16 files changed, 187 insertions, 145 deletions
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index b6cbeed226b1..b0e18d986e0a 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -3211,7 +3211,6 @@ int btrfs_truncate_item(struct btrfs_trans_handle *trans,
                        struct btrfs_path *path,
                        u32 new_size, int from_end)
 {
-        int ret = 0;
        int slot;
        struct extent_buffer *leaf;
        struct btrfs_item *item;
@@ -3309,12 +3308,11 @@ int btrfs_truncate_item(struct btrfs_trans_handle *trans,
        btrfs_set_item_size(leaf, item, new_size);
        btrfs_mark_buffer_dirty(leaf);
-        ret = 0;
        if (btrfs_leaf_free_space(root, leaf) < 0) {
                btrfs_print_leaf(root, leaf);
                BUG();
        }
-        return ret;
+        return 0;
 }
 /*
@@ -3324,7 +3322,6 @@ int btrfs_extend_item(struct btrfs_trans_handle *trans,
                      struct btrfs_root *root, struct btrfs_path *path,
                      u32 data_size)
 {
-        int ret = 0;
        int slot;
        struct extent_buffer *leaf;
        struct btrfs_item *item;
@@ -3389,12 +3386,11 @@ int btrfs_extend_item(struct btrfs_trans_handle *trans,
        btrfs_set_item_size(leaf, item, old_size + data_size);
        btrfs_mark_buffer_dirty(leaf);
-        ret = 0;
        if (btrfs_leaf_free_space(root, leaf) < 0) {
                btrfs_print_leaf(root, leaf);
                BUG();
        }
-        return ret;
+        return 0;
 }
 /*
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 0d50c57caf5d..026fc47b42cf 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1113,9 +1113,6 @@ struct btrfs_fs_info {
 struct btrfs_root {
        struct extent_buffer *node;
-        /* the node lock is held while changing the node pointer */
-        spinlock_t node_lock;
        struct extent_buffer *commit_root;
        struct btrfs_root *log_root;
        struct btrfs_root *reloc_root;
diff --git a/fs/btrfs/dir-item.c b/fs/btrfs/dir-item.c
index 1ddfca78e910..685f2593c4f0 100644
--- a/fs/btrfs/dir-item.c
+++ b/fs/btrfs/dir-item.c
@@ -50,7 +50,6 @@ static struct btrfs_dir_item *insert_with_overflow(struct btrfs_trans_handle
                if (di)
                        return ERR_PTR(-EEXIST);
                ret = btrfs_extend_item(trans, root, path, data_size);
-                WARN_ON(ret > 0);
        }
        if (ret < 0)
                return ERR_PTR(ret);
@@ -438,7 +437,7 @@ int verify_dir_item(struct btrfs_root *root,
                namelen = XATTR_NAME_MAX;
        if (btrfs_dir_name_len(leaf, dir_item) > namelen) {
-                printk(KERN_CRIT "btrfS: invalid dir item name len: %u\n",
+                printk(KERN_CRIT "btrfs: invalid dir item name len: %u\n",
                       (unsigned)btrfs_dir_data_len(leaf, dir_item));
                return 1;
        }
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 29a2475b9b14..16d335b342a2 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1053,7 +1053,6 @@ static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
        INIT_LIST_HEAD(&root->dirty_list);
        INIT_LIST_HEAD(&root->orphan_list);
        INIT_LIST_HEAD(&root->root_list);
-        spin_lock_init(&root->node_lock);
        spin_lock_init(&root->orphan_lock);
        spin_lock_init(&root->inode_lock);
        spin_lock_init(&root->accounting_lock);
@@ -1363,7 +1362,8 @@ static int btrfs_congested_fn(void *congested_data, int bdi_bits)
        struct btrfs_device *device;
        struct backing_dev_info *bdi;
-        list_for_each_entry(device, &info->fs_devices->devices, dev_list) {
+        rcu_read_lock();
+        list_for_each_entry_rcu(device, &info->fs_devices->devices, dev_list) {
                if (!device->bdev)
                        continue;
                bdi = blk_get_backing_dev_info(device->bdev);
@@ -1372,6 +1372,7 @@ static int btrfs_congested_fn(void *congested_data, int bdi_bits)
                        break;
                }
        }
+        rcu_read_unlock();
        return ret;
 }
@@ -2305,9 +2306,9 @@ int write_all_supers(struct btrfs_root *root, int max_mirrors)
        sb = &root->fs_info->super_for_commit;
        dev_item = &sb->dev_item;
-        mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
+        rcu_read_lock();
        head = &root->fs_info->fs_devices->devices;
-        list_for_each_entry(dev, head, dev_list) {
+        list_for_each_entry_rcu(dev, head, dev_list) {
                if (!dev->bdev) {
                        total_errors++;
                        continue;
@@ -2340,7 +2341,7 @@ int write_all_supers(struct btrfs_root *root, int max_mirrors)
        }
        total_errors = 0;
-        list_for_each_entry(dev, head, dev_list) {
