aboutsummaryrefslogtreecommitdiff
path: root/libpod/runtime_volume_linux.go
blob: d1ea7d4fd5956a9cdfc52e801b642e0e1b40c8d0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
// +build linux

package libpod

import (
	"context"
	"os"
	"path/filepath"
	"strings"
	"time"

	"github.com/containers/podman/v3/libpod/define"
	"github.com/containers/podman/v3/libpod/events"
	volplugin "github.com/containers/podman/v3/libpod/plugin"
	"github.com/containers/storage/drivers/quota"
	"github.com/containers/storage/pkg/stringid"
	pluginapi "github.com/docker/go-plugins-helpers/volume"
	"github.com/pkg/errors"
	"github.com/sirupsen/logrus"
)

// NewVolume creates a new empty volume
func (r *Runtime) NewVolume(ctx context.Context, options ...VolumeCreateOption) (*Volume, error) {
	r.lock.Lock()
	defer r.lock.Unlock()

	if !r.valid {
		return nil, define.ErrRuntimeStopped
	}
	return r.newVolume(ctx, options...)
}

// newVolume creates a new empty volume
func (r *Runtime) newVolume(ctx context.Context, options ...VolumeCreateOption) (_ *Volume, deferredErr error) {
	volume := newVolume(r)
	for _, option := range options {
		if err := option(volume); err != nil {
			return nil, errors.Wrapf(err, "error running volume create option")
		}
	}

	if volume.config.Name == "" {
		volume.config.Name = stringid.GenerateNonCryptoID()
	}
	if volume.config.Driver == "" {
		volume.config.Driver = define.VolumeDriverLocal
	}
	volume.config.CreatedTime = time.Now()

	// Check if volume with given name exists.
	exists, err := r.state.HasVolume(volume.config.Name)
	if err != nil {
		return nil, errors.Wrapf(err, "error checking if volume with name %s exists", volume.config.Name)
	}
	if exists {
		return nil, errors.Wrapf(define.ErrVolumeExists, "volume with name %s already exists", volume.config.Name)
	}

	// Plugin can be nil if driver is local, but that's OK - superfluous
	// assignment doesn't hurt much.
	plugin, err := r.getVolumePlugin(volume.config.Driver)
	if err != nil {
		return nil, errors.Wrapf(err, "volume %s uses volume plugin %s but it could not be retrieved", volume.config.Name, volume.config.Driver)
	}
	volume.plugin = plugin

	if volume.config.Driver == define.VolumeDriverLocal {
		logrus.Debugf("Validating options for local driver")
		// Validate options
		for key := range volume.config.Options {
			switch key {
			case "device", "o", "type", "UID", "GID", "SIZE", "INODES":
				// Do nothing, valid keys
			default:
				return nil, errors.Wrapf(define.ErrInvalidArg, "invalid mount option %s for driver 'local'", key)
			}
		}
	}

	// Now we get conditional: we either need to make the volume in the
	// volume plugin, or on disk if not using a plugin.
	if volume.plugin != nil {
		// We can't chown, or relabel, or similar the path the volume is
		// using, because it's not managed by us.
		// TODO: reevaluate this once we actually have volume plugins in
		// use in production - it may be safe, but I can't tell without
		// knowing what the actual plugin does...
		if err := makeVolumeInPluginIfNotExist(volume.config.Name, volume.config.Options, volume.plugin); err != nil {
			return nil, err
		}
	} else {
		// Create the mountpoint of this volume
		volPathRoot := filepath.Join(r.config.Engine.VolumePath, volume.config.Name)
		if err := os.MkdirAll(volPathRoot, 0700); err != nil {
			return nil, errors.Wrapf(err, "error creating volume directory %q", volPathRoot)
		}
		if err := os.Chown(volPathRoot, volume.config.UID, volume.config.GID); err != nil {
			return nil, errors.Wrapf(err, "error chowning volume directory %q to %d:%d", volPathRoot, volume.config.UID, volume.config.GID)
		}
		fullVolPath := filepath.Join(volPathRoot, "_data")
		if err := os.MkdirAll(fullVolPath, 0755); err != nil {
			return nil, errors.Wrapf(err, "error creating volume directory %q", fullVolPath)
		}
		if err := os.Chown(fullVolPath, volume.config.UID, volume.config.GID); err != nil {
			return nil, errors.Wrapf(err, "error chowning volume directory %q to %d:%d", fullVolPath, volume.config.UID, volume.config.GID)
		}
		if err := LabelVolumePath(fullVolPath); err != nil {
			return nil, err
		}
		projectQuotaSupported := false

