[thirdparty/systemd.git] / src / import / export-tar.c

/* SPDX-License-Identifier: LGPL-2.1-or-later */

#include <sys/stat.h>

#include "sd-daemon.h"
#include "sd-event.h"

#include "alloc-util.h"
#include "btrfs-util.h"
#include "export-tar.h"
#include "fd-util.h"
#include "format-util.h"
#include "import-common.h"
#include "log.h"
#include "pretty-print.h"
#include "process-util.h"
#include "ratelimit.h"
#include "string-util.h"
#include "terminal-util.h"
#include "time-util.h"
#include "tmpfile-util.h"

#define COPY_BUFFER_SIZE (16*1024)

typedef 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_ratelimit;

        bool eof;
        bool tried_splice;
} TarExport;

TarExport *tar_export_unref(TarExport *e) {
        if (!e)
                return NULL;

        sd_event_source_unref(e->output_event_source);

        if (e->tar_pid > 1)
                sigkill_wait(e->tar_pid);

        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 = new(TarExport, 1);
        if (!e)
                return -ENOMEM;

        *e = (TarExport) {
                .output_fd = -EBADF,
                .tar_fd = -EBADF,
                .on_finished = on_finished,
                .userdata = userdata,
                .quota_referenced = UINT64_MAX,
                .last_percent = UINT_MAX,
                .progress_ratelimit = { 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 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_MAX)
                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_below(&e->progress_ratelimit))
                return;

        sd_notifyf(false, "X_IMPORT_PROGRESS=%u%%", percent);

        if (isatty_safe(STDERR_FILENO))
                (void) draw_progress_barf(
                                percent,
                                "%s %s/%s",
                                glyph(GLYPH_ARROW_RIGHT),
                                FORMAT_BYTES(e->written_uncompressed),
                                FORMAT_BYTES(e->quota_referenced));
        else
                log_info("Exported %u%%.", percent);

        e->last_percent = percent;
}

static int tar_export_finish(TarExport *e) {
        int r;

        assert(e);
        assert(e->tar_fd >= 0);

        if (e->tar_pid > 0) {
                r = wait_for_terminate_and_check("tar", TAKE_PID(e->tar_pid), WAIT_LOG);
                if (r < 0)
                        return r;
                if (r != EXIT_SUCCESS)
                        return -EPROTO;
        }

        e->tar_fd = safe_close(e->tar_fd);

        return 0;
}

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 = tar_export_finish(e);
                        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 = tar_export_finish(e);
                        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 (r >= 0 && isatty_safe(STDERR_FILENO))
                clear_progress_bar(/* prefix= */ NULL);

        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 = -EBADF;
        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_MAX;

