1 files changed, 43 insertions, 16 deletions

diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 86c2663e00e6..67d23bd87950 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -2205,9 +2205,33 @@ static unsigned int ata_scsiop_noop(struct ata_scsi_args *args, u8 *rbuf)
 }
 
 /**
+ *      modecpy - Prepare response for MODE SENSE
+ *      @dest: output buffer
+ *      @src: data being copied
+ *      @n: length of mode page
+ *      @changeable: whether changeable parameters are requested
+ *
+ *      Generate a generic MODE SENSE page for either current or changeable
+ *      parameters.
+ *
+ *      LOCKING:
+ *      None.
+ */
+static void modecpy(u8 *dest, const u8 *src, int n, bool changeable)
+{
+        if (changeable) {
+                memcpy(dest, src, 2);
+                memset(dest + 2, 0, n - 2);
+        } else {
+                memcpy(dest, src, n);
+        }
+}
+
+/**
  *      ata_msense_caching - Simulate MODE SENSE caching info page
  *      @id: device IDENTIFY data
  *      @buf: output buffer
+ *      @changeable: whether changeable parameters are requested
  *
  *      Generate a caching info page, which conditionally indicates
  *      write caching to the SCSI layer, depending on device
@@ -2216,12 +2240,12 @@ static unsigned int ata_scsiop_noop(struct ata_scsi_args *args, u8 *rbuf)
  *      LOCKING:
  *      None.
  */
-static unsigned int ata_msense_caching(u16 *id, u8 *buf)
+static unsigned int ata_msense_caching(u16 *id, u8 *buf, bool changeable)
 {
-        memcpy(buf, def_cache_mpage, sizeof(def_cache_mpage));
-        if (ata_id_wcache_enabled(id))
+        modecpy(buf, def_cache_mpage, sizeof(def_cache_mpage), changeable);
+        if (!changeable && ata_id_wcache_enabled(id))
                 buf[2] |= (1 << 2);     /* write cache enable */
-        if (!ata_id_rahead_enabled(id))
+        if (!changeable && !ata_id_rahead_enabled(id))
                 buf[12] |= (1 << 5);    /* disable read ahead */
         return sizeof(def_cache_mpage);
 }
@@ -2229,30 +2253,33 @@ static unsigned int ata_msense_caching(u16 *id, u8 *buf)
 /**
  *      ata_msense_ctl_mode - Simulate MODE SENSE control mode page
  *      @buf: output buffer
+ *      @changeable: whether changeable parameters are requested
  *
  *      Generate a generic MODE SENSE control mode page.
  *
  *      LOCKING:
  *      None.
  */
-static unsigned int ata_msense_ctl_mode(u8 *buf)
+static unsigned int ata_msense_ctl_mode(u8 *buf, bool changeable)
 {
-        memcpy(buf, def_control_mpage, sizeof(def_control_mpage));
+        modecpy(buf, def_control_mpage, sizeof(def_control_mpage), changeable);
         return sizeof(def_control_mpage);
 }
 
 /**
  *      ata_msense_rw_recovery - Simulate MODE SENSE r/w error recovery page
  *      @buf: output buffer
+ *      @changeable: whether changeable parameters are requested
  *
  *      Generate a generic MODE SENSE r/w error recovery page.
  *
  *      LOCKING:
  *      None.
  */
-static unsigned int ata_msense_rw_recovery(u8 *buf)
+static unsigned int ata_msense_rw_recovery(u8 *buf, bool changeable)
 {
-        memcpy(buf, def_rw_recovery_mpage, sizeof(def_rw_recovery_mpage));
+        modecpy(buf, def_rw_recovery_mpage, sizeof(def_rw_recovery_mpage),
+                changeable);
         return sizeof(def_rw_recovery_mpage);
 }
 
@@ -2316,11 +2343,11 @@ static unsigned int ata_scsiop_mode_sense(struct ata_scsi_args *args, u8 *rbuf)
         page_control = scsicmd[2] >> 6;
         switch (page_control) {
         case 0: /* current */
+        case 1: /* changeable */
+        case 2: /* defaults */
                 break;  /* supported */
         case 3: /* saved */
                 goto saving_not_supp;
-        case 1: /* changeable */
-        case 2: /* defaults */
         default:
                 goto invalid_fld;
         }
@@ -2341,21 +2368,21 @@ static unsigned int ata_scsiop_mode_sense(struct ata_scsi_args *args, u8 *rbuf)
 
         switch(pg) {
         case RW_RECOVERY_MPAGE:
-                p += ata_msense_rw_recovery(p);
+                p += ata_msense_rw_recovery(p, page_control == 1);
                 break;
 
         case CACHE_MPAGE:
-                p += ata_msense_caching(args->id, p);
+                p += ata_msense_caching(args->id, p, page_control == 1);
                 break;
 
         case CONTROL_MPAGE:
-                p += ata_msense_ctl_mode(p);
+                p += ata_msense_ctl_mode(p, page_control == 1);
                 break;
 
         case ALL_MPAGES:
-                p += ata_msense_rw_recovery(p);
-                p += ata_msense_caching(args->id, p);
-                p += ata_msense_ctl_mode(p);
+                p += ata_msense_rw_recovery(p, page_control == 1);
+                p += ata_msense_caching(args->id, p, page_control == 1);
+                p += ata_msense_ctl_mode(p, page_control == 1);
                 break;
 
         default:                /* invalid page code */