Btrfs: remove dead code

This patch removes a bunch of dead code from the snapshot removal stuff.  It
was confusing me when doing the metadata ENOSPC stuff so I killed it.

Signed-off-by: Josef Bacik <jbacik@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
This commit is contained in:
Josef Bacik 2009-09-11 16:11:20 -04:00 committed by Chris Mason
parent f019f4264a
commit f61408b81c

View File

@ -4462,430 +4462,6 @@ struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
return buf;
}
#if 0
int btrfs_drop_leaf_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct extent_buffer *leaf)
{
u64 disk_bytenr;
u64 num_bytes;
struct btrfs_key key;
struct btrfs_file_extent_item *fi;
u32 nritems;
int i;
int ret;
BUG_ON(!btrfs_is_leaf(leaf));
nritems = btrfs_header_nritems(leaf);
for (i = 0; i < nritems; i++) {
cond_resched();
btrfs_item_key_to_cpu(leaf, &key, i);
/* only extents have references, skip everything else */
if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
continue;
fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
/* inline extents live in the btree, they don't have refs */
if (btrfs_file_extent_type(leaf, fi) ==
BTRFS_FILE_EXTENT_INLINE)
continue;
disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
/* holes don't have refs */
if (disk_bytenr == 0)
continue;
num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
ret = btrfs_free_extent(trans, root, disk_bytenr, num_bytes,
leaf->start, 0, key.objectid, 0);
BUG_ON(ret);
}
return 0;
}
static noinline int cache_drop_leaf_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_leaf_ref *ref)
{
int i;
int ret;
struct btrfs_extent_info *info;
struct refsort *sorted;
if (ref->nritems == 0)
return 0;
sorted = kmalloc(sizeof(*sorted) * ref->nritems, GFP_NOFS);
for (i = 0; i < ref->nritems; i++) {
sorted[i].bytenr = ref->extents[i].bytenr;
sorted[i].slot = i;
}
sort(sorted, ref->nritems, sizeof(struct refsort), refsort_cmp, NULL);
/*
* the items in the ref were sorted when the ref was inserted
* into the ref cache, so this is already in order
*/
for (i = 0; i < ref->nritems; i++) {
info = ref->extents + sorted[i].slot;
ret = btrfs_free_extent(trans, root, info->bytenr,
info->num_bytes, ref->bytenr,
ref->owner, ref->generation,
info->objectid, 0);
atomic_inc(&root->fs_info->throttle_gen);
wake_up(&root->fs_info->transaction_throttle);
cond_resched();
BUG_ON(ret);
info++;
}
kfree(sorted);
return 0;
}
static int drop_snap_lookup_refcount(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 start,
u64 len, u32 *refs)
{
int ret;
ret = btrfs_lookup_extent_refs(trans, root, start, len, refs);
BUG_ON(ret);
#if 0 /* some debugging code in case we see problems here */
/* if the refs count is one, it won't get increased again. But
* if the ref count is > 1, someone may be decreasing it at
* the same time we are.
*/
if (*refs != 1) {
struct extent_buffer *eb = NULL;
eb = btrfs_find_create_tree_block(root, start, len);
if (eb)
btrfs_tree_lock(eb);
mutex_lock(&root->fs_info->alloc_mutex);
ret = lookup_extent_ref(NULL, root, start, len, refs);
BUG_ON(ret);
mutex_unlock(&root->fs_info->alloc_mutex);
if (eb) {
btrfs_tree_unlock(eb);
free_extent_buffer(eb);
}
if (*refs == 1) {
printk(KERN_ERR "btrfs block %llu went down to one "
"during drop_snap\n", (unsigned long long)start);
}
}
#endif
cond_resched();
return ret;
}
/*
* this is used while deleting old snapshots, and it drops the refs
* on a whole subtree starting from a level 1 node.
*
* The idea is to sort all the leaf pointers, and then drop the
* ref on all the leaves in order. Most of the time the leaves
* will have ref cache entries, so no leaf IOs will be required to
* find the extents they have references on.
