xref: /illumos-gate/usr/src/uts/common/fs/zfs/sys/vdev_impl.h (revision 738f37bc3dcd61e8a893af0f2d466d76690b70ec)
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 (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
23  * Copyright (c) 2012, 2014 by Delphix. All rights reserved.
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 *max_size,
60     uint64_t *ashift);
61 typedef void	vdev_close_func_t(vdev_t *vd);
62 typedef uint64_t vdev_asize_func_t(vdev_t *vd, uint64_t psize);
63 typedef void	vdev_io_start_func_t(zio_t *zio);
64 typedef void	vdev_io_done_func_t(zio_t *zio);
65 typedef void	vdev_state_change_func_t(vdev_t *vd, int, int);
66 typedef void	vdev_hold_func_t(vdev_t *vd);
67 typedef void	vdev_rele_func_t(vdev_t *vd);
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 	vdev_hold_func_t		*vdev_op_hold;
77 	vdev_rele_func_t		*vdev_op_rele;
78 	char				vdev_op_type[16];
79 	boolean_t			vdev_op_leaf;
80 } vdev_ops_t;
81 
82 /*
83  * Virtual device properties
84  */
85 struct vdev_cache_entry {
86 	char		*ve_data;
87 	uint64_t	ve_offset;
88 	uint64_t	ve_lastused;
89 	avl_node_t	ve_offset_node;
90 	avl_node_t	ve_lastused_node;
91 	uint32_t	ve_hits;
92 	uint16_t	ve_missed_update;
93 	zio_t		*ve_fill_io;
94 };
95 
96 struct vdev_cache {
97 	avl_tree_t	vc_offset_tree;
98 	avl_tree_t	vc_lastused_tree;
99 	kmutex_t	vc_lock;
100 };
101 
102 typedef struct vdev_queue_class {
103 	uint32_t	vqc_active;
104 
105 	/*
106 	 * Sorted by offset or timestamp, depending on if the queue is
107 	 * LBA-ordered vs FIFO.
108 	 */
109 	avl_tree_t	vqc_queued_tree;
110 } vdev_queue_class_t;
111 
112 struct vdev_queue {
113 	vdev_t		*vq_vdev;
114 	vdev_queue_class_t vq_class[ZIO_PRIORITY_NUM_QUEUEABLE];
115 	avl_tree_t	vq_active_tree;
116 	uint64_t	vq_last_offset;
117 	hrtime_t	vq_io_complete_ts; /* time last i/o completed */
118 	kmutex_t	vq_lock;
119 };
120 
121 /*
122  * Virtual device descriptor
123  */
124 struct vdev {
125 	/*
126 	 * Common to all vdev types.
127 	 */
128 	uint64_t	vdev_id;	/* child number in vdev parent	*/
129 	uint64_t	vdev_guid;	/* unique ID for this vdev	*/
130 	uint64_t	vdev_guid_sum;	/* self guid + all child guids	*/
131 	uint64_t	vdev_orig_guid;	/* orig. guid prior to remove	*/
132 	uint64_t	vdev_asize;	/* allocatable device capacity	*/
133 	uint64_t	vdev_min_asize;	/* min acceptable asize		*/
134 	uint64_t	vdev_max_asize;	/* max acceptable asize		*/
135 	uint64_t	vdev_ashift;	/* block alignment shift	*/
136 	uint64_t	vdev_state;	/* see VDEV_STATE_* #defines	*/
137 	uint64_t	vdev_prevstate;	/* used when reopening a vdev	*/
138 	vdev_ops_t	*vdev_ops;	/* vdev operations		*/
139 	spa_t		*vdev_spa;	/* spa for this vdev		*/
140 	void		*vdev_tsd;	/* type-specific data		*/
141 	vnode_t		*vdev_name_vp;	/* vnode for pathname		*/
142 	vnode_t		*vdev_devid_vp;	/* vnode for devid		*/
143 	vdev_t		*vdev_top;	/* top-level vdev		*/
144 	vdev_t		*vdev_parent;	/* parent vdev			*/
145 	vdev_t		**vdev_child;	/* array of children		*/
146 	uint64_t	vdev_children;	/* number of children		*/
147 	vdev_stat_t	vdev_stat;	/* virtual device statistics	*/
148 	boolean_t	vdev_expanding;	/* expand the vdev?		*/
149 	boolean_t	vdev_reopening;	/* reopen in progress?		*/
150 	int		vdev_open_error; /* error on last open		*/
151 	kthread_t	*vdev_open_thread; /* thread opening children	*/
152 	uint64_t	vdev_crtxg;	/* txg when top-level was added */
153 
154 	/*
155 	 * Top-level vdev state.
