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50c957f702
freebsd-dev/module/zfs/zil.c
Ned Bass 50c957f702 Implement large_dnode pool feature 
Justification
-------------

This feature adds support for variable length dnodes. Our motivation is
to eliminate the overhead associated with using spill blocks.  Spill
blocks are used to store system attribute data (i.e. file metadata) that
does not fit in the dnode's bonus buffer. By allowing a larger bonus
buffer area the use of a spill block can be avoided.  Spill blocks
potentially incur an additional read I/O for every dnode in a dnode
block. As a worst case example, reading 32 dnodes from a 16k dnode block
and all of the spill blocks could issue 33 separate reads. Now suppose
those dnodes have size 1024 and therefore don't need spill blocks.  Then
the worst case number of blocks read is reduced to from 33 to two--one
per dnode block. In practice spill blocks may tend to be co-located on
disk with the dnode blocks so the reduction in I/O would not be this
drastic. In a badly fragmented pool, however, the improvement could be
significant.

ZFS-on-Linux systems that make heavy use of extended attributes would
benefit from this feature. In particular, ZFS-on-Linux supports the
xattr=sa dataset property which allows file extended attribute data
to be stored in the dnode bonus buffer as an alternative to the
traditional directory-based format. Workloads such as SELinux and the
Lustre distributed filesystem often store enough xattr data to force
spill bocks when xattr=sa is in effect. Large dnodes may therefore
provide a performance benefit to such systems.

Other use cases that may benefit from this feature include files with
large ACLs and symbolic links with long target names. Furthermore,
this feature may be desirable on other platforms in case future
applications or features are developed that could make use of a
larger bonus buffer area.

Implementation
--------------

The size of a dnode may be a multiple of 512 bytes up to the size of
a dnode block (currently 16384 bytes). A dn_extra_slots field was
added to the current on-disk dnode_phys_t structure to describe the
size of the physical dnode on disk. The 8 bits for this field were
taken from the zero filled dn_pad2 field. The field represents how
many "extra" dnode_phys_t slots a dnode consumes in its dnode block.
This convention results in a value of 0 for 512 byte dnodes which
preserves on-disk format compatibility with older software.

Similarly, the in-memory dnode_t structure has a new dn_num_slots field
to represent the total number of dnode_phys_t slots consumed on disk.
Thus dn->dn_num_slots is 1 greater than the corresponding
dnp->dn_extra_slots. This difference in convention was adopted
because, unlike on-disk structures, backward compatibility is not a
concern for in-memory objects, so we used a more natural way to
represent size for a dnode_t.

The default size for newly created dnodes is determined by the value of
a new "dnodesize" dataset property. By default the property is set to
"legacy" which is compatible with older software. Setting the property
to "auto" will allow the filesystem to choose the most suitable dnode
size. Currently this just sets the default dnode size to 1k, but future
code improvements could dynamically choose a size based on observed
workload patterns. Dnodes of varying sizes can coexist within the same
dataset and even within the same dnode block. For example, to enable
automatically-sized dnodes, run

 # zfs set dnodesize=auto tank/fish

The user can also specify literal values for the dnodesize property.
These are currently limited to powers of two from 1k to 16k. The
power-of-2 limitation is only for simplicity of the user interface.
Internally the implementation can handle any multiple of 512 up to 16k,
and consumers of the DMU API can specify any legal dnode value.

The size of a new dnode is determined at object allocation time and
stored as a new field in the znode in-memory structure. New DMU
interfaces are added to allow the consumer to specify the dnode size
that a newly allocated object should use. Existing interfaces are
unchanged to avoid having to update every call site and to preserve
compatibility with external consumers such as Lustre. The new
interfaces names are given below. The versions of these functions that
don't take a dnodesize parameter now just call the _dnsize() versions
with a dnodesize of 0, which means use the legacy dnode size.

New DMU interfaces:
  dmu_object_alloc_dnsize()
  dmu_object_claim_dnsize()
  dmu_object_reclaim_dnsize()

New ZAP interfaces:
  zap_create_dnsize()
  zap_create_norm_dnsize()
  zap_create_flags_dnsize()
  zap_create_claim_norm_dnsize()
  zap_create_link_dnsize()

The constant DN_MAX_BONUSLEN is renamed to DN_OLD_MAX_BONUSLEN. The
spa_maxdnodesize() function should be used to determine the maximum
bonus length for a pool.

These are a few noteworthy changes to key functions:

* The prototype for dnode_hold_impl() now takes a "slots" parameter.
  When the DNODE_MUST_BE_FREE flag is set, this parameter is used to
  ensure the hole at the specified object offset is large enough to
  hold the dnode being created. The slots parameter is also used
  to ensure a dnode does not span multiple dnode blocks. In both of
  these cases, if a failure occurs, ENOSPC is returned. Keep in mind,
  these failure cases are only possible when using DNODE_MUST_BE_FREE.

  If the DNODE_MUST_BE_ALLOCATED flag is set, "slots" must be 0.
  dnode_hold_impl() will check if the requested dnode is already
  consumed as an extra dnode slot by an large dnode, in which case
  it returns ENOENT.

* The function dmu_object_alloc() advances to the next dnode block
  if dnode_hold_impl() returns an error for a requested object.
  This is because the beginning of the next dnode block is the only
  location it can safely assume to either be a hole or a valid
  starting point for a dnode.

* dnode_next_offset_level() and other functions that iterate
  through dnode blocks may no longer use a simple array indexing
  scheme. These now use the current dnode's dn_num_slots field to
  advance to the next dnode in the block. This is to ensure we
  properly skip the current dnode's bonus area and don't interpret it
  as a valid dnode.

zdb
---
The zdb command was updated to display a dnode's size under the
"dnsize" column when the object is dumped.

For ZIL create log records, zdb will now display the slot count for
the object.

ztest
-----
Ztest chooses a random dnodesize for every newly created object. The
random distribution is more heavily weighted toward small dnodes to
better simulate real-world datasets.

Unused bonus buffer space is filled with non-zero values computed from
the object number, dataset id, offset, and generation number.  This
helps ensure that the dnode traversal code properly skips the interior
regions of large dnodes, and that these interior regions are not
overwritten by data belonging to other dnodes. A new test visits each
object in a dataset. It verifies that the actual dnode size matches what
was stored in the ztest block tag when it was created. It also verifies
that the unused bonus buffer space is filled with the expected data
patterns.

ZFS Test Suite
--------------
Added six new large dnode-specific tests, and integrated the dnodesize
property into existing tests for zfs allow and send/recv.

Send/Receive
------------
ZFS send streams for datasets containing large dnodes cannot be received
on pools that don't support the large_dnode feature. A send stream with
large dnodes sets a DMU_BACKUP_FEATURE_LARGE_DNODE flag which will be
unrecognized by an incompatible receiving pool so that the zfs receive
will fail gracefully.

While not implemented here, it may be possible to generate a
backward-compatible send stream from a dataset containing large
dnodes. The implementation may be tricky, however, because the send
object record for a large dnode would need to be resized to a 512
byte dnode, possibly kicking in a spill block in the process. This
means we would need to construct a new SA layout and possibly
register it in the SA layout object. The SA layout is normally just
sent as an ordinary object record. But if we are constructing new
layouts while generating the send stream we'd have to build the SA
layout object dynamically and send it at the end of the stream.

For sending and receiving between pools that do support large dnodes,
the drr_object send record type is extended with a new field to store
the dnode slot count. This field was repurposed from unused padding
in the structure.

ZIL Replay
----------
The dnode slot count is stored in the uppermost 8 bits of the lr_foid
field. The bits were unused as the object id is currently capped at
48 bits.

Resizing Dnodes
---------------
It should be possible to resize a dnode when it is dirtied if the
current dnodesize dataset property differs from the dnode's size, but
this functionality is not currently implemented. Clearly a dnode can
only grow if there are sufficient contiguous unused slots in the
dnode block, but it should always be possible to shrink a dnode.
Growing dnodes may be useful to reduce fragmentation in a pool with
many spill blocks in use. Shrinking dnodes may be useful to allow
sending a dataset to a pool that doesn't support the large_dnode
feature.

Feature Reference Counting
--------------------------
The reference count for the large_dnode pool feature tracks the
number of datasets that have ever contained a dnode of size larger
than 512 bytes. The first time a large dnode is created in a dataset
the dataset is converted to an extensible dataset. This is a one-way
operation and the only way to decrement the feature count is to
destroy the dataset, even if the dataset no longer contains any large
dnodes. The complexity of reference counting on a per-dnode basis was
too high, so we chose to track it on a per-dataset basis similarly to
the large_block feature.

