tenfourfox/dom/system/gonk/Volume.cpp

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2017-04-19 07:56:45 +00:00
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this file,
* You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "Volume.h"
#include "VolumeCommand.h"
#include "VolumeManager.h"
#include "VolumeManagerLog.h"
#include "nsIVolume.h"
#include "nsXULAppAPI.h"
#include <vold/ResponseCode.h>
namespace mozilla {
namespace system {
#if DEBUG_VOLUME_OBSERVER
void
VolumeObserverList::Broadcast(Volume* const& aVolume)
{
uint32_t size = mObservers.Length();
for (uint32_t i = 0; i < size; ++i) {
LOG("VolumeObserverList::Broadcast to [%u] %p volume '%s'",
i, mObservers[i], aVolume->NameStr());
mObservers[i]->Notify(aVolume);
}
}
#endif
VolumeObserverList Volume::sEventObserverList;
// We have a feature where volumes can be locked when mounted. This
// is used to prevent a volume from being shared with the PC while
// it is actively being used (say for storing an update image)
//
// We use WakeLocks (a poor choice of name, but it does what we want)
// from the PowerManagerService to determine when we're locked.
// In particular we'll create a wakelock called volume-NAME-GENERATION
// (where NAME is the volume name, and GENERATION is its generation
// number), and if this wakelock is locked, then we'll prevent a volume
// from being shared.
//
// Implementation Details:
//
// Since the AutoMounter can only control when something gets mounted
// and not when it gets unmounted (for example: a user pulls the SDCard)
// and because Volume and nsVolume data structures are maintained on
// separate threads, we have the potential for some race conditions.
// We eliminate the race conditions by introducing the concept of a
// generation number. Every time a volume transitions to the Mounted
// state, it gets assigned a new generation number. Whenever the state
// of a Volume changes, we send the updated state and current generation
// number to the main thread where it gets updated in the nsVolume.
//
// Since WakeLocks can only be queried from the main-thread, the
// nsVolumeService looks for WakeLock status changes, and forwards
// the results to the IOThread.
//
// If the Volume (IOThread) recieves a volume update where the generation
// number mismatches, then the update is simply ignored.
//
// When a Volume (IOThread) initially becomes mounted, we assume it to
// be locked until we get our first update from nsVolume (MainThread).
static int32_t sMountGeneration = 0;
static uint32_t sNextId = 1;
// We don't get media inserted/removed events at startup. So we
// assume it's present, and we'll be told that it's missing.
Volume::Volume(const nsCSubstring& aName)
: mMediaPresent(true),
mState(nsIVolume::STATE_INIT),
mName(aName),
mMountGeneration(-1),
mMountLocked(true), // Needs to agree with nsVolume::nsVolume
mSharingEnabled(false),
mFormatRequested(false),
mMountRequested(false),
mUnmountRequested(false),
mCanBeShared(true),
mIsSharing(false),
mIsFormatting(false),
mIsUnmounting(false),
mIsRemovable(false),
mIsHotSwappable(false),
mId(sNextId++)
{
DBG("Volume %s: created", NameStr());
}
void
Volume::Dump(const char* aLabel) const
{
LOG("%s: Volume: %s (%d) is %s and %s @ %s gen %d locked %d",
aLabel,
NameStr(),
Id(),
StateStr(),
MediaPresent() ? "inserted" : "missing",
MountPoint().get(),
MountGeneration(),
(int)IsMountLocked());
LOG("%s: Sharing %s Mounting %s Formating %s Unmounting %s",
aLabel,
CanBeShared() ? (IsSharingEnabled() ? (IsSharing() ? "en-y" : "en-n")
: "dis")
: "x",
IsMountRequested() ? "req" : "n",
IsFormatRequested() ? (IsFormatting() ? "req-y" : "req-n")
: (IsFormatting() ? "y" : "n"),
IsUnmountRequested() ? (IsUnmounting() ? "req-y" : "req-n")
: (IsUnmounting() ? "y" : "n"));
}
void
Volume::ResolveAndSetMountPoint(const nsCSubstring& aMountPoint)
{
nsCString mountPoint(aMountPoint);
char realPathBuf[PATH_MAX];
// Call realpath so that we wind up with a path which is compatible with
// functions like nsVolumeService::GetVolumeByPath.
if (realpath(mountPoint.get(), realPathBuf) < 0) {
// The path we were handed doesn't exist. Warn about it, but use it
// anyways assuming that the user knows what they're doing.
