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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /tools/hv/hv_fcopy_daemon.c | |
parent | Initial commit. (diff) | |
download | linux-430c2fc249ea5c0536abd21c23382884005c9093.tar.xz linux-430c2fc249ea5c0536abd21c23382884005c9093.zip |
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'tools/hv/hv_fcopy_daemon.c')
-rw-r--r-- | tools/hv/hv_fcopy_daemon.c | 266 |
1 files changed, 266 insertions, 0 deletions
diff --git a/tools/hv/hv_fcopy_daemon.c b/tools/hv/hv_fcopy_daemon.c new file mode 100644 index 000000000..16d629b22 --- /dev/null +++ b/tools/hv/hv_fcopy_daemon.c @@ -0,0 +1,266 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * An implementation of host to guest copy functionality for Linux. + * + * Copyright (C) 2014, Microsoft, Inc. + * + * Author : K. Y. Srinivasan <kys@microsoft.com> + */ + + +#include <sys/types.h> +#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> +#include <string.h> +#include <errno.h> +#include <linux/hyperv.h> +#include <linux/limits.h> +#include <syslog.h> +#include <sys/stat.h> +#include <fcntl.h> +#include <getopt.h> + +static int target_fd; +static char target_fname[PATH_MAX]; +static unsigned long long filesize; + +static int hv_start_fcopy(struct hv_start_fcopy *smsg) +{ + int error = HV_E_FAIL; + char *q, *p; + + filesize = 0; + p = (char *)smsg->path_name; + snprintf(target_fname, sizeof(target_fname), "%s/%s", + (char *)smsg->path_name, (char *)smsg->file_name); + + syslog(LOG_INFO, "Target file name: %s", target_fname); + /* + * Check to see if the path is already in place; if not, + * create if required. + */ + while ((q = strchr(p, '/')) != NULL) { + if (q == p) { + p++; + continue; + } + *q = '\0'; + if (access((char *)smsg->path_name, F_OK)) { + if (smsg->copy_flags & CREATE_PATH) { + if (mkdir((char *)smsg->path_name, 0755)) { + syslog(LOG_ERR, "Failed to create %s", + (char *)smsg->path_name); + goto done; + } + } else { + syslog(LOG_ERR, "Invalid path: %s", + (char *)smsg->path_name); + goto done; + } + } + p = q + 1; + *q = '/'; + } + + if (!access(target_fname, F_OK)) { + syslog(LOG_INFO, "File: %s exists", target_fname); + if (!(smsg->copy_flags & OVER_WRITE)) { + error = HV_ERROR_ALREADY_EXISTS; + goto done; + } + } + + target_fd = open(target_fname, + O_RDWR | O_CREAT | O_TRUNC | O_CLOEXEC, 0744); + if (target_fd == -1) { + syslog(LOG_INFO, "Open Failed: %s", strerror(errno)); + goto done; + } + + error = 0; +done: + if (error) + target_fname[0] = '\0'; + return error; +} + +static int hv_copy_data(struct hv_do_fcopy *cpmsg) +{ + ssize_t bytes_written; + int ret = 0; + + bytes_written = pwrite(target_fd, cpmsg->data, cpmsg->size, + cpmsg->offset); + + filesize += cpmsg->size; + if (bytes_written != cpmsg->size) { + switch (errno) { + case ENOSPC: + ret = HV_ERROR_DISK_FULL; + break; + default: + ret = HV_E_FAIL; + break; + } + syslog(LOG_ERR, "pwrite failed to write %llu bytes: %ld (%s)", + filesize, (long)bytes_written, strerror(errno)); + } + + return ret; +} + +/* + * Reset target_fname to "" in the two below functions for hibernation: if + * the fcopy operation is aborted by hibernation, the daemon should remove the + * partially-copied file; to achieve this, the hv_utils driver always fakes a + * CANCEL_FCOPY message upon suspend, and later when the VM resumes back, + * the daemon calls hv_copy_cancel() to remove the file; if