Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable

* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable:
  Btrfs: hold trans_mutex when using btrfs_record_root_in_trans
  Btrfs: make a lockdep class for the extent buffer locks
  Btrfs: fs/btrfs/volumes.c: remove useless kzalloc
  Btrfs: remove unused code in split_state()
  Btrfs: remove btrfs_init_path
  Btrfs: balance_level checks !child after access
  Btrfs: Avoid using __GFP_HIGHMEM with slab allocator
  Btrfs: don't clean old snapshots on sync(1)
  Btrfs: use larger metadata clusters in ssd mode
  Btrfs: process mount options on mount -o remount,
  Btrfs: make sure all pending extent operations are complete

13 files changed, 157 insertions, 84 deletions

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 35443cc4b9a9..42491d728e99 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -38,19 +38,12 @@ static int balance_node_right(struct btrfs_trans_handle *trans,
 static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
                    struct btrfs_path *path, int level, int slot);
 
-inline void btrfs_init_path(struct btrfs_path *p)
-{
-        memset(p, 0, sizeof(*p));
-}
-
 struct btrfs_path *btrfs_alloc_path(void)
 {
         struct btrfs_path *path;
-        path = kmem_cache_alloc(btrfs_path_cachep, GFP_NOFS);
-        if (path) {
-                btrfs_init_path(path);
+        path = kmem_cache_zalloc(btrfs_path_cachep, GFP_NOFS);
+        if (path)
                 path->reada = 1;
-        }
         return path;
 }
 
@@ -69,14 +62,38 @@ noinline void btrfs_set_path_blocking(struct btrfs_path *p)
 
 /*
  * reset all the locked nodes in the patch to spinning locks.
+ *
+ * held is used to keep lockdep happy, when lockdep is enabled
+ * we set held to a blocking lock before we go around and
+ * retake all the spinlocks in the path.  You can safely use NULL
+ * for held
  */
-noinline void btrfs_clear_path_blocking(struct btrfs_path *p)
+noinline void btrfs_clear_path_blocking(struct btrfs_path *p,
+                                        struct extent_buffer *held)
 {
         int i;
-        for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+        /* lockdep really cares that we take all of these spinlocks
+         * in the right order.  If any of the locks in the path are not
+         * currently blocking, it is going to complain.  So, make really
+         * really sure by forcing the path to blocking before we clear
+         * the path blocking.
+         */
+        if (held)
+                btrfs_set_lock_blocking(held);
+        btrfs_set_path_blocking(p);
+#endif
+
+        for (i = BTRFS_MAX_LEVEL - 1; i >= 0; i--) {
                 if (p->nodes[i] && p->locks[i])
                         btrfs_clear_lock_blocking(p->nodes[i]);
         }
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+        if (held)
+                btrfs_clear_lock_blocking(held);
+#endif
 }
 
 /* this also releases the path */
@@ -286,7 +303,7 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans,
                                                   trans->transid, level, &ins);
                 BUG_ON(ret);
                 cow = btrfs_init_new_buffer(trans, root, prealloc_dest,
-                                            buf->len);
+                                            buf->len, level);
         } else {
                 cow = btrfs_alloc_free_block(trans, root, buf->len,
                                              parent_start,
@@ -917,9 +934,9 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
 
                 /* promote the child to a root */
                 child = read_node_slot(root, mid, 0);
+                BUG_ON(!child);
                 btrfs_tree_lock(child);
                 btrfs_set_lock_blocking(child);
-                BUG_ON(!child);
                 ret = btrfs_cow_block(trans, root, child, mid, 0, &child, 0);
                 BUG_ON(ret);
 
@@ -1566,7 +1583,7 @@ cow_done:
                 if (!p->skip_locking)
                         p->locks[level] = 1;
 
-                btrfs_clear_path_blocking(p);
+                btrfs_clear_path_blocking(p, NULL);
 
                 /*
                  * we have a lock on b and as long as we aren't changing
@@ -1605,7 +1622,7 @@ cow_done:
 
