Commit 3dea642a authored by James Bottomley's avatar James Bottomley

[SCSI] Revert "[SCSI] Retrieve the Caching mode page"

This reverts commit 24d720b7.

Previously we thought there was little possibility that devices would
crash with this, but some have been found.
Reported-by: default avatarAlan Stern <stern@rowland.harvard.edu>
Cc: Luben Tuikov <ltuikov@yahoo.com>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@suse.de>
parent fee78712
......@@ -2027,14 +2027,10 @@ sd_read_cache_type(struct scsi_disk *sdkp, unsigned char *buffer)
int old_rcd = sdkp->RCD;
int old_dpofua = sdkp->DPOFUA;
if (sdp->skip_ms_page_8) {
if (sdp->type == TYPE_RBC)
goto defaults;
else {
modepage = 0x3F;
dbd = 0;
}
} else if (sdp->type == TYPE_RBC) {
if (sdp->skip_ms_page_8)
goto defaults;
if (sdp->type == TYPE_RBC) {
modepage = 6;
dbd = 8;
} else {
......@@ -2062,11 +2058,13 @@ sd_read_cache_type(struct scsi_disk *sdkp, unsigned char *buffer)
*/
if (len < 3)
goto bad_sense;
else if (len > SD_BUF_SIZE) {
sd_printk(KERN_NOTICE, sdkp, "Truncating mode parameter "
"data from %d to %d bytes\n", len, SD_BUF_SIZE);
len = SD_BUF_SIZE;
}
if (len > 20)
len = 20;
/* Take headers and block descriptors into account */
len += data.header_length + data.block_descriptor_length;
if (len > SD_BUF_SIZE)
goto bad_sense;
/* Get the data */
res = sd_do_mode_sense(sdp, dbd, modepage, buffer, len, &data, &sshdr);
......@@ -2074,45 +2072,16 @@ sd_read_cache_type(struct scsi_disk *sdkp, unsigned char *buffer)
if (scsi_status_is_good(res)) {
int offset = data.header_length + data.block_descriptor_length;
while (offset < len) {
u8 page_code = buffer[offset] & 0x3F;
u8 spf = buffer[offset] & 0x40;
if (page_code == 8 || page_code == 6) {
/* We're interested only in the first 3 bytes.
*/
if (len - offset <= 2) {
sd_printk(KERN_ERR, sdkp, "Incomplete "
"mode parameter data\n");
goto defaults;
} else {
modepage = page_code;
goto Page_found;
}
} else {
/* Go to the next page */
if (spf && len - offset > 3)
offset += 4 + (buffer[offset+2] << 8) +
buffer[offset+3];
else if (!spf && len - offset > 1)
offset += 2 + buffer[offset+1];
else {
sd_printk(KERN_ERR, sdkp, "Incomplete "
"mode parameter data\n");
goto defaults;
}
}
if (offset >= SD_BUF_SIZE - 2) {
sd_printk(KERN_ERR, sdkp, "Malformed MODE SENSE response\n");
goto defaults;
}
if (modepage == 0x3F) {
sd_printk(KERN_ERR, sdkp, "No Caching mode page "
"present\n");
goto defaults;
} else if ((buffer[offset] & 0x3f) != modepage) {
if ((buffer[offset] & 0x3f) != modepage) {
sd_printk(KERN_ERR, sdkp, "Got wrong page\n");
goto defaults;
}
Page_found:
if (modepage == 8) {
sdkp->WCE = ((buffer[offset + 2] & 0x04) != 0);
sdkp->RCD = ((buffer[offset + 2] & 0x01) != 0);
......
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