From: Lou Langholtz This fifth patch cleans up usage of the PARANOIA sanity checking macro and code. This patch modifies both drivers/block/nbd.c and include/linux/nbd.h. It's intended to be applied incrementally on top of my fourth patch (4.1 really if you count the memset addition as .1's worth) that simply removed unneeded blksize_bits field. Again, I wanted to get this smaller change out of the way before my next patch will is much more major. drivers/block/nbd.c | 36 +++++++++++++++++++++++++++++++----- include/linux/nbd.h | 13 ++++++------- 2 files changed, 37 insertions(+), 12 deletions(-) diff -puN drivers/block/nbd.c~nbd-paranioa-cleanups drivers/block/nbd.c --- 25/drivers/block/nbd.c~nbd-paranioa-cleanups 2003-06-26 18:39:33.000000000 -0700 +++ 25-akpm/drivers/block/nbd.c 2003-06-26 18:39:33.000000000 -0700 @@ -35,13 +35,13 @@ * 03-06-23 Enhance diagnostics support. * 03-06-24 Remove unneeded blksize_bits field from nbd_device struct. * + * 03-06-24 Cleanup PARANOIA usage & code. * * 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 */ -#define PARANOIA #include #include @@ -64,9 +64,12 @@ #include #include +/* Define PARANOIA in linux/nbd.h to turn on extra sanity checking */ #include +#ifdef PARANOIA #define LO_MAGIC 0x68797548 +#endif #ifdef NDEBUG #define dprintk(flags, fmt...) @@ -99,8 +102,10 @@ 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) @@ -397,7 +402,9 @@ 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); printk(KERN_NOTICE "%s: req should never be null\n", @@ -409,7 +416,9 @@ void nbd_clear_que(struct nbd_device *lo { struct request *req; +#ifdef PARANOIA BUG_ON(lo->magic != LO_MAGIC); +#endif do { req = NULL; @@ -448,7 +457,9 @@ 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); @@ -463,7 +474,9 @@ static void do_nbd_request(request_queue goto error_out; } } +#ifdef PARANOIA requests_in++; +#endif req->errors = 0; spin_unlock_irq(q->queue_lock); @@ -522,11 +535,13 @@ static int nbd_release(struct inode *ino { struct nbd_device *lo = inode->i_bdev->bd_disk->private_data; +#ifdef PARANOIA if (lo->refcnt <= 0) { printk(KERN_ALERT "%s: nbd_release: refcount(%d) <= 0\n", lo->disk->disk_name, lo->refcnt); BUG(); } +#endif lo->refcnt--; dprintk(DBG_RELEASE, "%s: nbd_release: refcnt=%d\n", lo->disk->disk_name, lo->refcnt); @@ -540,6 +555,9 @@ static int nbd_ioctl(struct inode *inode int error; struct request sreq ; +#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); @@ -642,13 +660,17 @@ static int nbd_ioctl(struct inode *inode case NBD_CLEAR_QUE: nbd_clear_que(lo); return 0; -#ifdef PARANOIA 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); - return 0; + 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", + inode->i_bdev->bd_disk->disk_name, + lo->queue_head.next, lo->queue_head.prev); #endif + return 0; } return -EINVAL; } @@ -671,10 +693,12 @@ 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" ); return -EIO; } +#endif for (i = 0; i < MAX_NBD; i++) { struct gendisk *disk = alloc_disk(1); @@ -708,7 +732,9 @@ static int __init nbd_init(void) struct gendisk *disk = nbd_dev[i].disk; nbd_dev[i].refcnt = 0; 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); diff -puN include/linux/nbd.h~nbd-paranioa-cleanups include/linux/nbd.h --- 25/include/linux/nbd.h~nbd-paranioa-cleanups 2003-06-26 18:39:33.000000000 -0700 +++ 25-akpm/include/linux/nbd.h 2003-06-26 18:39:33.000000000 -0700 @@ -7,6 +7,7 @@ * layer code. * 2003/06/24 Louis D. Langholtz * Removed unneeded blksize_bits field from nbd_device struct. + * Cleanup PARANOIA usage & code. */ #ifndef LINUX_NBD_H @@ -28,16 +29,12 @@ enum { NBD_CMD_DISC = 2 }; - -#ifdef PARANOIA -extern int requests_in; -extern int requests_out; -#endif - #define nbd_cmd(req) ((req)->cmd[0]) - #define MAX_NBD 128 +/* Define PARANOIA to include extra sanity checking code in here & driver */ +#define PARANOIA + struct nbd_device { int refcnt; int flags; @@ -46,7 +43,9 @@ struct nbd_device { #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 spinlock_t queue_lock; struct list_head queue_head;/* Requests are added here... */ struct semaphore tx_lock; _