--- /dev/null
+/*-*- 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;
+}
~ianmdlvl / elogind.git / blobdiff