6.5-stable review patch. If anyone has any objections, please let me know.
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From: Filipe Manana fdmanana@suse.com
commit 4490e803e1fe9fab8db5025e44e23b55df54078b upstream.
When joining a transaction with TRANS_JOIN_NOSTART, if we don't find a running transaction we end up creating one. This goes against the purpose of TRANS_JOIN_NOSTART which is to join a running transaction if its state is at or below the state TRANS_STATE_COMMIT_START, otherwise return an -ENOENT error and don't start a new transaction. So fix this to not create a new transaction if there's no running transaction at or below that state.
CC: stable@vger.kernel.org # 4.14+ Fixes: a6d155d2e363 ("Btrfs: fix deadlock between fiemap and transaction commits") Signed-off-by: Filipe Manana fdmanana@suse.com Signed-off-by: David Sterba dsterba@suse.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/btrfs/transaction.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)
--- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -292,10 +292,11 @@ loop: spin_unlock(&fs_info->trans_lock);
/* - * If we are ATTACH, we just want to catch the current transaction, - * and commit it. If there is no transaction, just return ENOENT. + * If we are ATTACH or TRANS_JOIN_NOSTART, we just want to catch the + * current transaction, and commit it. If there is no transaction, just + * return ENOENT. */ - if (type == TRANS_ATTACH) + if (type == TRANS_ATTACH || type == TRANS_JOIN_NOSTART) return -ENOENT;
/*