xref: /titanic_44/usr/src/uts/common/fs/zfs/sys/vdev_impl.h (revision a7e4abc5c7baff9f8dc9a53d493d79591782cdb5)
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) 2011, 2015 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 	avl_tree_t	vq_read_offset_tree;
117 	avl_tree_t	vq_write_offset_tree;
118 	uint64_t	vq_last_offset;
119 	hrtime_t	vq_io_complete_ts; /* time last i/o completed */
120 	kmutex_t	vq_lock;
121 };
122 
123 /*
124  * Virtual device descriptor
125  */
126 struct vdev {
127 	/*
128 	 * Common to all vdev types.
129 	 */
130 	uint64_t	vdev_id;	/* child number in vdev parent	*/
131 	uint64_t	vdev_guid;	/* unique ID for this vdev	*/
132 	uint64_t	vdev_guid_sum;	/* self guid + all child guids	*/
133 	uint64_t	vdev_orig_guid;	/* orig. guid prior to remove	*/
134 	uint64_t	vdev_asize;	/* allocatable device capacity	*/
135 	uint64_t	vdev_min_asize;	/* min acceptable asize		*/
136 	uint64_t	vdev_max_asize;	/* max acceptable asize		*/
137 	uint64_t	vdev_ashift;	/* block alignment shift	*/
138 	uint64_t	vdev_state;	/* see VDEV_STATE_* #defines	*/
139 	uint64_t	vdev_prevstate;	/* used when reopening a vdev	*/
140 	vdev_ops_t	*vdev_ops;	/* vdev operations		*/
141 	spa_t		*vdev_spa;	/* spa for this vdev		*/
142 	void		*vdev_tsd;	/* type-specific data		*/
143 	vnode_t		*vdev_name_vp;	/* vnode for pathname		*/
144 	vnode_t		*vdev_devid_vp;	/* vnode for devid		*/
145 	vdev_t		*vdev_top;	/* top-level vdev		*/
146 	vdev_t		*vdev_parent;	/* parent vdev			*/
147 	vdev_t		**vdev_child;	/* array of children		*/
148 	uint64_t	vdev_children;	/* number of children		*/
149 	vdev_stat_t	vdev_stat;	/* virtual device statistics	*/
150 	boolean_t	vdev_expanding;	/* expand the vdev?		*/
151 	boolean_t	vdev_reopening;	/* reopen in progress?		*/
152 	int		vdev_open_error; /* error on last open		*/
153 	kthread_t	*vdev_open_thread; /* thread opening children	*/
154 	uint64_t	vdev_crtxg;	/* txg when top-level was added */
155 	boolean_t	vdev_avoid_read; /* avoid reading if possible   */
156 
157 	/*
158 	 * Top-level vdev state.
159 	 */
160 	uint64_t	vdev_ms_array;	/* metaslab array object	*/
161 	uint64_t	vdev_ms_shift;	/* metaslab size shift		*/
162 	uint64_t	vdev_ms_count;	/* number of metaslabs		*/
163 	metaslab_group_t *vdev_mg;	/* metaslab group		*/
164 	metaslab_t	**vdev_ms;	/* metaslab array		*/
165 	txg_list_t	vdev_ms_list;	/* per-txg dirty metaslab lists	*/
166 	txg_list_t	vdev_dtl_list;	/* per-txg dirty DTL lists	*/
167 	txg_node_t	vdev_txg_node;	/* per-txg dirty vdev linkage	*/
168 	boolean_t	vdev_remove_wanted; /* async remove wanted?	*/
169 	boolean_t	vdev_probe_wanted; /* async probe wanted?	*/
170 	list_node_t	vdev_config_dirty_node; /* config dirty list	*/
171 	list_node_t	vdev_state_dirty_node; /* state dirty list	*/
172 	uint64_t	vdev_deflate_ratio; /* deflation ratio (x512)	*/
173 	uint64_t	vdev_islog;	/* is an intent log device	*/
174 	uint64_t	vdev_removing;	/* device is being removed?	*/
175 	boolean_t	vdev_ishole;	/* is a hole in the namespace 	*/
176 
177 	/*
178 	 * Leaf vdev state.
