patch-2.4.21 linux-2.4.21/drivers/ide/raid/pdcraid.c

• Lines: 603
• Date: 2003-06-13 07:51:34.000000000 -0700
• Orig file: linux-2.4.20/drivers/ide/raid/pdcraid.c
• Orig date: 1969-12-31 16:00:00.000000000 -0800

diff -urN linux-2.4.20/drivers/ide/raid/pdcraid.c linux-2.4.21/drivers/ide/raid/pdcraid.c
@@ -0,0 +1,602 @@
+/*
+   pdcraid.c  Copyright (C) 2001 Red Hat, Inc. All rights reserved.
+
+   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.  
+   
+   Authors: 	Arjan van de Ven <arjanv@redhat.com>
+   		
+   Based on work done by Søren Schmidt for FreeBSD  
+
+*/
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/smp_lock.h>
+#include <linux/blkdev.h>
+#include <linux/blkpg.h>
+#include <linux/genhd.h>
+#include <linux/ioctl.h>
+
+#include <linux/ide.h>
+#include <asm/uaccess.h>
+
+#include "ataraid.h"
+
+static int pdcraid_open(struct inode * inode, struct file * filp);
+static int pdcraid_release(struct inode * inode, struct file * filp);
+static int pdcraid_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg);
+static int pdcraid0_make_request (request_queue_t *q, int rw, struct buffer_head * bh);
+static int pdcraid1_make_request (request_queue_t *q, int rw, struct buffer_head * bh);
+
+struct disk_dev {
+	int major;
+	int minor;
+	int device;
+};
+
+static struct disk_dev devlist[]= {
+	{IDE0_MAJOR,  0,  -1 },
+	{IDE0_MAJOR, 64,  -1 },
+	{IDE1_MAJOR,  0,  -1 },
+	{IDE1_MAJOR, 64,  -1 },
+	{IDE2_MAJOR,  0,  -1 },
+	{IDE2_MAJOR, 64,  -1 },
+	{IDE3_MAJOR,  0,  -1 },
+	{IDE3_MAJOR, 64,  -1 },
+	{IDE4_MAJOR,  0,  -1 },
+	{IDE4_MAJOR, 64,  -1 },
+	{IDE5_MAJOR,  0,  -1 },
+	{IDE5_MAJOR, 64,  -1 },
+	{IDE6_MAJOR,  0,  -1 },
+	{IDE6_MAJOR, 64,  -1 },
+};
+
+
+struct pdcdisk {
+	kdev_t	device;
+	unsigned long sectors;
+	struct block_device *bdev;
+	unsigned long last_pos;
+};
+
+struct pdcraid {
+	unsigned int stride;
+	unsigned int disks;
+	unsigned long sectors;
+	struct geom geom;
+	
+	struct pdcdisk disk[8];
+	
+	unsigned long cutoff[8];
+	unsigned int cutoff_disks[8];
+};
+
+static struct raid_device_operations pdcraid0_ops = {
+        open:                   pdcraid_open,
+	release:                pdcraid_release,
+	ioctl:			pdcraid_ioctl,
+	make_request:		pdcraid0_make_request
+};
+
+static struct raid_device_operations pdcraid1_ops = {
+        open:                   pdcraid_open,
+	release:                pdcraid_release,
+	ioctl:			pdcraid_ioctl,
+	make_request:		pdcraid1_make_request
+};
+
+static struct pdcraid raid[16];
+
+
+static int pdcraid_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
+{
+	unsigned int minor;
+   	unsigned long sectors;
+
+	if (!inode || !inode->i_rdev) 
+		return -EINVAL;
+
+	minor = MINOR(inode->i_rdev)>>SHIFT;
+	
+	switch (cmd) {
+
+         	case BLKGETSIZE:   /* Return device size */
+ 			if (!arg)  return -EINVAL;
+			sectors = ataraid_gendisk.part[MINOR(inode->i_rdev)].nr_sects;
+			if (MINOR(inode->i_rdev)&15)
+				return put_user(sectors, (unsigned long *) arg);
+			return put_user(raid[minor].sectors , (unsigned long *) arg);
+			break;
+			
+
+		case HDIO_GETGEO:
+		{
+			struct hd_geometry *loc = (struct hd_geometry *) arg;
+			unsigned short bios_cyl = raid[minor].geom.cylinders; /* truncate */
+			
+			if (!loc) return -EINVAL;
+			if (put_user(raid[minor].geom.heads, (byte *) &loc->heads)) return -EFAULT;
+			if (put_user(raid[minor].geom.sectors, (byte *) &loc->sectors)) return -EFAULT;
