mmc: Avoid re-using minor numbers before the original device is closed.

Move the code which marks the minor number as free to mmc_blk_put() so
that it happens on the final close() (or removal), instead of doing it
at removal even when the device is still logically open.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>

1 files changed, 6 insertions, 8 deletions

diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index acaa05200ae7..aeb32a93f6a0 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -44,6 +44,9 @@
  * max 8 partitions per card
  */
 #define MMC_SHIFT       3
+#define MMC_NUM_MINORS  (256 >> MMC_SHIFT)
+
+static unsigned long dev_use[MMC_NUM_MINORS/(8*sizeof(unsigned long))];
 
 /*
  * There is one mmc_blk_data per slot.
@@ -80,6 +83,9 @@ static void mmc_blk_put(struct mmc_blk_data *md)
         mutex_lock(&open_lock);
         md->usage--;
         if (md->usage == 0) {
+                int devidx = md->disk->first_minor >> MMC_SHIFT;
+                __clear_bit(devidx, dev_use);
+
                 put_disk(md->disk);
                 kfree(md);
         }
@@ -406,9 +412,6 @@ static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
         return 0;
 }
 
-#define MMC_NUM_MINORS  (256 >> MMC_SHIFT)
-
-static unsigned long dev_use[MMC_NUM_MINORS/(8*sizeof(unsigned long))];
 
 static inline int mmc_blk_readonly(struct mmc_card *card)
 {
@@ -574,17 +577,12 @@ static void mmc_blk_remove(struct mmc_card *card)
         struct mmc_blk_data *md = mmc_get_drvdata(card);
 
         if (md) {
-                int devidx;
-
                 /* Stop new requests from getting into the queue */
                 del_gendisk(md->disk);
 
                 /* Then flush out any already in there */
                 mmc_cleanup_queue(&md->queue);
 
-                devidx = md->disk->first_minor >> MMC_SHIFT;
-                __clear_bit(devidx, dev_use);
-
                 mmc_blk_put(md);
         }
         mmc_set_drvdata(card, NULL);