1 files changed, 78 insertions, 39 deletions

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 5cf405b0828d..23e7d36ff325 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -276,7 +276,7 @@ loop_lock:
                  * is now congested.  Back off and let other work structs
                  * run instead
                  */
-                if (pending && bdi_write_congested(bdi) && batch_run > 32 &&
+                if (pending && bdi_write_congested(bdi) && batch_run > 8 &&
                     fs_info->fs_devices->open_devices > 1) {
                         struct io_context *ioc;
 
@@ -719,10 +719,9 @@ error:
  * called very infrequently and that a given device has a small number
  * of extents
  */
-static noinline int find_free_dev_extent(struct btrfs_trans_handle *trans,
-                                         struct btrfs_device *device,
-                                         u64 num_bytes, u64 *start,
-                                         u64 *max_avail)
+int find_free_dev_extent(struct btrfs_trans_handle *trans,
+                         struct btrfs_device *device, u64 num_bytes,
+                         u64 *start, u64 *max_avail)
 {
         struct btrfs_key key;
         struct btrfs_root *root = device->dev_root;
@@ -1736,6 +1735,10 @@ static int btrfs_relocate_chunk(struct btrfs_root *root,
         extent_root = root->fs_info->extent_root;
         em_tree = &root->fs_info->mapping_tree.map_tree;
 
+        ret = btrfs_can_relocate(extent_root, chunk_offset);
+        if (ret)
+                return -ENOSPC;
+
         /* step one, relocate all the extents inside this chunk */
         ret = btrfs_relocate_block_group(extent_root, chunk_offset);
         BUG_ON(ret);
@@ -1749,9 +1752,9 @@ static int btrfs_relocate_chunk(struct btrfs_root *root,
          * step two, delete the device extents and the
          * chunk tree entries
          */
-        spin_lock(&em_tree->lock);
+        read_lock(&em_tree->lock);
         em = lookup_extent_mapping(em_tree, chunk_offset, 1);
-        spin_unlock(&em_tree->lock);
+        read_unlock(&em_tree->lock);
 
         BUG_ON(em->start > chunk_offset ||
                em->start + em->len < chunk_offset);
@@ -1780,9 +1783,9 @@ static int btrfs_relocate_chunk(struct btrfs_root *root,
         ret = btrfs_remove_block_group(trans, extent_root, chunk_offset);
         BUG_ON(ret);
 
-        spin_lock(&em_tree->lock);
+        write_lock(&em_tree->lock);
         remove_extent_mapping(em_tree, em);
-        spin_unlock(&em_tree->lock);
+        write_unlock(&em_tree->lock);
 
         kfree(map);
         em->bdev = NULL;
@@ -1807,12 +1810,15 @@ static int btrfs_relocate_sys_chunks(struct btrfs_root *root)
         struct btrfs_key found_key;
         u64 chunk_tree = chunk_root->root_key.objectid;
         u64 chunk_type;
+        bool retried = false;
+        int failed = 0;
         int ret;
 
         path = btrfs_alloc_path();
         if (!path)
                 return -ENOMEM;
 
+again:
         key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
         key.offset = (u64)-1;
         key.type = BTRFS_CHUNK_ITEM_KEY;
@@ -1842,7 +1848,10 @@ static int btrfs_relocate_sys_chunks(struct btrfs_root *root)
                         ret = btrfs_relocate_chunk(chunk_root, chunk_tree,
                                                    found_key.objectid,
                                                    found_key.offset);
-                        BUG_ON(ret);
+                        if (ret == -ENOSPC)
+                                failed++;
+                        else if (ret)
+                                BUG();
                 }
 
