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zfs-builds-mm/zfs-0.8.1/module/zfs/dmu.c
root 3aa59630cc first
2019-07-06 23:40:11 +02:00

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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 http://www.opensolaris.org/os/licensing.
* 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) 2011, 2017 by Delphix. All rights reserved.
* Copyright (c) 2013 by Saso Kiselkov. All rights reserved.
* Copyright (c) 2013, Joyent, Inc. All rights reserved.
* Copyright (c) 2016, Nexenta Systems, Inc. All rights reserved.
* Copyright (c) 2015 by Chunwei Chen. All rights reserved.
* Copyright (c) 2019 Datto Inc.
*/
#include <sys/dmu.h>
#include <sys/dmu_impl.h>
#include <sys/dmu_tx.h>
#include <sys/dbuf.h>
#include <sys/dnode.h>
#include <sys/zfs_context.h>
#include <sys/dmu_objset.h>
#include <sys/dmu_traverse.h>
#include <sys/dsl_dataset.h>
#include <sys/dsl_dir.h>
#include <sys/dsl_pool.h>
#include <sys/dsl_synctask.h>
#include <sys/dsl_prop.h>
#include <sys/dmu_zfetch.h>
#include <sys/zfs_ioctl.h>
#include <sys/zap.h>
#include <sys/zio_checksum.h>
#include <sys/zio_compress.h>
#include <sys/sa.h>
#include <sys/zfeature.h>
#include <sys/abd.h>
#include <sys/trace_dmu.h>
#include <sys/zfs_rlock.h>
#ifdef _KERNEL
#include <sys/vmsystm.h>
#include <sys/zfs_znode.h>
#endif
/*
* Enable/disable nopwrite feature.
*/
int zfs_nopwrite_enabled = 1;
/*
* Tunable to control percentage of dirtied L1 blocks from frees allowed into
* one TXG. After this threshold is crossed, additional dirty blocks from frees
* will wait until the next TXG.
* A value of zero will disable this throttle.
*/
unsigned long zfs_per_txg_dirty_frees_percent = 5;
/*
* Enable/disable forcing txg sync when dirty in dmu_offset_next.
*/
int zfs_dmu_offset_next_sync = 0;
/*
* This can be used for testing, to ensure that certain actions happen
* while in the middle of a remap (which might otherwise complete too
* quickly). Used by ztest(8).
*/
int zfs_object_remap_one_indirect_delay_ms = 0;
const dmu_object_type_info_t dmu_ot[DMU_OT_NUMTYPES] = {
{DMU_BSWAP_UINT8, TRUE, FALSE, FALSE, "unallocated" },
{DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "object directory" },
{DMU_BSWAP_UINT64, TRUE, TRUE, FALSE, "object array" },
{DMU_BSWAP_UINT8, TRUE, FALSE, FALSE, "packed nvlist" },
{DMU_BSWAP_UINT64, TRUE, FALSE, FALSE, "packed nvlist size" },
{DMU_BSWAP_UINT64, TRUE, FALSE, FALSE, "bpobj" },
{DMU_BSWAP_UINT64, TRUE, FALSE, FALSE, "bpobj header" },
{DMU_BSWAP_UINT64, TRUE, FALSE, FALSE, "SPA space map header" },
{DMU_BSWAP_UINT64, TRUE, FALSE, FALSE, "SPA space map" },
{DMU_BSWAP_UINT64, TRUE, FALSE, TRUE, "ZIL intent log" },
{DMU_BSWAP_DNODE, TRUE, FALSE, TRUE, "DMU dnode" },
{DMU_BSWAP_OBJSET, TRUE, TRUE, FALSE, "DMU objset" },
{DMU_BSWAP_UINT64, TRUE, TRUE, FALSE, "DSL directory" },
{DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "DSL directory child map"},
{DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "DSL dataset snap map" },
{DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "DSL props" },
{DMU_BSWAP_UINT64, TRUE, TRUE, FALSE, "DSL dataset" },
{DMU_BSWAP_ZNODE, TRUE, FALSE, FALSE, "ZFS znode" },
{DMU_BSWAP_OLDACL, TRUE, FALSE, TRUE, "ZFS V0 ACL" },
{DMU_BSWAP_UINT8, FALSE, FALSE, TRUE, "ZFS plain file" },
{DMU_BSWAP_ZAP, TRUE, FALSE, TRUE, "ZFS directory" },
{DMU_BSWAP_ZAP, TRUE, FALSE, FALSE, "ZFS master node" },
{DMU_BSWAP_ZAP, TRUE, FALSE, TRUE, "ZFS delete queue" },
{DMU_BSWAP_UINT8, FALSE, FALSE, TRUE, "zvol object" },
{DMU_BSWAP_ZAP, TRUE, FALSE, FALSE, "zvol prop" },
{DMU_BSWAP_UINT8, FALSE, FALSE, TRUE, "other uint8[]" },
{DMU_BSWAP_UINT64, FALSE, FALSE, TRUE, "other uint64[]" },
{DMU_BSWAP_ZAP, TRUE, FALSE, FALSE, "other ZAP" },
{DMU_BSWAP_ZAP, TRUE, FALSE, FALSE, "persistent error log" },
{DMU_BSWAP_UINT8, TRUE, FALSE, FALSE, "SPA history" },
{DMU_BSWAP_UINT64, TRUE, FALSE, FALSE, "SPA history offsets" },
{DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "Pool properties" },
{DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "DSL permissions" },
{DMU_BSWAP_ACL, TRUE, FALSE, TRUE, "ZFS ACL" },
{DMU_BSWAP_UINT8, TRUE, FALSE, TRUE, "ZFS SYSACL" },
{DMU_BSWAP_UINT8, TRUE, FALSE, TRUE, "FUID table" },
{DMU_BSWAP_UINT64, TRUE, FALSE, FALSE, "FUID table size" },
{DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "DSL dataset next clones"},
{DMU_BSWAP_ZAP, TRUE, FALSE, FALSE, "scan work queue" },
{DMU_BSWAP_ZAP, TRUE, FALSE, TRUE, "ZFS user/group/project used" },
{DMU_BSWAP_ZAP, TRUE, FALSE, TRUE, "ZFS user/group/project quota"},
{DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "snapshot refcount tags"},
{DMU_BSWAP_ZAP, TRUE, FALSE, FALSE, "DDT ZAP algorithm" },
{DMU_BSWAP_ZAP, TRUE, FALSE, FALSE, "DDT statistics" },
{DMU_BSWAP_UINT8, TRUE, FALSE, TRUE, "System attributes" },
{DMU_BSWAP_ZAP, TRUE, FALSE, TRUE, "SA master node" },
{DMU_BSWAP_ZAP, TRUE, FALSE, TRUE, "SA attr registration" },
{DMU_BSWAP_ZAP, TRUE, FALSE, TRUE, "SA attr layouts" },
{DMU_BSWAP_ZAP, TRUE, FALSE, FALSE, "scan translations" },
{DMU_BSWAP_UINT8, FALSE, FALSE, TRUE, "deduplicated block" },
{DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "DSL deadlist map" },
{DMU_BSWAP_UINT64, TRUE, TRUE, FALSE, "DSL deadlist map hdr" },
{DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "DSL dir clones" },
{DMU_BSWAP_UINT64, TRUE, FALSE, FALSE, "bpobj subobj" }
};
const dmu_object_byteswap_info_t dmu_ot_byteswap[DMU_BSWAP_NUMFUNCS] = {
{ byteswap_uint8_array, "uint8" },
{ byteswap_uint16_array, "uint16" },
{ byteswap_uint32_array, "uint32" },
{ byteswap_uint64_array, "uint64" },
{ zap_byteswap, "zap" },
{ dnode_buf_byteswap, "dnode" },
{ dmu_objset_byteswap, "objset" },
{ zfs_znode_byteswap, "znode" },
{ zfs_oldacl_byteswap, "oldacl" },
{ zfs_acl_byteswap, "acl" }
};
int
dmu_buf_hold_noread_by_dnode(dnode_t *dn, uint64_t offset,
void *tag, dmu_buf_t **dbp)
{
uint64_t blkid;
dmu_buf_impl_t *db;
blkid = dbuf_whichblock(dn, 0, offset);
rw_enter(&dn->dn_struct_rwlock, RW_READER);
db = dbuf_hold(dn, blkid, tag);
rw_exit(&dn->dn_struct_rwlock);
if (db == NULL) {
*dbp = NULL;
return (SET_ERROR(EIO));
}
*dbp = &db->db;
return (0);
}
int
dmu_buf_hold_noread(objset_t *os, uint64_t object, uint64_t offset,
void *tag, dmu_buf_t **dbp)
{
dnode_t *dn;
uint64_t blkid;
dmu_buf_impl_t *db;
int err;
err = dnode_hold(os, object, FTAG, &dn);
if (err)
return (err);
blkid = dbuf_whichblock(dn, 0, offset);
rw_enter(&dn->dn_struct_rwlock, RW_READER);
db = dbuf_hold(dn, blkid, tag);
rw_exit(&dn->dn_struct_rwlock);
dnode_rele(dn, FTAG);
if (db == NULL) {
*dbp = NULL;
return (SET_ERROR(EIO));
}
*dbp = &db->db;
return (err);
}
int
dmu_buf_hold_by_dnode(dnode_t *dn, uint64_t offset,
void *tag, dmu_buf_t **dbp, int flags)
{
int err;
int db_flags = DB_RF_CANFAIL;
if (flags & DMU_READ_NO_PREFETCH)
db_flags |= DB_RF_NOPREFETCH;
if (flags & DMU_READ_NO_DECRYPT)
db_flags |= DB_RF_NO_DECRYPT;
err = dmu_buf_hold_noread_by_dnode(dn, offset, tag, dbp);
if (err == 0) {
dmu_buf_impl_t *db = (dmu_buf_impl_t *)(*dbp);
err = dbuf_read(db, NULL, db_flags);
if (err != 0) {
dbuf_rele(db, tag);
*dbp = NULL;
}
}
return (err);
}
int
dmu_buf_hold(objset_t *os, uint64_t object, uint64_t offset,
void *tag, dmu_buf_t **dbp, int flags)
{
int err;
int db_flags = DB_RF_CANFAIL;
if (flags & DMU_READ_NO_PREFETCH)
db_flags |= DB_RF_NOPREFETCH;
if (flags & DMU_READ_NO_DECRYPT)
db_flags |= DB_RF_NO_DECRYPT;
err = dmu_buf_hold_noread(os, object, offset, tag, dbp);
if (err == 0) {
dmu_buf_impl_t *db = (dmu_buf_impl_t *)(*dbp);
err = dbuf_read(db, NULL, db_flags);
if (err != 0) {
dbuf_rele(db, tag);
*dbp = NULL;
}
}
return (err);
}
int
dmu_bonus_max(void)
{
return (DN_OLD_MAX_BONUSLEN);
}
int
dmu_set_bonus(dmu_buf_t *db_fake, int newsize, dmu_tx_t *tx)
{
dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
dnode_t *dn;
int error;
DB_DNODE_ENTER(db);
dn = DB_DNODE(db);
if (dn->dn_bonus != db) {
error = SET_ERROR(EINVAL);
} else if (newsize < 0 || newsize > db_fake->db_size) {
error = SET_ERROR(EINVAL);
} else {
dnode_setbonuslen(dn, newsize, tx);
error = 0;
}
DB_DNODE_EXIT(db);
return (error);
}
int
dmu_set_bonustype(dmu_buf_t *db_fake, dmu_object_type_t type, dmu_tx_t *tx)
{
dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
dnode_t *dn;
int error;
DB_DNODE_ENTER(db);
dn = DB_DNODE(db);
if (!DMU_OT_IS_VALID(type)) {
error = SET_ERROR(EINVAL);
} else if (dn->dn_bonus != db) {
error = SET_ERROR(EINVAL);
} else {
dnode_setbonus_type(dn, type, tx);
error = 0;
}
DB_DNODE_EXIT(db);
return (error);
}
dmu_object_type_t
dmu_get_bonustype(dmu_buf_t *db_fake)
{
dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
dnode_t *dn;
dmu_object_type_t type;
DB_DNODE_ENTER(db);
dn = DB_DNODE(db);
type = dn->dn_bonustype;
DB_DNODE_EXIT(db);
return (type);
}
int
dmu_rm_spill(objset_t *os, uint64_t object, dmu_tx_t *tx)
{
dnode_t *dn;
int error;
error = dnode_hold(os, object, FTAG, &dn);
dbuf_rm_spill(dn, tx);
rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
dnode_rm_spill(dn, tx);
rw_exit(&dn->dn_struct_rwlock);
dnode_rele(dn, FTAG);
return (error);
}
/*
* Lookup and hold the bonus buffer for the provided dnode. If the dnode
* has not yet been allocated a new bonus dbuf a will be allocated.
