1 files changed, 220 insertions, 100 deletions

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index a0fa7253a2d7..a70c5790f8f5 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -310,6 +310,13 @@ static noinline int cow_file_range_inline(struct btrfs_root *root,
 	btrfs_delalloc_release_metadata(inode, end + 1 - start);
 	btrfs_drop_extent_cache(inode, start, aligned_end - 1, 0);
 out:
+	/*
+	 * Don't forget to free the reserved space, as for inlined extent
+	 * it won't count as data extent, free them directly here.
+	 * And at reserve time, it's always aligned to page size, so
+	 * just free one page here.
+	 */
+	btrfs_qgroup_free_data(inode, 0, PAGE_CACHE_SIZE);
 	btrfs_free_path(path);
 	btrfs_end_transaction(trans, root);
 	return ret;
@@ -1096,6 +1103,9 @@ static noinline void async_cow_submit(struct btrfs_work *work)
 	nr_pages = (async_cow->end - async_cow->start + PAGE_CACHE_SIZE) >>
 		PAGE_CACHE_SHIFT;
 
+	/*
+	 * atomic_sub_return implies a barrier for waitqueue_active
+	 */
 	if (atomic_sub_return(nr_pages, &root->fs_info->async_delalloc_pages) <
 	    5 * 1024 * 1024 &&
 	    waitqueue_active(&root->fs_info->async_submit_wait))
@@ -1294,8 +1304,14 @@ next_slot:
 		num_bytes = 0;
 		btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
 
-		if (found_key.objectid > ino ||
-		    found_key.type > BTRFS_EXTENT_DATA_KEY ||
+		if (found_key.objectid > ino)
+			break;
+		if (WARN_ON_ONCE(found_key.objectid < ino) ||
+		    found_key.type < BTRFS_EXTENT_DATA_KEY) {
+			path->slots[0]++;
+			goto next_slot;
+		}
+		if (found_key.type > BTRFS_EXTENT_DATA_KEY ||
 		    found_key.offset > end)
 			break;
 
@@ -1766,7 +1782,8 @@ static void btrfs_clear_bit_hook(struct inode *inode,
 
 		if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
 		    && do_list && !(state->state & EXTENT_NORESERVE))
-			btrfs_free_reserved_data_space(inode, len);
+			btrfs_free_reserved_data_space_noquota(inode,
+					state->start, len);
 
 		__percpu_counter_add(&root->fs_info->delalloc_bytes, -len,
 				     root->fs_info->delalloc_batch);
@@ -1861,15 +1878,15 @@ static int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
 			  u64 bio_offset)
 {
 	struct btrfs_root *root = BTRFS_I(inode)->root;
+	enum btrfs_wq_endio_type metadata = BTRFS_WQ_ENDIO_DATA;
 	int ret = 0;
 	int skip_sum;
-	int metadata = 0;
 	int async = !atomic_read(&BTRFS_I(inode)->sync_writers);
 
 	skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
 
 	if (btrfs_is_free_space_inode(inode))
-		metadata = 2;
+		metadata = BTRFS_WQ_ENDIO_FREE_SPACE;
 
 	if (!(rw & REQ_WRITE)) {
 		ret = btrfs_bio_wq_end_io(root->fs_info, bio, metadata);
@@ -1989,7 +2006,8 @@ again:
 		goto again;
 	}
 
-	ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
+	ret = btrfs_delalloc_reserve_space(inode, page_start,
+					   PAGE_CACHE_SIZE);
 	if (ret) {
 		mapping_set_error(page->mapping, ret);
 		end_extent_writepage(page, ret, page_start, page_end);
@@ -2115,7 +2133,13 @@ static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
 	ins.type = BTRFS_EXTENT_ITEM_KEY;
 	ret = btrfs_alloc_reserved_file_extent(trans, root,
 					root->root_key.objectid,
-					btrfs_ino(inode), file_pos, &ins);
+					btrfs_ino(inode), file_pos,
+					ram_bytes, &ins);
+	/*
+	 * Release the reserved range from inode dirty range map, as it is
+	 * already moved into delayed_ref_head
+	 */
+	btrfs_qgroup_release_data(inode, file_pos, ram_bytes);
 out:
 	btrfs_free_path(path);
 
