Btrfs: sort references by byte number during btrfs_inc_ref
[linux-2.6-block.git] / fs / btrfs / extent-tree.c
index 293da650873f5193c726c4883bc6ecc5114b0a1a..7a22f2e6ec47e7af91ef460b51b744cbb01809e6 100644 (file)
@@ -19,7 +19,7 @@
 #include <linux/pagemap.h>
 #include <linux/writeback.h>
 #include <linux/blkdev.h>
-#include <linux/version.h>
+#include <linux/sort.h>
 #include "compat.h"
 #include "hash.h"
 #include "crc32c.h"
@@ -30,7 +30,6 @@
 #include "volumes.h"
 #include "locking.h"
 #include "ref-cache.h"
-#include "compat.h"
 
 #define PENDING_EXTENT_INSERT 0
 #define PENDING_EXTENT_DELETE 1
@@ -326,10 +325,8 @@ static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info,
                                                  u64 flags)
 {
        struct list_head *head = &info->space_info;
-       struct list_head *cur;
        struct btrfs_space_info *found;
-       list_for_each(cur, head) {
-               found = list_entry(cur, struct btrfs_space_info, list);
+       list_for_each_entry(found, head, list) {
                if (found->flags == flags)
                        return found;
        }
@@ -1525,15 +1522,50 @@ out:
        return ret;
 }
 
-int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
-                 struct extent_buffer *orig_buf, struct extent_buffer *buf,
-                 u32 *nr_extents)
+/* when a block goes through cow, we update the reference counts of
+ * everything that block points to.  The internal pointers of the block
+ * can be in just about any order, and it is likely to have clusters of
+ * things that are close together and clusters of things that are not.
+ *
+ * To help reduce the seeks that come with updating all of these reference
+ * counts, sort them by byte number before actual updates are done.
+ *
+ * struct refsort is used to match byte number to slot in the btree block.
+ * we sort based on the byte number and then use the slot to actually
+ * find the item.
+ */
+struct refsort {
+       u64 bytenr;
+       u32 slot;
+};
+
+/*
+ * for passing into sort()
+ */
+static int refsort_cmp(const void *a_void, const void *b_void)
+{
+       const struct refsort *a = a_void;
+       const struct refsort *b = b_void;
+
+       if (a->bytenr < b->bytenr)
+               return -1;
+       if (a->bytenr > b->bytenr)
+               return 1;
+       return 0;
+}
+
+
+noinline int btrfs_inc_ref(struct btrfs_trans_handle *trans,
+                          struct btrfs_root *root,
+                          struct extent_buffer *orig_buf,
+                          struct extent_buffer *buf, u32 *nr_extents)
 {
        u64 bytenr;
        u64 ref_root;
        u64 orig_root;
        u64 ref_generation;
        u64 orig_generation;
+       struct refsort *sorted;
        u32 nritems;
        u32 nr_file_extents = 0;
        struct btrfs_key key;
@@ -1542,6 +1574,8 @@ int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
        int level;
        int ret = 0;
        int faili = 0;
+       int refi = 0;
+       int slot;
        int (*process_func)(struct btrfs_trans_handle *, struct btrfs_root *,
                            u64, u64, u64, u64, u64, u64, u64, u64);
 
@@ -1553,6 +1587,9 @@ int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
        nritems = btrfs_header_nritems(buf);
        level = btrfs_header_level(buf);
 
+       sorted = kmalloc(sizeof(struct refsort) * nritems, GFP_NOFS);
+       BUG_ON(!sorted);
+
        if (root->ref_cows) {
                process_func = __btrfs_inc_extent_ref;
        } else {
@@ -1565,6 +1602,11 @@ int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
                process_func = __btrfs_update_extent_ref;
        }
 
+       /*
+        * we make two passes through the items.  In the first pass we
+        * only record the byte number and slot.  Then we sort based on
+        * byte number and do the actual work based on the sorted results
+        */
        for (i = 0; i < nritems; i++) {
                cond_resched();
                if (level == 0) {
@@ -1581,6 +1623,32 @@ int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
                                continue;
 
                        nr_file_extents++;
+                       sorted[refi].bytenr = bytenr;
+                       sorted[refi].slot = i;
+                       refi++;
+               } else {
+                       bytenr = btrfs_node_blockptr(buf, i);
+                       sorted[refi].bytenr = bytenr;
+                       sorted[refi].slot = i;
+                       refi++;
+               }
+       }
+       /*
+        * if refi == 0, we didn't actually put anything into the sorted
+        * array and we're done
+        */
+       if (refi == 0)
+               goto out;
+
+       sort(sorted, refi, sizeof(struct refsort), refsort_cmp, NULL);
+
+       for (i = 0; i < refi; i++) {
+               cond_resched();
+               slot = sorted[i].slot;
+               bytenr = sorted[i].bytenr;
+
+               if (level == 0) {
+                       btrfs_item_key_to_cpu(buf, &key, slot);
 
                        ret = process_func(trans, root, bytenr,
                                           orig_buf->start, buf->start,
@@ -1589,25 +1657,25 @@ int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
                                           key.objectid);
 
