From 1e485991938851e12c96014858e7d2c9e7eed383 Mon Sep 17 00:00:00 2001
From: Peter Rajnoha <prajnoha@redhat.com>
Date: Mon, 12 Aug 2024 14:31:19 +0200
Subject: [PATCH] libdm: do not fail if GETVAL semctl fails for udev sync inc
 and dec

While performing udev sync semaphore's inc/dec operation, we use the
result from GETVAL semctl just to print a debug message with current
value of that sempahore, nothing else.

If the GETVAL fails for whetever reason while the actual inc/dec
completes successfully, just log a warning message about the GETVAL
(and print the debug messages without the actual semaphore value)
and return success for the inc/dec operation as a whole.
---
 device_mapper/libdm-common.c | 31 ++++++++++++++++---------------
 libdm/libdm-common.c         | 31 ++++++++++++++++---------------
 2 files changed, 32 insertions(+), 30 deletions(-)

diff --git a/device_mapper/libdm-common.c b/device_mapper/libdm-common.c
index db7c75277..ff96ed096 100644
--- a/device_mapper/libdm-common.c
+++ b/device_mapper/libdm-common.c
@@ -2443,14 +2443,14 @@ static int _udev_notify_sem_inc(uint32_t cookie, int semid)
 	}
 
  	if ((val = semctl(semid, 0, GETVAL)) < 0) {
-		log_error("cookie inc: semid %d: sem_ctl GETVAL failed for "
+		log_warn("cookie inc: semid %d: sem_ctl GETVAL failed for "
 			  "cookie 0x%" PRIx32 ": %s",
 			  semid, cookie, strerror(errno));
-		return 0;
-	}
-
-	log_debug_activation("Udev cookie 0x%" PRIx32 " (semid %d) incremented to %d",
-		  cookie, semid, val);
+		log_debug_activation("Udev cookie 0x%" PRIx32 " (semid %d) incremented.",
+				      cookie, semid);
+	} else
+		log_debug_activation("Udev cookie 0x%" PRIx32 " (semid %d) incremented to %d",
+				     cookie, semid, val);
 
 	return 1;
 }
@@ -2460,12 +2460,10 @@ static int _udev_notify_sem_dec(uint32_t cookie, int semid)
 	struct sembuf sb = {0, -1, IPC_NOWAIT};
 	int val;
 
- 	if ((val = semctl(semid, 0, GETVAL)) < 0) {
-		log_error("cookie dec: semid %d: sem_ctl GETVAL failed for "
-			  "cookie 0x%" PRIx32 ": %s",
-			  semid, cookie, strerror(errno));
-		return 0;
-	}
+ 	if ((val = semctl(semid, 0, GETVAL)) < 0)
+		log_warn("cookie dec: semid %d: sem_ctl GETVAL failed for "
+			 "cookie 0x%" PRIx32 ": %s",
+			 semid, cookie, strerror(errno));
 
 	if (semop(semid, &sb, 1) < 0) {
 		switch (errno) {
@@ -2484,9 +2482,12 @@ static int _udev_notify_sem_dec(uint32_t cookie, int semid)
 		return 0;
 	}
 
-	log_debug_activation("Udev cookie 0x%" PRIx32 " (semid %d) decremented to %d",
-			     cookie, semid, val - 1);
-
+	if (val < 0)
+		log_debug_activation("Udev cookie 0x%" PRIx32 " (semid %d) decremented.",
+				     cookie, semid);
+	else
+		log_debug_activation("Udev cookie 0x%" PRIx32 " (semid %d) decremented to %d",
+				     cookie, semid, val - 1);
 	return 1;
 }
 
diff --git a/libdm/libdm-common.c b/libdm/libdm-common.c
index 4054d6cc0..d347bfe16 100644
--- a/libdm/libdm-common.c
+++ b/libdm/libdm-common.c
@@ -2442,14 +2442,14 @@ static int _udev_notify_sem_inc(uint32_t cookie, int semid)
 	}
 
  	if ((val = semctl(semid, 0, GETVAL)) < 0) {
-		log_error("cookie inc: semid %d: sem_ctl GETVAL failed for "
+		log_warn("cookie inc: semid %d: sem_ctl GETVAL failed for "
 			  "cookie 0x%" PRIx32 ": %s",
 			  semid, cookie, strerror(errno));
-		return 0;
-	}
-
-	log_debug_activation("Udev cookie 0x%" PRIx32 " (semid %d) incremented to %d",
-		  cookie, semid, val);
+		log_debug_activation("Udev cookie 0x%" PRIx32 " (semid %d) incremented.",
+				      cookie, semid);
+	} else
+		log_debug_activation("Udev cookie 0x%" PRIx32 " (semid %d) incremented to %d",
+				     cookie, semid, val);
 
 	return 1;
 }
@@ -2459,12 +2459,10 @@ static int _udev_notify_sem_dec(uint32_t cookie, int semid)
 	struct sembuf sb = {0, -1, IPC_NOWAIT};
 	int val;
 
- 	if ((val = semctl(semid, 0, GETVAL)) < 0) {
-		log_error("cookie dec: semid %d: sem_ctl GETVAL failed for "
-			  "cookie 0x%" PRIx32 ": %s",
-			  semid, cookie, strerror(errno));
-		return 0;
-	}
+ 	if ((val = semctl(semid, 0, GETVAL)) < 0)
+		log_warn("cookie dec: semid %d: sem_ctl GETVAL failed for "
+			 "cookie 0x%" PRIx32 ": %s",
+			 semid, cookie, strerror(errno));
 
 	if (semop(semid, &sb, 1) < 0) {
 		switch (errno) {
@@ -2483,9 +2481,12 @@ static int _udev_notify_sem_dec(uint32_t cookie, int semid)
 		return 0;
 	}
 
-	log_debug_activation("Udev cookie 0x%" PRIx32 " (semid %d) decremented to %d",
-			     cookie, semid, val - 1);
-
+	if (val < 0)
+		log_debug_activation("Udev cookie 0x%" PRIx32 " (semid %d) decremented.",
+				     cookie, semid);
+	else
+		log_debug_activation("Udev cookie 0x%" PRIx32 " (semid %d) decremented to %d",
+				     cookie, semid, val - 1);
 	return 1;
 }