[PATCH 2/3] btrfs: switch extent_buffer spinning_writers from atomic to int

[David Sterba]

The spinning_writers is either 0 or 1 and always updated under the lock,
so we don't need the atomic_t semantics.

Signed-off-by: David Sterba <dste...@suse.com>
---
 fs/btrfs/extent_io.c  |  2 +-
 fs/btrfs/extent_io.h  |  2 +-
 fs/btrfs/locking.c    | 10 +++++-----
 fs/btrfs/print-tree.c |  2 +-
 4 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 57b6de9df7c4..71ee9e976307 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -4842,7 +4842,7 @@ __alloc_extent_buffer(struct btrfs_fs_info *fs_info, u64 
start,
        BUG_ON(len > MAX_INLINE_EXTENT_BUFFER_SIZE);
 
 #ifdef CONFIG_BTRFS_DEBUG
-       atomic_set(&eb->spinning_writers, 0);
+       eb->spinning_writers = 0;
        atomic_set(&eb->spinning_readers, 0);
        atomic_set(&eb->read_locks, 0);
        atomic_set(&eb->write_locks, 0);
diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index 201da61dfc21..5616b96c365d 100644
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -187,7 +187,7 @@ struct extent_buffer {
        wait_queue_head_t read_lock_wq;
        struct page *pages[INLINE_EXTENT_BUFFER_PAGES];
 #ifdef CONFIG_BTRFS_DEBUG
-       atomic_t spinning_writers;
+       int spinning_writers;
        atomic_t spinning_readers;
        atomic_t read_locks;
        atomic_t write_locks;
diff --git a/fs/btrfs/locking.c b/fs/btrfs/locking.c
index 5feb01147e19..270667627977 100644
--- a/fs/btrfs/locking.c
+++ b/fs/btrfs/locking.c
@@ -15,19 +15,19 @@
 #ifdef CONFIG_BTRFS_DEBUG
 static void btrfs_assert_spinning_writers_get(struct extent_buffer *eb)
 {
-       WARN_ON(atomic_read(&eb->spinning_writers));
-       atomic_inc(&eb->spinning_writers);
+       WARN_ON(eb->spinning_writers);
+       eb->spinning_writers++;
 }
 
 static void btrfs_assert_spinning_writers_put(struct extent_buffer *eb)
 {
-       WARN_ON(atomic_read(&eb->spinning_writers) != 1);
-       atomic_dec(&eb->spinning_writers);
+       WARN_ON(eb->spinning_writers != 1);
+       eb->spinning_writers--;
 }
 
 static void btrfs_assert_no_spinning_writers(struct extent_buffer *eb)
 {
-       WARN_ON(atomic_read(&eb->spinning_writers));
+       WARN_ON(eb->spinning_writers);
 }
 
 static void btrfs_assert_spinning_readers_get(struct extent_buffer *eb)
diff --git a/fs/btrfs/print-tree.c b/fs/btrfs/print-tree.c
index 7cb4f1fbe043..c5cc435ed39a 100644
--- a/fs/btrfs/print-tree.c
+++ b/fs/btrfs/print-tree.c
@@ -157,7 +157,7 @@ static void print_eb_refs_lock(struct extent_buffer *eb)
                   atomic_read(&eb->read_locks),
                   eb->blocking_writers,
                   atomic_read(&eb->blocking_readers),
-                  atomic_read(&eb->spinning_writers),
+                  eb->spinning_writers,
                   atomic_read(&eb->spinning_readers),
                   eb->lock_owner, current->pid);
 #endif
-- 
2.21.0