/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ /*** 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 <sys/sendfile.h> #include <libgen.h> #undef basename #include "sd-daemon.h" #include "util.h" #include "ratelimit.h" #include "btrfs-util.h" #include "copy.h" #include "import-common.h" #include "export-raw.h" #define COPY_BUFFER_SIZE (16*1024) struct RawExport { sd_event *event; RawExportFinished on_finished; void *userdata; char *path; int input_fd; int output_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; unsigned last_percent; RateLimit progress_rate_limit; struct stat st; bool eof; bool tried_reflink; bool tried_sendfile; }; RawExport *raw_export_unref(RawExport *e) { if (!e) return NULL; sd_event_source_unref(e->output_event_source); import_compress_free(&e->compress); sd_event_unref(e->event); safe_close(e->input_fd); free(e->buffer); free(e->path); free(e); return NULL; } int raw_export_new( RawExport **ret, sd_event *event, RawExportFinished on_finished, void *userdata) { _cleanup_(raw_export_unrefp) RawExport *e = NULL; int r; assert(ret); e = new0(RawExport, 1); if (!e) return -ENOMEM; e->output_fd = e->input_fd = -1; e->on_finished = on_finished; e->userdata = userdata; 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 raw_export_report_progress(RawExport *e) { unsigned percent; assert(e); if (e->written_uncompressed >= (uint64_t) e->st.st_size) percent = 100; else percent = (unsigned) ((e->written_uncompressed * UINT64_C(100)) / (uint64_t) e->st.st_size); 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 raw_export_process(RawExport *e) { ssize_t l; int r; assert(e); if (!e->tried_reflink && e->compress.type == IMPORT_COMPRESS_UNCOMPRESSED) { /* If we shall take an uncompressed snapshot we can * reflink source to destination directly. Let's see * if this works. */ r = btrfs_reflink(e->input_fd, e->output_fd); if (r >= 0) { r = 0; goto finish; } e->tried_reflink = true; } if (!e->tried_sendfile && e->compress.type == IMPORT_COMPRESS_UNCOMPRESSED) { l = sendfile(e->output_fd, e->input_fd, NULL, COPY_BUFFER_SIZE); if (l < 0) { if (errno == EAGAIN) return 0; e->tried_sendfile = true; } else if (l == 0) { r = 0; goto finish; } else { e->written_uncompressed += l; e->written_compressed += l; raw_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->input_fd, input, sizeof(input)); if (l < 0) { r = log_error_errno(errno, "Failed to read raw 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; raw_export_report_progress(e); return 0; finish: if (r >= 0) { (void) copy_times(e->input_fd, e->output_fd); (void) copy_xattr(e->input_fd, e->output_fd); } if (e->on_finished) e->on_finished(e, r, e->userdata); else sd_event_exit(e->event, r); return 0; } static int raw_export_on_output(sd_event_source *s, int fd, uint32_t revents, void *userdata) { RawExport *i = userdata; return raw_export_process(i); } static int raw_export_on_defer(sd_event_source *s, void *userdata) { RawExport *i = userdata; return raw_export_process(i); } static int reflink_snapshot(int fd, const char *path) { char *p, *d; int new_fd, r; p = strdupa(path); d = dirname(p); new_fd = open(d, O_TMPFILE|O_CLOEXEC|O_NOCTTY|O_RDWR, 0600); if (new_fd < 0) { _cleanup_free_ char *t = NULL; r = tempfn_random(path, &t); if (r < 0) return r; new_fd = open(t, O_CLOEXEC|O_CREAT|O_NOCTTY|O_RDWR, 0600); if (new_fd < 0) return -errno; (void) unlink(t); } r = btrfs_reflink(fd, new_fd); if (r < 0) { safe_close(new_fd); return r; } return new_fd; } int raw_export_start(RawExport *e, const char *path, int fd, ImportCompressType compress) { _cleanup_close_ int sfd = -1, tfd = -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; r = fd_nonblock(fd, true); if (r < 0) return r; r = free_and_strdup(&e->path, path); if (r < 0) return r; sfd = open(path, O_RDONLY|O_CLOEXEC|O_NOCTTY); if (sfd < 0) return -errno; if (fstat(sfd, &e->st) < 0) return -errno; if (!S_ISREG(e->st.st_mode)) return -ENOTTY; /* Try to take a reflink snapshot of the file, if we can t make the export atomic */ tfd = reflink_snapshot(sfd, path); if (tfd >= 0) { e->input_fd = tfd; tfd = -1; } else { e->input_fd = sfd; sfd = -1; } 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, raw_export_on_output, e); if (r == -EPERM) { r = sd_event_add_defer(e->event, &e->output_event_source, raw_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->output_fd = fd; return r; }