kernel/fs/zfs/sys/zil_impl.h

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
  23  * Copyright (c) 2012, 2017 by Delphix. All rights reserved.
  24  * Copyright (c) 2014 Integros [integros.com]
  25  */
  26
  27 /* Portions Copyright 2010 Robert Milkowski */
  28
  29 #ifndef _SYS_ZIL_IMPL_H
  30 #define _SYS_ZIL_IMPL_H
  31
  32 #include <sys/zil.h>
  33 #include <sys/dmu_objset.h>
  34
  35 #ifdef  __cplusplus
  36 extern "C" {
  37 #endif
  38
  39 /*
  40  * Possbile states for a given lwb structure. An lwb will start out in
  41  * the "closed" state, and then transition to the "opened" state via a
  42  * call to zil_lwb_write_open(). After the lwb is "open", it can
  43  * transition into the "issued" state via zil_lwb_write_issue(). After
  44  * the lwb's zio completes, and the vdev's are flushed, the lwb will
  45  * transition into the "done" state via zil_lwb_write_done(), and the
  46  * structure eventually freed.
  47  */
  48 typedef enum {
  49     LWB_STATE_CLOSED,
  50     LWB_STATE_OPENED,
  51     LWB_STATE_ISSUED,
  52     LWB_STATE_DONE,
  53     LWB_NUM_STATES
  54 } lwb_state_t;
  55
  56 /*
  57  * Log write block (lwb)
  58  *
  59  * Prior to an lwb being issued to disk via zil_lwb_write_issue(), it
  60  * will be protected by the zilog's "zl_writer_lock". Basically, prior
  61  * to it being issued, it will only be accessed by the thread that's
  62  * holding the "zl_writer_lock". After the lwb is issued, the zilog's
  63  * "zl_lock" is used to protect the lwb against concurrent access.
  64  */
  65 typedef struct lwb {
  66         zilog_t         *lwb_zilog;     /* back pointer to log struct */
  67         blkptr_t        lwb_blk;        /* on disk address of this log blk */
  68         boolean_t       lwb_slog;       /* lwb_blk is on SLOG device */
  69         int             lwb_nused;      /* # used bytes in buffer */
  70         int             lwb_sz;         /* size of block and buffer */
  71         lwb_state_t     lwb_state;      /* the state of this lwb */
  72         char            *lwb_buf;       /* log write buffer */
  73         zio_t           *lwb_write_zio; /* zio for the lwb buffer */
  74         zio_t           *lwb_root_zio;  /* root zio for lwb write and flushes */
  75         dmu_tx_t        *lwb_tx;        /* tx for log block allocation */
  76         uint64_t        lwb_max_txg;    /* highest txg in this lwb */
  77         list_node_t     lwb_node;       /* zilog->zl_lwb_list linkage */
  78         list_t          lwb_waiters;    /* list of zil_commit_waiter's */
  79         avl_tree_t      lwb_vdev_tree;  /* vdevs to flush after lwb write */
  80         kmutex_t        lwb_vdev_lock;  /* protects lwb_vdev_tree */
  81         hrtime_t        lwb_issued_timestamp; /* when was the lwb issued? */
  82 } lwb_t;
  83
  84 /*
  85  * ZIL commit waiter.
  86  *
  87  * This structure is allocated each time zil_commit() is called, and is
  88  * used by zil_commit() to communicate with other parts of the ZIL, such
  89  * that zil_commit() can know when it safe for it return. For more
  90  * details, see the comment above zil_commit().
  91  *
  92  * The "zcw_lock" field is used to protect the commit waiter against
  93  * concurrent access. This lock is often acquired while already holding
  94  * the zilog's "zl_writer_lock" or "zl_lock"; see the functions
  95  * zil_process_commit_list() and zil_lwb_flush_vdevs_done() as examples
  96  * of this. Thus, one must be careful not to acquire the
  97  * "zl_writer_lock" or "zl_lock" when already holding the "zcw_lock";
  98  * e.g. see the zil_commit_waiter_timeout() function.
  99  */
 100 typedef struct zil_commit_waiter {
 101         kcondvar_t      zcw_cv;         /* signalled when "done" */
 102         kmutex_t        zcw_lock;       /* protects fields of this struct */
 103         list_node_t     zcw_node;       /* linkage in lwb_t:lwb_waiter list */
 104         lwb_t           *zcw_lwb;       /* back pointer to lwb when linked */
 105         boolean_t       zcw_done;       /* B_TRUE when "done", else B_FALSE */
 106         int             zcw_zio_error;  /* contains the zio io_error value */
 107 } zil_commit_waiter_t;
 108
 109 /*
 110  * Intent log transaction lists
 111  */
 112 typedef struct itxs {
 113         list_t          i_sync_list;    /* list of synchronous itxs */
 114         avl_tree_t      i_async_tree;   /* tree of foids for async itxs */
 115 } itxs_t;
 116
 117 typedef struct itxg {
 118         kmutex_t        itxg_lock;      /* lock for this structure */
 119         uint64_t        itxg_txg;       /* txg for this chain */
 120         itxs_t          *itxg_itxs;     /* sync and async itxs */
 121 } itxg_t;
 122
 123 /* for async nodes we build up an AVL tree of lists of async itxs per file */
 124 typedef struct itx_async_node {
 125         uint64_t        ia_foid;        /* file object id */
 126         list_t          ia_list;        /* list of async itxs for this foid */
 127         avl_node_t      ia_node;        /* AVL tree linkage */
 128 } itx_async_node_t;
 129
 130 /*
 131  * Vdev flushing: during a zil_commit(), we build up an AVL tree of the vdevs
 132  * we've touched so we know which ones need a write cache flush at the end.
