ref: a3f2d6d23ed1be69fee607bdedadc0438fd01305
dir: /sys/src/cmd/ext4srv/ext4_fs.c/
#include "ext4_config.h"
#include "ext4_types.h"
#include "ext4_misc.h"
#include "ext4_debug.h"
#include "ext4_trans.h"
#include "ext4_fs.h"
#include "ext4_blockdev.h"
#include "ext4_super.h"
#include "ext4_crc32.h"
#include "ext4_block_group.h"
#include "ext4_balloc.h"
#include "ext4_bitmap.h"
#include "ext4_inode.h"
#include "ext4_ialloc.h"
#include "ext4_extent.h"
int ext4_fs_init(struct ext4_fs *fs, struct ext4_blockdev *bdev,
bool read_only)
{
int r, i;
u16int tmp;
u32int bsize;
assert(fs && bdev);
fs->bdev = bdev;
fs->read_only = read_only;
r = ext4_sb_read(fs->bdev, &fs->sb);
if (r != 0)
return r;
if (!ext4_sb_check(&fs->sb)) {
werrstr("superblock: %r");
return -1;
}
bsize = ext4_sb_get_block_size(&fs->sb);
if (bsize > EXT4_MAX_BLOCK_SIZE) {
werrstr("invalid block size: %d", bsize);
return -1;
}
r = ext4_fs_check_features(fs, &read_only);
if (r != 0)
return r;
if (read_only)
fs->read_only = read_only;
/* Compute limits for indirect block levels */
u32int blocks_id = bsize / sizeof(u32int);
fs->inode_block_limits[0] = EXT4_INODE_DIRECT_BLOCK_COUNT;
fs->inode_blocks_per_level[0] = 1;
for (i = 1; i < 4; i++) {
fs->inode_blocks_per_level[i] =
fs->inode_blocks_per_level[i - 1] * blocks_id;
fs->inode_block_limits[i] = fs->inode_block_limits[i - 1] +
fs->inode_blocks_per_level[i];
}
/*Validate FS*/
tmp = ext4_get16(&fs->sb, state);
if (tmp & EXT4_SUPERBLOCK_STATE_ERROR_FS)
ext4_dbg(DEBUG_FS, DBG_WARN
"last umount error: superblock fs_error flag\n");
if (!fs->read_only) {
/* Mark system as mounted */
ext4_set16(&fs->sb, state, EXT4_SUPERBLOCK_STATE_ERROR_FS);
r = ext4_sb_write(fs->bdev, &fs->sb);
if (r != 0)
return r;
/*Update mount count*/
ext4_set16(&fs->sb, mount_count, ext4_get16(&fs->sb, mount_count) + 1);
}
if(r == 0)
fs->uuid_crc32c = ext4_crc32c(EXT4_CRC32_INIT, fs->sb.uuid, sizeof(fs->sb.uuid));
return r;
}
int ext4_fs_fini(struct ext4_fs *fs)
{
assert(fs);
/*Set superblock state*/
ext4_set16(&fs->sb, state, EXT4_SUPERBLOCK_STATE_VALID_FS);
if (!fs->read_only)
return ext4_sb_write(fs->bdev, &fs->sb);
return 0;
}
static void ext4_fs_debug_features_inc(u32int features_incompatible)
{
if (features_incompatible & EXT4_FINCOM_COMPRESSION)
ext4_dbg(DEBUG_FS, DBG_NONE "compression\n");
if (features_incompatible & EXT4_FINCOM_FILETYPE)
ext4_dbg(DEBUG_FS, DBG_NONE "filetype\n");
if (features_incompatible & EXT4_FINCOM_RECOVER)
ext4_dbg(DEBUG_FS, DBG_NONE "recover\n");
if (features_incompatible & EXT4_FINCOM_JOURNAL_DEV)
ext4_dbg(DEBUG_FS, DBG_NONE "journal_dev\n");
if (features_incompatible & EXT4_FINCOM_META_BG)
ext4_dbg(DEBUG_FS, DBG_NONE "meta_bg\n");
if (features_incompatible & EXT4_FINCOM_EXTENTS)
ext4_dbg(DEBUG_FS, DBG_NONE "extents\n");
if (features_incompatible & EXT4_FINCOM_64BIT)
ext4_dbg(DEBUG_FS, DBG_NONE "64bit\n");
if (features_incompatible & EXT4_FINCOM_MMP)
ext4_dbg(DEBUG_FS, DBG_NONE "mnp\n");
if (features_incompatible & EXT4_FINCOM_FLEX_BG)
ext4_dbg(DEBUG_FS, DBG_NONE "flex_bg\n");
if (features_incompatible & EXT4_FINCOM_EA_INODE)
ext4_dbg(DEBUG_FS, DBG_NONE "ea_inode\n");
if (features_incompatible & EXT4_FINCOM_DIRDATA)
ext4_dbg(DEBUG_FS, DBG_NONE "dirdata\n");
if (features_incompatible & EXT4_FINCOM_BG_USE_META_CSUM)
ext4_dbg(DEBUG_FS, DBG_NONE "meta_csum\n");
if (features_incompatible & EXT4_FINCOM_LARGEDIR)
ext4_dbg(DEBUG_FS, DBG_NONE "largedir\n");
if (features_incompatible & EXT4_FINCOM_INLINE_DATA)
ext4_dbg(DEBUG_FS, DBG_NONE "inline_data\n");
}
static void ext4_fs_debug_features_comp(u32int features_compatible)
{
if (features_compatible & EXT4_FCOM_DIR_PREALLOC)
ext4_dbg(DEBUG_FS, DBG_NONE "dir_prealloc\n");
if (features_compatible & EXT4_FCOM_IMAGIC_INODES)
ext4_dbg(DEBUG_FS, DBG_NONE "imagic_inodes\n");
if (features_compatible & EXT4_FCOM_HAS_JOURNAL)
ext4_dbg(DEBUG_FS, DBG_NONE "has_journal\n");
if (features_compatible & EXT4_FCOM_EXT_ATTR)
ext4_dbg(DEBUG_FS, DBG_NONE "ext_attr\n");
if (features_compatible & EXT4_FCOM_RESIZE_INODE)
ext4_dbg(DEBUG_FS, DBG_NONE "resize_inode\n");
if (features_compatible & EXT4_FCOM_DIR_INDEX)
ext4_dbg(DEBUG_FS, DBG_NONE "dir_index\n");
}
static void ext4_fs_debug_features_ro(u32int features_ro)
{
if (features_ro & EXT4_FRO_COM_SPARSE_SUPER)
ext4_dbg(DEBUG_FS, DBG_NONE "sparse_super\n");
if (features_ro & EXT4_FRO_COM_LARGE_FILE)
ext4_dbg(DEBUG_FS, DBG_NONE "large_file\n");
if (features_ro & EXT4_FRO_COM_BTREE_DIR)
ext4_dbg(DEBUG_FS, DBG_NONE "btree_dir\n");
if (features_ro & EXT4_FRO_COM_HUGE_FILE)
ext4_dbg(DEBUG_FS, DBG_NONE "huge_file\n");
if (features_ro & EXT4_FRO_COM_GDT_CSUM)
ext4_dbg(DEBUG_FS, DBG_NONE "gtd_csum\n");
if (features_ro & EXT4_FRO_COM_DIR_NLINK)
ext4_dbg(DEBUG_FS, DBG_NONE "dir_nlink\n");
if (features_ro & EXT4_FRO_COM_EXTRA_ISIZE)
ext4_dbg(DEBUG_FS, DBG_NONE "extra_isize\n");
if (features_ro & EXT4_FRO_COM_QUOTA)
ext4_dbg(DEBUG_FS, DBG_NONE "quota\n");
if (features_ro & EXT4_FRO_COM_BIGALLOC)
ext4_dbg(DEBUG_FS, DBG_NONE "bigalloc\n");
if (features_ro & EXT4_FRO_COM_METADATA_CSUM)
ext4_dbg(DEBUG_FS, DBG_NONE "metadata_csum\n");
}