                                 btrfs_set_path_blocking(p);
                                 sret = split_node(trans, root, p, level);
-                                btrfs_clear_path_blocking(p);
+                                btrfs_clear_path_blocking(p, NULL);
 
                                 BUG_ON(sret > 0);
                                 if (sret) {
@@ -1625,7 +1642,7 @@ cow_done:
 
                                 btrfs_set_path_blocking(p);
                                 sret = balance_level(trans, root, p, level);
-                                btrfs_clear_path_blocking(p);
+                                btrfs_clear_path_blocking(p, NULL);
 
                                 if (sret) {
                                         ret = sret;
@@ -1688,13 +1705,13 @@ cow_done:
                         if (!p->skip_locking) {
                                 int lret;
 
-                                btrfs_clear_path_blocking(p);
+                                btrfs_clear_path_blocking(p, NULL);
                                 lret = btrfs_try_spin_lock(b);
 
                                 if (!lret) {
                                         btrfs_set_path_blocking(p);
                                         btrfs_tree_lock(b);
-                                        btrfs_clear_path_blocking(p);
+                                        btrfs_clear_path_blocking(p, b);
                                 }
                         }
                 } else {
@@ -1706,7 +1723,7 @@ cow_done:
                                 btrfs_set_path_blocking(p);
                                 sret = split_leaf(trans, root, key,
                                                       p, ins_len, ret == 0);
-                                btrfs_clear_path_blocking(p);
+                                btrfs_clear_path_blocking(p, NULL);
 
                                 BUG_ON(sret > 0);
                                 if (sret) {
@@ -3926,7 +3943,6 @@ find_next_key:
                                 btrfs_release_path(root, path);
                                 goto again;
                         } else {
-                                btrfs_clear_path_blocking(path);
                                 goto out;
                         }
                 }
@@ -3946,7 +3962,7 @@ find_next_key:
                 path->locks[level - 1] = 1;
                 path->nodes[level - 1] = cur;
                 unlock_up(path, level, 1);
-                btrfs_clear_path_blocking(path);
+                btrfs_clear_path_blocking(path, NULL);
         }
 out:
         if (ret == 0)
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 531db112c8bd..766b31ae3186 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -43,11 +43,7 @@ struct btrfs_ordered_sum;
 
 #define BTRFS_ACL_NOT_CACHED    ((void *)-1)
 
-#ifdef CONFIG_LOCKDEP
-# define BTRFS_MAX_LEVEL 7
-#else
-# define BTRFS_MAX_LEVEL 8
-#endif
+#define BTRFS_MAX_LEVEL 8
 
 /* holds pointers to all of the tree roots */
 #define BTRFS_ROOT_TREE_OBJECTID 1ULL
@@ -1715,7 +1711,8 @@ struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
                                              u64 empty_size);
 struct extent_buffer *btrfs_init_new_buffer(struct btrfs_trans_handle *trans,
                                             struct btrfs_root *root,
-                                            u64 bytenr, u32 blocksize);
+                                            u64 bytenr, u32 blocksize,
+                                            int level);
 int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
                        struct btrfs_root *root,
                        u64 num_bytes, u64 parent, u64 min_bytes,
@@ -1834,9 +1831,7 @@ int btrfs_realloc_node(struct btrfs_trans_handle *trans,
 void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p);
 struct btrfs_path *btrfs_alloc_path(void);
 void btrfs_free_path(struct btrfs_path *p);
-void btrfs_init_path(struct btrfs_path *p);
 void btrfs_set_path_blocking(struct btrfs_path *p);
-void btrfs_clear_path_blocking(struct btrfs_path *p);
 void btrfs_unlock_up_safe(struct btrfs_path *p, int level);
 
 int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 5aebddd71193..adda739a0215 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -75,6 +75,40 @@ struct async_submit_bio {
         struct btrfs_work work;
 };
 
