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Re: [PATCH v2 28/29] repack_without_refs(): don't lock or unlock the packed refs

From
Michael Haggerty <mhagger@alum.mit.edu>
Date
Jul 1, 2017, 17:11 UTC
Message-ID
<71e58288-483b-3cfb-00db-523a28c78549@alum.mit.edu>
In-Reply-To
<20170623195600.cvn26gt7o5rtywy6@sigill.intra.peff.net>
On 06/23/2017 09:56 PM, Jeff King wrote:
Show 11 quoted lines
> On Fri, Jun 23, 2017 at 09:01:46AM +0200, Michael Haggerty wrote:
> 
>> Change `repack_without_refs()` to expect the packed-refs lock to be
>> held already, and not to release the lock before returning. Change the
>> callers to deal with lock management.
>>
>> This change makes it possible for callers to hold the packed-refs lock
>> for a longer span of time, a possibility that will eventually make it
>> possible to fix some longstanding races.
> 
> This is the sort of clue I was thinking about in my last email. :)
I'll try to be better about that in the future.

And the reason to make `packed_ref_store` fulfill the `ref_store` interface is mostly indirect at the moment. It was important (to my sanity, if nothing else) to simplify the interface to the packed-refs code before rewriting its innards. Since the `ref_store` interface is familiar and is fairly close to what is needed, it seemed logical to use it.

Show 5 quoted lines
>> The only semantic change here is that `repack_without_refs()` used to
>> forgot to release the lock in the `if (!removed)` exit path. That
>> omission is now fixed.
> 
> s/used to forgot/previously forgot/ or similar?
Thanks; will fix.
Michael
Previous: Jeff KingNext: Michael Haggerty
Message 36 of 52 in “Create a reference backend for packed refs”
  1. 00/29 Create a reference backend for packed refsMichael Haggerty, Jun 23, 2017
  2. 01/29 t1408: add a test of stale packed refs covered by loose refsMichael Haggerty, Jun 23, 2017
  3. Jeff KingJun 23, 2017
  4. Junio C HamanoJun 23, 2017
  5. 02/29 add_packed_ref(): teach function to overwrite existing refsMichael Haggerty, Jun 23, 2017
  6. 07/29 validate_packed_ref_cache(): take a `packed_ref_store *` parameterMichael Haggerty, Jun 23, 2017
  7. 05/29 packed_ref_store: move `packed_refs_lock` member hereMichael Haggerty, Jun 23, 2017
  8. 03/29 packed_ref_store: new structMichael Haggerty, Jun 23, 2017
  9. 09/29 get_packed_refs(): take a `packed_ref_store *` parameterMichael Haggerty, Jun 23, 2017
  10. 04/29 packed_ref_store: move `packed_refs_path` hereMichael Haggerty, Jun 23, 2017
  11. 13/29 rollback_packed_refs(): take a `packed_ref_store *` parameterMichael Haggerty, Jun 23, 2017
  12. 12/29 commit_packed_refs(): take a `packed_ref_store *` parameterMichael Haggerty, Jun 23, 2017
  13. 14/29 get_packed_ref(): take a `packed_ref_store *` parameterMichael Haggerty, Jun 23, 2017
  14. 06/29 clear_packed_ref_cache(): take a `packed_ref_store *` parameterMichael Haggerty, Jun 23, 2017
  15. 17/29 packed_ref_store: support iterationMichael Haggerty, Jun 23, 2017
  16. Jeff KingJun 23, 2017
  17. 16/29 packed_peel_ref(): new function, extracted from `files_peel_ref()`Michael Haggerty, Jun 23, 2017
  18. 19/29 packed-backend: new module for handling packed referencesMichael Haggerty, Jun 23, 2017
  19. Jeff KingJun 23, 2017
  20. Stefan BellerJun 23, 2017
  21. Junio C HamanoJun 23, 2017
  22. 20/29 packed_ref_store: make class into a subclass of `ref_store`Michael Haggerty, Jun 23, 2017
  23. Jeff KingJun 23, 2017
  24. 21/29 commit_packed_refs(): report errors rather than dyingMichael Haggerty, Jun 23, 2017
  25. 22/29 commit_packed_refs(): use a staging file separate from the lockfileMichael Haggerty, Jun 23, 2017
  26. Jeff KingJun 23, 2017
  27. Michael HaggertyJun 24, 2017
  28. Jeff KingJun 24, 2017
  29. 24/29 packed_refs_lock(): report errors via a `struct strbuf *err`Michael Haggerty, Jun 23, 2017
  30. 26/29 clear_packed_ref_cache(): don't protest if the lock is heldMichael Haggerty, Jun 23, 2017
  31. Jeff KingJun 23, 2017
  32. 25/29 packed_refs_unlock(), packed_refs_is_locked(): new functionsMichael Haggerty, Jun 23, 2017
  33. 23/29 packed_refs_lock(): function renamed from lock_packed_refs()Michael Haggerty, Jun 23, 2017
  34. 28/29 repack_without_refs(): don't lock or unlock the packed refsMichael Haggerty, Jun 23, 2017
  35. Jeff KingJun 23, 2017
  36. Michael HaggertyJul 1, 2017
  37. 27/29 commit_packed_refs(): remove call to `packed_refs_unlock()`Michael Haggerty, Jun 23, 2017
  38. Jeff KingJun 23, 2017
  39. 29/29 read_packed_refs(): die if `packed-refs` contains bogus dataMichael Haggerty, Jun 23, 2017
  40. Jeff KingJun 23, 2017
  41. Michael HaggertyJul 1, 2017
  42. 11/29 lock_packed_refs(): take a `packed_ref_store *` parameterMichael Haggerty, Jun 23, 2017
  43. 10/29 add_packed_ref(): take a `packed_ref_store *` parameterMichael Haggerty, Jun 23, 2017
  44. 15/29 repack_without_refs(): take a `packed_ref_store *` parameterMichael Haggerty, Jun 23, 2017
  45. 18/29 packed_read_raw_ref(): new function, replacing `resolve_packed_ref()`Michael Haggerty, Jun 23, 2017
  46. 08/29 get_packed_ref_cache(): take a `packed_ref_store *` parameterMichael Haggerty, Jun 23, 2017
  47. Jeff KingJun 23, 2017
  48. Jeff KingJun 23, 2017
  49. Junio C HamanoJun 23, 2017
  50. Jeff KingJun 24, 2017
  51. Michael HaggertyJun 24, 2017
  52. Junio C HamanoJun 23, 2017

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