*
* For each leaf, any references it has are also dropped in order
*
* This ends up dropping the references in something close to optimal
* order for reading and modifying the extent allocation tree.
*/
static noinline int drop_level_one_refs(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path)
{
u64 bytenr;
u64 root_owner;
u64 root_gen;
struct extent_buffer *eb = path->nodes[1];
struct extent_buffer *leaf;
struct btrfs_leaf_ref *ref;
struct refsort *sorted = NULL;
int nritems = btrfs_header_nritems(eb);
int ret;
int i;
int refi = 0;
int slot = path->slots[1];
u32 blocksize = btrfs_level_size(root, 0);
u32 refs;
if (nritems == 0)
goto out;
root_owner = btrfs_header_owner(eb);
root_gen = btrfs_header_generation(eb);
sorted = kmalloc(sizeof(*sorted) * nritems, GFP_NOFS);
/*
* step one, sort all the leaf pointers so we don't scribble
* randomly into the extent allocation tree
*/
for (i = slot; i < nritems; i++) {
sorted[refi].bytenr = btrfs_node_blockptr(eb, i);
sorted[refi].slot = i;
refi++;
}
/*
* nritems won't be zero, but if we're picking up drop_snapshot
* after a crash, slot might be > 0, so double check things
* just in case.
*/
if (refi == 0)
goto out;
sort(sorted, refi, sizeof(struct refsort), refsort_cmp, NULL);
/*
* the first loop frees everything the leaves point to
*/
for (i = 0; i < refi; i++) {
u64 ptr_gen;
bytenr = sorted[i].bytenr;
/*
* check the reference count on this leaf. If it is > 1
* we just decrement it below and don't update any
* of the refs the leaf points to.
*/
ret = drop_snap_lookup_refcount(trans, root, bytenr,
blocksize, &refs);
BUG_ON(ret);
if (refs != 1)
continue;
ptr_gen = btrfs_node_ptr_generation(eb, sorted[i].slot);
/*
* the leaf only had one reference, which means the
* only thing pointing to this leaf is the snapshot
* we're deleting. It isn't possible for the reference
* count to increase again later
*
* The reference cache is checked for the leaf,
* and if found we'll be able to drop any refs held by
* the leaf without needing to read it in.
*/
ref = btrfs_lookup_leaf_ref(root, bytenr);
if (ref && ref->generation != ptr_gen) {
btrfs_free_leaf_ref(root, ref);
ref = NULL;
}
if (ref) {
ret = cache_drop_leaf_ref(trans, root, ref);
BUG_ON(ret);
btrfs_remove_leaf_ref(root, ref);
btrfs_free_leaf_ref(root, ref);
} else {
/*
* the leaf wasn't in the reference cache, so
* we have to read it.
*/
leaf = read_tree_block(root, bytenr, blocksize,
ptr_gen);
ret = btrfs_drop_leaf_ref(trans, root, leaf);
BUG_ON(ret);
free_extent_buffer(leaf);
}
atomic_inc(&root->fs_info->throttle_gen);
wake_up(&root->fs_info->transaction_throttle);
cond_resched();
}
/*
* run through the loop again to free the refs on the leaves.
* This is faster than doing it in the loop above because
* the leaves are likely to be clustered together. We end up
* working in nice chunks on the extent allocation tree.
*/
for (i = 0; i < refi; i++) {
bytenr = sorted[i].bytenr;
ret = btrfs_free_extent(trans, root, bytenr,
blocksize, eb->start,
root_owner, root_gen, 0, 1);
BUG_ON(ret);
atomic_inc(&root->fs_info->throttle_gen);
wake_up(&root->fs_info->transaction_throttle);
cond_resched();
}
out:
kfree(sorted);
/*
* update the path to show we've processed the entire level 1
* node. This will get saved into the root's drop_snapshot_progress
* field so these drops are not repeated again if this transaction
* commits.
*/
path->slots[1] = nritems;
return 0;
}
/*
* helper function for drop_snapshot, this walks down the tree dropping ref
* counts as it goes.
