freebsd-dev/include/sys/dnode.h
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

383 lines
13 KiB
C

/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
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*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
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*
* When distributing Covered Code, include this CDDL HEADER in each
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* 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]
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*/
/*
* Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2012, 2014 by Delphix. All rights reserved.
* Copyright (c) 2014 Spectra Logic Corporation, All rights reserved.
*/
#ifndef _SYS_DNODE_H
#define _SYS_DNODE_H
#include <sys/zfs_context.h>
#include <sys/avl.h>
#include <sys/spa.h>
#include <sys/txg.h>
#include <sys/zio.h>
#include <sys/refcount.h>
#include <sys/dmu_zfetch.h>
#include <sys/zrlock.h>
#ifdef __cplusplus
extern "C" {
#endif
/*
* dnode_hold() flags.
*/
#define DNODE_MUST_BE_ALLOCATED 1
#define DNODE_MUST_BE_FREE 2
/*
* dnode_next_offset() flags.
*/
#define DNODE_FIND_HOLE 1
#define DNODE_FIND_BACKWARDS 2
#define DNODE_FIND_HAVELOCK 4
/*
* Fixed constants.
*/
#define DNODE_SHIFT 9 /* 512 bytes */
#define DN_MIN_INDBLKSHIFT 12 /* 4k */
#define DN_MAX_INDBLKSHIFT 14 /* 16k */
#define DNODE_BLOCK_SHIFT 14 /* 16k */
#define DNODE_CORE_SIZE 64 /* 64 bytes for dnode sans blkptrs */
#define DN_MAX_OBJECT_SHIFT 48 /* 256 trillion (zfs_fid_t limit) */
#define DN_MAX_OFFSET_SHIFT 64 /* 2^64 bytes in a dnode */
/*
* dnode id flags
*
* Note: a file will never ever have its
* ids moved from bonus->spill
* and only in a crypto environment would it be on spill
*/
#define DN_ID_CHKED_BONUS 0x1
#define DN_ID_CHKED_SPILL 0x2
#define DN_ID_OLD_EXIST 0x4
#define DN_ID_NEW_EXIST 0x8
/*
* Derived constants.
*/
#define DNODE_MIN_SIZE (1 << DNODE_SHIFT)
#define DNODE_MAX_SIZE (1 << DNODE_BLOCK_SHIFT)
#define DNODE_BLOCK_SIZE (1 << DNODE_BLOCK_SHIFT)
#define DNODE_MIN_SLOTS (DNODE_MIN_SIZE >> DNODE_SHIFT)
#define DNODE_MAX_SLOTS (DNODE_MAX_SIZE >> DNODE_SHIFT)
#define DN_BONUS_SIZE(dnsize) ((dnsize) - DNODE_CORE_SIZE - \
(1 << SPA_BLKPTRSHIFT))
#define DN_SLOTS_TO_BONUSLEN(slots) DN_BONUS_SIZE((slots) << DNODE_SHIFT)
#define DN_OLD_MAX_BONUSLEN (DN_BONUS_SIZE(DNODE_MIN_SIZE))
#define DN_MAX_NBLKPTR ((DNODE_MIN_SIZE - DNODE_CORE_SIZE) >> SPA_BLKPTRSHIFT)
#define DN_MAX_OBJECT (1ULL << DN_MAX_OBJECT_SHIFT)
#define DN_ZERO_BONUSLEN (DN_BONUS_SIZE(DNODE_MAX_SIZE) + 1)
#define DN_KILL_SPILLBLK (1)
#define DNODES_PER_BLOCK_SHIFT (DNODE_BLOCK_SHIFT - DNODE_SHIFT)
#define DNODES_PER_BLOCK (1ULL << DNODES_PER_BLOCK_SHIFT)
#define DNODES_PER_LEVEL_SHIFT (DN_MAX_INDBLKSHIFT - SPA_BLKPTRSHIFT)
#define DNODES_PER_LEVEL (1ULL << DNODES_PER_LEVEL_SHIFT)
/* The +2 here is a cheesy way to round up */
#define DN_MAX_LEVELS (2 + ((DN_MAX_OFFSET_SHIFT - SPA_MINBLOCKSHIFT) / \
(DN_MIN_INDBLKSHIFT - SPA_BLKPTRSHIFT)))
#define DN_BONUS(dnp) ((void*)((dnp)->dn_bonus + \
