From ab1ddef98a715eddb65309ffa83267e4e84a571e Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Mon, 14 Nov 2022 08:33:09 -0500 Subject: filelock: new helper: vfs_inode_has_locks 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 --- fs/locks.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) (limited to 'fs') diff --git a/fs/locks.c b/fs/locks.c index 5876c8ff0edc..9ccf89b6c95d 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -2672,6 +2672,29 @@ 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 -- cgit v1.2.3