From 0d723081798deacf6a6e71a9a2cc1a6bd740f96b Mon Sep 17 00:00:00 2001 From: Jeff Mahoney Date: Wed, 8 Jun 2016 00:36:38 -0400 Subject: [PATCH] btrfs: account for non-CoW'd blocks in btrfs_abort_transaction Orabug: 25308019 [ Upstream commit 64c12921e11b3a0c10d088606e328c58e29274d8 ] The test for !trans->blocks_used in btrfs_abort_transaction is insufficient to determine whether it's safe to drop the transaction handle on the floor. btrfs_cow_block, informed by should_cow_block, can return blocks that have already been CoW'd in the current transaction. trans->blocks_used is only incremented for new block allocations. If an operation overlaps the blocks in the current transaction entirely and must abort the transaction, we'll happily let it clean up the trans handle even though it may have modified the blocks and will commit an incomplete operation. In the long-term, I'd like to do closer tracking of when the fs is actually modified so we can still recover as gracefully as possible, but that approach will need some discussion. In the short term, since this is the only code using trans->blocks_used, let's just switch it to a bool indicating whether any blocks were used and set it when should_cow_block returns false. Cc: stable@vger.kernel.org # 3.4+ Signed-off-by: Jeff Mahoney Reviewed-by: Filipe Manana Signed-off-by: David Sterba Signed-off-by: Sasha Levin (cherry picked from commit efe098c364208b0d1fcc1b252290df0fd225d352) Signed-off-by: Dhaval Giani --- fs/btrfs/ctree.c | 5 ++++- fs/btrfs/extent-tree.c | 2 +- fs/btrfs/super.c | 2 +- fs/btrfs/transaction.c | 1 - fs/btrfs/transaction.h | 2 +- 5 files changed, 7 insertions(+), 5 deletions(-) diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index 0f11ebc92f02..844c883a7169 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -1548,6 +1548,7 @@ noinline int btrfs_cow_block(struct btrfs_trans_handle *trans, trans->transid, root->fs_info->generation); if (!should_cow_block(trans, root, buf)) { + trans->dirty = true; *cow_ret = buf; return 0; } @@ -2767,8 +2768,10 @@ again: * then we don't want to set the path blocking, * so we test it here */ - if (!should_cow_block(trans, root, b)) + if (!should_cow_block(trans, root, b)) { + trans->dirty = true; goto cow_done; + } /* * must have write locks on this node and the diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index d1ae1322648a..2771bc32dbd9 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -7504,7 +7504,7 @@ btrfs_init_new_buffer(struct btrfs_trans_handle *trans, struct btrfs_root *root, set_extent_dirty(&trans->transaction->dirty_pages, buf->start, buf->start + buf->len - 1, GFP_NOFS); } - trans->blocks_used++; + trans->dirty = true; /* this returns a buffer locked for blocking */ return buf; } diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index 70734d89193a..a40b454aea44 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -262,7 +262,7 @@ void __btrfs_abort_transaction(struct btrfs_trans_handle *trans, trans->aborted = errno; /* Nothing used. The other threads that have joined this * transaction may be able to continue. */ - if (!trans->blocks_used && list_empty(&trans->new_bgs)) { + if (!trans->dirty && list_empty(&trans->new_bgs)) { const char *errstr; errstr = btrfs_decode_error(errno); diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index 00d18c2bdb0f..6d43b2ab183b 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -507,7 +507,6 @@ again: h->transid = cur_trans->transid; h->transaction = cur_trans; - h->blocks_used = 0; h->bytes_reserved = 0; h->root = root; h->delayed_ref_updates = 0; diff --git a/fs/btrfs/transaction.h b/fs/btrfs/transaction.h index 0b24755596ba..4ce102be6d6b 100644 --- a/fs/btrfs/transaction.h +++ b/fs/btrfs/transaction.h @@ -105,7 +105,6 @@ struct btrfs_trans_handle { u64 qgroup_reserved; unsigned long use_count; unsigned long blocks_reserved; - unsigned long blocks_used; unsigned long delayed_ref_updates; struct btrfs_transaction *transaction; struct btrfs_block_rsv *block_rsv; @@ -115,6 +114,7 @@ struct btrfs_trans_handle { bool allocating_chunk; bool reloc_reserved; bool sync; + bool dirty; unsigned int type; /* * this root is only needed to validate that the root passed to -- 2.50.1