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Diffstat (limited to 'tools/sfex.h')
| -rw-r--r-- | tools/sfex.h | 176 |
1 files changed, 176 insertions, 0 deletions
diff --git a/tools/sfex.h b/tools/sfex.h new file mode 100644 index 0000000..3795c29 --- /dev/null +++ b/tools/sfex.h @@ -0,0 +1,176 @@ +/*------------------------------------------------------------------------- + * + * Shared Disk File EXclusiveness Control Program(SF-EX) + * + * sfex.h --- Primary include file for SF-EX *.c files. + * + * Copyright (c) 2007 NIPPON TELEGRAPH AND TELEPHONE CORPORATION + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA + * 02110-1301, USA. + * + * $Id$ + * + *-------------------------------------------------------------------------*/ + +#ifndef SFEX_H +#define SFEX_H + +#include <clplumbing/cl_log.h> +#include <clplumbing/coredumps.h> +#include <clplumbing/realtime.h> + +#include <stdint.h> + +/* version, revision */ +/* These numbers are integer and, max number is 999. + If these numbers change, version numbers in the configure.ac + (AC_INIT, AM_INIT_AUTOMAKE) must change together. + */ +#define SFEX_VERSION 1 +#define SFEX_REVISION 3 + +#if 0 +#ifndef TRUE +# define TRUE 1 +#endif +#ifndef FALSE +# define FALSE 0 +#endif +#ifndef MIN +# define MIN(a, b) ((a) < (b) ? (a) : (b)) +#endif +#ifndef MAX +# define MAX(a, b) ((a) > (b) ? (a) : (b)) +#endif +#endif + +/* for Linux >= 2.6, the alignment should be 512 + for Linux < 2.6, the alignment should be sysconf(_SC_PAGESIZE) + we default to _SC_PAGESIZE + */ +#define SFEX_ODIRECT_ALIGNMENT sysconf(_SC_PAGESIZE) + +/* + * sfex_controldata --- control data + * + * This is allocated the head of sfex mata-data area. + * + * magic number --- 4 bytes. This is fixed in {0x01, 0x1f, 0x71, 0x7f}. + * + * version number --- 4 bytes. This is printable integer number and + * range is from 0 to 999. This must be left-justify, null(0x00) padding, and + * make a last byte null. + * + * revision number --- 4 bytes. This is printable integer number and + * range is from 0 to 999. This must be left-justify, null(0x00) padding, and + * make a last byte null. + * + * blocksize --- 8bytes. This is printable integer number and range is from + * 512 to 9999999. This must be left-justify, null(0x00) padding, and make a + * last byte null. This is a size of control data and lock data(one lock data + * size when there are plural), and it is shown by number of bytes. + * For avoiding partial writing, usually block size is set 512 byte etc. + * If you use direct I/O(if you spacificate --enable-directio for configure + * script), note that this value is used for input and output buffer alignment. + * (In the Linux kernel 2.6, if this value is not 512 multibles, direct I/O + * does not work) + + * number of locks --- 4 bytes. This is printable integer number and range + * is from 1 to 999. This must be left-justify, null(0x00) padding, and make + * a last byte null. This is the number of locks following this control data. + * + * padding --- The size of this member depend on blocksize. It is adjusted so + * that the whole of the control data including this padding area becomes + * blocksize. The contents of padding area are all 0x00. + */ +typedef struct sfex_controldata { + char magic[4]; /* magic number */ + int version; /* version number */ + int revision; /* revision number */ + size_t blocksize; /* block size */ + int numlocks; /* number of locks */ +} sfex_controldata; + +typedef struct sfex_controldata_ondisk { + uint8_t magic[4]; + uint8_t version[4]; + uint8_t revision[4]; + uint8_t blocksize[8]; + uint8_t numlocks[4]; +} sfex_controldata_ondisk; + +/* + * sfex_lockdata --- lock data + * + * This data(number is sfex_controldata.numlocks) are allocated behind of + * sfex_controldata in the sfex meta-data area. The meaning of each member + * and the storage method to mata data area are following; + * + * lock status --- 1 byte. printable character. Content is either one of + * following; + * SFEX_STATUS_UNLOCK: It show the status that no node locks. + * SFEX_STATUS_LOCK: It show the status that nodename node is holding lock. + * (But there is an exception. Refer to explanation of "count" member.) + * + * increment counter --- 4 bytes. This is printable integer number and range + * is from 1 to 999. This must be left-justify, null(0x00) padding, and make + * a last byte null. The node holding a lock increments this counter + * periodically. If this counter does not increment for a certain period of + * time, we consider that the lock is invalid. If it overflow, return to 0. + * Initial value is 0. + * + * node name --- 256bytes. This is printable string. This must be left-justify, + * null(0x00) padding, and make a last byte null. This is node name that update + * lock data last. The node name must be same to get uname(2). Initial values + * are white spaces. + * + * padding --- The size of this member depend on blocksize. It is adjusted so + * that the whole of the control data including this padding area becomes + * blocksize. The contents of padding area are all 0x00. + */ +typedef struct sfex_lockdata { + char status; /* status of lock */ + int count; /* increment counter */ + char nodename[256]; /* node name */ +} sfex_lockdata; + +typedef struct sfex_lockdata_ondisk { + uint8_t status; + uint8_t count[4]; + uint8_t nodename[256]; +} sfex_lockdata_ondisk; + +/* character for lock status. This is used in sfex_lockdata.status */ +#define SFEX_STATUS_UNLOCK 'u' /* unlock */ +#define SFEX_STATUS_LOCK 'l' /* lock */ + +/* features of each member of control data and lock data */ +#define SFEX_MAGIC "SFEX" +#define SFEX_MIN_NUMLOCKS 1 +#define SFEX_MAX_NUMLOCKS 999 +#define SFEX_MIN_COUNT 0 +#define SFEX_MAX_COUNT 999 +#define SFEX_MAX_NODENAME (sizeof(((sfex_lockdata *)0)->nodename) - 1) + +/* update macro for increment counter */ +#define SFEX_NEXT_COUNT(c) (c >= SFEX_MAX_COUNT ? c - SFEX_MAX_COUNT : c + 1) + +/* extern variables */ +extern const char *progname; +extern char *nodename; +extern unsigned long sector_size; + +#endif /* SFEX_H */ |