+        list_for_each_entry_rcu(dev, head, dev_list) {
                if (!dev->bdev)
                        continue;
                if (!dev->in_fs_metadata || !dev->writeable)
@@ -2350,7 +2351,7 @@ int write_all_supers(struct btrfs_root *root, int max_mirrors)
                if (ret)
                        total_errors++;
        }
-        mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
+        rcu_read_unlock();
        if (total_errors > max_errors) {
                printk(KERN_ERR "btrfs: %d errors while writing supers\n",
                       total_errors);
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 98ca149bdbc8..169bd62ce776 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -952,7 +952,6 @@ static int convert_extent_item_v0(struct btrfs_trans_handle *trans,
        BUG_ON(ret);
        ret = btrfs_extend_item(trans, root, path, new_size);
-        BUG_ON(ret);
        leaf = path->nodes[0];
        item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
@@ -1560,7 +1559,6 @@ int setup_inline_extent_backref(struct btrfs_trans_handle *trans,
        size = btrfs_extent_inline_ref_size(type);
        ret = btrfs_extend_item(trans, root, path, size);
-        BUG_ON(ret);
        ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
        refs = btrfs_extent_refs(leaf, ei);
@@ -1689,7 +1687,6 @@ int update_inline_extent_backref(struct btrfs_trans_handle *trans,
                                              end - ptr - size);
                item_size -= size;
                ret = btrfs_truncate_item(trans, root, path, item_size, 1);
-                BUG_ON(ret);
        }
        btrfs_mark_buffer_dirty(leaf);
        return 0;
@@ -3307,6 +3304,10 @@ static int shrink_delalloc(struct btrfs_trans_handle *trans,
        if (reserved == 0)
                return 0;
+        /* nothing to shrink - nothing to reclaim */
+        if (root->fs_info->delalloc_bytes == 0)
+                return 0;
        max_reclaim = min(reserved, to_reclaim);
        while (loops < 1024) {
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 64c8b361b539..a90c4a12556b 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -439,6 +439,15 @@ static int clear_state_bit(struct extent_io_tree *tree,
        return ret;
 }
+static struct extent_state *
+alloc_extent_state_atomic(struct extent_state *prealloc)
+{
+        if (!prealloc)
+                prealloc = alloc_extent_state(GFP_ATOMIC);
+        return prealloc;
+}
 /*
 * clear some bits on a range in the tree.  This may require splitting
 * or inserting elements in the tree, so the gfp mask is used to
@@ -476,8 +485,7 @@ int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
 again:
        if (!prealloc && (mask & __GFP_WAIT)) {
                prealloc = alloc_extent_state(mask);
-                if (!prealloc)
+                BUG_ON(!prealloc);
-                        return -ENOMEM;
        }
        spin_lock(&tree->lock);
@@ -529,8 +537,8 @@ hit_next:
         */
        if (state->start < start) {
-                if (!prealloc)
+                prealloc = alloc_extent_state_atomic(prealloc);
-                        prealloc = alloc_extent_state(GFP_ATOMIC);
+                BUG_ON(!prealloc);
                err = split_state(tree, state, prealloc, start);
                BUG_ON(err == -EEXIST);
                prealloc = NULL;
@@ -551,8 +559,8 @@ hit_next:
         * on the first half
         */
        if (state->start <= end && state->end > end) {
-                if (!prealloc)
+                prealloc = alloc_extent_state_atomic(prealloc);
-                        prealloc = alloc_extent_state(GFP_ATOMIC);
+                BUG_ON(!prealloc);
                err = split_state(tree, state, prealloc, end + 1);
                BUG_ON(err == -EEXIST);
                if (wake)
@@ -725,8 +733,7 @@ int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
 again:
        if (!prealloc && (mask & __GFP_WAIT)) {
                prealloc = alloc_extent_state(mask);
-                if (!prealloc)
+                BUG_ON(!prealloc);
-                        return -ENOMEM;
        }
        spin_lock(&tree->lock);
@@ -743,6 +750,8 @@ again:
         */
        node = tree_search(tree, start);
        if (!node) {
+                prealloc = alloc_extent_state_atomic(prealloc);
+                BUG_ON(!prealloc);
                err = insert_state(tree, prealloc, start, end, &bits);
                prealloc = NULL;
                BUG_ON(err == -EEXIST);
@@ -771,20 +780,18 @@ hit_next:
                if (err)
                        goto out;
+                next_node = rb_next(node);
                cache_state(state, cached_state);
                merge_state(tree, state);
                if (last_end == (u64)-1)
                        goto out;
