btrfs-progs/cmds-receive.c
David Sterba 28fdd0d2ae btrfs-progs: receive: improved error handling in process_snapshot
Signed-off-by: David Sterba <dsterba@suse.com>
2016-09-21 14:12:38 +02:00

1327 lines
30 KiB
C

/*
* Copyright (C) 2012 Alexander Block. All rights reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License v2 as published by the Free Software Foundation.
*
* This program 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
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
#include "kerncompat.h"
#include "androidcompat.h"
#include <unistd.h>
#include <stdint.h>
#include <dirent.h>
#include <fcntl.h>
#include <pthread.h>
#include <math.h>
#include <ftw.h>
#include <sys/wait.h>
#include <assert.h>
#include <getopt.h>
#include <limits.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/xattr.h>
#include <uuid/uuid.h>
#include "ctree.h"
#include "ioctl.h"
#include "commands.h"
#include "utils.h"
#include "list.h"
#include "btrfs-list.h"
#include "send.h"
#include "send-stream.h"
#include "send-utils.h"
static int g_verbose = 0;
struct btrfs_receive
{
int mnt_fd;
int dest_dir_fd;
int write_fd;
char write_path[PATH_MAX];
char *root_path;
char *dest_dir_path; /* relative to root_path */
char full_subvol_path[PATH_MAX];
char *full_root_path;
int dest_dir_chroot;
struct subvol_info cur_subvol;
/*
* Substitute for cur_subvol::path which is a pointer and we cannot
* change it to an array as it's a public API.
*/
char cur_subvol_path[PATH_MAX];
struct subvol_uuid_search sus;
int honor_end_cmd;
/*
* Buffer to store capabilities from security.capabilities xattr,
* usually 20 bytes, but make same room for potentially larger
* encodings. Must be set only once per file, denoted by length > 0.
*/
char cached_capabilities[64];
int cached_capabilities_len;
};
static int finish_subvol(struct btrfs_receive *r)
{
int ret;
int subvol_fd = -1;
struct btrfs_ioctl_received_subvol_args rs_args;
char uuid_str[BTRFS_UUID_UNPARSED_SIZE];
u64 flags;
if (r->cur_subvol_path[0] == 0)
return 0;
subvol_fd = openat(r->mnt_fd, r->cur_subvol_path,
O_RDONLY | O_NOATIME);
if (subvol_fd < 0) {
ret = -errno;
error("cannot open %s: %s\n",
r->cur_subvol_path, strerror(-ret));
goto out;
}
memset(&rs_args, 0, sizeof(rs_args));
memcpy(rs_args.uuid, r->cur_subvol.received_uuid, BTRFS_UUID_SIZE);
rs_args.stransid = r->cur_subvol.stransid;
if (g_verbose >= 1) {
uuid_unparse((u8*)rs_args.uuid, uuid_str);
fprintf(stderr, "BTRFS_IOC_SET_RECEIVED_SUBVOL uuid=%s, "
"stransid=%llu\n", uuid_str, rs_args.stransid);
}
ret = ioctl(subvol_fd, BTRFS_IOC_SET_RECEIVED_SUBVOL, &rs_args);
if (ret < 0) {
ret = -errno;
error("ioctl BTRFS_IOC_SET_RECEIVED_SUBVOL failed: %s",
strerror(-ret));
goto out;
}
r->cur_subvol.rtransid = rs_args.rtransid;
ret = ioctl(subvol_fd, BTRFS_IOC_SUBVOL_GETFLAGS, &flags);
if (ret < 0) {
ret = -errno;
error("ioctl BTRFS_IOC_SUBVOL_GETFLAGS failed: %s",
strerror(-ret));
goto out;
}
flags |= BTRFS_SUBVOL_RDONLY;
ret = ioctl(subvol_fd, BTRFS_IOC_SUBVOL_SETFLAGS, &flags);
if (ret < 0) {
ret = -errno;
error("failed to make subvolume read only: %s",
strerror(-ret));
goto out;
}
ret = 0;
out:
if (r->cur_subvol_path[0]) {
r->cur_subvol_path[0] = 0;
}
if (subvol_fd != -1)
close(subvol_fd);
return ret;
}
static int process_subvol(const char *path, const u8 *uuid, u64 ctransid,
void *user)
{
int ret;
struct btrfs_receive *r = user;
