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mirror_zfs/module/zfs/dmu_traverse.c
Richard Yao fdc2d30371
Cleanup: Specify unsignedness on things that should not be signed 
In #13871, zfs_vdev_aggregation_limit_non_rotating and
zfs_vdev_aggregation_limit being signed was pointed out as a possible
reason not to eliminate an unnecessary MAX(unsigned, 0) since the
unsigned value was assigned from them.

There is no reason for these module parameters to be signed and upon
inspection, it was found that there are a number of other module
parameters that are signed, but should not be, so we make them unsigned.
Making them unsigned made it clear that some other variables in the code
should also be unsigned, so we also make those unsigned. This prevents
users from setting negative values that could potentially cause bad
behaviors. It also makes the code slightly easier to understand.

Mostly module parameters that deal with timeouts, limits, bitshifts and
percentages are made unsigned by this. Any that are boolean are left
signed, since whether booleans should be considered signed or unsigned
does not matter.

Making zfs_arc_lotsfree_percent unsigned caused a
`zfs_arc_lotsfree_percent >= 0` check to become redundant, so it was
removed. Removing the check was also necessary to prevent a compiler
error from -Werror=type-limits.

Several end of line comments had to be moved to their own lines because
replacing int with uint_t caused us to exceed the 80 character limit
enforced by cstyle.pl.

The following were kept signed because they are passed to
taskq_create(), which expects signed values and modifying the
OpenSolaris/Illumos DDI is out of scope of this patch:

	* metaslab_load_pct
	* zfs_sync_taskq_batch_pct
	* zfs_zil_clean_taskq_nthr_pct
	* zfs_zil_clean_taskq_minalloc
	* zfs_zil_clean_taskq_maxalloc
	* zfs_arc_prune_task_threads

Also, negative values in those parameters was found to be harmless.

The following were left signed because either negative values make
sense, or more analysis was needed to determine whether negative values
should be disallowed:

	* zfs_metaslab_switch_threshold
	* zfs_pd_bytes_max
	* zfs_livelist_min_percent_shared

zfs_multihost_history was made static to be consistent with other
parameters.

A number of module parameters were marked as signed, but in reality
referenced unsigned variables. upgrade_errlog_limit is one of the
numerous examples. In the case of zfs_vdev_async_read_max_active, it was
already uint32_t, but zdb had an extern int declaration for it.

Interestingly, the documentation in zfs.4 was right for
upgrade_errlog_limit despite the module parameter being wrongly marked,
while the documentation for zfs_vdev_async_read_max_active (and friends)
was wrong. It was also wrong for zstd_abort_size, which was unsigned,
but was documented as signed.

Also, the documentation in zfs.4 incorrectly described the following
parameters as ulong when they were int:

	* zfs_arc_meta_adjust_restarts
	* zfs_override_estimate_recordsize

They are now uint_t as of this patch and thus the man page has been
updated to describe them as uint.

dbuf_state_index was left alone since it does nothing and perhaps should
be removed in another patch.

If any module parameters were missed, they were not found by `grep -r
'ZFS_MODULE_PARAM' | grep ', INT'`. I did find a few that grep missed,
but only because they were in files that had hits.

This patch intentionally did not attempt to address whether some of
these module parameters should be elevated to 64-bit parameters, because
the length of a long on 32-bit is 32-bit.

Lastly, it was pointed out during review that uint_t is a better match
for these variables than uint32_t because FreeBSD kernel parameter
definitions are designed for uint_t, whose bit width can change in
future memory models.  As a result, we change the existing parameters
that are uint32_t to use uint_t.

Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Neal Gompa <ngompa@datto.com>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes #13875
2022-09-27 16:42:41 -07:00

