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authorJeff Layton <jlayton@kernel.org>2022-11-14 08:33:09 -0500
committerJeff Layton <jlayton@kernel.org>2022-11-30 05:06:06 -0500
commitab1ddef98a715eddb65309ffa83267e4e84a571e (patch)
treee46db862227d19d37ab54a223c57e16af52599fe /fs/locks.c
parent7e8e5cc818bd93ee7f2699676f2e5b30d26d83f8 (diff)
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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 <xiubli@redhat.com> Reviewed-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Jeff Layton <jlayton@kernel.org>
Diffstat (limited to 'fs/locks.c')
-rw-r--r--fs/locks.c23
1 files changed, 23 insertions, 0 deletions
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 <linux/proc_fs.h>
#include <linux/seq_file.h>