1 files changed, 183 insertions, 60 deletions

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index c4bc570a396e..c3df14ce2cc2 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -17,6 +17,7 @@
  */
 
 #include <linux/sched.h>
+#include <linux/slab.h>
 #include "ctree.h"
 #include "disk-io.h"
 #include "transaction.h"
@@ -279,7 +280,8 @@ int btrfs_block_can_be_shared(struct btrfs_root *root,
 static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans,
                                        struct btrfs_root *root,
                                        struct extent_buffer *buf,
-                                       struct extent_buffer *cow)
+                                       struct extent_buffer *cow,
+                                       int *last_ref)
 {
         u64 refs;
         u64 owner;
@@ -365,6 +367,7 @@ static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans,
                         BUG_ON(ret);
                 }
                 clean_tree_block(trans, root, buf);
+                *last_ref = 1;
         }
         return 0;
 }
@@ -391,6 +394,7 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans,
         struct btrfs_disk_key disk_key;
         struct extent_buffer *cow;
         int level;
+        int last_ref = 0;
         int unlock_orig = 0;
         u64 parent_start;
 
@@ -441,7 +445,10 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans,
                             (unsigned long)btrfs_header_fsid(cow),
                             BTRFS_FSID_SIZE);
 
-        update_ref_for_cow(trans, root, buf, cow);
+        update_ref_for_cow(trans, root, buf, cow, &last_ref);
+
+        if (root->ref_cows)
+                btrfs_reloc_cow_block(trans, root, buf, cow);
 
         if (buf == root->node) {
                 WARN_ON(parent && parent != buf);
@@ -456,8 +463,8 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans,
                 extent_buffer_get(cow);
                 spin_unlock(&root->node_lock);
 
-                btrfs_free_tree_block(trans, root, buf->start, buf->len,
-                                parent_start, root->root_key.objectid, level);
+                btrfs_free_tree_block(trans, root, buf, parent_start,
+                                      last_ref);
                 free_extent_buffer(buf);
                 add_root_to_dirty_list(root);
         } else {
@@ -472,8 +479,8 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans,
                 btrfs_set_node_ptr_generation(parent, parent_slot,
                                               trans->transid);
                 btrfs_mark_buffer_dirty(parent);
-                btrfs_free_tree_block(trans, root, buf->start, buf->len,
-                                parent_start, root->root_key.objectid, level);
+                btrfs_free_tree_block(trans, root, buf, parent_start,
+                                      last_ref);
         }
         if (unlock_orig)
                 btrfs_tree_unlock(buf);
@@ -948,6 +955,22 @@ int btrfs_bin_search(struct extent_buffer *eb, struct btrfs_key *key,
         return bin_search(eb, key, level, slot);
 }
 
+static void root_add_used(struct btrfs_root *root, u32 size)
+{
+        spin_lock(&root->accounting_lock);
+        btrfs_set_root_used(&root->root_item,
+                            btrfs_root_used(&root->root_item) + size);
+        spin_unlock(&root->accounting_lock);
+}
+
+static void root_sub_used(struct btrfs_root *root, u32 size)
+{
+        spin_lock(&root->accounting_lock);
+        btrfs_set_root_used(&root->root_item,
+                            btrfs_root_used(&root->root_item) - size);
+        spin_unlock(&root->accounting_lock);
+}
+
 /* given a node and slot number, this reads the blocks it points to.  The
  * extent buffer is returned with a reference taken (but unlocked).
  * NULL is returned on error.
@@ -1018,7 +1041,11 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
                 btrfs_tree_lock(child);
                 btrfs_set_lock_blocking(child);
                 ret = btrfs_cow_block(trans, root, child, mid, 0, &child);
-                BUG_ON(ret);
+                if (ret) {
+                        btrfs_tree_unlock(child);
+                        free_extent_buffer(child);
+                        goto enospc;
+                }
 
