[PATCH 2/2] nbd: remove PARANOIA and other cleanups

From: Paul Clements
Date: Thu Feb 19 2004 - 13:21:20 EST


This patch removes the PARANOIA define (it was always defined anyway).
It also removes the requests_in/out counters (which weren't always
accurate, and are superfluous anyway, since the block layer keeps its
own in_flight counter). Also some minor cleanup of comments.

Thanks,
Paul--- 2_6_3_rc2/include/linux/nbd.h.PRISTINE Thu Feb 19 12:06:07 2004
+++ 2_6_3_rc2/include/linux/nbd.h Thu Feb 19 12:34:35 2004
@@ -8,6 +8,8 @@
* 2003/06/24 Louis D. Langholtz <ldl@xxxxxxxx>
* Removed unneeded blksize_bits field from nbd_device struct.
* Cleanup PARANOIA usage & code.
+ * 2004/02/19 Paul Clements
+ * Removed PARANOIA, plus various cleanup and comments
*/

#ifndef LINUX_NBD_H
@@ -32,22 +34,19 @@ enum {
#define nbd_cmd(req) ((req)->cmd[0])
#define MAX_NBD 128

-/* Define PARANOIA to include extra sanity checking code in here & driver */
-#define PARANOIA
-
/* userspace doesn't need the nbd_device structure */
#ifdef __KERNEL__

+/* values for flags field */
+#define NBD_READ_ONLY 0x0001
+#define NBD_WRITE_NOCHK 0x0002
+
struct nbd_device {
int flags;
int harderror; /* Code of hard error */
-#define NBD_READ_ONLY 0x0001
-#define NBD_WRITE_NOCHK 0x0002
struct socket * sock;
struct file * file; /* If == NULL, device is not ready, yet */
-#ifdef PARANOIA
- int magic; /* FIXME: not if debugging is off */
-#endif
+ int magic;
spinlock_t queue_lock;
struct list_head queue_head;/* Requests are added here... */
struct semaphore tx_lock;
@@ -58,16 +57,14 @@ struct nbd_device {

#endif

-/* This now IS in some kind of include file... */
-
-/* These are send over network in request/reply magic field */
+/* These are sent over the network in the request/reply magic fields */

#define NBD_REQUEST_MAGIC 0x25609513
#define NBD_REPLY_MAGIC 0x67446698
/* Do *not* use magics: 0x12560953 0x96744668. */

/*
- * This is packet used for communication between client and
+ * This is the packet used for communication between client and
* server. All data are in network byte order.
*/
struct nbd_request {
@@ -82,6 +79,10 @@ struct nbd_request {
#endif
;

+/*
+ * This is the reply packet that nbd-server sends back to the client after
+ * it has completed an I/O request (or an error occurs).
+ */
struct nbd_reply {
u32 magic;
u32 error; /* 0 = ok, else error */
--- 2_6_3_rc2/drivers/block/nbd.c.PROC_PARTITIONS_FIXES Thu Feb 19 11:49:15 2004
+++ 2_6_3_rc2/drivers/block/nbd.c Thu Feb 19 12:54:48 2004
@@ -36,7 +36,7 @@
* 03-06-24 Remove unneeded blksize_bits field from nbd_device struct.
* <ldl@xxxxxxxx>
* 03-06-24 Cleanup PARANOIA usage & code. <ldl@xxxxxxxx>
- *
+ * 04-02-19 Remove PARANOIA, plus various cleanups (Paul Clements)
* possible FIXME: make set_sock / set_blksize / set_size / do_it one syscall
* why not: would need verify_area and friends, would share yet another
* structure with userland
@@ -61,12 +61,9 @@
#include <asm/uaccess.h>
#include <asm/types.h>

-/* Define PARANOIA in linux/nbd.h to turn on extra sanity checking */
#include <linux/nbd.h>

-#ifdef PARANOIA
#define LO_MAGIC 0x68797548
-#endif

#ifdef NDEBUG
#define dprintk(flags, fmt...)
@@ -97,11 +94,6 @@ static struct nbd_device nbd_dev[MAX_NBD
*/
static spinlock_t nbd_lock = SPIN_LOCK_UNLOCKED;

-#ifdef PARANOIA
-static int requests_in;
-static int requests_out;
-#endif
-
#ifndef NDEBUG
static const char *ioctl_cmd_to_ascii(int cmd)
{
@@ -153,9 +145,6 @@ static void nbd_end_request(struct reque
}
spin_unlock(&lo->queue_lock);

