/*
* Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README
*/
/*
* Written by Alexander Zarochentcev.
*
* The kernel part of the (on-line) reiserfs resizer.
*/
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/vmalloc.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/reiserfs_fs.h>
#include <linux/reiserfs_fs_sb.h>
#include <linux/buffer_head.h>
int reiserfs_resize (struct super_block * s, unsigned long block_count_new)
{
int err = 0;
struct reiserfs_super_block * sb;
struct reiserfs_bitmap_info *bitmap;
struct reiserfs_bitmap_info *old_bitmap = SB_AP_BITMAP(s);
struct buffer_head * bh;
struct reiserfs_transaction_handle th;
unsigned int bmap_nr_new, bmap_nr;
unsigned int block_r_new, block_r;
struct reiserfs_list_bitmap * jb;
struct reiserfs_list_bitmap jbitmap[JOURNAL_NUM_BITMAPS];
unsigned long int block_count, free_blocks;
int i;
int copy_size ;
sb = SB_DISK_SUPER_BLOCK(s);
if (SB_BLOCK_COUNT(s) >= block_count_new) {
printk("can\'t shrink filesystem on-line\n");
return -EINVAL;
}
/* check the device size */
bh = sb_bread(s, block_count_new - 1);
if (!bh) {
printk("reiserfs_resize: can\'t read last block\n");
return -EINVAL;
}
bforget(bh);
/* old disk layout detection; those partitions can be mounted, but
* cannot be resized */
if (SB_BUFFER_WITH_SB(s)->b_blocknr * SB_BUFFER_WITH_SB(s)->b_size
!= REISERFS_DISK_OFFSET_IN_BYTES ) {
printk("reiserfs_resize: unable to resize a reiserfs without distributed bitmap (fs version < 3.5.12)\n");
return -ENOTSUPP;
}
/* count used bits in last bitmap block */
block_r = SB_BLOCK_COUNT(s) -
(SB_BMAP_NR(s) - 1) * s->s_blocksize * 8;
/* count bitmap blocks in new fs */
bmap_nr_new = block_count_new / ( s->s_blocksize * 8 );
block_r_new = block_count_new - bmap_nr_new * s->s_blocksize * 8;
if (block_r_new)
bmap_nr_new++;
else
block_r_new = s->s_blocksize * 8;
/* save old values */
block_count = SB_BLOCK_COUNT(s);
bmap_nr = SB_BMAP_NR(s);
/* resizing of reiserfs bitmaps (journal and real), if needed */
if (bmap_nr_new > bmap_nr) {
/* reallocate journal bitmaps */
if (reiserfs_allocate_list_bitmaps(s, jbitmap, bmap_nr_new) < 0) {
printk("reiserfs_resize: unable to allocate memory for journal bitmaps\n");
unlock_super(s) ;
return -ENOMEM ;
}
/* the new journal bitmaps are zero filled, now we copy in the bitmap
** node pointers from the old journal bitmap structs, and then
** transfer the new data structures into the journal struct.
**
** using the copy_size var below allows this code to work for
** both shrinking and expanding the FS.
*/
copy_size = bmap_nr_new < bmap_nr ? bmap_nr_new : bmap_nr ;
copy_size = copy_size * sizeof(struct reiserfs_list_bitmap_node *) ;
for (i = 0 ; i < JOURNAL_NUM_BITMAPS ; i++) {
struct reiserfs_bitmap_node **node_tmp ;
jb = SB_JOURNAL(s)->j_list_bitmap + i ;
memcpy(jbitmap[i].bitmaps, jb->bitmaps, copy_size) ;
/* just in case vfree schedules on us, copy the new
** pointer into the journal struct before freeing the
** old one
*/
node_tmp = jb->bitmaps ;
jb->bitmaps = jbitmap[i].bitmaps ;
vfree(node_tmp) ;
}
/* allocate additional bitmap blocks, reallocate array of bitmap
* block pointers */
bitmap = vmalloc(sizeof(struct reiserfs_bitmap_info) * bmap_nr_new);
if (!bitmap) {
/* Journal bitmaps are still supersized, but the memory isn't
* leaked, so I guess it's ok */
printk("reiserfs_resize: unable to allocate memory.\n");
return -ENOMEM;
}
memset (bitmap, 0, sizeof (struct reiserfs_bitmap_info) * SB_BMAP_NR(s));
for (i = 0; i < bmap_nr; i++)
bitmap[i] = old_bitmap[i];
/* This doesn't go through the journal, but it doesn't have to.
