Btrfs: allocator optimizations, truncate readahead

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

4 files changed, 129 insertions, 37 deletions

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index d8caeba5d758..5830b4333d83 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1081,7 +1081,7 @@ static inline void btrfs_mark_buffer_dirty(struct buffer_head *bh)
 struct btrfs_block_group_cache *btrfs_find_block_group(struct btrfs_root *root,
                                                  struct btrfs_block_group_cache
                                                  *hint, u64 search_start,
-                                                 int data);
+                                                 int data, int owner);
 int btrfs_inc_root_ref(struct btrfs_trans_handle *trans,
                        struct btrfs_root *root);
 struct buffer_head *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 678456d1e2f9..4c0262b57664 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -257,24 +257,30 @@ static struct address_space_operations btree_aops = {
 int readahead_tree_block(struct btrfs_root *root, u64 blocknr)
 {
         struct buffer_head *bh = NULL;
+        int ret = 0;
 
         bh = btrfs_find_create_tree_block(root, blocknr);
         if (!bh)
                 return 0;
-        if (buffer_uptodate(bh))
+        if (buffer_uptodate(bh)) {
+                ret = 1;
                 goto done;
-        if (test_set_buffer_locked(bh))
+        }
+        if (test_set_buffer_locked(bh)) {
+                ret = 1;
                 goto done;
+        }
         if (!buffer_uptodate(bh)) {
                 get_bh(bh);
                 bh->b_end_io = end_buffer_read_sync;
                 submit_bh(READ, bh);
         } else {
                 unlock_buffer(bh);
+                ret = 1;
         }
 done:
         brelse(bh);
-        return 0;
+        return ret;
 }
 
 struct buffer_head *read_tree_block(struct btrfs_root *root, u64 blocknr)
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 1497ff98f0d3..e3c6bfea3751 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -12,6 +12,33 @@ static int finish_current_insert(struct btrfs_trans_handle *trans, struct
 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
                                btrfs_root *extent_root);
 
+static void reada_extent_leaves(struct btrfs_root *root,
+                                struct btrfs_path *path, u64 limit)
+{
+        struct btrfs_node *node;
+        int i;
+        int nritems;
+        u64 item_objectid;
+        u64 blocknr;
+        int slot;
+        int ret;
+
+        if (!path->nodes[1])
+                return;
+        node = btrfs_buffer_node(path->nodes[1]);
+        slot = path->slots[1] + 1;
+        nritems = btrfs_header_nritems(&node->header);
+        for (i = slot; i < nritems && i < slot + 8; i++) {
+                item_objectid = btrfs_disk_key_objectid(&node->ptrs[i].key);
+                if (item_objectid > limit)
+                        break;
+                blocknr = btrfs_node_blockptr(node, i);
+                ret = readahead_tree_block(root, blocknr);
+                if (ret)
+                        break;
+        }
+}
+
 static int cache_block_group(struct btrfs_root *root,
                              struct btrfs_block_group_cache *block_group)
 {
@@ -24,6 +51,7 @@ static int cache_block_group(struct btrfs_root *root,
         u64 i;
         u64 last = 0;
         u64 hole_size;
+        u64 limit;
         int found = 0;
 
         root = root->fs_info->extent_root;
@@ -46,14 +74,17 @@ printk("cache block group %Lu\n", block_group->key.objectid);
                 return ret;
         if (ret && path->slots[0] > 0)
                 path->slots[0]--;
+        limit = block_group->key.objectid + block_group->key.offset;
+        reada_extent_leaves(root, path, limit);
         while(1) {
                 leaf = btrfs_buffer_leaf(path->nodes[0]);
                 slot = path->slots[0];
                 if (slot >= btrfs_header_nritems(&leaf->header)) {
+                        reada_extent_leaves(root, path, limit);
                         ret = btrfs_next_leaf(root, path);
-                        if (ret == 0)
+                        if (ret == 0) {
                                 continue;
-                        else {
+                        } else {
                                 if (found) {
                                         hole_size = block_group->key.objectid +
                                                 block_group->key.offset - last;
@@ -187,7 +218,7 @@ new_group:
                 return max((*cache_ret)->last_alloc, search_start);
         }
         cache = btrfs_find_block_group(root, cache,
-                                       last + cache->key.offset - 1, 0);
+                                       last + cache->key.offset - 1, 0, 0);
         *cache_ret = cache;
         goto again;
 }
@@ -195,7 +226,7 @@ new_group:
 struct btrfs_block_group_cache *btrfs_find_block_group(struct btrfs_root *root,
                                                  struct btrfs_block_group_cache
                                                  *hint, u64 search_start,
-                                                 int data)
+                                                 int data, int owner)
 {
         struct btrfs_block_group_cache *cache[8];
         struct btrfs_block_group_cache *found_group = NULL;
@@ -207,6 +238,10 @@ struct btrfs_block_group_cache *btrfs_find_block_group(struct btrfs_root *root,
         int i;
         int ret;
         int full_search = 0;
+        int factor = 8;
+
+        if (!owner)
+                factor = 5;
 
