btrfs: return void in functions without error conditions

Signed-off-by: Jeff Mahoney <jeffm@suse.com>

28 files changed, 249 insertions, 410 deletions

diff --git a/fs/btrfs/async-thread.c b/fs/btrfs/async-thread.c
index 0cc20b35c1c4..42704149b723 100644
--- a/fs/btrfs/async-thread.c
+++ b/fs/btrfs/async-thread.c
@@ -171,11 +171,11 @@ out:
         spin_unlock_irqrestore(&workers->lock, flags);
 }
 
-static noinline int run_ordered_completions(struct btrfs_workers *workers,
+static noinline void run_ordered_completions(struct btrfs_workers *workers,
                                             struct btrfs_work *work)
 {
         if (!workers->ordered)
-                return 0;
+                return;
 
         set_bit(WORK_DONE_BIT, &work->flags);
 
@@ -213,7 +213,6 @@ static noinline int run_ordered_completions(struct btrfs_workers *workers,
         }
 
         spin_unlock(&workers->order_lock);
-        return 0;
 }
 
 static void put_worker(struct btrfs_worker_thread *worker)
@@ -399,7 +398,7 @@ again:
 /*
  * this will wait for all the worker threads to shutdown
  */
-int btrfs_stop_workers(struct btrfs_workers *workers)
+void btrfs_stop_workers(struct btrfs_workers *workers)
 {
         struct list_head *cur;
         struct btrfs_worker_thread *worker;
@@ -427,7 +426,6 @@ int btrfs_stop_workers(struct btrfs_workers *workers)
                 put_worker(worker);
         }
         spin_unlock_irq(&workers->lock);
-        return 0;
 }
 
 /*
@@ -615,14 +613,14 @@ found:
  * it was taken from.  It is intended for use with long running work functions
  * that make some progress and want to give the cpu up for others.
  */
-int btrfs_requeue_work(struct btrfs_work *work)
+void btrfs_requeue_work(struct btrfs_work *work)
 {
         struct btrfs_worker_thread *worker = work->worker;
         unsigned long flags;
         int wake = 0;
 
         if (test_and_set_bit(WORK_QUEUED_BIT, &work->flags))
-                goto out;
+                return;
 
         spin_lock_irqsave(&worker->lock, flags);
         if (test_bit(WORK_HIGH_PRIO_BIT, &work->flags))
@@ -649,9 +647,6 @@ int btrfs_requeue_work(struct btrfs_work *work)
         if (wake)
                 wake_up_process(worker->task);
         spin_unlock_irqrestore(&worker->lock, flags);
-out:
-
-        return 0;
 }
 
 void btrfs_set_work_high_prio(struct btrfs_work *work)
diff --git a/fs/btrfs/async-thread.h b/fs/btrfs/async-thread.h
index f34cc31fa3c9..063698b90ce2 100644
--- a/fs/btrfs/async-thread.h
+++ b/fs/btrfs/async-thread.h
@@ -111,9 +111,9 @@ struct btrfs_workers {
 
 void btrfs_queue_worker(struct btrfs_workers *workers, struct btrfs_work *work);
 int btrfs_start_workers(struct btrfs_workers *workers);
-int btrfs_stop_workers(struct btrfs_workers *workers);
+void btrfs_stop_workers(struct btrfs_workers *workers);
 void btrfs_init_workers(struct btrfs_workers *workers, char *name, int max,
                         struct btrfs_workers *async_starter);
-int btrfs_requeue_work(struct btrfs_work *work);
+void btrfs_requeue_work(struct btrfs_work *work);
 void btrfs_set_work_high_prio(struct btrfs_work *work);
 #endif
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index d02c27cd14c7..0ed1ed22775f 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -226,8 +226,8 @@ out:
  * Clear the writeback bits on all of the file
  * pages for a compressed write
  */
-static noinline int end_compressed_writeback(struct inode *inode, u64 start,
-                                             unsigned long ram_size)
+static noinline void end_compressed_writeback(struct inode *inode, u64 start,
+                                              unsigned long ram_size)
 {
         unsigned long index = start >> PAGE_CACHE_SHIFT;
         unsigned long end_index = (start + ram_size - 1) >> PAGE_CACHE_SHIFT;
@@ -253,7 +253,6 @@ static noinline int end_compressed_writeback(struct inode *inode, u64 start,
                 index += ret;
         }
         /* the inode may be gone now */
-        return 0;
 }
 
 /*
@@ -734,7 +733,7 @@ struct btrfs_compress_op *btrfs_compress_op[] = {
         &btrfs_lzo_compress,
 };
 
-int __init btrfs_init_compress(void)
+void __init btrfs_init_compress(void)
 {
         int i;
 
@@ -744,7 +743,6 @@ int __init btrfs_init_compress(void)
                 atomic_set(&comp_alloc_workspace[i], 0);
                 init_waitqueue_head(&comp_workspace_wait[i]);
         }
-        return 0;
 }
 
 /*
diff --git a/fs/btrfs/compression.h b/fs/btrfs/compression.h
index a12059f4f0fd..9afb0a62ae82 100644
--- a/fs/btrfs/compression.h
+++ b/fs/btrfs/compression.h
@@ -19,7 +19,7 @@
 #ifndef __BTRFS_COMPRESSION_
 #define __BTRFS_COMPRESSION_
 
-int btrfs_init_compress(void);
+void btrfs_init_compress(void);
 void btrfs_exit_compress(void);
 
 int btrfs_compress_pages(int type, struct address_space *mapping,
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 0639a555e16e..9d472c2a8de8 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -36,7 +36,7 @@ static int balance_node_right(struct btrfs_trans_handle *trans,
                               struct btrfs_root *root,
                               struct extent_buffer *dst_buf,
                               struct extent_buffer *src_buf);
-static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
+static void del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
                    struct btrfs_path *path, int level, int slot);
 
 struct btrfs_path *btrfs_alloc_path(void)
@@ -1010,10 +1010,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
                 if (btrfs_header_nritems(right) == 0) {
                         clean_tree_block(trans, root, right);
                         btrfs_tree_unlock(right);
-                        wret = del_ptr(trans, root, path, level + 1, pslot +
-                                       1);
-                        if (wret)
-                                ret = wret;
+                        del_ptr(trans, root, path, level + 1, pslot + 1);
                         root_sub_used(root, right->len);
                         btrfs_free_tree_block(trans, root, right, 0, 1, 0);
                         free_extent_buffer(right);
@@ -1051,9 +1048,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
         if (btrfs_header_nritems(mid) == 0) {
                 clean_tree_block(trans, root, mid);
                 btrfs_tree_unlock(mid);
-                wret = del_ptr(trans, root, path, level + 1, pslot);
-                if (wret)
-                        ret = wret;
+                del_ptr(trans, root, path, level + 1, pslot);
                 root_sub_used(root, mid->len);
                 btrfs_free_tree_block(trans, root, mid, 0, 1, 0);
                 free_extent_buffer(mid);
@@ -1881,15 +1876,12 @@ done:
  * fixing up pointers when a given leaf/node is not in slot 0 of the
  * higher levels
  *
- * If this fails to write a tree block, it returns -1, but continues
- * fixing up the blocks in ram so the tree is consistent.
  */
-static int fixup_low_keys(struct btrfs_trans_handle *trans,
-                          struct btrfs_root *root, struct btrfs_path *path,
-                          struct btrfs_disk_key *key, int level)
+static void fixup_low_keys(struct btrfs_trans_handle *trans,
+                           struct btrfs_root *root, struct btrfs_path *path,
+                           struct btrfs_disk_key *key, int level)
 {
         int i;
-        int ret = 0;
         struct extent_buffer *t;
 
         for (i = level; i < BTRFS_MAX_LEVEL; i++) {
@@ -1902,7 +1894,6 @@ static int fixup_low_keys(struct btrfs_trans_handle *trans,
                 if (tslot != 0)
                         break;
         }
-        return ret;
 }
 
 /*
@@ -1911,9 +1902,9 @@ static int fixup_low_keys(struct btrfs_trans_handle *trans,
  * This function isn't completely safe. It's the caller's responsibility
  * that the new key won't break the order
  */
-int btrfs_set_item_key_safe(struct btrfs_trans_handle *trans,
-                            struct btrfs_root *root, struct btrfs_path *path,
-                            struct btrfs_key *new_key)
+void btrfs_set_item_key_safe(struct btrfs_trans_handle *trans,
+                             struct btrfs_root *root, struct btrfs_path *path,
+                             struct btrfs_key *new_key)
 {
         struct btrfs_disk_key disk_key;
         struct extent_buffer *eb;
@@ -1923,13 +1914,11 @@ int btrfs_set_item_key_safe(struct btrfs_trans_handle *trans,
         slot = path->slots[0];
         if (slot > 0) {
                 btrfs_item_key(eb, &disk_key, slot - 1);
-                if (comp_keys(&disk_key, new_key) >= 0)
-                        return -1;
+                BUG_ON(comp_keys(&disk_key, new_key) >= 0);
         }
         if (slot < btrfs_header_nritems(eb) - 1) {
                 btrfs_item_key(eb, &disk_key, slot + 1);
-                if (comp_keys(&disk_key, new_key) <= 0)
-                        return -1;
+                BUG_ON(comp_keys(&disk_key, new_key) <= 0);
         }
 
         btrfs_cpu_key_to_disk(&disk_key, new_key);
@@ -1937,7 +1926,6 @@ int btrfs_set_item_key_safe(struct btrfs_trans_handle *trans,
         btrfs_mark_buffer_dirty(eb);
         if (slot == 0)
                 fixup_low_keys(trans, root, path, &disk_key, 1);
-        return 0;
 }
 
 /*
@@ -2140,12 +2128,11 @@ static noinline int insert_new_root(struct btrfs_trans_handle *trans,
  *
  * slot and level indicate where you want the key to go, and
  * blocknr is the block the key points to.
- *
- * returns zero on success and < 0 on any error
  */
-static int insert_ptr(struct btrfs_trans_handle *trans, struct btrfs_root
-                      *root, struct btrfs_path *path, struct btrfs_disk_key
-                      *key, u64 bytenr, int slot, int level)
+static void insert_ptr(struct btrfs_trans_handle *trans,
+                       struct btrfs_root *root, struct btrfs_path *path,
+                       struct btrfs_disk_key *key, u64 bytenr,
+                       int slot, int level)
 {
         struct extent_buffer *lower;
         int nritems;
@@ -2155,8 +2142,7 @@ static int insert_ptr(struct btrfs_trans_handle *trans, struct btrfs_root
         lower = path->nodes[level];
         nritems = btrfs_header_nritems(lower);
         BUG_ON(slot > nritems);
-        if (nritems == BTRFS_NODEPTRS_PER_BLOCK(root))
-                BUG();
+        BUG_ON(nritems == BTRFS_NODEPTRS_PER_BLOCK(root));
         if (slot != nritems) {
                 memmove_extent_buffer(lower,
                               btrfs_node_key_ptr_offset(slot + 1),
@@ -2169,7 +2155,6 @@ static int insert_ptr(struct btrfs_trans_handle *trans, struct btrfs_root
         btrfs_set_node_ptr_generation(lower, slot, trans->transid);
         btrfs_set_header_nritems(lower, nritems + 1);
         btrfs_mark_buffer_dirty(lower);
-        return 0;
 }
 
