[merged] mqueue-sys_mq_open-do-not-call-mnt_drop_write-if-read-only.patch removed from -mm tree

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The patch titled
     Subject: mqueue: sys_mq_open: do not call mnt_drop_write() if read-only
has been removed from the -mm tree.  Its filename was
     mqueue-sys_mq_open-do-not-call-mnt_drop_write-if-read-only.patch

This patch was dropped because it was merged into mainline or a subsystem tree

------------------------------------------------------
From: Vladimir Davydov <vdavydov@xxxxxxxxxxxxx>
Subject: mqueue: sys_mq_open: do not call mnt_drop_write() if read-only

mnt_drop_write() must be called only if mnt_want_write() succeeded,
otherwise the mnt_writers counter will diverge.

mnt_writers counters are used to check if remounting FS as read-only is
OK, so after an extra mnt_drop_write() call, it would be impossible to
remount mqueue FS as read-only.  Besides, on umount a warning would be
printed like this one:

[  194.714880] =====================================
[  194.719680] [ BUG: bad unlock balance detected! ]
[  194.724488] 3.9.0-rc3 #5 Not tainted
[  194.728159] -------------------------------------
[  194.732958] a.out/12486 is trying to release lock (sb_writers) at:
[  194.739355] [<ffffffff811b177f>] mnt_drop_write+0x1f/0x30
[  194.744851] but there are no more locks to release!


Signed-off-by: Vladimir Davydov <vdavydov@xxxxxxxxxxxxx>
Cc: Doug Ledford <dledford@xxxxxxxxxx>
Cc: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---

 ipc/mqueue.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff -puN ipc/mqueue.c~mqueue-sys_mq_open-do-not-call-mnt_drop_write-if-read-only ipc/mqueue.c
--- a/ipc/mqueue.c~mqueue-sys_mq_open-do-not-call-mnt_drop_write-if-read-only
+++ a/ipc/mqueue.c
@@ -840,7 +840,8 @@ out_putfd:
 		fd = error;
 	}
 	mutex_unlock(&root->d_inode->i_mutex);
-	mnt_drop_write(mnt);
+	if (!ro)
+		mnt_drop_write(mnt);
 out_putname:
 	putname(name);
 	return fd;
_

Patches currently in -mm which might be from vdavydov@xxxxxxxxxxxxx are


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