/*

* Copyright (C) 2007 Oracle. All rights reserved.

* Copyright (C) 2008 Morey Roof. 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.

*/

#define _XOPEN_SOURCE 700

#define __USE_XOPEN2K8

#define __XOPEN2K8 /* due to an error in dirent.h, to get dirfd() */

#define _GNU_SOURCE /* O_NOATIME */

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#ifndef __CHECKER__

#include <sys/ioctl.h>

#include <sys/mount.h>

#endif

#include <sys/types.h>

#include <sys/stat.h>

#include <uuid/uuid.h>

#include <dirent.h>

#include <fcntl.h>

#include <unistd.h>

#include <mntent.h>

#include <ctype.h>

#include <linux/loop.h>

#include <linux/major.h>

#include <linux/kdev_t.h>

#include <limits.h>

#include <blkid/blkid.h>

#include "kerncompat.h"

#include "radix-tree.h"

#include "ctree.h"

#include "disk-io.h"

#include "transaction.h"

#include "crc32c.h"

#include "utils.h"

#include "volumes.h"

#include "ioctl.h"

#ifdef __CHECKER__

#define BLKGETSIZE64 0

static inline int ioctl(int fd, int define, u64 *size) { return 0; }

#endif

#ifndef BLKDISCARD

#define BLKDISCARD _IO(0x12,119)

#endif

static int

discard_blocks(int fd, u64 start, u64 len)

{

u64 range[2] = { start, len };

if (ioctl(fd, BLKDISCARD, &range) < 0)

return errno;

return 0;

}

static u64 reference_root_table[] = {

[1] = BTRFS_ROOT_TREE_OBJECTID,

[2] = BTRFS_EXTENT_TREE_OBJECTID,

[3] = BTRFS_CHUNK_TREE_OBJECTID,

[4] = BTRFS_DEV_TREE_OBJECTID,

[5] = BTRFS_FS_TREE_OBJECTID,

[6] = BTRFS_CSUM_TREE_OBJECTID,

};

int make_btrfs(int fd, const char *device, const char *label,

u64 blocks[7], u64 num_bytes, u32 nodesize,

u32 leafsize, u32 sectorsize, u32 stripesize)

{

struct btrfs_super_block super;

struct extent_buffer *buf;

struct btrfs_root_item root_item;

struct btrfs_disk_key disk_key;

struct btrfs_extent_item *extent_item;

struct btrfs_inode_item *inode_item;

struct btrfs_chunk *chunk;

struct btrfs_dev_item *dev_item;

struct btrfs_dev_extent *dev_extent;

u8 chunk_tree_uuid[BTRFS_UUID_SIZE];

u8 *ptr;

int i;

int ret;

u32 itemoff;

u32 nritems = 0;

u64 first_free;

u64 ref_root;

u32 array_size;

u32 item_size;

first_free = BTRFS_SUPER_INFO_OFFSET + sectorsize * 2 - 1;

first_free &= ~((u64)sectorsize - 1);

memset(&super, 0, sizeof(super));

num_bytes = (num_bytes / sectorsize) * sectorsize;

uuid_generate(super.fsid);

uuid_generate(super.dev_item.uuid);

uuid_generate(chunk_tree_uuid);

btrfs_set_super_bytenr(&super, blocks[0]);

btrfs_set_super_num_devices(&super, 1);

super.magic = cpu_to_le64(BTRFS_MAGIC);

btrfs_set_super_generation(&super, 1);

btrfs_set_super_root(&super, blocks[1]);

btrfs_set_super_chunk_root(&super, blocks[3]);

btrfs_set_super_total_bytes(&super, num_bytes);

btrfs_set_super_bytes_used(&super, 6 * leafsize);

btrfs_set_super_sectorsize(&super, sectorsize);

btrfs_set_super_leafsize(&super, leafsize);

btrfs_set_super_nodesize(&super, nodesize);

btrfs_set_super_stripesize(&super, stripesize);

btrfs_set_super_csum_type(&super, BTRFS_CSUM_TYPE_CRC32);

btrfs_set_super_chunk_root_generation(&super, 1);

btrfs_set_super_cache_generation(&super, -1);

if (label)

strncpy(super.label, label, BTRFS_LABEL_SIZE - 1);

buf = malloc(sizeof(*buf) + max(sectorsize, leafsize));

