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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 2011 Nexenta Systems, Inc. All rights reserved.
*/
#include <sys/dmu.h>
#include <sys/dmu_impl.h>
#include <sys/dbuf.h>
#include <sys/dmu_tx.h>
#include <sys/dmu_objset.h>
#include <sys/dsl_dataset.h> /* for dsl_dataset_block_freeable() */
#include <sys/dsl_dir.h> /* for dsl_dir_tempreserve_*() */
#include <sys/dsl_pool.h>
#include <sys/zap_impl.h> /* for fzap_default_block_shift */
#include <sys/spa.h>
#include <sys/sa.h>
#include <sys/sa_impl.h>
#include <sys/zfs_context.h>
#include <sys/varargs.h>
typedef void (*dmu_tx_hold_func_t)(dmu_tx_t *tx, struct dnode *dn,
uint64_t arg1, uint64_t arg2);
dmu_tx_t *
dmu_tx_create_dd(dsl_dir_t *dd)
{
dmu_tx_t *tx = kmem_zalloc(sizeof (dmu_tx_t), KM_SLEEP);
tx->tx_dir = dd;
if (dd)
tx->tx_pool = dd->dd_pool;
list_create(&tx->tx_holds, sizeof (dmu_tx_hold_t),
offsetof(dmu_tx_hold_t, txh_node));
list_create(&tx->tx_callbacks, sizeof (dmu_tx_callback_t),
offsetof(dmu_tx_callback_t, dcb_node));
#ifdef ZFS_DEBUG
refcount_create(&tx->tx_space_written);
refcount_create(&tx->tx_space_freed);
#endif
return (tx);
}
dmu_tx_t *
dmu_tx_create(objset_t *os)
{
dmu_tx_t *tx = dmu_tx_create_dd(os->os_dsl_dataset->ds_dir);
tx->tx_objset = os;
tx->tx_lastsnap_txg = dsl_dataset_prev_snap_txg(os->os_dsl_dataset);
return (tx);
}
dmu_tx_t *
dmu_tx_create_assigned(struct dsl_pool *dp, uint64_t txg)
{
dmu_tx_t *tx = dmu_tx_create_dd(NULL);
ASSERT3U(txg, <=, dp->dp_tx.tx_open_txg);
tx->tx_pool = dp;
tx->tx_txg = txg;
tx->tx_anyobj = TRUE;
return (tx);
}
int
dmu_tx_is_syncing(dmu_tx_t *tx)
{
return (tx->tx_anyobj);
}
int
dmu_tx_private_ok(dmu_tx_t *tx)
{
return (tx->tx_anyobj);
}
static dmu_tx_hold_t *
dmu_tx_hold_object_impl(dmu_tx_t *tx, objset_t *os, uint64_t object,
enum dmu_tx_hold_type type, uint64_t arg1, uint64_t arg2)
{
dmu_tx_hold_t *txh;
dnode_t *dn = NULL;
int err;
if (object != DMU_NEW_OBJECT) {
err = dnode_hold(os, object, tx, &dn);
if (err) {
tx->tx_err = err;
return (NULL);
}
if (err == 0 && tx->tx_txg != 0) {
mutex_enter(&dn->dn_mtx);
/*
* dn->dn_assigned_txg == tx->tx_txg doesn't pose a
* problem, but there's no way for it to happen (for
* now, at least).
*/
ASSERT(dn->dn_assigned_txg == 0);
dn->dn_assigned_txg = tx->tx_txg;
(void) refcount_add(&dn->dn_tx_holds, tx);
mutex_exit(&dn->dn_mtx);
}
}
txh = kmem_zalloc(sizeof (dmu_tx_hold_t), KM_SLEEP);
txh->txh_tx = tx;
txh->txh_dnode = dn;
#ifdef ZFS_DEBUG
txh->txh_type = type;
txh->txh_arg1 = arg1;
txh->txh_arg2 = arg2;
#endif
list_insert_tail(&tx->tx_holds, txh);
return (txh);
}
void
dmu_tx_add_new_object(dmu_tx_t *tx, objset_t *os, uint64_t object)
{
/*
* If we're syncing, they can manipulate any object anyhow, and
* the hold on the dnode_t can cause problems.
