staging: lustre: Remove unused memhog functionality

Remove IOC_LIBCFS_MEMHOG ioctl functionality as it is no longer needed thereby
making functions like - kportal_memhog_alloc(), kportal_memhog_free() and type -
struct libcfs_device_userstate unused.
Signed-off-by: Niranjan Dighe <ndighe@visteon.com>
Acked-by: James Simmons <jsimmons@infradead.org>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/lustre/include/linux/libcfs/libcfs_private.h

@@ -387,11 +387,6 @@ int cfs_percpt_atomic_summary(atomic_t **refs);
  * Support for temporary event tracing with minimal Heisenberg effect.
  * -------------------------------------------------------------------- */
 
-struct libcfs_device_userstate {
-	int	   ldu_memhog_pages;
-	struct page   *ldu_memhog_root_page;
-};
-
 #define MKSTR(ptr) ((ptr)) ? (ptr) : ""
 
 static inline int cfs_size_round4(int val)

drivers/staging/lustre/lustre/libcfs/linux/linux-module.c

@@ -98,14 +98,12 @@ int libcfs_ioctl_popdata(void *arg, void *data, int size)
 static int
 libcfs_psdev_open(struct inode *inode, struct file *file)
 {
-	struct libcfs_device_userstate **pdu = NULL;
 	int    rc = 0;
 
 	if (!inode)
 		return -EINVAL;
-	pdu = (struct libcfs_device_userstate **)&file->private_data;
 	if (libcfs_psdev_ops.p_open != NULL)
-		rc = libcfs_psdev_ops.p_open(0, (void *)pdu);
+		rc = libcfs_psdev_ops.p_open(0, NULL);
 	else
 		return -EPERM;
 	return rc;
@@ -115,14 +113,12 @@ libcfs_psdev_open(struct inode *inode, struct file *file)
 static int
 libcfs_psdev_release(struct inode *inode, struct file *file)
 {
-	struct libcfs_device_userstate *pdu;
 	int    rc = 0;
 
 	if (!inode)
 		return -EINVAL;
-	pdu = file->private_data;
 	if (libcfs_psdev_ops.p_close != NULL)
-		rc = libcfs_psdev_ops.p_close(0, (void *)pdu);
+		rc = libcfs_psdev_ops.p_close(0, NULL);
 	else
 		rc = -EPERM;
 	return rc;
@@ -152,14 +148,8 @@ static long libcfs_ioctl(struct file *file,
 			return -EPERM;
 		panic("debugctl-invoked panic");
 		return 0;
-	case IOC_LIBCFS_MEMHOG:
-		if (!capable(CFS_CAP_SYS_ADMIN))
-			return -EPERM;
-		/* go thought */
 	}
 
-	pfile.off = 0;
-	pfile.private_data = file->private_data;
 	if (libcfs_psdev_ops.p_ioctl != NULL)
 		rc = libcfs_psdev_ops.p_ioctl(&pfile, cmd, (void *)arg);
 	else

drivers/staging/lustre/lustre/libcfs/module.c

@@ -68,142 +68,16 @@ MODULE_LICENSE("GPL");
 
 static struct dentry *lnet_debugfs_root;
 
