/*** This file is part of systemd. Copyright 2015 Lennart Poettering systemd is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. systemd is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with systemd; If not, see <http://www.gnu.org/licenses/>. ***/ #include "sd-daemon.h" #include "alloc-util.h" #include "btrfs-util.h" #include "export-tar.h" #include "fd-util.h" #include "fileio.h" #include "import-common.h" #include "process-util.h" #include "ratelimit.h" #include "string-util.h" #include "util.h" #define COPY_BUFFER_SIZE (16*1024) struct TarExport { sd_event *event; TarExportFinished on_finished; void *userdata; char *path; char *temp_path; int output_fd; int tar_fd; ImportCompress compress; sd_event_source *output_event_source; void *buffer; size_t buffer_size; size_t buffer_allocated; uint64_t written_compressed; uint64_t written_uncompressed; pid_t tar_pid; struct stat st; uint64_t quota_referenced; unsigned last_percent; RateLimit progress_rate_limit; bool eof; bool tried_splice; }; TarExport *tar_export_unref(TarExport *e) { if (!e) return NULL; sd_event_source_unref(e->output_event_source); if (e->tar_pid > 1) { (void) kill_and_sigcont(e->tar_pid, SIGKILL); (void) wait_for_terminate(e->tar_pid, NULL); } if (e->temp_path) { (void) btrfs_subvol_remove(e->temp_path, BTRFS_REMOVE_QUOTA); free(e->temp_path); } import_compress_free(&e->compress); sd_event_unref(e->event); safe_close(e->tar_fd); free(e->buffer); free(e->path); return mfree(e); } int tar_export_new( TarExport **ret, sd_event *event, TarExportFinished on_finished, void *userdata) { _cleanup_(tar_export_unrefp) TarExport *e = NULL; int r; assert(ret); e = new0(TarExport, 1); if (!e) return -ENOMEM; e->output_fd = e->tar_fd = -1; e->on_finished = on_finished; e->userdata = userdata; e->quota_referenced = (uint64_t) -1; RATELIMIT_INIT(e->progress_rate_limit, 100 * USEC_PER_MSEC, 1); e->last_percent = (unsigned) -1; if (event) e->event = sd_event_ref(event); else { r = sd_event_default(&e->event); if (r < 0) return r; } *ret = e; e = NULL; return 0; } static void tar_export_report_progress(TarExport *e) { unsigned percent; assert(e); /* Do we have any quota info? If not, we don't know anything about the progress */ if (e->quota_referenced == (uint64_t) -1) return; if (e->written_uncompressed >= e->quota_referenced) percent = 100; else percent = (unsigned) ((e->written_uncompressed * UINT64_C(100)) / e->quota_referenced); if (percent == e->last_percent) return; if (!ratelimit_test(&e->progress_rate_limit)) return; sd_notifyf(false, "X_IMPORT_PROGRESS=%u", percent); log_info("Exported %u%%.", percent); e->last_percent = percent; } static int tar_export_process(TarExport *e) { ssize_t l; int r; assert(e); if (!e->tried_splice && e->compress.type == IMPORT_COMPRESS_UNCOMPRESSED) { l = splice(e->tar_fd, NULL, e->output_fd, NULL, COPY_BUFFER_SIZE, 0); if (l < 0) { if (errno == EAGAIN) return 0; e->tried_splice = true; } else if (l == 0) { r = 0; goto finish; } else { e->written_uncompressed += l; e->written_compressed += l; tar_export_report_progress(e); return 0; } } while (e->buffer_size <= 0) { uint8_t input[COPY_BUFFER_SIZE]; if (e->eof) { r = 0; goto finish; } l = read(e->tar_fd, input, sizeof(input)); if (l < 0) { r = log_error_errno(errno, "Failed to read tar file: %m"); goto finish; } if (l == 0) { e->eof = true; r = import_compress_finish(&e->compress, &e->buffer, &e->buffer_size, &e->buffer_allocated); } else { e->written_uncompressed += l; r = import_compress(&e->compress, input, l, &e->buffer, &e->buffer_size, &e->buffer_allocated); } if (r < 0) { r = log_error_errno(r, "Failed to encode: %m"); goto finish; } } l = write(e->output_fd, e->buffer, e->buffer_size); if (l < 0) { if (errno == EAGAIN) return 0; r = log_error_errno(errno, "Failed to write output file: %m"); goto finish; } assert((size_t) l <= e->buffer_size); memmove(e->buffer, (uint8_t*) e->buffer + l, e->buffer_size - l); e->buffer_size -= l; e->written_compressed += l; tar_export_report_progress(e); return 0; finish: if (e->on_finished) e->on_finished(e, r, e->userdata); else sd_event_exit(e->event, r); return 0; } static int tar_export_on_output(sd_event_source *s, int fd, uint32_t revents, void *userdata) { TarExport *i = userdata; return tar_export_process(i); } static int tar_export_on_defer(sd_event_source *s, void *userdata) { TarExport *i = userdata; return tar_export_process(i); } int tar_export_start(TarExport *e, const char *path, int fd, ImportCompressType compress) { _cleanup_close_ int sfd = -1; int r; assert(e); assert(path); assert(fd >= 0); assert(compress < _IMPORT_COMPRESS_TYPE_MAX); assert(compress != IMPORT_COMPRESS_UNKNOWN); if (e->output_fd >= 0) return -EBUSY; sfd = open(path, O_DIRECTORY|O_RDONLY|O_NOCTTY|O_CLOEXEC); if (sfd < 0) return -errno; if (fstat(sfd, &e->st) < 0) return -errno; r = fd_nonblock(fd, true); if (r < 0) return r; r = free_and_strdup(&e->path, path); if (r < 0) return r; e->quota_referenced = (uint64_t) -1; if (e->st.st_ino == 256) { /* might be a btrfs subvolume? */ BtrfsQuotaInfo q; r = btrfs_subvol_get_subtree_quota_fd(sfd, 0, &q); if (r >= 0) e->quota_referenced = q.referenced; e->temp_path = mfree(e->temp_path); r = tempfn_random(path, NULL, &e->temp_path); if (r < 0) return r; /* Let's try to make a snapshot, if we can, so that the export is atomic */ r = btrfs_subvol_snapshot_fd(sfd, e->temp_path, BTRFS_SNAPSHOT_READ_ONLY|BTRFS_SNAPSHOT_RECURSIVE); if (r < 0) { log_debug_errno(r, "Couldn't create snapshot %s of %s, not exporting atomically: %m", e->temp_path, path); e->temp_path = mfree(e->temp_path); } } r = import_compress_init(&e->compress, compress); if (r < 0) return r; r = sd_event_add_io(e->event, &e->output_event_source, fd, EPOLLOUT, tar_export_on_output, e); if (r == -EPERM) { r = sd_event_add_defer(e->event, &e->output_event_source, tar_export_on_defer, e); if (r < 0) return r; r = sd_event_source_set_enabled(e->output_event_source, SD_EVENT_ON); } if (r < 0) return r; e->tar_fd = import_fork_tar_c(e->temp_path ?: e->path, &e->tar_pid); if (e->tar_fd < 0) { e->output_event_source = sd_event_source_unref(e->output_event_source); return e->tar_fd; } e->output_fd = fd; return r; }