156 	 */
157 	uint64_t	vdev_ms_array;	/* metaslab array object	*/
158 	uint64_t	vdev_ms_shift;	/* metaslab size shift		*/
159 	uint64_t	vdev_ms_count;	/* number of metaslabs		*/
160 	metaslab_group_t *vdev_mg;	/* metaslab group		*/
161 	metaslab_t	**vdev_ms;	/* metaslab array		*/
162 	txg_list_t	vdev_ms_list;	/* per-txg dirty metaslab lists	*/
163 	txg_list_t	vdev_dtl_list;	/* per-txg dirty DTL lists	*/
164 	txg_node_t	vdev_txg_node;	/* per-txg dirty vdev linkage	*/
165 	boolean_t	vdev_remove_wanted; /* async remove wanted?	*/
166 	boolean_t	vdev_probe_wanted; /* async probe wanted?	*/
167 	list_node_t	vdev_config_dirty_node; /* config dirty list	*/
168 	list_node_t	vdev_state_dirty_node; /* state dirty list	*/
169 	uint64_t	vdev_deflate_ratio; /* deflation ratio (x512)	*/
170 	uint64_t	vdev_islog;	/* is an intent log device	*/
171 	uint64_t	vdev_removing;	/* device is being removed?	*/
172 	boolean_t	vdev_ishole;	/* is a hole in the namespace 	*/
173 
174 	/*
175 	 * Leaf vdev state.
176 	 */
177 	range_tree_t	*vdev_dtl[DTL_TYPES]; /* dirty time logs	*/
178 	space_map_t	*vdev_dtl_sm;	/* dirty time log space map	*/
179 	txg_node_t	vdev_dtl_node;	/* per-txg dirty DTL linkage	*/
180 	uint64_t	vdev_dtl_object; /* DTL object			*/
181 	uint64_t	vdev_psize;	/* physical device capacity	*/
182 	uint64_t	vdev_wholedisk;	/* true if this is a whole disk */
183 	uint64_t	vdev_offline;	/* persistent offline state	*/
184 	uint64_t	vdev_faulted;	/* persistent faulted state	*/
185 	uint64_t	vdev_degraded;	/* persistent degraded state	*/
186 	uint64_t	vdev_removed;	/* persistent removed state	*/
187 	uint64_t	vdev_resilver_txg; /* persistent resilvering state */
188 	uint64_t	vdev_nparity;	/* number of parity devices for raidz */
189 	char		*vdev_path;	/* vdev path (if any)		*/
190 	char		*vdev_devid;	/* vdev devid (if any)		*/
191 	char		*vdev_physpath;	/* vdev device path (if any)	*/
192 	char		*vdev_fru;	/* physical FRU location	*/
193 	uint64_t	vdev_not_present; /* not present during import	*/
194 	uint64_t	vdev_unspare;	/* unspare when resilvering done */
195 	boolean_t	vdev_nowritecache; /* true if flushwritecache failed */
196 	boolean_t	vdev_checkremove; /* temporary online test	*/
197 	boolean_t	vdev_forcefault; /* force online fault		*/
198 	boolean_t	vdev_splitting;	/* split or repair in progress  */
199 	boolean_t	vdev_delayed_close; /* delayed device close?	*/
200 	boolean_t	vdev_tmpoffline; /* device taken offline temporarily? */
201 	boolean_t	vdev_detached;	/* device detached?		*/
202 	boolean_t	vdev_cant_read;	/* vdev is failing all reads	*/
203 	boolean_t	vdev_cant_write; /* vdev is failing all writes	*/
204 	boolean_t	vdev_isspare;	/* was a hot spare		*/
205 	boolean_t	vdev_isl2cache;	/* was a l2cache device		*/
206 	vdev_queue_t	vdev_queue;	/* I/O deadline schedule queue	*/
207 	vdev_cache_t	vdev_cache;	/* physical block cache		*/
208 	spa_aux_vdev_t	*vdev_aux;	/* for l2cache vdevs		*/
209 	zio_t		*vdev_probe_zio; /* root of current probe	*/
210 	vdev_aux_t	vdev_label_aux;	/* on-disk aux state		*/
211 
212 	/*
213 	 * For DTrace to work in userland (libzpool) context, these fields must
214 	 * remain at the end of the structure.  DTrace will use the kernel's
215 	 * CTF definition for 'struct vdev', and since the size of a kmutex_t is
216 	 * larger in userland, the offsets for the rest of the fields would be
217 	 * incorrect.
