Btrfs: fix some ENOSPC problems

Commit Message

Josef Bacik Oct. 6, 2010, 7:56 p.m. UTC

None

Patch

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 5343e56..439e290 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -3433,35 +3433,46 @@  static int should_retry_reserve(struct btrfs_trans_handle *trans,
 	return 1;
 }
 
+/*
+ * Retries tells us how many times we've called reserve_metadata_bytes.  The
+ * idea is if this is the first call (retries == 0) then we will add to our
+ * reserved count if we can't make the allocation in order to hold our place
+ * while we go and try and free up space.  That way for retries > 1 we don't try
+ * and add space, we just check to see if the amount of unused space is >= the
+ * total space, meaning that our reservation is valid.
+ *
+ * However if we don't intend to retry this reservation, pass -1 as retries so
+ * that it short circuits this logic.
+ */
 static int reserve_metadata_bytes(struct btrfs_block_rsv *block_rsv,
-				  u64 num_bytes)
+				  u64 num_bytes, int retries)
 {
 	struct btrfs_space_info *space_info = block_rsv->space_info;
 	u64 unused;
 	int ret = -ENOSPC;
 
+	if (retries > 0)
+		num_bytes = 0;
+
 	spin_lock(&space_info->lock);
 	unused = space_info->bytes_used + space_info->bytes_reserved +
-		 space_info->bytes_pinned + space_info->bytes_readonly;
+		 space_info->bytes_pinned + space_info->bytes_readonly +
+		 space_info->bytes_may_use;
 
-	if (unused < space_info->total_bytes)
+	if (unused <= space_info->total_bytes)
 		unused = space_info->total_bytes - unused;
 	else
-		unused = 0;
+		unused = -1;
 
 	if (unused >= num_bytes) {
-		if (block_rsv->priority >= 10) {
+		if (retries <= 0)
 			space_info->bytes_reserved += num_bytes;
-			ret = 0;
-		} else {
-			if ((unused + block_rsv->reserved) *
-			    block_rsv->priority >=
-			    (num_bytes + block_rsv->reserved) * 10) {
-				space_info->bytes_reserved += num_bytes;
-				ret = 0;
-			}
-		}
+		ret = 0;
+	} else if (retries == 0) {
+		space_info->bytes_reserved += num_bytes;
+		ret = -EAGAIN;
 	}
+
 	spin_unlock(&space_info->lock);
 
 	return ret;
@@ -3613,7 +3624,7 @@  int btrfs_block_rsv_add(struct btrfs_trans_handle *trans,
 	if (num_bytes == 0)
 		return 0;
 again:
-	ret = reserve_metadata_bytes(block_rsv, num_bytes);
+	ret = reserve_metadata_bytes(block_rsv, num_bytes, *retries);
 	if (!ret) {
 		block_rsv_add_bytes(block_rsv, num_bytes, 1);
 		return 0;
@@ -3623,6 +3634,10 @@  again:
 	if (ret > 0)
 		goto again;
 
+	spin_lock(&block_rsv->space_info->lock);
+	block_rsv->space_info->bytes_reserved -= num_bytes;
+	spin_unlock(&block_rsv->space_info->lock);
+
 	return ret;
 }
 
@@ -3657,7 +3672,7 @@  int btrfs_block_rsv_check(struct btrfs_trans_handle *trans,
 		return 0;
 
 	if (block_rsv->refill_used) {
-		ret = reserve_metadata_bytes(block_rsv, num_bytes);
+		ret = reserve_metadata_bytes(block_rsv, num_bytes, -1);
 		if (!ret) {
 			block_rsv_add_bytes(block_rsv, num_bytes, 0);
 			return 0;
@@ -3736,6 +3751,8 @@  static u64 calc_global_metadata_size(struct btrfs_fs_info *fs_info)
 
 	sinfo = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA);
 	spin_lock(&sinfo->lock);
+	if (sinfo->flags & BTRFS_BLOCK_GROUP_DATA)
+		data_used = 0;
 	meta_used = sinfo->bytes_used;
 	spin_unlock(&sinfo->lock);
 
@@ -3763,7 +3780,8 @@  static void update_global_block_rsv(struct btrfs_fs_info *fs_info)
 	block_rsv->size = num_bytes;
 
 	num_bytes = sinfo->bytes_used + sinfo->bytes_pinned +
-		    sinfo->bytes_reserved + sinfo->bytes_readonly;
+		    sinfo->bytes_reserved + sinfo->bytes_readonly +
+		    sinfo->bytes_may_use;
 
 	if (sinfo->total_bytes > num_bytes) {
 		num_bytes = sinfo->total_bytes - num_bytes;
@@ -3937,13 +3955,16 @@  again:
 	}
 
 	to_reserve += calc_csum_metadata_size(inode, num_bytes);
-	ret = reserve_metadata_bytes(block_rsv, to_reserve);
+	ret = reserve_metadata_bytes(block_rsv, to_reserve, retries);
 	if (ret) {
 		spin_unlock(&BTRFS_I(inode)->accounting_lock);
 		ret = should_retry_reserve(NULL, root, block_rsv, to_reserve,
 					   &retries);
 		if (ret > 0)
 			goto again;
+		spin_lock(&block_rsv->space_info->lock);
+		block_rsv->space_info->bytes_reserved -= to_reserve;
+		spin_unlock(&block_rsv->space_info->lock);
 		return ret;
 	}
 
@@ -5575,7 +5596,7 @@  use_block_rsv(struct btrfs_trans_handle *trans,
 	block_rsv = get_block_rsv(trans, root);
 
 	if (block_rsv->size == 0) {
-		ret = reserve_metadata_bytes(block_rsv, blocksize);
+		ret = reserve_metadata_bytes(block_rsv, blocksize, -1);
 		if (ret)
 			return ERR_PTR(ret);
 		return block_rsv;