@@ -2573,7 +2597,7 @@ again:
 	ret = btrfs_inc_extent_ref(trans, root, new->bytenr,
 			new->disk_len, 0,
 			backref->root_id, backref->inum,
-			new->file_pos, 0);	/* start - extent_offset */
+			new->file_pos);	/* start - extent_offset */
 	if (ret) {
 		btrfs_abort_transaction(trans, root, ret);
 		goto out_free_path;
@@ -2599,7 +2623,6 @@ static void free_sa_defrag_extent(struct new_sa_defrag_extent *new)
 		return;
 
 	list_for_each_entry_safe(old, tmp, &new->head, list) {
-		list_del(&old->list);
 		kfree(old);
 	}
 	kfree(new);
@@ -2824,6 +2847,14 @@ static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
 
 	if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
 		BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */
+
+		/*
+		 * For mwrite(mmap + memset to write) case, we still reserve
+		 * space for NOCOW range.
+		 * As NOCOW won't cause a new delayed ref, just free the space
+		 */
+		btrfs_qgroup_free_data(inode, ordered_extent->file_offset,
+				       ordered_extent->len);
 		btrfs_ordered_update_i_size(inode, 0, ordered_extent);
 		if (nolock)
 			trans = btrfs_join_transaction_nolock(root);
@@ -3018,8 +3049,6 @@ static int __readpage_endio_check(struct inode *inode,
 	char *kaddr;
 	u32 csum_expected;
 	u32 csum = ~(u32)0;
-	static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL,
-				      DEFAULT_RATELIMIT_BURST);
 
 	csum_expected = *(((u32 *)io_bio->csum) + icsum);
 
@@ -3032,9 +3061,8 @@ static int __readpage_endio_check(struct inode *inode,
 	kunmap_atomic(kaddr);
 	return 0;
 zeroit:
-	if (__ratelimit(&_rs))
-		btrfs_warn(BTRFS_I(inode)->root->fs_info,
-			   "csum failed ino %llu off %llu csum %u expected csum %u",
+	btrfs_warn_rl(BTRFS_I(inode)->root->fs_info,
+		"csum failed ino %llu off %llu csum %u expected csum %u",
 			   btrfs_ino(inode), start, csum, csum_expected);
 	memset(kaddr + pgoff, 1, len);
 	flush_dcache_page(page);
@@ -4018,9 +4046,7 @@ int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
  */
 static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir)
 {
-	struct btrfs_trans_handle *trans;
 	struct btrfs_root *root = BTRFS_I(dir)->root;
-	int ret;
 
 	/*
 	 * 1 for the possible orphan item
@@ -4029,27 +4055,7 @@ static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir)
 	 * 1 for the inode ref
 	 * 1 for the inode
 	 */
-	trans = btrfs_start_transaction(root, 5);
-	if (!IS_ERR(trans) || PTR_ERR(trans) != -ENOSPC)
-		return trans;
-
-	if (PTR_ERR(trans) == -ENOSPC) {
-		u64 num_bytes = btrfs_calc_trans_metadata_size(root, 5);
-
-		trans = btrfs_start_transaction(root, 0);
-		if (IS_ERR(trans))
-			return trans;
-		ret = btrfs_cond_migrate_bytes(root->fs_info,
-					       &root->fs_info->trans_block_rsv,
-					       num_bytes, 5);
-		if (ret) {
-			btrfs_end_transaction(trans, root);
-			return ERR_PTR(ret);
-		}
-		trans->block_rsv = &root->fs_info->trans_block_rsv;
-		trans->bytes_reserved = num_bytes;
-	}
-	return trans;
+	return btrfs_start_transaction_fallback_global_rsv(root, 5, 5);
 }
 
 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
@@ -4217,6 +4223,47 @@ static int truncate_space_check(struct btrfs_trans_handle *trans,
 