 /*
@@ -2190,7 +2175,6 @@ static noinline int split_node(struct btrfs_trans_handle *trans,
         struct btrfs_disk_key disk_key;
         int mid;
         int ret;
-        int wret;
         u32 c_nritems;
 
         c = path->nodes[level];
@@ -2247,11 +2231,8 @@ static noinline int split_node(struct btrfs_trans_handle *trans,
         btrfs_mark_buffer_dirty(c);
         btrfs_mark_buffer_dirty(split);
 
-        wret = insert_ptr(trans, root, path, &disk_key, split->start,
-                          path->slots[level + 1] + 1,
-                          level + 1);
-        if (wret)
-                ret = wret;
+        insert_ptr(trans, root, path, &disk_key, split->start,
+                   path->slots[level + 1] + 1, level + 1);
 
         if (path->slots[level] >= mid) {
                 path->slots[level] -= mid;
@@ -2537,7 +2518,6 @@ static noinline int __push_leaf_left(struct btrfs_trans_handle *trans,
         u32 old_left_nritems;
         u32 nr;
         int ret = 0;
-        int wret;
         u32 this_item_size;
         u32 old_left_item_size;
 
@@ -2643,9 +2623,7 @@ static noinline int __push_leaf_left(struct btrfs_trans_handle *trans,
                 clean_tree_block(trans, root, right);
 
         btrfs_item_key(right, &disk_key, 0);
-        wret = fixup_low_keys(trans, root, path, &disk_key, 1);
-        if (wret)
-                ret = wret;
+        fixup_low_keys(trans, root, path, &disk_key, 1);
 
         /* then fixup the leaf pointer in the path */
         if (path->slots[0] < push_items) {
@@ -2738,21 +2716,17 @@ out:
 /*
  * split the path's leaf in two, making sure there is at least data_size
  * available for the resulting leaf level of the path.
- *
- * returns 0 if all went well and < 0 on failure.
  */
-static noinline int copy_for_split(struct btrfs_trans_handle *trans,
-                               struct btrfs_root *root,
-                               struct btrfs_path *path,
-                               struct extent_buffer *l,
-                               struct extent_buffer *right,
-                               int slot, int mid, int nritems)
+static noinline void copy_for_split(struct btrfs_trans_handle *trans,
+                                    struct btrfs_root *root,
+                                    struct btrfs_path *path,
+                                    struct extent_buffer *l,
+                                    struct extent_buffer *right,
+                                    int slot, int mid, int nritems)
 {
         int data_copy_size;
         int rt_data_off;
         int i;
-        int ret = 0;
-        int wret;
         struct btrfs_disk_key disk_key;
 
         nritems = nritems - mid;
@@ -2780,12 +2754,9 @@ static noinline int copy_for_split(struct btrfs_trans_handle *trans,
         }
 
         btrfs_set_header_nritems(l, mid);
-        ret = 0;
         btrfs_item_key(right, &disk_key, 0);
-        wret = insert_ptr(trans, root, path, &disk_key, right->start,
-                          path->slots[1] + 1, 1);
-        if (wret)
-                ret = wret;
+        insert_ptr(trans, root, path, &disk_key, right->start,
+                   path->slots[1] + 1, 1);
 
         btrfs_mark_buffer_dirty(right);
         btrfs_mark_buffer_dirty(l);
@@ -2803,8 +2774,6 @@ static noinline int copy_for_split(struct btrfs_trans_handle *trans,
         }
 
         BUG_ON(path->slots[0] < 0);
-
-        return ret;
 }
 
 /*
@@ -2993,12 +2962,8 @@ again:
         if (split == 0) {
                 if (mid <= slot) {
                         btrfs_set_header_nritems(right, 0);
-                        wret = insert_ptr(trans, root, path,
-                                          &disk_key, right->start,
-                                          path->slots[1] + 1, 1);
-                        if (wret)
-                                ret = wret;
-
+                        insert_ptr(trans, root, path, &disk_key, right->start,
+                                   path->slots[1] + 1, 1);
                         btrfs_tree_unlock(path->nodes[0]);
                         free_extent_buffer(path->nodes[0]);
                         path->nodes[0] = right;
@@ -3006,29 +2971,21 @@ again:
                         path->slots[1] += 1;
                 } else {
                         btrfs_set_header_nritems(right, 0);
-                        wret = insert_ptr(trans, root, path,
-                                          &disk_key,
-                                          right->start,
+                        insert_ptr(trans, root, path, &disk_key, right->start,
                                           path->slots[1], 1);
-                        if (wret)
-                                ret = wret;
                         btrfs_tree_unlock(path->nodes[0]);
                         free_extent_buffer(path->nodes[0]);
                         path->nodes[0] = right;
                         path->slots[0] = 0;
-                        if (path->slots[1] == 0) {
-                                wret = fixup_low_keys(trans, root,
-                                                path, &disk_key, 1);
-                                if (wret)
-                                        ret = wret;
-                        }
+                        if (path->slots[1] == 0)
+                                fixup_low_keys(trans, root, path,
+                                               &disk_key, 1);
                 }
                 btrfs_mark_buffer_dirty(right);
                 return ret;
         }
 
-        ret = copy_for_split(trans, root, path, l, right, slot, mid, nritems);
-        BUG_ON(ret);
+        copy_for_split(trans, root, path, l, right, slot, mid, nritems);
 
         if (split == 2) {
                 BUG_ON(num_doubles != 0);
@@ -3036,7 +2993,7 @@ again:
                 goto again;
         }
 
-        return ret;
+        return 0;
 
 push_for_double:
         push_for_double_split(trans, root, path, data_size);
@@ -3238,11 +3195,9 @@ int btrfs_duplicate_item(struct btrfs_trans_handle *trans,
                 return ret;
 
         path->slots[0]++;
-        ret = setup_items_for_insert(trans, root, path, new_key, &item_size,
-                                     item_size, item_size +
-                                     sizeof(struct btrfs_item), 1);
-        BUG_ON(ret);
-
+        setup_items_for_insert(trans, root, path, new_key, &item_size,
+                               item_size, item_size +
+                               sizeof(struct btrfs_item), 1);
         leaf = path->nodes[0];
         memcpy_extent_buffer(leaf,
                              btrfs_item_ptr_offset(leaf, path->slots[0]),
@@ -3257,10 +3212,10 @@ int btrfs_duplicate_item(struct btrfs_trans_handle *trans,
  * off the end of the item or if we shift the item to chop bytes off
  * the front.
  */
-int btrfs_truncate_item(struct btrfs_trans_handle *trans,
-                        struct btrfs_root *root,
-                        struct btrfs_path *path,
-                        u32 new_size, int from_end)
+void btrfs_truncate_item(struct btrfs_trans_handle *trans,
+                         struct btrfs_root *root,
+                         struct btrfs_path *path,
+                         u32 new_size, int from_end)
 {
         int slot;
         struct extent_buffer *leaf;
@@ -3277,7 +3232,7 @@ int btrfs_truncate_item(struct btrfs_trans_handle *trans,
 
         old_size = btrfs_item_size_nr(leaf, slot);
         if (old_size == new_size)
-                return 0;
+                return;
 
         nritems = btrfs_header_nritems(leaf);
         data_end = leaf_data_end(root, leaf);
@@ -3350,15 +3305,14 @@ int btrfs_truncate_item(struct btrfs_trans_handle *trans,
                 btrfs_print_leaf(root, leaf);
                 BUG();
         }
-        return 0;
 }
 
 /*
  * make the item pointed to by the path bigger, data_size is the new size.
  */
-int btrfs_extend_item(struct btrfs_trans_handle *trans,
-                      struct btrfs_root *root, struct btrfs_path *path,
-                      u32 data_size)
+void btrfs_extend_item(struct btrfs_trans_handle *trans,
+                       struct btrfs_root *root, struct btrfs_path *path,
+                       u32 data_size)
 {
         int slot;
         struct extent_buffer *leaf;
@@ -3416,7 +3370,6 @@ int btrfs_extend_item(struct btrfs_trans_handle *trans,
                 btrfs_print_leaf(root, leaf);
                 BUG();
         }
-        return 0;
 }
 
 /*
@@ -3544,7 +3497,7 @@ int btrfs_insert_some_items(struct btrfs_trans_handle *trans,
         ret = 0;
         if (slot == 0) {
                 btrfs_cpu_key_to_disk(&disk_key, cpu_key);
-                ret = fixup_low_keys(trans, root, path, &disk_key, 1);
+                fixup_low_keys(trans, root, path, &disk_key, 1);
         }
 
         if (btrfs_leaf_free_space(root, leaf) < 0) {
@@ -3562,17 +3515,16 @@ out:
  * to save stack depth by doing the bulk of the work in a function
  * that doesn't call btrfs_search_slot
  */
-int setup_items_for_insert(struct btrfs_trans_handle *trans,
-                           struct btrfs_root *root, struct btrfs_path *path,
-                           struct btrfs_key *cpu_key, u32 *data_size,
-                           u32 total_data, u32 total_size, int nr)
+void setup_items_for_insert(struct btrfs_trans_handle *trans,
+                            struct btrfs_root *root, struct btrfs_path *path,
+                            struct btrfs_key *cpu_key, u32 *data_size,
+                            u32 total_data, u32 total_size, int nr)
 {
         struct btrfs_item *item;
         int i;
         u32 nritems;
         unsigned int data_end;
         struct btrfs_disk_key disk_key;
-        int ret;
         struct extent_buffer *leaf;
         int slot;
 
@@ -3633,10 +3585,9 @@ int setup_items_for_insert(struct btrfs_trans_handle *trans,
 
         btrfs_set_header_nritems(leaf, nritems + nr);
 
-        ret = 0;
         if (slot == 0) {
                 btrfs_cpu_key_to_disk(&disk_key, cpu_key);
-                ret = fixup_low_keys(trans, root, path, &disk_key, 1);
+                fixup_low_keys(trans, root, path, &disk_key, 1);
         }
         btrfs_unlock_up_safe(path, 1);
         btrfs_mark_buffer_dirty(leaf);
@@ -3645,7 +3596,6 @@ int setup_items_for_insert(struct btrfs_trans_handle *trans,
                 btrfs_print_leaf(root, leaf);
                 BUG();
         }
-        return ret;
 }
 
