Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6 into for-linus-1

* 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6: (9356 commits)
  [media] rc: update for bitop name changes
  fs: simplify iget & friends
  fs: pull inode->i_lock up out of writeback_single_inode
  fs: rename inode_lock to inode_hash_lock
  fs: move i_wb_list out from under inode_lock
  fs: move i_sb_list out from under inode_lock
  fs: remove inode_lock from iput_final and prune_icache
  fs: Lock the inode LRU list separately
  fs: factor inode disposal
  fs: protect inode->i_state with inode->i_lock
  lib, arch: add filter argument to show_mem and fix private implementations
  SLUB: Write to per cpu data when allocating it
  slub: Fix debugobjects with lockless fastpath
  autofs4: Do not potentially dereference NULL pointer returned by fget() in autofs_dev_ioctl_setpipefd()
  autofs4 - remove autofs4_lock
  autofs4 - fix d_manage() return on rcu-walk
  autofs4 - fix autofs4_expire_indirect() traversal
  autofs4 - fix dentry leak in autofs4_expire_direct()
  autofs4 - reinstate last used update on access
  vfs - check non-mountpoint dentry might block in __follow_mount_rcu()
  ...

NOTE!

This merge commit was created to fix compilation error. The block
tree was merged upstream and removed the 'elv_queue_empty()'
function which the new 'mtdswap' driver is using. So a simple
merge of the mtd tree with upstream does not compile. And the
mtd tree has already be published, so re-basing it is not an option.

To fix this unfortunate situation, I had to merge upstream into the
mtd-2.6.git tree without committing, put the fixup patch on top of
this, and then commit this. The result is that we do not have commits
which do not compile.

In other words, this merge commit "merges" 3 things: the MTD tree, the
upstream tree, and the fixup patch.

1 files changed, 100 insertions, 62 deletions

diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index 60d684266959..a0390657451b 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -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;
 }