/* create the tree of root objects */

memset(buf->data, 0, leafsize);

buf->len = leafsize;

btrfs_set_header_bytenr(buf, blocks[1]);

btrfs_set_header_nritems(buf, 4);

btrfs_set_header_generation(buf, 1);

btrfs_set_header_backref_rev(buf, BTRFS_MIXED_BACKREF_REV);

btrfs_set_header_owner(buf, BTRFS_ROOT_TREE_OBJECTID);

write_extent_buffer(buf, super.fsid, (unsigned long)

btrfs_header_fsid(buf), BTRFS_FSID_SIZE);

write_extent_buffer(buf, chunk_tree_uuid, (unsigned long)

btrfs_header_chunk_tree_uuid(buf),

BTRFS_UUID_SIZE);

/* create the items for the root tree */

memset(&root_item, 0, sizeof(root_item));

inode_item = &root_item.inode;

btrfs_set_stack_inode_generation(inode_item, 1);

btrfs_set_stack_inode_size(inode_item, 3);

btrfs_set_stack_inode_nlink(inode_item, 1);

btrfs_set_stack_inode_nbytes(inode_item, leafsize);

btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);

btrfs_set_root_refs(&root_item, 1);

btrfs_set_root_used(&root_item, leafsize);

btrfs_set_root_generation(&root_item, 1);

memset(&disk_key, 0, sizeof(disk_key));

btrfs_set_disk_key_type(&disk_key, BTRFS_ROOT_ITEM_KEY);

btrfs_set_disk_key_offset(&disk_key, 0);

nritems = 0;

itemoff = __BTRFS_LEAF_DATA_SIZE(leafsize) - sizeof(root_item);

btrfs_set_root_bytenr(&root_item, blocks[2]);

btrfs_set_disk_key_objectid(&disk_key, BTRFS_EXTENT_TREE_OBJECTID);

btrfs_set_item_key(buf, &disk_key, nritems);

btrfs_set_item_offset(buf, btrfs_item_nr(buf, nritems), itemoff);

btrfs_set_item_size(buf, btrfs_item_nr(buf, nritems),

sizeof(root_item));

write_extent_buffer(buf, &root_item, btrfs_item_ptr_offset(buf,

nritems), sizeof(root_item));

nritems++;

itemoff = itemoff - sizeof(root_item);

btrfs_set_root_bytenr(&root_item, blocks[4]);

btrfs_set_disk_key_objectid(&disk_key, BTRFS_DEV_TREE_OBJECTID);

btrfs_set_item_key(buf, &disk_key, nritems);

btrfs_set_item_offset(buf, btrfs_item_nr(buf, nritems), itemoff);

btrfs_set_item_size(buf, btrfs_item_nr(buf, nritems),

sizeof(root_item));

write_extent_buffer(buf, &root_item,

btrfs_item_ptr_offset(buf, nritems),

sizeof(root_item));

nritems++;

itemoff = itemoff - sizeof(root_item);

btrfs_set_root_bytenr(&root_item, blocks[5]);

btrfs_set_disk_key_objectid(&disk_key, BTRFS_FS_TREE_OBJECTID);

btrfs_set_item_key(buf, &disk_key, nritems);

btrfs_set_item_offset(buf, btrfs_item_nr(buf, nritems), itemoff);

btrfs_set_item_size(buf, btrfs_item_nr(buf, nritems),

sizeof(root_item));

write_extent_buffer(buf, &root_item,

btrfs_item_ptr_offset(buf, nritems),

sizeof(root_item));

nritems++;

itemoff = itemoff - sizeof(root_item);

btrfs_set_root_bytenr(&root_item, blocks[6]);

btrfs_set_disk_key_objectid(&disk_key, BTRFS_CSUM_TREE_OBJECTID);

btrfs_set_item_key(buf, &disk_key, nritems);

btrfs_set_item_offset(buf, btrfs_item_nr(buf, nritems), itemoff);

btrfs_set_item_size(buf, btrfs_item_nr(buf, nritems),

sizeof(root_item));

write_extent_buffer(buf, &root_item,

btrfs_item_ptr_offset(buf, nritems),

sizeof(root_item));

nritems++;

csum_tree_block_size(buf, BTRFS_CRC32_SIZE, 0);

ret = pwrite(fd, buf->data, leafsize, blocks[1]);

BUG_ON(ret != leafsize);

/* create the items for the extent tree */

memset(buf->data+sizeof(struct btrfs_header), 0,

leafsize-sizeof(struct btrfs_header));

nritems = 0;

itemoff = __BTRFS_LEAF_DATA_SIZE(leafsize);

for (i = 1; i < 7; i++) {

BUG_ON(blocks[i] < first_free);

