ref: dee6a10ab37fef64f47ddfadeae02a9449fb9294
dir: /src/ext4_balloc.c/
/*
* Copyright (c) 2013 Grzegorz Kostka (kostka.grzegorz@gmail.com)
*
* HelenOS:
* Copyright (c) 2012 Martin Sucha
* Copyright (c) 2012 Frantisek Princ
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/** @addtogroup lwext4
* @{
*/
/**
* @file ext4_balloc.c
* @brief Physical block allocator.
*/
#include <ext4_config.h>
#include <ext4_types.h>
#include <ext4_misc.h>
#include <ext4_errno.h>
#include <ext4_debug.h>
#include <ext4_trans.h>
#include <ext4_balloc.h>
#include <ext4_super.h>
#include <ext4_crc32.h>
#include <ext4_block_group.h>
#include <ext4_fs.h>
#include <ext4_bitmap.h>
#include <ext4_inode.h>
/**@brief Compute number of block group from block address.
* @param sb superblock pointer.
* @param baddr Absolute address of block.
* @return Block group index
*/
uint32_t ext4_balloc_get_bgid_of_block(struct ext4_sblock *s,
uint64_t baddr)
{
if (ext4_get32(s, first_data_block) && baddr)
baddr--;
return (uint32_t)(baddr / ext4_get32(s, blocks_per_group));
}
/**@brief Compute the starting block address of a block group
* @param sb superblock pointer.
* @param bgid block group index
* @return Block address
*/
uint64_t ext4_balloc_get_block_of_bgid(struct ext4_sblock *s,
uint32_t bgid)
{
uint64_t baddr = 0;
if (ext4_get32(s, first_data_block))
baddr++;
baddr += bgid * ext4_get32(s, blocks_per_group);
return baddr;
}
#if CONFIG_META_CSUM_ENABLE
static uint32_t ext4_balloc_bitmap_csum(struct ext4_sblock *sb,
void *bitmap)
{
uint32_t checksum = 0;
if (ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM)) {
uint32_t blocks_per_group = ext4_get32(sb, blocks_per_group);
/* First calculate crc32 checksum against fs uuid */
checksum = ext4_crc32c(EXT4_CRC32_INIT, sb->uuid,
sizeof(sb->uuid));
/* Then calculate crc32 checksum against block_group_desc */
checksum = ext4_crc32c(checksum, bitmap, blocks_per_group / 8);
}
return checksum;
}
#else
#define ext4_balloc_bitmap_csum(...) 0
#endif
void ext4_balloc_set_bitmap_csum(struct ext4_sblock *sb,
struct ext4_bgroup *bg,
void *bitmap __unused)
{
int desc_size = ext4_sb_get_desc_size(sb);
uint32_t checksum = ext4_balloc_bitmap_csum(sb, bitmap);
uint16_t lo_checksum = to_le16(checksum & 0xFFFF),
hi_checksum = to_le16(checksum >> 16);
if (!ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM))
return;
/* See if we need to assign a 32bit checksum */
bg->block_bitmap_csum_lo = lo_checksum;
if (desc_size == EXT4_MAX_BLOCK_GROUP_DESCRIPTOR_SIZE)
bg->block_bitmap_csum_hi = hi_checksum;
}
#if CONFIG_META_CSUM_ENABLE
static bool
ext4_balloc_verify_bitmap_csum(struct ext4_sblock *sb,
struct ext4_bgroup *bg,
void *bitmap __unused)
{
int desc_size = ext4_sb_get_desc_size(sb);
uint32_t checksum = ext4_balloc_bitmap_csum(sb, bitmap);
uint16_t lo_checksum = to_le16(checksum & 0xFFFF),
hi_checksum = to_le16(checksum >> 16);
if (!ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM))
return true;
if (bg->block_bitmap_csum_lo != lo_checksum)
return false;
if (desc_size == EXT4_MAX_BLOCK_GROUP_DESCRIPTOR_SIZE)
if (bg->block_bitmap_csum_hi != hi_checksum)
return false;
return true;
}
#else
#define ext4_balloc_verify_bitmap_csum(...) true
#endif
int ext4_balloc_free_block(struct ext4_inode_ref *inode_ref, ext4_fsblk_t baddr)
{
struct ext4_fs *fs = inode_ref->fs;
struct ext4_sblock *sb = &fs->sb;
uint32_t bg_id = ext4_balloc_get_bgid_of_block(sb, baddr);
uint32_t index_in_group = ext4_fs_addr_to_idx_bg(sb, baddr);
/* Load block group reference */
struct ext4_block_group_ref bg_ref;
int rc = ext4_fs_get_block_group_ref(fs, bg_id, &bg_ref);
if (rc != EOK)
return rc;
struct ext4_bgroup *bg = bg_ref.block_group;
/* Load block with bitmap */
ext4_fsblk_t bitmap_block_addr =
ext4_bg_get_block_bitmap(bg, sb);
struct ext4_block bitmap_block;
rc = ext4_trans_block_get(fs->bdev, &bitmap_block, bitmap_block_addr);
if (rc != EOK) {
ext4_fs_put_block_group_ref(&bg_ref);
return rc;
}
if (!ext4_balloc_verify_bitmap_csum(sb, bg, bitmap_block.data)) {
ext4_dbg(DEBUG_BALLOC,
DBG_WARN "Bitmap checksum failed."
