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Illumos #3236 

3236 zio nop-write
Reviewed by: Matt Ahrens <matthew.ahrens@delphix.com>
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Christopher Siden <chris.siden@delphix.com>
Approved by: Garrett D'Amore <garrett@damore.org>

References:
  illumos/illumos-gate@80901aea8e
  https://www.illumos.org/issues/3236

Porting Notes

1. This patch is being merged dispite an increased instance of
   https://www.illumos.org/issues/3113 being triggered by ztest.

Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #1489
This commit is contained in:
George Wilson 2013-05-10 12:47:54 -07:00 committed by Brian Behlendorf
parent 831baf06ef
commit 03c6040bee
13 changed files with 369 additions and 76 deletions
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41
cmd/ztest/ztest.c
View File

@ -208,6 +208,7 @@ enum ztest_io_type {
ZTEST_IO_WRITE_ZEROES,
ZTEST_IO_TRUNCATE,
ZTEST_IO_SETATTR,
ZTEST_IO_REWRITE,
ZTEST_IO_TYPES
};
@ -1900,6 +1901,12 @@ ztest_get_data(void *arg, lr_write_t *lr, char *buf, zio_t *zio)
DMU_READ_NO_PREFETCH);
if (error == 0) {
blkptr_t *obp = dmu_buf_get_blkptr(db);
if (obp) {
ASSERT(BP_IS_HOLE(bp));
*bp = *obp;
}
zgd->zgd_db = db;
zgd->zgd_bp = bp;
@ -2048,6 +2055,9 @@ ztest_remove(ztest_ds_t *zd, ztest_od_t *od, int count)
continue;
}
/*
* No object was found.
*/
if (od->od_object == 0)
continue;
@ -2163,6 +2173,7 @@ ztest_prealloc(ztest_ds_t *zd, uint64_t object, uint64_t offset, uint64_t size)
static void
ztest_io(ztest_ds_t *zd, uint64_t object, uint64_t offset)
{
int err;
ztest_block_tag_t wbt;
dmu_object_info_t doi;
enum ztest_io_type io_type;
@ -2217,6 +2228,25 @@ ztest_io(ztest_ds_t *zd, uint64_t object, uint64_t offset)
break;
default:
break;
case ZTEST_IO_REWRITE:
(void) rw_enter(&ztest_name_lock, RW_READER);
err = ztest_dsl_prop_set_uint64(zd->zd_name,
ZFS_PROP_CHECKSUM, spa_dedup_checksum(ztest_spa),
B_FALSE);
VERIFY(err == 0 || err == ENOSPC);
err = ztest_dsl_prop_set_uint64(zd->zd_name,
ZFS_PROP_COMPRESSION,
ztest_random_dsl_prop(ZFS_PROP_COMPRESSION),
B_FALSE);
VERIFY(err == 0 || err == ENOSPC);
(void) rw_exit(&ztest_name_lock);
VERIFY0(dmu_read(zd->zd_os, object, offset, blocksize, data,
DMU_READ_NO_PREFETCH));
(void) ztest_write(zd, object, offset, blocksize, data);
break;
}
(void) rw_exit(&zd->zd_zilog_lock);
@ -2304,6 +2334,11 @@ ztest_zil_remount(ztest_ds_t *zd, uint64_t id)
{
objset_t *os = zd->zd_os;
/*
* We grab the zd_dirobj_lock to ensure that no other thread is
* updating the zil (i.e. adding in-memory log records) and the
* zd_zilog_lock to block any I/O.
*/
mutex_enter(&zd->zd_dirobj_lock);
(void) rw_enter(&zd->zd_zilog_lock, RW_WRITER);
@ -5121,8 +5156,8 @@ ztest_ddt_repair(ztest_ds_t *zd, uint64_t id)
/*
* Find out what block we got.
*/
VERIFY(dmu_buf_hold(os, object, 0, FTAG, &db,
DMU_READ_NO_PREFETCH) == 0);
VERIFY0(dmu_buf_hold(os, object, 0, FTAG, &db,
DMU_READ_NO_PREFETCH));
blk = *((dmu_buf_impl_t *)db)->db_blkptr;
dmu_buf_rele(db, FTAG);
@ -5824,6 +5859,8 @@ ztest_freeze(void)
kernel_init(FREAD | FWRITE);
VERIFY3U(0, ==, spa_open(ztest_opts.zo_pool, &spa, FTAG));
VERIFY3U(0, ==, ztest_dataset_open(0));
spa->spa_debug = B_TRUE;
ztest_spa = spa;
/*
* Force the first log block to be transactionally allocated.