BUG_ON(blocks[i] < blocks[i - 1]);

/* create extent item */

itemoff -= sizeof(struct btrfs_extent_item) +

sizeof(struct btrfs_tree_block_info);

btrfs_set_disk_key_objectid(&disk_key, blocks[i]);

btrfs_set_disk_key_offset(&disk_key, leafsize);

btrfs_set_disk_key_type(&disk_key, BTRFS_EXTENT_ITEM_KEY);

btrfs_set_item_key(buf, &disk_key, nritems);

btrfs_set_item_offset(buf, btrfs_item_nr(buf, nritems),

itemoff);

btrfs_set_item_size(buf, btrfs_item_nr(buf, nritems),

sizeof(struct btrfs_extent_item) +

sizeof(struct btrfs_tree_block_info));

extent_item = btrfs_item_ptr(buf, nritems,

struct btrfs_extent_item);

btrfs_set_extent_refs(buf, extent_item, 1);

btrfs_set_extent_generation(buf, extent_item, 1);

btrfs_set_extent_flags(buf, extent_item,

BTRFS_EXTENT_FLAG_TREE_BLOCK);

nritems++;

/* create extent ref */

ref_root = reference_root_table[i];

btrfs_set_disk_key_objectid(&disk_key, blocks[i]);

btrfs_set_disk_key_offset(&disk_key, ref_root);

btrfs_set_disk_key_type(&disk_key, BTRFS_TREE_BLOCK_REF_KEY);

btrfs_set_item_key(buf, &disk_key, nritems);

btrfs_set_item_offset(buf, btrfs_item_nr(buf, nritems),

itemoff);

btrfs_set_item_size(buf, btrfs_item_nr(buf, nritems), 0);

nritems++;

}

btrfs_set_header_bytenr(buf, blocks[2]);

btrfs_set_header_owner(buf, BTRFS_EXTENT_TREE_OBJECTID);

btrfs_set_header_nritems(buf, nritems);

csum_tree_block_size(buf, BTRFS_CRC32_SIZE, 0);

ret = pwrite(fd, buf->data, leafsize, blocks[2]);

BUG_ON(ret != leafsize);

/* create the chunk tree */

memset(buf->data+sizeof(struct btrfs_header), 0,

leafsize-sizeof(struct btrfs_header));

nritems = 0;

item_size = sizeof(*dev_item);

itemoff = __BTRFS_LEAF_DATA_SIZE(leafsize) - item_size;

/* first device 1 (there is no device 0) */

btrfs_set_disk_key_objectid(&disk_key, BTRFS_DEV_ITEMS_OBJECTID);

btrfs_set_disk_key_offset(&disk_key, 1);

btrfs_set_disk_key_type(&disk_key, BTRFS_DEV_ITEM_KEY);

btrfs_set_item_key(buf, &disk_key, nritems);

btrfs_set_item_offset(buf, btrfs_item_nr(buf, nritems), itemoff);

btrfs_set_item_size(buf, btrfs_item_nr(buf, nritems), item_size);

dev_item = btrfs_item_ptr(buf, nritems, struct btrfs_dev_item);

btrfs_set_device_id(buf, dev_item, 1);

btrfs_set_device_generation(buf, dev_item, 0);

btrfs_set_device_total_bytes(buf, dev_item, num_bytes);

btrfs_set_device_bytes_used(buf, dev_item,

BTRFS_MKFS_SYSTEM_GROUP_SIZE);

btrfs_set_device_io_align(buf, dev_item, sectorsize);

btrfs_set_device_io_width(buf, dev_item, sectorsize);

btrfs_set_device_sector_size(buf, dev_item, sectorsize);

btrfs_set_device_type(buf, dev_item, 0);

write_extent_buffer(buf, super.dev_item.uuid,

(unsigned long)btrfs_device_uuid(dev_item),

BTRFS_UUID_SIZE);

write_extent_buffer(buf, super.fsid,

(unsigned long)btrfs_device_fsid(dev_item),

BTRFS_UUID_SIZE);

read_extent_buffer(buf, &super.dev_item, (unsigned long)dev_item,

sizeof(*dev_item));

nritems++;

item_size = btrfs_chunk_item_size(1);

itemoff = itemoff - item_size;

