->dn_next_blksz[tx->tx_txg & TXG_MASK] = size;
if (db)
dbuf_rele(db, FTAG);
}
if (ibs) {
dn->dn_indblkshift = ibs;
dn->dn_next_indblkshift[tx->tx_txg & TXG_MASK] = ibs;
}
rw_exit(&dn->dn_struct_rwlock);
return (0);
fail:
rw_exit(&dn->dn_struct_rwlock);
return (SET_ERROR(ENOTSUP));
}
static void
dnode_set_nlevels_impl(dnode_t *dn, int new_nlevels, dmu_tx_t *tx)
{
uint64_t txgoff = tx->tx_txg & TXG_MASK;
int old_nlevels = dn->dn_nlevels;
dmu_buf_impl_t *db;
list_t *list;
dbuf_dirty_record_t *new, *dr, *dr_next;
ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock));
ASSERT3U(new_nlevels, >, dn->dn_nlevels);
dn->dn_nlevels = new_nlevels;
ASSERT3U(new_nlevels, >, dn->dn_next_nlevels[txgoff]);
dn->dn_next_nlevels[txgoff] = new_nlevels;
/* dirty the left indirects */
db = dbuf_hold_level(dn, old_nlevels, 0, FTAG);
ASSERT(db != NULL);
new = dbuf_dirty(db, tx);
dbuf_rele(db, FTAG);
/* transfer the dirty records to the new indirect */
mutex_enter(&dn->dn_mtx);
mutex_enter(&new->dt.di.dr_mtx);
list = &dn->dn_dirty_records[txgoff];
for (dr = list_head(list); dr; dr = dr_next) {
dr_next = list_next(&dn->dn_dirty_records[txgoff], dr);
IMPLY(dr->dr_dbuf == NULL, old_nlevels == 1);
if (dr->dr_dbuf == NULL ||
(dr->dr_dbuf->db_level == old_nlevels - 1 &&
dr->dr_dbuf->db_blkid != DMU_BONUS_BLKID &&
dr->dr_dbuf->db_blkid != DMU_SPILL_BLKID)) {
list_remove(&dn->dn_dirty_records[txgoff], dr);
list_insert_tail(&new->dt.di.dr_children, dr);
dr->dr_parent = new;
}
}
mutex_exit(&new->dt.di.dr_mtx);
mutex_exit(&dn->dn_mtx);
}
int
dnode_set_nlevels(dnode_t *dn, int nlevels, dmu_tx_t *tx)
{
int ret = 0;
rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
if (dn->dn_nlevels == nlevels) {
ret = 0;
goto out;
} else if (nlevels < dn->dn_nlevels) {
ret = SET_ERROR(EINVAL);
goto out;
}
dnode_set_nlevels_impl(dn, nlevels, tx);
out:
rw_exit(&dn->dn_struct_rwlock);
return (ret);
}
/* read-holding callers must not rely on the lock being continuously held */
void
dnode_new_blkid(dnode_t *dn, uint64_t blkid, dmu_tx_t *tx, boolean_t have_read,
boolean_t force)
{
int epbs, new_nlevels;
uint64_t sz;
ASSERT(blkid != DMU_BONUS_BLKID);
ASSERT(have_read ?
RW_READ_HELD(&dn->dn_struct_rwlock) :
RW_WRITE_HELD(&dn->dn_struct_rwlock));
/*
* if we have a read-lock, check to see if we need to do any work
* before upgrading to a write-lock.
*/
if (have_read) {
if (blkid <= dn->dn_maxblkid)
return;
if (!rw_tryupgrade(&dn->dn_struct_rwlock)) {
rw_exit(&dn->dn_struct_rwlock);
rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
}
}
/*
* Raw sends (indicated by the force flag) require that we take the
* given blkid even if the value is lower than the current value.
*/
if (!force && blkid <= dn->dn_maxblkid)
goto out;
/*
* We use the (otherwise unused) top bit of dn_next_maxblkid[txgoff]
* to indicate that this field is set. This allows us to set the
* maxblkid to 0 on an existing object in dnode_sync().
*/
dn->dn_maxblkid = blkid;
dn->dn_next_maxblkid[tx->tx_txg & TXG_MASK] =
blkid | DMU_NEXT_MAXBLKID_SET;
/*
* Compute the number of levels necessary to support the new maxblkid.
