Home | History | Annotate | Line # | Download | only in sys
      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 2010 Sun Microsystems, Inc.  All rights reserved.
     23  * Use is subject to license terms.
     24  */
     25 /*
     26  * Copyright (c) 2012, Joyent, Inc. All rights reserved.
     27  * Copyright (c) 2012, Martin Matuska <mm (at) FreeBSD.org>. All rights reserved.
     28  * Copyright (c) 2013, 2015 by Delphix. All rights reserved.
     29  */
     30 
     31 #ifndef _SYS_DMU_IMPL_H
     32 #define	_SYS_DMU_IMPL_H
     33 
     34 #include <sys/txg_impl.h>
     35 #include <sys/zio.h>
     36 #include <sys/dnode.h>
     37 #include <sys/kstat.h>
     38 #include <sys/zfs_context.h>
     39 #include <sys/zfs_ioctl.h>
     40 
     41 #ifdef	__cplusplus
     42 extern "C" {
     43 #endif
     44 
     45 /*
     46  * This is the locking strategy for the DMU.  Numbers in parenthesis are
     47  * cases that use that lock order, referenced below:
     48  *
     49  * ARC is self-contained
     50  * bplist is self-contained
     51  * refcount is self-contained
     52  * txg is self-contained (hopefully!)
     53  * zst_lock
     54  * zf_rwlock
     55  *
     56  * XXX try to improve evicting path?
     57  *
     58  * dp_config_rwlock > os_obj_lock > dn_struct_rwlock >
     59  * 	dn_dbufs_mtx > hash_mutexes > db_mtx > dd_lock > leafs
     60  *
     61  * dp_config_rwlock
     62  *    must be held before: everything
     63  *    protects dd namespace changes
     64  *    protects property changes globally
     65  *    held from:
     66  *    	dsl_dir_open/r:
     67  *    	dsl_dir_create_sync/w:
     68  *    	dsl_dir_sync_destroy/w:
     69  *    	dsl_dir_rename_sync/w:
     70  *    	dsl_prop_changed_notify/r:
     71  *
     72  * os_obj_lock
     73  *   must be held before:
     74  *   	everything except dp_config_rwlock
     75  *   protects os_obj_next
     76  *   held from:
     77  *   	dmu_object_alloc: dn_dbufs_mtx, db_mtx, hash_mutexes, dn_struct_rwlock
     78  *
     79  * dn_struct_rwlock
     80  *   must be held before:
     81  *   	everything except dp_config_rwlock and os_obj_lock
     82  *   protects structure of dnode (eg. nlevels)
     83  *   	db_blkptr can change when syncing out change to nlevels
     84  *   	dn_maxblkid
     85  *   	dn_nlevels
     86  *   	dn_*blksz*
     87  *   	phys nlevels, maxblkid, physical blkptr_t's (?)
     88  *   held from:
     89  *   	callers of dbuf_read_impl, dbuf_hold[_impl], dbuf_prefetch
     90  *   	dmu_object_info_from_dnode: dn_dirty_mtx (dn_datablksz)
     91  *   	dmu_tx_count_free:
     92  *   	dbuf_read_impl: db_mtx, dmu_zfetch()
     93  *   	dmu_zfetch: zf_rwlock/r, zst_lock, dbuf_prefetch()
     94  *   	dbuf_new_size: db_mtx
     95  *   	dbuf_dirty: db_mtx
     96  *	dbuf_findbp: (callers, phys? - the real need)
     97  *	dbuf_create: dn_dbufs_mtx, hash_mutexes, db_mtx (phys?)
