From: Lars Marowsky-Bree <[email protected]>
This patches adds the "nbds_max" parameter to the nbd kernel module,
which limits the number of nbds allocated. Previously, always all 128
entries were allocated unconditionally, which used to waste resources
and needlessly flood the hotplug system with events. (Defaults to 16
now.)
Signed-off-by: Lars Marowsky-Bree <[email protected]>
---
nbd.c | 16 +++++++++++++---
1 files changed, 13 insertions(+), 3 deletions(-)
Index: linux-2.6.11/drivers/block/nbd.c
===================================================================
--- linux-2.6.11.orig/drivers/block/nbd.c 2005-03-02 08:37:50.000000000 +0100
+++ linux-2.6.11/drivers/block/nbd.c 2005-04-14 13:08:40.100896527 +0200
@@ -78,6 +78,7 @@
#define DBG_RX 0x0200
#define DBG_TX 0x0400
static unsigned int debugflags;
+static unsigned int nbds_max;
#endif /* NDEBUG */
static struct nbd_device nbd_dev[MAX_NBD];
@@ -647,7 +648,13 @@ static int __init nbd_init(void)
return -EIO;
}
- for (i = 0; i < MAX_NBD; i++) {
+ if (nbds_max > MAX_NBD) {
+ printk(KERN_CRIT "nbd: cannot allocate more than %u nbds; %u requested.\n", MAX_NBD,
+ nbds_max);
+ return -EINVAL;
+ }
+
+ for (i = 0; i < nbds_max; i++) {
struct gendisk *disk = alloc_disk(1);
if (!disk)
goto out;
@@ -673,7 +680,7 @@ static int __init nbd_init(void)
dprintk(DBG_INIT, "nbd: debugflags=0x%x\n", debugflags);
devfs_mk_dir("nbd");
- for (i = 0; i < MAX_NBD; i++) {
+ for (i = 0; i < nbds_max; i++) {
struct gendisk *disk = nbd_dev[i].disk;
nbd_dev[i].file = NULL;
nbd_dev[i].magic = LO_MAGIC;
@@ -706,8 +713,9 @@ out:
static void __exit nbd_cleanup(void)
{
int i;
- for (i = 0; i < MAX_NBD; i++) {
+ for (i = 0; i < nbds_max; i++) {
struct gendisk *disk = nbd_dev[i].disk;
+ nbd_dev[i].magic = 0;
if (disk) {
del_gendisk(disk);
blk_cleanup_queue(disk->queue);
@@ -725,6 +733,8 @@ module_exit(nbd_cleanup);
MODULE_DESCRIPTION("Network Block Device");
MODULE_LICENSE("GPL");
+module_param(nbds_max, int, 16);
+MODULE_PARM_DESC(nbds_max, "How many network block devices to initialize.");
#ifndef NDEBUG
module_param(debugflags, int, 0644);
MODULE_PARM_DESC(debugflags, "flags for controlling debug output");
--
High Availability & Clustering
SUSE Labs, Research and Development
SUSE LINUX Products GmbH - A Novell Business
On 14/04/05 13:23 +0200, Lars Marowsky-Bree wrote:
> From: Lars Marowsky-Bree <[email protected]>
>
> This patches adds the "nbds_max" parameter to the nbd kernel module,
> which limits the number of nbds allocated. Previously, always all 128
> entries were allocated unconditionally, which used to waste resources
> and needlessly flood the hotplug system with events. (Defaults to 16
> now.)
>
...
>
> +module_param(nbds_max, int, 16);
This is permissions in sysfs (or 0 if no file is to be created).
> +MODULE_PARM_DESC(nbds_max, "How many network block devices to initialize.");
> #ifndef NDEBUG
> module_param(debugflags, int, 0644);
> MODULE_PARM_DESC(debugflags, "flags for controlling debug output");
On 2005-04-15T00:56:35, Domen Puncer <[email protected]> wrote:
> This is permissions in sysfs (or 0 if no file is to be created).
Duh. Should have caught that. Try this one.
Index: linux-2.6.11/drivers/block/nbd.c
===================================================================
--- linux-2.6.11.orig/drivers/block/nbd.c 2005-03-02 08:37:50.000000000 +0100
+++ linux-2.6.11/drivers/block/nbd.c 2005-04-15 09:36:10.374854551 +0200
@@ -78,6 +78,7 @@
#define DBG_RX 0x0200
#define DBG_TX 0x0400
static unsigned int debugflags;
+static unsigned int nbds_max = 16;
#endif /* NDEBUG */
static struct nbd_device nbd_dev[MAX_NBD];
@@ -647,7 +648,13 @@ static int __init nbd_init(void)
return -EIO;
}
- for (i = 0; i < MAX_NBD; i++) {
+ if (nbds_max > MAX_NBD) {
+ printk(KERN_CRIT "nbd: cannot allocate more than %u nbds; %u requested.\n", MAX_NBD,
+ nbds_max);
+ return -EINVAL;
+ }
+
+ for (i = 0; i < nbds_max; i++) {
struct gendisk *disk = alloc_disk(1);
if (!disk)
goto out;
@@ -673,7 +680,7 @@ static int __init nbd_init(void)
dprintk(DBG_INIT, "nbd: debugflags=0x%x\n", debugflags);
devfs_mk_dir("nbd");
- for (i = 0; i < MAX_NBD; i++) {
+ for (i = 0; i < nbds_max; i++) {
struct gendisk *disk = nbd_dev[i].disk;
nbd_dev[i].file = NULL;
nbd_dev[i].magic = LO_MAGIC;
@@ -706,8 +713,9 @@ out:
static void __exit nbd_cleanup(void)
{
int i;
- for (i = 0; i < MAX_NBD; i++) {
+ for (i = 0; i < nbds_max; i++) {
struct gendisk *disk = nbd_dev[i].disk;
+ nbd_dev[i].magic = 0;
if (disk) {
del_gendisk(disk);
blk_cleanup_queue(disk->queue);
@@ -725,6 +733,8 @@ module_exit(nbd_cleanup);
MODULE_DESCRIPTION("Network Block Device");
MODULE_LICENSE("GPL");
+module_param(nbds_max, int, 0444);
+MODULE_PARM_DESC(nbds_max, "How many network block devices to initialize.");
#ifndef NDEBUG
module_param(debugflags, int, 0644);
MODULE_PARM_DESC(debugflags, "flags for controlling debug output");
Sincerely,
Lars Marowsky-Br?e <[email protected]>
--
High Availability & Clustering
SUSE Labs, Research and Development
SUSE LINUX Products GmbH - A Novell Business