/* it searches for a window of zero bits with given minimum and maximum lengths in one bitmap
* block; */
static int scan_bitmap_block (struct reiserfs_transaction_handle *th,
int bmap_n, int *beg, int boundary, int min, int max, int unfm)
{
struct super_block *s = th->t_super;
struct reiserfs_bitmap_info *bi=&SB_AP_BITMAP(s)[bmap_n];
int end, next;
int org = *beg;
BUG_ON (!th->t_trans_id);
RFALSE(bmap_n >= SB_BMAP_NR (s), "Bitmap %d is out of range (0..%d)",bmap_n, SB_BMAP_NR (s) - 1);
PROC_INFO_INC( s, scan_bitmap.bmap );
/* this is unclear and lacks comments, explain how journal bitmaps
work here for the reader. Convey a sense of the design here. What
is a window? */
/* - I mean `a window of zero bits' as in description of this function - Zam. */
if ( !bi ) {
reiserfs_warning (s, "NULL bitmap info pointer for bitmap %d", bmap_n);
return 0;
}
if (buffer_locked (bi->bh)) {
PROC_INFO_INC( s, scan_bitmap.wait );
__wait_on_buffer (bi->bh);
}
while (1) {
cont:
if (bi->free_count < min)
return 0; // No free blocks in this bitmap
/* search for a first zero bit -- beggining of a window */
*beg = reiserfs_find_next_zero_le_bit
((unsigned long*)(bi->bh->b_data), boundary, *beg);
if (*beg + min > boundary) {
/* search for a zero bit fails or the rest of bitmap block
* cannot contain a zero window of minimum size */
return 0;
}
if (unfm && is_block_in_journal(s,bmap_n, *beg, beg))
continue;
/* first zero bit found; we check next bits */
for (end = *beg + 1;; end ++) {
if (end >= *beg + max || end >= boundary || reiserfs_test_le_bit (end, bi->bh->b_data)) {
next = end;
break;
}
/* finding the other end of zero bit window requires looking into journal structures (in
* case of searching for free blocks for unformatted nodes) */
if (unfm && is_block_in_journal(s, bmap_n, end, &next))
break;
}
/* now (*beg) points to beginning of zero bits window,
* (end) points to one bit after the window end */
if (end - *beg >= min) { /* it seems we have found window of proper size */
int i;
reiserfs_prepare_for_journal (s, bi->bh, 1);
/* try to set all blocks used checking are they still free */
for (i = *beg; i < end; i++) {
/* It seems that we should not check in journal again. */
if (reiserfs_test_and_set_le_bit (i, bi->bh->b_data)) {
/* bit was set by another process
* while we slept in prepare_for_journal() */
PROC_INFO_INC( s, scan_bitmap.stolen );
if (i >= *beg + min) {
/* we can continue with smaller set of allocated blocks,
* if length of this set is more or equal to `min' */
end = i;
break;
}
/* otherwise we clear all bit were set ... */
while (--i >= *beg)
reiserfs_test_and_clear_le_bit (i, bi->bh->b_data);
reiserfs_restore_prepared_buffer (s, bi->bh);
*beg = org;
/* ... and search again in current block from beginning */
goto cont;
}
}
bi->free_count -= (end - *beg);
journal_mark_dirty (th, s, bi->bh);
/* free block count calculation */
reiserfs_prepare_for_journal (s, SB_BUFFER_WITH_SB(s), 1);
PUT_SB_FREE_BLOCKS(s, SB_FREE_BLOCKS(s) - (end - *beg));
journal_mark_dirty (th, s, SB_BUFFER_WITH_SB(s));
return end - (*beg);
} else {
*beg = next;
}
}
}
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 *info;
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++) {
/* don't use read_bitmap_block since it will cache
* the uninitialized bitmap */
bh = sb_bread(s, i * s->s_blocksize * 8);
memset(bh->b_data, 0, sb_blocksize(sb));
reiserfs_test_and_set_le_bit(0, bh->b_data);
reiserfs_cache_bitmap_metadata(s, bh, bitmap + i);
set_buffer_uptodate(bh);
mark_buffer_dirty(bh);
sync_dirty_buffer(bh);
// update bitmap_info stuff
bitmap[i].first_zero_hint = 1;
bitmap[i].free_count = sb_blocksize(sb) * 8 - 1;
brelse(bh);
}
/* 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;
/* Extend old last bitmap block - new blocks have been made available */
info = SB_AP_BITMAP(s) + bmap_nr - 1;
bh = reiserfs_read_bitmap_block(s, bmap_nr - 1);
if (!bh) {
int jerr = journal_end(&th, s, 10);
if (jerr)
return jerr;
return -EIO;
}
reiserfs_prepare_for_journal(s, bh, 1);
for (i = block_r; i < s->s_blocksize * 8; i++)
reiserfs_test_and_clear_le_bit(i, bh->b_data);
info->free_count += s->s_blocksize * 8 - block_r;
if (!info->first_zero_hint)
info->first_zero_hint = block_r;
journal_mark_dirty(&th, s, bh);
brelse(bh);
/* Correct new last bitmap block - It may not be full */
info = SB_AP_BITMAP(s) + bmap_nr_new - 1;
bh = reiserfs_read_bitmap_block(s, bmap_nr_new - 1);
if (!bh) {
int jerr = journal_end(&th, s, 10);
if (jerr)
return jerr;
return -EIO;
}
reiserfs_prepare_for_journal(s, bh, 1);
for (i = block_r_new; i < s->s_blocksize * 8; i++)
reiserfs_test_and_set_le_bit(i, bh->b_data);
journal_mark_dirty(&th, s, bh);
brelse(bh);
info->free_count -= s->s_blocksize * 8 - block_r_new;
/* Extreme case where last bitmap is the only valid block in itself. */
if (!info->free_count)
info->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);
}
int reiserfs_resize (struct super_block * s, unsigned long block_count_new)
{
struct reiserfs_super_block * sb;
struct reiserfs_bitmap_info *bitmap;