Signed-off-by: Ned Bass <bass6@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #3542
2016-06-24 13:13:21 -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 http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2011, 2014 by Delphix. All rights reserved.
*/
/* Portions Copyright 2010 Robert Milkowski */
#include <sys/zfs_context.h>
#include <sys/spa.h>
#include <sys/dmu.h>
#include <sys/zap.h>
#include <sys/arc.h>
#include <sys/stat.h>
#include <sys/resource.h>
#include <sys/zil.h>
#include <sys/zil_impl.h>
#include <sys/dsl_dataset.h>
#include <sys/vdev_impl.h>
#include <sys/dmu_tx.h>
#include <sys/dsl_pool.h>
#include <sys/metaslab.h>
#include <sys/trace_zil.h>
/*
* The zfs intent log (ZIL) saves transaction records of system calls
* that change the file system in memory with enough information
* to be able to replay them. These are stored in memory until
* either the DMU transaction group (txg) commits them to the stable pool
* and they can be discarded, or they are flushed to the stable log
* (also in the pool) due to a fsync, O_DSYNC or other synchronous
* requirement. In the event of a panic or power fail then those log
* records (transactions) are replayed.
*
* There is one ZIL per file system. Its on-disk (pool) format consists
* of 3 parts:
*
* - ZIL header
* - ZIL blocks
* - ZIL records
*
* A log record holds a system call transaction. Log blocks can
* hold many log records and the blocks are chained together.
* Each ZIL block contains a block pointer (blkptr_t) to the next
* ZIL block in the chain. The ZIL header points to the first
* block in the chain. Note there is not a fixed place in the pool
* to hold blocks. They are dynamically allocated and freed as
* needed from the blocks available. Figure X shows the ZIL structure:
*/
/*
* See zil.h for more information about these fields.
*/
zil_stats_t zil_stats = {
{ "zil_commit_count", KSTAT_DATA_UINT64 },
{ "zil_commit_writer_count", KSTAT_DATA_UINT64 },
{ "zil_itx_count", KSTAT_DATA_UINT64 },
{ "zil_itx_indirect_count", KSTAT_DATA_UINT64 },
{ "zil_itx_indirect_bytes", KSTAT_DATA_UINT64 },
{ "zil_itx_copied_count", KSTAT_DATA_UINT64 },
{ "zil_itx_copied_bytes", KSTAT_DATA_UINT64 },
{ "zil_itx_needcopy_count", KSTAT_DATA_UINT64 },
{ "zil_itx_needcopy_bytes", KSTAT_DATA_UINT64 },
{ "zil_itx_metaslab_normal_count", KSTAT_DATA_UINT64 },
{ "zil_itx_metaslab_normal_bytes", KSTAT_DATA_UINT64 },
{ "zil_itx_metaslab_slog_count", KSTAT_DATA_UINT64 },
{ "zil_itx_metaslab_slog_bytes", KSTAT_DATA_UINT64 },
};
static kstat_t *zil_ksp;
/*
* Disable intent logging replay. This global ZIL switch affects all pools.
*/
int zil_replay_disable = 0;
/*
* Tunable parameter for debugging or performance analysis. Setting
* zfs_nocacheflush will cause corruption on power loss if a volatile
* out-of-order write cache is enabled.
*/
int zfs_nocacheflush = 0;
static kmem_cache_t *zil_lwb_cache;
static void zil_async_to_sync(zilog_t *zilog, uint64_t foid);
#define LWB_EMPTY(lwb) ((BP_GET_LSIZE(&lwb->lwb_blk) - \
sizeof (zil_chain_t)) == (lwb->lwb_sz - lwb->lwb_nused))
/*
* ziltest is by and large an ugly hack, but very useful in
* checking replay without tedious work.
* When running ziltest we want to keep all itx's and so maintain
* a single list in the zl_itxg[] that uses a high txg: ZILTEST_TXG
* We subtract TXG_CONCURRENT_STATES to allow for common code.
*/
#define ZILTEST_TXG (UINT64_MAX - TXG_CONCURRENT_STATES)
static int
zil_bp_compare(const void *x1, const void *x2)
{
const dva_t *dva1 = &((zil_bp_node_t *)x1)->zn_dva;
const dva_t *dva2 = &((zil_bp_node_t *)x2)->zn_dva;
if (DVA_GET_VDEV(dva1) < DVA_GET_VDEV(dva2))
return (-1);
if (DVA_GET_VDEV(dva1) > DVA_GET_VDEV(dva2))
return (1);
if (DVA_GET_OFFSET(dva1) < DVA_GET_OFFSET(dva2))
return (-1);
if (DVA_GET_OFFSET(dva1) > DVA_GET_OFFSET(dva2))
return (1);
return (0);
}
static void
zil_bp_tree_init(zilog_t *zilog)
{
avl_create(&zilog->zl_bp_tree, zil_bp_compare,
sizeof (zil_bp_node_t), offsetof(zil_bp_node_t, zn_node));
}
static void
zil_bp_tree_fini(zilog_t *zilog)
{
avl_tree_t *t = &zilog->zl_bp_tree;
zil_bp_node_t *zn;
void *cookie = NULL;
while ((zn = avl_destroy_nodes(t, &cookie)) != NULL)
kmem_free(zn, sizeof (zil_bp_node_t));
avl_destroy(t);
}
int
zil_bp_tree_add(zilog_t *zilog, const blkptr_t *bp)
{
avl_tree_t *t = &zilog->zl_bp_tree;
const dva_t *dva;
zil_bp_node_t *zn;
avl_index_t where;
if (BP_IS_EMBEDDED(bp))
return (0);
dva = BP_IDENTITY(bp);
if (avl_find(t, dva, &where) != NULL)
return (SET_ERROR(EEXIST));
zn = kmem_alloc(sizeof (zil_bp_node_t), KM_SLEEP);
zn->zn_dva = *dva;
avl_insert(t, zn, where);
return (0);
}
static zil_header_t *
zil_header_in_syncing_context(zilog_t *zilog)
{
return ((zil_header_t *)zilog->zl_header);
}
static void
zil_init_log_chain(zilog_t *zilog, blkptr_t *bp)
{
zio_cksum_t *zc = &bp->blk_cksum;
zc->zc_word[ZIL_ZC_GUID_0] = spa_get_random(-1ULL);
zc->zc_word[ZIL_ZC_GUID_1] = spa_get_random(-1ULL);
zc->zc_word[ZIL_ZC_OBJSET] = dmu_objset_id(zilog->zl_os);
zc->zc_word[ZIL_ZC_SEQ] = 1ULL;
}
/*
* Read a log block and make sure it's valid.
*/
static int
zil_read_log_block(zilog_t *zilog, const blkptr_t *bp, blkptr_t *nbp, void *dst,
char **end)
{
enum zio_flag zio_flags = ZIO_FLAG_CANFAIL;
arc_flags_t aflags = ARC_FLAG_WAIT;
arc_buf_t *abuf = NULL;
zbookmark_phys_t zb;
int error;
if (zilog->zl_header->zh_claim_txg == 0)
zio_flags |= ZIO_FLAG_SPECULATIVE | ZIO_FLAG_SCRUB;
if (!(zilog->zl_header->zh_flags & ZIL_CLAIM_LR_SEQ_VALID))
zio_flags |= ZIO_FLAG_SPECULATIVE;
SET_BOOKMARK(&zb, bp->blk_cksum.zc_word[ZIL_ZC_OBJSET],
ZB_ZIL_OBJECT, ZB_ZIL_LEVEL, bp->blk_cksum.zc_word[ZIL_ZC_SEQ]);
error = arc_read(NULL, zilog->zl_spa, bp, arc_getbuf_func, &abuf,
ZIO_PRIORITY_SYNC_READ, zio_flags, &aflags, &zb);
if (error == 0) {
zio_cksum_t cksum = bp->blk_cksum;
/*
* Validate the checksummed log block.
*
* Sequence numbers should be... sequential. The checksum
* verifier for the next block should be bp's checksum plus 1.
*
* Also check the log chain linkage and size used.
*/
cksum.zc_word[ZIL_ZC_SEQ]++;
if (BP_GET_CHECKSUM(bp) == ZIO_CHECKSUM_ZILOG2) {
zil_chain_t *zilc = abuf->b_data;
char *lr = (char *)(zilc + 1);
uint64_t len = zilc->zc_nused - sizeof (zil_chain_t);
if (bcmp(&cksum, &zilc->zc_next_blk.blk_cksum,
sizeof (cksum)) || BP_IS_HOLE(&zilc->zc_next_blk)) {
error = SET_ERROR(ECKSUM);
} else {
ASSERT3U(len, <=, SPA_OLD_MAXBLOCKSIZE);
bcopy(lr, dst, len);
*end = (char *)dst + len;
*nbp = zilc->zc_next_blk;
}
} else {
char *lr = abuf->b_data;
uint64_t size = BP_GET_LSIZE(bp);
zil_chain_t *zilc = (zil_chain_t *)(lr + size) - 1;
if (bcmp(&cksum, &zilc->zc_next_blk.blk_cksum,
sizeof (cksum)) || BP_IS_HOLE(&zilc->zc_next_blk) ||
(zilc->zc_nused > (size - sizeof (*zilc)))) {
error = SET_ERROR(ECKSUM);
} else {
ASSERT3U(zilc->zc_nused, <=,
SPA_OLD_MAXBLOCKSIZE);
bcopy(lr, dst, zilc->zc_nused);
*end = (char *)dst + zilc->zc_nused;
*nbp = zilc->zc_next_blk;
}
}
VERIFY(arc_buf_remove_ref(abuf, &abuf));
}
return (error);
}
/*
* Read a TX_WRITE log data block.
*/
static int
zil_read_log_data(zilog_t *zilog, const lr_write_t *lr, void *wbuf)
{
enum zio_flag zio_flags = ZIO_FLAG_CANFAIL;
const blkptr_t *bp = &lr->lr_blkptr;
arc_flags_t aflags = ARC_FLAG_WAIT;
arc_buf_t *abuf = NULL;
zbookmark_phys_t zb;
int error;
if (BP_IS_HOLE(bp)) {
if (wbuf != NULL)
bzero(wbuf, MAX(BP_GET_LSIZE(bp), lr->lr_length));
return (0);
}
if (zilog->zl_header->zh_claim_txg == 0)
zio_flags |= ZIO_FLAG_SPECULATIVE | ZIO_FLAG_SCRUB;
SET_BOOKMARK(&zb, dmu_objset_id(zilog->zl_os), lr->lr_foid,
ZB_ZIL_LEVEL, lr->lr_offset / BP_GET_LSIZE(bp));
error = arc_read(NULL, zilog->zl_spa, bp, arc_getbuf_func, &abuf,
ZIO_PRIORITY_SYNC_READ, zio_flags, &aflags, &zb);
if (error == 0) {
if (wbuf != NULL)
bcopy(abuf->b_data, wbuf, arc_buf_size(abuf));
(void) arc_buf_remove_ref(abuf, &abuf);
}
return (error);
}
/*
* Parse the intent log, and call parse_func for each valid record within.
*/
int
zil_parse(zilog_t *zilog, zil_parse_blk_func_t *parse_blk_func,
zil_parse_lr_func_t *parse_lr_func, void *arg, uint64_t txg)
{
const zil_header_t *zh = zilog->zl_header;
boolean_t claimed = !!zh->zh_claim_txg;
uint64_t claim_blk_seq = claimed ? zh->zh_claim_blk_seq : UINT64_MAX;
uint64_t claim_lr_seq = claimed ? zh->zh_claim_lr_seq : UINT64_MAX;
uint64_t max_blk_seq = 0;
uint64_t max_lr_seq = 0;
uint64_t blk_count = 0;
uint64_t lr_count = 0;
blkptr_t blk, next_blk;
