[PATCH] randomness made per-disk

	* per-major array eliminated, every disk is a separate source of
randomness

drivers/block/DAC960.c

@@ -3014,7 +3014,7 @@ static void DAC960_V1_ProcessCompletedCommand(DAC960_Command_T *Command)
 	      complete(Command->Completion);
 	      Command->Completion = NULL;
 	    }
-	  add_blkdev_randomness(DAC960_MAJOR + Controller->ControllerNumber);
+	  add_disk_randomness(Controller->disks[Command->LogicalDriveNumber]);
 	}
       else if ((CommandStatus == DAC960_V1_IrrecoverableDataError ||
 		CommandStatus == DAC960_V1_BadDataEncountered) &&
@@ -4120,7 +4120,7 @@ static void DAC960_V2_ProcessCompletedCommand(DAC960_Command_T *Command)
 	      complete(Command->Completion);
 	      Command->Completion = NULL;
 	    }
-	  add_blkdev_randomness(DAC960_MAJOR + Controller->ControllerNumber);
+	  add_disk_randomness(Controller->disks[Command->LogicalDriveNumber]);
 	}
       else if (Command->V2.RequestSense.SenseKey
 	       == DAC960_SenseKey_MediumError &&

drivers/block/floppy.c

@@ -2297,7 +2297,7 @@ static inline void end_request(struct request *req, int uptodate)
 {
 	if (end_that_request_first(req, uptodate, current_count_sectors))
 		return;
-	add_blkdev_randomness(MAJOR_NR);
+	add_disk_randomness(req->rq_disk);
 	floppy_off((int)req->rq_disk->private_data);
 	blkdev_dequeue_request(req);
 	end_that_request_last(req);

drivers/block/genhd.c

@@ -289,6 +289,7 @@ EXPORT_SYMBOL(disk_devclass);
 static void disk_release(struct device *dev)
 {
 	struct gendisk *disk = dev->driver_data;
+	kfree(disk->random);
 	kfree(disk->part);
 	kfree(disk);
 }
@@ -316,6 +317,7 @@ struct gendisk *alloc_disk(int minors)
 		disk->disk_dev.driver_data = disk;
 		device_initialize(&disk->disk_dev);
 	}
+	rand_initialize_disk(disk);
 	return disk;
 }
 

drivers/char/random.c

@@ -253,6 +253,7 @@
 #include <linux/init.h>
 #include <linux/fs.h>
 #include <linux/workqueue.h>
+#include <linux/genhd.h>
 
 #include <asm/processor.h>
 #include <asm/uaccess.h>
@@ -718,7 +719,6 @@ static struct timer_rand_state keyboard_timer_state;
 static struct timer_rand_state mouse_timer_state;
 static struct timer_rand_state extract_timer_state;
 static struct timer_rand_state *irq_timer_state[NR_IRQS];
-static struct timer_rand_state *blkdev_timer_state[MAX_BLKDEV];
 
 /*
  * This function adds entropy to the entropy "pool" by using timing
@@ -812,18 +812,12 @@ void add_interrupt_randomness(int irq)
 	add_timer_randomness(irq_timer_state[irq], 0x100+irq);
 }
 
-void add_blkdev_randomness(int major)
+void add_disk_randomness(struct gendisk *disk)
 {
-	if (major >= MAX_BLKDEV)
+	if (!disk || !disk->random)
 		return;
-
-	if (blkdev_timer_state[major] == 0) {
-		rand_initialize_blkdev(major, GFP_ATOMIC);
-		if (blkdev_timer_state[major] == 0)
-			return;
-	}
-		
-	add_timer_randomness(blkdev_timer_state[major], 0x200+major);
+	/* first major is 1, so we get >= 0x200 here */
+	add_timer_randomness(disk->random, 0x100+MKDEV(disk->major, disk->first_minor));
 }
 
 /******************************************************************
@@ -1447,8 +1441,6 @@ void __init rand_initialize(void)
 #endif
 	for (i = 0; i < NR_IRQS; i++)
 		irq_timer_state[i] = NULL;
-	for (i = 0; i < MAX_BLKDEV; i++)
-		blkdev_timer_state[i] = NULL;
 	memset(&keyboard_timer_state, 0, sizeof(struct timer_rand_state));
 	memset(&mouse_timer_state, 0, sizeof(struct timer_rand_state));
 	memset(&extract_timer_state, 0, sizeof(struct timer_rand_state));
@@ -1473,25 +1465,21 @@ void rand_initialize_irq(int irq)
 	}
 }
  
