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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 2009 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 #include <sys/avl.h>
     30 #include <sys/dmu.h>
     31 #include <sys/metaslab.h>
     32 #include <sys/nvpair.h>
     33 #include <sys/space_map.h>
     34 #include <sys/vdev.h>
     35 #include <sys/dkio.h>
     36 #include <sys/uberblock_impl.h>
     37 
     38 #ifdef	__cplusplus
     39 extern "C" {
     40 #endif
     41 
     42 /*
     43  * Virtual device descriptors.
     44  *
     45  * All storage pool operations go through the virtual device framework,
     46  * which provides data replication and I/O scheduling.
     47  */
     48 
     49 /*
     50  * Forward declarations that lots of things need.
     51  */
     52 typedef struct vdev_queue vdev_queue_t;
     53 typedef struct vdev_cache vdev_cache_t;
     54 typedef struct vdev_cache_entry vdev_cache_entry_t;
     55 
     56 /*
     57  * Virtual device operations
     58  */
     59 typedef int	vdev_open_func_t(vdev_t *vd, uint64_t *size, uint64_t *ashift);
     60 typedef void	vdev_close_func_t(vdev_t *vd);
     61 typedef uint64_t vdev_asize_func_t(vdev_t *vd, uint64_t psize);
     62 typedef int	vdev_io_start_func_t(zio_t *zio);
     63 typedef void	vdev_io_done_func_t(zio_t *zio);
     64 typedef void	vdev_state_change_func_t(vdev_t *vd, int, int);
     65 
     66 typedef struct vdev_ops {
     67 	vdev_open_func_t		*vdev_op_open;
     68 	vdev_close_func_t		*vdev_op_close;
     69 	vdev_asize_func_t		*vdev_op_asize;
     70 	vdev_io_start_func_t		*vdev_op_io_start;
     71 	vdev_io_done_func_t		*vdev_op_io_done;
     72 	vdev_state_change_func_t	*vdev_op_state_change;
     73 	char				vdev_op_type[16];
     74 	boolean_t			vdev_op_leaf;
     75 } vdev_ops_t;
     76 
     77 /*
     78  * Virtual device properties
     79  */
     80 struct vdev_cache_entry {
     81 	char		*ve_data;
     82 	uint64_t	ve_offset;
     83 	uint64_t	ve_lastused;
     84 	avl_node_t	ve_offset_node;
     85 	avl_node_t	ve_lastused_node;
     86 	uint32_t	ve_hits;
     87 	uint16_t	ve_missed_update;
     88 	zio_t		*ve_fill_io;
     89 };
     90 
     91 struct vdev_cache {
     92 	avl_tree_t	vc_offset_tree;
     93 	avl_tree_t	vc_lastused_tree;
     94 	kmutex_t	vc_lock;
     95 };
     96 
     97 struct vdev_queue {
     98 	avl_tree_t	vq_deadline_tree;
     99 	avl_tree_t	vq_read_tree;
    100 	avl_tree_t	vq_write_tree;
    101 	avl_tree_t	vq_pending_tree;
    102 	kmutex_t	vq_lock;
    103 };
    104 
    105 /*
    106  * Virtual device descriptor
    107  */
    108 struct vdev {
    109 	/*
    110 	 * Common to all vdev types.