struct btrfs_ioctl_vol_args args_v1;
char uuid_str[BTRFS_UUID_UNPARSED_SIZE];
ret = finish_subvol(r);
if (ret < 0)
goto out;
if (r->cur_subvol.path) {
error("subvol: another one already started, path ptr: %s",
r->cur_subvol.path);
ret = -EINVAL;
goto out;
}
if (r->cur_subvol_path[0]) {
error("subvol: another one already started, path buf: %s",
r->cur_subvol.path);
ret = -EINVAL;
goto out;
}
if (*r->dest_dir_path == 0) {
strncpy_null(r->cur_subvol_path, path);
} else {
ret = path_cat_out(r->cur_subvol_path, r->dest_dir_path, path);
if (ret < 0) {
error("subvol: path invalid: %s\n", path);
goto out;
}
}
ret = path_cat3_out(r->full_subvol_path, r->root_path,
r->dest_dir_path, path);
if (ret < 0) {
error("subvol: path invalid: %s", path);
goto out;
}
fprintf(stderr, "At subvol %s\n", path);
memcpy(r->cur_subvol.received_uuid, uuid, BTRFS_UUID_SIZE);
r->cur_subvol.stransid = ctransid;
if (g_verbose) {
uuid_unparse((u8*)r->cur_subvol.received_uuid, uuid_str);
fprintf(stderr, "receiving subvol %s uuid=%s, stransid=%llu\n",
path, uuid_str,
r->cur_subvol.stransid);
}
memset(&args_v1, 0, sizeof(args_v1));
strncpy_null(args_v1.name, path);
ret = ioctl(r->dest_dir_fd, BTRFS_IOC_SUBVOL_CREATE, &args_v1);
if (ret < 0) {
ret = -errno;
error("creating subvolume %s failed: %s", path, strerror(-ret));
goto out;
}
out:
return ret;
}
static int process_snapshot(const char *path, const u8 *uuid, u64 ctransid,
const u8 *parent_uuid, u64 parent_ctransid,
void *user)
{
int ret;
struct btrfs_receive *r = user;
char uuid_str[BTRFS_UUID_UNPARSED_SIZE];
struct btrfs_ioctl_vol_args_v2 args_v2;
struct subvol_info *parent_subvol = NULL;
ret = finish_subvol(r);
if (ret < 0)
goto out;
if (r->cur_subvol.path) {
error("snapshot: another one already started, path ptr: %s",
r->cur_subvol.path);
ret = -EINVAL;
goto out;
}
if (r->cur_subvol_path[0]) {
error("snapshot: another one already started, path buf: %s",
r->cur_subvol.path);
ret = -EINVAL;
goto out;
}
if (*r->dest_dir_path == 0) {
strncpy_null(r->cur_subvol_path, path);
} else {
ret = path_cat_out(r->cur_subvol_path, r->dest_dir_path, path);
if (ret < 0) {
error("snapshot: path invalid: %s", path);
goto out;
}
}
ret = path_cat3_out(r->full_subvol_path, r->root_path,
r->dest_dir_path, path);
if (ret < 0) {
error("snapshot: path invalid: %s", path);
goto out;
}
fprintf(stdout, "At snapshot %s\n", path);
memcpy(r->cur_subvol.received_uuid, uuid, BTRFS_UUID_SIZE);
r->cur_subvol.stransid = ctransid;
if (g_verbose) {
uuid_unparse((u8*)r->cur_subvol.received_uuid, uuid_str);
fprintf(stderr, "receiving snapshot %s uuid=%s, "
"ctransid=%llu ", path, uuid_str,
r->cur_subvol.stransid);
uuid_unparse(parent_uuid, uuid_str);
fprintf(stderr, "parent_uuid=%s, parent_ctransid=%llu\n",
uuid_str, parent_ctransid);
}
memset(&args_v2, 0, sizeof(args_v2));
strncpy_null(args_v2.name, path);
parent_subvol = subvol_uuid_search(&r->sus, 0, parent_uuid,
parent_ctransid, NULL, subvol_search_by_received_uuid);
if (!parent_subvol) {
parent_subvol = subvol_uuid_search(&r->sus, 0, parent_uuid,
parent_ctransid, NULL, subvol_search_by_uuid);
}
if (!parent_subvol) {
ret = -ENOENT;
error("cannot find parent subvolume");
goto out;
}
/*
* The path is resolved from the root subvol, but we could be in some
* subvolume under the root subvolume, so try and adjust the path to be
* relative to our root path.
