Re: [BUG] ub.c badness in current bk

From: Pete Zaitcev
Date: Fri Sep 17 2004 - 02:42:00 EST


On Thu, 16 Sep 2004 12:06:01 +1000
Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> wrote:

> ub: sizeof ub_scsi_cmd 60 ub_dev 924
> uba: device 2 capacity nsec 50 bsize 512
> uba: made changed
> uba: device 2 capacity nsec 126720 bsize 512
> uba: device 2 capacity nsec 126720 bsize 512
> uba: uba1
> uba: uba1
> kobject_register failed for uba1 (-17)

Please try this (includes the right size for REQUEST SENSE, it's vital):

--- linux-2.6.9-rc1/drivers/block/ub.c 2004-08-25 17:19:30.000000000 -0700
+++ linux-2.6.9-rc1-ub/drivers/block/ub.c 2004-09-17 00:24:50.227539272 -0700
@@ -1185,9 +1213,17 @@
goto error;
}

+ /*
+ * ``If the allocation length is eighteen or greater, and a device
+ * server returns less than eithteen bytes of data, the application
+ * client should assume that the bytes not transferred would have been
+ * zeroes had the device server returned those bytes.''
+ */
memset(&sc->top_sense, 0, UB_SENSE_SIZE);
+
scmd = &sc->top_rqs_cmd;
scmd->cdb[0] = REQUEST_SENSE;
+ scmd->cdb[4] = UB_SENSE_SIZE;
scmd->cdb_len = 6;
scmd->dir = UB_DIR_READ;
scmd->state = UB_CMDST_INIT;
@@ -1474,6 +1515,7 @@
static int ub_bd_media_changed(struct gendisk *disk)
{
struct ub_dev *sc = disk->private_data;
+ int ret;

if (!sc->removable)
return 0;
@@ -1493,10 +1535,10 @@
return 1;
}

- /* The sd.c clears this before returning (one-shot flag). Why? */
- /* P3 */ printk("%s: %s changed\n", sc->name,
- sc->changed? "is": "was not");
- return sc->changed;
+ ret = sc->changed;
+ /* P3 */ printk("%s: %s changed\n", sc->name, ret ? "is": "was not");
+ sc->changed = 0;
+ return ret;
}

static struct block_device_operations ub_bd_fops = {

Regardless of the result, I'd like to see the dmesg, and
cat $(find /sys -name diag)

-- Pete
-
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