2 files changed, 40 insertions, 0 deletions

diff --git a/drivers/mtd/ftl.c b/drivers/mtd/ftl.c
index f34f20c78911..9bf581c4f740 100644
--- a/drivers/mtd/ftl.c
+++ b/drivers/mtd/ftl.c
@@ -1005,6 +1005,29 @@ static int ftl_writesect(struct mtd_blktrans_dev *dev,
         return ftl_write((void *)dev, buf, block, 1);
 }
 
+static int ftl_discardsect(struct mtd_blktrans_dev *dev,
+                           unsigned long sector, unsigned nr_sects)
+{
+        partition_t *part = (void *)dev;
+        uint32_t bsize = 1 << part->header.EraseUnitSize;
+
+        DEBUG(1, "FTL erase sector %ld for %d sectors\n",
+              sector, nr_sects);
+
+        while (nr_sects) {
+                uint32_t old_addr = part->VirtualBlockMap[sector];
+                if (old_addr != 0xffffffff) {
+                        part->VirtualBlockMap[sector] = 0xffffffff;
+                        part->EUNInfo[old_addr/bsize].Deleted++;
+                        if (set_bam_entry(part, old_addr, 0))
+                                return -EIO;
+                }
+                nr_sects--;
+                sector++;
+        }
+
+        return 0;
+}
 /*====================================================================*/
 
 static void ftl_freepart(partition_t *part)
@@ -1069,6 +1092,7 @@ static struct mtd_blktrans_ops ftl_tr = {
         .blksize        = SECTOR_SIZE,
         .readsect       = ftl_readsect,
         .writesect      = ftl_writesect,
+        .discard        = ftl_discardsect,
         .getgeo         = ftl_getgeo,
         .add_mtd        = ftl_add_mtd,
         .remove_dev     = ftl_remove_dev,
diff --git a/drivers/mtd/mtd_blkdevs.c b/drivers/mtd/mtd_blkdevs.c
index 9ff007c4962c..681d5aca2af4 100644
--- a/drivers/mtd/mtd_blkdevs.c
+++ b/drivers/mtd/mtd_blkdevs.c
@@ -32,6 +32,14 @@ struct mtd_blkcore_priv {
         spinlock_t queue_lock;
 };
 
+static int blktrans_discard_request(struct request_queue *q,
+                                    struct request *req)
+{
+        req->cmd_type = REQ_TYPE_LINUX_BLOCK;
+        req->cmd[0] = REQ_LB_OP_DISCARD;
+        return 0;
+}
+
 static int do_blktrans_request(struct mtd_blktrans_ops *tr,
                                struct mtd_blktrans_dev *dev,
                                struct request *req)
@@ -44,6 +52,10 @@ static int do_blktrans_request(struct mtd_blktrans_ops *tr,
 
         buf = req->buffer;
 
+        if (req->cmd_type == REQ_TYPE_LINUX_BLOCK &&
+            req->cmd[0] == REQ_LB_OP_DISCARD)
+                return !tr->discard(dev, block, nsect);
+
         if (!blk_fs_request(req))
                 return 0;
 
@@ -367,6 +379,10 @@ int register_mtd_blktrans(struct mtd_blktrans_ops *tr)
 
         tr->blkcore_priv->rq->queuedata = tr;
         blk_queue_hardsect_size(tr->blkcore_priv->rq, tr->blksize);
+        if (tr->discard)
+                blk_queue_set_discard(tr->blkcore_priv->rq,
+                                      blktrans_discard_request);
+
         tr->blkshift = ffs(tr->blksize) - 1;
 
         tr->blkcore_priv->thread = kthread_run(mtd_blktrans_thread, tr,