xfs_copy: use POSIX signal API

uClibc doesn't provide the sigrelse or sighold calls, so this patch replaces
them with POSIX signal API calls (sigprocmask(2), etc).

Refer to Gentoo Bug #477758:
https://bugs.gentoo.org/show_bug.cgi?id=477758

Signed-off-by: Joshua Kinard <kumba@gentoo.org>
Suggested-by: René Rhéaume <rene.rheaume@gmail.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

diff --git a/copy/xfs_copy.c b/copy/xfs_copy.c
index 15a3f337d81139a1fee3621cd30cbad355bafdc0..3c8998c7b366339dd205e50b4513915f9883dc52 100644 (file)
--- a/copy/xfs_copy.c
+++ b/copy/xfs_copy.c
@@ -74,6 +74,16 @@ static int   format_logs(struct xfs_mount *);
 #define PRE    0x08            /* append strerror string */
 #define LAST   0x10            /* final message we print */
 
+void
+signal_maskfunc(int addset, int newset)
+{
+       sigset_t set;
+
+       sigemptyset(&set);
+       sigaddset(&set, addset);
+       sigprocmask(newset, &set, NULL);
+}
+
 void
 do_message(int flags, int code, const char *fmt, ...)
 {
@@ -477,9 +487,9 @@ write_wbuf(void)
                if (target[i].state != INACTIVE)
                        pthread_mutex_unlock(&targ[i].wait);    /* wake up */
 
-       sigrelse(SIGCHLD);
+       signal_maskfunc(SIGCHLD, SIG_UNBLOCK);
        pthread_mutex_lock(&mainwait);
-       sighold(SIGCHLD);
+       signal_maskfunc(SIGCHLD, SIG_BLOCK);
 }
 
 void
@@ -893,7 +903,7 @@ main(int argc, char **argv)
        /* set up sigchild signal handler */
 
        signal(SIGCHLD, handler);
-       sighold(SIGCHLD);
+       signal_maskfunc(SIGCHLD, SIG_BLOCK);
 
        /* make children */