*/
if (r->full_root_path) {
size_t root_len;
size_t sub_len;
root_len = strlen(r->full_root_path);
sub_len = strlen(parent_subvol->path);
/* First make sure the parent subvol is actually in our path */
if (sub_len < root_len ||
strstr(parent_subvol->path, r->full_root_path) == NULL) {
error(
"parent subvol is not reachable from inside the root subvol");
ret = -ENOENT;
goto out;
}
if (sub_len == root_len) {
parent_subvol->path[0] = '/';
parent_subvol->path[1] = '\0';
} else {
/*
* root path is foo/bar
* subvol path is foo/bar/baz
*
* we need to have baz be the path, so we need to move
* the bit after foo/bar/, so path + root_len + 1, and
* move the part we care about, so sub_len - root_len -
* 1.
*/
memmove(parent_subvol->path,
parent_subvol->path + root_len + 1,
sub_len - root_len - 1);
parent_subvol->path[sub_len - root_len - 1] = '\0';
}
}
/*if (rs_args.ctransid > rs_args.rtransid) {
if (!r->force) {
ret = -EINVAL;
fprintf(stderr, "ERROR: subvolume %s was modified after it was received.\n", r->subvol_parent_name);
goto out;
} else {
fprintf(stderr, "WARNING: subvolume %s was modified after it was received.\n", r->subvol_parent_name);
}
}*/
if (*parent_subvol->path == 0)
args_v2.fd = dup(r->mnt_fd);
else
args_v2.fd = openat(r->mnt_fd, parent_subvol->path,
O_RDONLY | O_NOATIME);
if (args_v2.fd < 0) {
ret = -errno;
if (errno != ENOENT)
error("cannot open %s: %s",
parent_subvol->path, strerror(-ret));
else
fprintf(stderr,
"It seems that you have changed your default "
"subvolume or you specify other subvolume to\n"
"mount btrfs, try to remount this btrfs filesystem "
"with fs tree, and run btrfs receive again!\n");
goto out;
}
ret = ioctl(r->dest_dir_fd, BTRFS_IOC_SNAP_CREATE_V2, &args_v2);
close(args_v2.fd);
if (ret < 0) {
ret = -errno;
error("creating snapshot %s -> %s failed: %s",
parent_subvol->path, path, strerror(-ret));
goto out;
}
out:
if (parent_subvol) {
free(parent_subvol->path);
free(parent_subvol);
}
return ret;
}
static int process_mkfile(const char *path, void *user)
{
int ret;
struct btrfs_receive *r = user;
char full_path[PATH_MAX];
ret = path_cat_out(full_path, r->full_subvol_path, path);
if (ret < 0) {
error("mkfile: path invalid: %s", path);
goto out;
}
if (g_verbose >= 2)
fprintf(stderr, "mkfile %s\n", path);
ret = creat(full_path, 0600);
if (ret < 0) {
ret = -errno;
error("mkfile %s failed: %s", path, strerror(-ret));
goto out;
}
close(ret);
ret = 0;
out:
return ret;
}
static int process_mkdir(const char *path, void *user)
{
int ret;
struct btrfs_receive *r = user;
char full_path[PATH_MAX];
ret = path_cat_out(full_path, r->full_subvol_path, path);
if (ret < 0) {
error("mkdir: path invalid: %s", path);
goto out;
}
if (g_verbose >= 2)
fprintf(stderr, "mkdir %s\n", path);
ret = mkdir(full_path, 0700);
if (ret < 0) {
ret = -errno;
error("mkdir %s failed: %s", path, strerror(-ret));
}
out:
return ret;
}
static int process_mknod(const char *path, u64 mode, u64 dev, void *user)
{
int ret;
struct btrfs_receive *r = user;
char full_path[PATH_MAX];
ret = path_cat_out(full_path, r->full_subvol_path, path);
if (ret < 0) {
error("mknod: path invalid: %s", path);
goto out;
}
if (g_verbose >= 2)
fprintf(stderr, "mknod %s mode=%llu, dev=%llu\n",
path, mode, dev);
ret = mknod(full_path, mode & S_IFMT, dev);
if (ret < 0) {
ret = -errno;
error("mknod %s failed: %s", path, strerror(-ret));
}
out:
return ret;
}
static int process_mkfifo(const char *path, void *user)
{
int ret;
struct btrfs_receive *r = user;
char full_path[PATH_MAX];
ret = path_cat_out(full_path, r->full_subvol_path, path);
if (ret < 0) {
error("mkfifo: path invalid: %s", path);
goto out;
