blob: 5f89880ed60e2a65a9cfdfb309538d5e512939a4 [file] [log] [blame] [raw]
/* SPDX-License-Identifier: LGPL-2.1+ */
#include "sd-daemon.h"
#include "alloc-util.h"
#include "btrfs-util.h"
#include "export-tar.h"
#include "fd-util.h"
#include "import-common.h"
#include "process-util.h"
#include "ratelimit.h"
#include "string-util.h"
#include "tmpfile-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_ratelimit;
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);
return mfree(e);
}
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 = new(TarExport, 1);
if (!e)
return -ENOMEM;
*e = (TarExport) {
.output_fd = -1,
.tar_fd = -1,
.on_finished = on_finished,
.userdata = userdata,
.quota_referenced = (uint64_t) -1,
.last_percent = (unsigned) -1,
.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 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_below(&e->progress_ratelimit))
return;
sd_notifyf(false, "X_IMPORT_PROGRESS=%u", percent);
log_info("Exported %u%%.", percent);
e->last_percent = percent;
}
static int tar_export_finish(TarExport *e) {
int r;
assert(e);
assert(e->tar_fd >= 0);
if (e->tar_pid > 0) {
r = wait_for_terminate_and_check("tar", e->tar_pid, WAIT_LOG);
e->tar_pid = 0;
if (r < 0)
return r;
if (r != EXIT_SUCCESS)
return -EPROTO;
}
e->tar_fd = safe_close(e->tar_fd);
return 0;
}
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 = tar_export_finish(e);
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 = tar_export_finish(e);
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;
}