Merge "dmuserd: Simple dm-user daemon"
diff --git a/fs_mgr/tools/Android.bp b/fs_mgr/tools/Android.bp
index 4d4aae4..d6ccc4b 100644
--- a/fs_mgr/tools/Android.bp
+++ b/fs_mgr/tools/Android.bp
@@ -29,3 +29,15 @@
cflags: ["-Werror"],
}
+
+cc_binary {
+ name: "dmuserd",
+ srcs: ["dmuserd.cpp"],
+
+ shared_libs: [
+ "libbase",
+ "liblog",
+ ],
+
+ cflags: ["-Werror"],
+}
diff --git a/fs_mgr/tools/dmuserd.cpp b/fs_mgr/tools/dmuserd.cpp
new file mode 100644
index 0000000..92f5878
--- /dev/null
+++ b/fs_mgr/tools/dmuserd.cpp
@@ -0,0 +1,319 @@
+// SPDX-License-Identifier: Apache-2.0
+
+#define _LARGEFILE64_SOURCE
+
+#include <errno.h>
+#include <fcntl.h>
+#include <getopt.h>
+#include <poll.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <sys/prctl.h>
+#include <unistd.h>
+#include <iostream>
+
+#define SECTOR_SIZE ((__u64)512)
+#define BUFFER_BYTES 4096
+
+#define MAX(a, b) ((a) > (b) ? (a) : (b))
+
+/* This should be replaced with linux/dm-user.h. */
+#ifndef _LINUX_DM_USER_H
+#define _LINUX_DM_USER_H
+
+#include <linux/types.h>
+
+#define DM_USER_REQ_MAP_READ 0
+#define DM_USER_REQ_MAP_WRITE 1
+#define DM_USER_REQ_MAP_FLUSH 2
+#define DM_USER_REQ_MAP_DISCARD 3
+#define DM_USER_REQ_MAP_SECURE_ERASE 4
+#define DM_USER_REQ_MAP_WRITE_SAME 5
+#define DM_USER_REQ_MAP_WRITE_ZEROES 6
+#define DM_USER_REQ_MAP_ZONE_OPEN 7
+#define DM_USER_REQ_MAP_ZONE_CLOSE 8
+#define DM_USER_REQ_MAP_ZONE_FINISH 9
+#define DM_USER_REQ_MAP_ZONE_APPEND 10
+#define DM_USER_REQ_MAP_ZONE_RESET 11
+#define DM_USER_REQ_MAP_ZONE_RESET_ALL 12
+
+#define DM_USER_REQ_MAP_FLAG_FAILFAST_DEV 0x00001
+#define DM_USER_REQ_MAP_FLAG_FAILFAST_TRANSPORT 0x00002
+#define DM_USER_REQ_MAP_FLAG_FAILFAST_DRIVER 0x00004
+#define DM_USER_REQ_MAP_FLAG_SYNC 0x00008
+#define DM_USER_REQ_MAP_FLAG_META 0x00010
+#define DM_USER_REQ_MAP_FLAG_PRIO 0x00020
+#define DM_USER_REQ_MAP_FLAG_NOMERGE 0x00040
+#define DM_USER_REQ_MAP_FLAG_IDLE 0x00080
+#define DM_USER_REQ_MAP_FLAG_INTEGRITY 0x00100
+#define DM_USER_REQ_MAP_FLAG_FUA 0x00200
+#define DM_USER_REQ_MAP_FLAG_PREFLUSH 0x00400
+#define DM_USER_REQ_MAP_FLAG_RAHEAD 0x00800
+#define DM_USER_REQ_MAP_FLAG_BACKGROUND 0x01000
+#define DM_USER_REQ_MAP_FLAG_NOWAIT 0x02000
+#define DM_USER_REQ_MAP_FLAG_CGROUP_PUNT 0x04000
+#define DM_USER_REQ_MAP_FLAG_NOUNMAP 0x08000
+#define DM_USER_REQ_MAP_FLAG_HIPRI 0x10000