}
if (g_verbose >= 2)
fprintf(stderr, "mkfifo %s\n", path);
ret = mkfifo(full_path, 0600);
if (ret < 0) {
ret = -errno;
error("mkfifo %s failed: %s", path, strerror(-ret));
}
out:
return ret;
}
static int process_mksock(const char *path, void *user)
{
int ret;
struct btrfs_receive *r = user;
char full_path[PATH_MAX];
ret = path_cat_out(full_path, r->full_subvol_path, path);
if (ret < 0) {
error("mksock: path invalid: %s", path);
goto out;
}
if (g_verbose >= 2)
fprintf(stderr, "mksock %s\n", path);
ret = mknod(full_path, 0600 | S_IFSOCK, 0);
if (ret < 0) {
ret = -errno;
error("mknod %s failed: %s", path, strerror(-ret));
}
out:
return ret;
}
static int process_symlink(const char *path, const char *lnk, void *user)
{
int ret;
struct btrfs_receive *r = user;
char full_path[PATH_MAX];
ret = path_cat_out(full_path, r->full_subvol_path, path);
if (ret < 0) {
error("symlink: path invalid: %s", path);
goto out;
}
if (g_verbose >= 2)
fprintf(stderr, "symlink %s -> %s\n", path, lnk);
ret = symlink(lnk, full_path);
if (ret < 0) {
ret = -errno;
error("symlink %s -> %s failed: %s", path,
lnk, strerror(-ret));
}
out:
return ret;
}
static int process_rename(const char *from, const char *to, void *user)
{
int ret;
struct btrfs_receive *r = user;
char full_from[PATH_MAX];
char full_to[PATH_MAX];
ret = path_cat_out(full_from, r->full_subvol_path, from);
if (ret < 0) {
error("rename: source path invalid: %s", from);
goto out;
}
ret = path_cat_out(full_to, r->full_subvol_path, to);
if (ret < 0) {
error("rename: target path invalid: %s", to);
goto out;
}
if (g_verbose >= 2)
fprintf(stderr, "rename %s -> %s\n", from, to);
ret = rename(full_from, full_to);
if (ret < 0) {
ret = -errno;
error("rename %s -> %s failed: %s", from,
to, strerror(-ret));
}
out:
return ret;
}
static int process_link(const char *path, const char *lnk, void *user)
{
int ret;
struct btrfs_receive *r = user;
char full_path[PATH_MAX];
char full_link_path[PATH_MAX];
ret = path_cat_out(full_path, r->full_subvol_path, path);
if (ret < 0) {
error("link: source path invalid: %s", full_path);
goto out;
}
ret = path_cat_out(full_link_path, r->full_subvol_path, lnk);
if (ret < 0) {
error("link: target path invalid: %s", full_link_path);
goto out;
}
if (g_verbose >= 2)
fprintf(stderr, "link %s -> %s\n", path, lnk);
ret = link(full_link_path, full_path);
if (ret < 0) {
ret = -errno;
error("link %s -> %s failed: %s", path, lnk, strerror(-ret));
}
out:
return ret;
}
static int process_unlink(const char *path, void *user)
{
int ret;
struct btrfs_receive *r = user;
char full_path[PATH_MAX];
ret = path_cat_out(full_path, r->full_subvol_path, path);
if (ret < 0) {
error("unlink: path invalid: %s", path);
goto out;
}
if (g_verbose >= 2)
fprintf(stderr, "unlink %s\n", path);
ret = unlink(full_path);
if (ret < 0) {
ret = -errno;
error("unlink %s failed. %s", path, strerror(-ret));
}
out:
return ret;
}
static int process_rmdir(const char *path, void *user)
{
int ret;
struct btrfs_receive *r = user;
char full_path[PATH_MAX];
ret = path_cat_out(full_path, r->full_subvol_path, path);
if (ret < 0) {
error("rmdir: path invalid: %s", path);
goto out;
}
if (g_verbose >= 2)
fprintf(stderr, "rmdir %s\n", path);
ret = rmdir(full_path);
if (ret < 0) {
ret = -errno;
error("rmdir %s failed: %s", path, strerror(-ret));
}
out:
return ret;
}
static int open_inode_for_write(struct btrfs_receive *r, const char *path)
{
int ret = 0;
if (r->write_fd != -1) {
if (strcmp(r->write_path, path) == 0)
goto out;
close(r->write_fd);
r->write_fd = -1;
}
r->write_fd = open(path, O_RDWR);
if (r->write_fd < 0) {
ret = -errno;
error("cannot open %s: %s", path, strerror(-ret));
