Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable: (39 commits)
  Btrfs: deal with errors from updating the tree log
  Btrfs: allow subvol deletion by unprivileged user with -o user_subvol_rm_allowed
  Btrfs: make SNAP_DESTROY async
  Btrfs: add SNAP_CREATE_ASYNC ioctl
  Btrfs: add START_SYNC, WAIT_SYNC ioctls
  Btrfs: async transaction commit
  Btrfs: fix deadlock in btrfs_commit_transaction
  Btrfs: fix lockdep warning on clone ioctl
  Btrfs: fix clone ioctl where range is adjacent to extent
  Btrfs: fix delalloc checks in clone ioctl
  Btrfs: drop unused variable in block_alloc_rsv
  Btrfs: cleanup warnings from gcc 4.6 (nonbugs)
  Btrfs: Fix variables set but not read (bugs found by gcc 4.6)
  Btrfs: Use ERR_CAST helpers
  Btrfs: use memdup_user helpers
  Btrfs: fix raid code for removing missing drives
  Btrfs: Switch the extent buffer rbtree into a radix tree
  Btrfs: restructure try_release_extent_buffer()
  Btrfs: use the flusher threads for delalloc throttling
  Btrfs: tune the chunk allocation to 5% of the FS as metadata
  ...

Fix up trivial conflicts in fs/btrfs/super.c and fs/fs-writeback.c, and
remove use of INIT_RCU_HEAD in fs/btrfs/extent_io.c (that init macro was
useless and removed in commit 5e8067adfdba: "rcu head remove init")

1 files changed, 153 insertions, 49 deletions

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 64f99cf..558cac2 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -319,8 +319,6 @@ static noinline int compress_file_range(struct inode *inode,
 	struct btrfs_root *root = BTRFS_I(inode)->root;
 	struct btrfs_trans_handle *trans;
 	u64 num_bytes;
-	u64 orig_start;
-	u64 disk_num_bytes;
 	u64 blocksize = root->sectorsize;
 	u64 actual_end;
 	u64 isize = i_size_read(inode);
@@ -335,8 +333,6 @@ static noinline int compress_file_range(struct inode *inode,
 	int i;
 	int will_compress;
 
-	orig_start = start;
-
 	actual_end = min_t(u64, isize, end + 1);
 again:
 	will_compress = 0;
@@ -371,7 +367,6 @@ again:
 	total_compressed = min(total_compressed, max_uncompressed);
 	num_bytes = (end - start + blocksize) & ~(blocksize - 1);
 	num_bytes = max(blocksize,  num_bytes);
-	disk_num_bytes = num_bytes;
 	total_in = 0;
 	ret = 0;
 
@@ -467,7 +462,6 @@ again:
 		if (total_compressed >= total_in) {
 			will_compress = 0;
 		} else {
-			disk_num_bytes = total_compressed;
 			num_bytes = total_in;
 		}
 	}
@@ -757,20 +751,17 @@ static noinline int cow_file_range(struct inode *inode,
 	u64 disk_num_bytes;
 	u64 cur_alloc_size;
 	u64 blocksize = root->sectorsize;
-	u64 actual_end;
-	u64 isize = i_size_read(inode);
 	struct btrfs_key ins;
 	struct extent_map *em;
 	struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 	int ret = 0;
 
+	BUG_ON(root == root->fs_info->tree_root);
 	trans = btrfs_join_transaction(root, 1);
 	BUG_ON(!trans);
 	btrfs_set_trans_block_group(trans, inode);
 	trans->block_rsv = &root->fs_info->delalloc_block_rsv;
 
-	actual_end = min_t(u64, isize, end + 1);
-
 	num_bytes = (end - start + blocksize) & ~(blocksize - 1);
 	num_bytes = max(blocksize,  num_bytes);
 	disk_num_bytes = num_bytes;
@@ -1035,10 +1026,16 @@ static noinline int run_delalloc_nocow(struct inode *inode,
 	int type;
 	int nocow;
 	int check_prev = 1;
+	bool nolock = false;
 
 	path = btrfs_alloc_path();
 	BUG_ON(!path);
-	trans = btrfs_join_transaction(root, 1);
+	if (root == root->fs_info->tree_root) {
+		nolock = true;
+		trans = btrfs_join_transaction_nolock(root, 1);
+	} else {
+		trans = btrfs_join_transaction(root, 1);
+	}
 	BUG_ON(!trans);
 