2
include/sys/dbuf.h
View File

@ -20,6 +20,7 @@
*/
/*
* Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2013 by Delphix. All rights reserved.
* Copyright (c) 2013 by Saso Kiselkov. All rights reserved.
*/
@ -131,6 +132,7 @@ typedef struct dbuf_dirty_record {
blkptr_t dr_overridden_by;
override_states_t dr_override_state;
uint8_t dr_copies;
boolean_t dr_nopwrite;
} dl;
} dt;
} dbuf_dirty_record_t;

5
include/sys/dmu.h
View File

@ -497,6 +497,11 @@ void dmu_evict_user(objset_t *os, dmu_buf_evict_func_t *func);
*/
void *dmu_buf_get_user(dmu_buf_t *db);
/*
* Returns the blkptr associated with this dbuf, or NULL if not set.
*/
struct blkptr *dmu_buf_get_blkptr(dmu_buf_t *db);
/*
* Indicate that you are going to modify the buffer's data (db_data).
*

12
include/sys/zio.h
View File

@ -196,7 +196,9 @@ enum zio_flag {
ZIO_FLAG_GANG_CHILD = 1 << 22,
ZIO_FLAG_DDT_CHILD = 1 << 23,
ZIO_FLAG_GODFATHER = 1 << 24,
ZIO_FLAG_FASTWRITE = 1 << 25
ZIO_FLAG_NOPWRITE = 1 << 25,
ZIO_FLAG_REEXECUTED = 1 << 26,
ZIO_FLAG_FASTWRITE = 1 << 27
};
#define ZIO_FLAG_MUSTSUCCEED 0
@ -296,8 +298,9 @@ typedef struct zio_prop {
dmu_object_type_t zp_type;
uint8_t zp_level;
uint8_t zp_copies;
uint8_t zp_dedup;
uint8_t zp_dedup_verify;
boolean_t zp_dedup;
boolean_t zp_dedup_verify;
boolean_t zp_nopwrite;
} zio_prop_t;
typedef struct zio_cksum_report zio_cksum_report_t;
@ -466,7 +469,8 @@ extern zio_t *zio_rewrite(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
void *data, uint64_t size, zio_done_func_t *done, void *private,
int priority, enum zio_flag flags, zbookmark_t *zb);
extern void zio_write_override(zio_t *zio, blkptr_t *bp, int copies);
extern void zio_write_override(zio_t *zio, blkptr_t *bp, int copies,
boolean_t nopwrite);
extern void zio_free(spa_t *spa, uint64_t txg, const blkptr_t *bp);