/* then we have chunk 0 */

btrfs_set_disk_key_objectid(&disk_key, BTRFS_FIRST_CHUNK_TREE_OBJECTID);

btrfs_set_disk_key_offset(&disk_key, 0);

btrfs_set_disk_key_type(&disk_key, BTRFS_CHUNK_ITEM_KEY);

btrfs_set_item_key(buf, &disk_key, nritems);

btrfs_set_item_offset(buf, btrfs_item_nr(buf, nritems), itemoff);

btrfs_set_item_size(buf, btrfs_item_nr(buf, nritems), item_size);

chunk = btrfs_item_ptr(buf, nritems, struct btrfs_chunk);

btrfs_set_chunk_length(buf, chunk, BTRFS_MKFS_SYSTEM_GROUP_SIZE);

btrfs_set_chunk_owner(buf, chunk, BTRFS_EXTENT_TREE_OBJECTID);

btrfs_set_chunk_stripe_len(buf, chunk, 64 * 1024);

btrfs_set_chunk_type(buf, chunk, BTRFS_BLOCK_GROUP_SYSTEM);

btrfs_set_chunk_io_align(buf, chunk, sectorsize);

btrfs_set_chunk_io_width(buf, chunk, sectorsize);

btrfs_set_chunk_sector_size(buf, chunk, sectorsize);

btrfs_set_chunk_num_stripes(buf, chunk, 1);

btrfs_set_stripe_devid_nr(buf, chunk, 0, 1);

btrfs_set_stripe_offset_nr(buf, chunk, 0, 0);

nritems++;

write_extent_buffer(buf, super.dev_item.uuid,

(unsigned long)btrfs_stripe_dev_uuid(&chunk->stripe),

BTRFS_UUID_SIZE);

/* copy the key for the chunk to the system array */

ptr = super.sys_chunk_array;

array_size = sizeof(disk_key);

memcpy(ptr, &disk_key, sizeof(disk_key));

ptr += sizeof(disk_key);

/* copy the chunk to the system array */

read_extent_buffer(buf, ptr, (unsigned long)chunk, item_size);

array_size += item_size;

ptr += item_size;

btrfs_set_super_sys_array_size(&super, array_size);

btrfs_set_header_bytenr(buf, blocks[3]);

btrfs_set_header_owner(buf, BTRFS_CHUNK_TREE_OBJECTID);

btrfs_set_header_nritems(buf, nritems);

csum_tree_block_size(buf, BTRFS_CRC32_SIZE, 0);

ret = pwrite(fd, buf->data, leafsize, blocks[3]);

/* create the device tree */

memset(buf->data+sizeof(struct btrfs_header), 0,

leafsize-sizeof(struct btrfs_header));

nritems = 0;

itemoff = __BTRFS_LEAF_DATA_SIZE(leafsize) -

sizeof(struct btrfs_dev_extent);

btrfs_set_disk_key_objectid(&disk_key, 1);

btrfs_set_disk_key_offset(&disk_key, 0);

btrfs_set_disk_key_type(&disk_key, BTRFS_DEV_EXTENT_KEY);

btrfs_set_item_key(buf, &disk_key, nritems);

btrfs_set_item_offset(buf, btrfs_item_nr(buf, nritems), itemoff);

btrfs_set_item_size(buf, btrfs_item_nr(buf, nritems),

sizeof(struct btrfs_dev_extent));

dev_extent = btrfs_item_ptr(buf, nritems, struct btrfs_dev_extent);

btrfs_set_dev_extent_chunk_tree(buf, dev_extent,

BTRFS_CHUNK_TREE_OBJECTID);

btrfs_set_dev_extent_chunk_objectid(buf, dev_extent,

BTRFS_FIRST_CHUNK_TREE_OBJECTID);

btrfs_set_dev_extent_chunk_offset(buf, dev_extent, 0);

write_extent_buffer(buf, chunk_tree_uuid,

(unsigned long)btrfs_dev_extent_chunk_tree_uuid(dev_extent),

BTRFS_UUID_SIZE);

btrfs_set_dev_extent_length(buf, dev_extent,

BTRFS_MKFS_SYSTEM_GROUP_SIZE);

nritems++;

btrfs_set_header_bytenr(buf, blocks[4]);

btrfs_set_header_owner(buf, BTRFS_DEV_TREE_OBJECTID);

btrfs_set_header_nritems(buf, nritems);

csum_tree_block_size(buf, BTRFS_CRC32_SIZE, 0);

ret = pwrite(fd, buf->data, leafsize, blocks[4]);

