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Vendor in latest containers/(common, image, storage)

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Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>
This commit is contained in:
Daniel J Walsh
2023-01-05 10:37:32 -05:00
parent 8e80c199d7
commit eea78ec7b3
87 changed files with 4156 additions and 1544 deletions
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180
vendor/github.com/containers/storage/containers.go generated vendored
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@ -141,16 +141,21 @@ type rwContainerStore interface {
}
type containerStore struct {
lockfile *lockfile.LockFile
dir string
jsonPath [numContainerLocationIndex]string
// The following fields are only set when constructing containerStore, and must never be modified afterwards.
// They are safe to access without any other locking.
lockfile *lockfile.LockFile // Synchronizes readers vs. writers of the _filesystem data_, both cross-process and in-process.
dir string
jsonPath [numContainerLocationIndex]string
inProcessLock sync.RWMutex // Can _only_ be obtained with lockfile held.
// The following fields can only be read/written with read/write ownership of inProcessLock, respectively.
// Almost all users should use startReading() or startWriting().
lastWrite lockfile.LastWrite
containers []*Container
idindex *truncindex.TruncIndex
byid map[string]*Container
bylayer map[string]*Container
byname map[string]*Container
loadMut sync.Mutex
}
func copyContainer(c *Container) *Container {
@ -202,6 +207,7 @@ func (c *Container) MountOpts() []string {
}
}
// The caller must hold r.inProcessLock for reading.
func containerLocation(c *Container) containerLocations {
if c.volatileStore {
return volatileContainerLocation
@ -216,9 +222,11 @@ func containerLocation(c *Container) containerLocations {
// should use startWriting() instead.
func (r *containerStore) startWritingWithReload(canReload bool) error {
r.lockfile.Lock()
r.inProcessLock.Lock()
succeeded := false
defer func() {
if !succeeded {
r.inProcessLock.Unlock()
r.lockfile.Unlock()
}
}()
@ -241,71 +249,135 @@ func (r *containerStore) startWriting() error {
// stopWriting releases locks obtained by startWriting.
func (r *containerStore) stopWriting() {
r.inProcessLock.Unlock()
r.lockfile.Unlock()
}
// startReading makes sure the store is fresh, and locks it for reading.
// If this succeeds, the caller MUST call stopReading().
func (r *containerStore) startReading() error {
// inProcessLocked calls the nested function with r.inProcessLock held for writing.
inProcessLocked := func(fn func() error) error {
r.inProcessLock.Lock()
defer r.inProcessLock.Unlock()
return fn()
}
r.lockfile.RLock()
unlockFn := r.lockfile.Unlock // A function to call to clean up, or nil
unlockFn := r.lockfile.Unlock // A function to call to clean up, or nil.
defer func() {
if unlockFn != nil {
unlockFn()
}
}()
r.inProcessLock.RLock()
unlockFn = r.stopReading
if tryLockedForWriting, err := r.reloadIfChanged(false); err != nil {
if !tryLockedForWriting {
return err
}
unlockFn()
unlockFn = nil
r.lockfile.Lock()
unlockFn = r.lockfile.Unlock
if _, err := r.reloadIfChanged(true); err != nil {
return err
}
unlockFn()
unlockFn = nil
r.lockfile.RLock()
unlockFn = r.lockfile.Unlock
// We need to check for a reload reload once more because the on-disk state could have been modified
// after we released the lock.
// If that, _again_, finds inconsistent state, just give up.
// We could, plausibly, retry a few times, but that inconsistent state (duplicate container names)
// shouldn’t be saved (by correct implementations) in the first place.
if _, err := r.reloadIfChanged(false); err != nil {
return fmt.Errorf("(even after successfully cleaning up once:) %w", err)
}
// If we are lucky, we can just hold the read locks, check that we are fresh, and continue.
_, modified, err := r.modified()
if err != nil {
return err
}
if modified {
// We are unlucky, and need to reload.