96
include/sys/zio_impl.h
View File

@ -37,6 +37,70 @@
extern "C" {
#endif
/*
* XXX -- Describe ZFS I/O pipleine here. Fill in as needed.
*
* The ZFS I/O pipeline is comprised of various stages which are defined
* in the zio_stage enum below. The individual stages are used to construct
* these basic I/O operations: Read, Write, Free, Claim, and Ioctl.
*
* I/O operations: (XXX - provide detail for each of the operations)
*
* Read:
* Write:
* Free:
* Claim:
* Ioctl:
*
* Although the most common pipeline are used by the basic I/O operations
* above, there are some helper pipelines (one could consider them
* sub-pipelines) which are used internally by the ZIO module and are
* explained below:
*
* Interlock Pipeline:
* The interlock pipeline is the most basic pipeline and is used by all
* of the I/O operations. The interlock pipeline does not perform any I/O
* and is used to coordinate the dependencies between I/Os that are being
* issued (i.e. the parent/child relationship).
*
* Vdev child Pipeline:
* The vdev child pipeline is responsible for performing the physical I/O.
* It is in this pipeline where the I/O are queued and possibly cached.
*
* In addition to performing I/O, the pipeline is also responsible for
* data transformations. The transformations performed are based on the
* specific properties that user may have selected and modify the
* behavior of the pipeline. Examples of supported transformations are
* compression, dedup, and nop writes. Transformations will either modify
* the data or the pipeline. This list below further describes each of
* the supported transformations:
*
* Compression:
* ZFS supports three different flavors of compression -- gzip, lzjb, and
* zle. Compression occurs as part of the write pipeline and is performed
* in the ZIO_STAGE_WRITE_BP_INIT stage.
*
* Dedup:
* Dedup reads are handled by the ZIO_STAGE_DDT_READ_START and
* ZIO_STAGE_DDT_READ_DONE stages. These stages are added to an existing
* read pipeline if the dedup bit is set on the block pointer.
* Writing a dedup block is performed by the ZIO_STAGE_DDT_WRITE stage
* and added to a write pipeline if a user has enabled dedup on that
* particular dataset.
*
* NOP Write:
* The NOP write feature is performed by the ZIO_STAGE_NOP_WRITE stage
* and is added to an existing write pipeline if a crypographically
* secure checksum (i.e. SHA256) is enabled and compression is turned on.
* The NOP write stage will compare the checksums of the current data
* on-disk (level-0 blocks only) and the data that is currently being written.
* If the checksum values are identical then the pipeline is converted to
* an interlock pipeline skipping block allocation and bypassing the
* physical I/O. The nop write feature can handle writes in either
* syncing or open context (i.e. zil writes) and as a result is mutually
* exclusive with dedup.
*/
/*
* zio pipeline stage definitions
*/
@ -50,27 +114,29 @@ enum zio_stage {
ZIO_STAGE_CHECKSUM_GENERATE = 1 << 5, /* -W--- */
ZIO_STAGE_DDT_READ_START = 1 << 6, /* R---- */
ZIO_STAGE_DDT_READ_DONE = 1 << 7, /* R---- */
ZIO_STAGE_DDT_WRITE = 1 << 8, /* -W--- */
ZIO_STAGE_DDT_FREE = 1 << 9, /* --F-- */
ZIO_STAGE_NOP_WRITE = 1 << 6, /* -W--- */
ZIO_STAGE_GANG_ASSEMBLE = 1 << 10, /* RWFC- */
ZIO_STAGE_GANG_ISSUE = 1 << 11, /* RWFC- */
ZIO_STAGE_DDT_READ_START = 1 << 7, /* R---- */
ZIO_STAGE_DDT_READ_DONE = 1 << 8, /* R---- */
ZIO_STAGE_DDT_WRITE = 1 << 9, /* -W--- */
ZIO_STAGE_DDT_FREE = 1 << 10, /* --F-- */
ZIO_STAGE_DVA_ALLOCATE = 1 << 12, /* -W--- */
ZIO_STAGE_DVA_FREE = 1 << 13, /* --F-- */
ZIO_STAGE_DVA_CLAIM = 1 << 14, /* ---C- */
ZIO_STAGE_GANG_ASSEMBLE = 1 << 11, /* RWFC- */
ZIO_STAGE_GANG_ISSUE = 1 << 12, /* RWFC- */
ZIO_STAGE_READY = 1 << 15, /* RWFCI */
ZIO_STAGE_DVA_ALLOCATE = 1 << 13, /* -W--- */
ZIO_STAGE_DVA_FREE = 1 << 14, /* --F-- */
ZIO_STAGE_DVA_CLAIM = 1 << 15, /* ---C- */
ZIO_STAGE_VDEV_IO_START = 1 << 16, /* RW--I */
ZIO_STAGE_VDEV_IO_DONE = 1 << 17, /* RW--I */
ZIO_STAGE_VDEV_IO_ASSESS = 1 << 18, /* RW--I */
ZIO_STAGE_READY = 1 << 16, /* RWFCI */
ZIO_STAGE_CHECKSUM_VERIFY = 1 << 19, /* R---- */
ZIO_STAGE_VDEV_IO_START = 1 << 17, /* RW--I */
ZIO_STAGE_VDEV_IO_DONE = 1 << 18, /* RW--I */
ZIO_STAGE_VDEV_IO_ASSESS = 1 << 19, /* RW--I */
ZIO_STAGE_DONE = 1 << 20 /* RWFCI */
ZIO_STAGE_CHECKSUM_VERIFY = 1 << 20, /* R---- */
ZIO_STAGE_DONE = 1 << 21 /* RWFCI */
};
#define ZIO_INTERLOCK_STAGES \

6
module/zfs/arc.c
View File

@ -3708,6 +3708,12 @@ arc_write_done(zio_t *zio)
arc_hdr_destroy(exists);
exists = buf_hash_insert(hdr, &hash_lock);
ASSERT3P(exists, ==, NULL);
} else if (zio->io_flags & ZIO_FLAG_NOPWRITE) {
/* nopwrite */
ASSERT(zio->io_prop.zp_nopwrite);
if (!BP_EQUAL(&zio->io_bp_orig, zio->io_bp))
panic("bad nopwrite, hdr=%p exists=%p",
(void *)hdr, (void *)exists);
} else {
/* Dedup */
ASSERT(hdr->b_datacnt == 1);