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/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or https://opensource.org/licenses/CDDL-1.0.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2012, 2018 by Delphix. All rights reserved.
*/
#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/dnode.h>
#include <sys/spa.h>
#include <sys/spa_impl.h>
#include <sys/zio.h>
#include <sys/dmu_impl.h>
#include <sys/sa.h>
#include <sys/sa_impl.h>
#include <sys/callb.h>
#include <sys/zfeature.h>
static int32_t zfs_pd_bytes_max = 50 * 1024 * 1024; /* 50MB */
static int32_t send_holes_without_birth_time = 1;
static uint_t zfs_traverse_indirect_prefetch_limit = 32;
typedef struct prefetch_data {
kmutex_t pd_mtx;
kcondvar_t pd_cv;
int32_t pd_bytes_fetched;
int pd_flags;
boolean_t pd_cancel;
boolean_t pd_exited;
zbookmark_phys_t pd_resume;
} prefetch_data_t;
typedef struct traverse_data {
spa_t *td_spa;
uint64_t td_objset;
blkptr_t *td_rootbp;
uint64_t td_min_txg;
zbookmark_phys_t *td_resume;
int td_flags;
prefetch_data_t *td_pfd;
boolean_t td_paused;
uint64_t td_hole_birth_enabled_txg;
blkptr_cb_t *td_func;
void *td_arg;
boolean_t td_realloc_possible;
} traverse_data_t;
static int traverse_dnode(traverse_data_t *td, const blkptr_t *bp,
const dnode_phys_t *dnp, uint64_t objset, uint64_t object);
static void prefetch_dnode_metadata(traverse_data_t *td, const dnode_phys_t *,
uint64_t objset, uint64_t object);
static int
traverse_zil_block(zilog_t *zilog, const blkptr_t *bp, void *arg,
uint64_t claim_txg)
{
traverse_data_t *td = arg;
zbookmark_phys_t zb;
if (BP_IS_HOLE(bp))
return (0);
if (claim_txg == 0 && bp->blk_birth >= spa_min_claim_txg(td->td_spa))
return (-1);
SET_BOOKMARK(&zb, td->td_objset, ZB_ZIL_OBJECT, ZB_ZIL_LEVEL,
bp->blk_cksum.zc_word[ZIL_ZC_SEQ]);
(void) td->td_func(td->td_spa, zilog, bp, &zb, NULL, td->td_arg);
return (0);
}
static int
traverse_zil_record(zilog_t *zilog, const lr_t *lrc, void *arg,
uint64_t claim_txg)
{
traverse_data_t *td = arg;
if (lrc->lrc_txtype == TX_WRITE) {
lr_write_t *lr = (lr_write_t *)lrc;
blkptr_t *bp = &lr->lr_blkptr;
zbookmark_phys_t zb;
if (BP_IS_HOLE(bp))
return (0);
if (claim_txg == 0 || bp->blk_birth < claim_txg)
return (0);
SET_BOOKMARK(&zb, td->td_objset, lr->lr_foid,
ZB_ZIL_LEVEL, lr->lr_offset / BP_GET_LSIZE(bp));
(void) td->td_func(td->td_spa, zilog, bp, &zb, NULL,
td->td_arg);
}
return (0);
}
static void
traverse_zil(traverse_data_t *td, zil_header_t *zh)
{
uint64_t claim_txg = zh->zh_claim_txg;
/*
* We only want to visit blocks that have been claimed but not yet
* replayed; plus blocks that are already stable in read-only mode.
*/
if (claim_txg == 0 && spa_writeable(td->td_spa))
return;
zilog_t *zilog = zil_alloc(spa_get_dsl(td->td_spa)->dp_meta_objset, zh);
(void) zil_parse(zilog, traverse_zil_block, traverse_zil_record, td,
claim_txg, !(td->td_flags & TRAVERSE_NO_DECRYPT));
zil_free(zilog);
}
typedef enum resume_skip {
RESUME_SKIP_ALL,
RESUME_SKIP_NONE,
RESUME_SKIP_CHILDREN
} resume_skip_t;
/*
* Returns RESUME_SKIP_ALL if td indicates that we are resuming a traversal and