goto out;
}
strncpy_null(r->write_path, path);
out:
return ret;
}
static void close_inode_for_write(struct btrfs_receive *r)
{
if(r->write_fd == -1)
return;
close(r->write_fd);
r->write_fd = -1;
r->write_path[0] = 0;
}
static int process_write(const char *path, const void *data, u64 offset,
u64 len, void *user)
{
int ret = 0;
struct btrfs_receive *r = user;
char full_path[PATH_MAX];
u64 pos = 0;
int w;
ret = path_cat_out(full_path, r->full_subvol_path, path);
if (ret < 0) {
error("write: path invalid: %s", path);
goto out;
}
ret = open_inode_for_write(r, full_path);
if (ret < 0)
goto out;
while (pos < len) {
w = pwrite(r->write_fd, (char*)data + pos, len - pos,
offset + pos);
if (w < 0) {
ret = -errno;
error("writing to %s failed: %s\n",
path, strerror(-ret));
goto out;
}
pos += w;
}
out:
return ret;
}
static int process_clone(const char *path, u64 offset, u64 len,
const u8 *clone_uuid, u64 clone_ctransid,
const char *clone_path, u64 clone_offset,
void *user)
{
int ret;
struct btrfs_receive *r = user;
struct btrfs_ioctl_clone_range_args clone_args;
struct subvol_info *si = NULL;
char full_path[PATH_MAX];
char *subvol_path = NULL;
char full_clone_path[PATH_MAX];
int clone_fd = -1;
ret = path_cat_out(full_path, r->full_subvol_path, path);
if (ret < 0) {
error("clone: source path invalid: %s", path);
goto out;
}
ret = open_inode_for_write(r, full_path);
if (ret < 0)
goto out;
si = subvol_uuid_search(&r->sus, 0, clone_uuid, clone_ctransid, NULL,
subvol_search_by_received_uuid);
if (!si) {
if (memcmp(clone_uuid, r->cur_subvol.received_uuid,
BTRFS_UUID_SIZE) == 0) {
/* TODO check generation of extent */
subvol_path = strdup(r->cur_subvol_path);
} else {
ret = -ENOENT;
error("clone: did not find source subvol");
goto out;
}
} else {
/*if (rs_args.ctransid > rs_args.rtransid) {
if (!r->force) {
ret = -EINVAL;
fprintf(stderr, "ERROR: subvolume %s was "
"modified after it was "
"received.\n",
r->subvol_parent_name);
goto out;
} else {
fprintf(stderr, "WARNING: subvolume %s was "
"modified after it was "
"received.\n",
r->subvol_parent_name);
}
}*/
subvol_path = strdup(si->path);
}
ret = path_cat_out(full_clone_path, subvol_path, clone_path);
if (ret < 0) {
error("clone: target path invalid: %s", clone_path);
goto out;
}
clone_fd = openat(r->mnt_fd, full_clone_path, O_RDONLY | O_NOATIME);
if (clone_fd < 0) {
ret = -errno;
error("cannot open %s: %s", full_clone_path, strerror(-ret));
goto out;
}
clone_args.src_fd = clone_fd;
clone_args.src_offset = clone_offset;
clone_args.src_length = len;
clone_args.dest_offset = offset;
ret = ioctl(r->write_fd, BTRFS_IOC_CLONE_RANGE, &clone_args);
if (ret < 0) {
ret = -errno;
error("failed to clone extents to %s\n%s\n",
path, strerror(-ret));
goto out;
}
out:
if (si) {
free(si->path);
free(si);
}
free(subvol_path);
if (clone_fd != -1)
close(clone_fd);
return ret;
}
static int process_set_xattr(const char *path, const char *name,
const void *data, int len, void *user)
{
int ret = 0;
struct btrfs_receive *r = user;
char full_path[PATH_MAX];
ret = path_cat_out(full_path, r->full_subvol_path, path);
if (ret < 0) {
error("set_xattr: path invalid: %s", path);
goto out;
}
if (strcmp("security.capability", name) == 0) {
if (g_verbose >= 3)
fprintf(stderr, "set_xattr: cache capabilities\n");
if (r->cached_capabilities_len)
warning("capabilities set multiple times per file: %s",
full_path);
if (len > sizeof(r->cached_capabilities)) {
error("capabilities encoded to %d bytes, buffer too small",
len);
ret = -E2BIG;
goto out;
}
r->cached_capabilities_len = len;
memcpy(r->cached_capabilities, data, len);
}
if (g_verbose >= 2) {