/* create the FS root */

memset(buf->data+sizeof(struct btrfs_header), 0,

leafsize-sizeof(struct btrfs_header));

btrfs_set_header_bytenr(buf, blocks[5]);

btrfs_set_header_owner(buf, BTRFS_FS_TREE_OBJECTID);

btrfs_set_header_nritems(buf, 0);

csum_tree_block_size(buf, BTRFS_CRC32_SIZE, 0);

ret = pwrite(fd, buf->data, leafsize, blocks[5]);

BUG_ON(ret != leafsize);

/* finally create the csum root */

memset(buf->data+sizeof(struct btrfs_header), 0,

leafsize-sizeof(struct btrfs_header));

btrfs_set_header_bytenr(buf, blocks[6]);

btrfs_set_header_owner(buf, BTRFS_CSUM_TREE_OBJECTID);

btrfs_set_header_nritems(buf, 0);

csum_tree_block_size(buf, BTRFS_CRC32_SIZE, 0);

ret = pwrite(fd, buf->data, leafsize, blocks[6]);

BUG_ON(ret != leafsize);

/* and write out the super block */

BUG_ON(sizeof(super) > sectorsize);

memset(buf->data, 0, sectorsize);

memcpy(buf->data, &super, sizeof(super));

buf->len = sectorsize;

csum_tree_block_size(buf, BTRFS_CRC32_SIZE, 0);

ret = pwrite(fd, buf->data, sectorsize, blocks[0]);

BUG_ON(ret != sectorsize);

free(buf);

return 0;

}

u64 btrfs_device_size(int fd, struct stat *st)

{

u64 size;

if (S_ISREG(st->st_mode)) {

return st->st_size;

}

if (!S_ISBLK(st->st_mode)) {

return 0;

}

if (ioctl(fd, BLKGETSIZE64, &size) >= 0) {

return size;

}

return 0;

}

static int zero_blocks(int fd, off_t start, size_t len)

{

char *buf = malloc(len);

int ret = 0;

ssize_t written;

if (!buf)

return -ENOMEM;

memset(buf, 0, len);

written = pwrite(fd, buf, len, start);

if (written != len)

ret = -EIO;

free(buf);

return ret;

}

static int zero_dev_start(int fd)

{

off_t start = 0;

size_t len = 2 * 1024 * 1024;

#ifdef __sparc__

/* don't overwrite the disk labels on sparc */

start = 1024;

len -= 1024;

#endif

return zero_blocks(fd, start, len);

}

static int zero_dev_end(int fd, u64 dev_size)

{

size_t len = 2 * 1024 * 1024;

off_t start = dev_size - len;

return zero_blocks(fd, start, len);

}

int btrfs_add_to_fsid(struct btrfs_trans_handle *trans,

struct btrfs_root *root, int fd, char *path,

u64 block_count, u32 io_width, u32 io_align,

u32 sectorsize)

{

struct btrfs_super_block *disk_super;

struct btrfs_super_block *super = root->fs_info->super_copy;

struct btrfs_device *device;

struct btrfs_dev_item *dev_item;

char *buf;

u64 total_bytes;

u64 num_devs;

int ret;

device = kzalloc(sizeof(*device), GFP_NOFS);

if (!device)

return -ENOMEM;

buf = kmalloc(sectorsize, GFP_NOFS);

if (!buf) {

kfree(device);

return -ENOMEM;

}

BUG_ON(sizeof(*disk_super) > sectorsize);

memset(buf, 0, sectorsize);

disk_super = (struct btrfs_super_block *)buf;

dev_item = &disk_super->dev_item;

uuid_generate(device->uuid);

device->devid = 0;

device->type = 0;

device->io_width = io_width;

device->io_align = io_align;

device->sector_size = sectorsize;

device->fd = fd;

device->writeable = 1;

device->total_bytes = block_count;

device->bytes_used = 0;

device->total_ios = 0;

device->dev_root = root->fs_info->dev_root;

ret = btrfs_add_device(trans, root, device);

