dnode_sync.c revision f676ed3419ae468da6c6831c143b0b54173e08d2
/*
* 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 2006 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
#include <sys/zfs_context.h>
#include <sys/dbuf.h>
#include <sys/dnode.h>
#include <sys/dmu.h>
#include <sys/dmu_tx.h>
#include <sys/dmu_objset.h>
#include <sys/dsl_dataset.h>
#include <sys/spa.h>
#include <sys/zio.h>
static void
dnode_increase_indirection(dnode_t *dn, dmu_tx_t *tx)
{
dmu_buf_impl_t *db;
int i;
uint64_t txg = tx->tx_txg;
ASSERT(dn->dn_phys->dn_type != DMU_OT_NONE);
ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock));
/* this dnode can't be paged out because it's dirty */
db = dbuf_hold_level(dn, dn->dn_phys->dn_nlevels, 0, FTAG);
ASSERT(db != NULL);
for (i = 0; i < dn->dn_phys->dn_nblkptr; i++)
if (!BP_IS_HOLE(&dn->dn_phys->dn_blkptr[i]))
break;
if (i != dn->dn_phys->dn_nblkptr) {
ASSERT(list_link_active(&db->db_dirty_node[txg&TXG_MASK]));
(void) dbuf_read(db, NULL,
DB_RF_HAVESTRUCT | DB_RF_MUST_SUCCEED);
arc_release(db->db_buf, db);
/* copy dnode's block pointers to new indirect block */
ASSERT3U(sizeof (blkptr_t) * dn->dn_phys->dn_nblkptr, <=,
db->db.db_size);
bcopy(dn->dn_phys->dn_blkptr, db->db.db_data,
sizeof (blkptr_t) * dn->dn_phys->dn_nblkptr);
}
dn->dn_phys->dn_nlevels += 1;
dprintf("os=%p obj=%llu, increase to %d\n",
dn->dn_objset, dn->dn_object,
dn->dn_phys->dn_nlevels);
/* set dbuf's parent pointers to new indirect buf */
for (i = 0; i < dn->dn_phys->dn_nblkptr; i++) {
dmu_buf_impl_t *child =
dbuf_find(dn, dn->dn_phys->dn_nlevels-2, i);
if (child == NULL)
continue;
if (child->db_dnode == NULL) {
mutex_exit(&child->db_mtx);
continue;
}
if (child->db_parent == NULL ||
child->db_parent == dn->dn_dbuf) {
dprintf_dbuf_bp(child, child->db_blkptr,
"changing db_blkptr to new indirect %s", "");
child->db_parent = db;
dbuf_add_ref(db, child);
if (db->db.db_data) {
child->db_blkptr =
(blkptr_t *)db->db.db_data + i;
} else {
child->db_blkptr = NULL;
}
dprintf_dbuf_bp(child, child->db_blkptr,
"changed db_blkptr to new indirect %s", "");
}
ASSERT3P(child->db_parent, ==, db);
mutex_exit(&child->db_mtx);
}
bzero(dn->dn_phys->dn_blkptr,
sizeof (blkptr_t) * dn->dn_phys->dn_nblkptr);
dbuf_rele(db, FTAG);
}
static void
free_blocks(dnode_t *dn, blkptr_t *bp, int num, dmu_tx_t *tx)
{
objset_impl_t *os = dn->dn_objset;
uint64_t bytesfreed = 0;
int i;
dprintf("os=%p obj=%llx num=%d\n", os, dn->dn_object, num);
for (i = 0; i < num; i++, bp++) {
if (BP_IS_HOLE(bp))
continue;
bytesfreed += BP_GET_ASIZE(bp);
ASSERT3U(bytesfreed >> DEV_BSHIFT, <=, dn->dn_phys->dn_secphys);
dsl_dataset_block_kill(os->os_dsl_dataset, bp, tx);
}
dnode_diduse_space(dn, -bytesfreed);
}
#ifdef ZFS_DEBUG
static void
