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From:   Christoph Hellwig <hch@lst.de>
To:     Christian Brauner <brauner@kernel.org>,
        Al Viro <viro@zeniv.linux.org.uk>
Cc:     Heiko Carstens <hca@linux.ibm.com>,
        Vasily Gorbik <gor@linux.ibm.com>,
        Alexander Gordeev <agordeev@linux.ibm.com>,
        Fenghua Yu <fenghua.yu@intel.com>,
        Reinette Chatre <reinette.chatre@intel.com>,
        Miquel Raynal <miquel.raynal@bootlin.com>,
        Richard Weinberger <richard@nod.at>,
        Vignesh Raghavendra <vigneshr@ti.com>,
        Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com>,
        Tejun Heo <tj@kernel.org>,
        Trond Myklebust <trond.myklebust@hammerspace.com>,
        Anna Schumaker <anna@kernel.org>,
        Kees Cook <keescook@chromium.org>,
        Damien Le Moal <dlemoal@kernel.org>,
        Naohiro Aota <naohiro.aota@wdc.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-s390@vger.kernel.org, linux-rdma@vger.kernel.org,
        linux-nfs@vger.kernel.org, linux-hardening@vger.kernel.org,
        cgroups@vger.kernel.org
Subject: [PATCH 10/19] USB: gadget/legacy: remove sb_mutex
Date:   Wed, 13 Sep 2023 08:10:04 -0300
Message-Id: <20230913111013.77623-11-hch@lst.de>
In-Reply-To: <20230913111013.77623-1-hch@lst.de>
References: <20230913111013.77623-1-hch@lst.de>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Creating new a new super_block vs freeing the old one for single instance
file systems is serialized by the wait for SB_DEAD.

Remove the superfluous sb_mutex.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/usb/gadget/legacy/inode.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/drivers/usb/gadget/legacy/inode.c b/drivers/usb/gadget/legacy/inode.c
index ce9e31f3d26bcc..a203266bc0dc82 100644
--- a/drivers/usb/gadget/legacy/inode.c
+++ b/drivers/usb/gadget/legacy/inode.c
@@ -229,7 +229,6 @@ static void put_ep (struct ep_data *data)
  */
 
 static const char *CHIP;
-static DEFINE_MUTEX(sb_mutex);		/* Serialize superblock operations */
 
 /*----------------------------------------------------------------------*/
 
@@ -2012,8 +2011,6 @@ gadgetfs_fill_super (struct super_block *sb, struct fs_context *fc)
 	struct dev_data	*dev;
 	int		rc;
 
-	mutex_lock(&sb_mutex);
-
 	if (the_device) {
 		rc = -ESRCH;
 		goto Done;
@@ -2069,7 +2066,6 @@ gadgetfs_fill_super (struct super_block *sb, struct fs_context *fc)
 	rc = -ENOMEM;
 
  Done:
-	mutex_unlock(&sb_mutex);
 	return rc;
 }
 
@@ -2092,7 +2088,6 @@ static int gadgetfs_init_fs_context(struct fs_context *fc)
 static void
 gadgetfs_kill_sb (struct super_block *sb)
 {
-	mutex_lock(&sb_mutex);
 	kill_litter_super (sb);
 	if (the_device) {
 		put_dev (the_device);
@@ -2100,7 +2095,6 @@ gadgetfs_kill_sb (struct super_block *sb)
 	}
 	kfree(CHIP);
 	CHIP = NULL;
-	mutex_unlock(&sb_mutex);
 }
 
 /*----------------------------------------------------------------------*/
-- 
2.39.2