+#define DM_USER_REQ_MAP_FLAG_DRV 0x20000
+#define DM_USER_REQ_MAP_FLAG_SWAP 0x40000
+
+#define DM_USER_RESP_SUCCESS 0
+#define DM_USER_RESP_ERROR 1
+#define DM_USER_RESP_UNSUPPORTED 2
+
+struct dm_user_message {
+ __u64 seq;
+ __u64 type;
+ __u64 flags;
+ __u64 sector;
+ __u64 len;
+ __u8 buf[];
+};
+
+#endif
+
+static bool verbose = false;
+
+size_t write_all(int fd, void* buf, size_t len) {
+ char* buf_c = (char*)buf;
+ ssize_t total = 0;
+ ssize_t once;
+
+ while (total < len) {
+ once = write(fd, buf_c + total, len - total);
+ if (once < 0) return once;
+ if (once == 0) {
+ errno = ENOSPC;
+ return 0;
+ }
+ total += once;
+ }
+
+ return total;
+}
+
+size_t read_all(int fd, void* buf, size_t len) {
+ char* buf_c = (char*)buf;
+ ssize_t total = 0;
+ ssize_t once;
+
+ while (total < len) {
+ once = read(fd, buf_c + total, len - total);
+ if (once < 0) return once;
+ if (once == 0) {
+ errno = ENOSPC;
+ return 0;
+ }
+ total += once;
+ }
+
+ return total;
+}
+
+int not_splice(int from, int to, __u64 count) {
+ while (count > 0) {
+ char buf[BUFFER_BYTES];
+ __u64 max = count > BUFFER_BYTES ? BUFFER_BYTES : count;
+
+ if (read_all(from, buf, max) <= 0) {
+ perror("Unable to read");
+ return -EIO;
+ }
+
+ if (write_all(to, buf, max) <= 0) {
+ perror("Unable to write");
+ return -EIO;
+ }
+
+ count -= max;
+ }
+
+ return 0;
+}
+
+int simple_daemon(char* control_path, char* backing_path) {
+ int control_fd = open(control_path, O_RDWR);
+ if (control_fd < 0) {
+ fprintf(stderr, "Unable to open control device %s\n", control_path);
+ return -1;
+ }
+
+ int backing_fd = open(backing_path, O_RDWR);
+ if (backing_fd < 0) {
+ fprintf(stderr, "Unable to open backing device %s\n", backing_path);
+ return -1;
+ }
+
+ while (1) {
+ struct dm_user_message msg;
+ char* base;
+ __u64 type;
+
+ if (verbose) std::cerr << "dmuserd: Waiting for message...\n";
+
+ if (read_all(control_fd, &msg, sizeof(msg)) < 0) {
+ if (errno == ENOTBLK) return 0;
+
+ perror("unable to read msg");
+ return -1;
+ }
+
+ if (verbose) {
+ std::string type;
+ switch (msg.type) {
+ case DM_USER_REQ_MAP_WRITE:
+ type = "write";
+ break;
+ case DM_USER_REQ_MAP_READ:
+ type = "read";
+ break;
+ case DM_USER_REQ_MAP_FLUSH:
+ type = "flush";
+ break;
+ default:
+ /*
+ * FIXME: Can't I do "whatever"s here rather that
+ * std::string("whatever")?