free_verify(dmu_buf_impl_t *db, uint64_t start, uint64_t end, dmu_tx_t *tx)
{
int off, num;
int i, err, epbs;
uint64_t txg = tx->tx_txg;
epbs = db->db_dnode->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT;
off = start - (db->db_blkid * 1<<epbs);
num = end - start + 1;
ASSERT3U(off, >=, 0);
ASSERT3U(num, >=, 0);
ASSERT3U(db->db_level, >, 0);
ASSERT3U(db->db.db_size, ==, 1<<db->db_dnode->dn_phys->dn_indblkshift);
ASSERT3U(off+num, <=, db->db.db_size >> SPA_BLKPTRSHIFT);
ASSERT(db->db_blkptr != NULL);
for (i = off; i < off+num; i++) {
uint64_t *buf;
int j;
dmu_buf_impl_t *child;
ASSERT(db->db_level == 1);
rw_enter(&db->db_dnode->dn_struct_rwlock, RW_READER);
err = dbuf_hold_impl(db->db_dnode, db->db_level-1,
(db->db_blkid << epbs) + i, TRUE, FTAG, &child);
rw_exit(&db->db_dnode->dn_struct_rwlock);
if (err == ENOENT)
continue;
ASSERT(err == 0);
ASSERT(child->db_level == 0);
ASSERT(!list_link_active(&child->db_dirty_node[txg&TXG_MASK]));
/* db_data_old better be zeroed */
if (child->db_d.db_data_old[txg & TXG_MASK]) {
buf = ((arc_buf_t *)child->db_d.db_data_old
[txg & TXG_MASK])->b_data;
for (j = 0; j < child->db.db_size >> 3; j++) {
if (buf[j] != 0) {
panic("freed data not zero: "
"child=%p i=%d off=%d num=%d\n",
child, i, off, num);
}
}
}
/*
* db_data better be zeroed unless it's dirty in a
* future txg.
*/
mutex_enter(&child->db_mtx);
buf = child->db.db_data;
if (buf != NULL && child->db_state != DB_FILL &&
!list_link_active(&child->db_dirty_node
[(txg+1) & TXG_MASK]) &&
!list_link_active(&child->db_dirty_node
[(txg+2) & TXG_MASK])) {
for (j = 0; j < child->db.db_size >> 3; j++) {
if (buf[j] != 0) {
panic("freed data not zero: "
"child=%p i=%d off=%d num=%d\n",
child, i, off, num);
}
}
}
mutex_exit(&child->db_mtx);
dbuf_rele(child, FTAG);
}
}
#endif
static int
free_children(dmu_buf_impl_t *db, uint64_t blkid, uint64_t nblks, int trunc,
dmu_tx_t *tx)
{
dnode_t *dn = db->db_dnode;
blkptr_t *bp;
dmu_buf_impl_t *subdb;
uint64_t start, end, dbstart, dbend, i;
int epbs, shift, err;
int txgoff = tx->tx_txg & TXG_MASK;
int all = TRUE;
(void) dbuf_read(db, NULL, DB_RF_MUST_SUCCEED);
arc_release(db->db_buf, db);
bp = (blkptr_t *)db->db.db_data;
epbs = db->db_dnode->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT;
shift = (db->db_level - 1) * epbs;
dbstart = db->db_blkid << epbs;
start = blkid >> shift;
if (dbstart < start) {
bp += start - dbstart;
all = FALSE;
} else {
start = dbstart;
}
dbend = ((db->db_blkid + 1) << epbs) - 1;
end = (blkid + nblks - 1) >> shift;
if (dbend <= end)
end = dbend;
else if (all)
all = trunc;
ASSERT3U(start, <=, end);
if (db->db_level == 1) {
FREE_VERIFY(db, start, end, tx);
free_blocks(dn, bp, end-start+1, tx);
ASSERT(all || list_link_active(&db->db_dirty_node[txgoff]));