+			if (put_user(bios_cyl, (unsigned short *) &loc->cylinders)) return -EFAULT;
+			if (put_user((unsigned)ataraid_gendisk.part[MINOR(inode->i_rdev)].start_sect,
+				(unsigned long *) &loc->start)) return -EFAULT;
+			return 0;
+		}
+
+		case HDIO_GETGEO_BIG:
+		{
+			struct hd_big_geometry *loc = (struct hd_big_geometry *) arg;
+			if (!loc) return -EINVAL;
+			if (put_user(raid[minor].geom.heads, (byte *) &loc->heads)) return -EFAULT;
+			if (put_user(raid[minor].geom.sectors, (byte *) &loc->sectors)) return -EFAULT;
+			if (put_user(raid[minor].geom.cylinders, (unsigned int *) &loc->cylinders)) return -EFAULT;
+			if (put_user((unsigned)ataraid_gendisk.part[MINOR(inode->i_rdev)].start_sect,
+				(unsigned long *) &loc->start)) return -EFAULT;
+			return 0;
+		}
+
+		default:
+			return blk_ioctl(inode->i_rdev, cmd, arg);
+	};
+
+	return 0;
+}
+
+
+static unsigned long partition_map_normal(unsigned long block, unsigned long partition_off, unsigned long partition_size, int stride)
+{
+	return block + partition_off;
+}
+
+static int pdcraid0_make_request (request_queue_t *q, int rw, struct buffer_head * bh)
+{
+	unsigned long rsect;
+	unsigned long rsect_left,rsect_accum = 0;
+	unsigned long block;
+	unsigned int disk=0,real_disk=0;
+	int i;
+	int device;
+	struct pdcraid *thisraid;
+
+	rsect = bh->b_rsector;
+	
+	/* Ok. We need to modify this sector number to a new disk + new sector number. 
+	 * If there are disks of different sizes, this gets tricky. 
+	 * Example with 3 disks (1Gb, 4Gb and 5 GB):
+	 * The first 3 Gb of the "RAID" are evenly spread over the 3 disks.
+	 * Then things get interesting. The next 2Gb (RAID view) are spread across disk 2 and 3
+	 * and the last 1Gb is disk 3 only.
+	 *
+	 * the way this is solved is like this: We have a list of "cutoff" points where everytime
+	 * a disk falls out of the "higher" count, we mark the max sector. So once we pass a cutoff
+	 * point, we have to divide by one less.
+	 */
+	
+	device = (bh->b_rdev >> SHIFT)&MAJOR_MASK;
+	thisraid = &raid[device];
+	if (thisraid->stride==0)
+		thisraid->stride=1;
+
+	/* Partitions need adding of the start sector of the partition to the requested sector */
+	
+	rsect = partition_map_normal(rsect, ataraid_gendisk.part[MINOR(bh->b_rdev)].start_sect, ataraid_gendisk.part[MINOR(bh->b_rdev)].nr_sects, thisraid->stride);
+
+	/* Woops we need to split the request to avoid crossing a stride barrier */
+	if ((rsect/thisraid->stride) != ((rsect+(bh->b_size/512)-1)/thisraid->stride)) {
+		return -1;  
+	}
+	
+	rsect_left = rsect;
+	
+	for (i=0;i<8;i++) {
+		if (thisraid->cutoff_disks[i]==0)
+			break;
+		if (rsect > thisraid->cutoff[i]) {
+			/* we're in the wrong area so far */
+			rsect_left -= thisraid->cutoff[i];
+			rsect_accum += thisraid->cutoff[i]/thisraid->cutoff_disks[i];
+		} else {
+			block = rsect_left / thisraid->stride;
+			disk = block % thisraid->cutoff_disks[i];
+			block = (block / thisraid->cutoff_disks[i]) * thisraid->stride;
+			rsect = rsect_accum + (rsect_left % thisraid->stride) + block;
+			break;
+		}
+	}
+	
+	for (i=0;i<8;i++) {
+		if ((disk==0) && (thisraid->disk[i].sectors > rsect_accum)) {
+			real_disk = i;
+			break;
+		}
+		if ((disk>0) && (thisraid->disk[i].sectors >= rsect_accum)) {
+			disk--;
+		}
+		
+	}
+	disk = real_disk;
+		
+	
+	/*
+	 * The new BH_Lock semantics in ll_rw_blk.c guarantee that this
+	 * is the only IO operation happening on this bh.
