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

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

#include <sys/sendfile.h>

#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_fcntl.h"
#include "ratelimit.h"
#include "stat-util.h"
#include "string-util.h"
#include "tmpfile-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_ratelimit;

        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 = -EBADF,
                .input_fd = -EBADF,
                .on_finished = on_finished,
                .userdata = userdata,
                .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 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_ratelimit))
                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 = 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, COPY_CRTIME);
                (void) copy_xattr(e->input_fd, NULL, e->output_fd, NULL, 0);
        }

        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 = 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 = -EBADF, tfd = -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;

        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;
}
Commit	Line	Data
db9ecf05	1	/* SPDX-License-Identifier: LGPL-2.1-or-later */
587fec42 LP	2
587fec42 LP	3	#include <sys/sendfile.h>
cf0fbc49	4
587fec42	5	#include "sd-daemon.h"
07630cea	6
b5efdb8a	7	#include "alloc-util.h"
587fec42 LP	8	#include "btrfs-util.h"
587fec42 LP	9	#include "copy.h"
587fec42	10	#include "export-raw.h"
3ffd4af2	11	#include "fd-util.h"
0c462ea4	12	#include "fs-util.h"
07630cea	13	#include "import-common.h"
0499585f	14	#include "missing_fcntl.h"
07630cea	15	#include "ratelimit.h"
3cc44114	16	#include "stat-util.h"
07630cea	17	#include "string-util.h"
e4de7287	18	#include "tmpfile-util.h"
587fec42 LP	19
	20	#define COPY_BUFFER_SIZE (16*1024)
	21
	22	struct RawExport {
	23	sd_event *event;
	24
	25	RawExportFinished on_finished;
	26	void *userdata;
	27
	28	char *path;
	29
	30	int input_fd;
	31	int output_fd;
	32
	33	ImportCompress compress;
	34
	35	sd_event_source *output_event_source;
	36
	37	void *buffer;
	38	size_t buffer_size;
	39	size_t buffer_allocated;
	40
	41	uint64_t written_compressed;
	42	uint64_t written_uncompressed;
	43
	44	unsigned last_percent;
5ac1530e	45	RateLimit progress_ratelimit;
587fec42 LP	46
	47	struct stat st;
	48
	49	bool eof;
	50	bool tried_reflink;
	51	bool tried_sendfile;
	52	};
	53
	54	RawExport raw_export_unref(RawExport e) {
	55	if (!e)
	56	return NULL;
	57
	58	sd_event_source_unref(e->output_event_source);
	59
	60	import_compress_free(&e->compress);
	61
	62	sd_event_unref(e->event);
	63
	64	safe_close(e->input_fd);
	65
	66	free(e->buffer);
	67	free(e->path);
6b430fdb	68	return mfree(e);
587fec42 LP	69	}
	70
	71	int raw_export_new(
	72	RawExport **ret,
	73	sd_event *event,
	74	RawExportFinished on_finished,
	75	void *userdata) {
	76
	77	_cleanup_(raw_export_unrefp) RawExport *e = NULL;
	78	int r;
	79
	80	assert(ret);
	81
0d94088e	82	e = new(RawExport, 1);
587fec42 LP	83	if (!e)
	84	return -ENOMEM;
	85
0d94088e	86	*e = (RawExport) {
