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 int depth; 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 depth = reiserfs_write_unlock_nested(s); 48 bh = sb_bread(s, block_count_new - 1); 49 reiserfs_write_lock_nested(s, depth); 50 if (!bh) { 51 printk("reiserfs_resize: can\'t read last block\n"); 52 return -EINVAL; 53 } 54 bforget(bh); 55 56 /* old disk layout detection; those partitions can be mounted, but 57 * cannot be resized */ 58 if (SB_BUFFER_WITH_SB(s)->b_blocknr * SB_BUFFER_WITH_SB(s)->b_size 59 != REISERFS_DISK_OFFSET_IN_BYTES) { 60 printk 61 ("reiserfs_resize: unable to resize a reiserfs without distributed bitmap (fs version < 3.5.12)\n"); 62 return -ENOTSUPP; 63 } 64 65 /* count used bits in last bitmap block */ 66 block_r = SB_BLOCK_COUNT(s) - 67 (reiserfs_bmap_count(s) - 1) * s->s_blocksize * 8; 68 69 /* count bitmap blocks in new fs */ 70 bmap_nr_new = block_count_new / (s->s_blocksize * 8); 71 block_r_new = block_count_new - bmap_nr_new * s->s_blocksize * 8; 72 if (block_r_new) 73 bmap_nr_new++; 74 else 75 block_r_new = s->s_blocksize * 8; 76 77 /* save old values */ 78 block_count = SB_BLOCK_COUNT(s); 79 bmap_nr = reiserfs_bmap_count(s); 80 81 /* resizing of reiserfs bitmaps (journal and real), if needed */ 82 if (bmap_nr_new > bmap_nr) { 83 /* reallocate journal bitmaps */ 84 if (reiserfs_allocate_list_bitmaps(s, jbitmap, bmap_nr_new) < 0) { 85 printk 86 ("reiserfs_resize: unable to allocate memory for journal bitmaps\n"); 87 return -ENOMEM; 88 } 89 /* the new journal bitmaps are zero filled, now we copy in the bitmap 90 ** node pointers from the old journal bitmap structs, and then 91 ** transfer the new data structures into the journal struct. 92 ** 93 ** using the copy_size var below allows this code to work for 94 ** both shrinking and expanding the FS. 95 */ 96 copy_size = bmap_nr_new < bmap_nr ? bmap_nr_new : bmap_nr; 97 copy_size = 98 copy_size * sizeof(struct reiserfs_list_bitmap_node *); 99 for (i = 0; i < JOURNAL_NUM_BITMAPS; i++) { 100 struct reiserfs_bitmap_node **node_tmp; 101 jb = SB_JOURNAL(s)->j_list_bitmap + i; 102 memcpy(jbitmap[i].bitmaps, jb->bitmaps, copy_size); 103 104 /* just in case vfree schedules on us, copy the new 105 ** pointer into the journal struct before freeing the 106 ** old one 107 */ 108 node_tmp = jb->bitmaps; 109 jb->bitmaps = jbitmap[i].bitmaps; 110 vfree(node_tmp); 111 } 112 113 /* allocate additional bitmap blocks, reallocate array of bitmap 114 * block pointers */ 115 bitmap = 116 vzalloc(sizeof(struct reiserfs_bitmap_info) * bmap_nr_new); 117 if (!bitmap) { 118 /* Journal bitmaps are still supersized, but the memory isn't 119 * leaked, so I guess it's ok */ 120 printk("reiserfs_resize: unable to allocate memory.\n"); 121 return -ENOMEM; 122 } 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 int depth; 132 /* don't use read_bitmap_block since it will cache 133 * the uninitialized bitmap */ 134 depth = reiserfs_write_unlock_nested(s); 135 bh = sb_bread(s, i * s->s_blocksize * 8); 136 reiserfs_write_lock_nested(s, depth); 137 if (!bh) { 138 vfree(bitmap); 139 return -EIO; 140 } 141 memset(bh->b_data, 0, sb_blocksize(sb)); 142 reiserfs_set_le_bit(0, bh->b_data); 143 reiserfs_cache_bitmap_metadata(s, bh, bitmap + i); 144 145 set_buffer_uptodate(bh); 146 mark_buffer_dirty(bh); 147 depth = reiserfs_write_unlock_nested(s); 148 sync_dirty_buffer(bh); 149 reiserfs_write_lock_nested(s, depth); 150 // update bitmap_info stuff 151 bitmap[i].free_count = sb_blocksize(sb) * 8 - 1; 152 brelse(bh); 153 } 154 /* free old bitmap blocks array */ 155 SB_AP_BITMAP(s) = bitmap; 156 vfree(old_bitmap); 157 } 158 159 /* begin transaction, if there was an error, it's fine. Yes, we have 160 * incorrect bitmaps now, but none of it is ever going to touch the 161 * disk anyway. */ 162 err = journal_begin(&th, s, 10); 163 if (err) 164 return err; 165 166 /* Extend old last bitmap block - new blocks have been made available */ 167 info = SB_AP_BITMAP(s) + bmap_nr - 1; 168 bh = reiserfs_read_bitmap_block(s, bmap_nr - 1); 169 if (!bh) { 170 int jerr = journal_end(&th, s, 10); 171 if (jerr) 172 return jerr; 173 return -EIO; 174 } 175 176 reiserfs_prepare_for_journal(s, bh, 1); 177 for (i = block_r; i < s->s_blocksize * 8; i++) 178 reiserfs_clear_le_bit(i, bh->b_data); 179 info->free_count += s->s_blocksize * 8 - block_r; 180 181 journal_mark_dirty(&th, s, bh); 182 brelse(bh); 183 184 /* Correct new last bitmap block - It may not be full */ 185 info = SB_AP_BITMAP(s) + bmap_nr_new - 1; 186 bh = reiserfs_read_bitmap_block(s, bmap_nr_new - 1); 187 if (!bh) { 188 int jerr = journal_end(&th, s, 10); 189 if (jerr) 190 return jerr; 191 return -EIO; 192 } 193 194 reiserfs_prepare_for_journal(s, bh, 1); 195 for (i = block_r_new; i < s->s_blocksize * 8; i++) 196 reiserfs_set_le_bit(i, bh->b_data); 197 journal_mark_dirty(&th, s, bh); 198 brelse(bh); 199 200 info->free_count -= s->s_blocksize * 8 - block_r_new; 201 /* update super */ 202 reiserfs_prepare_for_journal(s, SB_BUFFER_WITH_SB(s), 1); 203 free_blocks = SB_FREE_BLOCKS(s); 204 PUT_SB_FREE_BLOCKS(s, 205 free_blocks + (block_count_new - block_count - 206 (bmap_nr_new - bmap_nr))); 207 PUT_SB_BLOCK_COUNT(s, block_count_new); 208 PUT_SB_BMAP_NR(s, bmap_would_wrap(bmap_nr_new) ? : bmap_nr_new); 209 210 journal_mark_dirty(&th, s, SB_BUFFER_WITH_SB(s)); 211 212 SB_JOURNAL(s)->j_must_wait = 1; 213 return journal_end(&th, s, 10); 214 } 215