*/
if (!dmu_tx_is_syncing(tx)) {
(void) dmu_tx_hold_object_impl(tx, os,
object, THT_NEWOBJECT, 0, 0);
}
}
static int
dmu_tx_check_ioerr(zio_t *zio, dnode_t *dn, int level, uint64_t blkid)
{
int err;
dmu_buf_impl_t *db;
rw_enter(&dn->dn_struct_rwlock, RW_READER);
db = dbuf_hold_level(dn, level, blkid, FTAG);
rw_exit(&dn->dn_struct_rwlock);
if (db == NULL)
return (EIO);
err = dbuf_read(db, zio, DB_RF_CANFAIL | DB_RF_NOPREFETCH);
dbuf_rele(db, FTAG);
return (err);
}
static void
dmu_tx_count_twig(dmu_tx_hold_t *txh, dnode_t *dn, dmu_buf_impl_t *db,
int level, uint64_t blkid, boolean_t freeable, uint64_t *history)
{
objset_t *os = dn->dn_objset;
dsl_dataset_t *ds = os->os_dsl_dataset;
int epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT;
dmu_buf_impl_t *parent = NULL;
blkptr_t *bp = NULL;
uint64_t space;
if (level >= dn->dn_nlevels || history[level] == blkid)
return;
history[level] = blkid;
space = (level == 0) ? dn->dn_datablksz : (1ULL << dn->dn_indblkshift);
if (db == NULL || db == dn->dn_dbuf) {
ASSERT(level != 0);
db = NULL;
} else {
ASSERT(DB_DNODE(db) == dn);
ASSERT(db->db_level == level);
ASSERT(db->db.db_size == space);
ASSERT(db->db_blkid == blkid);
bp = db->db_blkptr;
parent = db->db_parent;
}
freeable = (bp && (freeable ||
dsl_dataset_block_freeable(ds, bp, bp->blk_birth)));
if (freeable)
txh->txh_space_tooverwrite += space;
else
txh->txh_space_towrite += space;
if (bp)
txh->txh_space_tounref += bp_get_dsize(os->os_spa, bp);
dmu_tx_count_twig(txh, dn, parent, level + 1,
blkid >> epbs, freeable, history);
}
/* ARGSUSED */
static void
dmu_tx_count_write(dmu_tx_hold_t *txh, uint64_t off, uint64_t len)
{
dnode_t *dn = txh->txh_dnode;
uint64_t start, end, i;
int min_bs, max_bs, min_ibs, max_ibs, epbs, bits;
int err = 0;
if (len == 0)
return;
min_bs = SPA_MINBLOCKSHIFT;
max_bs = SPA_MAXBLOCKSHIFT;
min_ibs = DN_MIN_INDBLKSHIFT;
max_ibs = DN_MAX_INDBLKSHIFT;
if (dn) {
uint64_t history[DN_MAX_LEVELS];
int nlvls = dn->dn_nlevels;
int delta;
/*
* For i/o error checking, read the first and last level-0
* blocks (if they are not aligned), and all the level-1 blocks.
*/
if (dn->dn_maxblkid == 0) {
delta = dn->dn_datablksz;
start = (off < dn->dn_datablksz) ? 0 : 1;
end = (off+len <= dn->dn_datablksz) ? 0 : 1;
if (start == 0 && (off > 0 || len < dn->dn_datablksz)) {
err = dmu_tx_check_ioerr(NULL, dn, 0, 0);
if (err)
goto out;
delta -= off;
}
} else {
zio_t *zio = zio_root(dn->dn_objset->os_spa,
NULL, NULL, ZIO_FLAG_CANFAIL);
/* first level-0 block */
start = off >> dn->dn_datablkshift;
if (P2PHASE(off, dn->dn_datablksz) ||
len < dn->dn_datablksz) {
err = dmu_tx_check_ioerr(zio, dn, 0, start);
if (err)
goto out;
}
/* last level-0 block */
end = (off+len-1) >> dn->dn_datablkshift;
if (end != start && end <= dn->dn_maxblkid &&
P2PHASE(off+len, dn->dn_datablksz)) {
err = dmu_tx_check_ioerr(zio, dn, 0, end);
if (err)
goto out;
}
/* level-1 blocks */
if (nlvls > 1) {
int shft = dn->dn_indblkshift - SPA_BLKPTRSHIFT;
for (i = (start>>shft)+1; i < end>>shft; i++) {
err = dmu_tx_check_ioerr(zio, dn, 1, i);
if (err)
goto out;
}
}
err = zio_wait(zio);
if (err)
goto out;
delta = P2NPHASE(off, dn->dn_datablksz);
}
if (dn->dn_maxblkid > 0) {
/*
* The blocksize can't change,
* so we can make a more precise estimate.
*/
ASSERT(dn->dn_datablkshift != 0);
min_bs = max_bs = dn->dn_datablkshift;
min_ibs = max_ibs = dn->dn_indblkshift;
} else if (dn->dn_indblkshift > max_ibs) {
/*
* This ensures that if we reduce DN_MAX_INDBLKSHIFT,
* the code will still work correctly on older pools.
*/
min_ibs = max_ibs = dn->dn_indblkshift;
}
/*
* If this write is not off the end of the file
* we need to account for overwrites/unref.
*/
if (start <= dn->dn_maxblkid) {
for (int l = 0; l < DN_MAX_LEVELS; l++)
history[l] = -1ULL;
}
while (start <= dn->dn_maxblkid) {
dmu_buf_impl_t *db;
rw_enter(&dn->dn_struct_rwlock, RW_READER);
err = dbuf_hold_impl(dn, 0, start, FALSE, FTAG, &db);
rw_exit(&dn->dn_struct_rwlock);
if (err) {
txh->txh_tx->tx_err = err;
return;
}
dmu_tx_count_twig(txh, dn, db, 0, start, B_FALSE,
history);
dbuf_rele(db, FTAG);
if (++start > end) {
/*
* Account for new indirects appearing
* before this IO gets assigned into a txg.
*/
bits = 64 - min_bs;
epbs = min_ibs - SPA_BLKPTRSHIFT;
for (bits -= epbs * (nlvls - 1);
bits >= 0; bits -= epbs)
txh->txh_fudge += 1ULL << max_ibs;
goto out;
}
off += delta;
if (len >= delta)
len -= delta;
delta = dn->dn_datablksz;
}
}
/*
* 'end' is the last thing we will access, not one past.
* This way we won't overflow when accessing the last byte.
*/
start = P2ALIGN(off, 1ULL << max_bs);
end = P2ROUNDUP(off + len, 1ULL << max_bs) - 1;
txh->txh_space_towrite += end - start + 1;
start >>= min_bs;
end >>= min_bs;
epbs = min_ibs - SPA_BLKPTRSHIFT;
/*
* The object contains at most 2^(64 - min_bs) blocks,
* and each indirect level maps 2^epbs.
*/
for (bits = 64 - min_bs; bits >= 0; bits -= epbs) {
start >>= epbs;
end >>= epbs;
ASSERT3U(end, >=, start);
txh->txh_space_towrite += (end - start + 1) << max_ibs;
if (start != 0) {
/*
* We also need a new blkid=0 indirect block
* to reference any existing file data.
