[PATCH] mtd: spi-nor: fix memory leak when using debugfs_lookup()

[Greg Kroah-Hartman]

When calling debugfs_lookup() the result must have dput() called on it,
otherwise the memory will leak over time.  Fix this up to be much
simpler logic and only create the root debugfs directory once when the
driver is first accessed.  That resolves the memory leak and makes
things more obvious as to what the intent is.

Cc: Tudor Ambarus <tudor.ambarus at microchip.com>
Cc: Pratyush Yadav <pratyush at kernel.org>
Cc: Michael Walle <michael at walle.cc>
Cc: Miquel Raynal <miquel.raynal at bootlin.com>
Cc: Richard Weinberger <richard at nod.at>
Cc: Vignesh Raghavendra <vigneshr at ti.com>
Cc: linux-mtd at lists.infradead.org
Cc: stable <stable at kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
---
 drivers/mtd/spi-nor/debugfs.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/mtd/spi-nor/debugfs.c b/drivers/mtd/spi-nor/debugfs.c
index df76cb5de3f9..3aab595e82d1 100644
--- a/drivers/mtd/spi-nor/debugfs.c
+++ b/drivers/mtd/spi-nor/debugfs.c
@@ -228,11 +228,11 @@ static void spi_nor_debugfs_unregister(void *data)
 
 void spi_nor_debugfs_register(struct spi_nor *nor)
 {
-	struct dentry *rootdir, *d;
+	static struct dentry *rootdir;
+	struct dentry *d;
 	int ret;
 
 	/* Create rootdir once. Will never be deleted again. */
-	rootdir = debugfs_lookup(SPI_NOR_DEBUGFS_ROOT, NULL);
 	if (!rootdir)
 		rootdir = debugfs_create_dir(SPI_NOR_DEBUGFS_ROOT, NULL);
 
-- 
2.37.3