| /* |
| * resize2fs.c --- ext2 main routine |
| * |
| * Copyright (C) 1997, 1998 by Theodore Ts'o and |
| * PowerQuest, Inc. |
| * |
| * Copyright (C) 1999, 2000 by Theosore Ts'o |
| * |
| * %Begin-Header% |
| * This file may be redistributed under the terms of the GNU Public |
| * License. |
| * %End-Header% |
| */ |
| |
| /* |
| * Resizing a filesystem consists of the following phases: |
| * |
| * 1. Adjust superblock and write out new parts of the inode |
| * table |
| * 2. Determine blocks which need to be relocated, and copy the |
| * contents of blocks from their old locations to the new ones. |
| * 3. Scan the inode table, doing the following: |
| * a. If blocks have been moved, update the block |
| * pointers in the inodes and indirect blocks to |
| * point at the new block locations. |
| * b. If parts of the inode table need to be evacuated, |
| * copy inodes from their old locations to their |
| * new ones. |
| * c. If (b) needs to be done, note which blocks contain |
| * directory information, since we will need to |
| * update the directory information. |
| * 4. Update the directory blocks with the new inode locations. |
| * 5. Move the inode tables, if necessary. |
| */ |
| |
| #include "resize2fs.h" |
| #include <time.h> |
| |
| #ifdef __linux__ /* Kludge for debugging */ |
| #define RESIZE2FS_DEBUG |
| #endif |
| |
| static void fix_uninit_block_bitmaps(ext2_filsys fs); |
| static errcode_t adjust_superblock(ext2_resize_t rfs, blk_t new_size); |
| static errcode_t blocks_to_move(ext2_resize_t rfs); |
| static errcode_t block_mover(ext2_resize_t rfs); |
| static errcode_t inode_scan_and_fix(ext2_resize_t rfs); |
| static errcode_t inode_ref_fix(ext2_resize_t rfs); |
| static errcode_t move_itables(ext2_resize_t rfs); |
| static errcode_t fix_resize_inode(ext2_filsys fs); |
| static errcode_t ext2fs_calculate_summary_stats(ext2_filsys fs); |
| static errcode_t fix_sb_journal_backup(ext2_filsys fs); |
| |
| /* |
| * Some helper CPP macros |
| */ |
| #define FS_BLOCK_BM(fs, i) ((fs)->group_desc[(i)].bg_block_bitmap) |
| #define FS_INODE_BM(fs, i) ((fs)->group_desc[(i)].bg_inode_bitmap) |
| #define FS_INODE_TB(fs, i) ((fs)->group_desc[(i)].bg_inode_table) |
| |
| #define IS_BLOCK_BM(fs, i, blk) ((blk) == FS_BLOCK_BM((fs),(i))) |
| #define IS_INODE_BM(fs, i, blk) ((blk) == FS_INODE_BM((fs),(i))) |
| |
| #define IS_INODE_TB(fs, i, blk) (((blk) >= FS_INODE_TB((fs), (i))) && \ |
| ((blk) < (FS_INODE_TB((fs), (i)) + \ |
| (fs)->inode_blocks_per_group))) |
| |
| #define META_OVERHEAD(fs) (2 + (fs)->inode_blocks_per_group) |
| #define SUPER_OVERHEAD(fs) (1 + (fs)->desc_blocks +\ |
| (fs)->super->s_reserved_gdt_blocks) |
| |
| /* |
| * This is the top-level routine which does the dirty deed.... |
| */ |
| errcode_t resize_fs(ext2_filsys fs, blk_t *new_size, int flags, |
| errcode_t (*progress)(ext2_resize_t rfs, int pass, |
| unsigned long cur, |
| unsigned long max_val)) |
| { |
| ext2_resize_t rfs; |
| errcode_t retval; |
| |
| retval = ext2fs_read_bitmaps(fs); |
| if (retval) |
| return retval; |
| |
| fs->super->s_state |= EXT2_ERROR_FS; |
| ext2fs_mark_super_dirty(fs); |
| ext2fs_flush(fs); |
| |
| /* |
| * Create the data structure |
| */ |
| retval = ext2fs_get_mem(sizeof(struct ext2_resize_struct), &rfs); |
| if (retval) |
| return retval; |
| memset(rfs, 0, sizeof(struct ext2_resize_struct)); |
| |
| fix_uninit_block_bitmaps(fs); |
| fs->priv_data = rfs; |
| rfs->old_fs = fs; |
| rfs->flags = flags; |
| rfs->itable_buf = 0; |
| rfs->progress = progress; |
| retval = ext2fs_dup_handle(fs, &rfs->new_fs); |
| if (retval) |
| goto errout; |
| |
| retval = adjust_superblock(rfs, *new_size); |
| if (retval) |
| goto errout; |
| |
| fix_uninit_block_bitmaps(rfs->new_fs); |
| /* Clear the block bitmap uninit flag for the last block group */ |
| rfs->new_fs->group_desc[rfs->new_fs->group_desc_count-1].bg_flags &= |
| ~EXT2_BG_BLOCK_UNINIT; |
| |
| *new_size = rfs->new_fs->super->s_blocks_count; |
| |
| retval = blocks_to_move(rfs); |
| if (retval) |
| goto errout; |
| |
| #ifdef RESIZE2FS_DEBUG |
| if (rfs->flags & RESIZE_DEBUG_BMOVE) |
| printf("Number of free blocks: %u/%u, Needed: %d\n", |
| rfs->old_fs->super->s_free_blocks_count, |
| rfs->new_fs->super->s_free_blocks_count, |
| rfs->needed_blocks); |
| #endif |
| |
| retval = block_mover(rfs); |
| if (retval) |
| goto errout; |
| |
| retval = inode_scan_and_fix(rfs); |
| if (retval) |
| goto errout; |
| |
| retval = inode_ref_fix(rfs); |
| if (retval) |
| goto errout; |
| |
| retval = move_itables(rfs); |
| if (retval) |
| goto errout; |
| |
| retval = ext2fs_calculate_summary_stats(rfs->new_fs); |
| if (retval) |
| goto errout; |
| |
| retval = fix_resize_inode(rfs->new_fs); |
| if (retval) |
| goto errout; |
| |
| retval = fix_sb_journal_backup(rfs->new_fs); |
| if (retval) |
| goto errout; |
| |
| rfs->new_fs->super->s_state &= ~EXT2_ERROR_FS; |
| rfs->new_fs->flags &= ~EXT2_FLAG_MASTER_SB_ONLY; |
| retval = ext2fs_close(rfs->new_fs); |
| if (retval) |
| goto errout; |
| |
| rfs->flags = flags; |
| |
| ext2fs_free(rfs->old_fs); |
| if (rfs->itable_buf) |
| ext2fs_free_mem(&rfs->itable_buf); |
| if (rfs->reserve_blocks) |
| ext2fs_free_block_bitmap(rfs->reserve_blocks); |
| if (rfs->move_blocks) |
| ext2fs_free_block_bitmap(rfs->move_blocks); |
| ext2fs_free_mem(&rfs); |
| |
| return 0; |
| |
| errout: |
| if (rfs->new_fs) |
| ext2fs_free(rfs->new_fs); |
| if (rfs->itable_buf) |
| ext2fs_free_mem(&rfs->itable_buf); |
| ext2fs_free_mem(&rfs); |
| return retval; |
| } |
| |
| /* |
| * Clean up the bitmaps for unitialized bitmaps |
| */ |
| static void fix_uninit_block_bitmaps(ext2_filsys fs) |
| { |
| blk_t i, blk, super_blk, old_desc_blk, new_desc_blk; |
| int old_desc_blocks; |
| dgrp_t g; |
| |
| if (!(EXT2_HAS_RO_COMPAT_FEATURE(fs->super, |
| EXT4_FEATURE_RO_COMPAT_GDT_CSUM))) |
| return; |
| |
| for (g=0; g < fs->group_desc_count; g++) { |
| if (!(fs->group_desc[g].bg_flags & EXT2_BG_BLOCK_UNINIT)) |
| continue; |
| |
| blk = (g * fs->super->s_blocks_per_group) + |
| fs->super->s_first_data_block; |
| |
| ext2fs_super_and_bgd_loc(fs, g, &super_blk, |
| &old_desc_blk, &new_desc_blk, 0); |
| |
| if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG) |
| old_desc_blocks = fs->super->s_first_meta_bg; |
| else |
| old_desc_blocks = fs->desc_blocks + |
| fs->super->s_reserved_gdt_blocks; |
| |
| for (i=0; i < fs->super->s_blocks_per_group; i++, blk++) { |
| if (blk >= fs->super->s_blocks_count) |
| break; |
| if ((blk == super_blk) || |
| (old_desc_blk && old_desc_blocks && |
| (blk >= old_desc_blk) && |
| (blk < old_desc_blk + old_desc_blocks)) || |
| (new_desc_blk && (blk == new_desc_blk)) || |
| (blk == fs->group_desc[g].bg_block_bitmap) || |
| (blk == fs->group_desc[g].bg_inode_bitmap) || |
| (blk >= fs->group_desc[g].bg_inode_table && |
| (blk < fs->group_desc[g].bg_inode_table |
| + fs->inode_blocks_per_group))) |
| ext2fs_fast_mark_block_bitmap(fs->block_map, blk); |
| else |
| ext2fs_fast_unmark_block_bitmap(fs->block_map, blk); |
| } |
| } |
| } |
| |
| /* -------------------------------------------------------------------- |
| * |
| * Resize processing, phase 1. |
| * |
| * In this phase we adjust the in-memory superblock information, and |
| * initialize any new parts of the inode table. The new parts of the |
| * inode table are created in virgin disk space, so we can abort here |
| * without any side effects. |
| * -------------------------------------------------------------------- |
| */ |
| |
| /* |
| * If the group descriptor's bitmap and inode table blocks are valid, |
