Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README |
| 3 | */ |
| 4 | |
| 5 | /* |
| 6 | * Written by Alexander Zarochentcev. |
| 7 | * |
| 8 | * The kernel part of the (on-line) reiserfs resizer. |
| 9 | */ |
| 10 | |
| 11 | #include <linux/kernel.h> |
| 12 | #include <linux/mm.h> |
| 13 | #include <linux/vmalloc.h> |
| 14 | #include <linux/string.h> |
| 15 | #include <linux/errno.h> |
| 16 | #include <linux/reiserfs_fs.h> |
| 17 | #include <linux/reiserfs_fs_sb.h> |
| 18 | #include <linux/buffer_head.h> |
| 19 | |
| 20 | int reiserfs_resize (struct super_block * s, unsigned long block_count_new) |
| 21 | { |
| 22 | int err = 0; |
| 23 | struct reiserfs_super_block * sb; |
| 24 | struct reiserfs_bitmap_info *bitmap; |
| 25 | struct reiserfs_bitmap_info *old_bitmap = SB_AP_BITMAP(s); |
| 26 | struct buffer_head * bh; |
| 27 | struct reiserfs_transaction_handle th; |
| 28 | unsigned int bmap_nr_new, bmap_nr; |
| 29 | unsigned int block_r_new, block_r; |
| 30 | |
| 31 | struct reiserfs_list_bitmap * jb; |
| 32 | struct reiserfs_list_bitmap jbitmap[JOURNAL_NUM_BITMAPS]; |
| 33 | |
| 34 | unsigned long int block_count, free_blocks; |
| 35 | int i; |
| 36 | int copy_size ; |
| 37 | |
| 38 | sb = SB_DISK_SUPER_BLOCK(s); |
| 39 | |
| 40 | if (SB_BLOCK_COUNT(s) >= block_count_new) { |
| 41 | printk("can\'t shrink filesystem on-line\n"); |
| 42 | return -EINVAL; |
| 43 | } |
| 44 | |
| 45 | /* check the device size */ |
| 46 | bh = sb_bread(s, block_count_new - 1); |
| 47 | if (!bh) { |
| 48 | printk("reiserfs_resize: can\'t read last block\n"); |
| 49 | return -EINVAL; |
| 50 | } |
| 51 | bforget(bh); |
| 52 | |
| 53 | /* old disk layout detection; those partitions can be mounted, but |
| 54 | * cannot be resized */ |
| 55 | if (SB_BUFFER_WITH_SB(s)->b_blocknr * SB_BUFFER_WITH_SB(s)->b_size |
| 56 | != REISERFS_DISK_OFFSET_IN_BYTES ) { |
| 57 | printk("reiserfs_resize: unable to resize a reiserfs without distributed bitmap (fs version < 3.5.12)\n"); |
| 58 | return -ENOTSUPP; |
| 59 | } |
| 60 | |
| 61 | /* count used bits in last bitmap block */ |
| 62 | block_r = SB_BLOCK_COUNT(s) - |
| 63 | (SB_BMAP_NR(s) - 1) * s->s_blocksize * 8; |
| 64 | |
| 65 | /* count bitmap blocks in new fs */ |
| 66 | bmap_nr_new = block_count_new / ( s->s_blocksize * 8 ); |
| 67 | block_r_new = block_count_new - bmap_nr_new * s->s_blocksize * 8; |
| 68 | if (block_r_new) |
| 69 | bmap_nr_new++; |
| 70 | else |
| 71 | block_r_new = s->s_blocksize * 8; |
| 72 | |
| 73 | /* save old values */ |
| 74 | block_count = SB_BLOCK_COUNT(s); |
| 75 | bmap_nr = SB_BMAP_NR(s); |
| 76 | |
| 77 | /* resizing of reiserfs bitmaps (journal and real), if needed */ |
| 78 | if (bmap_nr_new > bmap_nr) { |
| 79 | /* reallocate journal bitmaps */ |
| 80 | if (reiserfs_allocate_list_bitmaps(s, jbitmap, bmap_nr_new) < 0) { |
| 81 | printk("reiserfs_resize: unable to allocate memory for journal bitmaps\n"); |
| 82 | unlock_super(s) ; |
| 83 | return -ENOMEM ; |
| 84 | } |
| 85 | /* the new journal bitmaps are zero filled, now we copy in the bitmap |
| 86 | ** node pointers from the old journal bitmap structs, and then |
| 87 | ** transfer the new data structures into the journal struct. |
| 88 | ** |
| 89 | ** using the copy_size var below allows this code to work for |
| 90 | ** both shrinking and expanding the FS. |
| 91 | */ |
| 92 | copy_size = bmap_nr_new < bmap_nr ? bmap_nr_new : bmap_nr ; |
| 93 | copy_size = copy_size * sizeof(struct reiserfs_list_bitmap_node *) ; |
| 94 | for (i = 0 ; i < JOURNAL_NUM_BITMAPS ; i++) { |
| 95 | struct reiserfs_bitmap_node **node_tmp ; |
| 96 | jb = SB_JOURNAL(s)->j_list_bitmap + i ; |
| 97 | memcpy(jbitmap[i].bitmaps, jb->bitmaps, copy_size) ; |
| 98 | |
| 99 | /* just in case vfree schedules on us, copy the new |
