diff mbox series

[10/19] USB: gadget/legacy: remove sb_mutex

Message ID 20230913111013.77623-11-hch@lst.de
State New
Headers
Series [01/19] fs: reflow deactivate_locked_super |

Commit Message

Christoph Hellwig Sept. 13, 2023, 11:10 a.m. UTC 
  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(-)

Comments

Sergey Shtylyov Sept. 14, 2023, 10:22 a.m. UTC | #1 
On 9/13/23 2:10 PM, Christoph Hellwig wrote:

> Creating new a new super_block vs freeing the old one for single instance
           ^^^^^^^^^
   I can't parse that. :-)

> file systems is serialized by the wait for SB_DEAD.
> 
> Remove the superfluous sb_mutex.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
[...]

MBR, Sergey
Christoph Hellwig Sept. 26, 2023, 9:24 a.m. UTC | #2 
On Wed, Sep 13, 2023 at 12:10:56PM -0400, Alan Stern wrote:
> On Wed, Sep 13, 2023 at 08:10:04AM -0300, Christoph Hellwig wrote:
> > 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>
> > ---
> 
> You might mention that this is essentially a reversion of commit 
> d18dcfe9860e ("USB: gadgetfs: Fix race between mounting and 
> unmounting").

The difference we have now is that sb creation waits for the
old one to go way, but I'll add a notice on all that.
diff mbox series

Patch

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);
 }
 
 /*----------------------------------------------------------------------*/