254d1313 ZJS	87	.output_fd = -EBADF,
254d1313 ZJS	88	.input_fd = -EBADF,
0d94088e YW	89	.on_finished = on_finished,
0d94088e YW	90	.userdata = userdata,
f5fbe71d	91	.last_percent = UINT_MAX,
5ac1530e	92	.progress_ratelimit = { 100 * USEC_PER_MSEC, 1 },
0d94088e	93	};
587fec42	94
587fec42 LP	95	if (event)
	96	e->event = sd_event_ref(event);
	97	else {
	98	r = sd_event_default(&e->event);
	99	if (r < 0)
	100	return r;
	101	}
	102
1cc6c93a	103	*ret = TAKE_PTR(e);
587fec42 LP	104
	105	return 0;
	106	}
	107
	108	static void raw_export_report_progress(RawExport *e) {
	109	unsigned percent;
	110	assert(e);
	111
	112	if (e->written_uncompressed >= (uint64_t) e->st.st_size)
	113	percent = 100;
	114	else
	115	percent = (unsigned) ((e->written_uncompressed * UINT64_C(100)) / (uint64_t) e->st.st_size);
	116
	117	if (percent == e->last_percent)
	118	return;
	119
5ac1530e	120	if (!ratelimit_below(&e->progress_ratelimit))
587fec42 LP	121	return;
587fec42 LP	122
a986de68	123	sd_notifyf(false, "X_IMPORT_PROGRESS=%u%%", percent);
587fec42 LP	124	log_info("Exported %u%%.", percent);
	125
	126	e->last_percent = percent;
	127	}
	128
	129	static int raw_export_process(RawExport *e) {
	130	ssize_t l;
	131	int r;
	132
	133	assert(e);
	134
	135	if (!e->tried_reflink && e->compress.type == IMPORT_COMPRESS_UNCOMPRESSED) {
	136
	137	/* If we shall take an uncompressed snapshot we can
	138	* reflink source to destination directly. Let's see
	139	* if this works. */
	140
b640e274	141	r = reflink(e->input_fd, e->output_fd);
587fec42 LP	142	if (r >= 0) {
	143	r = 0;
	144	goto finish;
	145	}
	146
	147	e->tried_reflink = true;
	148	}
	149
	150	if (!e->tried_sendfile && e->compress.type == IMPORT_COMPRESS_UNCOMPRESSED) {
	151
	152	l = sendfile(e->output_fd, e->input_fd, NULL, COPY_BUFFER_SIZE);
	153	if (l < 0) {
	154	if (errno == EAGAIN)
	155	return 0;
	156
	157	e->tried_sendfile = true;
	158	} else if (l == 0) {
	159	r = 0;
	160	goto finish;
	161	} else {
	162	e->written_uncompressed += l;
	163	e->written_compressed += l;
	164
	165	raw_export_report_progress(e);
	166
	167	return 0;
	168	}
	169	}
	170
	171	while (e->buffer_size <= 0) {
	172	uint8_t input[COPY_BUFFER_SIZE];
	173
	174	if (e->eof) {
	175	r = 0;
	176	goto finish;
	177	}
	178
	179	l = read(e->input_fd, input, sizeof(input));
	180	if (l < 0) {
	181	r = log_error_errno(errno, "Failed to read raw file: %m");
	182	goto finish;
	183	}
	184
	185	if (l == 0) {
	186	e->eof = true;
	187	r = import_compress_finish(&e->compress, &e->buffer, &e->buffer_size, &e->buffer_allocated);
	188	} else {
	189	e->written_uncompressed += l;
	190	r = import_compress(&e->compress, input, l, &e->buffer, &e->buffer_size, &e->buffer_allocated);
	191	}
	192	if (r < 0) {
	193	r = log_error_errno(r, "Failed to encode: %m");
	194	goto finish;
	195	}
	196	}
	197
	198	l = write(e->output_fd, e->buffer, e->buffer_size);
	199	if (l < 0) {
	200	if (errno == EAGAIN)
	201	return 0;
	202
	203	r = log_error_errno(errno, "Failed to write output file: %m");
	204	goto finish;
	205	}
206
207	assert((size_t) l <= e->buffer_size);