218 	 */
219 	kmutex_t	vdev_dtl_lock;	/* vdev_dtl_{map,resilver}	*/
220 	kmutex_t	vdev_stat_lock;	/* vdev_stat			*/
221 	kmutex_t	vdev_probe_lock; /* protects vdev_probe_zio	*/
222 };
223 
224 #define	VDEV_RAIDZ_MAXPARITY	3
225 
226 #define	VDEV_PAD_SIZE		(8 << 10)
227 /* 2 padding areas (vl_pad1 and vl_pad2) to skip */
228 #define	VDEV_SKIP_SIZE		VDEV_PAD_SIZE * 2
229 #define	VDEV_PHYS_SIZE		(112 << 10)
230 #define	VDEV_UBERBLOCK_RING	(128 << 10)
231 
232 /* The largest uberblock we support is 8k. */
233 #define	MAX_UBERBLOCK_SHIFT (13)
234 #define	VDEV_UBERBLOCK_SHIFT(vd)	\
235 	MIN(MAX((vd)->vdev_top->vdev_ashift, UBERBLOCK_SHIFT), \
236 	    MAX_UBERBLOCK_SHIFT)
237 #define	VDEV_UBERBLOCK_COUNT(vd)	\
238 	(VDEV_UBERBLOCK_RING >> VDEV_UBERBLOCK_SHIFT(vd))
239 #define	VDEV_UBERBLOCK_OFFSET(vd, n)	\
240 	offsetof(vdev_label_t, vl_uberblock[(n) << VDEV_UBERBLOCK_SHIFT(vd)])
241 #define	VDEV_UBERBLOCK_SIZE(vd)		(1ULL << VDEV_UBERBLOCK_SHIFT(vd))
242 
243 typedef struct vdev_phys {
244 	char		vp_nvlist[VDEV_PHYS_SIZE - sizeof (zio_eck_t)];
245 	zio_eck_t	vp_zbt;
246 } vdev_phys_t;
247 
248 typedef struct vdev_label {
249 	char		vl_pad1[VDEV_PAD_SIZE];			/*  8K */
250 	char		vl_pad2[VDEV_PAD_SIZE];			/*  8K */
251 	vdev_phys_t	vl_vdev_phys;				/* 112K	*/
252 	char		vl_uberblock[VDEV_UBERBLOCK_RING];	/* 128K	*/
253 } vdev_label_t;							/* 256K total */
254 
255 /*
256  * vdev_dirty() flags
257  */
258 #define	VDD_METASLAB	0x01
259 #define	VDD_DTL		0x02
260 
261 /* Offset of embedded boot loader region on each label */
262 #define	VDEV_BOOT_OFFSET	(2 * sizeof (vdev_label_t))
263 /*
264  * Size of embedded boot loader region on each label.
265  * The total size of the first two labels plus the boot area is 4MB.
