@@ -14,35 +14,37 @@
static void btrfs_assert_tree_read_locked(struct extent_buffer *eb);
-/*
- * if we currently have a spinning reader or writer lock
- * (indicated by the rw flag) this will bump the count
- * of blocking holders and drop the spinlock.
- */
-void btrfs_set_lock_blocking_rw(struct extent_buffer *eb, int rw)
+void btrfs_set_lock_blocking_read(struct extent_buffer *eb)
{
/*
- * no lock is required. The lock owner may change if
- * we have a read lock, but it won't change to or away
- * from us. If we have the write lock, we are the owner
- * and it'll never change.
+ * No lock is required. The lock owner may change if we have a read
+ * lock, but it won't change to or away from us. If we have the write
+ * lock, we are the owner and it'll never change.
*/
if (eb->lock_nested && current->pid == eb->lock_owner)
return;
- if (rw == BTRFS_WRITE_LOCK) {
- if (atomic_read(&eb->blocking_writers) == 0) {
- WARN_ON(atomic_read(&eb->spinning_writers) != 1);
- atomic_dec(&eb->spinning_writers);
- btrfs_assert_tree_locked(eb);
- atomic_inc(&eb->blocking_writers);
- write_unlock(&eb->lock);
- }
- } else if (rw == BTRFS_READ_LOCK) {
- btrfs_assert_tree_read_locked(eb);
- atomic_inc(&eb->blocking_readers);
- WARN_ON(atomic_read(&eb->spinning_readers) == 0);
- atomic_dec(&eb->spinning_readers);
- read_unlock(&eb->lock);
+ btrfs_assert_tree_read_locked(eb);
+ atomic_inc(&eb->blocking_readers);
+ WARN_ON(atomic_read(&eb->spinning_readers) == 0);
+ atomic_dec(&eb->spinning_readers);
+ read_unlock(&eb->lock);
+}
+
+void btrfs_set_lock_blocking_write(struct extent_buffer *eb)
+{
+ /*
+ * No lock is required. The lock owner may change if we have a read
+ * lock, but it won't change to or away from us. If we have the write
+ * lock, we are the owner and it'll never change.
+ */
+ 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_tree_locked(eb);
+ atomic_inc(&eb->blocking_writers);
+ write_unlock(&eb->lock);
}
}
@@ -17,7 +17,8 @@ void btrfs_tree_unlock(struct extent_buffer *eb);
void btrfs_tree_read_lock(struct extent_buffer *eb);
void btrfs_tree_read_unlock(struct extent_buffer *eb);
void btrfs_tree_read_unlock_blocking(struct extent_buffer *eb);
-void btrfs_set_lock_blocking_rw(struct extent_buffer *eb, int rw);
+void btrfs_set_lock_blocking_read(struct extent_buffer *eb);
+void btrfs_set_lock_blocking_write(struct extent_buffer *eb);
void btrfs_clear_lock_blocking_rw(struct extent_buffer *eb, int rw);
void btrfs_assert_tree_locked(struct extent_buffer *eb);
int btrfs_try_tree_read_lock(struct extent_buffer *eb);
@@ -37,6 +38,18 @@ static inline void btrfs_tree_unlock_rw(struct extent_buffer *eb, int rw)
BUG();
}
+/*
+ * If we currently have a spinning reader or writer lock (indicated by the rw
+ * flag) this will bump the count of blocking holders and drop the spinlock.
+ */
+static inline void btrfs_set_lock_blocking_rw(struct extent_buffer *eb, int rw)
+{
+ if (rw == BTRFS_WRITE_LOCK)
+ btrfs_set_lock_blocking_write(eb);
+ else if (rw == BTRFS_READ_LOCK)
+ btrfs_set_lock_blocking_read(eb);
+}
+
static inline void btrfs_set_lock_blocking(struct extent_buffer *eb)
{
btrfs_set_lock_blocking_rw(eb, BTRFS_WRITE_LOCK);
There are many callers that hardcode the desired lock type so we can avoid the switch and call them directly. Split the current function to two but leave a helper that still takes the variable lock type to make current code compile. The call sites will be converted in followup patches. Signed-off-by: David Sterba <dsterba@suse.com> --- fs/btrfs/locking.c | 50 ++++++++++++++++++++++++---------------------- fs/btrfs/locking.h | 15 +++++++++++++- 2 files changed, 40 insertions(+), 25 deletions(-)