                start = last_end + 1;
-                if (start < end && prealloc && !need_resched()) {
+                if (next_node && start < end && prealloc && !need_resched()) {
-                        next_node = rb_next(node);
+                        state = rb_entry(next_node, struct extent_state,
-                        if (next_node) {
+                                         rb_node);
-                                state = rb_entry(next_node, struct extent_state,
+                        if (state->start == start)
-                                                 rb_node);
+                                goto hit_next;
-                                if (state->start == start)
-                                        goto hit_next;
-                        }
                }
                goto search_again;
        }
@@ -811,6 +818,9 @@ hit_next:
                        err = -EEXIST;
                        goto out;
                }
+                prealloc = alloc_extent_state_atomic(prealloc);
+                BUG_ON(!prealloc);
                err = split_state(tree, state, prealloc, start);
                BUG_ON(err == -EEXIST);
                prealloc = NULL;
@@ -841,14 +851,25 @@ hit_next:
                        this_end = end;
                else
                        this_end = last_start - 1;
+                prealloc = alloc_extent_state_atomic(prealloc);
+                BUG_ON(!prealloc);
+                /*
+                 * Avoid to free 'prealloc' if it can be merged with
+                 * the later extent.
+                 */
+                atomic_inc(&prealloc->refs);
                err = insert_state(tree, prealloc, start, this_end,
                                   &bits);
                BUG_ON(err == -EEXIST);
                if (err) {
+                        free_extent_state(prealloc);
                        prealloc = NULL;
                        goto out;
                }
                cache_state(prealloc, cached_state);
+                free_extent_state(prealloc);
                prealloc = NULL;
                start = this_end + 1;
                goto search_again;
@@ -865,6 +886,9 @@ hit_next:
                        err = -EEXIST;
                        goto out;
                }
+                prealloc = alloc_extent_state_atomic(prealloc);
+                BUG_ON(!prealloc);
                err = split_state(tree, state, prealloc, end + 1);
                BUG_ON(err == -EEXIST);
diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index b437cc790bfb..90d4ee52cd45 100644
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -502,7 +502,6 @@ static noinline int truncate_one_csum(struct btrfs_trans_handle *trans,
                u32 new_size = (bytenr - key->offset) >> blocksize_bits;
                new_size *= csum_size;
                ret = btrfs_truncate_item(trans, root, path, new_size, 1);
-                BUG_ON(ret);
        } else if (key->offset >= bytenr && csum_end > end_byte &&
                   end_byte > key->offset) {
                /*
@@ -515,7 +514,6 @@ static noinline int truncate_one_csum(struct btrfs_trans_handle *trans,
                new_size *= csum_size;
                ret = btrfs_truncate_item(trans, root, path, new_size, 0);
-                BUG_ON(ret);
                key->offset = end_byte;
                ret = btrfs_set_item_key_safe(trans, root, path, key);
@@ -558,10 +556,10 @@ int btrfs_del_csums(struct btrfs_trans_handle *trans,
                ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
                if (ret > 0) {
                        if (path->slots[0] == 0)
-                                goto out;
+                                break;
                        path->slots[0]--;
                } else if (ret < 0) {
-                        goto out;
+                        break;
                }
                leaf = path->nodes[0];
@@ -586,7 +584,8 @@ int btrfs_del_csums(struct btrfs_trans_handle *trans,
                /* delete the entire item, it is inside our range */
                if (key.offset >= bytenr && csum_end <= end_byte) {
                        ret = btrfs_del_item(trans, root, path);
-                        BUG_ON(ret);
+                        if (ret)
+                                goto out;
                        if (key.offset == bytenr)
                                break;
                } else if (key.offset < bytenr && csum_end > end_byte) {
@@ -640,9 +639,10 @@ int btrfs_del_csums(struct btrfs_trans_handle *trans,
                }
                btrfs_release_path(path);
        }
+        ret = 0;
 out:
        btrfs_free_path(path);
-        return 0;
+        return ret;
 }
 int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