179 	 */
180 	range_tree_t	*vdev_dtl[DTL_TYPES]; /* dirty time logs	*/
181 	space_map_t	*vdev_dtl_sm;	/* dirty time log space map	*/
182 	txg_node_t	vdev_dtl_node;	/* per-txg dirty DTL linkage	*/
183 	uint64_t	vdev_dtl_object; /* DTL object			*/
184 	uint64_t	vdev_psize;	/* physical device capacity	*/
185 	uint64_t	vdev_wholedisk;	/* true if this is a whole disk */
186 	uint64_t	vdev_offline;	/* persistent offline state	*/
187 	uint64_t	vdev_faulted;	/* persistent faulted state	*/
188 	uint64_t	vdev_degraded;	/* persistent degraded state	*/
189 	uint64_t	vdev_removed;	/* persistent removed state	*/
190 	uint64_t	vdev_resilver_txg; /* persistent resilvering state */
191 	uint64_t	vdev_nparity;	/* number of parity devices for raidz */
192 	char		*vdev_path;	/* vdev path (if any)		*/
193 	char		*vdev_devid;	/* vdev devid (if any)		*/
194 	char		*vdev_physpath;	/* vdev device path (if any)	*/
195 	char		*vdev_fru;	/* physical FRU location	*/
196 	uint64_t	vdev_not_present; /* not present during import	*/
197 	uint64_t	vdev_unspare;	/* unspare when resilvering done */
198 	boolean_t	vdev_nowritecache; /* true if flushwritecache failed */
199 	boolean_t	vdev_checkremove; /* temporary online test	*/
200 	boolean_t	vdev_forcefault; /* force online fault		*/
201 	boolean_t	vdev_splitting;	/* split or repair in progress  */
202 	boolean_t	vdev_delayed_close; /* delayed device close?	*/
203 	boolean_t	vdev_tmpoffline; /* device taken offline temporarily? */
204 	boolean_t	vdev_detached;	/* device detached?		*/
205 	boolean_t	vdev_cant_read;	/* vdev is failing all reads	*/
206 	boolean_t	vdev_cant_write; /* vdev is failing all writes	*/
207 	boolean_t	vdev_isspare;	/* was a hot spare		*/
208 	boolean_t	vdev_isl2cache;	/* was a l2cache device		*/
209 	vdev_queue_t	vdev_queue;	/* I/O deadline schedule queue	*/
210 	vdev_cache_t	vdev_cache;	/* physical block cache		*/
211 	spa_aux_vdev_t	*vdev_aux;	/* for l2cache and spares vdevs	*/
212 	zio_t		*vdev_probe_zio; /* root of current probe	*/
213 	vdev_aux_t	vdev_label_aux;	/* on-disk aux state		*/
214 
215 	/*
216 	 * For DTrace to work in userland (libzpool) context, these fields must
217 	 * remain at the end of the structure.  DTrace will use the kernel's
218 	 * CTF definition for 'struct vdev', and since the size of a kmutex_t is
219 	 * larger in userland, the offsets for the rest of the fields would be
220 	 * incorrect.
221 	 */
222 	kmutex_t	vdev_dtl_lock;	/* vdev_dtl_{map,resilver}	*/
223 	kmutex_t	vdev_stat_lock;	/* vdev_stat			*/
224 	kmutex_t	vdev_probe_lock; /* protects vdev_probe_zio	*/
225 };
226 
227 #define	VDEV_RAIDZ_MAXPARITY	3
228 
229 #define	VDEV_PAD_SIZE		(8 << 10)
230 /* 2 padding areas (vl_pad1 and vl_pad2) to skip */
231 #define	VDEV_SKIP_SIZE		VDEV_PAD_SIZE * 2
232 #define	VDEV_PHYS_SIZE		(112 << 10)
233 #define	VDEV_UBERBLOCK_RING	(128 << 10)
234 
235 /* The largest uberblock we support is 8k. */
236 #define	MAX_UBERBLOCK_SHIFT (13)
237 #define	VDEV_UBERBLOCK_SHIFT(vd)	\
238 	MIN(MAX((vd)->vdev_top->vdev_ashift, UBERBLOCK_SHIFT), \
239 	    MAX_UBERBLOCK_SHIFT)
240 #define	VDEV_UBERBLOCK_COUNT(vd)	\
241 	(VDEV_UBERBLOCK_RING >> VDEV_UBERBLOCK_SHIFT(vd))
242 #define	VDEV_UBERBLOCK_OFFSET(vd, n)	\
243 	offsetof(vdev_label_t, vl_uberblock[(n) << VDEV_UBERBLOCK_SHIFT(vd)])
244 #define	VDEV_UBERBLOCK_SIZE(vd)		(1ULL << VDEV_UBERBLOCK_SHIFT(vd))
245 
246 typedef struct vdev_phys {
247 	char		vp_nvlist[VDEV_PHYS_SIZE - sizeof (zio_eck_t)];
248 	zio_eck_t	vp_zbt;
249 } vdev_phys_t;
250 
251 typedef struct vdev_label {
252 	char		vl_pad1[VDEV_PAD_SIZE];			/*  8K */
253 	char		vl_pad2[VDEV_PAD_SIZE];			/*  8K */
254 	vdev_phys_t	vl_vdev_phys;				/* 112K	*/
255 	char		vl_uberblock[VDEV_UBERBLOCK_RING];	/* 128K	*/
256 } vdev_label_t;							/* 256K total */
257 
258 /*
259  * vdev_dirty() flags
260  */
261 #define	VDD_METASLAB	0x01
262 #define	VDD_DTL		0x02
263 
264 /* Offset of embedded boot loader region on each label */
265 #define	VDEV_BOOT_OFFSET	(2 * sizeof (vdev_label_t))
266 /*
267  * Size of embedded boot loader region on each label.
