xref: /illumos-gate/usr/src/uts/common/fs/zfs/sys/vdev_impl.h (revision c9fd6b31f4fa1345ad799549dc0f1101b9cef127)
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 2010 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 typedef void	vdev_hold_func_t(vdev_t *vd);
66 typedef void	vdev_rele_func_t(vdev_t *vd);
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 	vdev_hold_func_t		*vdev_op_hold;
76 	vdev_rele_func_t		*vdev_op_rele;
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_orig_guid;	/* orig. guid prior to remove	*/
120 	uint64_t	vdev_asize;	/* allocatable device capacity	*/
121 	uint64_t	vdev_min_asize;	/* min acceptable asize		*/
122 	uint64_t	vdev_ashift;	/* block alignment shift	*/
123 	uint64_t	vdev_state;	/* see VDEV_STATE_* #defines	*/
124 	uint64_t	vdev_prevstate;	/* used when reopening a vdev	*/
125 	vdev_ops_t	*vdev_ops;	/* vdev operations		*/
126 	spa_t		*vdev_spa;	/* spa for this vdev		*/
127 	void		*vdev_tsd;	/* type-specific data		*/
128 	vnode_t		*vdev_name_vp;	/* vnode for pathname		*/
129 	vnode_t		*vdev_devid_vp;	/* vnode for devid		*/
130 	vdev_t		*vdev_top;	/* top-level vdev		*/
131 	vdev_t		*vdev_parent;	/* parent vdev			*/
132 	vdev_t		**vdev_child;	/* array of children		*/
133 	uint64_t	vdev_children;	/* number of children		*/
134 	space_map_t	vdev_dtl[DTL_TYPES]; /* in-core dirty time logs	*/
135 	vdev_stat_t	vdev_stat;	/* virtual device statistics	*/
136 	boolean_t	vdev_expanding;	/* expand the vdev?		*/
137 	boolean_t	vdev_reopening;	/* reopen in progress?		*/
138 	int		vdev_open_error; /* error on last open		*/
139 	kthread_t	*vdev_open_thread; /* thread opening children	*/
140 	uint64_t	vdev_crtxg;	/* txg when top-level was added */
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 	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 	boolean_t	vdev_remove_wanted; /* async remove wanted?	*/
154 	boolean_t	vdev_probe_wanted; /* async probe wanted?	*/
155 	boolean_t	vdev_removing;	/* device is being removed?	*/
156 	list_node_t	vdev_config_dirty_node; /* config dirty list	*/
157 	list_node_t	vdev_state_dirty_node; /* state dirty list	*/
158 	uint64_t	vdev_deflate_ratio; /* deflation ratio (x512)	*/
159 	uint64_t	vdev_islog;	/* is an intent log device	*/
160 	uint64_t	vdev_ishole;	/* is a hole in the namespace 	*/
161 
162 	/*
163 	 * Leaf vdev state.