* the block indicated by zb does not need to be visited at all. Returns
* RESUME_SKIP_CHILDREN if we are resuming a post traversal and we reach the
* resume point. This indicates that this block should be visited but not its
* children (since they must have been visited in a previous traversal).
* Otherwise returns RESUME_SKIP_NONE.
*/
static resume_skip_t
resume_skip_check(traverse_data_t *td, const dnode_phys_t *dnp,
const zbookmark_phys_t *zb)
{
if (td->td_resume != NULL && !ZB_IS_ZERO(td->td_resume)) {
/*
* If we already visited this bp & everything below,
* don't bother doing it again.
*/
if (zbookmark_subtree_completed(dnp, zb, td->td_resume))
return (RESUME_SKIP_ALL);
/*
* If we found the block we're trying to resume from, zero
* the bookmark out to indicate that we have resumed.
*/
if (memcmp(zb, td->td_resume, sizeof (*zb)) == 0) {
memset(td->td_resume, 0, sizeof (*zb));
if (td->td_flags & TRAVERSE_POST)
return (RESUME_SKIP_CHILDREN);
}
}
return (RESUME_SKIP_NONE);
}
/*
* Returns B_TRUE, if prefetch read is issued, otherwise B_FALSE.
*/
static boolean_t
traverse_prefetch_metadata(traverse_data_t *td,
const blkptr_t *bp, const zbookmark_phys_t *zb)
{
arc_flags_t flags = ARC_FLAG_NOWAIT | ARC_FLAG_PREFETCH;
int zio_flags = ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE;
if (!(td->td_flags & TRAVERSE_PREFETCH_METADATA))
return (B_FALSE);
/*
* If we are in the process of resuming, don't prefetch, because
* some children will not be needed (and in fact may have already
* been freed).
*/
if (td->td_resume != NULL && !ZB_IS_ZERO(td->td_resume))
return (B_FALSE);
if (BP_IS_HOLE(bp) || bp->blk_birth <= td->td_min_txg)
return (B_FALSE);
if (BP_GET_LEVEL(bp) == 0 && BP_GET_TYPE(bp) != DMU_OT_DNODE)
return (B_FALSE);
ASSERT(!BP_IS_REDACTED(bp));
if ((td->td_flags & TRAVERSE_NO_DECRYPT) && BP_IS_PROTECTED(bp))
zio_flags |= ZIO_FLAG_RAW;
(void) arc_read(NULL, td->td_spa, bp, NULL, NULL,
ZIO_PRIORITY_ASYNC_READ, zio_flags, &flags, zb);
return (B_TRUE);
}
static boolean_t
prefetch_needed(prefetch_data_t *pfd, const blkptr_t *bp)
{
ASSERT(pfd->pd_flags & TRAVERSE_PREFETCH_DATA);
if (BP_IS_HOLE(bp) || BP_IS_EMBEDDED(bp) ||
BP_GET_TYPE(bp) == DMU_OT_INTENT_LOG || BP_IS_REDACTED(bp))
return (B_FALSE);
return (B_TRUE);
}
static int
traverse_visitbp(traverse_data_t *td, const dnode_phys_t *dnp,
const blkptr_t *bp, const zbookmark_phys_t *zb)
{
int err = 0;
arc_buf_t *buf = NULL;
prefetch_data_t *pd = td->td_pfd;
switch (resume_skip_check(td, dnp, zb)) {
case RESUME_SKIP_ALL:
return (0);
case RESUME_SKIP_CHILDREN:
goto post;
case RESUME_SKIP_NONE:
break;
default:
ASSERT(0);
}
if (bp->blk_birth == 0) {
/*
* Since this block has a birth time of 0 it must be one of
* two things: a hole created before the
* SPA_FEATURE_HOLE_BIRTH feature was enabled, or a hole
* which has always been a hole in an object.
*
* If a file is written sparsely, then the unwritten parts of
* the file were "always holes" -- that is, they have been
* holes since this object was allocated. However, we (and
* our callers) can not necessarily tell when an object was
* allocated. Therefore, if it's possible that this object