* Raw sends will ensure nlevels is set correctly for us.
*/
new_nlevels = 1;
epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT;
for (sz = dn->dn_nblkptr;
sz <= blkid && sz >= dn->dn_nblkptr; sz <<= epbs)
new_nlevels++;
ASSERT3U(new_nlevels, <=, DN_MAX_LEVELS);
if (!force) {
if (new_nlevels > dn->dn_nlevels)
dnode_set_nlevels_impl(dn, new_nlevels, tx);
} else {
ASSERT3U(dn->dn_nlevels, >=, new_nlevels);
}
out:
if (have_read)
rw_downgrade(&dn->dn_struct_rwlock);
}
static void
dnode_dirty_l1(dnode_t *dn, uint64_t l1blkid, dmu_tx_t *tx)
{
dmu_buf_impl_t *db = dbuf_hold_level(dn, 1, l1blkid, FTAG);
if (db != NULL) {
dmu_buf_will_dirty(&db->db, tx);
dbuf_rele(db, FTAG);
}
}
/*
* Dirty all the in-core level-1 dbufs in the range specified by start_blkid
* and end_blkid.
*/
static void
dnode_dirty_l1range(dnode_t *dn, uint64_t start_blkid, uint64_t end_blkid,
dmu_tx_t *tx)
{
dmu_buf_impl_t *db_search;
dmu_buf_impl_t *db;
avl_index_t where;
db_search = kmem_zalloc(sizeof (dmu_buf_impl_t), KM_SLEEP);
mutex_enter(&dn->dn_dbufs_mtx);
db_search->db_level = 1;
db_search->db_blkid = start_blkid + 1;
db_search->db_state = DB_SEARCH;
for (;;) {
db = avl_find(&dn->dn_dbufs, db_search, &where);
if (db == NULL)
db = avl_nearest(&dn->dn_dbufs, where, AVL_AFTER);
if (db == NULL || db->db_level != 1 ||
db->db_blkid >= end_blkid) {
break;
}
/*
* Setup the next blkid we want to search for.
*/
db_search->db_blkid = db->db_blkid + 1;
ASSERT3U(db->db_blkid, >=, start_blkid);
/*
* If the dbuf transitions to DB_EVICTING while we're trying
* to dirty it, then we will be unable to discover it in
* the dbuf hash table. This will result in a call to
* dbuf_create() which needs to acquire the dn_dbufs_mtx
* lock. To avoid a deadlock, we drop the lock before
* dirtying the level-1 dbuf.
*/
mutex_exit(&dn->dn_dbufs_mtx);
dnode_dirty_l1(dn, db->db_blkid, tx);
mutex_enter(&dn->dn_dbufs_mtx);
}
#ifdef ZFS_DEBUG
/*
* Walk all the in-core level-1 dbufs and verify they have been dirtied.
*/
db_search->db_level = 1;
db_search->db_blkid = start_blkid + 1;
db_search->db_state = DB_SEARCH;
db = avl_find(&dn->dn_dbufs, db_search, &where);
if (db == NULL)
db = avl_nearest(&dn->dn_dbufs, where, AVL_AFTER);
for (; db != NULL; db = AVL_NEXT(&dn->dn_dbufs, db)) {
if (db->db_level != 1 || db->db_blkid >= end_blkid)
break;
if (db->db_state != DB_EVICTING)
ASSERT(db->db_dirtycnt > 0);
}
#endif
kmem_free(db_search, sizeof (dmu_buf_impl_t));
mutex_exit(&dn->dn_dbufs_mtx);
}
void
dnode_set_dirtyctx(dnode_t *dn, dmu_tx_t *tx, const void *tag)
{
/*
* Don't set dirtyctx to SYNC if we're just modifying this as we
* initialize the objset.