char *lrbuf, *lrp;
int error = 0;
bzero(&next_blk, sizeof (blkptr_t));
/*
* Old logs didn't record the maximum zh_claim_lr_seq.
*/
if (!(zh->zh_flags & ZIL_CLAIM_LR_SEQ_VALID))
claim_lr_seq = UINT64_MAX;
/*
* Starting at the block pointed to by zh_log we read the log chain.
* For each block in the chain we strongly check that block to
* ensure its validity. We stop when an invalid block is found.
* For each block pointer in the chain we call parse_blk_func().
* For each record in each valid block we call parse_lr_func().
* If the log has been claimed, stop if we encounter a sequence
* number greater than the highest claimed sequence number.
*/
lrbuf = zio_buf_alloc(SPA_OLD_MAXBLOCKSIZE);
zil_bp_tree_init(zilog);
for (blk = zh->zh_log; !BP_IS_HOLE(&blk); blk = next_blk) {
uint64_t blk_seq = blk.blk_cksum.zc_word[ZIL_ZC_SEQ];
int reclen;
char *end = NULL;
if (blk_seq > claim_blk_seq)
break;
if ((error = parse_blk_func(zilog, &blk, arg, txg)) != 0)
break;
ASSERT3U(max_blk_seq, <, blk_seq);
max_blk_seq = blk_seq;
blk_count++;
if (max_lr_seq == claim_lr_seq && max_blk_seq == claim_blk_seq)
break;
error = zil_read_log_block(zilog, &blk, &next_blk, lrbuf, &end);
if (error != 0)
break;
for (lrp = lrbuf; lrp < end; lrp += reclen) {
lr_t *lr = (lr_t *)lrp;
reclen = lr->lrc_reclen;
ASSERT3U(reclen, >=, sizeof (lr_t));
if (lr->lrc_seq > claim_lr_seq)
goto done;
if ((error = parse_lr_func(zilog, lr, arg, txg)) != 0)
goto done;
ASSERT3U(max_lr_seq, <, lr->lrc_seq);
max_lr_seq = lr->lrc_seq;
lr_count++;
}
}
done:
zilog->zl_parse_error = error;
zilog->zl_parse_blk_seq = max_blk_seq;
zilog->zl_parse_lr_seq = max_lr_seq;
zilog->zl_parse_blk_count = blk_count;
zilog->zl_parse_lr_count = lr_count;
ASSERT(!claimed || !(zh->zh_flags & ZIL_CLAIM_LR_SEQ_VALID) ||
(max_blk_seq == claim_blk_seq && max_lr_seq == claim_lr_seq));
zil_bp_tree_fini(zilog);
zio_buf_free(lrbuf, SPA_OLD_MAXBLOCKSIZE);
return (error);
}
static int
zil_claim_log_block(zilog_t *zilog, blkptr_t *bp, void *tx, uint64_t first_txg)
{
/*
* Claim log block if not already committed and not already claimed.
* If tx == NULL, just verify that the block is claimable.
*/
if (BP_IS_HOLE(bp) || bp->blk_birth < first_txg ||
zil_bp_tree_add(zilog, bp) != 0)
return (0);
return (zio_wait(zio_claim(NULL, zilog->zl_spa,
tx == NULL ? 0 : first_txg, bp, spa_claim_notify, NULL,
ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | ZIO_FLAG_SCRUB)));
}
static int
zil_claim_log_record(zilog_t *zilog, lr_t *lrc, void *tx, uint64_t first_txg)
{
lr_write_t *lr = (lr_write_t *)lrc;
int error;
if (lrc->lrc_txtype != TX_WRITE)
return (0);
/*
* If the block is not readable, don't claim it. This can happen
* in normal operation when a log block is written to disk before
* some of the dmu_sync() blocks it points to. In this case, the
* transaction cannot have been committed to anyone (we would have
* waited for all writes to be stable first), so it is semantically
* correct to declare this the end of the log.
*/
if (lr->lr_blkptr.blk_birth >= first_txg &&
(error = zil_read_log_data(zilog, lr, NULL)) != 0)
return (error);
return (zil_claim_log_block(zilog, &lr->lr_blkptr, tx, first_txg));
}
/* ARGSUSED */
static int
zil_free_log_block(zilog_t *zilog, blkptr_t *bp, void *tx, uint64_t claim_txg)
{
zio_free_zil(zilog->zl_spa, dmu_tx_get_txg(tx), bp);
return (0);
}
static int
zil_free_log_record(zilog_t *zilog, lr_t *lrc, void *tx, uint64_t claim_txg)
{
lr_write_t *lr = (lr_write_t *)lrc;
blkptr_t *bp = &lr->lr_blkptr;
/*
* If we previously claimed it, we need to free it.
*/
if (claim_txg != 0 && lrc->lrc_txtype == TX_WRITE &&
bp->blk_birth >= claim_txg && zil_bp_tree_add(zilog, bp) == 0 &&
!BP_IS_HOLE(bp))
zio_free(zilog->zl_spa, dmu_tx_get_txg(tx), bp);
return (0);
}
static lwb_t *
zil_alloc_lwb(zilog_t *zilog, blkptr_t *bp, uint64_t txg, boolean_t fastwrite)
{
lwb_t *lwb;
lwb = kmem_cache_alloc(zil_lwb_cache, KM_SLEEP);
lwb->lwb_zilog = zilog;
lwb->lwb_blk = *bp;
lwb->lwb_fastwrite = fastwrite;
lwb->lwb_buf = zio_buf_alloc(BP_GET_LSIZE(bp));
lwb->lwb_max_txg = txg;
lwb->lwb_zio = NULL;
lwb->lwb_tx = NULL;
if (BP_GET_CHECKSUM(bp) == ZIO_CHECKSUM_ZILOG2) {
lwb->lwb_nused = sizeof (zil_chain_t);
lwb->lwb_sz = BP_GET_LSIZE(bp);
} else {
lwb->lwb_nused = 0;
lwb->lwb_sz = BP_GET_LSIZE(bp) - sizeof (zil_chain_t);
}
mutex_enter(&zilog->zl_lock);
list_insert_tail(&zilog->zl_lwb_list, lwb);
mutex_exit(&zilog->zl_lock);
return (lwb);
}
/*
* Called when we create in-memory log transactions so that we know
* to cleanup the itxs at the end of spa_sync().
*/
void
zilog_dirty(zilog_t *zilog, uint64_t txg)
{
dsl_pool_t *dp = zilog->zl_dmu_pool;
dsl_dataset_t *ds = dmu_objset_ds(zilog->zl_os);
if (ds->ds_is_snapshot)
panic("dirtying snapshot!");
if (txg_list_add(&dp->dp_dirty_zilogs, zilog, txg)) {
/* up the hold count until we can be written out */
dmu_buf_add_ref(ds->ds_dbuf, zilog);
}
}
boolean_t
zilog_is_dirty(zilog_t *zilog)
{
dsl_pool_t *dp = zilog->zl_dmu_pool;
int t;
for (t = 0; t < TXG_SIZE; t++) {
if (txg_list_member(&dp->dp_dirty_zilogs, zilog, t))
return (B_TRUE);
}
return (B_FALSE);
}
/*
* Create an on-disk intent log.
*/
static lwb_t *
zil_create(zilog_t *zilog)
{
const zil_header_t *zh = zilog->zl_header;
lwb_t *lwb = NULL;
uint64_t txg = 0;
dmu_tx_t *tx = NULL;
blkptr_t blk;
int error = 0;
boolean_t fastwrite = FALSE;
/*
* Wait for any previous destroy to complete.
*/
txg_wait_synced(zilog->zl_dmu_pool, zilog->zl_destroy_txg);
ASSERT(zh->zh_claim_txg == 0);
ASSERT(zh->zh_replay_seq == 0);
blk = zh->zh_log;
/*
* Allocate an initial log block if:
* - there isn't one already
* - the existing block is the wrong endianess
*/
if (BP_IS_HOLE(&blk) || BP_SHOULD_BYTESWAP(&blk)) {
tx = dmu_tx_create(zilog->zl_os);
VERIFY(dmu_tx_assign(tx, TXG_WAIT) == 0);
dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx);
txg = dmu_tx_get_txg(tx);
if (!BP_IS_HOLE(&blk)) {
zio_free_zil(zilog->zl_spa, txg, &blk);
BP_ZERO(&blk);
}
error = zio_alloc_zil(zilog->zl_spa, txg, &blk,
ZIL_MIN_BLKSZ, B_TRUE);
fastwrite = TRUE;
if (error == 0)
zil_init_log_chain(zilog, &blk);
}
/*
* Allocate a log write buffer (lwb) for the first log block.
*/
if (error == 0)
lwb = zil_alloc_lwb(zilog, &blk, txg, fastwrite);
/*
* If we just allocated the first log block, commit our transaction
* and wait for zil_sync() to stuff the block poiner into zh_log.
* (zh is part of the MOS, so we cannot modify it in open context.)
*/
if (tx != NULL) {
dmu_tx_commit(tx);
txg_wait_synced(zilog->zl_dmu_pool, txg);
}
ASSERT(bcmp(&blk, &zh->zh_log, sizeof (blk)) == 0);
return (lwb);
}
/*
* In one tx, free all log blocks and clear the log header.
* If keep_first is set, then we're replaying a log with no content.
* We want to keep the first block, however, so that the first
* synchronous transaction doesn't require a txg_wait_synced()
* in zil_create(). We don't need to txg_wait_synced() here either
* when keep_first is set, because both zil_create() and zil_destroy()
* will wait for any in-progress destroys to complete.
*/
void
zil_destroy(zilog_t *zilog, boolean_t keep_first)
{
const zil_header_t *zh = zilog->zl_header;
lwb_t *lwb;
dmu_tx_t *tx;
uint64_t txg;
/*
* Wait for any previous destroy to complete.
*/
txg_wait_synced(zilog->zl_dmu_pool, zilog->zl_destroy_txg);
zilog->zl_old_header = *zh; /* debugging aid */
if (BP_IS_HOLE(&zh->zh_log))
return;
tx = dmu_tx_create(zilog->zl_os);
VERIFY(dmu_tx_assign(tx, TXG_WAIT) == 0);
dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx);
txg = dmu_tx_get_txg(tx);
mutex_enter(&zilog->zl_lock);
ASSERT3U(zilog->zl_destroy_txg, <, txg);
zilog->zl_destroy_txg = txg;
zilog->zl_keep_first = keep_first;
if (!list_is_empty(&zilog->zl_lwb_list)) {
ASSERT(zh->zh_claim_txg == 0);
VERIFY(!keep_first);
while ((lwb = list_head(&zilog->zl_lwb_list)) != NULL) {
ASSERT(lwb->lwb_zio == NULL);
if (lwb->lwb_fastwrite)
metaslab_fastwrite_unmark(zilog->zl_spa,
&lwb->lwb_blk);
list_remove(&zilog->zl_lwb_list, lwb);
if (lwb->lwb_buf != NULL)
zio_buf_free(lwb->lwb_buf, lwb->lwb_sz);
zio_free_zil(zilog->zl_spa, txg, &lwb->lwb_blk);
kmem_cache_free(zil_lwb_cache, lwb);
}
} else if (!keep_first) {
zil_destroy_sync(zilog, tx);
}
mutex_exit(&zilog->zl_lock);
dmu_tx_commit(tx);
}
void
zil_destroy_sync(zilog_t *zilog, dmu_tx_t *tx)
{
ASSERT(list_is_empty(&zilog->zl_lwb_list));
(void) zil_parse(zilog, zil_free_log_block,
zil_free_log_record, tx, zilog->zl_header->zh_claim_txg);
