freebsd-nq/include/sys/zil.h
Giuseppe Di Natale 1b7c1e5ce9 OpenZFS 7578 - Fix/improve some aspects of ZIL writing
- After some ZIL changes 6 years ago zil_slog_limit got partially broken
due to zl_itx_list_sz not updated when async itx'es upgraded to sync.
Actually because of other changes about that time zl_itx_list_sz is not
really required to implement the functionality, so this patch removes
some unneeded broken code and variables.

 - Original idea of zil_slog_limit was to reduce chance of SLOG abuse by
single heavy logger, that increased latency for other (more latency critical)
loggers, by pushing heavy log out into the main pool instead of SLOG.  Beside
huge latency increase for heavy writers, this implementation caused double
write of all data, since the log records were explicitly prepared for SLOG.
Since we now have I/O scheduler, I've found it can be much more efficient
to reduce priority of heavy logger SLOG writes from ZIO_PRIORITY_SYNC_WRITE
to ZIO_PRIORITY_ASYNC_WRITE, while still leave them on SLOG.

 - Existing ZIL implementation had problem with space efficiency when it
has to write large chunks of data into log blocks of limited size.  In some
cases efficiency stopped to almost as low as 50%.  In case of ZIL stored on
spinning rust, that also reduced log write speed in half, since head had to
uselessly fly over allocated but not written areas.  This change improves
the situation by offloading problematic operations from z*_log_write() to
zil_lwb_commit(), which knows real situation of log blocks allocation and
can split large requests into pieces much more efficiently.  Also as side
effect it removes one of two data copy operations done by ZIL code WR_COPIED
case.

 - While there, untangle and unify code of z*_log_write() functions.
Also zfs_log_write() alike to zvol_log_write() can now handle writes crossing
block boundary, that may also improve efficiency if ZPL is made to do that.

Sponsored by:   iXsystems, Inc.

Authored by: Alexander Motin <mav@FreeBSD.org>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: Andriy Gapon <avg@FreeBSD.org>
Reviewed by: Steven Hartland <steven.hartland@multiplay.co.uk>
Reviewed by: Brad Lewis <brad.lewis@delphix.com>
Reviewed by: Richard Elling <Richard.Elling@RichardElling.com>
Approved by: Robert Mustacchi <rm@joyent.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Richard Yao <ryao@gentoo.org>
Ported-by: Giuseppe Di Natale <dinatale2@llnl.gov>

OpenZFS-issue: https://www.illumos.org/issues/7578
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/aeb13ac
Closes #6191
2017-06-09 09:15:37 -07:00

517 lines
18 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, 2017 by Delphix. All rights reserved.
*/
/* Portions Copyright 2010 Robert Milkowski */
#ifndef _SYS_ZIL_H
#define _SYS_ZIL_H
#include <sys/types.h>
#include <sys/spa.h>
#include <sys/zio.h>
#include <sys/dmu.h>
#ifdef __cplusplus
extern "C" {
#endif
struct dsl_pool;
struct dsl_dataset;
/*
* Intent log format:
*
* Each objset has its own intent log. The log header (zil_header_t)
* for objset N's intent log is kept in the Nth object of the SPA's
* intent_log objset. The log header points to a chain of log blocks,
* each of which contains log records (i.e., transactions) followed by
* a log block trailer (zil_trailer_t). The format of a log record
* depends on the record (or transaction) type, but all records begin
* with a common structure that defines the type, length, and txg.
*/
/*
* Intent log header - this on disk structure holds fields to manage
* the log. All fields are 64 bit to easily handle cross architectures.
*/
typedef struct zil_header {
uint64_t zh_claim_txg; /* txg in which log blocks were claimed */
uint64_t zh_replay_seq; /* highest replayed sequence number */
blkptr_t zh_log; /* log chain */
uint64_t zh_claim_blk_seq; /* highest claimed block sequence number */
uint64_t zh_flags; /* header flags */
uint64_t zh_claim_lr_seq; /* highest claimed lr sequence number */
uint64_t zh_pad[3];
} zil_header_t;
/*
* zh_flags bit settings
*/
#define ZIL_REPLAY_NEEDED 0x1 /* replay needed - internal only */
#define ZIL_CLAIM_LR_SEQ_VALID 0x2 /* zh_claim_lr_seq field is valid */
/*
* Log block chaining.