19
module/zfs/dbuf.c
View File

@ -823,13 +823,15 @@ dbuf_unoverride(dbuf_dirty_record_t *dr)
ASSERT(db->db_data_pending != dr);
/* free this block */
if (!BP_IS_HOLE(bp)) {
if (!BP_IS_HOLE(bp) && !dr->dt.dl.dr_nopwrite) {
spa_t *spa;
DB_GET_SPA(&spa, db);
zio_free(spa, txg, bp);
}
dr->dt.dl.dr_override_state = DR_NOT_OVERRIDDEN;
dr->dt.dl.dr_nopwrite = B_FALSE;
/*
* Release the already-written buffer, so we leave it in
* a consistent dirty state. Note that all callers are
@ -2269,6 +2271,13 @@ dmu_buf_freeable(dmu_buf_t *dbuf)
return (res);
}
blkptr_t *
dmu_buf_get_blkptr(dmu_buf_t *db)
{
dmu_buf_impl_t *dbi = (dmu_buf_impl_t *)db;
return (dbi->db_blkptr);
}
static void
dbuf_check_blkptr(dnode_t *dn, dmu_buf_impl_t *db)
{
@ -2622,7 +2631,11 @@ dbuf_write_done(zio_t *zio, arc_buf_t *buf, void *vdb)
ASSERT0(zio->io_error);
ASSERT(db->db_blkptr == bp);
if (zio->io_flags & ZIO_FLAG_IO_REWRITE) {
/*
* For nopwrites and rewrites we ensure that the bp matches our
* original and bypass all the accounting.
*/
if (zio->io_flags & (ZIO_FLAG_IO_REWRITE | ZIO_FLAG_NOPWRITE)) {
ASSERT(BP_EQUAL(bp, bp_orig));
} else {
objset_t *os;
@ -2822,7 +2835,7 @@ dbuf_write(dbuf_dirty_record_t *dr, arc_buf_t *data, dmu_tx_t *tx)
mutex_enter(&db->db_mtx);
dr->dt.dl.dr_override_state = DR_NOT_OVERRIDDEN;
zio_write_override(dr->dr_zio, &dr->dt.dl.dr_overridden_by,
dr->dt.dl.dr_copies);
dr->dt.dl.dr_copies, dr->dt.dl.dr_nopwrite);
mutex_exit(&db->db_mtx);
} else if (db->db_state == DB_NOFILL) {
ASSERT(zp.zp_checksum == ZIO_CHECKSUM_OFF);

