xref: /illumos-gate/usr/src/uts/common/fs/zfs/sys/vdev_impl.h (revision 35551380472894a564e057962b701af78f719377)
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, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #ifndef _SYS_VDEV_IMPL_H
28 #define	_SYS_VDEV_IMPL_H
29 
30 #pragma ident	"%Z%%M%	%I%	%E% SMI"
31 
32 #include <sys/avl.h>
33 #include <sys/dmu.h>
34 #include <sys/metaslab.h>
35 #include <sys/nvpair.h>
36 #include <sys/space_map.h>
37 #include <sys/vdev.h>
38 #include <sys/dkio.h>
39 #include <sys/uberblock_impl.h>
40 
41 #ifdef	__cplusplus
42 extern "C" {
43 #endif
44 
45 /*
46  * Virtual device descriptors.
47  *
48  * All storage pool operations go through the virtual device framework,
49  * which provides data replication and I/O scheduling.
50  */
51 
52 /*
53  * Forward declarations that lots of things need.
54  */
55 typedef struct vdev_queue vdev_queue_t;
56 typedef struct vdev_cache vdev_cache_t;
57 typedef struct vdev_cache_entry vdev_cache_entry_t;
58 
59 /*
60  * Virtual device operations
61  */
62 typedef int	vdev_open_func_t(vdev_t *vd, uint64_t *size, uint64_t *ashift);
63 typedef void	vdev_close_func_t(vdev_t *vd);
64 typedef uint64_t vdev_asize_func_t(vdev_t *vd, uint64_t psize);
65 typedef void	vdev_io_start_func_t(zio_t *zio);
66 typedef void	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_asize_func_t		*vdev_op_asize;
73 	vdev_io_start_func_t		*vdev_op_io_start;
74 	vdev_io_done_func_t		*vdev_op_io_done;
75 	vdev_state_change_func_t	*vdev_op_state_change;
76 	char				vdev_op_type[16];
77 	boolean_t			vdev_op_leaf;
78 } vdev_ops_t;
79 
80 /*
81  * Virtual device properties
82  */
83 struct vdev_cache_entry {
84 	char		*ve_data;
85 	uint64_t	ve_offset;
86 	uint64_t	ve_lastused;
87 	avl_node_t	ve_offset_node;
88 	avl_node_t	ve_lastused_node;
89 	uint32_t	ve_hits;
90 	uint16_t	ve_missed_update;
91 	zio_t		*ve_fill_io;
92 };
93 
94 struct vdev_cache {
95 	uint64_t	vc_size;
96 	uint64_t	vc_bshift;
97 	uint64_t	vc_blocksize;
98 	uint64_t	vc_max;
99 	avl_tree_t	vc_offset_tree;
100 	avl_tree_t	vc_lastused_tree;
101 	kmutex_t	vc_lock;
102 };
103 
104 struct vdev_queue {
105 	uint64_t	vq_min_pending;
106 	uint64_t	vq_max_pending;
107 	uint64_t	vq_agg_limit;
108 	uint64_t	vq_time_shift;
109 	uint64_t	vq_ramp_rate;
110 	avl_tree_t	vq_deadline_tree;
111 	avl_tree_t	vq_read_tree;
112 	avl_tree_t	vq_write_tree;
113 	avl_tree_t	vq_pending_tree;
114 	kmutex_t	vq_lock;
115 };
116 
117 /*
118  * Virtual device descriptor
119  */
120 struct vdev {
121 	/*
122 	 * Common to all vdev types.
123 	 */
124 	uint64_t	vdev_id;	/* child number in vdev parent	*/
125 	uint64_t	vdev_guid;	/* unique ID for this vdev	*/
126 	uint64_t	vdev_guid_sum;	/* self guid + all child guids	*/
127 	uint64_t	vdev_asize;	/* allocatable device capacity	*/
128 	uint64_t	vdev_ashift;	/* block alignment shift	*/
129 	uint64_t	vdev_state;	/* see VDEV_STATE_* #defines	*/
130 	vdev_ops_t	*vdev_ops;	/* vdev operations		*/
131 	spa_t		*vdev_spa;	/* spa for this vdev		*/
132 	void		*vdev_tsd;	/* type-specific data		*/
133 	vdev_t		*vdev_top;	/* top-level vdev		*/
134 	vdev_t		*vdev_parent;	/* parent vdev			*/
135 	vdev_t		**vdev_child;	/* array of children		*/
136 	uint64_t	vdev_children;	/* number of children		*/
137 	space_map_t	vdev_dtl_map;	/* dirty time log in-core state	*/
138 	space_map_t	vdev_dtl_scrub;	/* DTL for scrub repair writes	*/
139 	vdev_stat_t	vdev_stat;	/* virtual device statistics	*/
140 
141 	/*
142 	 * Top-level vdev state.