                 spin_lock(&root->node_lock);
                 root->node = child;
@@ -1033,11 +1060,12 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
                 btrfs_tree_unlock(mid);
                 /* once for the path */
                 free_extent_buffer(mid);
-                ret = btrfs_free_tree_block(trans, root, mid->start, mid->len,
-                                            0, root->root_key.objectid, level);
+
+                root_sub_used(root, mid->len);
+                btrfs_free_tree_block(trans, root, mid, 0, 1);
                 /* once for the root ptr */
                 free_extent_buffer(mid);
-                return ret;
+                return 0;
         }
         if (btrfs_header_nritems(mid) >
             BTRFS_NODEPTRS_PER_BLOCK(root) / 4)
@@ -1087,23 +1115,16 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
                 if (wret < 0 && wret != -ENOSPC)
                         ret = wret;
                 if (btrfs_header_nritems(right) == 0) {
-                        u64 bytenr = right->start;
-                        u32 blocksize = right->len;
-
                         clean_tree_block(trans, root, right);
                         btrfs_tree_unlock(right);
-                        free_extent_buffer(right);
-                        right = NULL;
                         wret = del_ptr(trans, root, path, level + 1, pslot +
                                        1);
                         if (wret)
                                 ret = wret;
-                        wret = btrfs_free_tree_block(trans, root,
-                                                     bytenr, blocksize, 0,
-                                                     root->root_key.objectid,
-                                                     level);
-                        if (wret)
-                                ret = wret;
+                        root_sub_used(root, right->len);
+                        btrfs_free_tree_block(trans, root, right, 0, 1);
+                        free_extent_buffer(right);
+                        right = NULL;
                 } else {
                         struct btrfs_disk_key right_key;
                         btrfs_node_key(right, &right_key, 0);
@@ -1135,21 +1156,15 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
                 BUG_ON(wret == 1);
         }
         if (btrfs_header_nritems(mid) == 0) {
-                /* we've managed to empty the middle node, drop it */
-                u64 bytenr = mid->start;
-                u32 blocksize = mid->len;
-
                 clean_tree_block(trans, root, mid);
                 btrfs_tree_unlock(mid);
-                free_extent_buffer(mid);
-                mid = NULL;
                 wret = del_ptr(trans, root, path, level + 1, pslot);
                 if (wret)
                         ret = wret;
-                wret = btrfs_free_tree_block(trans, root, bytenr, blocksize,
-                                         0, root->root_key.objectid, level);
-                if (wret)
-                        ret = wret;
+                root_sub_used(root, mid->len);
+                btrfs_free_tree_block(trans, root, mid, 0, 1);
+                free_extent_buffer(mid);
+                mid = NULL;
         } else {
                 /* update the parent key to reflect our changes */
                 struct btrfs_disk_key mid_key;
@@ -1589,7 +1604,7 @@ read_block_for_search(struct btrfs_trans_handle *trans,
         btrfs_release_path(NULL, p);
 
         ret = -EAGAIN;
-        tmp = read_tree_block(root, blocknr, blocksize, gen);
+        tmp = read_tree_block(root, blocknr, blocksize, 0);
         if (tmp) {
                 /*
                  * If the read above didn't mark this buffer up to date,
@@ -1739,7 +1754,6 @@ again:
                                               p->nodes[level + 1],
                                               p->slots[level + 1], &b);
                         if (err) {
-                                free_extent_buffer(b);
                                 ret = err;
                                 goto done;
                         }
@@ -2075,6 +2089,8 @@ static noinline int insert_new_root(struct btrfs_trans_handle *trans,
         if (IS_ERR(c))
                 return PTR_ERR(c);
 
+        root_add_used(root, root->nodesize);
+
         memset_extent_buffer(c, 0, 0, sizeof(struct btrfs_header));
         btrfs_set_header_nritems(c, 1);
         btrfs_set_header_level(c, level);
@@ -2133,6 +2149,7 @@ static int insert_ptr(struct btrfs_trans_handle *trans, struct btrfs_root
         int nritems;
 
         BUG_ON(!path->nodes[level]);
+        btrfs_assert_tree_locked(path->nodes[level]);
         lower = path->nodes[level];
         nritems = btrfs_header_nritems(lower);
         BUG_ON(slot > nritems);
@@ -2201,6 +2218,8 @@ static noinline int split_node(struct btrfs_trans_handle *trans,
         if (IS_ERR(split))
                 return PTR_ERR(split);
 
+        root_add_used(root, root->nodesize);
+
         memset_extent_buffer(split, 0, 0, sizeof(struct btrfs_header));
         btrfs_set_header_level(split, btrfs_header_level(c));
         btrfs_set_header_bytenr(split, split->start);
@@ -2285,12 +2304,17 @@ noinline int btrfs_leaf_free_space(struct btrfs_root *root,
         return ret;
 }
 