* was freed and then its object number reused, we need to
* visit all the holes with birth==0.
*
* If it isn't possible that the object number was reused,
* then if SPA_FEATURE_HOLE_BIRTH was enabled before we wrote
* all the blocks we will visit as part of this traversal,
* then this hole must have always existed, so we can skip
* it. We visit blocks born after (exclusive) td_min_txg.
*
* Note that the meta-dnode cannot be reallocated.
*/
if (!send_holes_without_birth_time &&
(!td->td_realloc_possible ||
zb->zb_object == DMU_META_DNODE_OBJECT) &&
td->td_hole_birth_enabled_txg <= td->td_min_txg)
return (0);
} else if (bp->blk_birth <= td->td_min_txg) {
return (0);
}
if (pd != NULL && !pd->pd_exited && prefetch_needed(pd, bp)) {
uint64_t size = BP_GET_LSIZE(bp);
mutex_enter(&pd->pd_mtx);
ASSERT(pd->pd_bytes_fetched >= 0);
while (pd->pd_bytes_fetched < size && !pd->pd_exited)
cv_wait_sig(&pd->pd_cv, &pd->pd_mtx);
pd->pd_bytes_fetched -= size;
cv_broadcast(&pd->pd_cv);
mutex_exit(&pd->pd_mtx);
}
if (BP_IS_HOLE(bp) || BP_IS_REDACTED(bp)) {
err = td->td_func(td->td_spa, NULL, bp, zb, dnp, td->td_arg);
if (err != 0)
goto post;
return (0);
}
if (td->td_flags & TRAVERSE_PRE) {
err = td->td_func(td->td_spa, NULL, bp, zb, dnp,
td->td_arg);
if (err == TRAVERSE_VISIT_NO_CHILDREN)
return (0);
if (err != 0)
goto post;
}
if (BP_GET_LEVEL(bp) > 0) {
uint32_t flags = ARC_FLAG_WAIT;
int32_t i, ptidx, pidx;
uint32_t prefetchlimit;
int32_t epb = BP_GET_LSIZE(bp) >> SPA_BLKPTRSHIFT;
zbookmark_phys_t *czb;
ASSERT(!BP_IS_PROTECTED(bp));
err = arc_read(NULL, td->td_spa, bp, arc_getbuf_func, &buf,
ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &flags, zb);
if (err != 0)
goto post;
czb = kmem_alloc(sizeof (zbookmark_phys_t), KM_SLEEP);
/*
* When performing a traversal it is beneficial to
* asynchronously read-ahead the upcoming indirect
* blocks since they will be needed shortly. However,
* since a 128k indirect (non-L0) block may contain up
* to 1024 128-byte block pointers, its preferable to not
* prefetch them all at once. Issuing a large number of
* async reads may effect performance, and the earlier
* the indirect blocks are prefetched the less likely
* they are to still be resident in the ARC when needed.
* Therefore, prefetching indirect blocks is limited to
* zfs_traverse_indirect_prefetch_limit=32 blocks by
* default.
*
* pidx: Index for which next prefetch to be issued.
* ptidx: Index at which next prefetch to be triggered.
*/
ptidx = 0;
pidx = 1;
prefetchlimit = zfs_traverse_indirect_prefetch_limit;
for (i = 0; i < epb; i++) {
if (prefetchlimit && i == ptidx) {
ASSERT3S(ptidx, <=, pidx);
for (uint32_t prefetched = 0; pidx < epb &&
prefetched < prefetchlimit; pidx++) {
SET_BOOKMARK(czb, zb->zb_objset,
zb->zb_object, zb->zb_level - 1,
zb->zb_blkid * epb + pidx);
if (traverse_prefetch_metadata(td,
&((blkptr_t *)buf->b_data)[pidx],
czb) == B_TRUE) {
prefetched++;
if (prefetched ==
MAX(prefetchlimit / 2, 1))
ptidx = pidx;
}
}
}
/* recursively visitbp() blocks below this */
SET_BOOKMARK(czb, zb->zb_objset, zb->zb_object,
zb->zb_level - 1,
zb->zb_blkid * epb + i);
