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Btrfs: Fixup the code to merge during path walks

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Add a bulk insert/remove test to random-test
Add the quick-test code back as another regression test

Signed-off-by: Chris Mason <chris.mason@oracle.com>
This commit is contained in:
Chris Mason
2007-03-01 15:16:26 -05:00
committed by David Woodhouse
parent bb8039515d
commit 79f95c82dc
4 changed files with 381 additions and 43 deletions
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137
fs/btrfs/ctree.c
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@@ -12,6 +12,9 @@ static int split_leaf(struct ctree_root *root, struct ctree_path *path,
int data_size);
static int push_node_left(struct ctree_root *root, struct tree_buffer *dst,
struct tree_buffer *src);
static int balance_node_right(struct ctree_root *root,
struct tree_buffer *dst_buf,
struct tree_buffer *src_buf);
static int del_ptr(struct ctree_root *root, struct ctree_path *path, int level,
int slot);
@@ -217,15 +220,16 @@ static int balance_level(struct ctree_root *root, struct ctree_path *path,
int ret = 0;
int wret;
int pslot;
int used = 0;
int count;
int orig_slot = path->slots[level];
u64 orig_ptr;
if (level == 0)
return 0;
mid_buf = path->nodes[level];
mid = &mid_buf->node;
orig_ptr = mid->blockptrs[orig_slot];
if (level < MAX_LEVEL - 1)
parent_buf = path->nodes[level + 1];
pslot = path->slots[level + 1];
@@ -253,24 +257,26 @@ static int balance_level(struct ctree_root *root, struct ctree_path *path,
if (mid->header.nritems > NODEPTRS_PER_BLOCK / 4)
return 0;
// print_tree(root, root->node);
left_buf = read_node_slot(root, parent_buf, pslot - 1);
right_buf = read_node_slot(root, parent_buf, pslot + 1);
if (right_buf) {
right = &right_buf->node;
used = right->header.nritems;
count = 1;
}
/* first, try to make some room in the middle buffer */
if (left_buf) {
left = &left_buf->node;
used += left->header.nritems;
orig_slot += left->header.nritems;
count++;
wret = push_node_left(root, left_buf, mid_buf);
if (wret < 0)
ret = wret;
}
if (left_buf)
push_node_left(root, left_buf, mid_buf);
/*
* then try to empty the right most buffer into the middle
*/
if (right_buf) {
push_node_left(root, mid_buf, right_buf);
right = &right_buf->node;
wret = push_node_left(root, mid_buf, right_buf);
if (wret < 0)
ret = wret;
if (right->header.nritems == 0) {
u64 blocknr = right_buf->blocknr;
tree_block_release(root, right_buf);
@@ -285,9 +291,29 @@ static int balance_level(struct ctree_root *root, struct ctree_path *path,
} else {
memcpy(parent->keys + pslot + 1, right->keys,
sizeof(struct key));
wret = write_tree_block(root, parent_buf);
if (wret)
ret = wret;
}
}
if (mid->header.nritems == 1) {
/*
* we're not allowed to leave a node with one item in the
* tree during a delete. A deletion from lower in the tree
* could try to delete the only pointer in this node.
* So, pull some keys from the left.
