xref: /illumos-gate/usr/src/uts/common/fs/zfs/sys/vdev_impl.h (revision d6bb6a8465e557cb946ef49d56ed3202f6218652)
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 2006 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	"%Z%%M%	%I%	%E% 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 uint64_t vdev_asize_func_t(vdev_t *vd, uint64_t psize);
64 typedef void	vdev_io_start_func_t(zio_t *zio);
65 typedef void	vdev_io_done_func_t(zio_t *zio);
66 typedef void	vdev_state_change_func_t(vdev_t *vd, int, int);
67 
68 typedef struct vdev_ops {
69 	vdev_open_func_t		*vdev_op_open;
70 	vdev_close_func_t		*vdev_op_close;
71 	vdev_asize_func_t		*vdev_op_asize;
72 	vdev_io_start_func_t		*vdev_op_io_start;
73 	vdev_io_done_func_t		*vdev_op_io_done;
74 	vdev_state_change_func_t	*vdev_op_state_change;
75 	char				vdev_op_type[16];
76 	boolean_t			vdev_op_leaf;
77 } vdev_ops_t;
78 
79 /*
80  * Virtual device properties
81  */
82 struct vdev_cache_entry {
83 	char		*ve_data;
84 	uint64_t	ve_offset;
85 	uint64_t	ve_lastused;
86 	avl_node_t	ve_offset_node;
87 	avl_node_t	ve_lastused_node;
88 	uint32_t	ve_hits;
89 	uint16_t	ve_missed_update;
90 	zio_t		*ve_fill_io;
91 };
92 
93 struct vdev_cache {
94 	uint64_t	vc_size;
95 	uint64_t	vc_bshift;
96 	uint64_t	vc_blocksize;
97 	uint64_t	vc_max;
98 	avl_tree_t	vc_offset_tree;
99 	avl_tree_t	vc_lastused_tree;
100 	kmutex_t	vc_lock;
101 };
102 
103 struct vdev_queue {
104 	uint64_t	vq_min_pending;
105 	uint64_t	vq_max_pending;
106 	uint64_t	vq_scrub_limit;
107 	uint64_t	vq_agg_limit;
108 	uint64_t	vq_time_shift;
109 	uint64_t	vq_ramp_rate;
110 	uint64_t	vq_scrub_count;
111 	avl_tree_t	vq_deadline_tree;
112 	avl_tree_t	vq_read_tree;
113 	avl_tree_t	vq_write_tree;
114 	avl_tree_t	vq_pending_tree;
115 	kmutex_t	vq_lock;
116 };
117 
118 /*
119  * Virtual device descriptor
120  */
121 struct vdev {
122 	/*
123 	 * Common to all vdev types.
124 	 */
125 	uint64_t	vdev_id;	/* child number in vdev parent	*/
126 	uint64_t	vdev_guid;	/* unique ID for this vdev	*/
127 	uint64_t	vdev_guid_sum;	/* self guid + all child guids	*/
128 	uint64_t	vdev_asize;	/* allocatable device capacity	*/
129 	uint64_t	vdev_ashift;	/* block alignment shift	*/
130 	uint64_t	vdev_state;	/* see VDEV_STATE_* #defines	*/
131 	vdev_ops_t	*vdev_ops;	/* vdev operations		*/
132 	spa_t		*vdev_spa;	/* spa for this vdev		*/
133 	void		*vdev_tsd;	/* type-specific data		*/
134 	vdev_t		*vdev_top;	/* top-level vdev		*/
135 	vdev_t		*vdev_parent;	/* parent vdev			*/
136 	vdev_t		**vdev_child;	/* array of children		*/
137 	uint64_t	vdev_children;	/* number of children		*/
138 	space_map_t	vdev_dtl_map;	/* dirty time log in-core state	*/
139 	space_map_t	vdev_dtl_scrub;	/* DTL for scrub repair writes	*/
140 	vdev_stat_t	vdev_stat;	/* virtual device statistics	*/
141 
142 	/*
143 	 * Top-level vdev state.