 	cow_start = (u64)-1;
@@ -1211,8 +1208,13 @@ out_check:
 		BUG_ON(ret);
 	}
 
-	ret = btrfs_end_transaction(trans, root);
-	BUG_ON(ret);
+	if (nolock) {
+		ret = btrfs_end_transaction_nolock(trans, root);
+		BUG_ON(ret);
+	} else {
+		ret = btrfs_end_transaction(trans, root);
+		BUG_ON(ret);
+	}
 	btrfs_free_path(path);
 	return 0;
 }
@@ -1289,6 +1291,8 @@ static int btrfs_set_bit_hook(struct inode *inode,
 	if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
 		struct btrfs_root *root = BTRFS_I(inode)->root;
 		u64 len = state->end + 1 - state->start;
+		int do_list = (root->root_key.objectid !=
+			       BTRFS_ROOT_TREE_OBJECTID);
 
 		if (*bits & EXTENT_FIRST_DELALLOC)
 			*bits &= ~EXTENT_FIRST_DELALLOC;
@@ -1298,7 +1302,7 @@ static int btrfs_set_bit_hook(struct inode *inode,
 		spin_lock(&root->fs_info->delalloc_lock);
 		BTRFS_I(inode)->delalloc_bytes += len;
 		root->fs_info->delalloc_bytes += len;
-		if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
+		if (do_list && list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
 			list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
 				      &root->fs_info->delalloc_inodes);
 		}
@@ -1321,6 +1325,8 @@ static int btrfs_clear_bit_hook(struct inode *inode,
 	if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
 		struct btrfs_root *root = BTRFS_I(inode)->root;
 		u64 len = state->end + 1 - state->start;
+		int do_list = (root->root_key.objectid !=
+			       BTRFS_ROOT_TREE_OBJECTID);
 
 		if (*bits & EXTENT_FIRST_DELALLOC)
 			*bits &= ~EXTENT_FIRST_DELALLOC;
@@ -1330,14 +1336,15 @@ static int btrfs_clear_bit_hook(struct inode *inode,
 		if (*bits & EXTENT_DO_ACCOUNTING)
 			btrfs_delalloc_release_metadata(inode, len);
 
-		if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID)
+		if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
+		    && do_list)
 			btrfs_free_reserved_data_space(inode, len);
 
 		spin_lock(&root->fs_info->delalloc_lock);
 		root->fs_info->delalloc_bytes -= len;
 		BTRFS_I(inode)->delalloc_bytes -= len;
 
-		if (BTRFS_I(inode)->delalloc_bytes == 0 &&
+		if (do_list && BTRFS_I(inode)->delalloc_bytes == 0 &&
 		    !list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
 			list_del_init(&BTRFS_I(inode)->delalloc_inodes);
 		}
@@ -1372,7 +1379,7 @@ int btrfs_merge_bio_hook(struct page *page, unsigned long offset,
 
 	if (map_length < length + size)
 		return 1;
-	return 0;
+	return ret;
 }
 
 /*
@@ -1426,7 +1433,10 @@ static int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
 
 	skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
 
-	ret = btrfs_bio_wq_end_io(root->fs_info, bio, 0);
+	if (root == root->fs_info->tree_root)
+		ret = btrfs_bio_wq_end_io(root->fs_info, bio, 2);
+	else
+		ret = btrfs_bio_wq_end_io(root->fs_info, bio, 0);
 	BUG_ON(ret);
 
 	if (!(rw & REQ_WRITE)) {
@@ -1662,6 +1672,7 @@ static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end)
 	struct extent_state *cached_state = NULL;
 	int compressed = 0;
 	int ret;
+	bool nolock = false;
 
 	ret = btrfs_dec_test_ordered_pending(inode, &ordered_extent, start,
 					     end - start + 1);
@@ -1669,11 +1680,17 @@ static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end)
 		return 0;
 	BUG_ON(!ordered_extent);
 
