<commit_before>//go:build linux
// +build linux

/*
   Copyright The containerd Authors.

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.
*/

package overlay

import (
	"context"
	"fmt"
	"os"
	"path/filepath"
	"strings"
	"syscall"

	"github.com/containerd/containerd/log"
	"github.com/containerd/containerd/mount"
	"github.com/containerd/containerd/snapshots"
	"github.com/containerd/containerd/snapshots/overlay/overlayutils"
	"github.com/containerd/containerd/snapshots/storage"
	"github.com/containerd/continuity/fs"
	"github.com/sirupsen/logrus"
)

// upperdirKey is a key of an optional label to each snapshot.
// This optional label of a snapshot contains the location of "upperdir" where
// the change set between this snapshot and its parent is stored.
const upperdirKey = "containerd.io/snapshot/overlay.upperdir"

// SnapshotterConfig is used to configure the overlay snapshotter instance
type SnapshotterConfig struct {
	asyncRemove   bool
	upperdirLabel bool
}

// Opt is an option to configure the overlay snapshotter
type Opt func(config *SnapshotterConfig) error

// AsynchronousRemove defers removal of filesystem content until
// the Cleanup method is called. Removals will make the snapshot
// referred to by the key unavailable and make the key immediately
// available for re-use.
func AsynchronousRemove(config *SnapshotterConfig) error {
	config.asyncRemove = true
	return nil
}

// WithUpperdirLabel adds as an optional label
// "containerd.io/snapshot/overlay.upperdir". This stores the location
// of the upperdir that contains the changeset between the labelled
// snapshot and its parent.
func WithUpperdirLabel(config *SnapshotterConfig) error {
	config.upperdirLabel = true
	return nil
}

type snapshotter struct {
	root          string
	ms            *storage.MetaStore
	asyncRemove   bool
	upperdirLabel bool
	indexOff      bool
	userxattr     bool // whether to enable "userxattr" mount option
}

// NewSnapshotter returns a Snapshotter which uses overlayfs. The overlayfs
// diffs are stored under the provided root. A metadata file is stored under
// the root.
func NewSnapshotter(root string, opts ...Opt) (snapshots.Snapshotter, error) {
	var config SnapshotterConfig
	for _, opt := range opts {
		if err := opt(&config); err != nil {
			return nil, err
		}
	}

	if err := os.MkdirAll(root, 0700); err != nil {
		return nil, err
	}
	supportsDType, err := fs.SupportsDType(root)
	if err != nil {
		return nil, err
	}
	if !supportsDType {
		return nil, fmt.Errorf("%s does not support d_type. If the backing filesystem is xfs, please reformat with ftype=1 to enable d_type support", root)
	}
	ms, err := storage.NewMetaStore(filepath.Join(root, "metadata.db"))
	if err != nil {
		return nil, err
	}

	if err := os.Mkdir(filepath.Join(root, "snapshots"), 0700); err != nil && !os.IsExist(err) {
		return nil, err
	}
	// figure out whether "userxattr" option is recognized by the kernel && needed
	userxattr, err := overlayutils.NeedsUserXAttr(root)
	if err != nil {
		logrus.WithError(err).Warnf("cannot detect whether \"userxattr\" option needs to be used, assuming to be %v", userxattr)
	}

	return &snapshotter{
		root:          root,
		ms:            ms,
		asyncRemove:   config.asyncRemove,
		upperdirLabel: config.upperdirLabel,
		indexOff:      supportsIndex(),
		userxattr:     userxattr,
	}, nil
}