     98  *	dbuf_prefetch: dn_dirty_mtx, hash_mutexes, db_mtx, dn_dbufs_mtx
     99  *	dbuf_hold_impl: hash_mutexes, db_mtx, dn_dbufs_mtx, dbuf_findbp()
    100  *	dnode_sync/w (increase_indirection): db_mtx (phys)
    101  *	dnode_set_blksz/w: dn_dbufs_mtx (dn_*blksz*)
    102  *	dnode_new_blkid/w: (dn_maxblkid)
    103  *	dnode_free_range/w: dn_dirty_mtx (dn_maxblkid)
    104  *	dnode_next_offset: (phys)
    105  *
    106  * dn_dbufs_mtx
    107  *    must be held before:
    108  *    	db_mtx, hash_mutexes
    109  *    protects:
    110  *    	dn_dbufs
    111  *    	dn_evicted
    112  *    held from:
    113  *    	dmu_evict_user: db_mtx (dn_dbufs)
    114  *    	dbuf_free_range: db_mtx (dn_dbufs)
    115  *    	dbuf_remove_ref: db_mtx, callees:
    116  *    		dbuf_hash_remove: hash_mutexes, db_mtx
    117  *    	dbuf_create: hash_mutexes, db_mtx (dn_dbufs)
    118  *    	dnode_set_blksz: (dn_dbufs)
    119  *
    120  * hash_mutexes (global)
    121  *   must be held before:
    122  *   	db_mtx
    123  *   protects dbuf_hash_table (global) and db_hash_next
    124  *   held from:
    125  *   	dbuf_find: db_mtx
    126  *   	dbuf_hash_insert: db_mtx
    127  *   	dbuf_hash_remove: db_mtx
    128  *
    129  * db_mtx (meta-leaf)
    130  *   must be held before:
    131  *   	dn_mtx, dn_dirty_mtx, dd_lock (leaf mutexes)
    132  *   protects:
    133  *   	db_state
    134  * 	db_holds
    135  * 	db_buf
    136  * 	db_changed
    137  * 	db_data_pending
    138  * 	db_dirtied
    139  * 	db_link
    140  * 	db_dirty_node (??)
    141  * 	db_dirtycnt
    142  * 	db_d.*
    143  * 	db.*
    144  *   held from:
    145  * 	dbuf_dirty: dn_mtx, dn_dirty_mtx
    146  * 	dbuf_dirty->dsl_dir_willuse_space: dd_lock
    147  * 	dbuf_dirty->dbuf_new_block->dsl_dataset_block_freeable: dd_lock
    148  * 	dbuf_undirty: dn_dirty_mtx (db_d)
    149  * 	dbuf_write_done: dn_dirty_mtx (db_state)
    150  * 	dbuf_*
    151  * 	dmu_buf_update_user: none (db_d)
    152  * 	dmu_evict_user: none (db_d) (maybe can eliminate)
    153  *   	dbuf_find: none (db_holds)
    154  *   	dbuf_hash_insert: none (db_holds)
    155  *   	dmu_buf_read_array_impl: none (db_state, db_changed)
    156  *   	dmu_sync: none (db_dirty_node, db_d)
    157  *   	dnode_reallocate: none (db)
    158  *
    159  * dn_mtx (leaf)
    160  *   protects:
    161  *   	dn_dirty_dbufs
    162  *   	dn_ranges
    163  *   	phys accounting
    164  * 	dn_allocated_txg
    165  * 	dn_free_txg
    166  * 	dn_assigned_txg
    167  * 	dd_assigned_tx
    168  * 	dn_notxholds
    169  * 	dn_dirtyctx
    170  * 	dn_dirtyctx_firstset
    171  * 	(dn_phys copy fields?)
    172  * 	(dn_phys contents?)
    173  *   held from:
    174  *   	dnode_*
    175  *   	dbuf_dirty: none
    176  *   	dbuf_sync: none (phys accounting)
    177  *   	dbuf_undirty: none (dn_ranges, dn_dirty_dbufs)
    178  *   	dbuf_write_done: none (phys accounting)
    179  *   	dmu_object_info_from_dnode: none (accounting)
    180  *   	dmu_tx_commit: none
    181  *   	dmu_tx_hold_object_impl: none
    182  *   	dmu_tx_try_assign: dn_notxholds(cv)
    183  *   	dmu_tx_unassign: none
    184  *
    185  * dd_lock
    186  *    must be held before:
    187  *      ds_lock
    188  *      ancestors' dd_lock
    189  *    protects:
    190  *    	dd_prop_cbs
    191  *    	dd_sync_*
    192  *    	dd_used_bytes
    193  *    	dd_tempreserved
    194  *    	dd_space_towrite
    195  *    	dd_myname
    196  *    	dd_phys accounting?