+	nolock = (root == root->fs_info->tree_root);
+
 	if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
 		BUG_ON(!list_empty(&ordered_extent->list));
 		ret = btrfs_ordered_update_i_size(inode, 0, ordered_extent);
 		if (!ret) {
-			trans = btrfs_join_transaction(root, 1);
+			if (nolock)
+				trans = btrfs_join_transaction_nolock(root, 1);
+			else
+				trans = btrfs_join_transaction(root, 1);
+			BUG_ON(!trans);
 			btrfs_set_trans_block_group(trans, inode);
 			trans->block_rsv = &root->fs_info->delalloc_block_rsv;
 			ret = btrfs_update_inode(trans, root, inode);
@@ -1686,7 +1703,10 @@ static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end)
 			 ordered_extent->file_offset + ordered_extent->len - 1,
 			 0, &cached_state, GFP_NOFS);
 
-	trans = btrfs_join_transaction(root, 1);
+	if (nolock)
+		trans = btrfs_join_transaction_nolock(root, 1);
+	else
+		trans = btrfs_join_transaction(root, 1);
 	btrfs_set_trans_block_group(trans, inode);
 	trans->block_rsv = &root->fs_info->delalloc_block_rsv;
 
@@ -1700,6 +1720,7 @@ static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end)
 						ordered_extent->len);
 		BUG_ON(ret);
 	} else {
+		BUG_ON(root == root->fs_info->tree_root);
 		ret = insert_reserved_file_extent(trans, inode,
 						ordered_extent->file_offset,
 						ordered_extent->start,
@@ -1724,9 +1745,15 @@ static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end)
 	ret = btrfs_update_inode(trans, root, inode);
 	BUG_ON(ret);
 out:
-	btrfs_delalloc_release_metadata(inode, ordered_extent->len);
-	if (trans)
-		btrfs_end_transaction(trans, root);
+	if (nolock) {
+		if (trans)
+			btrfs_end_transaction_nolock(trans, root);
+	} else {
+		btrfs_delalloc_release_metadata(inode, ordered_extent->len);
+		if (trans)
+			btrfs_end_transaction(trans, root);
+	}
+
 	/* once for us */
 	btrfs_put_ordered_extent(ordered_extent);
 	/* once for the tree */
@@ -2237,7 +2264,6 @@ void btrfs_orphan_cleanup(struct btrfs_root *root)
 {
 	struct btrfs_path *path;
 	struct extent_buffer *leaf;
-	struct btrfs_item *item;
 	struct btrfs_key key, found_key;
 	struct btrfs_trans_handle *trans;
 	struct inode *inode;
@@ -2275,7 +2301,6 @@ void btrfs_orphan_cleanup(struct btrfs_root *root)
 
 		/* pull out the item */
 		leaf = path->nodes[0];
-		item = btrfs_item_nr(leaf, path->slots[0]);
 		btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
 
 		/* make sure the item matches what we want */
@@ -2651,7 +2676,8 @@ int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
 
 	ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len,
 					   dir, index);
-	BUG_ON(ret);
+	if (ret == -ENOENT)
+		ret = 0;
 err:
 	btrfs_free_path(path);
 	if (ret)
@@ -2672,8 +2698,8 @@ static int check_path_shared(struct btrfs_root *root,
 {
 	struct extent_buffer *eb;
 	int level;
-	int ret;
 	u64 refs = 1;
+	int uninitialized_var(ret);
 
 	for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
 		if (!path->nodes[level])
@@ -2686,7 +2712,7 @@ static int check_path_shared(struct btrfs_root *root,
 		if (refs > 1)
 			return 1;
 	}
-	return 0;
+	return ret; /* XXX callers? */
 }
 
 /*
@@ -3196,7 +3222,7 @@ int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
 
 	BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);
 
-	if (root->ref_cows)
+	if (root->ref_cows || root == root->fs_info->tree_root)
 		btrfs_drop_extent_cache(inode, new_size & (~mask), (u64)-1, 0);
 
 	path = btrfs_alloc_path();
@@ -3344,7 +3370,8 @@ delete:
 		} else {
 			break;
 		}
-		if (found_extent && root->ref_cows) {
+		if (found_extent && (root->ref_cows ||
+				     root == root->fs_info->tree_root)) {
 			btrfs_set_path_blocking(path);
 			ret = btrfs_free_extent(trans, root, extent_start,
 						extent_num_bytes, 0,
@@ -3675,7 +3702,8 @@ void btrfs_evict_inode(struct inode *inode)
 	int ret;
 
 	truncate_inode_pages(&inode->i_data, 0);
-	if (inode->i_nlink && btrfs_root_refs(&root->root_item) != 0)
+	if (inode->i_nlink && (btrfs_root_refs(&root->root_item) != 0 ||
+			       root == root->fs_info->tree_root))
 		goto no_delete;
 
 	if (is_bad_inode(inode)) {
@@ -3888,7 +3916,14 @@ static void inode_tree_del(struct inode *inode)
 	}
 	spin_unlock(&root->inode_lock);
 