         if (data)
                 radix = &info->block_group_data_radix;
@@ -219,14 +254,14 @@ struct btrfs_block_group_cache *btrfs_find_block_group(struct btrfs_root *root,
                 if (shint->data == data) {
                         used = btrfs_block_group_used(&shint->item);
                         if (used + shint->pinned <
-                            (shint->key.offset * 8) / 10) {
+                            (shint->key.offset * factor) / 10) {
                                 return shint;
                         }
                 }
         }
         if (hint && hint->data == data) {
                 used = btrfs_block_group_used(&hint->item);
-                if (used + hint->pinned < (hint->key.offset * 8) / 10) {
+                if (used + hint->pinned < (hint->key.offset * factor) / 10) {
                         return hint;
                 }
                 if (used >= (hint->key.offset * 8) / 10) {
@@ -261,7 +296,7 @@ struct btrfs_block_group_cache *btrfs_find_block_group(struct btrfs_root *root,
                                 cache[i]->key.offset;
                         used = btrfs_block_group_used(&cache[i]->item);
                         if (used + cache[i]->pinned <
-                            (cache[i]->key.offset * 8) / 10) {
+                            (cache[i]->key.offset * factor) / 10) {
                                 found_group = cache[i];
                                 goto found;
                         }
@@ -272,6 +307,7 @@ struct btrfs_block_group_cache *btrfs_find_block_group(struct btrfs_root *root,
                                                      BTRFS_BLOCK_GROUP_AVAIL);
                         }
                 }
+                cond_resched();
         }
         last = hint_last;
 again:
@@ -295,13 +331,16 @@ again:
                                                      BTRFS_BLOCK_GROUP_AVAIL);
                         }
                 }
+                cond_resched();
         }
         if (!full_search) {
+printk("find block group doing full search data %d start %Lu\n", data, search_start);
                 last = search_start;
                 full_search = 1;
                 goto again;
         }
         if (!found_group) {
+printk("find block group bailing to zero data %d\n", data);
                 ret = radix_tree_gang_lookup(radix,
                                              (void **)&found_group, 0, 1);
                 BUG_ON(ret != 1);
@@ -554,8 +593,8 @@ static int update_block_group(struct btrfs_trans_handle *trans,
                                                       blocknr + i);
                                 }
                         }
-                        if (old_val < (cache->key.offset * 6) / 10 &&
-                            old_val + num >= (cache->key.offset * 6) / 10) {
+                        if (old_val < (cache->key.offset * 5) / 10 &&
+                            old_val + num >= (cache->key.offset * 5) / 10) {
 printk("group %Lu now available\n", cache->key.objectid);
                                 radix_tree_tag_set(cache->radix,
                                                    cache->key.objectid +
@@ -842,6 +881,7 @@ 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;
+        u64 limit;
 
         path = btrfs_alloc_path();
         ins->flags = 0;
@@ -858,11 +898,11 @@ static int find_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
         if (search_start) {
                 block_group = lookup_block_group(info, search_start);
                 block_group = btrfs_find_block_group(root, block_group,
-                                                     search_start, data);
+                                                     search_start, data, 1);
         } else {
                 block_group = btrfs_find_block_group(root,
                                                      trans->block_group, 0,
-                                                     data);
+                                                     data, 1);
         }
 
 check_failed:
@@ -916,6 +956,12 @@ check_failed:
                                 info->extent_tree_prealloc_nr = 0;
                                 total_found = 0;
                         }
+                        if (start_found)
+                                limit = last_block +
+                                        block_group->key.offset / 2;
+                        else
+                                limit = search_start +
+                                        block_group->key.offset / 2;
                         ret = btrfs_next_leaf(root, path);
                         if (ret == 0)
                                 continue;
@@ -960,6 +1006,7 @@ check_failed:
                 }
 next:
                 path->slots[0]++;
+                cond_resched();
         }
         // FIXME -ENOSPC
 check_pending:
@@ -1049,7 +1096,8 @@ printk("doing full scan!\n");
         block_group = lookup_block_group(info, search_start);
         if (!full_scan)
                 block_group = btrfs_find_block_group(root, block_group,
-                                                     search_start, data);
+                                                     search_start, data, 0);
+        cond_resched();
         goto check_failed;
 