143 	 */
144 	uint64_t	vdev_ms_array;	/* metaslab array object	*/
145 	uint64_t	vdev_ms_shift;	/* metaslab size shift		*/
146 	uint64_t	vdev_ms_count;	/* number of metaslabs		*/
147 	metaslab_group_t *vdev_mg;	/* metaslab group		*/
148 	metaslab_t	**vdev_ms;	/* metaslab array		*/
149 	space_map_obj_t	*vdev_smo;	/* metaslab space map array	*/
150 	txg_list_t	vdev_ms_list;	/* per-txg dirty metaslab lists	*/
151 	txg_list_t	vdev_dtl_list;	/* per-txg dirty DTL lists	*/
152 	txg_node_t	vdev_txg_node;	/* per-txg dirty vdev linkage	*/
153 	uint8_t		vdev_dirty[TXG_SIZE]; /* per-txg dirty flags	*/
154 	int		vdev_is_dirty;	/* on config dirty list?	*/
155 	list_node_t	vdev_dirty_node; /* config dirty list		*/
156 	zio_t		*vdev_io_retry;	/* I/O retry list		*/
157 	list_t		vdev_io_pending; /* I/O pending 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 	char		*vdev_path;	/* vdev path (if any)		*/
166 	char		*vdev_devid;	/* vdev devid (if any)		*/
167 	uint64_t	vdev_fault_arg; /* fault injection paramater	*/
168 	int		vdev_fault_mask; /* zio types to fault		*/
169 	uint8_t		vdev_fault_mode; /* fault injection mode	*/
170 	uint8_t		vdev_cache_active; /* vdev_cache and vdev_queue	*/
171 	uint8_t		vdev_offline;	/* device taken offline?	*/
172 	uint8_t		vdev_detached;	/* device detached?		*/
173 	vdev_queue_t	vdev_queue;	/* I/O deadline schedule queue	*/
174 	vdev_cache_t	vdev_cache;	/* physical block cache		*/
175 
176 	/*
177 	 * For DTrace to work in userland (libzpool) context, these fields must
178 	 * remain at the end of the structure.  DTrace will use the kernel's
179 	 * CTF definition for 'struct vdev', and since the size of a kmutex_t is
180 	 * larger in userland, the offsets for the rest fields would be
181 	 * incorrect.
182 	 */
183 	kmutex_t	vdev_dtl_lock;	/* vdev_dtl_{map,resilver}	*/
184 	kmutex_t	vdev_dirty_lock; /* vdev_dirty[]		*/
185 	kmutex_t	vdev_io_lock;	/* vdev_io_pending list		*/
186 	kcondvar_t	vdev_io_cv;	/* vdev_io_pending list empty?	*/
187 	kmutex_t	vdev_stat_lock;	/* vdev_stat			*/
188 };
189 
190 #define	VDEV_SKIP_SIZE		(8 << 10)
191 #define	VDEV_BOOT_HEADER_SIZE	(8 << 10)
192 #define	VDEV_PHYS_SIZE		(112 << 10)
193 #define	VDEV_UBERBLOCKS		((128 << 10) >> UBERBLOCK_SHIFT)
194 
195 #define	VDEV_BOOT_MAGIC		0x2f5b007b10c	/* ZFS boot block	*/
196 #define	VDEV_BOOT_VERSION	1		/* version number	*/
197 
198 typedef struct vdev_boot_header {
199 	uint64_t	vb_magic;		/* VDEV_BOOT_MAGIC	*/
200 	uint64_t	vb_version;		/* VDEV_BOOT_VERSION	*/
201 	uint64_t	vb_offset;		/* start offset	(bytes) */
202 	uint64_t	vb_size;		/* size (bytes)		*/
203 	char		vb_pad[VDEV_BOOT_HEADER_SIZE - 4 * sizeof (uint64_t)];
204 } vdev_boot_header_t;
205 
206 typedef struct vdev_phys {
207 	char		vp_nvlist[VDEV_PHYS_SIZE - sizeof (zio_block_tail_t)];
208 	zio_block_tail_t vp_zbt;
209 } vdev_phys_t;
210 
211 typedef struct vdev_label {
212 	char			vl_pad[VDEV_SKIP_SIZE];		/*   8K	*/
213 	vdev_boot_header_t	vl_boot_header;			/*   8K	*/
214 	vdev_phys_t		vl_vdev_phys;			/* 112K	*/
215 	uberblock_phys_t	vl_uberblock[VDEV_UBERBLOCKS];	/* 128K	*/
216 } vdev_label_t;							/* 256K total */
217 
218 /*
219  * Size and offset of embedded boot loader region on each label.