return (all);
}
for (i = start; i <= end; i++, bp++) {
if (BP_IS_HOLE(bp))
continue;
rw_enter(&dn->dn_struct_rwlock, RW_READER);
err = dbuf_hold_impl(dn, db->db_level-1, i, TRUE, FTAG, &subdb);
ASSERT3U(err, ==, 0);
rw_exit(&dn->dn_struct_rwlock);
if (free_children(subdb, blkid, nblks, trunc, tx)) {
ASSERT3P(subdb->db_blkptr, ==, bp);
free_blocks(dn, bp, 1, tx);
} else {
all = FALSE;
}
dbuf_rele(subdb, FTAG);
}
#ifdef ZFS_DEBUG
bp -= (end-start)+1;
for (i = start; i <= end; i++, bp++) {
if (i == start && blkid != 0)
continue;
else if (i == end && !trunc)
continue;
ASSERT3U(bp->blk_birth, ==, 0);
}
#endif
ASSERT(all || list_link_active(&db->db_dirty_node[txgoff]));
return (all);
}
/*
* free_range: Traverse the indicated range of the provided file
* and "free" all the blocks contained there.
*/
static void
dnode_sync_free_range(dnode_t *dn, uint64_t blkid, uint64_t nblks, dmu_tx_t *tx)
{
blkptr_t *bp = dn->dn_phys->dn_blkptr;
dmu_buf_impl_t *db;
int trunc, start, end, shift, i, err;
int dnlevel = dn->dn_phys->dn_nlevels;
if (blkid > dn->dn_phys->dn_maxblkid)
return;
ASSERT(dn->dn_phys->dn_maxblkid < UINT64_MAX);
trunc = blkid + nblks > dn->dn_phys->dn_maxblkid;
if (trunc)
nblks = dn->dn_phys->dn_maxblkid - blkid + 1;
/* There are no indirect blocks in the object */
if (dnlevel == 1) {
if (blkid >= dn->dn_phys->dn_nblkptr) {
/* this range was never made persistent */
return;
}
ASSERT3U(blkid + nblks, <=, dn->dn_phys->dn_nblkptr);
free_blocks(dn, bp + blkid, nblks, tx);
if (trunc) {
uint64_t off = (dn->dn_phys->dn_maxblkid + 1) *
(dn->dn_phys->dn_datablkszsec << SPA_MINBLOCKSHIFT);
dn->dn_phys->dn_maxblkid = (blkid ? blkid - 1 : 0);
ASSERT(off < dn->dn_phys->dn_maxblkid ||
dn->dn_phys->dn_maxblkid == 0 ||
dnode_next_offset(dn, FALSE, &off, 1, 1) == ESRCH);
}
return;
}
shift = (dnlevel - 1) * (dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT);
start = blkid >> shift;
ASSERT(start < dn->dn_phys->dn_nblkptr);
end = (blkid + nblks - 1) >> shift;
bp += start;
for (i = start; i <= end; i++, bp++) {
if (BP_IS_HOLE(bp))
continue;
rw_enter(&dn->dn_struct_rwlock, RW_READER);
err = dbuf_hold_impl(dn, dnlevel-1, i, TRUE, FTAG, &db);
ASSERT3U(err, ==, 0);
rw_exit(&dn->dn_struct_rwlock);
if (free_children(db, blkid, nblks, trunc, tx)) {
ASSERT3P(db->db_blkptr, ==, bp);
free_blocks(dn, bp, 1, tx);
}
dbuf_rele(db, FTAG);
}
if (trunc) {
uint64_t off = (dn->dn_phys->dn_maxblkid + 1) *
(dn->dn_phys->dn_datablkszsec << SPA_MINBLOCKSHIFT);
dn->dn_phys->dn_maxblkid = (blkid ? blkid - 1 : 0);
ASSERT(off < dn->dn_phys->dn_maxblkid ||
dn->dn_phys->dn_maxblkid == 0 ||
dnode_next_offset(dn, FALSE, &off, 1, 1) == ESRCH);
}
}
/*
* Try to kick all the dnodes dbufs out of the cache...