err = traverse_visitbp(td, dnp,
&((blkptr_t *)buf->b_data)[i], czb);
if (err != 0)
break;
}
kmem_free(czb, sizeof (zbookmark_phys_t));
} else if (BP_GET_TYPE(bp) == DMU_OT_DNODE) {
uint32_t flags = ARC_FLAG_WAIT;
uint32_t zio_flags = ZIO_FLAG_CANFAIL;
int32_t i;
int32_t epb = BP_GET_LSIZE(bp) >> DNODE_SHIFT;
dnode_phys_t *child_dnp;
/*
* dnode blocks might have their bonus buffers encrypted, so
* we must be careful to honor TRAVERSE_NO_DECRYPT
*/
if ((td->td_flags & TRAVERSE_NO_DECRYPT) && BP_IS_PROTECTED(bp))
zio_flags |= ZIO_FLAG_RAW;
err = arc_read(NULL, td->td_spa, bp, arc_getbuf_func, &buf,
ZIO_PRIORITY_ASYNC_READ, zio_flags, &flags, zb);
if (err != 0)
goto post;
child_dnp = buf->b_data;
for (i = 0; i < epb; i += child_dnp[i].dn_extra_slots + 1) {
prefetch_dnode_metadata(td, &child_dnp[i],
zb->zb_objset, zb->zb_blkid * epb + i);
}
/* recursively visitbp() blocks below this */
for (i = 0; i < epb; i += child_dnp[i].dn_extra_slots + 1) {
err = traverse_dnode(td, bp, &child_dnp[i],
zb->zb_objset, zb->zb_blkid * epb + i);
if (err != 0)
break;
}
} else if (BP_GET_TYPE(bp) == DMU_OT_OBJSET) {
uint32_t zio_flags = ZIO_FLAG_CANFAIL;
arc_flags_t flags = ARC_FLAG_WAIT;
objset_phys_t *osp;
if ((td->td_flags & TRAVERSE_NO_DECRYPT) && BP_IS_PROTECTED(bp))
zio_flags |= ZIO_FLAG_RAW;
err = arc_read(NULL, td->td_spa, bp, arc_getbuf_func, &buf,
ZIO_PRIORITY_ASYNC_READ, zio_flags, &flags, zb);
if (err != 0)
goto post;
osp = buf->b_data;
prefetch_dnode_metadata(td, &osp->os_meta_dnode, zb->zb_objset,
DMU_META_DNODE_OBJECT);
/*
* See the block comment above for the goal of this variable.
* If the maxblkid of the meta-dnode is 0, then we know that
* we've never had more than DNODES_PER_BLOCK objects in the
* dataset, which means we can't have reused any object ids.
*/
if (osp->os_meta_dnode.dn_maxblkid == 0)
td->td_realloc_possible = B_FALSE;
if (OBJSET_BUF_HAS_USERUSED(buf)) {
if (OBJSET_BUF_HAS_PROJECTUSED(buf))
prefetch_dnode_metadata(td,
&osp->os_projectused_dnode,
zb->zb_objset, DMU_PROJECTUSED_OBJECT);
prefetch_dnode_metadata(td, &osp->os_groupused_dnode,
zb->zb_objset, DMU_GROUPUSED_OBJECT);
prefetch_dnode_metadata(td, &osp->os_userused_dnode,
zb->zb_objset, DMU_USERUSED_OBJECT);
}
err = traverse_dnode(td, bp, &osp->os_meta_dnode, zb->zb_objset,
DMU_META_DNODE_OBJECT);
if (err == 0 && OBJSET_BUF_HAS_USERUSED(buf)) {
if (OBJSET_BUF_HAS_PROJECTUSED(buf))
err = traverse_dnode(td, bp,
&osp->os_projectused_dnode, zb->zb_objset,
DMU_PROJECTUSED_OBJECT);
if (err == 0)
err = traverse_dnode(td, bp,
&osp->os_groupused_dnode, zb->zb_objset,
DMU_GROUPUSED_OBJECT);
if (err == 0)
err = traverse_dnode(td, bp,
&osp->os_userused_dnode, zb->zb_objset,
DMU_USERUSED_OBJECT);
}
}
if (buf)
arc_buf_destroy(buf, &buf);
post:
if (err == 0 && (td->td_flags & TRAVERSE_POST))
err = td->td_func(td->td_spa, NULL, bp, zb, dnp, td->td_arg);
if ((td->td_flags & TRAVERSE_HARD) && (err == EIO || err == ECKSUM)) {
/*
* Ignore this disk error as requested by the HARD flag,
* and continue traversal.
*/
err = 0;
}
/*
* If we are stopping here, set td_resume.
*/
if (td->td_resume != NULL && err != 0 && !td->td_paused) {
