vhost_user_fs: Add the EXPLICIT_INVAL_DATA capability flag
Add EXPLICIT_INVAL_DATA capability flag, corresponding to
FUSE_EXPLICIT_INVAL_DATA introduced in FUSE 7.30.
@@ -146,6 +146,9 @@ const CACHE_SYMLINKS: u32 = 8_388_608;
/// Kernel supports zero-message opendir
const NO_OPENDIR_SUPPORT: u32 = 16_777_216;
+/// Only invalidate cached pages on explicit request
+const EXPLICIT_INVAL_DATA: u32 = 33_554_432;
+
bitflags! {
/// A bitfield passed in as a parameter to and returned from the `init` method of the
/// `FileSystem` trait.
@@ -341,6 +344,14 @@ bitflags! {
/// Setting (or not setting) the field in the `FsOptions` returned from the `init` method
/// has no effect.
const ZERO_MESSAGE_OPENDIR = NO_OPENDIR_SUPPORT;
+
+ /// Indicates support for explicit data invalidation. If this feature is enabled, the
+ /// server is fully responsible for data cache invalidation, and the kernel won't
+ /// invalidate files data cache on size change and only truncate that cache to new size
+ /// in case the size decreased.
+ ///
+ /// This feature is not currently supported.
+ const EXPLICIT_INVAL_DATA = EXPLICIT_INVAL_DATA;
}
}
