xref: /netbsd-src/external/gpl2/lvm2/dist/lib/metadata/metadata.h (revision 2d48ac808c43ea6701ba8f33cfc3645685301f79)
1 /*	$NetBSD: metadata.h,v 1.1.1.2 2009/02/18 11:17:14 haad Exp $	*/
2 
3 /*
4  * Copyright (C) 2001-2004 Sistina Software, Inc. All rights reserved.
5  * Copyright (C) 2004-2007 Red Hat, Inc. All rights reserved.
6  *
7  * This file is part of LVM2.
8  *
9  * This copyrighted material is made available to anyone wishing to use,
10  * modify, copy, or redistribute it subject to the terms and conditions
11  * of the GNU Lesser General Public License v.2.1.
12  *
13  * You should have received a copy of the GNU Lesser General Public License
14  * along with this program; if not, write to the Free Software Foundation,
15  * Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
16  */
17 
18 /*
19  * This is the in core representation of a volume group and its
20  * associated physical and logical volumes.
21  */
22 
23 #ifndef _LVM_METADATA_H
24 #define _LVM_METADATA_H
25 
26 #include "ctype.h"
27 #include "dev-cache.h"
28 #include "lvm-string.h"
29 #include "metadata-exported.h"
30 
31 //#define MAX_STRIPES 128U
32 //#define SECTOR_SHIFT 9L
33 #define SECTOR_SIZE ( 1L << SECTOR_SHIFT )
34 //#define STRIPE_SIZE_MIN ( (unsigned) lvm_getpagesize() >> SECTOR_SHIFT)	/* PAGESIZE in sectors */
35 //#define STRIPE_SIZE_MAX ( 512L * 1024L >> SECTOR_SHIFT)	/* 512 KB in sectors */
36 //#define STRIPE_SIZE_LIMIT ((UINT_MAX >> 2) + 1)
37 //#define PV_MIN_SIZE ( 512L * 1024L >> SECTOR_SHIFT)	/* 512 KB in sectors */
38 //#define MAX_RESTRICTED_LVS 255	/* Used by FMT_RESTRICTED_LVIDS */
39 #define MIRROR_LOG_OFFSET	2	/* sectors */
40 
41 /*
42  * Ceiling(n / sz)
43  */
44 #define dm_div_up(n, sz) (((n) + (sz) - 1) / (sz))
45 
46 /*
47  * Ceiling(n / size) * size
48  */
49 #define dm_round_up(n, sz) (dm_div_up((n), (sz)) * (sz))
50 
51 
52 /* Various flags */
53 /* Note that the bits no longer necessarily correspond to LVM1 disk format */
54 
55 //#define PARTIAL_VG		0x00000001U	/* VG */
56 //#define EXPORTED_VG          	0x00000002U	/* VG PV */
57 //#define RESIZEABLE_VG        	0x00000004U	/* VG */
58 
59 /* May any free extents on this PV be used or must they be left free? */
60 //#define ALLOCATABLE_PV         	0x00000008U	/* PV */
61 
62 #define SPINDOWN_LV          	0x00000010U	/* LV */
63 #define BADBLOCK_ON       	0x00000020U	/* LV */
64 //#define VISIBLE_LV		0x00000040U	/* LV */
65 //#define FIXED_MINOR		0x00000080U	/* LV */
66 /* FIXME Remove when metadata restructuring is completed */
67 //#define SNAPSHOT		0x00001000U	/* LV - internal use only */
68 //#define PVMOVE			0x00002000U	/* VG LV SEG */
69 //#define LOCKED			0x00004000U	/* LV */
70 //#define MIRRORED		0x00008000U	/* LV - internal use only */
71 #define VIRTUAL			0x00010000U	/* LV - internal use only */
72 //#define MIRROR_LOG		0x00020000U	/* LV */
73 //#define MIRROR_IMAGE		0x00040000U	/* LV */
74 //#define MIRROR_NOTSYNCED	0x00080000U	/* LV */
75 #define ACTIVATE_EXCL		0x00100000U	/* LV - internal use only */
76 #define PRECOMMITTED		0x00200000U	/* VG - internal use only */
77 //#define CONVERTING		0x00400000U	/* LV */
78 
79 //#define MISSING_PV		0x00800000U	/* PV */