* There has to be a left pointer at this point because
* otherwise we would have pulled some pointers from the
* right
*/
BUG_ON(!left_buf);
wret = balance_node_right(root, mid_buf, left_buf);
if (wret < 0)
ret = wret;
BUG_ON(wret == 1);
}
if (mid->header.nritems == 0) {
/* we've managed to empty the middle node, drop it */
u64 blocknr = mid_buf->blocknr;
tree_block_release(root, mid_buf);
mid_buf = NULL;
@@ -298,11 +324,17 @@ static int balance_level(struct ctree_root *root, struct ctree_path *path,
wret = free_extent(root, blocknr, 1);
if (wret)
ret = wret;
} else
} else {
/* update the parent key to reflect our changes */
memcpy(parent->keys + pslot, mid->keys, sizeof(struct key));
wret = write_tree_block(root, parent_buf);
if (wret)
ret = wret;
}
/* update the path */
if (left_buf) {
if (left->header.nritems >= orig_slot) {
if (left->header.nritems > orig_slot) {
left_buf->count++; // released below
path->nodes[level] = left_buf;
path->slots[level + 1] -= 1;
@@ -314,12 +346,15 @@ static int balance_level(struct ctree_root *root, struct ctree_path *path,
path->slots[level] = orig_slot;
}
}
/* double check we haven't messed things up */
check_block(path, level);
if (orig_ptr != path->nodes[level]->node.blockptrs[path->slots[level]])
BUG();
if (right_buf)
tree_block_release(root, right_buf);
if (left_buf)
tree_block_release(root, left_buf);
return ret;
}
@@ -378,6 +413,7 @@ again:
goto again;
c = &b->node;
slot = p->slots[level];
BUG_ON(c->header.nritems == 1);
}
b = read_tree_block(root, c->blockptrs[slot]);
} else {
@@ -433,13 +469,7 @@ static int fixup_low_keys(struct ctree_root *root,
/*
* try to push data from one node into the next node left in the
* tree. The src node is found at specified level in the path.
* If some bytes were pushed, return 0, otherwise return 1.
*
* Lower nodes/leaves in the path are not touched, higher nodes may
* be modified to reflect the push.
*
* The path is altered to reflect the push.
* tree.
*
* returns 0 if some ptrs were pushed left, < 0 if there was some horrible
* error, and > 0 if there was no room in the left hand block.
@@ -463,7 +493,8 @@ static int push_node_left(struct ctree_root *root, struct tree_buffer *dst_buf,
}
if (src_nritems < push_items)
push_items =src_nritems;
push_items = src_nritems;
memcpy(dst->keys + dst_nritems, src->keys,
push_items * sizeof(struct key));
memcpy(dst->blockptrs + dst_nritems, src->blockptrs,
@@ -487,6 +518,64 @@ static int push_node_left(struct ctree_root *root, struct tree_buffer *dst_buf,
return ret;
}
/*
* try to push data from one node into the next node right in the
* tree.
*
* returns 0 if some ptrs were pushed, < 0 if there was some horrible
* error, and > 0 if there was no room in the right hand block.
*
* this will only push up to 1/2 the contents of the left node over
*/
static int balance_node_right(struct ctree_root *root,
struct tree_buffer *dst_buf,
struct tree_buffer *src_buf)
{
struct node *src = &src_buf->node;
struct node *dst = &dst_buf->node;
int push_items = 0;
int max_push;
int src_nritems;
int dst_nritems;
int ret = 0;
int wret;
src_nritems = src->header.nritems;
dst_nritems = dst->header.nritems;
push_items = NODEPTRS_PER_BLOCK - dst_nritems;
if (push_items <= 0) {
return 1;
}
max_push = src_nritems / 2 + 1;
/* don't try to empty the node */
if (max_push > src_nritems)
return 1;
if (max_push < push_items)
push_items = max_push;
memmove(dst->keys + push_items, dst->keys,
dst_nritems * sizeof(struct key));
memmove(dst->blockptrs + push_items, dst->blockptrs,
dst_nritems * sizeof(u64));
memcpy(dst->keys, src->keys + src_nritems - push_items,
push_items * sizeof(struct key));
memcpy(dst->blockptrs, src->blockptrs + src_nritems - push_items,
push_items * sizeof(u64));
src->header.nritems -= push_items;
dst->header.nritems += push_items;
wret = write_tree_block(root, src_buf);
if (wret < 0)
ret = wret;
wret = write_tree_block(root, dst_buf);
if (wret < 0)
ret = wret;
return ret;
}
/*
* helper function to insert a new root level in the tree.
* A new node is allocated, and a single item is inserted to