144 	 */
145 	uint64_t	vdev_ms_array;	/* metaslab array object	*/
146 	uint64_t	vdev_ms_shift;	/* metaslab size shift		*/
147 	uint64_t	vdev_ms_count;	/* number of metaslabs		*/
148 	metaslab_group_t *vdev_mg;	/* metaslab group		*/
149 	metaslab_t	**vdev_ms;	/* metaslab array		*/
150 	space_map_obj_t	*vdev_smo;	/* metaslab space map array	*/
151 	txg_list_t	vdev_ms_list;	/* per-txg dirty metaslab lists	*/
152 	txg_list_t	vdev_dtl_list;	/* per-txg dirty DTL lists	*/
153 	txg_node_t	vdev_txg_node;	/* per-txg dirty vdev linkage	*/
154 	uint8_t		vdev_dirty[TXG_SIZE]; /* per-txg dirty flags	*/
155 	uint8_t		vdev_is_dirty;	/* on config dirty list?	*/
156 	uint8_t		vdev_reopen_wanted; /* async reopen wanted?	*/
157 	list_node_t	vdev_dirty_node; /* config dirty list		*/
158 
159 	/*
160 	 * Leaf vdev state.
161 	 */
162 	uint64_t	vdev_psize;	/* physical device capacity	*/
163 	space_map_obj_t	vdev_dtl;	/* dirty time log on-disk state	*/
164 	txg_node_t	vdev_dtl_node;	/* per-txg dirty DTL linkage	*/
165 	uint64_t	vdev_wholedisk;	/* true if this is a whole disk */
166 	char		*vdev_path;	/* vdev path (if any)		*/
167 	char		*vdev_devid;	/* vdev devid (if any)		*/
168 	uint64_t	vdev_fault_arg; /* fault injection paramater	*/
169 	int		vdev_fault_mask; /* zio types to fault		*/
170 	uint8_t		vdev_fault_mode; /* fault injection mode	*/
171 	uint8_t		vdev_cache_active; /* vdev_cache and vdev_queue	*/
172 	uint8_t		vdev_offline;	/* device taken offline?	*/
173 	uint8_t		vdev_tmpoffline; /* device taken offline temporarily? */
174 	uint8_t		vdev_detached;	/* device detached?		*/
175 	vdev_queue_t	vdev_queue;	/* I/O deadline schedule queue	*/
176 	vdev_cache_t	vdev_cache;	/* physical block cache		*/
177 	uint64_t	vdev_not_present; /* not present during import	*/
178 	hrtime_t	vdev_last_try;	/* last reopen time		*/
179 
180 	/*
181 	 * For DTrace to work in userland (libzpool) context, these fields must
182 	 * remain at the end of the structure.  DTrace will use the kernel's
183 	 * CTF definition for 'struct vdev', and since the size of a kmutex_t is
184 	 * larger in userland, the offsets for the rest fields would be
185 	 * incorrect.
186 	 */
187 	kmutex_t	vdev_dtl_lock;	/* vdev_dtl_{map,resilver}	*/
188 	kmutex_t	vdev_dirty_lock; /* vdev_dirty[]		*/
189 	kmutex_t	vdev_stat_lock;	/* vdev_stat			*/
190 };
191 
192 #define	VDEV_SKIP_SIZE		(8 << 10)
193 #define	VDEV_BOOT_HEADER_SIZE	(8 << 10)
194 #define	VDEV_PHYS_SIZE		(112 << 10)
195 #define	VDEV_UBERBLOCKS		((128 << 10) >> UBERBLOCK_SHIFT)
196 
197 #define	VDEV_BOOT_MAGIC		0x2f5b007b10c	/* ZFS boot block	*/
198 #define	VDEV_BOOT_VERSION	1		/* version number	*/
199 
200 typedef struct vdev_boot_header {
201 	uint64_t	vb_magic;		/* VDEV_BOOT_MAGIC	*/
202 	uint64_t	vb_version;		/* VDEV_BOOT_VERSION	*/
203 	uint64_t	vb_offset;		/* start offset	(bytes) */
204 	uint64_t	vb_size;		/* size (bytes)		*/
205 	char		vb_pad[VDEV_BOOT_HEADER_SIZE - 4 * sizeof (uint64_t)];
206 } vdev_boot_header_t;
207 
208 typedef struct vdev_phys {
209 	char		vp_nvlist[VDEV_PHYS_SIZE - sizeof (zio_block_tail_t)];
210 	zio_block_tail_t vp_zbt;
211 } vdev_phys_t;
212 
213 typedef struct vdev_label {
214 	char			vl_pad[VDEV_SKIP_SIZE];		/*   8K	*/
215 	vdev_boot_header_t	vl_boot_header;			/*   8K	*/
216 	vdev_phys_t		vl_vdev_phys;			/* 112K	*/
217 	uberblock_phys_t	vl_uberblock[VDEV_UBERBLOCKS];	/* 128K	*/
218 } vdev_label_t;							/* 256K total */
219 
220 /*
221  * Size and offset of embedded boot loader region on each label.