*/
txh->txh_space_towrite += 1ULL << max_ibs;
}
}
out:
if (txh->txh_space_towrite + txh->txh_space_tooverwrite >
2 * DMU_MAX_ACCESS)
err = EFBIG;
if (err)
txh->txh_tx->tx_err = err;
}
static void
dmu_tx_count_dnode(dmu_tx_hold_t *txh)
{
dnode_t *dn = txh->txh_dnode;
dnode_t *mdn = DMU_META_DNODE(txh->txh_tx->tx_objset);
uint64_t space = mdn->dn_datablksz +
((mdn->dn_nlevels-1) << mdn->dn_indblkshift);
if (dn && dn->dn_dbuf->db_blkptr &&
dsl_dataset_block_freeable(dn->dn_objset->os_dsl_dataset,
dn->dn_dbuf->db_blkptr, dn->dn_dbuf->db_blkptr->blk_birth)) {
txh->txh_space_tooverwrite += space;
txh->txh_space_tounref += space;
} else {
txh->txh_space_towrite += space;
if (dn && dn->dn_dbuf->db_blkptr)
txh->txh_space_tounref += space;
}
}
void
dmu_tx_hold_write(dmu_tx_t *tx, uint64_t object, uint64_t off, int len)
{
dmu_tx_hold_t *txh;
ASSERT(tx->tx_txg == 0);
ASSERT(len < DMU_MAX_ACCESS);
ASSERT(len == 0 || UINT64_MAX - off >= len - 1);
txh = dmu_tx_hold_object_impl(tx, tx->tx_objset,
object, THT_WRITE, off, len);
if (txh == NULL)
return;
dmu_tx_count_write(txh, off, len);
dmu_tx_count_dnode(txh);
}
static void
dmu_tx_count_free(dmu_tx_hold_t *txh, uint64_t off, uint64_t len)
{
uint64_t blkid, nblks, lastblk;
uint64_t space = 0, unref = 0, skipped = 0;
dnode_t *dn = txh->txh_dnode;
dsl_dataset_t *ds = dn->dn_objset->os_dsl_dataset;
spa_t *spa = txh->txh_tx->tx_pool->dp_spa;
int epbs;
if (dn->dn_nlevels == 0)
return;
/*
* The struct_rwlock protects us against dn_nlevels
* changing, in case (against all odds) we manage to dirty &
* sync out the changes after we check for being dirty.
* Also, dbuf_hold_impl() wants us to have the struct_rwlock.
*/
rw_enter(&dn->dn_struct_rwlock, RW_READER);
epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT;
if (dn->dn_maxblkid == 0) {
if (off == 0 && len >= dn->dn_datablksz) {
blkid = 0;
nblks = 1;
} else {
rw_exit(&dn->dn_struct_rwlock);
return;
}
} else {
blkid = off >> dn->dn_datablkshift;
nblks = (len + dn->dn_datablksz - 1) >> dn->dn_datablkshift;
if (blkid >= dn->dn_maxblkid) {
rw_exit(&dn->dn_struct_rwlock);
return;
}
if (blkid + nblks > dn->dn_maxblkid)
nblks = dn->dn_maxblkid - blkid;
}
if (dn->dn_nlevels == 1) {
int i;
for (i = 0; i < nblks; i++) {
blkptr_t *bp = dn->dn_phys->dn_blkptr;
ASSERT3U(blkid + i, <, dn->dn_nblkptr);
bp += blkid + i;
if (dsl_dataset_block_freeable(ds, bp, bp->blk_birth)) {
dprintf_bp(bp, "can free old%s", "");
space += bp_get_dsize(spa, bp);
}
unref += BP_GET_ASIZE(bp);
}
nblks = 0;
}
/*
* Add in memory requirements of higher-level indirects.
* This assumes a worst-possible scenario for dn_nlevels.
*/
{
uint64_t blkcnt = 1 + ((nblks >> epbs) >> epbs);
int level = (dn->dn_nlevels > 1) ? 2 : 1;
while (level++ < DN_MAX_LEVELS) {
txh->txh_memory_tohold += blkcnt << dn->dn_indblkshift;
blkcnt = 1 + (blkcnt >> epbs);
}
ASSERT(blkcnt <= dn->dn_nblkptr);
}
lastblk = blkid + nblks - 1;
while (nblks) {
dmu_buf_impl_t *dbuf;
uint64_t ibyte, new_blkid;
int epb = 1 << epbs;
int err, i, blkoff, tochk;
blkptr_t *bp;
ibyte = blkid << dn->dn_datablkshift;
err = dnode_next_offset(dn,
DNODE_FIND_HAVELOCK, &ibyte, 2, 1, 0);
new_blkid = ibyte >> dn->dn_datablkshift;
if (err == ESRCH) {
skipped += (lastblk >> epbs) - (blkid >> epbs) + 1;
break;
}
if (err) {
txh->txh_tx->tx_err = err;
break;
}
if (new_blkid > lastblk) {
skipped += (lastblk >> epbs) - (blkid >> epbs) + 1;
break;
}
if (new_blkid > blkid) {
ASSERT((new_blkid >> epbs) > (blkid >> epbs));
skipped += (new_blkid >> epbs) - (blkid >> epbs) - 1;
nblks -= new_blkid - blkid;
blkid = new_blkid;
}
blkoff = P2PHASE(blkid, epb);
tochk = MIN(epb - blkoff, nblks);
err = dbuf_hold_impl(dn, 1, blkid >> epbs, FALSE, FTAG, &dbuf);
if (err) {
txh->txh_tx->tx_err = err;
break;
}
txh->txh_memory_tohold += dbuf->db.db_size;
/*
* We don't check memory_tohold against DMU_MAX_ACCESS because
* memory_tohold is an over-estimation (especially the >L1
* indirect blocks), so it could fail. Callers should have
* already verified that they will not be holding too much
* memory.