* Returns ENOENT, EIO, or 0.
*/
int dmu_bonus_hold_by_dnode(dnode_t *dn, void *tag, dmu_buf_t **dbp,
uint32_t flags)
{
dmu_buf_impl_t *db;
int error;
uint32_t db_flags = DB_RF_MUST_SUCCEED;
if (flags & DMU_READ_NO_PREFETCH)
db_flags |= DB_RF_NOPREFETCH;
if (flags & DMU_READ_NO_DECRYPT)
db_flags |= DB_RF_NO_DECRYPT;
rw_enter(&dn->dn_struct_rwlock, RW_READER);
if (dn->dn_bonus == NULL) {
rw_exit(&dn->dn_struct_rwlock);
rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
if (dn->dn_bonus == NULL)
dbuf_create_bonus(dn);
}
db = dn->dn_bonus;
/* as long as the bonus buf is held, the dnode will be held */
if (zfs_refcount_add(&db->db_holds, tag) == 1) {
VERIFY(dnode_add_ref(dn, db));
atomic_inc_32(&dn->dn_dbufs_count);
}
/*
* Wait to drop dn_struct_rwlock until after adding the bonus dbuf's
* hold and incrementing the dbuf count to ensure that dnode_move() sees
* a dnode hold for every dbuf.
*/
rw_exit(&dn->dn_struct_rwlock);
error = dbuf_read(db, NULL, db_flags);
if (error) {
dnode_evict_bonus(dn);
dbuf_rele(db, tag);
*dbp = NULL;
return (error);
}
*dbp = &db->db;
return (0);
}
int
dmu_bonus_hold(objset_t *os, uint64_t object, void *tag, dmu_buf_t **dbp)
{
dnode_t *dn;
int error;
error = dnode_hold(os, object, FTAG, &dn);
if (error)
return (error);
error = dmu_bonus_hold_by_dnode(dn, tag, dbp, DMU_READ_NO_PREFETCH);
dnode_rele(dn, FTAG);
return (error);
}
/*
* returns ENOENT, EIO, or 0.
*
* This interface will allocate a blank spill dbuf when a spill blk
* doesn't already exist on the dnode.
*
* if you only want to find an already existing spill db, then
* dmu_spill_hold_existing() should be used.
*/
int
dmu_spill_hold_by_dnode(dnode_t *dn, uint32_t flags, void *tag, dmu_buf_t **dbp)
{
dmu_buf_impl_t *db = NULL;
int err;
if ((flags & DB_RF_HAVESTRUCT) == 0)
rw_enter(&dn->dn_struct_rwlock, RW_READER);
db = dbuf_hold(dn, DMU_SPILL_BLKID, tag);
if ((flags & DB_RF_HAVESTRUCT) == 0)
rw_exit(&dn->dn_struct_rwlock);
if (db == NULL) {
*dbp = NULL;
return (SET_ERROR(EIO));
}
err = dbuf_read(db, NULL, flags);
if (err == 0)
*dbp = &db->db;
else {
dbuf_rele(db, tag);
*dbp = NULL;
}
return (err);
}
int
dmu_spill_hold_existing(dmu_buf_t *bonus, void *tag, dmu_buf_t **dbp)
{
dmu_buf_impl_t *db = (dmu_buf_impl_t *)bonus;
dnode_t *dn;
int err;
DB_DNODE_ENTER(db);
dn = DB_DNODE(db);
if (spa_version(dn->dn_objset->os_spa) < SPA_VERSION_SA) {
err = SET_ERROR(EINVAL);
} else {
rw_enter(&dn->dn_struct_rwlock, RW_READER);
if (!dn->dn_have_spill) {
err = SET_ERROR(ENOENT);
} else {
err = dmu_spill_hold_by_dnode(dn,
DB_RF_HAVESTRUCT | DB_RF_CANFAIL, tag, dbp);
}
rw_exit(&dn->dn_struct_rwlock);
}
DB_DNODE_EXIT(db);
return (err);
}
int
dmu_spill_hold_by_bonus(dmu_buf_t *bonus, uint32_t flags, void *tag,
dmu_buf_t **dbp)
{
dmu_buf_impl_t *db = (dmu_buf_impl_t *)bonus;
dnode_t *dn;
int err;
uint32_t db_flags = DB_RF_CANFAIL;
if (flags & DMU_READ_NO_DECRYPT)
db_flags |= DB_RF_NO_DECRYPT;
DB_DNODE_ENTER(db);
dn = DB_DNODE(db);
err = dmu_spill_hold_by_dnode(dn, db_flags, tag, dbp);
DB_DNODE_EXIT(db);
return (err);
}
/*
* Note: longer-term, we should modify all of the dmu_buf_*() interfaces
* to take a held dnode rather than <os, object> -- the lookup is wasteful,
* and can induce severe lock contention when writing to several files
* whose dnodes are in the same block.
*/
static int
dmu_buf_hold_array_by_dnode(dnode_t *dn, uint64_t offset, uint64_t length,
boolean_t read, void *tag, int *numbufsp, dmu_buf_t ***dbpp, uint32_t flags)
{
dmu_buf_t **dbp;
uint64_t blkid, nblks, i;
uint32_t dbuf_flags;
int err;
zio_t *zio;
ASSERT(length <= DMU_MAX_ACCESS);
/*
* Note: We directly notify the prefetch code of this read, so that
* we can tell it about the multi-block read. dbuf_read() only knows
* about the one block it is accessing.
*/
dbuf_flags = DB_RF_CANFAIL | DB_RF_NEVERWAIT | DB_RF_HAVESTRUCT |
DB_RF_NOPREFETCH;
rw_enter(&dn->dn_struct_rwlock, RW_READER);
if (dn->dn_datablkshift) {
int blkshift = dn->dn_datablkshift;
nblks = (P2ROUNDUP(offset + length, 1ULL << blkshift) -
P2ALIGN(offset, 1ULL << blkshift)) >> blkshift;
} else {
if (offset + length > dn->dn_datablksz) {
zfs_panic_recover("zfs: accessing past end of object "
"%llx/%llx (size=%u access=%llu+%llu)",
(longlong_t)dn->dn_objset->
os_dsl_dataset->ds_object,
(longlong_t)dn->dn_object, dn->dn_datablksz,
(longlong_t)offset, (longlong_t)length);
rw_exit(&dn->dn_struct_rwlock);
return (SET_ERROR(EIO));
}
nblks = 1;
}
dbp = kmem_zalloc(sizeof (dmu_buf_t *) * nblks, KM_SLEEP);
zio = zio_root(dn->dn_objset->os_spa, NULL, NULL, ZIO_FLAG_CANFAIL);
blkid = dbuf_whichblock(dn, 0, offset);
for (i = 0; i < nblks; i++) {
dmu_buf_impl_t *db = dbuf_hold(dn, blkid + i, tag);
if (db == NULL) {
rw_exit(&dn->dn_struct_rwlock);
dmu_buf_rele_array(dbp, nblks, tag);
zio_nowait(zio);
return (SET_ERROR(EIO));
}
/* initiate async i/o */
if (read)
(void) dbuf_read(db, zio, dbuf_flags);
dbp[i] = &db->db;
}
if ((flags & DMU_READ_NO_PREFETCH) == 0 &&
DNODE_META_IS_CACHEABLE(dn) && length <= zfetch_array_rd_sz) {
dmu_zfetch(&dn->dn_zfetch, blkid, nblks,
read && DNODE_IS_CACHEABLE(dn));
}
rw_exit(&dn->dn_struct_rwlock);
/* wait for async i/o */
err = zio_wait(zio);
if (err) {
dmu_buf_rele_array(dbp, nblks, tag);
return (err);
}
/* wait for other io to complete */
if (read) {
for (i = 0; i < nblks; i++) {
dmu_buf_impl_t *db = (dmu_buf_impl_t *)dbp[i];
mutex_enter(&db->db_mtx);
while (db->db_state == DB_READ ||
db->db_state == DB_FILL)
cv_wait(&db->db_changed, &db->db_mtx);
if (db->db_state == DB_UNCACHED)
err = SET_ERROR(EIO);
mutex_exit(&db->db_mtx);
if (err) {
dmu_buf_rele_array(dbp, nblks, tag);
return (err);
}
}
}
*numbufsp = nblks;
*dbpp = dbp;
return (0);
}
static int
dmu_buf_hold_array(objset_t *os, uint64_t object, uint64_t offset,
uint64_t length, int read, void *tag, int *numbufsp, dmu_buf_t ***dbpp)
{
dnode_t *dn;
int err;
err = dnode_hold(os, object, FTAG, &dn);
if (err)
return (err);
err = dmu_buf_hold_array_by_dnode(dn, offset, length, read, tag,
numbufsp, dbpp, DMU_READ_PREFETCH);
dnode_rele(dn, FTAG);
return (err);
}
int
dmu_buf_hold_array_by_bonus(dmu_buf_t *db_fake, uint64_t offset,
uint64_t length, boolean_t read, void *tag, int *numbufsp,
dmu_buf_t ***dbpp)
{
dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
dnode_t *dn;
int err;
DB_DNODE_ENTER(db);
dn = DB_DNODE(db);
err = dmu_buf_hold_array_by_dnode(dn, offset, length, read, tag,
numbufsp, dbpp, DMU_READ_PREFETCH);
DB_DNODE_EXIT(db);
return (err);
}
void
dmu_buf_rele_array(dmu_buf_t **dbp_fake, int numbufs, void *tag)
{
int i;
dmu_buf_impl_t **dbp = (dmu_buf_impl_t **)dbp_fake;
if (numbufs == 0)
return;
for (i = 0; i < numbufs; i++) {
if (dbp[i])
dbuf_rele(dbp[i], tag);
}
kmem_free(dbp, sizeof (dmu_buf_t *) * numbufs);
}
/*
* Issue prefetch i/os for the given blocks. If level is greater than 0, the
* indirect blocks prefeteched will be those that point to the blocks containing
* the data starting at offset, and continuing to offset + len.