int ext4_fs_check_features(struct ext4_fs *fs, bool *read_only)
{
assert(fs && read_only);
u32int v;
if (ext4_get32(&fs->sb, rev_level) == 0) {
*read_only = false;
return 0;
}
ext4_dbg(DEBUG_FS, DBG_INFO "sblock features_incompatible:\n");
ext4_fs_debug_features_inc(ext4_get32(&fs->sb, features_incompatible));
ext4_dbg(DEBUG_FS, DBG_INFO "sblock features_compatible:\n");
ext4_fs_debug_features_comp(ext4_get32(&fs->sb, features_compatible));
ext4_dbg(DEBUG_FS, DBG_INFO "sblock features_read_only:\n");
ext4_fs_debug_features_ro(ext4_get32(&fs->sb, features_read_only));
/*Check features_incompatible*/
v = ext4_get32(&fs->sb, features_incompatible) &
~(EXT4_SUPPORTED_FINCOM | EXT_FINCOM_IGNORED);
if (v) {
ext4_dbg(DEBUG_FS, DBG_ERROR
"sblock has unsupported features incompatible:\n");
ext4_fs_debug_features_inc(v);
werrstr("unsupported features");
return -1;
}
/*Check features_read_only*/
v = ext4_get32(&fs->sb, features_read_only);
v &= ~EXT4_SUPPORTED_FRO_COM;
if (v) {
ext4_dbg(DEBUG_FS, DBG_WARN
"sblock has unsupported features read only:\n");
ext4_fs_debug_features_ro(v);
*read_only = true;
return 0;
}
*read_only = false;
return 0;
}
/**@brief Determine whether the block is inside the group.
* @param baddr block address
* @param bgid block group id
* @return Error code
*/
static bool ext4_block_in_group(struct ext4_sblock *s, ext4_fsblk_t baddr,
u32int bgid)
{
u32int actual_bgid;
actual_bgid = ext4_balloc_get_bgid_of_block(s, baddr);
if (actual_bgid == bgid)
return true;
return false;
}
/**@brief To avoid calling the atomic setbit hundreds or thousands of times, we only
* need to use it within a single byte (to ensure we get endianness right).
* We can use memset for the rest of the bitmap as there are no other users.
*/
static void ext4_fs_mark_bitmap_end(int start_bit, int end_bit, void *bitmap)
{
int i;
if (start_bit >= end_bit)
return;
for (i = start_bit; (unsigned)i < ((start_bit + 7) & ~7UL); i++)
ext4_bmap_bit_set(bitmap, i);
if (i < end_bit)
memset((char *)bitmap + (i >> 3), 0xff, (end_bit - i) >> 3);
}
/**@brief Initialize block bitmap in block group.
* @param bg_ref Reference to block group
* @return Error code
*/
static int ext4_fs_init_block_bitmap(struct ext4_block_group_ref *bg_ref)
{
struct ext4_fs *fs = bg_ref->fs;
struct ext4_sblock *sb = &fs->sb;
struct ext4_bgroup *bg = bg_ref->block_group;
int rc;
u32int bit, bit_max;
u32int group_blocks;
u16int inode_size = ext4_get16(sb, inode_size);
u32int block_size = ext4_sb_get_block_size(sb);
u32int inodes_per_group = ext4_get32(sb, inodes_per_group);
ext4_fsblk_t i;
ext4_fsblk_t bmp_blk = ext4_bg_get_block_bitmap(bg, sb);
ext4_fsblk_t bmp_inode = ext4_bg_get_inode_bitmap(bg, sb);
ext4_fsblk_t inode_table = ext4_bg_get_inode_table_first_block(bg, sb);
ext4_fsblk_t first_bg = ext4_balloc_get_block_of_bgid(sb, bg_ref->index);
u32int dsc_per_block = block_size / ext4_sb_get_desc_size(sb);
bool flex_bg = ext4_sb_feature_incom(sb, EXT4_FINCOM_FLEX_BG);
bool meta_bg = ext4_sb_feature_incom(sb, EXT4_FINCOM_META_BG);
u32int inode_table_bcnt = inodes_per_group * inode_size / block_size;
struct ext4_block block_bitmap;
rc = ext4_trans_block_get_noread(fs->bdev, &block_bitmap, bmp_blk);
if (rc != 0)
return rc;
memset(block_bitmap.data, 0, block_size);
bit_max = ext4_sb_is_super_in_bg(sb, bg_ref->index);
u32int count = ext4_sb_first_meta_bg(sb) * dsc_per_block;
if (!meta_bg || bg_ref->index < count) {
if (bit_max) {
bit_max += ext4_bg_num_gdb(sb, bg_ref->index);
bit_max += ext4_get16(sb, s_reserved_gdt_blocks);
}
} else { /* For META_BG_BLOCK_GROUPS */
bit_max += ext4_bg_num_gdb(sb, bg_ref->index);
}
for (bit = 0; bit < bit_max; bit++)
ext4_bmap_bit_set(block_bitmap.data, bit);
if (bg_ref->index == ext4_block_group_cnt(sb) - 1) {
/*
* Even though mke2fs always initialize first and last group
* if some other tool enabled the EXT4_BG_BLOCK_UNINIT we need
* to make sure we calculate the right free blocks
*/
group_blocks = (u32int)(ext4_sb_get_blocks_cnt(sb) -
ext4_get32(sb, first_data_block) -
ext4_get32(sb, blocks_per_group) *
(ext4_block_group_cnt(sb) - 1));
} else {
group_blocks = ext4_get32(sb, blocks_per_group);
}
bool in_bg;
in_bg = ext4_block_in_group(sb, bmp_blk, bg_ref->index);
if (!flex_bg || in_bg)
ext4_bmap_bit_set(block_bitmap.data,
(u32int)(bmp_blk - first_bg));
in_bg = ext4_block_in_group(sb, bmp_inode, bg_ref->index);
if (!flex_bg || in_bg)
ext4_bmap_bit_set(block_bitmap.data,
(u32int)(bmp_inode - first_bg));
for (i = inode_table; i < inode_table + inode_table_bcnt; i++) {
in_bg = ext4_block_in_group(sb, i, bg_ref->index);
if (!flex_bg || in_bg)
ext4_bmap_bit_set(block_bitmap.data,
(u32int)(i - first_bg));
}
/*
* Also if the number of blocks within the group is
* less than the blocksize * 8 ( which is the size
* of bitmap ), set rest of the block bitmap to 1
*/
ext4_fs_mark_bitmap_end(group_blocks, block_size * 8, block_bitmap.data);
ext4_trans_set_block_dirty(block_bitmap.buf);
ext4_balloc_set_bitmap_csum(fs, bg_ref->block_group, block_bitmap.data);
bg_ref->dirty = true;
/* Save bitmap */
return ext4_block_set(fs->bdev, &block_bitmap);
}
/**@brief Initialize i-node bitmap in block group.
