Address review feedback and add manpage notes

The inspect format for `.LockNumber` needed to be documented.

Signed-off-by: Matt Heon <mheon@redhat.com>

cmd/podman/system/locks.go

@@ -43,7 +43,7 @@ func runLocks() error {
 	if len(report.LockConflicts) > 0 {
 		fmt.Printf("\nLock conflicts have been detected. Recommend immediate use of `podman system renumber` to resolve.\n\n")
 	} else {
-		fmt.Printf("\nNo lock conflicts have been detected, system safe from deadlocks.\n\n")
+		fmt.Printf("\nNo lock conflicts have been detected.\n\n")
 	}
 
 	for _, lockNum := range report.LocksHeld {

docs/source/markdown/podman-container-inspect.1.md.in

@@ -43,6 +43,7 @@ Valid placeholders for the Go template are listed below:
 | .IsInfra                 | Is this an infra container? (string: true/false)   |
 | .IsService               | Is this a service container? (string: true/false)  |
 | .KubeExitCodePropagation | Kube exit-code propagation (string)                |
+| .LockNumber              | Number of the container's Libpod lock              |
 | .MountLabel              | SELinux label of mount (string)                    |
 | .Mounts                  | Mounts (array of strings)                          |
 | .Name                    | Container name (string)                            |

docs/source/markdown/podman-pod-inspect.1.md.in

@@ -44,6 +44,7 @@ Valid placeholders for the Go template are listed below:
 | .InfraContainerID    | Pod infrastructure ID                       |
 | .InspectPodData ...  | Nested structure, for experts only          |
 | .Labels              | Pod labels                                  |
+| .LockNumber          | Number of the pod's Libpod lock             |
 | .MemoryLimit         | Memory limit, bytes                         |
 | .MemorySwap          | Memory swap limit, in bytes                 |
 | .Mounts              | Mounts                                      |

docs/source/markdown/podman-volume-inspect.1.md

@@ -33,6 +33,7 @@ Valid placeholders for the Go template are listed below:
 | .Driver             | Volume driver                                          |
 | .GID                | GID the volume was created with                        |
 | .Labels             | Label information associated with the volume           |
+| .LockNumber         | Number of the volume's Libpod lock                     |
 | .MountCount         | Number of times the volume is mounted                  |
 | .Mountpoint         | Source of volume mount point                           |
 | .Name               | Volume name                                            |

docs/source/markdown/podman-volume-ls.1.md.in

@@ -42,6 +42,7 @@ Valid placeholders for the Go template are listed below:
 | .GID                      | GID of volume                                |
 | .InspectVolumeData ...    | Don't use                                    |
 | .Labels                   | Label information associated with the volume |
+| .LockNumber               | Number of the volume's Libpod lock           |
 | .MountCount               | Number of times the volume is mounted        |
 | .Mountpoint               | Source of volume mount point                 |
 | .Name                     | Volume name                                  |

libpod/lock/shm/shm_lock.c

@@ -568,7 +568,7 @@ int64_t available_locks(shm_struct_t *shm) {
   for (i = 0; i < shm->num_bitmaps; i++) {
     // Short-circuit to catch fully-empty bitmaps quick.
     if (shm->locks[i].bitmap == 0) {
-      free_locks += 32;
+      free_locks += sizeof(bitmap_t) * 8;
       continue;
     }
 
@@ -581,7 +581,7 @@ int64_t available_locks(shm_struct_t *shm) {
       count++;
     }
 
-    free_locks += 32 - count;
+    free_locks += (sizeof(bitmap_t) * 8) - count;
   }
 
   // Clear the mutex

libpod/runtime.go

@@ -1206,12 +1206,7 @@ func (r *Runtime) LockConflicts() (map[uint32][]string, []uint32, error) {
 	for _, ctr := range ctrs {
 		lockNum := ctr.lock.ID()
 		ctrString := fmt.Sprintf("container %s", ctr.ID())
-		locksArr, ok := locksInUse[lockNum]
+		locksInUse[lockNum] = append(locksInUse[lockNum], ctrString)
-		if ok {
-			locksInUse[lockNum] = append(locksArr, ctrString)
-		} else {
-			locksInUse[lockNum] = []string{ctrString}
-		}
 	}
 
 	pods, err := r.state.AllPods()
@@ -1221,12 +1216,7 @@ func (r *Runtime) LockConflicts() (map[uint32][]string, []uint32, error) {
 	for _, pod := range pods {
 		lockNum := pod.lock.ID()
 		podString := fmt.Sprintf("pod %s", pod.ID())
-		locksArr, ok := locksInUse[lockNum]
+		locksInUse[lockNum] = append(locksInUse[lockNum], podString)
-		if ok {
-			locksInUse[lockNum] = append(locksArr, podString)
-		} else {
-			locksInUse[lockNum] = []string{podString}
-		}
 	}
 
 	volumes, err := r.state.AllVolumes()
@@ -1236,12 +1226,7 @@ func (r *Runtime) LockConflicts() (map[uint32][]string, []uint32, error) {
 	for _, vol := range volumes {
 		lockNum := vol.lock.ID()
 		volString := fmt.Sprintf("volume %s", vol.Name())
-		locksArr, ok := locksInUse[lockNum]
+		locksInUse[lockNum] = append(locksInUse[lockNum], volString)
-		if ok {
-			locksInUse[lockNum] = append(locksArr, volString)
-		} else {
-			locksInUse[lockNum] = []string{volString}
-		}
 	}
 
 	// Now go through and find any entries with >1 item associated

test/e2e/info_test.go

@@ -177,7 +177,7 @@ var _ = Describe("Podman Info", func() {
 		Expect(session.OutputToString()).To(Equal(want))
 	})
 
-	It("Podman info: check lock count", func() {
+	It("Podman info: check lock count", Serial, func() {
 		// This should not run on architectures and OSes that use the file locks backend.
 		// Which, for now, is Linux + RISCV and FreeBSD, neither of which are in CI - so
 		// no skips.
@@ -197,6 +197,9 @@ var _ = Describe("Podman Info", func() {
 		free2, err := strconv.Atoi(info2.OutputToString())
 		Expect(err).To(Not(HaveOccurred()))
 
+		// Effectively, we are checking that 1 lock has been taken.
+		// We do this by comparing the number of locks after (plus 1), to the number of locks before.
+		// Don't check absolute numbers because there is a decent chance of contamination, containers that were never removed properly, etc.
 		Expect(free1).To(Equal(free2 + 1))
 	})
 })