*
* Note that if the indirect blocks above the blocks being prefetched are not
* in cache, they will be asychronously read in.
*/
void
dmu_prefetch(objset_t *os, uint64_t object, int64_t level, uint64_t offset,
uint64_t len, zio_priority_t pri)
{
dnode_t *dn;
uint64_t blkid;
int nblks, err;
if (len == 0) { /* they're interested in the bonus buffer */
dn = DMU_META_DNODE(os);
if (object == 0 || object >= DN_MAX_OBJECT)
return;
rw_enter(&dn->dn_struct_rwlock, RW_READER);
blkid = dbuf_whichblock(dn, level,
object * sizeof (dnode_phys_t));
dbuf_prefetch(dn, level, blkid, pri, 0);
rw_exit(&dn->dn_struct_rwlock);
return;
}
/*
* XXX - Note, if the dnode for the requested object is not
* already cached, we will do a *synchronous* read in the
* dnode_hold() call. The same is true for any indirects.
*/
err = dnode_hold(os, object, FTAG, &dn);
if (err != 0)
return;
rw_enter(&dn->dn_struct_rwlock, RW_READER);
/*
* offset + len - 1 is the last byte we want to prefetch for, and offset
* is the first. Then dbuf_whichblk(dn, level, off + len - 1) is the
* last block we want to prefetch, and dbuf_whichblock(dn, level,
* offset) is the first. Then the number we need to prefetch is the
* last - first + 1.
*/
if (level > 0 || dn->dn_datablkshift != 0) {
nblks = dbuf_whichblock(dn, level, offset + len - 1) -
dbuf_whichblock(dn, level, offset) + 1;
} else {
nblks = (offset < dn->dn_datablksz);
}
if (nblks != 0) {
blkid = dbuf_whichblock(dn, level, offset);
for (int i = 0; i < nblks; i++)
dbuf_prefetch(dn, level, blkid + i, pri, 0);
}
rw_exit(&dn->dn_struct_rwlock);
dnode_rele(dn, FTAG);
}
/*
* Get the next "chunk" of file data to free. We traverse the file from
* the end so that the file gets shorter over time (if we crashes in the
* middle, this will leave us in a better state). We find allocated file
* data by simply searching the allocated level 1 indirects.
*
* On input, *start should be the first offset that does not need to be
* freed (e.g. "offset + length"). On return, *start will be the first
* offset that should be freed and l1blks is set to the number of level 1
* indirect blocks found within the chunk.
*/
static int
get_next_chunk(dnode_t *dn, uint64_t *start, uint64_t minimum, uint64_t *l1blks)
{
uint64_t blks;
uint64_t maxblks = DMU_MAX_ACCESS >> (dn->dn_indblkshift + 1);
/* bytes of data covered by a level-1 indirect block */
uint64_t iblkrange = (uint64_t)dn->dn_datablksz *
EPB(dn->dn_indblkshift, SPA_BLKPTRSHIFT);
ASSERT3U(minimum, <=, *start);
/*
* Check if we can free the entire range assuming that all of the
* L1 blocks in this range have data. If we can, we use this
* worst case value as an estimate so we can avoid having to look
* at the object's actual data.
*/
uint64_t total_l1blks =
(roundup(*start, iblkrange) - (minimum / iblkrange * iblkrange)) /
iblkrange;
if (total_l1blks <= maxblks) {
*l1blks = total_l1blks;
*start = minimum;
return (0);
}
ASSERT(ISP2(iblkrange));
for (blks = 0; *start > minimum && blks < maxblks; blks++) {
int err;
/*
* dnode_next_offset(BACKWARDS) will find an allocated L1
* indirect block at or before the input offset. We must
* decrement *start so that it is at the end of the region
* to search.
*/
(*start)--;
err = dnode_next_offset(dn,
DNODE_FIND_BACKWARDS, start, 2, 1, 0);
/* if there are no indirect blocks before start, we are done */
if (err == ESRCH) {
*start = minimum;
break;
} else if (err != 0) {
*l1blks = blks;
return (err);
}
/* set start to the beginning of this L1 indirect */
*start = P2ALIGN(*start, iblkrange);
}
if (*start < minimum)
*start = minimum;
*l1blks = blks;
return (0);
}
/*
* If this objset is of type OST_ZFS return true if vfs's unmounted flag is set,
* otherwise return false.
* Used below in dmu_free_long_range_impl() to enable abort when unmounting
*/
/*ARGSUSED*/
static boolean_t
dmu_objset_zfs_unmounting(objset_t *os)
{
#ifdef _KERNEL
if (dmu_objset_type(os) == DMU_OST_ZFS)
return (zfs_get_vfs_flag_unmounted(os));
#endif
return (B_FALSE);
}
static int
dmu_free_long_range_impl(objset_t *os, dnode_t *dn, uint64_t offset,
uint64_t length)
{
uint64_t object_size;
int err;
uint64_t dirty_frees_threshold;
dsl_pool_t *dp = dmu_objset_pool(os);
if (dn == NULL)
return (SET_ERROR(EINVAL));
object_size = (dn->dn_maxblkid + 1) * dn->dn_datablksz;
if (offset >= object_size)
return (0);
if (zfs_per_txg_dirty_frees_percent <= 100)
dirty_frees_threshold =
zfs_per_txg_dirty_frees_percent * zfs_dirty_data_max / 100;
else
dirty_frees_threshold = zfs_dirty_data_max / 20;
if (length == DMU_OBJECT_END || offset + length > object_size)
length = object_size - offset;
while (length != 0) {
uint64_t chunk_end, chunk_begin, chunk_len;
uint64_t l1blks;
dmu_tx_t *tx;
if (dmu_objset_zfs_unmounting(dn->dn_objset))
return (SET_ERROR(EINTR));
chunk_end = chunk_begin = offset + length;
/* move chunk_begin backwards to the beginning of this chunk */
err = get_next_chunk(dn, &chunk_begin, offset, &l1blks);
if (err)
return (err);
ASSERT3U(chunk_begin, >=, offset);
ASSERT3U(chunk_begin, <=, chunk_end);
chunk_len = chunk_end - chunk_begin;
tx = dmu_tx_create(os);
dmu_tx_hold_free(tx, dn->dn_object, chunk_begin, chunk_len);
/*
* Mark this transaction as typically resulting in a net
* reduction in space used.
*/
dmu_tx_mark_netfree(tx);
err = dmu_tx_assign(tx, TXG_WAIT);
if (err) {
dmu_tx_abort(tx);
return (err);
}
uint64_t txg = dmu_tx_get_txg(tx);
mutex_enter(&dp->dp_lock);
uint64_t long_free_dirty =
dp->dp_long_free_dirty_pertxg[txg & TXG_MASK];
mutex_exit(&dp->dp_lock);
/*
* To avoid filling up a TXG with just frees, wait for
* the next TXG to open before freeing more chunks if
* we have reached the threshold of frees.
*/
if (dirty_frees_threshold != 0 &&
long_free_dirty >= dirty_frees_threshold) {
DMU_TX_STAT_BUMP(dmu_tx_dirty_frees_delay);
dmu_tx_commit(tx);
txg_wait_open(dp, 0, B_TRUE);
continue;
}
/*
* In order to prevent unnecessary write throttling, for each
* TXG, we track the cumulative size of L1 blocks being dirtied
* in dnode_free_range() below. We compare this number to a
* tunable threshold, past which we prevent new L1 dirty freeing
* blocks from being added into the open TXG. See
* dmu_free_long_range_impl() for details. The threshold
* prevents write throttle activation due to dirty freeing L1
* blocks taking up a large percentage of zfs_dirty_data_max.
*/
mutex_enter(&dp->dp_lock);
dp->dp_long_free_dirty_pertxg[txg & TXG_MASK] +=
l1blks << dn->dn_indblkshift;
mutex_exit(&dp->dp_lock);
DTRACE_PROBE3(free__long__range,
uint64_t, long_free_dirty, uint64_t, chunk_len,
uint64_t, txg);
dnode_free_range(dn, chunk_begin, chunk_len, tx);
dmu_tx_commit(tx);
length -= chunk_len;
}
return (0);
}
int
dmu_free_long_range(objset_t *os, uint64_t object,
uint64_t offset, uint64_t length)
{
dnode_t *dn;
int err;
err = dnode_hold(os, object, FTAG, &dn);
if (err != 0)
return (err);
err = dmu_free_long_range_impl(os, dn, offset, length);
/*
* It is important to zero out the maxblkid when freeing the entire
* file, so that (a) subsequent calls to dmu_free_long_range_impl()
* will take the fast path, and (b) dnode_reallocate() can verify
* that the entire file has been freed.
*/
if (err == 0 && offset == 0 && length == DMU_OBJECT_END)
dn->dn_maxblkid = 0;
dnode_rele(dn, FTAG);
return (err);
}
int
dmu_free_long_object(objset_t *os, uint64_t object)
{
dmu_tx_t *tx;
int err;
err = dmu_free_long_range(os, object, 0, DMU_OBJECT_END);
if (err != 0)
return (err);
tx = dmu_tx_create(os);
dmu_tx_hold_bonus(tx, object);
dmu_tx_hold_free(tx, object, 0, DMU_OBJECT_END);
dmu_tx_mark_netfree(tx);
err = dmu_tx_assign(tx, TXG_WAIT);
if (err == 0) {
if (err == 0)
err = dmu_object_free(os, object, tx);
dmu_tx_commit(tx);
} else {
dmu_tx_abort(tx);
}
return (err);
}
int
dmu_free_range(objset_t *os, uint64_t object, uint64_t offset,
uint64_t size, dmu_tx_t *tx)
{
dnode_t *dn;
int err = dnode_hold(os, object, FTAG, &dn);
if (err)
return (err);
ASSERT(offset < UINT64_MAX);
ASSERT(size == DMU_OBJECT_END || size <= UINT64_MAX - offset);
dnode_free_range(dn, offset, size, tx);
dnode_rele(dn, FTAG);
return (0);
}
static int
dmu_read_impl(dnode_t *dn, uint64_t offset, uint64_t size,
void *buf, uint32_t flags)
{
dmu_buf_t **dbp;
int numbufs, err = 0;
/*
* Deal with odd block sizes, where there can't be data past the first
* block. If we ever do the tail block optimization, we will need to
* handle that here as well.