}
int
zil_claim(dsl_pool_t *dp, dsl_dataset_t *ds, void *txarg)
{
dmu_tx_t *tx = txarg;
uint64_t first_txg = dmu_tx_get_txg(tx);
zilog_t *zilog;
zil_header_t *zh;
objset_t *os;
int error;
error = dmu_objset_own_obj(dp, ds->ds_object,
DMU_OST_ANY, B_FALSE, FTAG, &os);
if (error != 0) {
/*
* EBUSY indicates that the objset is inconsistent, in which
* case it can not have a ZIL.
*/
if (error != EBUSY) {
cmn_err(CE_WARN, "can't open objset for %llu, error %u",
(unsigned long long)ds->ds_object, error);
}
return (0);
}
zilog = dmu_objset_zil(os);
zh = zil_header_in_syncing_context(zilog);
if (spa_get_log_state(zilog->zl_spa) == SPA_LOG_CLEAR) {
if (!BP_IS_HOLE(&zh->zh_log))
zio_free_zil(zilog->zl_spa, first_txg, &zh->zh_log);
BP_ZERO(&zh->zh_log);
dsl_dataset_dirty(dmu_objset_ds(os), tx);
dmu_objset_disown(os, FTAG);
return (0);
}
/*
* Claim all log blocks if we haven't already done so, and remember
* the highest claimed sequence number. This ensures that if we can
* read only part of the log now (e.g. due to a missing device),
* but we can read the entire log later, we will not try to replay
* or destroy beyond the last block we successfully claimed.
*/
ASSERT3U(zh->zh_claim_txg, <=, first_txg);
if (zh->zh_claim_txg == 0 && !BP_IS_HOLE(&zh->zh_log)) {
(void) zil_parse(zilog, zil_claim_log_block,
zil_claim_log_record, tx, first_txg);
zh->zh_claim_txg = first_txg;
zh->zh_claim_blk_seq = zilog->zl_parse_blk_seq;
zh->zh_claim_lr_seq = zilog->zl_parse_lr_seq;
if (zilog->zl_parse_lr_count || zilog->zl_parse_blk_count > 1)
zh->zh_flags |= ZIL_REPLAY_NEEDED;
zh->zh_flags |= ZIL_CLAIM_LR_SEQ_VALID;
dsl_dataset_dirty(dmu_objset_ds(os), tx);
}
ASSERT3U(first_txg, ==, (spa_last_synced_txg(zilog->zl_spa) + 1));
dmu_objset_disown(os, FTAG);
return (0);
}
/*
* Check the log by walking the log chain.
* Checksum errors are ok as they indicate the end of the chain.
* Any other error (no device or read failure) returns an error.
*/
/* ARGSUSED */
int
zil_check_log_chain(dsl_pool_t *dp, dsl_dataset_t *ds, void *tx)
{
zilog_t *zilog;
objset_t *os;
blkptr_t *bp;
int error;
ASSERT(tx == NULL);
error = dmu_objset_from_ds(ds, &os);
if (error != 0) {
cmn_err(CE_WARN, "can't open objset %llu, error %d",
(unsigned long long)ds->ds_object, error);
return (0);
}
zilog = dmu_objset_zil(os);
bp = (blkptr_t *)&zilog->zl_header->zh_log;
/*
* Check the first block and determine if it's on a log device
* which may have been removed or faulted prior to loading this
* pool. If so, there's no point in checking the rest of the log
* as its content should have already been synced to the pool.
*/
if (!BP_IS_HOLE(bp)) {
vdev_t *vd;
boolean_t valid = B_TRUE;
spa_config_enter(os->os_spa, SCL_STATE, FTAG, RW_READER);
vd = vdev_lookup_top(os->os_spa, DVA_GET_VDEV(&bp->blk_dva[0]));
if (vd->vdev_islog && vdev_is_dead(vd))
valid = vdev_log_state_valid(vd);
spa_config_exit(os->os_spa, SCL_STATE, FTAG);
if (!valid)
return (0);
}
/*
* Because tx == NULL, zil_claim_log_block() will not actually claim
* any blocks, but just determine whether it is possible to do so.
* In addition to checking the log chain, zil_claim_log_block()
* will invoke zio_claim() with a done func of spa_claim_notify(),
* which will update spa_max_claim_txg. See spa_load() for details.
*/
error = zil_parse(zilog, zil_claim_log_block, zil_claim_log_record, tx,
zilog->zl_header->zh_claim_txg ? -1ULL : spa_first_txg(os->os_spa));
return ((error == ECKSUM || error == ENOENT) ? 0 : error);
}
static int
zil_vdev_compare(const void *x1, const void *x2)
{
const uint64_t v1 = ((zil_vdev_node_t *)x1)->zv_vdev;
const uint64_t v2 = ((zil_vdev_node_t *)x2)->zv_vdev;
if (v1 < v2)
return (-1);
if (v1 > v2)
return (1);
return (0);
}
void
zil_add_block(zilog_t *zilog, const blkptr_t *bp)
{
avl_tree_t *t = &zilog->zl_vdev_tree;
avl_index_t where;
zil_vdev_node_t *zv, zvsearch;
int ndvas = BP_GET_NDVAS(bp);
int i;
if (zfs_nocacheflush)
return;
ASSERT(zilog->zl_writer);
/*
* Even though we're zl_writer, we still need a lock because the
* zl_get_data() callbacks may have dmu_sync() done callbacks
* that will run concurrently.
*/
mutex_enter(&zilog->zl_vdev_lock);
for (i = 0; i < ndvas; i++) {
zvsearch.zv_vdev = DVA_GET_VDEV(&bp->blk_dva[i]);
if (avl_find(t, &zvsearch, &where) == NULL) {
zv = kmem_alloc(sizeof (*zv), KM_SLEEP);
zv->zv_vdev = zvsearch.zv_vdev;
avl_insert(t, zv, where);
}
}
mutex_exit(&zilog->zl_vdev_lock);
}
static void
zil_flush_vdevs(zilog_t *zilog)
{
spa_t *spa = zilog->zl_spa;
avl_tree_t *t = &zilog->zl_vdev_tree;
void *cookie = NULL;
zil_vdev_node_t *zv;
zio_t *zio;
ASSERT(zilog->zl_writer);
/*
* We don't need zl_vdev_lock here because we're the zl_writer,
* and all zl_get_data() callbacks are done.
*/
if (avl_numnodes(t) == 0)
return;
spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
zio = zio_root(spa, NULL, NULL, ZIO_FLAG_CANFAIL);
while ((zv = avl_destroy_nodes(t, &cookie)) != NULL) {
vdev_t *vd = vdev_lookup_top(spa, zv->zv_vdev);
if (vd != NULL)
zio_flush(zio, vd);
kmem_free(zv, sizeof (*zv));
}
/*
* Wait for all the flushes to complete. Not all devices actually
* support the DKIOCFLUSHWRITECACHE ioctl, so it's OK if it fails.
*/
(void) zio_wait(zio);
spa_config_exit(spa, SCL_STATE, FTAG);
}
/*
* Function called when a log block write completes
*/
static void
zil_lwb_write_done(zio_t *zio)
{
lwb_t *lwb = zio->io_private;
zilog_t *zilog = lwb->lwb_zilog;
dmu_tx_t *tx = lwb->lwb_tx;
ASSERT(BP_GET_COMPRESS(zio->io_bp) == ZIO_COMPRESS_OFF);
ASSERT(BP_GET_TYPE(zio->io_bp) == DMU_OT_INTENT_LOG);
ASSERT(BP_GET_LEVEL(zio->io_bp) == 0);
ASSERT(BP_GET_BYTEORDER(zio->io_bp) == ZFS_HOST_BYTEORDER);
ASSERT(!BP_IS_GANG(zio->io_bp));
ASSERT(!BP_IS_HOLE(zio->io_bp));
ASSERT(BP_GET_FILL(zio->io_bp) == 0);
/*
* Ensure the lwb buffer pointer is cleared before releasing
* the txg. If we have had an allocation failure and
* the txg is waiting to sync then we want want zil_sync()
* to remove the lwb so that it's not picked up as the next new
* one in zil_commit_writer(). zil_sync() will only remove
* the lwb if lwb_buf is null.
*/
zio_buf_free(lwb->lwb_buf, lwb->lwb_sz);
mutex_enter(&zilog->zl_lock);
lwb->lwb_zio = NULL;
lwb->lwb_fastwrite = FALSE;
lwb->lwb_buf = NULL;
lwb->lwb_tx = NULL;
mutex_exit(&zilog->zl_lock);
/*
* Now that we've written this log block, we have a stable pointer
* to the next block in the chain, so it's OK to let the txg in
* which we allocated the next block sync.
*/
dmu_tx_commit(tx);
}
/*
* Initialize the io for a log block.
*/
static void
zil_lwb_write_init(zilog_t *zilog, lwb_t *lwb)
{
zbookmark_phys_t zb;
SET_BOOKMARK(&zb, lwb->lwb_blk.blk_cksum.zc_word[ZIL_ZC_OBJSET],
ZB_ZIL_OBJECT, ZB_ZIL_LEVEL,
lwb->lwb_blk.blk_cksum.zc_word[ZIL_ZC_SEQ]);
if (zilog->zl_root_zio == NULL) {
zilog->zl_root_zio = zio_root(zilog->zl_spa, NULL, NULL,
ZIO_FLAG_CANFAIL);
}
/* Lock so zil_sync() doesn't fastwrite_unmark after zio is created */
mutex_enter(&zilog->zl_lock);
if (lwb->lwb_zio == NULL) {
if (!lwb->lwb_fastwrite) {
metaslab_fastwrite_mark(zilog->zl_spa, &lwb->lwb_blk);
lwb->lwb_fastwrite = 1;
}
lwb->lwb_zio = zio_rewrite(zilog->zl_root_zio, zilog->zl_spa,
0, &lwb->lwb_blk, lwb->lwb_buf, BP_GET_LSIZE(&lwb->lwb_blk),
zil_lwb_write_done, lwb, ZIO_PRIORITY_SYNC_WRITE,
ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE |
ZIO_FLAG_FASTWRITE, &zb);
}
mutex_exit(&zilog->zl_lock);
}
/*
* Define a limited set of intent log block sizes.
*
* These must be a multiple of 4KB. Note only the amount used (again
* aligned to 4KB) actually gets written. However, we can't always just
* allocate SPA_OLD_MAXBLOCKSIZE as the slog space could be exhausted.
*/
uint64_t zil_block_buckets[] = {
4096, /* non TX_WRITE */
8192+4096, /* data base */
32*1024 + 4096, /* NFS writes */
UINT64_MAX
};
/*
* Use the slog as long as the current commit size is less than the
* limit or the total list size is less than 2X the limit. Limit
* checking is disabled by setting zil_slog_limit to UINT64_MAX.
*/
unsigned long zil_slog_limit = 1024 * 1024;
#define USE_SLOG(zilog) (((zilog)->zl_cur_used < zil_slog_limit) || \
((zilog)->zl_itx_list_sz < (zil_slog_limit << 1)))
/*
* Start a log block write and advance to the next log block.
* Calls are serialized.
*/
static lwb_t *
zil_lwb_write_start(zilog_t *zilog, lwb_t *lwb)
{
lwb_t *nlwb = NULL;
zil_chain_t *zilc;
spa_t *spa = zilog->zl_spa;
blkptr_t *bp;
dmu_tx_t *tx;