+/* These are used to set the lockdep class on the extent buffer locks.
+ * The class is set by the readpage_end_io_hook after the buffer has
+ * passed csum validation but before the pages are unlocked.
+ *
+ * The lockdep class is also set by btrfs_init_new_buffer on freshly
+ * allocated blocks.
+ *
+ * The class is based on the level in the tree block, which allows lockdep
+ * to know that lower nodes nest inside the locks of higher nodes.
+ *
+ * We also add a check to make sure the highest level of the tree is
+ * the same as our lockdep setup here.  If BTRFS_MAX_LEVEL changes, this
+ * code needs update as well.
+ */
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+# if BTRFS_MAX_LEVEL != 8
+#  error
+# endif
+static struct lock_class_key btrfs_eb_class[BTRFS_MAX_LEVEL + 1];
+static const char *btrfs_eb_name[BTRFS_MAX_LEVEL + 1] = {
+        /* leaf */
+        "btrfs-extent-00",
+        "btrfs-extent-01",
+        "btrfs-extent-02",
+        "btrfs-extent-03",
+        "btrfs-extent-04",
+        "btrfs-extent-05",
+        "btrfs-extent-06",
+        "btrfs-extent-07",
+        /* highest possible level */
+        "btrfs-extent-08",
+};
+#endif
+
 /*
  * extents on the btree inode are pretty simple, there's one extent
  * that covers the entire device
@@ -347,6 +381,15 @@ static int check_tree_block_fsid(struct btrfs_root *root,
         return ret;
 }
 
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+void btrfs_set_buffer_lockdep_class(struct extent_buffer *eb, int level)
+{
+        lockdep_set_class_and_name(&eb->lock,
+                           &btrfs_eb_class[level],
+                           btrfs_eb_name[level]);
+}
+#endif
+
 static int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end,
                                struct extent_state *state)
 {
@@ -392,6 +435,8 @@ static int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end,
         }
         found_level = btrfs_header_level(eb);
 
+        btrfs_set_buffer_lockdep_class(eb, found_level);
+
         ret = csum_tree_block(root, eb, 1);
         if (ret)
                 ret = -EIO;
@@ -1777,7 +1822,6 @@ struct btrfs_root *open_ctree(struct super_block *sb,
         ret = find_and_setup_root(tree_root, fs_info,
                                   BTRFS_DEV_TREE_OBJECTID, dev_root);
         dev_root->track_dirty = 1;
-
         if (ret)
                 goto fail_extent_root;
 
diff --git a/fs/btrfs/disk-io.h b/fs/btrfs/disk-io.h
index 494a56eb2986..95029db227be 100644
--- a/fs/btrfs/disk-io.h
+++ b/fs/btrfs/disk-io.h
@@ -101,4 +101,14 @@ int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
 int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
                        struct btrfs_root *root);
 int btree_lock_page_hook(struct page *page);
+
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+void btrfs_set_buffer_lockdep_class(struct extent_buffer *eb, int level);
+#else
+static inline void btrfs_set_buffer_lockdep_class(struct extent_buffer *eb,
+                                                 int level)
+{
+}
+#endif
 #endif
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 7527523c2d2d..0a5d796c9f7e 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -1323,8 +1323,25 @@ int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
 int btrfs_extent_post_op(struct btrfs_trans_handle *trans,
                          struct btrfs_root *root)
 {
-        finish_current_insert(trans, root->fs_info->extent_root, 1);
-        del_pending_extents(trans, root->fs_info->extent_root, 1);
+        u64 start;
+        u64 end;
+        int ret;
+
+        while(1) {
+                finish_current_insert(trans, root->fs_info->extent_root, 1);
+                del_pending_extents(trans, root->fs_info->extent_root, 1);
+
+                /* is there more work to do? */
+                ret = find_first_extent_bit(&root->fs_info->pending_del,
+                                            0, &start, &end, EXTENT_WRITEBACK);
+                if (!ret)
+                        continue;
+                ret = find_first_extent_bit(&root->fs_info->extent_ins,
+                                            0, &start, &end, EXTENT_WRITEBACK);
+                if (!ret)
+                        continue;
+                break;
+        }
         return 0;
 }
 
