diff options
Diffstat (limited to 'fs/reiserfs/resize.c')
| -rw-r--r-- | fs/reiserfs/resize.c | 182 |
1 files changed, 182 insertions, 0 deletions
diff --git a/fs/reiserfs/resize.c b/fs/reiserfs/resize.c new file mode 100644 index 00000000000..170012078b7 --- /dev/null +++ b/fs/reiserfs/resize.c @@ -0,0 +1,182 @@ +/* + * 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 <linux/reiserfs_fs.h> +#include <linux/reiserfs_fs_sb.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 *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) - + (SB_BMAP_NR(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 = SB_BMAP_NR(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"); + unlock_super(s) ; + 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 = vmalloc(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; + } + memset (bitmap, 0, sizeof (struct reiserfs_bitmap_info) * SB_BMAP_NR(s)); + 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++) { + bitmap[i].bh = sb_getblk(s, i * s->s_blocksize * 8); + memset(bitmap[i].bh->b_data, 0, sb_blocksize(sb)); + reiserfs_test_and_set_le_bit(0, bitmap[i].bh->b_data); + + set_buffer_uptodate(bitmap[i].bh); + mark_buffer_dirty(bitmap[i].bh) ; + sync_dirty_buffer(bitmap[i].bh); + // update bitmap_info stuff + bitmap[i].first_zero_hint=1; + bitmap[i].free_count = sb_blocksize(sb) * 8 - 1; + } + /* 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; + + /* correct last bitmap blocks in old and new disk layout */ + reiserfs_prepare_for_journal(s, SB_AP_BITMAP(s)[bmap_nr - 1].bh, 1); + for (i = block_r; i < s->s_blocksize * 8; i++) + reiserfs_test_and_clear_le_bit(i, + SB_AP_BITMAP(s)[bmap_nr - 1].bh->b_data); + SB_AP_BITMAP(s)[bmap_nr - 1].free_count += s->s_blocksize * 8 - block_r; + if ( !SB_AP_BITMAP(s)[bmap_nr - 1].first_zero_hint) + SB_AP_BITMAP(s)[bmap_nr - 1].first_zero_hint = block_r; + + journal_mark_dirty(&th, s, SB_AP_BITMAP(s)[bmap_nr - 1].bh); + + reiserfs_prepare_for_journal(s, SB_AP_BITMAP(s)[bmap_nr_new - 1].bh, 1); + for (i = block_r_new; i < s->s_blocksize * 8; i++) + reiserfs_test_and_set_le_bit(i, + SB_AP_BITMAP(s)[bmap_nr_new - 1].bh->b_data); + journal_mark_dirty(&th, s, SB_AP_BITMAP(s)[bmap_nr_new - 1].bh); + + SB_AP_BITMAP(s)[bmap_nr_new - 1].free_count -= s->s_blocksize * 8 - block_r_new; + /* Extreme case where last bitmap is the only valid block in itself. */ + if ( !SB_AP_BITMAP(s)[bmap_nr_new - 1].free_count ) + SB_AP_BITMAP(s)[bmap_nr_new - 1].first_zero_hint = 0; + /* 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_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); +} |