164 	 */
165 	uint64_t	vdev_psize;	/* physical device capacity	*/
166 	space_map_obj_t	vdev_dtl_smo;	/* dirty time log space map obj	*/
167 	txg_node_t	vdev_dtl_node;	/* per-txg dirty DTL linkage	*/
168 	uint64_t	vdev_wholedisk;	/* true if this is a whole disk */
169 	uint64_t	vdev_offline;	/* persistent offline state	*/
170 	uint64_t	vdev_faulted;	/* persistent faulted state	*/
171 	uint64_t	vdev_degraded;	/* persistent degraded state	*/
172 	uint64_t	vdev_removed;	/* persistent removed state	*/
173 	uint64_t	vdev_nparity;	/* number of parity devices for raidz */
174 	char		*vdev_path;	/* vdev path (if any)		*/
175 	char		*vdev_devid;	/* vdev devid (if any)		*/
176 	char		*vdev_physpath;	/* vdev device path (if any)	*/
177 	char		*vdev_fru;	/* physical FRU location	*/
178 	uint64_t	vdev_not_present; /* not present during import	*/
179 	uint64_t	vdev_unspare;	/* unspare when resilvering done */
180 	hrtime_t	vdev_last_try;	/* last reopen time		*/
181 	boolean_t	vdev_nowritecache; /* true if flushwritecache failed */
182 	boolean_t	vdev_checkremove; /* temporary online test	*/
183 	boolean_t	vdev_forcefault; /* force online fault		*/
184 	boolean_t	vdev_splitting;	/* split or repair in progress  */
185 	uint8_t		vdev_tmpoffline; /* device taken offline temporarily? */
186 	uint8_t		vdev_detached;	/* device detached?		*/
187 	uint8_t		vdev_cant_read;	/* vdev is failing all reads	*/
188 	uint8_t		vdev_cant_write; /* vdev is failing all writes	*/
189 	uint64_t	vdev_isspare;	/* was a hot spare		*/
190 	uint64_t	vdev_isl2cache;	/* was a l2cache device		*/
191 	vdev_queue_t	vdev_queue;	/* I/O deadline schedule queue	*/
192 	vdev_cache_t	vdev_cache;	/* physical block cache		*/
193 	spa_aux_vdev_t	*vdev_aux;	/* for l2cache vdevs		*/
194 	zio_t		*vdev_probe_zio; /* root of current probe	*/
195 	vdev_aux_t	vdev_label_aux;	/* on-disk aux state		*/
196 
197 	/*
198 	 * For DTrace to work in userland (libzpool) context, these fields must
199 	 * remain at the end of the structure.  DTrace will use the kernel's
200 	 * CTF definition for 'struct vdev', and since the size of a kmutex_t is
201 	 * larger in userland, the offsets for the rest fields would be
202 	 * incorrect.
203 	 */
204 	kmutex_t	vdev_dtl_lock;	/* vdev_dtl_{map,resilver}	*/
205 	kmutex_t	vdev_stat_lock;	/* vdev_stat			*/
206 	kmutex_t	vdev_probe_lock; /* protects vdev_probe_zio	*/
207 };
208 
209 #define	VDEV_RAIDZ_MAXPARITY	3
210 
211 #define	VDEV_PAD_SIZE		(8 << 10)
212 /* 2 padding areas (vl_pad1 and vl_pad2) to skip */
213 #define	VDEV_SKIP_SIZE		VDEV_PAD_SIZE * 2
214 #define	VDEV_PHYS_SIZE		(112 << 10)
215 #define	VDEV_UBERBLOCK_RING	(128 << 10)
216 
217 #define	VDEV_UBERBLOCK_SHIFT(vd)	\
218 	MAX((vd)->vdev_top->vdev_ashift, UBERBLOCK_SHIFT)
219 #define	VDEV_UBERBLOCK_COUNT(vd)	\
220 	(VDEV_UBERBLOCK_RING >> VDEV_UBERBLOCK_SHIFT(vd))
221 #define	VDEV_UBERBLOCK_OFFSET(vd, n)	\
222 	offsetof(vdev_label_t, vl_uberblock[(n) << VDEV_UBERBLOCK_SHIFT(vd)])
223 #define	VDEV_UBERBLOCK_SIZE(vd)		(1ULL << VDEV_UBERBLOCK_SHIFT(vd))
224 
225 typedef struct vdev_phys {
226 	char		vp_nvlist[VDEV_PHYS_SIZE - sizeof (zio_eck_t)];
227 	zio_eck_t	vp_zbt;
228 } vdev_phys_t;
229 
230 typedef struct vdev_label {
231 	char		vl_pad1[VDEV_PAD_SIZE];			/*  8K */
232 	char		vl_pad2[VDEV_PAD_SIZE];			/*  8K */
233 	vdev_phys_t	vl_vdev_phys;				/* 112K	*/
234 	char		vl_uberblock[VDEV_UBERBLOCK_RING];	/* 128K	*/
235 } vdev_label_t;							/* 256K total */
236 
237 /*
238  * vdev_dirty() flags
239  */
240 #define	VDD_METASLAB	0x01
241 #define	VDD_DTL		0x02
242 
243 /*
244  * Size and offset of embedded boot loader region on each label.