(((dnp)->dn_nblkptr - 1) * sizeof (blkptr_t))))
#define DN_USED_BYTES(dnp) (((dnp)->dn_flags & DNODE_FLAG_USED_BYTES) ? \
(dnp)->dn_used : (dnp)->dn_used << SPA_MINBLOCKSHIFT)
#define EPB(blkshift, typeshift) (1 << (blkshift - typeshift))
struct dmu_buf_impl;
struct objset;
struct zio;
enum dnode_dirtycontext {
DN_UNDIRTIED,
DN_DIRTY_OPEN,
DN_DIRTY_SYNC
};
/* Is dn_used in bytes? if not, it's in multiples of SPA_MINBLOCKSIZE */
#define DNODE_FLAG_USED_BYTES (1<<0)
#define DNODE_FLAG_USERUSED_ACCOUNTED (1<<1)
/* Does dnode have a SA spill blkptr in bonus? */
#define DNODE_FLAG_SPILL_BLKPTR (1<<2)
typedef struct dnode_phys {
uint8_t dn_type; /* dmu_object_type_t */
uint8_t dn_indblkshift; /* ln2(indirect block size) */
uint8_t dn_nlevels; /* 1=dn_blkptr->data blocks */
uint8_t dn_nblkptr; /* length of dn_blkptr */
uint8_t dn_bonustype; /* type of data in bonus buffer */
uint8_t dn_checksum; /* ZIO_CHECKSUM type */
uint8_t dn_compress; /* ZIO_COMPRESS type */
uint8_t dn_flags; /* DNODE_FLAG_* */
uint16_t dn_datablkszsec; /* data block size in 512b sectors */
uint16_t dn_bonuslen; /* length of dn_bonus */
uint8_t dn_extra_slots; /* # of subsequent slots consumed */
uint8_t dn_pad2[3];
/* accounting is protected by dn_dirty_mtx */
uint64_t dn_maxblkid; /* largest allocated block ID */
uint64_t dn_used; /* bytes (or sectors) of disk space */
uint64_t dn_pad3[4];
/*
* The tail region is 448 bytes for a 512 byte dnode, and
* correspondingly larger for larger dnode sizes. The spill
* block pointer, when present, is always at the end of the tail
* region. There are three ways this space may be used, using
* a 512 byte dnode for this diagram:
*
* 0 64 128 192 256 320 384 448 (offset)
* +---------------+---------------+---------------+-------+
* | dn_blkptr[0] | dn_blkptr[1] | dn_blkptr[2] | / |
* +---------------+---------------+---------------+-------+
* | dn_blkptr[0] | dn_bonus[0..319] |
* +---------------+-----------------------+---------------+
* | dn_blkptr[0] | dn_bonus[0..191] | dn_spill |
* +---------------+-----------------------+---------------+
*/
union {
blkptr_t dn_blkptr[1+DN_OLD_MAX_BONUSLEN/sizeof (blkptr_t)];
struct {
blkptr_t __dn_ignore1;
uint8_t dn_bonus[DN_OLD_MAX_BONUSLEN];
};
struct {
blkptr_t __dn_ignore2;
uint8_t __dn_ignore3[DN_OLD_MAX_BONUSLEN -
sizeof (blkptr_t)];
blkptr_t dn_spill;
};
};
} dnode_phys_t;
#define DN_SPILL_BLKPTR(dnp) (blkptr_t *)((char *)(dnp) + \
(((dnp)->dn_extra_slots + 1) << DNODE_SHIFT) - (1 << SPA_BLKPTRSHIFT))
typedef struct dnode {
/*
* Protects the structure of the dnode, including the number of levels
* of indirection (dn_nlevels), dn_maxblkid, and dn_next_*
*/
krwlock_t dn_struct_rwlock;
/* Our link on dn_objset->os_dnodes list; protected by os_lock. */
list_node_t dn_link;
/* immutable: */
struct objset *dn_objset;
uint64_t dn_object;
struct dmu_buf_impl *dn_dbuf;
struct dnode_handle *dn_handle;
dnode_phys_t *dn_phys; /* pointer into dn->dn_dbuf->db.db_data */
/*
* Copies of stuff in dn_phys. They're valid in the open
* context (eg. even before the dnode is first synced).