@@ -768,7 +768,6 @@ again:
                        goto insert;
                ret = btrfs_extend_item(trans, root, path, diff);
-                BUG_ON(ret);
                goto csum;
        }
diff --git a/fs/btrfs/inode-item.c b/fs/btrfs/inode-item.c
index 64f1150bb48d..baa74f3db691 100644
--- a/fs/btrfs/inode-item.c
+++ b/fs/btrfs/inode-item.c
@@ -130,7 +130,6 @@ int btrfs_del_inode_ref(struct btrfs_trans_handle *trans,
                              item_size - (ptr + sub_item_len - item_start));
        ret = btrfs_truncate_item(trans, root, path,
                                  item_size - sub_item_len, 1);
-        BUG_ON(ret);
 out:
        btrfs_free_path(path);
        return ret;
@@ -167,7 +166,6 @@ int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans,
                old_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
                ret = btrfs_extend_item(trans, root, path, ins_len);
-                BUG_ON(ret);
                ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
                                     struct btrfs_inode_ref);
                ref = (struct btrfs_inode_ref *)((unsigned long)ref + old_size);
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 4d8ef95abf40..d378f8b70ef7 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -1323,7 +1323,7 @@ static int btrfs_set_bit_hook(struct inode *inode,
        /*
         * set_bit and clear bit hooks normally require _irqsave/restore
-         * but in this case, we are only testeing for the DELALLOC
+         * but in this case, we are only testing for the DELALLOC
         * bit, which is only set or cleared with irqs on
         */
        if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
@@ -1356,7 +1356,7 @@ static int btrfs_clear_bit_hook(struct inode *inode,
 {
        /*
         * set_bit and clear bit hooks normally require _irqsave/restore
-         * but in this case, we are only testeing for the DELALLOC
+         * but in this case, we are only testing for the DELALLOC
         * bit, which is only set or cleared with irqs on
         */
        if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
@@ -3286,7 +3286,6 @@ search_again:
                                    btrfs_file_extent_calc_inline_size(size);
                                ret = btrfs_truncate_item(trans, root, path,
                                                          size, 1);
-                                BUG_ON(ret);
                        } else if (root->ref_cows) {
                                inode_sub_bytes(inode, item_end + 1 -
                                                found_key.offset);
@@ -7167,6 +7166,7 @@ static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
                                      datasize);
        if (err) {
                drop_inode = 1;
+                btrfs_free_path(path);
                goto out_unlock;
        }
        leaf = path->nodes[0];
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index e0a061db4353..c4f17e4e2c9c 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -282,8 +282,9 @@ static noinline int btrfs_ioctl_fitrim(struct file *file, void __user *arg)
        if (!capable(CAP_SYS_ADMIN))
                return -EPERM;
-        mutex_lock(&fs_info->fs_devices->device_list_mutex);
+        rcu_read_lock();
-        list_for_each_entry(device, &fs_info->fs_devices->devices, dev_list) {
+        list_for_each_entry_rcu(device, &fs_info->fs_devices->devices,
+                                dev_list) {
                if (!device->bdev)
                        continue;
                q = bdev_get_queue(device->bdev);
@@ -293,7 +294,7 @@ static noinline int btrfs_ioctl_fitrim(struct file *file, void __user *arg)
                                     minlen);
                }
        }
-        mutex_unlock(&fs_info->fs_devices->device_list_mutex);
+        rcu_read_unlock();
        if (!num_devices)
                return -EOPNOTSUPP;
@@ -1279,7 +1280,6 @@ static noinline int copy_to_sk(struct btrfs_root *root,
        int nritems;
        int i;
        int slot;
-        int found = 0;
        int ret = 0;
        leaf = path->nodes[0];
@@ -1326,7 +1326,7 @@ static noinline int copy_to_sk(struct btrfs_root *root,
                                           item_off, item_len);
                        *sk_offset += item_len;
                }
-                found++;
+                (*num_found)++;
                if (*num_found >= sk->nr_items)
                        break;
@@ -1345,7 +1345,6 @@ advance_key:
        } else
                ret = 1;
 overflow:
-        *num_found += found;
        return ret;
 }
diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c
index 3bcfe5a7c330..ebe45443de06 100644