 error:
@@ -1102,7 +1150,7 @@ int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
          * in the correct block group.
          */
         if (data) {
-                ret = find_free_extent(trans, root, 0, search_start,
+                ret = find_free_extent(trans, root, 0, 0,
                                        search_end, &prealloc_key, 0);
                 if (ret) {
                         return ret;
@@ -1173,7 +1221,7 @@ struct buffer_head *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
         struct buffer_head *buf;
 
         ret = btrfs_alloc_extent(trans, root, root->root_key.objectid,
-                                 1, 0, (unsigned long)-1, &ins, 0);
+                                 1, hint, (unsigned long)-1, &ins, 0);
         if (ret) {
                 BUG();
                 return NULL;
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index eaa48f09d1c4..0f79490123cf 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -351,6 +351,35 @@ static int btrfs_free_inode(struct btrfs_trans_handle *trans,
         return ret;
 }
 
+static void reada_truncate(struct btrfs_root *root, struct btrfs_path *path,
+                           u64 objectid)
+{
+        struct btrfs_node *node;
+        int i;
+        int nritems;
+        u64 item_objectid;
+        u64 blocknr;
+        int slot;
+        int ret;
+
+        if (!path->nodes[1])
+                return;
+        node = btrfs_buffer_node(path->nodes[1]);
+        slot = path->slots[1];
+        if (slot == 0)
+                return;
+        nritems = btrfs_header_nritems(&node->header);
+        for (i = slot - 1; i >= 0; i--) {
+                item_objectid = btrfs_disk_key_objectid(&node->ptrs[i].key);
+                if (item_objectid != objectid)
+                        break;
+                blocknr = btrfs_node_blockptr(node, i);
+                ret = readahead_tree_block(root, blocknr);
+                if (ret)
+                        break;
+        }
+}
+
 static int btrfs_truncate_in_trans(struct btrfs_trans_handle *trans,
                                    struct btrfs_root *root,
                                    struct inode *inode)
@@ -386,6 +415,7 @@ static int btrfs_truncate_in_trans(struct btrfs_trans_handle *trans,
                         BUG_ON(path->slots[0] == 0);
                         path->slots[0]--;
                 }
+                reada_truncate(root, path, inode->i_ino);
                 leaf = btrfs_buffer_leaf(path->nodes[0]);
                 found_key = &leaf->items[path->slots[0]].key;
                 if (btrfs_disk_key_objectid(found_key) != inode->i_ino)
@@ -587,28 +617,30 @@ printk("adding new root for inode %lu root %p (found %p)\n", inode->i_ino, sub_r
         return d_splice_alias(inode, dentry);
 }
 
-static void reada_leaves(struct btrfs_root *root, struct btrfs_path *path)
+static void reada_leaves(struct btrfs_root *root, struct btrfs_path *path,
+                         u64 objectid)
 {
         struct btrfs_node *node;
         int i;
-        int nritems;
-        u64 objectid;
+        u32 nritems;
         u64 item_objectid;
         u64 blocknr;
         int slot;
+        int ret;
 
         if (!path->nodes[1])
                 return;
         node = btrfs_buffer_node(path->nodes[1]);
         slot = path->slots[1];
-        objectid = btrfs_disk_key_objectid(&node->ptrs[slot].key);
         nritems = btrfs_header_nritems(&node->header);
-        for (i = slot; i < nritems; i++) {
+        for (i = slot + 1; i < nritems; i++) {
                 item_objectid = btrfs_disk_key_objectid(&node->ptrs[i].key);
                 if (item_objectid != objectid)
                         break;
                 blocknr = btrfs_node_blockptr(node, i);
-                readahead_tree_block(root, blocknr);
+                ret = readahead_tree_block(root, blocknr);
+                if (ret)
+                        break;
         }
 }
 
@@ -646,21 +678,20 @@ static int btrfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
         if (ret < 0)
                 goto err;
         advance = 0;
-        reada_leaves(root, path);
+        reada_leaves(root, path, inode->i_ino);
         while(1) {
                 leaf = btrfs_buffer_leaf(path->nodes[0]);
                 nritems = btrfs_header_nritems(&leaf->header);
                 slot = path->slots[0];
                 if (advance || slot >= nritems) {
                         if (slot >= nritems -1) {
+                                reada_leaves(root, path, inode->i_ino);
                                 ret = btrfs_next_leaf(root, path);
                                 if (ret)
                                         break;
                                 leaf = btrfs_buffer_leaf(path->nodes[0]);
                                 nritems = btrfs_header_nritems(&leaf->header);
                                 slot = path->slots[0];
-                                if (path->slots[1] == 0)
-                                        reada_leaves(root, path);
                         } else {
                                 slot++;
                                 path->slots[0]++;
@@ -805,13 +836,18 @@ static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
         struct btrfs_inode_item inode_item;
         struct btrfs_key *location;
         int ret;
+        int owner;
 
         inode = new_inode(root->fs_info->sb);
         if (!inode)
                 return ERR_PTR(-ENOMEM);
 
