> Ok, I updated to 2.6.11.8, and indeed it does have problems that
> weren't there before - although in my case it can't mount the root
> partition because it's not quite ready yet. In part, it seems to be
> caused by the fact that the USB start up sequence introduces a new
> thread that delays the scsi_host_scan by 5 seconds, which is long
> enough to cause problems. I added some code to wait for not only the
> disk name to be online, but the partition, but even that doesn't seem
> to be quite enough.
> Is there anyplace generic that could be hooked that will report when a
> device is actually online and ready to run? Perhaps I was just lucky
> in the past with add_disk :-/
I "fixed" the problem by not letting storage_probe in storage/usb.c
finish until the scan_thread is done. That doesn't seem elegant -
perhaps there is a better place to put the
wait_for_completion(&us->scsi_scan_done) call so that the scanning
thread can go off and do its thing, but will still be waited on where
it counts?
I am including a copy of the patch inline, as well as attaching it. I
suspect that gmail will mangle the inline version some...
Thankyou,
Dave
diff -uprN -X dontdiff linux-2.6.11.8/drivers/block/genhd.c
linux-wakeup/drivers/block/genhd.c
--- linux-2.6.11.8/drivers/block/genhd.c 2005-04-30 03:27:21.000000000 +0200
+++ linux-wakeup/drivers/block/genhd.c 2005-05-02 19:22:13.000000000 +0200
@@ -14,9 +14,14 @@
#include <linux/slab.h>
#include <linux/kmod.h>
#include <linux/kobj_map.h>
+#include <linux/wait.h>
+#include <linux/sched.h>
#define MAX_PROBE_HASH 255 /* random */
+DECLARE_WAIT_QUEUE_HEAD(disk_wait_h);
+EXPORT_SYMBOL(disk_wait_h);
+
static struct subsystem block_subsys;
static DECLARE_MUTEX(block_subsys_sem);
@@ -58,6 +63,49 @@ int get_blkdev_list(char *p)
}
#endif
+/*
+ * Returns an array of all the block device names and partitions.
+ */
+
+char **get_blkdevs(void)
+{
+ int i = 0;
+ int n = 0;
+ int len = 0;
+ struct list_head *p;
+ char **names = NULL;
+ struct gendisk *sgp;
+ char buf[BDEVNAME_SIZE];
+
+ down_read(&block_subsys.rwsem);
+
+ list_for_each(p, &block_subsys.kset.list) {
+ len ++;
+ }
+
+ names = kmalloc(sizeof(char *) * len + 1, GFP_KERNEL);
+
+ list_for_each(p, &block_subsys.kset.list) {
+ sgp = list_entry(p, struct gendisk, kobj.entry);
+ names[i] = kmalloc(strlen(disk_name(sgp, 0, buf)), GFP_KERNEL);
+ strcpy(names[i], disk_name(sgp, 0, buf));
+
+ for (n = 0; n < sgp->minors - 1; n++) {
+ struct hd_struct *hd = sgp->part[n];
+ if (hd && hd->nr_sects) {
+ names[i] = kmalloc(strlen(disk_name(sgp, n+1, buf)), GFP_KERNEL);
+ strcpy(names[i], disk_name(sgp, n+1, buf));
+ i ++;
+ }
+ }
+ }
+ names[i] = NULL;
+ up_read(&block_subsys.rwsem);
+ return names;
+}
+
+EXPORT_SYMBOL(get_blkdevs);
+
int register_blkdev(unsigned int major, const char *name)
{
struct blk_major_name **n, *p;
@@ -192,6 +240,11 @@ void add_disk(struct gendisk *disk)
disk->minors, NULL, exact_match, exact_lock, disk);
register_disk(disk);
blk_register_queue(disk);
+
+ /* Wake up queue in init/main.c. */
+ printk("Waking up queue on %s\n",
+ disk->disk_name);