*/
if (dn->dn_maxblkid == 0) {
uint64_t newsz = offset > dn->dn_datablksz ? 0 :
MIN(size, dn->dn_datablksz - offset);
bzero((char *)buf + newsz, size - newsz);
size = newsz;
}
while (size > 0) {
uint64_t mylen = MIN(size, DMU_MAX_ACCESS / 2);
int i;
/*
* NB: we could do this block-at-a-time, but it's nice
* to be reading in parallel.
*/
err = dmu_buf_hold_array_by_dnode(dn, offset, mylen,
TRUE, FTAG, &numbufs, &dbp, flags);
if (err)
break;
for (i = 0; i < numbufs; i++) {
uint64_t tocpy;
int64_t bufoff;
dmu_buf_t *db = dbp[i];
ASSERT(size > 0);
bufoff = offset - db->db_offset;
tocpy = MIN(db->db_size - bufoff, size);
(void) memcpy(buf, (char *)db->db_data + bufoff, tocpy);
offset += tocpy;
size -= tocpy;
buf = (char *)buf + tocpy;
}
dmu_buf_rele_array(dbp, numbufs, FTAG);
}
return (err);
}
int
dmu_read(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
void *buf, uint32_t flags)
{
dnode_t *dn;
int err;
err = dnode_hold(os, object, FTAG, &dn);
if (err != 0)
return (err);
err = dmu_read_impl(dn, offset, size, buf, flags);
dnode_rele(dn, FTAG);
return (err);
}
int
dmu_read_by_dnode(dnode_t *dn, uint64_t offset, uint64_t size, void *buf,
uint32_t flags)
{
return (dmu_read_impl(dn, offset, size, buf, flags));
}
static void
dmu_write_impl(dmu_buf_t **dbp, int numbufs, uint64_t offset, uint64_t size,
const void *buf, dmu_tx_t *tx)
{
int i;
for (i = 0; i < numbufs; i++) {
uint64_t tocpy;
int64_t bufoff;
dmu_buf_t *db = dbp[i];
ASSERT(size > 0);
bufoff = offset - db->db_offset;
tocpy = MIN(db->db_size - bufoff, size);
ASSERT(i == 0 || i == numbufs-1 || tocpy == db->db_size);
if (tocpy == db->db_size)
dmu_buf_will_fill(db, tx);
else
dmu_buf_will_dirty(db, tx);
(void) memcpy((char *)db->db_data + bufoff, buf, tocpy);
if (tocpy == db->db_size)
dmu_buf_fill_done(db, tx);
offset += tocpy;
size -= tocpy;
buf = (char *)buf + tocpy;
}
}
void
dmu_write(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
const void *buf, dmu_tx_t *tx)
{
dmu_buf_t **dbp;
int numbufs;
if (size == 0)
return;
VERIFY0(dmu_buf_hold_array(os, object, offset, size,
FALSE, FTAG, &numbufs, &dbp));
dmu_write_impl(dbp, numbufs, offset, size, buf, tx);
dmu_buf_rele_array(dbp, numbufs, FTAG);
}
void
dmu_write_by_dnode(dnode_t *dn, uint64_t offset, uint64_t size,
const void *buf, dmu_tx_t *tx)
{
dmu_buf_t **dbp;
int numbufs;
if (size == 0)
return;
VERIFY0(dmu_buf_hold_array_by_dnode(dn, offset, size,
FALSE, FTAG, &numbufs, &dbp, DMU_READ_PREFETCH));
dmu_write_impl(dbp, numbufs, offset, size, buf, tx);
dmu_buf_rele_array(dbp, numbufs, FTAG);
}
static int
dmu_object_remap_one_indirect(objset_t *os, dnode_t *dn,
uint64_t last_removal_txg, uint64_t offset)
{
uint64_t l1blkid = dbuf_whichblock(dn, 1, offset);
dnode_t *dn_tx;
int err = 0;
rw_enter(&dn->dn_struct_rwlock, RW_READER);
dmu_buf_impl_t *dbuf = dbuf_hold_level(dn, 1, l1blkid, FTAG);
ASSERT3P(dbuf, !=, NULL);
/*
* If the block hasn't been written yet, this default will ensure
* we don't try to remap it.
*/
uint64_t birth = UINT64_MAX;
ASSERT3U(last_removal_txg, !=, UINT64_MAX);
if (dbuf->db_blkptr != NULL)
birth = dbuf->db_blkptr->blk_birth;
rw_exit(&dn->dn_struct_rwlock);
/*
* If this L1 was already written after the last removal, then we've
* already tried to remap it. An additional hold is taken after the
* dmu_tx_assign() to handle the case where the dnode is freed while
* waiting for the next open txg.
*/
if (birth <= last_removal_txg &&
dbuf_read(dbuf, NULL, DB_RF_MUST_SUCCEED) == 0 &&
dbuf_can_remap(dbuf)) {
dmu_tx_t *tx = dmu_tx_create(os);
dmu_tx_hold_remap_l1indirect(tx, dn->dn_object);
err = dmu_tx_assign(tx, TXG_WAIT);
if (err == 0) {
err = dnode_hold(os, dn->dn_object, FTAG, &dn_tx);
if (err == 0) {
(void) dbuf_dirty(dbuf, tx);
dnode_rele(dn_tx, FTAG);
}
dmu_tx_commit(tx);
} else {
dmu_tx_abort(tx);
}
}
dbuf_rele(dbuf, FTAG);
delay(MSEC_TO_TICK(zfs_object_remap_one_indirect_delay_ms));
return (err);
}
/*
* Remap all blockpointers in the object, if possible, so that they reference
* only concrete vdevs.
*
* To do this, iterate over the L0 blockpointers and remap any that reference
* an indirect vdev. Note that we only examine L0 blockpointers; since we
* cannot guarantee that we can remap all blockpointer anyways (due to split
* blocks), we do not want to make the code unnecessarily complicated to
* catch the unlikely case that there is an L1 block on an indirect vdev that
* contains no indirect blockpointers.
*/
int
dmu_object_remap_indirects(objset_t *os, uint64_t object,
uint64_t last_removal_txg)
{
uint64_t offset, l1span;
int err;
dnode_t *dn, *dn_tx;
err = dnode_hold(os, object, FTAG, &dn);
if (err != 0) {
return (err);
}
if (dn->dn_nlevels <= 1) {
if (issig(JUSTLOOKING) && issig(FORREAL)) {
err = SET_ERROR(EINTR);
}
/*
* If the dnode has no indirect blocks, we cannot dirty them.
* We still want to remap the blkptr(s) in the dnode if
* appropriate, so mark it as dirty. An additional hold is
* taken after the dmu_tx_assign() to handle the case where
* the dnode is freed while waiting for the next open txg.
*/
if (err == 0 && dnode_needs_remap(dn)) {
dmu_tx_t *tx = dmu_tx_create(os);
dmu_tx_hold_bonus(tx, object);
err = dmu_tx_assign(tx, TXG_WAIT);
if (err == 0) {
err = dnode_hold(os, object, FTAG, &dn_tx);
if (err == 0) {
dnode_setdirty(dn_tx, tx);
dnode_rele(dn_tx, FTAG);
}
dmu_tx_commit(tx);
} else {
dmu_tx_abort(tx);
}
}
dnode_rele(dn, FTAG);
return (err);
}
offset = 0;
l1span = 1ULL << (dn->dn_indblkshift - SPA_BLKPTRSHIFT +
dn->dn_datablkshift);
/*
* Find the next L1 indirect that is not a hole.
*/
while (dnode_next_offset(dn, 0, &offset, 2, 1, 0) == 0) {
if (issig(JUSTLOOKING) && issig(FORREAL)) {
err = SET_ERROR(EINTR);
break;
}
if ((err = dmu_object_remap_one_indirect(os, dn,
last_removal_txg, offset)) != 0) {
break;
}
offset += l1span;
}
dnode_rele(dn, FTAG);
return (err);
}
void
dmu_prealloc(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
dmu_tx_t *tx)
{
dmu_buf_t **dbp;
int numbufs, i;
if (size == 0)
return;
VERIFY(0 == dmu_buf_hold_array(os, object, offset, size,
FALSE, FTAG, &numbufs, &dbp));
for (i = 0; i < numbufs; i++) {
dmu_buf_t *db = dbp[i];
dmu_buf_will_not_fill(db, tx);
}
dmu_buf_rele_array(dbp, numbufs, FTAG);
}
void
dmu_write_embedded(objset_t *os, uint64_t object, uint64_t offset,
void *data, uint8_t etype, uint8_t comp, int uncompressed_size,
int compressed_size, int byteorder, dmu_tx_t *tx)
{
dmu_buf_t *db;
ASSERT3U(etype, <, NUM_BP_EMBEDDED_TYPES);
ASSERT3U(comp, <, ZIO_COMPRESS_FUNCTIONS);
VERIFY0(dmu_buf_hold_noread(os, object, offset,
FTAG, &db));
dmu_buf_write_embedded(db,
data, (bp_embedded_type_t)etype, (enum zio_compress)comp,
uncompressed_size, compressed_size, byteorder, tx);
dmu_buf_rele(db, FTAG);
}
/*
* DMU support for xuio
*/
kstat_t *xuio_ksp = NULL;
typedef struct xuio_stats {
/* loaned yet not returned arc_buf */
kstat_named_t xuiostat_onloan_rbuf;
kstat_named_t xuiostat_onloan_wbuf;
/* whether a copy is made when loaning out a read buffer */
kstat_named_t xuiostat_rbuf_copied;
kstat_named_t xuiostat_rbuf_nocopy;
/* whether a copy is made when assigning a write buffer */
kstat_named_t xuiostat_wbuf_copied;
kstat_named_t xuiostat_wbuf_nocopy;
} xuio_stats_t;
static xuio_stats_t xuio_stats = {
{ "onloan_read_buf", KSTAT_DATA_UINT64 },
{ "onloan_write_buf", KSTAT_DATA_UINT64 },
{ "read_buf_copied", KSTAT_DATA_UINT64 },
{ "read_buf_nocopy", KSTAT_DATA_UINT64 },
{ "write_buf_copied", KSTAT_DATA_UINT64 },
{ "write_buf_nocopy", KSTAT_DATA_UINT64 }
};
#define XUIOSTAT_INCR(stat, val) \
atomic_add_64(&xuio_stats.stat.value.ui64, (val))
#define XUIOSTAT_BUMP(stat) XUIOSTAT_INCR(stat, 1)
#ifdef HAVE_UIO_ZEROCOPY
int
dmu_xuio_init(xuio_t *xuio, int nblk)
{
dmu_xuio_t *priv;
uio_t *uio = &xuio->xu_uio;
uio->uio_iovcnt = nblk;
uio->uio_iov = kmem_zalloc(nblk * sizeof (iovec_t), KM_SLEEP);
priv = kmem_zalloc(sizeof (dmu_xuio_t), KM_SLEEP);
priv->cnt = nblk;
priv->bufs = kmem_zalloc(nblk * sizeof (arc_buf_t *), KM_SLEEP);
priv->iovp = (iovec_t *)uio->uio_iov;
XUIO_XUZC_PRIV(xuio) = priv;
if (XUIO_XUZC_RW(xuio) == UIO_READ)
XUIOSTAT_INCR(xuiostat_onloan_rbuf, nblk);
else
XUIOSTAT_INCR(xuiostat_onloan_wbuf, nblk);
return (0);
}
void
dmu_xuio_fini(xuio_t *xuio)
{
dmu_xuio_t *priv = XUIO_XUZC_PRIV(xuio);
int nblk = priv->cnt;
kmem_free(priv->iovp, nblk * sizeof (iovec_t));
kmem_free(priv->bufs, nblk * sizeof (arc_buf_t *));
kmem_free(priv, sizeof (dmu_xuio_t));
if (XUIO_XUZC_RW(xuio) == UIO_READ)
XUIOSTAT_INCR(xuiostat_onloan_rbuf, -nblk);
else
XUIOSTAT_INCR(xuiostat_onloan_wbuf, -nblk);
}
/*
* Initialize iov[priv->next] and priv->bufs[priv->next] with { off, n, abuf }
* and increase priv->next by 1.