*/
static noinline int walk_down_tree(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path, int *level)
{
u64 root_owner;
u64 root_gen;
u64 bytenr;
u64 ptr_gen;
struct extent_buffer *next;
struct extent_buffer *cur;
struct extent_buffer *parent;
u32 blocksize;
int ret;
u32 refs;
WARN_ON(*level < 0);
WARN_ON(*level >= BTRFS_MAX_LEVEL);
ret = drop_snap_lookup_refcount(trans, root, path->nodes[*level]->start,
path->nodes[*level]->len, &refs);
BUG_ON(ret);
if (refs > 1)
goto out;
/*
* walk down to the last node level and free all the leaves
*/
while (*level >= 0) {
WARN_ON(*level < 0);
WARN_ON(*level >= BTRFS_MAX_LEVEL);
cur = path->nodes[*level];
if (btrfs_header_level(cur) != *level)
WARN_ON(1);
if (path->slots[*level] >=
btrfs_header_nritems(cur))
break;
/* the new code goes down to level 1 and does all the
* leaves pointed to that node in bulk. So, this check
* for level 0 will always be false.
*
* But, the disk format allows the drop_snapshot_progress
* field in the root to leave things in a state where
* a leaf will need cleaning up here. If someone crashes
* with the old code and then boots with the new code,
* we might find a leaf here.
*/
if (*level == 0) {
ret = btrfs_drop_leaf_ref(trans, root, cur);
BUG_ON(ret);
break;
}
/*
* once we get to level one, process the whole node
* at once, including everything below it.
*/
if (*level == 1) {
ret = drop_level_one_refs(trans, root, path);
BUG_ON(ret);
break;
}
bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
blocksize = btrfs_level_size(root, *level - 1);
ret = drop_snap_lookup_refcount(trans, root, bytenr,
blocksize, &refs);
BUG_ON(ret);
/*
* if there is more than one reference, we don't need
* to read that node to drop any references it has. We
* just drop the ref we hold on that node and move on to the
* next slot in this level.
*/
if (refs != 1) {
parent = path->nodes[*level];
root_owner = btrfs_header_owner(parent);
root_gen = btrfs_header_generation(parent);
path->slots[*level]++;
ret = btrfs_free_extent(trans, root, bytenr,
blocksize, parent->start,
root_owner, root_gen,
*level - 1, 1);
BUG_ON(ret);
atomic_inc(&root->fs_info->throttle_gen);
wake_up(&root->fs_info->transaction_throttle);
cond_resched();
continue;
}
/*
* we need to keep freeing things in the next level down.
* read the block and loop around to process it
*/
next = read_tree_block(root, bytenr, blocksize, ptr_gen);
WARN_ON(*level <= 0);
if (path->nodes[*level-1])
free_extent_buffer(path->nodes[*level-1]);
path->nodes[*level-1] = next;
*level = btrfs_header_level(next);
path->slots[*level] = 0;
cond_resched();
}
out:
WARN_ON(*level < 0);
WARN_ON(*level >= BTRFS_MAX_LEVEL);
if (path->nodes[*level] == root->node) {
parent = path->nodes[*level];
bytenr = path->nodes[*level]->start;
} else {
parent = path->nodes[*level + 1];
bytenr = btrfs_node_blockptr(parent, path->slots[*level + 1]);
}
blocksize = btrfs_level_size(root, *level);
root_owner = btrfs_header_owner(parent);
root_gen = btrfs_header_generation(parent);
/*
* cleanup and free the reference on the last node
* we processed
*/
ret = btrfs_free_extent(trans, root, bytenr, blocksize,
parent->start, root_owner, root_gen,
*level, 1);
free_extent_buffer(path->nodes[*level]);
path->nodes[*level] = NULL;
*level += 1;
BUG_ON(ret);
cond_resched();
return 0;
}
#endif
struct walk_control {
u64 refs[BTRFS_MAX_LEVEL];
u64 flags[BTRFS_MAX_LEVEL];