ERR("ResolveAndSetMountPoint: realpath on '%s' failed: %d",
mountPoint.get(), errno);
mMountPoint = mountPoint;
} else {
mMountPoint = realPathBuf;
}
DBG("Volume %s: Setting mountpoint to '%s'", NameStr(), mMountPoint.get());
}
void Volume::SetFakeVolume(const nsACString& aMountPoint)
{
this->mMountLocked = false;
this->mCanBeShared = false;
ResolveAndSetMountPoint(aMountPoint);
SetState(nsIVolume::STATE_MOUNTED);
}
void
Volume::SetIsSharing(bool aIsSharing)
{
if (aIsSharing == mIsSharing) {
return;
}
mIsSharing = aIsSharing;
LOG("Volume %s: IsSharing set to %d state %s",
NameStr(), (int)mIsSharing, StateStr(mState));
sEventObserverList.Broadcast(this);
}
void
Volume::SetIsFormatting(bool aIsFormatting)
{
if (aIsFormatting == mIsFormatting) {
return;
}
mIsFormatting = aIsFormatting;
LOG("Volume %s: IsFormatting set to %d state %s",
NameStr(), (int)mIsFormatting, StateStr(mState));
if (mIsFormatting) {
sEventObserverList.Broadcast(this);
}
}
void
Volume::SetIsUnmounting(bool aIsUnmounting)
{
if (aIsUnmounting == mIsUnmounting) {
return;
}
mIsUnmounting = aIsUnmounting;
LOG("Volume %s: IsUnmounting set to %d state %s",
NameStr(), (int)mIsUnmounting, StateStr(mState));
sEventObserverList.Broadcast(this);
}
void
Volume::SetIsRemovable(bool aIsRemovable)
{
if (aIsRemovable == mIsRemovable) {
return;
}
mIsRemovable = aIsRemovable;
if (!mIsRemovable) {
mIsHotSwappable = false;
}
LOG("Volume %s: IsRemovable set to %d state %s",
NameStr(), (int)mIsRemovable, StateStr(mState));
sEventObserverList.Broadcast(this);
}
void
Volume::SetIsHotSwappable(bool aIsHotSwappable)
{
if (aIsHotSwappable == mIsHotSwappable) {
return;
}
mIsHotSwappable = aIsHotSwappable;
if (mIsHotSwappable) {
mIsRemovable = true;
}
LOG("Volume %s: IsHotSwappable set to %d state %s",
NameStr(), (int)mIsHotSwappable, StateStr(mState));
sEventObserverList.Broadcast(this);
}
bool
Volume::BoolConfigValue(const nsCString& aConfigValue, bool& aBoolValue)
{
if (aConfigValue.EqualsLiteral("1") ||
aConfigValue.LowerCaseEqualsLiteral("true")) {
aBoolValue = true;
return true;
}
if (aConfigValue.EqualsLiteral("0") ||
aConfigValue.LowerCaseEqualsLiteral("false")) {
aBoolValue = false;
return true;
}
return false;
}
void
Volume::SetConfig(const nsCString& aConfigName, const nsCString& aConfigValue)
{
if (aConfigName.LowerCaseEqualsLiteral("removable")) {
bool value = false;
if (BoolConfigValue(aConfigValue, value)) {
SetIsRemovable(value);
} else {
ERR("Volume %s: invalid value '%s' for configuration '%s'",
NameStr(), aConfigValue.get(), aConfigName.get());
}
return;
}
if (aConfigName.LowerCaseEqualsLiteral("hotswappable")) {
bool value = false;
if (BoolConfigValue(aConfigValue, value)) {
SetIsHotSwappable(value);
} else {
ERR("Volume %s: invalid value '%s' for configuration '%s'",
NameStr(), aConfigValue.get(), aConfigName.get());
}
return;
}
ERR("Volume %s: invalid config '%s'", NameStr(), aConfigName.get());
}
void
Volume::SetMediaPresent(bool aMediaPresent)
{
MOZ_ASSERT(XRE_IsParentProcess());
MOZ_ASSERT(MessageLoop::current() == XRE_GetIOMessageLoop());
// mMediaPresent is slightly redunant to the state, however
// when media is removed (while Idle), we get the following:
// 631 Volume sdcard /mnt/sdcard disk removed (179:0)
// 605 Volume sdcard /mnt/sdcard state changed from 1 (Idle-Unmounted) to 0 (No-Media)
//
// And on media insertion, we get:
// 630 Volume sdcard /mnt/sdcard disk inserted (179:0)
