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@suse.de> --- 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 :|