On Thu, Apr 28, 2022 at 06:24:11PM +0200, Claudio Fontana wrote: > On 4/28/22 2:54 PM, Daniel P. Berrangé wrote: > > On Wed, Apr 27, 2022 at 11:13:23PM +0200, Claudio Fontana wrote: > >> add arguments to runio to allow read/write from/to arbitrary > >> file descriptors, as opposed to just stdin and stdout. > >> > >> Signed-off-by: Claudio Fontana <cfontana@xxxxxxx> > >> --- > >> src/util/iohelper.c | 2 +- > >> src/util/runio.c | 10 +++++----- > >> src/util/runio.h | 17 ++++++++++++++++- > >> 3 files changed, 22 insertions(+), 7 deletions(-) > >> > >> diff --git a/src/util/iohelper.c b/src/util/iohelper.c > >> index 5a0098542e..93674c1e2f 100644 > >> --- a/src/util/iohelper.c > >> +++ b/src/util/iohelper.c > >> @@ -96,7 +96,7 @@ main(int argc, char **argv) > >> usage(EXIT_FAILURE); > >> } > >> > >> - if (fd < 0 || runIO(path, fd, oflags) < 0) > >> + if (fd < 0 || runIO(path, fd, oflags, STDIN_FILENO, STDOUT_FILENO) < 0) > >> goto error; > >> > >> return 0; > >> diff --git a/src/util/runio.c b/src/util/runio.c > >> index a7b902af7e..f42acddae9 100644 > >> --- a/src/util/runio.c > >> +++ b/src/util/runio.c > >> @@ -134,7 +134,7 @@ runIOCopy(const struct runIOParams p) > >> > >> > >> off_t > >> -runIO(const char *path, int fd, int oflags) > >> +runIO(const char *path, int fd, int oflags, int in_fd, int out_fd) > > > > This is getting rather wierd as a signature. > > > > If O_RDONLY, then in_fd is ignored, 'fd' is input. > > > > If O_WRONLY, then out_fd is ignored, 'fd' is output > > > > What about instead simply : > > > > runIO(const char *srcpath, int srcfd, > > const char *dstpath, int dstfd) > > > > so there's no read vs write distinction at all. > > maybe I am a bit confused/tired, but I don't see how this would work, > which side one of those is the disk, where we want to check for S_ISBLK and O_DIRECT, and buffer accordingly? We call fstat on the FD, we'll know which FD is a pipe/socket vs which FD is a file/blockdev. If we call fcntl(GET_FL) we can also discover if O_DIRECT is turned on or not. With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|