*/
void
dnode_evict_dbufs(dnode_t *dn)
{
int progress;
int pass = 0;
do {
dmu_buf_impl_t *db, *db_next;
int evicting = FALSE;
progress = FALSE;
mutex_enter(&dn->dn_dbufs_mtx);
for (db = list_head(&dn->dn_dbufs); db; db = db_next) {
/* dbuf_clear() may remove db from this list */
db_next = list_next(&dn->dn_dbufs, db);
mutex_enter(&db->db_mtx);
if (db->db_state == DB_EVICTING) {
progress = TRUE;
evicting = TRUE;
mutex_exit(&db->db_mtx);
} else if (refcount_is_zero(&db->db_holds)) {
progress = TRUE;
ASSERT(!arc_released(db->db_buf));
dbuf_clear(db); /* exits db_mtx for us */
} else {
mutex_exit(&db->db_mtx);
}
}
/*
* NB: we need to drop dn_dbufs_mtx between passes so
* that any DB_EVICTING dbufs can make progress.
* Ideally, we would have some cv we could wait on, but
* since we don't, just wait a bit to give the other
* thread a chance to run.
*/
mutex_exit(&dn->dn_dbufs_mtx);
if (evicting)
delay(1);
pass++;
ASSERT(pass < 100); /* sanity check */
} while (progress);
/*
* This function works fine even if it can't evict everything,
* but all of our callers need this assertion, so let's put it
* here (for now). Perhaps in the future there will be a try vs
* doall flag.
*/
if (list_head(&dn->dn_dbufs) != NULL) {
panic("dangling dbufs (dn=%p, dbuf=%p)\n",
dn, list_head(&dn->dn_dbufs));
}
rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
if (dn->dn_bonus && refcount_is_zero(&dn->dn_bonus->db_holds)) {
mutex_enter(&dn->dn_bonus->db_mtx);
dbuf_evict(dn->dn_bonus);
dn->dn_bonus = NULL;
}
rw_exit(&dn->dn_struct_rwlock);
}
static int
dnode_sync_free(dnode_t *dn, dmu_tx_t *tx)
{
dmu_buf_impl_t *db;
int txgoff = tx->tx_txg & TXG_MASK;
ASSERT(dmu_tx_is_syncing(tx));
/* Undirty all buffers */
while (db = list_head(&dn->dn_dirty_dbufs[txgoff])) {
mutex_enter(&db->db_mtx);
/* XXX - use dbuf_undirty()? */
list_remove(&dn->dn_dirty_dbufs[txgoff], db);
if (db->db_level == 0) {
ASSERT(db->db_blkid == DB_BONUS_BLKID ||
db->db_d.db_data_old[txgoff] == db->db_buf);
if (db->db_d.db_overridden_by[txgoff])
dbuf_unoverride(db, tx->tx_txg);
db->db_d.db_data_old[txgoff] = NULL;
}
db->db_dirtycnt -= 1;
mutex_exit(&db->db_mtx);
dbuf_rele(db, (void *)(uintptr_t)tx->tx_txg);
}
dnode_evict_dbufs(dn);
ASSERT3P(list_head(&dn->dn_dbufs), ==, NULL);
/*
* XXX - It would be nice to assert this, but we may still
* have residual holds from async evictions from the arc...
