Re: 2.5.54: ide-scsi still buggy?

Zwane Mwaikambo (zwane@holomorphy.com)
Tue, 7 Jan 2003 21:17:46 -0500 (EST)


On Wed, 8 Jan 2003, Lukas Hejtmanek wrote:

> Hello,
>
> ide-scsi emulation does not work for drive /dev/hdg, why?
>
> kernel boot parameters:
> kernel /boot/vmlinuz-2.5.54bk3 ro root=/dev/hda1 ide=reverse vga=4 hdg=ide-scsi
>
> It freezes kernel (sysrq do nothing) after lines:
> scsi0 : SCSI host adapter emulation for IDE ATAPI devices
> Vendor: TEAC Model: CD-W512EB Rev: 2
> Type: CD-ROM ANSI SCSI revision: 02
> scsi scan: host 0 channel 0 id 0 lun 0 identifier too long, length 60, max 50. Device might be improperly identified.
>
> while attaching it to /dev/hde works ok. Why?

This has been observed to cause an oops on some boxes and nothing on mine,
try this patch from Andries

diff -u --recursive --new-file -X /linux/dontdiff a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
--- a/drivers/scsi/scsi_scan.c Wed Jan 1 23:54:23 2003
+++ b/drivers/scsi/scsi_scan.c Sun Jan 5 14:22:21 2003
@@ -544,32 +544,6 @@
}

/**
- * scsi_check_id_size - check if size fits in the driverfs name
- * @sdev: Scsi_Device to use for error message
- * @size: the length of the id we want to store
- *
- * Description:
- * Use a function for this since the same code is used in various
- * places, and we only create one string and call to printk.
- *
- * Return:
- * 0 - fits
- * 1 - size too large
- **/
-static int scsi_check_id_size(Scsi_Device *sdev, int size)
-{
- if (size > DEVICE_NAME_SIZE) {
- printk(KERN_WARNING "scsi scan: host %d channel %d id %d lun %d"
- " identifier too long, length %d, max %d. Device might"
- " be improperly identified.\n", sdev->host->host_no,
- sdev->channel, sdev->id, sdev->lun, size,
- DEVICE_NAME_SIZE);
- return 1;
- } else
- return 0;
-}
-
-/**
* scsi_get_evpd_page - get a list of supported vpd pages
* @sdev: Scsi_Device to send an INQUIRY VPD
* @sreq: Scsi_Request associated with @sdev
@@ -715,17 +689,16 @@
* scsi_check_fill_deviceid - check the id and if OK fill it
* @sdev: device to use for error messages
* @id_page: id descriptor for INQUIRY VPD DEVICE ID, page 0x83
- * @name: store the id in name
+ * @name: store the id in name (of size DEVICE_NAME_SIZE > 26)
* @id_search: store if the id_page matches these values
*
* Description:
* Check if @id_page matches the @id_search, if so store an id (uid)
- * into name.
+ * into name, that is all zero on entrance.
*
* Return:
* 0: Success
* 1: No match
- * 2: Failure due to size constraints
**/
static int scsi_check_fill_deviceid(Scsi_Device *sdev, char *id_page,
char *name, const struct scsi_id_search_values *id_search)
@@ -755,70 +728,41 @@
if ((id_page[0] & 0x0f) != id_search->code_set)
return 1;

- name[0] = hex_str[id_search->id_type];
+ /*
+ * All OK - store ID
+ */
+ name[0] = hex_str[id_search->id_type];
+
+ /*
+ * Prepend the vendor and model before the id, since the id
+ * might not be unique across all vendors and models.
+ * The same code is used below, with a different size.
+ */
+ if (id_search->id_type == SCSI_ID_VENDOR_SPECIFIC) {
+ strncat(name, sdev->vendor, 8);
+ strncat(name, sdev->model, 16);
+ }
+
+ i = 4;
+ j = strlen(name);
if ((id_page[0] & 0x0f) == SCSI_ID_ASCII) {
/*
* ASCII descriptor.
*/
- if (id_search->id_type == SCSI_ID_VENDOR_SPECIFIC) {
- /*
- * Prepend the vendor and model before the id,
- * since the id might not be unique across all
- * vendors and models. The same code is used
- * below, with a differnt size.
- *
- * Need 1 byte for the idtype, 1 for trailing
- * '\0', 8 for vendor, 16 for model total 26, plus
- * the name descriptor length.
- */
- if (scsi_check_id_size(sdev, 26 + id_page[3]))
- return 2;
- else {
- strncat(name, sdev->vendor, 8);
- strncat(name, sdev->model, 16);
- }
- } else if (scsi_check_id_size (sdev, (2 + id_page[3])))
- /*
- * Need 1 byte for the idtype, 1 byte for
- * the trailing '\0', plus the descriptor length.
- */
- return 2;
- memcpy(&name[strlen(name)], &id_page[4], id_page[3]);
- return 0;
- } else if ((id_page[0] & 0x0f) == SCSI_ID_BINARY) {
- if (id_search->id_type == SCSI_ID_VENDOR_SPECIFIC) {
- /*
- * Prepend the vendor and model before the id.
- */
- if (scsi_check_id_size(sdev, 26 + (id_page[3] * 2)))
- return 2;
- else {
- strncat(name, sdev->vendor, 8);
- strncat(name, sdev->model, 16);
- }
- } else if (scsi_check_id_size(sdev, 2 + (id_page[3] * 2)))
- /*
- * Need 1 byte for the idtype, 1 for trailing
- * '\0', 8 for vendor, 16 for model total 26, plus
- * the name descriptor length.
- */
- return 2;
+ while (i < 4 + id_page[3] && j < DEVICE_NAME_SIZE-1)
+ name[j++] = id_page[i++];
+ } else {
/*
* Binary descriptor, convert to ASCII, using two bytes of
- * ASCII for each byte in the id_page. Store starting at
- * the end of name.
+ * ASCII for each byte in the id_page.
*/
- for(i = 4, j = strlen(name); i < 4 + id_page[3]; i++) {
+ while (i < 4 + id_page[3] && j < DEVICE_NAME_SIZE-2) {
name[j++] = hex_str[(id_page[i] & 0xf0) >> 4];
name[j++] = hex_str[id_page[i] & 0x0f];
+ i++;
}
- return 0;
}
- /*
- * Code set must have already matched.
- */
- printk(KERN_ERR "scsi scan: scsi_check_fill_deviceid unexpected state.\n");
- return 1;
+ return 0;
}