"Group: %" PRIu32"\n",
bg_ref.index);
}
/* Modify bitmap */
ext4_bmap_bit_clr(bitmap_block.data, index_in_group);
ext4_balloc_set_bitmap_csum(sb, bg, bitmap_block.data);
ext4_trans_set_block_dirty(bitmap_block.buf);
/* Release block with bitmap */
rc = ext4_block_set(fs->bdev, &bitmap_block);
if (rc != EOK) {
/* Error in saving bitmap */
ext4_fs_put_block_group_ref(&bg_ref);
return rc;
}
uint32_t block_size = ext4_sb_get_block_size(sb);
/* Update superblock free blocks count */
uint64_t sb_free_blocks = ext4_sb_get_free_blocks_cnt(sb);
sb_free_blocks++;
ext4_sb_set_free_blocks_cnt(sb, sb_free_blocks);
/* Update inode blocks count */
uint64_t ino_blocks = ext4_inode_get_blocks_count(sb, inode_ref->inode);
ino_blocks -= block_size / EXT4_INODE_BLOCK_SIZE;
ext4_inode_set_blocks_count(sb, inode_ref->inode, ino_blocks);
inode_ref->dirty = true;
/* Update block group free blocks count */
uint32_t free_blocks = ext4_bg_get_free_blocks_count(bg, sb);
free_blocks++;
ext4_bg_set_free_blocks_count(bg, sb, free_blocks);
bg_ref.dirty = true;
rc = ext4_trans_try_revoke_block(fs->bdev, baddr);
if (rc != EOK) {
bg_ref.dirty = false;
ext4_fs_put_block_group_ref(&bg_ref);
return rc;
}
ext4_bcache_invalidate_lba(fs->bdev->bc, baddr, 1);
/* Release block group reference */
rc = ext4_fs_put_block_group_ref(&bg_ref);
return rc;
}
int ext4_balloc_free_blocks(struct ext4_inode_ref *inode_ref,
ext4_fsblk_t first, uint32_t count)
{
int rc = EOK;
uint32_t blk_cnt = count;
struct ext4_fs *fs = inode_ref->fs;
struct ext4_sblock *sb = &fs->sb;
/* Compute indexes */
uint32_t bg_first = ext4_balloc_get_bgid_of_block(sb, first);
/* Compute indexes */
uint32_t bg_last = ext4_balloc_get_bgid_of_block(sb, first + count - 1);
if (!ext4_sb_feature_incom(sb, EXT4_FINCOM_FLEX_BG)) {
/*It is not possible without flex_bg that blocks are continuous
* and and last block belongs to other bg.*/
if (bg_last != bg_first) {
ext4_dbg(DEBUG_BALLOC, DBG_WARN "FLEX_BG: disabled & "
"bg_last: %"PRIu32" bg_first: %"PRIu32"\n",
bg_last, bg_first);
}
}
/* Load block group reference */
struct ext4_block_group_ref bg_ref;
while (bg_first <= bg_last) {
rc = ext4_fs_get_block_group_ref(fs, bg_first, &bg_ref);
if (rc != EOK)
return rc;
struct ext4_bgroup *bg = bg_ref.block_group;
uint32_t idx_in_bg_first;
idx_in_bg_first = ext4_fs_addr_to_idx_bg(sb, first);
/* Load block with bitmap */
ext4_fsblk_t bitmap_blk = ext4_bg_get_block_bitmap(bg, sb);
struct ext4_block blk;
rc = ext4_trans_block_get(fs->bdev, &blk, bitmap_blk);
if (rc != EOK) {
ext4_fs_put_block_group_ref(&bg_ref);
return rc;
}
if (!ext4_balloc_verify_bitmap_csum(sb, bg, blk.data)) {
ext4_dbg(DEBUG_BALLOC,
DBG_WARN "Bitmap checksum failed."
