diff --git a/secdiscard.cpp b/secdiscard.cpp index 4659eed..b91f321 100644 --- a/secdiscard.cpp +++ b/secdiscard.cpp @@ -50,6 +50,27 @@ bool overwrite_with_zeros(int fd, off64_t start, off64_t length); } // namespace +#ifndef F2FS_IOCTL_MAGIC +#define F2FS_IOCTL_MAGIC 0xf5 +#endif + +// F2FS-specific ioctl +// It requires the below kernel commit merged in v5.9-rc1. +// 9af846486d78 ("f2fs: add F2FS_IOC_SEC_TRIM_FILE ioctl") +// In android12-5.4, +// 7fc27297c44d ("Merge remote-tracking branch 'aosp/upstream-f2fs-stable-linux-5.4.y' +// into android12-5.4") +#ifndef F2FS_IOC_SEC_TRIM_FILE +struct f2fs_sectrim_range { + __u64 start; + __u64 len; + __u64 flags; +}; +#define F2FS_IOC_SEC_TRIM_FILE _IOW(F2FS_IOCTL_MAGIC, 20, struct f2fs_sectrim_range) +#define F2FS_TRIM_FILE_DISCARD 0x1 +#define F2FS_TRIM_FILE_ZEROOUT 0x2 +#endif + int main(int argc, const char* const argv[]) { android::base::InitLogging(const_cast(argv)); Options options; @@ -69,9 +90,6 @@ int main(int argc, const char* const argv[]) { // In android-4.14, // ce767d9a55bc ("f2fs: updates on v4.16-rc1") #ifndef F2FS_IOC_SET_PIN_FILE -#ifndef F2FS_IOCTL_MAGIC -#define F2FS_IOCTL_MAGIC 0xf5 -#endif #define F2FS_IOC_SET_PIN_FILE _IOW(F2FS_IOCTL_MAGIC, 13, __u32) #define F2FS_IOC_GET_PIN_FILE _IOR(F2FS_IOCTL_MAGIC, 14, __u32) #endif @@ -85,8 +103,31 @@ int main(int argc, const char* const argv[]) { ioctl(fd, F2FS_IOC_SET_PIN_FILE, &set); LOG(DEBUG) << "Securely discarding '" << target << "' unlink=" << options.unlink; - if (!secdiscard_path(target)) { - LOG(ERROR) << "Secure discard failed for: " << target; + struct f2fs_sectrim_range secRange; + secRange.start = 0; + secRange.len = -1; // until end of file + secRange.flags = F2FS_TRIM_FILE_DISCARD | F2FS_TRIM_FILE_ZEROOUT; + /* + * F2FS_IOC_SEC_TRIM_FILE is only supported by F2FS. + * 1. If device supports secure discard, it sends secure discard command on the file. + * 2. Otherwise, it sends discard command on the file. + * 3. Lastly, it overwrites zero data on it. + */ + int ret = ioctl(fd, F2FS_IOC_SEC_TRIM_FILE, &secRange); + if (ret != 0) { + if (errno == EOPNOTSUPP) { + // If device doesn't support any type of discard, just overwrite zero data. + secRange.flags = F2FS_TRIM_FILE_ZEROOUT; + ret = ioctl(fd, F2FS_IOC_SEC_TRIM_FILE, &secRange); + } + if (ret != 0 && errno != ENOTTY) { + PLOG(WARNING) << "F2FS_IOC_SEC_TRIM_FILE failed on " << target; + } + } + if (ret != 0) { + if (!secdiscard_path(target)) { + LOG(ERROR) << "Secure discard failed for: " << target; + } } if (options.unlink) { if (unlink(target.c_str()) != 0 && errno != ENOENT) {