struct btrfs_root *root = orig_root->fs_info->extent_root;
u64 total_needed = num_bytes;
u64 *last_ptr = NULL;
- u64 last_wanted = 0;
struct btrfs_block_group_cache *block_group = NULL;
- int chunk_alloc_done = 0;
int empty_cluster = 2 * 1024 * 1024;
int allowed_chunk_alloc = 0;
- struct list_head *head = NULL, *cur = NULL;
- int loop = 0;
- int extra_loop = 0;
+ int using_hint = 0;
struct btrfs_space_info *space_info;
WARN_ON(num_bytes < root->sectorsize);
ins->objectid = 0;
ins->offset = 0;
+ space_info = __find_space_info(root->fs_info, data);
+
if (orig_root->ref_cows || empty_size)
allowed_chunk_alloc = 1;
last_ptr = &root->fs_info->last_data_alloc;
if (last_ptr) {
- if (*last_ptr) {
+ if (*last_ptr)
hint_byte = *last_ptr;
- last_wanted = *last_ptr;
- } else
+ else
empty_size += empty_cluster;
} else {
empty_cluster = 0;
search_start = max(search_start, first_logical_byte(root, 0));
search_start = max(search_start, hint_byte);
- if (last_wanted && search_start != last_wanted) {
- last_wanted = 0;
+ if (search_start == hint_byte) {
+ using_hint = 1;
+ block_group = btrfs_lookup_block_group(root->fs_info,
+ search_start);
+ if (block_group && block_group_bits(block_group, data)) {
+ total_needed += empty_size;
+ down_read(&space_info->groups_sem);
+ goto have_block_group;
+ } else if (block_group) {
+ put_block_group(block_group);
+ }
+
empty_size += empty_cluster;
+ using_hint = 0;
}
- total_needed += empty_size;
- block_group = btrfs_lookup_block_group(root->fs_info, search_start);
- if (!block_group)
- block_group = btrfs_lookup_first_block_group(root->fs_info,
- search_start);
- space_info = __find_space_info(root->fs_info, data);
-
+search:
down_read(&space_info->groups_sem);
- while (1) {
+ list_for_each_entry(block_group, &space_info->block_groups, list) {
struct btrfs_free_space *free_space;
- /*
- * the only way this happens if our hint points to a block
- * group thats not of the proper type, while looping this
- * should never happen
- */
- if (empty_size)
- extra_loop = 1;
- if (!block_group)
- goto new_group_no_lock;
+ atomic_inc(&block_group->count);
+ search_start = block_group->key.objectid;
+have_block_group:
if (unlikely(!block_group->cached)) {
mutex_lock(&block_group->cache_mutex);
ret = cache_block_group(root, block_group);
mutex_unlock(&block_group->cache_mutex);
- if (ret)
+ if (ret) {
+ put_block_group(block_group);
break;
+ }
}
mutex_lock(&block_group->alloc_mutex);
- if (unlikely(!block_group_bits(block_group, data)))
- goto new_group;
if (unlikely(block_group->ro))
- goto new_group;
+ goto loop;
free_space = btrfs_find_free_space(block_group, search_start,
total_needed);
- if (free_space) {
- u64 start = block_group->key.objectid;
- u64 end = block_group->key.objectid +
- block_group->key.offset;
+ if (!free_space)
+ goto loop;
- search_start = stripe_align(root, free_space->offset);
+ search_start = stripe_align(root, free_space->offset);
- /* move on to the next group */
- if (search_start + num_bytes >= search_end)
- goto new_group;
+ /* move on to the next group */
+ if (search_start + num_bytes >= search_end)
+ goto loop;
- /* move on to the next group */
- if (search_start + num_bytes > end)
- goto new_group;
+ /* move on to the next group */
+ if (search_start + num_bytes >
+ block_group->key.objectid + block_group->key.offset)
+ goto loop;
- if (last_wanted && search_start != last_wanted) {
- total_needed += empty_cluster;
- empty_size += empty_cluster;
- last_wanted = 0;
- /*
- * if search_start is still in this block group
- * then we just re-search this block group
- */
- if (search_start >= start &&
- search_start < end) {
- mutex_unlock(&block_group->alloc_mutex);
- continue;
- }
+ if (using_hint && search_start > hint_byte)
+ goto loop;
- /* else we go to the next block group */
- goto new_group;
- }
+ if (exclude_nr > 0 &&
+ (search_start + num_bytes > exclude_start &&
+ search_start < exclude_start + exclude_nr)) {
+ search_start = exclude_start + exclude_nr;
- if (exclude_nr > 0 &&
- (search_start + num_bytes > exclude_start &&
- search_start < exclude_start + exclude_nr)) {
- search_start = exclude_start + exclude_nr;
- /*
- * if search_start is still in this block group
- * then we just re-search this block group
- */
- if (search_start >= start &&
- search_start < end) {
- mutex_unlock(&block_group->alloc_mutex);
- last_wanted = 0;
- continue;
- }
-
- /* else we go to the next block group */
- goto new_group;
+ /*
+ * if search_start is still in this block group
+ * then we just re-search this block group
+ */
+ if (search_start >= block_group->key.objectid &&
+ search_start < (block_group->key.objectid +
+ block_group->key.offset)) {
+ mutex_unlock(&block_group->alloc_mutex);
+ goto have_block_group;
}
+ goto loop;
+ }
- ins->objectid = search_start;
- ins->offset = num_bytes;
+ ins->objectid = search_start;
+ ins->offset = num_bytes;
- btrfs_remove_free_space_lock(block_group, search_start,
- num_bytes);
- /* we are all good, lets return */
- mutex_unlock(&block_group->alloc_mutex);
- break;
- }
-new_group:
+ btrfs_remove_free_space_lock(block_group, search_start,
+ num_bytes);
+ /* we are all good, lets return */
+ mutex_unlock(&block_group->alloc_mutex);
+ break;
+loop:
mutex_unlock(&block_group->alloc_mutex);
put_block_group(block_group);
- block_group = NULL;
-new_group_no_lock:
- /* don't try to compare new allocations against the
- * last allocation any more
- */
- last_wanted = 0;
-
- /*
- * Here's how this works.