 /*
@@ -3672,16 +3622,14 @@ int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
         if (ret == 0)
                 return -EEXIST;
         if (ret < 0)
-                goto out;
+                return ret;
 
         slot = path->slots[0];
         BUG_ON(slot < 0);
 
-        ret = setup_items_for_insert(trans, root, path, cpu_key, data_size,
+        setup_items_for_insert(trans, root, path, cpu_key, data_size,
                                total_data, total_size, nr);
-
-out:
-        return ret;
+        return 0;
 }
 
 /*
@@ -3717,13 +3665,11 @@ int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root
  * the tree should have been previously balanced so the deletion does not
  * empty a node.
  */
-static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
-                   struct btrfs_path *path, int level, int slot)
+static void del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
+                    struct btrfs_path *path, int level, int slot)
 {
         struct extent_buffer *parent = path->nodes[level];
         u32 nritems;
-        int ret = 0;
-        int wret;
 
         nritems = btrfs_header_nritems(parent);
         if (slot != nritems - 1) {
@@ -3743,12 +3689,9 @@ static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
                 struct btrfs_disk_key disk_key;
 
                 btrfs_node_key(parent, &disk_key, 0);
-                wret = fixup_low_keys(trans, root, path, &disk_key, level + 1);
-                if (wret)
-                        ret = wret;
+                fixup_low_keys(trans, root, path, &disk_key, level + 1);
         }
         btrfs_mark_buffer_dirty(parent);
-        return ret;
 }
 
 /*
@@ -3761,17 +3704,13 @@ static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
  * The path must have already been setup for deleting the leaf, including
  * all the proper balancing.  path->nodes[1] must be locked.
  */
-static noinline int btrfs_del_leaf(struct btrfs_trans_handle *trans,
-                                   struct btrfs_root *root,
-                                   struct btrfs_path *path,
-                                   struct extent_buffer *leaf)
+static noinline void btrfs_del_leaf(struct btrfs_trans_handle *trans,
+                                    struct btrfs_root *root,
+                                    struct btrfs_path *path,
+                                    struct extent_buffer *leaf)
 {
-        int ret;
-
         WARN_ON(btrfs_header_generation(leaf) != trans->transid);
-        ret = del_ptr(trans, root, path, 1, path->slots[1]);
-        if (ret)
-                return ret;
+        del_ptr(trans, root, path, 1, path->slots[1]);
 
         /*
          * btrfs_free_extent is expensive, we want to make sure we
@@ -3782,7 +3721,6 @@ static noinline int btrfs_del_leaf(struct btrfs_trans_handle *trans,
         root_sub_used(root, leaf->len);
 
         btrfs_free_tree_block(trans, root, leaf, 0, 1, 0);
-        return 0;
 }
 /*
  * delete the item at the leaf level in path.  If that empties
@@ -3839,8 +3777,7 @@ int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
                 } else {
                         btrfs_set_path_blocking(path);
                         clean_tree_block(trans, root, leaf);
-                        ret = btrfs_del_leaf(trans, root, path, leaf);
-                        BUG_ON(ret);
+                        btrfs_del_leaf(trans, root, path, leaf);
                 }
         } else {
                 int used = leaf_space_used(leaf, 0, nritems);
@@ -3848,10 +3785,7 @@ int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
                         struct btrfs_disk_key disk_key;
 
                         btrfs_item_key(leaf, &disk_key, 0);
-                        wret = fixup_low_keys(trans, root, path,
-                                              &disk_key, 1);
-                        if (wret)
-                                ret = wret;
+                        fixup_low_keys(trans, root, path, &disk_key, 1);
                 }
 
                 /* delete the leaf if it is mostly empty */
@@ -3879,9 +3813,9 @@ int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 
                         if (btrfs_header_nritems(leaf) == 0) {
                                 path->slots[1] = slot;
-                                ret = btrfs_del_leaf(trans, root, path, leaf);
-                                BUG_ON(ret);
+                                btrfs_del_leaf(trans, root, path, leaf);
                                 free_extent_buffer(leaf);
+                                ret = 0;
                         } else {
                                 /* if we're still in the path, make sure
                                  * we're dirty.  Otherwise, one of the
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 339e637ab272..30c5a247ab2b 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2485,8 +2485,8 @@ int btrfs_free_extent(struct btrfs_trans_handle *trans,
 int btrfs_free_reserved_extent(struct btrfs_root *root, u64 start, u64 len);
 int btrfs_free_and_pin_reserved_extent(struct btrfs_root *root,
                                        u64 start, u64 len);
-int btrfs_prepare_extent_commit(struct btrfs_trans_handle *trans,
-                                struct btrfs_root *root);
+void btrfs_prepare_extent_commit(struct btrfs_trans_handle *trans,
+                                 struct btrfs_root *root);
 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
                                struct btrfs_root *root);
 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
@@ -2549,8 +2549,8 @@ void btrfs_block_rsv_release(struct btrfs_root *root,
                              u64 num_bytes);
 int btrfs_set_block_group_ro(struct btrfs_root *root,
                              struct btrfs_block_group_cache *cache);
-int btrfs_set_block_group_rw(struct btrfs_root *root,
-                             struct btrfs_block_group_cache *cache);
+void btrfs_set_block_group_rw(struct btrfs_root *root,
+                              struct btrfs_block_group_cache *cache);
 void btrfs_put_block_group_cache(struct btrfs_fs_info *info);
 u64 btrfs_account_ro_block_groups_free_space(struct btrfs_space_info *sinfo);
 int btrfs_error_unpin_extent_range(struct btrfs_root *root,
@@ -2569,9 +2569,9 @@ int btrfs_comp_cpu_keys(struct btrfs_key *k1, struct btrfs_key *k2);
 int btrfs_previous_item(struct btrfs_root *root,
                         struct btrfs_path *path, u64 min_objectid,
                         int type);
-int btrfs_set_item_key_safe(struct btrfs_trans_handle *trans,
-                            struct btrfs_root *root, struct btrfs_path *path,
-                            struct btrfs_key *new_key);
+void btrfs_set_item_key_safe(struct btrfs_trans_handle *trans,
+                             struct btrfs_root *root, struct btrfs_path *path,
+                             struct btrfs_key *new_key);
 struct extent_buffer *btrfs_root_node(struct btrfs_root *root);
 struct extent_buffer *btrfs_lock_root_node(struct btrfs_root *root);
 int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path,
@@ -2591,12 +2591,13 @@ int btrfs_copy_root(struct btrfs_trans_handle *trans,
                       struct extent_buffer **cow_ret, u64 new_root_objectid);
 int btrfs_block_can_be_shared(struct btrfs_root *root,
                               struct extent_buffer *buf);
-int btrfs_extend_item(struct btrfs_trans_handle *trans, struct btrfs_root
-                      *root, struct btrfs_path *path, u32 data_size);
-int btrfs_truncate_item(struct btrfs_trans_handle *trans,
-                        struct btrfs_root *root,
-                        struct btrfs_path *path,
-                        u32 new_size, int from_end);
+void btrfs_extend_item(struct btrfs_trans_handle *trans,
+                       struct btrfs_root *root, struct btrfs_path *path,
+                       u32 data_size);
+void btrfs_truncate_item(struct btrfs_trans_handle *trans,
+                         struct btrfs_root *root,
+                         struct btrfs_path *path,
+                         u32 new_size, int from_end);
 int btrfs_split_item(struct btrfs_trans_handle *trans,
                      struct btrfs_root *root,
                      struct btrfs_path *path,
@@ -2630,10 +2631,10 @@ static inline int btrfs_del_item(struct btrfs_trans_handle *trans,
         return btrfs_del_items(trans, root, path, path->slots[0], 1);
 }
 
-int setup_items_for_insert(struct btrfs_trans_handle *trans,
-                           struct btrfs_root *root, struct btrfs_path *path,
-                           struct btrfs_key *cpu_key, u32 *data_size,
-                           u32 total_data, u32 total_size, int nr);
+void setup_items_for_insert(struct btrfs_trans_handle *trans,
+                            struct btrfs_root *root, struct btrfs_path *path,
+                            struct btrfs_key *cpu_key, u32 *data_size,
+                            u32 total_data, u32 total_size, int nr);
 int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root
                       *root, struct btrfs_key *key, void *data, u32 data_size);
 int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
@@ -2911,7 +2912,7 @@ int btrfs_orphan_cleanup(struct btrfs_root *root);
 void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans,
                               struct btrfs_root *root);
 int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size);
-int btrfs_invalidate_inodes(struct btrfs_root *root);
+void btrfs_invalidate_inodes(struct btrfs_root *root);
 void btrfs_add_delayed_iput(struct inode *inode);
 void btrfs_run_delayed_iputs(struct btrfs_root *root);
 int btrfs_prealloc_file_range(struct inode *inode, int mode,
@@ -3021,10 +3022,10 @@ void btrfs_reloc_post_snapshot(struct btrfs_trans_handle *trans,
 /* scrub.c */
 int btrfs_scrub_dev(struct btrfs_root *root, u64 devid, u64 start, u64 end,
                     struct btrfs_scrub_progress *progress, int readonly);
-int btrfs_scrub_pause(struct btrfs_root *root);
-int btrfs_scrub_pause_super(struct btrfs_root *root);
-int btrfs_scrub_continue(struct btrfs_root *root);
-int btrfs_scrub_continue_super(struct btrfs_root *root);
+void btrfs_scrub_pause(struct btrfs_root *root);
+void btrfs_scrub_pause_super(struct btrfs_root *root);
+void btrfs_scrub_continue(struct btrfs_root *root);
+void btrfs_scrub_continue_super(struct btrfs_root *root);
 int btrfs_scrub_cancel(struct btrfs_root *root);
 int btrfs_scrub_cancel_dev(struct btrfs_root *root, struct btrfs_device *dev);
 int btrfs_scrub_cancel_devid(struct btrfs_root *root, u64 devid);
diff --git a/fs/btrfs/delayed-inode.c b/fs/btrfs/delayed-inode.c
index fe4cd0f1cef1..6829590d0fbb 100644
--- a/fs/btrfs/delayed-inode.c
+++ b/fs/btrfs/delayed-inode.c
@@ -836,10 +836,8 @@ static int btrfs_batch_insert_items(struct btrfs_trans_handle *trans,
         btrfs_clear_path_blocking(path, NULL, 0);
 