-void rand_initialize_blkdev(int major, int mode)
+void rand_initialize_disk(struct gendisk *disk)
 {
 	struct timer_rand_state *state;
 	
-	if (major >= MAX_BLKDEV || blkdev_timer_state[major])
-		return;
-
 	/*
 	 * If kmalloc returns null, we just won't use that entropy
 	 * source.
 	 */
-	state = kmalloc(sizeof(struct timer_rand_state), mode);
+	state = kmalloc(sizeof(struct timer_rand_state), GFP_KERNEL);
 	if (state) {
 		memset(state, 0, sizeof(struct timer_rand_state));
-		blkdev_timer_state[major] = state;
+		disk->random = state;
 	}
 }
 
-
 static ssize_t
 random_read(struct file * file, char * buf, size_t nbytes, loff_t *ppos)
 {
@@ -2309,7 +2297,7 @@ __u32 check_tcp_syn_cookie(__u32 cookie, __u32 saddr, __u32 daddr, __u16 sport,
 EXPORT_SYMBOL(add_keyboard_randomness);
 EXPORT_SYMBOL(add_mouse_randomness);
 EXPORT_SYMBOL(add_interrupt_randomness);
-EXPORT_SYMBOL(add_blkdev_randomness);
+EXPORT_SYMBOL(add_disk_randomness);
 EXPORT_SYMBOL(batch_entropy_store);
 EXPORT_SYMBOL(generate_random_uuid);
 

drivers/ide/ide.c

@@ -406,7 +406,7 @@ int ide_end_request (ide_drive_t *drive, int uptodate, int nr_sectors)
 	}
 
 	if (!end_that_request_first(rq, uptodate, nr_sectors)) {
-		add_blkdev_randomness(major(rq->rq_dev));
+		add_disk_randomness(rq->rq_disk);
 		if (!blk_rq_tagged(rq))
 			blkdev_dequeue_request(rq);
 		else

drivers/s390/block/dasd.c

@@ -1496,7 +1496,7 @@ dasd_end_request(struct request *req, int uptodate)
 {
 	if (end_that_request_first(req, uptodate, req->hard_nr_sectors))
 		BUG();
-	add_blkdev_randomness(major(req->rq_dev));
+	add_disk_randomness(req->rq_disk);
 	end_that_request_last(req);
 	return;
 }

drivers/scsi/scsi_lib.c

@@ -357,7 +357,7 @@ static Scsi_Cmnd *__scsi_end_request(Scsi_Cmnd * SCpnt,
 		return SCpnt;
 	}
 
-	add_blkdev_randomness(major(req->rq_dev));
+	add_disk_randomness(req->rq_disk);
 
 	spin_lock_irqsave(q->queue_lock, flags);
 

include/linux/blk.h

@@ -8,7 +8,8 @@
 #include <linux/compiler.h>
 
 extern void set_device_ro(kdev_t dev,int flag);
-extern void add_blkdev_randomness(int major);
+extern void add_disk_randomness(struct gendisk *disk);
+extern void rand_initialize_disk(struct gendisk *disk);
 
 #ifdef CONFIG_BLK_DEV_RAM
 
@@ -62,7 +63,7 @@ static inline void end_request(struct request *req, int uptodate)
 	if (end_that_request_first(req, uptodate, req->hard_cur_sectors))
 		return;
 
-	add_blkdev_randomness(major(req->rq_dev));
+	add_disk_randomness(req->rq_disk);
 	blkdev_dequeue_request(req);
 	end_that_request_last(req);
 }

include/linux/genhd.h

@@ -93,6 +93,9 @@ struct gendisk {
 	struct device *driverfs_dev;
 	struct device disk_dev;
 
+	struct timer_rand_state *random;
+
+
 	unsigned sync_io;		/* RAID */
 	unsigned reads, writes;
 	unsigned rio, wio;

include/linux/random.h

@@ -44,14 +44,12 @@ struct rand_pool_info {
 
 extern void rand_initialize(void);
 extern void rand_initialize_irq(int irq);
-extern void rand_initialize_blkdev(int irq, int mode);
 
 extern void batch_entropy_store(u32 a, u32 b, int num);
 
 extern void add_keyboard_randomness(unsigned char scancode);
 extern void add_mouse_randomness(__u32 mouse_data);
 extern void add_interrupt_randomness(int irq);
-extern void add_blkdev_randomness(int major);
 
 extern void get_random_bytes(void *buf, int nbytes);
 void generate_random_uuid(unsigned char uuid_out[16]);