On Wed, Jan 20, 2021 at 07:38:38PM -0800, Linus Torvalds wrote: > On Wed, Jan 20, 2021 at 5:45 PM Al Viro <v...@zeniv.linux.org.uk> wrote: > > > > splice() triggers an error for seekable destination with O_APPEND and > > with NULL off_out. > > Ok, that's just broken. > > > Same for splice() to socket with > > fcntl(sock_fd, F_SETFL, O_APPEND); > > done first. > > Same. > > As long as you don't pass a position pointer, I think both should just work. > > Not that I imagine it matters for a lot of people..
I think that most users of splice() on sockets got used to falling back to recv/send on splice failure due to various cases not being supported historically (UNIX family sockets immediately come to my mind but I seem to remember other combinations). Thus I guess that most users of splice() detect that it doesn't work either due to lower than expected performance or while running strace. Willy