*/
if (dn->dn_dirtyctx == DN_UNDIRTIED) {
dsl_dataset_t *ds = dn->dn_objset->os_dsl_dataset;
if (ds != NULL) {
rrw_enter(&ds->ds_bp_rwlock, RW_READER, tag);
}
if (!BP_IS_HOLE(dn->dn_objset->os_rootbp)) {
if (dmu_tx_is_syncing(tx))
dn->dn_dirtyctx = DN_DIRTY_SYNC;
else
dn->dn_dirtyctx = DN_DIRTY_OPEN;
dn->dn_dirtyctx_firstset = tag;
}
if (ds != NULL) {
rrw_exit(&ds->ds_bp_rwlock, tag);
}
}
}
static void
dnode_partial_zero(dnode_t *dn, uint64_t off, uint64_t blkoff, uint64_t len,
dmu_tx_t *tx)
{
dmu_buf_impl_t *db;
int res;
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) {
db_lock_type_t dblt;
boolean_t dirty;
dblt = dmu_buf_lock_parent(db, RW_READER, FTAG);
/* don't dirty if not on disk and not 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) {
caddr_t data;
dmu_buf_will_dirty(&db->db, tx);
data = db->db.db_data;
memset(data + blkoff, 0, len);
}
dbuf_rele(db, FTAG);
}
}
void
dnode_free_range(dnode_t *dn, uint64_t off, uint64_t len, dmu_tx_t *tx)
{
uint64_t blkoff, blkid, nblks;
int blksz, blkshift, head, tail;
int trunc = FALSE;
int epbs;
blksz = dn->dn_datablksz;
blkshift = dn->dn_datablkshift;
epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT;
if (len == DMU_OBJECT_END) {
len = UINT64_MAX - off;
trunc = TRUE;
}
/*
* First, block align the region to free:
*/
if (ISP2(blksz)) {
head = P2NPHASE(off, blksz);
blkoff = P2PHASE(off, blksz);
if ((off >> blkshift) > dn->dn_maxblkid)
return;
} else {
ASSERT(dn->dn_maxblkid == 0);
if (off == 0 && len >= blksz) {
/*
* Freeing the whole block; fast-track this request.
*/
blkid = 0;
nblks = 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 */
return;
} else {
/* Freeing part of the block. */
head = blksz - off;
ASSERT3U(head, >, 0);
}
blkoff = off;
}
/* zero out any partial block data at the start of the range */
if (head) {
ASSERT3U(blkoff + head, ==, blksz);
if (len < head)
head = len;
dnode_partial_zero(dn, off, blkoff, head, tx);
off += head;
len -= head;
}
/* If the range was less than one block, we're done */
if (len == 0)
return;
/* If the remaining range is past end of file, we're done */
if ((off >> blkshift) > dn->dn_maxblkid)
return;
ASSERT(ISP2(blksz));
if (trunc)
tail = 0;
else
tail = P2PHASE(len, blksz);
ASSERT0(P2PHASE(off, blksz));
/* zero out any partial block data at the end of the range */
if (tail) {
if (len < tail)
tail = len;
dnode_partial_zero(dn, off + len, 0, tail, tx);
len -= tail;
}
/* If the range did not include a full block, we are done */
if (len == 0)
return;
ASSERT(IS_P2ALIGNED(off, blksz));
ASSERT(trunc || IS_P2ALIGNED(len, blksz));
blkid = off >> blkshift;
nblks = len >> blkshift;
if (trunc)
nblks += 1;
/*
* Dirty all the indirect blocks in this range. Note that only
* the first and last indirect blocks can actually be written
* (if they were partially freed) -- they must be dirtied, even if
* they do not exist on disk yet. The interior blocks will
* be freed by free_children(), so they will not actually be written.
* Even though these interior blocks will not be written, we
* dirty them for two reasons:
*
* - It ensures that the indirect blocks remain in memory until
* syncing context. (They have already been prefetched by
* dmu_tx_hold_free(), so we don't have to worry about reading
* them serially here.)
*
* - The dirty space accounting will put pressure on the txg sync
* mechanism to begin syncing, and to delay transactions if there
* is a large amount of freeing. Even though these indirect
* blocks will not be written, we could need to write the same
* 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, first, tx);
if (trunc)
last = dn->dn_maxblkid >> epbs;
else
last = (blkid + nblks - 1) >> epbs;
if (last != first)
dnode_dirty_l1(dn, last, tx);
dnode_dirty_l1range(dn, first, last, tx);
int shift = dn->dn_datablkshift + dn->dn_indblkshift -
SPA_BLKPTRSHIFT;
for (uint64_t i = first + 1; i < last; i++) {
/*
* Set i to the blockid of the next non-hole
* level-1 indirect block at or after i. Note
* that dnode_next_offset() operates in terms of
* level-0-equivalent bytes.
