提交 037e6390 编写于 作者: C Chris Mason 提交者: David Woodhouse

Btrfs: get rid of add recursion

Signed-off-by: NChris Mason <chris.mason@oracle.com>
上级 a28ec197
CC=gcc
CFLAGS = -g -Wall
CFLAGS = -Wall
headers = radix-tree.h ctree.h disk-io.h kerncompat.h print-tree.h list.h
objects = ctree.o disk-io.o radix-tree.o mkfs.o extent-tree.o print-tree.o
......
......@@ -995,15 +995,6 @@ static int split_leaf(struct ctree_root *root, struct ctree_path *path,
int ret;
int wret;
wret = push_leaf_left(root, path, data_size);
if (wret < 0)
return wret;
if (wret) {
wret = push_leaf_right(root, path, data_size);
if (wret < 0)
return wret;
}
l_buf = path->nodes[0];
l = &l_buf->leaf;
......
......@@ -6,6 +6,11 @@
#include "disk-io.h"
#include "print-tree.h"
static int find_free_extent(struct ctree_root *orig_root, u64 num_blocks,
u64 search_start, u64 search_end, struct key *ins);
static int finish_current_insert(struct ctree_root *extent_root);
static int run_pending(struct ctree_root *extent_root);
/*
* pending extents are blocks that we're trying to allocate in the extent
* map while trying to grow the map because of other allocations. To avoid
......@@ -13,8 +18,7 @@
* other allocations are done. The pending tag is also used in the same
* manner for deletes.
*/
#define CTREE_EXTENT_PENDING_ADD 0
#define CTREE_EXTENT_PENDING_DEL 1
#define CTREE_EXTENT_PENDING_DEL 0
static int inc_block_ref(struct ctree_root *root, u64 blocknr)
{
......@@ -23,6 +27,9 @@ static int inc_block_ref(struct ctree_root *root, u64 blocknr)
struct key key;
struct leaf *l;
struct extent_item *item;
struct key ins;
find_free_extent(root->extent_root, 0, 0, (u64)-1, &ins);
init_path(&path);
key.objectid = blocknr;
key.flags = 0;
......@@ -38,6 +45,8 @@ static int inc_block_ref(struct ctree_root *root, u64 blocknr)
BUG_ON(list_empty(&path.nodes[0]->dirty));
release_path(root->extent_root, &path);
finish_current_insert(root->extent_root);
run_pending(root->extent_root);
return 0;
}
......@@ -99,6 +108,28 @@ int btrfs_finish_extent_commit(struct ctree_root *root)
return 0;
}
static int finish_current_insert(struct ctree_root *extent_root)
{
struct key ins;
struct extent_item extent_item;
int i;
int ret;
extent_item.refs = 1;
extent_item.owner = extent_root->node->node.header.parentid;
ins.offset = 1;
ins.flags = 0;
for (i = 0; i < extent_root->current_insert.flags; i++) {
ins.objectid = extent_root->current_insert.objectid + i;
ret = insert_item(extent_root, &ins, &extent_item,
sizeof(extent_item));
BUG_ON(ret);
}
extent_root->current_insert.offset = 0;
return 0;
}
/*
* remove an extent from the root, returns 0 on success
*/
......@@ -110,10 +141,13 @@ int __free_extent(struct ctree_root *root, u64 blocknr, u64 num_blocks)
int ret;
struct item *item;
struct extent_item *ei;
struct key ins;
key.objectid = blocknr;
key.flags = 0;
key.offset = num_blocks;
find_free_extent(root, 0, 0, (u64)-1, &ins);
init_path(&path);
ret = search_slot(extent_root, &key, &path, -1, 1);
