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 *info; 26 struct reiserfs_bitmap_info *old_bitmap = SB_AP_BITMAP(s); 27 struct buffer_head *bh; 28 struct reiserfs_transaction_handle th; 29 unsigned int bmap_nr_new, bmap_nr; 30 unsigned int block_r_new, block_r; 31 32 struct reiserfs_list_bitmap *jb; 33 struct reiserfs_list_bitmap jbitmap[JOURNAL_NUM_BITMAPS]; 34 35 unsigned long int block_count, free_blocks; 36 int i; 37 int copy_size; 38 39 sb = SB_DISK_SUPER_BLOCK(s); 40 41 if (SB_BLOCK_COUNT(s) >= block_count_new) { 42 printk("can\'t shrink filesystem on-line\n"); 43 return -EINVAL; 44 } 45 46 /* check the device size */ 47 bh = sb_bread(s, block_count_new - 1); 48 if (!bh) { 49 printk("reiserfs_resize: can\'t read last block\n"); 50 return -EINVAL; 51 } 52 bforget(bh); 53 54 /* old disk layout detection; those partitions can be mounted, but 55 * cannot be resized */ 56 if (SB_BUFFER_WITH_SB(s)->b_blocknr * SB_BUFFER_WITH_SB(s)->b_size 57 != REISERFS_DISK_OFFSET_IN_BYTES) { 58 printk 59 ("reiserfs_resize: unable to resize a reiserfs without distributed bitmap (fs version < 3.5.12)\n"); 60 return -ENOTSUPP; 61 } 62 63 /* count used bits in last bitmap block */ 64 block_r = SB_BLOCK_COUNT(s) - 65 (reiserfs_bmap_count(s) - 1) * s->s_blocksize * 8; 66 67 /* count bitmap blocks in new fs */ 68 bmap_nr_new = block_count_new / (s->s_blocksize * 8); 69 block_r_new = block_count_new - bmap_nr_new * s->s_blocksize * 8; 70 if (block_r_new) 71 bmap_nr_new++; 72 else 73 block_r_new = s->s_blocksize * 8; 74 75 /* save old values */ 76 block_count = SB_BLOCK_COUNT(s); 77 bmap_nr = reiserfs_bmap_count(s); 78 79 /* resizing of reiserfs bitmaps (journal and real), if needed */ 80 if (bmap_nr_new > bmap_nr) { 81 /* reallocate journal bitmaps */ 82 if (reiserfs_allocate_list_bitmaps(s, jbitmap, bmap_nr_new) < 0) { 83 printk 84 ("reiserfs_resize: unable to allocate memory for journal bitmaps\n"); 85 return -ENOMEM; 86 } 87 /* the new journal bitmaps are zero filled, now we copy in the bitmap 88 ** node pointers from the old journal bitmap structs, and then 89 ** transfer the new data structures into the journal struct. 90 ** 91 ** using the copy_size var below allows this code to work for 92 ** both shrinking and expanding the FS. 93 */ 94 copy_size = bmap_nr_new < bmap_nr ? bmap_nr_new : bmap_nr; 95 copy_size = 96 copy_size * sizeof(struct reiserfs_list_bitmap_node *); 97 for (i = 0; i < JOURNAL_NUM_BITMAPS; i++) { 98 struct reiserfs_bitmap_node **node_tmp; 99 jb = SB_JOURNAL(s)->j_list_bitmap + i; 100 memcpy(jbitmap[i].bitmaps, jb->bitmaps, copy_size); 101 102 /* just in case vfree schedules on us, copy the new 103 ** pointer into the journal struct before freeing the 104 ** old one 105 */ 106 node_tmp = jb->bitmaps; 107 jb->bitmaps = jbitmap[i].bitmaps; 108 vfree(node_tmp); 109 } 110 111 /* allocate additional bitmap blocks, reallocate array of bitmap 112 * block pointers */ 113 bitmap = 114 vmalloc(sizeof(struct reiserfs_bitmap_info) * bmap_nr_new); 115 if (!bitmap) { 116 /* Journal bitmaps are still supersized, but the memory isn't 117 * leaked, so I guess it's ok */ 118 printk("reiserfs_resize: unable to allocate memory.