From 194e691aaf96c98d44ff04ea634fc4acf9d86a19 Mon Sep 17 00:00:00 2001
From: Conrad Meyer <cem@FreeBSD.org>
Date: Fri, 15 Feb 2019 22:51:09 +0000
Subject: [PATCH] FUSE: Only "dirty" cached file size when data is dirty

Most users of fuse_vnode_setsize() set the cached fvdat->filesize and update
the buf cache bounds as a result of either a read from the underlying FUSE
filesystem, or as part of a write-through type operation (like truncate =>
VOP_SETATTR).  In these cases, do not set the FN_SIZECHANGE flag, which
indicates that an inode's data is dirty (in particular, that the local buf
cache and fvdat->filesize have dirty extended data).

PR:		230258 (related)
---
 sys/fs/fuse/fuse_io.c    | 5 ++++-
 sys/fs/fuse/fuse_node.c  | 1 +
 sys/fs/fuse/fuse_vnops.c | 5 +++--
 3 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/sys/fs/fuse/fuse_io.c b/sys/fs/fuse/fuse_io.c
index 8fa7dc06f79d..25f63a9511fc 100644
--- a/sys/fs/fuse/fuse_io.c
+++ b/sys/fs/fuse/fuse_io.c
@@ -362,8 +362,11 @@ fuse_write_directbackend(struct vnode *vp, struct uio *uio,
 		}
 		uio->uio_resid += diff;
 		uio->uio_offset -= diff;
-		if (uio->uio_offset > fvdat->filesize)
+		if (uio->uio_offset > fvdat->filesize &&
+		    fuse_data_cache_enable) {
 			fuse_vnode_setsize(vp, cred, uio->uio_offset);
+			fvdat->flag &= ~FN_SIZECHANGE;
+		}
 	}
 
 	fdisp_destroy(&fdi);
diff --git a/sys/fs/fuse/fuse_node.c b/sys/fs/fuse/fuse_node.c
index e8b16335272d..dee7f328b5ac 100644
--- a/sys/fs/fuse/fuse_node.c
+++ b/sys/fs/fuse/fuse_node.c
@@ -375,6 +375,7 @@ fuse_vnode_refreshsize(struct vnode *vp, struct ucred *cred)
 	struct vattr va;
 
 	if ((fvdat->flag & FN_SIZECHANGE) != 0 ||
+	    fuse_data_cache_enable == 0 ||
 	    (fuse_refresh_size == 0 && fvdat->filesize != 0))
 		return;
 
diff --git a/sys/fs/fuse/fuse_vnops.c b/sys/fs/fuse/fuse_vnops.c
index 618b01944712..6ab93bb16f36 100644
--- a/sys/fs/fuse/fuse_vnops.c
+++ b/sys/fs/fuse/fuse_vnops.c
@@ -538,6 +538,7 @@ fuse_vnop_getattr(struct vop_getattr_args *ap)
 
 		if (fvdat->filesize != new_filesize) {
 			fuse_vnode_setsize(vp, cred, new_filesize);
+			fvdat->flag &= ~FN_SIZECHANGE;
 		}
 	}
 	debug_printf("fuse_getattr e: returning 0\n");
@@ -1637,9 +1638,9 @@ fuse_vnop_setattr(struct vop_setattr_args *ap)
 			err = EAGAIN;
 		}
 	}
-	if (!err && !sizechanged) {
+	if (err == 0)
 		cache_attrs(vp, (struct fuse_attr_out *)fdi.answ, NULL);
-	}
+
 out:
 	fdisp_destroy(&fdi);
 	if (!err && sizechanged) {