git/refs, branch v2.22.2

Merge branch 'jk/refs-double-abort'

2019-04-16T10:28:11Z

A corner case bug in the refs API has been corrected. * jk/refs-double-abort: refs/files-backend: don't look at an aborted transaction refs/files-backend: handle packed transaction prepare failure

Merge branch 'nd/rewritten-ref-is-per-worktree'

2019-04-09T17:14:23Z

"git rebase" uses the refs/rewritten/ hierarchy to store its intermediate states, which inherently makes the hierarchy per worktree, but it didn't quite work well. * nd/rewritten-ref-is-per-worktree: Make sure refs/rewritten/ is per-worktree files-backend.c: reduce duplication in add_per_worktree_entries_to_dir() files-backend.c: factor out per-worktree code in loose_fill_ref_dir()

refs/files-backend: don't look at an aborted transaction

2019-03-22T06:52:54Z

When deleting refs, we hold packed-refs.lock and prepare a packed transaction to drop the refs from the packed-refs file. If it turns out that we don't need to rewrite the packed refs (e.g., because none of the deletions were present in the file), then we abort the transaction. If that abort succeeds, then the transaction struct will have been freed, and we set our local pointer to NULL so we don't look at it again. However, if it fails, then the struct will _still_ have been freed (because ref_transaction_abort() always frees). But we don't clean up the pointer, and will jump to our cleanup code, which will try to abort it again, causing a use-after-free. It's actually impossible for this to trigger in practice, since packed_transaction_abort() will never return anything but success. But let's fix it anyway, since that's more than we should assume about the packed-refs code (after all, we are already bothering to check for an error result which cannot be triggered). Signed-off-by: Jeff King Signed-off-by: Junio C Hamano

refs/files-backend: handle packed transaction prepare failure

2019-03-22T06:52:49Z

In files_transaction_prepare(), if we have to delete some refs, we use a subordinate packed_transaction to do so. It's rare for that sub-transaction's prepare step to fail, since we hold the packed-refs lock. But if it does, we trigger a BUG() due to these steps: - we've attached the packed transaction to the files transaction as backend_data->packed_transaction - when the prepare step fails, the packed transaction cleans itself up, putting itself into the CLOSED state - the error value from preparing the packed transaction lets us know in files_transaction_prepare() that we should also clean up and return an error. We call files_transaction_cleanup(), which tries to abort backend_data->packed_transaction. Since it's already CLOSED, that triggers an assertion in ref_transaction_abort(). We can fix that by disconnecting the packed transaction from the outer files transaction, and then free-ing (not aborting!) it ourselves. A few other options/alternatives I considered: - we could just make it a noop to abort a CLOSED transaction. But that seems less safe, since clearly this code expects (and enforces) a particular set of state transitions. - we could have files_transaction_cleanup() selectively call abort() vs free() based on the state of the on the packed transaction. That's basically a more restricted version of the above, but also potentially unsafe. - instead of disconnecting backend_data->packed_transaction on error, we could wait to install it until we successfully prepare. That might make the flow a little simpler, but it introduces a hassle. Earlier parts of files_transaction_prepare() that encounter an error will jump to the cleanup label, and expect that cleaning up the outer transaction will clean up the packed transaction, too. We'd have to adjust those sites to clean up the packed transaction. Signed-off-by: Jeff King Signed-off-by: Junio C Hamano

Make sure refs/rewritten/ is per-worktree

2019-03-08T02:57:47Z

a9be29c981 (sequencer: make refs generated by the `label` command worktree-local, 2018-04-25) adds refs/rewritten/ as per-worktree reference space. Unfortunately (my bad) there are a couple places that need update to make sure it's really per-worktree. - add_per_worktree_entries_to_dir() is updated to make sure ref listing look at per-worktree refs/rewritten/ instead of per-repo one [1] - common_list[] is updated so that git_path() returns the correct location. This includes "rev-parse --git-path". This mess is created by me. I started trying to fix it with the introduction of refs/worktree, where all refs will be per-worktree without special treatments. Unfortunate refs/rewritten came before refs/worktree so this is all we can do. This also fixes logs/refs/worktree not being per-worktree. [1] note that ref listing still works sometimes. For example, if you have .git/worktrees/foo/refs/rewritten/bar AND the directory .git/worktrees/refs/rewritten, refs/rewritten/bar will show up. add_per_worktree_entries_to_dir() is only needed when the directory .git/worktrees/refs/rewritten is missing. Reported-by: Phillip Wood Signed-off-by: Nguyễn Thái Ngọc Duy Signed-off-by: Junio C Hamano

files-backend.c: reduce duplication in add_per_worktree_entries_to_dir()

2019-03-08T02:57:47Z

This function is duplicated to handle refs/bisect/ and refs/worktree/ and a third prefix is coming. Time to clean up. This also fixes incorrect "refs/worktrees/" length in this code. The correct length is 14 not 11. The test in the next patch will also cover this. Signed-off-by: Nguyễn Thái Ngọc Duy Signed-off-by: Junio C Hamano

files-backend.c: factor out per-worktree code in loose_fill_ref_dir()

2019-03-08T02:57:47Z

This is the first step for further cleaning up and extending this function. Signed-off-by: Nguyễn Thái Ngọc Duy Signed-off-by: Junio C Hamano

files-backend: drop refs parameter from split_symref_update()

2019-02-14T23:26:15Z

This parameter was added in fcc42ea0c9 (split_symref_update(): add a files_ref_store argument, 2016-09-04) without comment, but never used. The splitting is purely mechanical, and doesn't depend on the particular ref-store. Let's drop this parameter in the name of simplicity. Signed-off-by: Jeff King Signed-off-by: Junio C Hamano

Merge branch 'nd/per-worktree-ref-iteration'

2018-11-26T14:13:43Z

Build fix. * nd/per-worktree-ref-iteration: files-backend.c: fix build error on Solaris

files-backend.c: fix build error on Solaris

2018-11-26T06:22:58Z

This function files_reflog_path returns void, which usually means "return;" not returning "void value" from another function. Reported-by: Ævar Arnfjörð Bjarmason Signed-off-by: Nguyễn Thái Ngọc Duy Signed-off-by: Junio C Hamano