5.15-stable review patch. If anyone has any objections, please let me know.
------------------
From: Dai Ngo <dai.ngo@xxxxxxxxxx>
[ Upstream commit 591502c5cb325b1c6ec59ab161927d606b918aa0 ]
Add helper locks_owner_has_blockers to check if there is any blockers
for a given lockowner.
Reviewed-by: J. Bruce Fields <bfields@xxxxxxxxxxxx>
Signed-off-by: Dai Ngo <dai.ngo@xxxxxxxxxx>
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
Reviewed-by: Jeff Layton <jlayton@xxxxxxxxxx>
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---
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 4899a4666f24d..f8c4844ebcce4 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -376,6 +376,34 @@ 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 f32723d937fb5..9b7ce642d4f08 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1212,6 +1212,8 @@ 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)
@@ -1352,6 +1354,11 @@ 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)
--
2.43.0