| * release them in the new filesystem data structure, and mark them as |
| * reserved so the old inode table blocks don't get overwritten. |
| */ |
| static void free_gdp_blocks(ext2_filsys fs, |
| ext2fs_block_bitmap reserve_blocks, |
| struct ext2_group_desc *gdp) |
| { |
| blk_t blk; |
| int j; |
| |
| if (gdp->bg_block_bitmap && |
| (gdp->bg_block_bitmap < fs->super->s_blocks_count)) { |
| ext2fs_block_alloc_stats(fs, gdp->bg_block_bitmap, -1); |
| ext2fs_mark_block_bitmap(reserve_blocks, |
| gdp->bg_block_bitmap); |
| } |
| |
| if (gdp->bg_inode_bitmap && |
| (gdp->bg_inode_bitmap < fs->super->s_blocks_count)) { |
| ext2fs_block_alloc_stats(fs, gdp->bg_inode_bitmap, -1); |
| ext2fs_mark_block_bitmap(reserve_blocks, |
| gdp->bg_inode_bitmap); |
| } |
| |
| if (gdp->bg_inode_table == 0 || |
| (gdp->bg_inode_table >= fs->super->s_blocks_count)) |
| return; |
| |
| for (blk = gdp->bg_inode_table, j = 0; |
| j < fs->inode_blocks_per_group; j++, blk++) { |
| if (blk >= fs->super->s_blocks_count) |
| break; |
| ext2fs_block_alloc_stats(fs, blk, -1); |
| ext2fs_mark_block_bitmap(reserve_blocks, blk); |
| } |
| } |
| |
| /* |
| * This routine is shared by the online and offline resize routines. |
| * All of the information which is adjusted in memory is done here. |
| * |
| * The reserve_blocks parameter is only needed when shrinking the |
| * filesystem. |
| */ |
| errcode_t adjust_fs_info(ext2_filsys fs, ext2_filsys old_fs, |
| ext2fs_block_bitmap reserve_blocks, blk_t new_size) |
| { |
| errcode_t retval; |
| int overhead = 0; |
| int rem; |
| blk_t blk, group_block; |
| ext2_ino_t real_end; |
| int adj, old_numblocks, numblocks, adjblocks; |
| unsigned long i, j, old_desc_blocks, max_group; |
| unsigned int meta_bg, meta_bg_size; |
| int has_super, csum_flag; |
| unsigned long long new_inodes; /* u64 to check for overflow */ |
| double percent; |
| |
| fs->super->s_blocks_count = new_size; |
| |
| retry: |
| fs->group_desc_count = ext2fs_div_ceil(fs->super->s_blocks_count - |
| fs->super->s_first_data_block, |
| EXT2_BLOCKS_PER_GROUP(fs->super)); |
| if (fs->group_desc_count == 0) |
| return EXT2_ET_TOOSMALL; |
| fs->desc_blocks = ext2fs_div_ceil(fs->group_desc_count, |
| EXT2_DESC_PER_BLOCK(fs->super)); |
| |
| /* |
| * Overhead is the number of bookkeeping blocks per group. It |
| * includes the superblock backup, the group descriptor |
| * backups, the inode bitmap, the block bitmap, and the inode |
| * table. |
| */ |
| overhead = (int) (2 + fs->inode_blocks_per_group); |
| |
| if (ext2fs_bg_has_super(fs, fs->group_desc_count - 1)) |
| overhead += 1 + fs->desc_blocks + |
| fs->super->s_reserved_gdt_blocks; |
| |
| /* |
| * See if the last group is big enough to support the |
| * necessary data structures. If not, we need to get rid of |
| * it. |
| */ |
| rem = (fs->super->s_blocks_count - fs->super->s_first_data_block) % |
| fs->super->s_blocks_per_group; |
| if ((fs->group_desc_count == 1) && rem && (rem < overhead)) |
| return EXT2_ET_TOOSMALL; |
| if (rem && (rem < overhead+50)) { |
| fs->super->s_blocks_count -= rem; |
| goto retry; |
| } |
| /* |
| * Adjust the number of inodes |
| */ |
| new_inodes =(unsigned long long) fs->super->s_inodes_per_group * fs->group_desc_count; |
| if (new_inodes > ~0U) { |
| fprintf(stderr, _("inodes (%llu) must be less than %u"), |
| new_inodes, ~0U); |
| return EXT2_ET_TOO_MANY_INODES; |
| } |
| fs->super->s_inodes_count = fs->super->s_inodes_per_group * |
| fs->group_desc_count; |
| |
| /* |
| * Adjust the number of free blocks |
| */ |
| blk = old_fs->super->s_blocks_count; |
| if (blk > fs->super->s_blocks_count) |
| fs->super->s_free_blocks_count -= |
| (blk - fs->super->s_blocks_count); |
| else |
| fs->super->s_free_blocks_count += |
| (fs->super->s_blocks_count - blk); |
| |
| /* |
| * Adjust the number of reserved blocks |
| */ |
| percent = (old_fs->super->s_r_blocks_count * 100.0) / |
| old_fs->super->s_blocks_count; |
| fs->super->s_r_blocks_count = (unsigned int) (percent * |
| fs->super->s_blocks_count / 100.0); |
| |
| /* |
| * Adjust the bitmaps for size |
| */ |
| retval = ext2fs_resize_inode_bitmap(fs->super->s_inodes_count, |
| fs->super->s_inodes_count, |
| fs->inode_map); |
| if (retval) goto errout; |
| |
| real_end = ((EXT2_BLOCKS_PER_GROUP(fs->super) |
| * fs->group_desc_count)) - 1 + |
| fs->super->s_first_data_block; |
| retval = ext2fs_resize_block_bitmap(fs->super->s_blocks_count-1, |
| real_end, fs->block_map); |
| |
| if (retval) goto errout; |
| |
| /* |
| * Reallocate the group descriptors as necessary. |
| */ |
| if (old_fs->desc_blocks != fs->desc_blocks) { |
| retval = ext2fs_resize_mem(old_fs->desc_blocks * |
| fs->blocksize, |
| fs->desc_blocks * fs->blocksize, |
| &fs->group_desc); |
| if (retval) |
| goto errout; |
| if (fs->desc_blocks > old_fs->desc_blocks) |
| memset((char *) fs->group_desc + |
| (old_fs->desc_blocks * fs->blocksize), 0, |
| (fs->desc_blocks - old_fs->desc_blocks) * |
| fs->blocksize); |
| } |
| |
| /* |
| * If the resize_inode feature is set, and we are changing the |
| * number of descriptor blocks, then adjust |
| * s_reserved_gdt_blocks if possible to avoid needing to move |
| * the inode table either now or in the future. |
| */ |
| if ((fs->super->s_feature_compat & |
| EXT2_FEATURE_COMPAT_RESIZE_INODE) && |
| (old_fs->desc_blocks != fs->desc_blocks)) { |
| int new; |
| |
| new = ((int) fs->super->s_reserved_gdt_blocks) + |
| (old_fs->desc_blocks - fs->desc_blocks); |
| if (new < 0) |
| new = 0; |
| if (new > (int) fs->blocksize/4) |
| new = fs->blocksize/4; |
| fs->super->s_reserved_gdt_blocks = new; |
| } |
| |
| /* |
| * If we are shrinking the number of block groups, we're done |
| * and can exit now. |
| */ |
| if (old_fs->group_desc_count > fs->group_desc_count) { |
| /* |
| * Check the block groups that we are chopping off |
| * and free any blocks associated with their metadata |
| */ |
| for (i = fs->group_desc_count; |
| i < old_fs->group_desc_count; i++) { |
| free_gdp_blocks(fs, reserve_blocks, |
| &old_fs->group_desc[i]); |
| } |
| retval = 0; |
| goto errout; |
| } |
| |
| /* |
| * Fix the count of the last (old) block group |
| */ |
| old_numblocks = (old_fs->super->s_blocks_count - |
| old_fs->super->s_first_data_block) % |
| old_fs->super->s_blocks_per_group; |
| if (!old_numblocks) |
| old_numblocks = old_fs->super->s_blocks_per_group; |
| if (old_fs->group_desc_count == fs->group_desc_count) { |
| numblocks = (fs->super->s_blocks_count - |
| fs->super->s_first_data_block) % |
| fs->super->s_blocks_per_group; |
| if (!numblocks) |
| numblocks = fs->super->s_blocks_per_group; |
| } else |
| numblocks = fs->super->s_blocks_per_group; |
| i = old_fs->group_desc_count - 1; |
| fs->group_desc[i].bg_free_blocks_count += (numblocks-old_numblocks); |
| ext2fs_group_desc_csum_set(fs, i); |
| |
| /* |
| * If the number of block groups is staying the same, we're |
| * done and can exit now. (If the number block groups is |
| * shrinking, we had exited earlier.) |
| */ |
| if (old_fs->group_desc_count >= fs->group_desc_count) { |
| retval = 0; |
| goto errout; |
| } |
| |
| /* |
| * Initialize the new block group descriptors |
| */ |
| group_block = fs->super->s_first_data_block + |
| old_fs->group_desc_count * fs->super->s_blocks_per_group; |
| |
| csum_flag = EXT2_HAS_RO_COMPAT_FEATURE(fs->super, |
| EXT4_FEATURE_RO_COMPAT_GDT_CSUM); |
| adj = old_fs->group_desc_count; |
| max_group = fs->group_desc_count - adj; |
| if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG) |