+ wake_up_interruptible(&disk_wait_h);
}
EXPORT_SYMBOL(add_disk);
diff -uprN -X dontdiff linux-2.6.11.8/drivers/usb/storage/usb.c
linux-wakeup/drivers/usb/storage/usb.c
--- linux-2.6.11.8/drivers/usb/storage/usb.c 2005-04-30 03:25:25.000000000 +0200
+++ linux-wakeup/drivers/usb/storage/usb.c 2005-05-03 12:15:29.000000000 +0200
@@ -1009,6 +1009,7 @@ static int storage_probe(struct usb_inte
/* Start up the thread for delayed SCSI-device scanning */
result = kernel_thread(usb_stor_scan_thread, us, CLONE_VM);
+
if (result < 0) {
printk(KERN_WARNING USB_STORAGE
"Unable to start the device-scanning thread\n");
@@ -1016,6 +1017,8 @@ static int storage_probe(struct usb_inte
goto BadDevice;
}
+ wait_for_completion(&us->scsi_scan_done);
+
return 0;
/* We come here if there are any problems */
diff -uprN -X dontdiff linux-2.6.11.8/include/linux/genhd.h
linux-wakeup/include/linux/genhd.h
--- linux-2.6.11.8/include/linux/genhd.h 2005-04-30 03:24:13.000000000 +0200
+++ linux-wakeup/include/linux/genhd.h 2005-05-02 12:04:50.000000000 +0200
@@ -16,6 +16,10 @@
#include <linux/smp.h>
#include <linux/string.h>
#include <linux/fs.h>
+#include <linux/wait.h>
+
+/* Wait queue to wait on disks coming online. */
+extern wait_queue_head_t disk_wait_h;
enum {
/* These three have identical behaviour; use the second one if DOS FDISK gets
@@ -232,6 +236,7 @@ extern struct gendisk *get_gendisk(dev_t
extern void set_device_ro(struct block_device *bdev, int flag);
extern void set_disk_ro(struct gendisk *disk, int flag);
+extern char **get_blkdevs(void);
/* drivers/char/random.c */
extern void add_disk_randomness(struct gendisk *disk);
diff -uprN -X dontdiff linux-2.6.11.8/init/do_mounts.c
linux-wakeup/init/do_mounts.c
--- linux-2.6.11.8/init/do_mounts.c 2005-04-30 03:26:32.000000000 +0200
+++ linux-wakeup/init/do_mounts.c 2005-05-02 19:22:51.000000000 +0200
@@ -12,6 +12,8 @@
#include <linux/nfs_fs_sb.h>
#include <linux/nfs_mount.h>
+#include <linux/genhd.h>
+
#include "do_mounts.h"
extern int get_filesystem_list(char * buf);
@@ -360,8 +362,35 @@ void __init change_floppy(char *fmt, ...
}
#endif
+/*
+ * match_root_name - Returns 1 if the root_device_name appears amongst
+ * the list of block devices, 0 otherwise.
+ */
+
+static int __init match_root_name(void) {
+ char **names = NULL;
+ int i = 0;
+ int match = 0;
+
+ names = get_blkdevs();
+ while (names[i] != NULL) {
+ if (match == 0 && strncmp(names[i],
+ root_device_name,
+ strlen(root_device_name)) == 0) {
+ match = 1;
+ printk("Block device %s matches %s root_device_name, continuing\n",
+ names[i], root_device_name);
+ }
+ kfree(names[i]);
+ i ++;
+ }
+ kfree(names);
+ return match;
+}
+
void __init mount_root(void)
{
+
#ifdef CONFIG_ROOT_NFS
if (MAJOR(ROOT_DEV) == UNNAMED_MAJOR) {
if (mount_nfs_root())
@@ -383,6 +412,14 @@ void __init mount_root(void)
change_floppy("root floppy");
}
#endif
+
+ /* Here, we wait for the root device to show up, or if it's
+ * already there, we just go on. */
+ while (!match_root_name()) {
+ printk("Waiting for root device to wake us up\n");
+ interruptible_sleep_on(&disk_wait_h);