        if (btrfs_might_be_subvol(&e->st)) {
                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_at(sfd, NULL, AT_FDCWD, 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;
}
Commit	Line	Data
	1	/* SPDX-License-Identifier: LGPL-2.1-or-later */
	2
	3	#include <sys/stat.h>
	4
	5	#include "sd-daemon.h"
	6	#include "sd-event.h"
	7
	8	#include "alloc-util.h"
	9	#include "btrfs-util.h"
	10	#include "export-tar.h"
	11	#include "fd-util.h"
	12	#include "format-util.h"
	13	#include "import-common.h"
	14	#include "log.h"
	15	#include "pretty-print.h"
	16	#include "process-util.h"
	17	#include "ratelimit.h"
	18	#include "string-util.h"
	19	#include "terminal-util.h"
	20	#include "time-util.h"
	21	#include "tmpfile-util.h"
	22
	23	#define COPY_BUFFER_SIZE (16*1024)
	24
	25	typedef struct TarExport {
	26	sd_event *event;
	27
	28	TarExportFinished on_finished;
	29	void *userdata;
	30
	31	char *path;
	32	char *temp_path;
	33
	34	int output_fd;
	35	int tar_fd;
	36
	37	ImportCompress compress;
	38
	39	sd_event_source *output_event_source;
	40
	41	void *buffer;
	42	size_t buffer_size;
	43	size_t buffer_allocated;
	44
	45	uint64_t written_compressed;
	46	uint64_t written_uncompressed;
	47
	48	pid_t tar_pid;
	49
	50	struct stat st;
	51	uint64_t quota_referenced;
	52
	53	unsigned last_percent;
	54	RateLimit progress_ratelimit;
	55
	56	bool eof;
	57	bool tried_splice;
	58	} TarExport;
	59
	60	TarExport tar_export_unref(TarExport e) {
	61	if (!e)
	62	return NULL;
	63
	64	sd_event_source_unref(e->output_event_source);
	65
	66	if (e->tar_pid > 1)
	67	sigkill_wait(e->tar_pid);
	68
	69	if (e->temp_path) {
	70	(void) btrfs_subvol_remove(e->temp_path, BTRFS_REMOVE_QUOTA);
	71	free(e->temp_path);
	72	}
	73
	74	import_compress_free(&e->compress);
	75
	76	sd_event_unref(e->event);
	77
	78	safe_close(e->tar_fd);
	79
	80	free(e->buffer);
	81	free(e->path);
	82	return mfree(e);
	83	}
	84
	85	int tar_export_new(
	86	TarExport **ret,
	87	sd_event *event,
	88	TarExportFinished on_finished,
	89	void *userdata) {
	90
	91	_cleanup_(tar_export_unrefp) TarExport *e = NULL;
	92	int r;
	93
	94	assert(ret);
	95
	96	e = new(TarExport, 1);
	97	if (!e)
	98	return -ENOMEM;
	99
	100	*e = (TarExport) {
	101	.output_fd = -EBADF,
	102	.tar_fd = -EBADF,
	103	.on_finished = on_finished,
	104	.userdata = userdata,
	105	.quota_referenced = UINT64_MAX,
	106	.last_percent = UINT_MAX,
	107	.progress_ratelimit = { 100 * USEC_PER_MSEC, 1 },
	108	};
	109
	110	if (event)
	111	e->event = sd_event_ref(event);
	112	else {
	113	r = sd_event_default(&e->event);
	114	if (r < 0)
	115	return r;
	116	}
	117
	118	*ret = TAKE_PTR(e);
	119
	120	return 0;
	121	}
	122
	123	static void tar_export_report_progress(TarExport *e) {
	124	unsigned percent;
	125	assert(e);
	126
	127	/* Do we have any quota info? If not, we don't know anything about the progress */
	128	if (e->quota_referenced == UINT64_MAX)
	129	return;
	130
	131	if (e->written_uncompressed >= e->quota_referenced)
	132	percent = 100;
	133	else
	134	percent = (unsigned) ((e->written_uncompressed * UINT64_C(100)) / e->quota_referenced);
	135
	136	if (percent == e->last_percent)
	137	return;
	138
	139	if (!ratelimit_below(&e->progress_ratelimit))
	140	return;
	141
	142	sd_notifyf(false, "X_IMPORT_PROGRESS=%u%%", percent);
	143
	144	if (isatty_safe(STDERR_FILENO))
	145	(void) draw_progress_barf(
	146	percent,
	147	"%s %s/%s",
	148	glyph(GLYPH_ARROW_RIGHT),
	149	FORMAT_BYTES(e->written_uncompressed),
	150	FORMAT_BYTES(e->quota_referenced));
	151	else
	152	log_info("Exported %u%%.", percent);
	153
	154	e->last_percent = percent;
	155	}
	156
	157	static int tar_export_finish(TarExport *e) {
	158	int r;
	159
	160	assert(e);
	161	assert(e->tar_fd >= 0);
	162
	163	if (e->tar_pid > 0) {
	164	r = wait_for_terminate_and_check("tar", TAKE_PID(e->tar_pid), WAIT_LOG);
	165	if (r < 0)
	166	return r;
	167	if (r != EXIT_SUCCESS)
	168	return -EPROTO;
	169	}
	170
	171	e->tar_fd = safe_close(e->tar_fd);
	172
	173	return 0;
	174	}
	175
	176	static int tar_export_process(TarExport *e) {
	177	ssize_t l;
	178	int r;
	179
	180	assert(e);
	181
	182	if (!e->tried_splice && e->compress.type == IMPORT_COMPRESS_UNCOMPRESSED) {
	183
	184	l = splice(e->tar_fd, NULL, e->output_fd, NULL, COPY_BUFFER_SIZE, 0);