*/
uint64_t ibyte = i << shift;
int err = dnode_next_offset(dn, DNODE_FIND_HAVELOCK,
&ibyte, 2, 1, 0);
i = ibyte >> shift;
if (i >= last)
break;
/*
* Normally we should not see an error, either
* from dnode_next_offset() or dbuf_hold_level()
* (except for ESRCH from dnode_next_offset).
* If there is an i/o error, then when we read
* this block in syncing context, it will use
* ZIO_FLAG_MUSTSUCCEED, and thus hang/panic according
* to the "failmode" property. dnode_next_offset()
* doesn't have a flag to indicate MUSTSUCCEED.
*/
if (err != 0)
break;
dnode_dirty_l1(dn, i, tx);
}
rw_exit(&dn->dn_struct_rwlock);
}
done:
/*
* Add this range to the dnode range list.
* We will finish up this free operation in the syncing phase.
*/
mutex_enter(&dn->dn_mtx);
{
int txgoff = tx->tx_txg & TXG_MASK;
if (dn->dn_free_ranges[txgoff] == NULL) {
dn->dn_free_ranges[txgoff] = range_tree_create(NULL,
RANGE_SEG64, NULL, 0, 0);
}
range_tree_clear(dn->dn_free_ranges[txgoff], blkid, nblks);
range_tree_add(dn->dn_free_ranges[txgoff], blkid, nblks);
}
dprintf_dnode(dn, "blkid=%llu nblks=%llu txg=%llu\n",
(u_longlong_t)blkid, (u_longlong_t)nblks,
(u_longlong_t)tx->tx_txg);
mutex_exit(&dn->dn_mtx);
dbuf_free_range(dn, blkid, blkid + nblks - 1, tx);
dnode_setdirty(dn, tx);
}
static boolean_t
dnode_spill_freed(dnode_t *dn)
{
int i;
mutex_enter(&dn->dn_mtx);
for (i = 0; i < TXG_SIZE; i++) {
if (dn->dn_rm_spillblk[i] == DN_KILL_SPILLBLK)
break;
}
mutex_exit(&dn->dn_mtx);
return (i < TXG_SIZE);
}
/* return TRUE if this blkid was freed in a recent txg, or FALSE if it wasn't */
uint64_t
dnode_block_freed(dnode_t *dn, uint64_t blkid)
{
int i;
if (blkid == DMU_BONUS_BLKID)
return (FALSE);
if (dn->dn_free_txg)
return (TRUE);
if (blkid == DMU_SPILL_BLKID)
return (dnode_spill_freed(dn));
mutex_enter(&dn->dn_mtx);
for (i = 0; i < TXG_SIZE; i++) {
if (dn->dn_free_ranges[i] != NULL &&
range_tree_contains(dn->dn_free_ranges[i], blkid, 1))
break;
}
mutex_exit(&dn->dn_mtx);
return (i < TXG_SIZE);
}
/* call from syncing context when we actually write/free space for this dnode */
void
dnode_diduse_space(dnode_t *dn, int64_t delta)
{
uint64_t space;
dprintf_dnode(dn, "dn=%p dnp=%p used=%llu delta=%lld\n",
dn, dn->dn_phys,
(u_longlong_t)dn->dn_phys->dn_used,
(longlong_t)delta);
mutex_enter(&dn->dn_mtx);
space = DN_USED_BYTES(dn->dn_phys);
if (delta > 0) {
ASSERT3U(space + delta, >=, space); /* no overflow */
} else {
ASSERT3U(space, >=, -delta); /* no underflow */
}
space += delta;
if (spa_version(dn->dn_objset->os_spa) < SPA_VERSION_DNODE_BYTES) {
ASSERT((dn->dn_phys->dn_flags & DNODE_FLAG_USED_BYTES) == 0);
ASSERT0(P2PHASE(space, 1<<DEV_BSHIFT));
dn->dn_phys->dn_used = space >> DEV_BSHIFT;
} else {
dn->dn_phys->dn_used = space;
dn->dn_phys->dn_flags |= DNODE_FLAG_USED_BYTES;
}
mutex_exit(&dn->dn_mtx);
}
/*
* Scans a block at the indicated "level" looking for a hole or data,
* depending on 'flags'.
