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

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

#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_fcntl.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_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 = -1,
                .input_fd = -1,
                .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 = 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, COPY_CRTIME);
                (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
db9ecf05	1	/* SPDX-License-Identifier: LGPL-2.1-or-later */
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"
0c462ea4	18	#include "fs-util.h"
07630cea	19	#include "import-common.h"
0499585f	20	#include "missing_fcntl.h"
07630cea	21	#include "ratelimit.h"
3cc44114	22	#include "stat-util.h"
07630cea	23	#include "string-util.h"
e4de7287	24	#include "tmpfile-util.h"
07630cea	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;
5ac1530e	52	RateLimit progress_ratelimit;
587fec42 LP	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,
f5fbe71d	98	.last_percent = UINT_MAX,
5ac1530e	99	.progress_ratelimit = { 100 * USEC_PER_MSEC, 1 },
0d94088e	100	};
587fec42	101
587fec42 LP	102	if (event)
	103	e->event = sd_event_ref(event);
	104	else {
	105	r = sd_event_default(&e->event);
	106	if (r < 0)
	107	return r;
	108	}
	109
1cc6c93a	110	*ret = TAKE_PTR(e);
587fec42 LP	111
	112	return 0;
	113	}
	114
	115	static void raw_export_report_progress(RawExport *e) {
	116	unsigned percent;
	117	assert(e);
	118
	119	if (e->written_uncompressed >= (uint64_t) e->st.st_size)
	120	percent = 100;
	121	else
	122	percent = (unsigned) ((e->written_uncompressed * UINT64_C(100)) / (uint64_t) e->st.st_size);
	123
	124	if (percent == e->last_percent)
	125	return;
	126
5ac1530e	127	if (!ratelimit_below(&e->progress_ratelimit))
587fec42 LP	128	return;
	129
	130	sd_notifyf(false, "X_IMPORT_PROGRESS=%u", percent);
	131	log_info("Exported %u%%.", percent);
	132
	133	e->last_percent = percent;
	134	}
	135
	136	static int raw_export_process(RawExport *e) {
	137	ssize_t l;
	138	int r;
	139
	140	assert(e);
	141
	142	if (!e->tried_reflink && e->compress.type == IMPORT_COMPRESS_UNCOMPRESSED) {
	143
	144	/* If we shall take an uncompressed snapshot we can
	145	* reflink source to destination directly. Let's see
	146	* if this works. */
	147
	148	r = btrfs_reflink(e->input_fd, e->output_fd);
	149	if (r >= 0) {
	150	r = 0;
	151	goto finish;
	152	}
	153
	154	e->tried_reflink = true;
	155	}
	156
	157	if (!e->tried_sendfile && e->compress.type == IMPORT_COMPRESS_UNCOMPRESSED) {
	158
	159	l = sendfile(e->output_fd, e->input_fd, NULL, COPY_BUFFER_SIZE);
	160	if (l < 0) {
	161	if (errno == EAGAIN)
	162	return 0;
	163
	164	e->tried_sendfile = true;
	165	} else if (l == 0) {
	166	r = 0;
	167	goto finish;
	168	} else {
	169	e->written_uncompressed += l;
	170	e->written_compressed += l;
	171
	172	raw_export_report_progress(e);
	173
	174	return 0;
	175	}
	176	}
	177
	178	while (e->buffer_size <= 0) {
	179	uint8_t input[COPY_BUFFER_SIZE];
	180
	181	if (e->eof) {
	182	r = 0;
	183	goto finish;
	184	}
	185
	186	l = read(e->input_fd, input, sizeof(input));
	187	if (l < 0) {
	188	r = log_error_errno(errno, "Failed to read raw file: %m");
	189	goto finish;
	190	}
	191
192	if (l == 0) {
193	e->eof = true;
194	r = import_compress_finish(&e->compress, &e->buffer, &e->buffer_size, &e->buffer_allocated);
195	} else {
196	e->written_uncompressed += l;