 }
 
+static int truncate_inline_extent(struct inode *inode,
+				  struct btrfs_path *path,
+				  struct btrfs_key *found_key,
+				  const u64 item_end,
+				  const u64 new_size)
+{
+	struct extent_buffer *leaf = path->nodes[0];
+	int slot = path->slots[0];
+	struct btrfs_file_extent_item *fi;
+	u32 size = (u32)(new_size - found_key->offset);
+	struct btrfs_root *root = BTRFS_I(inode)->root;
+
+	fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
+
+	if (btrfs_file_extent_compression(leaf, fi) != BTRFS_COMPRESS_NONE) {
+		loff_t offset = new_size;
+		loff_t page_end = ALIGN(offset, PAGE_CACHE_SIZE);
+
+		/*
+		 * Zero out the remaining of the last page of our inline extent,
+		 * instead of directly truncating our inline extent here - that
+		 * would be much more complex (decompressing all the data, then
+		 * compressing the truncated data, which might be bigger than
+		 * the size of the inline extent, resize the extent, etc).
+		 * We release the path because to get the page we might need to
+		 * read the extent item from disk (data not in the page cache).
+		 */
+		btrfs_release_path(path);
+		return btrfs_truncate_page(inode, offset, page_end - offset, 0);
+	}
+
+	btrfs_set_file_extent_ram_bytes(leaf, fi, size);
+	size = btrfs_file_extent_calc_inline_size(size);
+	btrfs_truncate_item(root, path, size, 1);
+
+	if (test_bit(BTRFS_ROOT_REF_COWS, &root->state))
+		inode_sub_bytes(inode, item_end + 1 - new_size);
+
+	return 0;
+}
+
 /*
  * this can truncate away extent items, csum items and directory items.
  * It starts at a high offset and removes keys until it can't find
@@ -4411,27 +4458,40 @@ search_again:
 			 * special encodings
 			 */
 			if (!del_item &&
-			    btrfs_file_extent_compression(leaf, fi) == 0 &&
 			    btrfs_file_extent_encryption(leaf, fi) == 0 &&
 			    btrfs_file_extent_other_encoding(leaf, fi) == 0) {
-				u32 size = new_size - found_key.offset;
-
-				if (test_bit(BTRFS_ROOT_REF_COWS, &root->state))
-					inode_sub_bytes(inode, item_end + 1 -
-							new_size);
 
 				/*
-				 * update the ram bytes to properly reflect
-				 * the new size of our item
+				 * Need to release path in order to truncate a
+				 * compressed extent. So delete any accumulated
+				 * extent items so far.
 				 */
-				btrfs_set_file_extent_ram_bytes(leaf, fi, size);
-				size =
-				    btrfs_file_extent_calc_inline_size(size);
-				btrfs_truncate_item(root, path, size, 1);
+				if (btrfs_file_extent_compression(leaf, fi) !=
+				    BTRFS_COMPRESS_NONE && pending_del_nr) {
+					err = btrfs_del_items(trans, root, path,
+							      pending_del_slot,
+							      pending_del_nr);
+					if (err) {
+						btrfs_abort_transaction(trans,
+									root,
+									err);
+						goto error;
+					}
+					pending_del_nr = 0;
+				}
+
+				err = truncate_inline_extent(inode, path,
+							     &found_key,
+							     item_end,
+							     new_size);
+				if (err) {
+					btrfs_abort_transaction(trans,
+								root, err);
+					goto error;
+				}
 			} else if (test_bit(BTRFS_ROOT_REF_COWS,
 					    &root->state)) {
-				inode_sub_bytes(inode, item_end + 1 -
-						found_key.offset);
+				inode_sub_bytes(inode, item_end + 1 - new_size);
 			}
 		}
 delete:
@@ -4461,7 +4521,7 @@ delete:
 			ret = btrfs_free_extent(trans, root, extent_start,
 						extent_num_bytes, 0,
 						btrfs_header_owner(leaf),
-						ino, extent_offset, 0);
+						ino, extent_offset);
 			BUG_ON(ret);
 			if (btrfs_should_throttle_delayed_refs(trans, root))
 				btrfs_async_run_delayed_refs(root,
@@ -4575,14 +4635,17 @@ int btrfs_truncate_page(struct inode *inode, loff_t from, loff_t len,
 	if ((offset & (blocksize - 1)) == 0 &&
 	    (!len || ((len & (blocksize - 1)) == 0)))
 		goto out;
-	ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
+	ret = btrfs_delalloc_reserve_space(inode,
+			round_down(from, PAGE_CACHE_SIZE), PAGE_CACHE_SIZE);
 	if (ret)
 		goto out;
 