         /* insert the keys of the items */
-        ret = setup_items_for_insert(trans, root, path, keys, data_size,
-                                     total_data_size, total_size, nitems);
-        if (ret)
-                goto error;
+        setup_items_for_insert(trans, root, path, keys, data_size,
+                               total_data_size, total_size, nitems);
 
         /* insert the dir index items */
         slot = path->slots[0];
diff --git a/fs/btrfs/delayed-ref.c b/fs/btrfs/delayed-ref.c
index 29ecd543d807..69f22e3ab3bc 100644
--- a/fs/btrfs/delayed-ref.c
+++ b/fs/btrfs/delayed-ref.c
@@ -420,7 +420,7 @@ update_existing_head_ref(struct btrfs_delayed_ref_node *existing,
  * this does all the dirty work in terms of maintaining the correct
  * overall modification count.
  */
-static noinline int add_delayed_ref_head(struct btrfs_fs_info *fs_info,
+static noinline void add_delayed_ref_head(struct btrfs_fs_info *fs_info,
                                         struct btrfs_trans_handle *trans,
                                         struct btrfs_delayed_ref_node *ref,
                                         u64 bytenr, u64 num_bytes,
@@ -494,13 +494,12 @@ static noinline int add_delayed_ref_head(struct btrfs_fs_info *fs_info,
                 delayed_refs->num_entries++;
                 trans->delayed_ref_updates++;
         }
-        return 0;
 }
 
 /*
  * helper to insert a delayed tree ref into the rbtree.
  */
-static noinline int add_delayed_tree_ref(struct btrfs_fs_info *fs_info,
+static noinline void add_delayed_tree_ref(struct btrfs_fs_info *fs_info,
                                          struct btrfs_trans_handle *trans,
                                          struct btrfs_delayed_ref_node *ref,
                                          u64 bytenr, u64 num_bytes, u64 parent,
@@ -554,13 +553,12 @@ static noinline int add_delayed_tree_ref(struct btrfs_fs_info *fs_info,
                 delayed_refs->num_entries++;
                 trans->delayed_ref_updates++;
         }
-        return 0;
 }
 
 /*
  * helper to insert a delayed data ref into the rbtree.
  */
-static noinline int add_delayed_data_ref(struct btrfs_fs_info *fs_info,
+static noinline void add_delayed_data_ref(struct btrfs_fs_info *fs_info,
                                          struct btrfs_trans_handle *trans,
                                          struct btrfs_delayed_ref_node *ref,
                                          u64 bytenr, u64 num_bytes, u64 parent,
@@ -616,7 +614,6 @@ static noinline int add_delayed_data_ref(struct btrfs_fs_info *fs_info,
                 delayed_refs->num_entries++;
                 trans->delayed_ref_updates++;
         }
-        return 0;
 }
 
 /*
@@ -634,7 +631,6 @@ int btrfs_add_delayed_tree_ref(struct btrfs_fs_info *fs_info,
         struct btrfs_delayed_tree_ref *ref;
         struct btrfs_delayed_ref_head *head_ref;
         struct btrfs_delayed_ref_root *delayed_refs;
-        int ret;
 
         BUG_ON(extent_op && extent_op->is_data);
         ref = kmalloc(sizeof(*ref), GFP_NOFS);
@@ -656,14 +652,12 @@ int btrfs_add_delayed_tree_ref(struct btrfs_fs_info *fs_info,
          * insert both the head node and the new ref without dropping
          * the spin lock
          */
-        ret = add_delayed_ref_head(fs_info, trans, &head_ref->node, bytenr,
+        add_delayed_ref_head(fs_info, trans, &head_ref->node, bytenr,
                                    num_bytes, action, 0);
-        BUG_ON(ret);
 
-        ret = add_delayed_tree_ref(fs_info, trans, &ref->node, bytenr,
+        add_delayed_tree_ref(fs_info, trans, &ref->node, bytenr,
                                    num_bytes, parent, ref_root, level, action,
                                    for_cow);
-        BUG_ON(ret);
         if (!need_ref_seq(for_cow, ref_root) &&
             waitqueue_active(&delayed_refs->seq_wait))
                 wake_up(&delayed_refs->seq_wait);
@@ -685,7 +679,6 @@ int btrfs_add_delayed_data_ref(struct btrfs_fs_info *fs_info,
         struct btrfs_delayed_data_ref *ref;
         struct btrfs_delayed_ref_head *head_ref;
         struct btrfs_delayed_ref_root *delayed_refs;
-        int ret;
 
         BUG_ON(extent_op && !extent_op->is_data);
         ref = kmalloc(sizeof(*ref), GFP_NOFS);
@@ -707,14 +700,12 @@ int btrfs_add_delayed_data_ref(struct btrfs_fs_info *fs_info,
          * insert both the head node and the new ref without dropping
          * the spin lock
          */
-        ret = add_delayed_ref_head(fs_info, trans, &head_ref->node, bytenr,
+        add_delayed_ref_head(fs_info, trans, &head_ref->node, bytenr,
                                    num_bytes, action, 1);
-        BUG_ON(ret);
 
-        ret = add_delayed_data_ref(fs_info, trans, &ref->node, bytenr,
+        add_delayed_data_ref(fs_info, trans, &ref->node, bytenr,
                                    num_bytes, parent, ref_root, owner, offset,
                                    action, for_cow);
-        BUG_ON(ret);
         if (!need_ref_seq(for_cow, ref_root) &&
             waitqueue_active(&delayed_refs->seq_wait))
                 wake_up(&delayed_refs->seq_wait);
@@ -729,7 +720,6 @@ int btrfs_add_delayed_extent_op(struct btrfs_fs_info *fs_info,
 {
         struct btrfs_delayed_ref_head *head_ref;
         struct btrfs_delayed_ref_root *delayed_refs;
-        int ret;
 
         head_ref = kmalloc(sizeof(*head_ref), GFP_NOFS);
         if (!head_ref)
@@ -740,10 +730,9 @@ int btrfs_add_delayed_extent_op(struct btrfs_fs_info *fs_info,
         delayed_refs = &trans->transaction->delayed_refs;
         spin_lock(&delayed_refs->lock);
 
-        ret = add_delayed_ref_head(fs_info, trans, &head_ref->node, bytenr,
+        add_delayed_ref_head(fs_info, trans, &head_ref->node, bytenr,
                                    num_bytes, BTRFS_UPDATE_DELAYED_HEAD,
                                    extent_op->is_data);
-        BUG_ON(ret);
 
         if (waitqueue_active(&delayed_refs->seq_wait))
                 wake_up(&delayed_refs->seq_wait);
diff --git a/fs/btrfs/dir-item.c b/fs/btrfs/dir-item.c
index 31d84e78129b..76743308bd9f 100644
--- a/fs/btrfs/dir-item.c
+++ b/fs/btrfs/dir-item.c
@@ -49,9 +49,8 @@ static struct btrfs_dir_item *insert_with_overflow(struct btrfs_trans_handle
                 di = btrfs_match_dir_item_name(root, path, name, name_len);
                 if (di)
                         return ERR_PTR(-EEXIST);
-                ret = btrfs_extend_item(trans, root, path, data_size);
-        }
-        if (ret < 0)
+                btrfs_extend_item(trans, root, path, data_size);
+        } else if (ret < 0)
                 return ERR_PTR(ret);
         WARN_ON(ret > 0);
         leaf = path->nodes[0];
@@ -383,8 +382,8 @@ int btrfs_delete_one_dir_name(struct btrfs_trans_handle *trans,
                 start = btrfs_item_ptr_offset(leaf, path->slots[0]);
                 memmove_extent_buffer(leaf, ptr, ptr + sub_item_len,
                         item_len - (ptr + sub_item_len - start));
-                ret = btrfs_truncate_item(trans, root, path,
-                                          item_len - sub_item_len, 1);
+                btrfs_truncate_item(trans, root, path,
+                                    item_len - sub_item_len, 1);
         }
         return ret;
 }
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 2e4428bd60ec..73ccadce90bc 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -50,12 +50,12 @@ static void end_workqueue_fn(struct btrfs_work *work);
 static void free_fs_root(struct btrfs_root *root);
 static void btrfs_check_super_valid(struct btrfs_fs_info *fs_info,
                                     int read_only);
-static int btrfs_destroy_ordered_operations(struct btrfs_root *root);
-static int btrfs_destroy_ordered_extents(struct btrfs_root *root);
+static void btrfs_destroy_ordered_operations(struct btrfs_root *root);
+static void btrfs_destroy_ordered_extents(struct btrfs_root *root);
 static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
                                       struct btrfs_root *root);
-static int btrfs_destroy_pending_snapshots(struct btrfs_transaction *t);
-static int btrfs_destroy_delalloc_inodes(struct btrfs_root *root);
+static void btrfs_destroy_pending_snapshots(struct btrfs_transaction *t);
+static void btrfs_destroy_delalloc_inodes(struct btrfs_root *root);
 static int btrfs_destroy_marked_extents(struct btrfs_root *root,
                                         struct extent_io_tree *dirty_pages,
                                         int mark);
@@ -1139,10 +1139,10 @@ void clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
         }
 }
 
-static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
-                        u32 stripesize, struct btrfs_root *root,
-                        struct btrfs_fs_info *fs_info,
-                        u64 objectid)
+static void __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
+                         u32 stripesize, struct btrfs_root *root,
+                         struct btrfs_fs_info *fs_info,
+                         u64 objectid)
 {
         root->node = NULL;
         root->commit_root = NULL;
@@ -1194,7 +1194,6 @@ static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
         root->defrag_running = 0;
         root->root_key.objectid = objectid;
         root->anon_dev = 0;
-        return 0;
 }
 
 static int __must_check find_and_setup_root(struct btrfs_root *tree_root,
@@ -2897,7 +2896,7 @@ int write_ctree_super(struct btrfs_trans_handle *trans,
         return ret;
 }
 
-int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
+void btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
 {
         spin_lock(&fs_info->fs_roots_radix_lock);
         radix_tree_delete(&fs_info->fs_roots_radix,
@@ -2910,7 +2909,6 @@ int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
         __btrfs_remove_free_space_cache(root->free_ino_pinned);
         __btrfs_remove_free_space_cache(root->free_ino_ctl);
         free_fs_root(root);
-        return 0;
 }
 
 static void free_fs_root(struct btrfs_root *root)
@@ -2927,7 +2925,7 @@ static void free_fs_root(struct btrfs_root *root)
         kfree(root);
 }
 