-	if (empty && btrfs_root_refs(&root->root_item) == 0) {
+	/*
+	 * Free space cache has inodes in the tree root, but the tree root has a
+	 * root_refs of 0, so this could end up dropping the tree root as a
+	 * snapshot, so we need the extra !root->fs_info->tree_root check to
+	 * make sure we don't drop it.
+	 */
+	if (empty && btrfs_root_refs(&root->root_item) == 0 &&
+	    root != root->fs_info->tree_root) {
 		synchronize_srcu(&root->fs_info->subvol_srcu);
 		spin_lock(&root->inode_lock);
 		empty = RB_EMPTY_ROOT(&root->inode_tree);
@@ -4282,14 +4317,24 @@ int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc)
 	struct btrfs_root *root = BTRFS_I(inode)->root;
 	struct btrfs_trans_handle *trans;
 	int ret = 0;
+	bool nolock = false;
 
 	if (BTRFS_I(inode)->dummy_inode)
 		return 0;
 
+	smp_mb();
+	nolock = (root->fs_info->closing && root == root->fs_info->tree_root);
+
 	if (wbc->sync_mode == WB_SYNC_ALL) {
-		trans = btrfs_join_transaction(root, 1);
+		if (nolock)
+			trans = btrfs_join_transaction_nolock(root, 1);
+		else
+			trans = btrfs_join_transaction(root, 1);
 		btrfs_set_trans_block_group(trans, inode);
-		ret = btrfs_commit_transaction(trans, root);
+		if (nolock)
+			ret = btrfs_end_transaction_nolock(trans, root);
+		else
+			ret = btrfs_commit_transaction(trans, root);
 	}
 	return ret;
 }
@@ -5645,7 +5690,6 @@ static void btrfs_submit_direct(int rw, struct bio *bio, struct inode *inode,
 	struct btrfs_root *root = BTRFS_I(inode)->root;
 	struct btrfs_dio_private *dip;
 	struct bio_vec *bvec = bio->bi_io_vec;
-	u64 start;
 	int skip_sum;
 	int write = rw & REQ_WRITE;
 	int ret = 0;
@@ -5671,7 +5715,6 @@ static void btrfs_submit_direct(int rw, struct bio *bio, struct inode *inode,
 	dip->inode = inode;
 	dip->logical_offset = file_offset;
 
-	start = dip->logical_offset;
 	dip->bytes = 0;
 	do {
 		dip->bytes += bvec->bv_len;
@@ -6308,6 +6351,21 @@ void btrfs_destroy_inode(struct inode *inode)
 		spin_unlock(&root->fs_info->ordered_extent_lock);
 	}
 
+	if (root == root->fs_info->tree_root) {
+		struct btrfs_block_group_cache *block_group;
+
+		block_group = btrfs_lookup_block_group(root->fs_info,
+						BTRFS_I(inode)->block_group);
+		if (block_group && block_group->inode == inode) {
+			spin_lock(&block_group->lock);
+			block_group->inode = NULL;
+			spin_unlock(&block_group->lock);
+			btrfs_put_block_group(block_group);
+		} else if (block_group) {
+			btrfs_put_block_group(block_group);
+		}
+	}
+
 	spin_lock(&root->orphan_lock);
 	if (!list_empty(&BTRFS_I(inode)->i_orphan)) {
 		printk(KERN_INFO "BTRFS: inode %lu still on the orphan list\n",
@@ -6340,7 +6398,8 @@ int btrfs_drop_inode(struct inode *inode)
 {
 	struct btrfs_root *root = BTRFS_I(inode)->root;
 