 again:
 	page = find_or_create_page(mapping, index, mask);
 	if (!page) {
-		btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
+		btrfs_delalloc_release_space(inode,
+				round_down(from, PAGE_CACHE_SIZE),
+				PAGE_CACHE_SIZE);
 		ret = -ENOMEM;
 		goto out;
 	}
@@ -4650,7 +4713,8 @@ again:
 
 out_unlock:
 	if (ret)
-		btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
+		btrfs_delalloc_release_space(inode, page_start,
+					     PAGE_CACHE_SIZE);
 	unlock_page(page);
 	page_cache_release(page);
 out:
@@ -5048,6 +5112,18 @@ static void evict_inode_truncate_pages(struct inode *inode)
 		spin_unlock(&io_tree->lock);
 
 		lock_extent_bits(io_tree, start, end, 0, &cached_state);
+
+		/*
+		 * If still has DELALLOC flag, the extent didn't reach disk,
+		 * and its reserved space won't be freed by delayed_ref.
+		 * So we need to free its reserved space here.
+		 * (Refer to comment in btrfs_invalidatepage, case 2)
+		 *
+		 * Note, end is the bytenr of last byte, so we need + 1 here.
+		 */
+		if (state->state & EXTENT_DELALLOC)
+			btrfs_qgroup_free_data(inode, start, end - start + 1);
+
 		clear_extent_bit(io_tree, start, end,
 				 EXTENT_LOCKED | EXTENT_DIRTY |
 				 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
@@ -5084,7 +5160,8 @@ void btrfs_evict_inode(struct inode *inode)
 		goto no_delete;
 	}
 	/* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */
-	btrfs_wait_ordered_range(inode, 0, (u64)-1);
+	if (!special_file(inode->i_mode))
+		btrfs_wait_ordered_range(inode, 0, (u64)-1);
 
 	btrfs_free_io_failure_record(inode, 0, (u64)-1);
 
@@ -6267,9 +6344,6 @@ static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
 	u64 objectid;
 	u64 index = 0;
 
-	if (!new_valid_dev(rdev))
-		return -EINVAL;
-
 	/*
 	 * 2 for inode item and ref
 	 * 2 for dir items
@@ -7408,6 +7482,32 @@ static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
 	return em;
 }
 
+struct btrfs_dio_data {
+	u64 outstanding_extents;
+	u64 reserve;
+};
+
+static void adjust_dio_outstanding_extents(struct inode *inode,
+					   struct btrfs_dio_data *dio_data,
+					   const u64 len)
+{
+	unsigned num_extents;
+
+	num_extents = (unsigned) div64_u64(len + BTRFS_MAX_EXTENT_SIZE - 1,
+					   BTRFS_MAX_EXTENT_SIZE);
+	/*
+	 * If we have an outstanding_extents count still set then we're
+	 * within our reservation, otherwise we need to adjust our inode
+	 * counter appropriately.
+	 */
+	if (dio_data->outstanding_extents) {
+		dio_data->outstanding_extents -= num_extents;
+	} else {
+		spin_lock(&BTRFS_I(inode)->lock);
+		BTRFS_I(inode)->outstanding_extents += num_extents;
+		spin_unlock(&BTRFS_I(inode)->lock);
+	}
+}
 
 static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
 				   struct buffer_head *bh_result, int create)
@@ -7415,10 +7515,10 @@ static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
 	struct extent_map *em;
 	struct btrfs_root *root = BTRFS_I(inode)->root;
 	struct extent_state *cached_state = NULL;
+	struct btrfs_dio_data *dio_data = NULL;
 	u64 start = iblock << inode->i_blkbits;
 	u64 lockstart, lockend;
 	u64 len = bh_result->b_size;
-	u64 *outstanding_extents = NULL;
 	int unlock_bits = EXTENT_LOCKED;
 	int ret = 0;
 
@@ -7436,7 +7536,7 @@ static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
 		 * that anything that needs to check if there's a transction doesn't get
 		 * confused.
 		 */
-		outstanding_extents = current->journal_info;
+		dio_data = current->journal_info;
 		current->journal_info = NULL;
 	}
 