* @param bg_ref Reference to block group
* @return Error code
*/
static int ext4_fs_init_inode_bitmap(struct ext4_block_group_ref *bg_ref)
{
int rc;
struct ext4_sblock *sb = &bg_ref->fs->sb;
struct ext4_bgroup *bg = bg_ref->block_group;
/* Load bitmap */
ext4_fsblk_t bitmap_block_addr = ext4_bg_get_inode_bitmap(bg, sb);
struct ext4_block b;
rc = ext4_trans_block_get_noread(bg_ref->fs->bdev, &b, bitmap_block_addr);
if (rc != 0)
return rc;
/* Initialize all bitmap bits to zero */
u32int block_size = ext4_sb_get_block_size(sb);
u32int inodes_per_group = ext4_get32(sb, inodes_per_group);
memset(b.data, 0, (inodes_per_group + 7) / 8);
u32int start_bit = inodes_per_group;
u32int end_bit = block_size * 8;
u32int i;
for (i = start_bit; i < ((start_bit + 7) & ~7UL); i++)
ext4_bmap_bit_set(b.data, i);
if (i < end_bit)
memset(b.data + (i >> 3), 0xff, (end_bit - i) >> 3);
ext4_trans_set_block_dirty(b.buf);
ext4_ialloc_set_bitmap_csum(bg_ref->fs, bg, b.data);
bg_ref->dirty = true;
/* Save bitmap */
return ext4_block_set(bg_ref->fs->bdev, &b);
}
/**@brief Initialize i-node table in block group.
* @param bg_ref Reference to block group
* @return Error code
*/
static int ext4_fs_init_inode_table(struct ext4_block_group_ref *bg_ref)
{
struct ext4_sblock *sb = &bg_ref->fs->sb;
struct ext4_bgroup *bg = bg_ref->block_group;
u32int inode_size = ext4_get16(sb, inode_size);
u32int block_size = ext4_sb_get_block_size(sb);
u32int inodes_per_block = block_size / inode_size;
u32int inodes_in_group = ext4_inodes_in_group_cnt(sb, bg_ref->index);
u32int table_blocks = inodes_in_group / inodes_per_block;
ext4_fsblk_t fblock;
if (inodes_in_group % inodes_per_block)
table_blocks++;
/* Compute initialization bounds */
ext4_fsblk_t first_block = ext4_bg_get_inode_table_first_block(bg, sb);
ext4_fsblk_t last_block = first_block + table_blocks - 1;
/* Initialization of all itable blocks */
for (fblock = first_block; fblock <= last_block; ++fblock) {
struct ext4_block b;
int rc = ext4_trans_block_get_noread(bg_ref->fs->bdev, &b, fblock);
if (rc != 0)
return rc;
memset(b.data, 0, block_size);
ext4_trans_set_block_dirty(b.buf);
rc = ext4_block_set(bg_ref->fs->bdev, &b);
if (rc != 0)
return rc;
}
return 0;
}
static ext4_fsblk_t ext4_fs_get_descriptor_block(struct ext4_sblock *s,
u32int bgid,
u32int dsc_per_block)
{
u32int first_meta_bg, dsc_id;
int has_super = 0;
dsc_id = bgid / dsc_per_block;
first_meta_bg = ext4_sb_first_meta_bg(s);
bool meta_bg = ext4_sb_feature_incom(s, EXT4_FINCOM_META_BG);
if (!meta_bg || dsc_id < first_meta_bg)
return ext4_get32(s, first_data_block) + dsc_id + 1;
if (ext4_sb_is_super_in_bg(s, bgid))
has_super = 1;
return (has_super + ext4_fs_first_bg_block_no(s, bgid));
}
/**@brief Compute checksum of block group descriptor.
* @param sb Superblock
* @param bgid Index of block group in the filesystem
* @param bg Block group to compute checksum for
* @return Checksum value
*/
static u16int ext4_fs_bg_checksum(struct ext4_fs *fs, u32int bgid, struct ext4_bgroup *bg)
{
struct ext4_sblock *sb = &fs->sb;
/* If checksum not supported, 0 will be returned */
u16int crc = 0;
/* Compute the checksum only if the filesystem supports it */
if (ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM)) {
/* Use metadata_csum algorithm instead */
u32int le32_bgid = to_le32(bgid);
u32int orig_checksum, checksum;
/* Preparation: temporarily set bg checksum to 0 */
orig_checksum = bg->checksum;
bg->checksum = 0;
/* First calculate crc32 checksum against fs uuid */
checksum = fs->uuid_crc32c;
/* Then calculate crc32 checksum against bgid */
checksum = ext4_crc32_u(checksum, le32_bgid);
/* Finally calculate crc32 checksum against block_group_desc */
checksum = ext4_crc32c(checksum, bg, ext4_sb_get_desc_size(sb));
bg->checksum = orig_checksum;
crc = checksum & 0xFFFF;
return crc;
}
if (ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_GDT_CSUM)) {
u8int *base = (u8int *)bg;
u8int *checksum = (u8int *)&bg->checksum;
u32int offset = (u32int)(checksum - base);
/* Convert block group index to little endian */
u32int group = to_le32(bgid);
/* Initialization */
crc = ext4_bg_crc16(~0, sb->uuid, sizeof(sb->uuid));
/* Include index of block group */
crc = ext4_bg_crc16(crc, (u8int *)&group, sizeof(group));
/* Compute crc from the first part (stop before checksum field)
*/
crc = ext4_bg_crc16(crc, (u8int *)bg, offset);
/* Skip checksum */
offset += sizeof(bg->checksum);
/* Checksum of the rest of block group descriptor */
if ((ext4_sb_feature_incom(sb, EXT4_FINCOM_64BIT)) &&
(offset < ext4_sb_get_desc_size(sb))) {
const u8int *start = ((u8int *)bg) + offset;
usize len = ext4_sb_get_desc_size(sb) - offset;
crc = ext4_bg_crc16(crc, start, len);
}
}
return crc;
}
static bool ext4_fs_verify_bg_csum(struct ext4_fs *fs,
u32int bgid,
struct ext4_bgroup *bg)
{
if (!ext4_sb_feature_ro_com(&fs->sb, EXT4_FRO_COM_METADATA_CSUM))
return true;
return ext4_fs_bg_checksum(fs, bgid, bg) == to_le16(bg->checksum);
}
int ext4_fs_get_block_group_ref(struct ext4_fs *fs, u32int bgid,
struct ext4_block_group_ref *ref)
{
/* Compute number of descriptors, that fits in one data block */
u32int block_size = ext4_sb_get_block_size(&fs->sb);
u32int dsc_cnt = block_size / ext4_sb_get_desc_size(&fs->sb);
/* Block group descriptor table starts at the next block after
* superblock */
u64int block_id = ext4_fs_get_descriptor_block(&fs->sb, bgid, dsc_cnt);
u32int offset = (bgid % dsc_cnt) * ext4_sb_get_desc_size(&fs->sb);
int rc = ext4_trans_block_get(fs->bdev, &ref->block, block_id);
if (rc != 0)
return rc;
ref->block_group = (void *)(ref->block.data + offset);
ref->fs = fs;
ref->index = bgid;
ref->dirty = false;
struct ext4_bgroup *bg = ref->block_group;
if (!ext4_fs_verify_bg_csum(fs, bgid, bg)) {
ext4_dbg(DEBUG_FS,
DBG_WARN "Block group descriptor checksum failed."
