Btrfs: Add back the online defragging code

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

1 files changed, 88 insertions, 89 deletions

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 34de83630ae9..08ddf1873ab1 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -155,55 +155,49 @@ int btrfs_cow_block(struct btrfs_trans_handle *trans,
         return ret;
 }
 
-#if 0
-static int close_blocks(u64 blocknr, u64 other)
+static int close_blocks(u64 blocknr, u64 other, u32 blocksize)
 {
-        if (blocknr < other && other - blocknr < 8)
+        if (blocknr < other && other - (blocknr + blocksize) < 32768)
                 return 1;
-        if (blocknr > other && blocknr - other < 8)
+        if (blocknr > other && blocknr - (other + blocksize) < 32768)
                 return 1;
         return 0;
 }
 
-static int should_defrag_leaf(struct extent_buffer *eb)
+static int should_defrag_leaf(struct extent_buffer *leaf)
 {
-        return 0;
-        struct btrfs_leaf *leaf = btrfs_buffer_leaf(eb);
-        struct btrfs_disk_key *key;
+        struct btrfs_key key;
         u32 nritems;
 
-        if (buffer_defrag(bh))
+        if (btrfs_buffer_defrag(leaf))
                 return 1;
 
-        nritems = btrfs_header_nritems(&leaf->header);
+        nritems = btrfs_header_nritems(leaf);
         if (nritems == 0)
                 return 0;
 
-        key = &leaf->items[0].key;
-        if (btrfs_disk_key_type(key) == BTRFS_DIR_ITEM_KEY)
+        btrfs_item_key_to_cpu(leaf, &key, 0);
+        if (key.type == BTRFS_DIR_ITEM_KEY)
                 return 1;
 
-        key = &leaf->items[nritems-1].key;
-        if (btrfs_disk_key_type(key) == BTRFS_DIR_ITEM_KEY)
+
+        btrfs_item_key_to_cpu(leaf, &key, nritems - 1);
+        if (key.type == BTRFS_DIR_ITEM_KEY)
                 return 1;
         if (nritems > 4) {
-                key = &leaf->items[nritems/2].key;
-                if (btrfs_disk_key_type(key) == BTRFS_DIR_ITEM_KEY)
+                btrfs_item_key_to_cpu(leaf, &key, nritems / 2);
+                if (key.type == BTRFS_DIR_ITEM_KEY)
                         return 1;
         }
         return 0;
 }
-#endif
 
 int btrfs_realloc_node(struct btrfs_trans_handle *trans,
                        struct btrfs_root *root, struct extent_buffer *parent,
                        int cache_only, u64 *last_ret)
 {
-        return 0;
-#if 0
-        struct btrfs_node *parent_node;
-        struct extent_buffer *cur_eb;
-        struct extent_buffer *tmp_eb;
+        struct extent_buffer *cur;
+        struct extent_buffer *tmp;
         u64 blocknr;
         u64 search_start = *last_ret;
         u64 last_block = 0;
@@ -214,6 +208,8 @@ int btrfs_realloc_node(struct btrfs_trans_handle *trans,
         int i;
         int err = 0;
         int parent_level;
+        int uptodate;
+        u32 blocksize;
 
         if (trans->transaction != root->fs_info->running_transaction) {
                 printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
@@ -225,12 +221,12 @@ int btrfs_realloc_node(struct btrfs_trans_handle *trans,
                        root->fs_info->generation);
                 WARN_ON(1);
         }
-        if (buffer_defrag_done(parent))
+        if (btrfs_buffer_defrag_done(parent))
                 return 0;
 
-        parent_node = btrfs_buffer_node(parent);
-        parent_nritems = btrfs_header_nritems(&parent_node->header);
-        parent_level = btrfs_header_level(&parent_node->header);
+        parent_nritems = btrfs_header_nritems(parent);
+        parent_level = btrfs_header_level(parent);
+        blocksize = btrfs_level_size(root, parent_level - 1);
 
         start_slot = 0;
         end_slot = parent_nritems;
@@ -240,56 +236,60 @@ int btrfs_realloc_node(struct btrfs_trans_handle *trans,
 
         for (i = start_slot; i < end_slot; i++) {
                 int close = 1;
-                blocknr = btrfs_node_blockptr(parent_node, i);
+                blocknr = btrfs_node_blockptr(parent, i);
                 if (last_block == 0)
                         last_block = blocknr;
                 if (i > 0) {
-                        other = btrfs_node_blockptr(parent_node, i - 1);
-                        close = close_blocks(blocknr, other);
+                        other = btrfs_node_blockptr(parent, i - 1);
+                        close = close_blocks(blocknr, other, blocksize);
                 }
                 if (close && i < end_slot - 1) {
-                        other = btrfs_node_blockptr(parent_node, i + 1);
-                        close = close_blocks(blocknr, other);
+                        other = btrfs_node_blockptr(parent, i + 1);
+                        close = close_blocks(blocknr, other, blocksize);
                 }
                 if (close) {
                         last_block = blocknr;
                         continue;
                 }
 