    197  *    held from:
    198  *    	dsl_dir_*
    199  *    	dsl_prop_changed_notify: none (dd_prop_cbs)
    200  *    	dsl_prop_register: none (dd_prop_cbs)
    201  *    	dsl_prop_unregister: none (dd_prop_cbs)
    202  *    	dsl_dataset_block_freeable: none (dd_sync_*)
    203  *
    204  * os_lock (leaf)
    205  *   protects:
    206  *   	os_dirty_dnodes
    207  *   	os_free_dnodes
    208  *   	os_dnodes
    209  *   	os_downgraded_dbufs
    210  *   	dn_dirtyblksz
    211  *   	dn_dirty_link
    212  *   held from:
    213  *   	dnode_create: none (os_dnodes)
    214  *   	dnode_destroy: none (os_dnodes)
    215  *   	dnode_setdirty: none (dn_dirtyblksz, os_*_dnodes)
    216  *   	dnode_free: none (dn_dirtyblksz, os_*_dnodes)
    217  *
    218  * ds_lock
    219  *    protects:
    220  *    	ds_objset
    221  *    	ds_open_refcount
    222  *    	ds_snapname
    223  *    	ds_phys accounting
    224  *	ds_phys userrefs zapobj
    225  *	ds_reserved
    226  *    held from:
    227  *    	dsl_dataset_*
    228  *
    229  * dr_mtx (leaf)
    230  *    protects:
    231  *	dr_children
    232  *    held from:
    233  *	dbuf_dirty
    234  *	dbuf_undirty
    235  *	dbuf_sync_indirect
    236  *	dnode_new_blkid
    237  */
    238 
    239 struct objset;
    240 struct dmu_pool;
    241 
    242 typedef struct dmu_xuio {
    243 	int next;
    244 	int cnt;
    245 	struct arc_buf **bufs;
    246 	iovec_t *iovp;
    247 } dmu_xuio_t;
    248 
    249 typedef struct xuio_stats {
    250 	/* loaned yet not returned arc_buf */
    251 	kstat_named_t xuiostat_onloan_rbuf;
    252 	kstat_named_t xuiostat_onloan_wbuf;
    253 	/* whether a copy is made when loaning out a read buffer */
    254 	kstat_named_t xuiostat_rbuf_copied;
    255 	kstat_named_t xuiostat_rbuf_nocopy;
    256 	/* whether a copy is made when assigning a write buffer */
    257 	kstat_named_t xuiostat_wbuf_copied;
    258 	kstat_named_t xuiostat_wbuf_nocopy;
    259 } xuio_stats_t;
    260 
    261 static xuio_stats_t xuio_stats = {
    262 	{ "onloan_read_buf",	KSTAT_DATA_UINT64 },
    263 	{ "onloan_write_buf",	KSTAT_DATA_UINT64 },
    264 	{ "read_buf_copied",	KSTAT_DATA_UINT64 },
    265 	{ "read_buf_nocopy",	KSTAT_DATA_UINT64 },
    266 	{ "write_buf_copied",	KSTAT_DATA_UINT64 },
    267 	{ "write_buf_nocopy",	KSTAT_DATA_UINT64 }
    268 };
    269 
    270 #define	XUIOSTAT_INCR(stat, val)	\
    271 	atomic_add_64(&xuio_stats.stat.value.ui64, (val))
    272 #define	XUIOSTAT_BUMP(stat)	XUIOSTAT_INCR(stat, 1)
    273 
    274 /*
    275  * The list of data whose inclusion in a send stream can be pending from
    276  * one call to backup_cb to another.  Multiple calls to dump_free() and
    277  * dump_freeobjects() can be aggregated into a single DRR_FREE or
    278  * DRR_FREEOBJECTS replay record.
    279  */
    280 typedef enum {
    281 	PENDING_NONE,
    282 	PENDING_FREE,
    283 	PENDING_FREEOBJECTS
    284 } dmu_pendop_t;
    285 
    286 typedef struct dmu_sendarg {
    287 	list_node_t dsa_link;
    288 	dmu_replay_record_t *dsa_drr;
    289 	kthread_t *dsa_td;
    290 	struct file *dsa_fp;
    291 	int dsa_outfd;
    292 	struct proc *dsa_proc;
    293 	offset_t *dsa_off;
    294 	objset_t *dsa_os;
    295 	zio_cksum_t dsa_zc;
    296 	uint64_t dsa_toguid;
    297 	int dsa_err;
    298 	dmu_pendop_t dsa_pending_op;
    299 	uint64_t dsa_featureflags;
    300 	uint64_t dsa_last_data_object;
    301 	uint64_t dsa_last_data_offset;
    302 	uint64_t dsa_resume_object;
    303 	uint64_t dsa_resume_offset;
    304 	boolean_t dsa_sent_begin;
    305 	boolean_t dsa_sent_end;
    306 } dmu_sendarg_t;
    307 
    308 void dmu_object_zapify(objset_t *, uint64_t, dmu_object_type_t, dmu_tx_t *);
    309 void dmu_object_free_zapified(objset_t *, uint64_t, dmu_tx_t *);
    310 int dmu_buf_hold_noread(objset_t *, uint64_t, uint64_t,
    311     void *, dmu_buf_t **);
    312 
    313 #ifdef	__cplusplus
    314 }
    315 #endif
    316 
    317 #endif	/* _SYS_DMU_IMPL_H */
    318