138
module/zfs/dmu.c
View File

@ -41,12 +41,18 @@
#include <sys/zfs_ioctl.h>
#include <sys/zap.h>
#include <sys/zio_checksum.h>
#include <sys/zio_compress.h>
#include <sys/sa.h>
#ifdef _KERNEL
#include <sys/vmsystm.h>
#include <sys/zfs_znode.h>
#endif
/*
* Enable/disable nopwrite feature.
*/
int zfs_nopwrite_enabled = 1;
const dmu_object_type_info_t dmu_ot[DMU_OT_NUMTYPES] = {
{ DMU_BSWAP_UINT8, TRUE, "unallocated" },
{ DMU_BSWAP_ZAP, TRUE, "object directory" },
@ -1473,6 +1479,16 @@ dmu_sync_done(zio_t *zio, arc_buf_t *buf, void *varg)
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) {
ASSERTV(blkptr_t *bp = zio->io_bp);
ASSERTV(blkptr_t *bp_orig = &zio->io_bp_orig);
ASSERTV(uint8_t chksum = BP_GET_CHECKSUM(bp_orig));
ASSERT(BP_EQUAL(bp, bp_orig));
ASSERT(zio->io_prop.zp_compress != ZIO_COMPRESS_OFF);
ASSERT(zio_checksum_table[chksum].ci_dedup);
}
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;
@ -1494,11 +1510,22 @@ dmu_sync_late_arrival_done(zio_t *zio)
{
blkptr_t *bp = zio->io_bp;
dmu_sync_arg_t *dsa = zio->io_private;
ASSERTV(blkptr_t *bp_orig = &zio->io_bp_orig);
if (zio->io_error == 0 && !BP_IS_HOLE(bp)) {
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);
/*
* If we didn't allocate a new block (i.e. ZIO_FLAG_NOPWRITE)
* then there is nothing to do here. Otherwise, free the
* newly allocated block in this txg.
*/
if (zio->io_flags & ZIO_FLAG_NOPWRITE) {
ASSERT(BP_EQUAL(bp, bp_orig));
} else {
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);
@ -1544,7 +1571,7 @@ dmu_sync_late_arrival(zio_t *pio, objset_t *os, dmu_sync_cb_t *done, zgd_t *zgd,
*
* Return values:
*
* EEXIST: this txg has already been synced, so there's nothing to to.
* 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.
@ -1576,7 +1603,6 @@ dmu_sync(zio_t *pio, uint64_t txg, dmu_sync_cb_t *done, zgd_t *zgd)
dnode_t *dn;
ASSERT(pio != NULL);
ASSERT(BP_IS_HOLE(bp));
ASSERT(txg != 0);
SET_BOOKMARK(&zb, ds->ds_object,
@ -1631,6 +1657,23 @@ dmu_sync(zio_t *pio, uint64_t txg, dmu_sync_cb_t *done, zgd_t *zgd)
return (SET_ERROR(ENOENT));
}
ASSERT(dr->dr_next == NULL || dr->dr_next->dr_txg < txg);
/*
* Assume the on-disk data is X, the current syncing data is Y,
* and the current in-memory data is Z (currently in dmu_sync).
* X and Z are identical but Y is has been modified. Normally,
* when X and Z are the same we will perform a nopwrite but if Y
* is different we must disable nopwrite since the resulting write
* of Y to disk can free the block containing X. If we allowed a
* nopwrite to occur the block pointing to Z would reference a freed
* block. Since this is a rare case we simplify this by disabling
* nopwrite if the current dmu_sync-ing dbuf has been modified in
* a previous transaction.
*/
if (dr->dr_next)
zp.zp_nopwrite = B_FALSE;
ASSERT(dr->dr_txg == txg);
if (dr->dt.dl.dr_override_state == DR_IN_DMU_SYNC ||
dr->dt.dl.dr_override_state == DR_OVERRIDDEN) {
@ -1715,14 +1758,26 @@ dmu_write_policy(objset_t *os, dnode_t *dn, int level, int wp, zio_prop_t *zp)
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;
boolean_t dedup = B_FALSE;
boolean_t nopwrite = B_FALSE;
boolean_t dedup_verify = os->os_dedup_verify;
int copies = os->os_copies;
/*
* Determine checksum setting.
* 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 = zfs_mdcomp_disable ? ZIO_COMPRESS_EMPTY :
ZIO_COMPRESS_LZJB;
/*
* Metadata always gets checksummed. If the data
* checksum is multi-bit correctable, and it's not a
@ -1733,45 +1788,47 @@ dmu_write_policy(objset_t *os, dnode_t *dn, int level, int wp, zio_prop_t *zp)
if (zio_checksum_table[checksum].ci_correctable < 1 ||
zio_checksum_table[checksum].ci_eck)
checksum = ZIO_CHECKSUM_FLETCHER_4;
} else {
checksum = zio_checksum_select(dn->dn_checksum, checksum);
}
} else if (wp & WP_NOFILL) {
ASSERT(level == 0);
/*
* Determine compression setting.
*/
if (ismd) {
/*
* XXX -- we should design a compression algorithm
* that specializes in arrays of bps.
* 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 = zfs_mdcomp_disable ? ZIO_COMPRESS_EMPTY :
ZIO_COMPRESS_LZJB;
compress = ZIO_COMPRESS_OFF;
checksum = ZIO_CHECKSUM_OFF;
} else {
compress = zio_compress_select(dn->dn_compress, compress);
}
/*
* 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.
*/
dedup = (!ismd && dedup_checksum != ZIO_CHECKSUM_OFF);
if (dedup) {
checksum = dedup_checksum;
if (!zio_checksum_table[checksum].ci_dedup)
dedup_verify = 1;
}
checksum = (dedup_checksum == ZIO_CHECKSUM_OFF) ?
zio_checksum_select(dn->dn_checksum, checksum) :
dedup_checksum;
if (wp & WP_DMU_SYNC)
dedup = 0;
/*
* 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_dedup)
dedup_verify = B_TRUE;
}
if (wp & WP_NOFILL) {
ASSERT(!ismd && level == 0);
checksum = ZIO_CHECKSUM_OFF;
compress = ZIO_COMPRESS_OFF;
dedup = B_FALSE;
/*
* Enable nopwrite if we have a cryptographically secure
* checksum that has no known collisions (i.e. SHA-256)
* 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_dedup &&
compress != ZIO_COMPRESS_OFF && zfs_nopwrite_enabled);
}
zp->zp_checksum = checksum;
@ -1781,6 +1838,7 @@ dmu_write_policy(objset_t *os, dnode_t *dn, int level, int wp, zio_prop_t *zp)
zp->zp_copies = MIN(copies + ismd, spa_max_replication(os->os_spa));
zp->zp_dedup = dedup;
zp->zp_dedup_verify = dedup && dedup_verify;
zp->zp_nopwrite = nopwrite;
}
int
@ -2005,4 +2063,8 @@ EXPORT_SYMBOL(dmu_ot);
module_param(zfs_mdcomp_disable, int, 0644);
MODULE_PARM_DESC(zfs_mdcomp_disable, "Disable meta data compression");
module_param(zfs_nopwrite_enabled, int, 0644);
MODULE_PARM_DESC(zfs_nopwrite_enabled, "Enable NOP writes");
#endif