*
* Log blocks are chained together. Originally they were chained at the
* end of the block. For performance reasons the chain was moved to the
* beginning of the block which allows writes for only the data being used.
* The older position is supported for backwards compatability.
*
* The zio_eck_t contains a zec_cksum which for the intent log is
* the sequence number of this log block. A seq of 0 is invalid.
* The zec_cksum is checked by the SPA against the sequence
* number passed in the blk_cksum field of the blkptr_t
*/
typedef struct zil_chain {
uint64_t zc_pad;
blkptr_t zc_next_blk; /* next block in chain */
uint64_t zc_nused; /* bytes in log block used */
zio_eck_t zc_eck; /* block trailer */
} zil_chain_t;
#define ZIL_MIN_BLKSZ 4096ULL
/*
* 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)
/*
* The words of a log block checksum.
*/
#define ZIL_ZC_GUID_0 0
#define ZIL_ZC_GUID_1 1
#define ZIL_ZC_OBJSET 2
#define ZIL_ZC_SEQ 3
typedef enum zil_create {
Z_FILE,
Z_DIR,
Z_XATTRDIR,
} zil_create_t;
/*
* size of xvattr log section.
* its composed of lr_attr_t + xvattr bitmap + 2 64 bit timestamps
* for create time and a single 64 bit integer for all of the attributes,
* and 4 64 bit integers (32 bytes) for the scanstamp.
*
*/
#define ZIL_XVAT_SIZE(mapsize) \
sizeof (lr_attr_t) + (sizeof (uint32_t) * (mapsize - 1)) + \
(sizeof (uint64_t) * 7)
/*
* Size of ACL in log. The ACE data is padded out to properly align
* on 8 byte boundary.
*/
#define ZIL_ACE_LENGTH(x) (roundup(x, sizeof (uint64_t)))
/*
* Intent log transaction types and record structures
*/
#define TX_CREATE 1 /* Create file */
#define TX_MKDIR 2 /* Make directory */
#define TX_MKXATTR 3 /* Make XATTR directory */
#define TX_SYMLINK 4 /* Create symbolic link to a file */
#define TX_REMOVE 5 /* Remove file */
#define TX_RMDIR 6 /* Remove directory */
#define TX_LINK 7 /* Create hard link to a file */
#define TX_RENAME 8 /* Rename a file */
#define TX_WRITE 9 /* File write */
#define TX_TRUNCATE 10 /* Truncate a file */
#define TX_SETATTR 11 /* Set file attributes */
#define TX_ACL_V0 12 /* Set old formatted ACL */
#define TX_ACL 13 /* Set ACL */
#define TX_CREATE_ACL 14 /* create with ACL */
#define TX_CREATE_ATTR 15 /* create + attrs */
#define TX_CREATE_ACL_ATTR 16 /* create with ACL + attrs */
#define TX_MKDIR_ACL 17 /* mkdir with ACL */
#define TX_MKDIR_ATTR 18 /* mkdir with attr */
#define TX_MKDIR_ACL_ATTR 19 /* mkdir with ACL + attrs */
#define TX_WRITE2 20 /* dmu_sync EALREADY write */
#define TX_MAX_TYPE 21 /* Max transaction type */
/*
* The transactions for mkdir, symlink, remove, rmdir, link, and rename
* may have the following bit set, indicating the original request
* specified case-insensitive handling of names.
*/
#define TX_CI ((uint64_t)0x1 << 63) /* case-insensitive behavior requested */
/*
* Transactions for write, truncate, setattr, acl_v0, and acl can be logged
* out of order. For convenience in the code, all such records must have
* lr_foid at the same offset.
*/
#define TX_OOO(txtype) \
((txtype) == TX_WRITE || \
(txtype) == TX_TRUNCATE || \
(txtype) == TX_SETATTR || \
(txtype) == TX_ACL_V0 || \
(txtype) == TX_ACL || \
(txtype) == TX_WRITE2)
/*
* The number of dnode slots consumed by the object is stored in the 8
* unused upper bits of the object ID. We subtract 1 from the value
* stored on disk for compatibility with implementations that don't
* support large dnodes. The slot count for a single-slot dnode will
* contain 0 for those bits to preserve the log record format for
* "small" dnodes.