"Block group index: %ud\n",
bgid);
}
if (ext4_bg_has_flag(bg, EXT4_BLOCK_GROUP_BLOCK_UNINIT)) {
rc = ext4_fs_init_block_bitmap(ref);
if (rc != 0) {
ext4_block_set(fs->bdev, &ref->block);
return rc;
}
ext4_bg_clear_flag(bg, EXT4_BLOCK_GROUP_BLOCK_UNINIT);
ref->dirty = true;
}
if (ext4_bg_has_flag(bg, EXT4_BLOCK_GROUP_INODE_UNINIT)) {
rc = ext4_fs_init_inode_bitmap(ref);
if (rc != 0) {
ext4_block_set(ref->fs->bdev, &ref->block);
return rc;
}
ext4_bg_clear_flag(bg, EXT4_BLOCK_GROUP_INODE_UNINIT);
if (!ext4_bg_has_flag(bg, EXT4_BLOCK_GROUP_ITABLE_ZEROED)) {
rc = ext4_fs_init_inode_table(ref);
if (rc != 0) {
ext4_block_set(fs->bdev, &ref->block);
return rc;
}
ext4_bg_set_flag(bg, EXT4_BLOCK_GROUP_ITABLE_ZEROED);
}
ref->dirty = true;
}
return 0;
}
int ext4_fs_put_block_group_ref(struct ext4_block_group_ref *ref)
{
/* Check if reference modified */
if (ref->dirty) {
/* Compute new checksum of block group */
u16int cs;
cs = ext4_fs_bg_checksum(ref->fs, ref->index, ref->block_group);
ref->block_group->checksum = to_le16(cs);
/* Mark block dirty for writing changes to physical device */
ext4_trans_set_block_dirty(ref->block.buf);
}
/* Put back block, that contains block group descriptor */
return ext4_block_set(ref->fs->bdev, &ref->block);
}
static u32int ext4_fs_inode_checksum(struct ext4_inode_ref *inode_ref)
{
u32int checksum = 0;
struct ext4_sblock *sb = &inode_ref->fs->sb;
u16int inode_size = ext4_get16(sb, inode_size);
if (ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM)) {
u32int orig_checksum;
u32int ino_index = to_le32(inode_ref->index);
u32int ino_gen =
to_le32(ext4_inode_get_generation(inode_ref->inode));
/* Preparation: temporarily set bg checksum to 0 */
orig_checksum = ext4_inode_get_csum(sb, inode_ref->inode);
ext4_inode_set_csum(sb, inode_ref->inode, 0);
/* First calculate crc32 checksum against fs uuid */
checksum = inode_ref->fs->uuid_crc32c;
/* Then calculate crc32 checksum against inode number
* and inode generation */
checksum = ext4_crc32_u(checksum, ino_index);
checksum = ext4_crc32_u(checksum, ino_gen);
/* Finally calculate crc32 checksum against
* the entire inode */
checksum = ext4_crc32c(checksum, inode_ref->inode, inode_size);
ext4_inode_set_csum(sb, inode_ref->inode, orig_checksum);
/* If inode size is not large enough to hold the
* upper 16bit of the checksum */
if (inode_size == EXT4_GOOD_OLD_INODE_SIZE)
checksum &= 0xFFFF;
}
return checksum;
}
static void ext4_fs_set_inode_checksum(struct ext4_inode_ref *inode_ref)
{
struct ext4_sblock *sb = &inode_ref->fs->sb;
if (!ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM))
return;
u32int csum = ext4_fs_inode_checksum(inode_ref);
ext4_inode_set_csum(sb, inode_ref->inode, csum);
}
static bool ext4_fs_verify_inode_csum(struct ext4_inode_ref *inode_ref)
{
struct ext4_sblock *sb = &inode_ref->fs->sb;
if (!ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM))
return true;
return ext4_inode_get_csum(sb, inode_ref->inode) ==
ext4_fs_inode_checksum(inode_ref);
}
static int
__ext4_fs_get_inode_ref(struct ext4_fs *fs, u32int index,
struct ext4_inode_ref *ref,
bool initialized)
{
/* Compute number of i-nodes, that fits in one data block */
u32int inodes_per_group = ext4_get32(&fs->sb, inodes_per_group);
/*
* Inode numbers are 1-based, but it is simpler to work with 0-based
* when computing indices
*/
index -= 1;
u32int block_group = index / inodes_per_group;
u32int offset_in_group = index % inodes_per_group;
/* Load block group, where i-node is located */
struct ext4_block_group_ref bg_ref;
int rc = ext4_fs_get_block_group_ref(fs, block_group, &bg_ref);
if (rc != 0) {
return rc;
}
/* Load block address, where i-node table is located */
ext4_fsblk_t inode_table_start =
ext4_bg_get_inode_table_first_block(bg_ref.block_group, &fs->sb);
/* Put back block group reference (not needed more) */
rc = ext4_fs_put_block_group_ref(&bg_ref);
if (rc != 0) {
return rc;
}
/* Compute position of i-node in the block group */
u16int inode_size = ext4_get16(&fs->sb, inode_size);
u32int block_size = ext4_sb_get_block_size(&fs->sb);
u32int byte_offset_in_group = offset_in_group * inode_size;
/* Compute block address */
ext4_fsblk_t block_id =
inode_table_start + (byte_offset_in_group / block_size);
rc = ext4_trans_block_get(fs->bdev, &ref->block, block_id);
if (rc != 0) {
return rc;
}
/* Compute position of i-node in the data block */
u32int offset_in_block = byte_offset_in_group % block_size;
ref->inode = (struct ext4_inode *)(ref->block.data + offset_in_block);
/* We need to store the original value of index in the reference */
ref->index = index + 1;
ref->fs = fs;
ref->dirty = false;
if (initialized && !ext4_fs_verify_inode_csum(ref)) {
ext4_dbg(DEBUG_FS,
DBG_WARN "Inode checksum failed."