    111 	 */
    112 	uint64_t	vdev_id;	/* child number in vdev parent	*/
    113 	uint64_t	vdev_guid;	/* unique ID for this vdev	*/
    114 	uint64_t	vdev_guid_sum;	/* self guid + all child guids	*/
    115 	uint64_t	vdev_asize;	/* allocatable device capacity	*/
    116 	uint64_t	vdev_min_asize;	/* min acceptable asize		*/
    117 	uint64_t	vdev_ashift;	/* block alignment shift	*/
    118 	uint64_t	vdev_state;	/* see VDEV_STATE_* #defines	*/
    119 	uint64_t	vdev_prevstate;	/* used when reopening a vdev	*/
    120 	vdev_ops_t	*vdev_ops;	/* vdev operations		*/
    121 	spa_t		*vdev_spa;	/* spa for this vdev		*/
    122 	void		*vdev_tsd;	/* type-specific data		*/
    123 	vdev_t		*vdev_top;	/* top-level vdev		*/
    124 	vdev_t		*vdev_parent;	/* parent vdev			*/
    125 	vdev_t		**vdev_child;	/* array of children		*/
    126 	uint64_t	vdev_children;	/* number of children		*/
    127 	space_map_t	vdev_dtl[DTL_TYPES]; /* in-core dirty time logs	*/
    128 	vdev_stat_t	vdev_stat;	/* virtual device statistics	*/
    129 	boolean_t	vdev_expanding;	/* expand the vdev?		*/
    130 	boolean_t	vdev_reopening;	/* reopen in progress?		*/
    131 	int		vdev_open_error; /* error on last open		*/
    132 	kthread_t	*vdev_open_thread; /* thread opening children	*/
    133 	uint64_t	vdev_crtxg;	/* txg when top-level was added */
    134 
    135 	/*
    136 	 * Top-level vdev state.
    137 	 */
    138 	uint64_t	vdev_ms_array;	/* metaslab array object	*/
    139 	uint64_t	vdev_ms_shift;	/* metaslab size shift		*/
    140 	uint64_t	vdev_ms_count;	/* number of metaslabs		*/
    141 	metaslab_group_t *vdev_mg;	/* metaslab group		*/
    142 	metaslab_t	**vdev_ms;	/* metaslab array		*/
    143 	txg_list_t	vdev_ms_list;	/* per-txg dirty metaslab lists	*/
    144 	txg_list_t	vdev_dtl_list;	/* per-txg dirty DTL lists	*/
    145 	txg_node_t	vdev_txg_node;	/* per-txg dirty vdev linkage	*/
    146 	boolean_t	vdev_remove_wanted; /* async remove wanted?	*/
    147 	boolean_t	vdev_probe_wanted; /* async probe wanted?	*/
    148 	boolean_t	vdev_removing;	/* device is being removed?	*/
    149 	list_node_t	vdev_config_dirty_node; /* config dirty list	*/
    150 	list_node_t	vdev_state_dirty_node; /* state dirty list	*/
    151 	uint64_t	vdev_deflate_ratio; /* deflation ratio (x512)	*/
    152 	uint64_t	vdev_islog;	/* is an intent log device	*/
    153 	uint64_t	vdev_ishole;	/* is a hole in the namespace 	*/
    154 
    155 	/*
    156 	 * Leaf vdev state.
    157 	 */
    158 	uint64_t	vdev_psize;	/* physical device capacity	*/
    159 	space_map_obj_t	vdev_dtl_smo;	/* dirty time log space map obj	*/
    160 	txg_node_t	vdev_dtl_node;	/* per-txg dirty DTL linkage	*/
    161 	uint64_t	vdev_wholedisk;	/* true if this is a whole disk */
    162 	uint64_t	vdev_offline;	/* persistent offline state	*/
    163 	uint64_t	vdev_faulted;	/* persistent faulted state	*/
    164 	uint64_t	vdev_degraded;	/* persistent degraded state	*/
    165 	uint64_t	vdev_removed;	/* persistent removed state	*/
    166 	uint64_t	vdev_nparity;	/* number of parity devices for raidz */
    167 	char		*vdev_path;	/* vdev path (if any)		*/
    168 	char		*vdev_devid;	/* vdev devid (if any)		*/