*/
int
dmu_xuio_add(xuio_t *xuio, arc_buf_t *abuf, offset_t off, size_t n)
{
struct iovec *iov;
uio_t *uio = &xuio->xu_uio;
dmu_xuio_t *priv = XUIO_XUZC_PRIV(xuio);
int i = priv->next++;
ASSERT(i < priv->cnt);
ASSERT(off + n <= arc_buf_lsize(abuf));
iov = (iovec_t *)uio->uio_iov + i;
iov->iov_base = (char *)abuf->b_data + off;
iov->iov_len = n;
priv->bufs[i] = abuf;
return (0);
}
int
dmu_xuio_cnt(xuio_t *xuio)
{
dmu_xuio_t *priv = XUIO_XUZC_PRIV(xuio);
return (priv->cnt);
}
arc_buf_t *
dmu_xuio_arcbuf(xuio_t *xuio, int i)
{
dmu_xuio_t *priv = XUIO_XUZC_PRIV(xuio);
ASSERT(i < priv->cnt);
return (priv->bufs[i]);
}
void
dmu_xuio_clear(xuio_t *xuio, int i)
{
dmu_xuio_t *priv = XUIO_XUZC_PRIV(xuio);
ASSERT(i < priv->cnt);
priv->bufs[i] = NULL;
}
#endif /* HAVE_UIO_ZEROCOPY */
static void
xuio_stat_init(void)
{
xuio_ksp = kstat_create("zfs", 0, "xuio_stats", "misc",
KSTAT_TYPE_NAMED, sizeof (xuio_stats) / sizeof (kstat_named_t),
KSTAT_FLAG_VIRTUAL);
if (xuio_ksp != NULL) {
xuio_ksp->ks_data = &xuio_stats;
kstat_install(xuio_ksp);
}
}
static void
xuio_stat_fini(void)
{
if (xuio_ksp != NULL) {
kstat_delete(xuio_ksp);
xuio_ksp = NULL;
}
}
void
xuio_stat_wbuf_copied(void)
{
XUIOSTAT_BUMP(xuiostat_wbuf_copied);
}
void
xuio_stat_wbuf_nocopy(void)
{
XUIOSTAT_BUMP(xuiostat_wbuf_nocopy);
}
#ifdef _KERNEL
int
dmu_read_uio_dnode(dnode_t *dn, uio_t *uio, uint64_t size)
{
dmu_buf_t **dbp;
int numbufs, i, err;
#ifdef HAVE_UIO_ZEROCOPY
xuio_t *xuio = NULL;
#endif
/*
* NB: we could do this block-at-a-time, but it's nice
* to be reading in parallel.
*/
err = dmu_buf_hold_array_by_dnode(dn, uio->uio_loffset, size,
TRUE, FTAG, &numbufs, &dbp, 0);
if (err)
return (err);
for (i = 0; i < numbufs; i++) {
uint64_t tocpy;
int64_t bufoff;
dmu_buf_t *db = dbp[i];
ASSERT(size > 0);
bufoff = uio->uio_loffset - db->db_offset;
tocpy = MIN(db->db_size - bufoff, size);
#ifdef HAVE_UIO_ZEROCOPY
if (xuio) {
dmu_buf_impl_t *dbi = (dmu_buf_impl_t *)db;
arc_buf_t *dbuf_abuf = dbi->db_buf;
arc_buf_t *abuf = dbuf_loan_arcbuf(dbi);
err = dmu_xuio_add(xuio, abuf, bufoff, tocpy);
if (!err) {
uio->uio_resid -= tocpy;
uio->uio_loffset += tocpy;
}
if (abuf == dbuf_abuf)
XUIOSTAT_BUMP(xuiostat_rbuf_nocopy);
else
XUIOSTAT_BUMP(xuiostat_rbuf_copied);
} else
#endif
err = uiomove((char *)db->db_data + bufoff, tocpy,
UIO_READ, uio);
if (err)
break;
size -= tocpy;
}
dmu_buf_rele_array(dbp, numbufs, FTAG);
return (err);
}
/*
* Read 'size' bytes into the uio buffer.
* From object zdb->db_object.
* Starting at offset uio->uio_loffset.
*
* If the caller already has a dbuf in the target object
* (e.g. its bonus buffer), this routine is faster than dmu_read_uio(),
* because we don't have to find the dnode_t for the object.
*/
int
dmu_read_uio_dbuf(dmu_buf_t *zdb, uio_t *uio, uint64_t size)
{
dmu_buf_impl_t *db = (dmu_buf_impl_t *)zdb;
dnode_t *dn;
int err;
if (size == 0)
return (0);
DB_DNODE_ENTER(db);
dn = DB_DNODE(db);
err = dmu_read_uio_dnode(dn, uio, size);
DB_DNODE_EXIT(db);
return (err);
}
/*
* Read 'size' bytes into the uio buffer.
* From the specified object
* Starting at offset uio->uio_loffset.
*/
int
dmu_read_uio(objset_t *os, uint64_t object, uio_t *uio, uint64_t size)
{
dnode_t *dn;
int err;
if (size == 0)
return (0);
err = dnode_hold(os, object, FTAG, &dn);
if (err)
return (err);
err = dmu_read_uio_dnode(dn, uio, size);
dnode_rele(dn, FTAG);
return (err);
}
int
dmu_write_uio_dnode(dnode_t *dn, uio_t *uio, uint64_t size, dmu_tx_t *tx)
{
dmu_buf_t **dbp;
int numbufs;
int err = 0;
int i;
err = dmu_buf_hold_array_by_dnode(dn, uio->uio_loffset, size,
FALSE, FTAG, &numbufs, &dbp, DMU_READ_PREFETCH);
if (err)
return (err);
for (i = 0; i < numbufs; i++) {
uint64_t tocpy;
int64_t bufoff;
dmu_buf_t *db = dbp[i];
ASSERT(size > 0);
bufoff = uio->uio_loffset - db->db_offset;
tocpy = MIN(db->db_size - bufoff, size);
ASSERT(i == 0 || i == numbufs-1 || tocpy == db->db_size);
if (tocpy == db->db_size)
dmu_buf_will_fill(db, tx);
else
dmu_buf_will_dirty(db, tx);
/*
* XXX uiomove could block forever (eg.nfs-backed
* pages). There needs to be a uiolockdown() function
* to lock the pages in memory, so that uiomove won't
* block.
*/
err = uiomove((char *)db->db_data + bufoff, tocpy,
UIO_WRITE, uio);
if (tocpy == db->db_size)
dmu_buf_fill_done(db, tx);
if (err)
break;
size -= tocpy;
}
dmu_buf_rele_array(dbp, numbufs, FTAG);
return (err);
}
/*
* Write 'size' bytes from the uio buffer.
* To object zdb->db_object.
* Starting at offset uio->uio_loffset.
*
* If the caller already has a dbuf in the target object
* (e.g. its bonus buffer), this routine is faster than dmu_write_uio(),
* because we don't have to find the dnode_t for the object.
*/
int
dmu_write_uio_dbuf(dmu_buf_t *zdb, uio_t *uio, uint64_t size,
dmu_tx_t *tx)
{
dmu_buf_impl_t *db = (dmu_buf_impl_t *)zdb;
dnode_t *dn;
int err;
if (size == 0)
return (0);
DB_DNODE_ENTER(db);
dn = DB_DNODE(db);
err = dmu_write_uio_dnode(dn, uio, size, tx);
DB_DNODE_EXIT(db);
return (err);
}
/*
* Write 'size' bytes from the uio buffer.
* To the specified object.
* Starting at offset uio->uio_loffset.
*/
int
dmu_write_uio(objset_t *os, uint64_t object, uio_t *uio, uint64_t size,
dmu_tx_t *tx)
{
dnode_t *dn;
int err;
if (size == 0)
return (0);
err = dnode_hold(os, object, FTAG, &dn);
if (err)
return (err);
err = dmu_write_uio_dnode(dn, uio, size, tx);
dnode_rele(dn, FTAG);
return (err);
}
#endif /* _KERNEL */
/*
* Allocate a loaned anonymous arc buffer.
*/
arc_buf_t *
dmu_request_arcbuf(dmu_buf_t *handle, int size)
{
dmu_buf_impl_t *db = (dmu_buf_impl_t *)handle;
return (arc_loan_buf(db->db_objset->os_spa, B_FALSE, size));
}
/*
* Free a loaned arc buffer.
*/
void
dmu_return_arcbuf(arc_buf_t *buf)
{
arc_return_buf(buf, FTAG);
arc_buf_destroy(buf, FTAG);
}
void
dmu_copy_from_buf(objset_t *os, uint64_t object, uint64_t offset,
dmu_buf_t *handle, dmu_tx_t *tx)
{
dmu_buf_t *dst_handle;
dmu_buf_impl_t *dstdb;
dmu_buf_impl_t *srcdb = (dmu_buf_impl_t *)handle;
dmu_object_type_t type;
arc_buf_t *abuf;
uint64_t datalen;
boolean_t byteorder;
uint8_t salt[ZIO_DATA_SALT_LEN];
uint8_t iv[ZIO_DATA_IV_LEN];
uint8_t mac[ZIO_DATA_MAC_LEN];
ASSERT3P(srcdb->db_buf, !=, NULL);
/* hold the db that we want to write to */
VERIFY0(dmu_buf_hold(os, object, offset, FTAG, &dst_handle,
DMU_READ_NO_DECRYPT));
dstdb = (dmu_buf_impl_t *)dst_handle;
datalen = arc_buf_size(srcdb->db_buf);
DB_DNODE_ENTER(dstdb);
type = DB_DNODE(dstdb)->dn_type;
DB_DNODE_EXIT(dstdb);
/* allocated an arc buffer that matches the type of srcdb->db_buf */
if (arc_is_encrypted(srcdb->db_buf)) {
arc_get_raw_params(srcdb->db_buf, &byteorder, salt, iv, mac);
abuf = arc_loan_raw_buf(os->os_spa, dmu_objset_id(os),
byteorder, salt, iv, mac, type,
datalen, arc_buf_lsize(srcdb->db_buf),
arc_get_compression(srcdb->db_buf));
} else {
/* we won't get a compressed db back from dmu_buf_hold() */
ASSERT3U(arc_get_compression(srcdb->db_buf),
==, ZIO_COMPRESS_OFF);
abuf = arc_loan_buf(os->os_spa,
DMU_OT_IS_METADATA(type), datalen);
}
ASSERT3U(datalen, ==, arc_buf_size(abuf));
/* copy the data to the new buffer and assign it to the dstdb */
bcopy(srcdb->db_buf->b_data, abuf->b_data, datalen);
dbuf_assign_arcbuf(dstdb, abuf, tx);
dmu_buf_rele(dst_handle, FTAG);
}
/*
* When possible directly assign passed loaned arc buffer to a dbuf.
