linux/fs/btrfs/misc.h
David Sterba 602cbe91fb 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>
2019-09-09 14:59:15 +02:00

34 lines
771 B
C

/* 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