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-rw-r--r--src/import/export-raw.c332
1 files changed, 332 insertions, 0 deletions
diff --git a/src/import/export-raw.c b/src/import/export-raw.c
new file mode 100644
index 0000000..6a02b47
--- /dev/null
+++ b/src/import/export-raw.c
@@ -0,0 +1,332 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <sys/sendfile.h>
+
+/* When we include libgen.h because we need dirname() we immediately
+ * undefine basename() since libgen.h defines it as a macro to the POSIX
+ * version which is really broken. We prefer GNU basename(). */
+#include <libgen.h>
+#undef basename
+
+#include "sd-daemon.h"
+
+#include "alloc-util.h"
+#include "btrfs-util.h"
+#include "copy.h"
+#include "export-raw.h"
+#include "fd-util.h"
+#include "fs-util.h"
+#include "import-common.h"
+#include "missing.h"
+#include "ratelimit.h"
+#include "stat-util.h"
+#include "string-util.h"
+#include "tmpfile-util.h"
+#include "util.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);
+ return mfree(e);
+}
+
+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 = new(RawExport, 1);
+ if (!e)
+ return -ENOMEM;
+
+ *e = (RawExport) {
+ .output_fd = -1,
+ .input_fd = -1,
+ .on_finished = on_finished,
+ .userdata = userdata,
+ .last_percent = (unsigned) -1,
+ };
+
+ RATELIMIT_INIT(e->progress_rate_limit, 100 * USEC_PER_MSEC, 1);
+
+ if (event)
+ e->event = sd_event_ref(event);
+ else {
+ r = sd_event_default(&e->event);
+ if (r < 0)
+ return r;
+ }
+
+ *ret = TAKE_PTR(e);
+
+ 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_below(&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) {
+ int new_fd, r;
+
+ new_fd = open_parent(path, O_TMPFILE|O_CLOEXEC|O_RDWR, 0600);
+ if (new_fd < 0) {
+ _cleanup_free_ char *t = NULL;
+
+ r = tempfn_random(path, NULL, &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;
+ r = stat_verify_regular(&e->st);
+ if (r < 0)
+ return r;
+
+ /* 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 = TAKE_FD(tfd);
+ else
+ e->input_fd = TAKE_FD(sfd);
+
+ 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;
+}