"Inode: %ud\n",
ref->index);
}
return 0;
}
int ext4_fs_get_inode_ref(struct ext4_fs *fs, u32int index,
struct ext4_inode_ref *ref)
{
return __ext4_fs_get_inode_ref(fs, index, ref, true);
}
int ext4_fs_put_inode_ref(struct ext4_inode_ref *ref)
{
/* Check if reference modified */
if (ref->dirty) {
/* Mark block dirty for writing changes to physical device */
ext4_fs_set_inode_checksum(ref);
ext4_trans_set_block_dirty(ref->block.buf);
}
/* Put back block, that contains i-node */
return ext4_block_set(ref->fs->bdev, &ref->block);
}
void ext4_fs_inode_blocks_init(struct ext4_fs *fs,
struct ext4_inode_ref *inode_ref)
{
struct ext4_inode *inode = inode_ref->inode;
/* Reset blocks array. For inode which is not directory or file, just
* fill in blocks with 0 */
switch (ext4_inode_type(&fs->sb, inode)) {
case EXT4_INODE_MODE_FILE:
case EXT4_INODE_MODE_DIRECTORY:
break;
default:
return;
}
/* Initialize extents if needed */
if (ext4_sb_feature_incom(&fs->sb, EXT4_FINCOM_EXTENTS)) {
ext4_inode_set_flag(inode, EXT4_INODE_FLAG_EXTENTS);
/* Initialize extent root header */
ext4_extent_tree_init(inode_ref);
}
inode_ref->dirty = true;
}
u32int ext4_fs_correspond_inode_mode(int filetype)
{
switch (filetype) {
case EXT4_DE_DIR:
return EXT4_INODE_MODE_DIRECTORY;
case EXT4_DE_REG_FILE:
return EXT4_INODE_MODE_FILE;
case EXT4_DE_SYMLINK:
return EXT4_INODE_MODE_SOFTLINK;
case EXT4_DE_CHRDEV:
return EXT4_INODE_MODE_CHARDEV;
case EXT4_DE_BLKDEV:
return EXT4_INODE_MODE_BLOCKDEV;
case EXT4_DE_FIFO:
return EXT4_INODE_MODE_FIFO;
case EXT4_DE_SOCK:
return EXT4_INODE_MODE_SOCKET;
}
/* FIXME: unsupported filetype */
return EXT4_INODE_MODE_FILE;
}
int ext4_fs_alloc_inode(struct ext4_fs *fs, struct ext4_inode_ref *inode_ref,
int filetype)
{
/* Check if newly allocated i-node will be a directory */
bool is_dir;
u16int inode_size = ext4_get16(&fs->sb, inode_size);
is_dir = (filetype == EXT4_DE_DIR);
/* Allocate inode by allocation algorithm */
u32int index;
int rc = ext4_ialloc_alloc_inode(fs, &index, is_dir);
if (rc != 0)
return rc;
/* Load i-node from on-disk i-node table */
rc = __ext4_fs_get_inode_ref(fs, index, inode_ref, false);
if (rc != 0) {
ext4_ialloc_free_inode(fs, index, is_dir);
return rc;
}
/* Initialize i-node */
struct ext4_inode *inode = inode_ref->inode;
memset(inode, 0, inode_size);
u32int mode;
if (is_dir) {
/*
* Default directory permissions to be compatible with other
* systems
* 0777 (octal) == rwxrwxrwx
*/
mode = 0777;
mode |= EXT4_INODE_MODE_DIRECTORY;
} else if (filetype == EXT4_DE_SYMLINK) {
/*
* Default symbolic link permissions to be compatible with other systems
* 0777 (octal) == rwxrwxrwx
*/
mode = 0777;
mode |= EXT4_INODE_MODE_SOFTLINK;
} else {
/*
* Default file permissions to be compatible with other systems
* 0666 (octal) == rw-rw-rw-
*/
mode = 0666;
mode |= ext4_fs_correspond_inode_mode(filetype);
}
ext4_inode_set_mode(&fs->sb, inode, mode);
ext4_inode_set_links_cnt(inode, 0);
ext4_inode_set_uid(inode, 0);
ext4_inode_set_gid(inode, 0);
ext4_inode_set_size(inode, 0);
ext4_inode_set_access_time(inode, 0);
ext4_inode_set_change_inode_time(inode, 0);
ext4_inode_set_modif_time(inode, 0);
ext4_inode_set_del_time(inode, 0);
ext4_inode_set_blocks_count(&fs->sb, inode, 0);
ext4_inode_set_flags(inode, 0);
ext4_inode_set_generation(inode, 0);
if (inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
u16int size = ext4_get16(&fs->sb, want_extra_isize);
ext4_inode_set_extra_isize(&fs->sb, inode, size);
}
memset(inode->blocks, 0, sizeof(inode->blocks));
inode_ref->dirty = true;
return 0;
}
int ext4_fs_free_inode(struct ext4_inode_ref *inode_ref)
{
struct ext4_fs *fs = inode_ref->fs;
u32int offset;
u32int suboff;
int rc;
/* For extents must be data block destroyed by other way */
if ((ext4_sb_feature_incom(&fs->sb, EXT4_FINCOM_EXTENTS)) &&
(ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_EXTENTS))) {
/* Data structures are released during truncate operation... */
goto finish;
}
/* Release all indirect (no data) blocks */
/* 1) Single indirect */
ext4_fsblk_t fblock = ext4_inode_get_indirect_block(inode_ref->inode, 0);
if (fblock != 0) {
int rc = ext4_balloc_free_block(inode_ref, fblock);
if (rc != 0)
return rc;
ext4_inode_set_indirect_block(inode_ref->inode, 0, 0);
}
u32int block_size = ext4_sb_get_block_size(&fs->sb);
u32int count = block_size / sizeof(u32int);
struct ext4_block block;
/* 2) Double indirect */
fblock = ext4_inode_get_indirect_block(inode_ref->inode, 1);
if (fblock != 0) {
int rc = ext4_trans_block_get(fs->bdev, &block, fblock);
if (rc != 0)
return rc;
ext4_fsblk_t ind_block;
for (offset = 0; offset < count; ++offset) {
ind_block = to_le32(((u32int *)block.data)[offset]);
if (ind_block == 0)
continue;
rc = ext4_balloc_free_block(inode_ref, ind_block);
if (rc != 0) {
ext4_block_set(fs->bdev, &block);
return rc;
}
}
ext4_block_set(fs->bdev, &block);
rc = ext4_balloc_free_block(inode_ref, fblock);
if (rc != 0)
return rc;
ext4_inode_set_indirect_block(inode_ref->inode, 1, 0);
}
/* 3) Tripple indirect */
struct ext4_block subblock;
fblock = ext4_inode_get_indirect_block(inode_ref->inode, 2);
if (fblock == 0)
goto finish;
rc = ext4_trans_block_get(fs->bdev, &block, fblock);
if (rc != 0)
return rc;
ext4_fsblk_t ind_block;
for (offset = 0; offset < count; ++offset) {
ind_block = to_le32(((u32int *)block.data)[offset]);
if (ind_block == 0)
continue;
rc = ext4_trans_block_get(fs->bdev, &subblock,
ind_block);
if (rc != 0) {
ext4_block_set(fs->bdev, &block);
return rc;
}
ext4_fsblk_t ind_subblk;
for (suboff = 0; suboff < count; ++suboff) {
ind_subblk = to_le32(((u32int *)subblock.data)[suboff]);
if (ind_subblk == 0)
continue;
rc = ext4_balloc_free_block(inode_ref, ind_subblk);
if (rc != 0) {
ext4_block_set(fs->bdev, &subblock);
ext4_block_set(fs->bdev, &block);
return rc;
}
}
ext4_block_set(fs->bdev, &subblock);
rc = ext4_balloc_free_block(inode_ref,
ind_block);
if (rc != 0) {