@@ -7444,8 +7544,11 @@ static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
 	 * If this errors out it's because we couldn't invalidate pagecache for
 	 * this range and we need to fallback to buffered.
 	 */
-	if (lock_extent_direct(inode, lockstart, lockend, &cached_state, create))
-		return -ENOTBLK;
+	if (lock_extent_direct(inode, lockstart, lockend, &cached_state,
+			       create)) {
+		ret = -ENOTBLK;
+		goto err;
+	}
 
 	em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
 	if (IS_ERR(em)) {
@@ -7563,22 +7666,11 @@ unlock:
 		if (start + len > i_size_read(inode))
 			i_size_write(inode, start + len);
 
-		/*
-		 * If we have an outstanding_extents count still set then we're
-		 * within our reservation, otherwise we need to adjust our inode
-		 * counter appropriately.
-		 */
-		if (*outstanding_extents) {
-			(*outstanding_extents)--;
-		} else {
-			spin_lock(&BTRFS_I(inode)->lock);
-			BTRFS_I(inode)->outstanding_extents++;
-			spin_unlock(&BTRFS_I(inode)->lock);
-		}
-
-		current->journal_info = outstanding_extents;
-		btrfs_free_reserved_data_space(inode, len);
-		set_bit(BTRFS_INODE_DIO_READY, &BTRFS_I(inode)->runtime_flags);
+		adjust_dio_outstanding_extents(inode, dio_data, len);
+		btrfs_free_reserved_data_space(inode, start, len);
+		WARN_ON(dio_data->reserve < len);
+		dio_data->reserve -= len;
+		current->journal_info = dio_data;
 	}
 
 	/*
@@ -7601,8 +7693,17 @@ unlock:
 unlock_err:
 	clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
 			 unlock_bits, 1, 0, &cached_state, GFP_NOFS);
-	if (outstanding_extents)
-		current->journal_info = outstanding_extents;
+err:
+	if (dio_data)
+		current->journal_info = dio_data;
+	/*
+	 * Compensate the delalloc release we do in btrfs_direct_IO() when we
+	 * write less data then expected, so that we don't underflow our inode's
+	 * outstanding extents counter.
+	 */
+	if (create && dio_data)
+		adjust_dio_outstanding_extents(inode, dio_data, len);
+
 	return ret;
 }
 
@@ -8329,7 +8430,8 @@ static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
 {
 	struct file *file = iocb->ki_filp;
 	struct inode *inode = file->f_mapping->host;
-	u64 outstanding_extents = 0;
+	struct btrfs_root *root = BTRFS_I(inode)->root;
+	struct btrfs_dio_data dio_data = { 0 };
 	size_t count = 0;
 	int flags = 0;
 	bool wakeup = true;
@@ -8364,10 +8466,10 @@ static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
 			mutex_unlock(&inode->i_mutex);
 			relock = true;
 		}
-		ret = btrfs_delalloc_reserve_space(inode, count);
+		ret = btrfs_delalloc_reserve_space(inode, offset, count);
 		if (ret)
 			goto out;
-		outstanding_extents = div64_u64(count +
+		dio_data.outstanding_extents = div64_u64(count +
 						BTRFS_MAX_EXTENT_SIZE - 1,
 						BTRFS_MAX_EXTENT_SIZE);
 