// 605 Volume sdcard /mnt/sdcard state changed from 0 (No-Media) to 2 (Pending)
// 605 Volume sdcard /mnt/sdcard state changed from 2 (Pending) to 1 (Idle-Unmounted)
//
// On media removal while the media is mounted:
// 632 Volume sdcard /mnt/sdcard bad removal (179:1)
// 605 Volume sdcard /mnt/sdcard state changed from 4 (Mounted) to 5 (Unmounting)
// 605 Volume sdcard /mnt/sdcard state changed from 5 (Unmounting) to 1 (Idle-Unmounted)
// 631 Volume sdcard /mnt/sdcard disk removed (179:0)
// 605 Volume sdcard /mnt/sdcard state changed from 1 (Idle-Unmounted) to 0 (No-Media)
//
// When sharing with a PC, it goes Mounted -> Idle -> Shared
// When unsharing with a PC, it goes Shared -> Idle -> Mounted
//
// The AutoMounter needs to know whether the media is present or not when
// processing the Idle state.
if (mMediaPresent == aMediaPresent) {
return;
}
LOG("Volume: %s media %s", NameStr(), aMediaPresent ? "inserted" : "removed");
mMediaPresent = aMediaPresent;
sEventObserverList.Broadcast(this);
}
void
Volume::SetSharingEnabled(bool aSharingEnabled)
{
mSharingEnabled = aSharingEnabled;
LOG("SetSharingMode for volume %s to %d canBeShared = %d",
NameStr(), (int)mSharingEnabled, (int)mCanBeShared);
sEventObserverList.Broadcast(this);
}
void
Volume::SetFormatRequested(bool aFormatRequested)
{
mFormatRequested = aFormatRequested;
LOG("SetFormatRequested for volume %s to %d CanBeFormatted = %d",
NameStr(), (int)mFormatRequested, (int)CanBeFormatted());
}
void
Volume::SetMountRequested(bool aMountRequested)
{
mMountRequested = aMountRequested;
LOG("SetMountRequested for volume %s to %d CanBeMounted = %d",
NameStr(), (int)mMountRequested, (int)CanBeMounted());
}
void
Volume::SetUnmountRequested(bool aUnmountRequested)
{
mUnmountRequested = aUnmountRequested;
LOG("SetUnmountRequested for volume %s to %d CanBeMounted = %d",
NameStr(), (int)mUnmountRequested, (int)CanBeMounted());
}
void
Volume::SetState(Volume::STATE aNewState)
{
MOZ_ASSERT(XRE_IsParentProcess());
MOZ_ASSERT(MessageLoop::current() == XRE_GetIOMessageLoop());
if (aNewState == mState) {
return;
}
if (aNewState == nsIVolume::STATE_MOUNTED) {
mMountGeneration = ++sMountGeneration;
LOG("Volume %s (%u): changing state from %s to %s @ '%s' (%d observers) "
"mountGeneration = %d, locked = %d",
NameStr(), mId, StateStr(mState),
StateStr(aNewState), mMountPoint.get(), sEventObserverList.Length(),
mMountGeneration, (int)mMountLocked);
} else {
LOG("Volume %s (%u): changing state from %s to %s (%d observers)",
NameStr(), mId, StateStr(mState),
StateStr(aNewState), sEventObserverList.Length());
}
switch (aNewState) {
case nsIVolume::STATE_NOMEDIA:
// Cover the startup case where we don't get insertion/removal events
mMediaPresent = false;
mIsSharing = false;
mUnmountRequested = false;
mMountRequested = false;
mIsUnmounting = false;
break;
case nsIVolume::STATE_MOUNTED:
case nsIVolume::STATE_MOUNT_FAIL:
mMountRequested = false;
mIsFormatting = false;
mIsSharing = false;
mIsUnmounting = false;
break;
case nsIVolume::STATE_FORMATTING:
mFormatRequested = false;
mIsFormatting = true;
mIsSharing = false;
mIsUnmounting = false;
break;
case nsIVolume::STATE_SHARED:
case nsIVolume::STATE_SHAREDMNT:
// Covers startup cases. Normally, mIsSharing would be set to true
// when we issue the command to initiate the sharing process, but
// it's conceivable that a volume could already be in a shared state
// when b2g starts.