@@ -2211,13 +2228,12 @@ static int finish_current_insert(struct btrfs_trans_handle *trans,
         u64 end;
         u64 priv;
         u64 search = 0;
-        u64 skipped = 0;
         struct btrfs_fs_info *info = extent_root->fs_info;
         struct btrfs_path *path;
         struct pending_extent_op *extent_op, *tmp;
         struct list_head insert_list, update_list;
         int ret;
-        int num_inserts = 0, max_inserts;
+        int num_inserts = 0, max_inserts, restart = 0;
 
         path = btrfs_alloc_path();
         INIT_LIST_HEAD(&insert_list);
@@ -2233,19 +2249,19 @@ again:
                 ret = find_first_extent_bit(&info->extent_ins, search, &start,
                                             &end, EXTENT_WRITEBACK);
                 if (ret) {
-                        if (skipped && all && !num_inserts &&
+                        if (restart && !num_inserts &&
                             list_empty(&update_list)) {
-                                skipped = 0;
+                                restart = 0;
                                 search = 0;
                                 continue;
                         }
-                        mutex_unlock(&info->extent_ins_mutex);
                         break;
                 }
 
                 ret = try_lock_extent(&info->extent_ins, start, end, GFP_NOFS);
                 if (!ret) {
-                        skipped = 1;
+                        if (all)
+                                restart = 1;
                         search = end + 1;
                         if (need_resched()) {
                                 mutex_unlock(&info->extent_ins_mutex);
@@ -2264,7 +2280,7 @@ again:
                         list_add_tail(&extent_op->list, &insert_list);
                         search = end + 1;
                         if (num_inserts == max_inserts) {
-                                mutex_unlock(&info->extent_ins_mutex);
+                                restart = 1;
                                 break;
                         }
                 } else if (extent_op->type == PENDING_BACKREF_UPDATE) {
@@ -2280,7 +2296,6 @@ again:
          * somebody marked this thing for deletion then just unlock it and be
          * done, the free_extents will handle it
          */
-        mutex_lock(&info->extent_ins_mutex);
         list_for_each_entry_safe(extent_op, tmp, &update_list, list) {
                 clear_extent_bits(&info->extent_ins, extent_op->bytenr,
                                   extent_op->bytenr + extent_op->num_bytes - 1,
@@ -2302,6 +2317,10 @@ again:
         if (!list_empty(&update_list)) {
                 ret = update_backrefs(trans, extent_root, path, &update_list);
                 BUG_ON(ret);
+
+                /* we may have COW'ed new blocks, so lets start over */
+                if (all)
+                        restart = 1;
         }
 
         /*
@@ -2309,9 +2328,9 @@ again:
          * need to make sure everything is cleaned then reset everything and
          * go back to the beginning
          */
-        if (!num_inserts && all && skipped) {
+        if (!num_inserts && restart) {
                 search = 0;
-                skipped = 0;
+                restart = 0;
                 INIT_LIST_HEAD(&update_list);
                 INIT_LIST_HEAD(&insert_list);
                 goto again;
@@ -2368,27 +2387,19 @@ again:
         BUG_ON(ret);
 
         /*
-         * if we broke out of the loop in order to insert stuff because we hit
-         * the maximum number of inserts at a time we can handle, then loop
-         * back and pick up where we left off
+         * if restart is set for whatever reason we need to go back and start
+         * searching through the pending list again.
+         *
+         * We just inserted some extents, which could have resulted in new
+         * blocks being allocated, which would result in new blocks needing
+         * updates, so if all is set we _must_ restart to get the updated
+         * blocks.
          */
-        if (num_inserts == max_inserts) {
-                INIT_LIST_HEAD(&insert_list);
-                INIT_LIST_HEAD(&update_list);
-                num_inserts = 0;
-                goto again;
-        }
-
-        /*
-         * again, if we need to make absolutely sure there are no more pending
-         * extent operations left and we know that we skipped some, go back to
-         * the beginning and do it all again
-         */
-        if (all && skipped) {
+        if (restart || all) {
                 INIT_LIST_HEAD(&insert_list);
                 INIT_LIST_HEAD(&update_list);
                 search = 0;
-                skipped = 0;
+                restart = 0;
                 num_inserts = 0;
                 goto again;
         }
@@ -2709,6 +2720,8 @@ again:
                 goto again;
         }
 