@ -7129,288 +6705,6 @@ int btrfs_prepare_block_group_relocation(struct btrfs_root *root,
return 0;
}
#if 0
static int __insert_orphan_inode(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 objectid, u64 size)
{
struct btrfs_path *path;
struct btrfs_inode_item *item;
struct extent_buffer *leaf;
int ret;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
path->leave_spinning = 1;
ret = btrfs_insert_empty_inode(trans, root, path, objectid);
if (ret)
goto out;
leaf = path->nodes[0];
item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_inode_item);
memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
btrfs_set_inode_generation(leaf, item, 1);
btrfs_set_inode_size(leaf, item, size);
btrfs_set_inode_mode(leaf, item, S_IFREG | 0600);
btrfs_set_inode_flags(leaf, item, BTRFS_INODE_NOCOMPRESS);
btrfs_mark_buffer_dirty(leaf);
btrfs_release_path(root, path);
out:
btrfs_free_path(path);
return ret;
}
static noinline struct inode *create_reloc_inode(struct btrfs_fs_info *fs_info,
struct btrfs_block_group_cache *group)
{
struct inode *inode = NULL;
struct btrfs_trans_handle *trans;
struct btrfs_root *root;
struct btrfs_key root_key;
u64 objectid = BTRFS_FIRST_FREE_OBJECTID;
int err = 0;
root_key.objectid = BTRFS_DATA_RELOC_TREE_OBJECTID;
root_key.type = BTRFS_ROOT_ITEM_KEY;
root_key.offset = (u64)-1;
root = btrfs_read_fs_root_no_name(fs_info, &root_key);
if (IS_ERR(root))
return ERR_CAST(root);
trans = btrfs_start_transaction(root, 1);
BUG_ON(!trans);
err = btrfs_find_free_objectid(trans, root, objectid, &objectid);
if (err)
goto out;
err = __insert_orphan_inode(trans, root, objectid, group->key.offset);
BUG_ON(err);
err = btrfs_insert_file_extent(trans, root, objectid, 0, 0, 0,
group->key.offset, 0, group->key.offset,
0, 0, 0);
BUG_ON(err);
inode = btrfs_iget_locked(root->fs_info->sb, objectid, root);
if (inode->i_state & I_NEW) {
BTRFS_I(inode)->root = root;
BTRFS_I(inode)->location.objectid = objectid;
BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY;
BTRFS_I(inode)->location.offset = 0;
btrfs_read_locked_inode(inode);
unlock_new_inode(inode);
BUG_ON(is_bad_inode(inode));
} else {
BUG_ON(1);
}
BTRFS_I(inode)->index_cnt = group->key.objectid;
err = btrfs_orphan_add(trans, inode);
out:
btrfs_end_transaction(trans, root);
if (err) {
if (inode)
iput(inode);
inode = ERR_PTR(err);
}
return inode;
}
int btrfs_reloc_clone_csums(struct inode *inode, u64 file_pos, u64 len)
{
struct btrfs_ordered_sum *sums;
struct btrfs_sector_sum *sector_sum;
struct btrfs_ordered_extent *ordered;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct list_head list;
size_t offset;
int ret;
u64 disk_bytenr;
INIT_LIST_HEAD(&list);
ordered = btrfs_lookup_ordered_extent(inode, file_pos);
BUG_ON(ordered->file_offset != file_pos || ordered->len != len);
disk_bytenr = file_pos + BTRFS_I(inode)->index_cnt;
ret = btrfs_lookup_csums_range(root->fs_info->csum_root, disk_bytenr,
disk_bytenr + len - 1, &list);
while (!list_empty(&list)) {
sums = list_entry(list.next, struct btrfs_ordered_sum, list);
list_del_init(&sums->list);
sector_sum = sums->sums;
sums->bytenr = ordered->start;
offset = 0;
while (offset < sums->len) {
sector_sum->bytenr += ordered->start - disk_bytenr;
sector_sum++;
offset += root->sectorsize;
}
btrfs_add_ordered_sum(inode, ordered, sums);
}
btrfs_put_ordered_extent(ordered);
return 0;
}
int btrfs_relocate_block_group(struct btrfs_root *root, u64 group_start)
{