+/*
+ * min slot controls the lowest index we're willing to push to the
+ * right.  We'll push up to and including min_slot, but no lower
+ */
 static noinline int __push_leaf_right(struct btrfs_trans_handle *trans,
                                       struct btrfs_root *root,
                                       struct btrfs_path *path,
                                       int data_size, int empty,
                                       struct extent_buffer *right,
-                                      int free_space, u32 left_nritems)
+                                      int free_space, u32 left_nritems,
+                                      u32 min_slot)
 {
         struct extent_buffer *left = path->nodes[0];
         struct extent_buffer *upper = path->nodes[1];
@@ -2308,7 +2332,7 @@ static noinline int __push_leaf_right(struct btrfs_trans_handle *trans,
         if (empty)
                 nr = 0;
         else
-                nr = 1;
+                nr = max_t(u32, 1, min_slot);
 
         if (path->slots[0] >= left_nritems)
                 push_space += data_size;
@@ -2414,6 +2438,9 @@ static noinline int __push_leaf_right(struct btrfs_trans_handle *trans,
 
         if (left_nritems)
                 btrfs_mark_buffer_dirty(left);
+        else
+                clean_tree_block(trans, root, left);
+
         btrfs_mark_buffer_dirty(right);
 
         btrfs_item_key(right, &disk_key, 0);
@@ -2447,10 +2474,14 @@ out_unlock:
  *
  * returns 1 if the push failed because the other node didn't have enough
  * room, 0 if everything worked out and < 0 if there were major errors.
+ *
+ * this will push starting from min_slot to the end of the leaf.  It won't
+ * push any slot lower than min_slot
  */
 static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
-                           *root, struct btrfs_path *path, int data_size,
-                           int empty)
+                           *root, struct btrfs_path *path,
+                           int min_data_size, int data_size,
+                           int empty, u32 min_slot)
 {
         struct extent_buffer *left = path->nodes[0];
         struct extent_buffer *right;
@@ -2492,8 +2523,8 @@ static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
         if (left_nritems == 0)
                 goto out_unlock;
 
-        return __push_leaf_right(trans, root, path, data_size, empty,
-                                right, free_space, left_nritems);
+        return __push_leaf_right(trans, root, path, min_data_size, empty,
+                                right, free_space, left_nritems, min_slot);
 out_unlock:
         btrfs_tree_unlock(right);
         free_extent_buffer(right);
@@ -2503,12 +2534,17 @@ out_unlock:
 /*
  * push some data in the path leaf to the left, trying to free up at
  * least data_size bytes.  returns zero if the push worked, nonzero otherwise
+ *
+ * max_slot can put a limit on how far into the leaf we'll push items.  The
+ * item at 'max_slot' won't be touched.  Use (u32)-1 to make us do all the
+ * items
  */
 static noinline int __push_leaf_left(struct btrfs_trans_handle *trans,
                                      struct btrfs_root *root,
                                      struct btrfs_path *path, int data_size,
                                      int empty, struct extent_buffer *left,
-                                     int free_space, int right_nritems)
+                                     int free_space, u32 right_nritems,
+                                     u32 max_slot)
 {
         struct btrfs_disk_key disk_key;
         struct extent_buffer *right = path->nodes[0];
@@ -2527,9 +2563,9 @@ static noinline int __push_leaf_left(struct btrfs_trans_handle *trans,
         slot = path->slots[1];
 
         if (empty)
-                nr = right_nritems;
+                nr = min(right_nritems, max_slot);
         else
-                nr = right_nritems - 1;
+                nr = min(right_nritems - 1, max_slot);
 
         for (i = 0; i < nr; i++) {
                 item = btrfs_item_nr(right, i);
@@ -2659,6 +2695,8 @@ static noinline int __push_leaf_left(struct btrfs_trans_handle *trans,
         btrfs_mark_buffer_dirty(left);
         if (right_nritems)
                 btrfs_mark_buffer_dirty(right);
+        else
+                clean_tree_block(trans, root, right);
 