                 if (found_key.offset == 0)
@@ -1850,6 +1859,14 @@ static int btrfs_relocate_sys_chunks(struct btrfs_root *root)
                 key.offset = found_key.offset - 1;
         }
         ret = 0;
+        if (failed && !retried) {
+                failed = 0;
+                retried = true;
+                goto again;
+        } else if (failed && retried) {
+                WARN_ON(1);
+                ret = -ENOSPC;
+        }
 error:
         btrfs_free_path(path);
         return ret;
@@ -1894,6 +1911,8 @@ int btrfs_balance(struct btrfs_root *dev_root)
                         continue;
 
                 ret = btrfs_shrink_device(device, old_size - size_to_free);
+                if (ret == -ENOSPC)
+                        break;
                 BUG_ON(ret);
 
                 trans = btrfs_start_transaction(dev_root, 1);
@@ -1938,9 +1957,8 @@ int btrfs_balance(struct btrfs_root *dev_root)
                 chunk = btrfs_item_ptr(path->nodes[0],
                                        path->slots[0],
                                        struct btrfs_chunk);
-                key.offset = found_key.offset;
                 /* chunk zero is special */
-                if (key.offset == 0)
+                if (found_key.offset == 0)
                         break;
 
                 btrfs_release_path(chunk_root, path);
@@ -1948,7 +1966,8 @@ int btrfs_balance(struct btrfs_root *dev_root)
                                            chunk_root->root_key.objectid,
                                            found_key.objectid,
                                            found_key.offset);
-                BUG_ON(ret);
+                BUG_ON(ret && ret != -ENOSPC);
+                key.offset = found_key.offset - 1;
         }
         ret = 0;
 error:
@@ -1974,10 +1993,13 @@ int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
         u64 chunk_offset;
         int ret;
         int slot;
+        int failed = 0;
+        bool retried = false;
         struct extent_buffer *l;
         struct btrfs_key key;
         struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
         u64 old_total = btrfs_super_total_bytes(super_copy);
+        u64 old_size = device->total_bytes;
         u64 diff = device->total_bytes - new_size;
 
         if (new_size >= device->total_bytes)
@@ -1987,12 +2009,6 @@ int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
         if (!path)
                 return -ENOMEM;
 
-        trans = btrfs_start_transaction(root, 1);
-        if (!trans) {
-                ret = -ENOMEM;
-                goto done;
-        }
-
         path->reada = 2;
 
         lock_chunks(root);
@@ -2001,8 +2017,8 @@ int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
         if (device->writeable)
                 device->fs_devices->total_rw_bytes -= diff;
         unlock_chunks(root);
-        btrfs_end_transaction(trans, root);
 
+again:
         key.objectid = device->devid;
         key.offset = (u64)-1;
         key.type = BTRFS_DEV_EXTENT_KEY;
@@ -2017,6 +2033,7 @@ int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
                         goto done;
                 if (ret) {
                         ret = 0;
+                        btrfs_release_path(root, path);
                         break;
                 }
 
@@ -2024,14 +2041,18 @@ int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
                 slot = path->slots[0];
                 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
 
-                if (key.objectid != device->devid)
+                if (key.objectid != device->devid) {
+                        btrfs_release_path(root, path);
                         break;
+                }
 
                 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
                 length = btrfs_dev_extent_length(l, dev_extent);
 
-                if (key.offset + length <= new_size)
+                if (key.offset + length <= new_size) {
+                        btrfs_release_path(root, path);
                         break;
+                }
 
                 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
                 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
@@ -2040,8 +2061,26 @@ int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
 
                 ret = btrfs_relocate_chunk(root, chunk_tree, chunk_objectid,
                                            chunk_offset);
-                if (ret)
+                if (ret && ret != -ENOSPC)
                         goto done;
+                if (ret == -ENOSPC)
+                        failed++;
+                key.offset -= 1;
+        }
+
+        if (failed && !retried) {
+                failed = 0;
+                retried = true;
+                goto again;
+        } else if (failed && retried) {
+                ret = -ENOSPC;
+                lock_chunks(root);
+
+                device->total_bytes = old_size;
+                if (device->writeable)
+                        device->fs_devices->total_rw_bytes += diff;
+                unlock_chunks(root);
+                goto done;
         }
 