*
* If level > 0, then we are scanning an indirect block looking at its
* pointers. If level == 0, then we are looking at a block of dnodes.
*
* If we don't find what we are looking for in the block, we return ESRCH.
* Otherwise, return with *offset pointing to the beginning (if searching
* forwards) or end (if searching backwards) of the range covered by the
* block pointer we matched on (or dnode).
*
* The basic search algorithm used below by dnode_next_offset() is to
* use this function to search up the block tree (widen the search) until
* we find something (i.e., we don't return ESRCH) and then search back
* down the tree (narrow the search) until we reach our original search
* level.
*/
static int
dnode_next_offset_level(dnode_t *dn, int flags, uint64_t *offset,
int lvl, uint64_t blkfill, uint64_t txg)
{
dmu_buf_impl_t *db = NULL;
void *data = NULL;
uint64_t epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT;
uint64_t epb = 1ULL << epbs;
uint64_t minfill, maxfill;
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);
if (lvl == dn->dn_phys->dn_nlevels) {
error = 0;
epb = dn->dn_phys->dn_nblkptr;
data = dn->dn_phys->dn_blkptr;
} else {
uint64_t blkid = dbuf_whichblock(dn, lvl, *offset);
error = dbuf_hold_impl(dn, lvl, blkid, TRUE, FALSE, FTAG, &db);
if (error) {
if (error != ENOENT)
return (error);
if (hole)
return (0);
/*
* This can only happen when we are searching up
* the block tree for data. We don't really need to
* adjust the offset, as we will just end up looking
* at the pointer to this block in its parent, and its
* going to be unallocated, so we will skip over it.
*/
return (SET_ERROR(ESRCH));
}
error = dbuf_read(db, NULL,
DB_RF_CANFAIL | DB_RF_HAVESTRUCT |
DB_RF_NO_DECRYPT | DB_RF_NOPREFETCH);
if (error) {
dbuf_rele(db, FTAG);
return (error);
}
data = db->db.db_data;
rw_enter(&db->db_rwlock, RW_READER);
}
if (db != NULL && txg != 0 && (db->db_blkptr == NULL ||
BP_GET_LOGICAL_BIRTH(db->db_blkptr) <= txg ||
BP_IS_HOLE(db->db_blkptr))) {
/*
* This can only happen when we are searching up the tree
* and these conditions mean that we need to keep climbing.
*/
error = SET_ERROR(ESRCH);
} else if (lvl == 0) {
dnode_phys_t *dnp = data;
ASSERT(dn->dn_type == DMU_OT_DNODE);
ASSERT(!(flags & DNODE_FIND_BACKWARDS));
for (i = (*offset >> DNODE_SHIFT) & (blkfill - 1);
i < blkfill; i += dnp[i].dn_extra_slots + 1) {
if ((dnp[i].dn_type == DMU_OT_NONE) == hole)
break;
}
if (i == blkfill)
error = SET_ERROR(ESRCH);
*offset = (*offset & ~(DNODE_BLOCK_SIZE - 1)) +
(i << DNODE_SHIFT);
} else {
blkptr_t *bp = data;
uint64_t start = *offset;
span = (lvl - 1) * epbs + dn->dn_datablkshift;
minfill = 0;
maxfill = blkfill << ((lvl - 1) * epbs);
if (hole)
maxfill--;
else
minfill++;
if (span >= 8 * sizeof (*offset)) {
/* This only happens on the highest indirection level */
ASSERT3U((lvl - 1), ==, dn->dn_phys->dn_nlevels - 1);
*offset = 0;
} else {
*offset = *offset >> span;
}
for (i = BF64_GET(*offset, 0, epbs);
i >= 0 && i < epb; i += inc) {
if (BP_GET_FILL(&bp[i]) >= minfill &&
BP_GET_FILL(&bp[i]) <= maxfill &&
(hole || BP_GET_LOGICAL_BIRTH(&bp[i]) > txg))
break;
if (inc > 0 || *offset > 0)
*offset += inc;
}
if (span >= 8 * sizeof (*offset)) {
*offset = start;
} else {
*offset = *offset << span;
}
if (inc < 0) {
/* traversing backwards; position offset at the end */
if (span < 8 * sizeof (*offset))
*offset = MIN(*offset + (1ULL << span) - 1,
start);
} else if (*offset < start) {
*offset = start;
}
if (i < 0 || i >= epb)
error = SET_ERROR(ESRCH);
}
if (db != NULL) {
rw_exit(&db->db_rwlock);
dbuf_rele(db, FTAG);
}
return (error);
}
/*
* Find the next hole, data, or sparse region at or after *offset.