\n"); 119 return -ENOMEM; 120 } 121 memset(bitmap, 0, 122 sizeof(struct reiserfs_bitmap_info) * bmap_nr_new); 123 for (i = 0; i < bmap_nr; i++) 124 bitmap[i] = old_bitmap[i]; 125 126 /* This doesn't go through the journal, but it doesn't have to. 127 * The changes are still atomic: We're synced up when the journal 128 * transaction begins, and the new bitmaps don't matter if the 129 * transaction fails. */ 130 for (i = bmap_nr; i < bmap_nr_new; i++) { 131 /* don't use read_bitmap_block since it will cache 132 * the uninitialized bitmap */ 133 bh = sb_bread(s, i * s->s_blocksize * 8); 134 if (!bh) { 135 vfree(bitmap); 136 return -EIO; 137 } 138 memset(bh->b_data, 0, sb_blocksize(sb)); 139 reiserfs_test_and_set_le_bit(0, bh->b_data); 140 reiserfs_cache_bitmap_metadata(s, bh, bitmap + i); 141 142 set_buffer_uptodate(bh); 143 mark_buffer_dirty(bh); 144 sync_dirty_buffer(bh); 145 // update bitmap_info stuff 146 bitmap[i].free_count = sb_blocksize(sb) * 8 - 1; 147 brelse(bh); 148 } 149 /* free old bitmap blocks array */ 150 SB_AP_BITMAP(s) = bitmap; 151 vfree(old_bitmap); 152 } 153 154 /* begin transaction, if there was an error, it's fine. Yes, we have 155 * incorrect bitmaps now, but none of it is ever going to touch the 156 * disk anyway. */ 157 err = journal_begin(&th, s, 10); 158 if (err) 159 return err; 160 161 /* Extend old last bitmap block - new blocks have been made available */ 162 info = SB_AP_BITMAP(s) + bmap_nr - 1; 163 bh = reiserfs_read_bitmap_block(s, bmap_nr - 1); 164 if (!bh) { 165 int jerr = journal_end(&th, s, 10); 166 if (jerr) 167 return jerr; 168 return -EIO; 169 } 170 171 reiserfs_prepare_for_journal(s, bh, 1); 172 for (i = block_r; i < s->s_blocksize * 8; i++) 173 reiserfs_test_and_clear_le_bit(i, bh->b_data); 174 info->free_count += s->s_blocksize * 8 - block_r; 175 176 journal_mark_dirty(&th, s, bh); 177 brelse(bh); 178 179 /* Correct new last bitmap block - It may not be full */ 180 info = SB_AP_BITMAP(s) + bmap_nr_new - 1; 181 bh = reiserfs_read_bitmap_block(s, bmap_nr_new - 1); 182 if (!bh) { 183 int jerr = journal_end(&th, s, 10); 184 if (jerr) 185 return jerr; 186 return -EIO; 187 } 188 189 reiserfs_prepare_for_journal(s, bh, 1); 190 for (i = block_r_new; i < s->s_blocksize * 8; i++) 191 reiserfs_test_and_set_le_bit(i, bh->b_data); 192 journal_mark_dirty(&th, s, bh); 193 brelse(bh); 194 195 info->free_count -= s->s_blocksize * 8 - block_r_new; 196 /* update super */ 197 reiserfs_prepare_for_journal(s, SB_BUFFER_WITH_SB(s), 1); 198 free_blocks = SB_FREE_BLOCKS(s); 199 PUT_SB_FREE_BLOCKS(s, 200 free_blocks + (block_count_new - block_count - 201 (bmap_nr_new - bmap_nr))); 202 PUT_SB_BLOCK_COUNT(s, block_count_new); 203 PUT_SB_BMAP_NR(s, bmap_would_wrap(bmap_nr_new) ? : bmap_nr_new); 204 s->s_dirt = 1; 205 206 journal_mark_dirty(&th, s, SB_BUFFER_WITH_SB(s)); 207 208 SB_JOURNAL(s)->j_must_wait = 1; 209 return journal_end(&th, s, 10); 210 } 211