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Btrfs: Make the resizer work based on shrinking and growing devices
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Signed-off-by: Chris Mason <chris.mason@oracle.com>
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Chris Mason committed Sep 25, 2008
1 parent 5e478dc commit 8f18cf1
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Showing 6 changed files with 407 additions and 108 deletions.
1 change: 1 addition & 0 deletions fs/btrfs/ctree.h
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Original file line number Diff line number Diff line change
Expand Up @@ -474,6 +474,7 @@ struct btrfs_block_group_cache {
u64 pinned;
u64 flags;
int cached;
int ro;
};

struct btrfs_device;
Expand Down
4 changes: 4 additions & 0 deletions fs/btrfs/disk-io.c
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Original file line number Diff line number Diff line change
Expand Up @@ -818,6 +818,10 @@ struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
return fs_info->tree_root;
if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
return fs_info->extent_root;
if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
return fs_info->chunk_root;
if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
return fs_info->dev_root;

root = radix_tree_lookup(&fs_info->fs_roots_radix,
(unsigned long)location->objectid);
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145 changes: 57 additions & 88 deletions fs/btrfs/extent-tree.c
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Original file line number Diff line number Diff line change
Expand Up @@ -187,6 +187,7 @@ static int noinline find_search_start(struct btrfs_root *root,

if (!cache)
goto out;

total_fs_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy);
free_space_cache = &root->fs_info->free_space_cache;

Expand All @@ -196,7 +197,7 @@ static int noinline find_search_start(struct btrfs_root *root,
goto out;

last = max(search_start, cache->key.objectid);
if (!block_group_bits(cache, data)) {
if (!block_group_bits(cache, data) || cache->ro) {
goto new_group;
}

Expand All @@ -221,6 +222,8 @@ static int noinline find_search_start(struct btrfs_root *root,
continue;
}
spin_unlock_irq(&free_space_cache->lock);
if (cache->ro)
goto new_group;
if (start + num > cache->key.objectid + cache->key.offset)
goto new_group;
if (start + num > total_fs_bytes)
Expand Down Expand Up @@ -319,15 +322,15 @@ struct btrfs_block_group_cache *btrfs_find_block_group(struct btrfs_root *root,
if (search_start && search_start < total_fs_bytes) {
struct btrfs_block_group_cache *shint;
shint = btrfs_lookup_block_group(info, search_start);
if (shint && block_group_bits(shint, data)) {
if (shint && block_group_bits(shint, data) && !shint->ro) {
used = btrfs_block_group_used(&shint->item);
if (used + shint->pinned <
div_factor(shint->key.offset, factor)) {
return shint;
}
}
}
if (hint && block_group_bits(hint, data) &&
if (hint && !hint->ro && block_group_bits(hint, data) &&
hint->key.objectid < total_fs_bytes) {
used = btrfs_block_group_used(&hint->item);
if (used + hint->pinned <
Expand Down Expand Up @@ -364,7 +367,7 @@ struct btrfs_block_group_cache *btrfs_find_block_group(struct btrfs_root *root,
if (cache->key.objectid > total_fs_bytes)
break;

if (block_group_bits(cache, data)) {
if (!cache->ro && block_group_bits(cache, data)) {
if (full_search)
free_check = cache->key.offset;
else
Expand Down Expand Up @@ -1020,6 +1023,7 @@ static int update_space_info(struct btrfs_fs_info *info, u64 flags,
if (found) {
found->total_bytes += total_bytes;
found->bytes_used += bytes_used;
found->full = 0;
WARN_ON(found->total_bytes < found->bytes_used);
*space_info = found;
return 0;
Expand Down Expand Up @@ -1700,7 +1704,6 @@ int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
u64 super_used;
u64 root_used;
u64 search_start = 0;
u64 new_hint;
u64 alloc_profile;
u32 sizes[2];
struct btrfs_fs_info *info = root->fs_info;
Expand All @@ -1724,7 +1727,7 @@ int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
data = BTRFS_BLOCK_GROUP_METADATA | alloc_profile;
}
again:
if (root->ref_cows) {
if (root != root->fs_info->extent_root) {
if (!(data & BTRFS_BLOCK_GROUP_METADATA)) {
ret = do_chunk_alloc(trans, root->fs_info->extent_root,
2 * 1024 * 1024,
Expand All @@ -1738,10 +1741,6 @@ int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
BUG_ON(ret);
}

new_hint = max(hint_byte, root->fs_info->alloc_start);
if (new_hint < btrfs_super_total_bytes(&info->super_copy))
hint_byte = new_hint;

