1 files changed, 75 insertions, 24 deletions

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 956496182c80..365024b0c407 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -583,7 +583,7 @@ static int sd_prep_fn(struct request_queue *q, struct request *rq)
                  * quietly refuse to do anything to a changed disc until 
                  * the changed bit has been reset
                  */
-                /* printk("SCSI disk has been changed. Prohibiting further I/O.\n"); */
+                /* printk("SCSI disk has been changed or is not present. Prohibiting further I/O.\n"); */
                 goto out;
         }
 
@@ -1023,7 +1023,6 @@ static int sd_media_changed(struct gendisk *disk)
          */
         if (!scsi_device_online(sdp)) {
                 set_media_not_present(sdkp);
-                retval = 1;
                 goto out;
         }
 
@@ -1054,7 +1053,6 @@ static int sd_media_changed(struct gendisk *disk)
                        /* 0x3a is medium not present */
                        sshdr->asc == 0x3a)) {
                 set_media_not_present(sdkp);
-                retval = 1;
                 goto out;
         }
 
@@ -1065,12 +1063,27 @@ static int sd_media_changed(struct gendisk *disk)
          */
         sdkp->media_present = 1;
 
-        retval = sdp->changed;
-        sdp->changed = 0;
 out:
-        if (retval != sdkp->previous_state)
+        /*
+         * Report a media change under the following conditions:
+         *
+         *      Medium is present now and wasn't present before.
+         *      Medium wasn't present before and is present now.
+         *      Medium was present at all times, but it changed while
+         *              we weren't looking (sdp->changed is set).
+         *
+         * If there was no medium before and there is no medium now then
+         * don't report a change, even if a medium was inserted and removed
+         * while we weren't looking.
+         */
+        retval = (sdkp->media_present != sdkp->previous_state ||
+                        (sdkp->media_present && sdp->changed));
+        if (retval)
                 sdev_evt_send_simple(sdp, SDEV_EVT_MEDIA_CHANGE, GFP_KERNEL);
-        sdkp->previous_state = retval;
+        sdkp->previous_state = sdkp->media_present;
+
+        /* sdp->changed indicates medium was changed or is not present */
+        sdp->changed = !sdkp->media_present;
         kfree(sshdr);
         return retval;
 }
@@ -1175,6 +1188,12 @@ static unsigned int sd_completed_bytes(struct scsi_cmnd *scmd)
         u64 end_lba = blk_rq_pos(scmd->request) + (scsi_bufflen(scmd) / 512);
         u64 bad_lba;
         int info_valid;
+        /*
+         * resid is optional but mostly filled in.  When it's unused,
+         * its value is zero, so we assume the whole buffer transferred
+         */
+        unsigned int transferred = scsi_bufflen(scmd) - scsi_get_resid(scmd);
+        unsigned int good_bytes;
 
         if (scmd->request->cmd_type != REQ_TYPE_FS)
                 return 0;
@@ -1208,7 +1227,8 @@ static unsigned int sd_completed_bytes(struct scsi_cmnd *scmd)
         /* This computation should always be done in terms of
          * the resolution of the device's medium.
          */
-        return (bad_lba - start_lba) * scmd->device->sector_size;
+        good_bytes = (bad_lba - start_lba) * scmd->device->sector_size;
+        return min(good_bytes, transferred);
 }
 
 /**
@@ -1902,10 +1922,14 @@ 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)
-                goto defaults;
-
-        if (sdp->type == TYPE_RBC) {
+        if (sdp->skip_ms_page_8) {
+                if (sdp->type == TYPE_RBC)
+                        goto defaults;
+                else {
+                        modepage = 0x3F;
+                        dbd = 0;
+                }
+        } else if (sdp->type == TYPE_RBC) {
                 modepage = 6;
                 dbd = 8;
         } else {
@@ -1933,13 +1957,11 @@ sd_read_cache_type(struct scsi_disk *sdkp, unsigned char *buffer)
          */
         if (len < 3)
                 goto bad_sense;
-        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;
+        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;
+        }
 
         /* Get the data */
         res = sd_do_mode_sense(sdp, dbd, modepage, buffer, len, &data, &sshdr);
@@ -1947,16 +1969,45 @@ 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;
 
-                if (offset >= SD_BUF_SIZE - 2) {
-                        sd_printk(KERN_ERR, sdkp, "Malformed MODE SENSE response\n");
-                        goto defaults;
+                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 ((buffer[offset] & 0x3f) != modepage) {
+                if (modepage == 0x3F) {
+                        sd_printk(KERN_ERR, sdkp, "No Caching mode page "
+                                  "present\n");
+                        goto defaults;
+                } else 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);