*/
err = dbuf_read(dbuf, NULL, DB_RF_HAVESTRUCT | DB_RF_CANFAIL);
if (err != 0) {
txh->txh_tx->tx_err = err;
dbuf_rele(dbuf, FTAG);
break;
}
bp = dbuf->db.db_data;
bp += blkoff;
for (i = 0; i < tochk; i++) {
if (dsl_dataset_block_freeable(ds, &bp[i],
bp[i].blk_birth)) {
dprintf_bp(&bp[i], "can free old%s", "");
space += bp_get_dsize(spa, &bp[i]);
}
unref += BP_GET_ASIZE(bp);
}
dbuf_rele(dbuf, FTAG);
blkid += tochk;
nblks -= tochk;
}
rw_exit(&dn->dn_struct_rwlock);
/* account for new level 1 indirect blocks that might show up */
if (skipped > 0) {
txh->txh_fudge += skipped << dn->dn_indblkshift;
skipped = MIN(skipped, DMU_MAX_DELETEBLKCNT >> epbs);
txh->txh_memory_tohold += skipped << dn->dn_indblkshift;
}
txh->txh_space_tofree += space;
txh->txh_space_tounref += unref;
}
void
dmu_tx_hold_free(dmu_tx_t *tx, uint64_t object, uint64_t off, uint64_t len)
{
dmu_tx_hold_t *txh;
dnode_t *dn;
uint64_t start, end, i;
int err, shift;
zio_t *zio;
ASSERT(tx->tx_txg == 0);
txh = dmu_tx_hold_object_impl(tx, tx->tx_objset,
object, THT_FREE, off, len);
if (txh == NULL)
return;
dn = txh->txh_dnode;
/* first block */
if (off != 0)
dmu_tx_count_write(txh, off, 1);
/* last block */
if (len != DMU_OBJECT_END)
dmu_tx_count_write(txh, off+len, 1);
dmu_tx_count_dnode(txh);
if (off >= (dn->dn_maxblkid+1) * dn->dn_datablksz)
return;
if (len == DMU_OBJECT_END)
len = (dn->dn_maxblkid+1) * dn->dn_datablksz - off;
/*
* For i/o error checking, read the first and last level-0
* blocks, and all the level-1 blocks. The above count_write's
* have already taken care of the level-0 blocks.
*/
if (dn->dn_nlevels > 1) {
shift = dn->dn_datablkshift + dn->dn_indblkshift -
SPA_BLKPTRSHIFT;
start = off >> shift;
end = dn->dn_datablkshift ? ((off+len) >> shift) : 0;
zio = zio_root(tx->tx_pool->dp_spa,
NULL, NULL, ZIO_FLAG_CANFAIL);
for (i = start; i <= end; i++) {
uint64_t ibyte = i << shift;
err = dnode_next_offset(dn, 0, &ibyte, 2, 1, 0);
i = ibyte >> shift;
if (err == ESRCH)
break;
if (err) {
tx->tx_err = err;
return;
}
err = dmu_tx_check_ioerr(zio, dn, 1, i);
if (err) {
tx->tx_err = err;
return;
}
}
err = zio_wait(zio);
if (err) {
tx->tx_err = err;
return;
}
}
dmu_tx_count_free(txh, off, len);
}
void
dmu_tx_hold_zap(dmu_tx_t *tx, uint64_t object, int add, const char *name)
{
dmu_tx_hold_t *txh;
dnode_t *dn;
uint64_t nblocks;
int epbs, err;
ASSERT(tx->tx_txg == 0);
txh = dmu_tx_hold_object_impl(tx, tx->tx_objset,
object, THT_ZAP, add, (uintptr_t)name);
if (txh == NULL)
return;
dn = txh->txh_dnode;
dmu_tx_count_dnode(txh);
if (dn == NULL) {
/*
* We will be able to fit a new object's entries into one leaf
* block. So there will be at most 2 blocks total,
* including the header block.
*/
dmu_tx_count_write(txh, 0, 2 << fzap_default_block_shift);
return;
}
ASSERT3P(dmu_ot[dn->dn_type].ot_byteswap, ==, zap_byteswap);
if (dn->dn_maxblkid == 0 && !add) {
blkptr_t *bp;
/*
* If there is only one block (i.e. this is a micro-zap)
* and we are not adding anything, the accounting is simple.
*/
err = dmu_tx_check_ioerr(NULL, dn, 0, 0);
if (err) {
tx->tx_err = err;
return;
}
/*
* Use max block size here, since we don't know how much
* the size will change between now and the dbuf dirty call.
*/
bp = &dn->dn_phys->dn_blkptr[0];
if (dsl_dataset_block_freeable(dn->dn_objset->os_dsl_dataset,
bp, bp->blk_birth))
txh->txh_space_tooverwrite += SPA_MAXBLOCKSIZE;
else
txh->txh_space_towrite += SPA_MAXBLOCKSIZE;
if (!BP_IS_HOLE(bp))
txh->txh_space_tounref += SPA_MAXBLOCKSIZE;
return;
}
if (dn->dn_maxblkid > 0 && name) {
/*
* access the name in this fat-zap so that we'll check
* for i/o errors to the leaf blocks, etc.