WARN_ON(num_bytes < root->sectorsize);
ret = find_free_extent(trans, root, num_bytes, empty_size,
search_start, search_end, hint_byte, ins,
Expand Down Expand Up @@ -2473,33 +2472,46 @@ static int noinline relocate_one_extent(struct btrfs_root *extent_root,
return ret;
}

int btrfs_shrink_extent_tree(struct btrfs_root *root, u64 new_size)
int btrfs_shrink_extent_tree(struct btrfs_root *root, u64 shrink_start)
{
struct btrfs_trans_handle *trans;
struct btrfs_root *tree_root = root->fs_info->tree_root;
struct btrfs_path *path;
u64 cur_byte;
u64 total_found;
u64 shrink_last_byte;
struct btrfs_block_group_cache *shrink_block_group;
struct btrfs_fs_info *info = root->fs_info;
struct extent_io_tree *block_group_cache;
struct btrfs_key key;
struct btrfs_key found_key;
struct extent_buffer *leaf;
u32 nritems;
int ret;
int progress = 0;

btrfs_set_super_total_bytes(&info->super_copy, new_size);
clear_extent_dirty(&info->free_space_cache, new_size, (u64)-1,
GFP_NOFS);
block_group_cache = &info->block_group_cache;
shrink_block_group = btrfs_lookup_block_group(root->fs_info,
shrink_start);
BUG_ON(!shrink_block_group);

shrink_last_byte = shrink_start + shrink_block_group->key.offset;

shrink_block_group->space_info->total_bytes -=
shrink_block_group->key.offset;
printk("shrink_extent_tree %Lu -> %Lu type %Lu\n", shrink_start, shrink_last_byte, shrink_block_group->flags);
path = btrfs_alloc_path();
root = root->fs_info->extent_root;
path->reada = 2;

again:
trans = btrfs_start_transaction(root, 1);
do_chunk_alloc(trans, root->fs_info->extent_root,
btrfs_block_group_used(&shrink_block_group->item) +
2 * 1024 * 1024, shrink_block_group->flags);
btrfs_end_transaction(trans, root);
shrink_block_group->ro = 1;

total_found = 0;
key.objectid = new_size;
key.objectid = shrink_start;
key.offset = 0;
key.type = 0;
cur_byte = key.objectid;
Expand All @@ -2511,10 +2523,12 @@ int btrfs_shrink_extent_tree(struct btrfs_root *root, u64 new_size)
ret = btrfs_previous_item(root, path, 0, BTRFS_EXTENT_ITEM_KEY);
if (ret < 0)
goto out;

if (ret == 0) {
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
if (found_key.objectid + found_key.offset > new_size) {
if (found_key.objectid + found_key.offset > shrink_start &&
found_key.objectid < shrink_last_byte) {
cur_byte = found_key.objectid;
key.objectid = cur_byte;
}
Expand Down Expand Up @@ -2543,6 +2557,9 @@ int btrfs_shrink_extent_tree(struct btrfs_root *root, u64 new_size)

btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);

if (found_key.objectid >= shrink_last_byte)
break;

if (progress && need_resched()) {
memcpy(&key, &found_key, sizeof(key));
mutex_unlock(&root->fs_info->fs_mutex);
Expand Down Expand Up @@ -2583,82 +2600,38 @@ int btrfs_shrink_extent_tree(struct btrfs_root *root, u64 new_size)
goto again;
}

/*
* we've freed all the extents, now remove the block
* group item from the tree
*/
trans = btrfs_start_transaction(root, 1);
key.objectid = new_size;
key.offset = 0;
key.type = 0;
while(1) {
u64 ptr;

ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret < 0)
goto out;

leaf = path->nodes[0];
nritems = btrfs_header_nritems(leaf);
bg_next:
if (path->slots[0] >= nritems) {
ret = btrfs_next_leaf(root, path);
if (ret < 0)
break;
if (ret == 1) {
ret = 0;
break;
}
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
memcpy(&key, &shrink_block_group->key, sizeof(key));

/*
* btrfs_next_leaf doesn't cow buffers, we have to
* do the search again
*/
memcpy(&key, &found_key, sizeof(key));
btrfs_release_path(root, path);
goto resched_check;
}
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret > 0)
ret = -EIO;
if (ret < 0)
goto out;

btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
if (btrfs_key_type(&found_key) != BTRFS_BLOCK_GROUP_ITEM_KEY) {
printk("shrinker found key %Lu %u %Lu\n",
found_key.objectid, found_key.type,
found_key.offset);
path->slots[0]++;
goto bg_next;
}
ret = get_state_private(&info->block_group_cache,
found_key.objectid, &ptr);
if (!ret)
kfree((void *)(unsigned long)ptr);
leaf = path->nodes[0];
nritems = btrfs_header_nritems(leaf);
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
kfree(shrink_block_group);

clear_extent_bits(&info->block_group_cache, found_key.objectid,
found_key.objectid + found_key.offset - 1,
(unsigned int)-1, GFP_NOFS);
clear_extent_bits(&info->block_group_cache, found_key.objectid,
found_key.objectid + found_key.offset - 1,
(unsigned int)-1, GFP_NOFS);

key.objectid = found_key.objectid + 1;
btrfs_del_item(trans, root, path);
btrfs_release_path(root, path);
resched_check:
if (need_resched()) {
mutex_unlock(&root->fs_info->fs_mutex);
cond_resched();
mutex_lock(&root->fs_info->fs_mutex);
}
}
clear_extent_dirty(&info->free_space_cache, new_size, (u64)-1,
btrfs_del_item(trans, root, path);
clear_extent_dirty(&info->free_space_cache,
shrink_start, shrink_last_byte - 1,
GFP_NOFS);
btrfs_commit_transaction(trans, root);
out:
btrfs_free_path(path);
return ret;
}

int btrfs_grow_extent_tree(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 new_size)
{
btrfs_set_super_total_bytes(&root->fs_info->super_copy, new_size);
return 0;
}

int find_first_block_group(struct btrfs_root *root, struct btrfs_path *path,
struct btrfs_key *key)
{
Expand Down Expand Up @@ -2726,7 +2699,7 @@ int btrfs_read_block_groups(struct btrfs_root *root)

leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
cache = kmalloc(sizeof(*cache), GFP_NOFS);
cache = kzalloc(sizeof(*cache), GFP_NOFS);
if (!cache) {
ret = -ENOMEM;
break;
Expand All @@ -2736,8 +2709,6 @@ int btrfs_read_block_groups(struct btrfs_root *root)
btrfs_item_ptr_offset(leaf, path->slots[0]),
sizeof(cache->item));
memcpy(&cache->key, &found_key, sizeof(found_key));
cache->cached = 0;
cache->pinned = 0;

key.objectid = found_key.objectid + found_key.offset;
btrfs_release_path(root, path);
Expand Down Expand Up @@ -2789,12 +2760,10 @@ int btrfs_make_block_group(struct btrfs_trans_handle *trans,
extent_root = root->fs_info->extent_root;
block_group_cache = &root->fs_info->block_group_cache;

cache = kmalloc(sizeof(*cache), GFP_NOFS);
cache = kzalloc(sizeof(*cache), GFP_NOFS);
BUG_ON(!cache);
cache->key.objectid = chunk_offset;
cache->key.offset = size;
cache->cached = 0;
cache->pinned = 0;

btrfs_set_key_type(&cache->key, BTRFS_BLOCK_GROUP_ITEM_KEY);
memset(&cache->item, 0, sizeof(cache->item));
Expand Down
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