[PATCH 2/8] virtiofsd: Announce FUSE_ATTR_FLAGS

[Max Reitz <mreitz@redhat.com>]

The fuse_attr.flags field is currently just initialized to 0, which is
valid.  Thus, there is no reason not to always announce FUSE_ATTR_FLAGS
(when the kernel supports it).

Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 tools/virtiofsd/fuse_common.h   | 8 ++++++++
 tools/virtiofsd/fuse_lowlevel.c | 7 +++++++
 2 files changed, 15 insertions(+)

diff --git a/tools/virtiofsd/fuse_common.h b/tools/virtiofsd/fuse_common.h
index 686c42c0a5..870544fe13 100644
--- a/tools/virtiofsd/fuse_common.h
+++ b/tools/virtiofsd/fuse_common.h
@@ -352,6 +352,14 @@ struct fuse_file_info {
  */
 #define FUSE_CAP_NO_OPENDIR_SUPPORT (1 << 24)
 
+/**
+ * Indicates that the client will provide fuse_attr.flags, and the kernel will
+ * interpret it.
+ *
+ * This feature is enabled by default when supported by the kernel.
+ */
+#define FUSE_CAP_ATTR_FLAGS (1 << 27)
+
 /**
  * Ioctl flags
  *
diff --git a/tools/virtiofsd/fuse_lowlevel.c b/tools/virtiofsd/fuse_lowlevel.c
index 2dd36ec03b..e9e2652d33 100644
--- a/tools/virtiofsd/fuse_lowlevel.c
+++ b/tools/virtiofsd/fuse_lowlevel.c
@@ -1988,6 +1988,9 @@ static void do_init(fuse_req_t req, fuse_ino_t nodeid,
             bufsize = max_bufsize;
         }
     }
+    if (arg->flags & FUSE_ATTR_FLAGS) {
+        se->conn.capable |= FUSE_CAP_ATTR_FLAGS;
+    }
 #ifdef HAVE_SPLICE
 #ifdef HAVE_VMSPLICE
     se->conn.capable |= FUSE_CAP_SPLICE_WRITE | FUSE_CAP_SPLICE_MOVE;
@@ -2014,6 +2017,7 @@ static void do_init(fuse_req_t req, fuse_ino_t nodeid,
     LL_SET_DEFAULT(1, FUSE_CAP_ASYNC_DIO);
     LL_SET_DEFAULT(1, FUSE_CAP_IOCTL_DIR);
     LL_SET_DEFAULT(1, FUSE_CAP_ATOMIC_O_TRUNC);
+    LL_SET_DEFAULT(1, FUSE_CAP_ATTR_FLAGS);
     LL_SET_DEFAULT(se->op.write_buf, FUSE_CAP_SPLICE_READ);
     LL_SET_DEFAULT(se->op.getlk && se->op.setlk, FUSE_CAP_POSIX_LOCKS);
     LL_SET_DEFAULT(se->op.flock, FUSE_CAP_FLOCK_LOCKS);
@@ -2103,6 +2107,9 @@ static void do_init(fuse_req_t req, fuse_ino_t nodeid,
     if (se->conn.want & FUSE_CAP_POSIX_ACL) {
         outarg.flags |= FUSE_POSIX_ACL;
     }
+    if (se->conn.want & FUSE_CAP_ATTR_FLAGS) {
+        outarg.flags |= FUSE_ATTR_FLAGS;
+    }
     outarg.max_readahead = se->conn.max_readahead;
     outarg.max_write = se->conn.max_write;
     if (se->conn.max_background >= (1 << 16)) {
-- 
2.26.2