*/
err = zap_lookup(dn->dn_objset, dn->dn_object, name,
8, 0, NULL);
if (err == EIO) {
tx->tx_err = err;
return;
}
}
err = zap_count_write(dn->dn_objset, dn->dn_object, name, add,
&txh->txh_space_towrite, &txh->txh_space_tooverwrite);
/*
* If the modified blocks are scattered to the four winds,
* we'll have to modify an indirect twig for each.
*/
epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT;
for (nblocks = dn->dn_maxblkid >> epbs; nblocks != 0; nblocks >>= epbs)
if (dn->dn_objset->os_dsl_dataset->ds_phys->ds_prev_snap_obj)
txh->txh_space_towrite += 3 << dn->dn_indblkshift;
else
txh->txh_space_tooverwrite += 3 << dn->dn_indblkshift;
}
void
dmu_tx_hold_bonus(dmu_tx_t *tx, uint64_t object)
{
dmu_tx_hold_t *txh;
ASSERT(tx->tx_txg == 0);
txh = dmu_tx_hold_object_impl(tx, tx->tx_objset,
object, THT_BONUS, 0, 0);
if (txh)
dmu_tx_count_dnode(txh);
}
void
dmu_tx_hold_space(dmu_tx_t *tx, uint64_t space)
{
dmu_tx_hold_t *txh;
ASSERT(tx->tx_txg == 0);
txh = dmu_tx_hold_object_impl(tx, tx->tx_objset,
DMU_NEW_OBJECT, THT_SPACE, space, 0);
txh->txh_space_towrite += space;
}
int
dmu_tx_holds(dmu_tx_t *tx, uint64_t object)
{
dmu_tx_hold_t *txh;
int holds = 0;
/*
* By asserting that the tx is assigned, we're counting the
* number of dn_tx_holds, which is the same as the number of
* dn_holds. Otherwise, we'd be counting dn_holds, but
* dn_tx_holds could be 0.
*/
ASSERT(tx->tx_txg != 0);
/* if (tx->tx_anyobj == TRUE) */
/* return (0); */
for (txh = list_head(&tx->tx_holds); txh;
txh = list_next(&tx->tx_holds, txh)) {
if (txh->txh_dnode && txh->txh_dnode->dn_object == object)
holds++;
}
return (holds);
}
#ifdef ZFS_DEBUG
void
dmu_tx_dirty_buf(dmu_tx_t *tx, dmu_buf_impl_t *db)
{
dmu_tx_hold_t *txh;
int match_object = FALSE, match_offset = FALSE;
dnode_t *dn;
DB_DNODE_ENTER(db);
dn = DB_DNODE(db);
ASSERT(tx->tx_txg != 0);
ASSERT(tx->tx_objset == NULL || dn->dn_objset == tx->tx_objset);
ASSERT3U(dn->dn_object, ==, db->db.db_object);
if (tx->tx_anyobj) {
DB_DNODE_EXIT(db);
return;
}
/* XXX No checking on the meta dnode for now */
if (db->db.db_object == DMU_META_DNODE_OBJECT) {
DB_DNODE_EXIT(db);
return;
}
for (txh = list_head(&tx->tx_holds); txh;
txh = list_next(&tx->tx_holds, txh)) {
ASSERT(dn == NULL || dn->dn_assigned_txg == tx->tx_txg);
if (txh->txh_dnode == dn && txh->txh_type != THT_NEWOBJECT)
match_object = TRUE;
if (txh->txh_dnode == NULL || txh->txh_dnode == dn) {
int datablkshift = dn->dn_datablkshift ?
dn->dn_datablkshift : SPA_MAXBLOCKSHIFT;
int epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT;
int shift = datablkshift + epbs * db->db_level;
uint64_t beginblk = shift >= 64 ? 0 :
(txh->txh_arg1 >> shift);
uint64_t endblk = shift >= 64 ? 0 :
((txh->txh_arg1 + txh->txh_arg2 - 1) >> shift);
uint64_t blkid = db->db_blkid;
/* XXX txh_arg2 better not be zero... */
dprintf("found txh type %x beginblk=%llx endblk=%llx\n",
txh->txh_type, beginblk, endblk);
switch (txh->txh_type) {
case THT_WRITE:
if (blkid >= beginblk && blkid <= endblk)
match_offset = TRUE;
/*
* We will let this hold work for the bonus
* or spill buffer so that we don't need to
* hold it when creating a new object.
*/
if (blkid == DMU_BONUS_BLKID ||
blkid == DMU_SPILL_BLKID)
match_offset = TRUE;
/*
* They might have to increase nlevels,
* thus dirtying the new TLIBs. Or the
* might have to change the block size,
* thus dirying the new lvl=0 blk=0.
*/
if (blkid == 0)
match_offset = TRUE;
break;
case THT_FREE:
/*
* We will dirty all the level 1 blocks in
* the free range and perhaps the first and
* last level 0 block.
*/
if (blkid >= beginblk && (blkid <= endblk ||
txh->txh_arg2 == DMU_OBJECT_END))
match_offset = TRUE;
break;
case THT_SPILL:
if (blkid == DMU_SPILL_BLKID)
match_offset = TRUE;
break;
case THT_BONUS:
if (blkid == DMU_BONUS_BLKID)
match_offset = TRUE;
break;
case THT_ZAP:
match_offset = TRUE;
break;
case THT_NEWOBJECT:
match_object = TRUE;
break;
default:
ASSERT(!"bad txh_type");
}
}
if (match_object && match_offset) {
DB_DNODE_EXIT(db);
return;
}
}
DB_DNODE_EXIT(db);
panic("dirtying dbuf obj=%llx lvl=%u blkid=%llx but not tx_held\n",
(u_longlong_t)db->db.db_object, db->db_level,
(u_longlong_t)db->db_blkid);
}
#endif
static int
dmu_tx_try_assign(dmu_tx_t *tx, uint64_t txg_how)
{
dmu_tx_hold_t *txh;
spa_t *spa = tx->tx_pool->dp_spa;
uint64_t memory, asize, fsize, usize;
uint64_t towrite, tofree, tooverwrite, tounref, tohold, fudge;
ASSERT3U(tx->tx_txg, ==, 0);
if (tx->tx_err)
return (tx->tx_err);
if (spa_suspended(spa)) {
/*
* If the user has indicated a blocking failure mode
* then return ERESTART which will block in dmu_tx_wait().