	185	if (l < 0) {
	186	if (errno == EAGAIN)
	187	return 0;
	188
	189	e->tried_splice = true;
	190	} else if (l == 0) {
	191	r = tar_export_finish(e);
	192	goto finish;
	193	} else {
	194	e->written_uncompressed += l;
	195	e->written_compressed += l;
	196
	197	tar_export_report_progress(e);
	198
	199	return 0;
	200	}
	201	}
	202
	203	while (e->buffer_size <= 0) {
	204	uint8_t input[COPY_BUFFER_SIZE];
	205
	206	if (e->eof) {
	207	r = tar_export_finish(e);
	208	goto finish;
	209	}
	210
	211	l = read(e->tar_fd, input, sizeof(input));
	212	if (l < 0) {
	213	r = log_error_errno(errno, "Failed to read tar file: %m");
	214	goto finish;
	215	}
	216
	217	if (l == 0) {
	218	e->eof = true;
	219	r = import_compress_finish(&e->compress, &e->buffer, &e->buffer_size, &e->buffer_allocated);
	220	} else {
	221	e->written_uncompressed += l;
	222	r = import_compress(&e->compress, input, l, &e->buffer, &e->buffer_size, &e->buffer_allocated);
	223	}
	224	if (r < 0) {
	225	r = log_error_errno(r, "Failed to encode: %m");
	226	goto finish;
	227	}
	228	}
	229
	230	l = write(e->output_fd, e->buffer, e->buffer_size);
	231	if (l < 0) {
	232	if (errno == EAGAIN)
	233	return 0;
	234
	235	r = log_error_errno(errno, "Failed to write output file: %m");
	236	goto finish;
	237	}
	238
	239	assert((size_t) l <= e->buffer_size);
	240	memmove(e->buffer, (uint8_t*) e->buffer + l, e->buffer_size - l);
	241	e->buffer_size -= l;
	242	e->written_compressed += l;
	243
	244	tar_export_report_progress(e);
	245
	246	return 0;
	247
	248	finish:
	249	if (r >= 0 && isatty_safe(STDERR_FILENO))
	250	clear_progress_bar(/* prefix= */ NULL);
	251
	252	if (e->on_finished)
	253	e->on_finished(e, r, e->userdata);
	254	else
	255	sd_event_exit(e->event, r);
	256
	257	return 0;
	258	}
	259
	260	static int tar_export_on_output(sd_event_source s, int fd, uint32_t revents, void userdata) {
	261	TarExport *i = userdata;
	262
	263	return tar_export_process(i);
	264	}
	265
	266	static int tar_export_on_defer(sd_event_source s, void userdata) {
	267	TarExport *i = userdata;
	268
	269	return tar_export_process(i);
	270	}
	271
	272	int tar_export_start(TarExport e, const char path, int fd, ImportCompressType compress) {
	273	_cleanup_close_ int sfd = -EBADF;
	274	int r;
	275
	276	assert(e);
	277	assert(path);
	278	assert(fd >= 0);
	279	assert(compress < _IMPORT_COMPRESS_TYPE_MAX);
	280	assert(compress != IMPORT_COMPRESS_UNKNOWN);
	281
	282	if (e->output_fd >= 0)
	283	return -EBUSY;
	284
	285	sfd = open(path, O_DIRECTORY\|O_RDONLY\|O_NOCTTY\|O_CLOEXEC);
	286	if (sfd < 0)
	287	return -errno;
	288
	289	if (fstat(sfd, &e->st) < 0)
	290	return -errno;
	291
	292	r = fd_nonblock(fd, true);
	293	if (r < 0)
	294	return r;
	295
	296	r = free_and_strdup(&e->path, path);
	297	if (r < 0)
	298	return r;
	299
	300	e->quota_referenced = UINT64_MAX;
	301
	302	if (btrfs_might_be_subvol(&e->st)) {
	303	BtrfsQuotaInfo q;
	304
	305	r = btrfs_subvol_get_subtree_quota_fd(sfd, 0, &q);
	306	if (r >= 0)
	307	e->quota_referenced = q.referenced;
	308
	309	e->temp_path = mfree(e->temp_path);
	310
	311	r = tempfn_random(path, NULL, &e->temp_path);
	312	if (r < 0)
	313	return r;
	314
	315	/* Let's try to make a snapshot, if we can, so that the export is atomic */
	316	r = btrfs_subvol_snapshot_at(sfd, NULL, AT_FDCWD, e->temp_path, BTRFS_SNAPSHOT_READ_ONLY\|BTRFS_SNAPSHOT_RECURSIVE);
	317	if (r < 0) {
	318	log_debug_errno(r, "Couldn't create snapshot %s of %s, not exporting atomically: %m", e->temp_path, path);
	319	e->temp_path = mfree(e->temp_path);
	320	}
	321	}
	322
	323	r = import_compress_init(&e->compress, compress);
	324	if (r < 0)
	325	return r;
	326
	327	r = sd_event_add_io(e->event, &e->output_event_source, fd, EPOLLOUT, tar_export_on_output, e);
	328	if (r == -EPERM) {
	329	r = sd_event_add_defer(e->event, &e->output_event_source, tar_export_on_defer, e);
	330	if (r < 0)
	331	return r;
	332
	333	r = sd_event_source_set_enabled(e->output_event_source, SD_EVENT_ON);
	334	}
	335	if (r < 0)
	336	return r;
	337
	338	e->tar_fd = import_fork_tar_c(e->temp_path ?: e->path, &e->tar_pid);
	339	if (e->tar_fd < 0) {
	340	e->output_event_source = sd_event_source_unref(e->output_event_source);
	341	return e->tar_fd;
	342	}
	343
	344	e->output_fd = fd;
	345	return r;
	346	}