208	memmove(e->buffer, (uint8_t*) e->buffer + l, e->buffer_size - l);
209	e->buffer_size -= l;
210	e->written_compressed += l;
211
212	raw_export_report_progress(e);
213
214	return 0;
215
216	finish:
217	if (r >= 0) {
adc6f43b	218	(void) copy_times(e->input_fd, e->output_fd, COPY_CRTIME);
c17cfe6e	219	(void) copy_xattr(e->input_fd, NULL, e->output_fd, NULL, 0);
587fec42 LP	220	}
	221
	222	if (e->on_finished)
	223	e->on_finished(e, r, e->userdata);
	224	else
	225	sd_event_exit(e->event, r);
	226
	227	return 0;
	228	}
	229
	230	static int raw_export_on_output(sd_event_source s, int fd, uint32_t revents, void userdata) {
	231	RawExport *i = userdata;
	232
	233	return raw_export_process(i);
	234	}
	235
	236	static int raw_export_on_defer(sd_event_source s, void userdata) {
	237	RawExport *i = userdata;
	238
	239	return raw_export_process(i);
	240	}
	241
	242	static int reflink_snapshot(int fd, const char *path) {
587fec42 LP	243	int new_fd, r;
587fec42 LP	244
0c462ea4	245	new_fd = open_parent(path, O_TMPFILE\|O_CLOEXEC\|O_RDWR, 0600);
587fec42 LP	246	if (new_fd < 0) {
	247	_cleanup_free_ char *t = NULL;
	248
14bcf25c	249	r = tempfn_random(path, NULL, &t);
587fec42 LP	250	if (r < 0)
	251	return r;
	252
	253	new_fd = open(t, O_CLOEXEC\|O_CREAT\|O_NOCTTY\|O_RDWR, 0600);
	254	if (new_fd < 0)
	255	return -errno;
	256
	257	(void) unlink(t);
	258	}
	259
b640e274	260	r = reflink(fd, new_fd);
587fec42 LP	261	if (r < 0) {
	262	safe_close(new_fd);
	263	return r;
	264	}
	265
	266	return new_fd;
	267	}
	268
	269	int raw_export_start(RawExport e, const char path, int fd, ImportCompressType compress) {
254d1313	270	_cleanup_close_ int sfd = -EBADF, tfd = -EBADF;
587fec42 LP	271	int r;
	272
	273	assert(e);
	274	assert(path);
	275	assert(fd >= 0);
	276	assert(compress < _IMPORT_COMPRESS_TYPE_MAX);
	277	assert(compress != IMPORT_COMPRESS_UNKNOWN);
	278
	279	if (e->output_fd >= 0)
	280	return -EBUSY;
	281
	282	r = fd_nonblock(fd, true);
	283	if (r < 0)
	284	return r;
	285
	286	r = free_and_strdup(&e->path, path);
	287	if (r < 0)
	288	return r;
	289
	290	sfd = open(path, O_RDONLY\|O_CLOEXEC\|O_NOCTTY);
	291	if (sfd < 0)
	292	return -errno;
	293
	294	if (fstat(sfd, &e->st) < 0)
	295	return -errno;
3cc44114 LP	296	r = stat_verify_regular(&e->st);
	297	if (r < 0)
	298	return r;
587fec42 LP	299
	300	/* Try to take a reflink snapshot of the file, if we can t make the export atomic */
	301	tfd = reflink_snapshot(sfd, path);
c10d6bdb LP	302	if (tfd >= 0)
	303	e->input_fd = TAKE_FD(tfd);
	304	else
	305	e->input_fd = TAKE_FD(sfd);
587fec42 LP	306
	307	r = import_compress_init(&e->compress, compress);
	308	if (r < 0)
	309	return r;
	310
	311	r = sd_event_add_io(e->event, &e->output_event_source, fd, EPOLLOUT, raw_export_on_output, e);
	312	if (r == -EPERM) {
	313	r = sd_event_add_defer(e->event, &e->output_event_source, raw_export_on_defer, e);
	314	if (r < 0)
	315	return r;
	316
	317	r = sd_event_source_set_enabled(e->output_event_source, SD_EVENT_ON);
	318	}
	319	if (r < 0)
	320	return r;
	321
	322	e->output_fd = fd;
	323	return r;
	324	}