if (ret) {
......@@ -140,53 +174,10 @@ int __free_extent(struct ctree_root *root, u64 blocknr, u64 num_blocks)
BUG();
}
release_path(extent_root, &path);
finish_current_insert(extent_root);
return ret;
}
/*
* insert all of the pending extents reserved during the original
* allocation. (CTREE_EXTENT_PENDING). Returns zero if it all worked out
*/
static int insert_pending_extents(struct ctree_root *extent_root)
{
int ret;
struct key key;
struct extent_item item;
struct tree_buffer *gang[4];
int i;
// FIXME -ENOSPC
item.owner = extent_root->node->node.header.parentid;
item.refs = 1;
while(1) {
ret = radix_tree_gang_lookup_tag(&extent_root->cache_radix,
(void **)gang, 0,
ARRAY_SIZE(gang),
CTREE_EXTENT_PENDING_ADD);
if (!ret)
break;
for (i = 0; i < ret; i++) {
key.objectid = gang[i]->blocknr;
key.flags = 0;
key.offset = 1;
ret = insert_item(extent_root, &key, &item,
sizeof(item));
if (ret) {
printf("%Lu already in tree\n", key.objectid);
print_tree(extent_root, extent_root->node);
BUG();
// FIXME undo it and return sane
return ret;
}
radix_tree_tag_clear(&extent_root->cache_radix,
gang[i]->blocknr,
CTREE_EXTENT_PENDING_ADD);
tree_block_release(extent_root, gang[i]);
}
}
return 0;
}
/*
* find all the blocks marked as pending in the radix tree and remove
* them from the extent map
......@@ -218,12 +209,8 @@ static int del_pending_extents(struct ctree_root *extent_root)
static int run_pending(struct ctree_root *extent_root)
{
while(radix_tree_tagged(&extent_root->cache_radix,
CTREE_EXTENT_PENDING_DEL) ||
radix_tree_tagged(&extent_root->cache_radix,
CTREE_EXTENT_PENDING_ADD)) {
insert_pending_extents(extent_root);
CTREE_EXTENT_PENDING_DEL))
del_pending_extents(extent_root);
}
return 0;
}
......@@ -241,19 +228,8 @@ int free_extent(struct ctree_root *root, u64 blocknr, u64 num_blocks)
if (root == extent_root) {
t = find_tree_block(root, blocknr);
if (radix_tree_tag_get(&root->cache_radix, blocknr,
CTREE_EXTENT_PENDING_ADD)) {
radix_tree_tag_clear(&root->cache_radix,
blocknr,
CTREE_EXTENT_PENDING_ADD);
/* once for us */
tree_block_release(root, t);
/* once for the pending add */
tree_block_release(root, t);
} else {
radix_tree_tag_set(&root->cache_radix, blocknr,
radix_tree_tag_set(&root->cache_radix, blocknr,
CTREE_EXTENT_PENDING_DEL);
}
return 0;
}
key.objectid = blocknr;
......@@ -281,9 +257,11 @@ static int find_free_extent(struct ctree_root *orig_root, u64 num_blocks,
u64 hole_size = 0;
int slot = 0;
u64 last_block;
u64 test_block;
int start_found;
struct leaf *l;
struct ctree_root * root = orig_root->extent_root;
int total_needed = num_blocks + MAX_LEVEL * 3;
check_failed:
init_path(&path);
......@@ -306,22 +284,34 @@ static int find_free_extent(struct ctree_root *orig_root, u64 num_blocks,
goto error;
if (!start_found) {
ins->objectid = search_start;
ins->offset = num_blocks;
ins->offset = (u64)-1;
start_found = 1;
goto check_pending;
}
ins->objectid = last_block > search_start ?
