1 /*
2  * Copyright 2000-2002 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/vmalloc.h>
13 #include <linux/locks.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 
reiserfs_resize(struct super_block * s,unsigned long block_count_new)19 int reiserfs_resize (struct super_block * s, unsigned long block_count_new)
20 {
21 	struct reiserfs_super_block * sb;
22         struct reiserfs_bitmap_info *bitmap;
23 	struct buffer_head * bh;
24 	struct reiserfs_transaction_handle th;
25 	unsigned int bmap_nr_new, bmap_nr;
26 	unsigned int block_r_new, block_r;
27 
28 	struct reiserfs_list_bitmap * jb;
29 	struct reiserfs_list_bitmap jbitmap[JOURNAL_NUM_BITMAPS];
30 
31 	unsigned long int block_count, free_blocks;
32 	int i;
33 	int copy_size ;
34 
35 	sb = SB_DISK_SUPER_BLOCK(s);
36 
37 	if (SB_BLOCK_COUNT(s) >= block_count_new) {
38 		reiserfs_warning(s, "can\'t shrink filesystem on-line\n");
39 		return -EINVAL;
40 	}
41 
42 	/* check the device size */
43 	bh = sb_bread(s, block_count_new - 1);
44 	if (!bh) {
45 		reiserfs_warning(s, "reiserfs_resize: can\'t read last block\n");
46 		return -EINVAL;
47 	}
48 	bforget(bh);
49 
50 	/* old disk layout detection; those partitions can be mounted, but
51 	 * cannot be resized */
52 	if (SB_BUFFER_WITH_SB(s)->b_blocknr *	SB_BUFFER_WITH_SB(s)->b_size
53 		!= REISERFS_DISK_OFFSET_IN_BYTES ) {
54 		reiserfs_warning(s, "reiserfs_resize: unable to resize a reiserfs without distributed bitmap (fs version < 3.5.12)\n");
55 		return -ENOTSUPP;
56 	}
57 
58 	/* count used bits in last bitmap block */
59 	block_r = SB_BLOCK_COUNT(s) -
60 	        (SB_BMAP_NR(s) - 1) * s->s_blocksize * 8;
61 
62 	/* count bitmap blocks in new fs */
63 	bmap_nr_new = block_count_new / ( s->s_blocksize * 8 );
64 	block_r_new = block_count_new - bmap_nr_new * s->s_blocksize * 8;
65 	if (block_r_new)
66 		bmap_nr_new++;
67 	else
68 		block_r_new = s->s_blocksize * 8;
69 
70 	/* save old values */
71 	block_count = SB_BLOCK_COUNT(s);
72 	bmap_nr     = SB_BMAP_NR(s);
73 
74 	/* resizing of reiserfs bitmaps (journal and real), if needed */
75 	if (bmap_nr_new > bmap_nr) {
76 	    /* reallocate journal bitmaps */
77 	    if (reiserfs_allocate_list_bitmaps(s, jbitmap, bmap_nr_new) < 0) {
78 		reiserfs_warning(s, "reiserfs_resize: unable to allocate memory for journal bitmaps\n");
79 		unlock_super(s) ;
80 		return -ENOMEM ;
81 	    }
82 	    /* the new journal bitmaps are zero filled, now we copy in the bitmap
83 	    ** node pointers from the old journal bitmap structs, and then
84 	    ** transfer the new data structures into the journal struct.
85 	    **
86 	    ** using the copy_size var below allows this code to work for
87 	    ** both shrinking and expanding the FS.
