From 0a16c7d7aecfae8987197e50116ebfc338cbe0a2 Mon Sep 17 00:00:00 2001 From: Omar Sandoval Date: Tue, 6 Jun 2017 16:45:29 -0700 Subject: [PATCH] Btrfs: always account pinned bytes when dropping a tree block ref MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Currently, we only increment total_bytes_pinned in btrfs_free_tree_block() when dropping the last reference on the block. However, when the delayed ref is run later, we will decrement total_bytes_pinned regardless of whether it was the last reference or not. This causes the counter to underflow when the reference we dropped was not the last reference. Fix it by incrementing the counter unconditionally, which is what btrfs_free_extent() does. This makes total_bytes_pinned an overestimate when references to shared extents are dropped, but in the worst case this will just make us try to commit the transaction to try to free up space and find we didn't free enough. Signed-off-by: Omar Sandoval Tested-by: Holger Hoffstätte Reviewed-by: Liu Bo Signed-off-by: David Sterba --- fs/btrfs/extent-tree.c | 17 ++++++++--------- 1 file changed, 8 insertions(+), 9 deletions(-) diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 152e04773767..40c80ed8d1f9 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -7193,10 +7193,7 @@ void btrfs_free_tree_block(struct btrfs_trans_handle *trans, BUG_ON(ret); /* -ENOMEM */ } - if (!last_ref) - return; - - if (btrfs_header_generation(buf) == trans->transid) { + if (last_ref && btrfs_header_generation(buf) == trans->transid) { struct btrfs_block_group_cache *cache; if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) { @@ -7227,11 +7224,13 @@ out: add_pinned_bytes(fs_info, buf->len, btrfs_header_level(buf), root->root_key.objectid); - /* - * Deleting the buffer, clear the corrupt flag since it doesn't matter - * anymore. - */ - clear_bit(EXTENT_BUFFER_CORRUPT, &buf->bflags); + if (last_ref) { + /* + * Deleting the buffer, clear the corrupt flag since it doesn't + * matter anymore. + */ + clear_bit(EXTENT_BUFFER_CORRUPT, &buf->bflags); + } } /* Can return -ENOMEM */ -- 2.11.0