/* * Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README */ /* * Written by Alexander Zarochentcev. * * The kernel part of the (on-line) reiserfs resizer. */ #include #include #include #include #include #include #include int reiserfs_resize(struct super_block *s, unsigned long block_count_new) { int err = 0; struct reiserfs_super_block *sb; struct reiserfs_bitmap_info *bitmap; struct reiserfs_bitmap_info *info; struct reiserfs_bitmap_info *old_bitmap = SB_AP_BITMAP(s); struct buffer_head *bh; struct reiserfs_transaction_handle th; unsigned int bmap_nr_new, bmap_nr; unsigned int block_r_new, block_r; struct reiserfs_list_bitmap *jb; struct reiserfs_list_bitmap jbitmap[JOURNAL_NUM_BITMAPS]; unsigned long int block_count, free_blocks; int i; int copy_size; sb = SB_DISK_SUPER_BLOCK(s); if (SB_BLOCK_COUNT(s) >= block_count_new) { printk("can\'t shrink filesystem on-line\n"); return -EINVAL; } /* check the device size */ bh = sb_bread(s, block_count_new - 1); if (!bh) { printk("reiserfs_resize: can\'t read last block\n"); return -EINVAL; } bforget(bh); /* old disk layout detection; those partitions can be mounted, but * cannot be resized */ if (SB_BUFFER_WITH_SB(s)->b_blocknr * SB_BUFFER_WITH_SB(s)->b_size != REISERFS_DISK_OFFSET_IN_BYTES) { printk ("reiserfs_resize: unable to resize a reiserfs without distributed bitmap (fs version < 3.5.12)\n"); return -ENOTSUPP; } /* count used bits in last bitmap block */ block_r = SB_BLOCK_COUNT(s) - (reiserfs_bmap_count(s) - 1) * s->s_blocksize * 8; /* count bitmap blocks in new fs */ bmap_nr_new = block_count_new / (s->s_blocksize * 8); block_r_new = block_count_new - bmap_nr_new * s->s_blocksize * 8; if (block_r_new) bmap_nr_new++; else block_r_new = s->s_blocksize * 8; /* save old values */ block_count = SB_BLOCK_COUNT(s); bmap_nr = reiserfs_bmap_count(s); /* resizing of reiserfs bitmaps (journal and real), if needed */ if (bmap_nr_new > bmap_nr) { /* reallocate journal bitmaps */ if (reiserfs_allocate_list_bitmaps(s, jbitmap, bmap_nr_new) < 0) { printk ("reiserfs_resize: unable to allocate memory for journal bitmaps\n"); return -ENOMEM; } /* the new journal bitmaps are zero filled, now we copy in the bitmap ** node pointers from the old journal bitmap structs, and then ** transfer the new data structures into the journal struct. ** ** using the copy_size var below allows this code to work for ** both shrinking and expanding the FS. */ copy_size = bmap_nr_new < bmap_nr ? bmap_nr_new : bmap_nr; copy_size = copy_size * sizeof(struct reiserfs_list_bitmap_node *); for (i = 0; i < JOURNAL_NUM_BITMAPS; i++) { struct reiserfs_bitmap_node **node_tmp; jb = SB_JOURNAL(s)->j_list_bitmap + i; memcpy(jbitmap[i].bitmaps, jb->bitmaps, copy_size); /* just in case vfree schedules on us, copy the new ** pointer into the journal struct before freeing the ** old one */ node_tmp = jb->bitmaps; jb->bitmaps = jbitmap[i].bitmaps; vfree(node_tmp); } /* allocate additional bitmap blocks, reallocate array of bitmap * block pointers */ bitmap = vzalloc(sizeof(struct reiserfs_bitmap_info) * bmap_nr_new); if (!bitmap) { /* Journal bitmaps are still supersized, but the memory isn't * leaked, so I guess it's ok */ printk("reiserfs_resize: unable to allocate memory.\n"); return -ENOMEM; } for (i = 0; i < bmap_nr; i++) bitmap[i] = old_bitmap[i]; /* This doesn't go through the journal, but it doesn't have to. * The changes are still atomic: We're synced up when the journal * transaction begins, and the new bitmaps don't matter if the * transaction fails. */ for (i = bmap_nr; i < bmap_nr_new; i++) { /* don't use read_bitmap_block since it will cache * the uninitialized bitmap */ bh = sb_bread(s, i * s->s_blocksize * 8); if (!bh) { vfree(bitmap); return -EIO; } memset(bh->b_data, 0, sb_blocksize(sb)); reiserfs_set_le_bit(0, bh->b_data); reiserfs_cache_bitmap_metadata(s, bh, bitmap + i); set_buffer_uptodate(bh); mark_buffer_dirty(bh); reiserfs_write_unlock(s); sync_dirty_buffer(bh); reiserfs_write_lock(s); // update bitmap_info stuff bitmap[i].free_count = sb_blocksize(sb) * 8 - 1; brelse(bh); } /* free old bitmap blocks array */ SB_AP_BITMAP(s) = bitmap; vfree(old_bitmap); } /* begin transaction, if there was an error, it's fine. Yes, we have * incorrect bitmaps now, but none of it is ever going to touch the * disk anyway. */ err = journal_begin(&th, s, 10); if (err) return err; /* Extend old last bitmap block - new blocks have been made available */ info = SB_AP_BITMAP(s) + bmap_nr - 1; bh = reiserfs_read_bitmap_block(s, bmap_nr - 1); if (!bh) { int jerr = journal_end(&th, s, 10); if (jerr) return jerr; return -EIO; } reiserfs_prepare_for_journal(s, bh, 1); for (i = block_r; i < s->s_blocksize * 8; i++) reiserfs_clear_le_bit(i, bh->b_data); info->free_count += s->s_blocksize * 8 - block_r; journal_mark_dirty(&th, s, bh); brelse(bh); /* Correct new last bitmap block - It may not be full */ info = SB_AP_BITMAP(s) + bmap_nr_new - 1; bh = reiserfs_read_bitmap_block(s, bmap_nr_new - 1); if (!bh) { int jerr = journal_end(&th, s, 10); if (jerr) return jerr; return -EIO; } reiserfs_prepare_for_journal(s, bh, 1); for (i = block_r_new; i < s->s_blocksize * 8; i++) reiserfs_set_le_bit(i, bh->b_data); journal_mark_dirty(&th, s, bh); brelse(bh); info->free_count -= s->s_blocksize * 8 - block_r_new; /* update super */ reiserfs_prepare_for_journal(s, SB_BUFFER_WITH_SB(s), 1); free_blocks = SB_FREE_BLOCKS(s); PUT_SB_FREE_BLOCKS(s, free_blocks + (block_count_new - block_count - (bmap_nr_new - bmap_nr))); PUT_SB_BLOCK_COUNT(s, block_count_new); PUT_SB_BMAP_NR(s, bmap_would_wrap(bmap_nr_new) ? : bmap_nr_new); s->s_dirt = 1; journal_mark_dirty(&th, s, SB_BUFFER_WITH_SB(s)); SB_JOURNAL(s)->j_must_wait = 1; return journal_end(&th, s, 10); }