// NOTE: Multiple goroutines can get to this place approximately simultaneously.
r.inProcessLock.RUnlock()
unlockFn = r.lockfile.Unlock
// r.lastWrite can change at this point if another goroutine reloads the store before us. That’s why we don’t unconditionally
// trigger a load below; we (lock and) reloadIfChanged() again.
// First try reloading with r.lockfile held for reading.
// r.inProcessLock will serialize all goroutines that got here;
// each will re-check on-disk state vs. r.lastWrite, and the first one will actually reload the data.
var tryLockedForWriting bool
if err := inProcessLocked(func() error {
// We could optimize this further: The r.lockfile.GetLastWrite() value shouldn’t change as long as we hold r.lockfile,
// so if r.lastWrite was already updated, we don’t need to actually read the on-filesystem lock.
var err error
tryLockedForWriting, err = r.reloadIfChanged(false)
return err
}); err != nil {
if !tryLockedForWriting {
return err
}
// Not good enough, we need r.lockfile held for writing. So, let’s do that.
unlockFn()
unlockFn = nil
r.lockfile.Lock()
unlockFn = r.lockfile.Unlock
if err := inProcessLocked(func() error {
_, err := r.reloadIfChanged(true)
return err
}); err != nil {
return err
}
unlockFn()
unlockFn = nil
r.lockfile.RLock()
unlockFn = r.lockfile.Unlock
// We need to check for a reload once more because the on-disk state could have been modified
// after we released the lock.
// If that, _again_, finds inconsistent state, just give up.
// We could, plausibly, retry a few times, but that inconsistent state (duplicate container names)
// shouldn’t be saved (by correct implementations) in the first place.
if err := inProcessLocked(func() error {
_, err := r.reloadIfChanged(false)
return err
}); err != nil {
return fmt.Errorf("(even after successfully cleaning up once:) %w", err)
}
}
// NOTE that we hold neither a read nor write inProcessLock at this point. That’s fine in ordinary operation, because
// the on-filesystem r.lockfile should protect us against (cooperating) writers, and any use of r.inProcessLock
// protects us against in-process writers modifying data.
// In presence of non-cooperating writers, we just ensure that 1) the in-memory data is not clearly out-of-date
// and 2) access to the in-memory data is not racy;
// but we can’t protect against those out-of-process writers modifying _files_ while we are assuming they are in a consistent state.
r.inProcessLock.RLock()
}
unlockFn = nil
return nil
}
// stopReading releases locks obtained by startReading.
func (r *containerStore) stopReading() {
r.inProcessLock.RUnlock()
r.lockfile.Unlock()
}
// modified returns true if the on-disk state has changed (i.e. if reloadIfChanged may need to modify the store),
// and a lockfile.LastWrite value for that update.
//
// The caller must hold r.lockfile for reading _or_ writing.
// The caller must hold r.inProcessLock for reading or writing.
func (r *containerStore) modified() (lockfile.LastWrite, bool, error) {
return r.lockfile.ModifiedSince(r.lastWrite)
}
// reloadIfChanged reloads the contents of the store from disk if it is changed.
//
// The caller must hold r.lockfile for reading _or_ writing; lockedForWriting is true
// if it is held for writing.
//
// The caller must hold r.inProcessLock for WRITING.
//
// If !lockedForWriting and this function fails, the return value indicates whether
// reloadIfChanged() with lockedForWriting could succeed.
func (r *containerStore) reloadIfChanged(lockedForWriting bool) (bool, error) {
r.loadMut.Lock()
defer r.loadMut.Unlock()
lastWrite, modified, err := r.lockfile.ModifiedSince(r.lastWrite)
lastWrite, modified, err := r.modified()
if err != nil {
return false, err
}
// We require callers to always hold r.inProcessLock for WRITING, even if they might not end up calling r.load()
// and modify no fields, to ensure they see fresh data:
// r.lockfile.Modified() only returns true once per change. Without an exclusive lock,
// one goroutine might see r.lockfile.Modified() == true and decide to load, and in the meanwhile another one could
// see r.lockfile.Modified() == false and proceed to use in-memory data without noticing it is stale.
if modified {
if tryLockedForWriting, err := r.load(lockedForWriting); err != nil {
return tryLockedForWriting, err // r.lastWrite is unchanged, so we will load the next time again.