                        if (ret) {
-                               faili = i;
+                               faili = slot;
                                WARN_ON(1);
                                goto fail;
                        }
                } else {
-                       bytenr = btrfs_node_blockptr(buf, i);
                        ret = process_func(trans, root, bytenr,
                                           orig_buf->start, buf->start,
                                           orig_root, ref_root,
                                           orig_generation, ref_generation,
                                           level - 1);
                        if (ret) {
-                               faili = i;
+                               faili = slot;
                                WARN_ON(1);
                                goto fail;
                        }
                }
        }
 out:
+       kfree(sorted);
        if (nr_extents) {
                if (level == 0)
                        *nr_extents = nr_file_extents;
@@ -1616,6 +1684,7 @@ out:
        }
        return 0;
 fail:
+       kfree(sorted);
        WARN_ON(1);
        return ret;
 }
@@ -2159,7 +2228,8 @@ again:
                ret = find_first_extent_bit(&info->extent_ins, search, &start,
                                            &end, EXTENT_WRITEBACK);
                if (ret) {
-                       if (skipped && all && !num_inserts) {
+                       if (skipped && all && !num_inserts &&
+                           list_empty(&update_list)) {
                                skipped = 0;
                                search = 0;
                                continue;
@@ -2547,6 +2617,7 @@ again:
                if (ret) {
                        if (all && skipped && !nr) {
                                search = 0;
+                               skipped = 0;
                                continue;
                        }
                        mutex_unlock(&info->extent_ins_mutex);
@@ -2700,13 +2771,9 @@ static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
        /* if metadata always pin */
        if (owner_objectid < BTRFS_FIRST_FREE_OBJECTID) {
                if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
-                       struct btrfs_block_group_cache *cache;
-
-                       /* btrfs_free_reserved_extent */
-                       cache = btrfs_lookup_block_group(root->fs_info, bytenr);
-                       BUG_ON(!cache);
-                       btrfs_add_free_space(cache, bytenr, num_bytes);
-                       put_block_group(cache);
+                       mutex_lock(&root->fs_info->pinned_mutex);
+                       btrfs_update_pinned_extents(root, bytenr, num_bytes, 1);
+                       mutex_unlock(&root->fs_info->pinned_mutex);
                        update_reserved_extents(root, bytenr, num_bytes, 0);
                        return 0;
                }
@@ -3014,7 +3081,6 @@ loop_check:
 static void dump_space_info(struct btrfs_space_info *info, u64 bytes)
 {
        struct btrfs_block_group_cache *cache;
-       struct list_head *l;
 
        printk(KERN_INFO "space_info has %llu free, is %sfull\n",
               (unsigned long long)(info->total_bytes - info->bytes_used -
@@ -3022,8 +3088,7 @@ static void dump_space_info(struct btrfs_space_info *info, u64 bytes)
               (info->full) ? "" : "not ");
 
        down_read(&info->groups_sem);
-       list_for_each(l, &info->block_groups) {
-               cache = list_entry(l, struct btrfs_block_group_cache, list);
+       list_for_each_entry(cache, &info->block_groups, list) {
                spin_lock(&cache->lock);
                printk(KERN_INFO "block group %llu has %llu bytes, %llu used "
                       "%llu pinned %llu reserved\n",
@@ -4444,7 +4509,7 @@ static noinline int replace_one_extent(struct btrfs_trans_handle *trans,
        u64 lock_end = 0;
        u64 num_bytes;
        u64 ext_offset;
-       u64 first_pos;
+       u64 search_end = (u64)-1;
        u32 nritems;
        int nr_scaned = 0;
        int extent_locked = 0;
@@ -4452,7 +4517,6 @@ static noinline int replace_one_extent(struct btrfs_trans_handle *trans,
        int ret;
 
        memcpy(&key, leaf_key, sizeof(key));
-       first_pos = INT_LIMIT(loff_t) - extent_key->offset;
        if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS) {
                if (key.objectid < ref_path->owner_objectid ||
                    (key.objectid == ref_path->owner_objectid &&
@@ -4501,7 +4565,7 @@ next:
                        if ((key.objectid > ref_path->owner_objectid) ||
                            (key.objectid == ref_path->owner_objectid &&
                             key.type > BTRFS_EXTENT_DATA_KEY) ||
-                           (key.offset >= first_pos + extent_key->offset))
+                           key.offset >= search_end)
                                break;
                }
 
@@ -4534,8 +4598,10 @@ next:
                num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
                ext_offset = btrfs_file_extent_offset(leaf, fi);
 
-               if (first_pos > key.offset - ext_offset)
-                       first_pos = key.offset - ext_offset;
+               if (search_end == (u64)-1) {
+                       search_end = key.offset - ext_offset +
+                               btrfs_file_extent_ram_bytes(leaf, fi);
+               }
 
                if (!extent_locked) {
                        lock_start = key.offset;
@@ -4724,7 +4790,7 @@ next:
                }
 skip:
                if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS &&
-                   key.offset >= first_pos + extent_key->offset)
+                   key.offset >= search_end)
                        break;
 
                cond_resched();
@@ -5957,9 +6023,11 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
        path = btrfs_alloc_path();
        BUG_ON(!path);
 
-       btrfs_remove_free_space_cache(block_group);
+       spin_lock(&root->fs_info->block_group_cache_lock);
        rb_erase(&block_group->cache_node,
                 &root->fs_info->block_group_cache_tree);
+       spin_unlock(&root->fs_info->block_group_cache_lock);
+       btrfs_remove_free_space_cache(block_group);
        down_write(&block_group->space_info->groups_sem);
        list_del(&block_group->list);
        up_write(&block_group->space_info->groups_sem);