From: Paolo 'Blaisorblade' Giarrusso Add documentation about some fields in struct ubd, whose meaning is non-obvious due to struct names (should change names altogether, I agree). Signed-off-by: Paolo 'Blaisorblade' Giarrusso Cc: Jeff Dike Signed-off-by: Andrew Morton --- arch/um/drivers/ubd_kern.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff -puN arch/um/drivers/ubd_kern.c~uml-ubd-driver-document-some-struct-fields arch/um/drivers/ubd_kern.c --- a/arch/um/drivers/ubd_kern.c~uml-ubd-driver-document-some-struct-fields +++ a/arch/um/drivers/ubd_kern.c @@ -150,8 +150,9 @@ static struct gendisk *fake_gendisk[MAX_ static struct openflags global_openflags = OPEN_FLAGS; struct cow { - /* This is the backing file, actually */ + /* backing file name */ char *file; + /* backing file fd */ int fd; unsigned long *bitmap; unsigned long bitmap_len; @@ -160,6 +161,8 @@ struct cow { }; struct ubd { + /* name (and fd, below) of the file opened for writing, either the + * backing or the cow file. */ char *file; int count; int fd; _