80 //#define PARTIAL_LV		0x01000000U	/* LV - derived flag, not
81 //						   written out in metadata*/
82 
83 #define POSTORDER_FLAG		0x02000000U /* Not real flags, reserved for  */
84 #define POSTORDER_OPEN_FLAG	0x04000000U /* temporary use inside vg_read. */
85 
86 //#define LVM_READ              	0x00000100U	/* LV VG */
87 //#define LVM_WRITE             	0x00000200U	/* LV VG */
88 //#define CLUSTERED         	0x00000400U	/* VG */
89 #define SHARED            	0x00000800U	/* VG */
90 
91 /* Format features flags */
92 //#define FMT_SEGMENTS		0x00000001U	/* Arbitrary segment params? */
93 //#define FMT_MDAS		0x00000002U	/* Proper metadata areas? */
94 //#define FMT_TAGS		0x00000004U	/* Tagging? */
95 //#define FMT_UNLIMITED_VOLS	0x00000008U	/* Unlimited PVs/LVs? */
96 //#define FMT_RESTRICTED_LVIDS	0x00000010U	/* LVID <= 255 */
97 //#define FMT_ORPHAN_ALLOCATABLE	0x00000020U	/* Orphan PV allocatable? */
98 #define FMT_PRECOMMIT		0x00000040U	/* Supports pre-commit? */
99 //#define FMT_RESIZE_PV		0x00000080U	/* Supports pvresize? */
100 //#define FMT_UNLIMITED_STRIPESIZE 0x00000100U	/* Unlimited stripe size? */
101 
102 struct metadata_area;
103 
104 /* Per-format per-metadata area operations */
105 struct metadata_area_ops {
106 	struct volume_group *(*vg_read) (struct format_instance * fi,
107 					 const char *vg_name,
108 					 struct metadata_area * mda);
109 	struct volume_group *(*vg_read_precommit) (struct format_instance * fi,
110 					 const char *vg_name,
111 					 struct metadata_area * mda);
112 	/*
113 	 * Write out complete VG metadata.  You must ensure internal
114 	 * consistency before calling. eg. PEs can't refer to PVs not
115 	 * part of the VG.
116 	 *
117 	 * It is also the responsibility of the caller to ensure external
118 	 * consistency, eg by calling pv_write() if removing PVs from
119 	 * a VG or calling vg_write() a second time if splitting a VG
120 	 * into two.
121 	 *
122 	 * vg_write() should not read or write from any PVs not included
123 	 * in the volume_group structure it is handed.
124 	 * (format1 currently breaks this rule.)
125 	 */
126 	int (*vg_write) (struct format_instance * fid, struct volume_group * vg,
127 			 struct metadata_area * mda);
128 	int (*vg_precommit) (struct format_instance * fid,
129 			     struct volume_group * vg,
130 			     struct metadata_area * mda);
131 	int (*vg_commit) (struct format_instance * fid,
132 			  struct volume_group * vg, struct metadata_area * mda);
133 	int (*vg_revert) (struct format_instance * fid,
134 			  struct volume_group * vg, struct metadata_area * mda);
135 	int (*vg_remove) (struct format_instance * fi, struct volume_group * vg,
136 			  struct metadata_area * mda);
137 
138 	/*
139 	 * Returns number of free sectors in given metadata area.
140 	 */
141 	uint64_t (*mda_free_sectors) (struct metadata_area *mda);
142 
143 	/*
144 	 * Returns number of total sectors in given metadata area.
145 	 */
146 	uint64_t (*mda_total_sectors) (struct metadata_area *mda);
147 
148 	/*
149 	 * Check if metadata area belongs to vg
150 	 */
151 	int (*mda_in_vg) (struct format_instance * fi,
152 			    struct volume_group * vg, struct metadata_area *mda);
153 	/*
154 	 * Analyze a metadata area on a PV.