+ }
+
create_dev("/dev/root", ROOT_DEV, root_device_name);
mount_block_root("/dev/root", root_mountflags);
}
diff -uprN -X dontdiff linux-2.6.11.8/init/main.c linux-wakeup/init/main.c
--- linux-2.6.11.8/init/main.c 2005-04-30 03:24:18.000000000 +0200
+++ linux-wakeup/init/main.c 2005-05-02 12:04:50.000000000 +0200
@@ -47,6 +47,11 @@
#include <linux/mempolicy.h>
#include <linux/key.h>
+#include <linux/genhd.h>
+#include <linux/wait.h>
+#include <linux/sched.h>
+
+
#include <asm/io.h>
#include <asm/bugs.h>
#include <asm/setup.h>
diff -uprN -X dontdiff linux-2.6.11.8/drivers/block/genhd.c linux-wakeup/drivers/block/genhd.c
--- linux-2.6.11.8/drivers/block/genhd.c 2005-04-30 03:27:21.000000000 +0200
+++ linux-wakeup/drivers/block/genhd.c 2005-05-02 19:22:13.000000000 +0200
@@ -14,9 +14,14 @@
#include <linux/slab.h>
#include <linux/kmod.h>
#include <linux/kobj_map.h>
+#include <linux/wait.h>
+#include <linux/sched.h>
#define MAX_PROBE_HASH 255 /* random */
+DECLARE_WAIT_QUEUE_HEAD(disk_wait_h);
+EXPORT_SYMBOL(disk_wait_h);
+
static struct subsystem block_subsys;
static DECLARE_MUTEX(block_subsys_sem);
@@ -58,6 +63,49 @@ int get_blkdev_list(char *p)
}
#endif
+/*
+ * Returns an array of all the block device names and partitions.
+ */
+
+char **get_blkdevs(void)
+{
+ int i = 0;
+ int n = 0;
+ int len = 0;
+ struct list_head *p;
+ char **names = NULL;
+ struct gendisk *sgp;
+ char buf[BDEVNAME_SIZE];
+
+ down_read(&block_subsys.rwsem);
+
+ list_for_each(p, &block_subsys.kset.list) {
+ len ++;
+ }
+
+ names = kmalloc(sizeof(char *) * len + 1, GFP_KERNEL);
+
+ list_for_each(p, &block_subsys.kset.list) {
+ sgp = list_entry(p, struct gendisk, kobj.entry);
+ names[i] = kmalloc(strlen(disk_name(sgp, 0, buf)), GFP_KERNEL);
+ strcpy(names[i], disk_name(sgp, 0, buf));
+
+ for (n = 0; n < sgp->minors - 1; n++) {
+ struct hd_struct *hd = sgp->part[n];
+ if (hd && hd->nr_sects) {
+ names[i] = kmalloc(strlen(disk_name(sgp, n+1, buf)), GFP_KERNEL);
+ strcpy(names[i], disk_name(sgp, n+1, buf));
+ i ++;
+ }
+ }
+ }
+ names[i] = NULL;
+ up_read(&block_subsys.rwsem);
+ return names;
+}
+
+EXPORT_SYMBOL(get_blkdevs);
+
int register_blkdev(unsigned int major, const char *name)
{
struct blk_major_name **n, *p;
@@ -192,6 +240,11 @@ void add_disk(struct gendisk *disk)
disk->minors, NULL, exact_match, exact_lock, disk);
register_disk(disk);
blk_register_queue(disk);
+
+ /* Wake up queue in init/main.c. */
+ printk("Waking up queue on %s\n",
+ disk->disk_name);
+ wake_up_interruptible(&disk_wait_h);
}
EXPORT_SYMBOL(add_disk);
diff -uprN -X dontdiff linux-2.6.11.8/drivers/usb/storage/usb.c linux-wakeup/drivers/usb/storage/usb.c
--- linux-2.6.11.8/drivers/usb/storage/usb.c 2005-04-30 03:25:25.000000000 +0200
+++ linux-wakeup/drivers/usb/storage/usb.c 2005-05-03 12:15:29.000000000 +0200
@@ -1009,6 +1009,7 @@ static int storage_probe(struct usb_inte
/* Start up the thread for delayed SCSI-device scanning */
result = kernel_thread(usb_stor_scan_thread, us, CLONE_VM);
+
if (result < 0) {
printk(KERN_WARNING USB_STORAGE
"Unable to start the device-scanning thread\n");