* Otherwise, return EIO so that an error can get
* propagated back to the VOP calls.
*
* Note that we always honor the txg_how flag regardless
* of the failuremode setting.
*/
if (spa_get_failmode(spa) == ZIO_FAILURE_MODE_CONTINUE &&
txg_how != TXG_WAIT)
return (EIO);
return (ERESTART);
}
tx->tx_txg = txg_hold_open(tx->tx_pool, &tx->tx_txgh);
tx->tx_needassign_txh = NULL;
/*
* NB: No error returns are allowed after txg_hold_open, but
* before processing the dnode holds, due to the
* dmu_tx_unassign() logic.
*/
towrite = tofree = tooverwrite = tounref = tohold = fudge = 0;
for (txh = list_head(&tx->tx_holds); txh;
txh = list_next(&tx->tx_holds, txh)) {
dnode_t *dn = txh->txh_dnode;
if (dn != NULL) {
mutex_enter(&dn->dn_mtx);
if (dn->dn_assigned_txg == tx->tx_txg - 1) {
mutex_exit(&dn->dn_mtx);
tx->tx_needassign_txh = txh;
return (ERESTART);
}
if (dn->dn_assigned_txg == 0)
dn->dn_assigned_txg = tx->tx_txg;
ASSERT3U(dn->dn_assigned_txg, ==, tx->tx_txg);
(void) refcount_add(&dn->dn_tx_holds, tx);
mutex_exit(&dn->dn_mtx);
}
towrite += txh->txh_space_towrite;
tofree += txh->txh_space_tofree;
tooverwrite += txh->txh_space_tooverwrite;
tounref += txh->txh_space_tounref;
tohold += txh->txh_memory_tohold;
fudge += txh->txh_fudge;
}
/*
* NB: This check must be after we've held the dnodes, so that
* the dmu_tx_unassign() logic will work properly
*/
if (txg_how >= TXG_INITIAL && txg_how != tx->tx_txg)
return (ERESTART);
/*
* If a snapshot has been taken since we made our estimates,
* assume that we won't be able to free or overwrite anything.
*/
if (tx->tx_objset &&
dsl_dataset_prev_snap_txg(tx->tx_objset->os_dsl_dataset) >
tx->tx_lastsnap_txg) {
towrite += tooverwrite;
tooverwrite = tofree = 0;
}
/* needed allocation: worst-case estimate of write space */
asize = spa_get_asize(tx->tx_pool->dp_spa, towrite + tooverwrite);
/* freed space estimate: worst-case overwrite + free estimate */
fsize = spa_get_asize(tx->tx_pool->dp_spa, tooverwrite) + tofree;
/* convert unrefd space to worst-case estimate */
usize = spa_get_asize(tx->tx_pool->dp_spa, tounref);
/* calculate memory footprint estimate */
memory = towrite + tooverwrite + tohold;
#ifdef ZFS_DEBUG
/*
* Add in 'tohold' to account for our dirty holds on this memory
* XXX - the "fudge" factor is to account for skipped blocks that
* we missed because dnode_next_offset() misses in-core-only blocks.
*/
tx->tx_space_towrite = asize +
spa_get_asize(tx->tx_pool->dp_spa, tohold + fudge);
tx->tx_space_tofree = tofree;
tx->tx_space_tooverwrite = tooverwrite;
tx->tx_space_tounref = tounref;
#endif
if (tx->tx_dir && asize != 0) {
int err = dsl_dir_tempreserve_space(tx->tx_dir, memory,
asize, fsize, usize, &tx->tx_tempreserve_cookie, tx);
if (err)
return (err);
}
return (0);
}
static void
dmu_tx_unassign(dmu_tx_t *tx)
{
dmu_tx_hold_t *txh;
if (tx->tx_txg == 0)
return;
txg_rele_to_quiesce(&tx->tx_txgh);
for (txh = list_head(&tx->tx_holds); txh != tx->tx_needassign_txh;
txh = list_next(&tx->tx_holds, txh)) {
dnode_t *dn = txh->txh_dnode;
if (dn == NULL)
continue;
mutex_enter(&dn->dn_mtx);
ASSERT3U(dn->dn_assigned_txg, ==, tx->tx_txg);
if (refcount_remove(&dn->dn_tx_holds, tx) == 0) {
dn->dn_assigned_txg = 0;
cv_broadcast(&dn->dn_notxholds);
}
mutex_exit(&dn->dn_mtx);
}
txg_rele_to_sync(&tx->tx_txgh);
tx->tx_lasttried_txg = tx->tx_txg;
tx->tx_txg = 0;
}
/*
* Assign tx to a transaction group. txg_how can be one of:
*
* (1) TXG_WAIT. If the current open txg is full, waits until there's
* a new one. This should be used when you're not holding locks.
* If will only fail if we're truly out of space (or over quota).
*
* (2) TXG_NOWAIT. If we can't assign into the current open txg without
* blocking, returns immediately with ERESTART. This should be used
* whenever you're holding locks. On an ERESTART error, the caller
* should drop locks, do a dmu_tx_wait(tx), and try again.