*
* ASSERT3U(refcount_count(&dn->dn_holds), ==, 1);
*/
/* Undirty next bits */
dn->dn_next_nlevels[txgoff] = 0;
dn->dn_next_indblkshift[txgoff] = 0;
dn->dn_next_blksz[txgoff] = 0;
/* free up all the blocks in the file. */
dnode_sync_free_range(dn, 0, dn->dn_phys->dn_maxblkid+1, tx);
ASSERT3U(dn->dn_phys->dn_secphys, ==, 0);
/* ASSERT(blkptrs are zero); */
ASSERT(dn->dn_phys->dn_type != DMU_OT_NONE);
ASSERT(dn->dn_type != DMU_OT_NONE);
ASSERT(dn->dn_free_txg > 0);
if (dn->dn_allocated_txg != dn->dn_free_txg)
dbuf_will_dirty(dn->dn_dbuf, tx);
bzero(dn->dn_phys, sizeof (dnode_phys_t));
mutex_enter(&dn->dn_mtx);
dn->dn_type = DMU_OT_NONE;
dn->dn_maxblkid = 0;
dn->dn_allocated_txg = 0;
mutex_exit(&dn->dn_mtx);
ASSERT(dn->dn_object != DMU_META_DNODE_OBJECT);
dnode_rele(dn, (void *)(uintptr_t)tx->tx_txg);
/*
* Now that we've released our hold, the dnode may
* be evicted, so we musn't access it.
*/
return (1);
}
/*
* Write out the dnode's dirty buffers at the specified level.
* This may create more dirty buffers at the next level up.
*
* NOTE: The dnode is kept in memory by being dirty. Once the
* dirty bit is cleared, it may be evicted. Beware of this!
*/
int
dnode_sync(dnode_t *dn, int level, zio_t *zio, dmu_tx_t *tx)
{
free_range_t *rp;
int txgoff = tx->tx_txg & TXG_MASK;
dnode_phys_t *dnp = dn->dn_phys;
ASSERT(dmu_tx_is_syncing(tx));
ASSERT(dnp->dn_type != DMU_OT_NONE || dn->dn_allocated_txg);
DNODE_VERIFY(dn);
/*
* Make sure the dbuf for the dn_phys is released before we modify it.
*/
if (dn->dn_dbuf)
arc_release(dn->dn_dbuf->db_buf, dn->dn_dbuf);
mutex_enter(&dn->dn_mtx);
if (dn->dn_allocated_txg == tx->tx_txg) {
/* The dnode is newly allocated or reallocated */
if (dnp->dn_type == DMU_OT_NONE) {
/* this is a first alloc, not a realloc */
/* XXX shouldn't the phys already be zeroed? */
bzero(dnp, DNODE_CORE_SIZE);
dnp->dn_nlevels = 1;
}
if (dn->dn_nblkptr > dnp->dn_nblkptr) {
/* zero the new blkptrs we are gaining */
bzero(dnp->dn_blkptr + dnp->dn_nblkptr,
sizeof (blkptr_t) *
(dn->dn_nblkptr - dnp->dn_nblkptr));
}
dnp->dn_type = dn->dn_type;
dnp->dn_bonustype = dn->dn_bonustype;
dnp->dn_bonuslen = dn->dn_bonuslen;
dnp->dn_nblkptr = dn->dn_nblkptr;
}
ASSERT(level != 0 || dnp->dn_nlevels > 1 ||
BP_IS_HOLE(&dnp->dn_blkptr[0]) ||
BP_GET_LSIZE(&dnp->dn_blkptr[0]) ==
dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT);
if (dn->dn_next_blksz[txgoff]) {
ASSERT(P2PHASE(dn->dn_next_blksz[txgoff],
SPA_MINBLOCKSIZE) == 0);
ASSERT(BP_IS_HOLE(&dnp->dn_blkptr[0]) ||
list_head(&dn->dn_dirty_dbufs[txgoff]) != NULL);
dnp->dn_datablkszsec =
dn->dn_next_blksz[txgoff] >> SPA_MINBLOCKSHIFT;
dn->dn_next_blksz[txgoff] = 0;
}
if (dn->dn_next_indblkshift[txgoff]) {
ASSERT(dnp->dn_nlevels == 1);
dnp->dn_indblkshift = dn->dn_next_indblkshift[txgoff];
dn->dn_next_indblkshift[txgoff] = 0;
}
/*
* Just take the live (open-context) values for checksum and compress.