@@ -8376,7 +8478,8 @@ static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
 		 * do the accounting properly if we go over the number we
 		 * originally calculated.  Abuse current->journal_info for this.
 		 */
-		current->journal_info = &outstanding_extents;
+		dio_data.reserve = round_up(count, root->sectorsize);
+		current->journal_info = &dio_data;
 	} else if (test_bit(BTRFS_INODE_READDIO_NEED_LOCK,
 				     &BTRFS_I(inode)->runtime_flags)) {
 		inode_dio_end(inode);
@@ -8391,18 +8494,11 @@ static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
 	if (iov_iter_rw(iter) == WRITE) {
 		current->journal_info = NULL;
 		if (ret < 0 && ret != -EIOCBQUEUED) {
-			/*
-			 * If the error comes from submitting stage,
-			 * btrfs_get_blocsk_direct() has free'd data space,
-			 * and metadata space will be handled by
-			 * finish_ordered_fn, don't do that again to make
-			 * sure bytes_may_use is correct.
-			 */
-			if (!test_and_clear_bit(BTRFS_INODE_DIO_READY,
-				     &BTRFS_I(inode)->runtime_flags))
-				btrfs_delalloc_release_space(inode, count);
+			if (dio_data.reserve)
+				btrfs_delalloc_release_space(inode, offset,
+							     dio_data.reserve);
 		} else if (ret >= 0 && (size_t)ret < count)
-			btrfs_delalloc_release_space(inode,
+			btrfs_delalloc_release_space(inode, offset,
 						     count - (size_t)ret);
 	}
 out:
@@ -8561,6 +8657,18 @@ static void btrfs_invalidatepage(struct page *page, unsigned int offset,
 		}
 	}
 
+	/*
+	 * Qgroup reserved space handler
+	 * Page here will be either
+	 * 1) Already written to disk
+	 *    In this case, its reserved space is released from data rsv map
+	 *    and will be freed by delayed_ref handler finally.
+	 *    So even we call qgroup_free_data(), it won't decrease reserved
+	 *    space.
+	 * 2) Not written to disk
+	 *    This means the reserved space should be freed here.
+	 */
+	btrfs_qgroup_free_data(inode, page_start, PAGE_CACHE_SIZE);
 	if (!inode_evicting) {
 		clear_extent_bit(tree, page_start, page_end,
 				 EXTENT_LOCKED | EXTENT_DIRTY |
@@ -8611,7 +8719,11 @@ int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
 	u64 page_end;
 
 	sb_start_pagefault(inode->i_sb);
-	ret  = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
+	page_start = page_offset(page);
+	page_end = page_start + PAGE_CACHE_SIZE - 1;
+
+	ret = btrfs_delalloc_reserve_space(inode, page_start,
+					   PAGE_CACHE_SIZE);
 	if (!ret) {
 		ret = file_update_time(vma->vm_file);
 		reserved = 1;
@@ -8630,8 +8742,6 @@ int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
 again:
 	lock_page(page);
 	size = i_size_read(inode);
-	page_start = page_offset(page);
-	page_end = page_start + PAGE_CACHE_SIZE - 1;
 
 	if ((page->mapping != inode->i_mapping) ||
 	    (page_start >= size)) {
@@ -8708,7 +8818,7 @@ out_unlock:
 	}
 	unlock_page(page);
 out:
-	btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
+	btrfs_delalloc_release_space(inode, page_start, PAGE_CACHE_SIZE);
 out_noreserve:
 	sb_end_pagefault(inode->i_sb);
 	return ret;
@@ -8997,6 +9107,7 @@ void btrfs_destroy_inode(struct inode *inode)
 			btrfs_put_ordered_extent(ordered);
 		}
 	}
+	btrfs_qgroup_check_reserved_leak(inode);
 	inode_tree_del(inode);
 	btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
 free:
@@ -9633,6 +9744,7 @@ static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
 	u64 cur_offset = start;
 	u64 i_size;
 	u64 cur_bytes;
+	u64 last_alloc = (u64)-1;
 	int ret = 0;
 	bool own_trans = true;
 
@@ -9649,6 +9761,13 @@ static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
 
 		cur_bytes = min(num_bytes, 256ULL * 1024 * 1024);
 		cur_bytes = max(cur_bytes, min_size);
+		/*
+		 * If we are severely fragmented we could end up with really
+		 * small allocations, so if the allocator is returning small
+		 * chunks lets make its job easier by only searching for those
+		 * sized chunks.
+		 */
+		cur_bytes = min(cur_bytes, last_alloc);
 		ret = btrfs_reserve_extent(root, cur_bytes, min_size, 0,
 					   *alloc_hint, &ins, 1, 0);
 		if (ret) {
@@ -9657,6 +9776,7 @@ static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
 			break;
 		}
 
+		last_alloc = ins.offset;
 		ret = insert_reserved_file_extent(trans, inode,
 						  cur_offset, ins.objectid,
 						  ins.offset, ins.offset,