td->td_resume->zb_objset = zb->zb_objset;
td->td_resume->zb_object = zb->zb_object;
td->td_resume->zb_level = 0;
/*
* If we have stopped on an indirect block (e.g. due to
* i/o error), we have not visited anything below it.
* Set the bookmark to the first level-0 block that we need
* to visit. This way, the resuming code does not need to
* deal with resuming from indirect blocks.
*
* Note, if zb_level <= 0, dnp may be NULL, so we don't want
* to dereference it.
*/
td->td_resume->zb_blkid = zb->zb_blkid;
if (zb->zb_level > 0) {
td->td_resume->zb_blkid <<= zb->zb_level *
(dnp->dn_indblkshift - SPA_BLKPTRSHIFT);
}
td->td_paused = B_TRUE;
}
return (err);
}
static void
prefetch_dnode_metadata(traverse_data_t *td, const dnode_phys_t *dnp,
uint64_t objset, uint64_t object)
{
int j;
zbookmark_phys_t czb;
for (j = 0; j < dnp->dn_nblkptr; j++) {
SET_BOOKMARK(&czb, objset, object, dnp->dn_nlevels - 1, j);
traverse_prefetch_metadata(td, &dnp->dn_blkptr[j], &czb);
}
if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) {
SET_BOOKMARK(&czb, objset, object, 0, DMU_SPILL_BLKID);
traverse_prefetch_metadata(td, DN_SPILL_BLKPTR(dnp), &czb);
}
}
static int
traverse_dnode(traverse_data_t *td, const blkptr_t *bp, const dnode_phys_t *dnp,
uint64_t objset, uint64_t object)
{
int j, err = 0;
zbookmark_phys_t czb;
if (object != DMU_META_DNODE_OBJECT && td->td_resume != NULL &&
object < td->td_resume->zb_object)
return (0);
if (td->td_flags & TRAVERSE_PRE) {
SET_BOOKMARK(&czb, objset, object, ZB_DNODE_LEVEL,
ZB_DNODE_BLKID);
err = td->td_func(td->td_spa, NULL, bp, &czb, dnp,
td->td_arg);
if (err == TRAVERSE_VISIT_NO_CHILDREN)
return (0);
if (err != 0)
return (err);
}
for (j = 0; j < dnp->dn_nblkptr; j++) {
SET_BOOKMARK(&czb, objset, object, dnp->dn_nlevels - 1, j);
err = traverse_visitbp(td, dnp, &dnp->dn_blkptr[j], &czb);
if (err != 0)
break;
}
if (err == 0 && (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR)) {
SET_BOOKMARK(&czb, objset, object, 0, DMU_SPILL_BLKID);
err = traverse_visitbp(td, dnp, DN_SPILL_BLKPTR(dnp), &czb);
}
if (err == 0 && (td->td_flags & TRAVERSE_POST)) {
SET_BOOKMARK(&czb, objset, object, ZB_DNODE_LEVEL,
ZB_DNODE_BLKID);
err = td->td_func(td->td_spa, NULL, bp, &czb, dnp,
td->td_arg);
if (err == TRAVERSE_VISIT_NO_CHILDREN)
return (0);
if (err != 0)
return (err);
}
return (err);
}
static int
traverse_prefetcher(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
const zbookmark_phys_t *zb, const dnode_phys_t *dnp, void *arg)
{
(void) zilog, (void) dnp;
prefetch_data_t *pfd = arg;
int zio_flags = ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE;
arc_flags_t aflags = ARC_FLAG_NOWAIT | ARC_FLAG_PREFETCH |
ARC_FLAG_PRESCIENT_PREFETCH;
ASSERT(pfd->pd_bytes_fetched >= 0);
if (zb->zb_level == ZB_DNODE_LEVEL)
return (0);
if (pfd->pd_cancel)
return (SET_ERROR(EINTR));
if (!prefetch_needed(pfd, bp))
return (0);
mutex_enter(&pfd->pd_mtx);
while (!pfd->pd_cancel && pfd->pd_bytes_fetched >= zfs_pd_bytes_max)
cv_wait_sig(&pfd->pd_cv, &pfd->pd_mtx);
pfd->pd_bytes_fetched += BP_GET_LSIZE(bp);
cv_broadcast(&pfd->pd_cv);
mutex_exit(&pfd->pd_mtx);