+	 */
+	bh->b_rdev = thisraid->disk[disk].device;
+	bh->b_rsector = rsect;
+
+	/*
+	 * Let the main block layer submit the IO and resolve recursion:
+	 */
+	return 1;
+}
+
+static int pdcraid1_write_request(request_queue_t *q, int rw, struct buffer_head * bh)
+{
+	struct buffer_head *bh1;
+	struct ataraid_bh_private *private;
+	int device;
+	int i;
+
+	device = (bh->b_rdev >> SHIFT)&MAJOR_MASK;
+	private = ataraid_get_private();
+	if (private==NULL)
+		BUG();
+
+	private->parent = bh;
+	
+	atomic_set(&private->count,raid[device].disks);
+
+
+	for (i = 0; i< raid[device].disks; i++) { 
+		bh1=ataraid_get_bhead();
+		/* If this ever fails we're doomed */
+		if (!bh1)
+			BUG();
+	
+		/* dupe the bufferhead and update the parts that need to be different */
+		memcpy(bh1, bh, sizeof(*bh));
+		
+		bh1->b_end_io = ataraid_end_request;
+		bh1->b_private = private;
+		bh1->b_rsector += ataraid_gendisk.part[MINOR(bh->b_rdev)].start_sect; /* partition offset */
+		bh1->b_rdev = raid[device].disk[i].device;
+
+		/* update the last known head position for the drive */
+		raid[device].disk[i].last_pos = bh1->b_rsector+(bh1->b_size>>9);
+
+		generic_make_request(rw,bh1);
+	}
+	return 0;
+}
+
+static int pdcraid1_read_request (request_queue_t *q, int rw, struct buffer_head * bh)
+{
+	int device;
+	int dist;
+	int bestsofar,bestdist,i;
+	static int previous;
+
+	/* Reads are simple in principle. Pick a disk and go. 
+	   Initially I cheat by just picking the one which the last known
+	   head position is closest by.
+	   Later on, online/offline checking and performance needs adding */
+	
+	device = (bh->b_rdev >> SHIFT)&MAJOR_MASK;
+	bh->b_rsector += ataraid_gendisk.part[MINOR(bh->b_rdev)].start_sect;
+
+	bestsofar = 0; 
+	bestdist = raid[device].disk[0].last_pos - bh->b_rsector;
+	if (bestdist<0) 
+		bestdist=-bestdist;
+	if (bestdist>4095)
+		bestdist=4095;
+
+	for (i=1 ; i<raid[device].disks; i++) {
+		dist = raid[device].disk[i].last_pos - bh->b_rsector;
+		if (dist<0) 
+			dist = -dist;
+		if (dist>4095)
+			dist=4095;
+		
+		if (bestdist==dist) {  /* it's a tie; try to do some read balancing */
+			if ((previous>bestsofar)&&(previous<=i))  
+				bestsofar = i;
+			previous = (previous + 1) % raid[device].disks;
+		} else if (bestdist>dist) {
+			bestdist = dist;
+			bestsofar = i;
+		}
+	
+	}
+	
+	bh->b_rdev = raid[device].disk[bestsofar].device; 
+	raid[device].disk[bestsofar].last_pos = bh->b_rsector+(bh->b_size>>9);
+
+	/*
+	 * Let the main block layer submit the IO and resolve recursion:
+	 */
+                          	
+	return 1;
+}
+
+
+static int pdcraid1_make_request (request_queue_t *q, int rw, struct buffer_head * bh)
+{
+	/* Read and Write are totally different cases; split them totally here */
+	if (rw==READA)
+		rw = READ;
+	
+	if (rw==READ)
+		return pdcraid1_read_request(q,rw,bh);
+	else
+		return pdcraid1_write_request(q,rw,bh);
+}
+
+#include "pdcraid.h"
+
+static unsigned long calc_pdcblock_offset (int major,int minor)
+{
+	unsigned long lba = 0;
+	kdev_t dev;
+	ide_drive_t *ideinfo;
+	
+	dev = MKDEV(major,minor);
