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 } 183