static inline void displace_large_file(reiserfs_blocknr_hint_t *hint)
{
if ( TEST_OPTION(displace_based_on_dirid, hint->th->t_super))
hint->search_start = hint->beg + keyed_hash((char *)(&INODE_PKEY(hint->inode)->k_dir_id), 4) % (hint->end - hint->beg);
else
hint->search_start = hint->beg + keyed_hash((char *)(&INODE_PKEY(hint->inode)->k_objectid), 4) % (hint->end - hint->beg);
}
static inline void hash_formatted_node(reiserfs_blocknr_hint_t *hint)
{
char * hash_in;
if (!hint->inode)
hash_in = (char*)&hint->key.k_dir_id;
else if ( TEST_OPTION(displace_based_on_dirid, hint->th->t_super))
hash_in = (char *)(&INODE_PKEY(hint->inode)->k_dir_id);
else
hash_in = (char *)(&INODE_PKEY(hint->inode)->k_objectid);
hint->search_start = hint->beg + keyed_hash(hash_in, 4) % (hint->end - hint->beg);
}
/*
* the packing is returned in disk byte order
*/
u32 reiserfs_choose_packing(struct inode *dir) {
u32 packing;
if (TEST_OPTION(packing_groups, dir->i_sb)) {
u32 parent_dir = le32_to_cpu(INODE_PKEY(dir)->k_dir_id);
/*
* some versions of reiserfsck expect packing locality 1 to be
* special
*/
if (parent_dir == 1 || block_group_used(dir->i_sb,parent_dir))
packing = INODE_PKEY(dir)->k_objectid;
else
packing = INODE_PKEY(dir)->k_dir_id;
} else
packing = INODE_PKEY(dir)->k_objectid;
return packing;
}
static void inline new_hashed_relocation (reiserfs_blocknr_hint_t * hint)
{
char * hash_in;
if (hint->formatted_node) {
hash_in = (char*)&hint->key.k_dir_id;
} else {
if (!hint->inode) {
//hint->search_start = hint->beg;
hash_in = (char*)&hint->key.k_dir_id;
} else if ( TEST_OPTION(displace_based_on_dirid, hint->th->t_super))
hash_in = (char *)(&INODE_PKEY(hint->inode)->k_dir_id);
else
hash_in = (char *)(&INODE_PKEY(hint->inode)->k_objectid);
}
hint->search_start = hint->beg + keyed_hash(hash_in, 4) % (hint->end - hint->beg);
}
/* Tries to find contiguous zero bit window (given size) in given region of
* bitmap and place new blocks there. Returns number of allocated blocks. */
static int scan_bitmap (struct reiserfs_transaction_handle *th,
unsigned long *start, unsigned long finish,
int min, int max, int unfm, unsigned long file_block)
{
int nr_allocated=0;
struct super_block * s = th->t_super;
/* find every bm and bmap and bmap_nr in this file, and change them all to bitmap_blocknr
* - Hans, it is not a block number - Zam. */
int bm, off;
int end_bm, end_off;
int off_max = s->s_blocksize << 3;
PROC_INFO_INC( s, scan_bitmap.call );
if ( SB_FREE_BLOCKS(s) <= 0)
return 0; // No point in looking for more free blocks
get_bit_address (s, *start, &bm, &off);
get_bit_address (s, finish, &end_bm, &end_off);
// With this option set first we try to find a bitmap that is at least 10%
// free, and if that fails, then we fall back to old whole bitmap scanning
if ( TEST_OPTION(skip_busy, s) && SB_FREE_BLOCKS(s) > SB_BLOCK_COUNT(s)/20 ) {
for (; bm < end_bm; bm++, off = 0) {
if ( ( off && (!unfm || (file_block != 0))) || SB_AP_BITMAP(s)[bm].free_count > (s->s_blocksize << 3) / 10 )
nr_allocated = scan_bitmap_block(th, bm, &off, off_max, min, max, unfm);
if (nr_allocated)
goto ret;
}
get_bit_address (s, *start, &bm, &off);
}
for (; bm < end_bm; bm++, off = 0) {
nr_allocated = scan_bitmap_block(th, bm, &off, off_max, min, max, unfm);
if (nr_allocated)
goto ret;
}
nr_allocated = scan_bitmap_block(th, bm, &off, end_off + 1, min, max, unfm);
ret:
*start = bm * off_max + off;
return nr_allocated;
}
static void determine_search_start(reiserfs_blocknr_hint_t *hint,
int amount_needed)
{
struct super_block *s = hint->th->t_super;
int unfm_hint;
hint->beg = 0;
hint->end = SB_BLOCK_COUNT(s) - 1;
/* This is former border algorithm. Now with tunable border offset */
if (concentrating_formatted_nodes(s))
set_border_in_hint(s, hint);
#ifdef DISPLACE_NEW_PACKING_LOCALITIES
/* whenever we create a new directory, we displace it. At first we will
hash for location, later we might look for a moderately empty place for
it */
if (displacing_new_packing_localities(s)
&& hint->th->displace_new_blocks) {
displace_new_packing_locality(hint);
/* we do not continue determine_search_start,
* if new packing locality is being displaced */
return;
}
#endif
