Merge tag 'mm-nonmm-stable-2022-10-11' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull non-MM updates from Andrew Morton:

 - hfs and hfsplus kmap API modernization (Fabio Francesco)

 - make crash-kexec work properly when invoked from an NMI-time panic
   (Valentin Schneider)

 - ntfs bugfixes (Hawkins Jiawei)

 - improve IPC msg scalability by replacing atomic_t's with percpu
   counters (Jiebin Sun)

 - nilfs2 cleanups (Minghao Chi)

 - lots of other single patches all over the tree!

* tag 'mm-nonmm-stable-2022-10-11' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (71 commits)
  include/linux/entry-common.h: remove has_signal comment of arch_do_signal_or_restart() prototype
  proc: test how it holds up with mapping'less process
  mailmap: update Frank Rowand email address
  ia64: mca: use strscpy() is more robust and safer
  init/Kconfig: fix unmet direct dependencies
  ia64: update config files
  nilfs2: replace WARN_ONs by nilfs_error for checkpoint acquisition failure
  fork: remove duplicate included header files
  init/main.c: remove unnecessary (void*) conversions
  proc: mark more files as permanent
  nilfs2: remove the unneeded result variable
  nilfs2: delete unnecessary checks before brelse()
  checkpatch: warn for non-standard fixes tag style
  usr/gen_init_cpio.c: remove unnecessary -1 values from int file
  ipc/msg: mitigate the lock contention with percpu counter
  percpu: add percpu_counter_add_local and percpu_counter_sub_local
  fs/ocfs2: fix repeated words in comments
  relay: use kvcalloc to alloc page array in relay_alloc_page_array
  proc: make config PROC_CHILDREN depend on PROC_FS
  fs: uninline inode_maybe_inc_iversion()
  ...

1 files changed, 5 insertions, 9 deletions

diff --git a/fs/buffer.c b/fs/buffer.c
index b927f6981ad1..d9c6d1fbb6dd 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -1453,19 +1453,15 @@ EXPORT_SYMBOL(set_bh_page);
 
 static void discard_buffer(struct buffer_head * bh)
 {
-	unsigned long b_state, b_state_old;
+	unsigned long b_state;
 
 	lock_buffer(bh);
 	clear_buffer_dirty(bh);
 	bh->b_bdev = NULL;
-	b_state = bh->b_state;
-	for (;;) {
-		b_state_old = cmpxchg(&bh->b_state, b_state,
-				      (b_state & ~BUFFER_FLAGS_DISCARD));
-		if (b_state_old == b_state)
-			break;
-		b_state = b_state_old;
-	}
+	b_state = READ_ONCE(bh->b_state);
+	do {
+	} while (!try_cmpxchg(&bh->b_state, &b_state,
+			      b_state & ~BUFFER_FLAGS_DISCARD));
 	unlock_buffer(bh);
 }