Commit 591502c5 authored by Dai Ngo's avatar Dai Ngo Committed by Chuck Lever
Browse files

fs/lock: add helper locks_owner_has_blockers to check for blockers 



Add helper locks_owner_has_blockers to check if there is any blockers
for a given lockowner.

Reviewed-by: default avatarJ. Bruce Fields <bfields@fieldses.org>
Signed-off-by: default avatarDai Ngo <dai.ngo@oracle.com>
Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
Reviewed-by: default avatarJeff Layton <jlayton@kernel.org>
parent d76cc46b

fs/locks.c

+28 −0
Original line number Diff line number Diff line
@@ -300,6 +300,34 @@ void locks_release_private(struct file_lock *fl) 
}

EXPORT_SYMBOL_GPL(locks_release_private);



/**

 * locks_owner_has_blockers - Check for blocking lock requests

 * @flctx: file lock context

 * @owner: lock owner

 *

 * Return values:

 *   %true: @owner has at least one blocker

 *   %false: @owner has no blockers

 */

bool locks_owner_has_blockers(struct file_lock_context *flctx,

		fl_owner_t owner)

{

	struct file_lock *fl;



	spin_lock(&flctx->flc_lock);

	list_for_each_entry(fl, &flctx->flc_posix, fl_list) {

		if (fl->fl_owner != owner)

			continue;

		if (!list_empty(&fl->fl_blocked_requests)) {

			spin_unlock(&flctx->flc_lock);

			return true;

		}

	}

	spin_unlock(&flctx->flc_lock);

	return false;

}

EXPORT_SYMBOL_GPL(locks_owner_has_blockers);



/* Free a lock which is not in use. */

void locks_free_lock(struct file_lock *fl)

{

include/linux/fs.h

+7 −0
Original line number Diff line number Diff line
@@ -1174,6 +1174,8 @@ extern void lease_unregister_notifier(struct notifier_block *); 
struct files_struct;

extern void show_fd_locks(struct seq_file *f,

			 struct file *filp, struct files_struct *files);

extern bool locks_owner_has_blockers(struct file_lock_context *flctx,

			fl_owner_t owner);

#else /* !CONFIG_FILE_LOCKING */

static inline int fcntl_getlk(struct file *file, unsigned int cmd,

			      struct flock __user *user)
@@ -1309,6 +1311,11 @@ static inline int lease_modify(struct file_lock *fl, int arg, 
struct files_struct;

static inline void show_fd_locks(struct seq_file *f,

			struct file *filp, struct files_struct *files) {}

static inline bool locks_owner_has_blockers(struct file_lock_context *flctx,

			fl_owner_t owner)

{

	return false;

}

#endif /* !CONFIG_FILE_LOCKING */



static inline struct inode *file_inode(const struct file *f)