Btrfs: Faster deletes, add Makefile and kerncompat

Signed-off-by: Chris Mason <chris.mason@oracle.com>

diff --git a/fs/btrfs/Makefile b/fs/btrfs/Makefile
new file mode 100644 (file)
index 0000000..9f84c08
--- /dev/null
+++ b/fs/btrfs/Makefile
@@ -0,0 +1,7 @@
+
+ctree: ctree.o
+       gcc -g -O2 -Wall -o ctree ctree.c
+
+clean:
+       rm ctree ctree.o
+

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 893fd56960a0abca7af3943239c6056f80fee5a0..4bf5e92584bd309b2abda1323ca62fa616bcd7f3 100644 (file)
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -615,9 +615,9 @@ int del_ptr(struct ctree_root *root, struct ctree_path *path, int level)
                        if (node->header.nritems) {
                                push_node_right(root, path, level);
                        }
-                       path->slots[level+1] = tslot;
                        if (node->header.nritems)
                                break;
+                       path->slots[level+1] = tslot;
                }
                if (node == root->node) {
                        printf("root is now null!\n");
@@ -632,22 +632,15 @@ int del_ptr(struct ctree_root *root, struct ctree_path *path, int level)
        return 0;
 }
 
-int del_item(struct ctree_root *root, struct key *key)
+int del_item(struct ctree_root *root, struct ctree_path *path)
 {
-       int ret;
        int slot;
        struct leaf *leaf;
-       struct ctree_path path;
        int doff;
        int dsize;
 
-       init_path(&path);
-       ret = search_slot(root, key, &path);
-       if (ret != 0)
-               return -1;
-
-       leaf = (struct leaf *)path.nodes[0];
-       slot = path.slots[0];
+       leaf = (struct leaf *)path->nodes[0];
+       slot = path->slots[0];
        doff = leaf->items[slot].offset;
        dsize = leaf->items[slot].size;
 
@@ -665,23 +658,26 @@ int del_item(struct ctree_root *root, struct key *key)
        }
        leaf->header.nritems -= 1;
        if (leaf->header.nritems == 0) {
+               if (leaf == (struct leaf *)root->node)
+                       root->node = NULL;
+               else
+                       del_ptr(root, path, 1);
                free(leaf);
-               del_ptr(root, &path, 1);
        } else {
                if (slot == 0)
-                       fixup_low_keys(&path, &leaf->items[0].key, 1);
+                       fixup_low_keys(path, &leaf->items[0].key, 1);
                if (leaf_space_used(leaf, 0, leaf->header.nritems) <
                    LEAF_DATA_SIZE / 4) {
                        /* push_leaf_left fixes the path.
                         * make sure the path still points to our leaf
                         * for possible call to del_ptr below
                         */
-                       slot = path.slots[1];
-                       push_leaf_left(root, &path, 1);
-                       path.slots[1] = slot;
+                       slot = path->slots[1];
+                       push_leaf_left(root, path, 1);
                        if (leaf->header.nritems == 0) {
                                free(leaf);
-                               del_ptr(root, &path, 1);
+                               path->slots[1] = slot;
+                               del_ptr(root, path, 1);
                        }
                }
        }
@@ -753,11 +749,12 @@ int main() {
        struct leaf *first_node = malloc(sizeof(struct leaf));
        struct ctree_root root;
        struct key ins;
+       struct key last = { (u64)-1, 0, 0};
        char *buf;
        int i;
        int num;
        int ret;
-       int run_size = 10000000;
+       int run_size = 100000;
        int max_key = 100000000;
        int tree_size = 0;
        struct ctree_path path;
@@ -783,8 +780,6 @@ int main() {
        for (i = 0; i < run_size; i++) {
                num = next_key(i, max_key);
                ins.objectid = num;
-               ins.offset = 0;
-               ins.flags = 0;
                init_path(&path);
                ret = search_slot(&root, &ins, &path);
                if (ret) {
@@ -800,11 +795,56 @@ int main() {
        printf("all searches good\n");
        i = 0;
        srand(55);
+       for (i = 0 ; i < run_size/4; i++) {
+               num = next_key(i, max_key);
+               ins.objectid = num;
+               init_path(&path);
+               ret = search_slot(&root, &ins, &path);
+               if (ret)
+                       continue;
+               ret = del_item(&root, &path);
+               if (ret != 0)
+                       BUG();
+               tree_size--;
+       }
+       srand(128);
        for (i = 0; i < run_size; i++) {
+               buf = malloc(64);
                num = next_key(i, max_key);
+               sprintf(buf, "string-%d", num);
                ins.objectid = num;
-               del_item(&root, &ins);
+               ret = insert_item(&root, &ins, buf, strlen(buf));
+               if (!ret)
+                       tree_size++;
+       }
+       while(root.node) {
+               struct leaf *leaf;
+               int slot;
+               ins.objectid = (u64)-1;
+               init_path(&path);
+               ret = search_slot(&root, &ins, &path);
+               if (ret == 0)
+                       BUG();
+
+               leaf = (struct leaf *)(path.nodes[0]);
+               slot = path.slots[0];
+               if (slot != leaf->header.nritems)
+                       BUG();
+               while(path.slots[0] > 0) {
+                       path.slots[0] -= 1;
+                       slot = path.slots[0];
+                       leaf = (struct leaf *)(path.nodes[0]);
+
+                       if (comp_keys(&last, &leaf->items[slot].key) <= 0)
+                               BUG();
+                       memcpy(&last, &leaf->items[slot].key, sizeof(last));
+                       ret = del_item(&root, &path);
+                       if (ret != 0)
+                               BUG();
+                       tree_size--;
+               }
        }
        print_tree(root.node);
+       printf("tree size is now %d\n", tree_size);
        return 0;
 }

