ref: 61098c719f30316c4bac054170c262d0419849a9
dir: /src/ext4_balloc.c/
/* * Copyright (c) 2013 Grzegorz Kostka ([email protected]) * * 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); } /** * @} */