@@ -1016,6 +1017,8 @@ static int storage_probe(struct usb_inte
goto BadDevice;
}
+ wait_for_completion(&us->scsi_scan_done);
+
return 0;
/* We come here if there are any problems */
diff -uprN -X dontdiff linux-2.6.11.8/include/linux/genhd.h linux-wakeup/include/linux/genhd.h
--- linux-2.6.11.8/include/linux/genhd.h 2005-04-30 03:24:13.000000000 +0200
+++ linux-wakeup/include/linux/genhd.h 2005-05-02 12:04:50.000000000 +0200
@@ -16,6 +16,10 @@
#include <linux/smp.h>
#include <linux/string.h>
#include <linux/fs.h>
+#include <linux/wait.h>
+
+/* Wait queue to wait on disks coming online. */
+extern wait_queue_head_t disk_wait_h;
enum {
/* These three have identical behaviour; use the second one if DOS FDISK gets
@@ -232,6 +236,7 @@ extern struct gendisk *get_gendisk(dev_t
extern void set_device_ro(struct block_device *bdev, int flag);
extern void set_disk_ro(struct gendisk *disk, int flag);
+extern char **get_blkdevs(void);
/* drivers/char/random.c */
extern void add_disk_randomness(struct gendisk *disk);
diff -uprN -X dontdiff linux-2.6.11.8/init/do_mounts.c linux-wakeup/init/do_mounts.c
--- linux-2.6.11.8/init/do_mounts.c 2005-04-30 03:26:32.000000000 +0200
+++ linux-wakeup/init/do_mounts.c 2005-05-02 19:22:51.000000000 +0200
@@ -12,6 +12,8 @@
#include <linux/nfs_fs_sb.h>
#include <linux/nfs_mount.h>
+#include <linux/genhd.h>
+
#include "do_mounts.h"
extern int get_filesystem_list(char * buf);
@@ -360,8 +362,35 @@ void __init change_floppy(char *fmt, ...
}
#endif
+/*
+ * match_root_name - Returns 1 if the root_device_name appears amongst
+ * the list of block devices, 0 otherwise.
+ */
+
+static int __init match_root_name(void) {
+ char **names = NULL;
+ int i = 0;
+ int match = 0;
+
+ names = get_blkdevs();
+ while (names[i] != NULL) {
+ if (match == 0 && strncmp(names[i],
+ root_device_name,
+ strlen(root_device_name)) == 0) {
+ match = 1;
+ printk("Block device %s matches %s root_device_name, continuing\n",
+ names[i], root_device_name);
+ }
+ kfree(names[i]);
+ i ++;
+ }
+ kfree(names);
+ return match;
+}
+
void __init mount_root(void)
{
+
#ifdef CONFIG_ROOT_NFS
if (MAJOR(ROOT_DEV) == UNNAMED_MAJOR) {
if (mount_nfs_root())
@@ -383,6 +412,14 @@ void __init mount_root(void)
change_floppy("root floppy");
}
#endif
+
+ /* Here, we wait for the root device to show up, or if it's
+ * already there, we just go on. */
+ while (!match_root_name()) {
+ printk("Waiting for root device to wake us up\n");
+ interruptible_sleep_on(&disk_wait_h);
+ }
+
create_dev("/dev/root", ROOT_DEV, root_device_name);
mount_block_root("/dev/root", root_mountflags);
}
diff -uprN -X dontdiff linux-2.6.11.8/init/main.c linux-wakeup/init/main.c
--- linux-2.6.11.8/init/main.c 2005-04-30 03:24:18.000000000 +0200
+++ linux-wakeup/init/main.c 2005-05-02 12:04:50.000000000 +0200
@@ -47,6 +47,11 @@
#include <linux/mempolicy.h>
#include <linux/key.h>
+#include <linux/genhd.h>
+#include <linux/wait.h>
+#include <linux/sched.h>
+
+
#include <asm/io.h>
#include <asm/bugs.h>
#include <asm/setup.h>
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