1 /* $NetBSD: label.h,v 1.1.1.1 2008/12/22 00:18:02 haad Exp $ */ 2 3 /* 4 * Copyright (C) 2002-2004 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 #ifndef _LVM_LABEL_H 19 #define _LVM_LABEL_H 20 21 #include "uuid.h" 22 #include "device.h" 23 24 #define LABEL_ID "LABELONE" 25 #define LABEL_SIZE SECTOR_SIZE /* Think very carefully before changing this */ 26 #define LABEL_SCAN_SECTORS 4L 27 #define LABEL_SCAN_SIZE (LABEL_SCAN_SECTORS << SECTOR_SHIFT) 28 29 struct labeller; 30 31 /* On disk - 32 bytes */ 32 struct label_header { 33 int8_t id[8]; /* LABELONE */ 34 uint64_t sector_xl; /* Sector number of this label */ 35 uint32_t crc_xl; /* From next field to end of sector */ 36 uint32_t offset_xl; /* Offset from start of struct to contents */ 37 int8_t type[8]; /* LVM2 001 */ 38 } __attribute__ ((packed)); 39 40 /* In core */ 41 struct label { 42 char type[8]; 43 uint64_t sector; 44 struct labeller *labeller; 45 void *info; 46 }; 47 48 struct labeller; 49 50 struct label_ops { 51 /* 52 * Is the device labelled with this format ? 53 */ 54 int (*can_handle) (struct labeller * l, void *buf, uint64_t sector); 55 56 /* 57 * Write a label to a volume. 58 */ 59 int (*write) (struct label * label, void *buf); 60 61 /* 62 * Read a label from a volume. 63 */ 64 int (*read) (struct labeller * l, struct device * dev, 65 void *buf, struct label ** label); 66 67 /* 68 * Additional consistency checks for the paranoid. 69 */ 70 int (*verify) (struct labeller * l, void *buf, uint64_t sector); 71 72 /* 73 * Populate label_type etc. 74 */ 75 int (*initialise_label) (struct labeller * l, struct label * label); 76 77 /* 78 * Destroy a previously read label. 79 */ 80 void (*destroy_label) (struct labeller * l, struct label * label); 81 82 /* 83 * Destructor. 84 */ 85 void (*destroy) (struct labeller * l); 86 }; 87 88 struct labeller { 89 struct label_ops *ops; 90 const void *private; 91 }; 92 93 int label_init(void); 94 void label_exit(void); 95 96 int label_register_handler(const char *name, struct labeller *handler); 97 98 struct labeller *label_get_handler(const char *name); 99 100 int label_remove(struct device *dev); 101 int label_read(struct device *dev, struct label **result, 102 uint64_t scan_sector); 103 int label_write(struct device *dev, struct label *label); 104 int label_verify(struct device *dev); 105 struct label *label_create(struct labeller *labeller); 106 void label_destroy(struct label *label); 107 108 #endif 109