"Group: %" PRIu32"\n",
bg_ref.index);
}
uint32_t free_cnt;
free_cnt = ext4_sb_get_block_size(sb) * 8 - idx_in_bg_first;
/*If last block, free only count blocks*/
free_cnt = count > free_cnt ? free_cnt : count;
/* Modify bitmap */
ext4_bmap_bits_free(blk.data, idx_in_bg_first, free_cnt);
ext4_balloc_set_bitmap_csum(sb, bg, blk.data);
ext4_trans_set_block_dirty(blk.buf);
count -= free_cnt;
first += free_cnt;
/* Release block with bitmap */
rc = ext4_block_set(fs->bdev, &blk);
if (rc != EOK) {
ext4_fs_put_block_group_ref(&bg_ref);
return rc;
}
uint32_t block_size = ext4_sb_get_block_size(sb);
/* Update superblock free blocks count */
uint64_t sb_free_blocks = ext4_sb_get_free_blocks_cnt(sb);
sb_free_blocks += free_cnt;
ext4_sb_set_free_blocks_cnt(sb, sb_free_blocks);
/* Update inode blocks count */
uint64_t ino_blocks;
ino_blocks = ext4_inode_get_blocks_count(sb, inode_ref->inode);
ino_blocks -= free_cnt * (block_size / EXT4_INODE_BLOCK_SIZE);
ext4_inode_set_blocks_count(sb, inode_ref->inode, ino_blocks);
inode_ref->dirty = true;
/* Update block group free blocks count */
uint32_t free_blocks;
free_blocks = ext4_bg_get_free_blocks_count(bg, sb);
free_blocks += free_cnt;
ext4_bg_set_free_blocks_count(bg, sb, free_blocks);
bg_ref.dirty = true;
/* Release block group reference */
rc = ext4_fs_put_block_group_ref(&bg_ref);
if (rc != EOK)
break;
bg_first++;
}
uint32_t i;
for (i = 0;i < blk_cnt;i++) {
rc = ext4_trans_try_revoke_block(fs->bdev, first + i);
if (rc != EOK)
return rc;
}
ext4_bcache_invalidate_lba(fs->bdev->bc, first, count);
/*All blocks should be released*/
ext4_assert(count == 0);
return rc;
}
int ext4_balloc_alloc_block(struct ext4_inode_ref *inode_ref,
ext4_fsblk_t goal,
ext4_fsblk_t *fblock)
{
ext4_fsblk_t alloc = 0;
ext4_fsblk_t bmp_blk_adr;
uint32_t rel_blk_idx = 0;
uint64_t free_blocks;
int r;
struct ext4_sblock *sb = &inode_ref->fs->sb;
/* Load block group number for goal and relative index */
uint32_t bg_id = ext4_balloc_get_bgid_of_block(sb, goal);
uint32_t idx_in_bg = ext4_fs_addr_to_idx_bg(sb, goal);
struct ext4_block b;
struct ext4_block_group_ref bg_ref;
/* Load block group reference */
r = ext4_fs_get_block_group_ref(inode_ref->fs, bg_id, &bg_ref);
if (r != EOK)
return r;
struct ext4_bgroup *bg = bg_ref.block_group;
free_blocks = ext4_bg_get_free_blocks_count(bg_ref.block_group, sb);
if (free_blocks == 0) {
/* This group has no free blocks */
goto goal_failed;
}
/* Compute indexes */
ext4_fsblk_t first_in_bg;
first_in_bg = ext4_balloc_get_block_of_bgid(sb, bg_ref.index);
uint32_t first_in_bg_index;
first_in_bg_index = ext4_fs_addr_to_idx_bg(sb, first_in_bg);
if (idx_in_bg < first_in_bg_index)
idx_in_bg = first_in_bg_index;
/* Load block with bitmap */
bmp_blk_adr = ext4_bg_get_block_bitmap(bg_ref.block_group, sb);
r = ext4_trans_block_get(inode_ref->fs->bdev, &b, bmp_blk_adr);
if (r != EOK) {
ext4_fs_put_block_group_ref(&bg_ref);
return r;
}
if (!ext4_balloc_verify_bitmap_csum(sb, bg, b.data)) {
ext4_dbg(DEBUG_BALLOC,
DBG_WARN "Bitmap checksum failed."
