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authorJames Bottomley <James.Bottomley@suse.de>2011-03-23 09:58:28 -0500
committerJames Bottomley <James.Bottomley@suse.de>2011-03-23 12:53:09 -0500
commit3dea642afd9187728d119fce5c82a7ed9faa9b6a (patch)
treee19500e36674b99c91db2afed6168b2eb08a4233 /drivers
parentfee787129d4d6a5e967a69ea3dea3e38ba556b3d (diff)
[SCSI] Revert "[SCSI] Retrieve the Caching mode page"
This reverts commit 24d720b726c1a85f1962831ac30ad4d2ef8276b1. Previously we thought there was little possibility that devices would crash with this, but some have been found. Reported-by: Alan Stern <stern@rowland.harvard.edu> Cc: Luben Tuikov <ltuikov@yahoo.com> Signed-off-by: James Bottomley <James.Bottomley@suse.de>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/scsi/sd.c63
1 files changed, 16 insertions, 47 deletions
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 7ff61d76b4c5..b61ebec6bca7 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -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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