-static int del_fs_roots(struct btrfs_fs_info *fs_info)
+static void del_fs_roots(struct btrfs_fs_info *fs_info)
 {
         int ret;
         struct btrfs_root *gang[8];
@@ -2956,7 +2954,6 @@ static int del_fs_roots(struct btrfs_fs_info *fs_info)
                 for (i = 0; i < ret; i++)
                         btrfs_free_fs_root(fs_info, gang[i]);
         }
-        return 0;
 }
 
 int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
@@ -3299,7 +3296,7 @@ int btrfs_error_commit_super(struct btrfs_root *root)
         return ret;
 }
 
-static int btrfs_destroy_ordered_operations(struct btrfs_root *root)
+static void btrfs_destroy_ordered_operations(struct btrfs_root *root)
 {
         struct btrfs_inode *btrfs_inode;
         struct list_head splice;
@@ -3321,11 +3318,9 @@ static int btrfs_destroy_ordered_operations(struct btrfs_root *root)
 
         spin_unlock(&root->fs_info->ordered_extent_lock);
         mutex_unlock(&root->fs_info->ordered_operations_mutex);
-
-        return 0;
 }
 
-static int btrfs_destroy_ordered_extents(struct btrfs_root *root)
+static void btrfs_destroy_ordered_extents(struct btrfs_root *root)
 {
         struct list_head splice;
         struct btrfs_ordered_extent *ordered;
@@ -3357,8 +3352,6 @@ static int btrfs_destroy_ordered_extents(struct btrfs_root *root)
         }
 
         spin_unlock(&root->fs_info->ordered_extent_lock);
-
-        return 0;
 }
 
 static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
@@ -3413,7 +3406,7 @@ static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
         return ret;
 }
 
-static int btrfs_destroy_pending_snapshots(struct btrfs_transaction *t)
+static void btrfs_destroy_pending_snapshots(struct btrfs_transaction *t)
 {
         struct btrfs_pending_snapshot *snapshot;
         struct list_head splice;
@@ -3431,11 +3424,9 @@ static int btrfs_destroy_pending_snapshots(struct btrfs_transaction *t)
 
                 kfree(snapshot);
         }
-
-        return 0;
 }
 
-static int btrfs_destroy_delalloc_inodes(struct btrfs_root *root)
+static void btrfs_destroy_delalloc_inodes(struct btrfs_root *root)
 {
         struct btrfs_inode *btrfs_inode;
         struct list_head splice;
@@ -3455,8 +3446,6 @@ static int btrfs_destroy_delalloc_inodes(struct btrfs_root *root)
         }
 
         spin_unlock(&root->fs_info->delalloc_lock);
-
-        return 0;
 }
 
 static int btrfs_destroy_marked_extents(struct btrfs_root *root,
diff --git a/fs/btrfs/disk-io.h b/fs/btrfs/disk-io.h
index ca34237ae384..1608492d485f 100644
--- a/fs/btrfs/disk-io.h
+++ b/fs/btrfs/disk-io.h
@@ -64,7 +64,7 @@ struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
 int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info);
 void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr);
 void __btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr);
-int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root);
+void btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root);
 void btrfs_mark_buffer_dirty(struct extent_buffer *buf);
 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid);
 int btrfs_set_buffer_uptodate(struct extent_buffer *buf);
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index c32a9bffe9e4..0daa1df16439 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -1010,7 +1010,7 @@ static int convert_extent_item_v0(struct btrfs_trans_handle *trans,
                 return ret;
         BUG_ON(ret);
 
-        ret = btrfs_extend_item(trans, root, path, new_size);
+        btrfs_extend_item(trans, root, path, new_size);
 
         leaf = path->nodes[0];
         item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
@@ -1592,13 +1592,13 @@ out:
  * helper to add new inline back ref
  */
 static noinline_for_stack
-int setup_inline_extent_backref(struct btrfs_trans_handle *trans,
-                                struct btrfs_root *root,
-                                struct btrfs_path *path,
-                                struct btrfs_extent_inline_ref *iref,
-                                u64 parent, u64 root_objectid,
-                                u64 owner, u64 offset, int refs_to_add,
-                                struct btrfs_delayed_extent_op *extent_op)
+void setup_inline_extent_backref(struct btrfs_trans_handle *trans,
+                                 struct btrfs_root *root,
+                                 struct btrfs_path *path,
+                                 struct btrfs_extent_inline_ref *iref,
+                                 u64 parent, u64 root_objectid,
+                                 u64 owner, u64 offset, int refs_to_add,
+                                 struct btrfs_delayed_extent_op *extent_op)
 {
         struct extent_buffer *leaf;
         struct btrfs_extent_item *ei;
@@ -1608,7 +1608,6 @@ int setup_inline_extent_backref(struct btrfs_trans_handle *trans,
         u64 refs;
         int size;
         int type;
-        int ret;
 
         leaf = path->nodes[0];
         ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
@@ -1617,7 +1616,7 @@ int setup_inline_extent_backref(struct btrfs_trans_handle *trans,
         type = extent_ref_type(parent, owner);
         size = btrfs_extent_inline_ref_size(type);
 
-        ret = btrfs_extend_item(trans, root, path, size);
+        btrfs_extend_item(trans, root, path, size);
 
         ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
         refs = btrfs_extent_refs(leaf, ei);
@@ -1652,7 +1651,6 @@ int setup_inline_extent_backref(struct btrfs_trans_handle *trans,
                 btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid);
         }
         btrfs_mark_buffer_dirty(leaf);
-        return 0;
 }
 
 static int lookup_extent_backref(struct btrfs_trans_handle *trans,
@@ -1687,12 +1685,12 @@ static int lookup_extent_backref(struct btrfs_trans_handle *trans,
  * helper to update/remove inline back ref
  */
 static noinline_for_stack
-int update_inline_extent_backref(struct btrfs_trans_handle *trans,
-                                 struct btrfs_root *root,
-                                 struct btrfs_path *path,
-                                 struct btrfs_extent_inline_ref *iref,
-                                 int refs_to_mod,
-                                 struct btrfs_delayed_extent_op *extent_op)
+void update_inline_extent_backref(struct btrfs_trans_handle *trans,
+                                  struct btrfs_root *root,
+                                  struct btrfs_path *path,
+                                  struct btrfs_extent_inline_ref *iref,
+                                  int refs_to_mod,
+                                  struct btrfs_delayed_extent_op *extent_op)
 {
         struct extent_buffer *leaf;
         struct btrfs_extent_item *ei;
@@ -1703,7 +1701,6 @@ int update_inline_extent_backref(struct btrfs_trans_handle *trans,
         u32 item_size;
         int size;
         int type;
-        int ret;
         u64 refs;
 
         leaf = path->nodes[0];
@@ -1745,10 +1742,9 @@ int update_inline_extent_backref(struct btrfs_trans_handle *trans,
                         memmove_extent_buffer(leaf, ptr, ptr + size,
                                               end - ptr - size);
                 item_size -= size;
-                ret = btrfs_truncate_item(trans, root, path, item_size, 1);
+                btrfs_truncate_item(trans, root, path, item_size, 1);
         }
         btrfs_mark_buffer_dirty(leaf);
-        return 0;
 }
 
 static noinline_for_stack
@@ -1768,13 +1764,13 @@ int insert_inline_extent_backref(struct btrfs_trans_handle *trans,
                                            root_objectid, owner, offset, 1);
         if (ret == 0) {
                 BUG_ON(owner < BTRFS_FIRST_FREE_OBJECTID);
-                ret = update_inline_extent_backref(trans, root, path, iref,
-                                                   refs_to_add, extent_op);
+                update_inline_extent_backref(trans, root, path, iref,
+                                             refs_to_add, extent_op);
         } else if (ret == -ENOENT) {
-                ret = setup_inline_extent_backref(trans, root, path, iref,
-                                                  parent, root_objectid,
-                                                  owner, offset, refs_to_add,
-                                                  extent_op);
+                setup_inline_extent_backref(trans, root, path, iref, parent,
+                                            root_objectid, owner, offset,
+                                            refs_to_add, extent_op);
+                ret = 0;
         }
         return ret;
 }
@@ -1804,12 +1800,12 @@ static int remove_extent_backref(struct btrfs_trans_handle *trans,
                                  struct btrfs_extent_inline_ref *iref,
                                  int refs_to_drop, int is_data)
 {
-        int ret;
+        int ret = 0;
 
         BUG_ON(!is_data && refs_to_drop != 1);
         if (iref) {
-                ret = update_inline_extent_backref(trans, root, path, iref,
-                                                   -refs_to_drop, NULL);
+                update_inline_extent_backref(trans, root, path, iref,
+                                             -refs_to_drop, NULL);
         } else if (is_data) {
                 ret = remove_extent_data_ref(trans, root, path, refs_to_drop);
         } else {
@@ -4734,7 +4730,7 @@ static int btrfs_update_reserved_bytes(struct btrfs_block_group_cache *cache,
         return ret;
 }
 
-int btrfs_prepare_extent_commit(struct btrfs_trans_handle *trans,
+void btrfs_prepare_extent_commit(struct btrfs_trans_handle *trans,
                                 struct btrfs_root *root)
 {
         struct btrfs_fs_info *fs_info = root->fs_info;
@@ -4764,7 +4760,6 @@ int btrfs_prepare_extent_commit(struct btrfs_trans_handle *trans,
         up_write(&fs_info->extent_commit_sem);
 
         update_global_block_rsv(fs_info);
-        return 0;
 }
 
 static int unpin_extent_range(struct btrfs_root *root, u64 start, u64 end)
@@ -7189,7 +7184,7 @@ u64 btrfs_account_ro_block_groups_free_space(struct btrfs_space_info *sinfo)
         return free_bytes;
 }
 
-int btrfs_set_block_group_rw(struct btrfs_root *root,
+void btrfs_set_block_group_rw(struct btrfs_root *root,
                               struct btrfs_block_group_cache *cache)
 {
         struct btrfs_space_info *sinfo = cache->space_info;
@@ -7205,7 +7200,6 @@ int btrfs_set_block_group_rw(struct btrfs_root *root,
         cache->ro = 0;
         spin_unlock(&cache->lock);
         spin_unlock(&sinfo->lock);
-        return 0;
 }
 
 /*
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 8368baa1f372..65216fabacbb 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -142,6 +142,7 @@ static struct extent_state *alloc_extent_state(gfp_t mask)
 #endif
         atomic_set(&state->refs, 1);
         init_waitqueue_head(&state->wq);
+        trace_alloc_extent_state(state, mask, _RET_IP_);
         return state;
 }
 
@@ -159,6 +160,7 @@ void free_extent_state(struct extent_state *state)
                 list_del(&state->leak_list);
                 spin_unlock_irqrestore(&leak_lock, flags);
 #endif
+                trace_free_extent_state(state, _RET_IP_);
                 kmem_cache_free(extent_state_cache, state);
         }
 }
@@ -617,8 +619,8 @@ search_again:
         goto again;
 }
 