		q, err := quota.NewControl(r.config.Engine.VolumePath)
		if err == nil {
			projectQuotaSupported = true
		}
		quota := quota.Quota{}
		if volume.config.Size > 0 || volume.config.Inodes > 0 {
			if !projectQuotaSupported {
				return nil, errors.New("Volume options size and inodes not supported. Filesystem does not support Project Quota")
			}
			quota.Size = volume.config.Size
			quota.Inodes = volume.config.Inodes
		}
		if projectQuotaSupported {
			if err := q.SetQuota(fullVolPath, quota); err != nil {
				return nil, errors.Wrapf(err, "failed to set size quota size=%d inodes=%d for volume directory %q", volume.config.Size, volume.config.Inodes, fullVolPath)
			}
		}

		volume.config.MountPoint = fullVolPath
	}

	lock, err := r.lockManager.AllocateLock()
	if err != nil {
		return nil, errors.Wrapf(err, "error allocating lock for new volume")
	}
	volume.lock = lock
	volume.config.LockID = volume.lock.ID()

	defer func() {
		if deferredErr != nil {
			if err := volume.lock.Free(); err != nil {
				logrus.Errorf("Error freeing volume lock after failed creation: %v", err)
			}
		}
	}()

	volume.valid = true

	// Add the volume to state
	if err := r.state.AddVolume(volume); err != nil {
		return nil, errors.Wrapf(err, "error adding volume to state")
	}
	defer volume.newVolumeEvent(events.Create)
	return volume, nil
}

// makeVolumeInPluginIfNotExist makes a volume in the given volume plugin if it
// does not already exist.
func makeVolumeInPluginIfNotExist(name string, options map[string]string, plugin *volplugin.VolumePlugin) error {
	// Ping the volume plugin to see if it exists first.
	// If it does, use the existing volume in the plugin.
	// Options may not match exactly, but not much we can do about
	// that. Not complaining avoids a lot of the sync issues we see
	// with c/storage and libpod DB.
	needsCreate := true
	getReq := new(pluginapi.GetRequest)
	getReq.Name = name
	if resp, err := plugin.GetVolume(getReq); err == nil {
		// TODO: What do we do if we get a 200 response, but the
		// Volume is nil? The docs on the Plugin API are very
		// nonspecific, so I don't know if this is valid or
		// not...
		if resp != nil {
			needsCreate = false
			logrus.Infof("Volume %q already exists in plugin %q, using existing volume", name, plugin.Name)
		}
	}
	if needsCreate {
		createReq := new(pluginapi.CreateRequest)
		createReq.Name = name
		createReq.Options = options
		if err := plugin.CreateVolume(createReq); err != nil {
			return errors.Wrapf(err, "error creating volume %q in plugin %s", name, plugin.Name)
		}
	}

	return nil
}

// removeVolume removes the specified volume from state as well tears down its mountpoint and storage
func (r *Runtime) removeVolume(ctx context.Context, v *Volume, force bool) error {
	if !v.valid {
		if ok, _ := r.state.HasVolume(v.Name()); !ok {
			return nil
		}
		return define.ErrVolumeRemoved
	}

	v.lock.Lock()
	defer v.lock.Unlock()

	// Update volume status to pick up a potential removal from state
	if err := v.update(); err != nil {
		return err
	}

	deps, err := r.state.VolumeInUse(v)
	if err != nil {
		return err
	}
	if len(deps) != 0 {
		depsStr := strings.Join(deps, ", ")
		if !force {
			return errors.Wrapf(define.ErrVolumeBeingUsed, "volume %s is being used by the following container(s): %s", v.Name(), depsStr)
		}