197	r = import_compress(&e->compress, input, l, &e->buffer, &e->buffer_size, &e->buffer_allocated);
198	}
199	if (r < 0) {
200	r = log_error_errno(r, "Failed to encode: %m");
201	goto finish;
202	}
203	}
204
205	l = write(e->output_fd, e->buffer, e->buffer_size);
206	if (l < 0) {
207	if (errno == EAGAIN)
208	return 0;
209
210	r = log_error_errno(errno, "Failed to write output file: %m");
211	goto finish;
212	}
213
214	assert((size_t) l <= e->buffer_size);
215	memmove(e->buffer, (uint8_t*) e->buffer + l, e->buffer_size - l);
216	e->buffer_size -= l;
217	e->written_compressed += l;
218
219	raw_export_report_progress(e);
220
221	return 0;
222
223	finish:
224	if (r >= 0) {
adc6f43b	225	(void) copy_times(e->input_fd, e->output_fd, COPY_CRTIME);
587fec42 LP	226	(void) copy_xattr(e->input_fd, e->output_fd);
	227	}
	228
	229	if (e->on_finished)
	230	e->on_finished(e, r, e->userdata);
	231	else
	232	sd_event_exit(e->event, r);
	233
	234	return 0;
	235	}
	236
	237	static int raw_export_on_output(sd_event_source s, int fd, uint32_t revents, void userdata) {
	238	RawExport *i = userdata;
	239
	240	return raw_export_process(i);
	241	}
	242
	243	static int raw_export_on_defer(sd_event_source s, void userdata) {
	244	RawExport *i = userdata;
	245
	246	return raw_export_process(i);
	247	}
	248
	249	static int reflink_snapshot(int fd, const char *path) {
587fec42 LP	250	int new_fd, r;
587fec42 LP	251
0c462ea4	252	new_fd = open_parent(path, O_TMPFILE\|O_CLOEXEC\|O_RDWR, 0600);
587fec42 LP	253	if (new_fd < 0) {
	254	_cleanup_free_ char *t = NULL;
	255
14bcf25c	256	r = tempfn_random(path, NULL, &t);
587fec42 LP	257	if (r < 0)
	258	return r;
	259
	260	new_fd = open(t, O_CLOEXEC\|O_CREAT\|O_NOCTTY\|O_RDWR, 0600);
	261	if (new_fd < 0)
	262	return -errno;
	263
	264	(void) unlink(t);
	265	}
	266
	267	r = btrfs_reflink(fd, new_fd);
	268	if (r < 0) {
	269	safe_close(new_fd);
	270	return r;
	271	}
	272
	273	return new_fd;
	274	}
	275
	276	int raw_export_start(RawExport e, const char path, int fd, ImportCompressType compress) {
	277	_cleanup_close_ int sfd = -1, tfd = -1;
	278	int r;
	279
	280	assert(e);
	281	assert(path);
	282	assert(fd >= 0);
	283	assert(compress < _IMPORT_COMPRESS_TYPE_MAX);
	284	assert(compress != IMPORT_COMPRESS_UNKNOWN);
	285
	286	if (e->output_fd >= 0)
	287	return -EBUSY;
	288
	289	r = fd_nonblock(fd, true);
	290	if (r < 0)
	291	return r;
	292
	293	r = free_and_strdup(&e->path, path);
	294	if (r < 0)
	295	return r;
	296
	297	sfd = open(path, O_RDONLY\|O_CLOEXEC\|O_NOCTTY);
	298	if (sfd < 0)
	299	return -errno;
	300
	301	if (fstat(sfd, &e->st) < 0)
	302	return -errno;
3cc44114 LP	303	r = stat_verify_regular(&e->st);
	304	if (r < 0)
	305	return r;
587fec42 LP	306
	307	/* Try to take a reflink snapshot of the file, if we can t make the export atomic */
	308	tfd = reflink_snapshot(sfd, path);
c10d6bdb LP	309	if (tfd >= 0)
	310	e->input_fd = TAKE_FD(tfd);
	311	else
	312	e->input_fd = TAKE_FD(sfd);
587fec42 LP	313
	314	r = import_compress_init(&e->compress, compress);
	315	if (r < 0)
	316	return r;
	317
	318	r = sd_event_add_io(e->event, &e->output_event_source, fd, EPOLLOUT, raw_export_on_output, e);
	319	if (r == -EPERM) {
	320	r = sd_event_add_defer(e->event, &e->output_event_source, raw_export_on_defer, e);
	321	if (r < 0)
	322	return r;
	323
	324	r = sd_event_source_set_enabled(e->output_event_source, SD_EVENT_ON);
	325	}
	326	if (r < 0)
	327	return r;
	328
	329	e->output_fd = fd;
	330	return r;
	331	}