ext4_block_set(fs->bdev, &block);
return rc;
}
}
ext4_block_set(fs->bdev, &block);
rc = ext4_balloc_free_block(inode_ref, fblock);
if (rc != 0)
return rc;
ext4_inode_set_indirect_block(inode_ref->inode, 2, 0);
finish:
/* Mark inode dirty for writing to the physical device */
inode_ref->dirty = true;
/* Free block with extended attributes if present */
ext4_fsblk_t xattr_block =
ext4_inode_get_file_acl(inode_ref->inode, &fs->sb);
if (xattr_block) {
int rc = ext4_balloc_free_block(inode_ref, xattr_block);
if (rc != 0)
return rc;
ext4_inode_set_file_acl(inode_ref->inode, &fs->sb, 0);
}
/* Free inode by allocator */
if (ext4_inode_is_type(&fs->sb, inode_ref->inode,
EXT4_INODE_MODE_DIRECTORY))
rc = ext4_ialloc_free_inode(fs, inode_ref->index, true);
else
rc = ext4_ialloc_free_inode(fs, inode_ref->index, false);
return rc;
}
/**@brief Release data block from i-node
* @param inode_ref I-node to release block from
* @param iblock Logical block to be released
* @return Error code
*/
static int ext4_fs_release_inode_block(struct ext4_inode_ref *inode_ref,
ext4_lblk_t iblock)
{
ext4_fsblk_t fblock;
struct ext4_fs *fs = inode_ref->fs;
/* Extents are handled otherwise = there is not support in this function
*/
assert(!(
ext4_sb_feature_incom(&fs->sb, EXT4_FINCOM_EXTENTS) &&
(ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_EXTENTS))));
struct ext4_inode *inode = inode_ref->inode;
/* Handle simple case when we are dealing with direct reference */
if (iblock < EXT4_INODE_DIRECT_BLOCK_COUNT) {
fblock = ext4_inode_get_direct_block(inode, iblock);
/* Sparse file */
if (fblock == 0)
return 0;
ext4_inode_set_direct_block(inode, iblock, 0);
return ext4_balloc_free_block(inode_ref, fblock);
}
/* Determine the indirection level needed to get the desired block */
unsigned int level = 0;
unsigned int i;
for (i = 1; i < 4; i++) {
if (iblock < fs->inode_block_limits[i]) {
level = i;
break;
}
}
if (level == 0) {
werrstr(Eio);
return -1;
}
/* Compute offsets for the topmost level */
u32int block_offset_in_level =
(u32int)(iblock - fs->inode_block_limits[level - 1]);
ext4_fsblk_t current_block =
ext4_inode_get_indirect_block(inode, level - 1);
u32int offset_in_block =
(u32int)(block_offset_in_level / fs->inode_blocks_per_level[level - 1]);
/*
* Navigate through other levels, until we find the block number
* or find null reference meaning we are dealing with sparse file
*/
struct ext4_block block;
while (level > 0) {
/* Sparse check */
if (current_block == 0)
return 0;
int rc = ext4_trans_block_get(fs->bdev, &block, current_block);
if (rc != 0)
return rc;
current_block =
to_le32(((u32int *)block.data)[offset_in_block]);
/* Set zero if physical data block address found */
if (level == 1) {
((u32int *)block.data)[offset_in_block] = to_le32(0);
ext4_trans_set_block_dirty(block.buf);
}
rc = ext4_block_set(fs->bdev, &block);
if (rc != 0)
return rc;
level--;
/*
* If we are on the last level, break here as
* there is no next level to visit
*/
if (level == 0)
break;
/* Visit the next level */
block_offset_in_level %= fs->inode_blocks_per_level[level];
offset_in_block = (u32int)(block_offset_in_level /
fs->inode_blocks_per_level[level - 1]);
}
fblock = current_block;
if (fblock == 0)
return 0;
/* Physical block is not referenced, it can be released */
return ext4_balloc_free_block(inode_ref, fblock);
}
int ext4_fs_truncate_inode(struct ext4_inode_ref *inode_ref, u64int new_size)
{
struct ext4_sblock *sb = &inode_ref->fs->sb;
u32int i;
int r;
bool v;
/* Check flags, if i-node can be truncated */
if (!ext4_inode_can_truncate(sb, inode_ref->inode)) {
werrstr(Einval);
return -1;
}
/* If sizes are equal, nothing has to be done. */
u64int old_size = ext4_inode_get_size(sb, inode_ref->inode);
if (old_size == new_size)
return 0;
/* It's not supported to make the larger file by truncate operation */
if (old_size < new_size) {
werrstr(Einval);
return -1;
}
/* For symbolic link which is small enough */
v = ext4_inode_is_type(sb, inode_ref->inode, EXT4_INODE_MODE_SOFTLINK);
if (v && old_size < sizeof(inode_ref->inode->blocks) &&
!ext4_inode_get_blocks_count(sb, inode_ref->inode)) {
char *content = (char *)inode_ref->inode->blocks + new_size;
memset(content, 0,
sizeof(inode_ref->inode->blocks) - (u32int)new_size);
ext4_inode_set_size(inode_ref->inode, new_size);
inode_ref->dirty = true;
return 0;
}
i = ext4_inode_type(sb, inode_ref->inode);
if (i == EXT4_INODE_MODE_CHARDEV ||
i == EXT4_INODE_MODE_BLOCKDEV ||
i == EXT4_INODE_MODE_SOCKET) {
inode_ref->inode->blocks[0] = 0;
inode_ref->inode->blocks[1] = 0;
inode_ref->dirty = true;
return 0;
}
/* Compute how many blocks will be released */
u32int block_size = ext4_sb_get_block_size(sb);
u32int new_blocks_cnt = (u32int)((new_size + block_size - 1) / block_size);
u32int old_blocks_cnt = (u32int)((old_size + block_size - 1) / block_size);
u32int diff_blocks_cnt = old_blocks_cnt - new_blocks_cnt;
if ((ext4_sb_feature_incom(sb, EXT4_FINCOM_EXTENTS)) &&
(ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_EXTENTS))) {
/* Extents require special operation */
if (diff_blocks_cnt) {
r = ext4_extent_remove_space(inode_ref, new_blocks_cnt,
EXT4_EXTENT_MAX_BLOCKS);
if (r != 0)
return r;
}
} else {
/* Release data blocks from the end of file */
/* Starting from 1 because of logical blocks are numbered from 0
*/
for (i = 0; i < diff_blocks_cnt; ++i) {
r = ext4_fs_release_inode_block(inode_ref,
new_blocks_cnt + i);
if (r != 0)
return r;
}
}
/* Update i-node */
ext4_inode_set_size(inode_ref->inode, new_size);
inode_ref->dirty = true;
return 0;
}
/**@brief Compute 'goal' for inode index
* @param inode_ref Reference to inode, to allocate block for
* @return goal
*/
ext4_fsblk_t ext4_fs_inode_to_goal_block(struct ext4_inode_ref *inode_ref)
{
u32int grp_inodes = ext4_get32(&inode_ref->fs->sb, inodes_per_group);
return (inode_ref->index - 1) / grp_inodes;
}
/**@brief Compute 'goal' for allocation algorithm (For blockmap).