* Where necessary, these are protected by dn_struct_rwlock.
*/
dmu_object_type_t dn_type; /* object type */
uint16_t dn_bonuslen; /* bonus length */
uint8_t dn_bonustype; /* bonus type */
uint8_t dn_nblkptr; /* number of blkptrs (immutable) */
uint8_t dn_checksum; /* ZIO_CHECKSUM type */
uint8_t dn_compress; /* ZIO_COMPRESS type */
uint8_t dn_nlevels;
uint8_t dn_indblkshift;
uint8_t dn_datablkshift; /* zero if blksz not power of 2! */
uint8_t dn_moved; /* Has this dnode been moved? */
uint16_t dn_datablkszsec; /* in 512b sectors */
uint32_t dn_datablksz; /* in bytes */
uint64_t dn_maxblkid;
uint8_t dn_next_type[TXG_SIZE];
uint8_t dn_num_slots; /* metadnode slots consumed on disk */
uint8_t dn_next_nblkptr[TXG_SIZE];
uint8_t dn_next_nlevels[TXG_SIZE];
uint8_t dn_next_indblkshift[TXG_SIZE];
uint8_t dn_next_bonustype[TXG_SIZE];
uint8_t dn_rm_spillblk[TXG_SIZE]; /* for removing spill blk */
uint16_t dn_next_bonuslen[TXG_SIZE];
uint32_t dn_next_blksz[TXG_SIZE]; /* next block size in bytes */
/* protected by dn_dbufs_mtx; declared here to fill 32-bit hole */
uint32_t dn_dbufs_count; /* count of dn_dbufs */
/* There are no level-0 blocks of this blkid or higher in dn_dbufs */
uint64_t dn_unlisted_l0_blkid;
/* protected by os_lock: */
list_node_t dn_dirty_link[TXG_SIZE]; /* next on dataset's dirty */
/* protected by dn_mtx: */
kmutex_t dn_mtx;
list_t dn_dirty_records[TXG_SIZE];
struct range_tree *dn_free_ranges[TXG_SIZE];
uint64_t dn_allocated_txg;
uint64_t dn_free_txg;
uint64_t dn_assigned_txg;
kcondvar_t dn_notxholds;
enum dnode_dirtycontext dn_dirtyctx;
uint8_t *dn_dirtyctx_firstset; /* dbg: contents meaningless */
/* protected by own devices */
refcount_t dn_tx_holds;
refcount_t dn_holds;
kmutex_t dn_dbufs_mtx;
/*
* Descendent dbufs, ordered by dbuf_compare. Note that dn_dbufs
* can contain multiple dbufs of the same (level, blkid) when a
* dbuf is marked DB_EVICTING without being removed from
* dn_dbufs. To maintain the avl invariant that there cannot be
* duplicate entries, we order the dbufs by an arbitrary value -
* their address in memory. This means that dn_dbufs cannot be used to
* directly look up a dbuf. Instead, callers must use avl_walk, have
* a reference to the dbuf, or look up a non-existant node with
* db_state = DB_SEARCH (see dbuf_free_range for an example).
*/
avl_tree_t dn_dbufs;
/* protected by dn_struct_rwlock */
struct dmu_buf_impl *dn_bonus; /* bonus buffer dbuf */
boolean_t dn_have_spill; /* have spill or are spilling */
/* parent IO for current sync write */
zio_t *dn_zio;
/* used in syncing context */
uint64_t dn_oldused; /* old phys used bytes */
uint64_t dn_oldflags; /* old phys dn_flags */
uint64_t dn_olduid, dn_oldgid;
uint64_t dn_newuid, dn_newgid;
int dn_id_flags;
/* holds prefetch structure */
struct zfetch dn_zfetch;
} dnode_t;
/*
* Adds a level of indirection between the dbuf and the dnode to avoid
* iterating descendent dbufs in dnode_move(). Handles are not allocated
* individually, but as an array of child dnodes in dnode_hold_impl().
