From 843ccf9f46baff289946e897b11fd813de62d06f Mon Sep 17 00:00:00 2001
From: David Sterba <dsterba@suse.com>
Date: Fri, 24 Aug 2018 14:56:28 +0200
Subject: [PATCH] btrfs: use assertion helpers for spinning writers
Use the helpers where open coded. On non-debug builds, the warnings will
not trigger and extent_buffer::spining_writers become unused and can be
moved to the appropriate section, saving a few bytes.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: David Sterba <dsterba@suse.com>
---
fs/btrfs/extent_io.c | 5 ++++-
fs/btrfs/extent_io.h | 2 +-
fs/btrfs/locking.c | 16 ++++++----------
3 files changed, 11 insertions(+), 12 deletions(-)
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index cc3941ae1ff62..fc0451c3e24e4 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -4682,7 +4682,6 @@ __alloc_extent_buffer(struct btrfs_fs_info *fs_info, u64 start,
atomic_set(&eb->blocking_readers, 0);
atomic_set(&eb->blocking_writers, 0);
atomic_set(&eb->spinning_readers, 0);
- atomic_set(&eb->spinning_writers, 0);
eb->lock_nested = 0;
init_waitqueue_head(&eb->write_lock_wq);
init_waitqueue_head(&eb->read_lock_wq);
@@ -4700,6 +4699,10 @@ __alloc_extent_buffer(struct btrfs_fs_info *fs_info, u64 start,
> MAX_INLINE_EXTENT_BUFFER_SIZE);
BUG_ON(len > MAX_INLINE_EXTENT_BUFFER_SIZE);
+#ifdef CONFIG_BTRFS_DEBUG
+ atomic_set(&eb->spinning_writers, 0);
+#endif
+
return eb;
}
diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index 1e5be66c7e0b2..3577ef33bc367 100644
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -166,7 +166,6 @@ struct extent_buffer {
atomic_t blocking_writers;
atomic_t blocking_readers;
atomic_t spinning_readers;
- atomic_t spinning_writers;
short lock_nested;
/* >= 0 if eb belongs to a log tree, -1 otherwise */
short log_index;
@@ -185,6 +184,7 @@ 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;
struct list_head leak_list;
#endif
};
diff --git a/fs/btrfs/locking.c b/fs/btrfs/locking.c
index 13ef1decdea60..a5a3c5118f613 100644
--- a/fs/btrfs/locking.c
+++ b/fs/btrfs/locking.c
@@ -64,8 +64,7 @@ void btrfs_set_lock_blocking_write(struct extent_buffer *eb)
if (eb->lock_nested && current->pid == eb->lock_owner)
return;
if (atomic_read(&eb->blocking_writers) == 0) {
- WARN_ON(atomic_read(&eb->spinning_writers) != 1);
- atomic_dec(&eb->spinning_writers);
+ btrfs_assert_spinning_writers_put(eb);
btrfs_assert_tree_locked(eb);
atomic_inc(&eb->blocking_writers);
write_unlock(&eb->lock);
@@ -101,8 +100,7 @@ void btrfs_clear_lock_blocking_write(struct extent_buffer *eb)
return;
BUG_ON(atomic_read(&eb->blocking_writers) != 1);
write_lock(&eb->lock);
- WARN_ON(atomic_read(&eb->spinning_writers));
- atomic_inc(&eb->spinning_writers);
+ btrfs_assert_spinning_writers_get(eb);
/* atomic_dec_and_test implies a barrier */
if (atomic_dec_and_test(&eb->blocking_writers))
cond_wake_up_nomb(&eb->write_lock_wq);
@@ -200,7 +198,7 @@ int btrfs_try_tree_write_lock(struct extent_buffer *eb)
return 0;
}
atomic_inc(&eb->write_locks);
- atomic_inc(&eb->spinning_writers);
+ btrfs_assert_spinning_writers_get(eb);
eb->lock_owner = current->pid;
return 1;
}
@@ -266,8 +264,7 @@ again:
write_unlock(&eb->lock);
goto again;
}
- WARN_ON(atomic_read(&eb->spinning_writers));
- atomic_inc(&eb->spinning_writers);
+ btrfs_assert_spinning_writers_get(eb);
atomic_inc(&eb->write_locks);
eb->lock_owner = current->pid;
}
@@ -286,14 +283,13 @@ void btrfs_tree_unlock(struct extent_buffer *eb)
atomic_dec(&eb->write_locks);
if (blockers) {
- WARN_ON(atomic_read(&eb->spinning_writers));
+ btrfs_assert_no_spinning_writers(eb);
atomic_dec(&eb->blocking_writers);
/* Use the lighter barrier after atomic */
smp_mb__after_atomic();
cond_wake_up_nomb(&eb->write_lock_wq);
} else {
- WARN_ON(atomic_read(&eb->spinning_writers) != 1);
- atomic_dec(&eb->spinning_writers);
+ btrfs_assert_spinning_writers_put(eb);
write_unlock(&eb->lock);
}
}
--
2.30.2