fuse: serialize dirops by default
Negotiate with userspace filesystems whether they support parallel readdir
and lookup. Disable parallelism by default for fear of breaking fuse
filesystems.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Fixes: 9902af79c01a ("parallel lookups: actual switch to rwsem")
Fixes: d9b3dbdcfd62 ("fuse: switch to ->iterate_shared()")
diff --git a/include/uapi/linux/fuse.h b/include/uapi/linux/fuse.h
index 5974fae..27e1736 100644
--- a/include/uapi/linux/fuse.h
+++ b/include/uapi/linux/fuse.h
@@ -105,6 +105,9 @@
*
* 7.24
* - add FUSE_LSEEK for SEEK_HOLE and SEEK_DATA support
+ *
+ * 7.25
+ * - add FUSE_PARALLEL_DIROPS
*/
#ifndef _LINUX_FUSE_H
@@ -140,7 +143,7 @@
#define FUSE_KERNEL_VERSION 7
/** Minor version number of this interface */
-#define FUSE_KERNEL_MINOR_VERSION 24
+#define FUSE_KERNEL_MINOR_VERSION 25
/** The node ID of the root inode */
#define FUSE_ROOT_ID 1
@@ -234,6 +237,7 @@
* FUSE_ASYNC_DIO: asynchronous direct I/O submission
* FUSE_WRITEBACK_CACHE: use writeback cache for buffered writes
* FUSE_NO_OPEN_SUPPORT: kernel supports zero-message opens
+ * FUSE_PARALLEL_DIROPS: allow parallel lookups and readdir
*/
#define FUSE_ASYNC_READ (1 << 0)
#define FUSE_POSIX_LOCKS (1 << 1)
@@ -253,6 +257,7 @@
#define FUSE_ASYNC_DIO (1 << 15)
#define FUSE_WRITEBACK_CACHE (1 << 16)
#define FUSE_NO_OPEN_SUPPORT (1 << 17)
+#define FUSE_PARALLEL_DIROPS (1 << 18)
/**
* CUSE INIT request/reply flags