Ronnie Sahlberg[PATCH v8 00/44] Use ref transactions for all ref updates
This patch series can also be found at https://github.com/rsahlberg/git/tree/ref-transactions
This patch series is based on next and expands on the transaction API. It converts all ref updates, inside refs.c as well as external, to use the transaction API for updates. This makes most of the ref updates to become atomic when there are failures locking or writing to a ref.
This version completes the work to convert all ref updates to use transactions. Now that all updates are through transactions I will start working on cleaning up the reading of refs and to create an api for managing reflogs but all that will go in a different patch series.
Version 8: - Updates after review by JN - Improve commit messages - Add a patch that adds an err argument to repack_without_refs - Add a patch that adds an err argument to delete_loose_ref - Better document that a _update/_delete/_create failure means the whole transaction has failed and needs rollback.
Version 7: - Updated commit messages per JNs review comments. - Changed REF_ISPRUNING and REF_ISPACKONLY to be private flags and not exposed through refs.h
Version 6: - Convert all updates in refs.c to use transactions too.
Version 5: - Reword commit messages for having _create/_delete/_update returning success/failure. There are no conditions yet that return an error from these failures but there will be in the future. So we still check the return from these functions in the callers in preparation for this. - Don't leak memory by just passing a strbuf_detach() pointer to functions. Use <obj>.buf and explicitely strbuf_release the data afterwards. - Remove the function update_ref_lock. - Remove the function update_ref_write. - Track transaction status and die(BUG:) if we call _create/_delete/_update/ _commit for a transaction that is not OPEN.
Version 4: - Rename patch series from "Use ref transactions from most callers" to "Use ref transactions for all ref updates". - Convert all external ref writes to use transactions and make write_ref_sha1 and lock_ref_sha1 static functions. - Change the ref commit and free handling so we no longer pass pointer to pointer to _commit. _commit no longer frees the transaction. The caller MUST call _free itself. - Change _commit to take a strbuf pointer instead of a char* for error reporting back to the caller. - Re-add the walker patch after fixing it.
Version 3: - Remove the walker patch for now. Walker needs more complex solution so defer it until the basics are done. - Remove the onerr argument to ref_transaction_commit(). All callers that need to die() on error now have to do this explicitely. - Pass an error string from ref_transaction_commit() back to the callers so that they can craft a nice error message upon failures. - Make ref_transaction_rollback() accept NULL as argument. - Change ref_transaction_commit() to take a pointer to pointer argument for the transaction and have it clear the callers pointer to NULL when invoked. This allows for much nicer handling of transaction rollback on failure. Version 2: - Add a patch to ref_transaction_commit to make it honor onerr even if the error triggered in ref_Transaction_commit itself rather than in a call to other functions (that already honor onerr). - Add a patch to make the update_ref() helper function use transactions internally. - Change ref_transaction_update to die() instead of error() if we pass if a NULL old_sha1 but have have_old == true. - Change ref_transaction_create to die() instead of error() if new_sha1 is false but we pass it a null_sha1. - Change ref_transaction_delete die() instead of error() if we pass if a NULL old_sha1 but have have_old == true. - Change several places to do if(!transaction || ref_transaction_update() || ref_Transaction_commit()) die(generic-message) instead of checking each step separately and having a different message for each failure. Most users are likely not interested in what step of the transaction failed and only whether it failed or not. - Change commit.c to only pass a pointer to ref_transaction_update iff current_head is non-NULL. The previous patch used to compute a garbage pointer for current_head->object.sha1 and relied on the fact that ref_transaction_update would not try to dereference this pointer if !!current_head was 0. - Updated commit message for the walker_fetch change to try to justify why the change in locking semantics should not be harmful.
Ronnie Sahlberg (44):
refs.c: constify the sha arguments for
ref_transaction_create|delete|update
refs.c: allow passing NULL to ref_transaction_free
refs.c: add a strbuf argument to ref_transaction_commit for error
logging
refs.c: add an err argument to repack_without_refs
refs.c: make ref_update_reject_duplicates take a strbuf argument for
errors
refs.c: add an err argument ro delete_loose_ref
refs.c: make update_ref_write update a strbuf on failure
update-ref.c: log transaction error from the update_ref
refs.c: remove the onerr argument to ref_transaction_commit
refs.c: change ref_transaction_update() to do error checking and
return status
refs.c: change ref_transaction_create to do error checking and return
status
refs.c: ref_transaction_delete to check for error and return status
tag.c: use ref transactions when doing updates
replace.c: use the ref transaction functions for updates
commit.c: use ref transactions for updates
sequencer.c: use ref transactions for all ref updates
fast-import.c: change update_branch to use ref transactions
branch.c: use ref transaction for all ref updates
refs.c: change update_ref to use a transaction
refs.c: free the transaction before returning when number of updates
is 0
refs.c: ref_transaction_commit should not free the transaction
fetch.c: clear errno before calling functions that might set it
fetch.c: change s_update_ref to use a ref transaction
fetch.c: use a single ref transaction for all ref updates
receive-pack.c: use a reference transaction for updating the refs
fast-import.c: use a ref transaction when dumping tags
walker.c: use ref transaction for ref updates
refs.c: make write_ref_sha1 static
refs.c: make lock_ref_sha1 static
refs.c: add transaction.status and track OPEN/CLOSED/ERROR
refs.c: remove the update_ref_lock function
refs.c: remove the update_ref_write function
refs.c: remove lock_ref_sha1
refs.c: make prune_ref use a transaction to delete the ref
refs.c: make delete_ref use a transaction
refs.c: pass the ref log message to _create/delete/update instead of
_commit
refs.c: pass NULL as *flags to read_ref_full
refs.c: pack all refs before we start to rename a ref
refs.c: move the check for valid refname to lock_ref_sha1_basic
refs.c: call lock_ref_sha1_basic directly from commit
refs.c: add a new flag for transaction delete for refs we know are
packed only
refs.c: pass a skip list to name_conflict_fn
refs.c: make rename_ref use a transaction
refs.c: remove forward declaration of write_ref_sha1branch.c | 31 ++-- builtin/commit.c | 24 ++- builtin/fetch.c | 29 ++-- builtin/receive-pack.c | 20 +-- builtin/replace.c | 15 +- builtin/tag.c | 15 +- builtin/update-ref.c | 32 ++-- fast-import.c | 39 +++-- refs.c | 443 ++++++++++++++++++++++++++++--------------------- refs.h | 54 +++--- sequencer.c | 24 ++- t/t3200-branch.sh | 2 +- walker.c | 51 +++--- 13 files changed, 449 insertions(+), 330 deletions(-)
-- 2.0.0.rc3.477.g0f8edf7
