#include "sd-daemon.h"

#include "alloc-util.h"

#include "btrfs-util.h"

#include "export-tar.h"

#include "fd-util.h"

#include "fileio.h"

#include "import-common.h"

#include "process-util.h"

#include "ratelimit.h"

#include "string-util.h"

#include "util.h"

#define COPY_BUFFER_SIZE (16*1024)

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_rate_limit;

bool eof;

bool tried_splice;

};

TarExport *tar_export_unref(TarExport *e) {

if (!e)

return NULL;

sd_event_source_unref(e->output_event_source);

if (e->tar_pid > 1) {

(void) kill_and_sigcont(e->tar_pid, SIGKILL);

(void) wait_for_terminate(e->tar_pid, NULL);

}

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);

free(e);

return NULL;

}

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 = new0(TarExport, 1);

if (!e)

return -ENOMEM;

e->output_fd = e->tar_fd = -1;

e->on_finished = on_finished;

e->userdata = userdata;

e->quota_referenced = (uint64_t) -1;

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 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_t) -1)

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_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 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 = 0;

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 = 0;

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 (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 = -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;

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_t) -1;

if (e->st.st_ino == 256) { /* might be a btrfs subvolume? */

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_fd(sfd, 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;

}