// Stat returns the info for an active or committed snapshot by name or
// key.
//
// Should be used for parent resolution, existence checks and to discern
// the kind of snapshot.
func (o *snapshotter) Stat(ctx context.Context, key string) (snapshots.Info, error) {
	ctx, t, err := o.ms.TransactionContext(ctx, false)
	if err != nil {
		return snapshots.Info{}, err
	}
	defer t.Rollback()
	id, info, _, err := storage.GetInfo(ctx, key)
	if err != nil {
		return snapshots.Info{}, err
	}

	if o.upperdirLabel {
		if info.Labels == nil {
			info.Labels = make(map[string]string)
		}
		info.Labels[upperdirKey] = o.upperPath(id)
	}

	return info, nil
}

func (o *snapshotter) Update(ctx context.Context, info snapshots.Info, fieldpaths ...string) (snapshots.Info, error) {
	ctx, t, err := o.ms.TransactionContext(ctx, true)
	if err != nil {
		return snapshots.Info{}, err
	}

	info, err = storage.UpdateInfo(ctx, info, fieldpaths...)
	if err != nil {
		t.Rollback()
		return snapshots.Info{}, err
	}

	if o.upperdirLabel {
		id, _, _, err := storage.GetInfo(ctx, info.Name)
		if err != nil {
			return snapshots.Info{}, err
		}
		if info.Labels == nil {
			info.Labels = make(map[string]string)
		}
		info.Labels[upperdirKey] = o.upperPath(id)
	}

	if err := t.Commit(); err != nil {
		return snapshots.Info{}, err
	}

	return info, nil
}

// Usage returns the resources taken by the snapshot identified by key.
//
// For active snapshots, this will scan the usage of the overlay "diff" (aka
// "upper") directory and may take some time.
//
// For committed snapshots, the value is returned from the metadata database.
func (o *snapshotter) Usage(ctx context.Context, key string) (snapshots.Usage, error) {
	ctx, t, err := o.ms.TransactionContext(ctx, false)
	if err != nil {
		return snapshots.Usage{}, err<commit_msg>tx rollback when GetInfo return error<commit_after>//go:build linux
// +build linux

/*
   Copyright The containerd Authors.

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.
*/

package overlay

import (
	"context"
	"fmt"
	"os"
	"path/filepath"
	"strings"
	"syscall"

	"github.com/containerd/containerd/log"
	"github.com/containerd/containerd/mount"
	"github.com/containerd/containerd/snapshots"
	"github.com/containerd/containerd/snapshots/overlay/overlayutils"
	"github.com/containerd/containerd/snapshots/storage"
	"github.com/containerd/continuity/fs"
	"github.com/sirupsen/logrus"
)

// upperdirKey is a key of an optional label to each snapshot.
// This optional label of a snapshot contains the location of "upperdir" where
// the change set between this snapshot and its parent is stored.
const upperdirKey = "containerd.io/snapshot/overlay.upperdir"

// SnapshotterConfig is used to configure the overlay snapshotter instance
type SnapshotterConfig struct {
	asyncRemove   bool
	upperdirLabel bool
}

// Opt is an option to configure the overlay snapshotter
type Opt func(config *SnapshotterConfig) error

// AsynchronousRemove defers removal of filesystem content until
// the Cleanup method is called. Removals will make the snapshot
// referred to by the key unavailable and make the key immediately
// available for re-use.
func AsynchronousRemove(config *SnapshotterConfig) error {
	config.asyncRemove = true
	return nil
}

// WithUpperdirLabel adds as an optional label
// "containerd.io/snapshot/overlay.upperdir". This stores the location
// of the upperdir that contains the changeset between the labelled
// snapshot and its parent.
func WithUpperdirLabel(config *SnapshotterConfig) error {
	config.upperdirLabel = true
	return nil
}

type snapshotter struct {
	root          string
	ms            *storage.MetaStore
	asyncRemove   bool
	upperdirLabel bool
	indexOff      bool
	userxattr     bool // whether to enable "userxattr" mount option
}

