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

/* 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 "fileio.h"
#include "fs-util.h"
#include "import-common.h"
#include "missing.h"
#include "ratelimit.h"
#include "stat-util.h"
#include "string-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;
}
Commit	Line	Data
53e1b683	1	/* SPDX-License-Identifier: LGPL-2.1+ */
587fec42 LP	2
587fec42 LP	3	#include <sys/sendfile.h>
cf0fbc49 TA	4
	5	/* When we include libgen.h because we need dirname() we immediately
	6	* undefine basename() since libgen.h defines it as a macro to the POSIX
	7	* version which is really broken. We prefer GNU basename(). */
587fec42 LP	8	#include <libgen.h>
	9	#undef basename
	10
	11	#include "sd-daemon.h"
07630cea	12
b5efdb8a	13	#include "alloc-util.h"
587fec42 LP	14	#include "btrfs-util.h"
587fec42 LP	15	#include "copy.h"
587fec42	16	#include "export-raw.h"
3ffd4af2	17	#include "fd-util.h"
0d39fa9c	18	#include "fileio.h"
0c462ea4	19	#include "fs-util.h"
07630cea	20	#include "import-common.h"
4a6d3523	21	#include "missing.h"
07630cea	22	#include "ratelimit.h"
3cc44114	23	#include "stat-util.h"
07630cea LP	24	#include "string-util.h"
07630cea LP	25	#include "util.h"
587fec42 LP	26
	27	#define COPY_BUFFER_SIZE (16*1024)
	28
	29	struct RawExport {
	30	sd_event *event;
	31
	32	RawExportFinished on_finished;
	33	void *userdata;
	34
	35	char *path;
	36
	37	int input_fd;
	38	int output_fd;
	39
	40	ImportCompress compress;
	41
	42	sd_event_source *output_event_source;
	43
	44	void *buffer;
	45	size_t buffer_size;
	46	size_t buffer_allocated;
	47
	48	uint64_t written_compressed;
	49	uint64_t written_uncompressed;
	50
	51	unsigned last_percent;
	52	RateLimit progress_rate_limit;
	53
	54	struct stat st;
	55
	56	bool eof;
	57	bool tried_reflink;
	58	bool tried_sendfile;
	59	};
	60
	61	RawExport raw_export_unref(RawExport e) {
	62	if (!e)
	63	return NULL;
	64
	65	sd_event_source_unref(e->output_event_source);
	66
	67	import_compress_free(&e->compress);
	68
	69	sd_event_unref(e->event);
	70
	71	safe_close(e->input_fd);
	72
	73	free(e->buffer);
	74	free(e->path);
6b430fdb	75	return mfree(e);
587fec42 LP	76	}
	77
	78	int raw_export_new(
	79	RawExport **ret,
	80	sd_event *event,
	81	RawExportFinished on_finished,
	82	void *userdata) {
	83
	84	_cleanup_(raw_export_unrefp) RawExport *e = NULL;
	85	int r;
	86
	87	assert(ret);
	88
0d94088e	89	e = new(RawExport, 1);
587fec42 LP	90	if (!e)
	91	return -ENOMEM;
	92
0d94088e YW	93	*e = (RawExport) {
	94	.output_fd = -1,
	95	.input_fd = -1,
	96	.on_finished = on_finished,
	97	.userdata = userdata,
	98	.last_percent = (unsigned) -1,
	99	};
587fec42 LP	100
587fec42 LP	101	RATELIMIT_INIT(e->progress_rate_limit, 100 * USEC_PER_MSEC, 1);
587fec42 LP	102
	103	if (event)
	104	e->event = sd_event_ref(event);
	105	else {
	106	r = sd_event_default(&e->event);
	107	if (r < 0)
	108	return r;
	109	}
	110
1cc6c93a	111	*ret = TAKE_PTR(e);
587fec42 LP	112
	113	return 0;
	114	}
	115
	116	static void raw_export_report_progress(RawExport *e) {
	117	unsigned percent;
	118	assert(e);
	119
	120	if (e->written_uncompressed >= (uint64_t) e->st.st_size)
	121	percent = 100;
	122	else
	123	percent = (unsigned) ((e->written_uncompressed * UINT64_C(100)) / (uint64_t) e->st.st_size);
	124
	125	if (percent == e->last_percent)
	126	return;
	127
7994ac1d	128	if (!ratelimit_below(&e->progress_rate_limit))
587fec42 LP	129	return;
	130
	131	sd_notifyf(false, "X_IMPORT_PROGRESS=%u", percent);
	132	log_info("Exported %u%%.", percent);
	133
	134	e->last_percent = percent;
	135	}
	136
	137	static int raw_export_process(RawExport *e) {
	138	ssize_t l;
	139	int r;
	140
	141	assert(e);
	142
	143	if (!e->tried_reflink && e->compress.type == IMPORT_COMPRESS_UNCOMPRESSED) {
	144
	145	/* If we shall take an uncompressed snapshot we can
	146	* reflink source to destination directly. Let's see
	147	* if this works. */
	148
	149	r = btrfs_reflink(e->input_fd, e->output_fd);
	150	if (r >= 0) {
	151	r = 0;
	152	goto finish;
	153	}
	154
	155	e->tried_reflink = true;
	156	}
	157
	158	if (!e->tried_sendfile && e->compress.type == IMPORT_COMPRESS_UNCOMPRESSED) {
	159
	160	l = sendfile(e->output_fd, e->input_fd, NULL, COPY_BUFFER_SIZE);