1
module/zfs/dsl_pool.c
View File

@ -421,7 +421,6 @@ dsl_pool_sync(dsl_pool_t *dp, uint64_t txg)
* clean up our in-memory structures accumulated while syncing:
*
* - move dead blocks from the pending deadlist to the on-disk deadlist
* - clean up zil records
* - release hold from dsl_dataset_dirty()
*/
while ((ds = list_remove_head(&synced_datasets))) {

1
module/zfs/spa_misc.c
View File

@ -245,7 +245,6 @@ int spa_mode_global;
* Secondly, the value determines if an I/O is considered "hung".
* Any I/O that has not completed in zfs_deadman_synctime is considered
* "hung" resulting in a zevent being posted.
* 1000 zfs_txg_synctime_ms (i.e. 1000 seconds).
*/
unsigned long zfs_deadman_synctime = 1000ULL;

6
module/zfs/zfs_vnops.c
View File

@ -1050,6 +1050,12 @@ zfs_get_data(void *arg, lr_write_t *lr, char *buf, zio_t *zio)
DMU_READ_NO_PREFETCH);
if (error == 0) {
blkptr_t *obp = dmu_buf_get_blkptr(db);
if (obp) {
ASSERT(BP_IS_HOLE(bp));
*bp = *obp;
}
zgd->zgd_db = db;
zgd->zgd_bp = bp;