| old_desc_blocks = fs->super->s_first_meta_bg; |
| else |
| old_desc_blocks = fs->desc_blocks + |
| fs->super->s_reserved_gdt_blocks; |
| for (i = old_fs->group_desc_count; |
| i < fs->group_desc_count; i++) { |
| memset(&fs->group_desc[i], 0, |
| sizeof(struct ext2_group_desc)); |
| adjblocks = 0; |
| |
| fs->group_desc[i].bg_flags = 0; |
| if (csum_flag) |
| fs->group_desc[i].bg_flags |= EXT2_BG_INODE_UNINIT | |
| EXT2_BG_INODE_ZEROED; |
| if (i == fs->group_desc_count-1) { |
| numblocks = (fs->super->s_blocks_count - |
| fs->super->s_first_data_block) % |
| fs->super->s_blocks_per_group; |
| if (!numblocks) |
| numblocks = fs->super->s_blocks_per_group; |
| } else { |
| numblocks = fs->super->s_blocks_per_group; |
| if (csum_flag) |
| fs->group_desc[i].bg_flags |= |
| EXT2_BG_BLOCK_UNINIT; |
| } |
| |
| has_super = ext2fs_bg_has_super(fs, i); |
| if (has_super) { |
| ext2fs_block_alloc_stats(fs, group_block, +1); |
| adjblocks++; |
| } |
| meta_bg_size = EXT2_DESC_PER_BLOCK(fs->super); |
| meta_bg = i / meta_bg_size; |
| if (!(fs->super->s_feature_incompat & |
| EXT2_FEATURE_INCOMPAT_META_BG) || |
| (meta_bg < fs->super->s_first_meta_bg)) { |
| if (has_super) { |
| for (j=0; j < old_desc_blocks; j++) |
| ext2fs_block_alloc_stats(fs, |
| group_block + 1 + j, +1); |
| adjblocks += old_desc_blocks; |
| } |
| } else { |
| if (has_super) |
| has_super = 1; |
| if (((i % meta_bg_size) == 0) || |
| ((i % meta_bg_size) == 1) || |
| ((i % meta_bg_size) == (meta_bg_size-1))) |
| ext2fs_block_alloc_stats(fs, |
| group_block + has_super, +1); |
| } |
| |
| adjblocks += 2 + fs->inode_blocks_per_group; |
| |
| numblocks -= adjblocks; |
| fs->super->s_free_blocks_count -= adjblocks; |
| fs->super->s_free_inodes_count += |
| fs->super->s_inodes_per_group; |
| fs->group_desc[i].bg_free_blocks_count = numblocks; |
| fs->group_desc[i].bg_free_inodes_count = |
| fs->super->s_inodes_per_group; |
| fs->group_desc[i].bg_used_dirs_count = 0; |
| ext2fs_group_desc_csum_set(fs, i); |
| |
| retval = ext2fs_allocate_group_table(fs, i, 0); |
| if (retval) goto errout; |
| |
| group_block += fs->super->s_blocks_per_group; |
| } |
| retval = 0; |
| |
| errout: |
| return (retval); |
| } |
| |
| /* |
| * This routine adjusts the superblock and other data structures, both |
| * in disk as well as in memory... |
| */ |
| static errcode_t adjust_superblock(ext2_resize_t rfs, blk_t new_size) |
| { |
| ext2_filsys fs; |
| int adj = 0; |
| errcode_t retval; |
| blk_t group_block; |
| unsigned long i; |
| unsigned long max_group; |
| |
| fs = rfs->new_fs; |
| ext2fs_mark_super_dirty(fs); |
| ext2fs_mark_bb_dirty(fs); |
| ext2fs_mark_ib_dirty(fs); |
| |
| retval = ext2fs_allocate_block_bitmap(fs, _("reserved blocks"), |
| &rfs->reserve_blocks); |
| if (retval) |
| return retval; |
| |
| retval = adjust_fs_info(fs, rfs->old_fs, rfs->reserve_blocks, new_size); |
| if (retval) |
| goto errout; |
| |
| /* |
| * Check to make sure there are enough inodes |
| */ |
| if ((rfs->old_fs->super->s_inodes_count - |
| rfs->old_fs->super->s_free_inodes_count) > |
| rfs->new_fs->super->s_inodes_count) { |
| retval = ENOSPC; |
| goto errout; |
| } |
| |
| /* |
| * If we are shrinking the number block groups, we're done and |
| * can exit now. |
| */ |
| if (rfs->old_fs->group_desc_count > fs->group_desc_count) { |
| retval = 0; |
| goto errout; |
| } |
| |
| /* |
| * If the number of block groups is staying the same, we're |
| * done and can exit now. (If the number block groups is |
| * shrinking, we had exited earlier.) |
| */ |
| if (rfs->old_fs->group_desc_count >= fs->group_desc_count) { |
| retval = 0; |
| goto errout; |
| } |
| |
| /* |
| * Initialize the new block group descriptors |
| */ |
| retval = ext2fs_get_array(fs->blocksize, fs->inode_blocks_per_group, |
| &rfs->itable_buf); |
| if (retval) |
| goto errout; |
| |
| memset(rfs->itable_buf, 0, fs->blocksize * fs->inode_blocks_per_group); |
| group_block = fs->super->s_first_data_block + |
| rfs->old_fs->group_desc_count * fs->super->s_blocks_per_group; |
| |
| adj = rfs->old_fs->group_desc_count; |
| max_group = fs->group_desc_count - adj; |
| if (rfs->progress) { |
| retval = rfs->progress(rfs, E2_RSZ_EXTEND_ITABLE_PASS, |
| 0, max_group); |
| if (retval) |
| goto errout; |
| } |
| for (i = rfs->old_fs->group_desc_count; |
| i < fs->group_desc_count; i++) { |
| /* |
| * Write out the new inode table |
| */ |
| retval = io_channel_write_blk(fs->io, |
| fs->group_desc[i].bg_inode_table, |
| fs->inode_blocks_per_group, |
| rfs->itable_buf); |
| if (retval) goto errout; |
| |
| io_channel_flush(fs->io); |
| if (rfs->progress) { |
| retval = rfs->progress(rfs, E2_RSZ_EXTEND_ITABLE_PASS, |
| i - adj + 1, max_group); |
| if (retval) |
| goto errout; |
| } |
| group_block += fs->super->s_blocks_per_group; |
| } |
| io_channel_flush(fs->io); |
| retval = 0; |
| |
| errout: |
| return retval; |
| } |
| |
| /* -------------------------------------------------------------------- |
| * |
| * Resize processing, phase 2. |
| * |
| * In this phase we adjust determine which blocks need to be moved, in |
| * blocks_to_move(). We then copy the blocks to their ultimate new |
| * destinations using block_mover(). Since we are copying blocks to |
| * their new locations, again during this pass we can abort without |
| * any problems. |
| * -------------------------------------------------------------------- |
| */ |
| |
| /* |
| * This helper function creates a block bitmap with all of the |
| * filesystem meta-data blocks. |
| */ |
| static errcode_t mark_table_blocks(ext2_filsys fs, |
| ext2fs_block_bitmap bmap) |
| { |
| blk_t b; |
| unsigned int j; |
| dgrp_t i; |
| unsigned long meta_bg_size; |
| unsigned int old_desc_blocks; |
| |
| meta_bg_size = EXT2_DESC_PER_BLOCK(fs->super); |
| if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG) |
| old_desc_blocks = fs->super->s_first_meta_bg; |
| else |
| old_desc_blocks = fs->desc_blocks + |
| fs->super->s_reserved_gdt_blocks; |
| for (i = 0; i < fs->group_desc_count; i++) { |
| ext2fs_reserve_super_and_bgd(fs, i, bmap); |
| |
| /* |
| * Mark the blocks used for the inode table |
| */ |
| for (j = 0, b = fs->group_desc[i].bg_inode_table; |
| j < (unsigned int) fs->inode_blocks_per_group; |
| j++, b++) |
| ext2fs_mark_block_bitmap(bmap, b); |
| |
| /* |
| * Mark block used for the block bitmap |
| */ |
| ext2fs_mark_block_bitmap(bmap, |
| fs->group_desc[i].bg_block_bitmap); |
| |
| /* |
| * Mark block used for the inode bitmap |
| */ |
| ext2fs_mark_block_bitmap(bmap, |
| fs->group_desc[i].bg_inode_bitmap); |
| } |
| return 0; |
| } |
| |
| /* |
| * This function checks to see if a particular block (either a |
| * superblock or a block group descriptor) overlaps with an inode or |
| * block bitmap block, or with the inode table. |
| */ |
| static void mark_fs_metablock(ext2_resize_t rfs, |
| ext2fs_block_bitmap meta_bmap, |
| int group, blk_t blk) |
| { |
| ext2_filsys fs = rfs->new_fs; |
| |
| ext2fs_mark_block_bitmap(rfs->reserve_blocks, blk); |
| ext2fs_block_alloc_stats(fs, blk, +1); |
| |
| /* |
| * Check to see if we overlap with the inode or block bitmap, |
| * or the inode tables. If not, and the block is in use, then |
| * mark it as a block to be moved. |
| */ |
| if (IS_BLOCK_BM(fs, group, blk)) { |
| FS_BLOCK_BM(fs, group) = 0; |
| rfs->needed_blocks++; |
| } else if (IS_INODE_BM(fs, group, blk)) { |
| FS_INODE_BM(fs, group) = 0; |
| rfs->needed_blocks++; |
| } else if (IS_INODE_TB(fs, group, blk)) { |
| FS_INODE_TB(fs, group) = 0; |
| rfs->needed_blocks++; |