*
* (3) A specific txg. Use this if you need to ensure that multiple
* transactions all sync in the same txg. Like TXG_NOWAIT, it
* returns ERESTART if it can't assign you into the requested txg.
*/
int
dmu_tx_assign(dmu_tx_t *tx, uint64_t txg_how)
{
int err;
ASSERT(tx->tx_txg == 0);
ASSERT(txg_how != 0);
ASSERT(!dsl_pool_sync_context(tx->tx_pool));
while ((err = dmu_tx_try_assign(tx, txg_how)) != 0) {
dmu_tx_unassign(tx);
if (err != ERESTART || txg_how != TXG_WAIT)
return (err);
dmu_tx_wait(tx);
}
txg_rele_to_quiesce(&tx->tx_txgh);
return (0);
}
void
dmu_tx_wait(dmu_tx_t *tx)
{
spa_t *spa = tx->tx_pool->dp_spa;
ASSERT(tx->tx_txg == 0);
/*
* It's possible that the pool has become active after this thread
* has tried to obtain a tx. If that's the case then his
* tx_lasttried_txg would not have been assigned.
*/
if (spa_suspended(spa) || tx->tx_lasttried_txg == 0) {
txg_wait_synced(tx->tx_pool, spa_last_synced_txg(spa) + 1);
} else if (tx->tx_needassign_txh) {
dnode_t *dn = tx->tx_needassign_txh->txh_dnode;
mutex_enter(&dn->dn_mtx);
while (dn->dn_assigned_txg == tx->tx_lasttried_txg - 1)
cv_wait(&dn->dn_notxholds, &dn->dn_mtx);
mutex_exit(&dn->dn_mtx);
tx->tx_needassign_txh = NULL;
} else {
txg_wait_open(tx->tx_pool, tx->tx_lasttried_txg + 1);
}
}
void
dmu_tx_willuse_space(dmu_tx_t *tx, int64_t delta)
{
#ifdef ZFS_DEBUG
if (tx->tx_dir == NULL || delta == 0)
return;
if (delta > 0) {
ASSERT3U(refcount_count(&tx->tx_space_written) + delta, <=,
tx->tx_space_towrite);
(void) refcount_add_many(&tx->tx_space_written, delta, NULL);
} else {
(void) refcount_add_many(&tx->tx_space_freed, -delta, NULL);
}
#endif
}
void
dmu_tx_commit(dmu_tx_t *tx)
{
dmu_tx_hold_t *txh;
ASSERT(tx->tx_txg != 0);
while (txh = list_head(&tx->tx_holds)) {
dnode_t *dn = txh->txh_dnode;
list_remove(&tx->tx_holds, txh);
kmem_free(txh, sizeof (dmu_tx_hold_t));
if (dn == NULL)
continue;
mutex_enter(&dn->dn_mtx);
ASSERT3U(dn->dn_assigned_txg, ==, tx->tx_txg);
if (refcount_remove(&dn->dn_tx_holds, tx) == 0) {
dn->dn_assigned_txg = 0;
cv_broadcast(&dn->dn_notxholds);
}
mutex_exit(&dn->dn_mtx);
dnode_rele(dn, tx);
}
if (tx->tx_tempreserve_cookie)
dsl_dir_tempreserve_clear(tx->tx_tempreserve_cookie, tx);
if (!list_is_empty(&tx->tx_callbacks))
txg_register_callbacks(&tx->tx_txgh, &tx->tx_callbacks);
if (tx->tx_anyobj == FALSE)
txg_rele_to_sync(&tx->tx_txgh);
list_destroy(&tx->tx_callbacks);
list_destroy(&tx->tx_holds);
#ifdef ZFS_DEBUG
dprintf("towrite=%llu written=%llu tofree=%llu freed=%llu\n",
tx->tx_space_towrite, refcount_count(&tx->tx_space_written),
tx->tx_space_tofree, refcount_count(&tx->tx_space_freed));
refcount_destroy_many(&tx->tx_space_written,
refcount_count(&tx->tx_space_written));
refcount_destroy_many(&tx->tx_space_freed,
refcount_count(&tx->tx_space_freed));
#endif
kmem_free(tx, sizeof (dmu_tx_t));
}
void
dmu_tx_abort(dmu_tx_t *tx)
{
dmu_tx_hold_t *txh;
ASSERT(tx->tx_txg == 0);
while (txh = list_head(&tx->tx_holds)) {
dnode_t *dn = txh->txh_dnode;
list_remove(&tx->tx_holds, txh);
kmem_free(txh, sizeof (dmu_tx_hold_t));
if (dn != NULL)
dnode_rele(dn, tx);
}
/*
* Call any registered callbacks with an error code.
*/
if (!list_is_empty(&tx->tx_callbacks))
dmu_tx_do_callbacks(&tx->tx_callbacks, ECANCELED);
list_destroy(&tx->tx_callbacks);
list_destroy(&tx->tx_holds);
#ifdef ZFS_DEBUG
refcount_destroy_many(&tx->tx_space_written,
refcount_count(&tx->tx_space_written));
refcount_destroy_many(&tx->tx_space_freed,
refcount_count(&tx->tx_space_freed));
#endif
kmem_free(tx, sizeof (dmu_tx_t));
}
uint64_t
dmu_tx_get_txg(dmu_tx_t *tx)
{
ASSERT(tx->tx_txg != 0);
return (tx->tx_txg);
}
void
dmu_tx_callback_register(dmu_tx_t *tx, dmu_tx_callback_func_t *func, void *data)
{
dmu_tx_callback_t *dcb;
dcb = kmem_alloc(sizeof (dmu_tx_callback_t), KM_SLEEP);
dcb->dcb_func = func;
dcb->dcb_data = data;
list_insert_tail(&tx->tx_callbacks, dcb);
}
/*
* Call all the commit callbacks on a list, with a given error code.
