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

 /* SPDX-License-Identifier: LGPL-2.1+ */
 /***
   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>

 /* When we include libgen.h because we need dirname() we immediately
  * undefine basename() since libgen.h defines it as a macro to the POSIX
  * version which is really broken. We prefer GNU basename(). */
 #include <libgen.h>
 #undef basename

 #include "sd-daemon.h"

 #include "alloc-util.h"
 #include "btrfs-util.h"
 #include "copy.h"
 #include "export-raw.h"
 #include "fd-util.h"
 #include "fileio.h"
 #include "import-common.h"
 #include "missing.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);
         return mfree(e);
 }

 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
                  * reflink source to destination directly. Let's see
                  * if this works. */

                 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;
 }
	/* SPDX-License-Identifier: LGPL-2.1+ */
	/***
	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>

	/* When we include libgen.h because we need dirname() we immediately
	* undefine basename() since libgen.h defines it as a macro to the POSIX
	* version which is really broken. We prefer GNU basename(). */
	#include <libgen.h>
	#undef basename

	#include "sd-daemon.h"

	#include "alloc-util.h"
	#include "btrfs-util.h"
	#include "copy.h"
	#include "export-raw.h"
	#include "fd-util.h"
	#include "fileio.h"
	#include "import-common.h"
	#include "missing.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);
	return mfree(e);
	}

	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
	* reflink source to destination directly. Let's see
	* if this works. */

	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;
	}