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/*
* orphan.c --- utility function to handle orphan file
*
* Copyright (C) 2015 Jan Kara.
*
* %Begin-Header%
* This file may be redistributed under the terms of the GNU Library
* General Public License, version 2.
* %End-Header%
*/
#include "config.h"
#include <string.h>
#include "ext2_fs.h"
#include "ext2fsP.h"
errcode_t ext2fs_truncate_orphan_file(ext2_filsys fs)
{
struct ext2_inode inode;
errcode_t err;
ext2_ino_t ino = fs->super->s_orphan_file_inum;
err = ext2fs_read_inode(fs, ino, &inode);
if (err)
return err;
err = ext2fs_punch(fs, ino, &inode, NULL, 0, ~0ULL);
if (err)
return err;
fs->flags &= ~EXT2_FLAG_SUPER_ONLY;
memset(&inode, 0, sizeof(struct ext2_inode));
err = ext2fs_write_inode(fs, ino, &inode);
ext2fs_clear_feature_orphan_file(fs->super);
ext2fs_clear_feature_orphan_present(fs->super);
ext2fs_mark_super_dirty(fs);
/* Need to update group descriptors as well */
fs->flags &= ~EXT2_FLAG_SUPER_ONLY;
return err;
}
__u32 ext2fs_do_orphan_file_block_csum(ext2_filsys fs, ext2_ino_t ino,
__u32 gen, blk64_t blk, char *buf)
{
int inodes_per_ob = ext2fs_inodes_per_orphan_block(fs);
__u32 crc;
ino = ext2fs_cpu_to_le32(ino);
gen = ext2fs_cpu_to_le32(gen);
blk = ext2fs_cpu_to_le64(blk);
crc = ext2fs_crc32c_le(fs->csum_seed, (unsigned char *)&ino,
sizeof(ino));
crc = ext2fs_crc32c_le(crc, (unsigned char *)&gen, sizeof(gen));
crc = ext2fs_crc32c_le(crc, (unsigned char *)&blk, sizeof(blk));
crc = ext2fs_crc32c_le(crc, (unsigned char *)buf,
inodes_per_ob * sizeof(__u32));
return ext2fs_cpu_to_le32(crc);
}
struct mkorphan_info {
char *buf;
char *zerobuf;
blk_t num_blocks;
blk_t alloc_blocks;
blk64_t last_blk;
errcode_t err;
ext2_ino_t ino;
__u32 generation;
};
static int mkorphan_proc(ext2_filsys fs,
blk64_t *blocknr,
e2_blkcnt_t blockcnt,
blk64_t ref_block EXT2FS_ATTR((unused)),
int ref_offset EXT2FS_ATTR((unused)),
void *priv_data)
{
struct mkorphan_info *oi = (struct mkorphan_info *)priv_data;
blk64_t new_blk;
errcode_t err;
/* Can we just continue in currently allocated cluster? */
if (blockcnt &&
EXT2FS_B2C(fs, oi->last_blk) == EXT2FS_B2C(fs, oi->last_blk + 1)) {
new_blk = oi->last_blk + 1;
} else {
err = ext2fs_new_block2(fs, oi->last_blk, 0, &new_blk);
if (err) {
oi->err = err;
return BLOCK_ABORT;
}
ext2fs_block_alloc_stats2(fs, new_blk, +1);
oi->alloc_blocks++;
}
if (blockcnt >= 0) {
if (ext2fs_has_feature_metadata_csum(fs->super)) {
struct ext4_orphan_block_tail *tail;
tail = ext2fs_orphan_block_tail(fs, oi->buf);
tail->ob_checksum = ext2fs_do_orphan_file_block_csum(fs,
oi->ino, oi->generation, new_blk, oi->buf);
}
err = io_channel_write_blk64(fs->io, new_blk, 1, oi->buf);
} else /* zerobuf is used to initialize new indirect blocks... */
err = io_channel_write_blk64(fs->io, new_blk, 1, oi->zerobuf);
if (err) {
oi->err = err;
return BLOCK_ABORT;
}
oi->last_blk = new_blk;
*blocknr = new_blk;
if (blockcnt >= 0 && --oi->num_blocks == 0)
return BLOCK_CHANGED | BLOCK_ABORT;
return BLOCK_CHANGED;
}
errcode_t ext2fs_create_orphan_file(ext2_filsys fs, blk_t num_blocks)
{
struct ext2_inode inode;
ext2_ino_t ino = fs->super->s_orphan_file_inum;
errcode_t err;
char *buf = NULL, *zerobuf = NULL;
struct mkorphan_info oi;
struct ext4_orphan_block_tail *ob_tail;
if (!ino) {
err = ext2fs_new_inode(fs, EXT2_ROOT_INO, LINUX_S_IFREG | 0600,
0, &ino);
if (err)
return err;
ext2fs_inode_alloc_stats2(fs, ino, +1, 0);
