Btrfs: use a separate flag for search_start vs a hint in find_free_extent

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

1 files changed, 42 insertions, 27 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index b6dc020bdde9..85616b458e18 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -5,8 +5,9 @@
 #include "transaction.h"
 
 static int find_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
-                            *orig_root, u64 num_blocks, u64 search_start, u64
-                            search_end, struct btrfs_key *ins, int data);
+                            *orig_root, u64 num_blocks, u64 search_start,
+                            u64 search_end, u64 hint_block,
+                            struct btrfs_key *ins, 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
@@ -157,12 +158,6 @@ static struct btrfs_block_group_cache *lookup_block_group(struct
                     block_group->key.objectid + block_group->key.offset)
                         return block_group;
         }
-        WARN_ON(1);
-        printk("lookup_block_group fails for blocknr %Lu\n", blocknr);
-        printk("last ret was %d\n", ret);
-        if (ret) {
-                printk("last block group was %Lu %Lu\n", block_group->key.objectid, block_group->key.offset);
-        }
         return NULL;
 }
 
@@ -378,7 +373,7 @@ int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
         struct btrfs_key ins;
         u32 refs;
 
-        find_free_extent(trans, root->fs_info->extent_root, 0, 0, (u64)-1,
+        find_free_extent(trans, root->fs_info->extent_root, 0, 0, (u64)-1, 0,
                          &ins, 0);
         path = btrfs_alloc_path();
         BUG_ON(!path);
@@ -495,7 +490,7 @@ static int write_one_cache_group(struct btrfs_trans_handle *trans,
         struct btrfs_block_group_item *bi;
         struct btrfs_key ins;
 
-        find_free_extent(trans, extent_root, 0, 0, (u64)-1, &ins, 0);
+        find_free_extent(trans, extent_root, 0, 0, (u64)-1, 0, &ins, 0);
         ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
         BUG_ON(ret);
         bi = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
@@ -788,7 +783,7 @@ static int __free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
         btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
         key.offset = num_blocks;
 
-        find_free_extent(trans, root, 0, 0, (u64)-1, &ins, 0);
+        find_free_extent(trans, root, 0, 0, (u64)-1, 0, &ins, 0);
         path = btrfs_alloc_path();
         BUG_ON(!path);
         btrfs_init_path(path);
@@ -906,7 +901,8 @@ 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, struct btrfs_key *ins, int data)
+                            search_end, u64 hint_block,
+                            struct btrfs_key *ins, int data)
 {
         struct btrfs_path *path;
         struct btrfs_key key;
@@ -926,6 +922,7 @@ static int find_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
         int level;
         struct btrfs_block_group_cache *block_group;
         int full_scan = 0;
+        int wrapped = 0;
         u64 limit;
 
         path = btrfs_alloc_path();
@@ -940,10 +937,10 @@ static int find_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
         }
         if (search_end == (u64)-1)
                 search_end = btrfs_super_total_blocks(info->disk_super);
-        if (search_start) {
-                block_group = lookup_block_group(info, search_start);
+        if (hint_block) {
+                block_group = lookup_block_group(info, hint_block);
                 block_group = btrfs_find_block_group(root, block_group,
-                                                     search_start, data, 1);
+                                                     hint_block, data, 1);
         } else {
                 block_group = btrfs_find_block_group(root,
                                                      trans->block_group, 0,
@@ -954,7 +951,7 @@ check_failed:
         if (!block_group->data)
                 search_start = find_search_start(root, &block_group,
                                                  search_start, total_needed);
-        else
+        else if (!full_scan)
                 search_start = max(block_group->last_alloc, search_start);
 
         btrfs_init_path(path);
@@ -1039,7 +1036,7 @@ check_failed:
 
                 start_found = 1;
                 last_block = key.objectid + key.offset;
-                if (last_block >= block_group->key.objectid +
+                if (!full_scan && last_block >= block_group->key.objectid +
                     block_group->key.offset) {
                         btrfs_release_path(root, path);
                         search_start = block_group->key.objectid +
@@ -1059,10 +1056,15 @@ check_pending:
         BUG_ON(ins->objectid < search_start);
 
         if (ins->objectid + num_blocks >= search_end) {
-                if (full_scan)
-                        return -ENOSPC;
+                if (full_scan) {
+                        ret = -ENOSPC;
+                        goto error;
+                }
                 search_start = orig_search_start;
-                full_scan = 1;
+                if (wrapped)
+                        full_scan = 1;
+                else
+                        wrapped = 1;
                 goto new_group;
         }
         for (test_block = ins->objectid;
@@ -1132,14 +1134,20 @@ check_pending:
 new_group:
         if (search_start + num_blocks >= search_end) {
                 search_start = orig_search_start;
-printk("doing full scan!\n");
-                full_scan = 1;
+                if (full_scan) {
+                        ret = -ENOSPC;
+                        goto error;
+                }
+                if (wrapped)
+                        full_scan = 1;
+                else
+                        wrapped = 1;
         }
         block_group = lookup_block_group(info, search_start);
+        cond_resched();
         if (!full_scan)
                 block_group = btrfs_find_block_group(root, block_group,
                                                      search_start, data, 0);
-        cond_resched();
         goto check_failed;
 
 error:
@@ -1156,12 +1164,13 @@ error:
  */
 int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
                        struct btrfs_root *root, u64 owner,
-                       u64 num_blocks, u64 search_start,
+                       u64 num_blocks, u64 hint_block,
                        u64 search_end, struct btrfs_key *ins, int data)
 {
         int ret;
         int pending_ret;
         u64 super_blocks_used;
+        u64 search_start = 0;
         struct btrfs_fs_info *info = root->fs_info;
         struct btrfs_root *extent_root = info->extent_root;
         struct btrfs_extent_item extent_item;
@@ -1193,7 +1202,7 @@ int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
          */
         if (data) {
                 ret = find_free_extent(trans, root, 0, 0,
-                                       search_end, &prealloc_key, 0);
+                                       search_end, 0, &prealloc_key, 0);
                 if (ret) {
                         return ret;
                 }
@@ -1204,9 +1213,11 @@ int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
                         search_start = info->extent_tree_prealloc[0] + 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, ins, data);
+                               search_end, hint_block, ins, data);
         if (ret) {
                 return ret;
         }
@@ -1226,8 +1237,12 @@ int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
                 else
                         search_start = ins->objectid + ins->offset;
 
+                if (hint_block < search_start)
+                        hint_block = search_start;
+
                 ret = find_free_extent(trans, root, 0, search_start,
-                                       search_end, &prealloc_key, 0);
+                                       search_end, hint_block,
+                                       &prealloc_key, 0);
                 if (ret) {
                         return ret;
                 }