    169 	char		*vdev_physpath;	/* vdev device path (if any)	*/
    170 	char		*vdev_fru;	/* physical FRU location	*/
    171 	uint64_t	vdev_not_present; /* not present during import	*/
    172 	uint64_t	vdev_unspare;	/* unspare when resilvering done */
    173 	hrtime_t	vdev_last_try;	/* last reopen time		*/
    174 	boolean_t	vdev_nowritecache; /* true if flushwritecache failed */
    175 	boolean_t	vdev_checkremove; /* temporary online test	*/
    176 	boolean_t	vdev_forcefault; /* force online fault		*/
    177 	uint8_t		vdev_tmpoffline; /* device taken offline temporarily? */
    178 	uint8_t		vdev_detached;	/* device detached?		*/
    179 	uint8_t		vdev_cant_read;	/* vdev is failing all reads	*/
    180 	uint8_t		vdev_cant_write; /* vdev is failing all writes	*/
    181 	uint64_t	vdev_isspare;	/* was a hot spare		*/
    182 	uint64_t	vdev_isl2cache;	/* was a l2cache device		*/
    183 	vdev_queue_t	vdev_queue;	/* I/O deadline schedule queue	*/
    184 	vdev_cache_t	vdev_cache;	/* physical block cache		*/
    185 	spa_aux_vdev_t	*vdev_aux;	/* for l2cache vdevs		*/
    186 	zio_t		*vdev_probe_zio; /* root of current probe	*/
    187 	vdev_aux_t	vdev_label_aux;	/* on-disk aux state		*/
    188 
    189 	/*
    190 	 * For DTrace to work in userland (libzpool) context, these fields must
    191 	 * remain at the end of the structure.  DTrace will use the kernel's
    192 	 * CTF definition for 'struct vdev', and since the size of a kmutex_t is
    193 	 * larger in userland, the offsets for the rest fields would be
    194 	 * incorrect.
    195 	 */
    196 	kmutex_t	vdev_dtl_lock;	/* vdev_dtl_{map,resilver}	*/
    197 	kmutex_t	vdev_stat_lock;	/* vdev_stat			*/
    198 	kmutex_t	vdev_probe_lock; /* protects vdev_probe_zio	*/
    199 };
    200 
    201 #define	VDEV_RAIDZ_MAXPARITY	3
    202 
    203 #define	VDEV_PAD_SIZE		(8 << 10)
    204 /* 2 padding areas (vl_pad1 and vl_pad2) to skip */
    205 #define	VDEV_SKIP_SIZE		VDEV_PAD_SIZE * 2
    206 #define	VDEV_PHYS_SIZE		(112 << 10)
    207 #define	VDEV_UBERBLOCK_RING	(128 << 10)
    208 
    209 #define	VDEV_UBERBLOCK_SHIFT(vd)	\
    210 	MAX((vd)->vdev_top->vdev_ashift, UBERBLOCK_SHIFT)
    211 #define	VDEV_UBERBLOCK_COUNT(vd)	\
    212 	(VDEV_UBERBLOCK_RING >> VDEV_UBERBLOCK_SHIFT(vd))
    213 #define	VDEV_UBERBLOCK_OFFSET(vd, n)	\
    214 	offsetof(vdev_label_t, vl_uberblock[(n) << VDEV_UBERBLOCK_SHIFT(vd)])
    215 #define	VDEV_UBERBLOCK_SIZE(vd)		(1ULL << VDEV_UBERBLOCK_SHIFT(vd))
    216 
    217 typedef struct vdev_phys {
    218 	char		vp_nvlist[VDEV_PHYS_SIZE - sizeof (zio_block_tail_t)];
    219 	zio_block_tail_t vp_zbt;
    220 } vdev_phys_t;
    221 
    222 typedef struct vdev_label {
    223 	char		vl_pad1[VDEV_PAD_SIZE];			/*  8K */
    224 	char		vl_pad2[VDEV_PAD_SIZE];			/*  8K */
    225 	vdev_phys_t	vl_vdev_phys;				/* 112K	*/
    226 	char		vl_uberblock[VDEV_UBERBLOCK_RING];	/* 128K	*/
    227 } vdev_label_t;							/* 256K total */
    228 
    229 /*
    230  * vdev_dirty() flags
    231  */
    232 #define	VDD_METASLAB	0x01
    233 #define	VDD_DTL		0x02
    234 
    235 /*
    236  * Size and offset of embedded boot loader region on each label.
