/**
* nilfs_palloc_find_available_slot - find available slot in a group
* @bitmap: bitmap of the group
* @target: offset number of an entry in the group (start point)
* @bsize: size in bits
* @lock: spin lock protecting @bitmap
*/
static int nilfs_palloc_find_available_slot(unsigned char *bitmap,
unsigned long target,
unsigned int bsize,
spinlock_t *lock)
{
int pos, end = bsize;
if (likely(target < bsize)) {
pos = target;
do {
pos = nilfs_find_next_zero_bit(bitmap, end, pos);
if (pos >= end)
break;
if (!nilfs_set_bit_atomic(lock, pos, bitmap))
return pos;
} while (++pos < end);
end = target;
}
/* wrap around */
for (pos = 0; pos < end; pos++) {
pos = nilfs_find_next_zero_bit(bitmap, end, pos);
if (pos >= end)
break;
if (!nilfs_set_bit_atomic(lock, pos, bitmap))
return pos;
}
return -ENOSPC;
}
/**
* nilfs_palloc_find_available_slot - find available slot in a group
* @inode: inode of metadata file using this allocator
* @group: group number
* @target: offset number of an entry in the group (start point)
* @bitmap: bitmap of the group
* @bsize: size in bits
*/
static int nilfs_palloc_find_available_slot(struct inode *inode,
unsigned long group,
unsigned long target,
unsigned char *bitmap,
int bsize)
{
int curr, pos, end, i;
if (target > 0) {
end = (target + BITS_PER_LONG - 1) & ~(BITS_PER_LONG - 1);
if (end > bsize)
end = bsize;
pos = nilfs_find_next_zero_bit(bitmap, end, target);
if (pos < end &&
!nilfs_set_bit_atomic(
nilfs_mdt_bgl_lock(inode, group), pos, bitmap))
return pos;
} else
end = 0;
for (i = 0, curr = end;
i < bsize;
i += BITS_PER_LONG, curr += BITS_PER_LONG) {
/* wrap around */
if (curr >= bsize)
curr = 0;
while (*((unsigned long *)bitmap + curr / BITS_PER_LONG)
!= ~0UL) {
end = curr + BITS_PER_LONG;
if (end > bsize)
end = bsize;
pos = nilfs_find_next_zero_bit(bitmap, end, curr);
if ((pos < end) &&
!nilfs_set_bit_atomic(
nilfs_mdt_bgl_lock(inode, group), pos,
bitmap))
return pos;
}
}
return -ENOSPC;
}