+ */
+ type = std::string("(unknown, id=") + std::to_string(msg.type) + ")";
+ break;
+ }
+
+ std::string flags;
+ if (msg.flags & DM_USER_REQ_MAP_FLAG_SYNC) {
+ if (!flags.empty()) flags += "|";
+ flags += "S";
+ }
+ if (msg.flags & DM_USER_REQ_MAP_FLAG_META) {
+ if (!flags.empty()) flags += "|";
+ flags += "M";
+ }
+ if (msg.flags & DM_USER_REQ_MAP_FLAG_FUA) {
+ if (!flags.empty()) flags += "|";
+ flags += "FUA";
+ }
+ if (msg.flags & DM_USER_REQ_MAP_FLAG_PREFLUSH) {
+ if (!flags.empty()) flags += "|";
+ flags += "F";
+ }
+
+ std::cerr << "dmuserd: Got " << type << " request " << flags << " for sector "
+ << std::to_string(msg.sector) << " with length " << std::to_string(msg.len)
+ << "\n";
+ }
+
+ type = msg.type;
+ switch (type) {
+ case DM_USER_REQ_MAP_READ:
+ msg.type = DM_USER_RESP_SUCCESS;
+ break;
+ case DM_USER_REQ_MAP_WRITE:
+ if (msg.flags & DM_USER_REQ_MAP_FLAG_PREFLUSH ||
+ msg.flags & DM_USER_REQ_MAP_FLAG_FUA) {
+ if (fsync(backing_fd) < 0) {
+ perror("Unable to fsync(), just sync()ing instead");
+ sync();
+ }
+ }
+ msg.type = DM_USER_RESP_SUCCESS;
+ if (lseek64(backing_fd, msg.sector * SECTOR_SIZE, SEEK_SET) < 0) {
+ perror("Unable to seek");
+ return -1;
+ }
+ if (not_splice(control_fd, backing_fd, msg.len) < 0) {
+ if (errno == ENOTBLK) return 0;
+ std::cerr << "unable to handle write data\n";
+ return -1;
+ }
+ if (msg.flags & DM_USER_REQ_MAP_FLAG_FUA) {
+ if (fsync(backing_fd) < 0) {
+ perror("Unable to fsync(), just sync()ing instead");
+ sync();
+ }
+ }
+ break;
+ case DM_USER_REQ_MAP_FLUSH:
+ msg.type = DM_USER_RESP_SUCCESS;
+ if (fsync(backing_fd) < 0) {
+ perror("Unable to fsync(), just sync()ing instead");
+ sync();
+ }
+ break;
+ default:
+ std::cerr << "dmuserd: unsupported op " << std::to_string(msg.type) << "\n";
+ msg.type = DM_USER_RESP_UNSUPPORTED;
+ break;
+ }
+
+ if (verbose) std::cerr << "dmuserd: Responding to message\n";
+
+ if (write_all(control_fd, &msg, sizeof(msg)) < 0) {
+ if (errno == ENOTBLK) return 0;
+ perror("unable to write msg");
+ return -1;
+ }
+
+ switch (type) {
+ case DM_USER_REQ_MAP_READ:
+ if (verbose) std::cerr << "dmuserd: Sending read data\n";
+ if (lseek64(backing_fd, msg.sector * SECTOR_SIZE, SEEK_SET) < 0) {
+ perror("Unable to seek");
+ return -1;
+ }
+ if (not_splice(backing_fd, control_fd, msg.len) < 0) {
+ if (errno == ENOTBLK) return 0;
+ std::cerr << "unable to handle read data\n";
+ return -1;
+ }
+ break;
+ }
+ }
+
+ /* The daemon doesn't actully terminate for this test. */
+ perror("Unable to read from control device");
+ return -1;
+}
+
+void usage(char* prog) {
+ printf("Usage: %s\n", prog);
+ printf(" Handles block requests in userspace, backed by memory\n");
+ printf(" -h Display this help message\n");
+ printf(" -c <control dev> Control device to use for the test\n");
+ printf(" -b <store path> The file to use as a backing store, otherwise memory\n");
+ printf(" -v Enable verbose mode\n");
+}
+
+int main(int argc, char* argv[]) {
+ char* control_path = NULL;
+ char* backing_path = NULL;
+ char* store;
+ int c;
+
+ prctl(PR_SET_IO_FLUSHER, 0, 0, 0, 0);
+
+ while ((c = getopt(argc, argv, "h:c:s:b:v")) != -1) {
+ switch (c) {
+ case 'h':
+ usage(basename(argv[0]));
+ exit(0);
+ case 'c':
+ control_path = strdup(optarg);
+ break;
+ case 'b':
+ backing_path = strdup(optarg);
+ break;
+ case 'v':
+ verbose = true;
+ break;
+ default:
+ usage(basename(argv[0]));
+ exit(1);
+ }
+ }
+
+ int r = simple_daemon(control_path, backing_path);
+ if (r) fprintf(stderr, "simple_daemon() errored out\n");
+ return r;
+}