Btrfs: Allow find_free_extent callers to pass in an exclusion range

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

1 files changed, 30 insertions, 49 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 7e550343aee7..01dc30579287 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -25,7 +25,8 @@
 static int find_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
                             *orig_root, u64 num_blocks, u64 search_start,
                             u64 search_end, u64 hint_block,
-                            struct btrfs_key *ins, int data);
+                            struct btrfs_key *ins, u64 exclude_start,
+                            u64 exclude_nr, int data);
 static int finish_current_insert(struct btrfs_trans_handle *trans, struct
                                  btrfs_root *extent_root);
 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
@@ -407,7 +408,7 @@ int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
         if (!path)
                 return -ENOMEM;
         ret = find_free_extent(trans, root->fs_info->extent_root, 0, 0,
-                               (u64)-1, 0, &ins, 0);
+                               (u64)-1, 0, &ins, 0, 0, 0);
         if (ret) {
                 btrfs_free_path(path);
                 return ret;
@@ -559,7 +560,8 @@ static int write_one_cache_group(struct btrfs_trans_handle *trans,
         struct btrfs_block_group_item *bi;
         struct btrfs_key ins;
 
-        ret = find_free_extent(trans, extent_root, 0, 0, (u64)-1, 0, &ins, 0);
+        ret = find_free_extent(trans, extent_root, 0, 0, (u64)-1, 0, &ins,
+                               0, 0, 0);
         /* FIXME, set bit to recalc cache groups on next mount */
         if (ret)
                 return ret;
@@ -868,7 +870,7 @@ static int __free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
         if (!path)
                 return -ENOMEM;
 
-        ret = find_free_extent(trans, root, 0, 0, (u64)-1, 0, &ins, 0);
+        ret = find_free_extent(trans, root, 0, 0, (u64)-1, 0, &ins, 0, 0, 0);
         if (ret) {
                 btrfs_free_path(path);
                 return ret;
@@ -987,7 +989,8 @@ int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
 static int find_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
                             *orig_root, u64 num_blocks, u64 search_start, u64
                             search_end, u64 hint_block,
-                            struct btrfs_key *ins, int data)
+                            struct btrfs_key *ins, u64 exclude_start,
+                            u64 exclude_nr, int data)
 {
         struct btrfs_path *path;
         struct btrfs_key key;
@@ -1191,6 +1194,11 @@ check_pending:
                         goto new_group;
                 }
         }
+        if (exclude_nr > 0 && (ins->objectid + num_blocks > exclude_start &&
+            ins->objectid < exclude_start + exclude_nr)) {
+                search_start = exclude_start + exclude_nr;
+                goto new_group;
+        }
         if (fill_prealloc) {
                 int nr;
                 test_block = ins->objectid;
@@ -1267,6 +1275,8 @@ int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
         int pending_ret;
         u64 super_blocks_used;
         u64 search_start = 0;
+        u64 exclude_start = 0;
+        u64 exclude_nr = 0;
         struct btrfs_fs_info *info = root->fs_info;
         struct btrfs_root *extent_root = info->extent_root;
         struct btrfs_extent_item extent_item;
@@ -1298,33 +1308,19 @@ int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
          */
         if (data) {
                 ret = find_free_extent(trans, root, 0, 0,
-                                       search_end, 0, &prealloc_key, 0);
-                if (ret) {
+                                       search_end, 0, &prealloc_key, 0, 0, 0);
+                if (ret)
                         return ret;
-                }
-                if (prealloc_key.objectid + prealloc_key.offset >= search_end) {
-                        int nr = info->extent_tree_prealloc_nr;
-                        search_end = info->extent_tree_prealloc[nr - 1] - 1;
-                } else {
-                        search_start = info->extent_tree_prealloc[0] + 1;
-                }
+                exclude_nr = info->extent_tree_prealloc_nr;
+                exclude_start = info->extent_tree_prealloc[exclude_nr - 1];
         }
-        if (hint_block < search_start)
-                hint_block = search_start;
+
         /* do the real allocation */
         ret = find_free_extent(trans, root, num_blocks, search_start,
-                               search_end, hint_block, ins, data);
-        if (ret) {
-                if (search_start == 0)
-                        return ret;
-                search_end = search_start - 1;
-                search_start = 0;
-                hint_block = search_start;
-                ret = find_free_extent(trans, root, num_blocks, search_start,
-                                       search_end, hint_block, ins, data);
-                if (ret)
-                        return ret;
-        }
+                               search_end, hint_block, ins,
+                               exclude_start, exclude_nr, data);
+        if (ret)
+                return ret;
 
         /*
          * if we're doing a metadata allocation, preallocate space in the
@@ -1336,29 +1332,14 @@ int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
          * The unused prealloc will get reused the next time around.
          */
         if (!data) {
-                if (ins->objectid + ins->offset >= search_end)
-                        search_end = ins->objectid - 1;
-                else
-                        search_start = ins->objectid + ins->offset;
-
-                if (hint_block < search_start)
-                        hint_block = search_start;
-
+                exclude_start = ins->objectid;
+                exclude_nr = ins->offset;
                 ret = find_free_extent(trans, root, 0, search_start,
                                        search_end, hint_block,
-                                       &prealloc_key, 0);
-                if (ret) {
-                        if (search_start == 0)
-                                return ret;
-                        search_end = search_start - 1;
-                        search_start = 0;
-                        hint_block = search_start;
-                        ret = find_free_extent(trans, root, 0, search_start,
-                                               search_end, hint_block,
-                                               &prealloc_key, 0);
-                        if (ret)
-                                return ret;
-                }
+                                       &prealloc_key, exclude_start,
+                                       exclude_nr, 0);
+                if (ret)
+                        return ret;
         }
 
         super_blocks_used = btrfs_super_blocks_used(&info->super_copy);