#include <sys/sendfile.h>

#include <libgen.h>

#undef basename

#include "sd-daemon.h"

#include "btrfs-util.h"

#include "copy.h"

#include "export-raw.h"

#include "fd-util.h"

#include "import-common.h"

#include "ratelimit.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);

free(e);

return NULL;

}

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 = new0(RawExport, 1);

if (!e)

return -ENOMEM;

e->output_fd = e->input_fd = -1;

e->on_finished = on_finished;

e->userdata = userdata;

RATELIMIT_INIT(e->progress_rate_limit, 100 * USEC_PER_MSEC, 1);

e->last_percent = (unsigned) -1;

if (event)

e->event = sd_event_ref(event);

else {

r = sd_event_default(&e->event);

if (r < 0)

return r;

}

*ret = e;

e = NULL;

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_test(&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

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) {

char *p, *d;

int new_fd, r;

p = strdupa(path);

d = dirname(p);

new_fd = open(d, O_TMPFILE|O_CLOEXEC|O_NOCTTY|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;

if (!S_ISREG(e->st.st_mode))

return -ENOTTY;

/* 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 = tfd;

tfd = -1;

} else {

e->input_fd = sfd;

sfd = -1;

}

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;

}