mIsSharing = true;
mIsUnmounting = false;
mIsFormatting = false;
break;
case nsIVolume::STATE_UNMOUNTING:
mIsUnmounting = true;
mIsFormatting = false;
mIsSharing = false;
break;
case nsIVolume::STATE_IDLE: // Fall through
case nsIVolume::STATE_CHECKMNT: // Fall through
default:
break;
}
mState = aNewState;
sEventObserverList.Broadcast(this);
}
void
Volume::SetMountPoint(const nsCSubstring& aMountPoint)
{
MOZ_ASSERT(XRE_IsParentProcess());
MOZ_ASSERT(MessageLoop::current() == XRE_GetIOMessageLoop());
if (mMountPoint.Equals(aMountPoint)) {
return;
}
ResolveAndSetMountPoint(aMountPoint);
}
void
Volume::StartMount(VolumeResponseCallback* aCallback)
{
MOZ_ASSERT(XRE_IsParentProcess());
MOZ_ASSERT(MessageLoop::current() == XRE_GetIOMessageLoop());
StartCommand(new VolumeActionCommand(this, "mount", "", aCallback));
}
void
Volume::StartUnmount(VolumeResponseCallback* aCallback)
{
MOZ_ASSERT(XRE_IsParentProcess());
MOZ_ASSERT(MessageLoop::current() == XRE_GetIOMessageLoop());
StartCommand(new VolumeActionCommand(this, "unmount", "force", aCallback));
}
void
Volume::StartFormat(VolumeResponseCallback* aCallback)
{
MOZ_ASSERT(XRE_IsParentProcess());
MOZ_ASSERT(MessageLoop::current() == XRE_GetIOMessageLoop());
StartCommand(new VolumeActionCommand(this, "format", "", aCallback));
}
void
Volume::StartShare(VolumeResponseCallback* aCallback)
{
MOZ_ASSERT(XRE_IsParentProcess());
MOZ_ASSERT(MessageLoop::current() == XRE_GetIOMessageLoop());
StartCommand(new VolumeActionCommand(this, "share", "ums", aCallback));
}
void
Volume::StartUnshare(VolumeResponseCallback* aCallback)
{
MOZ_ASSERT(XRE_IsParentProcess());
MOZ_ASSERT(MessageLoop::current() == XRE_GetIOMessageLoop());
StartCommand(new VolumeActionCommand(this, "unshare", "ums", aCallback));
}
void
Volume::StartCommand(VolumeCommand* aCommand)
{
MOZ_ASSERT(XRE_IsParentProcess());
MOZ_ASSERT(MessageLoop::current() == XRE_GetIOMessageLoop());
VolumeManager::PostCommand(aCommand);
}
//static
void
Volume::RegisterVolumeObserver(Volume::EventObserver* aObserver, const char* aName)
{
MOZ_ASSERT(XRE_IsParentProcess());
MOZ_ASSERT(MessageLoop::current() == XRE_GetIOMessageLoop());
sEventObserverList.AddObserver(aObserver);
DBG("Added Volume Observer '%s' @%p, length = %u",
aName, aObserver, sEventObserverList.Length());
// Send an initial event to the observer (for each volume)
size_t numVolumes = VolumeManager::NumVolumes();
for (size_t volIndex = 0; volIndex < numVolumes; volIndex++) {
RefPtr<Volume> vol = VolumeManager::GetVolume(volIndex);
aObserver->Notify(vol);
}
}
//static
void
Volume::UnregisterVolumeObserver(Volume::EventObserver* aObserver, const char* aName)
{
MOZ_ASSERT(XRE_IsParentProcess());
MOZ_ASSERT(MessageLoop::current() == XRE_GetIOMessageLoop());