a file is copied + * successfully before suspend, hv_copy_finished() must reset target_fname to + * avoid that the file can be incorrectly removed upon resume, since the faked + * CANCEL_FCOPY message is spurious in this case. + */ +static int hv_copy_finished(void) +{ + close(target_fd); + target_fname[0] = '\0'; + return 0; +} +static int hv_copy_cancel(void) +{ + close(target_fd); + if (strlen(target_fname) > 0) { + unlink(target_fname); + target_fname[0] = '\0'; + } + return 0; + +} + +void print_usage(char *argv[]) +{ + fprintf(stderr, "Usage: %s [options]\n" + "Options are:\n" + " -n, --no-daemon stay in foreground, don't daemonize\n" + " -h, --help print this help\n", argv[0]); +} + +int main(int argc, char *argv[]) +{ + int fcopy_fd = -1; + int error; + int daemonize = 1, long_index = 0, opt; + int version = FCOPY_CURRENT_VERSION; + union { + struct hv_fcopy_hdr hdr; + struct hv_start_fcopy start; + struct hv_do_fcopy copy; + __u32 kernel_modver; + } buffer = { }; + int in_handshake; + + static struct option long_options[] = { + {"help", no_argument, 0, 'h' }, + {"no-daemon", no_argument, 0, 'n' }, + {0, 0, 0, 0 } + }; + + while ((opt = getopt_long(argc, argv, "hn", long_options, + &long_index)) != -1) { + switch (opt) { + case 'n': + daemonize = 0; + break; + case 'h': + default: + print_usage(argv); + exit(EXIT_FAILURE); + } + } + + if (daemonize && daemon(1, 0)) { + syslog(LOG_ERR, "daemon() failed; error: %s", strerror(errno)); + exit(EXIT_FAILURE); + } + + openlog("HV_FCOPY", 0, LOG_USER); + syslog(LOG_INFO, "starting; pid is:%d", getpid()); + +reopen_fcopy_fd: + if (fcopy_fd != -1) + close(fcopy_fd); + /* Remove any possible partially-copied file on error */ + hv_copy_cancel(); + in_handshake = 1; + fcopy_fd = open("/dev/vmbus/hv_fcopy", O_RDWR); + + if (fcopy_fd < 0) { + syslog(LOG_ERR, "open /dev/vmbus/hv_fcopy failed; error: %d %s", + errno, strerror(errno)); + exit(EXIT_FAILURE); + } + + /* + * Register with the kernel. + */ + if ((write(fcopy_fd, &version, sizeof(int))) != sizeof(int)) { + syslog(LOG_ERR, "Registration failed: %s", strerror(errno)); + exit(EXIT_FAILURE); + } + + while (1) { + /* + * In this loop we process fcopy messages after the + * handshake is complete. + */ + ssize_t len; + + len = pread(fcopy_fd, &buffer, sizeof(buffer), 0); + if (len < 0) { + syslog(LOG_ERR, "pread failed: %s", strerror(errno)); + goto reopen_fcopy_fd; + } + + if (in_handshake) { + if (len != sizeof(buffer.kernel_modver)) { + syslog(LOG_ERR, "invalid version negotiation"); + exit(EXIT_FAILURE); + } + in_handshake = 0; + syslog(LOG_INFO, "kernel module version: %u", + buffer.kernel_modver); + continue; + } + + switch (buffer.hdr.operation) { + case START_FILE_COPY: + error = hv_start_fcopy(&buffer.start); + break; + case WRITE_TO_FILE: + error = hv_copy_data(&buffer.copy); + break; + case COMPLETE_FCOPY: + error = hv_copy_finished(); + break; + case CANCEL_FCOPY: + error = hv_copy_cancel(); + break; + + default: + error = HV_E_FAIL; + syslog(LOG_ERR, "Unknown operation: %d", + buffer.hdr.operation); + + } + + /* + * pwrite() may return an error due to the faked CANCEL_FCOPY + * message upon hibernation. Ignore the error by resetting the + * dev file, i.e. closing and re-opening it. + */ + if (pwrite(fcopy_fd, &error, sizeof(int), 0) != sizeof(int)) { + syslog(LOG_ERR, "pwrite failed: %s", strerror(errno)); + goto reopen_fcopy_fd; + } + } +} |