+ mmap_lock-change-trace-and-locking-order.patch added to -mm tree

+ mmap_lock-change-trace-and-locking-order.patch added to -mm tree

[akpm]

The patch titled
     Subject: mmap_lock: change trace and locking order
has been added to the -mm tree.  Its filename is
     mmap_lock-change-trace-and-locking-order.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/mmap_lock-change-trace-and-locking-order.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/mmap_lock-change-trace-and-locking-order.patch

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------------------------------------------------------
From: Liam Howlett <liam.howlett@oracle.com>
Subject: mmap_lock: change trace and locking order

Print to the trace log before releasing the lock to avoid racing with
other trace log printers of the same lock type.

Link: https://lkml.kernel.org/r/20210903022041.1843024-1-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Suggested-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michel Lespinasse <walken.cr@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 include/linux/mmap_lock.h |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

--- a/include/linux/mmap_lock.h~mmap_lock-change-trace-and-locking-order
+++ a/include/linux/mmap_lock.h
@@ -101,14 +101,14 @@ static inline bool mmap_write_trylock(st
 
 static inline void mmap_write_unlock(struct mm_struct *mm)
 {
-	up_write(&mm->mmap_lock);
 	__mmap_lock_trace_released(mm, true);
+	up_write(&mm->mmap_lock);
 }
 
 static inline void mmap_write_downgrade(struct mm_struct *mm)
 {
-	downgrade_write(&mm->mmap_lock);
 	__mmap_lock_trace_acquire_returned(mm, false, true);
+	downgrade_write(&mm->mmap_lock);
 }
 
 static inline void mmap_read_lock(struct mm_struct *mm)
@@ -140,8 +140,8 @@ static inline bool mmap_read_trylock(str
 
 static inline void mmap_read_unlock(struct mm_struct *mm)
 {
-	up_read(&mm->mmap_lock);
 	__mmap_lock_trace_released(mm, false);
+	up_read(&mm->mmap_lock);
 }
 
 static inline bool mmap_read_trylock_non_owner(struct mm_struct *mm)
@@ -155,8 +155,8 @@ static inline bool mmap_read_trylock_non
 
 static inline void mmap_read_unlock_non_owner(struct mm_struct *mm)
 {
-	up_read_non_owner(&mm->mmap_lock);
 	__mmap_lock_trace_released(mm, false);
+	up_read_non_owner(&mm->mmap_lock);
 }
 
 static inline void mmap_assert_locked(struct mm_struct *mm)
_

Patches currently in -mm which might be from liam.howlett@oracle.com are

mmap_lock-change-trace-and-locking-order.patch