BUG_ON(ret);

total_bytes = btrfs_super_total_bytes(super) + block_count;

btrfs_set_super_total_bytes(super, total_bytes);

num_devs = btrfs_super_num_devices(super) + 1;

btrfs_set_super_num_devices(super, num_devs);

memcpy(disk_super, super, sizeof(*disk_super));

printf("adding device %s id %llu\n", path,

(unsigned long long)device->devid);

btrfs_set_super_bytenr(disk_super, BTRFS_SUPER_INFO_OFFSET);

btrfs_set_stack_device_id(dev_item, device->devid);

btrfs_set_stack_device_type(dev_item, device->type);

btrfs_set_stack_device_io_align(dev_item, device->io_align);

btrfs_set_stack_device_io_width(dev_item, device->io_width);

btrfs_set_stack_device_sector_size(dev_item, device->sector_size);

btrfs_set_stack_device_total_bytes(dev_item, device->total_bytes);

btrfs_set_stack_device_bytes_used(dev_item, device->bytes_used);

memcpy(&dev_item->uuid, device->uuid, BTRFS_UUID_SIZE);

ret = pwrite(fd, buf, sectorsize, BTRFS_SUPER_INFO_OFFSET);

BUG_ON(ret != sectorsize);

kfree(buf);

list_add(&device->dev_list, &root->fs_info->fs_devices->devices);

device->fs_devices = root->fs_info->fs_devices;

return 0;

}

int btrfs_prepare_device(int fd, char *file, int zero_end, u64 *block_count_ret,

u64 max_block_count, int *mixed, int nodiscard)

{

u64 block_count;

u64 bytenr;

struct stat st;

int i, ret;

ret = fstat(fd, &st);

if (ret < 0) {

fprintf(stderr, "unable to stat %s\n", file);

exit(1);

}

block_count = btrfs_device_size(fd, &st);

if (block_count == 0) {

fprintf(stderr, "unable to find %s size\n", file);

exit(1);

}

if (max_block_count)

block_count = min(block_count, max_block_count);

zero_end = 1;

if (block_count < 1024 * 1024 * 1024 && !(*mixed)) {

printf("SMALL VOLUME: forcing mixed metadata/data groups\n");

*mixed = 1;

}

if (!nodiscard) {

/*

* We intentionally ignore errors from the discard ioctl. It is

* not necessary for the mkfs functionality but just an optimization.

*/

discard_blocks(fd, 0, block_count);

}

ret = zero_dev_start(fd);

if (ret) {

fprintf(stderr, "failed to zero device start %d\n", ret);

exit(1);

}

for (i = 0 ; i < BTRFS_SUPER_MIRROR_MAX; i++) {

bytenr = btrfs_sb_offset(i);

if (bytenr >= block_count)

break;

zero_blocks(fd, bytenr, BTRFS_SUPER_INFO_SIZE);

}

if (zero_end) {

ret = zero_dev_end(fd, block_count);

if (ret) {

fprintf(stderr, "failed to zero device end %d\n", ret);

exit(1);

}

}

*block_count_ret = block_count;

return 0;

}

int btrfs_make_root_dir(struct btrfs_trans_handle *trans,

struct btrfs_root *root, u64 objectid)

{

int ret;

struct btrfs_inode_item inode_item;

time_t now = time(NULL);

memset(&inode_item, 0, sizeof(inode_item));

btrfs_set_stack_inode_generation(&inode_item, trans->transid);

btrfs_set_stack_inode_size(&inode_item, 0);

btrfs_set_stack_inode_nlink(&inode_item, 1);

btrfs_set_stack_inode_nbytes(&inode_item, root->leafsize);

btrfs_set_stack_inode_mode(&inode_item, S_IFDIR | 0755);

btrfs_set_stack_timespec_sec(&inode_item.atime, now);

btrfs_set_stack_timespec_nsec(&inode_item.atime, 0);

btrfs_set_stack_timespec_sec(&inode_item.ctime, now);

btrfs_set_stack_timespec_nsec(&inode_item.ctime, 0);

btrfs_set_stack_timespec_sec(&inode_item.mtime, now);

btrfs_set_stack_timespec_nsec(&inode_item.mtime, 0);

btrfs_set_stack_timespec_sec(&inode_item.otime, 0);

btrfs_set_stack_timespec_nsec(&inode_item.otime, 0);

if (root->fs_info->tree_root == root)

btrfs_set_super_root_dir(root->fs_info->super_copy, objectid);

ret = btrfs_insert_inode(trans, root, objectid, &inode_item);

if (ret)

goto error;

ret = btrfs_insert_inode_ref(trans, root, "..", 2, objectid, objectid, 0);

if (ret)

goto error;

btrfs_set_root_dirid(&root->root_item, objectid);

ret = 0;

error:

return ret;

}

/*

* checks if a path is a block device node

* Returns negative errno on failure, otherwise

* returns 1 for blockdev, 0 for not-blockdev

*/

int is_block_device(const char *path) {

struct stat statbuf;

if (stat(path, &statbuf) < 0)

return -errno;

return S_ISBLK(statbuf.st_mode);

}

/*

* Find the mount point for a mounted device.