fprintf(stderr, "set_xattr %s - name=%s data_len=%d "
"data=%.*s\n", path, name, len,
len, (char*)data);
}
ret = lsetxattr(full_path, name, data, len, 0);
if (ret < 0) {
ret = -errno;
error("lsetxattr %s %s=%.*s failed: %s",
path, name, len, (char*)data, strerror(-ret));
goto out;
}
out:
return ret;
}
static int process_remove_xattr(const char *path, const char *name, void *user)
{
int ret = 0;
struct btrfs_receive *r = user;
char full_path[PATH_MAX];
ret = path_cat_out(full_path, r->full_subvol_path, path);
if (ret < 0) {
error("remove_xattr: path invalid: %s", path);
goto out;
}
if (g_verbose >= 2) {
fprintf(stderr, "remove_xattr %s - name=%s\n",
path, name);
}
ret = lremovexattr(full_path, name);
if (ret < 0) {
ret = -errno;
error("lremovexattr %s %s failed: %s",
path, name, strerror(-ret));
goto out;
}
out:
return ret;
}
static int process_truncate(const char *path, u64 size, void *user)
{
int ret = 0;
struct btrfs_receive *r = user;
char full_path[PATH_MAX];
ret = path_cat_out(full_path, r->full_subvol_path, path);
if (ret < 0) {
error("truncate: path invalid: %s", path);
goto out;
}
if (g_verbose >= 2)
fprintf(stderr, "truncate %s size=%llu\n", path, size);
ret = truncate(full_path, size);
if (ret < 0) {
ret = -errno;
error("truncate %s failed: %s", path, strerror(-ret));
goto out;
}
out:
return ret;
}
static int process_chmod(const char *path, u64 mode, void *user)
{
int ret = 0;
struct btrfs_receive *r = user;
char full_path[PATH_MAX];
ret = path_cat_out(full_path, r->full_subvol_path, path);
if (ret < 0) {
error("chmod: path invalid: %s", path);
goto out;
}
if (g_verbose >= 2)
fprintf(stderr, "chmod %s - mode=0%o\n", path, (int)mode);
ret = chmod(full_path, mode);
if (ret < 0) {
ret = -errno;
error("chmod %s failed: %s", path, strerror(-ret));
goto out;
}
out:
return ret;
}
static int process_chown(const char *path, u64 uid, u64 gid, void *user)
{
int ret = 0;
struct btrfs_receive *r = user;
char full_path[PATH_MAX];
ret = path_cat_out(full_path, r->full_subvol_path, path);
if (ret < 0) {
error("chown: path invalid: %s", path);
goto out;
}
if (g_verbose >= 2)
fprintf(stderr, "chown %s - uid=%llu, gid=%llu\n", path,
uid, gid);
ret = lchown(full_path, uid, gid);
if (ret < 0) {
ret = -errno;
error("chown %s failed: %s", path, strerror(-ret));
goto out;
}
if (r->cached_capabilities_len) {
if (g_verbose >= 2)
fprintf(stderr, "chown: restore capabilities\n");
ret = lsetxattr(full_path, "security.capability",
r->cached_capabilities,
r->cached_capabilities_len, 0);
memset(r->cached_capabilities, 0,
sizeof(r->cached_capabilities));
r->cached_capabilities_len = 0;
if (ret < 0) {
ret = -errno;
error("restoring capabilities %s: %s",
path, strerror(-ret));
goto out;
}
}
out:
return ret;
}
static int process_utimes(const char *path, struct timespec *at,
struct timespec *mt, struct timespec *ct,
void *user)
{
int ret = 0;
struct btrfs_receive *r = user;
char full_path[PATH_MAX];
struct timespec tv[2];
ret = path_cat_out(full_path, r->full_subvol_path, path);
if (ret < 0) {
error("utimes: path invalid: %s", path);
goto out;
}
if (g_verbose >= 2)
fprintf(stderr, "utimes %s\n", path);
tv[0] = *at;
tv[1] = *mt;
ret = utimensat(AT_FDCWD, full_path, tv, AT_SYMLINK_NOFOLLOW);
if (ret < 0) {
ret = -errno;
error("utimes %s failed: %s",
path, strerror(-ret));
goto out;
}
out:
return ret;
}
static int process_update_extent(const char *path, u64 offset, u64 len,
void *user)
{
if (g_verbose >= 2)
fprintf(stderr, "update_extent %s: offset=%llu, len=%llu\n",
path, (unsigned long long)offset,
(unsigned long long)len);
/*
* Sent with BTRFS_SEND_FLAG_NO_FILE_DATA, nothing to do.
