]> git.karo-electronics.de Git - mv-sheeva.git/blobdiff - fs/btrfs/free-space-cache.c
Merge tag 'v2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
[mv-sheeva.git] / fs / btrfs / free-space-cache.c
index 60d684266959bbf8f96c14873e9a1f57e069a29e..a0390657451b920dac20e17aa04bcc86a0b583e0 100644 (file)
@@ -987,11 +987,18 @@ tree_search_offset(struct btrfs_block_group_cache *block_group,
        return entry;
 }
 
-static void unlink_free_space(struct btrfs_block_group_cache *block_group,
-                             struct btrfs_free_space *info)
+static inline void
+__unlink_free_space(struct btrfs_block_group_cache *block_group,
+                   struct btrfs_free_space *info)
 {
        rb_erase(&info->offset_index, &block_group->free_space_offset);
        block_group->free_extents--;
+}
+
+static void unlink_free_space(struct btrfs_block_group_cache *block_group,
+                             struct btrfs_free_space *info)
+{
+       __unlink_free_space(block_group, info);
        block_group->free_space -= info->bytes;
 }
 
@@ -1016,14 +1023,18 @@ static void recalculate_thresholds(struct btrfs_block_group_cache *block_group)
        u64 max_bytes;
        u64 bitmap_bytes;
        u64 extent_bytes;
+       u64 size = block_group->key.offset;
 
        /*
         * The goal is to keep the total amount of memory used per 1gb of space
         * at or below 32k, so we need to adjust how much memory we allow to be
         * used by extent based free space tracking
         */
-       max_bytes = MAX_CACHE_BYTES_PER_GIG *
-               (div64_u64(block_group->key.offset, 1024 * 1024 * 1024));
+       if (size < 1024 * 1024 * 1024)
+               max_bytes = MAX_CACHE_BYTES_PER_GIG;
+       else
+               max_bytes = MAX_CACHE_BYTES_PER_GIG *
+                       div64_u64(size, 1024 * 1024 * 1024);
 
        /*
         * we want to account for 1 more bitmap than what we have so we can make
@@ -1171,6 +1182,16 @@ static void add_new_bitmap(struct btrfs_block_group_cache *block_group,
        recalculate_thresholds(block_group);
 }
 
+static void free_bitmap(struct btrfs_block_group_cache *block_group,
+                       struct btrfs_free_space *bitmap_info)
+{
+       unlink_free_space(block_group, bitmap_info);
+       kfree(bitmap_info->bitmap);
+       kfree(bitmap_info);
+       block_group->total_bitmaps--;
+       recalculate_thresholds(block_group);
+}
+
 static noinline int remove_from_bitmap(struct btrfs_block_group_cache *block_group,
                              struct btrfs_free_space *bitmap_info,
                              u64 *offset, u64 *bytes)
@@ -1195,6 +1216,7 @@ again:
         */
        search_start = *offset;
        search_bytes = *bytes;
+       search_bytes = min(search_bytes, end - search_start + 1);
        ret = search_bitmap(block_group, bitmap_info, &search_start,
                            &search_bytes);
        BUG_ON(ret < 0 || search_start != *offset);
@@ -1211,13 +1233,8 @@ again:
 
        if (*bytes) {
                struct rb_node *next = rb_next(&bitmap_info->offset_index);
-               if (!bitmap_info->bytes) {
-                       unlink_free_space(block_group, bitmap_info);
-                       kfree(bitmap_info->bitmap);
-                       kfree(bitmap_info);
-                       block_group->total_bitmaps--;
-                       recalculate_thresholds(block_group);
-               }
+               if (!bitmap_info->bytes)
+                       free_bitmap(block_group, bitmap_info);
 
                /*
                 * no entry after this bitmap, but we still have bytes to
@@ -1250,13 +1267,8 @@ again:
                        return -EAGAIN;
 
                goto again;
-       } else if (!bitmap_info->bytes) {
-               unlink_free_space(block_group, bitmap_info);
-               kfree(bitmap_info->bitmap);
-               kfree(bitmap_info);
-               block_group->total_bitmaps--;
-               recalculate_thresholds(block_group);
-       }
+       } else if (!bitmap_info->bytes)
+               free_bitmap(block_group, bitmap_info);
 
        return 0;
 }
@@ -1359,22 +1371,14 @@ out:
        return ret;
 }
 
-int btrfs_add_free_space(struct btrfs_block_group_cache *block_group,
-                        u64 offset, u64 bytes)
+bool try_merge_free_space(struct btrfs_block_group_cache *block_group,
+                         struct btrfs_free_space *info, bool update_stat)
 {
-       struct btrfs_free_space *right_info = NULL;
-       struct btrfs_free_space *left_info = NULL;
-       struct btrfs_free_space *info = NULL;
-       int ret = 0;
-
-       info = kzalloc(sizeof(struct btrfs_free_space), GFP_NOFS);
-       if (!info)
-               return -ENOMEM;
-
-       info->offset = offset;
-       info->bytes = bytes;
-
-       spin_lock(&block_group->tree_lock);
+       struct btrfs_free_space *left_info;
+       struct btrfs_free_space *right_info;
+       bool merged = false;
+       u64 offset = info->offset;
+       u64 bytes = info->bytes;
 
