This is a note to let you know that I've just added the patch titled
fs/lock: add helper locks_owner_has_blockers to check for blockers
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
fs-lock-add-helper-locks_owner_has_blockers-to-check.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 656ab4cf3b6d6c56f156211c9b69e0b3ffe1dd83
Author: Dai Ngo <dai.ngo@xxxxxxxxxx>
Date: Mon May 2 14:19:24 2022 -0700
fs/lock: add helper locks_owner_has_blockers to check for blockers
[ 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>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/fs/locks.c b/fs/locks.c
index 101867933e4d3..118df2812f8aa 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 c0459446e1440..17dc1ee8c6cb2 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1163,6 +1163,8 @@ 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)
@@ -1303,6 +1305,11 @@ 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)