+        if (!err)
+                finish_current_insert(trans, extent_root, 0);
         return err;
 }
 
@@ -2859,7 +2872,8 @@ static noinline int find_free_extent(struct btrfs_trans_handle *trans,
 
         if (data & BTRFS_BLOCK_GROUP_METADATA) {
                 last_ptr = &root->fs_info->last_alloc;
-                empty_cluster = 64 * 1024;
+                if (!btrfs_test_opt(root, SSD))
+                        empty_cluster = 64 * 1024;
         }
 
         if ((data & BTRFS_BLOCK_GROUP_DATA) && btrfs_test_opt(root, SSD))
@@ -3402,7 +3416,8 @@ int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
 
 struct extent_buffer *btrfs_init_new_buffer(struct btrfs_trans_handle *trans,
                                             struct btrfs_root *root,
-                                            u64 bytenr, u32 blocksize)
+                                            u64 bytenr, u32 blocksize,
+                                            int level)
 {
         struct extent_buffer *buf;
 
@@ -3410,6 +3425,7 @@ struct extent_buffer *btrfs_init_new_buffer(struct btrfs_trans_handle *trans,
         if (!buf)
                 return ERR_PTR(-ENOMEM);
         btrfs_set_header_generation(buf, trans->transid);
+        btrfs_set_buffer_lockdep_class(buf, level);
         btrfs_tree_lock(buf);
         clean_tree_block(trans, root, buf);
 
@@ -3453,7 +3469,8 @@ struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
                 return ERR_PTR(ret);
         }
 
-        buf = btrfs_init_new_buffer(trans, root, ins.objectid, blocksize);
+        buf = btrfs_init_new_buffer(trans, root, ins.objectid,
+                                    blocksize, level);
         return buf;
 }
 
@@ -5641,7 +5658,9 @@ static noinline int relocate_one_extent(struct btrfs_root *extent_root,
                         prev_block = block_start;
                 }
 
+                mutex_lock(&extent_root->fs_info->trans_mutex);
                 btrfs_record_root_in_trans(found_root);
+                mutex_unlock(&extent_root->fs_info->trans_mutex);
                 if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
                         /*
                          * try to update data extent references while
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 37d43b516b79..ebe6b29e6069 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -415,8 +415,6 @@ static int split_state(struct extent_io_tree *tree, struct extent_state *orig,
 
         node = tree_insert(&tree->state, prealloc->end, &prealloc->rb_node);
         if (node) {
-                struct extent_state *found;
-                found = rb_entry(node, struct extent_state, rb_node);
                 free_extent_state(prealloc);
                 return -EEXIST;
         }
diff --git a/fs/btrfs/inode-map.c b/fs/btrfs/inode-map.c
index 2aa79873eb46..cc7334d833c9 100644
--- a/fs/btrfs/inode-map.c
+++ b/fs/btrfs/inode-map.c
@@ -84,7 +84,6 @@ int btrfs_find_free_objectid(struct btrfs_trans_handle *trans,
         search_key.type = 0;
         search_key.offset = 0;
 
-        btrfs_init_path(path);
         start_found = 0;
         ret = btrfs_search_slot(trans, root, &search_key, path, 0, 0);
         if (ret < 0)
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 8f0706210a47..3cee77ae03c8 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -2531,8 +2531,6 @@ noinline int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
         key.offset = (u64)-1;
         key.type = (u8)-1;
 