        /*
         * first we want to see if there is free space adjacent to the range we
@@ -1388,37 +1392,62 @@ int btrfs_add_free_space(struct btrfs_block_group_cache *block_group,
        else
                left_info = tree_search_offset(block_group, offset - 1, 0, 0);
 
-       /*
-        * If there was no extent directly to the left or right of this new
-        * extent then we know we're going to have to allocate a new extent, so
-        * before we do that see if we need to drop this into a bitmap
-        */
-       if ((!left_info || left_info->bitmap) &&
-           (!right_info || right_info->bitmap)) {
-               ret = insert_into_bitmap(block_group, info);
-
-               if (ret < 0) {
-                       goto out;
-               } else if (ret) {
-                       ret = 0;
-                       goto out;
-               }
-       }
-
        if (right_info && !right_info->bitmap) {
-               unlink_free_space(block_group, right_info);
+               if (update_stat)
+                       unlink_free_space(block_group, right_info);
+               else
+                       __unlink_free_space(block_group, right_info);
                info->bytes += right_info->bytes;
                kfree(right_info);
+               merged = true;
        }
 
        if (left_info && !left_info->bitmap &&
            left_info->offset + left_info->bytes == offset) {
-               unlink_free_space(block_group, left_info);
+               if (update_stat)
+                       unlink_free_space(block_group, left_info);
+               else
+                       __unlink_free_space(block_group, left_info);
                info->offset = left_info->offset;
                info->bytes += left_info->bytes;
                kfree(left_info);
+               merged = true;
        }
 
+       return merged;
+}
+
+int btrfs_add_free_space(struct btrfs_block_group_cache *block_group,
+                        u64 offset, u64 bytes)
+{
+       struct btrfs_free_space *info;
+       int ret = 0;
+
+       info = kzalloc(sizeof(struct btrfs_free_space), GFP_NOFS);
+       if (!info)
+               return -ENOMEM;
+
+       info->offset = offset;
+       info->bytes = bytes;
+
+       spin_lock(&block_group->tree_lock);
+
+       if (try_merge_free_space(block_group, info, true))
+               goto link;
+
+       /*
+        * There was no extent directly to the left or right of this new
+        * extent then we know we're going to have to allocate a new extent, so
+        * before we do that see if we need to drop this into a bitmap
+        */
+       ret = insert_into_bitmap(block_group, info);
+       if (ret < 0) {
+               goto out;
+       } else if (ret) {
+               ret = 0;
+               goto out;
+       }
+link:
        ret = link_free_space(block_group, info);
        if (ret)
                kfree(info);
@@ -1621,6 +1650,7 @@ __btrfs_return_cluster_to_free_space(
                node = rb_next(&entry->offset_index);
                rb_erase(&entry->offset_index, &cluster->root);
                BUG_ON(entry->bitmap);
+               try_merge_free_space(block_group, entry, false);
                tree_insert_offset(&block_group->free_space_offset,
                                   entry->offset, &entry->offset_index, 0);
        }
@@ -1685,13 +1715,8 @@ u64 btrfs_find_space_for_alloc(struct btrfs_block_group_cache *block_group,
        ret = offset;
        if (entry->bitmap) {
                bitmap_clear_bits(block_group, entry, offset, bytes);
-               if (!entry->bytes) {
-                       unlink_free_space(block_group, entry);
-                       kfree(entry->bitmap);
-                       kfree(entry);
-                       block_group->total_bitmaps--;
-                       recalculate_thresholds(block_group);
-               }
+               if (!entry->bytes)
+                       free_bitmap(block_group, entry);
        } else {
                unlink_free_space(block_group, entry);
                entry->offset += bytes;
@@ -1789,6 +1814,8 @@ static u64 btrfs_alloc_from_bitmap(struct btrfs_block_group_cache *block_group,
 
        ret = search_start;
        bitmap_clear_bits(block_group, entry, ret, bytes);
+       if (entry->bytes == 0)
+               free_bitmap(block_group, entry);
 out:
        spin_unlock(&cluster->lock);
        spin_unlock(&block_group->tree_lock);
@@ -1842,15 +1869,26 @@ u64 btrfs_alloc_from_cluster(struct btrfs_block_group_cache *block_group,
                entry->offset += bytes;
                entry->bytes -= bytes;
 
-               if (entry->bytes == 0) {
+               if (entry->bytes == 0)
                        rb_erase(&entry->offset_index, &cluster->root);
-                       kfree(entry);
-               }
                break;
        }
 out:
        spin_unlock(&cluster->lock);
 
+       if (!ret)
+               return 0;
+
+       spin_lock(&block_group->tree_lock);
+
+       block_group->free_space -= bytes;
+       if (entry->bytes == 0) {
+               block_group->free_extents--;
+               kfree(entry);
+       }
+
+       spin_unlock(&block_group->tree_lock);
+
        return ret;
 }