diff options
Diffstat (limited to 'src/grp-machine/grp-import/systemd-export/export-tar.c')
| -rw-r--r-- | src/grp-machine/grp-import/systemd-export/export-tar.c | 327 |
1 files changed, 327 insertions, 0 deletions
diff --git a/src/grp-machine/grp-import/systemd-export/export-tar.c b/src/grp-machine/grp-import/systemd-export/export-tar.c new file mode 100644 index 0000000000..541f033c3e --- /dev/null +++ b/src/grp-machine/grp-import/systemd-export/export-tar.c @@ -0,0 +1,327 @@ +/*** + This file is part of systemd. + + Copyright 2015 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include <systemd/sd-daemon.h> + +#include "import-common.h" +#include "systemd-basic/alloc-util.h" +#include "systemd-basic/btrfs-util.h" +#include "systemd-basic/fd-util.h" +#include "systemd-basic/fileio.h" +#include "systemd-basic/process-util.h" +#include "systemd-basic/ratelimit.h" +#include "systemd-basic/string-util.h" +#include "systemd-basic/util.h" + +#include "export-tar.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); + 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 = 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; +} |