src/import/export-tar.c - systemd-stable - Rivoreo Source Code Repositories

 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/

 /***
   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 <sys/sendfile.h>

 #include "sd-daemon.h"
 #include "util.h"
 #include "ratelimit.h"
 #include "btrfs-util.h"
 #include "import-common.h"
 #include "export-tar.h"
 #include "process-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, false);
                 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_quota_fd(sfd, &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;
 }
	/-- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil --/

	/***
	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 <sys/sendfile.h>

	#include "sd-daemon.h"
	#include "util.h"
	#include "ratelimit.h"
	#include "btrfs-util.h"
	#include "import-common.h"
	#include "export-tar.h"
	#include "process-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, false);
	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_quota_fd(sfd, &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;
	}