105
module/zfs/zio.c
View File

@ -723,9 +723,7 @@ zio_write(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
DMU_OT_IS_VALID(zp->zp_type) &&
zp->zp_level < 32 &&
zp->zp_copies > 0 &&
zp->zp_copies <= spa_max_replication(spa) &&
zp->zp_dedup <= 1 &&
zp->zp_dedup_verify <= 1);
zp->zp_copies <= spa_max_replication(spa));
zio = zio_create(pio, spa, txg, bp, data, size, done, private,
ZIO_TYPE_WRITE, priority, flags, NULL, 0, zb,
@ -753,13 +751,20 @@ zio_rewrite(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp, void *data,
}
void
zio_write_override(zio_t *zio, blkptr_t *bp, int copies)
zio_write_override(zio_t *zio, blkptr_t *bp, int copies, boolean_t nopwrite)
{
ASSERT(zio->io_type == ZIO_TYPE_WRITE);
ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
ASSERT(zio->io_stage == ZIO_STAGE_OPEN);
ASSERT(zio->io_txg == spa_syncing_txg(zio->io_spa));
/*
* We must reset the io_prop to match the values that existed
* when the bp was first written by dmu_sync() keeping in mind
* that nopwrite and dedup are mutually exclusive.
*/
zio->io_prop.zp_dedup = nopwrite ? B_FALSE : zio->io_prop.zp_dedup;
zio->io_prop.zp_nopwrite = nopwrite;
zio->io_prop.zp_copies = copies;
zio->io_bp_override = bp;
}
@ -1051,6 +1056,19 @@ zio_write_bp_init(zio_t *zio)
*bp = *zio->io_bp_override;
zio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
/*
* If we've been overridden and nopwrite is set then
* set the flag accordingly to indicate that a nopwrite
* has already occurred.
*/
if (!BP_IS_HOLE(bp) && zp->zp_nopwrite) {
ASSERT(!zp->zp_dedup);
zio->io_flags |= ZIO_FLAG_NOPWRITE;
return (ZIO_PIPELINE_CONTINUE);
}
ASSERT(!zp->zp_nopwrite);
if (BP_IS_HOLE(bp) || !zp->zp_dedup)
return (ZIO_PIPELINE_CONTINUE);
@ -1138,6 +1156,11 @@ zio_write_bp_init(zio_t *zio)
ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE));
zio->io_pipeline = ZIO_DDT_WRITE_PIPELINE;
}
if (zp->zp_nopwrite) {
ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE));
zio->io_pipeline |= ZIO_STAGE_NOP_WRITE;
}
}
return (ZIO_PIPELINE_CONTINUE);
@ -1404,6 +1427,7 @@ zio_reexecute(zio_t *pio)
pio->io_stage = pio->io_orig_stage;
pio->io_pipeline = pio->io_orig_pipeline;
pio->io_reexecute = 0;
pio->io_flags |= ZIO_FLAG_REEXECUTED;
pio->io_error = 0;
for (w = 0; w < ZIO_WAIT_TYPES; w++)
pio->io_state[w] = 0;
@ -1887,8 +1911,9 @@ zio_write_gang_block(zio_t *pio)
zp.zp_type = DMU_OT_NONE;
zp.zp_level = 0;
zp.zp_copies = gio->io_prop.zp_copies;
zp.zp_dedup = 0;
zp.zp_dedup_verify = 0;
zp.zp_dedup = B_FALSE;
zp.zp_dedup_verify = B_FALSE;
zp.zp_nopwrite = B_FALSE;
zio_nowait(zio_write(zio, spa, txg, &gbh->zg_blkptr[g],
(char *)pio->io_data + (pio->io_size - resid), lsize, &zp,
@ -1912,6 +1937,62 @@ zio_write_gang_block(zio_t *pio)
return (ZIO_PIPELINE_CONTINUE);
}
/*
* The zio_nop_write stage in the pipeline determines if allocating
* a new bp is necessary. By leveraging a cryptographically secure checksum,
* such as SHA256, we can compare the checksums of the new data and the old
* to determine if allocating a new block is required. The nopwrite
* feature can handle writes in either syncing or open context (i.e. zil
* writes) and as a result is mutually exclusive with dedup.
*/
static int
zio_nop_write(zio_t *zio)
{
blkptr_t *bp = zio->io_bp;
blkptr_t *bp_orig = &zio->io_bp_orig;
zio_prop_t *zp = &zio->io_prop;
ASSERT(BP_GET_LEVEL(bp) == 0);
ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE));
ASSERT(zp->zp_nopwrite);
ASSERT(!zp->zp_dedup);
ASSERT(zio->io_bp_override == NULL);
ASSERT(IO_IS_ALLOCATING(zio));
/*
* Check to see if the original bp and the new bp have matching
* characteristics (i.e. same checksum, compression algorithms, etc).
* If they don't then just continue with the pipeline which will
* allocate a new bp.
*/
if (BP_IS_HOLE(bp_orig) ||
!zio_checksum_table[BP_GET_CHECKSUM(bp)].ci_dedup ||
BP_GET_CHECKSUM(bp) != BP_GET_CHECKSUM(bp_orig) ||
BP_GET_COMPRESS(bp) != BP_GET_COMPRESS(bp_orig) ||
BP_GET_DEDUP(bp) != BP_GET_DEDUP(bp_orig) ||
zp->zp_copies != BP_GET_NDVAS(bp_orig))
return (ZIO_PIPELINE_CONTINUE);
/*
* If the checksums match then reset the pipeline so that we
* avoid allocating a new bp and issuing any I/O.
*/
if (ZIO_CHECKSUM_EQUAL(bp->blk_cksum, bp_orig->blk_cksum)) {
ASSERT(zio_checksum_table[zp->zp_checksum].ci_dedup);
ASSERT3U(BP_GET_PSIZE(bp), ==, BP_GET_PSIZE(bp_orig));
ASSERT3U(BP_GET_LSIZE(bp), ==, BP_GET_LSIZE(bp_orig));
ASSERT(zp->zp_compress != ZIO_COMPRESS_OFF);
ASSERT(bcmp(&bp->blk_prop, &bp_orig->blk_prop,
sizeof (uint64_t)) == 0);
*bp = *bp_orig;
zio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
zio->io_flags |= ZIO_FLAG_NOPWRITE;
}
return (ZIO_PIPELINE_CONTINUE);
}
/*
* ==========================================================================
* Dedup
@ -2186,7 +2267,7 @@ zio_ddt_write(zio_t *zio)
zio->io_stage = ZIO_STAGE_OPEN;
BP_ZERO(bp);
} else {
zp->zp_dedup = 0;
zp->zp_dedup = B_FALSE;
}
zio->io_pipeline = ZIO_WRITE_PIPELINE;
ddt_exit(ddt);
@ -2815,7 +2896,8 @@ zio_ready(zio_t *zio)
if (zio->io_ready) {
ASSERT(IO_IS_ALLOCATING(zio));
ASSERT(bp->blk_birth == zio->io_txg || BP_IS_HOLE(bp));
ASSERT(bp->blk_birth == zio->io_txg || BP_IS_HOLE(bp) ||
(zio->io_flags & ZIO_FLAG_NOPWRITE));
ASSERT(zio->io_children[ZIO_CHILD_GANG][ZIO_WAIT_READY] == 0);
zio->io_ready(zio);
@ -2893,6 +2975,8 @@ zio_done(zio_t *zio)
ASSERT(BP_COUNT_GANG(zio->io_bp) == 0 ||
(BP_COUNT_GANG(zio->io_bp) == BP_GET_NDVAS(zio->io_bp)));
}
if (zio->io_flags & ZIO_FLAG_NOPWRITE)
VERIFY(BP_EQUAL(zio->io_bp, &zio->io_bp_orig));
}
/*
@ -3015,7 +3099,7 @@ zio_done(zio_t *zio)
if ((zio->io_error || zio->io_reexecute) &&
IO_IS_ALLOCATING(zio) && zio->io_gang_leader == zio &&
!(zio->io_flags & ZIO_FLAG_IO_REWRITE))
!(zio->io_flags & (ZIO_FLAG_IO_REWRITE | ZIO_FLAG_NOPWRITE)))
zio_dva_unallocate(zio, zio->io_gang_tree, zio->io_bp);
zio_gang_tree_free(&zio->io_gang_tree);
@ -3112,7 +3196,7 @@ zio_done(zio_t *zio)
}
if (zio->io_flags & ZIO_FLAG_FASTWRITE && zio->io_bp &&
!BP_IS_HOLE(zio->io_bp)) {
!BP_IS_HOLE(zio->io_bp) && !(zio->io_flags & ZIO_FLAG_NOPWRITE)) {
metaslab_fastwrite_unmark(zio->io_spa, zio->io_bp);
}
@ -3159,6 +3243,7 @@ static zio_pipe_stage_t *zio_pipeline[] = {
zio_issue_async,
zio_write_bp_init,
zio_checksum_generate,
zio_nop_write,
zio_ddt_read_start,
zio_ddt_read_done,
zio_ddt_write,