sEventObserverList.RemoveObserver(aObserver);
DBG("Removed Volume Observer '%s' @%p, length = %u",
aName, aObserver, sEventObserverList.Length());
}
//static
void
Volume::UpdateMountLock(const nsACString& aVolumeName,
const int32_t& aMountGeneration,
const bool& aMountLocked)
{
MOZ_ASSERT(XRE_IsParentProcess());
MOZ_ASSERT(MessageLoop::current() == XRE_GetIOMessageLoop());
RefPtr<Volume> vol = VolumeManager::FindVolumeByName(aVolumeName);
if (!vol || (vol->mMountGeneration != aMountGeneration)) {
return;
}
if (vol->mMountLocked != aMountLocked) {
vol->mMountLocked = aMountLocked;
DBG("Volume::UpdateMountLock for '%s' to %d\n", vol->NameStr(), (int)aMountLocked);
sEventObserverList.Broadcast(vol);
}
}
void
Volume::HandleVoldResponse(int aResponseCode, nsCWhitespaceTokenizer& aTokenizer)
{
MOZ_ASSERT(XRE_IsParentProcess());
MOZ_ASSERT(MessageLoop::current() == XRE_GetIOMessageLoop());
// The volume name will have already been parsed, and the tokenizer will point
// to the token after the volume name
switch (aResponseCode) {
case ::ResponseCode::VolumeListResult: {
// Each line will look something like:
//
// sdcard /mnt/sdcard 1
//
nsDependentCSubstring mntPoint(aTokenizer.nextToken());
SetMountPoint(mntPoint);
nsresult errCode;
nsCString state(aTokenizer.nextToken());
if (state.EqualsLiteral("X")) {
// Special state for creating fake volumes which can't be shared.
mCanBeShared = false;
SetState(nsIVolume::STATE_MOUNTED);
} else {
SetState((STATE)state.ToInteger(&errCode));
}
break;
}
case ::ResponseCode::VolumeStateChange: {
// Format of the line looks something like:
//
// Volume sdcard /mnt/sdcard state changed from 7 (Shared-Unmounted) to 1 (Idle-Unmounted)
//
// So we parse out the state after the string " to "
while (aTokenizer.hasMoreTokens()) {
nsAutoCString token(aTokenizer.nextToken());
if (token.EqualsLiteral("to")) {
nsresult errCode;
token = aTokenizer.nextToken();
STATE newState = (STATE)(token.ToInteger(&errCode));
if (newState == nsIVolume::STATE_MOUNTED) {
// We set the state to STATE_CHECKMNT here, and the once the
// AutoMounter detects that the volume is actually accessible
// then the AutoMounter will set the volume as STATE_MOUNTED.
SetState(nsIVolume::STATE_CHECKMNT);
} else {
if (State() == nsIVolume::STATE_CHECKING && newState == nsIVolume::STATE_IDLE) {
LOG("Mount of volume '%s' failed", NameStr());
SetState(nsIVolume::STATE_MOUNT_FAIL);
} else {
SetState(newState);
}
}
break;
}
}
break;
}
case ::ResponseCode::VolumeDiskInserted:
SetMediaPresent(true);
break;
case ::ResponseCode::VolumeDiskRemoved: // fall-thru
case ::ResponseCode::VolumeBadRemoval:
SetMediaPresent(false);
break;
default:
LOG("Volume: %s unrecognized reponse code (ignored)", NameStr());
break;
}
}
} // namespace system
} // namespace mozilla