266  */
267 #define	VDEV_BOOT_SIZE		(7ULL << 19)			/* 3.5M */
268 
269 /*
270  * Size of label regions at the start and end of each leaf device.
271  */
272 #define	VDEV_LABEL_START_SIZE	(2 * sizeof (vdev_label_t) + VDEV_BOOT_SIZE)
273 #define	VDEV_LABEL_END_SIZE	(2 * sizeof (vdev_label_t))
274 #define	VDEV_LABELS		4
275 #define	VDEV_BEST_LABEL		VDEV_LABELS
276 
277 #define	VDEV_ALLOC_LOAD		0
278 #define	VDEV_ALLOC_ADD		1
279 #define	VDEV_ALLOC_SPARE	2
280 #define	VDEV_ALLOC_L2CACHE	3
281 #define	VDEV_ALLOC_ROOTPOOL	4
282 #define	VDEV_ALLOC_SPLIT	5
283 #define	VDEV_ALLOC_ATTACH	6
284 
285 /*
286  * Allocate or free a vdev
287  */
288 extern vdev_t *vdev_alloc_common(spa_t *spa, uint_t id, uint64_t guid,
289     vdev_ops_t *ops);
290 extern int vdev_alloc(spa_t *spa, vdev_t **vdp, nvlist_t *config,
291     vdev_t *parent, uint_t id, int alloctype);
292 extern void vdev_free(vdev_t *vd);
293 
294 /*
295  * Add or remove children and parents
296  */
297 extern void vdev_add_child(vdev_t *pvd, vdev_t *cvd);
298 extern void vdev_remove_child(vdev_t *pvd, vdev_t *cvd);
299 extern void vdev_compact_children(vdev_t *pvd);
300 extern vdev_t *vdev_add_parent(vdev_t *cvd, vdev_ops_t *ops);
301 extern void vdev_remove_parent(vdev_t *cvd);
302 
303 /*
304  * vdev sync load and sync
305  */
306 extern void vdev_load_log_state(vdev_t *nvd, vdev_t *ovd);
307 extern boolean_t vdev_log_state_valid(vdev_t *vd);
308 extern void vdev_load(vdev_t *vd);
309 extern int vdev_dtl_load(vdev_t *vd);
310 extern void vdev_sync(vdev_t *vd, uint64_t txg);
311 extern void vdev_sync_done(vdev_t *vd, uint64_t txg);
312 extern void vdev_dirty(vdev_t *vd, int flags, void *arg, uint64_t txg);
313 extern void vdev_dirty_leaves(vdev_t *vd, int flags, uint64_t txg);
314 
315 /*
316  * Available vdev types.
317  */
318 extern vdev_ops_t vdev_root_ops;
319 extern vdev_ops_t vdev_mirror_ops;
320 extern vdev_ops_t vdev_replacing_ops;
321 extern vdev_ops_t vdev_raidz_ops;
322 extern vdev_ops_t vdev_disk_ops;
323 extern vdev_ops_t vdev_file_ops;
324 extern vdev_ops_t vdev_missing_ops;
325 extern vdev_ops_t vdev_hole_ops;
326 extern vdev_ops_t vdev_spare_ops;
327 
328 /*
329  * Common size functions
330  */
331 extern uint64_t vdev_default_asize(vdev_t *vd, uint64_t psize);
332 extern uint64_t vdev_get_min_asize(vdev_t *vd);
333 extern void vdev_set_min_asize(vdev_t *vd);
334 
335 /*
336  * Global variables
337  */
338 /* zdb uses this tunable, so it must be declared here to make lint happy. */
339 extern int zfs_vdev_cache_size;
340 
341 /*
342  * The vdev_buf_t is used to translate between zio_t and buf_t, and back again.
343  */
344 typedef struct vdev_buf {
345 	buf_t	vb_buf;		/* buffer that describes the io */
346 	zio_t	*vb_io;		/* pointer back to the original zio_t */
347 } vdev_buf_t;
348 
349 #ifdef	__cplusplus
350 }
351 #endif
352 
353 #endif	/* _SYS_VDEV_IMPL_H */
354