* On success, returns 0 with mountpoint in *mp.

* On failure, returns -errno (not mounted yields -EINVAL)

* Is noisy on failures, expects to be given a mounted device.

*/

int get_btrfs_mount(const char *dev, char *mp, size_t mp_size) {

int ret;

int fd = -1;

ret = is_block_device(dev);

if (ret <= 0) {

if (!ret) {

fprintf(stderr, "%s is not a block device\n", dev);

ret = -EINVAL;

} else {

fprintf(stderr, "Could not check %s: %s\n",

dev, strerror(-ret));

}

goto out;

}

fd = open(dev, O_RDONLY);

if (fd < 0) {

ret = -errno;

fprintf(stderr, "Could not open %s: %s\n", dev, strerror(errno));

goto out;

}

ret = check_mounted_where(fd, dev, mp, mp_size, NULL);

if (!ret) {

fprintf(stderr, "%s is not a mounted btrfs device\n", dev);

ret = -EINVAL;

} else { /* mounted, all good */

ret = 0;

}

out:

if (fd != -1)

close(fd);

if (ret)

fprintf(stderr, "Could not get mountpoint for %s\n", dev);

return ret;

}

/*

* Given a pathname, return a filehandle to:

* the original pathname or,

* if the pathname is a mounted btrfs device, to its mountpoint.

*

* On error, return -1, errno should be set.

*/

int open_path_or_dev_mnt(const char *path)

{

char mp[BTRFS_PATH_NAME_MAX + 1];

int fdmnt;

if (is_block_device(path)) {

int ret;

ret = get_btrfs_mount(path, mp, sizeof(mp));

if (ret < 0) {

/* not a mounted btrfs dev */

errno = EINVAL;

return -1;

}

fdmnt = open_file_or_dir(mp);

} else {

fdmnt = open_file_or_dir(path);

}

return fdmnt;

}

/* checks if a device is a loop device */

int is_loop_device (const char* device) {

struct stat statbuf;

if(stat(device, &statbuf) < 0)

return -errno;

return (S_ISBLK(statbuf.st_mode) &&

MAJOR(statbuf.st_rdev) == LOOP_MAJOR);

}

/* Takes a loop device path (e.g. /dev/loop0) and returns

* the associated file (e.g. /images/my_btrfs.img) */

int resolve_loop_device(const char* loop_dev, char* loop_file, int max_len)

{

int ret;

FILE *f;

char fmt[20];

char p[PATH_MAX];

char real_loop_dev[PATH_MAX];

if (!realpath(loop_dev, real_loop_dev))

return -errno;

snprintf(p, PATH_MAX, "/sys/block/%s/loop/backing_file", strrchr(real_loop_dev, '/'));

if (!(f = fopen(p, "r")))

return -errno;

snprintf(fmt, 20, "%%%i[^\n]", max_len-1);

ret = fscanf(f, fmt, loop_file);

fclose(f);

if (ret == EOF)

return -errno;

return 0;

}

/* Checks whether a and b are identical or device

* files associated with the same block device

*/

int is_same_blk_file(const char* a, const char* b)

{

struct stat st_buf_a, st_buf_b;

char real_a[PATH_MAX];

char real_b[PATH_MAX];

if(!realpath(a, real_a) ||

!realpath(b, real_b))

{

return -errno;

}

/* Identical path? */

if(strcmp(real_a, real_b) == 0)

return 1;

if(stat(a, &st_buf_a) < 0 ||

stat(b, &st_buf_b) < 0)

{

if (errno == ENOENT)

return 0;

return -errno;

}

/* Same blockdevice? */

if(S_ISBLK(st_buf_a.st_mode) &&

S_ISBLK(st_buf_b.st_mode) &&

st_buf_a.st_rdev == st_buf_b.st_rdev)

{

return 1;

}

/* Hardlink? */

if (st_buf_a.st_dev == st_buf_b.st_dev &&

st_buf_a.st_ino == st_buf_b.st_ino)

{

return 1;

}

return 0;

}

/* checks if a and b are identical or device

* files associated with the same block device or

* if one file is a loop device that uses the other

* file.