*/
return 0;
}
static struct btrfs_send_ops send_ops = {
.subvol = process_subvol,
.snapshot = process_snapshot,
.mkfile = process_mkfile,
.mkdir = process_mkdir,
.mknod = process_mknod,
.mkfifo = process_mkfifo,
.mksock = process_mksock,
.symlink = process_symlink,
.rename = process_rename,
.link = process_link,
.unlink = process_unlink,
.rmdir = process_rmdir,
.write = process_write,
.clone = process_clone,
.set_xattr = process_set_xattr,
.remove_xattr = process_remove_xattr,
.truncate = process_truncate,
.chmod = process_chmod,
.chown = process_chown,
.utimes = process_utimes,
.update_extent = process_update_extent,
};
static int do_receive(struct btrfs_receive *r, const char *tomnt,
char *realmnt, int r_fd, u64 max_errors)
{
u64 subvol_id;
int ret;
char *dest_dir_full_path;
char root_subvol_path[PATH_MAX];
int end = 0;
dest_dir_full_path = realpath(tomnt, NULL);
if (!dest_dir_full_path) {
ret = -errno;
error("realpath(%s) failed: %s", tomnt, strerror(-ret));
goto out;
}
r->dest_dir_fd = open(dest_dir_full_path, O_RDONLY | O_NOATIME);
if (r->dest_dir_fd < 0) {
ret = -errno;
error("cannot open destination directory %s: %s",
dest_dir_full_path, strerror(-ret));
goto out;
}
if (realmnt[0]) {
r->root_path = realmnt;
} else {
ret = find_mount_root(dest_dir_full_path, &r->root_path);
if (ret < 0) {
error("failed to determine mount point for %s: %s",
dest_dir_full_path, strerror(-ret));
ret = -EINVAL;
goto out;
}
if (ret > 0) {
error("%s doesn't belong to btrfs mount point",
dest_dir_full_path);
ret = -EINVAL;
goto out;
}
}
r->mnt_fd = open(r->root_path, O_RDONLY | O_NOATIME);
if (r->mnt_fd < 0) {
ret = -errno;
error("cannot open %s: %s", r->root_path, strerror(-ret));
goto out;
}
/*
* If we use -m or a default subvol we want to resolve the path to the
* subvolume we're sitting in so that we can adjust the paths of any
* subvols we want to receive in.
*/
ret = btrfs_list_get_path_rootid(r->mnt_fd, &subvol_id);
if (ret) {
error("cannot resolve our subvolid: %d",
ret);
goto out;
}
root_subvol_path[0] = 0;
ret = btrfs_subvolid_resolve(r->mnt_fd, root_subvol_path,
PATH_MAX, subvol_id);
if (ret) {
error("cannot resolve our subvol path");
goto out;
}
/*
* Ok we're inside of a subvol off of the root subvol, we need to
* actually set full_root_path.
*/
if (*root_subvol_path)
r->full_root_path = root_subvol_path;
if (r->dest_dir_chroot) {
if (chroot(dest_dir_full_path)) {
ret = -errno;
error("failed to chroot to %s: %s",
dest_dir_full_path, strerror(-ret));
goto out;
}
if (chdir("/")) {
ret = -errno;
error("failed to chdir to / after chroot: %s",
strerror(-ret));
goto out;
}
fprintf(stderr, "Chroot to %s\n", dest_dir_full_path);
r->root_path = strdup("/");
r->dest_dir_path = r->root_path;
} else {
/*
* find_mount_root returns a root_path that is a subpath of
* dest_dir_full_path. Now get the other part of root_path,
* which is the destination dir relative to root_path.
