linux-kernel - [PATCH] mtdpart: propagate _get/put

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Date:	Wed, 29 Jun 2016 22:14:23 +0200
From:	Richard Weinberger <richard@....at>
To:	computersforpeace@...il.com
Cc:	dwmw2@...radead.org, linux-mtd@...ts.infradead.org,
	linux-kernel@...r.kernel.org, Richard Weinberger <richard@....at>
Subject: [PATCH] mtdpart: propagate _get/put_device()

If the master device has callbacks for _get/put_device()
and this MTD has slaves a get_mtd_device() call on paritions
will never issue the registered callbacks.
Fix this by propergating _get/put_device() down.

Signed-off-by: Richard Weinberger <richard@....at>
---
Hi!

I've found this issue while heavily reworking nandsim.
With my changes applied you can add/remove MTD's during
runtime. I figured that nandsim's refcounting goes nuts.
After tracking down the root cause I figured that
_get/put_device() has no effect on MTD slaves.

Thanks,
//richard

---
 drivers/mtd/mtdpart.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c
index 1f13e32..938dbeb 100644
--- a/drivers/mtd/mtdpart.c
+++ b/drivers/mtd/mtdpart.c
@@ -317,6 +317,19 @@ static int part_block_markbad(struct mtd_info *mtd, loff_t ofs)
 	return res;
 }
 
+static int part_get_device(struct mtd_info *mtd)
+{
+	struct mtd_part *part = mtd_to_part(mtd);
+	return part->master->_get_device(part->master);
+}
+
+static void part_put_device(struct mtd_info *mtd)
+{
+	struct mtd_part *part = mtd_to_part(mtd);
+	part->master->_put_device(part->master);
+}
+
+
 static int part_ooblayout_ecc(struct mtd_info *mtd, int section,
 			      struct mtd_oob_region *oobregion)
 {
@@ -463,6 +476,12 @@ static struct mtd_part *allocate_partition(struct mtd_info *master,
 		slave->mtd._block_isbad = part_block_isbad;
 	if (master->_block_markbad)
 		slave->mtd._block_markbad = part_block_markbad;
+
+	if (master->_get_device)
+		slave->mtd._get_device = part_get_device;
+	if (master->_put_device)
+		slave->mtd._put_device = part_put_device;
+
 	slave->mtd._erase = part_erase;
 	slave->master = master;
 	slave->offset = part->offset;
-- 
2.7.3