-	if (btrfs_root_refs(&root->root_item) == 0)
+	if (btrfs_root_refs(&root->root_item) == 0 &&
+	    root != root->fs_info->tree_root)
 		return 1;
 	else
 		return generic_drop_inode(inode);
@@ -6609,7 +6668,8 @@ int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
 	return 0;
 }
 
-int btrfs_start_one_delalloc_inode(struct btrfs_root *root, int delay_iput)
+int btrfs_start_one_delalloc_inode(struct btrfs_root *root, int delay_iput,
+				   int sync)
 {
 	struct btrfs_inode *binode;
 	struct inode *inode = NULL;
@@ -6631,7 +6691,26 @@ int btrfs_start_one_delalloc_inode(struct btrfs_root *root, int delay_iput)
 	spin_unlock(&root->fs_info->delalloc_lock);
 
 	if (inode) {
-		write_inode_now(inode, 0);
+		if (sync) {
+			filemap_write_and_wait(inode->i_mapping);
+			/*
+			 * We have to do this because compression doesn't
+			 * actually set PG_writeback until it submits the pages
+			 * for IO, which happens in an async thread, so we could
+			 * race and not actually wait for any writeback pages
+			 * because they've not been submitted yet.  Technically
+			 * this could still be the case for the ordered stuff
+			 * since the async thread may not have started to do its
+			 * work yet.  If this becomes the case then we need to
+			 * figure out a way to make sure that in writepage we
+			 * wait for any async pages to be submitted before
+			 * returning so that fdatawait does what its supposed to
+			 * do.
+			 */
+			btrfs_wait_ordered_range(inode, 0, (u64)-1);
+		} else {
+			filemap_flush(inode->i_mapping);
+		}
 		if (delay_iput)
 			btrfs_add_delayed_iput(inode);
 		else
@@ -6757,27 +6836,33 @@ out_unlock:
 	return err;
 }
 
-int btrfs_prealloc_file_range(struct inode *inode, int mode,
-			      u64 start, u64 num_bytes, u64 min_size,
-			      loff_t actual_len, u64 *alloc_hint)
+static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
+				       u64 start, u64 num_bytes, u64 min_size,
+				       loff_t actual_len, u64 *alloc_hint,
+				       struct btrfs_trans_handle *trans)
 {
-	struct btrfs_trans_handle *trans;
 	struct btrfs_root *root = BTRFS_I(inode)->root;
 	struct btrfs_key ins;
 	u64 cur_offset = start;
 	int ret = 0;
+	bool own_trans = true;
 
+	if (trans)
+		own_trans = false;
 	while (num_bytes > 0) {
-		trans = btrfs_start_transaction(root, 3);
-		if (IS_ERR(trans)) {
-			ret = PTR_ERR(trans);
-			break;
+		if (own_trans) {
+			trans = btrfs_start_transaction(root, 3);
+			if (IS_ERR(trans)) {
+				ret = PTR_ERR(trans);
+				break;
+			}
 		}
 
 		ret = btrfs_reserve_extent(trans, root, num_bytes, min_size,
 					   0, *alloc_hint, (u64)-1, &ins, 1);
 		if (ret) {
-			btrfs_end_transaction(trans, root);
+			if (own_trans)
+				btrfs_end_transaction(trans, root);
 			break;
 		}
 
@@ -6810,11 +6895,30 @@ int btrfs_prealloc_file_range(struct inode *inode, int mode,
 		ret = btrfs_update_inode(trans, root, inode);
 		BUG_ON(ret);
 
-		btrfs_end_transaction(trans, root);
+		if (own_trans)
+			btrfs_end_transaction(trans, root);
 	}
 	return ret;
 }
 
+int btrfs_prealloc_file_range(struct inode *inode, int mode,
+			      u64 start, u64 num_bytes, u64 min_size,
+			      loff_t actual_len, u64 *alloc_hint)
+{
+	return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
+					   min_size, actual_len, alloc_hint,
+					   NULL);
+}
+
+int btrfs_prealloc_file_range_trans(struct inode *inode,
+				    struct btrfs_trans_handle *trans, int mode,
+				    u64 start, u64 num_bytes, u64 min_size,
+				    loff_t actual_len, u64 *alloc_hint)
+{
+	return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
+					   min_size, actual_len, alloc_hint, trans);
+}
+
 static long btrfs_fallocate(struct inode *inode, int mode,
 			    loff_t offset, loff_t len)
 {