| } else if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super, |
| EXT4_FEATURE_RO_COMPAT_GDT_CSUM) && |
| (fs->group_desc[group].bg_flags & EXT2_BG_BLOCK_UNINIT)) { |
| /* |
| * If the block bitmap is uninitialized, which means |
| * nothing other than standard metadata in use. |
| */ |
| return; |
| } else if (ext2fs_test_block_bitmap(rfs->old_fs->block_map, blk) && |
| !ext2fs_test_block_bitmap(meta_bmap, blk)) { |
| ext2fs_mark_block_bitmap(rfs->move_blocks, blk); |
| rfs->needed_blocks++; |
| } |
| } |
| |
| |
| /* |
| * This routine marks and unmarks reserved blocks in the new block |
| * bitmap. It also determines which blocks need to be moved and |
| * places this information into the move_blocks bitmap. |
| */ |
| static errcode_t blocks_to_move(ext2_resize_t rfs) |
| { |
| int j, has_super; |
| dgrp_t i, max_groups, g; |
| blk_t blk, group_blk; |
| unsigned long old_blocks, new_blocks; |
| unsigned int meta_bg, meta_bg_size; |
| errcode_t retval; |
| ext2_filsys fs, old_fs; |
| ext2fs_block_bitmap meta_bmap; |
| __u32 save_incompat_flag; |
| |
| fs = rfs->new_fs; |
| old_fs = rfs->old_fs; |
| if (old_fs->super->s_blocks_count > fs->super->s_blocks_count) |
| fs = rfs->old_fs; |
| |
| retval = ext2fs_allocate_block_bitmap(fs, _("blocks to be moved"), |
| &rfs->move_blocks); |
| if (retval) |
| return retval; |
| |
| retval = ext2fs_allocate_block_bitmap(fs, _("meta-data blocks"), |
| &meta_bmap); |
| if (retval) |
| return retval; |
| |
| retval = mark_table_blocks(old_fs, meta_bmap); |
| if (retval) |
| return retval; |
| |
| fs = rfs->new_fs; |
| |
| /* |
| * If we're shrinking the filesystem, we need to move all of |
| * the blocks that don't fit any more |
| */ |
| for (blk = fs->super->s_blocks_count; |
| blk < old_fs->super->s_blocks_count; blk++) { |
| g = ext2fs_group_of_blk(fs, blk); |
| if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super, |
| EXT4_FEATURE_RO_COMPAT_GDT_CSUM) && |
| (old_fs->group_desc[g].bg_flags & EXT2_BG_BLOCK_UNINIT)) { |
| /* |
| * The block bitmap is uninitialized, so skip |
| * to the next block group. |
| */ |
| blk = ((g+1) * fs->super->s_blocks_per_group) + |
| fs->super->s_first_data_block - 1; |
| continue; |
| } |
| if (ext2fs_test_block_bitmap(old_fs->block_map, blk) && |
| !ext2fs_test_block_bitmap(meta_bmap, blk)) { |
| ext2fs_mark_block_bitmap(rfs->move_blocks, blk); |
| rfs->needed_blocks++; |
| } |
| ext2fs_mark_block_bitmap(rfs->reserve_blocks, blk); |
| } |
| |
| if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG) { |
| old_blocks = old_fs->super->s_first_meta_bg; |
| new_blocks = fs->super->s_first_meta_bg; |
| } else { |
| old_blocks = old_fs->desc_blocks + old_fs->super->s_reserved_gdt_blocks; |
| new_blocks = fs->desc_blocks + fs->super->s_reserved_gdt_blocks; |
| } |
| |
| if (old_blocks == new_blocks) { |
| retval = 0; |
| goto errout; |
| } |
| |
| max_groups = fs->group_desc_count; |
| if (max_groups > old_fs->group_desc_count) |
| max_groups = old_fs->group_desc_count; |
| group_blk = old_fs->super->s_first_data_block; |
| /* |
| * If we're reducing the number of descriptor blocks, this |
| * makes life easy. :-) We just have to mark some extra |
| * blocks as free. |
| */ |
| if (old_blocks > new_blocks) { |
| for (i = 0; i < max_groups; i++) { |
| if (!ext2fs_bg_has_super(fs, i)) { |
| group_blk += fs->super->s_blocks_per_group; |
| continue; |
| } |
| for (blk = group_blk+1+new_blocks; |
| blk < group_blk+1+old_blocks; blk++) { |
| ext2fs_block_alloc_stats(fs, blk, -1); |
| rfs->needed_blocks--; |
| } |
| group_blk += fs->super->s_blocks_per_group; |
| } |
| retval = 0; |
| goto errout; |
| } |
| /* |
| * If we're increasing the number of descriptor blocks, life |
| * gets interesting.... |
| */ |
| meta_bg_size = EXT2_DESC_PER_BLOCK(fs->super); |
| for (i = 0; i < max_groups; i++) { |
| has_super = ext2fs_bg_has_super(fs, i); |
| if (has_super) |
| mark_fs_metablock(rfs, meta_bmap, i, group_blk); |
| |
| meta_bg = i / meta_bg_size; |
| if (!(fs->super->s_feature_incompat & |
| EXT2_FEATURE_INCOMPAT_META_BG) || |
| (meta_bg < fs->super->s_first_meta_bg)) { |
| if (has_super) { |
| for (blk = group_blk+1; |
| blk < group_blk + 1 + new_blocks; blk++) |
| mark_fs_metablock(rfs, meta_bmap, |
| i, blk); |
| } |
| } else { |
| if (has_super) |
| has_super = 1; |
| if (((i % meta_bg_size) == 0) || |
| ((i % meta_bg_size) == 1) || |
| ((i % meta_bg_size) == (meta_bg_size-1))) |
| mark_fs_metablock(rfs, meta_bmap, i, |
| group_blk + has_super); |
| } |
| |
| if (fs->group_desc[i].bg_inode_table && |
| fs->group_desc[i].bg_inode_bitmap && |
| fs->group_desc[i].bg_block_bitmap) |
| goto next_group; |
| |
| /* |
| * Reserve the existing meta blocks that we know |
| * aren't to be moved. |
| */ |
| if (fs->group_desc[i].bg_block_bitmap) |
| ext2fs_mark_block_bitmap(rfs->reserve_blocks, |
| fs->group_desc[i].bg_block_bitmap); |
| if (fs->group_desc[i].bg_inode_bitmap) |
| ext2fs_mark_block_bitmap(rfs->reserve_blocks, |
| fs->group_desc[i].bg_inode_bitmap); |
| if (fs->group_desc[i].bg_inode_table) |
| for (blk = fs->group_desc[i].bg_inode_table, j=0; |
| j < fs->inode_blocks_per_group ; j++, blk++) |
| ext2fs_mark_block_bitmap(rfs->reserve_blocks, |
| blk); |
| |
| /* |
| * Allocate the missing data structures |
| * |
| * XXX We have a problem with FLEX_BG and off-line |
| * resizing where we are growing the size of the |
| * filesystem. ext2fs_allocate_group_table() will try |
| * to reserve the inode table in the desired flex_bg |
| * location. However, passing rfs->reserve_blocks |
| * doesn't work since it only has reserved the blocks |
| * that will be used in the new block group -- and |
| * with flex_bg, we can and will allocate the tables |
| * outside of the block group. And we can't pass in |
| * the fs->block_map because it doesn't handle |
| * overlapping inode table movements right. So for |
| * now, we temporarily disable flex_bg to force |
| * ext2fs_allocate_group_tables() to allocate the bg |
| * metadata in side the block group, and the restore |
| * it afterwards. Ugly, until we can fix this up |
| * right later. |
| */ |
| save_incompat_flag = fs->super->s_feature_incompat; |
| fs->super->s_feature_incompat &= ~EXT4_FEATURE_INCOMPAT_FLEX_BG; |
| retval = ext2fs_allocate_group_table(fs, i, |
| rfs->reserve_blocks); |
| fs->super->s_feature_incompat = save_incompat_flag; |
| if (retval) |
| goto errout; |
| |
| /* |
| * For those structures that have changed, we need to |
| * do bookkeepping. |
| */ |
| if (FS_BLOCK_BM(old_fs, i) != |
| (blk = FS_BLOCK_BM(fs, i))) { |
| ext2fs_block_alloc_stats(fs, blk, +1); |
| if (ext2fs_test_block_bitmap(old_fs->block_map, blk) && |
| !ext2fs_test_block_bitmap(meta_bmap, blk)) |
| ext2fs_mark_block_bitmap(rfs->move_blocks, |
| blk); |
| } |
| if (FS_INODE_BM(old_fs, i) != |
| (blk = FS_INODE_BM(fs, i))) { |
| ext2fs_block_alloc_stats(fs, blk, +1); |
| if (ext2fs_test_block_bitmap(old_fs->block_map, blk) && |
| !ext2fs_test_block_bitmap(meta_bmap, blk)) |
| ext2fs_mark_block_bitmap(rfs->move_blocks, |
| blk); |
| } |
| |
| /* |
| * The inode table, if we need to relocate it, is |
| * handled specially. We have to reserve the blocks |
| * for both the old and the new inode table, since we |
| * can't have the inode table be destroyed during the |
| * block relocation phase. |
| */ |
| if (FS_INODE_TB(fs, i) == FS_INODE_TB(old_fs, i)) |
| goto next_group; /* inode table not moved */ |
| |
| rfs->needed_blocks += fs->inode_blocks_per_group; |
| |
| /* |
| * Mark the new inode table as in use in the new block |
| * allocation bitmap, and move any blocks that might |