* @param inode_ref Reference to inode, to allocate block for
* @param goal
* @return error code
*/
int ext4_fs_indirect_find_goal(struct ext4_inode_ref *inode_ref,
ext4_fsblk_t *goal)
{
int r;
struct ext4_sblock *sb = &inode_ref->fs->sb;
*goal = 0;
u64int inode_size = ext4_inode_get_size(sb, inode_ref->inode);
u32int block_size = ext4_sb_get_block_size(sb);
u32int iblock_cnt = (u32int)(inode_size / block_size);
if (inode_size % block_size != 0)
iblock_cnt++;
/* If inode has some blocks, get last block address + 1 */
if (iblock_cnt > 0) {
r = ext4_fs_get_inode_dblk_idx(inode_ref, iblock_cnt - 1,
goal, false);
if (r != 0)
return r;
if (*goal != 0) {
(*goal)++;
return r;
}
/* If goal == 0, sparse file -> continue */
}
/* Identify block group of inode */
u32int inodes_per_bg = ext4_get32(sb, inodes_per_group);
u32int block_group = (inode_ref->index - 1) / inodes_per_bg;
block_size = ext4_sb_get_block_size(sb);
/* Load block group reference */
struct ext4_block_group_ref bg_ref;
r = ext4_fs_get_block_group_ref(inode_ref->fs, block_group, &bg_ref);
if (r != 0)
return r;
struct ext4_bgroup *bg = bg_ref.block_group;
/* Compute indexes */
u32int bg_count = ext4_block_group_cnt(sb);
ext4_fsblk_t itab_first_block = ext4_bg_get_inode_table_first_block(bg, sb);
u16int itab_item_size = ext4_get16(sb, inode_size);
u32int itab_bytes;
/* Check for last block group */
if (block_group < bg_count - 1) {
itab_bytes = inodes_per_bg * itab_item_size;
} else {
/* Last block group could be smaller */
u32int inodes_cnt = ext4_get32(sb, inodes_count);
itab_bytes = (inodes_cnt - ((bg_count - 1) * inodes_per_bg));
itab_bytes *= itab_item_size;
}
ext4_fsblk_t inode_table_blocks = itab_bytes / block_size;
if (itab_bytes % block_size)
inode_table_blocks++;
*goal = itab_first_block + inode_table_blocks;
return ext4_fs_put_block_group_ref(&bg_ref);
}
static int ext4_fs_get_inode_dblk_idx_internal(struct ext4_inode_ref *inode_ref,
ext4_lblk_t iblock, ext4_fsblk_t *fblock,
bool extent_create,
bool support_unwritten)
{
struct ext4_fs *fs = inode_ref->fs;
/* For empty file is situation simple */
if (ext4_inode_get_size(&fs->sb, inode_ref->inode) == 0) {
*fblock = 0;
return 0;
}
ext4_fsblk_t current_block;
USED(extent_create);
USED(support_unwritten);
/* Handle i-node using extents */
if ((ext4_sb_feature_incom(&fs->sb, EXT4_FINCOM_EXTENTS)) &&
(ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_EXTENTS))) {
ext4_fsblk_t current_fsblk;
int rc = ext4_extent_get_blocks(inode_ref, iblock, 1,
¤t_fsblk, extent_create, nil);
if (rc != 0)
return rc;
current_block = current_fsblk;
*fblock = current_block;
return 0;
}
struct ext4_inode *inode = inode_ref->inode;
/* Direct block are read directly from array in i-node structure */
if (iblock < EXT4_INODE_DIRECT_BLOCK_COUNT) {
current_block =
ext4_inode_get_direct_block(inode, (u32int)iblock);
*fblock = current_block;
return 0;
}
/* Determine indirection level of the target block */
unsigned int l = 0;
unsigned int i;
for (i = 1; i < 4; i++) {
if (iblock < fs->inode_block_limits[i]) {
l = i;
break;
}
}
if (l == 0) {
werrstr(Eio);
return -1;
}
/* Compute offsets for the topmost level */
u32int blk_off_in_lvl = (u32int)(iblock - fs->inode_block_limits[l - 1]);
current_block = ext4_inode_get_indirect_block(inode, l - 1);
u32int off_in_blk = (u32int)(blk_off_in_lvl / fs->inode_blocks_per_level[l - 1]);
/* Sparse file */
if (current_block == 0) {
*fblock = 0;
return 0;
}
struct ext4_block block;
/*
* Navigate through other levels, until we find the block number
* or find null reference meaning we are dealing with sparse file
*/
while (l > 0) {
/* Load indirect block */
int rc = ext4_trans_block_get(fs->bdev, &block, current_block);
if (rc != 0)
return rc;
/* Read block address from indirect block */
current_block =
to_le32(((u32int *)block.data)[off_in_blk]);
/* Put back indirect block untouched */
rc = ext4_block_set(fs->bdev, &block);
if (rc != 0)
return rc;
/* Check for sparse file */
if (current_block == 0) {
*fblock = 0;
return 0;
}
/* Jump to the next level */
l--;
/* Termination condition - we have address of data block loaded
*/
if (l == 0)
break;
/* Visit the next level */
blk_off_in_lvl %= fs->inode_blocks_per_level[l];
off_in_blk = (u32int)(blk_off_in_lvl / fs->inode_blocks_per_level[l - 1]);
}
*fblock = current_block;
return 0;
}
int ext4_fs_get_inode_dblk_idx(struct ext4_inode_ref *inode_ref,
ext4_lblk_t iblock, ext4_fsblk_t *fblock,
bool support_unwritten)
{
return ext4_fs_get_inode_dblk_idx_internal(inode_ref, iblock, fblock,
false, support_unwritten);
}
int ext4_fs_init_inode_dblk_idx(struct ext4_inode_ref *inode_ref,
ext4_lblk_t iblock, ext4_fsblk_t *fblock)
{
return ext4_fs_get_inode_dblk_idx_internal(inode_ref, iblock, fblock,
true, true);
}
static int ext4_fs_set_inode_data_block_index(struct ext4_inode_ref *inode_ref,
ext4_lblk_t iblock, ext4_fsblk_t fblock)
{
struct ext4_fs *fs = inode_ref->fs;
/* Handle inode using extents */
if ((ext4_sb_feature_incom(&fs->sb, EXT4_FINCOM_EXTENTS)) &&
(ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_EXTENTS))) {
/* Not reachable */
werrstr("impossible feature combination in extents");
return -1;
}
/* Handle simple case when we are dealing with direct reference */
if (iblock < EXT4_INODE_DIRECT_BLOCK_COUNT) {
ext4_inode_set_direct_block(inode_ref->inode, (u32int)iblock,
(u32int)fblock);
inode_ref->dirty = true;
return 0;
}
/* Determine the indirection level needed to get the desired block */
unsigned int l = 0;
unsigned int i;
for (i = 1; i < 4; i++) {
if (iblock < fs->inode_block_limits[i]) {
l = i;
break;
}
}
if (l == 0) {
werrstr(Eio);
return -1;
}
u32int block_size = ext4_sb_get_block_size(&fs->sb);