*/
typedef struct dnode_handle {
/* Protects dnh_dnode from modification by dnode_move(). */
zrlock_t dnh_zrlock;
dnode_t *dnh_dnode;
} dnode_handle_t;
typedef struct dnode_children {
dmu_buf_user_t dnc_dbu; /* User evict data */
size_t dnc_count; /* number of children */
dnode_handle_t dnc_children[]; /* sized dynamically */
} dnode_children_t;
typedef struct free_range {
avl_node_t fr_node;
uint64_t fr_blkid;
uint64_t fr_nblks;
} free_range_t;
void dnode_special_open(struct objset *dd, dnode_phys_t *dnp,
uint64_t object, dnode_handle_t *dnh);
void dnode_special_close(dnode_handle_t *dnh);
void dnode_setbonuslen(dnode_t *dn, int newsize, dmu_tx_t *tx);
void dnode_setbonus_type(dnode_t *dn, dmu_object_type_t, dmu_tx_t *tx);
void dnode_rm_spill(dnode_t *dn, dmu_tx_t *tx);
int dnode_hold(struct objset *dd, uint64_t object,
void *ref, dnode_t **dnp);
int dnode_hold_impl(struct objset *dd, uint64_t object, int flag, int dn_slots,
void *ref, dnode_t **dnp);
boolean_t dnode_add_ref(dnode_t *dn, void *ref);
void dnode_rele(dnode_t *dn, void *ref);
void dnode_rele_and_unlock(dnode_t *dn, void *tag);
void dnode_setdirty(dnode_t *dn, dmu_tx_t *tx);
void dnode_sync(dnode_t *dn, dmu_tx_t *tx);
void dnode_allocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, int ibs,
dmu_object_type_t bonustype, int bonuslen, int dn_slots, dmu_tx_t *tx);
void dnode_reallocate(dnode_t *dn, dmu_object_type_t ot, int blocksize,
dmu_object_type_t bonustype, int bonuslen, int dn_slots, dmu_tx_t *tx);
void dnode_free(dnode_t *dn, dmu_tx_t *tx);
void dnode_byteswap(dnode_phys_t *dnp);
void dnode_buf_byteswap(void *buf, size_t size);
void dnode_verify(dnode_t *dn);
int dnode_set_blksz(dnode_t *dn, uint64_t size, int ibs, dmu_tx_t *tx);
void dnode_free_range(dnode_t *dn, uint64_t off, uint64_t len, dmu_tx_t *tx);
void dnode_diduse_space(dnode_t *dn, int64_t space);
void dnode_willuse_space(dnode_t *dn, int64_t space, dmu_tx_t *tx);
void dnode_new_blkid(dnode_t *dn, uint64_t blkid, dmu_tx_t *tx, boolean_t);
uint64_t dnode_block_freed(dnode_t *dn, uint64_t blkid);
void dnode_init(void);
void dnode_fini(void);
int dnode_next_offset(dnode_t *dn, int flags, uint64_t *off,
int minlvl, uint64_t blkfill, uint64_t txg);
void dnode_evict_dbufs(dnode_t *dn);
void dnode_evict_bonus(dnode_t *dn);
#ifdef ZFS_DEBUG
/*
* There should be a ## between the string literal and fmt, to make it
* clear that we're joining two strings together, but that piece of shit
* gcc doesn't support that preprocessor token.
*/
#define dprintf_dnode(dn, fmt, ...) do { \
if (zfs_flags & ZFS_DEBUG_DPRINTF) { \
char __db_buf[32]; \
uint64_t __db_obj = (dn)->dn_object; \
if (__db_obj == DMU_META_DNODE_OBJECT) \
(void) strcpy(__db_buf, "mdn"); \
else \
(void) snprintf(__db_buf, sizeof (__db_buf), "%lld", \
(u_longlong_t)__db_obj);\
dprintf_ds((dn)->dn_objset->os_dsl_dataset, "obj=%s " fmt, \
__db_buf, __VA_ARGS__); \
} \
_NOTE(CONSTCOND) } while (0)
#define DNODE_VERIFY(dn) dnode_verify(dn)
#define FREE_VERIFY(db, start, end, tx) free_verify(db, start, end, tx)
#else
#define dprintf_dnode(db, fmt, ...)
#define DNODE_VERIFY(dn)
#define FREE_VERIFY(db, start, end, tx)
#endif
#ifdef __cplusplus
}
#endif
#endif /* _SYS_DNODE_H */