uint64_t txg;
uint64_t zil_blksz, wsz;
int i, error;
boolean_t use_slog;
if (BP_GET_CHECKSUM(&lwb->lwb_blk) == ZIO_CHECKSUM_ZILOG2) {
zilc = (zil_chain_t *)lwb->lwb_buf;
bp = &zilc->zc_next_blk;
} else {
zilc = (zil_chain_t *)(lwb->lwb_buf + lwb->lwb_sz);
bp = &zilc->zc_next_blk;
}
ASSERT(lwb->lwb_nused <= lwb->lwb_sz);
/*
* Allocate the next block and save its address in this block
* before writing it in order to establish the log chain.
* Note that if the allocation of nlwb synced before we wrote
* the block that points at it (lwb), we'd leak it if we crashed.
* Therefore, we don't do dmu_tx_commit() until zil_lwb_write_done().
* We dirty the dataset to ensure that zil_sync() will be called
* to clean up in the event of allocation failure or I/O failure.
*/
tx = dmu_tx_create(zilog->zl_os);
VERIFY(dmu_tx_assign(tx, TXG_WAIT) == 0);
dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx);
txg = dmu_tx_get_txg(tx);
lwb->lwb_tx = tx;
/*
* Log blocks are pre-allocated. Here we select the size of the next
* block, based on size used in the last block.
* - first find the smallest bucket that will fit the block from a
* limited set of block sizes. This is because it's faster to write
* blocks allocated from the same metaslab as they are adjacent or
* close.
* - next find the maximum from the new suggested size and an array of
* previous sizes. This lessens a picket fence effect of wrongly
* guesssing the size if we have a stream of say 2k, 64k, 2k, 64k
* requests.
*
* Note we only write what is used, but we can't just allocate
* the maximum block size because we can exhaust the available
* pool log space.
*/
zil_blksz = zilog->zl_cur_used + sizeof (zil_chain_t);
for (i = 0; zil_blksz > zil_block_buckets[i]; i++)
continue;
zil_blksz = zil_block_buckets[i];
if (zil_blksz == UINT64_MAX)
zil_blksz = SPA_OLD_MAXBLOCKSIZE;
zilog->zl_prev_blks[zilog->zl_prev_rotor] = zil_blksz;
for (i = 0; i < ZIL_PREV_BLKS; i++)
zil_blksz = MAX(zil_blksz, zilog->zl_prev_blks[i]);
zilog->zl_prev_rotor = (zilog->zl_prev_rotor + 1) & (ZIL_PREV_BLKS - 1);
BP_ZERO(bp);
use_slog = USE_SLOG(zilog);
error = zio_alloc_zil(spa, txg, bp, zil_blksz,
USE_SLOG(zilog));
if (use_slog) {
ZIL_STAT_BUMP(zil_itx_metaslab_slog_count);
ZIL_STAT_INCR(zil_itx_metaslab_slog_bytes, lwb->lwb_nused);
} else {
ZIL_STAT_BUMP(zil_itx_metaslab_normal_count);
ZIL_STAT_INCR(zil_itx_metaslab_normal_bytes, lwb->lwb_nused);
}
if (error == 0) {
ASSERT3U(bp->blk_birth, ==, txg);
bp->blk_cksum = lwb->lwb_blk.blk_cksum;
bp->blk_cksum.zc_word[ZIL_ZC_SEQ]++;
/*
* Allocate a new log write buffer (lwb).
*/
nlwb = zil_alloc_lwb(zilog, bp, txg, TRUE);
/* Record the block for later vdev flushing */
zil_add_block(zilog, &lwb->lwb_blk);
}
if (BP_GET_CHECKSUM(&lwb->lwb_blk) == ZIO_CHECKSUM_ZILOG2) {
/* For Slim ZIL only write what is used. */
wsz = P2ROUNDUP_TYPED(lwb->lwb_nused, ZIL_MIN_BLKSZ, uint64_t);
ASSERT3U(wsz, <=, lwb->lwb_sz);
zio_shrink(lwb->lwb_zio, wsz);
} else {
wsz = lwb->lwb_sz;
}
zilc->zc_pad = 0;
zilc->zc_nused = lwb->lwb_nused;
zilc->zc_eck.zec_cksum = lwb->lwb_blk.blk_cksum;
/*
* clear unused data for security
*/
bzero(lwb->lwb_buf + lwb->lwb_nused, wsz - lwb->lwb_nused);
zio_nowait(lwb->lwb_zio); /* Kick off the write for the old log block */
/*
* If there was an allocation failure then nlwb will be null which
* forces a txg_wait_synced().
*/
return (nlwb);
}
static lwb_t *
zil_lwb_commit(zilog_t *zilog, itx_t *itx, lwb_t *lwb)
{
lr_t *lrc = &itx->itx_lr; /* common log record */
lr_write_t *lrw = (lr_write_t *)lrc;
char *lr_buf;
uint64_t txg = lrc->lrc_txg;
uint64_t reclen = lrc->lrc_reclen;
uint64_t dlen = 0;
if (lwb == NULL)
return (NULL);
ASSERT(lwb->lwb_buf != NULL);
ASSERT(zilog_is_dirty(zilog) ||
spa_freeze_txg(zilog->zl_spa) != UINT64_MAX);
if (lrc->lrc_txtype == TX_WRITE && itx->itx_wr_state == WR_NEED_COPY)
dlen = P2ROUNDUP_TYPED(
lrw->lr_length, sizeof (uint64_t), uint64_t);
zilog->zl_cur_used += (reclen + dlen);
zil_lwb_write_init(zilog, lwb);
/*
* If this record won't fit in the current log block, start a new one.
*/
if (lwb->lwb_nused + reclen + dlen > lwb->lwb_sz) {
lwb = zil_lwb_write_start(zilog, lwb);
if (lwb == NULL)
return (NULL);
zil_lwb_write_init(zilog, lwb);
ASSERT(LWB_EMPTY(lwb));
if (lwb->lwb_nused + reclen + dlen > lwb->lwb_sz) {
txg_wait_synced(zilog->zl_dmu_pool, txg);
return (lwb);
}
}
lr_buf = lwb->lwb_buf + lwb->lwb_nused;
bcopy(lrc, lr_buf, reclen);
lrc = (lr_t *)lr_buf;
lrw = (lr_write_t *)lrc;
ZIL_STAT_BUMP(zil_itx_count);
/*
* If it's a write, fetch the data or get its blkptr as appropriate.
*/
if (lrc->lrc_txtype == TX_WRITE) {
if (txg > spa_freeze_txg(zilog->zl_spa))
txg_wait_synced(zilog->zl_dmu_pool, txg);
if (itx->itx_wr_state == WR_COPIED) {
ZIL_STAT_BUMP(zil_itx_copied_count);
ZIL_STAT_INCR(zil_itx_copied_bytes, lrw->lr_length);
} else {
char *dbuf;
int error;
if (dlen) {
ASSERT(itx->itx_wr_state == WR_NEED_COPY);
dbuf = lr_buf + reclen;
lrw->lr_common.lrc_reclen += dlen;
ZIL_STAT_BUMP(zil_itx_needcopy_count);
ZIL_STAT_INCR(zil_itx_needcopy_bytes,
lrw->lr_length);
} else {
ASSERT(itx->itx_wr_state == WR_INDIRECT);
dbuf = NULL;
ZIL_STAT_BUMP(zil_itx_indirect_count);
ZIL_STAT_INCR(zil_itx_indirect_bytes,
lrw->lr_length);
}
error = zilog->zl_get_data(
itx->itx_private, lrw, dbuf, lwb->lwb_zio);
if (error == EIO) {
txg_wait_synced(zilog->zl_dmu_pool, txg);
return (lwb);
}
if (error != 0) {
ASSERT(error == ENOENT || error == EEXIST ||
error == EALREADY);
return (lwb);
}
}
}
/*
* We're actually making an entry, so update lrc_seq to be the
* log record sequence number. Note that this is generally not
* equal to the itx sequence number because not all transactions
* are synchronous, and sometimes spa_sync() gets there first.
*/
lrc->lrc_seq = ++zilog->zl_lr_seq; /* we are single threaded */
lwb->lwb_nused += reclen + dlen;
lwb->lwb_max_txg = MAX(lwb->lwb_max_txg, txg);
ASSERT3U(lwb->lwb_nused, <=, lwb->lwb_sz);
ASSERT0(P2PHASE(lwb->lwb_nused, sizeof (uint64_t)));
return (lwb);
}
itx_t *
zil_itx_create(uint64_t txtype, size_t lrsize)
{
itx_t *itx;
lrsize = P2ROUNDUP_TYPED(lrsize, sizeof (uint64_t), size_t);
itx = zio_data_buf_alloc(offsetof(itx_t, itx_lr) + lrsize);
itx->itx_lr.lrc_txtype = txtype;
itx->itx_lr.lrc_reclen = lrsize;
itx->itx_sod = lrsize; /* if write & WR_NEED_COPY will be increased */
itx->itx_lr.lrc_seq = 0; /* defensive */
itx->itx_sync = B_TRUE; /* default is synchronous */
itx->itx_callback = NULL;
itx->itx_callback_data = NULL;
return (itx);
}
void
zil_itx_destroy(itx_t *itx)
{
zio_data_buf_free(itx, offsetof(itx_t, itx_lr)+itx->itx_lr.lrc_reclen);
}
/*
* Free up the sync and async itxs. The itxs_t has already been detached
* so no locks are needed.
*/
static void
zil_itxg_clean(itxs_t *itxs)
{
itx_t *itx;
list_t *list;
avl_tree_t *t;
void *cookie;
itx_async_node_t *ian;
list = &itxs->i_sync_list;
while ((itx = list_head(list)) != NULL) {
if (itx->itx_callback != NULL)
itx->itx_callback(itx->itx_callback_data);
list_remove(list, itx);
zil_itx_destroy(itx);
}
cookie = NULL;
t = &itxs->i_async_tree;
while ((ian = avl_destroy_nodes(t, &cookie)) != NULL) {
list = &ian->ia_list;
while ((itx = list_head(list)) != NULL) {
if (itx->itx_callback != NULL)
itx->itx_callback(itx->itx_callback_data);
list_remove(list, itx);
zil_itx_destroy(itx);
}
list_destroy(list);
kmem_free(ian, sizeof (itx_async_node_t));
}
avl_destroy(t);
kmem_free(itxs, sizeof (itxs_t));
}
static int
zil_aitx_compare(const void *x1, const void *x2)
{
const uint64_t o1 = ((itx_async_node_t *)x1)->ia_foid;
const uint64_t o2 = ((itx_async_node_t *)x2)->ia_foid;
if (o1 < o2)
return (-1);
if (o1 > o2)
return (1);
return (0);
}
/*
* Remove all async itx with the given oid.
*/
static void
zil_remove_async(zilog_t *zilog, uint64_t oid)
{
uint64_t otxg, txg;
itx_async_node_t *ian;
avl_tree_t *t;
avl_index_t where;
list_t clean_list;
itx_t *itx;
ASSERT(oid != 0);
list_create(&clean_list, sizeof (itx_t), offsetof(itx_t, itx_node));
if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) /* ziltest support */
otxg = ZILTEST_TXG;
else
otxg = spa_last_synced_txg(zilog->zl_spa) + 1;
for (txg = otxg; txg < (otxg + TXG_CONCURRENT_STATES); txg++) {
itxg_t *itxg = &zilog->zl_itxg[txg & TXG_MASK];
mutex_enter(&itxg->itxg_lock);
if (itxg->itxg_txg != txg) {
mutex_exit(&itxg->itxg_lock);
continue;
}
/*
* Locate the object node and append its list.
*/
t = &itxg->itxg_itxs->i_async_tree;