-#ifdef PARANOIA
- requests_out++;
-#endif
spin_lock_irqsave(q->queue_lock, flags);
if (!end_that_request_first(req, uptodate, req->nr_sectors)) {
end_that_request_last(req);
@@ -217,10 +206,6 @@ static int sock_xmit(struct socket *sock
}

if (result <= 0) {
-#ifdef PARANOIA
- printk(KERN_ERR "nbd: %s - sock=%p at buf=%p, size=%d returned %d.\n",
- send? "send": "receive", sock, buf, size, result);
-#endif
if (result == 0)
result = -EPIPE; /* short read */
break;
@@ -414,9 +399,8 @@ void nbd_do_it(struct nbd_device *lo)
{
struct request *req;

-#ifdef PARANOIA
BUG_ON(lo->magic != LO_MAGIC);
-#endif
+
while ((req = nbd_read_stat(lo)) != NULL)
nbd_end_request(req);
return;
@@ -426,9 +410,7 @@ void nbd_clear_que(struct nbd_device *lo
{
struct request *req;

-#ifdef PARANOIA
BUG_ON(lo->magic != LO_MAGIC);
-#endif

do {
req = NULL;
@@ -467,9 +449,9 @@ static void do_nbd_request(request_queue
goto error_out;

lo = req->rq_disk->private_data;
-#ifdef PARANOIA
+
BUG_ON(lo->magic != LO_MAGIC);
-#endif
+
if (!lo->file) {
printk(KERN_ERR "%s: Request when not-ready\n",
lo->disk->disk_name);
@@ -484,9 +466,6 @@ static void do_nbd_request(request_queue
goto error_out;
}
}
-#ifdef PARANOIA
- requests_in++;
-#endif

req->errors = 0;
spin_unlock_irq(q->queue_lock);
@@ -527,7 +506,7 @@ static void do_nbd_request(request_queue
spin_lock_irq(q->queue_lock);
continue;

- error_out:
+error_out:
req->errors++;
spin_unlock(q->queue_lock);
nbd_end_request(req);
@@ -545,9 +524,9 @@ static int nbd_ioctl(struct inode *inode

if (!capable(CAP_SYS_ADMIN))
return -EPERM;
-#ifdef PARANOIA
+
BUG_ON(lo->magic != LO_MAGIC);
-#endif
+
/* Anyone capable of this syscall can do *real bad* things */
dprintk(DBG_IOCTL, "%s: nbd_ioctl cmd=%s(0x%x) arg=%lu\n",
lo->disk->disk_name, ioctl_cmd_to_ascii(cmd), cmd, arg);
@@ -663,15 +642,10 @@ static int nbd_ioctl(struct inode *inode
nbd_clear_que(lo);
return 0;
case NBD_PRINT_DEBUG:
-#ifdef PARANOIA
- printk(KERN_INFO "%s: next = %p, prev = %p. Global: in %d, out %d\n",
- inode->i_bdev->bd_disk->disk_name, lo->queue_head.next,
- lo->queue_head.prev, requests_in, requests_out);
-#else
- printk(KERN_INFO "%s: next = %p, prev = %p\n",
+ printk(KERN_INFO "%s: next = %p, prev = %p, head = %p\n",
inode->i_bdev->bd_disk->disk_name,
- lo->queue_head.next, lo->queue_head.prev);
-#endif
+ lo->queue_head.next, lo->queue_head.prev,
+ &lo->queue_head);
return 0;
}
return -EINVAL;
@@ -693,12 +667,10 @@ static int __init nbd_init(void)
int err = -ENOMEM;
int i;

-#ifdef PARANOIA
if (sizeof(struct nbd_request) != 28) {
- printk(KERN_CRIT "nbd: Sizeof nbd_request needs to be 28 in order to work!\n" );
+ printk(KERN_CRIT "nbd: sizeof nbd_request needs to be 28 in order to work!\n" );
return -EIO;
}
-#endif

for (i = 0; i < MAX_NBD; i++) {
struct gendisk *disk = alloc_disk(1);
@@ -729,9 +701,7 @@ static int __init nbd_init(void)
for (i = 0; i < MAX_NBD; i++) {
struct gendisk *disk = nbd_dev[i].disk;
nbd_dev[i].file = NULL;
-#ifdef PARANOIA
nbd_dev[i].magic = LO_MAGIC;
-#endif
nbd_dev[i].flags = 0;
spin_lock_init(&nbd_dev[i].queue_lock);
INIT_LIST_HEAD(&nbd_dev[i].queue_head);