* The changes are still atomic: We're synced up when the journal
* transaction begins, and the new bitmaps don't matter if the
* transaction fails. */
for (i = bmap_nr; i < bmap_nr_new; i++) {
bitmap[i].bh = sb_getblk(s, i * s->s_blocksize * 8);
memset(bitmap[i].bh->b_data, 0, sb_blocksize(sb));
reiserfs_test_and_set_le_bit(0, bitmap[i].bh->b_data);
set_buffer_uptodate(bitmap[i].bh);
mark_buffer_dirty(bitmap[i].bh) ;
sync_dirty_buffer(bitmap[i].bh);
// update bitmap_info stuff
bitmap[i].first_zero_hint=1;
bitmap[i].free_count = sb_blocksize(sb) * 8 - 1;
}
/* free old bitmap blocks array */
SB_AP_BITMAP(s) = bitmap;
vfree (old_bitmap);
}
/* begin transaction, if there was an error, it's fine. Yes, we have
* incorrect bitmaps now, but none of it is ever going to touch the
* disk anyway. */
err = journal_begin(&th, s, 10);
if (err)
return err;
/* correct last bitmap blocks in old and new disk layout */
reiserfs_prepare_for_journal(s, SB_AP_BITMAP(s)[bmap_nr - 1].bh, 1);
for (i = block_r; i < s->s_blocksize * 8; i++)
reiserfs_test_and_clear_le_bit(i,
SB_AP_BITMAP(s)[bmap_nr - 1].bh->b_data);
SB_AP_BITMAP(s)[bmap_nr - 1].free_count += s->s_blocksize * 8 - block_r;
if ( !SB_AP_BITMAP(s)[bmap_nr - 1].first_zero_hint)
SB_AP_BITMAP(s)[bmap_nr - 1].first_zero_hint = block_r;
journal_mark_dirty(&th, s, SB_AP_BITMAP(s)[bmap_nr - 1].bh);
reiserfs_prepare_for_journal(s, SB_AP_BITMAP(s)[bmap_nr_new - 1].bh, 1);
for (i = block_r_new; i < s->s_blocksize * 8; i++)
reiserfs_test_and_set_le_bit(i,
SB_AP_BITMAP(s)[bmap_nr_new - 1].bh->b_data);
journal_mark_dirty(&th, s, SB_AP_BITMAP(s)[bmap_nr_new - 1].bh);
SB_AP_BITMAP(s)[bmap_nr_new - 1].free_count -= s->s_blocksize * 8 - block_r_new;
/* Extreme case where last bitmap is the only valid block in itself. */
if ( !SB_AP_BITMAP(s)[bmap_nr_new - 1].free_count )
SB_AP_BITMAP(s)[bmap_nr_new - 1].first_zero_hint = 0;
/* update super */
reiserfs_prepare_for_journal(s, SB_BUFFER_WITH_SB(s), 1) ;
free_blocks = SB_FREE_BLOCKS(s);
PUT_SB_FREE_BLOCKS(s, free_blocks + (block_count_new - block_count - (bmap_nr_new - bmap_nr)));
PUT_SB_BLOCK_COUNT(s, block_count_new);
PUT_SB_BMAP_NR(s, bmap_nr_new);
s->s_dirt = 1;
journal_mark_dirty(&th, s, SB_BUFFER_WITH_SB(s));
SB_JOURNAL(s)->j_must_wait = 1;
return journal_end(&th, s, 10);
}
