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Diffstat (limited to 'pfinet/linux-src/include/linux/md.h')
| -rw-r--r-- | pfinet/linux-src/include/linux/md.h | 300 |
1 files changed, 300 insertions, 0 deletions
diff --git a/pfinet/linux-src/include/linux/md.h b/pfinet/linux-src/include/linux/md.h new file mode 100644 index 00000000..f4f4f548 --- /dev/null +++ b/pfinet/linux-src/include/linux/md.h @@ -0,0 +1,300 @@ +/* + md.h : Multiple Devices driver for Linux + Copyright (C) 1994-96 Marc ZYNGIER + <zyngier@ufr-info-p7.ibp.fr> or + <maz@gloups.fdn.fr> + + 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, or (at your option) + any later version. + + You should have received a copy of the GNU General Public License + (for example /usr/src/linux/COPYING); if not, write to the Free + Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. +*/ + +#ifndef _MD_H +#define _MD_H + +#include <linux/major.h> +#include <linux/ioctl.h> +#include <linux/types.h> + +/* + * Different major versions are not compatible. + * Different minor versions are only downward compatible. + * Different patchlevel versions are downward and upward compatible. + */ +#define MD_MAJOR_VERSION 0 +#define MD_MINOR_VERSION 36 +#define MD_PATCHLEVEL_VERSION 6 + +#define MD_DEFAULT_DISK_READAHEAD (256 * 1024) + +/* ioctls */ +#define REGISTER_DEV _IO (MD_MAJOR, 1) +#define START_MD _IO (MD_MAJOR, 2) +#define STOP_MD _IO (MD_MAJOR, 3) +#define REGISTER_DEV_NEW _IO (MD_MAJOR, 4) + +/* + personalities : + Byte 0 : Chunk size factor + Byte 1 : Fault tolerance count for each physical device + ( 0 means no fault tolerance, + 0xFF means always tolerate faults), not used by now. + Byte 2 : Personality + Byte 3 : Reserved. + */ + +#define FAULT_SHIFT 8 +#define PERSONALITY_SHIFT 16 + +#define FACTOR_MASK 0x000000FFUL +#define FAULT_MASK 0x0000FF00UL +#define PERSONALITY_MASK 0x00FF0000UL + +#define MD_RESERVED 0 /* Not used by now */ +#define LINEAR (1UL << PERSONALITY_SHIFT) +#define STRIPED (2UL << PERSONALITY_SHIFT) +#define RAID0 STRIPED +#define RAID1 (3UL << PERSONALITY_SHIFT) +#define RAID5 (4UL << PERSONALITY_SHIFT) +#define MAX_PERSONALITY 5 + +/* + * MD superblock. + * + * The MD superblock maintains some statistics on each MD configuration. + * Each real device in the MD set contains it near the end of the device. + * Some of the ideas are copied from the ext2fs implementation. + * + * We currently use 4096 bytes as follows: + * + * word offset function + * + * 0 - 31 Constant generic MD device information. + * 32 - 63 Generic state information. + * 64 - 127 Personality specific information. + * 128 - 511 12 32-words descriptors of the disks in the raid set. + * 512 - 911 Reserved. + * 912 - 1023 Disk specific descriptor. + */ + +/* + * If x is the real device size in bytes, we return an apparent size of: + * + * y = (x & ~(MD_RESERVED_BYTES - 1)) - MD_RESERVED_BYTES + * + * and place the 4kB superblock at offset y. + */ +#define MD_RESERVED_BYTES (64 * 1024) +#define MD_RESERVED_SECTORS (MD_RESERVED_BYTES / 512) +#define MD_RESERVED_BLOCKS (MD_RESERVED_BYTES / BLOCK_SIZE) + +#define MD_NEW_SIZE_SECTORS(x) ((x & ~(MD_RESERVED_SECTORS - 1)) - MD_RESERVED_SECTORS) +#define