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      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 2007 Sun Microsystems, Inc.  All rights reserved.
     23  * Use is subject to license terms.
     24  */
     25 
     26 #ifndef _SYS_VDEV_IMPL_H
     27 #define	_SYS_VDEV_IMPL_H
     28 
     29 #pragma ident	"@(#)vdev_impl.h	1.19	07/11/27 SMI"
     30 
     31 #include <sys/avl.h>
     32 #include <sys/dmu.h>
     33 #include <sys/metaslab.h>
     34 #include <sys/nvpair.h>
     35 #include <sys/space_map.h>
     36 #include <sys/vdev.h>
     37 #include <sys/dkio.h>
     38 #include <sys/uberblock_impl.h>
     39 
     40 #ifdef	__cplusplus
     41 extern "C" {
     42 #endif
     43 
     44 /*
     45  * Virtual device descriptors.
     46  *
     47  * All storage pool operations go through the virtual device framework,
     48  * which provides data replication and I/O scheduling.
     49  */
     50 
     51 /*
     52  * Forward declarations that lots of things need.
     53  */
     54 typedef struct vdev_queue vdev_queue_t;
     55 typedef struct vdev_cache vdev_cache_t;
     56 typedef struct vdev_cache_entry vdev_cache_entry_t;
     57 
     58 /*
     59  * Virtual device operations
     60  */
     61 typedef int	vdev_open_func_t(vdev_t *vd, uint64_t *size, uint64_t *ashift);
     62 typedef void	vdev_close_func_t(vdev_t *vd);
     63 typedef int	vdev_probe_func_t(vdev_t *vd);
     64 typedef uint64_t vdev_asize_func_t(vdev_t *vd, uint64_t psize);
     65 typedef int	vdev_io_start_func_t(zio_t *zio);
     66 typedef int	vdev_io_done_func_t(zio_t *zio);
     67 typedef void	vdev_state_change_func_t(vdev_t *vd, int, int);
     68 
     69 typedef struct vdev_ops {
     70 	vdev_open_func_t		*vdev_op_open;
     71 	vdev_close_func_t		*vdev_op_close;
     72 	vdev_probe_func_t		*vdev_op_probe;
     73 	vdev_asize_func_t		*vdev_op_asize;
     74 	vdev_io_start_func_t		*vdev_op_io_start;
     75 	vdev_io_done_func_t		*vdev_op_io_done;
     76 	vdev_state_change_func_t	*vdev_op_state_change;
     77 	char				vdev_op_type[16];
     78 	boolean_t			vdev_op_leaf;
     79 } vdev_ops_t;
     80 
     81 /*
     82  * Virtual device properties
     83  */
     84 struct vdev_cache_entry {
     85 	char		*ve_data;
     86 	uint64_t	ve_offset;
     87 	uint64_t	ve_lastused;
     88 	avl_node_t	ve_offset_node;
     89 	avl_node_t	ve_lastused_node;
     90 	uint32_t	ve_hits;
     91 	uint16_t	ve_missed_update;
     92 	zio_t		*ve_fill_io;
     93 };
     94 
     95 struct vdev_cache {
     96 	avl_tree_t	vc_offset_tree;
     97 	avl_tree_t	vc_lastused_tree;
     98 	kmutex_t	vc_lock;
     99 };
    100 
    101 struct vdev_queue {
    102 	avl_tree_t	vq_deadline_tree;
    103 	avl_tree_t	vq_read_tree;
    104 	avl_tree_t	vq_write_tree;
    105 	avl_tree_t	vq_pending_tree;
    106 	kmutex_t	vq_lock;
    107 };
    108 
    109 /*
    110  * Virtual device descriptor
    111  */
    112 struct vdev {
    113 	/*
    114 	 * Common to all vdev types.
    115 	 */
    116 	uint64_t	vdev_id;	/* child number in vdev parent	*/
    117 	uint64_t	vdev_guid;	/* unique ID for this vdev	*/
    118 	uint64_t	vdev_guid_sum;	/* self guid + all child guids	*/
    119 	uint64_t	vdev_asize;	/* allocatable device capacity	*/
    120 	uint64_t	vdev_ashift;	/* block alignment shift	*/
    121 	uint64_t	vdev_state;	/* see VDEV_STATE_* #defines	*/
    122 	uint64_t	vdev_prevstate;	/* used when reopening a vdev	*/
    123 	vdev_ops_t	*vdev_ops;	/* vdev operations		*/
    124 	spa_t		*vdev_spa;	/* spa for this vdev		*/
    125 	void		*vdev_tsd;	/* type-specific data		*/
    126 	vdev_t		*vdev_top;	/* top-level vdev		*/
    127 	vdev_t		*vdev_parent;	/* parent vdev			*/
    128 	vdev_t		**vdev_child;	/* array of children		*/
    129 	uint64_t	vdev_children;	/* number of children		*/
    130 	space_map_t	vdev_dtl_map;	/* dirty time log in-core state	*/
    131 	space_map_t	vdev_dtl_scrub;	/* DTL for scrub repair writes	*/
    132 	vdev_stat_t	vdev_stat;	/* virtual device statistics	*/
    133 
    134 	/*
    135 	 * Top-level vdev state.