--- a/fs/btrfs/root-tree.c
+++ b/fs/btrfs/root-tree.c
@@ -338,7 +338,10 @@ again:
                *sequence = btrfs_root_ref_sequence(leaf, ref);
                ret = btrfs_del_item(trans, tree_root, path);
-                BUG_ON(ret);
+                if (ret) {
+                        err = ret;
+                        goto out;
+                }
        } else
                err = -ENOENT;
@@ -350,6 +353,7 @@ again:
                goto again;
        }
+out:
        btrfs_free_path(path);
        return err;
 }
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 006655c1d1f7..cd0c7cd2c8fb 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -507,8 +507,10 @@ static struct dentry *get_default_root(struct super_block *sb,
         */
        dir_id = btrfs_super_root_dir(&root->fs_info->super_copy);
        di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0);
-        if (IS_ERR(di))
+        if (IS_ERR(di)) {
+                btrfs_free_path(path);
                return ERR_CAST(di);
+        }
        if (!di) {
                /*
                 * Ok the default dir item isn't there.  This is weird since
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 0f5537e60bb4..592396c6dc47 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -382,7 +382,6 @@ insert:
                } else if (found_size < item_size) {
                        ret = btrfs_extend_item(trans, root, path,
                                                item_size - found_size);
-                        BUG_ON(ret);
                }
        } else if (ret) {
                return ret;
@@ -590,6 +589,7 @@ static noinline int replay_one_extent(struct btrfs_trans_handle *trans,
                                                ins.objectid, ins.offset,
                                                0, root->root_key.objectid,
                                                key->objectid, offset);
+                                BUG_ON(ret);
                        } else {
                                /*
                                 * insert the extent pointer in the extent
@@ -678,7 +678,10 @@ static noinline int drop_one_dir_item(struct btrfs_trans_handle *trans,
        btrfs_release_path(path);
        inode = read_one_inode(root, location.objectid);
-        BUG_ON(!inode);
+        if (!inode) {
+                kfree(name);
+                return -EIO;
+        }
        ret = link_to_fixup_dir(trans, root, path, location.objectid);
        BUG_ON(ret);
@@ -817,7 +820,10 @@ static noinline int add_inode_ref(struct btrfs_trans_handle *trans,
                return -ENOENT;
        inode = read_one_inode(root, key->objectid);
-        BUG_ON(!inode);
+        if (!inode) {
+                iput(dir);
+                return -EIO;
+        }
        ref_ptr = btrfs_item_ptr_offset(eb, slot);
        ref_end = ref_ptr + btrfs_item_size_nr(eb, slot);
@@ -1051,11 +1057,13 @@ static noinline int fixup_inode_link_counts(struct btrfs_trans_handle *trans,
                        break;
                ret = btrfs_del_item(trans, root, path);
-                BUG_ON(ret);
+                if (ret)
+                        goto out;
                btrfs_release_path(path);
                inode = read_one_inode(root, key.offset);
-                BUG_ON(!inode);
+                if (!inode)
+                        return -EIO;
                ret = fixup_inode_link_count(trans, root, inode);
                BUG_ON(ret);
@@ -1069,8 +1077,10 @@ static noinline int fixup_inode_link_counts(struct btrfs_trans_handle *trans,
                 */
                key.offset = (u64)-1;
        }
+        ret = 0;
+out:
        btrfs_release_path(path);
-        return 0;
+        return ret;
 }
@@ -1089,7 +1099,8 @@ static noinline int link_to_fixup_dir(struct btrfs_trans_handle *trans,
        struct inode *inode;
        inode = read_one_inode(root, objectid);
-        BUG_ON(!inode);
+        if (!inode)
+                return -EIO;
        key.objectid = BTRFS_TREE_LOG_FIXUP_OBJECTID;
        btrfs_set_key_type(&key, BTRFS_ORPHAN_ITEM_KEY);
@@ -1176,7 +1187,8 @@ static noinline int replay_one_name(struct btrfs_trans_handle *trans,
        int ret;
        dir = read_one_inode(root, key->objectid);
-        BUG_ON(!dir);
+        if (!dir)
+                return -EIO;
        name_len = btrfs_dir_name_len(eb, di);
        name = kmalloc(name_len, GFP_NOFS);
@@ -1432,7 +1444,10 @@ again:
                        btrfs_release_path(path);
                        btrfs_release_path(log_path);
                        inode = read_one_inode(root, location.objectid);
-                        BUG_ON(!inode);
+                        if (!inode) {
+                                kfree(name);
+                                return -EIO;