struct btrfs_trans_handle *trans;
struct btrfs_path *path;
struct btrfs_fs_info *info = root->fs_info;
struct extent_buffer *leaf;
struct inode *reloc_inode;
struct btrfs_block_group_cache *block_group;
struct btrfs_key key;
u64 skipped;
u64 cur_byte;
u64 total_found;
u32 nritems;
int ret;
int progress;
int pass = 0;
root = root->fs_info->extent_root;
block_group = btrfs_lookup_block_group(info, group_start);
BUG_ON(!block_group);
printk(KERN_INFO "btrfs relocating block group %llu flags %llu\n",
(unsigned long long)block_group->key.objectid,
(unsigned long long)block_group->flags);
path = btrfs_alloc_path();
BUG_ON(!path);
reloc_inode = create_reloc_inode(info, block_group);
BUG_ON(IS_ERR(reloc_inode));
__alloc_chunk_for_shrink(root, block_group, 1);
set_block_group_readonly(block_group);
btrfs_start_delalloc_inodes(info->tree_root);
btrfs_wait_ordered_extents(info->tree_root, 0);
again:
skipped = 0;
total_found = 0;
progress = 0;
key.objectid = block_group->key.objectid;
key.offset = 0;
key.type = 0;
cur_byte = key.objectid;
trans = btrfs_start_transaction(info->tree_root, 1);
btrfs_commit_transaction(trans, info->tree_root);
mutex_lock(&root->fs_info->cleaner_mutex);
btrfs_clean_old_snapshots(info->tree_root);
btrfs_remove_leaf_refs(info->tree_root, (u64)-1, 1);
mutex_unlock(&root->fs_info->cleaner_mutex);
trans = btrfs_start_transaction(info->tree_root, 1);
btrfs_commit_transaction(trans, info->tree_root);
while (1) {
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto out;
next:
leaf = path->nodes[0];
nritems = btrfs_header_nritems(leaf);
if (path->slots[0] >= nritems) {
ret = btrfs_next_leaf(root, path);
if (ret < 0)
goto out;
if (ret == 1) {
ret = 0;
break;
}
leaf = path->nodes[0];
nritems = btrfs_header_nritems(leaf);
}
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
if (key.objectid >= block_group->key.objectid +
block_group->key.offset)
break;
if (progress && need_resched()) {
btrfs_release_path(root, path);
cond_resched();
progress = 0;
continue;
}
progress = 1;
if (btrfs_key_type(&key) != BTRFS_EXTENT_ITEM_KEY ||
key.objectid + key.offset <= cur_byte) {
path->slots[0]++;
goto next;
}
total_found++;
cur_byte = key.objectid + key.offset;
btrfs_release_path(root, path);
__alloc_chunk_for_shrink(root, block_group, 0);
ret = relocate_one_extent(root, path, &key, block_group,
reloc_inode, pass);
BUG_ON(ret < 0);
if (ret > 0)
skipped++;
key.objectid = cur_byte;
key.type = 0;
key.offset = 0;
}
btrfs_release_path(root, path);
if (pass == 0) {
btrfs_wait_ordered_range(reloc_inode, 0, (u64)-1);
invalidate_mapping_pages(reloc_inode->i_mapping, 0, -1);
}
if (total_found > 0) {
printk(KERN_INFO "btrfs found %llu extents in pass %d\n",
(unsigned long long)total_found, pass);
pass++;
if (total_found == skipped && pass > 2) {
iput(reloc_inode);
reloc_inode = create_reloc_inode(info, block_group);
pass = 0;
}
goto again;
}
/* delete reloc_inode */
iput(reloc_inode);
/* unpin extents in this range */
trans = btrfs_start_transaction(info->tree_root, 1);
btrfs_commit_transaction(trans, info->tree_root);
spin_lock(&block_group->lock);
WARN_ON(block_group->pinned > 0);
WARN_ON(block_group->reserved > 0);
WARN_ON(btrfs_block_group_used(&block_group->item) > 0);
spin_unlock(&block_group->lock);
btrfs_put_block_group(block_group);
ret = 0;
out:
btrfs_free_path(path);
return ret;
}
#endif
/*
* checks to see if its even possible to relocate this block group.
*