245  * The total size of the first two labels plus the boot area is 4MB.
246  */
247 #define	VDEV_BOOT_OFFSET	(2 * sizeof (vdev_label_t))
248 #define	VDEV_BOOT_SIZE		(7ULL << 19)			/* 3.5M	*/
249 
250 /*
251  * Size of label regions at the start and end of each leaf device.
252  */
253 #define	VDEV_LABEL_START_SIZE	(2 * sizeof (vdev_label_t) + VDEV_BOOT_SIZE)
254 #define	VDEV_LABEL_END_SIZE	(2 * sizeof (vdev_label_t))
255 #define	VDEV_LABELS		4
256 
257 #define	VDEV_ALLOC_LOAD		0
258 #define	VDEV_ALLOC_ADD		1
259 #define	VDEV_ALLOC_SPARE	2
260 #define	VDEV_ALLOC_L2CACHE	3
261 #define	VDEV_ALLOC_ROOTPOOL	4
262 #define	VDEV_ALLOC_SPLIT	5
263 
264 /*
265  * Allocate or free a vdev
266  */
267 extern vdev_t *vdev_alloc_common(spa_t *spa, uint_t id, uint64_t guid,
268     vdev_ops_t *ops);
269 extern int vdev_alloc(spa_t *spa, vdev_t **vdp, nvlist_t *config,
270     vdev_t *parent, uint_t id, int alloctype);
271 extern void vdev_free(vdev_t *vd);
272 
273 /*
274  * Add or remove children and parents
275  */
276 extern void vdev_add_child(vdev_t *pvd, vdev_t *cvd);
277 extern void vdev_remove_child(vdev_t *pvd, vdev_t *cvd);
278 extern void vdev_compact_children(vdev_t *pvd);
279 extern vdev_t *vdev_add_parent(vdev_t *cvd, vdev_ops_t *ops);
280 extern void vdev_remove_parent(vdev_t *cvd);
281 
282 /*
283  * vdev sync load and sync
284  */
285 extern void vdev_load_log_state(vdev_t *nvd, vdev_t *ovd);
286 extern void vdev_load(vdev_t *vd);
287 extern void vdev_sync(vdev_t *vd, uint64_t txg);
288 extern void vdev_sync_done(vdev_t *vd, uint64_t txg);
289 extern void vdev_dirty(vdev_t *vd, int flags, void *arg, uint64_t txg);
290 
291 /*
292  * Available vdev types.
293  */
294 extern vdev_ops_t vdev_root_ops;
295 extern vdev_ops_t vdev_mirror_ops;
296 extern vdev_ops_t vdev_replacing_ops;
297 extern vdev_ops_t vdev_raidz_ops;
298 extern vdev_ops_t vdev_disk_ops;
299 extern vdev_ops_t vdev_file_ops;
300 extern vdev_ops_t vdev_missing_ops;
301 extern vdev_ops_t vdev_hole_ops;
302 extern vdev_ops_t vdev_spare_ops;
303 
304 /*
305  * Common size functions
306  */
307 extern uint64_t vdev_default_asize(vdev_t *vd, uint64_t psize);
308 extern uint64_t vdev_get_min_asize(vdev_t *vd);
309 extern void vdev_set_min_asize(vdev_t *vd);
310 
311 /*
312  * zdb uses this tunable, so it must be declared here to make lint happy.
313  */
314 extern int zfs_vdev_cache_size;
315 
316 #ifdef	__cplusplus
317 }
318 #endif
319 
320 #endif	/* _SYS_VDEV_IMPL_H */
321