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 "reiserfs.h" 17 #include <linux/buffer_head.h> 18 19 int reiserfs_resize(struct super_block *s, unsigned long block_count_new) 20 { 21 int err = 0; 22 struct reiserfs_super_block *sb; 23 struct reiserfs_bitmap_info *bitmap; 24 struct reiserfs_bitmap_info *info; 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 58 ("reiserfs_resize: unable to resize a reiserfs without distributed bitmap (fs version < 3.5.12)\n"); 59 return -ENOTSUPP; 60 } 61 62 /* count used bits in last bitmap block */ 63 block_r = SB_BLOCK_COUNT(s) - 64 (reiserfs_bmap_count(s) - 1) * s->s_blocksize * 8; 65 66 /* count bitmap blocks in new fs */ 67 bmap_nr_new = block_count_new / (s->s_blocksize * 8); 68 block_r_new = block_count_new - bmap_nr_new * s->s_blocksize * 8; 69 if (block_r_new) 70 bmap_nr_new++; 71 else 72 block_r_new = s->s_blocksize * 8; 73 74 /* save old values */ 75 block_count = SB_BLOCK_COUNT(s); 76 bmap_nr = reiserfs_bmap_count(s); 77 78 /* resizing of reiserfs bitmaps (journal and real), if needed */ 79 if (bmap_nr_new > bmap_nr) { 80 /* reallocate journal bitmaps */ 81 if (reiserfs_allocate_list_bitmaps(s, jbitmap, bmap_nr_new) < 0) { 82 printk 83 ("reiserfs_resize: unable to allocate memory for journal bitmaps\n"); 84 return -ENOMEM; 85 } 86 /* the new journal bitmaps are zero filled, now we copy in the bitmap 87 ** node pointers from the old journal bitmap structs, and then 88 ** transfer the new data structures into the journal struct. 89 ** 90 ** using the copy_size var below allows this code to work for 91 ** both shrinking and expanding the FS. 92 */ 93 copy_size = bmap_nr_new < bmap_nr ? bmap_nr_new : bmap_nr; 94 copy_size = 95 copy_size * sizeof(struct reiserfs_list_bitmap_node *); 96 for (i = 0; i < JOURNAL_NUM_BITMAPS; i++) { 97 struct reiserfs_bitmap_node **node_tmp; 98 jb = SB_JOURNAL(s)->j_list_bitmap + i; 99 memcpy(jbitmap[i].bitmaps, jb->bitmaps, copy_size); 100 101 /* just in case vfree schedules on us, copy the new 102 ** pointer into the journal struct before freeing the 103 ** old one 104 */ 105 node_tmp = jb->bitmaps; 106 jb->bitmaps = jbitmap[i].bitmaps; 107 vfree(node_tmp); 108 } 109 110 /* allocate additional bitmap blocks, reallocate array of bitmap 111 * block pointers */ 112 bitmap = 113 vzalloc(sizeof(struct reiserfs_bitmap_info) * bmap_nr_new); 114 if (!bitmap) { 115 /* Journal bitmaps are still supersized, but the memory isn't 116 * leaked, so I guess it's ok */ 117 printk("reiserfs_resize: unable to allocate memory.\n"); 118 return -ENOMEM; 119 } 120 for (i = 0; i < bmap_nr; i++) 121 bitmap[i] = old_bitmap[i]; 122 123 /* This doesn't go through the journal, but it doesn't have to. 124 * The changes are still atomic: We're synced up when the journal 125 * transaction begins, and the new bitmaps don't matter if the 126 * transaction fails. */ 127 for (i = bmap_nr; i < bmap_nr_new; i++) { 128 /* don't use read_bitmap_block since it will cache 129 * the uninitialized bitmap */ 130 bh = sb_bread(s, i * s->s_blocksize * 8); 131 if (!bh) { 132 vfree(bitmap); 133 return -EIO; 134 } 135 memset(bh->b_data, 0, sb_blocksize(sb)); 136 reiserfs_set_le_bit(0, bh->b_data); 137 reiserfs_cache_bitmap_metadata(s, bh, bitmap + i); 138 139 set_buffer_uptodate(bh); 140 mark_buffer_dirty(bh); 141 reiserfs_write_unlock(s); 142 sync_dirty_buffer(bh); 143 reiserfs_write_lock(s); 144 // update bitmap_info stuff 145 bitmap[i].free_count = sb_blocksize(sb) * 8 - 1; 146 brelse(bh); 147 } 148 /* free old bitmap blocks array */ 149 SB_AP_BITMAP(s) = bitmap; 150 vfree(old_bitmap); 151 } 152 153 /* begin transaction, if there was an error, it's fine. Yes, we have 154 * incorrect bitmaps now, but none of it is ever going to touch the 155 * disk anyway. */ 156 err = journal_begin(&th, s, 10); 157 if (err) 158 return err; 159 160 /* Extend old last bitmap block - new blocks have been made available */ 161 info = SB_AP_BITMAP(s) + bmap_nr - 1; 162 bh = reiserfs_read_bitmap_block(s, bmap_nr - 1); 163 if (!bh) { 164 int jerr = journal_end(&th, s, 10); 165 if (jerr) 166 return jerr; 167 return -EIO; 168 } 169 170 reiserfs_prepare_for_journal(s, bh, 1); 171 for (i = block_r; i < s->s_blocksize * 8; i++) 172 reiserfs_clear_le_bit(i, bh->b_data); 173 info->free_count += s->s_blocksize * 8 - block_r; 174 175 journal_mark_dirty(&th, s, bh); 176 brelse(bh); 177 178 /* Correct new last bitmap block - It may not be full */ 179 info = SB_AP_BITMAP(s) + bmap_nr_new - 1; 180 bh = reiserfs_read_bitmap_block(s, bmap_nr_new - 1); 181 if (!bh) { 182 int jerr = journal_end(&th, s, 10); 183 if (jerr) 184 return jerr; 185 return -EIO; 186 } 187 188 reiserfs_prepare_for_journal(s, bh, 1); 189 for (i = block_r_new; i < s->s_blocksize * 8; i++) 190 reiserfs_set_le_bit(i, bh->b_data); 191 journal_mark_dirty(&th, s, bh); 192 brelse(bh); 193 194 info->free_count -= s->s_blocksize * 8 - block_r_new; 195 /* update super */ 196 reiserfs_prepare_for_journal(s, SB_BUFFER_WITH_SB(s), 1); 197 free_blocks = SB_FREE_BLOCKS(s); 198 PUT_SB_FREE_BLOCKS(s, 199 free_blocks + (block_count_new - block_count - 200 (bmap_nr_new - bmap_nr))); 201 PUT_SB_BLOCK_COUNT(s, block_count_new); 202 PUT_SB_BMAP_NR(s, bmap_would_wrap(bmap_nr_new) ? : bmap_nr_new); 203 204 journal_mark_dirty(&th, s, SB_BUFFER_WITH_SB(s)); 205 206 SB_JOURNAL(s)->j_must_wait = 1; 207 return journal_end(&th, s, 10); 208 } 209