         /* Shrinking succeeded, else we would be at "done". */
@@ -2294,9 +2333,9 @@ again:
         em->block_len = em->len;
 
         em_tree = &extent_root->fs_info->mapping_tree.map_tree;
-        spin_lock(&em_tree->lock);
+        write_lock(&em_tree->lock);
         ret = add_extent_mapping(em_tree, em);
-        spin_unlock(&em_tree->lock);
+        write_unlock(&em_tree->lock);
         BUG_ON(ret);
         free_extent_map(em);
 
@@ -2491,9 +2530,9 @@ int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
         int readonly = 0;
         int i;
 
-        spin_lock(&map_tree->map_tree.lock);
+        read_lock(&map_tree->map_tree.lock);
         em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
-        spin_unlock(&map_tree->map_tree.lock);
+        read_unlock(&map_tree->map_tree.lock);
         if (!em)
                 return 1;
 
@@ -2518,11 +2557,11 @@ void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree)
         struct extent_map *em;
 
         while (1) {
-                spin_lock(&tree->map_tree.lock);
+                write_lock(&tree->map_tree.lock);
                 em = lookup_extent_mapping(&tree->map_tree, 0, (u64)-1);
                 if (em)
                         remove_extent_mapping(&tree->map_tree, em);
-                spin_unlock(&tree->map_tree.lock);
+                write_unlock(&tree->map_tree.lock);
                 if (!em)
                         break;
                 kfree(em->bdev);
@@ -2540,9 +2579,9 @@ int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len)
         struct extent_map_tree *em_tree = &map_tree->map_tree;
         int ret;
 
-        spin_lock(&em_tree->lock);
+        read_lock(&em_tree->lock);
         em = lookup_extent_mapping(em_tree, logical, len);
-        spin_unlock(&em_tree->lock);
+        read_unlock(&em_tree->lock);
         BUG_ON(!em);
 
         BUG_ON(em->start > logical || em->start + em->len < logical);
@@ -2604,9 +2643,9 @@ again:
                 atomic_set(&multi->error, 0);
         }
 
-        spin_lock(&em_tree->lock);
+        read_lock(&em_tree->lock);
         em = lookup_extent_mapping(em_tree, logical, *length);
-        spin_unlock(&em_tree->lock);
+        read_unlock(&em_tree->lock);
 
         if (!em && unplug_page)
                 return 0;
@@ -2763,9 +2802,9 @@ int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
         u64 stripe_nr;
         int i, j, nr = 0;
 
-        spin_lock(&em_tree->lock);
+        read_lock(&em_tree->lock);
         em = lookup_extent_mapping(em_tree, chunk_start, 1);
-        spin_unlock(&em_tree->lock);
+        read_unlock(&em_tree->lock);
 
         BUG_ON(!em || em->start != chunk_start);
         map = (struct map_lookup *)em->bdev;
@@ -3053,9 +3092,9 @@ static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
         logical = key->offset;
         length = btrfs_chunk_length(leaf, chunk);
 
-        spin_lock(&map_tree->map_tree.lock);
+        read_lock(&map_tree->map_tree.lock);
         em = lookup_extent_mapping(&map_tree->map_tree, logical, 1);
-        spin_unlock(&map_tree->map_tree.lock);
+        read_unlock(&map_tree->map_tree.lock);
 
         /* already mapped? */
         if (em && em->start <= logical && em->start + em->len > logical) {
@@ -3114,9 +3153,9 @@ static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
                 map->stripes[i].dev->in_fs_metadata = 1;
         }
 
-        spin_lock(&map_tree->map_tree.lock);
+        write_lock(&map_tree->map_tree.lock);
         ret = add_extent_mapping(&map_tree->map_tree, em);
-        spin_unlock(&map_tree->map_tree.lock);
+        write_unlock(&map_tree->map_tree.lock);
         BUG_ON(ret);
         free_extent_map(em);