-static int wait_on_state(struct extent_io_tree *tree,
-                         struct extent_state *state)
+static void wait_on_state(struct extent_io_tree *tree,
+                          struct extent_state *state)
                 __releases(tree->lock)
                 __acquires(tree->lock)
 {
@@ -628,7 +630,6 @@ static int wait_on_state(struct extent_io_tree *tree,
         schedule();
         spin_lock(&tree->lock);
         finish_wait(&state->wq, &wait);
-        return 0;
 }
 
 /*
@@ -636,7 +637,7 @@ static int wait_on_state(struct extent_io_tree *tree,
  * The range [start, end] is inclusive.
  * The tree lock is taken by this function
  */
-int wait_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, int bits)
+void wait_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, int bits)
 {
         struct extent_state *state;
         struct rb_node *node;
@@ -673,7 +674,6 @@ again:
         }
 out:
         spin_unlock(&tree->lock);
-        return 0;
 }
 
 static void set_state_bits(struct extent_io_tree *tree,
@@ -1359,9 +1359,9 @@ out:
         return found;
 }
 
-static noinline int __unlock_for_delalloc(struct inode *inode,
-                                          struct page *locked_page,
-                                          u64 start, u64 end)
+static noinline void __unlock_for_delalloc(struct inode *inode,
+                                           struct page *locked_page,
+                                           u64 start, u64 end)
 {
         int ret;
         struct page *pages[16];
@@ -1371,7 +1371,7 @@ static noinline int __unlock_for_delalloc(struct inode *inode,
         int i;
 
         if (index == locked_page->index && end_index == index)
-                return 0;
+                return;
 
         while (nr_pages > 0) {
                 ret = find_get_pages_contig(inode->i_mapping, index,
@@ -1386,7 +1386,6 @@ static noinline int __unlock_for_delalloc(struct inode *inode,
                 index += ret;
                 cond_resched();
         }
-        return 0;
 }
 
 static noinline int lock_delalloc_pages(struct inode *inode,
@@ -1777,39 +1776,34 @@ int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,
  * helper function to set a given page up to date if all the
  * extents in the tree for that page are up to date
  */
-static int check_page_uptodate(struct extent_io_tree *tree,
-                               struct page *page)
+static void check_page_uptodate(struct extent_io_tree *tree, struct page *page)
 {
         u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
         u64 end = start + PAGE_CACHE_SIZE - 1;
         if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1, NULL))
                 SetPageUptodate(page);
-        return 0;
 }
 
 /*
  * helper function to unlock a page if all the extents in the tree
  * for that page are unlocked
  */
-static int check_page_locked(struct extent_io_tree *tree,
-                             struct page *page)
+static void check_page_locked(struct extent_io_tree *tree, struct page *page)
 {
         u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
         u64 end = start + PAGE_CACHE_SIZE - 1;
         if (!test_range_bit(tree, start, end, EXTENT_LOCKED, 0, NULL))
                 unlock_page(page);
-        return 0;
 }
 
 /*
  * helper function to end page writeback if all the extents
  * in the tree for that page are done with writeback
  */
-static int check_page_writeback(struct extent_io_tree *tree,
-                             struct page *page)
+static void check_page_writeback(struct extent_io_tree *tree,
+                                 struct page *page)
 {
         end_page_writeback(page);
-        return 0;
 }
 
 /*
@@ -3835,7 +3829,7 @@ void free_extent_buffer(struct extent_buffer *eb)
         WARN_ON(1);
 }
 
-int clear_extent_buffer_dirty(struct extent_io_tree *tree,
+void clear_extent_buffer_dirty(struct extent_io_tree *tree,
                               struct extent_buffer *eb)
 {
         unsigned long i;
@@ -3867,7 +3861,6 @@ int clear_extent_buffer_dirty(struct extent_io_tree *tree,
                 ClearPageError(page);
                 unlock_page(page);
         }
-        return 0;
 }
 
 int set_extent_buffer_dirty(struct extent_io_tree *tree,
diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index cecc3518c121..f7f321ee4ba1 100644
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -287,8 +287,8 @@ void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
                            unsigned long src_offset, unsigned long len);
 void memset_extent_buffer(struct extent_buffer *eb, char c,
                           unsigned long start, unsigned long len);
-int wait_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, int bits);
-int clear_extent_buffer_dirty(struct extent_io_tree *tree,
+void wait_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, int bits);
+void clear_extent_buffer_dirty(struct extent_io_tree *tree,
                               struct extent_buffer *eb);
 int set_extent_buffer_dirty(struct extent_io_tree *tree,
                              struct extent_buffer *eb);
diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index c7fb3a4247d3..edb69b4d5335 100644
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -483,18 +483,17 @@ int btrfs_csum_one_bio(struct btrfs_root *root, struct inode *inode,
  * This calls btrfs_truncate_item with the correct args based on the
  * overlap, and fixes up the key as required.
  */
-static noinline int truncate_one_csum(struct btrfs_trans_handle *trans,
-                                      struct btrfs_root *root,
-                                      struct btrfs_path *path,
-                                      struct btrfs_key *key,
-                                      u64 bytenr, u64 len)
+static noinline void truncate_one_csum(struct btrfs_trans_handle *trans,
+                                       struct btrfs_root *root,
+                                       struct btrfs_path *path,
+                                       struct btrfs_key *key,
+                                       u64 bytenr, u64 len)
 {
         struct extent_buffer *leaf;
         u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
         u64 csum_end;
         u64 end_byte = bytenr + len;
         u32 blocksize_bits = root->fs_info->sb->s_blocksize_bits;
-        int ret;
 
         leaf = path->nodes[0];
         csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size;
@@ -510,7 +509,7 @@ 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);
+                btrfs_truncate_item(trans, root, path, new_size, 1);
         } else if (key->offset >= bytenr && csum_end > end_byte &&
                    end_byte > key->offset) {
                 /*
@@ -522,15 +521,13 @@ static noinline int truncate_one_csum(struct btrfs_trans_handle *trans,
                 u32 new_size = (csum_end - end_byte) >> blocksize_bits;
                 new_size *= csum_size;
 
-                ret = btrfs_truncate_item(trans, root, path, new_size, 0);
+                btrfs_truncate_item(trans, root, path, new_size, 0);
 
                 key->offset = end_byte;
-                ret = btrfs_set_item_key_safe(trans, root, path, key);
-                BUG_ON(ret);
+                btrfs_set_item_key_safe(trans, root, path, key);
         } else {
                 BUG();
         }
-        return 0;
 }
 
 /*
@@ -639,9 +636,7 @@ int btrfs_del_csums(struct btrfs_trans_handle *trans,
 
                         key.offset = end_byte - 1;
                 } else {
-                        ret = truncate_one_csum(trans, root, path,
-                                                &key, bytenr, len);
-                        BUG_ON(ret);
+                        truncate_one_csum(trans, root, path, &key, bytenr, len);
                         if (key.offset < bytenr)
                                 break;
                 }
@@ -772,7 +767,7 @@ again:
                 if (diff != csum_size)
                         goto insert;
 
-                ret = btrfs_extend_item(trans, root, path, diff);
+                btrfs_extend_item(trans, root, path, diff);
                 goto csum;
         }
 
diff --git a/fs/btrfs/inode-item.c b/fs/btrfs/inode-item.c
index baa74f3db691..c0792409bb6a 100644
--- a/fs/btrfs/inode-item.c
+++ b/fs/btrfs/inode-item.c
@@ -128,7 +128,7 @@ int btrfs_del_inode_ref(struct btrfs_trans_handle *trans,
         item_start = btrfs_item_ptr_offset(leaf, path->slots[0]);
         memmove_extent_buffer(leaf, ptr, ptr + sub_item_len,
                               item_size - (ptr + sub_item_len - item_start));
-        ret = btrfs_truncate_item(trans, root, path,
+        btrfs_truncate_item(trans, root, path,
                                   item_size - sub_item_len, 1);
 out:
         btrfs_free_path(path);
@@ -165,7 +165,7 @@ int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans,
                         goto out;
 
                 old_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
-                ret = btrfs_extend_item(trans, root, path, ins_len);
+                btrfs_extend_item(trans, root, path, ins_len);
                 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 5394bdb314ca..dc800eefdbc7 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -3164,8 +3164,8 @@ search_again:
                                 }
                                 size =
                                     btrfs_file_extent_calc_inline_size(size);
-                                ret = btrfs_truncate_item(trans, root, path,
-                                                          size, 1);
+                                btrfs_truncate_item(trans, root, path,
+                                                    size, 1);
                         } else if (root->ref_cows) {
                                 inode_sub_bytes(inode, item_end + 1 -
                                                 found_key.offset);
@@ -3782,7 +3782,7 @@ static void inode_tree_del(struct inode *inode)
         }
 }
 
-int btrfs_invalidate_inodes(struct btrfs_root *root)
+void btrfs_invalidate_inodes(struct btrfs_root *root)
 {
         struct rb_node *node;
         struct rb_node *prev;
@@ -3842,7 +3842,6 @@ again:
                 node = rb_next(node);
         }
         spin_unlock(&root->inode_lock);
-        return 0;
 }
 
 static int btrfs_init_locked_inode(struct inode *inode, void *p)
diff --git a/fs/btrfs/locking.c b/fs/btrfs/locking.c
index 5e178d8f7167..272f911203ff 100644
--- a/fs/btrfs/locking.c
+++ b/fs/btrfs/locking.c
@@ -208,7 +208,7 @@ void btrfs_tree_read_unlock_blocking(struct extent_buffer *eb)
  * take a spinning write lock.  This will wait for both
  * blocking readers or writers
  */
-int btrfs_tree_lock(struct extent_buffer *eb)
+void btrfs_tree_lock(struct extent_buffer *eb)
 {
 again:
         wait_event(eb->read_lock_wq, atomic_read(&eb->blocking_readers) == 0);
@@ -230,13 +230,12 @@ again:
         atomic_inc(&eb->spinning_writers);
         atomic_inc(&eb->write_locks);
         eb->lock_owner = current->pid;
-        return 0;
 }
 
 /*
  * drop a spinning or a blocking write lock.
  */
-int btrfs_tree_unlock(struct extent_buffer *eb)
+void btrfs_tree_unlock(struct extent_buffer *eb)
 {
         int blockers = atomic_read(&eb->blocking_writers);
 