+	ideinfo = get_info_ptr (dev);
+	if (ideinfo==NULL)
+		return 0;
+	
+	
+	/* first sector of the last cluster */
+	if (ideinfo->head==0) 
+		return 0;
+	if (ideinfo->sect==0)
+		return 0;
+	lba = (ideinfo->capacity / (ideinfo->head*ideinfo->sect));
+	lba = lba * (ideinfo->head*ideinfo->sect);
+	lba = lba - ideinfo->sect;
+
+	return lba;
+}
+
+
+static int read_disk_sb (int major, int minor, unsigned char *buffer,int bufsize)
+{
+	int ret = -EINVAL;
+	struct buffer_head *bh = NULL;
+	kdev_t dev = MKDEV(major,minor);
+	unsigned long sb_offset;
+
+	if (blksize_size[major]==NULL)   /* device doesn't exist */
+		return -EINVAL;
+                       
+	
+	/*
+	 * Calculate the position of the superblock,
+	 * it's at first sector of the last cylinder
+	 */
+	sb_offset = calc_pdcblock_offset(major,minor)/8;
+	/* The /8 transforms sectors into 4Kb blocks */
+
+	if (sb_offset==0)
+		return -1;	
+	
+	set_blocksize (dev, 4096);
+
+	bh = bread (dev, sb_offset, 4096);
+	
+	if (bh) {
+		memcpy (buffer, bh->b_data, bufsize);
+	} else {
+		printk(KERN_ERR "pdcraid: Error reading superblock.\n");
+		goto abort;
+	}
+	ret = 0;
+abort:
+	if (bh)
+		brelse (bh);
+	return ret;
+}
+
+static unsigned int calc_sb_csum (unsigned int* ptr)
+{	
+	unsigned int sum;
+	int count;
+	
+	sum = 0;
+	for (count=0;count<511;count++)
+		sum += *ptr++;
+	
+	return sum;
+}
+
+static int cookie = 0;
+
+static void __init probedisk(int devindex,int device, int raidlevel)
+{
+	int i;
+	int major, minor;
+        struct promise_raid_conf *prom;
+	static unsigned char block[4096];
+	struct block_device *bdev;
+
+	if (devlist[devindex].device!=-1) /* already assigned to another array */
+		return;
+	
+	major = devlist[devindex].major;
+	minor = devlist[devindex].minor; 
+
+        if (read_disk_sb(major,minor,(unsigned char*)&block,sizeof(block)))
+        	return;
+                                                                                                                 
+        prom = (struct promise_raid_conf*)&block[512];
+
+        /* the checksums must match */
+	if (prom->checksum != calc_sb_csum((unsigned int*)prom))
+		return;
+	if (prom->raid.type!=raidlevel) /* different raidlevel */
+		return;
+
+	if ((cookie!=0) && (cookie != prom->raid.magic_1)) /* different array */
+		return;
+	
+	cookie = prom->raid.magic_1;
+
+	/* This looks evil. But basically, we have to search for our adapternumber
+	   in the arraydefinition, both of which are in the superblock */	
+        for (i=0;(i<prom->raid.total_disks)&&(i<8);i++) {
+        	if ( (prom->raid.disk[i].channel== prom->raid.channel) &&
+        	     (prom->raid.disk[i].device == prom->raid.device) ) {
+
+        	        bdev = bdget(MKDEV(major,minor));
+        	        if (bdev && blkdev_get(bdev, FMODE_READ|FMODE_WRITE, 0, BDEV_RAW) == 0) {
+				raid[device].disk[i].bdev = bdev;
+			}
+			raid[device].disk[i].device = MKDEV(major,minor);
+			raid[device].disk[i].sectors = prom->raid.disk_secs;
+			raid[device].stride = (1<<prom->raid.raid0_shift);
+			raid[device].disks = prom->raid.total_disks;