/* all persons should feel encouraged to add more special cases here and
* test them */
if (displacing_large_files(s) && !hint->formatted_node
&& this_blocknr_allocation_would_make_it_a_large_file(hint)) {
displace_large_file(hint);
return;
}
/* if none of our special cases is relevant, use the left neighbor in the
tree order of the new node we are allocating for */
if (hint->formatted_node && TEST_OPTION(hashed_formatted_nodes,s)) {
hash_formatted_node(hint);
return;
}
unfm_hint = get_left_neighbor(hint);
/* Mimic old block allocator behaviour, that is if VFS allowed for preallocation,
new blocks are displaced based on directory ID. Also, if suggested search_start
is less than last preallocated block, we start searching from it, assuming that
HDD dataflow is faster in forward direction */
if ( TEST_OPTION(old_way, s)) {
if (!hint->formatted_node) {
if ( !reiserfs_hashed_relocation(s))
old_way(hint);
else if (!reiserfs_no_unhashed_relocation(s))
old_hashed_relocation(hint);
if ( hint->inode && hint->search_start < REISERFS_I(hint->inode)->i_prealloc_block)
hint->search_start = REISERFS_I(hint->inode)->i_prealloc_block;
}
return;
}
/* This is an approach proposed by Hans */
if ( TEST_OPTION(hundredth_slices, s) && ! (displacing_large_files(s) && !hint->formatted_node)) {
hundredth_slices(hint);
return;
}
/* old_hashed_relocation only works on unformatted */
if (!unfm_hint && !hint->formatted_node &&
TEST_OPTION(old_hashed_relocation, s))
{
old_hashed_relocation(hint);
}
/* new_hashed_relocation works with both formatted/unformatted nodes */
if ((!unfm_hint || hint->formatted_node) &&
TEST_OPTION(new_hashed_relocation, s))
{
new_hashed_relocation(hint);
}
/* dirid grouping works only on unformatted nodes */
if (!unfm_hint && !hint->formatted_node && TEST_OPTION(dirid_groups,s))
{
dirid_groups(hint);
}
#ifdef DISPLACE_NEW_PACKING_LOCALITIES
if (hint->formatted_node && TEST_OPTION(dirid_groups,s))
{
dirid_groups(hint);
}
#endif
/* oid grouping works only on unformatted nodes */
if (!unfm_hint && !hint->formatted_node && TEST_OPTION(oid_groups,s))
{
oid_groups(hint);
}
return;
}
/* Tries to find contiguous zero bit window (given size) in given region of
* bitmap and place new blocks there. Returns number of allocated blocks. */
static int scan_bitmap (struct reiserfs_transaction_handle *th,
b_blocknr_t *start, b_blocknr_t finish,
int min, int max, int unfm, unsigned long file_block)
{
int nr_allocated=0;
struct super_block * s = th->t_super;
/* find every bm and bmap and bmap_nr in this file, and change them all to bitmap_blocknr
* - Hans, it is not a block number - Zam. */
int bm, off;
int end_bm, end_off;
int off_max = s->s_blocksize << 3;
BUG_ON (!th->t_trans_id);
PROC_INFO_INC( s, scan_bitmap.call );
if ( SB_FREE_BLOCKS(s) <= 0)
return 0; // No point in looking for more free blocks
get_bit_address (s, *start, &bm, &off);
get_bit_address (s, finish, &end_bm, &end_off);
if (bm > SB_BMAP_NR(s))
return 0;
if (end_bm > SB_BMAP_NR(s))
end_bm = SB_BMAP_NR(s);
/* When the bitmap is more than 10% free, anyone can allocate.
* When it's less than 10% free, only files that already use the
* bitmap are allowed. Once we pass 80% full, this restriction
* is lifted.
*
* We do this so that files that grow later still have space close to
* their original allocation. This improves locality, and presumably
* performance as a result.
*
* This is only an allocation policy and does not make up for getting a
* bad hint. Decent hinting must be implemented for this to work well.
*/
if ( TEST_OPTION(skip_busy, s) && SB_FREE_BLOCKS(s) > SB_BLOCK_COUNT(s)/20 ) {
for (; bm < end_bm; bm++, off = 0) {
if ( ( off && (!unfm || (file_block != 0))) || SB_AP_BITMAP(s)[bm].free_count > (s->s_blocksize << 3) / 10 )
nr_allocated = scan_bitmap_block(th, bm, &off, off_max, min, max, unfm);
if (nr_allocated)
goto ret;
}
/* we know from above that start is a reasonable number */
get_bit_address (s, *start, &bm, &off);
}
for (; bm < end_bm; bm++, off = 0) {
nr_allocated = scan_bitmap_block(th, bm, &off, off_max, min, max, unfm);
if (nr_allocated)
goto ret;
}
nr_allocated = scan_bitmap_block(th, bm, &off, end_off + 1, min, max, unfm);
ret:
*start = bm * off_max + off;
return nr_allocated;
}