"Group: %" PRIu32"\n",
bg_ref.index);
}
/* Check if goal is free */
if (ext4_bmap_is_bit_clr(b.data, idx_in_bg)) {
ext4_bmap_bit_set(b.data, idx_in_bg);
ext4_balloc_set_bitmap_csum(sb, bg_ref.block_group,
b.data);
ext4_trans_set_block_dirty(b.buf);
r = ext4_block_set(inode_ref->fs->bdev, &b);
if (r != EOK) {
ext4_fs_put_block_group_ref(&bg_ref);
return r;
}
alloc = ext4_fs_bg_idx_to_addr(sb, idx_in_bg, bg_id);
goto success;
}
uint32_t blk_in_bg = ext4_blocks_in_group_cnt(sb, bg_id);
uint32_t end_idx = (idx_in_bg + 63) & ~63;
if (end_idx > blk_in_bg)
end_idx = blk_in_bg;
/* Try to find free block near to goal */
uint32_t tmp_idx;
for (tmp_idx = idx_in_bg + 1; tmp_idx < end_idx; ++tmp_idx) {
if (ext4_bmap_is_bit_clr(b.data, tmp_idx)) {
ext4_bmap_bit_set(b.data, tmp_idx);
ext4_balloc_set_bitmap_csum(sb, bg, b.data);
ext4_trans_set_block_dirty(b.buf);
r = ext4_block_set(inode_ref->fs->bdev, &b);
if (r != EOK)
return r;
alloc = ext4_fs_bg_idx_to_addr(sb, tmp_idx, bg_id);
goto success;
}
}
/* Find free bit in bitmap */
r = ext4_bmap_bit_find_clr(b.data, idx_in_bg, blk_in_bg, &rel_blk_idx);
if (r == EOK) {
ext4_bmap_bit_set(b.data, rel_blk_idx);
ext4_balloc_set_bitmap_csum(sb, bg_ref.block_group, b.data);
ext4_trans_set_block_dirty(b.buf);
r = ext4_block_set(inode_ref->fs->bdev, &b);
if (r != EOK)
return r;
alloc = ext4_fs_bg_idx_to_addr(sb, rel_blk_idx, bg_id);
goto success;
}
/* No free block found yet */
r = ext4_block_set(inode_ref->fs->bdev, &b);
if (r != EOK) {
ext4_fs_put_block_group_ref(&bg_ref);
return r;
}
goal_failed:
r = ext4_fs_put_block_group_ref(&bg_ref);
if (r != EOK)
return r;
/* Try other block groups */
uint32_t block_group_count = ext4_block_group_cnt(sb);
uint32_t bgid = (bg_id + 1) % block_group_count;
uint32_t count = block_group_count;
while (count > 0) {
r = ext4_fs_get_block_group_ref(inode_ref->fs, bgid, &bg_ref);
if (r != EOK)
return r;
struct ext4_bgroup *bg = bg_ref.block_group;
free_blocks = ext4_bg_get_free_blocks_count(bg, sb);
if (free_blocks == 0) {
/* This group has no free blocks */
goto next_group;
}
/* Load block with bitmap */
bmp_blk_adr = ext4_bg_get_block_bitmap(bg, sb);
r = ext4_trans_block_get(inode_ref->fs->bdev, &b, bmp_blk_adr);
if (r != EOK) {
ext4_fs_put_block_group_ref(&bg_ref);
return r;
}
if (!ext4_balloc_verify_bitmap_csum(sb, bg, b.data)) {
ext4_dbg(DEBUG_BALLOC,
DBG_WARN "Bitmap checksum failed."
