On Tue, 8 Feb 2011 17:39:19 +0200
Alexander Nezhinsky <alexandern@xxxxxxxxxxxx> wrote:
> Some fixes in call_program():
> 1) if fork() fails, previously open pipe file descriptors should be closed.
> 2) the redirect script is invoked from a fork'ed process so tgt has to wait
> for its child. Currently this is done synchronously using waitpid().
> Sometimes the system call is interrupted by a signal (most probably by
> a SIGCHLD signal from the very process that is being waited upon).
> To overcome this waitpid() is called repeatedly while the error code
> is "Interrupted by a signal".
>
> Signed-off-by: Alexander Nezhinsky <alexandern@xxxxxxxxxxxx>
> ---
> usr/tgtd.c | 20 +++++++++++++++-----
> 1 files changed, 15 insertions(+), 5 deletions(-)
>
> diff --git a/usr/tgtd.c b/usr/tgtd.c
> index c3abca8..619ecb0 100644
> --- a/usr/tgtd.c
> +++ b/usr/tgtd.c
> @@ -285,14 +285,20 @@ int call_program(const char *cmd, void (*callback)(void *data, int result),
> argv[i] = NULL;
>
> ret = pipe(fds);
> - if (ret < 0)
> + if (ret < 0) {
> + eprintf("pipe create failed for %s, %m\n", cmd);
> return ret;
> + }
>
> - eprintf("%d %d\n", fds[0], fds[1]);
> + dprintf("%s, pipe: %d %d\n", cmd, fds[0], fds[1]);
>
> pid = fork();
> - if (pid < 0)
> + if (pid < 0) {
> + eprintf("fork failed for: %s, %m\n", cmd);
> + close(fds[0]);
> + close(fds[1]);
> return pid;
> + }
>
> if (!pid) {
> close(1);
> @@ -302,10 +308,14 @@ int call_program(const char *cmd, void (*callback)(void *data, int result),
> exit(-1);
> } else {
> close(fds[1]);
> - waitpid(pid, &i, 0);
> + do {
> + ret = waitpid(pid, &i, 0);
> + if (ret < 0 && errno != EINTR)
> + eprintf("waitpid failed for: %s, %m\n", cmd);
Do we need 'break' here? If we hit an error here, we need to give up
and free the allocated resource?
> + } while (ret < 0 && errno == EINTR);
> ret = read(fds[0], output, op_len);
> if (ret < 0)
> - eprintf("failed to get the output from <%s>.", cmd);
> + eprintf("failed to get the output from: %s\n", cmd);
>
> if (callback)
> callback(data, WEXITSTATUS(i));
> --
> 1.6.5.5
> --
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