[git commit] makedevs: make special node creation idempotent

[Denys Vlasenko]

commit: https://git.busybox.net/busybox/commit/?id=2c769c69b269f43d8c9ecf4a7f5ce5cce290750a
branch: https://git.busybox.net/busybox/commit/?id=refs/heads/master

When makedevs is called for a second time with the same device file,
it fails because the files already exist and mknod() gives -EEXIST.

Ignore EEXIST errors.

Signed-off-by: Denys Vlasenko <vda.linux at googlemail.com>
---
 miscutils/makedevs.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/miscutils/makedevs.c b/miscutils/makedevs.c
index 6278ee7..c5eeed0 100644
--- a/miscutils/makedevs.c
+++ b/miscutils/makedevs.c
@@ -157,8 +157,11 @@ int makedevs_main(int argc, char **argv)
 
 		/* if mode != S_IFCHR and != S_IFBLK,
 		 * third param in mknod() ignored */
-		if (mknod(nodname, mode, makedev(Smajor, Sminor)))
+		if (mknod(nodname, mode, makedev(Smajor, Sminor)) != 0
+		 && errno != EEXIST
+		) {
 			bb_perror_msg("can't create '%s'", nodname);
+		}
 
 		/*if (nodname == basedev)*/ /* ex. /dev/hda - to /dev/hda1 ... */
 			nodname = buf;
@@ -279,7 +282,9 @@ int makedevs_main(int argc UNUSED_PARAM, char **argv)
 			for (i = start; i <= start + count; i++) {
 				sprintf(full_name_inc, count ? "%s%u" : "%s", full_name, i);
 				rdev = makedev(major, minor + (i - start) * increment);
-				if (mknod(full_name_inc, mode, rdev) < 0) {
+				if (mknod(full_name_inc, mode, rdev) != 0
+				  && errno != EEXIST
+				) {
 					bb_perror_msg("line %d: can't create node %s", linenum, full_name_inc);
 					ret = EXIT_FAILURE;
 				} else if (chown(full_name_inc, uid, gid) < 0) {