last_block : search_start;
ins->offset = num_blocks;
ins->offset = (u64)-1;
goto check_pending;
}
if (slot == 0) {
int last_slot = l->header.nritems - 1;
u64 span = l->items[last_slot].key.objectid;
span -= l->items[slot].key.objectid;
if (span + total_needed > last_slot - slot) {
path.slots[0] = last_slot + 1;
key = &l->items[last_slot].key;
last_block = key->objectid + key->offset;
start_found = 1;
continue;
}
}
key = &l->items[slot].key;
if (key->objectid >= search_start) {
if (start_found) {
hole_size = key->objectid - last_block;
if (hole_size > num_blocks) {
if (hole_size > total_needed) {
ins->objectid = last_block;
ins->offset = num_blocks;
ins->offset = hole_size;
goto check_pending;
}
} else
......@@ -337,23 +327,18 @@ static int find_free_extent(struct ctree_root *orig_root, u64 num_blocks,
*/
release_path(root, &path);
BUG_ON(ins->objectid < search_start);
if (1 || orig_root->extent_root == orig_root) {
BUG_ON(num_blocks != 1);
if ((root->current_insert.objectid <= ins->objectid &&
root->current_insert.objectid +
root->current_insert.offset > ins->objectid) ||
(root->current_insert.objectid > ins->objectid &&
root->current_insert.objectid <= ins->objectid +
ins->offset) ||
radix_tree_lookup(&root->pinned_radix, ins->objectid) ||
radix_tree_tag_get(&root->cache_radix, ins->objectid,
CTREE_EXTENT_PENDING_ADD)) {
search_start = ins->objectid + 1;
for (test_block = ins->objectid;
test_block < ins->objectid + total_needed; test_block++) {
if (radix_tree_lookup(&root->pinned_radix, test_block)) {
search_start = test_block + 1;
goto check_failed;
}
}
if (ins->offset != 1)
BUG();
BUG_ON(root->current_insert.offset);
root->current_insert.offset = total_needed;
root->current_insert.objectid = ins->objectid + num_blocks;
root->current_insert.flags = 0;
ins->offset = num_blocks;
return 0;
error:
release_path(root, &path);
......@@ -368,43 +353,41 @@ static int find_free_extent(struct ctree_root *orig_root, u64 num_blocks,
* returns 0 if everything worked, non-zero otherwise.
*/
int alloc_extent(struct ctree_root *root, u64 num_blocks, u64 search_start,
u64 search_end, u64 owner, struct key *ins,
struct tree_buffer **buf)
u64 search_end, u64 owner, struct key *ins)
{
int ret;
int pending_ret;
struct ctree_root *extent_root = root->extent_root;
struct extent_item extent_item;
extent_item.refs = 1;
extent_item.owner = owner;
ret = find_free_extent(root, num_blocks, search_start, search_end, ins);
if (ret)
return ret;
if (root != root->extent_root) {
memcpy(&root->extent_root->current_insert, ins, sizeof(*ins));
ret = insert_item(root->extent_root, ins, &extent_item,
sizeof(extent_item));
memset(&root->extent_root->current_insert, 0,
sizeof(struct key));
pending_ret = run_pending(root->extent_root);
if (ret)
return ret;
if (pending_ret)
return pending_ret;
*buf = find_tree_block(root, ins->objectid);
dirty_tree_block(root, *buf);
if (root == extent_root) {
BUG_ON(extent_root->current_insert.offset == 0);
BUG_ON(num_blocks != 1);
BUG_ON(extent_root->current_insert.flags ==
extent_root->current_insert.offset);
ins->offset = 1;
ins->objectid = extent_root->current_insert.objectid +
extent_root->current_insert.flags++;
return 0;
}
/* we're allocating an extent for the extent tree, don't recurse */
BUG_ON(ins->offset != 1);
*buf = find_tree_block(root, ins->objectid);
BUG_ON(!*buf);
radix_tree_tag_set(&root->cache_radix, ins->objectid,
CTREE_EXTENT_PENDING_ADD);
(*buf)->count++;
dirty_tree_block(root, *buf);
return 0;
ret = find_free_extent(root, num_blocks, search_start,
search_end, ins);
if (ret)
return ret;
ret = insert_item(extent_root, ins, &extent_item,
sizeof(extent_item));
finish_current_insert(extent_root);
pending_ret = run_pending(extent_root);
if (ret)
return ret;
if (pending_ret)
return pending_ret;
return 0;
}
/*
......@@ -415,19 +398,17 @@ struct tree_buffer *alloc_free_block(struct ctree_root *root)
{
struct key ins;
int ret;
struct tree_buffer *buf = NULL;
struct tree_buffer *buf;
ret = alloc_extent(root, 1, 0, (unsigned long)-1,
root->node->node.header.parentid,
&ins, &buf);
&ins);
if (ret) {
BUG();
return NULL;
}
if (root != root->extent_root)
BUG_ON(radix_tree_tag_get(&root->extent_root->cache_radix,
buf->blocknr,
CTREE_EXTENT_PENDING_ADD));
buf = find_tree_block(root, ins.objectid);
dirty_tree_block(root, buf);
return buf;
}
......
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