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>

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index cc3941ae1ff62f5cdcfada5b805aa762b26baa9d..fc0451c3e24e485cb3be0779eb0448cbf8a68c8c 100644 (file)
--- 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 1e5be66c7e0b20c004b8c018b3da411e00089c9c..3577ef33bc36761e4bedc4c106259ee045a2d619 100644 (file)
--- 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 13ef1decdea60b2b9b9e365ca990ba02e0f9d66d..a5a3c5118f613b27f39dac8d88a9ee9099b81069 100644 (file)
--- 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 @@ void btrfs_tree_lock(struct extent_buffer *eb)
                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);
        }
 }