    136 	 */
    137 	uint64_t	vdev_ms_array;	/* metaslab array object	*/
    138 	uint64_t	vdev_ms_shift;	/* metaslab size shift		*/
    139 	uint64_t	vdev_ms_count;	/* number of metaslabs		*/
    140 	metaslab_group_t *vdev_mg;	/* metaslab group		*/
    141 	metaslab_t	**vdev_ms;	/* metaslab array		*/
    142 	txg_list_t	vdev_ms_list;	/* per-txg dirty metaslab lists	*/
    143 	txg_list_t	vdev_dtl_list;	/* per-txg dirty DTL lists	*/
    144 	txg_node_t	vdev_txg_node;	/* per-txg dirty vdev linkage	*/
    145 	boolean_t	vdev_remove_wanted; /* async remove wanted?	*/
    146 	list_node_t	vdev_dirty_node; /* config dirty list		*/
    147 	uint64_t	vdev_deflate_ratio; /* deflation ratio (x512)	*/
    148 	uint64_t	vdev_islog;	/* is an intent log device	*/
    149 
    150 	/*
    151 	 * Leaf vdev state.
    152 	 */
    153 	uint64_t	vdev_psize;	/* physical device capacity	*/
    154 	space_map_obj_t	vdev_dtl;	/* dirty time log on-disk state	*/
    155 	txg_node_t	vdev_dtl_node;	/* per-txg dirty DTL linkage	*/
    156 	uint64_t	vdev_wholedisk;	/* true if this is a whole disk */
    157 	uint64_t	vdev_offline;	/* persistent offline state	*/
    158 	uint64_t	vdev_faulted;	/* persistent faulted state	*/
    159 	uint64_t	vdev_degraded;	/* persistent degraded state	*/
    160 	uint64_t	vdev_removed;	/* persistent removed state	*/
    161 	uint64_t	vdev_nparity;	/* number of parity devices for raidz */
    162 	char		*vdev_path;	/* vdev path (if any)		*/
    163 	char		*vdev_devid;	/* vdev devid (if any)		*/
    164 	char		*vdev_physpath;	/* vdev device path (if any)	*/
    165 	uint64_t	vdev_fault_arg; /* fault injection paramater	*/
    166 	int		vdev_fault_mask; /* zio types to fault		*/
    167 	uint8_t		vdev_fault_mode; /* fault injection mode	*/
    168 	uint8_t		vdev_tmpoffline; /* device taken offline temporarily? */
    169 	uint8_t		vdev_detached;	/* device detached?		*/
    170 	uint64_t	vdev_isspare;	/* was a hot spare		*/
    171 	uint64_t	vdev_isl2cache;	/* was a l2cache device		*/
    172 	vdev_queue_t	vdev_queue;	/* I/O deadline schedule queue	*/
    173 	vdev_cache_t	vdev_cache;	/* physical block cache		*/
    174 	uint64_t	vdev_not_present; /* not present during import	*/
    175 	hrtime_t	vdev_last_try;	/* last reopen time		*/
    176 	boolean_t	vdev_nowritecache; /* true if flushwritecache failed */
    177 	uint64_t	vdev_unspare;	/* unspare when resilvering done */
    178 	boolean_t	vdev_checkremove; /* temporary online test	*/
    179 	boolean_t	vdev_forcefault; /* force online fault		*/
    180 	boolean_t	vdev_is_failing; /* device errors seen		*/
    181 
    182 	/*
    183 	 * For DTrace to work in userland (libzpool) context, these fields must
    184 	 * remain at the end of the structure.  DTrace will use the kernel's
    185 	 * CTF definition for 'struct vdev', and since the size of a kmutex_t is
    186 	 * larger in userland, the offsets for the rest fields would be
    187 	 * incorrect.