| * be necessary. |
| */ |
| for (blk = fs->group_desc[i].bg_inode_table, j=0; |
| j < fs->inode_blocks_per_group ; j++, blk++) { |
| ext2fs_block_alloc_stats(fs, blk, +1); |
| if (ext2fs_test_block_bitmap(old_fs->block_map, blk) && |
| !ext2fs_test_block_bitmap(meta_bmap, blk)) |
| ext2fs_mark_block_bitmap(rfs->move_blocks, |
| blk); |
| } |
| |
| /* |
| * Make sure the old inode table is reserved in the |
| * block reservation bitmap. |
| */ |
| for (blk = rfs->old_fs->group_desc[i].bg_inode_table, j=0; |
| j < fs->inode_blocks_per_group ; j++, blk++) |
| ext2fs_mark_block_bitmap(rfs->reserve_blocks, blk); |
| |
| next_group: |
| group_blk += rfs->new_fs->super->s_blocks_per_group; |
| } |
| retval = 0; |
| |
| errout: |
| if (meta_bmap) |
| ext2fs_free_block_bitmap(meta_bmap); |
| |
| return retval; |
| } |
| |
| /* |
| * This helper function tries to allocate a new block. We try to |
| * avoid hitting the original group descriptor blocks at least at |
| * first, since we want to make it possible to recover from a badly |
| * aborted resize operation as much as possible. |
| * |
| * In the future, I may further modify this routine to balance out |
| * where we get the new blocks across the various block groups. |
| * Ideally we would allocate blocks that corresponded with the block |
| * group of the containing inode, and keep contiguous blocks |
| * together. However, this very difficult to do efficiently, since we |
| * don't have the necessary information up front. |
| */ |
| |
| #define AVOID_OLD 1 |
| #define DESPERATION 2 |
| |
| static void init_block_alloc(ext2_resize_t rfs) |
| { |
| rfs->alloc_state = AVOID_OLD; |
| rfs->new_blk = rfs->new_fs->super->s_first_data_block; |
| #if 0 |
| /* HACK for testing */ |
| if (rfs->new_fs->super->s_blocks_count > |
| rfs->old_fs->super->s_blocks_count) |
| rfs->new_blk = rfs->old_fs->super->s_blocks_count; |
| #endif |
| } |
| |
| static blk_t get_new_block(ext2_resize_t rfs) |
| { |
| ext2_filsys fs = rfs->new_fs; |
| |
| while (1) { |
| if (rfs->new_blk >= fs->super->s_blocks_count) { |
| if (rfs->alloc_state == DESPERATION) |
| return 0; |
| |
| #ifdef RESIZE2FS_DEBUG |
| if (rfs->flags & RESIZE_DEBUG_BMOVE) |
| printf("Going into desperation mode " |
| "for block allocations\n"); |
| #endif |
| rfs->alloc_state = DESPERATION; |
| rfs->new_blk = fs->super->s_first_data_block; |
| continue; |
| } |
| if (ext2fs_test_block_bitmap(fs->block_map, rfs->new_blk) || |
| ext2fs_test_block_bitmap(rfs->reserve_blocks, |
| rfs->new_blk) || |
| ((rfs->alloc_state == AVOID_OLD) && |
| (rfs->new_blk < rfs->old_fs->super->s_blocks_count) && |
| ext2fs_test_block_bitmap(rfs->old_fs->block_map, |
| rfs->new_blk))) { |
| rfs->new_blk++; |
| continue; |
| } |
| return rfs->new_blk; |
| } |
| } |
| |
| static errcode_t resize2fs_get_alloc_block(ext2_filsys fs, blk64_t goal, |
| blk64_t *ret) |
| { |
| ext2_resize_t rfs = (ext2_resize_t) fs->priv_data; |
| blk_t blk; |
| |
| blk = get_new_block(rfs); |
| if (!blk) |
| return ENOSPC; |
| |
| #ifdef RESIZE2FS_DEBUG |
| if (rfs->flags & 0xF) |
| printf("get_alloc_block allocating %u\n", blk); |
| #endif |
| |
| ext2fs_mark_block_bitmap(rfs->old_fs->block_map, blk); |
| ext2fs_mark_block_bitmap(rfs->new_fs->block_map, blk); |
| *ret = (blk64_t) blk; |
| return 0; |
| } |
| |
| static errcode_t block_mover(ext2_resize_t rfs) |
| { |
| blk_t blk, old_blk, new_blk; |
| ext2_filsys fs = rfs->new_fs; |
| ext2_filsys old_fs = rfs->old_fs; |
| errcode_t retval; |
| int size, c; |
| int to_move, moved; |
| ext2_badblocks_list badblock_list = 0; |
| int bb_modified = 0; |
| |
| fs->get_alloc_block = resize2fs_get_alloc_block; |
| old_fs->get_alloc_block = resize2fs_get_alloc_block; |
| |
| retval = ext2fs_read_bb_inode(old_fs, &badblock_list); |
| if (retval) |
| return retval; |
| |
| new_blk = fs->super->s_first_data_block; |
| if (!rfs->itable_buf) { |
| retval = ext2fs_get_array(fs->blocksize, |
| fs->inode_blocks_per_group, |
| &rfs->itable_buf); |
| if (retval) |
| return retval; |
| } |
| retval = ext2fs_create_extent_table(&rfs->bmap, 0); |
| if (retval) |
| return retval; |
| |
| /* |
| * The first step is to figure out where all of the blocks |
| * will go. |
| */ |
| to_move = moved = 0; |
| init_block_alloc(rfs); |
| for (blk = old_fs->super->s_first_data_block; |
| blk < old_fs->super->s_blocks_count; blk++) { |
| if (!ext2fs_test_block_bitmap(old_fs->block_map, blk)) |
| continue; |
| if (!ext2fs_test_block_bitmap(rfs->move_blocks, blk)) |
| continue; |
| if (ext2fs_badblocks_list_test(badblock_list, blk)) { |
| ext2fs_badblocks_list_del(badblock_list, blk); |
| bb_modified++; |
| continue; |
| } |
| |
| new_blk = get_new_block(rfs); |
| if (!new_blk) { |
| retval = ENOSPC; |
| goto errout; |
| } |
| ext2fs_block_alloc_stats(fs, new_blk, +1); |
| ext2fs_add_extent_entry(rfs->bmap, blk, new_blk); |
| to_move++; |
| } |
| |
| if (to_move == 0) { |
| if (rfs->bmap) { |
| ext2fs_free_extent_table(rfs->bmap); |
| rfs->bmap = 0; |
| } |
| retval = 0; |
| goto errout; |
| } |
| |
| /* |
| * Step two is to actually move the blocks |
| */ |
| retval = ext2fs_iterate_extent(rfs->bmap, 0, 0, 0); |
| if (retval) goto errout; |
| |
| if (rfs->progress) { |
| retval = (rfs->progress)(rfs, E2_RSZ_BLOCK_RELOC_PASS, |
| 0, to_move); |
| if (retval) |
| goto errout; |
| } |
| while (1) { |
| retval = ext2fs_iterate_extent(rfs->bmap, &old_blk, &new_blk, &size); |
| if (retval) goto errout; |
| if (!size) |
| break; |
| #ifdef RESIZE2FS_DEBUG |
| if (rfs->flags & RESIZE_DEBUG_BMOVE) |
| printf("Moving %d blocks %u->%u\n", |
| size, old_blk, new_blk); |
| #endif |
| do { |
| c = size; |
| if (c > fs->inode_blocks_per_group) |
| c = fs->inode_blocks_per_group; |
| retval = io_channel_read_blk(fs->io, old_blk, c, |
| rfs->itable_buf); |
| if (retval) goto errout; |
| retval = io_channel_write_blk(fs->io, new_blk, c, |
| rfs->itable_buf); |
| if (retval) goto errout; |
| size -= c; |
| new_blk += c; |
| old_blk += c; |
| moved += c; |
| if (rfs->progress) { |
| io_channel_flush(fs->io); |
| retval = (rfs->progress)(rfs, |
| E2_RSZ_BLOCK_RELOC_PASS, |
| moved, to_move); |
| if (retval) |
| goto errout; |
| } |
| } while (size > 0); |
| io_channel_flush(fs->io); |
| } |
| |
| errout: |
| if (badblock_list) { |
| if (!retval && bb_modified) |
| retval = ext2fs_update_bb_inode(old_fs, |
| badblock_list); |
| ext2fs_badblocks_list_free(badblock_list); |
| } |
| return retval; |
| } |
| |
| |
| /* -------------------------------------------------------------------- |
| * |
| * Resize processing, phase 3 |
| * |
| * -------------------------------------------------------------------- |
| */ |
| |
| |
| struct process_block_struct { |
| ext2_resize_t rfs; |
| ext2_ino_t ino; |
| struct ext2_inode * inode; |
| errcode_t error; |
| int is_dir; |
| int changed; |
| }; |
| |
| static int process_block(ext2_filsys fs, blk_t *block_nr, |
| e2_blkcnt_t blockcnt, |
| blk_t ref_block EXT2FS_ATTR((unused)), |
| int ref_offset EXT2FS_ATTR((unused)), void *priv_data) |
| { |
| struct process_block_struct *pb; |
| errcode_t retval; |
| blk_t block, new_block; |
| int ret = 0; |
| |
| pb = (struct process_block_struct *) priv_data; |
| block = *block_nr; |
| if (pb->rfs->bmap) { |
| new_block = ext2fs_extent_translate(pb->rfs->bmap, block); |
| if (new_block) { |
| *block_nr = new_block; |
| ret |= BLOCK_CHANGED; |
| pb->changed = 1; |
| #ifdef RESIZE2FS_DEBUG |
| if (pb->rfs->flags & RESIZE_DEBUG_BMOVE) |
| printf("ino=%u, blockcnt=%lld, %u->%u\n", |