-        btrfs_init_path(path);
-
 search_again:
         ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
         if (ret < 0)
@@ -4263,7 +4261,7 @@ static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
 {
         if (PageWriteback(page) || PageDirty(page))
                 return 0;
-        return __btrfs_releasepage(page, gfp_flags);
+        return __btrfs_releasepage(page, gfp_flags & GFP_NOFS);
 }
 
 static void btrfs_invalidatepage(struct page *page, unsigned long offset)
diff --git a/fs/btrfs/locking.c b/fs/btrfs/locking.c
index 9ebe9385129b..85506c4a3af7 100644
--- a/fs/btrfs/locking.c
+++ b/fs/btrfs/locking.c
@@ -25,21 +25,10 @@
 #include "extent_io.h"
 #include "locking.h"
 
-/*
- * btrfs_header_level() isn't free, so don't call it when lockdep isn't
- * on
- */
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
-static inline void spin_nested(struct extent_buffer *eb)
-{
-        spin_lock_nested(&eb->lock, BTRFS_MAX_LEVEL - btrfs_header_level(eb));
-}
-#else
 static inline void spin_nested(struct extent_buffer *eb)
 {
         spin_lock(&eb->lock);
 }
-#endif
 
 /*
  * Setting a lock to blocking will drop the spinlock and set the
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index f3fd7e2cbc38..19a4daf03ccb 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -379,7 +379,6 @@ int btrfs_sync_fs(struct super_block *sb, int wait)
         btrfs_start_delalloc_inodes(root);
         btrfs_wait_ordered_extents(root, 0);
 
-        btrfs_clean_old_snapshots(root);
         trans = btrfs_start_transaction(root, 1);
         ret = btrfs_commit_transaction(trans, root);
         sb->s_dirt = 0;
@@ -511,6 +510,10 @@ static int btrfs_remount(struct super_block *sb, int *flags, char *data)
         struct btrfs_root *root = btrfs_sb(sb);
         int ret;
 
+        ret = btrfs_parse_options(root, data);
+        if (ret)
+                return -EINVAL;
+
         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
                 return 0;
 
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 919172de5c9a..4112d53d4f4d 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -688,7 +688,9 @@ static noinline int drop_dirty_roots(struct btrfs_root *tree_root,
                 num_bytes -= btrfs_root_used(&dirty->root->root_item);
                 bytes_used = btrfs_root_used(&root->root_item);
                 if (num_bytes) {
+                        mutex_lock(&root->fs_info->trans_mutex);
                         btrfs_record_root_in_trans(root);
+                        mutex_unlock(&root->fs_info->trans_mutex);
                         btrfs_set_root_used(&root->root_item,
                                             bytes_used - num_bytes);
                 }
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 20794290256b..9c462fbd60fa 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -2832,7 +2832,9 @@ again:
                 BUG_ON(!wc.replay_dest);
 
                 wc.replay_dest->log_root = log;
+                mutex_lock(&fs_info->trans_mutex);
                 btrfs_record_root_in_trans(wc.replay_dest);
+                mutex_unlock(&fs_info->trans_mutex);
                 ret = walk_log_tree(trans, log, &wc);
                 BUG_ON(ret);
 
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index bcd14ebccae1..1316139bf9e8 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2894,10 +2894,6 @@ static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
                 free_extent_map(em);
         }
 
-        map = kzalloc(sizeof(*map), GFP_NOFS);
-        if (!map)
-                return -ENOMEM;
-
         em = alloc_extent_map(GFP_NOFS);
         if (!em)
                 return -ENOMEM;
@@ -3106,6 +3102,8 @@ int btrfs_read_sys_array(struct btrfs_root *root)
         if (!sb)
                 return -ENOMEM;
         btrfs_set_buffer_uptodate(sb);
+        btrfs_set_buffer_lockdep_class(sb, 0);
+
         write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE);
         array_size = btrfs_super_sys_array_size(super_copy);