+                        }
                        ret = link_to_fixup_dir(trans, root,
                                                path, location.objectid);
@@ -2589,7 +2604,8 @@ static int drop_objectid_items(struct btrfs_trans_handle *trans,
                        break;
                ret = btrfs_del_item(trans, log, path);
-                BUG_ON(ret);
+                if (ret)
+                        break;
                btrfs_release_path(path);
        }
        btrfs_release_path(path);
diff --git a/fs/btrfs/version.sh b/fs/btrfs/version.sh
deleted file mode 100644
index 1ca1952fd917..000000000000
--- a/fs/btrfs/version.sh
+++ /dev/null
@@ -1,43 +0,0 @@
-#!/bin/bash
-#
-# determine-version -- report a useful version for releases
-#
-# Copyright 2008, Aron Griffis <agriffis@n01se.net>
-# Copyright 2008, Oracle
-# Released under the GNU GPLv2
- 
-v="v0.16"
-which git &> /dev/null
-if [ $? == 0 ]; then
-    git branch >& /dev/null
-    if [ $? == 0 ]; then
-            if head=`git rev-parse --verify HEAD 2>/dev/null`; then
-                if tag=`git describe --tags 2>/dev/null`; then
-                    v="$tag"
-                fi
-                # Are there uncommitted changes?
-                git update-index --refresh --unmerged > /dev/null
-                if git diff-index --name-only HEAD | \
-                    grep -v "^scripts/package" \
-                    | read dummy; then
-                    v="$v"-dirty
-                fi
-            fi
-    fi
-fi
- 
-echo "#ifndef __BUILD_VERSION" > .build-version.h
-echo "#define __BUILD_VERSION" >> .build-version.h
-echo "#define BTRFS_BUILD_VERSION \"Btrfs $v\"" >> .build-version.h
-echo "#endif" >> .build-version.h
-diff -q version.h .build-version.h >& /dev/null
-if [ $? == 0 ]; then
-    rm .build-version.h
-    exit 0
-fi
-mv .build-version.h version.h
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index b8fc2fa91fdf..c48214ef5c09 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -350,7 +350,7 @@ static noinline int device_list_add(const char *path,
                INIT_LIST_HEAD(&device->dev_alloc_list);
                mutex_lock(&fs_devices->device_list_mutex);
-                list_add(&device->dev_list, &fs_devices->devices);
+                list_add_rcu(&device->dev_list, &fs_devices->devices);
                mutex_unlock(&fs_devices->device_list_mutex);
                device->fs_devices = fs_devices;
@@ -393,7 +393,7 @@ static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig)
        fs_devices->latest_trans = orig->latest_trans;
        memcpy(fs_devices->fsid, orig->fsid, sizeof(fs_devices->fsid));
-        mutex_lock(&orig->device_list_mutex);
+        /* We have held the volume lock, it is safe to get the devices. */
        list_for_each_entry(orig_dev, &orig->devices, dev_list) {
                device = kzalloc(sizeof(*device), GFP_NOFS);
                if (!device)
@@ -416,10 +416,8 @@ static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig)
                device->fs_devices = fs_devices;
                fs_devices->num_devices++;
        }
-        mutex_unlock(&orig->device_list_mutex);
        return fs_devices;
 error:
-        mutex_unlock(&orig->device_list_mutex);
        free_fs_devices(fs_devices);
        return ERR_PTR(-ENOMEM);
 }
@@ -430,7 +428,7 @@ int btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices)
        mutex_lock(&uuid_mutex);
 again:
-        mutex_lock(&fs_devices->device_list_mutex);
+        /* This is the initialized path, it is safe to release the devices. */
        list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
                if (device->in_fs_metadata)
                        continue;
@@ -450,7 +448,6 @@ again:
                kfree(device->name);
                kfree(device);
        }
-        mutex_unlock(&fs_devices->device_list_mutex);
        if (fs_devices->seed) {
                fs_devices = fs_devices->seed;
@@ -461,6 +458,29 @@ again:
        return 0;
 }
+static void __free_device(struct work_struct *work)
+{
+        struct btrfs_device *device;
+        device = container_of(work, struct btrfs_device, rcu_work);
+        if (device->bdev)
+                blkdev_put(device->bdev, device->mode);
+        kfree(device->name);
+        kfree(device);
+}
+static void free_device(struct rcu_head *head)
+{
+        struct btrfs_device *device;
+        device = container_of(head, struct btrfs_device, rcu);
+        INIT_WORK(&device->rcu_work, __free_device);
+        schedule_work(&device->rcu_work);
+}
 static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
 {
        struct btrfs_device *device;
@@ -468,20 +488,32 @@ static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
        if (--fs_devices->opened > 0)