/* Compute offsets for the topmost level */
u32int blk_off_in_lvl = (u32int)(iblock - fs->inode_block_limits[l - 1]);
ext4_fsblk_t current_block =
ext4_inode_get_indirect_block(inode_ref->inode, l - 1);
u32int off_in_blk = (u32int)(blk_off_in_lvl / fs->inode_blocks_per_level[l - 1]);
ext4_fsblk_t new_blk;
struct ext4_block block;
struct ext4_block new_block;
/* Is needed to allocate indirect block on the i-node level */
if (current_block == 0) {
/* Allocate new indirect block */
ext4_fsblk_t goal;
int rc = ext4_fs_indirect_find_goal(inode_ref, &goal);
if (rc != 0)
return rc;
rc = ext4_balloc_alloc_block(inode_ref, goal, &new_blk);
if (rc != 0)
return rc;
/* Update i-node */
ext4_inode_set_indirect_block(inode_ref->inode, l - 1,
(u32int)new_blk);
inode_ref->dirty = true;
/* Load newly allocated block */
rc = ext4_trans_block_get_noread(fs->bdev, &new_block, new_blk);
if (rc != 0) {
ext4_balloc_free_block(inode_ref, new_blk);
return rc;
}
/* Initialize new block */
memset(new_block.data, 0, block_size);
ext4_trans_set_block_dirty(new_block.buf);
/* Put back the allocated block */
rc = ext4_block_set(fs->bdev, &new_block);
if (rc != 0)
return rc;
current_block = new_blk;
}
/*
* Navigate through other levels, until we find the block number
* or find null reference meaning we are dealing with sparse file
*/
while (l > 0) {
int rc = ext4_trans_block_get(fs->bdev, &block, current_block);
if (rc != 0)
return rc;
current_block = to_le32(((u32int *)block.data)[off_in_blk]);
if ((l > 1) && (current_block == 0)) {
ext4_fsblk_t goal;
rc = ext4_fs_indirect_find_goal(inode_ref, &goal);
if (rc != 0) {
ext4_block_set(fs->bdev, &block);
return rc;
}
/* Allocate new block */
rc =
ext4_balloc_alloc_block(inode_ref, goal, &new_blk);
if (rc != 0) {
ext4_block_set(fs->bdev, &block);
return rc;
}
/* Load newly allocated block */
rc = ext4_trans_block_get_noread(fs->bdev, &new_block,
new_blk);
if (rc != 0) {
ext4_block_set(fs->bdev, &block);
return rc;
}
/* Initialize allocated block */
memset(new_block.data, 0, block_size);
ext4_trans_set_block_dirty(new_block.buf);
rc = ext4_block_set(fs->bdev, &new_block);
if (rc != 0) {
ext4_block_set(fs->bdev, &block);
return rc;
}
/* Write block address to the parent */
u32int * p = (u32int * )block.data;
p[off_in_blk] = to_le32((u32int)new_blk);
ext4_trans_set_block_dirty(block.buf);
current_block = new_blk;
}
/* Will be finished, write the fblock address */
if (l == 1) {
u32int * p = (u32int * )block.data;
p[off_in_blk] = to_le32((u32int)fblock);
ext4_trans_set_block_dirty(block.buf);
}
rc = ext4_block_set(fs->bdev, &block);
if (rc != 0)
return rc;
l--;
/*
* If we are on the last level, break here as
* there is no next level to visit
*/
if (l == 0)
break;
/* Visit the next level */
blk_off_in_lvl %= fs->inode_blocks_per_level[l];
off_in_blk = (u32int)(blk_off_in_lvl / fs->inode_blocks_per_level[l - 1]);
}
return 0;
}
int ext4_fs_append_inode_dblk(struct ext4_inode_ref *inode_ref,
ext4_fsblk_t *fblock, ext4_lblk_t *iblock)
{
/* Handle extents separately */
if ((ext4_sb_feature_incom(&inode_ref->fs->sb, EXT4_FINCOM_EXTENTS)) &&
(ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_EXTENTS))) {
int rc;
ext4_fsblk_t current_fsblk;
struct ext4_sblock *sb = &inode_ref->fs->sb;
u64int inode_size = ext4_inode_get_size(sb, inode_ref->inode);
u32int block_size = ext4_sb_get_block_size(sb);
*iblock = (u32int)((inode_size + block_size - 1) / block_size);
rc = ext4_extent_get_blocks(inode_ref, *iblock, 1,
¤t_fsblk, true, nil);
if (rc != 0)
return rc;
*fblock = current_fsblk;
assert(*fblock);
ext4_inode_set_size(inode_ref->inode, inode_size + block_size);
inode_ref->dirty = true;
return rc;
}
struct ext4_sblock *sb = &inode_ref->fs->sb;
/* Compute next block index and allocate data block */
u64int inode_size = ext4_inode_get_size(sb, inode_ref->inode);
u32int block_size = ext4_sb_get_block_size(sb);
/* Align size i-node size */
if ((inode_size % block_size) != 0)
inode_size += block_size - (inode_size % block_size);
/* Logical blocks are numbered from 0 */
u32int new_block_idx = (u32int)(inode_size / block_size);
/* Allocate new physical block */
ext4_fsblk_t goal, phys_block;
int rc = ext4_fs_indirect_find_goal(inode_ref, &goal);
if (rc != 0)
return rc;
rc = ext4_balloc_alloc_block(inode_ref, goal, &phys_block);
if (rc != 0)
return rc;
/* Add physical block address to the i-node */
rc = ext4_fs_set_inode_data_block_index(inode_ref, new_block_idx,
phys_block);
if (rc != 0) {
ext4_balloc_free_block(inode_ref, phys_block);
return rc;
}
/* Update i-node */
ext4_inode_set_size(inode_ref->inode, inode_size + block_size);
inode_ref->dirty = true;
*fblock = phys_block;
*iblock = new_block_idx;
return 0;
}
void ext4_fs_inode_links_count_inc(struct ext4_inode_ref *inode_ref)
{
u16int link;
bool is_dx;
link = ext4_inode_get_links_cnt(inode_ref->inode);
link++;
ext4_inode_set_links_cnt(inode_ref->inode, link);
is_dx = ext4_sb_feature_com(&inode_ref->fs->sb, EXT4_FCOM_DIR_INDEX) &&
ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_INDEX);
if (is_dx && link > 1) {
if (link >= EXT4_LINK_MAX || link == 2) {
ext4_inode_set_links_cnt(inode_ref->inode, 1);
u32int v;
v = ext4_get32(&inode_ref->fs->sb, features_read_only);
v |= EXT4_FRO_COM_DIR_NLINK;
ext4_set32(&inode_ref->fs->sb, features_read_only, v);
}
}
}
void ext4_fs_inode_links_count_dec(struct ext4_inode_ref *inode_ref)
{
u16int links = ext4_inode_get_links_cnt(inode_ref->inode);
if (!ext4_inode_is_type(&inode_ref->fs->sb, inode_ref->inode,
EXT4_INODE_MODE_DIRECTORY)) {
if (links > 0)
ext4_inode_set_links_cnt(inode_ref->inode, links - 1);
return;
}
if (links > 2)
ext4_inode_set_links_cnt(inode_ref->inode, links - 1);
}