| pb->ino, blockcnt, block, new_block); |
| #endif |
| block = new_block; |
| } |
| } |
| if (pb->is_dir) { |
| retval = ext2fs_add_dir_block(fs->dblist, pb->ino, |
| block, (int) blockcnt); |
| if (retval) { |
| pb->error = retval; |
| ret |= BLOCK_ABORT; |
| } |
| } |
| return ret; |
| } |
| |
| /* |
| * Progress callback |
| */ |
| static errcode_t progress_callback(ext2_filsys fs, |
| ext2_inode_scan scan EXT2FS_ATTR((unused)), |
| dgrp_t group, void * priv_data) |
| { |
| ext2_resize_t rfs = (ext2_resize_t) priv_data; |
| errcode_t retval; |
| |
| /* |
| * This check is to protect against old ext2 libraries. It |
| * shouldn't be needed against new libraries. |
| */ |
| if ((group+1) == 0) |
| return 0; |
| |
| if (rfs->progress) { |
| io_channel_flush(fs->io); |
| retval = (rfs->progress)(rfs, E2_RSZ_INODE_SCAN_PASS, |
| group+1, fs->group_desc_count); |
| if (retval) |
| return retval; |
| } |
| |
| return 0; |
| } |
| |
| static errcode_t inode_scan_and_fix(ext2_resize_t rfs) |
| { |
| struct process_block_struct pb; |
| ext2_ino_t ino, new_inode; |
| struct ext2_inode *inode = NULL; |
| ext2_inode_scan scan = NULL; |
| errcode_t retval; |
| char *block_buf = 0; |
| ext2_ino_t start_to_move; |
| blk_t orig_size, new_block; |
| int inode_size; |
| |
| if ((rfs->old_fs->group_desc_count <= |
| rfs->new_fs->group_desc_count) && |
| !rfs->bmap) |
| return 0; |
| |
| /* |
| * Save the original size of the old filesystem, and |
| * temporarily set the size to be the new size if the new size |
| * is larger. We need to do this to avoid catching an error |
| * by the block iterator routines |
| */ |
| orig_size = rfs->old_fs->super->s_blocks_count; |
| if (orig_size < rfs->new_fs->super->s_blocks_count) |
| rfs->old_fs->super->s_blocks_count = |
| rfs->new_fs->super->s_blocks_count; |
| |
| retval = ext2fs_open_inode_scan(rfs->old_fs, 0, &scan); |
| if (retval) goto errout; |
| |
| retval = ext2fs_init_dblist(rfs->old_fs, 0); |
| if (retval) goto errout; |
| retval = ext2fs_get_array(rfs->old_fs->blocksize, 3, &block_buf); |
| if (retval) goto errout; |
| |
| start_to_move = (rfs->new_fs->group_desc_count * |
| rfs->new_fs->super->s_inodes_per_group); |
| |
| if (rfs->progress) { |
| retval = (rfs->progress)(rfs, E2_RSZ_INODE_SCAN_PASS, |
| 0, rfs->old_fs->group_desc_count); |
| if (retval) |
| goto errout; |
| } |
| ext2fs_set_inode_callback(scan, progress_callback, (void *) rfs); |
| pb.rfs = rfs; |
| pb.inode = inode; |
| pb.error = 0; |
| new_inode = EXT2_FIRST_INODE(rfs->new_fs->super); |
| inode_size = EXT2_INODE_SIZE(rfs->new_fs->super); |
| inode = malloc(inode_size); |
| if (!inode) { |
| retval = ENOMEM; |
| goto errout; |
| } |
| /* |
| * First, copy all of the inodes that need to be moved |
| * elsewhere in the inode table |
| */ |
| while (1) { |
| retval = ext2fs_get_next_inode_full(scan, &ino, inode, inode_size); |
| if (retval) goto errout; |
| if (!ino) |
| break; |
| |
| if (inode->i_links_count == 0 && ino != EXT2_RESIZE_INO) |
| continue; /* inode not in use */ |
| |
| pb.is_dir = LINUX_S_ISDIR(inode->i_mode); |
| pb.changed = 0; |
| |
| if (inode->i_file_acl && rfs->bmap) { |
| new_block = ext2fs_extent_translate(rfs->bmap, |
| inode->i_file_acl); |
| if (new_block) { |
| inode->i_file_acl = new_block; |
| retval = ext2fs_write_inode_full(rfs->old_fs, |
| ino, inode, inode_size); |
| if (retval) goto errout; |
| } |
| } |
| |
| if (ext2fs_inode_has_valid_blocks(inode) && |
| (rfs->bmap || pb.is_dir)) { |
| pb.ino = ino; |
| retval = ext2fs_block_iterate2(rfs->old_fs, |
| ino, 0, block_buf, |
| process_block, &pb); |
| if (retval) |
| goto errout; |
| if (pb.error) { |
| retval = pb.error; |
| goto errout; |
| } |
| } |
| |
| if (ino <= start_to_move) |
| continue; /* Don't need to move it. */ |
| |
| /* |
| * Find a new inode |
| */ |
| retval = ext2fs_new_inode(rfs->new_fs, 0, 0, 0, &new_inode); |
| if (retval) |
| goto errout; |
| |
| ext2fs_inode_alloc_stats2(rfs->new_fs, new_inode, +1, |
| pb.is_dir); |
| if (pb.changed) { |
| /* Get the new version of the inode */ |
| retval = ext2fs_read_inode_full(rfs->old_fs, ino, |
| inode, inode_size); |
| if (retval) goto errout; |
| } |
| inode->i_ctime = time(0); |
| retval = ext2fs_write_inode_full(rfs->old_fs, new_inode, |
| inode, inode_size); |
| if (retval) goto errout; |
| |
| #ifdef RESIZE2FS_DEBUG |
| if (rfs->flags & RESIZE_DEBUG_INODEMAP) |
| printf("Inode moved %u->%u\n", ino, new_inode); |
| #endif |
| if (!rfs->imap) { |
| retval = ext2fs_create_extent_table(&rfs->imap, 0); |
| if (retval) |
| goto errout; |
| } |
| ext2fs_add_extent_entry(rfs->imap, ino, new_inode); |
| } |
| io_channel_flush(rfs->old_fs->io); |
| |
| errout: |
| rfs->old_fs->super->s_blocks_count = orig_size; |
| if (rfs->bmap) { |
| ext2fs_free_extent_table(rfs->bmap); |
| rfs->bmap = 0; |
| } |
| if (scan) |
| ext2fs_close_inode_scan(scan); |
| if (block_buf) |
| ext2fs_free_mem(&block_buf); |
| free(inode); |
| return retval; |
| } |
| |
| /* -------------------------------------------------------------------- |
| * |
| * Resize processing, phase 4. |
| * |
| * -------------------------------------------------------------------- |
| */ |
| |
| struct istruct { |
| ext2_resize_t rfs; |
| errcode_t err; |
| unsigned int max_dirs; |
| unsigned int num; |
| }; |
| |
| static int check_and_change_inodes(ext2_ino_t dir, |
| int entry EXT2FS_ATTR((unused)), |
| struct ext2_dir_entry *dirent, int offset, |
| int blocksize EXT2FS_ATTR((unused)), |
| char *buf EXT2FS_ATTR((unused)), |
| void *priv_data) |
| { |
| struct istruct *is = (struct istruct *) priv_data; |
| struct ext2_inode inode; |
| ext2_ino_t new_inode; |
| errcode_t retval; |
| |
| if (is->rfs->progress && offset == 0) { |
| io_channel_flush(is->rfs->old_fs->io); |
| is->err = (is->rfs->progress)(is->rfs, |
| E2_RSZ_INODE_REF_UPD_PASS, |
| ++is->num, is->max_dirs); |
| if (is->err) |
| return DIRENT_ABORT; |
| } |
| |
| if (!dirent->inode) |
| return 0; |
| |
| new_inode = ext2fs_extent_translate(is->rfs->imap, dirent->inode); |
| |
| if (!new_inode) |
| return 0; |
| #ifdef RESIZE2FS_DEBUG |
| if (is->rfs->flags & RESIZE_DEBUG_INODEMAP) |
| printf("Inode translate (dir=%u, name=%.*s, %u->%u)\n", |
| dir, dirent->name_len&0xFF, dirent->name, |
| dirent->inode, new_inode); |
| #endif |
| |
| dirent->inode = new_inode; |
| |
| /* Update the directory mtime and ctime */ |
| retval = ext2fs_read_inode(is->rfs->old_fs, dir, &inode); |
| if (retval == 0) { |
| inode.i_mtime = inode.i_ctime = time(0); |
| is->err = ext2fs_write_inode(is->rfs->old_fs, dir, &inode); |
| if (is->err) |
| return DIRENT_ABORT; |
| } |
| |
| return DIRENT_CHANGED; |
| } |
| |
| static errcode_t inode_ref_fix(ext2_resize_t rfs) |
| { |
| errcode_t retval; |
| struct istruct is; |
| |
| if (!rfs->imap) |
| return 0; |
| |
| /* |
| * Now, we iterate over all of the directories to update the |
| * inode references |
| */ |
| is.num = 0; |
| is.max_dirs = ext2fs_dblist_count(rfs->old_fs->dblist); |
| is.rfs = rfs; |
| is.err = 0; |
| |
| if (rfs->progress) { |
| retval = (rfs->progress)(rfs, E2_RSZ_INODE_REF_UPD_PASS, |
| 0, is.max_dirs); |
| if (retval) |
| goto errout; |
| } |
| |
| retval = ext2fs_dblist_dir_iterate(rfs->old_fs->dblist, |
| DIRENT_FLAG_INCLUDE_EMPTY, 0, |
| check_and_change_inodes, &is); |
| if (retval) |
| goto errout; |
| if (is.err) { |
| retval = is.err; |
| goto errout; |
| } |
| |
| if (rfs->progress && (is.num < is.max_dirs)) |
| (rfs->progress)(rfs, E2_RSZ_INODE_REF_UPD_PASS, |
| is.max_dirs, is.max_dirs); |
| |
| errout: |