if ((pfd->pd_flags & TRAVERSE_NO_DECRYPT) && BP_IS_PROTECTED(bp))
zio_flags |= ZIO_FLAG_RAW;
(void) arc_read(NULL, spa, bp, NULL, NULL, ZIO_PRIORITY_ASYNC_READ,
zio_flags, &aflags, zb);
return (0);
}
static void
traverse_prefetch_thread(void *arg)
{
traverse_data_t *td_main = arg;
traverse_data_t td = *td_main;
zbookmark_phys_t czb;
fstrans_cookie_t cookie = spl_fstrans_mark();
td.td_func = traverse_prefetcher;
td.td_arg = td_main->td_pfd;
td.td_pfd = NULL;
td.td_resume = &td_main->td_pfd->pd_resume;
SET_BOOKMARK(&czb, td.td_objset,
ZB_ROOT_OBJECT, ZB_ROOT_LEVEL, ZB_ROOT_BLKID);
(void) traverse_visitbp(&td, NULL, td.td_rootbp, &czb);
mutex_enter(&td_main->td_pfd->pd_mtx);
td_main->td_pfd->pd_exited = B_TRUE;
cv_broadcast(&td_main->td_pfd->pd_cv);
mutex_exit(&td_main->td_pfd->pd_mtx);
spl_fstrans_unmark(cookie);
}
/*
* NB: dataset must not be changing on-disk (eg, is a snapshot or we are
* in syncing context).
*/
static int
traverse_impl(spa_t *spa, dsl_dataset_t *ds, uint64_t objset, blkptr_t *rootbp,
uint64_t txg_start, zbookmark_phys_t *resume, int flags,
blkptr_cb_t func, void *arg)
{
traverse_data_t *td;
prefetch_data_t *pd;
zbookmark_phys_t *czb;
int err;
ASSERT(ds == NULL || objset == ds->ds_object);
ASSERT(!(flags & TRAVERSE_PRE) || !(flags & TRAVERSE_POST));
td = kmem_alloc(sizeof (traverse_data_t), KM_SLEEP);
pd = kmem_zalloc(sizeof (prefetch_data_t), KM_SLEEP);
czb = kmem_alloc(sizeof (zbookmark_phys_t), KM_SLEEP);
td->td_spa = spa;
td->td_objset = objset;
td->td_rootbp = rootbp;
td->td_min_txg = txg_start;
td->td_resume = resume;
td->td_func = func;
td->td_arg = arg;
td->td_pfd = pd;
td->td_flags = flags;
td->td_paused = B_FALSE;
td->td_realloc_possible = (txg_start == 0 ? B_FALSE : B_TRUE);
if (spa_feature_is_active(spa, SPA_FEATURE_HOLE_BIRTH)) {
VERIFY(spa_feature_enabled_txg(spa,
SPA_FEATURE_HOLE_BIRTH, &td->td_hole_birth_enabled_txg));
} else {
td->td_hole_birth_enabled_txg = UINT64_MAX;
}
pd->pd_flags = flags;
if (resume != NULL)
pd->pd_resume = *resume;
mutex_init(&pd->pd_mtx, NULL, MUTEX_DEFAULT, NULL);
cv_init(&pd->pd_cv, NULL, CV_DEFAULT, NULL);
SET_BOOKMARK(czb, td->td_objset,
ZB_ROOT_OBJECT, ZB_ROOT_LEVEL, ZB_ROOT_BLKID);
/* See comment on ZIL traversal in dsl_scan_visitds. */
if (ds != NULL && !ds->ds_is_snapshot && !BP_IS_HOLE(rootbp)) {
enum zio_flag zio_flags = ZIO_FLAG_CANFAIL;
uint32_t flags = ARC_FLAG_WAIT;
objset_phys_t *osp;
arc_buf_t *buf;
ASSERT(!BP_IS_REDACTED(rootbp));
if ((td->td_flags & TRAVERSE_NO_DECRYPT) &&
BP_IS_PROTECTED(rootbp))
zio_flags |= ZIO_FLAG_RAW;
err = arc_read(NULL, td->td_spa, rootbp, arc_getbuf_func,
&buf, ZIO_PRIORITY_ASYNC_READ, zio_flags, &flags, czb);
if (err != 0) {
/*
* If both TRAVERSE_HARD and TRAVERSE_PRE are set,
* continue to visitbp so that td_func can be called
* in pre stage, and err will reset to zero.
*/
if (!(td->td_flags & TRAVERSE_HARD) ||
!(td->td_flags & TRAVERSE_PRE))
goto out;
} else {
osp = buf->b_data;
traverse_zil(td, &osp->os_zil_header);
arc_buf_destroy(buf, &buf);
}
}
if (!(flags & TRAVERSE_PREFETCH_DATA) ||
taskq_dispatch(spa->spa_prefetch_taskq, traverse_prefetch_thread,