*/

int is_same_loop_file(const char* a, const char* b)

{

char res_a[PATH_MAX];

char res_b[PATH_MAX];

const char* final_a;

const char* final_b;

int ret;

/* Resolve a if it is a loop device */

if((ret = is_loop_device(a)) < 0) {

if (ret == -ENOENT)

return 0;

return ret;

} else if (ret) {

if ((ret = resolve_loop_device(a, res_a, sizeof(res_a))) < 0)

return ret;

final_a = res_a;

} else {

final_a = a;

}

/* Resolve b if it is a loop device */

if ((ret = is_loop_device(b)) < 0) {

if (ret == -ENOENT)

return 0;

return ret;

} else if (ret) {

if((ret = resolve_loop_device(b, res_b, sizeof(res_b))) < 0)

return ret;

final_b = res_b;

} else {

final_b = b;

}

return is_same_blk_file(final_a, final_b);

}

/* Checks if a file exists and is a block or regular file*/

int is_existing_blk_or_reg_file(const char* filename)

{

struct stat st_buf;

if(stat(filename, &st_buf) < 0) {

if(errno == ENOENT)

return 0;

else

return -errno;

}

return (S_ISBLK(st_buf.st_mode) || S_ISREG(st_buf.st_mode));

}

/* Checks if a file is used (directly or indirectly via a loop device)

* by a device in fs_devices

*/

int blk_file_in_dev_list(struct btrfs_fs_devices* fs_devices, const char* file)

{

int ret;

struct list_head *head;

struct list_head *cur;

struct btrfs_device *device;

head = &fs_devices->devices;

list_for_each(cur, head) {

device = list_entry(cur, struct btrfs_device, dev_list);

if((ret = is_same_loop_file(device->name, file)))

return ret;

}

return 0;

}

/*

* returns 1 if the device was mounted, < 0 on error or 0 if everything

* is safe to continue.

*/

int check_mounted(const char* file)

{

int fd;

int ret;

fd = open(file, O_RDONLY);

if (fd < 0) {

fprintf (stderr, "check_mounted(): Could not open %s\n", file);

return -errno;

}

ret = check_mounted_where(fd, file, NULL, 0, NULL);

close(fd);

return ret;

}

int check_mounted_where(int fd, const char *file, char *where, int size,

struct btrfs_fs_devices **fs_dev_ret)

{

int ret;

u64 total_devs = 1;

int is_btrfs;

struct btrfs_fs_devices *fs_devices_mnt = NULL;

FILE *f;

struct mntent *mnt;

/* scan the initial device */

ret = btrfs_scan_one_device(fd, file, &fs_devices_mnt,

&total_devs, BTRFS_SUPER_INFO_OFFSET);

is_btrfs = (ret >= 0);

/* scan other devices */

if (is_btrfs && total_devs > 1) {

if((ret = btrfs_scan_for_fsid(fs_devices_mnt, total_devs, 1)))

return ret;

}

/* iterate over the list of currently mountes filesystems */

if ((f = setmntent ("/proc/mounts", "r")) == NULL)

return -errno;

while ((mnt = getmntent (f)) != NULL) {

if(is_btrfs) {

if(strcmp(mnt->mnt_type, "btrfs") != 0)

continue;

ret = blk_file_in_dev_list(fs_devices_mnt, mnt->mnt_fsname);

} else {

/* ignore entries in the mount table that are not

associated with a file*/

if((ret = is_existing_blk_or_reg_file(mnt->mnt_fsname)) < 0)

goto out_mntloop_err;

else if(!ret)

continue;

ret = is_same_loop_file(file, mnt->mnt_fsname);

}

if(ret < 0)

goto out_mntloop_err;

else if(ret)

break;

}

/* Did we find an entry in mnt table? */

if (mnt && size && where) {

strncpy(where, mnt->mnt_dir, size);

where[size-1] = 0;

}

if (fs_dev_ret)

*fs_dev_ret = fs_devices_mnt;

ret = (mnt != NULL);

out_mntloop_err:

endmntent (f);

return ret;

}

struct pending_dir {

struct list_head list;

char name[PATH_MAX];

};

void btrfs_register_one_device(char *fname)

{

struct btrfs_ioctl_vol_args args;

int fd;

int ret;

int e;

fd = open("/dev/btrfs-control", O_RDONLY);

if (fd < 0) {

fprintf(stderr, "failed to open /dev/btrfs-control "

"skipping device registration: %s\n",

strerror(errno));

return;

}

strncpy(args.name, fname, BTRFS_PATH_NAME_MAX);

args.name[BTRFS_PATH_NAME_MAX-1] = 0;

ret = ioctl(fd, BTRFS_IOC_SCAN_DEV, &args);

e = errno;