88 	    */
89 	    copy_size = bmap_nr_new < bmap_nr ? bmap_nr_new : bmap_nr ;
90 	    copy_size = copy_size * sizeof(struct reiserfs_list_bitmap_node *) ;
91 	    for (i = 0 ; i < JOURNAL_NUM_BITMAPS ; i++) {
92 		struct reiserfs_bitmap_node **node_tmp ;
93 		jb = SB_JOURNAL(s)->j_list_bitmap + i ;
94 		memcpy(jbitmap[i].bitmaps, jb->bitmaps, copy_size) ;
95 
96 		/* just in case vfree schedules on us, copy the new
97 		** pointer into the journal struct before freeing the
98 		** old one
99 		*/
100 		node_tmp = jb->bitmaps ;
101 		jb->bitmaps = jbitmap[i].bitmaps ;
102 		vfree(node_tmp) ;
103 	    }
104 
105 	    /* allocate additional bitmap blocks, reallocate array of bitmap
106 	     * block pointers */
107 	    bitmap = vmalloc(sizeof(struct reiserfs_bitmap_info) * bmap_nr_new);
108 	    if (!bitmap) {
109 		reiserfs_warning(s, "reiserfs_resize: unable to allocate memory.\n");
110 		return -ENOMEM;
111 	    }
112 	    for (i = 0; i < bmap_nr; i++)
113 		bitmap[i] = SB_AP_BITMAP(s)[i];
114 	    for (i = bmap_nr; i < bmap_nr_new; i++) {
115 		bitmap[i].bh = sb_getblk(s, i * s->s_blocksize * 8);
116 		memset(bitmap[i].bh->b_data, 0, sb_blocksize(sb));
117 		reiserfs_test_and_set_le_bit(0, bitmap[i].bh->b_data);
118 
119 		mark_buffer_dirty(bitmap[i].bh) ;
120 		mark_buffer_uptodate(bitmap[i].bh, 1);
121 		ll_rw_block(WRITE, 1, &bitmap[i].bh);
122 		wait_on_buffer(bitmap[i].bh);
123 		bitmap[i].first_zero_hint=1;
124 		bitmap[i].free_count = s->s_blocksize * 8 - 1;
125 	    }
126 	    /* free old bitmap blocks array */
127 	    vfree(SB_AP_BITMAP(s));
128 
129 	    SB_AP_BITMAP(s) = bitmap;
130 	}
131 
132 	/* begin transaction */
133 	journal_begin(&th, s, 10);
134 
135 	/* correct last bitmap blocks in old and new disk layout */
136 	reiserfs_prepare_for_journal(s, SB_AP_BITMAP(s)[bmap_nr - 1].bh, 1);
137 	for (i = block_r; i < s->s_blocksize * 8; i++)
138 	    reiserfs_test_and_clear_le_bit(i,
139 					   SB_AP_BITMAP(s)[bmap_nr - 1].bh->b_data);
140 	SB_AP_BITMAP(s)[bmap_nr - 1].free_count += s->s_blocksize * 8 - block_r;
141 	if ( !SB_AP_BITMAP(s)[bmap_nr - 1].first_zero_hint)
142 	    SB_AP_BITMAP(s)[bmap_nr - 1].first_zero_hint = block_r;
143 	journal_mark_dirty(&th, s, SB_AP_BITMAP(s)[bmap_nr - 1].bh);
144 
145 	reiserfs_prepare_for_journal(s, SB_AP_BITMAP(s)[bmap_nr_new - 1].bh, 1);
146 	for (i = block_r_new; i < s->s_blocksize * 8; i++)
147 	    reiserfs_test_and_set_le_bit(i,
148 					 SB_AP_BITMAP(s)[bmap_nr_new - 1].bh->b_data);
149 	journal_mark_dirty(&th, s, SB_AP_BITMAP(s)[bmap_nr_new - 1].bh);
150 
151 	SB_AP_BITMAP(s)[bmap_nr_new - 1].free_count -= s->s_blocksize * 8 - block_r_new;
152 	/* Extreme case where last bitmap is the only valid block in itself. */
153 	if ( !SB_AP_BITMAP(s)[bmap_nr_new - 1].free_count )
154 	    SB_AP_BITMAP(s)[bmap_nr_new - 1].first_zero_hint = 0;
155  	/* update super */
156 	reiserfs_prepare_for_journal(s, SB_BUFFER_WITH_SB(s), 1) ;
157 	free_blocks = SB_FREE_BLOCKS(s);
158 	PUT_SB_FREE_BLOCKS(s, free_blocks + (block_count_new - block_count - (bmap_nr_new - bmap_nr)));
159 	PUT_SB_BLOCK_COUNT(s, block_count_new);
160 	PUT_SB_BMAP_NR(s, bmap_nr_new);
161 	s->s_dirt = 1;
162 
163 	journal_mark_dirty(&th, s, SB_BUFFER_WITH_SB(s));
164 
165 	SB_JOURNAL(s)->j_must_wait = 1;
166 	journal_end(&th, s, 10);
167 
168 	return 0;
169 }
170 
171