         btrfs_item_key(right, &disk_key, 0);
         wret = fixup_low_keys(trans, root, path, &disk_key, 1);
@@ -2668,8 +2706,6 @@ static noinline int __push_leaf_left(struct btrfs_trans_handle *trans,
         /* then fixup the leaf pointer in the path */
         if (path->slots[0] < push_items) {
                 path->slots[0] += old_left_nritems;
-                if (btrfs_header_nritems(path->nodes[0]) == 0)
-                        clean_tree_block(trans, root, path->nodes[0]);
                 btrfs_tree_unlock(path->nodes[0]);
                 free_extent_buffer(path->nodes[0]);
                 path->nodes[0] = left;
@@ -2690,10 +2726,14 @@ out:
 /*
  * push some data in the path leaf to the left, trying to free up at
  * least data_size bytes.  returns zero if the push worked, nonzero otherwise
+ *
+ * max_slot can put a limit on how far into the leaf we'll push items.  The
+ * item at 'max_slot' won't be touched.  Use (u32)-1 to make us push all the
+ * items
  */
 static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
-                          *root, struct btrfs_path *path, int data_size,
-                          int empty)
+                          *root, struct btrfs_path *path, int min_data_size,
+                          int data_size, int empty, u32 max_slot)
 {
         struct extent_buffer *right = path->nodes[0];
         struct extent_buffer *left;
@@ -2739,8 +2779,9 @@ static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
                 goto out;
         }
 
-        return __push_leaf_left(trans, root, path, data_size,
-                               empty, left, free_space, right_nritems);
+        return __push_leaf_left(trans, root, path, min_data_size,
+                               empty, left, free_space, right_nritems,
+                               max_slot);
 out:
         btrfs_tree_unlock(left);
         free_extent_buffer(left);
@@ -2833,6 +2874,64 @@ static noinline int copy_for_split(struct btrfs_trans_handle *trans,
 }
 
 /*
+ * double splits happen when we need to insert a big item in the middle
+ * of a leaf.  A double split can leave us with 3 mostly empty leaves:
+ * leaf: [ slots 0 - N] [ our target ] [ N + 1 - total in leaf ]
+ *          A                 B                 C
+ *
+ * We avoid this by trying to push the items on either side of our target
+ * into the adjacent leaves.  If all goes well we can avoid the double split
+ * completely.
+ */
+static noinline int push_for_double_split(struct btrfs_trans_handle *trans,
+                                          struct btrfs_root *root,
+                                          struct btrfs_path *path,
+                                          int data_size)
+{
+        int ret;
+        int progress = 0;
+        int slot;
+        u32 nritems;
+
+        slot = path->slots[0];
+
+        /*
+         * try to push all the items after our slot into the
+         * right leaf
+         */
+        ret = push_leaf_right(trans, root, path, 1, data_size, 0, slot);
+        if (ret < 0)
+                return ret;
+
+        if (ret == 0)
+                progress++;
+
+        nritems = btrfs_header_nritems(path->nodes[0]);
+        /*
+         * our goal is to get our slot at the start or end of a leaf.  If
+         * we've done so we're done
+         */
+        if (path->slots[0] == 0 || path->slots[0] == nritems)
+                return 0;
+
+        if (btrfs_leaf_free_space(root, path->nodes[0]) >= data_size)
+                return 0;
+
+        /* try to push all the items before our slot into the next leaf */
+        slot = path->slots[0];
+        ret = push_leaf_left(trans, root, path, 1, data_size, 0, slot);
+        if (ret < 0)
+                return ret;
+
+        if (ret == 0)
+                progress++;
+
+        if (progress)
+                return 0;
+        return 1;
+}
+
+/*
  * split the path's leaf in two, making sure there is at least data_size
  * available for the resulting leaf level of the path.
  *
@@ -2854,6 +2953,7 @@ static noinline int split_leaf(struct btrfs_trans_handle *trans,
         int wret;
         int split;
         int num_doubles = 0;
+        int tried_avoid_double = 0;
 
         l = path->nodes[0];
         slot = path->slots[0];
@@ -2862,12 +2962,14 @@ static noinline int split_leaf(struct btrfs_trans_handle *trans,
                 return -EOVERFLOW;
 
