diff options
Diffstat (limited to 'fs/reiserfs/resize.c')
| -rw-r--r-- | fs/reiserfs/resize.c | 230 |
1 files changed, 230 insertions, 0 deletions
diff --git a/fs/reiserfs/resize.c b/fs/reiserfs/resize.c new file mode 100644 index 000000000..8096c74c3 --- /dev/null +++ b/fs/reiserfs/resize.c @@ -0,0 +1,230 @@ +/* + * Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README + */ + +/* + * Written by Alexander Zarochentcev. + * + * The kernel part of the (on-line) reiserfs resizer. + */ + +#include <linux/kernel.h> +#include <linux/mm.h> +#include <linux/vmalloc.h> +#include <linux/string.h> +#include <linux/errno.h> +#include "reiserfs.h" +#include <linux/buffer_head.h> + +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; + int depth; + + 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 */ + depth = reiserfs_write_unlock_nested(s); + bh = sb_bread(s, block_count_new - 1); + reiserfs_write_lock_nested(s, depth); + 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 i + * 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(array_size(bmap_nr_new, + sizeof(struct reiserfs_bitmap_info))); + 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++) { + int depth; + /* + * don't use read_bitmap_block since it will cache + * the uninitialized bitmap + */ + depth = reiserfs_write_unlock_nested(s); + bh = sb_bread(s, i * s->s_blocksize * 8); + reiserfs_write_lock_nested(s, depth); + 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); + depth = reiserfs_write_unlock_nested(s); + sync_dirty_buffer(bh); + reiserfs_write_lock_nested(s, depth); + /* 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); + 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, 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); + 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, 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); + + journal_mark_dirty(&th, SB_BUFFER_WITH_SB(s)); + + SB_JOURNAL(s)->j_must_wait = 1; + return journal_end(&th); +} |