*/
#define LR_FOID_GET_SLOTS(oid) (BF64_GET((oid), 56, 8) + 1)
#define LR_FOID_SET_SLOTS(oid, x) BF64_SET((oid), 56, 8, (x) - 1)
#define LR_FOID_GET_OBJ(oid) BF64_GET((oid), 0, DN_MAX_OBJECT_SHIFT)
#define LR_FOID_SET_OBJ(oid, x) BF64_SET((oid), 0, DN_MAX_OBJECT_SHIFT, (x))
/*
* Format of log records.
* The fields are carefully defined to allow them to be aligned
* and sized the same on sparc & intel architectures.
* Each log record has a common structure at the beginning.
*
* The log record on disk (lrc_seq) holds the sequence number of all log
* records which is used to ensure we don't replay the same record.
*/
typedef struct { /* common log record header */
uint64_t lrc_txtype; /* intent log transaction type */
uint64_t lrc_reclen; /* transaction record length */
uint64_t lrc_txg; /* dmu transaction group number */
uint64_t lrc_seq; /* see comment above */
} lr_t;
/*
* Common start of all out-of-order record types (TX_OOO() above).
*/
typedef struct {
lr_t lr_common; /* common portion of log record */
uint64_t lr_foid; /* object id */
} lr_ooo_t;
/*
* Handle option extended vattr attributes.
*
* Whenever new attributes are added the version number
* will need to be updated as will code in
* zfs_log.c and zfs_replay.c
*/
typedef struct {
uint32_t lr_attr_masksize; /* number of elements in array */
uint32_t lr_attr_bitmap; /* First entry of array */
/* remainder of array and any additional fields */
} lr_attr_t;
/*
* log record for creates without optional ACL.
* This log record does support optional xvattr_t attributes.
*/
typedef struct {
lr_t lr_common; /* common portion of log record */
uint64_t lr_doid; /* object id of directory */
uint64_t lr_foid; /* object id of created file object */
uint64_t lr_mode; /* mode of object */
uint64_t lr_uid; /* uid of object */
uint64_t lr_gid; /* gid of object */
uint64_t lr_gen; /* generation (txg of creation) */
uint64_t lr_crtime[2]; /* creation time */
uint64_t lr_rdev; /* rdev of object to create */
/* name of object to create follows this */
/* for symlinks, link content follows name */
/* for creates with xvattr data, the name follows the xvattr info */
} lr_create_t;
/*
* FUID ACL record will be an array of ACEs from the original ACL.
* If this array includes ephemeral IDs, the record will also include
* an array of log-specific FUIDs to replace the ephemeral IDs.
* Only one copy of each unique domain will be present, so the log-specific
* FUIDs will use an index into a compressed domain table. On replay this
* information will be used to construct real FUIDs (and bypass idmap,
* since it may not be available).
*/
/*
* Log record for creates with optional ACL
* This log record is also used for recording any FUID
* information needed for replaying the create. If the
* file doesn't have any actual ACEs then the lr_aclcnt
* would be zero.
*
* After lr_acl_flags, there are a lr_acl_bytes number of variable sized ace's.
* If create is also setting xvattr's, then acl data follows xvattr.
* If ACE FUIDs are needed then they will follow the xvattr_t. Following
* the FUIDs will be the domain table information. The FUIDs for the owner
* and group will be in lr_create. Name follows ACL data.