    237  * The total size of the first two labels plus the boot area is 4MB.
    238  */
    239 #define	VDEV_BOOT_OFFSET	(2 * sizeof (vdev_label_t))
    240 #define	VDEV_BOOT_SIZE		(7ULL << 19)			/* 3.5M	*/
    241 
    242 /*
    243  * Size of label regions at the start and end of each leaf device.
    244  */
    245 #define	VDEV_LABEL_START_SIZE	(2 * sizeof (vdev_label_t) + VDEV_BOOT_SIZE)
    246 #define	VDEV_LABEL_END_SIZE	(2 * sizeof (vdev_label_t))
    247 #define	VDEV_LABELS		4
    248 
    249 #define	VDEV_ALLOC_LOAD		0
    250 #define	VDEV_ALLOC_ADD		1
    251 #define	VDEV_ALLOC_SPARE	2
    252 #define	VDEV_ALLOC_L2CACHE	3
    253 #define	VDEV_ALLOC_ROOTPOOL	4
    254 
    255 /*
    256  * Allocate or free a vdev
    257  */
    258 extern vdev_t *vdev_alloc_common(spa_t *spa, uint_t id, uint64_t guid,
    259     vdev_ops_t *ops);
    260 extern int vdev_alloc(spa_t *spa, vdev_t **vdp, nvlist_t *config,
    261     vdev_t *parent, uint_t id, int alloctype);
    262 extern void vdev_free(vdev_t *vd);
    263 
    264 /*
    265  * Add or remove children and parents
    266  */
    267 extern void vdev_add_child(vdev_t *pvd, vdev_t *cvd);
    268 extern void vdev_remove_child(vdev_t *pvd, vdev_t *cvd);
    269 extern void vdev_compact_children(vdev_t *pvd);
    270 extern vdev_t *vdev_add_parent(vdev_t *cvd, vdev_ops_t *ops);
    271 extern void vdev_remove_parent(vdev_t *cvd);
    272 
    273 /*
    274  * vdev sync load and sync
    275  */
    276 extern void vdev_load_log_state(vdev_t *nvd, vdev_t *ovd);
    277 extern void vdev_load(vdev_t *vd);
    278 extern void vdev_sync(vdev_t *vd, uint64_t txg);
    279 extern void vdev_sync_done(vdev_t *vd, uint64_t txg);
    280 extern void vdev_dirty(vdev_t *vd, int flags, void *arg, uint64_t txg);
    281 
    282 /*
    283  * Available vdev types.
    284  */
    285 extern vdev_ops_t vdev_root_ops;
    286 extern vdev_ops_t vdev_mirror_ops;
    287 extern vdev_ops_t vdev_replacing_ops;
    288 extern vdev_ops_t vdev_raidz_ops;
    289 extern vdev_ops_t vdev_disk_ops;
    290 extern vdev_ops_t vdev_file_ops;
    291 extern vdev_ops_t vdev_missing_ops;
    292 extern vdev_ops_t vdev_hole_ops;
    293 extern vdev_ops_t vdev_spare_ops;
    294 
    295 /*
    296  * Common size functions
    297  */
    298 extern uint64_t vdev_default_asize(vdev_t *vd, uint64_t psize);
    299 extern uint64_t vdev_get_min_asize(vdev_t *vd);
    300 extern void vdev_set_min_asize(vdev_t *vd);
    301 
    302 /*
    303  * zdb uses this tunable, so it must be declared here to make lint happy.
    304  */
    305 extern int zfs_vdev_cache_size;
    306 
    307 #ifdef	__cplusplus
    308 }
    309 #endif
    310 
    311 #endif	/* _SYS_VDEV_IMPL_H */
    312