secdiscard: should pin_file to avoid moving blocks in F2FS
This file should avoid F2FS GC, since it directly access block device based
on fibmap.
Bug: 111659036
Change-Id: I15aef8175c23ba4029eb580e2dba59c77cca8227
Signed-off-by: Jaegeuk Kim <jaegeuk@google.com>
diff --git a/secdiscard.cpp b/secdiscard.cpp
index f9532ea..60834e8 100644
--- a/secdiscard.cpp
+++ b/secdiscard.cpp
@@ -57,7 +57,33 @@
usage(argv[0]);
return -1;
}
+
for (auto const &target: options.targets) {
+// F2FS-specific ioctl
+// It requires the below kernel commit merged in v4.16-rc1.
+// 1ad71a27124c ("f2fs: add an ioctl to disable GC for specific file")
+// In android-4.4,
+// 56ee1e817908 ("f2fs: updates on v4.16-rc1")
+// In android-4.9,
+// 2f17e34672a8 ("f2fs: updates on v4.16-rc1")
+// 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 _IOW(F2FS_IOCTL_MAGIC, 14, __u32)
+#endif
+ android::base::unique_fd fd(TEMP_FAILURE_RETRY(open(
+ target.c_str(), O_WRONLY, 0)));
+ if (fd == -1) {
+ LOG(ERROR) << "Secure discard open failed for: " << target;
+ return 0;
+ }
+ __u32 set = 1;
+ 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;
@@ -67,6 +93,8 @@
PLOG(ERROR) << "Unable to unlink: " << target;
}
}
+ set = 0;
+ ioctl(fd, F2FS_IOC_SET_PIN_FILE, &set);
LOG(DEBUG) << "Discarded: " << target;
}
return 0;