ref: 3d5dca521797b5a91ebc4281fbaf58211bb4f40f
dir: /sys/src/cmd/ext4srv/ext4_balloc.c/
#include "ext4_config.h"
#include "ext4_types.h"
#include "ext4_misc.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
*/
u32int ext4_balloc_get_bgid_of_block(struct ext4_sblock *s,
u64int baddr)
{
if (ext4_get32(s, first_data_block) && baddr)
baddr--;
return (u32int)(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
*/
u64int ext4_balloc_get_block_of_bgid(struct ext4_sblock *s,
u32int bgid)
{
u64int baddr = 0;
if (ext4_get32(s, first_data_block))
baddr++;
baddr += bgid * ext4_get32(s, blocks_per_group);
return baddr;
}
static u32int ext4_balloc_bitmap_csum(struct ext4_fs *fs, void *bitmap)
{
u32int checksum = 0;
if (ext4_sb_feature_ro_com(&fs->sb, EXT4_FRO_COM_METADATA_CSUM)) {
u32int blocks_per_group = ext4_get32(&fs->sb, blocks_per_group);
/* First calculate crc32 checksum against fs uuid */
checksum = fs->uuid_crc32c;
/* Then calculate crc32 checksum against block_group_desc */
checksum = ext4_crc32c(checksum, bitmap, blocks_per_group / 8);
}
return checksum;
}
void ext4_balloc_set_bitmap_csum(struct ext4_fs *fs,
struct ext4_bgroup *bg,
void *bitmap)
{
int desc_size = ext4_sb_get_desc_size(&fs->sb);
u32int checksum = ext4_balloc_bitmap_csum(fs, bitmap);
u16int lo_checksum = to_le16(checksum & 0xFFFF),
hi_checksum = to_le16(checksum >> 16);
if (!ext4_sb_feature_ro_com(&fs->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;
}
static bool
ext4_balloc_verify_bitmap_csum(struct ext4_fs *fs,
struct ext4_bgroup *bg,
void *bitmap)
{
struct ext4_sblock *sb = &fs->sb;
int desc_size = ext4_sb_get_desc_size(sb);
u32int checksum = ext4_balloc_bitmap_csum(fs, bitmap);
u16int 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;
}
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;
u32int bg_id = ext4_balloc_get_bgid_of_block(sb, baddr);
u32int 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 != 0)
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 != 0) {
ext4_fs_put_block_group_ref(&bg_ref);
return rc;
}
if (!ext4_balloc_verify_bitmap_csum(fs, bg, bitmap_block.data)) {
ext4_dbg(DEBUG_BALLOC,
DBG_WARN "Bitmap checksum failed."
"Group: %ud\n",
bg_ref.index);
}
/* Modify bitmap */
ext4_bmap_bit_clr(bitmap_block.data, index_in_group);
ext4_balloc_set_bitmap_csum(fs, 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 != 0) {
/* Error in saving bitmap */
ext4_fs_put_block_group_ref(&bg_ref);
return rc;
}
u32int block_size = ext4_sb_get_block_size(sb);
/* Update superblock free blocks count */
u64int 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 */
u64int 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 */
u32int 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 != 0) {
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, u32int count)
{
int rc = 0;
u32int blk_cnt = count;
ext4_fsblk_t start_block = first;
struct ext4_fs *fs = inode_ref->fs;
struct ext4_sblock *sb = &fs->sb;
/* Compute indexes */
u32int bg_first = ext4_balloc_get_bgid_of_block(sb, first);
/* Compute indexes */
u32int 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: %ud bg_first: %ud\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 != 0)
return rc;
struct ext4_bgroup *bg = bg_ref.block_group;
u32int 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 != 0) {
ext4_fs_put_block_group_ref(&bg_ref);
return rc;
}
if (!ext4_balloc_verify_bitmap_csum(fs, bg, blk.data)) {
ext4_dbg(DEBUG_BALLOC,
DBG_WARN "Bitmap checksum failed."
"Group: %ud\n",
bg_ref.index);
}
u32int 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(fs, 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 != 0) {
ext4_fs_put_block_group_ref(&bg_ref);
return rc;
}
u32int block_size = ext4_sb_get_block_size(sb);
/* Update superblock free blocks count */
u64int 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 */
u64int 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 */
u32int 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 != 0)
break;
bg_first++;
}
u32int i;
for (i = 0;i < blk_cnt;i++) {
rc = ext4_trans_try_revoke_block(fs->bdev, start_block + i);
if (rc != 0)
return rc;
}
ext4_bcache_invalidate_lba(fs->bdev->bc, start_block, blk_cnt);
/*All blocks should be released*/
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;
ext4_fsblk_t bmp_blk_adr;
u32int rel_blk_idx = 0;
u64int free_blocks;
int r;
struct ext4_fs *fs = inode_ref->fs;
struct ext4_sblock *sb = &fs->sb;
/* Load block group number for goal and relative index */
u32int bg_id = ext4_balloc_get_bgid_of_block(sb, goal);
u32int 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(fs, bg_id, &bg_ref);
if (r != 0)
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);
u32int 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(fs->bdev, &b, bmp_blk_adr);
if (r != 0) {
ext4_fs_put_block_group_ref(&bg_ref);
return r;
}
if (!ext4_balloc_verify_bitmap_csum(fs, bg, b.data)) {
ext4_dbg(DEBUG_BALLOC,
DBG_WARN "Bitmap checksum failed."