*/
typedef struct {
lr_create_t lr_create; /* common create portion */
uint64_t lr_aclcnt; /* number of ACEs in ACL */
uint64_t lr_domcnt; /* number of unique domains */
uint64_t lr_fuidcnt; /* number of real fuids */
uint64_t lr_acl_bytes; /* number of bytes in ACL */
uint64_t lr_acl_flags; /* ACL flags */
} lr_acl_create_t;
typedef struct {
lr_t lr_common; /* common portion of log record */
uint64_t lr_doid; /* obj id of directory */
/* name of object to remove follows this */
} lr_remove_t;
typedef struct {
lr_t lr_common; /* common portion of log record */
uint64_t lr_doid; /* obj id of directory */
uint64_t lr_link_obj; /* obj id of link */
/* name of object to link follows this */
} lr_link_t;
typedef struct {
lr_t lr_common; /* common portion of log record */
uint64_t lr_sdoid; /* obj id of source directory */
uint64_t lr_tdoid; /* obj id of target directory */
/* 2 strings: names of source and destination follow this */
} lr_rename_t;
typedef struct {
lr_t lr_common; /* common portion of log record */
uint64_t lr_foid; /* file object to write */
uint64_t lr_offset; /* offset to write to */
uint64_t lr_length; /* user data length to write */
uint64_t lr_blkoff; /* no longer used */
blkptr_t lr_blkptr; /* spa block pointer for replay */
/* write data will follow for small writes */
} lr_write_t;
typedef struct {
lr_t lr_common; /* common portion of log record */
uint64_t lr_foid; /* object id of file to truncate */
uint64_t lr_offset; /* offset to truncate from */
uint64_t lr_length; /* length to truncate */
} lr_truncate_t;
typedef struct {
lr_t lr_common; /* common portion of log record */
uint64_t lr_foid; /* file object to change attributes */
uint64_t lr_mask; /* mask of attributes to set */
uint64_t lr_mode; /* mode to set */
uint64_t lr_uid; /* uid to set */
uint64_t lr_gid; /* gid to set */
uint64_t lr_size; /* size to set */
uint64_t lr_atime[2]; /* access time */
uint64_t lr_mtime[2]; /* modification time */
/* optional attribute lr_attr_t may be here */
} lr_setattr_t;
typedef struct {
lr_t lr_common; /* common portion of log record */
uint64_t lr_foid; /* obj id of file */
uint64_t lr_aclcnt; /* number of acl entries */
/* lr_aclcnt number of ace_t entries follow this */
} lr_acl_v0_t;
typedef struct {
lr_t lr_common; /* common portion of log record */
uint64_t lr_foid; /* obj id of file */
uint64_t lr_aclcnt; /* number of ACEs in ACL */
uint64_t lr_domcnt; /* number of unique domains */
uint64_t lr_fuidcnt; /* number of real fuids */
uint64_t lr_acl_bytes; /* number of bytes in ACL */
uint64_t lr_acl_flags; /* ACL flags */
/* lr_acl_bytes number of variable sized ace's follows */
} lr_acl_t;
/*
* ZIL structure definitions, interface function prototype and globals.
*/
/*
* Writes are handled in three different ways:
*
* WR_INDIRECT:
* In this mode, if we need to commit the write later, then the block
* is immediately written into the file system (using dmu_sync),
* and a pointer to the block is put into the log record.
* When the txg commits the block is linked in.
* This saves additionally writing the data into the log record.
* There are a few requirements for this to occur:
* - write is greater than zfs/zvol_immediate_write_sz
* - not using slogs (as slogs are assumed to always be faster
* than writing into the main pool)
* - the write occupies only one block
* WR_COPIED:
* If we know we'll immediately be committing the
* transaction (FSYNC or FDSYNC), then we allocate a larger
* log record here for the data and copy the data in.
* WR_NEED_COPY:
* Otherwise we don't allocate a buffer, and *if* we need to
* flush the write later then a buffer is allocated and
* we retrieve the data using the dmu.
*/
typedef enum {
WR_INDIRECT, /* indirect - a large write (dmu_sync() data */
/* and put blkptr in log, rather than actual data) */
WR_COPIED, /* immediate - data is copied into lr_write_t */
WR_NEED_COPY, /* immediate - data needs to be copied if pushed */
WR_NUM_STATES /* number of states */
} itx_wr_state_t;
typedef void (*zil_callback_t)(void *data);
typedef struct itx {
list_node_t itx_node; /* linkage on zl_itx_list */
void *itx_private; /* type-specific opaque data */
itx_wr_state_t itx_wr_state; /* write state */
uint8_t itx_sync; /* synchronous transaction */
zil_callback_t itx_callback; /* Called when the itx is persistent */
void *itx_callback_data; /* User data for the callback */
uint64_t itx_oid; /* object id */
lr_t itx_lr; /* common part of log record */
/* followed by type-specific part of lr_xx_t and its immediate data */
} itx_t;
/*
* Used for zil kstat.
*/
typedef struct zil_stats {
/*
* Number of times a ZIL commit (e.g. fsync) has been requested.