+			raid[device].sectors = prom->raid.total_secs;
+			raid[device].geom.heads = prom->raid.heads+1;
+			raid[device].geom.sectors = prom->raid.sectors;
+			raid[device].geom.cylinders = prom->raid.cylinders+1;
+			devlist[devindex].device=device;
+        	     }
+        }
+	               
+}
+
+static void __init fill_cutoff(int device)
+{
+	int i,j;
+	unsigned long smallest;
+	unsigned long bar;
+	int count;
+	
+	bar = 0;
+	for (i=0;i<8;i++) {
+		smallest = ~0;
+		for (j=0;j<8;j++) 
+			if ((raid[device].disk[j].sectors < smallest) && (raid[device].disk[j].sectors>bar))
+				smallest = raid[device].disk[j].sectors;
+		count = 0;
+		for (j=0;j<8;j++) 
+			if (raid[device].disk[j].sectors >= smallest)
+				count++;
+				
+		smallest = smallest * count;
+		bar = smallest;
+		raid[device].cutoff[i] = smallest;
+		raid[device].cutoff_disks[i] = count;
+	}
+}
+			   
+static __init int pdcraid_init_one(int device,int raidlevel)
+{
+	int i, count;
+
+	for (i=0; i<14; i++)
+		probedisk(i, device, raidlevel);
+	
+	if (raidlevel==0)
+		fill_cutoff(device);
+	
+	/* Initialize the gendisk structure */
+	
+	ataraid_register_disk(device,raid[device].sectors);        
+		
+	count=0;
+	
+	for (i=0;i<8;i++) {
+		if (raid[device].disk[i].device!=0) {
+			printk(KERN_INFO "Drive %i is %li Mb (%i / %i) \n",
+				i,raid[device].disk[i].sectors/2048,MAJOR(raid[device].disk[i].device),MINOR(raid[device].disk[i].device));
+			count++;
+		}
+	}
+	if (count) {
+		printk(KERN_INFO "Raid%i array consists of %i drives. \n",raidlevel,count);
+		return 0;
+	} else {
+		return -ENODEV;
+	}
+}
+
+static __init int pdcraid_init(void)
+{
+	int retval, device, count = 0;
+
+	do {
+		cookie = 0;
+		device=ataraid_get_device(&pdcraid0_ops);
+		if (device<0)
+			break;
+		retval = pdcraid_init_one(device,0);
+		if (retval) {
+			ataraid_release_device(device);
+			break;
+		} else {
+			count++;
+		}
+	} while (1);
+
+	do {
+	
+		cookie = 0;
+		device=ataraid_get_device(&pdcraid1_ops);
+		if (device<0)
+			break;
+		retval = pdcraid_init_one(device,1);
+		if (retval) {
+			ataraid_release_device(device);
+			break;
+		} else {
+			count++;
+		}
+	} while (1);
+
+	if (count) {
+		printk(KERN_INFO "Promise Fasttrak(tm) Softwareraid driver for linux version 0.03beta\n");
+		return 0;
+	}
+	printk(KERN_DEBUG "Promise Fasttrak(tm) Softwareraid driver 0.03beta: No raid array found\n");
+	return -ENODEV;
+}
+
+static void __exit pdcraid_exit (void)
+{
+	int i,device;
+	for (device = 0; device<16; device++) {
+		for (i=0;i<8;i++) {
+			struct block_device *bdev = raid[device].disk[i].bdev;
+			raid[device].disk[i].bdev = NULL;
+			if (bdev)
+				blkdev_put(bdev, BDEV_RAW);
+		}	
+		if (raid[device].sectors)
+			ataraid_release_device(device);
+	}
+}
+
+static int pdcraid_open(struct inode * inode, struct file * filp) 
+{
+	MOD_INC_USE_COUNT;
+	return 0;
+}
+static int pdcraid_release(struct inode * inode, struct file * filp)
+{	
+	MOD_DEC_USE_COUNT;
+	return 0;
+}
+
+module_init(pdcraid_init);
+module_exit(pdcraid_exit);
+MODULE_LICENSE("GPL");