"Group: %ud\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(fs, bg_ref.block_group, b.data);
ext4_trans_set_block_dirty(b.buf);
r = ext4_block_set(fs->bdev, &b);
if (r != 0) {
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;
}
u32int blk_in_bg = ext4_blocks_in_group_cnt(sb, bg_id);
u32int 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 */
u32int 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(fs, bg, b.data);
ext4_trans_set_block_dirty(b.buf);
r = ext4_block_set(fs->bdev, &b);
if (r != 0) {
ext4_fs_put_block_group_ref(&bg_ref);
return r;
}
alloc = ext4_fs_bg_idx_to_addr(sb, tmp_idx, bg_id);
goto success;
}
}
/* Find free bit in bitmap */
bool no_space;
r = ext4_bmap_bit_find_clr(b.data, idx_in_bg, blk_in_bg, &rel_blk_idx, &no_space);
if (r == 0) {
ext4_bmap_bit_set(b.data, rel_blk_idx);
ext4_balloc_set_bitmap_csum(fs, bg_ref.block_group, b.data);
ext4_trans_set_block_dirty(b.buf);
r = ext4_block_set(fs->bdev, &b);
if (r != 0) {
ext4_fs_put_block_group_ref(&bg_ref);
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(fs->bdev, &b);
if (r != 0) {
ext4_fs_put_block_group_ref(&bg_ref);
return r;
}
goal_failed:
r = ext4_fs_put_block_group_ref(&bg_ref);
if (r != 0)
return r;
/* Try other block groups */
u32int block_group_count = ext4_block_group_cnt(sb);
u32int bgid = (bg_id + 1) % block_group_count;
u32int count = block_group_count;
while (count > 0) {
r = ext4_fs_get_block_group_ref(fs, bgid, &bg_ref);
if (r != 0)
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(fs->bdev, &b, bmp_blk_adr);
if (r != 0) {
ext4_fs_put_block_group_ref(&bg_ref);
return r;
}
if (!ext4_balloc_verify_bitmap_csum(fs, bg, b.data)) {
ext4_dbg(DEBUG_BALLOC,
DBG_WARN "Bitmap checksum failed."
"Group: %ud\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;
bool no_space;
r = ext4_bmap_bit_find_clr(b.data, idx_in_bg, blk_in_bg, &rel_blk_idx, &no_space);
if (r == 0) {
ext4_bmap_bit_set(b.data, rel_blk_idx);
ext4_balloc_set_bitmap_csum(fs, bg, b.data);
ext4_trans_set_block_dirty(b.buf);
r = ext4_block_set(fs->bdev, &b);
if (r != 0) {
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(fs->bdev, &b);
if (r != 0) {
ext4_fs_put_block_group_ref(&bg_ref);
return r;
}
next_group:
r = ext4_fs_put_block_group_ref(&bg_ref);
if (r != 0) {
return r;
}
/* Goto next group */
bgid = (bgid + 1) % block_group_count;
count--;
}
werrstr("no free blocks");
return -1;
success:
/* Empty command - because of syntax */
;
u32int block_size = ext4_sb_get_block_size(sb);
/* Update superblock free blocks count */
u64int 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 */
u64int 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 */
u32int 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 */
u32int block_group = ext4_balloc_get_bgid_of_block(sb, baddr);
u32int 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 != 0)
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 != 0) {
ext4_fs_put_block_group_ref(&bg_ref);
return rc;
}
if (!ext4_balloc_verify_bitmap_csum(fs, bg_ref.block_group, b.data)) {
ext4_dbg(DEBUG_BALLOC,
DBG_WARN "Bitmap checksum failed."
"Group: %ud\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(fs, 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 != 0) {
/* Error in saving bitmap */
ext4_fs_put_block_group_ref(&bg_ref);
return rc;
}
/* If block is not free, return */
if (!(*free))
goto terminate;
u32int block_size = ext4_sb_get_block_size(sb);
/* Update superblock free blocks count */
u64int 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 */
u64int 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 */
u32int 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);
}