*/
kstat_named_t zil_commit_count;
/*
* Number of times the ZIL has been flushed to stable storage.
* This is less than zil_commit_count when commits are "merged"
* (see the documentation above zil_commit()).
*/
kstat_named_t zil_commit_writer_count;
/*
* Number of transactions (reads, writes, renames, etc.)
* that have been commited.
*/
kstat_named_t zil_itx_count;
/*
* See the documentation for itx_wr_state_t above.
* Note that "bytes" accumulates the length of the transactions
* (i.e. data), not the actual log record sizes.
*/
kstat_named_t zil_itx_indirect_count;
kstat_named_t zil_itx_indirect_bytes;
kstat_named_t zil_itx_copied_count;
kstat_named_t zil_itx_copied_bytes;
kstat_named_t zil_itx_needcopy_count;
kstat_named_t zil_itx_needcopy_bytes;
/*
* Transactions which have been allocated to the "normal"
* (i.e. not slog) storage pool. Note that "bytes" accumulate
* the actual log record sizes - which do not include the actual
* data in case of indirect writes.
*/
kstat_named_t zil_itx_metaslab_normal_count;
kstat_named_t zil_itx_metaslab_normal_bytes;
/*
* Transactions which have been allocated to the "slog" storage pool.
* If there are no separate log devices, this is the same as the
* "normal" pool.
*/
kstat_named_t zil_itx_metaslab_slog_count;
kstat_named_t zil_itx_metaslab_slog_bytes;
} zil_stats_t;
extern zil_stats_t zil_stats;
#define ZIL_STAT_INCR(stat, val) \
atomic_add_64(&zil_stats.stat.value.ui64, (val));
#define ZIL_STAT_BUMP(stat) \
ZIL_STAT_INCR(stat, 1);
typedef int zil_parse_blk_func_t(zilog_t *zilog, blkptr_t *bp, void *arg,
uint64_t txg);
typedef int zil_parse_lr_func_t(zilog_t *zilog, lr_t *lr, void *arg,
uint64_t txg);
typedef int (*const zil_replay_func_t)(void *, char *, boolean_t);
typedef int zil_get_data_t(void *arg, lr_write_t *lr, char *dbuf, zio_t *zio);
extern 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);
extern void zil_init(void);
extern void zil_fini(void);
extern zilog_t *zil_alloc(objset_t *os, zil_header_t *zh_phys);
extern void zil_free(zilog_t *zilog);
extern zilog_t *zil_open(objset_t *os, zil_get_data_t *get_data);
extern void zil_close(zilog_t *zilog);
extern void zil_replay(objset_t *os, void *arg,
zil_replay_func_t replay_func[TX_MAX_TYPE]);
extern boolean_t zil_replaying(zilog_t *zilog, dmu_tx_t *tx);
extern void zil_destroy(zilog_t *zilog, boolean_t keep_first);
extern void zil_destroy_sync(zilog_t *zilog, dmu_tx_t *tx);
extern itx_t *zil_itx_create(uint64_t txtype, size_t lrsize);
extern void zil_itx_destroy(itx_t *itx);
extern void zil_itx_assign(zilog_t *zilog, itx_t *itx, dmu_tx_t *tx);
extern void zil_commit(zilog_t *zilog, uint64_t oid);
extern int zil_vdev_offline(const char *osname, void *txarg);
extern int zil_claim(struct dsl_pool *dp,
struct dsl_dataset *ds, void *txarg);
extern int zil_check_log_chain(struct dsl_pool *dp,
struct dsl_dataset *ds, void *tx);
extern void zil_sync(zilog_t *zilog, dmu_tx_t *tx);
extern void zil_clean(zilog_t *zilog, uint64_t synced_txg);
extern int zil_suspend(const char *osname, void **cookiep);
extern void zil_resume(void *cookie);
extern void zil_add_block(zilog_t *zilog, const blkptr_t *bp);
extern int zil_bp_tree_add(zilog_t *zilog, const blkptr_t *bp);
extern void zil_set_sync(zilog_t *zilog, uint64_t syncval);
extern void zil_set_logbias(zilog_t *zilog, uint64_t slogval);
extern int zil_replay_disable;
#ifdef __cplusplus
}
#endif
#endif /* _SYS_ZIL_H */