// NewSnapshotter returns a Snapshotter which uses overlayfs. The overlayfs
// diffs are stored under the provided root. A metadata file is stored under
// the root.
func NewSnapshotter(root string, opts ...Opt) (snapshots.Snapshotter, error) {
	var config SnapshotterConfig
	for _, opt := range opts {
		if err := opt(&config); err != nil {
			return nil, err
		}
	}

	if err := os.MkdirAll(root, 0700); err != nil {
		return nil, err
	}
	supportsDType, err := fs.SupportsDType(root)
	if err != nil {
		return nil, err
	}
	if !supportsDType {
		return nil, fmt.Errorf("%s does not support d_type. If the backing filesystem is xfs, please reformat with ftype=1 to enable d_type support", root)
	}
	ms, err := storage.NewMetaStore(filepath.Join(root, "metadata.db"))
	if err != nil {
		return nil, err
	}

	if err := os.Mkdir(filepath.Join(root, "snapshots"), 0700); err != nil && !os.IsExist(err) {
		return nil, err
	}
	// figure out whether "userxattr" option is recognized by the kernel && needed
	userxattr, err := overlayutils.NeedsUserXAttr(root)
	if err != nil {
		logrus.WithError(err).Warnf("cannot detect whether \"userxattr\" option needs to be used, assuming to be %v", userxattr)
	}

	return &snapshotter{
		root:          root,
		ms:            ms,
		asyncRemove:   config.asyncRemove,
		upperdirLabel: config.upperdirLabel,
		indexOff:      supportsIndex(),
		userxattr:     userxattr,
	}, nil
}

// Stat returns the info for an active or committed snapshot by name or
// key.
//
// Should be used for parent resolution, existence checks and to discern
// the kind of snapshot.
func (o *snapshotter) Stat(ctx context.Context, key string) (snapshots.Info, error) {
	ctx, t, err := o.ms.TransactionContext(ctx, false)
	if err != nil {
		return snapshots.Info{}, err
	}
	defer t.Rollback()
	id, info, _, err := storage.GetInfo(ctx, key)
	if err != nil {
		return snapshots.Info{}, err
	}

	if o.upperdirLabel {
		if info.Labels == nil {
			info.Labels = make(map[string]string)
		}
		info.Labels[upperdirKey] = o.upperPath(id)
	}

	return info, nil
}

func (o *snapshotter) Update(ctx context.Context, info snapshots.Info, fieldpaths ...string) (snapshots.Info, error) {
	ctx, t, err := o.ms.TransactionContext(ctx, true)
	if err != nil {
		return snapshots.Info{}, err
	}

	rollback := true
	defer func() {
		if rollback {
			if rerr := t.Rollback(); rerr != nil {
				log.G(ctx).WithError(rerr).Warn("failed to rollback transaction")
			}
		}
	}()

	info, err = storage.UpdateInfo(ctx, info, fieldpaths...)
	if err != nil {
		return snapshots.Info{}, err
	}

	if o.upperdirLabel {
		id, _, _, err := storage.GetInfo(ctx, info.Name)
		if err != nil {
			return snapshots.Info{}, err
		}
		if info.Labels == nil {
			info.Labels = make(map[string]string)
		}
		info.Labels[upperdirKey] = o.upperPath(id)
	}

	rollback = false
	if err := t.Commit(); err != nil {
		return snapshots.Info{}, err
	}

	return info, nil
}

// Usage returns the resources taken by the snapshot identified by key.
//
// For active snapshots, this will scan the usage of the overlay "diff" (aka
// "upper") directory and may take some time.
//
// For committed snapshots, the value is returned from the metadata database.
func (o *snapshotter) Usage(ctx context.Context, key string) (snapshots.Usage, error) {
	ctx, t, err := o.ms.TransactionContext(ctx, false)
	if err != nil {
		return snapshots.Usage{}, err
{'fraction_non_alphanumeric': 0.10402568106888774, 'fraction_numerical': 0.0022557695644629533, 'mean_word_length': 3.670583468395462, 'pattern_counts': {'":': 0, '<': 3, '<?xml version=': 0, '>': 3, 'https://': 0, 'lorem ipsum': 0, 'www.': 2, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
{'dir': 'git-commits-cleaned', 'id': '7031277', 'n_tokens_mistral': 3680, 'n_tokens_neox': 3541, 'n_words': 1254}