-                cur_bh = btrfs_find_tree_block(root, blocknr);
-                if (!cur_bh || !buffer_uptodate(cur_bh) ||
-                    buffer_locked(cur_bh) ||
-                    (parent_level != 1 && !buffer_defrag(cur_bh)) ||
-                    (parent_level == 1 && !should_defrag_leaf(cur_bh))) {
+                cur = btrfs_find_tree_block(root, blocknr, blocksize);
+                if (cur)
+                        uptodate = btrfs_buffer_uptodate(cur);
+                else
+                        uptodate = 0;
+                if (!cur || !uptodate ||
+                    (parent_level != 1 && !btrfs_buffer_defrag(cur)) ||
+                    (parent_level == 1 && !should_defrag_leaf(cur))) {
                         if (cache_only) {
-                                brelse(cur_bh);
+                                free_extent_buffer(cur);
                                 continue;
                         }
-                        if (!cur_bh || !buffer_uptodate(cur_bh) ||
-                            buffer_locked(cur_bh)) {
-                                brelse(cur_bh);
-                                cur_bh = read_tree_block(root, blocknr);
+                        if (!cur) {
+                                cur = read_tree_block(root, blocknr,
+                                                         blocksize);
+                        } else if (!uptodate) {
+                                btrfs_read_buffer(cur);
                         }
                 }
                 if (search_start == 0)
-                        search_start = last_block & ~((u64)65535);
+                        search_start = last_block;
 
-                err = __btrfs_cow_block(trans, root, cur_bh, parent, i,
-                                        &tmp_bh, search_start,
-                                        min(8, end_slot - i));
+                err = __btrfs_cow_block(trans, root, cur, parent, i,
+                                        &tmp, search_start,
+                                        min(16 * blocksize,
+                                            (end_slot - i) * blocksize));
                 if (err) {
-                        brelse(cur_bh);
+                        free_extent_buffer(cur);
                         break;
                 }
-                search_start = bh_blocknr(tmp_bh);
+                search_start = tmp->start;
                 *last_ret = search_start;
                 if (parent_level == 1)
-                        clear_buffer_defrag(tmp_bh);
-                set_buffer_defrag_done(tmp_bh);
-                brelse(tmp_bh);
+                        btrfs_clear_buffer_defrag(tmp);
+                btrfs_set_buffer_defrag_done(tmp);
+                free_extent_buffer(tmp);
         }
         return err;
-#endif
 }
 
 /*
@@ -892,22 +892,17 @@ static int push_nodes_for_insert(struct btrfs_trans_handle *trans,
 static void reada_for_search(struct btrfs_root *root, struct btrfs_path *path,
                              int level, int slot)
 {
-        return;
-#if 0
         struct extent_buffer *node;
-        int i;
         u32 nritems;
-        u64 bytenr;
         u64 search;
-        u64 cluster_start;
-        int ret;
-        int nread = 0;
+        u64 lowest_read;
+        u64 highest_read;
+        u64 nread = 0;
         int direction = path->reada;
-        int level;
-        struct radix_tree_root found;
-        unsigned long gang[8];
         struct extent_buffer *eb;
-
+        u32 nr;
+        u32 blocksize;
+        u32 nscan = 0;
 
         if (level == 0)
                 return;
@@ -917,42 +912,46 @@ static void reada_for_search(struct btrfs_root *root, struct btrfs_path *path,
 
         node = path->nodes[level];
         search = btrfs_node_blockptr(node, slot);
-        eb = btrfs_find_tree_block(root, search);
+        blocksize = btrfs_level_size(root, level - 1);
+        eb = btrfs_find_tree_block(root, search, blocksize);
         if (eb) {
                 free_extent_buffer(eb);
                 return;
         }
 
-        init_bit_radix(&found);
+        highest_read = search;
+        lowest_read = search;
+
         nritems = btrfs_header_nritems(node);
-        level = btrfs_header_level(node) - 1;
-        for (i = slot; i < nritems; i++) {
-                bytenr = btrfs_node_blockptr(node, i);
-                set_radix_bit(&found, blocknr);
-        }
-        if (direction > 0) {
-                cluster_start = search - 4;
-                if (cluster_start > search)
-                        cluster_start = 0;
-        } else
-                cluster_start = search + 4;
+        nr = slot;
         while(1) {
-                ret = find_first_radix_bit(&found, gang, 0, ARRAY_SIZE(gang));
-                if (!ret)
-                        break;
-                for (i = 0; i < ret; i++) {
-                        blocknr = gang[i];
-                        clear_radix_bit(&found, blocknr);
-                        if (path->reada == 1 && nread > 16)
-                                continue;
-                        if (close_blocks(cluster_start, blocknr)) {
-                                readahead_tree_block(root, blocknr);
-                                nread++;
-                                cluster_start = blocknr;
-                        }
+                if (direction < 0) {
+                        if (nr == 0)
+                                break;
+                        nr--;
+                } else if (direction > 0) {
+                        nr++;
+                        if (nr >= nritems)
+                                break;
                 }
+                search = btrfs_node_blockptr(node, nr);
+                if ((search >= lowest_read && search <= highest_read) ||
+                    (search < lowest_read && lowest_read - search <= 32768) ||
+                    (search > highest_read && search - highest_read <= 32768)) {
+                        readahead_tree_block(root, search, blocksize);
+                        nread += blocksize;
+                }
+                nscan++;
+                if (path->reada < 2 && (nread > (256 * 1024) || nscan > 32))
+                        break;
+                if(nread > (1024 * 1024) || nscan > 128)
+                        break;
+
+                if (search < lowest_read)
+                        lowest_read = search;
+                if (search > highest_read)
+                        highest_read = search;
         }
-#endif
 }
 /*
  * look for key in the tree.  path is filled in with nodes along the way