/**
@@ -834,7 +778,7 @@
* 0: Failure
* 1: Success
**/
-int scsi_get_deviceid(Scsi_Device *sdev, Scsi_Request *sreq)
+static int scsi_get_deviceid(Scsi_Device *sdev, Scsi_Request *sreq)
{
unsigned char *id_page;
unsigned char scsi_cmd[MAX_COMMAND_SIZE];
@@ -879,14 +823,14 @@
}

/*
- * Search for a match in the proiritized id_search_list.
+ * Search for a match in the prioritized id_search_list.
*/
for (id_idx = 0; id_idx < ARRAY_SIZE(id_search_list); id_idx++) {
/*
* Examine each descriptor returned. There is normally only
* one or a small number of descriptors.
*/
- for(scnt = 4; scnt <= id_page[3] + 3;
+ for (scnt = 4; scnt <= id_page[3] + 3;
scnt += id_page[scnt + 3] + 4) {
if ((scsi_check_fill_deviceid(sdev, &id_page[scnt],
sdev->sdev_driverfs_dev.name,
@@ -941,12 +885,11 @@
{
unsigned char *serialnumber_page;
unsigned char scsi_cmd[MAX_COMMAND_SIZE];
- int max_lgth = 255;
+ const int max_lgth = 255;
+ int len;

- retry:
serialnumber_page = kmalloc(max_lgth, GFP_ATOMIC |
- (sdev->host->unchecked_isa_dma) ?
- GFP_DMA : 0);
+ (sdev->host->unchecked_isa_dma) ? GFP_DMA : 0);
if (!serialnumber_page) {
printk(KERN_WARNING "scsi scan: Allocation failure identifying"
" host %d channel %d id %d lun %d, device might be"
@@ -969,26 +912,19 @@

if (sreq->sr_result)
goto leave;
- /*
- * check to see if response was truncated
- */
- if (serialnumber_page[3] > max_lgth) {
- max_lgth = serialnumber_page[3] + 4;
- kfree(serialnumber_page);
- goto retry;
- }

/*
- * Need 1 byte for SCSI_UID_SER_NUM, 1 for trailing '\0', 8 for
- * vendor, 16 for model = 26, plus serial number size.
+ * a check to see if response was truncated is superfluous,
+ * since serialnumber_page[3] cannot be larger than 255
*/
- if (scsi_check_id_size (sdev, (26 + serialnumber_page[3])))
- goto leave;
+
sdev->sdev_driverfs_dev.name[0] = SCSI_UID_SER_NUM;
strncat(sdev->sdev_driverfs_dev.name, sdev->vendor, 8);
strncat(sdev->sdev_driverfs_dev.name, sdev->model, 16);
- strncat(sdev->sdev_driverfs_dev.name, &serialnumber_page[4],
- serialnumber_page[3]);
+ len = serialnumber_page[3];
+ if (len > DEVICE_NAME_SIZE-26)
+ len = DEVICE_NAME_SIZE-26;
+ strncat(sdev->sdev_driverfs_dev.name, &serialnumber_page[4], len);
kfree(serialnumber_page);
return 1;
leave:
@@ -1002,23 +938,19 @@
* @sdev: get a default name for this device
*
* Description:
- * Set the name of @sdev to the concatenation of the vendor, model,
- * and revision found in @sdev.
+ * Set the name of @sdev (of size DEVICE_NAME_SIZE > 29) to the
+ * concatenation of the vendor, model, and revision found in @sdev.
*
* Return:
* 1: Success
**/
int scsi_get_default_name(Scsi_Device *sdev)
{
- if (scsi_check_id_size(sdev, 29))
- return 0;
- else {
- sdev->sdev_driverfs_dev.name[0] = SCSI_UID_UNKNOWN;
- strncpy(&sdev->sdev_driverfs_dev.name[1], sdev->vendor, 8);
- strncat(sdev->sdev_driverfs_dev.name, sdev->model, 16);
- strncat(sdev->sdev_driverfs_dev.name, sdev->rev, 4);
- return 1;
- }
+ sdev->sdev_driverfs_dev.name[0] = SCSI_UID_UNKNOWN;
+ strncpy(&sdev->sdev_driverfs_dev.name[1], sdev->vendor, 8);
+ strncat(sdev->sdev_driverfs_dev.name, sdev->model, 16);
+ strncat(sdev->sdev_driverfs_dev.name, sdev->rev, 4);
+ return 1;
}

/**

-- 
function.linuxpower.ca
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