@@ -255,7 +254,6 @@ int btrfs_tree_unlock(struct extent_buffer *eb)
                 atomic_dec(&eb->spinning_writers);
                 write_unlock(&eb->lock);
         }
-        return 0;
 }
 
 void btrfs_assert_tree_locked(struct extent_buffer *eb)
diff --git a/fs/btrfs/locking.h b/fs/btrfs/locking.h
index 17247ddb81a0..ca52681e5f40 100644
--- a/fs/btrfs/locking.h
+++ b/fs/btrfs/locking.h
@@ -24,8 +24,8 @@
 #define BTRFS_WRITE_LOCK_BLOCKING 3
 #define BTRFS_READ_LOCK_BLOCKING 4
 
-int btrfs_tree_lock(struct extent_buffer *eb);
-int btrfs_tree_unlock(struct extent_buffer *eb);
+void btrfs_tree_lock(struct extent_buffer *eb);
+void btrfs_tree_unlock(struct extent_buffer *eb);
 int btrfs_try_spin_lock(struct extent_buffer *eb);
 
 void btrfs_tree_read_lock(struct extent_buffer *eb);
diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c
index 2857f28e20e2..bbf6d0d9aebe 100644
--- a/fs/btrfs/ordered-data.c
+++ b/fs/btrfs/ordered-data.c
@@ -257,9 +257,9 @@ int btrfs_add_ordered_extent_compress(struct inode *inode, u64 file_offset,
  * when an ordered extent is finished.  If the list covers more than one
  * ordered extent, it is split across multiples.
  */
-int btrfs_add_ordered_sum(struct inode *inode,
-                          struct btrfs_ordered_extent *entry,
-                          struct btrfs_ordered_sum *sum)
+void btrfs_add_ordered_sum(struct inode *inode,
+                           struct btrfs_ordered_extent *entry,
+                           struct btrfs_ordered_sum *sum)
 {
         struct btrfs_ordered_inode_tree *tree;
 
@@ -267,7 +267,6 @@ int btrfs_add_ordered_sum(struct inode *inode,
         spin_lock(&tree->lock);
         list_add_tail(&sum->list, &entry->list);
         spin_unlock(&tree->lock);
-        return 0;
 }
 
 /*
@@ -392,7 +391,7 @@ out:
  * used to drop a reference on an ordered extent.  This will free
  * the extent if the last reference is dropped
  */
-int btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry)
+void btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry)
 {
         struct list_head *cur;
         struct btrfs_ordered_sum *sum;
@@ -408,7 +407,6 @@ int btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry)
                 }
                 kfree(entry);
         }
-        return 0;
 }
 
 /*
@@ -416,8 +414,8 @@ int btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry)
  * and you must wake_up entry->wait.  You must hold the tree lock
  * while you call this function.
  */
-static int __btrfs_remove_ordered_extent(struct inode *inode,
-                                struct btrfs_ordered_extent *entry)
+static void __btrfs_remove_ordered_extent(struct inode *inode,
+                                          struct btrfs_ordered_extent *entry)
 {
         struct btrfs_ordered_inode_tree *tree;
         struct btrfs_root *root = BTRFS_I(inode)->root;
@@ -444,35 +442,30 @@ static int __btrfs_remove_ordered_extent(struct inode *inode,
                 list_del_init(&BTRFS_I(inode)->ordered_operations);
         }
         spin_unlock(&root->fs_info->ordered_extent_lock);
-
-        return 0;
 }
 
 /*
  * remove an ordered extent from the tree.  No references are dropped
  * but any waiters are woken.
  */
-int btrfs_remove_ordered_extent(struct inode *inode,
-                                struct btrfs_ordered_extent *entry)
+void btrfs_remove_ordered_extent(struct inode *inode,
+                                 struct btrfs_ordered_extent *entry)
 {
         struct btrfs_ordered_inode_tree *tree;
-        int ret;
 
         tree = &BTRFS_I(inode)->ordered_tree;
         spin_lock(&tree->lock);
-        ret = __btrfs_remove_ordered_extent(inode, entry);
+        __btrfs_remove_ordered_extent(inode, entry);
         spin_unlock(&tree->lock);
         wake_up(&entry->wait);
-
-        return ret;
 }
 
 /*
  * wait for all the ordered extents in a root.  This is done when balancing
  * space between drives.
  */
-int btrfs_wait_ordered_extents(struct btrfs_root *root,
-                               int nocow_only, int delay_iput)
+void btrfs_wait_ordered_extents(struct btrfs_root *root,
+                                int nocow_only, int delay_iput)
 {
         struct list_head splice;
         struct list_head *cur;
@@ -520,7 +513,6 @@ int btrfs_wait_ordered_extents(struct btrfs_root *root,
                 spin_lock(&root->fs_info->ordered_extent_lock);
         }
         spin_unlock(&root->fs_info->ordered_extent_lock);
-        return 0;
 }
 
 /*
@@ -533,7 +525,7 @@ int btrfs_wait_ordered_extents(struct btrfs_root *root,
  * extra check to make sure the ordered operation list really is empty
  * before we return
  */
-int btrfs_run_ordered_operations(struct btrfs_root *root, int wait)
+void btrfs_run_ordered_operations(struct btrfs_root *root, int wait)
 {
         struct btrfs_inode *btrfs_inode;
         struct inode *inode;
@@ -581,8 +573,6 @@ again:
 
         spin_unlock(&root->fs_info->ordered_extent_lock);
         mutex_unlock(&root->fs_info->ordered_operations_mutex);
-
-        return 0;
 }
 
 /*
@@ -617,7 +607,7 @@ void btrfs_start_ordered_extent(struct inode *inode,
 /*
  * Used to wait on ordered extents across a large range of bytes.
  */
-int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len)
+void btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len)
 {
         u64 end;
         u64 orig_end;
@@ -672,7 +662,6 @@ again:
                 schedule_timeout(1);
                 goto again;
         }
-        return 0;
 }
 
 /*
@@ -956,9 +945,8 @@ out:
  * If trans is not null, we'll do a friendly check for a transaction that
  * is already flushing things and force the IO down ourselves.
  */
-int btrfs_add_ordered_operation(struct btrfs_trans_handle *trans,
-                                struct btrfs_root *root,
-                                struct inode *inode)
+void btrfs_add_ordered_operation(struct btrfs_trans_handle *trans,
+                                 struct btrfs_root *root, struct inode *inode)
 {
         u64 last_mod;
 
@@ -969,7 +957,7 @@ int btrfs_add_ordered_operation(struct btrfs_trans_handle *trans,
          * commit, we can safely return without doing anything
          */
         if (last_mod < root->fs_info->last_trans_committed)
-                return 0;
+                return;
 
         /*
          * the transaction is already committing.  Just start the IO and
@@ -977,7 +965,7 @@ int btrfs_add_ordered_operation(struct btrfs_trans_handle *trans,
          */
         if (trans && root->fs_info->running_transaction->blocked) {
                 btrfs_wait_ordered_range(inode, 0, (u64)-1);
-                return 0;
+                return;
         }
 
         spin_lock(&root->fs_info->ordered_extent_lock);
@@ -986,6 +974,4 @@ int btrfs_add_ordered_operation(struct btrfs_trans_handle *trans,
                               &root->fs_info->ordered_operations);
         }
         spin_unlock(&root->fs_info->ordered_extent_lock);
-
-        return 0;
 }
diff --git a/fs/btrfs/ordered-data.h b/fs/btrfs/ordered-data.h
index ff1f69aa1883..c355ad4dc1a6 100644
--- a/fs/btrfs/ordered-data.h
+++ b/fs/btrfs/ordered-data.h
@@ -138,8 +138,8 @@ btrfs_ordered_inode_tree_init(struct btrfs_ordered_inode_tree *t)
         t->last = NULL;
 }
 
-int btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry);
-int btrfs_remove_ordered_extent(struct inode *inode,
+void btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry);
+void btrfs_remove_ordered_extent(struct inode *inode,
                                 struct btrfs_ordered_extent *entry);
 int btrfs_dec_test_ordered_pending(struct inode *inode,
                                    struct btrfs_ordered_extent **cached,
@@ -154,14 +154,14 @@ int btrfs_add_ordered_extent_dio(struct inode *inode, u64 file_offset,
 int btrfs_add_ordered_extent_compress(struct inode *inode, u64 file_offset,
                                       u64 start, u64 len, u64 disk_len,
                                       int type, int compress_type);
-int btrfs_add_ordered_sum(struct inode *inode,
-                          struct btrfs_ordered_extent *entry,
-                          struct btrfs_ordered_sum *sum);
+void btrfs_add_ordered_sum(struct inode *inode,
+                           struct btrfs_ordered_extent *entry,
+                           struct btrfs_ordered_sum *sum);
 struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct inode *inode,
                                                          u64 file_offset);
 void btrfs_start_ordered_extent(struct inode *inode,
                                 struct btrfs_ordered_extent *entry, int wait);
-int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len);
+void btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len);
 struct btrfs_ordered_extent *
 btrfs_lookup_first_ordered_extent(struct inode * inode, u64 file_offset);
 struct btrfs_ordered_extent *btrfs_lookup_ordered_range(struct inode *inode,
@@ -170,10 +170,10 @@ struct btrfs_ordered_extent *btrfs_lookup_ordered_range(struct inode *inode,
 int btrfs_ordered_update_i_size(struct inode *inode, u64 offset,
                                 struct btrfs_ordered_extent *ordered);
 int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr, u32 *sum);
-int btrfs_run_ordered_operations(struct btrfs_root *root, int wait);
-int btrfs_add_ordered_operation(struct btrfs_trans_handle *trans,
-                                struct btrfs_root *root,
-                                struct inode *inode);
-int btrfs_wait_ordered_extents(struct btrfs_root *root,
-                               int nocow_only, int delay_iput);
+void btrfs_run_ordered_operations(struct btrfs_root *root, int wait);
+void btrfs_add_ordered_operation(struct btrfs_trans_handle *trans,
+                                 struct btrfs_root *root,
+                                 struct inode *inode);
+void btrfs_wait_ordered_extents(struct btrfs_root *root,
+                                int nocow_only, int delay_iput);
 #endif
diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index abc0fbffa510..a2e8aa40f3f5 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -948,12 +948,12 @@ static int scrub_checksum_super(struct scrub_bio *sbio, void *buffer)
         return fail;
 }
 