@ -315,6 +387,7 @@ func (r *containerStore) reloadIfChanged(lockedForWriting bool) (bool, error) {
return false, nil
}
// Requires startReading or startWriting.
func (r *containerStore) Containers() ([]Container, error) {
containers := make([]Container, len(r.containers))
for i := range r.containers {
@ -326,6 +399,7 @@ func (r *containerStore) Containers() ([]Container, error) {
// This looks for datadirs in the store directory that are not referenced
// by the json file and removes it. These can happen in the case of unclean
// shutdowns or regular restarts in transient store mode.
// Requires startReading.
func (r *containerStore) GarbageCollect() error {
entries, err := os.ReadDir(r.dir)
if err != nil {
@ -371,6 +445,7 @@ func (r *containerStore) datapath(id, key string) string {
//
// The caller must hold r.lockfile for reading _or_ writing; lockedForWriting is true
// if it is held for writing.
// The caller must hold r.inProcessLock for WRITING.
//
// If !lockedForWriting and this function fails, the return value indicates whether
// retrying with lockedForWriting could succeed.
@ -441,8 +516,9 @@ func (r *containerStore) load(lockedForWriting bool) (bool, error) {
return false, nil
}
// Save saves the contents of the store to disk. It should be called with
// the lock held, locked for writing.
// save saves the contents of the store to disk.
// The caller must hold r.lockfile locked for writing.
// The caller must hold r.inProcessLock for reading (but usually holds it for writing in order to make the desired changes).
func (r *containerStore) save(saveLocations containerLocations) error {
r.lockfile.AssertLockedForWriting()
for locationIndex := 0; locationIndex < numContainerLocationIndex; locationIndex++ {
@ -483,6 +559,9 @@ func (r *containerStore) save(saveLocations containerLocations) error {
return nil
}
// saveFor saves the contents of the store relevant for modifiedContainer to disk.
// The caller must hold r.lockfile locked for writing.
// The caller must hold r.inProcessLock for reading (but usually holds it for writing in order to make the desired changes).
func (r *containerStore) saveFor(modifiedContainer *Container) error {
return r.save(containerLocation(modifiedContainer))
}
@ -503,16 +582,17 @@ func newContainerStore(dir string, runDir string, transient bool) (rwContainerSt
return nil, err
}
cstore := containerStore{
lockfile: lockfile,
dir: dir,
containers: []*Container{},
byid: make(map[string]*Container),
bylayer: make(map[string]*Container),
byname: make(map[string]*Container),
lockfile: lockfile,
dir: dir,
jsonPath: [numContainerLocationIndex]string{
filepath.Join(dir, "containers.json"),
filepath.Join(volatileDir, "volatile-containers.json"),
},
containers: []*Container{},
byid: make(map[string]*Container),
bylayer: make(map[string]*Container),
byname: make(map[string]*Container),
}
if err := cstore.startWritingWithReload(false); err != nil {
@ -529,6 +609,7 @@ func newContainerStore(dir string, runDir string, transient bool) (rwContainerSt
return &cstore, nil
}
// Requires startReading or startWriting.
func (r *containerStore) lookup(id string) (*Container, bool) {
if container, ok := r.byid[id]; ok {
return container, ok
@ -544,6 +625,7 @@ func (r *containerStore) lookup(id string) (*Container, bool) {
return nil, false
}
// Requires startWriting.
func (r *containerStore) ClearFlag(id string, flag string) error {
container, ok := r.lookup(id)
if !ok {
@ -553,6 +635,7 @@ func (r *containerStore) ClearFlag(id string, flag string) error {
return r.saveFor(container)
}
// Requires startWriting.