         BTRFS_I(inode)->root = root;
-        group = btrfs_find_block_group(root, group, 0, 0);
+        if (mode & S_IFDIR)
+                owner = 0;
+        else
+                owner = 1;
+        group = btrfs_find_block_group(root, group, 0, 0, owner);
         BTRFS_I(inode)->block_group = group;
 
         inode->i_uid = current->fsuid;
@@ -1562,7 +1598,7 @@ failed:
 static int drop_extents(struct btrfs_trans_handle *trans,
                           struct btrfs_root *root,
                           struct inode *inode,
-                          u64 start, u64 end)
+                          u64 start, u64 end, u64 *hint_block)
 {
         int ret;
         struct btrfs_key key;
@@ -1659,17 +1695,14 @@ static int drop_extents(struct btrfs_trans_handle *trans,
                                 new_num = (start - key.offset) >>
                                         inode->i_blkbits;
                                 old_num = btrfs_file_extent_num_blocks(extent);
+                                *hint_block =
+                                        btrfs_file_extent_disk_blocknr(extent);
                                 inode->i_blocks -= (old_num - new_num) << 3;
                                 btrfs_set_file_extent_num_blocks(extent,
                                                                  new_num);
                                 mark_buffer_dirty(path->nodes[0]);
                         } else {
                                 WARN_ON(1);
-                                /*
-                                ret = btrfs_truncate_item(trans, root, path,
-                                                          start - key.offset);
-                                BUG_ON(ret);
-                                */
                         }
                 }
                 if (!keep) {
@@ -1683,6 +1716,8 @@ static int drop_extents(struct btrfs_trans_handle *trans,
                                       btrfs_file_extent_disk_num_blocks(extent);
                                 extent_num_blocks =
                                       btrfs_file_extent_num_blocks(extent);
+                                *hint_block =
+                                        btrfs_file_extent_disk_blocknr(extent);
                         }
                         ret = btrfs_del_item(trans, root, path);
                         BUG_ON(ret);
@@ -1831,6 +1866,7 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
         u64 start_pos;
         u64 num_blocks;
         u64 alloc_extent_start;
+        u64 hint_block;
         struct btrfs_trans_handle *trans;
         struct btrfs_key ins;
         pinned[0] = NULL;
@@ -1871,6 +1907,7 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
         }
         if (first_index != last_index &&
             (last_index << PAGE_CACHE_SHIFT) < inode->i_size &&
+            pos + count < inode->i_size &&
             (count & (PAGE_CACHE_SIZE - 1))) {
                 pinned[1] = grab_cache_page(inode->i_mapping, last_index);
                 if (!PageUptodate(pinned[1])) {
@@ -1892,18 +1929,20 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
         btrfs_set_trans_block_group(trans, inode);
         /* FIXME blocksize != 4096 */
         inode->i_blocks += num_blocks << 3;
+        hint_block = 0;
         if (start_pos < inode->i_size) {
                 /* FIXME blocksize != pagesize */
                 ret = drop_extents(trans, root, inode,
                                    start_pos,
                                    (pos + count + root->blocksize -1) &
-                                   ~((u64)root->blocksize - 1));
+                                   ~((u64)root->blocksize - 1), &hint_block);
                 BUG_ON(ret);
         }
         if (inode->i_size >= PAGE_CACHE_SIZE || pos + count < inode->i_size ||
             pos + count - start_pos > BTRFS_MAX_INLINE_DATA_SIZE(root)) {
                 ret = btrfs_alloc_extent(trans, root, inode->i_ino,
-                                         num_blocks, 1, (u64)-1, &ins, 1);
+                                         num_blocks, hint_block, (u64)-1,
+                                         &ins, 1);
                 BUG_ON(ret);
                 ret = btrfs_insert_file_extent(trans, root, inode->i_ino,
                                        start_pos, ins.objectid, ins.offset);
@@ -2455,7 +2494,6 @@ static int btrfs_get_sb(struct file_system_type *fs_type,
                            btrfs_fill_super, mnt);
 }
 
-
 static int btrfs_getattr(struct vfsmount *mnt,
                          struct dentry *dentry, struct kstat *stat)
 {