                return 0;
+        mutex_lock(&fs_devices->device_list_mutex);
        list_for_each_entry(device, &fs_devices->devices, dev_list) {
-                if (device->bdev) {
+                struct btrfs_device *new_device;
-                        blkdev_put(device->bdev, device->mode);
+                if (device->bdev)
                        fs_devices->open_devices--;
-                }
                if (device->writeable) {
                        list_del_init(&device->dev_alloc_list);
                        fs_devices->rw_devices--;
                }
-                device->bdev = NULL;
+                new_device = kmalloc(sizeof(*new_device), GFP_NOFS);
-                device->writeable = 0;
+                BUG_ON(!new_device);
-                device->in_fs_metadata = 0;
+                memcpy(new_device, device, sizeof(*new_device));
+                new_device->name = kstrdup(device->name, GFP_NOFS);
+                BUG_ON(!new_device->name);
+                new_device->bdev = NULL;
+                new_device->writeable = 0;
+                new_device->in_fs_metadata = 0;
+                list_replace_rcu(&device->dev_list, &new_device->dev_list);
+                call_rcu(&device->rcu, free_device);
        }
+        mutex_unlock(&fs_devices->device_list_mutex);
        WARN_ON(fs_devices->open_devices);
        WARN_ON(fs_devices->rw_devices);
        fs_devices->opened = 0;
@@ -584,6 +616,7 @@ static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
                        list_add(&device->dev_alloc_list,
                                 &fs_devices->alloc_list);
                }
+                brelse(bh);
                continue;
 error_brelse:
@@ -933,14 +966,14 @@ static int btrfs_free_dev_extent(struct btrfs_trans_handle *trans,
        if (ret > 0) {
                ret = btrfs_previous_item(root, path, key.objectid,
                                          BTRFS_DEV_EXTENT_KEY);
-                BUG_ON(ret);
+                if (ret)
+                        goto out;
                leaf = path->nodes[0];
                btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
                extent = btrfs_item_ptr(leaf, path->slots[0],
                                        struct btrfs_dev_extent);
                BUG_ON(found_key.offset > start || found_key.offset +
                       btrfs_dev_extent_length(leaf, extent) < start);
-                ret = 0;
        } else if (ret == 0) {
                leaf = path->nodes[0];
                extent = btrfs_item_ptr(leaf, path->slots[0],
@@ -951,8 +984,8 @@ static int btrfs_free_dev_extent(struct btrfs_trans_handle *trans,
        if (device->bytes_used > 0)
                device->bytes_used -= btrfs_dev_extent_length(leaf, extent);
        ret = btrfs_del_item(trans, root, path);
-        BUG_ON(ret);
+out:
        btrfs_free_path(path);
        return ret;
 }
@@ -1187,11 +1220,13 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path)
        struct block_device *bdev;
        struct buffer_head *bh = NULL;
        struct btrfs_super_block *disk_super;
+        struct btrfs_fs_devices *cur_devices;
        u64 all_avail;
        u64 devid;
        u64 num_devices;
        u8 *dev_uuid;
        int ret = 0;
+        bool clear_super = false;
        mutex_lock(&uuid_mutex);
        mutex_lock(&root->fs_info->volume_mutex);
@@ -1222,14 +1257,16 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path)
                device = NULL;
                devices = &root->fs_info->fs_devices->devices;
-                mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
+                /*
+                 * It is safe to read the devices since the volume_mutex
+                 * is held.
+                 */
                list_for_each_entry(tmp, devices, dev_list) {
                        if (tmp->in_fs_metadata && !tmp->bdev) {
                                device = tmp;
                                break;
                        }
                }
-                mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
                bdev = NULL;
                bh = NULL;
                disk_super = NULL;
@@ -1271,8 +1308,11 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path)
        }
        if (device->writeable) {
+                lock_chunks(root);
                list_del_init(&device->dev_alloc_list);
+                unlock_chunks(root);
                root->fs_info->fs_devices->rw_devices--;
+                clear_super = true;
        }
        ret = btrfs_shrink_device(device, 0);
@@ -1291,9 +1331,10 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path)
         * the device list while someone else is writing out all
         * the device supers.