* If this is not possible copy the contents of passed arc buf via
* dmu_write().
*/
int
dmu_assign_arcbuf_by_dnode(dnode_t *dn, uint64_t offset, arc_buf_t *buf,
dmu_tx_t *tx)
{
dmu_buf_impl_t *db;
objset_t *os = dn->dn_objset;
uint64_t object = dn->dn_object;
uint32_t blksz = (uint32_t)arc_buf_lsize(buf);
uint64_t blkid;
rw_enter(&dn->dn_struct_rwlock, RW_READER);
blkid = dbuf_whichblock(dn, 0, offset);
db = dbuf_hold(dn, blkid, FTAG);
if (db == NULL)
return (SET_ERROR(EIO));
rw_exit(&dn->dn_struct_rwlock);
/*
* We can only assign if the offset is aligned, the arc buf is the
* same size as the dbuf, and the dbuf is not metadata.
*/
if (offset == db->db.db_offset && blksz == db->db.db_size) {
dbuf_assign_arcbuf(db, buf, tx);
dbuf_rele(db, FTAG);
} else {
/* compressed bufs must always be assignable to their dbuf */
ASSERT3U(arc_get_compression(buf), ==, ZIO_COMPRESS_OFF);
ASSERT(!(buf->b_flags & ARC_BUF_FLAG_COMPRESSED));
dbuf_rele(db, FTAG);
dmu_write(os, object, offset, blksz, buf->b_data, tx);
dmu_return_arcbuf(buf);
XUIOSTAT_BUMP(xuiostat_wbuf_copied);
}
return (0);
}
int
dmu_assign_arcbuf_by_dbuf(dmu_buf_t *handle, uint64_t offset, arc_buf_t *buf,
dmu_tx_t *tx)
{
int err;
dmu_buf_impl_t *dbuf = (dmu_buf_impl_t *)handle;
DB_DNODE_ENTER(dbuf);
err = dmu_assign_arcbuf_by_dnode(DB_DNODE(dbuf), offset, buf, tx);
DB_DNODE_EXIT(dbuf);
return (err);
}
typedef struct {
dbuf_dirty_record_t *dsa_dr;
dmu_sync_cb_t *dsa_done;
zgd_t *dsa_zgd;
dmu_tx_t *dsa_tx;
} dmu_sync_arg_t;
/* ARGSUSED */
static void
dmu_sync_ready(zio_t *zio, arc_buf_t *buf, void *varg)
{
dmu_sync_arg_t *dsa = varg;
dmu_buf_t *db = dsa->dsa_zgd->zgd_db;
blkptr_t *bp = zio->io_bp;
if (zio->io_error == 0) {
if (BP_IS_HOLE(bp)) {
/*
* A block of zeros may compress to a hole, but the
* block size still needs to be known for replay.
*/
BP_SET_LSIZE(bp, db->db_size);
} else if (!BP_IS_EMBEDDED(bp)) {
ASSERT(BP_GET_LEVEL(bp) == 0);
BP_SET_FILL(bp, 1);
}
}
}
static void
dmu_sync_late_arrival_ready(zio_t *zio)
{
dmu_sync_ready(zio, NULL, zio->io_private);
}
/* ARGSUSED */
static void
dmu_sync_done(zio_t *zio, arc_buf_t *buf, void *varg)
{
dmu_sync_arg_t *dsa = varg;
dbuf_dirty_record_t *dr = dsa->dsa_dr;
dmu_buf_impl_t *db = dr->dr_dbuf;
zgd_t *zgd = dsa->dsa_zgd;
/*
* Record the vdev(s) backing this blkptr so they can be flushed after
* the writes for the lwb have completed.
*/
if (zio->io_error == 0) {
zil_lwb_add_block(zgd->zgd_lwb, zgd->zgd_bp);
}
mutex_enter(&db->db_mtx);
ASSERT(dr->dt.dl.dr_override_state == DR_IN_DMU_SYNC);
if (zio->io_error == 0) {
dr->dt.dl.dr_nopwrite = !!(zio->io_flags & ZIO_FLAG_NOPWRITE);
if (dr->dt.dl.dr_nopwrite) {
blkptr_t *bp = zio->io_bp;
blkptr_t *bp_orig = &zio->io_bp_orig;
uint8_t chksum = BP_GET_CHECKSUM(bp_orig);
ASSERT(BP_EQUAL(bp, bp_orig));
VERIFY(BP_EQUAL(bp, db->db_blkptr));
ASSERT(zio->io_prop.zp_compress != ZIO_COMPRESS_OFF);
VERIFY(zio_checksum_table[chksum].ci_flags &
ZCHECKSUM_FLAG_NOPWRITE);
}
dr->dt.dl.dr_overridden_by = *zio->io_bp;
dr->dt.dl.dr_override_state = DR_OVERRIDDEN;
dr->dt.dl.dr_copies = zio->io_prop.zp_copies;
/*
* Old style holes are filled with all zeros, whereas
* new-style holes maintain their lsize, type, level,
* and birth time (see zio_write_compress). While we
* need to reset the BP_SET_LSIZE() call that happened
* in dmu_sync_ready for old style holes, we do *not*
* want to wipe out the information contained in new
* style holes. Thus, only zero out the block pointer if
* it's an old style hole.
*/
if (BP_IS_HOLE(&dr->dt.dl.dr_overridden_by) &&
dr->dt.dl.dr_overridden_by.blk_birth == 0)
BP_ZERO(&dr->dt.dl.dr_overridden_by);
} else {
dr->dt.dl.dr_override_state = DR_NOT_OVERRIDDEN;
}
cv_broadcast(&db->db_changed);
mutex_exit(&db->db_mtx);
dsa->dsa_done(dsa->dsa_zgd, zio->io_error);
kmem_free(dsa, sizeof (*dsa));
}
static void
dmu_sync_late_arrival_done(zio_t *zio)
{
blkptr_t *bp = zio->io_bp;
dmu_sync_arg_t *dsa = zio->io_private;
zgd_t *zgd = dsa->dsa_zgd;
if (zio->io_error == 0) {
/*
* Record the vdev(s) backing this blkptr so they can be
* flushed after the writes for the lwb have completed.
*/
zil_lwb_add_block(zgd->zgd_lwb, zgd->zgd_bp);
if (!BP_IS_HOLE(bp)) {
ASSERTV(blkptr_t *bp_orig = &zio->io_bp_orig);
ASSERT(!(zio->io_flags & ZIO_FLAG_NOPWRITE));
ASSERT(BP_IS_HOLE(bp_orig) || !BP_EQUAL(bp, bp_orig));
ASSERT(zio->io_bp->blk_birth == zio->io_txg);
ASSERT(zio->io_txg > spa_syncing_txg(zio->io_spa));
zio_free(zio->io_spa, zio->io_txg, zio->io_bp);
}
}
dmu_tx_commit(dsa->dsa_tx);
dsa->dsa_done(dsa->dsa_zgd, zio->io_error);
abd_put(zio->io_abd);
kmem_free(dsa, sizeof (*dsa));
}
static int
dmu_sync_late_arrival(zio_t *pio, objset_t *os, dmu_sync_cb_t *done, zgd_t *zgd,
zio_prop_t *zp, zbookmark_phys_t *zb)
{
dmu_sync_arg_t *dsa;
dmu_tx_t *tx;
tx = dmu_tx_create(os);
dmu_tx_hold_space(tx, zgd->zgd_db->db_size);
if (dmu_tx_assign(tx, TXG_WAIT) != 0) {
dmu_tx_abort(tx);
/* Make zl_get_data do txg_waited_synced() */
return (SET_ERROR(EIO));
}
/*
* In order to prevent the zgd's lwb from being free'd prior to
* dmu_sync_late_arrival_done() being called, we have to ensure
* the lwb's "max txg" takes this tx's txg into account.
*/
zil_lwb_add_txg(zgd->zgd_lwb, dmu_tx_get_txg(tx));
dsa = kmem_alloc(sizeof (dmu_sync_arg_t), KM_SLEEP);
dsa->dsa_dr = NULL;
dsa->dsa_done = done;
dsa->dsa_zgd = zgd;
dsa->dsa_tx = tx;
/*
* Since we are currently syncing this txg, it's nontrivial to
* determine what BP to nopwrite against, so we disable nopwrite.
*
* When syncing, the db_blkptr is initially the BP of the previous
* txg. We can not nopwrite against it because it will be changed
* (this is similar to the non-late-arrival case where the dbuf is
* dirty in a future txg).
*
* Then dbuf_write_ready() sets bp_blkptr to the location we will write.
* We can not nopwrite against it because although the BP will not
* (typically) be changed, the data has not yet been persisted to this
* location.
*
* Finally, when dbuf_write_done() is called, it is theoretically
* possible to always nopwrite, because the data that was written in
* this txg is the same data that we are trying to write. However we
* would need to check that this dbuf is not dirty in any future
* txg's (as we do in the normal dmu_sync() path). For simplicity, we
* don't nopwrite in this case.
*/
zp->zp_nopwrite = B_FALSE;
zio_nowait(zio_write(pio, os->os_spa, dmu_tx_get_txg(tx), zgd->zgd_bp,
abd_get_from_buf(zgd->zgd_db->db_data, zgd->zgd_db->db_size),
zgd->zgd_db->db_size, zgd->zgd_db->db_size, zp,
dmu_sync_late_arrival_ready, NULL, NULL, dmu_sync_late_arrival_done,
dsa, ZIO_PRIORITY_SYNC_WRITE, ZIO_FLAG_CANFAIL, zb));
return (0);
}
/*
* Intent log support: sync the block associated with db to disk.
* N.B. and XXX: the caller is responsible for making sure that the
* data isn't changing while dmu_sync() is writing it.
*
* Return values:
*
* EEXIST: this txg has already been synced, so there's nothing to do.
* The caller should not log the write.
*
* ENOENT: the block was dbuf_free_range()'d, so there's nothing to do.
* The caller should not log the write.
*
* EALREADY: this block is already in the process of being synced.
* The caller should track its progress (somehow).
*
* EIO: could not do the I/O.
* The caller should do a txg_wait_synced().
*
* 0: the I/O has been initiated.
* The caller should log this blkptr in the done callback.
* It is possible that the I/O will fail, in which case
* the error will be reported to the done callback and
* propagated to pio from zio_done().
