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8cd597c41c
Copy the metadata out of the initial async read buffer instead of performing another two synchronous reads (first to check vgname, second to read all metadata.)
136 lines
3.4 KiB
C
136 lines
3.4 KiB
C
/*
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* Copyright (C) 2002-2004 Sistina Software, Inc. All rights reserved.
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* Copyright (C) 2004-2007 Red Hat, Inc. All rights reserved.
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*
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* This file is part of LVM2.
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*
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* This copyrighted material is made available to anyone wishing to use,
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* modify, copy, or redistribute it subject to the terms and conditions
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* of the GNU Lesser General Public License v.2.1.
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*
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* You should have received a copy of the GNU Lesser General Public License
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* along with this program; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#ifndef _LVM_LABEL_H
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#define _LVM_LABEL_H
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#include "uuid.h"
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#include "device.h"
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#include "toolcontext.h"
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#include <libaio.h>
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#define LABEL_ID "LABELONE"
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#define LABEL_SIZE SECTOR_SIZE /* Think very carefully before changing this */
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#define LABEL_SCAN_SECTORS 4L
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#define LABEL_SCAN_SIZE (LABEL_SCAN_SECTORS << SECTOR_SHIFT)
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struct labeller;
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void allow_reads_with_lvmetad(void);
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/*
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* This is the amount of data read from each device
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* at the start of label scan. It's meant to be big
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* enough to cover all the headers and metadata that
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* need to be read during label scan for common cases.
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*/
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#define ASYNC_SCAN_SIZE (128 * 1024)
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struct label_read_data {
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char *buf; /* ASYNC_SCAN_SIZE aligned memory buffer */
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struct iocb iocb;
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struct device *dev;
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struct dm_list list;
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int buf_len; /* ASYNC_SCAN_SIZE */
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int try_sync;
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int read_done;
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int read_result;
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int process_done;
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};
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/* On disk - 32 bytes */
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struct label_header {
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int8_t id[8]; /* LABELONE */
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uint64_t sector_xl; /* Sector number of this label */
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uint32_t crc_xl; /* From next field to end of sector */
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uint32_t offset_xl; /* Offset from start of struct to contents */
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int8_t type[8]; /* LVM2 001 */
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} __attribute__ ((packed));
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/* In core */
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struct label {
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char type[8];
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uint64_t sector;
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struct labeller *labeller;
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struct device *dev;
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void *info;
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};
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struct labeller;
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struct label_ops {
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/*
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* Is the device labelled with this format ?
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*/
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int (*can_handle) (struct labeller * l, void *buf, uint64_t sector);
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/*
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* Write a label to a volume.
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*/
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int (*write) (struct label * label, void *buf);
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/*
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* Read a label from a volume.
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*/
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int (*read) (struct labeller * l, struct device * dev,
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void *label_buf,
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struct label_read_data *ld, struct label ** label);
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/*
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* Additional consistency checks for the paranoid.
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*/
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int (*verify) (struct labeller * l, void *buf, uint64_t sector);
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/*
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* Populate label_type etc.
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*/
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int (*initialise_label) (struct labeller * l, struct label * label);
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/*
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* Destroy a previously read label.
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*/
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void (*destroy_label) (struct labeller * l, struct label * label);
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/*
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* Destructor.
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*/
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void (*destroy) (struct labeller * l);
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};
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struct labeller {
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struct label_ops *ops;
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const struct format_type *fmt;
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};
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int label_init(void);
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void label_exit(void);
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int label_register_handler(struct labeller *handler);
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struct labeller *label_get_handler(const char *name);
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int label_remove(struct device *dev);
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int label_read(struct device *dev, struct label **label, uint64_t scan_sector);
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int label_write(struct device *dev, struct label *label);
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int label_verify(struct device *dev);
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struct label *label_create(struct labeller *labeller);
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void label_destroy(struct label *label);
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int label_scan_async(struct cmd_context *cmd);
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int label_scan_sync(struct cmd_context *cmd);
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#endif
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