ian = avl_find(t, &oid, &where);
if (ian != NULL)
list_move_tail(&clean_list, &ian->ia_list);
mutex_exit(&itxg->itxg_lock);
}
while ((itx = list_head(&clean_list)) != NULL) {
if (itx->itx_callback != NULL)
itx->itx_callback(itx->itx_callback_data);
list_remove(&clean_list, itx);
zil_itx_destroy(itx);
}
list_destroy(&clean_list);
}
void
zil_itx_assign(zilog_t *zilog, itx_t *itx, dmu_tx_t *tx)
{
uint64_t txg;
itxg_t *itxg;
itxs_t *itxs, *clean = NULL;
/*
* Object ids can be re-instantiated in the next txg so
* remove any async transactions to avoid future leaks.
* This can happen if a fsync occurs on the re-instantiated
* object for a WR_INDIRECT or WR_NEED_COPY write, which gets
* the new file data and flushes a write record for the old object.
*/
if ((itx->itx_lr.lrc_txtype & ~TX_CI) == TX_REMOVE)
zil_remove_async(zilog, itx->itx_oid);
/*
* Ensure the data of a renamed file is committed before the rename.
*/
if ((itx->itx_lr.lrc_txtype & ~TX_CI) == TX_RENAME)
zil_async_to_sync(zilog, itx->itx_oid);
if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX)
txg = ZILTEST_TXG;
else
txg = dmu_tx_get_txg(tx);
itxg = &zilog->zl_itxg[txg & TXG_MASK];
mutex_enter(&itxg->itxg_lock);
itxs = itxg->itxg_itxs;
if (itxg->itxg_txg != txg) {
if (itxs != NULL) {
/*
* The zil_clean callback hasn't got around to cleaning
* this itxg. Save the itxs for release below.
* This should be rare.
*/
atomic_add_64(&zilog->zl_itx_list_sz, -itxg->itxg_sod);
itxg->itxg_sod = 0;
clean = itxg->itxg_itxs;
}
ASSERT(itxg->itxg_sod == 0);
itxg->itxg_txg = txg;
itxs = itxg->itxg_itxs = kmem_zalloc(sizeof (itxs_t),
KM_SLEEP);
list_create(&itxs->i_sync_list, sizeof (itx_t),
offsetof(itx_t, itx_node));
avl_create(&itxs->i_async_tree, zil_aitx_compare,
sizeof (itx_async_node_t),
offsetof(itx_async_node_t, ia_node));
}
if (itx->itx_sync) {
list_insert_tail(&itxs->i_sync_list, itx);
atomic_add_64(&zilog->zl_itx_list_sz, itx->itx_sod);
itxg->itxg_sod += itx->itx_sod;
} else {
avl_tree_t *t = &itxs->i_async_tree;
uint64_t foid =
LR_FOID_GET_OBJ(((lr_ooo_t *)&itx->itx_lr)->lr_foid);
itx_async_node_t *ian;
avl_index_t where;
ian = avl_find(t, &foid, &where);
if (ian == NULL) {
ian = kmem_alloc(sizeof (itx_async_node_t),
KM_SLEEP);
list_create(&ian->ia_list, sizeof (itx_t),
offsetof(itx_t, itx_node));
ian->ia_foid = foid;
avl_insert(t, ian, where);
}
list_insert_tail(&ian->ia_list, itx);
}
itx->itx_lr.lrc_txg = dmu_tx_get_txg(tx);
zilog_dirty(zilog, txg);
mutex_exit(&itxg->itxg_lock);
/* Release the old itxs now we've dropped the lock */
if (clean != NULL)
zil_itxg_clean(clean);
}
/*
* If there are any in-memory intent log transactions which have now been
* synced then start up a taskq to free them. We should only do this after we
* have written out the uberblocks (i.e. txg has been comitted) so that
* don't inadvertently clean out in-memory log records that would be required
* by zil_commit().
*/
void
zil_clean(zilog_t *zilog, uint64_t synced_txg)
{
itxg_t *itxg = &zilog->zl_itxg[synced_txg & TXG_MASK];
itxs_t *clean_me;
mutex_enter(&itxg->itxg_lock);
if (itxg->itxg_itxs == NULL || itxg->itxg_txg == ZILTEST_TXG) {
mutex_exit(&itxg->itxg_lock);
return;
}
ASSERT3U(itxg->itxg_txg, <=, synced_txg);
ASSERT(itxg->itxg_txg != 0);
ASSERT(zilog->zl_clean_taskq != NULL);
atomic_add_64(&zilog->zl_itx_list_sz, -itxg->itxg_sod);
itxg->itxg_sod = 0;
clean_me = itxg->itxg_itxs;
itxg->itxg_itxs = NULL;
itxg->itxg_txg = 0;
mutex_exit(&itxg->itxg_lock);
/*
* Preferably start a task queue to free up the old itxs but
* if taskq_dispatch can't allocate resources to do that then
* free it in-line. This should be rare. Note, using TQ_SLEEP
* created a bad performance problem.
*/
if (taskq_dispatch(zilog->zl_clean_taskq,
(void (*)(void *))zil_itxg_clean, clean_me, TQ_NOSLEEP) == 0)
zil_itxg_clean(clean_me);
}
/*
* Get the list of itxs to commit into zl_itx_commit_list.
*/
static void
zil_get_commit_list(zilog_t *zilog)
{
uint64_t otxg, txg;
list_t *commit_list = &zilog->zl_itx_commit_list;
uint64_t push_sod = 0;
if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) /* ziltest support */
otxg = ZILTEST_TXG;
else
otxg = spa_last_synced_txg(zilog->zl_spa) + 1;
for (txg = otxg; txg < (otxg + TXG_CONCURRENT_STATES); txg++) {
itxg_t *itxg = &zilog->zl_itxg[txg & TXG_MASK];
mutex_enter(&itxg->itxg_lock);
if (itxg->itxg_txg != txg) {
mutex_exit(&itxg->itxg_lock);
continue;
}
list_move_tail(commit_list, &itxg->itxg_itxs->i_sync_list);
push_sod += itxg->itxg_sod;
itxg->itxg_sod = 0;
mutex_exit(&itxg->itxg_lock);
}
atomic_add_64(&zilog->zl_itx_list_sz, -push_sod);
}
/*
* Move the async itxs for a specified object to commit into sync lists.
*/
static void
zil_async_to_sync(zilog_t *zilog, uint64_t foid)
{
uint64_t otxg, txg;
itx_async_node_t *ian;
avl_tree_t *t;
avl_index_t where;
if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) /* ziltest support */
otxg = ZILTEST_TXG;
else
otxg = spa_last_synced_txg(zilog->zl_spa) + 1;
for (txg = otxg; txg < (otxg + TXG_CONCURRENT_STATES); txg++) {
itxg_t *itxg = &zilog->zl_itxg[txg & TXG_MASK];
mutex_enter(&itxg->itxg_lock);
if (itxg->itxg_txg != txg) {
mutex_exit(&itxg->itxg_lock);
continue;
}
/*
* If a foid is specified then find that node and append its
* list. Otherwise walk the tree appending all the lists
* to the sync list. We add to the end rather than the
* beginning to ensure the create has happened.
*/
t = &itxg->itxg_itxs->i_async_tree;
if (foid != 0) {
ian = avl_find(t, &foid, &where);
if (ian != NULL) {
list_move_tail(&itxg->itxg_itxs->i_sync_list,
&ian->ia_list);
}
} else {
void *cookie = NULL;
while ((ian = avl_destroy_nodes(t, &cookie)) != NULL) {
list_move_tail(&itxg->itxg_itxs->i_sync_list,
&ian->ia_list);
list_destroy(&ian->ia_list);
kmem_free(ian, sizeof (itx_async_node_t));
}
}
mutex_exit(&itxg->itxg_lock);
}
}
static void
zil_commit_writer(zilog_t *zilog)
{
uint64_t txg;
itx_t *itx;
lwb_t *lwb;
spa_t *spa = zilog->zl_spa;
int error = 0;
ASSERT(zilog->zl_root_zio == NULL);
mutex_exit(&zilog->zl_lock);
zil_get_commit_list(zilog);
/*
* Return if there's nothing to commit before we dirty the fs by
* calling zil_create().
*/
if (list_head(&zilog->zl_itx_commit_list) == NULL) {
mutex_enter(&zilog->zl_lock);
return;
}
if (zilog->zl_suspend) {
lwb = NULL;
} else {
lwb = list_tail(&zilog->zl_lwb_list);
if (lwb == NULL)
lwb = zil_create(zilog);
}
DTRACE_PROBE1(zil__cw1, zilog_t *, zilog);
for (itx = list_head(&zilog->zl_itx_commit_list); itx != NULL;
itx = list_next(&zilog->zl_itx_commit_list, itx)) {
txg = itx->itx_lr.lrc_txg;
ASSERT(txg);
if (txg > spa_last_synced_txg(spa) || txg > spa_freeze_txg(spa))
lwb = zil_lwb_commit(zilog, itx, lwb);
}
DTRACE_PROBE1(zil__cw2, zilog_t *, zilog);
/* write the last block out */
if (lwb != NULL && lwb->lwb_zio != NULL)
lwb = zil_lwb_write_start(zilog, lwb);
zilog->zl_cur_used = 0;
/*
* Wait if necessary for the log blocks to be on stable storage.
*/
if (zilog->zl_root_zio) {
error = zio_wait(zilog->zl_root_zio);
zilog->zl_root_zio = NULL;
zil_flush_vdevs(zilog);
}
if (error || lwb == NULL)
txg_wait_synced(zilog->zl_dmu_pool, 0);
while ((itx = list_head(&zilog->zl_itx_commit_list))) {
txg = itx->itx_lr.lrc_txg;
ASSERT(txg);
if (itx->itx_callback != NULL)
itx->itx_callback(itx->itx_callback_data);
list_remove(&zilog->zl_itx_commit_list, itx);
zil_itx_destroy(itx);
}
mutex_enter(&zilog->zl_lock);
/*
* Remember the highest committed log sequence number for ztest.
* We only update this value when all the log writes succeeded,
* because ztest wants to ASSERT that it got the whole log chain.
*/
if (error == 0 && lwb != NULL)
zilog->zl_commit_lr_seq = zilog->zl_lr_seq;
}
/*
* Commit zfs transactions to stable storage.
* If foid is 0 push out all transactions, otherwise push only those
* for that object or might reference that object.
*
* itxs are committed in batches. In a heavily stressed zil there will be
* a commit writer thread who is writing out a bunch of itxs to the log
* for a set of committing threads (cthreads) in the same batch as the writer.
* Those cthreads are all waiting on the same cv for that batch.
*
* There will also be a different and growing batch of threads that are
* waiting to commit (qthreads). When the committing batch completes
* a transition occurs such that the cthreads exit and the qthreads become
* cthreads. One of the new cthreads becomes the writer thread for the
