patch "usb: f_mass_storage: limit number of reported LUNs" added to usb-linus

patch "usb: f_mass_storage: limit number of reported LUNs" added to usb-linus

[gregkh]

This is a note to let you know that I've just added the patch titled

    usb: f_mass_storage: limit number of reported LUNs

to my usb git tree which can be found at
    git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-linus branch.

The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.

If you have any questions about this process, please let me know.


>From 8515bac01a983d277148e4fcc5f235bf603de577 Mon Sep 17 00:00:00 2001
From: Michal Nazarewicz <mina86@mina86.com>
Date: Fri, 19 Jun 2015 23:56:34 +0200
Subject: usb: f_mass_storage: limit number of reported LUNs

Mass storage function created via configfs always reports eight LUNs
to the hosts even if only one LUN has been configured.  Adjust the
number when the USB function is allocated based on LUNs that user
has created.

Cc: <stable@vger.kernel.org>
Tested-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
---
 drivers/usb/gadget/function/f_mass_storage.c | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/gadget/function/f_mass_storage.c b/drivers/usb/gadget/function/f_mass_storage.c
index d2259c663996..f936268d26c6 100644
--- a/drivers/usb/gadget/function/f_mass_storage.c
+++ b/drivers/usb/gadget/function/f_mass_storage.c
@@ -2786,7 +2786,7 @@ int fsg_common_set_nluns(struct fsg_common *common, int nluns)
 		return -EINVAL;
 	}
 
-	curlun = kcalloc(nluns, sizeof(*curlun), GFP_KERNEL);
+	curlun = kcalloc(FSG_MAX_LUNS, sizeof(*curlun), GFP_KERNEL);
 	if (unlikely(!curlun))
 		return -ENOMEM;
 
@@ -2796,8 +2796,6 @@ int fsg_common_set_nluns(struct fsg_common *common, int nluns)
 	common->luns = curlun;
 	common->nluns = nluns;
 
-	pr_info("Number of LUNs=%d\n", common->nluns);
-
 	return 0;
 }
 EXPORT_SYMBOL_GPL(fsg_common_set_nluns);
@@ -3563,14 +3561,26 @@ static struct usb_function *fsg_alloc(struct usb_function_instance *fi)
 	struct fsg_opts *opts = fsg_opts_from_func_inst(fi);
 	struct fsg_common *common = opts->common;
 	struct fsg_dev *fsg;
+	unsigned nluns, i;
 
 	fsg = kzalloc(sizeof(*fsg), GFP_KERNEL);
 	if (unlikely(!fsg))
 		return ERR_PTR(-ENOMEM);
 
 	mutex_lock(&opts->lock);
+	if (!opts->refcnt) {
+		for (nluns = i = 0; i < FSG_MAX_LUNS; ++i)
+			if (common->luns[i])
+				nluns = i + 1;
+		if (!nluns)
+			pr_warn("No LUNS defined, continuing anyway\n");
+		else
+			common->nluns = nluns;
+		pr_info("Number of LUNs=%u\n", common->nluns);
+	}
 	opts->refcnt++;
 	mutex_unlock(&opts->lock);
+
 	fsg->function.name	= FSG_DRIVER_DESC;
 	fsg->function.bind	= fsg_bind;
 	fsg->function.unbind	= fsg_unbind;
-- 
2.4.5