int VolumeManager::unshareVolume(const char *label, const char *method) {
Volume *v = lookupVolume(label);
if (!v) {
errno = ENOENT;
return -1;
}
if (strcmp(method, "ums")) {
errno = ENOSYS;
return -1;
}
if (v->getState() != Volume::State_Shared) {
errno = EINVAL;
return -1;
}
int fd;
int lun_number;
// /mnt/sdcard to lun0 and anything else to lun1. Fix this.
if (v->isPrimaryStorage()) {
lun_number = 0;
} else {
lun_number = SECOND_LUN_NUM;
}
if ((fd = openLun(lun_number)) < 0) {
return -1;
}
char ch = 0;
if (write(fd, &ch, 1) < 0) {
SLOGE("Unable to write to ums lunfile (%s)", strerror(errno));
close(fd);
return -1;
}
close(fd);
v->handleVolumeUnshared();
if (--mUmsSharingCount == 0 && mSavedDirtyRatio != -1) {
FILE* fp;
if ((fp = fopen("/proc/sys/vm/dirty_ratio", "r+"))) {
fprintf(fp, "%d\n", mSavedDirtyRatio);
fclose(fp);
} else {
SLOGE("Failed to open /proc/sys/vm/dirty_ratio (%s)", strerror(errno));
}
mSavedDirtyRatio = -1;
}
return 0;
}
int VolumeManager::shareVolume(const char *label, const char *method) {
Volume *v = lookupVolume(label);
if (!v) {
errno = ENOENT;
return -1;
}
/*
* Eventually, we'll want to support additional share back-ends,
* some of which may work while the media is mounted. For now,
* we just support UMS
*/
if (strcmp(method, "ums")) {
errno = ENOSYS;
return -1;
}
if (v->getState() == Volume::State_NoMedia) {
errno = ENODEV;
return -1;
}
if (v->getState() != Volume::State_Idle) {
// You need to unmount manually befoe sharing
errno = EBUSY;
return -1;
}
if (mVolManagerDisabled) {
errno = EBUSY;
return -1;
}
dev_t d = v->getShareDevice();
if ((MAJOR(d) == 0) && (MINOR(d) == 0)) {
// This volume does not support raw disk access
errno = EINVAL;
return -1;
}
#ifdef VOLD_EMMC_SHARES_DEV_MAJOR
// If emmc and sdcard share dev major number, vold may pick
// incorrectly based on partition nodes alone. Use device nodes instead.
v->getDeviceNodes((dev_t *) &d, 1);
if ((MAJOR(d) == 0) && (MINOR(d) == 0)) {
// This volume does not support raw disk access
errno = EINVAL;
return -1;
}
#endif
int fd;
char nodepath[255];
int written = snprintf(nodepath,
sizeof(nodepath), "/dev/block/vold/%d:%d",
MAJOR(d), MINOR(d));
if ((written < 0) || (size_t(written) >= sizeof(nodepath))) {
SLOGE("shareVolume failed: couldn't construct nodepath");
return -1;
}
if ((fd = openLun(v->getLunNumber())) < 0) {
return -1;
}
if (write(fd, nodepath, strlen(nodepath)) < 0) {
SLOGE("Unable to write to ums lunfile (%s)", strerror(errno));
close(fd);
return -1;
}
close(fd);
v->handleVolumeShared();
if (mUmsSharingCount++ == 0) {
FILE* fp;
mSavedDirtyRatio = -1; // in case we fail
if ((fp = fopen("/proc/sys/vm/dirty_ratio", "r+"))) {
char line[16];
if (fgets(line, sizeof(line), fp) && sscanf(line, "%d", &mSavedDirtyRatio)) {
fprintf(fp, "%d\n", mUmsDirtyRatio);
} else {
SLOGE("Failed to read dirty_ratio (%s)", strerror(errno));
}
fclose(fp);
} else {
SLOGE("Failed to open /proc/sys/vm/dirty_ratio (%s)", strerror(errno));
}
}
return 0;
}