         /* first try to make some room by pushing left and right */
-        if (data_size && ins_key->type != BTRFS_DIR_ITEM_KEY) {
-                wret = push_leaf_right(trans, root, path, data_size, 0);
+        if (data_size) {
+                wret = push_leaf_right(trans, root, path, data_size,
+                                       data_size, 0, 0);
                 if (wret < 0)
                         return wret;
                 if (wret) {
-                        wret = push_leaf_left(trans, root, path, data_size, 0);
+                        wret = push_leaf_left(trans, root, path, data_size,
+                                              data_size, 0, (u32)-1);
                         if (wret < 0)
                                 return wret;
                 }
@@ -2901,6 +3003,8 @@ again:
                                 if (mid != nritems &&
                                     leaf_space_used(l, mid, nritems - mid) +
                                     data_size > BTRFS_LEAF_DATA_SIZE(root)) {
+                                        if (data_size && !tried_avoid_double)
+                                                goto push_for_double;
                                         split = 2;
                                 }
                         }
@@ -2917,6 +3021,8 @@ again:
                                 if (mid != nritems &&
                                     leaf_space_used(l, mid, nritems - mid) +
                                     data_size > BTRFS_LEAF_DATA_SIZE(root)) {
+                                        if (data_size && !tried_avoid_double)
+                                                goto push_for_double;
                                         split = 2 ;
                                 }
                         }
@@ -2931,10 +3037,10 @@ again:
         right = btrfs_alloc_free_block(trans, root, root->leafsize, 0,
                                         root->root_key.objectid,
                                         &disk_key, 0, l->start, 0);
-        if (IS_ERR(right)) {
-                BUG_ON(1);
+        if (IS_ERR(right))
                 return PTR_ERR(right);
-        }
+
+        root_add_used(root, root->leafsize);
 
         memset_extent_buffer(right, 0, 0, sizeof(struct btrfs_header));
         btrfs_set_header_bytenr(right, right->start);
@@ -2997,6 +3103,13 @@ again:
         }
 
         return ret;
+
+push_for_double:
+        push_for_double_split(trans, root, path, data_size);
+        tried_avoid_double = 1;
+        if (btrfs_leaf_free_space(root, path->nodes[0]) >= data_size)
+                return 0;
+        goto again;
 }
 
 static noinline int setup_leaf_for_split(struct btrfs_trans_handle *trans,
@@ -3040,6 +3153,10 @@ static noinline int setup_leaf_for_split(struct btrfs_trans_handle *trans,
         if (ret > 0 || item_size != btrfs_item_size_nr(leaf, path->slots[0]))
                 goto err;
 
+        /* the leaf has  changed, it now has room.  return now */
+        if (btrfs_leaf_free_space(root, path->nodes[0]) >= ins_len)
+                goto err;
+
         if (key.type == BTRFS_EXTENT_DATA_KEY) {
                 fi = btrfs_item_ptr(leaf, path->slots[0],
                                     struct btrfs_file_extent_item);
@@ -3049,7 +3166,8 @@ static noinline int setup_leaf_for_split(struct btrfs_trans_handle *trans,
 
         btrfs_set_path_blocking(path);
         ret = split_leaf(trans, root, &key, path, ins_len, 1);
-        BUG_ON(ret);
+        if (ret)
+                goto err;
 
         path->keep_locks = 0;
         btrfs_unlock_up_safe(path, 1);
@@ -3791,9 +3909,10 @@ static noinline int btrfs_del_leaf(struct btrfs_trans_handle *trans,
          */
         btrfs_unlock_up_safe(path, 0);
 
-        ret = btrfs_free_tree_block(trans, root, leaf->start, leaf->len,
-                                    0, root->root_key.objectid, 0);
-        return ret;
+        root_sub_used(root, leaf->len);
+
+        btrfs_free_tree_block(trans, root, leaf, 0, 1);
+        return 0;
 }
 /*
  * delete the item at the leaf level in path.  If that empties
@@ -3860,6 +3979,8 @@ int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
                 if (leaf == root->node) {
                         btrfs_set_header_level(leaf, 0);
                 } else {
+                        btrfs_set_path_blocking(path);
+                        clean_tree_block(trans, root, leaf);
                         ret = btrfs_del_leaf(trans, root, path, leaf);
                         BUG_ON(ret);
                 }
@@ -3885,13 +4006,15 @@ int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
                         extent_buffer_get(leaf);
 
                         btrfs_set_path_blocking(path);
-                        wret = push_leaf_left(trans, root, path, 1, 1);
+                        wret = push_leaf_left(trans, root, path, 1, 1,
+                                              1, (u32)-1);
                         if (wret < 0 && wret != -ENOSPC)
                                 ret = wret;
 
                         if (path->nodes[0] == leaf &&
                             btrfs_header_nritems(leaf)) {
-                                wret = push_leaf_right(trans, root, path, 1, 1);
+                                wret = push_leaf_right(trans, root, path, 1,
+                                                       1, 1, 0);
                                 if (wret < 0 && wret != -ENOSPC)
                                         ret = wret;
                         }