    188 	 */
    189 	kmutex_t	vdev_dtl_lock;	/* vdev_dtl_{map,resilver}	*/
    190 	kmutex_t	vdev_stat_lock;	/* vdev_stat			*/
    191 };
    192 
    193 #define	VDEV_SKIP_SIZE		(8 << 10)
    194 #define	VDEV_BOOT_HEADER_SIZE	(8 << 10)
    195 #define	VDEV_PHYS_SIZE		(112 << 10)
    196 #define	VDEV_UBERBLOCK_RING	(128 << 10)
    197 
    198 #define	VDEV_UBERBLOCK_SHIFT(vd)	\
    199 	MAX((vd)->vdev_top->vdev_ashift, UBERBLOCK_SHIFT)
    200 #define	VDEV_UBERBLOCK_COUNT(vd)	\
    201 	(VDEV_UBERBLOCK_RING >> VDEV_UBERBLOCK_SHIFT(vd))
    202 #define	VDEV_UBERBLOCK_OFFSET(vd, n)	\
    203 	offsetof(vdev_label_t, vl_uberblock[(n) << VDEV_UBERBLOCK_SHIFT(vd)])
    204 #define	VDEV_UBERBLOCK_SIZE(vd)		(1ULL << VDEV_UBERBLOCK_SHIFT(vd))
    205 
    206 /* ZFS boot block */
    207 #define	VDEV_BOOT_MAGIC		0x2f5b007b10cULL
    208 #define	VDEV_BOOT_VERSION	1		/* version number	*/
    209 
    210 typedef struct vdev_boot_header {
    211 	uint64_t	vb_magic;		/* VDEV_BOOT_MAGIC	*/
    212 	uint64_t	vb_version;		/* VDEV_BOOT_VERSION	*/
    213 	uint64_t	vb_offset;		/* start offset	(bytes) */
    214 	uint64_t	vb_size;		/* size (bytes)		*/
    215 	char		vb_pad[VDEV_BOOT_HEADER_SIZE - 4 * sizeof (uint64_t)];
    216 } vdev_boot_header_t;
    217 
    218 typedef struct vdev_phys {
    219 	char		vp_nvlist[VDEV_PHYS_SIZE - sizeof (zio_block_tail_t)];
    220 	zio_block_tail_t vp_zbt;
    221 } vdev_phys_t;
    222 
    223 typedef struct vdev_label {
    224 	char		vl_pad[VDEV_SKIP_SIZE];			/*   8K	*/
    225 	vdev_boot_header_t vl_boot_header;			/*   8K	*/
    226 	vdev_phys_t	vl_vdev_phys;				/* 112K	*/
    227 	char		vl_uberblock[VDEV_UBERBLOCK_RING];	/* 128K	*/
    228 } vdev_label_t;							/* 256K total */
    229 
    230 /*
    231  * vdev_dirty() flags
    232  */
    233 #define	VDD_METASLAB	0x01
    234 #define	VDD_DTL		0x02
    235 
    236 /*
    237  * Size and offset of embedded boot loader region on each label.
    238  * The total size of the first two labels plus the boot area is 4MB.
    239  */
    240 #define	VDEV_BOOT_OFFSET	(2 * sizeof (vdev_label_t))
    241 #define	VDEV_BOOT_SIZE		(7ULL << 19)			/* 3.5M	*/
    242 
    243 /*
    244  * Size of label regions at the start and end of each leaf device.
    245  */
    246 #define	VDEV_LABEL_START_SIZE	(2 * sizeof (vdev_label_t) + VDEV_BOOT_SIZE)
    247 #define	VDEV_LABEL_END_SIZE	(2 * sizeof (vdev_label_t))
    248 #define	VDEV_LABELS		4
    249 
    250 #define	VDEV_ALLOC_LOAD		0
    251 #define	VDEV_ALLOC_ADD		1
    252 #define	VDEV_ALLOC_SPARE	2
    253 #define	VDEV_ALLOC_L2CACHE	3
    254 
    255 /*
    256  * Allocate or free a vdev
    257  */
    258 extern int vdev_alloc(spa_t *spa, vdev_t **vdp, nvlist_t *config,
    259     vdev_t *parent, uint_t id, int alloctype);
    260 extern void vdev_free(vdev_t *vd);
    261 
    262 /*
    263  * Add or remove children and parents
    264  */
    265 extern void vdev_add_child(vdev_t *pvd, vdev_t *cvd);
    266 extern void vdev_remove_child(vdev_t *pvd, vdev_t *cvd);
    267 extern void vdev_compact_children(vdev_t *pvd);
    268 extern vdev_t *vdev_add_parent(vdev_t *cvd, vdev_ops_t *ops);
    269 extern void vdev_remove_parent(vdev_t *cvd);
    270 
    271 /*
    272  * vdev sync load and sync
    273  */
    274 extern void vdev_load(vdev_t *vd);
    275 extern void vdev_sync(vdev_t *vd, uint64_t txg);
    276 extern void vdev_sync_done(vdev_t *vd, uint64_t txg);
    277 extern void vdev_dirty(vdev_t *vd, int flags, void *arg, uint64_t txg);
    278 
    279 /*
    280  * Available vdev types.
    281  */
    282 extern vdev_ops_t vdev_root_ops;
    283 extern vdev_ops_t vdev_mirror_ops;
    284 extern vdev_ops_t vdev_replacing_ops;
    285 extern vdev_ops_t vdev_raidz_ops;
    286 extern vdev_ops_t vdev_disk_ops;
    287 extern vdev_ops_t vdev_file_ops;
    288 extern vdev_ops_t vdev_missing_ops;
    289 extern vdev_ops_t vdev_spare_ops;
    290 
    291 /*
    292  * Common size functions
    293  */
    294 extern uint64_t vdev_default_asize(vdev_t *vd, uint64_t psize);
    295 extern uint64_t vdev_get_rsize(vdev_t *vd);
    296 
    297 /*
    298  * zdb uses this tunable, so it must be declared here to make lint happy.
    299  */
    300 extern int zfs_vdev_cache_size;
    301 
    302 #ifdef	__cplusplus
    303 }
    304 #endif
    305 
    306 #endif	/* _SYS_VDEV_IMPL_H */
    307