-static int scrub_submit(struct scrub_dev *sdev)
+static void scrub_submit(struct scrub_dev *sdev)
 {
         struct scrub_bio *sbio;
 
         if (sdev->curr == -1)
-                return 0;
+                return;
 
         sbio = sdev->bios[sdev->curr];
         sbio->err = 0;
@@ -961,8 +961,6 @@ static int scrub_submit(struct scrub_dev *sdev)
         atomic_inc(&sdev->in_flight);
 
         btrfsic_submit_bio(READ, sbio->bio);
-
-        return 0;
 }
 
 static int scrub_page(struct scrub_dev *sdev, u64 logical, u64 len,
@@ -1008,9 +1006,7 @@ again:
                 sbio->bio = bio;
         } else if (sbio->physical + sbio->count * PAGE_SIZE != physical ||
                    sbio->logical + sbio->count * PAGE_SIZE != logical) {
-                ret = scrub_submit(sdev);
-                if (ret)
-                        return ret;
+                scrub_submit(sdev);
                 goto again;
         }
         sbio->spag[sbio->count].flags = flags;
@@ -1025,9 +1021,7 @@ again:
         ret = bio_add_page(sbio->bio, page, PAGE_SIZE, 0);
         if (!ret) {
                 __free_page(page);
-                ret = scrub_submit(sdev);
-                if (ret)
-                        return ret;
+                scrub_submit(sdev);
                 goto again;
         }
 
@@ -1036,13 +1030,8 @@ again:
                 memcpy(sbio->spag[sbio->count].csum, csum, sdev->csum_size);
         }
         ++sbio->count;
-        if (sbio->count == SCRUB_PAGES_PER_BIO || force) {
-                int ret;
-
-                ret = scrub_submit(sdev);
-                if (ret)
-                        return ret;
-        }
+        if (sbio->count == SCRUB_PAGES_PER_BIO || force)
+                scrub_submit(sdev);
 
         return 0;
 }
@@ -1656,7 +1645,7 @@ int btrfs_scrub_dev(struct btrfs_root *root, u64 devid, u64 start, u64 end,
         return ret;
 }
 
-int btrfs_scrub_pause(struct btrfs_root *root)
+void btrfs_scrub_pause(struct btrfs_root *root)
 {
         struct btrfs_fs_info *fs_info = root->fs_info;
 
@@ -1671,29 +1660,24 @@ int btrfs_scrub_pause(struct btrfs_root *root)
                 mutex_lock(&fs_info->scrub_lock);
         }
         mutex_unlock(&fs_info->scrub_lock);
-
-        return 0;
 }
 
-int btrfs_scrub_continue(struct btrfs_root *root)
+void btrfs_scrub_continue(struct btrfs_root *root)
 {
         struct btrfs_fs_info *fs_info = root->fs_info;
 
         atomic_dec(&fs_info->scrub_pause_req);
         wake_up(&fs_info->scrub_pause_wait);
-        return 0;
 }
 
-int btrfs_scrub_pause_super(struct btrfs_root *root)
+void btrfs_scrub_pause_super(struct btrfs_root *root)
 {
         down_write(&root->fs_info->scrub_super_lock);
-        return 0;
 }
 
-int btrfs_scrub_continue_super(struct btrfs_root *root)
+void btrfs_scrub_continue_super(struct btrfs_root *root)
 {
         up_write(&root->fs_info->scrub_super_lock);
-        return 0;
 }
 
 int btrfs_scrub_cancel(struct btrfs_root *root)
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 9774e38a0532..ae7963b2d527 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -1408,9 +1408,7 @@ static int __init init_btrfs_fs(void)
         if (err)
                 return err;
 
-        err = btrfs_init_compress();
-        if (err)
-                goto free_sysfs;
+        btrfs_init_compress();
 
         err = btrfs_init_cachep();
         if (err)
@@ -1451,7 +1449,6 @@ free_cachep:
         btrfs_destroy_cachep();
 free_compress:
         btrfs_exit_compress();
-free_sysfs:
         btrfs_exit_sysfs();
         return err;
 }
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 04b77e3ceb7a..6e256d90fd2f 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -1214,8 +1214,7 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
 
                 if (flush_on_commit || snap_pending) {
                         btrfs_start_delalloc_inodes(root, 1);
-                        ret = btrfs_wait_ordered_extents(root, 0, 1);
-                        BUG_ON(ret);
+                        btrfs_wait_ordered_extents(root, 0, 1);
                 }
 
                 ret = btrfs_run_delayed_items(trans, root);
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 966cc74f5d6c..37b52b8c6727 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -212,14 +212,13 @@ int btrfs_pin_log_trans(struct btrfs_root *root)
  * indicate we're done making changes to the log tree
  * and wake up anyone waiting to do a sync
  */
-int btrfs_end_log_trans(struct btrfs_root *root)
+void btrfs_end_log_trans(struct btrfs_root *root)
 {
         if (atomic_dec_and_test(&root->log_writers)) {
                 smp_mb();
                 if (waitqueue_active(&root->log_writer_wait))
                         wake_up(&root->log_writer_wait);
         }
-        return 0;
 }
 
 
@@ -378,12 +377,11 @@ insert:
                 u32 found_size;
                 found_size = btrfs_item_size_nr(path->nodes[0],
                                                 path->slots[0]);
-                if (found_size > item_size) {
+                if (found_size > item_size)
                         btrfs_truncate_item(trans, root, path, item_size, 1);
-                } else if (found_size < item_size) {
-                        ret = btrfs_extend_item(trans, root, path,
-                                                item_size - found_size);
-                }
+                else if (found_size < item_size)
+                        btrfs_extend_item(trans, root, path,
+                                          item_size - found_size);
         } else if (ret) {
                 return ret;
         }
@@ -1963,8 +1961,8 @@ static int wait_log_commit(struct btrfs_trans_handle *trans,
         return 0;
 }
 
-static int wait_for_writer(struct btrfs_trans_handle *trans,
-                           struct btrfs_root *root)
+static void wait_for_writer(struct btrfs_trans_handle *trans,
+                            struct btrfs_root *root)
 {
         DEFINE_WAIT(wait);
         while (root->fs_info->last_trans_log_full_commit !=
@@ -1978,7 +1976,6 @@ static int wait_for_writer(struct btrfs_trans_handle *trans,
                 mutex_lock(&root->log_mutex);
                 finish_wait(&root->log_writer_wait, &wait);
         }
-        return 0;
 }
 
 /*
diff --git a/fs/btrfs/tree-log.h b/fs/btrfs/tree-log.h
index 2270ac58d746..862ac813f6b8 100644
--- a/fs/btrfs/tree-log.h
+++ b/fs/btrfs/tree-log.h
@@ -38,7 +38,7 @@ int btrfs_del_inode_ref_in_log(struct btrfs_trans_handle *trans,
                                struct btrfs_root *root,
                                const char *name, int name_len,
                                struct inode *inode, u64 dirid);
-int btrfs_end_log_trans(struct btrfs_root *root);
+void btrfs_end_log_trans(struct btrfs_root *root);
 int btrfs_pin_log_trans(struct btrfs_root *root);
 int btrfs_log_inode_parent(struct btrfs_trans_handle *trans,
                     struct btrfs_root *root, struct inode *inode,
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index ef41f285a475..1c5f8a4a2bbd 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -67,7 +67,7 @@ static void free_fs_devices(struct btrfs_fs_devices *fs_devices)
         kfree(fs_devices);
 }
 
-int btrfs_cleanup_fs_uuids(void)
+void btrfs_cleanup_fs_uuids(void)
 {
         struct btrfs_fs_devices *fs_devices;
 
@@ -77,7 +77,6 @@ int btrfs_cleanup_fs_uuids(void)
                 list_del(&fs_devices->list);
                 free_fs_devices(fs_devices);
         }
-        return 0;
 }
 
 static noinline struct btrfs_device *__find_device(struct list_head *head,
@@ -130,7 +129,7 @@ static void requeue_list(struct btrfs_pending_bios *pending_bios,
  * the list if the block device is congested.  This way, multiple devices
  * can make progress from a single worker thread.
  */
-static noinline int run_scheduled_bios(struct btrfs_device *device)
+static noinline void run_scheduled_bios(struct btrfs_device *device)
 {
         struct bio *pending;
         struct backing_dev_info *bdi;
@@ -316,7 +315,6 @@ loop_lock:
 
 done:
         blk_finish_plug(&plug);
-        return 0;
 }
 
 static void pending_bios_fn(struct btrfs_work *work)
@@ -455,7 +453,7 @@ error:
         return ERR_PTR(-ENOMEM);
 }
 
-int btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices)
+void btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices)
 {
         struct btrfs_device *device, *next;
 
@@ -503,7 +501,6 @@ again:
         fs_devices->latest_trans = latest_transid;
 
         mutex_unlock(&uuid_mutex);
-        return 0;
 }
 
 static void __free_device(struct work_struct *work)
@@ -3967,7 +3964,7 @@ struct async_sched {
  * This will add one bio to the pending list for a device and make sure
  * the work struct is scheduled.
  */
-static noinline int schedule_bio(struct btrfs_root *root,
+static noinline void schedule_bio(struct btrfs_root *root,
                                  struct btrfs_device *device,
                                  int rw, struct bio *bio)
 {
@@ -3979,7 +3976,7 @@ static noinline int schedule_bio(struct btrfs_root *root,
                 bio_get(bio);
                 btrfsic_submit_bio(rw, bio);
                 bio_put(bio);
-                return 0;
+                return;
         }
 
         /*
@@ -4013,7 +4010,6 @@ static noinline int schedule_bio(struct btrfs_root *root,
         if (should_queue)
                 btrfs_queue_worker(&root->fs_info->submit_workers,
                                    &device->work);
-        return 0;
 }
 
 int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
@@ -4215,7 +4211,7 @@ static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
         return 0;
 }
 
-static int fill_device_from_item(struct extent_buffer *leaf,
+static void fill_device_from_item(struct extent_buffer *leaf,
                                  struct btrfs_dev_item *dev_item,
                                  struct btrfs_device *device)
 {
@@ -4232,8 +4228,6 @@ static int fill_device_from_item(struct extent_buffer *leaf,
 
         ptr = (unsigned long)btrfs_device_uuid(dev_item);
         read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
-
-        return 0;
 }
 
 static int open_seed_devices(struct btrfs_root *root, u8 *fsid)
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 19ac95048b88..bb6b03f97aaa 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -260,12 +260,12 @@ int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
 int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
                           struct btrfs_fs_devices **fs_devices_ret);
 int btrfs_close_devices(struct btrfs_fs_devices *fs_devices);
-int btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices);
+void btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices);
 int btrfs_add_device(struct btrfs_trans_handle *trans,
                      struct btrfs_root *root,
                      struct btrfs_device *device);
 int btrfs_rm_device(struct btrfs_root *root, char *device_path);
-int btrfs_cleanup_fs_uuids(void);
+void btrfs_cleanup_fs_uuids(void);
 int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len);
 int btrfs_grow_device(struct btrfs_trans_handle *trans,
                       struct btrfs_device *device, u64 new_size);