* The value 'blkfill' tells us how many items we expect to find
* in an L0 data block; this value is 1 for normal objects,
* DNODES_PER_BLOCK for the meta dnode, and some fraction of
* DNODES_PER_BLOCK when searching for sparse regions thereof.
*
* Examples:
*
* dnode_next_offset(dn, flags, offset, 1, 1, 0);
* Finds the next/previous hole/data in a file.
* Used in dmu_offset_next().
*
* dnode_next_offset(mdn, flags, offset, 0, DNODES_PER_BLOCK, txg);
* Finds the next free/allocated dnode an objset's meta-dnode.
* Only finds objects that have new contents since txg (ie.
* bonus buffer changes and content removal are ignored).
* Used in dmu_object_next().
*
* dnode_next_offset(mdn, DNODE_FIND_HOLE, offset, 2, DNODES_PER_BLOCK >> 2, 0);
* Finds the next L2 meta-dnode bp that's at most 1/4 full.
* Used in dmu_object_alloc().
*/
int
dnode_next_offset(dnode_t *dn, int flags, uint64_t *offset,
int minlvl, uint64_t blkfill, uint64_t txg)
{
uint64_t initial_offset = *offset;
int lvl, maxlvl;
int error = 0;
if (!(flags & DNODE_FIND_HAVELOCK))
rw_enter(&dn->dn_struct_rwlock, RW_READER);
if (dn->dn_phys->dn_nlevels == 0) {
error = SET_ERROR(ESRCH);
goto out;
}
if (dn->dn_datablkshift == 0) {
if (*offset < dn->dn_datablksz) {
if (flags & DNODE_FIND_HOLE)
*offset = dn->dn_datablksz;
} else {
error = SET_ERROR(ESRCH);
}
goto out;
}
maxlvl = dn->dn_phys->dn_nlevels;
for (lvl = minlvl; lvl <= maxlvl; lvl++) {
error = dnode_next_offset_level(dn,
flags, offset, lvl, blkfill, txg);
if (error != ESRCH)
break;
}
while (error == 0 && --lvl >= minlvl) {
error = dnode_next_offset_level(dn,
flags, offset, lvl, blkfill, txg);
}
/*
* There's always a "virtual hole" at the end of the object, even
* if all BP's which physically exist are non-holes.
*/
if ((flags & DNODE_FIND_HOLE) && error == ESRCH && txg == 0 &&
minlvl == 1 && blkfill == 1 && !(flags & DNODE_FIND_BACKWARDS)) {
error = 0;
}
if (error == 0 && (flags & DNODE_FIND_BACKWARDS ?
initial_offset < *offset : initial_offset > *offset))
error = SET_ERROR(ESRCH);
out:
if (!(flags & DNODE_FIND_HAVELOCK))
rw_exit(&dn->dn_struct_rwlock);
return (error);
}
#if defined(_KERNEL)
EXPORT_SYMBOL(dnode_hold);
EXPORT_SYMBOL(dnode_rele);
EXPORT_SYMBOL(dnode_set_nlevels);
EXPORT_SYMBOL(dnode_set_blksz);
EXPORT_SYMBOL(dnode_free_range);
EXPORT_SYMBOL(dnode_evict_dbufs);
EXPORT_SYMBOL(dnode_evict_bonus);
#endif
ZFS_MODULE_PARAM(zfs, zfs_, default_bs, INT, ZMOD_RW,
"Default dnode block shift");
ZFS_MODULE_PARAM(zfs, zfs_, default_ibs, INT, ZMOD_RW,
"Default dnode indirect block shift");
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