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authorOpenShift Merge Robot <openshift-merge-robot@users.noreply.github.com>2019-02-21 23:11:24 +0100
committerGitHub <noreply@github.com>2019-02-21 23:11:24 +0100
commiteb6243226a08254f15657c3728bb4dd8949ee6cd (patch)
tree25fea4777a578895b9ac0f5f6c2e19860fc2e4bd /libpod/lock/shm
parentb4c10790d514538277a937a443219e4310cb057f (diff)
parent19eb72f4206192b22856eef24ce3815eac3d7bda (diff)
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Merge pull request #2350 from mheon/lock_renumber
Add lock renumbering
Diffstat (limited to 'libpod/lock/shm')
-rw-r--r--libpod/lock/shm/shm_lock.c36
-rw-r--r--libpod/lock/shm/shm_lock.go16
-rw-r--r--libpod/lock/shm/shm_lock.h1
-rw-r--r--libpod/lock/shm/shm_lock_test.go28
4 files changed, 72 insertions, 9 deletions
diff --git a/libpod/lock/shm/shm_lock.c b/libpod/lock/shm/shm_lock.c
index 4af58d857..d11fce71a 100644
--- a/libpod/lock/shm/shm_lock.c
+++ b/libpod/lock/shm/shm_lock.c
@@ -203,6 +203,8 @@ shm_struct_t *setup_lock_shm(char *path, uint32_t num_locks, int *error_code) {
// terminating NULL byte.
// Returns a valid pointer on success or NULL on error.
// If an error occurs, negative ERRNO values will be written to error_code.
+// ERANGE is returned for a mismatch between num_locks and the number of locks
+// available in the the SHM lock struct.
shm_struct_t *open_lock_shm(char *path, uint32_t num_locks, int *error_code) {
int shm_fd;
shm_struct_t *shm;
@@ -255,11 +257,11 @@ shm_struct_t *open_lock_shm(char *path, uint32_t num_locks, int *error_code) {
// Need to check the SHM to see if it's actually our locks
if (shm->magic != MAGIC) {
- *error_code = -1 * errno;
+ *error_code = -1 * EBADF;
goto CLEANUP;
}
if (shm->num_locks != (num_bitmaps * BITMAP_SIZE)) {
- *error_code = -1 * errno;
+ *error_code = -1 * ERANGE;
goto CLEANUP;
}
@@ -407,6 +409,36 @@ int32_t deallocate_semaphore(shm_struct_t *shm, uint32_t sem_index) {
return 0;
}
+// Deallocate all semaphores unconditionally.
+// Returns negative ERRNO values.
+int32_t deallocate_all_semaphores(shm_struct_t *shm) {
+ int ret_code;
+ uint i;
+
+ if (shm == NULL) {
+ return -1 * EINVAL;
+ }
+
+ // Lock the mutex controlling access to our shared memory
+ ret_code = take_mutex(&(shm->segment_lock));
+ if (ret_code != 0) {
+ return -1 * ret_code;
+ }
+
+ // Iterate through all bitmaps and reset to unused
+ for (i = 0; i < shm->num_bitmaps; i++) {
+ shm->locks[i].bitmap = 0;
+ }
+
+ // Unlock the allocation control mutex
+ ret_code = release_mutex(&(shm->segment_lock));
+ if (ret_code != 0) {
+ return -1 * ret_code;
+ }
+
+ return 0;
+}
+
// Lock a given semaphore
// Does not check if the semaphore is allocated - this ensures that, even for
// removed containers, we can still successfully lock to check status (and
diff --git a/libpod/lock/shm/shm_lock.go b/libpod/lock/shm/shm_lock.go
index 87d28e5c1..e70ea8743 100644
--- a/libpod/lock/shm/shm_lock.go
+++ b/libpod/lock/shm/shm_lock.go
@@ -155,6 +155,22 @@ func (locks *SHMLocks) DeallocateSemaphore(sem uint32) error {
return nil
}
+// DeallocateAllSemaphores frees all semaphores so they can be reallocated to
+// other containers and pods.
+func (locks *SHMLocks) DeallocateAllSemaphores() error {
+ if !locks.valid {
+ return errors.Wrapf(syscall.EINVAL, "locks have already been closed")
+ }
+
+ retCode := C.deallocate_all_semaphores(locks.lockStruct)
+ if retCode < 0 {
+ // Negative errno return from C
+ return syscall.Errno(-1 * retCode)
+ }
+
+ return nil
+}
+
// LockSemaphore locks the given semaphore.
// If the semaphore is already locked, LockSemaphore will block until the lock
// can be acquired.
diff --git a/libpod/lock/shm/shm_lock.h b/libpod/lock/shm/shm_lock.h
index 8e7e23fb7..58e4297e2 100644
--- a/libpod/lock/shm/shm_lock.h
+++ b/libpod/lock/shm/shm_lock.h
@@ -40,6 +40,7 @@ shm_struct_t *open_lock_shm(char *path, uint32_t num_locks, int *error_code);
int32_t close_lock_shm(shm_struct_t *shm);
int64_t allocate_semaphore(shm_struct_t *shm);
int32_t deallocate_semaphore(shm_struct_t *shm, uint32_t sem_index);
+int32_t deallocate_all_semaphores(shm_struct_t *shm);
int32_t lock_semaphore(shm_struct_t *shm, uint32_t sem_index);
int32_t unlock_semaphore(shm_struct_t *shm, uint32_t sem_index);
diff --git a/libpod/lock/shm/shm_lock_test.go b/libpod/lock/shm/shm_lock_test.go
index 594eb5d8e..830035881 100644
--- a/libpod/lock/shm/shm_lock_test.go
+++ b/libpod/lock/shm/shm_lock_test.go
@@ -4,7 +4,6 @@ import (
"fmt"
"os"
"runtime"
- "syscall"
"testing"
"time"
@@ -53,12 +52,8 @@ func runLockTest(t *testing.T, testFunc func(*testing.T, *SHMLocks)) {
}
defer func() {
// Deallocate all locks
- // Ignore ENOENT (lock is not allocated)
- var i uint32
- for i = 0; i < numLocks; i++ {
- if err := locks.DeallocateSemaphore(i); err != nil && err != syscall.ENOENT {
- t.Fatalf("Error deallocating semaphore %d: %v", i, err)
- }
+ if err := locks.DeallocateAllSemaphores(); err != nil {
+ t.Fatalf("Error deallocating semaphores: %v", err)
}
if err := locks.Close(); err != nil {
@@ -212,6 +207,25 @@ func TestAllocateDeallocateCycle(t *testing.T) {
})
}
+// Test that DeallocateAllSemaphores deallocates all semaphores
+func TestDeallocateAllSemaphoresDeallocatesAll(t *testing.T) {
+ runLockTest(t, func(t *testing.T, locks *SHMLocks) {
+ // Allocate a lock
+ locks1, err := locks.AllocateSemaphore()
+ assert.NoError(t, err)
+
+ // Free all locks
+ err = locks.DeallocateAllSemaphores()
+ assert.NoError(t, err)
+
+ // Allocate another lock
+ locks2, err := locks.AllocateSemaphore()
+ assert.NoError(t, err)
+
+ assert.Equal(t, locks1, locks2)
+ })
+}
+
// Test that locks actually lock
func TestLockSemaphoreActuallyLocks(t *testing.T) {
runLockTest(t, func(t *testing.T, locks *SHMLocks) {