patch-2.1.63 linux/include/linux/md.h

• Lines: 288
• Date: Sat Nov 8 11:39:13 1997
• Orig file: v2.1.62/linux/include/linux/md.h
• Orig date: Tue Oct 29 17:06:23 1996

diff -u --recursive --new-file v2.1.62/linux/include/linux/md.h linux/include/linux/md.h
@@ -1,4 +1,3 @@
-
 /*
    md.h : Multiple Devices driver for Linux
           Copyright (C) 1994-96 Marc ZYNGIER
@@ -19,10 +18,19 @@
 #define _MD_H
 
 #include <linux/major.h>
-#include <linux/mm.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_VERSION "0.35"
+#define MD_DEFAULT_DISK_READAHEAD	(256 * 1024)
 
 /* ioctls */
 #define REGISTER_DEV _IO (MD_MAJOR, 1)
@@ -42,9 +50,9 @@
 #define FAULT_SHIFT       8
 #define PERSONALITY_SHIFT 16
 
-#define FACTOR_MASK       0xFFUL
-#define FAULT_MASK        0xFF00UL
-#define PERSONALITY_MASK  0xFF0000UL
+#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)
@@ -54,15 +62,159 @@
 #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/types.h>
+#include <linux/mm.h>
 #include <linux/fs.h>
 #include <linux/blkdev.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 */
 
+#if SUPPORT_RECONSTRUCTION
+#define MAX_MD_THREADS (MAX_MD_DEV * 3)	/* Max number of kernel threads */
+#else
+#define MAX_MD_THREADS (MAX_MD_DEV)	/* Max number of kernel threads */
+#endif /* SUPPORT_RECONSTRUCTION */
+
 #define FACTOR(a)         ((a)->repartition & FACTOR_MASK)
 #define MAX_FAULT(a)      (((a)->repartition & FAULT_MASK)>>8)
 #define PERSONALITY(a)    ((a)->repartition & PERSONALITY_MASK)
@@ -76,40 +228,75 @@
   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 *md_dev, kdev_t *rdev,
-	     unsigned long *rsector, unsigned long size);
-  int (*run)(int minor, struct md_dev *md_dev);
-  int (*stop)(int minor, struct md_dev *md_dev);
-  int (*status)(char *page, int minor, struct md_dev *md_dev);
+  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;
-  int repartition;
-  int busy;
-  int nb_dev;
-  void *private;
+  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;
+	__u32			flags;
 };
 
+#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