13
module/zfs/zvol.c
View File

@ -35,6 +35,7 @@
* needs to be run before opening and using a device.
*/
#include <sys/dbuf.h>
#include <sys/dmu_traverse.h>
#include <sys/dsl_dataset.h>
#include <sys/dsl_prop.h>
@ -815,8 +816,10 @@ zvol_get_data(void *arg, lr_write_t *lr, char *buf, zio_t *zio)
{
zvol_state_t *zv = arg;
objset_t *os = zv->zv_objset;
uint64_t object = ZVOL_OBJ;
uint64_t offset = lr->lr_offset;
uint64_t size = lr->lr_length;
blkptr_t *bp = &lr->lr_blkptr;
dmu_buf_t *db;
zgd_t *zgd;
int error;
@ -836,14 +839,20 @@ zvol_get_data(void *arg, lr_write_t *lr, char *buf, zio_t *zio)
* we don't have to write the data twice.
*/
if (buf != NULL) { /* immediate write */
error = dmu_read(os, ZVOL_OBJ, offset, size, buf,
error = dmu_read(os, object, offset, size, buf,
DMU_READ_NO_PREFETCH);
} else {
size = zv->zv_volblocksize;
offset = P2ALIGN_TYPED(offset, size, uint64_t);
error = dmu_buf_hold(os, ZVOL_OBJ, offset, zgd, &db,
error = dmu_buf_hold(os, object, offset, zgd, &db,
DMU_READ_NO_PREFETCH);
if (error == 0) {
blkptr_t *obp = dmu_buf_get_blkptr(db);
if (obp) {
ASSERT(BP_IS_HOLE(bp));
*bp = *obp;
}
zgd->zgd_db = db;
zgd->zgd_bp = &lr->lr_blkptr;