*/
int
dmu_sync(zio_t *pio, uint64_t txg, dmu_sync_cb_t *done, zgd_t *zgd)
{
dmu_buf_impl_t *db = (dmu_buf_impl_t *)zgd->zgd_db;
objset_t *os = db->db_objset;
dsl_dataset_t *ds = os->os_dsl_dataset;
dbuf_dirty_record_t *dr;
dmu_sync_arg_t *dsa;
zbookmark_phys_t zb;
zio_prop_t zp;
dnode_t *dn;
ASSERT(pio != NULL);
ASSERT(txg != 0);
SET_BOOKMARK(&zb, ds->ds_object,
db->db.db_object, db->db_level, db->db_blkid);
DB_DNODE_ENTER(db);
dn = DB_DNODE(db);
dmu_write_policy(os, dn, db->db_level, WP_DMU_SYNC, &zp);
DB_DNODE_EXIT(db);
/*
* If we're frozen (running ziltest), we always need to generate a bp.
*/
if (txg > spa_freeze_txg(os->os_spa))
return (dmu_sync_late_arrival(pio, os, done, zgd, &zp, &zb));
/*
* Grabbing db_mtx now provides a barrier between dbuf_sync_leaf()
* and us. If we determine that this txg is not yet syncing,
* but it begins to sync a moment later, that's OK because the
* sync thread will block in dbuf_sync_leaf() until we drop db_mtx.
*/
mutex_enter(&db->db_mtx);
if (txg <= spa_last_synced_txg(os->os_spa)) {
/*
* This txg has already synced. There's nothing to do.
*/
mutex_exit(&db->db_mtx);
return (SET_ERROR(EEXIST));
}
if (txg <= spa_syncing_txg(os->os_spa)) {
/*
* This txg is currently syncing, so we can't mess with
* the dirty record anymore; just write a new log block.
*/
mutex_exit(&db->db_mtx);
return (dmu_sync_late_arrival(pio, os, done, zgd, &zp, &zb));
}
dr = db->db_last_dirty;
while (dr && dr->dr_txg != txg)
dr = dr->dr_next;
if (dr == NULL) {
/*
* There's no dr for this dbuf, so it must have been freed.
* There's no need to log writes to freed blocks, so we're done.
*/
mutex_exit(&db->db_mtx);
return (SET_ERROR(ENOENT));
}
ASSERT(dr->dr_next == NULL || dr->dr_next->dr_txg < txg);
if (db->db_blkptr != NULL) {
/*
* We need to fill in zgd_bp with the current blkptr so that
* the nopwrite code can check if we're writing the same
* data that's already on disk. We can only nopwrite if we
* are sure that after making the copy, db_blkptr will not
* change until our i/o completes. We ensure this by
* holding the db_mtx, and only allowing nopwrite if the
* block is not already dirty (see below). This is verified
* by dmu_sync_done(), which VERIFYs that the db_blkptr has
* not changed.
*/
*zgd->zgd_bp = *db->db_blkptr;
}
/*
* Assume the on-disk data is X, the current syncing data (in
* txg - 1) is Y, and the current in-memory data is Z (currently
* in dmu_sync).
*
* We usually want to perform a nopwrite if X and Z are the
* same. However, if Y is different (i.e. the BP is going to
* change before this write takes effect), then a nopwrite will
* be incorrect - we would override with X, which could have
* been freed when Y was written.
*
* (Note that this is not a concern when we are nop-writing from
* syncing context, because X and Y must be identical, because
* all previous txgs have been synced.)
*
* Therefore, we disable nopwrite if the current BP could change
* before this TXG. There are two ways it could change: by
* being dirty (dr_next is non-NULL), or by being freed
* (dnode_block_freed()). This behavior is verified by
* zio_done(), which VERIFYs that the override BP is identical
* to the on-disk BP.
*/
DB_DNODE_ENTER(db);
dn = DB_DNODE(db);
if (dr->dr_next != NULL || dnode_block_freed(dn, db->db_blkid))
zp.zp_nopwrite = B_FALSE;
DB_DNODE_EXIT(db);
ASSERT(dr->dr_txg == txg);
if (dr->dt.dl.dr_override_state == DR_IN_DMU_SYNC ||
dr->dt.dl.dr_override_state == DR_OVERRIDDEN) {
/*
* We have already issued a sync write for this buffer,
* or this buffer has already been synced. It could not
* have been dirtied since, or we would have cleared the state.
*/
mutex_exit(&db->db_mtx);
return (SET_ERROR(EALREADY));
}
ASSERT(dr->dt.dl.dr_override_state == DR_NOT_OVERRIDDEN);
dr->dt.dl.dr_override_state = DR_IN_DMU_SYNC;
mutex_exit(&db->db_mtx);
dsa = kmem_alloc(sizeof (dmu_sync_arg_t), KM_SLEEP);
dsa->dsa_dr = dr;
dsa->dsa_done = done;
dsa->dsa_zgd = zgd;
dsa->dsa_tx = NULL;
zio_nowait(arc_write(pio, os->os_spa, txg,
zgd->zgd_bp, dr->dt.dl.dr_data, DBUF_IS_L2CACHEABLE(db),
&zp, dmu_sync_ready, NULL, NULL, dmu_sync_done, dsa,
ZIO_PRIORITY_SYNC_WRITE, ZIO_FLAG_CANFAIL, &zb));
return (0);
}
int
dmu_object_set_nlevels(objset_t *os, uint64_t object, int nlevels, dmu_tx_t *tx)
{
dnode_t *dn;
int err;
err = dnode_hold(os, object, FTAG, &dn);
if (err)
return (err);
err = dnode_set_nlevels(dn, nlevels, tx);
dnode_rele(dn, FTAG);
return (err);
}
int
dmu_object_set_blocksize(objset_t *os, uint64_t object, uint64_t size, int ibs,
dmu_tx_t *tx)
{
dnode_t *dn;
int err;
err = dnode_hold(os, object, FTAG, &dn);
if (err)
return (err);
err = dnode_set_blksz(dn, size, ibs, tx);
dnode_rele(dn, FTAG);
return (err);
}
int
dmu_object_set_maxblkid(objset_t *os, uint64_t object, uint64_t maxblkid,
dmu_tx_t *tx)
{
dnode_t *dn;
int err;
err = dnode_hold(os, object, FTAG, &dn);
if (err)
return (err);
rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
dnode_new_blkid(dn, maxblkid, tx, B_FALSE, B_TRUE);
rw_exit(&dn->dn_struct_rwlock);
dnode_rele(dn, FTAG);
return (0);
}
void
dmu_object_set_checksum(objset_t *os, uint64_t object, uint8_t checksum,
dmu_tx_t *tx)
{
dnode_t *dn;
/*
* Send streams include each object's checksum function. This
* check ensures that the receiving system can understand the
* checksum function transmitted.
*/
ASSERT3U(checksum, <, ZIO_CHECKSUM_LEGACY_FUNCTIONS);
VERIFY0(dnode_hold(os, object, FTAG, &dn));
ASSERT3U(checksum, <, ZIO_CHECKSUM_FUNCTIONS);
dn->dn_checksum = checksum;
dnode_setdirty(dn, tx);
dnode_rele(dn, FTAG);
}
void
dmu_object_set_compress(objset_t *os, uint64_t object, uint8_t compress,
dmu_tx_t *tx)
{
dnode_t *dn;
/*
* Send streams include each object's compression function. This
* check ensures that the receiving system can understand the
* compression function transmitted.
*/
ASSERT3U(compress, <, ZIO_COMPRESS_LEGACY_FUNCTIONS);
VERIFY0(dnode_hold(os, object, FTAG, &dn));
dn->dn_compress = compress;
dnode_setdirty(dn, tx);
dnode_rele(dn, FTAG);
}
/*
* When the "redundant_metadata" property is set to "most", only indirect
* blocks of this level and higher will have an additional ditto block.
*/
int zfs_redundant_metadata_most_ditto_level = 2;
void
dmu_write_policy(objset_t *os, dnode_t *dn, int level, int wp, zio_prop_t *zp)
{
dmu_object_type_t type = dn ? dn->dn_type : DMU_OT_OBJSET;
boolean_t ismd = (level > 0 || DMU_OT_IS_METADATA(type) ||
(wp & WP_SPILL));
enum zio_checksum checksum = os->os_checksum;
enum zio_compress compress = os->os_compress;
enum zio_checksum dedup_checksum = os->os_dedup_checksum;
boolean_t dedup = B_FALSE;
boolean_t nopwrite = B_FALSE;
boolean_t dedup_verify = os->os_dedup_verify;
boolean_t encrypt = B_FALSE;
int copies = os->os_copies;
/*
* We maintain different write policies for each of the following
* types of data:
* 1. metadata
* 2. preallocated blocks (i.e. level-0 blocks of a dump device)
* 3. all other level 0 blocks
*/
if (ismd) {
/*
* XXX -- we should design a compression algorithm
* that specializes in arrays of bps.
*/
compress = zio_compress_select(os->os_spa,
ZIO_COMPRESS_ON, ZIO_COMPRESS_ON);
/*
* Metadata always gets checksummed. If the data
* checksum is multi-bit correctable, and it's not a
* ZBT-style checksum, then it's suitable for metadata
* as well. Otherwise, the metadata checksum defaults
* to fletcher4.
*/
if (!(zio_checksum_table[checksum].ci_flags &
ZCHECKSUM_FLAG_METADATA) ||
(zio_checksum_table[checksum].ci_flags &
ZCHECKSUM_FLAG_EMBEDDED))
checksum = ZIO_CHECKSUM_FLETCHER_4;
if (os->os_redundant_metadata == ZFS_REDUNDANT_METADATA_ALL ||
(os->os_redundant_metadata ==
ZFS_REDUNDANT_METADATA_MOST &&
(level >= zfs_redundant_metadata_most_ditto_level ||
DMU_OT_IS_METADATA(type) || (wp & WP_SPILL))))
copies++;
} else if (wp & WP_NOFILL) {
ASSERT(level == 0);
/*
* If we're writing preallocated blocks, we aren't actually
* writing them so don't set any policy properties. These
* blocks are currently only used by an external subsystem
* outside of zfs (i.e. dump) and not written by the zio
* pipeline.
*/
compress = ZIO_COMPRESS_OFF;
checksum = ZIO_CHECKSUM_OFF;
} else {
compress = zio_compress_select(os->os_spa, dn->dn_compress,
compress);
checksum = (dedup_checksum == ZIO_CHECKSUM_OFF) ?
zio_checksum_select(dn->dn_checksum, checksum) :
dedup_checksum;
/*
* Determine dedup setting. If we are in dmu_sync(),
* we won't actually dedup now because that's all
* done in syncing context; but we do want to use the
* dedup checkum. If the checksum is not strong
* enough to ensure unique signatures, force
* dedup_verify.
*/
if (dedup_checksum != ZIO_CHECKSUM_OFF) {
dedup = (wp & WP_DMU_SYNC) ? B_FALSE : B_TRUE;
if (!(zio_checksum_table[checksum].ci_flags &
ZCHECKSUM_FLAG_DEDUP))
dedup_verify = B_TRUE;
}
/*
* Enable nopwrite if we have secure enough checksum
* algorithm (see comment in zio_nop_write) and
* compression is enabled. We don't enable nopwrite if
* dedup is enabled as the two features are mutually
* exclusive.