| ext2fs_free_extent_table(rfs->imap); |
| rfs->imap = 0; |
| return retval; |
| } |
| |
| |
| /* -------------------------------------------------------------------- |
| * |
| * Resize processing, phase 5. |
| * |
| * In this phase we actually move the inode table around, and then |
| * update the summary statistics. This is scary, since aborting here |
| * will potentially scramble the filesystem. (We are moving the |
| * inode tables around in place, and so the potential for lost data, |
| * or at the very least scrambling the mapping between filenames and |
| * inode numbers is very high in case of a power failure here.) |
| * -------------------------------------------------------------------- |
| */ |
| |
| |
| /* |
| * A very scary routine --- this one moves the inode table around!!! |
| * |
| * After this you have to use the rfs->new_fs file handle to read and |
| * write inodes. |
| */ |
| static errcode_t move_itables(ext2_resize_t rfs) |
| { |
| int n, num, size, diff; |
| dgrp_t i, max_groups; |
| ext2_filsys fs = rfs->new_fs; |
| char *cp; |
| blk_t old_blk, new_blk, blk; |
| errcode_t retval; |
| int j, to_move, moved; |
| |
| max_groups = fs->group_desc_count; |
| if (max_groups > rfs->old_fs->group_desc_count) |
| max_groups = rfs->old_fs->group_desc_count; |
| |
| size = fs->blocksize * fs->inode_blocks_per_group; |
| if (!rfs->itable_buf) { |
| retval = ext2fs_get_mem(size, &rfs->itable_buf); |
| if (retval) |
| return retval; |
| } |
| |
| /* |
| * Figure out how many inode tables we need to move |
| */ |
| to_move = moved = 0; |
| for (i=0; i < max_groups; i++) |
| if (rfs->old_fs->group_desc[i].bg_inode_table != |
| fs->group_desc[i].bg_inode_table) |
| to_move++; |
| |
| if (to_move == 0) |
| return 0; |
| |
| if (rfs->progress) { |
| retval = rfs->progress(rfs, E2_RSZ_MOVE_ITABLE_PASS, |
| 0, to_move); |
| if (retval) |
| goto errout; |
| } |
| |
| rfs->old_fs->flags |= EXT2_FLAG_MASTER_SB_ONLY; |
| |
| for (i=0; i < max_groups; i++) { |
| old_blk = rfs->old_fs->group_desc[i].bg_inode_table; |
| new_blk = fs->group_desc[i].bg_inode_table; |
| diff = new_blk - old_blk; |
| |
| #ifdef RESIZE2FS_DEBUG |
| if (rfs->flags & RESIZE_DEBUG_ITABLEMOVE) |
| printf("Itable move group %d block %u->%u (diff %d)\n", |
| i, old_blk, new_blk, diff); |
| #endif |
| |
| if (!diff) |
| continue; |
| |
| retval = io_channel_read_blk(fs->io, old_blk, |
| fs->inode_blocks_per_group, |
| rfs->itable_buf); |
| if (retval) |
| goto errout; |
| /* |
| * The end of the inode table segment often contains |
| * all zeros, and we're often only moving the inode |
| * table down a block or two. If so, we can optimize |
| * things by not rewriting blocks that we know to be zero |
| * already. |
| */ |
| for (cp = rfs->itable_buf+size-1, n=0; n < size; n++, cp--) |
| if (*cp) |
| break; |
| n = n >> EXT2_BLOCK_SIZE_BITS(fs->super); |
| #ifdef RESIZE2FS_DEBUG |
| if (rfs->flags & RESIZE_DEBUG_ITABLEMOVE) |
| printf("%d blocks of zeros...\n", n); |
| #endif |
| num = fs->inode_blocks_per_group; |
| if (n > diff) |
| num -= n; |
| |
| retval = io_channel_write_blk(fs->io, new_blk, |
| num, rfs->itable_buf); |
| if (retval) { |
| io_channel_write_blk(fs->io, old_blk, |
| num, rfs->itable_buf); |
| goto errout; |
| } |
| if (n > diff) { |
| retval = io_channel_write_blk(fs->io, |
| old_blk + fs->inode_blocks_per_group, |
| diff, (rfs->itable_buf + |
| (fs->inode_blocks_per_group - diff) * |
| fs->blocksize)); |
| if (retval) |
| goto errout; |
| } |
| |
| for (blk = rfs->old_fs->group_desc[i].bg_inode_table, j=0; |
| j < fs->inode_blocks_per_group ; j++, blk++) |
| ext2fs_block_alloc_stats(fs, blk, -1); |
| |
| rfs->old_fs->group_desc[i].bg_inode_table = new_blk; |
| ext2fs_group_desc_csum_set(rfs->old_fs, i); |
| ext2fs_mark_super_dirty(rfs->old_fs); |
| ext2fs_flush(rfs->old_fs); |
| |
| if (rfs->progress) { |
| retval = rfs->progress(rfs, E2_RSZ_MOVE_ITABLE_PASS, |
| ++moved, to_move); |
| if (retval) |
| goto errout; |
| } |
| } |
| mark_table_blocks(fs, fs->block_map); |
| ext2fs_flush(fs); |
| #ifdef RESIZE2FS_DEBUG |
| if (rfs->flags & RESIZE_DEBUG_ITABLEMOVE) |
| printf("Inode table move finished.\n"); |
| #endif |
| return 0; |
| |
| errout: |
| return retval; |
| } |
| |
| /* |
| * Fix the resize inode |
| */ |
| static errcode_t fix_resize_inode(ext2_filsys fs) |
| { |
| struct ext2_inode inode; |
| errcode_t retval; |
| char * block_buf; |
| |
| if (!(fs->super->s_feature_compat & |
| EXT2_FEATURE_COMPAT_RESIZE_INODE)) |
| return 0; |
| |
| retval = ext2fs_get_mem(fs->blocksize, &block_buf); |
| if (retval) goto errout; |
| |
| retval = ext2fs_read_inode(fs, EXT2_RESIZE_INO, &inode); |
| if (retval) goto errout; |
| |
| ext2fs_iblk_set(fs, &inode, 1); |
| |
| retval = ext2fs_write_inode(fs, EXT2_RESIZE_INO, &inode); |
| if (retval) goto errout; |
| |
| if (!inode.i_block[EXT2_DIND_BLOCK]) { |
| /* |
| * Avoid zeroing out block #0; that's rude. This |
| * should never happen anyway since the filesystem |
| * should be fsck'ed and we assume it is consistent. |
| */ |
| fprintf(stderr, |
| _("Should never happen: resize inode corrupt!\n")); |
| exit(1); |
| } |
| |
| memset(block_buf, 0, fs->blocksize); |
| |
| retval = io_channel_write_blk(fs->io, inode.i_block[EXT2_DIND_BLOCK], |
| 1, block_buf); |
| if (retval) goto errout; |
| |
| retval = ext2fs_create_resize_inode(fs); |
| if (retval) |
| goto errout; |
| |
| errout: |
| if (block_buf) |
| ext2fs_free_mem(&block_buf); |
| return retval; |
| } |
| |
| /* |
| * Finally, recalculate the summary information |
| */ |
| static errcode_t ext2fs_calculate_summary_stats(ext2_filsys fs) |
| { |
| blk_t blk; |
| ext2_ino_t ino; |
| unsigned int group = 0; |
| unsigned int count = 0; |
| int total_free = 0; |
| int group_free = 0; |
| int uninit = 0; |
| blk_t super_blk, old_desc_blk, new_desc_blk; |
| int old_desc_blocks; |
| |
| /* |
| * First calculate the block statistics |
| */ |
| uninit = fs->group_desc[group].bg_flags & EXT2_BG_BLOCK_UNINIT; |
| ext2fs_super_and_bgd_loc(fs, group, &super_blk, &old_desc_blk, |
| &new_desc_blk, 0); |
| if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG) |
| old_desc_blocks = fs->super->s_first_meta_bg; |
| else |
| old_desc_blocks = fs->desc_blocks + |
| fs->super->s_reserved_gdt_blocks; |
| for (blk = fs->super->s_first_data_block; |
| blk < fs->super->s_blocks_count; blk++) { |
| if ((uninit && |
| !((blk == super_blk) || |
| ((old_desc_blk && old_desc_blocks && |
| (blk >= old_desc_blk) && |
| (blk < old_desc_blk + old_desc_blocks))) || |
| ((new_desc_blk && (blk == new_desc_blk))) || |
| (blk == fs->group_desc[group].bg_block_bitmap) || |
| (blk == fs->group_desc[group].bg_inode_bitmap) || |
| ((blk >= fs->group_desc[group].bg_inode_table && |
| (blk < fs->group_desc[group].bg_inode_table |
| + fs->inode_blocks_per_group))))) || |
| (!ext2fs_fast_test_block_bitmap(fs->block_map, blk))) { |
| group_free++; |
| total_free++; |
| } |
| count++; |
| if ((count == fs->super->s_blocks_per_group) || |
| (blk == fs->super->s_blocks_count-1)) { |
| fs->group_desc[group].bg_free_blocks_count = |
| group_free; |
| ext2fs_group_desc_csum_set(fs, group); |
| group++; |
| if (group >= fs->group_desc_count) |
| break; |
| count = 0; |
| group_free = 0; |
| uninit = (fs->group_desc[group].bg_flags & |
| EXT2_BG_BLOCK_UNINIT); |
| ext2fs_super_and_bgd_loc(fs, group, &super_blk, |
| &old_desc_blk, |
| &new_desc_blk, 0); |
| if (fs->super->s_feature_incompat & |
| EXT2_FEATURE_INCOMPAT_META_BG) |
| old_desc_blocks = fs->super->s_first_meta_bg; |
| else |
| old_desc_blocks = fs->desc_blocks + |