- * loop == 0: we were searching a block group via a hint
- * and didn't find anything, so we start at
- * the head of the block groups and keep searching
- * loop == 1: we're searching through all of the block groups
- * if we hit the head again we have searched
- * all of the block groups for this space and we
- * need to try and allocate, if we cant error out.
- * loop == 2: we allocated more space and are looping through
- * all of the block groups again.
- */
- if (loop == 0) {
- head = &space_info->block_groups;
- cur = head->next;
- loop++;
- } else if (loop == 1 && cur == head) {
- int keep_going;
-
- /* at this point we give up on the empty_size
- * allocations and just try to allocate the min
- * space.
- *
- * The extra_loop field was set if an empty_size
- * allocation was attempted above, and if this
- * is try we need to try the loop again without
- * the additional empty_size.
- */
- total_needed -= empty_size;
- empty_size = 0;
- keep_going = extra_loop;
- loop++;
-
- if (allowed_chunk_alloc && !chunk_alloc_done) {
- up_read(&space_info->groups_sem);
- ret = do_chunk_alloc(trans, root, num_bytes +
- 2 * 1024 * 1024, data, 1);
- down_read(&space_info->groups_sem);
- if (ret < 0)
- goto loop_check;
- head = &space_info->block_groups;
- /*
- * we've allocated a new chunk, keep
- * trying
- */
- keep_going = 1;
- chunk_alloc_done = 1;
- } else if (!allowed_chunk_alloc) {
- space_info->force_alloc = 1;
- }
-loop_check:
- if (keep_going) {
- cur = head->next;
- extra_loop = 0;
- } else {
- break;
- }
- } else if (cur == head) {
- break;
+ if (using_hint) {
+ empty_size += empty_cluster;
+ total_needed += empty_cluster;
+ using_hint = 0;
+ up_read(&space_info->groups_sem);
+ goto search;
}
+ }
+ up_read(&space_info->groups_sem);
- block_group = list_entry(cur, struct btrfs_block_group_cache,
- list);
- atomic_inc(&block_group->count);
+ if (!ins->objectid && (empty_size || allowed_chunk_alloc)) {
+ int try_again = empty_size;
- search_start = block_group->key.objectid;
- cur = cur->next;
+ total_needed -= empty_size;
+ empty_size = 0;
+
+ if (allowed_chunk_alloc) {
+ ret = do_chunk_alloc(trans, root, num_bytes +
+ 2 * 1024 * 1024, data, 1);
+ if (!ret)
+ try_again = 1;
+ allowed_chunk_alloc = 0;
+ } else {
+ space_info->force_alloc = 1;
+ }
+
+ if (try_again)
+ goto search;
+ ret = -ENOSPC;
+ } else if (!ins->objectid) {
+ ret = -ENOSPC;
}
/* we found what we needed */
if (last_ptr)
*last_ptr = ins->objectid + ins->offset;
+ put_block_group(block_group);
ret = 0;
- } else if (!ret) {
- printk(KERN_ERR "btrfs searching for %llu bytes, "
- "num_bytes %llu, loop %d, allowed_alloc %d\n",
- (unsigned long long)total_needed,
- (unsigned long long)num_bytes,
- loop, allowed_chunk_alloc);
- ret = -ENOSPC;
}
- if (block_group)
- put_block_group(block_group);
- up_read(&space_info->groups_sem);
return ret;
}
git://ftp.safe.ca / safe / jmp / linux-2.6 / commitdiff