9pfs: Introduce futimens file op

Add an futimens operation to the fs driver and use if when a fid has
a valid file descriptor. This is required to support more cases where
the client wants to do an action on an unlinked file which it still
has an open file decriptor for.

Only 9P2000.L was considered.

Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Message-Id: <20250312152933.383967-5-groug@kaod.org>
Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/hw/9pfs/9p-synth.c b/hw/9pfs/9p-synth.c
index 3d28afc4d0..9cd1884224 100644
--- a/hw/9pfs/9p-synth.c
+++ b/hw/9pfs/9p-synth.c
@@ -424,6 +424,13 @@ static int synth_utimensat(FsContext *fs_ctx, V9fsPath *path,
     return 0;
 }
 
+static int synth_futimens(FsContext *fs_ctx, int fid_type, V9fsFidOpenState *fs,
+                          const struct timespec *buf)
+{
+    errno = ENOSYS;
+    return -1;
+}
+
 static int synth_remove(FsContext *ctx, const char *path)
 {
     errno = EPERM;
@@ -664,4 +671,5 @@ FileOperations synth_ops = {
     .unlinkat     = synth_unlinkat,
     .has_valid_file_handle = synth_has_valid_file_handle,
     .ftruncate    = synth_ftruncate,
+    .futimens     = synth_futimens,
 };