[MMC] Use command class to determine read-only status

If a card doesn't support the "write block" command class then
any attempts to open the device should reflect this by denying
write access.

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

diff --git a/drivers/mmc/mmc_block.c b/drivers/mmc/mmc_block.c
index fa83f15fdf161d8eafda24958a8e9ccb6ebc2573..9b629856c7358bc8061d8413b13e4ab331071426 100644 (file)
--- a/drivers/mmc/mmc_block.c
+++ b/drivers/mmc/mmc_block.c
@@ -85,6 +85,12 @@ static void mmc_blk_put(struct mmc_blk_data *md)
        up(&open_lock);
 }
 
+static inline int mmc_blk_readonly(struct mmc_card *card)
+{
+       return mmc_card_readonly(card) ||
+              !(card->csd.cmdclass & CCC_BLOCK_WRITE);
+}
+
 static int mmc_blk_open(struct inode *inode, struct file *filp)
 {
        struct mmc_blk_data *md;
@@ -97,7 +103,7 @@ static int mmc_blk_open(struct inode *inode, struct file *filp)
                ret = 0;
 
                if ((filp->f_mode & FMODE_WRITE) &&
-                       mmc_card_readonly(md->queue.card))
+                       mmc_blk_readonly(md->queue.card))
                        ret = -EROFS;
        }
 
@@ -410,7 +416,7 @@ static int mmc_blk_probe(struct mmc_card *card)
        printk(KERN_INFO "%s: %s %s %dKiB %s\n",
                md->disk->disk_name, mmc_card_id(card), mmc_card_name(card),
                (card->csd.capacity << card->csd.read_blkbits) / 1024,
-               mmc_card_readonly(card)?"(ro)":"");
+               mmc_blk_readonly(card)?"(ro)":"");
 
        mmc_set_drvdata(card, md);
        add_disk(md->disk);