220  * The total size of the first two labels plus the boot area is 4MB.
221  */
222 #define	VDEV_BOOT_OFFSET	(2 * sizeof (vdev_label_t))
223 #define	VDEV_BOOT_SIZE		(7ULL << 19)			/* 3.5M	*/
224 
225 /*
226  * vdev_dirty[] flags
227  */
228 #define	VDD_ALLOC	0x01	/* allocated from in this txg		*/
229 #define	VDD_FREE	0x02	/* freed to in this txg			*/
230 #define	VDD_ADD		0x04	/* added to the pool in this txg	*/
231 #define	VDD_DTL		0x08	/* dirty time log entry in this txg	*/
232 
233 /*
234  * Size of label regions at the start and end of each leaf device.
235  */
236 #define	VDEV_LABEL_START_SIZE	(2 * sizeof (vdev_label_t) + VDEV_BOOT_SIZE)
237 #define	VDEV_LABEL_END_SIZE	(2 * sizeof (vdev_label_t))
238 #define	VDEV_LABELS		4
239 
240 #define	VDEV_ALLOC_LOAD		0
241 #define	VDEV_ALLOC_ADD		1
242 
243 /*
244  * Allocate or free a vdev
245  */
246 extern vdev_t *vdev_alloc(spa_t *spa, nvlist_t *config, vdev_t *parent,
247     uint_t id, int alloctype);
248 extern void vdev_free(vdev_t *vd);
249 
250 /*
251  * Add or remove children and parents
252  */
253 extern void vdev_add_child(vdev_t *pvd, vdev_t *cvd);
254 extern void vdev_remove_child(vdev_t *pvd, vdev_t *cvd);
255 extern void vdev_compact_children(vdev_t *pvd);
256 extern vdev_t *vdev_add_parent(vdev_t *cvd, vdev_ops_t *ops);
257 extern void vdev_remove_parent(vdev_t *cvd);
258 
259 /*
260  * vdev sync load and sync
261  */
262 extern int vdev_load(vdev_t *vd, int import);
263 extern void vdev_sync(vdev_t *vd, uint64_t txg);
264 extern void vdev_sync_done(vdev_t *vd, uint64_t txg);
265 extern void vdev_dirty(vdev_t *vd, uint8_t flags, uint64_t txg);
266 
267 /*
268  * Available vdev types.
269  */
270 extern vdev_ops_t vdev_root_ops;
271 extern vdev_ops_t vdev_mirror_ops;
272 extern vdev_ops_t vdev_replacing_ops;
273 extern vdev_ops_t vdev_raidz_ops;
274 extern vdev_ops_t vdev_disk_ops;
275 extern vdev_ops_t vdev_file_ops;
276 extern vdev_ops_t vdev_missing_ops;
277 
278 /*
279  * Common asize function
280  */
281 extern uint64_t vdev_default_asize(vdev_t *vd, uint64_t psize);
282 
283 #ifdef	__cplusplus
284 }
285 #endif
286 
287 #endif	/* _SYS_VDEV_IMPL_H */
288