* batch. Any new threads arriving become new qthreads.
*
* Only 2 condition variables are needed and there's no transition
* between the two cvs needed. They just flip-flop between qthreads
* and cthreads.
*
* Using this scheme we can efficiently wakeup up only those threads
* that have been committed.
*/
void
zil_commit(zilog_t *zilog, uint64_t foid)
{
uint64_t mybatch;
if (zilog->zl_sync == ZFS_SYNC_DISABLED)
return;
ZIL_STAT_BUMP(zil_commit_count);
/* move the async itxs for the foid to the sync queues */
zil_async_to_sync(zilog, foid);
mutex_enter(&zilog->zl_lock);
mybatch = zilog->zl_next_batch;
while (zilog->zl_writer) {
cv_wait(&zilog->zl_cv_batch[mybatch & 1], &zilog->zl_lock);
if (mybatch <= zilog->zl_com_batch) {
mutex_exit(&zilog->zl_lock);
return;
}
}
zilog->zl_next_batch++;
zilog->zl_writer = B_TRUE;
ZIL_STAT_BUMP(zil_commit_writer_count);
zil_commit_writer(zilog);
zilog->zl_com_batch = mybatch;
zilog->zl_writer = B_FALSE;
/* wake up one thread to become the next writer */
cv_signal(&zilog->zl_cv_batch[(mybatch+1) & 1]);
/* wake up all threads waiting for this batch to be committed */
cv_broadcast(&zilog->zl_cv_batch[mybatch & 1]);
mutex_exit(&zilog->zl_lock);
}
/*
* Called in syncing context to free committed log blocks and update log header.
*/
void
zil_sync(zilog_t *zilog, dmu_tx_t *tx)
{
zil_header_t *zh = zil_header_in_syncing_context(zilog);
uint64_t txg = dmu_tx_get_txg(tx);
spa_t *spa = zilog->zl_spa;
uint64_t *replayed_seq = &zilog->zl_replayed_seq[txg & TXG_MASK];
lwb_t *lwb;
/*
* We don't zero out zl_destroy_txg, so make sure we don't try
* to destroy it twice.
*/
if (spa_sync_pass(spa) != 1)
return;
mutex_enter(&zilog->zl_lock);
ASSERT(zilog->zl_stop_sync == 0);
if (*replayed_seq != 0) {
ASSERT(zh->zh_replay_seq < *replayed_seq);
zh->zh_replay_seq = *replayed_seq;
*replayed_seq = 0;
}
if (zilog->zl_destroy_txg == txg) {
blkptr_t blk = zh->zh_log;
ASSERT(list_head(&zilog->zl_lwb_list) == NULL);
bzero(zh, sizeof (zil_header_t));
bzero(zilog->zl_replayed_seq, sizeof (zilog->zl_replayed_seq));
if (zilog->zl_keep_first) {
/*
* If this block was part of log chain that couldn't
* be claimed because a device was missing during
* zil_claim(), but that device later returns,
* then this block could erroneously appear valid.
* To guard against this, assign a new GUID to the new
* log chain so it doesn't matter what blk points to.
*/
zil_init_log_chain(zilog, &blk);
zh->zh_log = blk;
}
}
while ((lwb = list_head(&zilog->zl_lwb_list)) != NULL) {
zh->zh_log = lwb->lwb_blk;
if (lwb->lwb_buf != NULL || lwb->lwb_max_txg > txg)
break;
ASSERT(lwb->lwb_zio == NULL);
list_remove(&zilog->zl_lwb_list, lwb);
zio_free_zil(spa, txg, &lwb->lwb_blk);
kmem_cache_free(zil_lwb_cache, lwb);
/*
* If we don't have anything left in the lwb list then
* we've had an allocation failure and we need to zero
* out the zil_header blkptr so that we don't end
* up freeing the same block twice.
*/
if (list_head(&zilog->zl_lwb_list) == NULL)
BP_ZERO(&zh->zh_log);
}
/*
* Remove fastwrite on any blocks that have been pre-allocated for
* the next commit. This prevents fastwrite counter pollution by
* unused, long-lived LWBs.
*/
for (; lwb != NULL; lwb = list_next(&zilog->zl_lwb_list, lwb)) {
if (lwb->lwb_fastwrite && !lwb->lwb_zio) {
metaslab_fastwrite_unmark(zilog->zl_spa, &lwb->lwb_blk);
lwb->lwb_fastwrite = 0;
}
}
mutex_exit(&zilog->zl_lock);
}
void
zil_init(void)
{
zil_lwb_cache = kmem_cache_create("zil_lwb_cache",
sizeof (struct lwb), 0, NULL, NULL, NULL, NULL, NULL, 0);
zil_ksp = kstat_create("zfs", 0, "zil", "misc",
KSTAT_TYPE_NAMED, sizeof (zil_stats) / sizeof (kstat_named_t),
KSTAT_FLAG_VIRTUAL);
if (zil_ksp != NULL) {
zil_ksp->ks_data = &zil_stats;
kstat_install(zil_ksp);
}
}
void
zil_fini(void)
{
kmem_cache_destroy(zil_lwb_cache);
if (zil_ksp != NULL) {
kstat_delete(zil_ksp);
zil_ksp = NULL;
}
}
void
zil_set_sync(zilog_t *zilog, uint64_t sync)
{
zilog->zl_sync = sync;
}
void
zil_set_logbias(zilog_t *zilog, uint64_t logbias)
{
zilog->zl_logbias = logbias;
}
zilog_t *
zil_alloc(objset_t *os, zil_header_t *zh_phys)
{
zilog_t *zilog;
int i;
zilog = kmem_zalloc(sizeof (zilog_t), KM_SLEEP);
zilog->zl_header = zh_phys;
zilog->zl_os = os;
zilog->zl_spa = dmu_objset_spa(os);
zilog->zl_dmu_pool = dmu_objset_pool(os);
zilog->zl_destroy_txg = TXG_INITIAL - 1;
zilog->zl_logbias = dmu_objset_logbias(os);
zilog->zl_sync = dmu_objset_syncprop(os);
zilog->zl_next_batch = 1;
mutex_init(&zilog->zl_lock, NULL, MUTEX_DEFAULT, NULL);
for (i = 0; i < TXG_SIZE; i++) {
mutex_init(&zilog->zl_itxg[i].itxg_lock, NULL,
MUTEX_DEFAULT, NULL);
}
list_create(&zilog->zl_lwb_list, sizeof (lwb_t),
offsetof(lwb_t, lwb_node));
list_create(&zilog->zl_itx_commit_list, sizeof (itx_t),
offsetof(itx_t, itx_node));
mutex_init(&zilog->zl_vdev_lock, NULL, MUTEX_DEFAULT, NULL);
avl_create(&zilog->zl_vdev_tree, zil_vdev_compare,
sizeof (zil_vdev_node_t), offsetof(zil_vdev_node_t, zv_node));
cv_init(&zilog->zl_cv_writer, NULL, CV_DEFAULT, NULL);
cv_init(&zilog->zl_cv_suspend, NULL, CV_DEFAULT, NULL);
cv_init(&zilog->zl_cv_batch[0], NULL, CV_DEFAULT, NULL);
cv_init(&zilog->zl_cv_batch[1], NULL, CV_DEFAULT, NULL);
return (zilog);
}
void
zil_free(zilog_t *zilog)
{
int i;
zilog->zl_stop_sync = 1;
ASSERT0(zilog->zl_suspend);
ASSERT0(zilog->zl_suspending);
ASSERT(list_is_empty(&zilog->zl_lwb_list));
list_destroy(&zilog->zl_lwb_list);
avl_destroy(&zilog->zl_vdev_tree);
mutex_destroy(&zilog->zl_vdev_lock);
ASSERT(list_is_empty(&zilog->zl_itx_commit_list));
list_destroy(&zilog->zl_itx_commit_list);
for (i = 0; i < TXG_SIZE; i++) {
/*
* It's possible for an itx to be generated that doesn't dirty
* a txg (e.g. ztest TX_TRUNCATE). So there's no zil_clean()
* callback to remove the entry. We remove those here.
*
* Also free up the ziltest itxs.
*/
if (zilog->zl_itxg[i].itxg_itxs)
zil_itxg_clean(zilog->zl_itxg[i].itxg_itxs);
mutex_destroy(&zilog->zl_itxg[i].itxg_lock);
}
mutex_destroy(&zilog->zl_lock);
cv_destroy(&zilog->zl_cv_writer);
cv_destroy(&zilog->zl_cv_suspend);
cv_destroy(&zilog->zl_cv_batch[0]);
cv_destroy(&zilog->zl_cv_batch[1]);
kmem_free(zilog, sizeof (zilog_t));
}
/*
* Open an intent log.
*/
zilog_t *
zil_open(objset_t *os, zil_get_data_t *get_data)
{
zilog_t *zilog = dmu_objset_zil(os);
ASSERT(zilog->zl_clean_taskq == NULL);
ASSERT(zilog->zl_get_data == NULL);
ASSERT(list_is_empty(&zilog->zl_lwb_list));
zilog->zl_get_data = get_data;
zilog->zl_clean_taskq = taskq_create("zil_clean", 1, defclsyspri,
2, 2, TASKQ_PREPOPULATE);
return (zilog);
}
/*
* Close an intent log.
*/
void
zil_close(zilog_t *zilog)
{
lwb_t *lwb;
uint64_t txg = 0;
zil_commit(zilog, 0); /* commit all itx */
/*
* The lwb_max_txg for the stubby lwb will reflect the last activity
* for the zil. After a txg_wait_synced() on the txg we know all the
* callbacks have occurred that may clean the zil. Only then can we
* destroy the zl_clean_taskq.
*/
mutex_enter(&zilog->zl_lock);
lwb = list_tail(&zilog->zl_lwb_list);
if (lwb != NULL)
txg = lwb->lwb_max_txg;
mutex_exit(&zilog->zl_lock);
if (txg)
txg_wait_synced(zilog->zl_dmu_pool, txg);
if (txg < spa_freeze_txg(zilog->zl_spa))
ASSERT(!zilog_is_dirty(zilog));
taskq_destroy(zilog->zl_clean_taskq);
zilog->zl_clean_taskq = NULL;
zilog->zl_get_data = NULL;
/*
* We should have only one LWB left on the list; remove it now.
*/
mutex_enter(&zilog->zl_lock);
lwb = list_head(&zilog->zl_lwb_list);
if (lwb != NULL) {
ASSERT(lwb == list_tail(&zilog->zl_lwb_list));
ASSERT(lwb->lwb_zio == NULL);
if (lwb->lwb_fastwrite)
metaslab_fastwrite_unmark(zilog->zl_spa, &lwb->lwb_blk);
list_remove(&zilog->zl_lwb_list, lwb);
zio_buf_free(lwb->lwb_buf, lwb->lwb_sz);
kmem_cache_free(zil_lwb_cache, lwb);
}
mutex_exit(&zilog->zl_lock);
}
static char *suspend_tag = "zil suspending";
/*
* Suspend an intent log. While in suspended mode, we still honor
* synchronous semantics, but we rely on txg_wait_synced() to do it.
* On old version pools, we suspend the log briefly when taking a
* snapshot so that it will have an empty intent log.
*
* Long holds are not really intended to be used the way we do here --
* held for such a short time. A concurrent caller of dsl_dataset_long_held()
* could fail. Therefore we take pains to only put a long hold if it is
* actually necessary. Fortunately, it will only be necessary if the
* objset is currently mounted (or the ZVOL equivalent). In that case it