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) {
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] = SB_AP_BITMAP(s)[i];
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 */
vfree(SB_AP_BITMAP(s));
SB_AP_BITMAP(s) = bitmap;
}
/* begin transaction */
journal_begin(&th, s, 10);
/* 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;
journal_end(&th, s, 10);
return 0;
}
static int do_reiserfs_new_blocknrs (struct reiserfs_transaction_handle *th,
unsigned long * free_blocknrs,
unsigned long search_start,
int amount_needed, int priority,
int for_unformatted,
int for_prealloc)
{
struct super_block * s = th->t_super;
int i, j;
unsigned long * block_list_start = free_blocknrs;
int init_amount_needed = amount_needed;
unsigned long new_block = 0 ;
if (SB_FREE_BLOCKS (s) < SPARE_SPACE && !priority)
/* we can answer NO_DISK_SPACE being asked for new block with
priority 0 */
return NO_DISK_SPACE;
RFALSE( !s, "vs-4090: trying to get new block from nonexistent device");
RFALSE( search_start == MAX_B_NUM,
"vs-4100: we are optimizing location based on "
"the bogus location of a temp buffer (%lu).", search_start);
RFALSE( amount_needed < 1 || amount_needed > 2,
"vs-4110: amount_needed parameter incorrect (%d)", amount_needed);
/* We continue the while loop if another process snatches our found
* free block from us after we find it but before we successfully
* mark it as in use */
while (amount_needed--) {
/* skip over any blocknrs already gotten last time. */
if (*(free_blocknrs) != 0) {
RFALSE( is_reusable (s, *free_blocknrs, 1) == 0,
"vs-4120: bad blocknr on free_blocknrs list");
free_blocknrs++;
continue;
}
/* look for zero bits in bitmap */
if (find_zero_bit_in_bitmap(s,search_start, &i, &j,for_unformatted) == 0) {
if (find_zero_bit_in_bitmap(s,search_start,&i,&j, for_unformatted) == 0) {
/* recode without the goto and without
the if. It will require a
duplicate for. This is worth the
code clarity. Your way was
admirable, and just a bit too
clever in saving instructions.:-)
I'd say create a new function, but
that would slow things also, yes?
-Hans */
free_and_return:
for ( ; block_list_start != free_blocknrs; block_list_start++) {
reiserfs_free_block (th, *block_list_start);
*block_list_start = 0;
}
if (for_prealloc)
return NO_MORE_UNUSED_CONTIGUOUS_BLOCKS;
else
return NO_DISK_SPACE;
}
}
/* i and j now contain the results of the search. i = bitmap block
number containing free block, j = offset in this block. we
compute the blocknr which is our result, store it in
free_blocknrs, and increment the pointer so that on the next
loop we will insert into the next location in the array. Also
in preparation for the next loop, search_start is changed so
that the next search will not rescan the same range but will
start where this search finished. Note that while it is
possible that schedule has occurred and blocks have been freed
in that range, it is perhaps more important that the blocks
returned be near each other than that they be near their other
neighbors, and it also simplifies and speeds the code this way. */
/* journal: we need to make sure the block we are giving out is not
** a log block, horrible things would happen there.
*/
new_block = (i * (s->s_blocksize << 3)) + j;
if (for_prealloc && (new_block - 1) != search_start) {
/* preallocated blocks must be contiguous, bail if we didnt find one.
** this is not a bug. We want to do the check here, before the
** bitmap block is prepared, and before we set the bit and log the
** bitmap.
**
** If we do the check after this function returns, we have to
** call reiserfs_free_block for new_block, which would be pure
** overhead.
**
** for_prealloc should only be set if the caller can deal with the
** NO_MORE_UNUSED_CONTIGUOUS_BLOCKS return value. This can be
** returned before the disk is actually full
*/
goto free_and_return ;
}
search_start = new_block ;
if (search_start >= reiserfs_get_journal_block(s) &&
search_start < (reiserfs_get_journal_block(s) + JOURNAL_BLOCK_COUNT)) {
reiserfs_warning("vs-4130: reiserfs_new_blocknrs: trying to allocate log block %lu\n",
search_start) ;
search_start++ ;
amount_needed++ ;
continue ;
}
reiserfs_prepare_for_journal(s, SB_AP_BITMAP(s)[i], 1) ;
RFALSE( buffer_locked (SB_AP_BITMAP (s)[i]) ||
is_reusable (s, search_start, 0) == 0,
"vs-4140: bitmap block is locked or bad block number found");
/* if this bit was already set, we've scheduled, and someone else
** has allocated it. loop around and try again
*/
if (reiserfs_test_and_set_le_bit (j, SB_AP_BITMAP (s)[i]->b_data)) {
reiserfs_warning("vs-4150: reiserfs_new_blocknrs, block not free");
reiserfs_restore_prepared_buffer(s, SB_AP_BITMAP(s)[i]) ;
amount_needed++ ;
continue ;
}
journal_mark_dirty (th, s, SB_AP_BITMAP (s)[i]);
*free_blocknrs = search_start ;
free_blocknrs ++;
}
reiserfs_prepare_for_journal(s, SB_BUFFER_WITH_SB(s), 1) ;
/* update free block count in super block */
PUT_SB_FREE_BLOCKS( s, SB_FREE_BLOCKS(s) - init_amount_needed );
journal_mark_dirty (th, s, SB_BUFFER_WITH_SB (s));
s->s_dirt = 1;
return CARRY_ON;
}