diff --git a/fs/btrfs/kerncompat.h b/fs/btrfs/kerncompat.h
new file mode 100644 (file)
index 0000000..3a4bb4d
--- /dev/null
+++ b/fs/btrfs/kerncompat.h
@@ -0,0 +1,68 @@
+#ifndef __KERNCOMPAT
+#define __KERNCOMPAT
+#define gfp_t int
+#define get_cpu_var(p) (p)
+#define __get_cpu_var(p) (p)
+#define BITS_PER_LONG 64
+#define __GFP_BITS_SHIFT 20
+#define __GFP_BITS_MASK ((int)((1 << __GFP_BITS_SHIFT) - 1))
+#define __read_mostly
+#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
+#define __force
+#define PAGE_SHIFT 12
+#define ULONG_MAX       (~0UL)
+#define BUG() abort()
+
+typedef unsigned int u32;
+typedef unsigned long u64;
+typedef unsigned char u8;
+typedef unsigned short u16;
+
+typedef unsigned long pgoff_t;
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+struct vma_shared { int prio_tree_node; };
+struct vm_area_struct {
+       unsigned long vm_pgoff;
+       unsigned long vm_start;
+       unsigned long vm_end;
+       struct vma_shared shared;
+};
+
+struct page {
+       unsigned long index;
+};
+
+static inline void preempt_enable(void) { do {; } while(0);}
+static inline void preempt_disable(void) { do {; } while(0);}
+
+static inline void __set_bit(int bit, unsigned long *map) {
+       unsigned long *p = map + bit / BITS_PER_LONG;
+       bit = bit & (BITS_PER_LONG -1);
+       *p |= 1UL << bit;
+}
+
+static inline int test_bit(int bit, unsigned long *map) {
+       unsigned long *p = map + bit / BITS_PER_LONG;
+       bit = bit & (BITS_PER_LONG -1);
+       return *p & (1UL << bit) ? 1 : 0;
+}
+
+static inline void __clear_bit(int bit, unsigned long *map) {
+       unsigned long *p = map + bit / BITS_PER_LONG;
+       bit = bit & (BITS_PER_LONG -1);
+       *p &= ~(1UL << bit);
+}
+#define BUG_ON(c) do { if (c) abort(); } while (0)
+
+#define container_of(ptr, type, member) ({                      \
+        const typeof( ((type *)0)->member ) *__mptr = (ptr);    \
+               (type *)( (char *)__mptr - __builtin_offsetof(type,member) );})
+
+#endif
+
+#define ENOMEM 5
+#define EEXIST 6