| 100 | ** pointer into the journal struct before freeing the |
| 101 | ** old one |
| 102 | */ |
| 103 | node_tmp = jb->bitmaps ; |
| 104 | jb->bitmaps = jbitmap[i].bitmaps ; |
| 105 | vfree(node_tmp) ; |
| 106 | } |
| 107 | |
| 108 | /* allocate additional bitmap blocks, reallocate array of bitmap |
| 109 | * block pointers */ |
| 110 | bitmap = vmalloc(sizeof(struct reiserfs_bitmap_info) * bmap_nr_new); |
| 111 | if (!bitmap) { |
| 112 | /* Journal bitmaps are still supersized, but the memory isn't |
| 113 | * leaked, so I guess it's ok */ |
| 114 | printk("reiserfs_resize: unable to allocate memory.\n"); |
| 115 | return -ENOMEM; |
| 116 | } |
| 117 | memset (bitmap, 0, sizeof (struct reiserfs_bitmap_info) * SB_BMAP_NR(s)); |
| 118 | for (i = 0; i < bmap_nr; i++) |
| 119 | bitmap[i] = old_bitmap[i]; |
| 120 | |
| 121 | /* This doesn't go through the journal, but it doesn't have to. |
| 122 | * The changes are still atomic: We're synced up when the journal |
| 123 | * transaction begins, and the new bitmaps don't matter if the |
| 124 | * transaction fails. */ |
| 125 | for (i = bmap_nr; i < bmap_nr_new; i++) { |
| 126 | bitmap[i].bh = sb_getblk(s, i * s->s_blocksize * 8); |
| 127 | memset(bitmap[i].bh->b_data, 0, sb_blocksize(sb)); |
| 128 | reiserfs_test_and_set_le_bit(0, bitmap[i].bh->b_data); |
| 129 | |
| 130 | set_buffer_uptodate(bitmap[i].bh); |
| 131 | mark_buffer_dirty(bitmap[i].bh) ; |
| 132 | sync_dirty_buffer(bitmap[i].bh); |
| 133 | // update bitmap_info stuff |
| 134 | bitmap[i].first_zero_hint=1; |
| 135 | bitmap[i].free_count = sb_blocksize(sb) * 8 - 1; |
| 136 | } |
| 137 | /* free old bitmap blocks array */ |
| 138 | SB_AP_BITMAP(s) = bitmap; |
| 139 | vfree (old_bitmap); |
| 140 | } |
| 141 | |
| 142 | /* begin transaction, if there was an error, it's fine. Yes, we have |
| 143 | * incorrect bitmaps now, but none of it is ever going to touch the |
| 144 | * disk anyway. */ |
| 145 | err = journal_begin(&th, s, 10); |
| 146 | if (err) |
| 147 | return err; |
| 148 | |
| 149 | /* correct last bitmap blocks in old and new disk layout */ |
| 150 | reiserfs_prepare_for_journal(s, SB_AP_BITMAP(s)[bmap_nr - 1].bh, 1); |
| 151 | for (i = block_r; i < s->s_blocksize * 8; i++) |
| 152 | reiserfs_test_and_clear_le_bit(i, |
| 153 | SB_AP_BITMAP(s)[bmap_nr - 1].bh->b_data); |
| 154 | SB_AP_BITMAP(s)[bmap_nr - 1].free_count += s->s_blocksize * 8 - block_r; |
| 155 | if ( !SB_AP_BITMAP(s)[bmap_nr - 1].first_zero_hint) |
| 156 | SB_AP_BITMAP(s)[bmap_nr - 1].first_zero_hint = block_r; |
| 157 | |
| 158 | journal_mark_dirty(&th, s, SB_AP_BITMAP(s)[bmap_nr - 1].bh); |
| 159 | |
| 160 | reiserfs_prepare_for_journal(s, SB_AP_BITMAP(s)[bmap_nr_new - 1].bh, 1); |
| 161 | for (i = block_r_new; i < s->s_blocksize * 8; i++) |
| 162 | reiserfs_test_and_set_le_bit(i, |
| 163 | SB_AP_BITMAP(s)[bmap_nr_new - 1].bh->b_data); |
| 164 | journal_mark_dirty(&th, s, SB_AP_BITMAP(s)[bmap_nr_new - 1].bh); |
| 165 | |
| 166 | SB_AP_BITMAP(s)[bmap_nr_new - 1].free_count -= s->s_blocksize * 8 - block_r_new; |
| 167 | /* Extreme case where last bitmap is the only valid block in itself. */ |
| 168 | if ( !SB_AP_BITMAP(s)[bmap_nr_new - 1].free_count ) |
| 169 | SB_AP_BITMAP(s)[bmap_nr_new - 1].first_zero_hint = 0; |
| 170 | /* update super */ |
| 171 | reiserfs_prepare_for_journal(s, SB_BUFFER_WITH_SB(s), 1) ; |
| 172 | free_blocks = SB_FREE_BLOCKS(s); |
| 173 | PUT_SB_FREE_BLOCKS(s, free_blocks + (block_count_new - block_count - (bmap_nr_new - bmap_nr))); |
| 174 | PUT_SB_BLOCK_COUNT(s, block_count_new); |
| 175 | PUT_SB_BMAP_NR(s, bmap_nr_new); |
| 176 | s->s_dirt = 1; |
| 177 | |
| 178 | journal_mark_dirty(&th, s, SB_BUFFER_WITH_SB(s)); |
| 179 | |
| 180 | SB_JOURNAL(s)->j_must_wait = 1; |
| 181 | return journal_end(&th, s, 10); |
| 182 | } |