 133  */
 134 typedef struct zil_vdev_node {
 135         uint64_t        zv_vdev;        /* vdev to be flushed */
 136         avl_node_t      zv_node;        /* AVL tree linkage */
 137 } zil_vdev_node_t;
 138
 139 #define ZIL_PREV_BLKS 16
 140
 141 /*
 142  * Stable storage intent log management structure.  One per dataset.
 143  */
 144 struct zilog {
 145         kmutex_t        zl_lock;        /* protects most zilog_t fields */
 146         struct dsl_pool *zl_dmu_pool;   /* DSL pool */
 147         spa_t           *zl_spa;        /* handle for read/write log */
 148         const zil_header_t *zl_header;  /* log header buffer */
 149         objset_t        *zl_os;         /* object set we're logging */
 150         zil_get_data_t  *zl_get_data;   /* callback to get object content */
 151         lwb_t           *zl_last_lwb_opened; /* most recent lwb opened */
 152         hrtime_t        zl_last_lwb_latency; /* zio latency of last lwb done */
 153         uint64_t        zl_lr_seq;      /* on-disk log record sequence number */
 154         uint64_t        zl_commit_lr_seq; /* last committed on-disk lr seq */
 155         uint64_t        zl_destroy_txg; /* txg of last zil_destroy() */
 156         uint64_t        zl_replayed_seq[TXG_SIZE]; /* last replayed rec seq */
 157         uint64_t        zl_replaying_seq; /* current replay seq number */
 158         uint32_t        zl_suspend;     /* log suspend count */
 159         kcondvar_t      zl_cv_suspend;  /* log suspend completion */
 160         uint8_t         zl_suspending;  /* log is currently suspending */
 161         uint8_t         zl_keep_first;  /* keep first log block in destroy */
 162         uint8_t         zl_replay;      /* replaying records while set */
 163         uint8_t         zl_stop_sync;   /* for debugging */
 164         kmutex_t        zl_writer_lock; /* single writer, per ZIL, at a time */
 165         uint8_t         zl_logbias;     /* latency or throughput */
 166         uint8_t         zl_sync;        /* synchronous or asynchronous */
 167         int             zl_parse_error; /* last zil_parse() error */
 168         uint64_t        zl_parse_blk_seq; /* highest blk seq on last parse */
 169         uint64_t        zl_parse_lr_seq; /* highest lr seq on last parse */
 170         uint64_t        zl_parse_blk_count; /* number of blocks parsed */
 171         uint64_t        zl_parse_lr_count; /* number of log records parsed */
 172         itxg_t          zl_itxg[TXG_SIZE]; /* intent log txg chains */
 173         list_t          zl_itx_commit_list; /* itx list to be committed */
 174         uint64_t        zl_cur_used;    /* current commit log size used */
 175         list_t          zl_lwb_list;    /* in-flight log write list */
 176         avl_tree_t      zl_bp_tree;     /* track bps during log parse */
 177         clock_t         zl_replay_time; /* lbolt of when replay started */
 178         uint64_t        zl_replay_blks; /* number of log blocks replayed */
 179         zil_header_t    zl_old_header;  /* debugging aid */
 180         uint_t          zl_prev_blks[ZIL_PREV_BLKS]; /* size - sector rounded */
 181         uint_t          zl_prev_rotor;  /* rotor for zl_prev[] */
 182         txg_node_t      zl_dirty_link;  /* protected by dp_dirty_zilogs list */
 183         uint64_t        zl_dirty_max_txg; /* highest txg used to dirty zilog */
 184 };
 185
 186 typedef struct zil_bp_node {
 187         dva_t           zn_dva;
 188         avl_node_t      zn_node;
 189 } zil_bp_node_t;
 190
 191 /*
 192  * Maximum amount of write data that can be put into single log block.
 193  */
 194 #define ZIL_MAX_LOG_DATA (SPA_OLD_MAXBLOCKSIZE - sizeof (zil_chain_t) - \
 195     sizeof (lr_write_t))
 196
 197 /*
 198  * Maximum amount of log space we agree to waste to reduce number of
 199  * WR_NEED_COPY chunks to reduce zl_get_data() overhead (~12%).
 200  */
 201 #define ZIL_MAX_WASTE_SPACE (ZIL_MAX_LOG_DATA / 8)
 202
 203 /*
 204  * Maximum amount of write data for WR_COPIED.  Fall back to WR_NEED_COPY
 205  * as more space efficient if we can't fit at least two log records into
 206  * maximum sized log block.
 207  */
 208 #define ZIL_MAX_COPIED_DATA ((SPA_OLD_MAXBLOCKSIZE - \
 209     sizeof (zil_chain_t)) / 2 - sizeof (lr_write_t))
 210
 211 #ifdef  __cplusplus
 212 }
 213 #endif
 214
 215 #endif  /* _SYS_ZIL_IMPL_H */