155 	 */
156 	int (*pv_analyze_mda) (const struct format_type * fmt,
157 			       struct metadata_area *mda);
158 
159 };
160 
161 struct metadata_area {
162 	struct dm_list list;
163 	struct metadata_area_ops *ops;
164 	void *metadata_locn;
165 };
166 
167 #define seg_pvseg(seg, s)	(seg)->areas[(s)].u.pv.pvseg
168 #define seg_dev(seg, s)		(seg)->areas[(s)].u.pv.pvseg->pv->dev
169 #define seg_pe(seg, s)		(seg)->areas[(s)].u.pv.pvseg->pe
170 #define seg_le(seg, s)		(seg)->areas[(s)].u.lv.le
171 
172 struct name_list {
173 	struct dm_list list;
174 	char *name;
175 };
176 
177 struct mda_list {
178 	struct dm_list list;
179 	struct device_area mda;
180 };
181 
182 struct peg_list {
183 	struct dm_list list;
184 	struct pv_segment *peg;
185 };
186 
187 struct seg_list {
188 	struct dm_list list;
189 	unsigned count;
190 	struct lv_segment *seg;
191 };
192 
193 /*
194  * Ownership of objects passes to caller.
195  */
196 struct format_handler {
197 	/*
198 	 * Scan any metadata areas that aren't referenced in PV labels
199 	 */
200 	int (*scan) (const struct format_type * fmt);
201 
202 	/*
203 	 * Return PV with given path.
204 	 */
205 	int (*pv_read) (const struct format_type * fmt, const char *pv_name,
206 			struct physical_volume * pv, struct dm_list * mdas);
207 
208 	/*
209 	 * Tweak an already filled out a pv ready for importing into a
210 	 * vg.  eg. pe_count is format specific.
211 	 */
212 	int (*pv_setup) (const struct format_type * fmt,
213 			 uint64_t pe_start, uint32_t extent_count,
214 			 uint32_t extent_size,
215 			 int pvmetadatacopies,
216 			 uint64_t pvmetadatasize, struct dm_list * mdas,
217 			 struct physical_volume * pv, struct volume_group * vg);
218 
219 	/*
220 	 * Write a PV structure to disk. Fails if the PV is in a VG ie
221 	 * pv->vg_name must be a valid orphan VG name
222 	 */
223 	int (*pv_write) (const struct format_type * fmt,
224 			 struct physical_volume * pv, struct dm_list * mdas,
225 			 int64_t label_sector);
226 
227 	/*
228 	 * Tweak an already filled out a lv eg, check there
229 	 * aren't too many extents.
230 	 */
231 	int (*lv_setup) (struct format_instance * fi,
232 			 struct logical_volume * lv);
233 
234 	/*
235 	 * Tweak an already filled out vg.  eg, max_pv is format
236 	 * specific.
237 	 */
238 	int (*vg_setup) (struct format_instance * fi, struct volume_group * vg);
239 
240 	/*
241 	 * Check whether particular segment type is supported.