		// We need to remove all containers using the volume
		for _, dep := range deps {
			ctr, err := r.state.Container(dep)
			if err != nil {
				// If the container's removed, no point in
				// erroring.
				if errors.Cause(err) == define.ErrNoSuchCtr || errors.Cause(err) == define.ErrCtrRemoved {
					continue
				}

				return errors.Wrapf(err, "error removing container %s that depends on volume %s", dep, v.Name())
			}

			logrus.Debugf("Removing container %s (depends on volume %q)", ctr.ID(), v.Name())

			// TODO: do we want to set force here when removing
			// containers?
			// I'm inclined to say no, in case someone accidentally
			// wipes a container they're using...
			if err := r.removeContainer(ctx, ctr, false, false, false); err != nil {
				return errors.Wrapf(err, "error removing container %s that depends on volume %s", ctr.ID(), v.Name())
			}
		}
	}

	// If the volume is still mounted - force unmount it
	if err := v.unmount(true); err != nil {
		if force {
			// If force is set, evict the volume, even if errors
			// occur. Otherwise we'll never be able to get rid of
			// them.
			logrus.Errorf("Error unmounting volume %s: %v", v.Name(), err)
		} else {
			return errors.Wrapf(err, "error unmounting volume %s", v.Name())
		}
	}

	// Set volume as invalid so it can no longer be used
	v.valid = false

	var removalErr error

	// If we use a volume plugin, we need to remove from the plugin.
	if v.UsesVolumeDriver() {
		canRemove := true

		// Do we have a volume driver?
		if v.plugin == nil {
			canRemove = false
			removalErr = errors.Wrapf(define.ErrMissingPlugin, "cannot remove volume %s from plugin %s, but it has been removed from Podman", v.Name(), v.Driver())
		} else {
			// Ping the plugin first to verify the volume still
			// exists.
			// We're trying to be very tolerant of missing volumes
			// in the backend, to avoid the problems we see with
			// sync between c/storage and the Libpod DB.
			getReq := new(pluginapi.GetRequest)
			getReq.Name = v.Name()
			if _, err := v.plugin.GetVolume(getReq); err != nil {
				canRemove = false
				removalErr = errors.Wrapf(err, "volume %s could not be retrieved from plugin %s, but it has been removed from Podman", v.Name(), v.Driver())
			}
		}
		if canRemove {
			req := new(pluginapi.RemoveRequest)
			req.Name = v.Name()
			if err := v.plugin.RemoveVolume(req); err != nil {
				return errors.Wrapf(err, "volume %s could not be removed from plugin %s", v.Name(), v.Driver())
			}
		}
	}

	// Remove the volume from the state
	if err := r.state.RemoveVolume(v); err != nil {
		if removalErr != nil {
			logrus.Errorf("Error removing volume %s from plugin %s: %v", v.Name(), v.Driver(), removalErr)
		}
		return errors.Wrapf(err, "error removing volume %s", v.Name())
	}

	// Free the volume's lock
	if err := v.lock.Free(); err != nil {
		if removalErr == nil {
			removalErr = errors.Wrapf(err, "error freeing lock for volume %s", v.Name())
		} else {
			logrus.Errorf("Error freeing lock for volume %q: %v", v.Name(), err)
		}
	}

	// Delete the mountpoint path of the volume, that is delete the volume
	// from /var/lib/containers/storage/volumes
	if err := v.teardownStorage(); err != nil {
		if removalErr == nil {
			removalErr = errors.Wrapf(err, "error cleaning up volume storage for %q", v.Name())
		} else {
			logrus.Errorf("Error cleaning up volume storage for volume %q: %v", v.Name(), err)
		}
	}

	defer v.newVolumeEvent(events.Remove)
	logrus.Debugf("Removed volume %s", v.Name())
	return removalErr
}