* will already have a long hold, so we are not really making things any worse.
*
* Ideally, we would locate the existing long-holder (i.e. the zfsvfs_t or
* zvol_state_t), and use their mechanism to prevent their hold from being
* dropped (e.g. VFS_HOLD()). However, that would be even more pain for
* very little gain.
*
* if cookiep == NULL, this does both the suspend & resume.
* Otherwise, it returns with the dataset "long held", and the cookie
* should be passed into zil_resume().
*/
int
zil_suspend(const char *osname, void **cookiep)
{
objset_t *os;
zilog_t *zilog;
const zil_header_t *zh;
int error;
error = dmu_objset_hold(osname, suspend_tag, &os);
if (error != 0)
return (error);
zilog = dmu_objset_zil(os);
mutex_enter(&zilog->zl_lock);
zh = zilog->zl_header;
if (zh->zh_flags & ZIL_REPLAY_NEEDED) { /* unplayed log */
mutex_exit(&zilog->zl_lock);
dmu_objset_rele(os, suspend_tag);
return (SET_ERROR(EBUSY));
}
/*
* Don't put a long hold in the cases where we can avoid it. This
* is when there is no cookie so we are doing a suspend & resume
* (i.e. called from zil_vdev_offline()), and there's nothing to do
* for the suspend because it's already suspended, or there's no ZIL.
*/
if (cookiep == NULL && !zilog->zl_suspending &&
(zilog->zl_suspend > 0 || BP_IS_HOLE(&zh->zh_log))) {
mutex_exit(&zilog->zl_lock);
dmu_objset_rele(os, suspend_tag);
return (0);
}
dsl_dataset_long_hold(dmu_objset_ds(os), suspend_tag);
dsl_pool_rele(dmu_objset_pool(os), suspend_tag);
zilog->zl_suspend++;
if (zilog->zl_suspend > 1) {
/*
* Someone else is already suspending it.
* Just wait for them to finish.
*/
while (zilog->zl_suspending)
cv_wait(&zilog->zl_cv_suspend, &zilog->zl_lock);
mutex_exit(&zilog->zl_lock);
if (cookiep == NULL)
zil_resume(os);
else
*cookiep = os;
return (0);
}
/*
* If there is no pointer to an on-disk block, this ZIL must not
* be active (e.g. filesystem not mounted), so there's nothing
* to clean up.
*/
if (BP_IS_HOLE(&zh->zh_log)) {
ASSERT(cookiep != NULL); /* fast path already handled */
*cookiep = os;
mutex_exit(&zilog->zl_lock);
return (0);
}
zilog->zl_suspending = B_TRUE;
mutex_exit(&zilog->zl_lock);
zil_commit(zilog, 0);
zil_destroy(zilog, B_FALSE);
mutex_enter(&zilog->zl_lock);
zilog->zl_suspending = B_FALSE;
cv_broadcast(&zilog->zl_cv_suspend);
mutex_exit(&zilog->zl_lock);
if (cookiep == NULL)
zil_resume(os);
else
*cookiep = os;
return (0);
}
void
zil_resume(void *cookie)
{
objset_t *os = cookie;
zilog_t *zilog = dmu_objset_zil(os);
mutex_enter(&zilog->zl_lock);
ASSERT(zilog->zl_suspend != 0);
zilog->zl_suspend--;
mutex_exit(&zilog->zl_lock);
dsl_dataset_long_rele(dmu_objset_ds(os), suspend_tag);
dsl_dataset_rele(dmu_objset_ds(os), suspend_tag);
}
typedef struct zil_replay_arg {
zil_replay_func_t *zr_replay;
void *zr_arg;
boolean_t zr_byteswap;
char *zr_lr;
} zil_replay_arg_t;
static int
zil_replay_error(zilog_t *zilog, lr_t *lr, int error)
{
char name[MAXNAMELEN];
zilog->zl_replaying_seq--; /* didn't actually replay this one */
dmu_objset_name(zilog->zl_os, name);
cmn_err(CE_WARN, "ZFS replay transaction error %d, "
"dataset %s, seq 0x%llx, txtype %llu %s\n", error, name,
(u_longlong_t)lr->lrc_seq,
(u_longlong_t)(lr->lrc_txtype & ~TX_CI),
(lr->lrc_txtype & TX_CI) ? "CI" : "");
return (error);
}
static int
zil_replay_log_record(zilog_t *zilog, lr_t *lr, void *zra, uint64_t claim_txg)
{
zil_replay_arg_t *zr = zra;
const zil_header_t *zh = zilog->zl_header;
uint64_t reclen = lr->lrc_reclen;
uint64_t txtype = lr->lrc_txtype;
int error = 0;
zilog->zl_replaying_seq = lr->lrc_seq;
if (lr->lrc_seq <= zh->zh_replay_seq) /* already replayed */
return (0);
if (lr->lrc_txg < claim_txg) /* already committed */
return (0);
/* Strip case-insensitive bit, still present in log record */
txtype &= ~TX_CI;
if (txtype == 0 || txtype >= TX_MAX_TYPE)
return (zil_replay_error(zilog, lr, EINVAL));
/*
* If this record type can be logged out of order, the object
* (lr_foid) may no longer exist. That's legitimate, not an error.
*/
if (TX_OOO(txtype)) {
error = dmu_object_info(zilog->zl_os,
LR_FOID_GET_OBJ(((lr_ooo_t *)lr)->lr_foid), NULL);
if (error == ENOENT || error == EEXIST)
return (0);
}
/*
* Make a copy of the data so we can revise and extend it.
*/
bcopy(lr, zr->zr_lr, reclen);
/*
* If this is a TX_WRITE with a blkptr, suck in the data.
*/
if (txtype == TX_WRITE && reclen == sizeof (lr_write_t)) {
error = zil_read_log_data(zilog, (lr_write_t *)lr,
zr->zr_lr + reclen);
if (error != 0)
return (zil_replay_error(zilog, lr, error));
}
/*
* The log block containing this lr may have been byteswapped
* so that we can easily examine common fields like lrc_txtype.
* However, the log is a mix of different record types, and only the
* replay vectors know how to byteswap their records. Therefore, if
* the lr was byteswapped, undo it before invoking the replay vector.
*/
if (zr->zr_byteswap)
byteswap_uint64_array(zr->zr_lr, reclen);
/*
* We must now do two things atomically: replay this log record,
* and update the log header sequence number to reflect the fact that
* we did so. At the end of each replay function the sequence number
* is updated if we are in replay mode.
*/
error = zr->zr_replay[txtype](zr->zr_arg, zr->zr_lr, zr->zr_byteswap);
if (error != 0) {
/*
* The DMU's dnode layer doesn't see removes until the txg
* commits, so a subsequent claim can spuriously fail with
* EEXIST. So if we receive any error we try syncing out
* any removes then retry the transaction. Note that we
* specify B_FALSE for byteswap now, so we don't do it twice.
*/
txg_wait_synced(spa_get_dsl(zilog->zl_spa), 0);
error = zr->zr_replay[txtype](zr->zr_arg, zr->zr_lr, B_FALSE);
if (error != 0)
return (zil_replay_error(zilog, lr, error));
}
return (0);
}
/* ARGSUSED */
static int
zil_incr_blks(zilog_t *zilog, blkptr_t *bp, void *arg, uint64_t claim_txg)
{
zilog->zl_replay_blks++;
return (0);
}
/*
* If this dataset has a non-empty intent log, replay it and destroy it.
*/
void
zil_replay(objset_t *os, void *arg, zil_replay_func_t replay_func[TX_MAX_TYPE])
{
zilog_t *zilog = dmu_objset_zil(os);
const zil_header_t *zh = zilog->zl_header;
zil_replay_arg_t zr;
if ((zh->zh_flags & ZIL_REPLAY_NEEDED) == 0) {
zil_destroy(zilog, B_TRUE);
return;
}
zr.zr_replay = replay_func;
zr.zr_arg = arg;
zr.zr_byteswap = BP_SHOULD_BYTESWAP(&zh->zh_log);
zr.zr_lr = vmem_alloc(2 * SPA_MAXBLOCKSIZE, KM_SLEEP);
/*
* Wait for in-progress removes to sync before starting replay.
*/
txg_wait_synced(zilog->zl_dmu_pool, 0);
zilog->zl_replay = B_TRUE;
zilog->zl_replay_time = ddi_get_lbolt();
ASSERT(zilog->zl_replay_blks == 0);
(void) zil_parse(zilog, zil_incr_blks, zil_replay_log_record, &zr,
zh->zh_claim_txg);
vmem_free(zr.zr_lr, 2 * SPA_MAXBLOCKSIZE);
zil_destroy(zilog, B_FALSE);
txg_wait_synced(zilog->zl_dmu_pool, zilog->zl_destroy_txg);
zilog->zl_replay = B_FALSE;
}
boolean_t
zil_replaying(zilog_t *zilog, dmu_tx_t *tx)
{
if (zilog->zl_sync == ZFS_SYNC_DISABLED)
return (B_TRUE);
if (zilog->zl_replay) {
dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx);
zilog->zl_replayed_seq[dmu_tx_get_txg(tx) & TXG_MASK] =
zilog->zl_replaying_seq;
return (B_TRUE);
}
return (B_FALSE);
}
/* ARGSUSED */
int
zil_vdev_offline(const char *osname, void *arg)
{
int error;
error = zil_suspend(osname, NULL);
if (error != 0)
return (SET_ERROR(EEXIST));
return (0);
}
#if defined(_KERNEL) && defined(HAVE_SPL)
EXPORT_SYMBOL(zil_alloc);
EXPORT_SYMBOL(zil_free);
EXPORT_SYMBOL(zil_open);
EXPORT_SYMBOL(zil_close);
EXPORT_SYMBOL(zil_replay);
EXPORT_SYMBOL(zil_replaying);
EXPORT_SYMBOL(zil_destroy);
EXPORT_SYMBOL(zil_destroy_sync);
EXPORT_SYMBOL(zil_itx_create);
EXPORT_SYMBOL(zil_itx_destroy);
EXPORT_SYMBOL(zil_itx_assign);
EXPORT_SYMBOL(zil_commit);
EXPORT_SYMBOL(zil_vdev_offline);
EXPORT_SYMBOL(zil_claim);
EXPORT_SYMBOL(zil_check_log_chain);
EXPORT_SYMBOL(zil_sync);
EXPORT_SYMBOL(zil_clean);
EXPORT_SYMBOL(zil_suspend);
EXPORT_SYMBOL(zil_resume);
EXPORT_SYMBOL(zil_add_block);
EXPORT_SYMBOL(zil_bp_tree_add);
EXPORT_SYMBOL(zil_set_sync);
EXPORT_SYMBOL(zil_set_logbias);
module_param(zil_replay_disable, int, 0644);
MODULE_PARM_DESC(zil_replay_disable, "Disable intent logging replay");
module_param(zfs_nocacheflush, int, 0644);
MODULE_PARM_DESC(zfs_nocacheflush, "Disable cache flushes");
module_param(zil_slog_limit, ulong, 0644);
MODULE_PARM_DESC(zil_slog_limit, "Max commit bytes to separate log device");
#endif
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