func (r *containerStore) SetFlag(id string, flag string, value interface{}) error {
container, ok := r.lookup(id)
if !ok {
@ -565,6 +648,7 @@ func (r *containerStore) SetFlag(id string, flag string, value interface{}) erro
return r.saveFor(container)
}
// Requires startWriting.
func (r *containerStore) Create(id string, names []string, image, layer, metadata string, options *ContainerOptions) (container *Container, err error) {
if id == "" {
id = stringid.GenerateRandomID()
@ -624,6 +708,7 @@ func (r *containerStore) Create(id string, names []string, image, layer, metadat
return container, err
}
// Requires startReading or startWriting.
func (r *containerStore) Metadata(id string) (string, error) {
if container, ok := r.lookup(id); ok {
return container.Metadata, nil
@ -631,6 +716,7 @@ func (r *containerStore) Metadata(id string) (string, error) {
return "", ErrContainerUnknown
}
// Requires startWriting.
func (r *containerStore) SetMetadata(id, metadata string) error {
if container, ok := r.lookup(id); ok {
container.Metadata = metadata
@ -639,10 +725,12 @@ func (r *containerStore) SetMetadata(id, metadata string) error {
return ErrContainerUnknown
}
// The caller must hold r.inProcessLock for writing.
func (r *containerStore) removeName(container *Container, name string) {
container.Names = stringSliceWithoutValue(container.Names, name)
}
// Requires startWriting.
func (r *containerStore) updateNames(id string, names []string, op updateNameOperation) error {
container, ok := r.lookup(id)
if !ok {
@ -666,6 +754,7 @@ func (r *containerStore) updateNames(id string, names []string, op updateNameOpe
return r.saveFor(container)
}
// Requires startWriting.
func (r *containerStore) Delete(id string) error {
container, ok := r.lookup(id)
if !ok {
@ -704,6 +793,7 @@ func (r *containerStore) Delete(id string) error {
return nil
}
// Requires startReading or startWriting.
func (r *containerStore) Get(id string) (*Container, error) {
if container, ok := r.lookup(id); ok {
return copyContainer(container), nil
@ -711,6 +801,7 @@ func (r *containerStore) Get(id string) (*Container, error) {
return nil, ErrContainerUnknown
}
// Requires startReading or startWriting.
func (r *containerStore) Lookup(name string) (id string, err error) {
if container, ok := r.lookup(name); ok {
return container.ID, nil
@ -718,11 +809,13 @@ func (r *containerStore) Lookup(name string) (id string, err error) {
return "", ErrContainerUnknown
}
// Requires startReading or startWriting.
func (r *containerStore) Exists(id string) bool {
_, ok := r.lookup(id)
return ok
}
// Requires startReading or startWriting.
func (r *containerStore) BigData(id, key string) ([]byte, error) {
if key == "" {
return nil, fmt.Errorf("can't retrieve container big data value for empty name: %w", ErrInvalidBigDataName)
@ -790,6 +883,7 @@ func (r *containerStore) BigDataDigest(id, key string) (digest.Digest, error) {
return "", ErrDigestUnknown
}
// Requires startReading or startWriting.
func (r *containerStore) BigDataNames(id string) ([]string, error) {
c, ok := r.lookup(id)
if !ok {
@ -798,6 +892,7 @@ func (r *containerStore) BigDataNames(id string) ([]string, error) {
return copyStringSlice(c.BigDataNames), nil
}
// Requires startWriting.
func (r *containerStore) SetBigData(id, key string, data []byte) error {
if key == "" {
return fmt.Errorf("can't set empty name for container big data item: %w", ErrInvalidBigDataName)
@ -844,6 +939,7 @@ func (r *containerStore) SetBigData(id, key string, data []byte) error {
return err
}
// Requires startWriting.
func (r *containerStore) Wipe() error {
ids := make([]string, 0, len(r.byid))
for id := range r.byid {