"Group: %" PRIu32"\n",
bg_ref.index);
}
/* Compute indexes */
first_in_bg = ext4_balloc_get_block_of_bgid(sb, bgid);
idx_in_bg = ext4_fs_addr_to_idx_bg(sb, first_in_bg);
blk_in_bg = ext4_blocks_in_group_cnt(sb, bgid);
first_in_bg_index = ext4_fs_addr_to_idx_bg(sb, first_in_bg);
if (idx_in_bg < first_in_bg_index)
idx_in_bg = first_in_bg_index;
r = ext4_bmap_bit_find_clr(b.data, idx_in_bg, blk_in_bg,
&rel_blk_idx);
if (r == EOK) {
ext4_bmap_bit_set(b.data, rel_blk_idx);
ext4_balloc_set_bitmap_csum(sb, bg, b.data);
ext4_trans_set_block_dirty(b.buf);
r = ext4_block_set(inode_ref->fs->bdev, &b);
if (r != EOK) {
ext4_fs_put_block_group_ref(&bg_ref);
return r;
}
alloc = ext4_fs_bg_idx_to_addr(sb, rel_blk_idx, bgid);
goto success;
}
r = ext4_block_set(inode_ref->fs->bdev, &b);
if (r != EOK) {
ext4_fs_put_block_group_ref(&bg_ref);
return r;
}
next_group:
r = ext4_fs_put_block_group_ref(&bg_ref);
if (r != EOK) {
return r;
}
/* Goto next group */
bgid = (bgid + 1) % block_group_count;
count--;
}
return ENOSPC;
success:
/* Empty command - because of syntax */
;
uint32_t block_size = ext4_sb_get_block_size(sb);
/* Update superblock free blocks count */
uint64_t sb_free_blocks = ext4_sb_get_free_blocks_cnt(sb);
sb_free_blocks--;
ext4_sb_set_free_blocks_cnt(sb, sb_free_blocks);
/* Update inode blocks (different block size!) count */
uint64_t ino_blocks = ext4_inode_get_blocks_count(sb, inode_ref->inode);
ino_blocks += block_size / EXT4_INODE_BLOCK_SIZE;
ext4_inode_set_blocks_count(sb, inode_ref->inode, ino_blocks);
inode_ref->dirty = true;
/* Update block group free blocks count */
uint32_t fb_cnt = ext4_bg_get_free_blocks_count(bg_ref.block_group, sb);
fb_cnt--;
ext4_bg_set_free_blocks_count(bg_ref.block_group, sb, fb_cnt);
bg_ref.dirty = true;
r = ext4_fs_put_block_group_ref(&bg_ref);
*fblock = alloc;
return r;
}
int ext4_balloc_try_alloc_block(struct ext4_inode_ref *inode_ref,
ext4_fsblk_t baddr, bool *free)
{
int rc;
struct ext4_fs *fs = inode_ref->fs;
struct ext4_sblock *sb = &fs->sb;
/* Compute indexes */
uint32_t block_group = ext4_balloc_get_bgid_of_block(sb, baddr);
uint32_t index_in_group = ext4_fs_addr_to_idx_bg(sb, baddr);
/* Load block group reference */
struct ext4_block_group_ref bg_ref;
rc = ext4_fs_get_block_group_ref(fs, block_group, &bg_ref);
if (rc != EOK)
return rc;
/* Load block with bitmap */
ext4_fsblk_t bmp_blk_addr;
bmp_blk_addr = ext4_bg_get_block_bitmap(bg_ref.block_group, sb);
struct ext4_block b;
rc = ext4_trans_block_get(fs->bdev, &b, bmp_blk_addr);
if (rc != EOK) {
ext4_fs_put_block_group_ref(&bg_ref);
return rc;
}
if (!ext4_balloc_verify_bitmap_csum(sb, bg_ref.block_group, b.data)) {
ext4_dbg(DEBUG_BALLOC,
DBG_WARN "Bitmap checksum failed."
"Group: %" PRIu32"\n",
bg_ref.index);
}
/* Check if block is free */
*free = ext4_bmap_is_bit_clr(b.data, index_in_group);
/* Allocate block if possible */
if (*free) {
ext4_bmap_bit_set(b.data, index_in_group);
ext4_balloc_set_bitmap_csum(sb, bg_ref.block_group, b.data);
ext4_trans_set_block_dirty(b.buf);
}
/* Release block with bitmap */
rc = ext4_block_set(fs->bdev, &b);
if (rc != EOK) {
/* Error in saving bitmap */
ext4_fs_put_block_group_ref(&bg_ref);
return rc;
}
/* If block is not free, return */
if (!(*free))
goto terminate;
uint32_t block_size = ext4_sb_get_block_size(sb);
/* Update superblock free blocks count */
uint64_t sb_free_blocks = ext4_sb_get_free_blocks_cnt(sb);
sb_free_blocks--;
ext4_sb_set_free_blocks_cnt(sb, sb_free_blocks);
/* Update inode blocks count */
uint64_t ino_blocks = ext4_inode_get_blocks_count(sb, inode_ref->inode);
ino_blocks += block_size / EXT4_INODE_BLOCK_SIZE;
ext4_inode_set_blocks_count(sb, inode_ref->inode, ino_blocks);
inode_ref->dirty = true;
/* Update block group free blocks count */
uint32_t fb_cnt = ext4_bg_get_free_blocks_count(bg_ref.block_group, sb);
fb_cnt--;
ext4_bg_set_free_blocks_count(bg_ref.block_group, sb, fb_cnt);
bg_ref.dirty = true;
terminate:
return ext4_fs_put_block_group_ref(&bg_ref);
}
/**
* @}
*/