| fs->super->s_reserved_gdt_blocks; |
| } |
| } |
| fs->super->s_free_blocks_count = total_free; |
| |
| /* |
| * Next, calculate the inode statistics |
| */ |
| group_free = 0; |
| total_free = 0; |
| count = 0; |
| group = 0; |
| |
| /* Protect loop from wrap-around if s_inodes_count maxed */ |
| uninit = fs->group_desc[group].bg_flags & EXT2_BG_INODE_UNINIT; |
| for (ino = 1; ino <= fs->super->s_inodes_count && ino > 0; ino++) { |
| if (uninit || |
| !ext2fs_fast_test_inode_bitmap(fs->inode_map, ino)) { |
| group_free++; |
| total_free++; |
| } |
| count++; |
| if ((count == fs->super->s_inodes_per_group) || |
| (ino == fs->super->s_inodes_count)) { |
| fs->group_desc[group].bg_free_inodes_count = |
| group_free; |
| ext2fs_group_desc_csum_set(fs, group); |
| group++; |
| if (group >= fs->group_desc_count) |
| break; |
| count = 0; |
| group_free = 0; |
| uninit = (fs->group_desc[group].bg_flags & |
| EXT2_BG_INODE_UNINIT); |
| } |
| } |
| fs->super->s_free_inodes_count = total_free; |
| ext2fs_mark_super_dirty(fs); |
| return 0; |
| } |
| |
| /* |
| * Journal may have been relocated; update the backup journal blocks |
| * in the superblock. |
| */ |
| static errcode_t fix_sb_journal_backup(ext2_filsys fs) |
| { |
| errcode_t retval; |
| struct ext2_inode inode; |
| |
| if (!(fs->super->s_feature_compat & EXT3_FEATURE_COMPAT_HAS_JOURNAL)) |
| return 0; |
| |
| /* External journal? Nothing to do. */ |
| if (fs->super->s_journal_dev && !fs->super->s_journal_inum) |
| return 0; |
| |
| retval = ext2fs_read_inode(fs, fs->super->s_journal_inum, &inode); |
| if (retval) |
| return retval; |
| memcpy(fs->super->s_jnl_blocks, inode.i_block, EXT2_N_BLOCKS*4); |
| fs->super->s_jnl_blocks[16] = inode.i_size; |
| fs->super->s_jnl_backup_type = EXT3_JNL_BACKUP_BLOCKS; |
| ext2fs_mark_super_dirty(fs); |
| return 0; |
| } |
| |
| /* |
| * calcluate the minimum number of blocks the given fs can be resized to |
| */ |
| blk_t calculate_minimum_resize_size(ext2_filsys fs) |
| { |
| blk_t inode_count, blks_needed, groups, data_blocks; |
| blk_t grp, data_needed, last_start; |
| int overhead = 0, num_of_superblocks = 0; |
| int extra_groups = 0; |
| int flexbg_size = 1 << fs->super->s_log_groups_per_flex; |
| |
| /* |
| * first figure out how many group descriptors we need to |
| * handle the number of inodes we have |
| */ |
| inode_count = fs->super->s_inodes_count - |
| fs->super->s_free_inodes_count; |
| blks_needed = ext2fs_div_ceil(inode_count, |
| fs->super->s_inodes_per_group) * |
| EXT2_BLOCKS_PER_GROUP(fs->super); |
| groups = ext2fs_div_ceil(blks_needed, |
| EXT2_BLOCKS_PER_GROUP(fs->super)); |
| |
| /* |
| * we need to figure out how many backup superblocks we have so we can |
| * account for that in the metadata |
| */ |
| for (grp = 0; grp < fs->group_desc_count; grp++) { |
| if (ext2fs_bg_has_super(fs, grp)) |
| num_of_superblocks++; |
| } |
| |
| /* calculate how many blocks are needed for data */ |
| data_needed = fs->super->s_blocks_count - |
| fs->super->s_free_blocks_count; |
| data_needed -= SUPER_OVERHEAD(fs) * num_of_superblocks; |
| data_needed -= META_OVERHEAD(fs) * fs->group_desc_count; |
| |
| if (fs->super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_FLEX_BG) { |
| /* |
| * For ext4 we need to allow for up to a flex_bg worth |
| * of inode tables of slack space so the resize |
| * operation can be guaranteed to finish. |
| */ |
| extra_groups = flexbg_size - (groups & (flexbg_size - 1)); |
| data_needed += META_OVERHEAD(fs) * extra_groups; |
| extra_groups = groups % flexbg_size; |
| } |
| |
| /* |
| * figure out how many data blocks we have given the number of groups |
| * we need for our inodes |
| */ |
| data_blocks = groups * EXT2_BLOCKS_PER_GROUP(fs->super); |
| last_start = 0; |
| for (grp = 0; grp < groups; grp++) { |
| overhead = META_OVERHEAD(fs); |
| |
| if (ext2fs_bg_has_super(fs, grp)) |
| overhead += SUPER_OVERHEAD(fs); |
| |
| /* |
| * we want to keep track of how much data we can store in |
| * the groups leading up to the last group so we can determine |
| * how big the last group needs to be |
| */ |
| if (grp != (groups - 1)) |
| last_start += EXT2_BLOCKS_PER_GROUP(fs->super) - |
| overhead; |
| |
| data_blocks -= overhead; |
| } |
| |
| /* |
| * if we need more group descriptors in order to accomodate our data |
| * then we need to add them here |
| */ |
| while (data_needed > data_blocks) { |
| blk_t remainder = data_needed - data_blocks; |
| blk_t extra_grps; |
| |
| /* figure out how many more groups we need for the data */ |
| extra_grps = ext2fs_div_ceil(remainder, |
| EXT2_BLOCKS_PER_GROUP(fs->super)); |
| |
| data_blocks += extra_grps * EXT2_BLOCKS_PER_GROUP(fs->super); |
| |
| /* ok we have to account for the last group */ |
| overhead = META_OVERHEAD(fs); |
| if (ext2fs_bg_has_super(fs, groups-1)) |
| overhead += SUPER_OVERHEAD(fs); |
| last_start += EXT2_BLOCKS_PER_GROUP(fs->super) - overhead; |
| |
| for (grp = groups; grp < groups+extra_grps; grp++) { |
| overhead = META_OVERHEAD(fs); |
| if (ext2fs_bg_has_super(fs, grp)) |
| overhead += SUPER_OVERHEAD(fs); |
| |
| /* |
| * again, we need to see how much data we cram into |
| * all of the groups leading up to the last group |
| */ |
| if (grp != (groups + extra_grps - 1)) |
| last_start += EXT2_BLOCKS_PER_GROUP(fs->super) |
| - overhead; |
| |
| data_blocks -= overhead; |
| } |
| |
| groups += extra_grps; |
| extra_groups += extra_grps; |
| if (fs->super->s_feature_incompat |
| & EXT4_FEATURE_INCOMPAT_FLEX_BG |
| && extra_groups > flexbg_size) { |
| /* |
| * For ext4 we need to allow for up to a flex_bg worth |
| * of inode tables of slack space so the resize |
| * operation can be guaranteed to finish. |
| */ |
| extra_groups = flexbg_size - |
| (groups & (flexbg_size - 1)); |
| data_needed += META_OVERHEAD(fs) * extra_groups; |
| extra_groups = groups % flexbg_size; |
| } |
| } |
| |
| /* now for the fun voodoo */ |
| overhead = META_OVERHEAD(fs); |
| |
| /* |
| * if this is the case then the last group is going to have data in it |
| * so we need to adjust the size of the last group accordingly |
| */ |
| if (last_start < data_needed) { |
| blk_t remainder = data_needed - last_start; |
| |
| /* |
| * 50 is a magic number that mkfs/resize uses to see if its |
| * even worth making/resizing the fs. basically you need to |
| * have at least 50 blocks in addition to the blocks needed |
| * for the metadata in the last group |
| */ |
| if (remainder > 50) |
| overhead += remainder; |
| else |
| overhead += 50; |
| } else |
| overhead += 50; |
| |
| if (ext2fs_bg_has_super(fs, groups-1)) |
| overhead += SUPER_OVERHEAD(fs); |
| |
| /* |
| * since our last group doesn't have to be BLOCKS_PER_GROUP large, we |
| * only do groups-1, and then add the number of blocks needed to |
| * handle the group descriptor metadata+data that we need |
| */ |
| blks_needed = (groups-1) * EXT2_BLOCKS_PER_GROUP(fs->super); |
| blks_needed += overhead; |
| |
| /* |
| * If at this point we've already added up more "needed" than |
| * the current size, just return current size as minimum. |
| */ |
| if (blks_needed >= fs->super->s_blocks_count) |
| return fs->super->s_blocks_count; |
| /* |
| * We need to reserve a few extra blocks if extents are |
| * enabled, in case we need to grow the extent tree. The more |
| * we shrink the file system, the more space we need. |
| */ |
| if (fs->super->s_feature_incompat & EXT3_FEATURE_INCOMPAT_EXTENTS) |
| blks_needed += (fs->super->s_blocks_count - blks_needed)/500; |
| |
| return blks_needed; |
| } |