freebsd-dev/include/sys/dnode.h
Alexander Motin 755065f3dc OpenZFS 6322 - ZFS indirect block predictive prefetch
For quite some time I was thinking about possibility to prefetch
ZFS indirection tables while doing sequential reads or writes.
Recent changes in predictive prefetcher made that much easier to
do. My tests on zvol with 16KB block size on 5x striped and 2x
mirrored pool of 10 disks show almost double throughput on sequential
read, and almost tripple on sequential rewrite. While for read alike
effect can be received from increasing maximal prefetch distance
(though at higher memory cost), for rewrite there is no other
solution so far.

Authored by: Alexander Motin <mav@freebsd.org>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Paul Dagnelie <pcd@delphix.com>
Approved by: Robert Mustacchi <rm@joyent.com>
Ported-by: kernelOfTruth kerneloftruth@gmail.com
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>

OpenZFS-issue: https://www.illumos.org/issues/6322
OpenZFS-commit: https://github.com/illumos/illumos-gate/commit/cb92f413
Closes #5040

Porting notes:
- Change from upstream in module/zfs/dbuf.c in 'int dbuf_read' due
  to commit 5f6d0b6 'Handle block pointers with a corrupt logical size'

- Difference from upstream in module/zfs/dmu_zfetch.c,
  uint32_t zfetch_max_idistance -> unsigned int zfetch_max_idistance

- Variables have been initialized at the beginning of the function
 (void dmu_zfetch) to resemble the order of occurrence and account
 for C99, C11 mode errors.
2016-08-30 14:26:55 -07:00

398 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").
* 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) 2012, 2016 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 */
/*
* If we ever increase this value beyond 20, we need to revisit all logic that
* does x << level * ebps to handle overflow. With a 1M indirect block size,
* 4 levels of indirect blocks would not be able to guarantee addressing an
* entire object, so 5 levels will be used, but 5 * (20 - 7) = 65.
*/
#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))
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;
};
/*
* 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);
#define DNODE_IS_CACHEABLE(_dn) \
((_dn)->dn_objset->os_primary_cache == ZFS_CACHE_ALL || \
(DMU_OT_IS_METADATA((_dn)->dn_type) && \
(_dn)->dn_objset->os_primary_cache == ZFS_CACHE_METADATA))
#define DNODE_META_IS_CACHEABLE(_dn) \
((_dn)->dn_objset->os_primary_cache == ZFS_CACHE_ALL || \
(_dn)->dn_objset->os_primary_cache == ZFS_CACHE_METADATA)
#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 */