*/
nopwrite = (!dedup && (zio_checksum_table[checksum].ci_flags &
ZCHECKSUM_FLAG_NOPWRITE) &&
compress != ZIO_COMPRESS_OFF && zfs_nopwrite_enabled);
}
/*
* All objects in an encrypted objset are protected from modification
* via a MAC. Encrypted objects store their IV and salt in the last DVA
* in the bp, so we cannot use all copies. Encrypted objects are also
* not subject to nopwrite since writing the same data will still
* result in a new ciphertext. Only encrypted blocks can be dedup'd
* to avoid ambiguity in the dedup code since the DDT does not store
* object types.
*/
if (os->os_encrypted && (wp & WP_NOFILL) == 0) {
encrypt = B_TRUE;
if (DMU_OT_IS_ENCRYPTED(type)) {
copies = MIN(copies, SPA_DVAS_PER_BP - 1);
nopwrite = B_FALSE;
} else {
dedup = B_FALSE;
}
if (level <= 0 &&
(type == DMU_OT_DNODE || type == DMU_OT_OBJSET)) {
compress = ZIO_COMPRESS_EMPTY;
}
}
zp->zp_compress = compress;
zp->zp_checksum = checksum;
zp->zp_type = (wp & WP_SPILL) ? dn->dn_bonustype : type;
zp->zp_level = level;
zp->zp_copies = MIN(copies, spa_max_replication(os->os_spa));
zp->zp_dedup = dedup;
zp->zp_dedup_verify = dedup && dedup_verify;
zp->zp_nopwrite = nopwrite;
zp->zp_encrypt = encrypt;
zp->zp_byteorder = ZFS_HOST_BYTEORDER;
bzero(zp->zp_salt, ZIO_DATA_SALT_LEN);
bzero(zp->zp_iv, ZIO_DATA_IV_LEN);
bzero(zp->zp_mac, ZIO_DATA_MAC_LEN);
zp->zp_zpl_smallblk = DMU_OT_IS_FILE(zp->zp_type) ?
os->os_zpl_special_smallblock : 0;
ASSERT3U(zp->zp_compress, !=, ZIO_COMPRESS_INHERIT);
}
/*
* This function is only called from zfs_holey_common() for zpl_llseek()
* in order to determine the location of holes. In order to accurately
* report holes all dirty data must be synced to disk. This causes extremely
* poor performance when seeking for holes in a dirty file. As a compromise,
* only provide hole data when the dnode is clean. When a dnode is dirty
* report the dnode as having no holes which is always a safe thing to do.
*/
int
dmu_offset_next(objset_t *os, uint64_t object, boolean_t hole, uint64_t *off)
{
dnode_t *dn;
int i, err;
boolean_t clean = B_TRUE;
err = dnode_hold(os, object, FTAG, &dn);
if (err)
return (err);
/*
* Check if dnode is dirty
*/
for (i = 0; i < TXG_SIZE; i++) {
if (multilist_link_active(&dn->dn_dirty_link[i])) {
clean = B_FALSE;
break;
}
}
/*
* If compatibility option is on, sync any current changes before
* we go trundling through the block pointers.
*/
if (!clean && zfs_dmu_offset_next_sync) {
clean = B_TRUE;
dnode_rele(dn, FTAG);
txg_wait_synced(dmu_objset_pool(os), 0);
err = dnode_hold(os, object, FTAG, &dn);
if (err)
return (err);
}
if (clean)
err = dnode_next_offset(dn,
(hole ? DNODE_FIND_HOLE : 0), off, 1, 1, 0);
else
err = SET_ERROR(EBUSY);
dnode_rele(dn, FTAG);
return (err);
}
void
__dmu_object_info_from_dnode(dnode_t *dn, dmu_object_info_t *doi)
{
dnode_phys_t *dnp = dn->dn_phys;
doi->doi_data_block_size = dn->dn_datablksz;
doi->doi_metadata_block_size = dn->dn_indblkshift ?
1ULL << dn->dn_indblkshift : 0;
doi->doi_type = dn->dn_type;
doi->doi_bonus_type = dn->dn_bonustype;
doi->doi_bonus_size = dn->dn_bonuslen;
doi->doi_dnodesize = dn->dn_num_slots << DNODE_SHIFT;
doi->doi_indirection = dn->dn_nlevels;
doi->doi_checksum = dn->dn_checksum;
doi->doi_compress = dn->dn_compress;
doi->doi_nblkptr = dn->dn_nblkptr;
doi->doi_physical_blocks_512 = (DN_USED_BYTES(dnp) + 256) >> 9;
doi->doi_max_offset = (dn->dn_maxblkid + 1) * dn->dn_datablksz;
doi->doi_fill_count = 0;
for (int i = 0; i < dnp->dn_nblkptr; i++)
doi->doi_fill_count += BP_GET_FILL(&dnp->dn_blkptr[i]);
}
void
dmu_object_info_from_dnode(dnode_t *dn, dmu_object_info_t *doi)
{
rw_enter(&dn->dn_struct_rwlock, RW_READER);
mutex_enter(&dn->dn_mtx);
__dmu_object_info_from_dnode(dn, doi);
mutex_exit(&dn->dn_mtx);
rw_exit(&dn->dn_struct_rwlock);
}
/*
* Get information on a DMU object.
* If doi is NULL, just indicates whether the object exists.
*/
int
dmu_object_info(objset_t *os, uint64_t object, dmu_object_info_t *doi)
{
dnode_t *dn;
int err = dnode_hold(os, object, FTAG, &dn);
if (err)
return (err);
if (doi != NULL)
dmu_object_info_from_dnode(dn, doi);
dnode_rele(dn, FTAG);
return (0);
}
/*
* As above, but faster; can be used when you have a held dbuf in hand.
*/
void
dmu_object_info_from_db(dmu_buf_t *db_fake, dmu_object_info_t *doi)
{
dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
DB_DNODE_ENTER(db);
dmu_object_info_from_dnode(DB_DNODE(db), doi);
DB_DNODE_EXIT(db);
}
/*
* Faster still when you only care about the size.
* This is specifically optimized for zfs_getattr().
*/
void
dmu_object_size_from_db(dmu_buf_t *db_fake, uint32_t *blksize,
u_longlong_t *nblk512)
{
dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
dnode_t *dn;
DB_DNODE_ENTER(db);
dn = DB_DNODE(db);
*blksize = dn->dn_datablksz;
/* add in number of slots used for the dnode itself */
*nblk512 = ((DN_USED_BYTES(dn->dn_phys) + SPA_MINBLOCKSIZE/2) >>
SPA_MINBLOCKSHIFT) + dn->dn_num_slots;
DB_DNODE_EXIT(db);
}
void
dmu_object_dnsize_from_db(dmu_buf_t *db_fake, int *dnsize)
{
dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
dnode_t *dn;
DB_DNODE_ENTER(db);
dn = DB_DNODE(db);
*dnsize = dn->dn_num_slots << DNODE_SHIFT;
DB_DNODE_EXIT(db);
}
void
byteswap_uint64_array(void *vbuf, size_t size)
{
uint64_t *buf = vbuf;
size_t count = size >> 3;
int i;
ASSERT((size & 7) == 0);
for (i = 0; i < count; i++)
buf[i] = BSWAP_64(buf[i]);
}
void
byteswap_uint32_array(void *vbuf, size_t size)
{
uint32_t *buf = vbuf;
size_t count = size >> 2;
int i;
ASSERT((size & 3) == 0);
for (i = 0; i < count; i++)
buf[i] = BSWAP_32(buf[i]);
}
void
byteswap_uint16_array(void *vbuf, size_t size)
{
uint16_t *buf = vbuf;
size_t count = size >> 1;
int i;
ASSERT((size & 1) == 0);
for (i = 0; i < count; i++)
buf[i] = BSWAP_16(buf[i]);
}
/* ARGSUSED */
void
byteswap_uint8_array(void *vbuf, size_t size)
{
}
void
dmu_init(void)
{
abd_init();
zfs_dbgmsg_init();
sa_cache_init();
xuio_stat_init();
dmu_objset_init();
dnode_init();
zfetch_init();
dmu_tx_init();
l2arc_init();
arc_init();
dbuf_init();
}
void
dmu_fini(void)
{
arc_fini(); /* arc depends on l2arc, so arc must go first */
l2arc_fini();
dmu_tx_fini();
zfetch_fini();
dbuf_fini();
dnode_fini();
dmu_objset_fini();
xuio_stat_fini();
sa_cache_fini();
zfs_dbgmsg_fini();
abd_fini();
}
#if defined(_KERNEL)
EXPORT_SYMBOL(dmu_bonus_hold);
EXPORT_SYMBOL(dmu_bonus_hold_by_dnode);
EXPORT_SYMBOL(dmu_buf_hold_array_by_bonus);
EXPORT_SYMBOL(dmu_buf_rele_array);
EXPORT_SYMBOL(dmu_prefetch);
EXPORT_SYMBOL(dmu_free_range);
EXPORT_SYMBOL(dmu_free_long_range);
EXPORT_SYMBOL(dmu_free_long_object);
EXPORT_SYMBOL(dmu_read);
EXPORT_SYMBOL(dmu_read_by_dnode);
EXPORT_SYMBOL(dmu_write);
EXPORT_SYMBOL(dmu_write_by_dnode);
EXPORT_SYMBOL(dmu_prealloc);
EXPORT_SYMBOL(dmu_object_info);
EXPORT_SYMBOL(dmu_object_info_from_dnode);
EXPORT_SYMBOL(dmu_object_info_from_db);
EXPORT_SYMBOL(dmu_object_size_from_db);
EXPORT_SYMBOL(dmu_object_dnsize_from_db);
EXPORT_SYMBOL(dmu_object_set_nlevels);
EXPORT_SYMBOL(dmu_object_set_blocksize);
EXPORT_SYMBOL(dmu_object_set_maxblkid);
EXPORT_SYMBOL(dmu_object_set_checksum);
EXPORT_SYMBOL(dmu_object_set_compress);
EXPORT_SYMBOL(dmu_write_policy);
EXPORT_SYMBOL(dmu_sync);
EXPORT_SYMBOL(dmu_request_arcbuf);
EXPORT_SYMBOL(dmu_return_arcbuf);
EXPORT_SYMBOL(dmu_assign_arcbuf_by_dnode);
EXPORT_SYMBOL(dmu_assign_arcbuf_by_dbuf);
EXPORT_SYMBOL(dmu_buf_hold);
EXPORT_SYMBOL(dmu_ot);
/* BEGIN CSTYLED */
module_param(zfs_nopwrite_enabled, int, 0644);
MODULE_PARM_DESC(zfs_nopwrite_enabled, "Enable NOP writes");
module_param(zfs_per_txg_dirty_frees_percent, ulong, 0644);
MODULE_PARM_DESC(zfs_per_txg_dirty_frees_percent,
"percentage of dirtied blocks from frees in one TXG");
module_param(zfs_dmu_offset_next_sync, int, 0644);
MODULE_PARM_DESC(zfs_dmu_offset_next_sync,
"Enable forcing txg sync to find holes");
/* END CSTYLED */
#endif
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