-static void kportal_memhog_free(struct libcfs_device_userstate *ldu)
-{
-	struct page **level0p = &ldu->ldu_memhog_root_page;
-	struct page **level1p;
-	struct page **level2p;
-	int	   count1;
-	int	   count2;
-
-	if (*level0p != NULL) {
-
-		level1p = (struct page **)page_address(*level0p);
-		count1 = 0;
-
-		while (count1 < PAGE_CACHE_SIZE/sizeof(struct page *) &&
-		       *level1p != NULL) {
-
-			level2p = (struct page **)page_address(*level1p);
-			count2 = 0;
-
-			while (count2 < PAGE_CACHE_SIZE/sizeof(struct page *) &&
-			       *level2p != NULL) {
-
-				__free_page(*level2p);
-				ldu->ldu_memhog_pages--;
-				level2p++;
-				count2++;
-			}
-
-			__free_page(*level1p);
-			ldu->ldu_memhog_pages--;
-			level1p++;
-			count1++;
-		}
-
-		__free_page(*level0p);
-		ldu->ldu_memhog_pages--;
-
-		*level0p = NULL;
-	}
-
-	LASSERT(ldu->ldu_memhog_pages == 0);
-}
-
-static int kportal_memhog_alloc(struct libcfs_device_userstate *ldu, int npages,
-		     gfp_t flags)
-{
-	struct page **level0p;
-	struct page **level1p;
-	struct page **level2p;
-	int	   count1;
-	int	   count2;
-
-	LASSERT(ldu->ldu_memhog_pages == 0);
-	LASSERT(ldu->ldu_memhog_root_page == NULL);
-
-	if (npages < 0)
-		return -EINVAL;
-
-	if (npages == 0)
-		return 0;
-
-	level0p = &ldu->ldu_memhog_root_page;
-	*level0p = alloc_page(flags);
-	if (*level0p == NULL)
-		return -ENOMEM;
-	ldu->ldu_memhog_pages++;
-
-	level1p = (struct page **)page_address(*level0p);
-	count1 = 0;
-	memset(level1p, 0, PAGE_CACHE_SIZE);
-
-	while (ldu->ldu_memhog_pages < npages &&
-	       count1 < PAGE_CACHE_SIZE/sizeof(struct page *)) {
-
-		if (cfs_signal_pending())
-			return -EINTR;
-
-		*level1p = alloc_page(flags);
-		if (*level1p == NULL)
-			return -ENOMEM;
-		ldu->ldu_memhog_pages++;
-
-		level2p = (struct page **)page_address(*level1p);
-		count2 = 0;
-		memset(level2p, 0, PAGE_CACHE_SIZE);
-
-		while (ldu->ldu_memhog_pages < npages &&
-		       count2 < PAGE_CACHE_SIZE/sizeof(struct page *)) {
-
-			if (cfs_signal_pending())
-				return -EINTR;
-
-			*level2p = alloc_page(flags);
-			if (*level2p == NULL)
-				return -ENOMEM;
-			ldu->ldu_memhog_pages++;
-
-			level2p++;
-			count2++;
-		}
-
-		level1p++;
-		count1++;
-	}
-
-	return 0;
-}
-
 /* called when opening /dev/device */
 static int libcfs_psdev_open(unsigned long flags, void *args)
 {
-	struct libcfs_device_userstate *ldu;
-
 	try_module_get(THIS_MODULE);
-
-	LIBCFS_ALLOC(ldu, sizeof(*ldu));
-	if (ldu != NULL) {
-		ldu->ldu_memhog_pages = 0;
-		ldu->ldu_memhog_root_page = NULL;
-	}
-	*(struct libcfs_device_userstate **)args = ldu;
-
 	return 0;
 }
 
 /* called when closing /dev/device */
 static int libcfs_psdev_release(unsigned long flags, void *args)
 {
-	struct libcfs_device_userstate *ldu;
-
-	ldu = (struct libcfs_device_userstate *)args;
-	if (ldu != NULL) {
-		kportal_memhog_free(ldu);
-		LIBCFS_FREE(ldu, sizeof(*ldu));
-	}
-
 	module_put(THIS_MODULE);
 	return 0;
 }
@@ -260,19 +134,6 @@ static int libcfs_ioctl_int(struct cfs_psdev_file *pfile, unsigned long cmd,
 			return -EINVAL;
 		libcfs_debug_mark_buffer(data->ioc_inlbuf1);
 		return 0;
-	case IOC_LIBCFS_MEMHOG:
-		if (pfile->private_data == NULL) {
-			err = -EINVAL;
-		} else {
-			kportal_memhog_free(pfile->private_data);
-			/* XXX The ioc_flags is not GFP flags now, need to be fixed */
-			err = kportal_memhog_alloc(pfile->private_data,
-						   data->ioc_count,
-						   data->ioc_flags);
-			if (err != 0)
-				kportal_memhog_free(pfile->private_data);
-		}
-		break;
 
 	default: {
 		struct libcfs_ioctl_handler *hand;