From 602cbe91fb012a923a9fea880e600e004eb1543b Mon Sep 17 00:00:00 2001 From: David Sterba Date: Wed, 21 Aug 2019 18:48:25 +0200 Subject: 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 Signed-off-by: David Sterba --- fs/btrfs/misc.h | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) create mode 100644 fs/btrfs/misc.h (limited to 'fs/btrfs/misc.h') 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 +#include + +#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 -- cgit v1.2.3-70-g09d2