On Wed, 26 May 2010, Changli Gao wrote: > On Wed, May 26, 2010 at 6:29 PM, Miklos Szeredi <miklos@xxxxxxxxxx> wrote: > > On Wed, 26 May 2010, Changli Gao wrote: > >> allow non-block splice only when in file is seekable. > >> > >> do_splice_to() is split to two parts: read data from in file to spd, and move > >> data from spd to pipe. If there isn't much space in pipe for the data in spd, > >> and the splice is called with non-block flag, the data dropped due to non > >> enough space in pipe will be lost forever when in file isn't seekable. > > > > This is a gratuitous ABI change. I don't think we should hold the > > hand of application writers, > > Yea, it is an ABI change. But without that, we'll fail user silently > currently. Some fundamental change is needed to fix this issue fully, > if you think it is a bug. I don't think it's a bug. The same thing will happen without SPLICE_F_NONBLOCK if splice_to_pipe() is interrupted by a signal while it blocks. To prevent data loss the application needs to be aware of the fact that doing a splice from a non-seekable fd needs to be done carefully, making sure that it doesn't block on the pipe. Miklos -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
