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From: Dai Ngo <dai.ngo@oracle.com>
To: chuck.lever@oracle.com, bfields@fieldses.org
Cc: jlayton@redhat.com, viro@zeniv.linux.org.uk,
	linux-nfs@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: [PATCH RFC v24 4/7] fs/lock: add helper locks_owner_has_blockers to check for blockers
Date: Sun,  1 May 2022 10:38:13 -0700	[thread overview]
Message-ID: <1651426696-15509-5-git-send-email-dai.ngo@oracle.com> (raw)
In-Reply-To: <1651426696-15509-1-git-send-email-dai.ngo@oracle.com>

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

Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
---
 fs/locks.c         | 28 ++++++++++++++++++++++++++++
 include/linux/fs.h |  7 +++++++
 2 files changed, 35 insertions(+)

diff --git a/fs/locks.c b/fs/locks.c
index 8c6df10cd9ed..c369841ef7d1 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -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)
 {
diff --git a/include/linux/fs.h b/include/linux/fs.h
index bbde95387a23..b8ed7f974fb4 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -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)
-- 
2.9.5


  parent reply	other threads:[~2022-05-01 17:38 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-05-01 17:38 [PATCH RFC v24 0/7] NFSD: Initial implementation of NFSv4 Courteous Server Dai Ngo
2022-05-01 17:38 ` [PATCH RFC v24 1/7] NFSD: add courteous server support for thread with only delegation Dai Ngo
2022-05-02 15:23   ` J. Bruce Fields
2022-05-01 17:38 ` [PATCH RFC v24 2/7] NFSD: add support for share reservation conflict to courteous server Dai Ngo
2022-05-02 15:31   ` J. Bruce Fields
2022-05-01 17:38 ` [PATCH RFC v24 3/7] NFSD: move create/destroy of laundry_wq to init_nfsd and exit_nfsd Dai Ngo
2022-05-02 15:35   ` J. Bruce Fields
2022-05-01 17:38 ` Dai Ngo [this message]
2022-05-02 15:43   ` [PATCH RFC v24 4/7] fs/lock: add helper locks_owner_has_blockers to check for blockers J. Bruce Fields
2022-05-01 17:38 ` [PATCH RFC v24 5/7] fs/lock: add 2 callbacks to lock_manager_operations to resolve conflict Dai Ngo
2022-05-02 15:53   ` J. Bruce Fields
2022-05-01 17:38 ` [PATCH RFC v24 6/7] NFSD: add support for lock conflict to courteous server Dai Ngo
2022-05-02 16:00   ` J. Bruce Fields
2022-05-01 17:38 ` [PATCH RFC v24 7/7] NFSD: Show state of courtesy client in client info Dai Ngo
2022-05-02 16:06   ` J. Bruce Fields
2022-05-02 16:07 ` [PATCH RFC v24 0/7] NFSD: Initial implementation of NFSv4 Courteous Server J. Bruce Fields

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