* Strictly speaking it's a future leak, but nothing bad happens if we
* start using the new checksum or compress algorithm a little early.
*/
dnp->dn_checksum = dn->dn_checksum;
dnp->dn_compress = dn->dn_compress;
mutex_exit(&dn->dn_mtx);
/* process all the "freed" ranges in the file */
if (dn->dn_free_txg == 0 || dn->dn_free_txg > tx->tx_txg) {
for (rp = avl_last(&dn->dn_ranges[txgoff]); rp != NULL;
rp = AVL_PREV(&dn->dn_ranges[txgoff], rp))
dnode_sync_free_range(dn,
rp->fr_blkid, rp->fr_nblks, tx);
}
mutex_enter(&dn->dn_mtx);
for (rp = avl_first(&dn->dn_ranges[txgoff]); rp; ) {
free_range_t *last = rp;
rp = AVL_NEXT(&dn->dn_ranges[txgoff], rp);
avl_remove(&dn->dn_ranges[txgoff], last);
kmem_free(last, sizeof (free_range_t));
}
mutex_exit(&dn->dn_mtx);
if (dn->dn_free_txg > 0 && dn->dn_free_txg <= tx->tx_txg) {
ASSERT3U(level, ==, 0);
return (dnode_sync_free(dn, tx));
}
if (dn->dn_next_nlevels[txgoff]) {
int new_lvl = dn->dn_next_nlevels[txgoff];
rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
while (new_lvl > dnp->dn_nlevels)
dnode_increase_indirection(dn, tx);
rw_exit(&dn->dn_struct_rwlock);
dn->dn_next_nlevels[txgoff] = 0;
}
if (level == dnp->dn_nlevels) {
uint64_t off = (dn->dn_phys->dn_maxblkid + 1) *
(dn->dn_phys->dn_datablkszsec << SPA_MINBLOCKSHIFT);
/* we've already synced out all data and indirect blocks */
/* there are no more dirty dbufs under this dnode */
ASSERT3P(list_head(&dn->dn_dirty_dbufs[txgoff]), ==, NULL);
ASSERT(dn->dn_free_txg == 0 || dn->dn_free_txg >= tx->tx_txg);
/* XXX this is expensive. remove once 6343073 is closed. */
/* NB: the "off < maxblkid" is to catch overflow */
/*
* NB: if blocksize is changing, we could get confused,
* so only bother if there are multiple blocks and thus
* it can't be changing.
*/
if (!(off < dn->dn_phys->dn_maxblkid ||
dn->dn_phys->dn_maxblkid == 0 ||
dnode_next_offset(dn, FALSE, &off, 1, 1) == ESRCH))
panic("data after EOF: off=%llu\n", (u_longlong_t)off);
ASSERT(dnp->dn_nlevels > 1 ||
BP_IS_HOLE(&dnp->dn_blkptr[0]) ||
BP_GET_LSIZE(&dnp->dn_blkptr[0]) ==
dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT);
if (dn->dn_object != DMU_META_DNODE_OBJECT) {
dbuf_will_dirty(dn->dn_dbuf, tx);
dnode_rele(dn, (void *)(uintptr_t)tx->tx_txg);
}
/*
* Now that we've dropped the reference, the dnode may
* be evicted, so we musn't access it.
*/
return (1);
} else {
dmu_buf_impl_t *db, *db_next;
list_t *list = &dn->dn_dirty_dbufs[txgoff];
/*
* Iterate over the list, removing and sync'ing dbufs
* which are on the level we want, and leaving others.
*/
for (db = list_head(list); db; db = db_next) {
db_next = list_next(list, db);
if (db->db_level == level) {
list_remove(list, db);
dbuf_sync(db, zio, tx);
}
}
return (0);
}
}