242 	 */
243 	int (*segtype_supported) (struct format_instance *fid,
244 				  const struct segment_type *segtype);
245 
246 	/*
247 	 * Create format instance with a particular metadata area
248 	 */
249 	struct format_instance *(*create_instance) (const struct format_type *
250 						    fmt, const char *vgname,
251 						    const char *vgid,
252 						    void *context);
253 
254 	/*
255 	 * Destructor for format instance
256 	 */
257 	void (*destroy_instance) (struct format_instance * fid);
258 
259 	/*
260 	 * Destructor for format type
261 	 */
262 	void (*destroy) (const struct format_type * fmt);
263 };
264 
265 /*
266  * Utility functions
267  */
268 unsigned long pe_align(struct physical_volume *pv);
269 int vg_validate(struct volume_group *vg);
270 
271 int pv_write_orphan(struct cmd_context *cmd, struct physical_volume *pv);
272 
273 /* Manipulate PV structures */
274 int pv_add(struct volume_group *vg, struct physical_volume *pv);
275 int pv_remove(struct volume_group *vg, struct physical_volume *pv);
276 struct physical_volume *pv_find(struct volume_group *vg, const char *pv_name);
277 
278 /* Find a PV within a given VG */
279 int get_pv_from_vg_by_id(const struct format_type *fmt, const char *vg_name,
280 			 const char *vgid, const char *pvid,
281 			 struct physical_volume *pv);
282 
283 struct lv_list *find_lv_in_vg_by_lvid(struct volume_group *vg,
284 				      const union lvid *lvid);
285 
286 struct lv_list *find_lv_in_lv_list(const struct dm_list *ll,
287 				   const struct logical_volume *lv);
288 
289 /* Return the VG that contains a given LV (based on path given in lv_name) */
290 /* or environment var */
291 struct volume_group *find_vg_with_lv(const char *lv_name);
292 
293 /* Find LV with given lvid (used during activation) */
294 struct logical_volume *lv_from_lvid(struct cmd_context *cmd,
295 				    const char *lvid_s,
296 				    unsigned precommitted);
297 
298 /* FIXME Merge these functions with ones above */
299 struct physical_volume *find_pv(struct volume_group *vg, struct device *dev);
300 
301 struct pv_list *find_pv_in_pv_list(const struct dm_list *pl,
302 				   const struct physical_volume *pv);
303 
304 /* Find LV segment containing given LE */
305 struct lv_segment *find_seg_by_le(const struct logical_volume *lv, uint32_t le);
306 
307 /* Find PV segment containing given LE */
308 struct pv_segment *find_peg_by_pe(const struct physical_volume *pv, uint32_t pe);
309 
310 /*
311  * Remove a dev_dir if present.
312  */
313 const char *strip_dir(const char *vg_name, const char *dir);
314 
315 /*
316  * Checks that an lv has no gaps or overlapping segments.
317  * Set complete_vg to perform additional VG level checks.
318  */
319 int check_lv_segments(struct logical_volume *lv, int complete_vg);
320 
321 /*
322  * Sometimes (eg, after an lvextend), it is possible to merge two
323  * adjacent segments into a single segment.  This function trys
324  * to merge as many segments as possible.
325  */
326 int lv_merge_segments(struct logical_volume *lv);
327 
328 /*
329  * Ensure there's a segment boundary at a given LE, splitting if necessary
330  */
331 int lv_split_segment(struct logical_volume *lv, uint32_t le);
332 
333 /*
334  * Add/remove upward link from underlying LV to the segment using it
335  * FIXME: ridiculously long name
336  */
337 int add_seg_to_segs_using_this_lv(struct logical_volume *lv, struct lv_segment *seg);
338 int remove_seg_from_segs_using_this_lv(struct logical_volume *lv, struct lv_segment *seg);
339 struct lv_segment *get_only_segment_using_this_lv(struct logical_volume *lv);
340 
341 /*
342  * Count LVs that are visible from user's perspective.
343  */
344 unsigned displayable_lvs_in_vg(const struct volume_group *vg);
345 
346 /*
347  * For internal metadata caching.
348  */
349 int export_vg_to_buffer(struct volume_group *vg, char **buf);
350 struct volume_group *import_vg_from_buffer(char *buf,
351 					   struct format_instance *fid);
352 
353 /*
354  * Mirroring functions
355  */
356 
357 /*
358  * Given mirror image or mirror log segment, find corresponding mirror segment
359  */
360 int fixup_imported_mirrors(struct volume_group *vg);
361 
362 /*
363  * Begin skeleton for external LVM library
364  */
365 struct id pv_id(const pv_t *pv);
366 const struct format_type *pv_format_type(const pv_t *pv);
367 struct id pv_vgid(const pv_t *pv);
368 
369 pv_t *pv_by_path(struct cmd_context *cmd, const char *pv_name);
370 int add_pv_to_vg(struct volume_group *vg, const char *pv_name,
371 		 struct physical_volume *pv);
372 
373 #endif
374