MD_NEW_SIZE_BLOCKS(x) ((x & ~(MD_RESERVED_BLOCKS - 1)) - MD_RESERVED_BLOCKS) + +#define MD_SB_BYTES 4096 +#define MD_SB_WORDS (MD_SB_BYTES / 4) +#define MD_SB_BLOCKS (MD_SB_BYTES / BLOCK_SIZE) +#define MD_SB_SECTORS (MD_SB_BYTES / 512) + +/* + * The following are counted in 32-bit words + */ +#define MD_SB_GENERIC_OFFSET 0 +#define MD_SB_PERSONALITY_OFFSET 64 +#define MD_SB_DISKS_OFFSET 128 +#define MD_SB_DESCRIPTOR_OFFSET 992 + +#define MD_SB_GENERIC_CONSTANT_WORDS 32 +#define MD_SB_GENERIC_STATE_WORDS 32 +#define MD_SB_GENERIC_WORDS (MD_SB_GENERIC_CONSTANT_WORDS + MD_SB_GENERIC_STATE_WORDS) +#define MD_SB_PERSONALITY_WORDS 64 +#define MD_SB_DISKS_WORDS 384 +#define MD_SB_DESCRIPTOR_WORDS 32 +#define MD_SB_RESERVED_WORDS (1024 - MD_SB_GENERIC_WORDS - MD_SB_PERSONALITY_WORDS - MD_SB_DISKS_WORDS - MD_SB_DESCRIPTOR_WORDS) +#define MD_SB_EQUAL_WORDS (MD_SB_GENERIC_WORDS + MD_SB_PERSONALITY_WORDS + MD_SB_DISKS_WORDS) +#define MD_SB_DISKS (MD_SB_DISKS_WORDS / MD_SB_DESCRIPTOR_WORDS) + +/* + * Device "operational" state bits + */ +#define MD_FAULTY_DEVICE 0 /* Device is faulty / operational */ +#define MD_ACTIVE_DEVICE 1 /* Device is a part or the raid set / spare disk */ +#define MD_SYNC_DEVICE 2 /* Device is in sync with the raid set */ + +typedef struct md_device_descriptor_s { + __u32 number; /* 0 Device number in the entire set */ + __u32 major; /* 1 Device major number */ + __u32 minor; /* 2 Device minor number */ + __u32 raid_disk; /* 3 The role of the device in the raid set */ + __u32 state; /* 4 Operational state */ + __u32 reserved[MD_SB_DESCRIPTOR_WORDS - 5]; +} md_descriptor_t; + +#define MD_SB_MAGIC 0xa92b4efc + +/* + * Superblock state bits + */ +#define MD_SB_CLEAN 0 +#define MD_SB_ERRORS 1 + +typedef struct md_superblock_s { + + /* + * Constant generic information + */ + __u32 md_magic; /* 0 MD identifier */ + __u32 major_version; /* 1 major version to which the set conforms */ + __u32 minor_version; /* 2 minor version to which the set conforms */ + __u32 patch_version; /* 3 patchlevel version to which the set conforms */ + __u32 gvalid_words; /* 4 Number of non-reserved words in this section */ + __u32 set_magic; /* 5 Raid set identifier */ + __u32 ctime; /* 6 Creation time */ + __u32 level; /* 7 Raid personality (mirroring, raid5, ...) */ + __u32 size; /* 8 Apparent size of each individual disk, in kB */ + __u32 nr_disks; /* 9 Number of total disks in the raid set */ + __u32 raid_disks; /* 10 Number of disks in a fully functional raid set */ + __u32 gstate_creserved[MD_SB_GENERIC_CONSTANT_WORDS - 11]; + + /* + * Generic state information + */ + __u32 utime; /* 0 Superblock update time */ + __u32 state; /* 1 State bits (clean, ...) */ + __u32 active_disks; /* 2 Number of currently active disks (some non-faulty disks might not be in sync) */ + __u32 working_disks; /* 3 Number of working disks */ + __u32 failed_disks; /* 4 Number of failed disks */ + __u32 spare_disks; /* 5 Number of spare disks */ + __u32 gstate_sreserved[MD_SB_GENERIC_STATE_WORDS - 6]; + + /* + * Personality information + */ + __u32 parity_algorithm; + __u32 chunk_size; + __u32 pstate_reserved[MD_SB_PERSONALITY_WORDS - 2]; + + /* + * Disks information + */ + md_descriptor_t disks[MD_SB_DISKS]; + + /* + * Reserved + */ + __u32 reserved[MD_SB_RESERVED_WORDS]; + + /* + * Active descriptor + */ + md_descriptor_t descriptor; +} md_superblock_t; + +#ifdef __KERNEL__ + +#include <linux/mm.h> +#include <linux/fs.h> +#include <linux/blkdev.h> +#include <asm/semaphore.h> + +/* + * Kernel-based reconstruction is mostly working, but still requires + * some additional work. + */ +#define SUPPORT_RECONSTRUCTION 0 + +#define MAX_REAL 8 /* Max number of physical dev per md dev */ +#define MAX_MD_DEV 4 /* Max number of md dev */ + +#define FACTOR(a) ((a)->repartition & FACTOR_MASK) +#define MAX_FAULT(a) (((a)->repartition & FAULT_MASK)>>8) +#define PERSONALITY(a) ((a)->repartition & PERSONALITY_MASK) + +#define FACTOR_SHIFT(a) (PAGE_SHIFT + (a) - 10) + +struct real_dev +{ + kdev_t dev; /* Device number */ + int size; /* Device size (in blocks) */ + int offset; /* Real device offset (in blocks) in md dev + (only used in linear mode) */ + struct inode *inode; /* Lock inode */ + md_superblock_t *sb; + u32 sb_offset; +}; + +struct md_dev; + +#define SPARE_INACTIVE 0 +#define SPARE_WRITE 1 +#define SPARE_ACTIVE 2 + +struct md_personality +{ + char *name; + int (*map)(struct md_dev *mddev, kdev_t *rdev, + unsigned long *rsector, unsigned long size); + int (*make_request)(struct md_dev *mddev, int rw, struct buffer_head * bh); + void (*end_request)(struct buffer_head * bh, int uptodate); + int (*run)(int minor, struct md_dev *mddev); + int (*stop)(int minor, struct md_dev *mddev); + int (*status)(char *page, int minor, struct md_dev *mddev); + int (*ioctl)(struct inode *inode, struct file *file, + unsigned int cmd, unsigned long arg); + int max_invalid_dev; + int (*error_handler)(struct md_dev *mddev, kdev_t dev); + +/* + * Some personalities (RAID-1, RAID-5) can get disks hot-added and + * hot-removed. Hot removal is different from failure. (failure marks + * a disk inactive, but the disk is still part of the array) + */ + int (*hot_add_disk) (struct md_dev *mddev, kdev_t dev); + int (*hot_remove_disk) (struct md_dev *mddev, kdev_t dev); + int (*mark_spare) (struct md_dev *mddev, md_descriptor_t *descriptor, int state); +}; + +struct md_dev +{ + struct real_dev devices[MAX_REAL]; + struct md_personality *pers; + md_superblock_t *sb; + int sb_dirty; + int repartition; + int busy; + int nb_dev; + void *private; +}; + +struct md_thread { + void (*run) (void *data); + void *data; + struct wait_queue *wqueue; + unsigned long flags; + struct semaphore *sem; + struct task_struct *tsk; +}; + +#define THREAD_WAKEUP 0 + +extern struct md_dev md_dev[MAX_MD_DEV]; +extern int md_size[MAX_MD_DEV]; +extern int md_maxreadahead[MAX_MD_DEV]; + +extern char *partition_name (kdev_t dev); + +extern int register_md_personality (int p_num, struct md_personality *p); +extern int unregister_md_personality (int p_num); +extern struct md_thread *md_register_thread (void (*run) (void *data), void *data); +extern void md_unregister_thread (struct md_thread *thread); +extern void md_wakeup_thread(struct md_thread *thread); +extern int md_update_sb (int minor); +extern int md_do_sync(struct md_dev *mddev); + +#endif __KERNEL__ +#endif _MD_H |