         */
+        cur_devices = device->fs_devices;
        mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
-        list_del_init(&device->dev_list);
+        list_del_rcu(&device->dev_list);
-        mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
        device->fs_devices->num_devices--;
@@ -1307,34 +1348,36 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path)
        if (device->bdev == root->fs_info->fs_devices->latest_bdev)
                root->fs_info->fs_devices->latest_bdev = next_device->bdev;
-        if (device->bdev) {
+        if (device->bdev)
-                blkdev_put(device->bdev, device->mode);
-                device->bdev = NULL;
                device->fs_devices->open_devices--;
-        }
+        call_rcu(&device->rcu, free_device);
+        mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
        num_devices = btrfs_super_num_devices(&root->fs_info->super_copy) - 1;
        btrfs_set_super_num_devices(&root->fs_info->super_copy, num_devices);
-        if (device->fs_devices->open_devices == 0) {
+        if (cur_devices->open_devices == 0) {
                struct btrfs_fs_devices *fs_devices;
                fs_devices = root->fs_info->fs_devices;
                while (fs_devices) {
-                        if (fs_devices->seed == device->fs_devices)
+                        if (fs_devices->seed == cur_devices)
                                break;
                        fs_devices = fs_devices->seed;
                }
-                fs_devices->seed = device->fs_devices->seed;
+                fs_devices->seed = cur_devices->seed;
-                device->fs_devices->seed = NULL;
+                cur_devices->seed = NULL;
-                __btrfs_close_devices(device->fs_devices);
+                lock_chunks(root);
-                free_fs_devices(device->fs_devices);
+                __btrfs_close_devices(cur_devices);
+                unlock_chunks(root);
+                free_fs_devices(cur_devices);
        }
        /*
         * at this point, the device is zero sized.  We want to
         * remove it from the devices list and zero out the old super
         */
-        if (device->writeable) {
+        if (clear_super) {
                /* make sure this device isn't detected as part of
                 * the FS anymore
                 */
@@ -1343,8 +1386,6 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path)
                sync_dirty_buffer(bh);
        }
-        kfree(device->name);
-        kfree(device);
        ret = 0;
 error_brelse:
@@ -1358,8 +1399,10 @@ out:
        return ret;
 error_undo:
        if (device->writeable) {
+                lock_chunks(root);
                list_add(&device->dev_alloc_list,
                         &root->fs_info->fs_devices->alloc_list);
+                unlock_chunks(root);
                root->fs_info->fs_devices->rw_devices++;
        }
        goto error_brelse;
@@ -1399,7 +1442,12 @@ static int btrfs_prepare_sprout(struct btrfs_trans_handle *trans,
        INIT_LIST_HEAD(&seed_devices->devices);
        INIT_LIST_HEAD(&seed_devices->alloc_list);
        mutex_init(&seed_devices->device_list_mutex);
-        list_splice_init(&fs_devices->devices, &seed_devices->devices);
+        mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
+        list_splice_init_rcu(&fs_devices->devices, &seed_devices->devices,
+                              synchronize_rcu);
+        mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
        list_splice_init(&fs_devices->alloc_list, &seed_devices->alloc_list);
        list_for_each_entry(device, &seed_devices->devices, dev_list) {
                device->fs_devices = seed_devices;
@@ -1596,7 +1644,7 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
         * half setup
         */
        mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
-        list_add(&device->dev_list, &root->fs_info->fs_devices->devices);
+        list_add_rcu(&device->dev_list, &root->fs_info->fs_devices->devices);
        list_add(&device->dev_alloc_list,
                 &root->fs_info->fs_devices->alloc_list);
        root->fs_info->fs_devices->num_devices++;
@@ -1754,10 +1802,9 @@ static int btrfs_free_chunk(struct btrfs_trans_handle *trans,
        BUG_ON(ret);
        ret = btrfs_del_item(trans, root, path);
-        BUG_ON(ret);
        btrfs_free_path(path);
-        return 0;
+        return ret;
 }
 static int btrfs_del_sys_chunk(struct btrfs_root *root, u64 chunk_objectid, u64
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 7c58a7b2d99f..7c12d61ae7ae 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -89,6 +89,8 @@ struct btrfs_device {
        struct scrub_dev *scrub_device;
        struct btrfs_work work;
+        struct rcu_head rcu;
+        struct work_struct rcu_work;
 };
 struct btrfs_fs_devices {