ext2fs_mark_ib_dirty(fs);
}
err = ext2fs_read_inode(fs, ino, &inode);
if (err)
return err;
if (EXT2_I_SIZE(&inode)) {
err = ext2fs_truncate_orphan_file(fs);
if (err)
return err;
}
memset(&inode, 0, sizeof(struct ext2_inode));
if (ext2fs_has_feature_extents(fs->super)) {
inode.i_flags |= EXT4_EXTENTS_FL;
err = ext2fs_write_inode(fs, ino, &inode);
if (err)
return err;
}
err = ext2fs_get_mem(fs->blocksize, &buf);
if (err)
return err;
err = ext2fs_get_mem(fs->blocksize, &zerobuf);
if (err)
goto out;
memset(buf, 0, fs->blocksize);
memset(zerobuf, 0, fs->blocksize);
ob_tail = ext2fs_orphan_block_tail(fs, buf);
ob_tail->ob_magic = ext2fs_cpu_to_le32(EXT4_ORPHAN_BLOCK_MAGIC);
oi.num_blocks = num_blocks;
oi.alloc_blocks = 0;
oi.last_blk = 0;
oi.generation = inode.i_generation;
oi.ino = ino;
oi.buf = buf;
oi.zerobuf = zerobuf;
oi.err = 0;
err = ext2fs_block_iterate3(fs, ino, BLOCK_FLAG_APPEND,
0, mkorphan_proc, &oi);
if (err)
goto out;
if (oi.err) {
err = oi.err;
goto out;
}
/* Reread inode after blocks were allocated */
err = ext2fs_read_inode(fs, ino, &inode);
if (err)
goto out;
ext2fs_iblk_set(fs, &inode, 0);
inode.i_atime = inode.i_mtime =
inode.i_ctime = fs->now ? fs->now : time(0);
inode.i_links_count = 1;
inode.i_mode = LINUX_S_IFREG | 0600;
ext2fs_iblk_add_blocks(fs, &inode, oi.alloc_blocks);
err = ext2fs_inode_size_set(fs, &inode,
(unsigned long long)fs->blocksize * num_blocks);
if (err)
goto out;
err = ext2fs_write_new_inode(fs, ino, &inode);
if (err)
goto out;
fs->super->s_orphan_file_inum = ino;
ext2fs_set_feature_orphan_file(fs->super);
ext2fs_mark_super_dirty(fs);
/* Need to update group descriptors as well */
fs->flags &= ~EXT2_FLAG_SUPER_ONLY;
out:
if (buf)
ext2fs_free_mem(&buf);
if (zerobuf)
ext2fs_free_mem(&zerobuf);
return err;
}
/*
* Find reasonable size for orphan file. We choose orphan file size to be
* between 32 and 512 filesystem blocks and not more than 1/4096 of the
* filesystem unless it is really small.
*/
e2_blkcnt_t ext2fs_default_orphan_file_blocks(ext2_filsys fs)
{
__u64 num_blocks = ext2fs_blocks_count(fs->super);
e2_blkcnt_t blks = 512;
if (num_blocks < 128 * 1024)
blks = 32;
else if (num_blocks < 2 * 1024 * 1024)
blks = num_blocks / 4096;
return (blks + EXT2FS_CLUSTER_MASK(fs)) & ~EXT2FS_CLUSTER_MASK(fs);
}
static errcode_t ext2fs_orphan_file_block_csum(ext2_filsys fs, ext2_ino_t ino,
blk64_t blk, char *buf,
__u32 *crcp)
{
struct ext2_inode inode;
errcode_t retval;
retval = ext2fs_read_inode(fs, ino, &inode);
if (retval)
return retval;
*crcp = ext2fs_do_orphan_file_block_csum(fs, ino, inode.i_generation,
blk, buf);
return 0;
}
errcode_t ext2fs_orphan_file_block_csum_set(ext2_filsys fs, ext2_ino_t ino,
blk64_t blk, char *buf)
{
struct ext4_orphan_block_tail *tail;
if (!ext2fs_has_feature_metadata_csum(fs->super))
return 0;
tail = ext2fs_orphan_block_tail(fs, buf);
return ext2fs_orphan_file_block_csum(fs, ino, blk, buf,
&tail->ob_checksum);
}
int ext2fs_orphan_file_block_csum_verify(ext2_filsys fs, ext2_ino_t ino,
blk64_t blk, char *buf)
{
struct ext4_orphan_block_tail *tail;
__u32 crc;
errcode_t retval;
if (!ext2fs_has_feature_metadata_csum(fs->super))
return 1;
retval = ext2fs_orphan_file_block_csum(fs, ino, blk, buf, &crc);
if (retval)
return 0;
tail = ext2fs_orphan_block_tail(fs, buf);
return ext2fs_le32_to_cpu(tail->ob_checksum) == crc;
}
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