Patch "usb: f_mass_storage: limit number of reported LUNs" has been added to the 4.1-stable tree

Patch "usb: f_mass_storage: limit number of reported LUNs" has been added to the 4.1-stable tree

[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 the 4.1-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     usb-f_mass_storage-limit-number-of-reported-luns.patch
and it can be found in the queue-4.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>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

From: Michal Nazarewicz <mina86@mina86.com>

commit 8515bac01a983d277148e4fcc5f235bf603de577 upstream.

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.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/usb/gadget/function/f_mass_storage.c |   16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

--- 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_comm
 		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_comm
 	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(st
 	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;


Patches currently in stable-queue which might be from mina86@mina86.com are

queue-4.1/usb-f_mass_storage-limit-number-of-reported-luns.patch