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authorDavid Sterba <dsterba@suse.com>2019-08-21 18:48:25 +0200
committerDavid Sterba <dsterba@suse.com>2019-09-09 14:59:15 +0200
commit602cbe91fb012a923a9fea880e600e004eb1543b (patch)
tree726a8c9f2373aa9136c7f3d7c6f404534f1a168d /fs/btrfs/misc.h
parentd2979aa25fc8de6498d906ae6b46b028457d6400 (diff)
downloadlinux-602cbe91fb012a923a9fea880e600e004eb1543b.tar.bz2
btrfs: move cond_wake_up functions out of ctree
The file ctree.h serves as a header for everything and has become quite bloated. Split some helpers that are generic and create a new file that should be the catch-all for code that's not btrfs-specific. Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs/misc.h')
-rw-r--r--fs/btrfs/misc.h33
1 files changed, 33 insertions, 0 deletions
diff --git a/fs/btrfs/misc.h b/fs/btrfs/misc.h
new file mode 100644
index 000000000000..ef3901238ddd
--- /dev/null
+++ b/fs/btrfs/misc.h
@@ -0,0 +1,33 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef BTRFS_MISC_H
+#define BTRFS_MISC_H
+
+#include <linux/sched.h>
+#include <linux/wait.h>
+
+#define in_range(b, first, len) ((b) >= (first) && (b) < (first) + (len))
+
+static inline void cond_wake_up(struct wait_queue_head *wq)
+{
+ /*
+ * This implies a full smp_mb barrier, see comments for
+ * waitqueue_active why.
+ */
+ if (wq_has_sleeper(wq))
+ wake_up(wq);
+}
+
+static inline void cond_wake_up_nomb(struct wait_queue_head *wq)
+{
+ /*
+ * Special case for conditional wakeup where the barrier required for
+ * waitqueue_active is implied by some of the preceding code. Eg. one
+ * of such atomic operations (atomic_dec_and_return, ...), or a
+ * unlock/lock sequence, etc.
+ */
+ if (waitqueue_active(wq))
+ wake_up(wq);
+}
+
+#endif