	161	if (l < 0) {
	162	if (errno == EAGAIN)
	163	return 0;
	164
	165	e->tried_sendfile = true;
	166	} else if (l == 0) {
	167	r = 0;
	168	goto finish;
	169	} else {
	170	e->written_uncompressed += l;
	171	e->written_compressed += l;
	172
	173	raw_export_report_progress(e);
	174
	175	return 0;
	176	}
	177	}
	178
	179	while (e->buffer_size <= 0) {
	180	uint8_t input[COPY_BUFFER_SIZE];
	181
	182	if (e->eof) {
	183	r = 0;
	184	goto finish;
	185	}
	186
	187	l = read(e->input_fd, input, sizeof(input));
	188	if (l < 0) {
	189	r = log_error_errno(errno, "Failed to read raw file: %m");
	190	goto finish;
	191	}
	192
193	if (l == 0) {
194	e->eof = true;
195	r = import_compress_finish(&e->compress, &e->buffer, &e->buffer_size, &e->buffer_allocated);
196	} else {
197	e->written_uncompressed += l;
198	r = import_compress(&e->compress, input, l, &e->buffer, &e->buffer_size, &e->buffer_allocated);
199	}
200	if (r < 0) {
201	r = log_error_errno(r, "Failed to encode: %m");
202	goto finish;
203	}
204	}
205
206	l = write(e->output_fd, e->buffer, e->buffer_size);
207	if (l < 0) {
208	if (errno == EAGAIN)
209	return 0;
210
211	r = log_error_errno(errno, "Failed to write output file: %m");
212	goto finish;
213	}
214
215	assert((size_t) l <= e->buffer_size);
216	memmove(e->buffer, (uint8_t*) e->buffer + l, e->buffer_size - l);
217	e->buffer_size -= l;
218	e->written_compressed += l;
219
220	raw_export_report_progress(e);
221
222	return 0;
223
224	finish:
225	if (r >= 0) {
226	(void) copy_times(e->input_fd, e->output_fd);
227	(void) copy_xattr(e->input_fd, e->output_fd);
228	}
229
230	if (e->on_finished)
231	e->on_finished(e, r, e->userdata);
232	else
233	sd_event_exit(e->event, r);
234
235	return 0;
236	}
237
238	static int raw_export_on_output(sd_event_source s, int fd, uint32_t revents, void userdata) {
239	RawExport *i = userdata;
240
241	return raw_export_process(i);
242	}
243
244	static int raw_export_on_defer(sd_event_source s, void userdata) {
245	RawExport *i = userdata;
246
247	return raw_export_process(i);
248	}
249
250	static int reflink_snapshot(int fd, const char *path) {
587fec42 LP	251	int new_fd, r;
587fec42 LP	252
0c462ea4	253	new_fd = open_parent(path, O_TMPFILE\|O_CLOEXEC\|O_RDWR, 0600);
587fec42 LP	254	if (new_fd < 0) {
	255	_cleanup_free_ char *t = NULL;
	256
14bcf25c	257	r = tempfn_random(path, NULL, &t);
587fec42 LP	258	if (r < 0)
	259	return r;
	260
	261	new_fd = open(t, O_CLOEXEC\|O_CREAT\|O_NOCTTY\|O_RDWR, 0600);
	262	if (new_fd < 0)
	263	return -errno;
	264
	265	(void) unlink(t);
	266	}
	267
	268	r = btrfs_reflink(fd, new_fd);
	269	if (r < 0) {
	270	safe_close(new_fd);
	271	return r;
	272	}
	273
	274	return new_fd;
	275	}
	276
	277	int raw_export_start(RawExport e, const char path, int fd, ImportCompressType compress) {
	278	_cleanup_close_ int sfd = -1, tfd = -1;
	279	int r;
	280
	281	assert(e);
	282	assert(path);
	283	assert(fd >= 0);
	284	assert(compress < _IMPORT_COMPRESS_TYPE_MAX);
	285	assert(compress != IMPORT_COMPRESS_UNKNOWN);
	286
	287	if (e->output_fd >= 0)
	288	return -EBUSY;
	289
	290	r = fd_nonblock(fd, true);
	291	if (r < 0)
	292	return r;
	293
	294	r = free_and_strdup(&e->path, path);
	295	if (r < 0)
	296	return r;
	297
	298	sfd = open(path, O_RDONLY\|O_CLOEXEC\|O_NOCTTY);
	299	if (sfd < 0)
	300	return -errno;
	301
	302	if (fstat(sfd, &e->st) < 0)
	303	return -errno;
3cc44114 LP	304	r = stat_verify_regular(&e->st);
	305	if (r < 0)
	306	return r;
587fec42 LP	307
	308	/* Try to take a reflink snapshot of the file, if we can t make the export atomic */
	309	tfd = reflink_snapshot(sfd, path);
c10d6bdb LP	310	if (tfd >= 0)
	311	e->input_fd = TAKE_FD(tfd);
	312	else
	313	e->input_fd = TAKE_FD(sfd);
587fec42 LP	314
	315	r = import_compress_init(&e->compress, compress);
	316	if (r < 0)
	317	return r;
	318
	319	r = sd_event_add_io(e->event, &e->output_event_source, fd, EPOLLOUT, raw_export_on_output, e);
	320	if (r == -EPERM) {
	321	r = sd_event_add_defer(e->event, &e->output_event_source, raw_export_on_defer, e);
	322	if (r < 0)
	323	return r;
	324
	325	r = sd_event_source_set_enabled(e->output_event_source, SD_EVENT_ON);
	326	}
	327	if (r < 0)
	328	return r;
	329
	330	e->output_fd = fd;
	331	return r;
	332	}