From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C9C737474 for ; Tue, 10 Jan 2023 18:34:57 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4C97AC433D2; Tue, 10 Jan 2023 18:34:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1673375697; bh=wNagAmtUkz9/B1EWjCfdTu7kBluw3+0WyuecC1saY7o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=eD8+JGa3aB9cZVF/TUjQGuvBUp2Ton6a2vIa8L8YNwlrzjgL94vzpXiIXqTxhx16D A6ilGx3bCEJGxBNSxK0KXds1B9U6zNcDmQrfEGjJfgl5Dmo7rAesiJd2AE9IxVbTcx fJftPFjEtmmbUOgfBfBpqdPZ3dd4bdpcTyNdXPJA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Xiubo Li , Christoph Hellwig , Jeff Layton , Sasha Levin Subject: [PATCH 5.15 241/290] filelock: new helper: vfs_inode_has_locks Date: Tue, 10 Jan 2023 19:05:33 +0100 Message-Id: <20230110180040.319842782@linuxfoundation.org> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20230110180031.620810905@linuxfoundation.org> References: <20230110180031.620810905@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Jeff Layton [ Upstream commit ab1ddef98a715eddb65309ffa83267e4e84a571e ] Ceph has a need to know whether a particular inode has any locks set on it. It's currently tracking that by a num_locks field in its filp->private_data, but that's problematic as it tries to decrement this field when releasing locks and that can race with the file being torn down. Add a new vfs_inode_has_locks helper that just returns whether any locks are currently held on the inode. Reviewed-by: Xiubo Li Reviewed-by: Christoph Hellwig Signed-off-by: Jeff Layton Stable-dep-of: 461ab10ef7e6 ("ceph: switch to vfs_inode_has_locks() to fix file lock bug") Signed-off-by: Sasha Levin --- fs/locks.c | 23 +++++++++++++++++++++++ include/linux/fs.h | 6 ++++++ 2 files changed, 29 insertions(+) diff --git a/fs/locks.c b/fs/locks.c index 3d6fb4ae847b..82a4487e95b3 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -2703,6 +2703,29 @@ int vfs_cancel_lock(struct file *filp, struct file_lock *fl) } EXPORT_SYMBOL_GPL(vfs_cancel_lock); +/** + * vfs_inode_has_locks - are any file locks held on @inode? + * @inode: inode to check for locks + * + * Return true if there are any FL_POSIX or FL_FLOCK locks currently + * set on @inode. + */ +bool vfs_inode_has_locks(struct inode *inode) +{ + struct file_lock_context *ctx; + bool ret; + + ctx = smp_load_acquire(&inode->i_flctx); + if (!ctx) + return false; + + spin_lock(&ctx->flc_lock); + ret = !list_empty(&ctx->flc_posix) || !list_empty(&ctx->flc_flock); + spin_unlock(&ctx->flc_lock); + return ret; +} +EXPORT_SYMBOL_GPL(vfs_inode_has_locks); + #ifdef CONFIG_PROC_FS #include #include diff --git a/include/linux/fs.h b/include/linux/fs.h index 68fcf3ec9cf6..1e1ac116dd13 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1195,6 +1195,7 @@ extern int locks_delete_block(struct file_lock *); extern int vfs_test_lock(struct file *, struct file_lock *); extern int vfs_lock_file(struct file *, unsigned int, struct file_lock *, struct file_lock *); extern int vfs_cancel_lock(struct file *filp, struct file_lock *fl); +bool vfs_inode_has_locks(struct inode *inode); extern int locks_lock_inode_wait(struct inode *inode, struct file_lock *fl); extern int __break_lease(struct inode *inode, unsigned int flags, unsigned int type); extern void lease_get_mtime(struct inode *, struct timespec64 *time); @@ -1307,6 +1308,11 @@ static inline int vfs_cancel_lock(struct file *filp, struct file_lock *fl) return 0; } +static inline bool vfs_inode_has_locks(struct inode *inode) +{ + return false; +} + static inline int locks_lock_inode_wait(struct inode *inode, struct file_lock *fl) { return -ENOLCK; -- 2.35.1