222  * The total size of the first two labels plus the boot area is 4MB.
223  */
224 #define	VDEV_BOOT_OFFSET	(2 * sizeof (vdev_label_t))
225 #define	VDEV_BOOT_SIZE		(7ULL << 19)			/* 3.5M	*/
226 
227 /*
228  * vdev_dirty[] flags
229  */
230 #define	VDD_ALLOC	0x01	/* allocated from in this txg		*/
231 #define	VDD_FREE	0x02	/* freed to in this txg			*/
232 #define	VDD_ADD		0x04	/* added to the pool in this txg	*/
233 #define	VDD_DTL		0x08	/* dirty time log entry in this txg	*/
234 
235 /*
236  * Size of label regions at the start and end of each leaf device.
237  */
238 #define	VDEV_LABEL_START_SIZE	(2 * sizeof (vdev_label_t) + VDEV_BOOT_SIZE)
239 #define	VDEV_LABEL_END_SIZE	(2 * sizeof (vdev_label_t))
240 #define	VDEV_LABELS		4
241 
242 #define	VDEV_ALLOC_LOAD		0
243 #define	VDEV_ALLOC_ADD		1
244 
245 /*
246  * Allocate or free a vdev
247  */
248 extern vdev_t *vdev_alloc(spa_t *spa, nvlist_t *config, vdev_t *parent,
249     uint_t id, int alloctype);
250 extern void vdev_free(vdev_t *vd);
251 
252 /*
253  * Add or remove children and parents
254  */
255 extern void vdev_add_child(vdev_t *pvd, vdev_t *cvd);
256 extern void vdev_remove_child(vdev_t *pvd, vdev_t *cvd);
257 extern void vdev_compact_children(vdev_t *pvd);
258 extern vdev_t *vdev_add_parent(vdev_t *cvd, vdev_ops_t *ops);
259 extern void vdev_remove_parent(vdev_t *cvd);
260 
261 /*
262  * vdev sync load and sync
263  */
264 extern int vdev_load(vdev_t *vd);
265 extern void vdev_sync(vdev_t *vd, uint64_t txg);
266 extern void vdev_sync_done(vdev_t *vd, uint64_t txg);
267 extern void vdev_dirty(vdev_t *vd, uint8_t flags, uint64_t txg);
268 
269 /*
270  * Available vdev types.
271  */
272 extern vdev_ops_t vdev_root_ops;
273 extern vdev_ops_t vdev_mirror_ops;
274 extern vdev_ops_t vdev_replacing_ops;
275 extern vdev_ops_t vdev_raidz_ops;
276 extern vdev_ops_t vdev_disk_ops;
277 extern vdev_ops_t vdev_file_ops;
278 extern vdev_ops_t vdev_missing_ops;
279 
280 /*
281  * Common size functions
282  */
283 extern uint64_t vdev_default_asize(vdev_t *vd, uint64_t psize);
284 extern uint64_t vdev_get_rsize(vdev_t *vd);
285 
286 #ifdef	__cplusplus
287 }
288 #endif
289 
290 #endif	/* _SYS_VDEV_IMPL_H */
291