*/
void
dmu_tx_do_callbacks(list_t *cb_list, int error)
{
dmu_tx_callback_t *dcb;
while (dcb = list_head(cb_list)) {
list_remove(cb_list, dcb);
dcb->dcb_func(dcb->dcb_data, error);
kmem_free(dcb, sizeof (dmu_tx_callback_t));
}
}
/*
* Interface to hold a bunch of attributes.
* used for creating new files.
* attrsize is the total size of all attributes
* to be added during object creation
*
* For updating/adding a single attribute dmu_tx_hold_sa() should be used.
*/
/*
* hold necessary attribute name for attribute registration.
* should be a very rare case where this is needed. If it does
* happen it would only happen on the first write to the file system.
*/
static void
dmu_tx_sa_registration_hold(sa_os_t *sa, dmu_tx_t *tx)
{
int i;
if (!sa->sa_need_attr_registration)
return;
for (i = 0; i != sa->sa_num_attrs; i++) {
if (!sa->sa_attr_table[i].sa_registered) {
if (sa->sa_reg_attr_obj)
dmu_tx_hold_zap(tx, sa->sa_reg_attr_obj,
B_TRUE, sa->sa_attr_table[i].sa_name);
else
dmu_tx_hold_zap(tx, DMU_NEW_OBJECT,
B_TRUE, sa->sa_attr_table[i].sa_name);
}
}
}
void
dmu_tx_hold_spill(dmu_tx_t *tx, uint64_t object)
{
dnode_t *dn;
dmu_tx_hold_t *txh;
txh = dmu_tx_hold_object_impl(tx, tx->tx_objset, object,
THT_SPILL, 0, 0);
dn = txh->txh_dnode;
if (dn == NULL)
return;
/* If blkptr doesn't exist then add space to towrite */
if (!(dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR)) {
txh->txh_space_towrite += SPA_MAXBLOCKSIZE;
} else {
blkptr_t *bp;
bp = &dn->dn_phys->dn_spill;
if (dsl_dataset_block_freeable(dn->dn_objset->os_dsl_dataset,
bp, bp->blk_birth))
txh->txh_space_tooverwrite += SPA_MAXBLOCKSIZE;
else
txh->txh_space_towrite += SPA_MAXBLOCKSIZE;
if (!BP_IS_HOLE(bp))
txh->txh_space_tounref += SPA_MAXBLOCKSIZE;
}
}
void
dmu_tx_hold_sa_create(dmu_tx_t *tx, int attrsize)
{
sa_os_t *sa = tx->tx_objset->os_sa;
dmu_tx_hold_bonus(tx, DMU_NEW_OBJECT);
if (tx->tx_objset->os_sa->sa_master_obj == 0)
return;
if (tx->tx_objset->os_sa->sa_layout_attr_obj)
dmu_tx_hold_zap(tx, sa->sa_layout_attr_obj, B_TRUE, NULL);
else {
dmu_tx_hold_zap(tx, sa->sa_master_obj, B_TRUE, SA_LAYOUTS);
dmu_tx_hold_zap(tx, sa->sa_master_obj, B_TRUE, SA_REGISTRY);
dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, B_TRUE, NULL);
dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, B_TRUE, NULL);
}
dmu_tx_sa_registration_hold(sa, tx);
if (attrsize <= DN_MAX_BONUSLEN && !sa->sa_force_spill)
return;
(void) dmu_tx_hold_object_impl(tx, tx->tx_objset, DMU_NEW_OBJECT,
THT_SPILL, 0, 0);
}
/*
* Hold SA attribute
*
* dmu_tx_hold_sa(dmu_tx_t *tx, sa_handle_t *, attribute, add, size)
*
* variable_size is the total size of all variable sized attributes
* passed to this function. It is not the total size of all
* variable size attributes that *may* exist on this object.
*/
void
dmu_tx_hold_sa(dmu_tx_t *tx, sa_handle_t *hdl, boolean_t may_grow)
{
uint64_t object;
sa_os_t *sa = tx->tx_objset->os_sa;
ASSERT(hdl != NULL);
object = sa_handle_object(hdl);
dmu_tx_hold_bonus(tx, object);
if (tx->tx_objset->os_sa->sa_master_obj == 0)
return;
if (tx->tx_objset->os_sa->sa_reg_attr_obj == 0 ||
tx->tx_objset->os_sa->sa_layout_attr_obj == 0) {
dmu_tx_hold_zap(tx, sa->sa_master_obj, B_TRUE, SA_LAYOUTS);
dmu_tx_hold_zap(tx, sa->sa_master_obj, B_TRUE, SA_REGISTRY);
dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, B_TRUE, NULL);
dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, B_TRUE, NULL);
}
dmu_tx_sa_registration_hold(sa, tx);
if (may_grow && tx->tx_objset->os_sa->sa_layout_attr_obj)
dmu_tx_hold_zap(tx, sa->sa_layout_attr_obj, B_TRUE, NULL);
if (sa->sa_force_spill || may_grow || hdl->sa_spill) {
ASSERT(tx->tx_txg == 0);
dmu_tx_hold_spill(tx, object);
} else {
dmu_buf_impl_t *db = (dmu_buf_impl_t *)hdl->sa_bonus;
dnode_t *dn;
DB_DNODE_ENTER(db);
dn = DB_DNODE(db);
if (dn->dn_have_spill) {
ASSERT(tx->tx_txg == 0);
dmu_tx_hold_spill(tx, object);
}
DB_DNODE_EXIT(db);
}
}