268  * The total size of the first two labels plus the boot area is 4MB.
269  */
270 #define	VDEV_BOOT_SIZE		(7ULL << 19)			/* 3.5M */
271 
272 /*
273  * Size of label regions at the start and end of each leaf device.
274  */
275 #define	VDEV_LABEL_START_SIZE	(2 * sizeof (vdev_label_t) + VDEV_BOOT_SIZE)
276 #define	VDEV_LABEL_END_SIZE	(2 * sizeof (vdev_label_t))
277 #define	VDEV_LABELS		4
278 #define	VDEV_BEST_LABEL		VDEV_LABELS
279 
280 #define	VDEV_ALLOC_LOAD		0
281 #define	VDEV_ALLOC_ADD		1
282 #define	VDEV_ALLOC_SPARE	2
283 #define	VDEV_ALLOC_L2CACHE	3
284 #define	VDEV_ALLOC_ROOTPOOL	4
285 #define	VDEV_ALLOC_SPLIT	5
286 #define	VDEV_ALLOC_ATTACH	6
287 
288 /*
289  * Allocate or free a vdev
290  */
291 extern vdev_t *vdev_alloc_common(spa_t *spa, uint_t id, uint64_t guid,
292     vdev_ops_t *ops);
293 extern int vdev_alloc(spa_t *spa, vdev_t **vdp, nvlist_t *config,
294     vdev_t *parent, uint_t id, int alloctype);
295 extern void vdev_free(vdev_t *vd);
296 
297 /*
298  * Add or remove children and parents
299  */
300 extern void vdev_add_child(vdev_t *pvd, vdev_t *cvd);
301 extern void vdev_remove_child(vdev_t *pvd, vdev_t *cvd);
302 extern void vdev_compact_children(vdev_t *pvd);
303 extern vdev_t *vdev_add_parent(vdev_t *cvd, vdev_ops_t *ops);
304 extern void vdev_remove_parent(vdev_t *cvd);
305 
306 /*
307  * vdev sync load and sync
308  */
309 extern void vdev_load_log_state(vdev_t *nvd, vdev_t *ovd);
310 extern boolean_t vdev_log_state_valid(vdev_t *vd);
311 extern void vdev_load(vdev_t *vd);
312 extern int vdev_dtl_load(vdev_t *vd);
313 extern void vdev_sync(vdev_t *vd, uint64_t txg);
314 extern void vdev_sync_done(vdev_t *vd, uint64_t txg);
315 extern void vdev_dirty(vdev_t *vd, int flags, void *arg, uint64_t txg);
316 extern void vdev_dirty_leaves(vdev_t *vd, int flags, uint64_t txg);
317 
318 /*
319  * Available vdev types.
320  */
321 extern vdev_ops_t vdev_root_ops;
322 extern vdev_ops_t vdev_mirror_ops;
323 extern vdev_ops_t vdev_replacing_ops;
324 extern vdev_ops_t vdev_raidz_ops;
325 extern vdev_ops_t vdev_disk_ops;
326 extern vdev_ops_t vdev_file_ops;
327 extern vdev_ops_t vdev_missing_ops;
328 extern vdev_ops_t vdev_hole_ops;
329 extern vdev_ops_t vdev_spare_ops;
330 
331 /*
332  * Common size functions
333  */
334 extern uint64_t vdev_default_asize(vdev_t *vd, uint64_t psize);
335 extern uint64_t vdev_get_min_asize(vdev_t *vd);
336 extern void vdev_set_min_asize(vdev_t *vd);
337 
338 /*
339  * Global variables
340  */
341 /* zdb uses this tunable, so it must be declared here to make lint happy. */
342 extern int zfs_vdev_cache_size;
343 
344 /*
345  * The vdev_buf_t is used to translate between zio_t and buf_t, and back again.
346  */
347 typedef struct vdev_buf {
348 	buf_t	vb_buf;		/* buffer that describes the io */
349 	zio_t	*vb_io;		/* pointer back to the original zio_t */
350 } vdev_buf_t;
351 
352 #ifdef	__cplusplus
353 }
354 #endif
355 
356 #endif	/* _SYS_VDEV_IMPL_H */
357