*/
r->dest_dir_path = dest_dir_full_path + strlen(r->root_path);
while (r->dest_dir_path[0] == '/')
r->dest_dir_path++;
}
ret = subvol_uuid_search_init(r->mnt_fd, &r->sus);
if (ret < 0)
goto out;
while (!end) {
if (r->cached_capabilities_len) {
if (g_verbose >= 3)
fprintf(stderr, "clear cached capabilities\n");
memset(r->cached_capabilities, 0,
sizeof(r->cached_capabilities));
r->cached_capabilities_len = 0;
}
ret = btrfs_read_and_process_send_stream(r_fd, &send_ops, r,
r->honor_end_cmd,
max_errors);
if (ret < 0)
goto out;
if (ret)
end = 1;
close_inode_for_write(r);
ret = finish_subvol(r);
if (ret < 0)
goto out;
}
ret = 0;
out:
if (r->write_fd != -1) {
close(r->write_fd);
r->write_fd = -1;
}
if (r->root_path != realmnt)
free(r->root_path);
r->root_path = NULL;
r->dest_dir_path = NULL;
free(dest_dir_full_path);
subvol_uuid_search_finit(&r->sus);
if (r->mnt_fd != -1) {
close(r->mnt_fd);
r->mnt_fd = -1;
}
if (r->dest_dir_fd != -1) {
close(r->dest_dir_fd);
r->dest_dir_fd = -1;
}
return ret;
}
int cmd_receive(int argc, char **argv)
{
char *tomnt = NULL;
char fromfile[PATH_MAX];
char realmnt[PATH_MAX];
struct btrfs_receive r;
int receive_fd = fileno(stdin);
u64 max_errors = 1;
int ret = 0;
memset(&r, 0, sizeof(r));
r.mnt_fd = -1;
r.write_fd = -1;
r.dest_dir_fd = -1;
r.dest_dir_chroot = 0;
realmnt[0] = 0;
fromfile[0] = 0;
while (1) {
int c;
static const struct option long_opts[] = {
{ "max-errors", required_argument, NULL, 'E' },
{ "chroot", no_argument, NULL, 'C' },
{ NULL, 0, NULL, 0 }
};
c = getopt_long(argc, argv, "Cevf:m:", long_opts, NULL);
if (c < 0)
break;
switch (c) {
case 'v':
g_verbose++;
break;
case 'f':
if (arg_copy_path(fromfile, optarg, sizeof(fromfile))) {
error("input file path too long (%zu)",
strlen(optarg));
ret = 1;
goto out;
}
break;
case 'e':
r.honor_end_cmd = 1;
break;
case 'C':
r.dest_dir_chroot = 1;
break;
case 'E':
max_errors = arg_strtou64(optarg);
break;
case 'm':
if (arg_copy_path(realmnt, optarg, sizeof(realmnt))) {
error("mount point path too long (%zu)",
strlen(optarg));
ret = 1;
goto out;
}
break;
case '?':
default:
error("receive args invalid");
return 1;
}
}
if (check_argc_exact(argc - optind, 1))
usage(cmd_receive_usage);
tomnt = argv[optind];
if (fromfile[0]) {
receive_fd = open(fromfile, O_RDONLY | O_NOATIME);
if (receive_fd < 0) {
error("cannot open %s: %s", fromfile, strerror(errno));
goto out;
}
}
ret = do_receive(&r, tomnt, realmnt, receive_fd, max_errors);
if (receive_fd != fileno(stdin))
close(receive_fd);
out:
return !!ret;
}
const char * const cmd_receive_usage[] = {
"btrfs receive [-ve] [-f <infile>] [--max-errors <N>] <mount>",
"Receive subvolumes from stdin.",
"Receives one or more subvolumes that were previously",
"sent with btrfs send. The received subvolumes are stored",
"into <mount>.",
"btrfs receive will fail in case a receiving subvolume",
"already exists. It will also fail in case a previously",
"received subvolume was changed after it was received.",
"After receiving a subvolume, it is immediately set to",
"read only.\n",
"-v Enable verbose debug output. Each",
" occurrence of this option increases the",
" verbose level more.",
"-f <infile> By default, btrfs receive uses stdin",
" to receive the subvolumes. Use this",
" option to specify a file to use instead.",
"-e Terminate after receiving an <end cmd>",
" in the data stream. Without this option,",
" the receiver terminates only if an error",
" is recognized or on EOF.",
"-C|--chroot confine the process to <mount> using chroot",
"--max-errors <N> Terminate as soon as N errors happened while",
" processing commands from the send stream.",
" Default value is 1. A value of 0 means no limit.",
"-m <mountpoint> The root mount point of the destination fs.",
" If you do not have /proc use this to tell us where ",
" this file system is mounted.",
NULL
};