xref: /illumos-gate/usr/src/uts/common/fs/zfs/sys/vdev_impl.h (revision 92a0208178405fef708b0283ffcaa02fbc3468ff)
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 2008 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 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 	spa_aux_vdev_t	*vdev_aux;	/* for l2cache vdevs		*/
182 
183 	/*
184 	 * For DTrace to work in userland (libzpool) context, these fields must
185 	 * remain at the end of the structure.  DTrace will use the kernel's
186 	 * CTF definition for 'struct vdev', and since the size of a kmutex_t is
187 	 * larger in userland, the offsets for the rest fields would be
188 	 * incorrect.
189 	 */
190 	kmutex_t	vdev_dtl_lock;	/* vdev_dtl_{map,resilver}	*/
191 	kmutex_t	vdev_stat_lock;	/* vdev_stat			*/
192 };
193 
194 #define	VDEV_SKIP_SIZE		(8 << 10)
195 #define	VDEV_BOOT_HEADER_SIZE	(8 << 10)
196 #define	VDEV_PHYS_SIZE		(112 << 10)
197 #define	VDEV_UBERBLOCK_RING	(128 << 10)
198 
199 #define	VDEV_UBERBLOCK_SHIFT(vd)	\
200 	MAX((vd)->vdev_top->vdev_ashift, UBERBLOCK_SHIFT)
201 #define	VDEV_UBERBLOCK_COUNT(vd)	\
202 	(VDEV_UBERBLOCK_RING >> VDEV_UBERBLOCK_SHIFT(vd))
203 #define	VDEV_UBERBLOCK_OFFSET(vd, n)	\
204 	offsetof(vdev_label_t, vl_uberblock[(n) << VDEV_UBERBLOCK_SHIFT(vd)])
205 #define	VDEV_UBERBLOCK_SIZE(vd)		(1ULL << VDEV_UBERBLOCK_SHIFT(vd))
206 
207 /* ZFS boot block */
208 #define	VDEV_BOOT_MAGIC		0x2f5b007b10cULL
209 #define	VDEV_BOOT_VERSION	1		/* version number	*/
210 
211 typedef struct vdev_boot_header {
212 	uint64_t	vb_magic;		/* VDEV_BOOT_MAGIC	*/
213 	uint64_t	vb_version;		/* VDEV_BOOT_VERSION	*/
214 	uint64_t	vb_offset;		/* start offset	(bytes) */
215 	uint64_t	vb_size;		/* size (bytes)		*/
216 	char		vb_pad[VDEV_BOOT_HEADER_SIZE - 4 * sizeof (uint64_t)];
217 } vdev_boot_header_t;
218 
219 typedef struct vdev_phys {
220 	char		vp_nvlist[VDEV_PHYS_SIZE - sizeof (zio_block_tail_t)];
221 	zio_block_tail_t vp_zbt;
222 } vdev_phys_t;
223 
224 typedef struct vdev_label {
225 	char		vl_pad[VDEV_SKIP_SIZE];			/*   8K	*/
226 	vdev_boot_header_t vl_boot_header;			/*   8K	*/
227 	vdev_phys_t	vl_vdev_phys;				/* 112K	*/
228 	char		vl_uberblock[VDEV_UBERBLOCK_RING];	/* 128K	*/
229 } vdev_label_t;							/* 256K total */
230 
231 /*
232  * vdev_dirty() flags
233  */
234 #define	VDD_METASLAB	0x01
235 #define	VDD_DTL		0x02
236 
237 /*
238  * Size and offset of embedded boot loader region on each label.
239  * The total size of the first two labels plus the boot area is 4MB.
240  */
241 #define	VDEV_BOOT_OFFSET	(2 * sizeof (vdev_label_t))
242 #define	VDEV_BOOT_SIZE		(7ULL << 19)			/* 3.5M	*/
243 
244 /*
245  * Size of label regions at the start and end of each leaf device.
246  */
247 #define	VDEV_LABEL_START_SIZE	(2 * sizeof (vdev_label_t) + VDEV_BOOT_SIZE)
248 #define	VDEV_LABEL_END_SIZE	(2 * sizeof (vdev_label_t))
249 #define	VDEV_LABELS		4
250 
251 #define	VDEV_ALLOC_LOAD		0
252 #define	VDEV_ALLOC_ADD		1
253 #define	VDEV_ALLOC_SPARE	2
254 #define	VDEV_ALLOC_L2CACHE	3
255 
256 /*
257  * Allocate or free a vdev
258  */
259 extern int vdev_alloc(spa_t *spa, vdev_t **vdp, nvlist_t *config,
260     vdev_t *parent, uint_t id, int alloctype);
261 extern void vdev_free(vdev_t *vd);
262 
263 /*
264  * Add or remove children and parents
265  */
266 extern void vdev_add_child(vdev_t *pvd, vdev_t *cvd);
267 extern void vdev_remove_child(vdev_t *pvd, vdev_t *cvd);
268 extern void vdev_compact_children(vdev_t *pvd);
269 extern vdev_t *vdev_add_parent(vdev_t *cvd, vdev_ops_t *ops);
270 extern void vdev_remove_parent(vdev_t *cvd);
271 
272 /*
273  * vdev sync load and sync
274  */
275 extern void vdev_load(vdev_t *vd);
276 extern void vdev_sync(vdev_t *vd, uint64_t txg);
277 extern void vdev_sync_done(vdev_t *vd, uint64_t txg);
278 extern void vdev_dirty(vdev_t *vd, int flags, void *arg, uint64_t txg);
279 
280 /*
281  * Available vdev types.
282  */
283 extern vdev_ops_t vdev_root_ops;
284 extern vdev_ops_t vdev_mirror_ops;
285 extern vdev_ops_t vdev_replacing_ops;
286 extern vdev_ops_t vdev_raidz_ops;
287 extern vdev_ops_t vdev_disk_ops;
288 extern vdev_ops_t vdev_file_ops;
289 extern vdev_ops_t vdev_missing_ops;
290 extern vdev_ops_t vdev_spare_ops;
291 
292 /*
293  * Common size functions
294  */
295 extern uint64_t vdev_default_asize(vdev_t *vd, uint64_t psize);
296 extern uint64_t vdev_get_rsize(vdev_t *vd);
297 
298 /*
299  * zdb uses this tunable, so it must be declared here to make lint happy.
300  */
301 extern int zfs_vdev_cache_size;
302 
303 #ifdef	__cplusplus
304 }
305 #endif
306 
307 #endif	/* _SYS_VDEV_IMPL_H */
308