td, TQ_NOQUEUE) == TASKQID_INVALID)
pd->pd_exited = B_TRUE;
err = traverse_visitbp(td, NULL, rootbp, czb);
mutex_enter(&pd->pd_mtx);
pd->pd_cancel = B_TRUE;
cv_broadcast(&pd->pd_cv);
while (!pd->pd_exited)
cv_wait_sig(&pd->pd_cv, &pd->pd_mtx);
mutex_exit(&pd->pd_mtx);
out:
mutex_destroy(&pd->pd_mtx);
cv_destroy(&pd->pd_cv);
kmem_free(czb, sizeof (zbookmark_phys_t));
kmem_free(pd, sizeof (struct prefetch_data));
kmem_free(td, sizeof (struct traverse_data));
return (err);
}
/*
* NB: dataset must not be changing on-disk (eg, is a snapshot or we are
* in syncing context).
*/
int
traverse_dataset_resume(dsl_dataset_t *ds, uint64_t txg_start,
zbookmark_phys_t *resume,
int flags, blkptr_cb_t func, void *arg)
{
return (traverse_impl(ds->ds_dir->dd_pool->dp_spa, ds, ds->ds_object,
&dsl_dataset_phys(ds)->ds_bp, txg_start, resume, flags, func, arg));
}
int
traverse_dataset(dsl_dataset_t *ds, uint64_t txg_start,
int flags, blkptr_cb_t func, void *arg)
{
return (traverse_dataset_resume(ds, txg_start, NULL, flags, func, arg));
}
int
traverse_dataset_destroyed(spa_t *spa, blkptr_t *blkptr,
uint64_t txg_start, zbookmark_phys_t *resume, int flags,
blkptr_cb_t func, void *arg)
{
return (traverse_impl(spa, NULL, ZB_DESTROYED_OBJSET,
blkptr, txg_start, resume, flags, func, arg));
}
/*
* NB: pool must not be changing on-disk (eg, from zdb or sync context).
*/
int
traverse_pool(spa_t *spa, uint64_t txg_start, int flags,
blkptr_cb_t func, void *arg)
{
int err;
dsl_pool_t *dp = spa_get_dsl(spa);
objset_t *mos = dp->dp_meta_objset;
boolean_t hard = (flags & TRAVERSE_HARD);
/* visit the MOS */
err = traverse_impl(spa, NULL, 0, spa_get_rootblkptr(spa),
txg_start, NULL, flags, func, arg);
if (err != 0)
return (err);
/* visit each dataset */
for (uint64_t obj = 1; err == 0;
err = dmu_object_next(mos, &obj, B_FALSE, txg_start)) {
dmu_object_info_t doi;
err = dmu_object_info(mos, obj, &doi);
if (err != 0) {
if (hard)
continue;
break;
}
if (doi.doi_bonus_type == DMU_OT_DSL_DATASET) {
dsl_dataset_t *ds;
uint64_t txg = txg_start;
dsl_pool_config_enter(dp, FTAG);
err = dsl_dataset_hold_obj(dp, obj, FTAG, &ds);
dsl_pool_config_exit(dp, FTAG);
if (err != 0) {
if (hard)
continue;
break;
}
if (dsl_dataset_phys(ds)->ds_prev_snap_txg > txg)
txg = dsl_dataset_phys(ds)->ds_prev_snap_txg;
err = traverse_dataset(ds, txg, flags, func, arg);
dsl_dataset_rele(ds, FTAG);
if (err != 0)
break;
}
}
if (err == ESRCH)
err = 0;
return (err);
}
EXPORT_SYMBOL(traverse_dataset);
EXPORT_SYMBOL(traverse_pool);
ZFS_MODULE_PARAM(zfs, zfs_, pd_bytes_max, INT, ZMOD_RW,
"Max number of bytes to prefetch");
ZFS_MODULE_PARAM(zfs, zfs_, traverse_indirect_prefetch_limit, UINT, ZMOD_RW,
"Traverse prefetch number of blocks pointed by indirect block");
#if defined(_KERNEL)
module_param_named(ignore_hole_birth, send_holes_without_birth_time, int, 0644);
MODULE_PARM_DESC(ignore_hole_birth,
"Alias for send_holes_without_birth_time");
#endif
/* CSTYLED */
ZFS_MODULE_PARAM(zfs, , send_holes_without_birth_time, INT, ZMOD_RW,
"Ignore hole_birth txg for zfs send");
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