From 81d20007f966e36cc8c9161b7117f3f1affdba02 Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Fri, 28 Aug 2015 00:10:35 +0200 Subject: copy: add splice() based fallback Apparently, sendfile() does not work between fifos and ttys, but splice() does, hence let's optionally fall back to that. This is useful to implement the fallback pager this way. --- src/basic/copy.c | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) (limited to 'src/basic') diff --git a/src/basic/copy.c b/src/basic/copy.c index 33427c6a73..cc5faa80a1 100644 --- a/src/basic/copy.c +++ b/src/basic/copy.c @@ -30,7 +30,7 @@ #define COPY_BUFFER_SIZE (16*1024) int copy_bytes(int fdf, int fdt, off_t max_bytes, bool try_reflink) { - bool try_sendfile = true; + bool try_sendfile = true, try_splice = true; int r; assert(fdf >= 0); @@ -69,7 +69,23 @@ int copy_bytes(int fdf, int fdt, off_t max_bytes, bool try_reflink) { } else if (n == 0) /* EOF */ break; else if (n > 0) - /* Succcess! */ + /* Success! */ + goto next; + } + + /* The try splice, unless we already tried */ + if (try_splice) { + n = splice(fdf, NULL, fdt, NULL, m, 0); + if (n < 0) { + if (errno != EINVAL && errno != ENOSYS) + return -errno; + + try_splice = false; + /* use fallback below */ + } else if (n == 0) /* EOF */ + break; + else if (n > 0) + /* Success! */ goto next; } -- cgit v1.2.3-54-g00ecf