From: Michael Haggerty <mhagger@alum.mit.edu>
To: Junio C Hamano <gitster@pobox.com>
Cc: Jeff King <peff@peff.net>, Johan Herland <johan@herland.net>,
Ramsay Jones <ramsay@ramsay1.demon.co.uk>,
git@vger.kernel.org, Michael Haggerty <mhagger@alum.mit.edu>
Subject: [PATCH v3 07/12] packed_ref_cache: increment refcount when locked
Date: Thu, 20 Jun 2013 10:37:49 +0200 [thread overview]
Message-ID: <1371717474-28942-8-git-send-email-mhagger@alum.mit.edu> (raw)
In-Reply-To: <1371717474-28942-1-git-send-email-mhagger@alum.mit.edu>
Increment the packed_ref_cache reference count while it is locked to
prevent its being freed.
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
---
refs.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/refs.c b/refs.c
index f33d224..a5a5b5d 100644
--- a/refs.c
+++ b/refs.c
@@ -820,7 +820,9 @@ struct packed_ref_cache {
/*
* Iff the packed-refs file associated with this instance is
* currently locked for writing, this points at the associated
- * lock (which is owned by somebody else).
+ * lock (which is owned by somebody else). The referrer count
+ * is also incremented when the file is locked and decremented
+ * when it is unlocked.
*/
struct lock_file *lock;
};
@@ -2099,6 +2101,8 @@ int lock_packed_refs(int flags)
/* Read the current packed-refs while holding the lock: */
packed_ref_cache = get_packed_ref_cache(&ref_cache);
packed_ref_cache->lock = &packlock;
+ /* Increment the reference count to prevent it from being freed: */
+ acquire_packed_ref_cache(packed_ref_cache);
return 0;
}
@@ -2119,6 +2123,7 @@ int commit_packed_refs(void)
if (commit_lock_file(packed_ref_cache->lock))
error = -1;
packed_ref_cache->lock = NULL;
+ release_packed_ref_cache(packed_ref_cache);
return error;
}
@@ -2131,6 +2136,7 @@ void rollback_packed_refs(void)
die("internal error: packed-refs not locked");
rollback_lock_file(packed_ref_cache->lock);
packed_ref_cache->lock = NULL;
+ release_packed_ref_cache(packed_ref_cache);
clear_packed_ref_cache(&ref_cache);
}
--
1.8.3.1
next prev parent reply other threads:[~2013-06-20 8:39 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-06-20 8:37 [PATCH v3 00/12] Fix some reference-related races Michael Haggerty
2013-06-20 8:37 ` [PATCH v3 01/12] repack_without_ref(): split list curation and entry writing Michael Haggerty
2013-06-20 8:37 ` [PATCH v3 02/12] pack_refs(): split creation of packed refs " Michael Haggerty
2013-06-20 8:37 ` [PATCH v3 03/12] refs: wrap the packed refs cache in a level of indirection Michael Haggerty
2013-06-20 8:37 ` [PATCH v3 04/12] refs: implement simple transactions for the packed-refs file Michael Haggerty
2013-06-20 8:37 ` [PATCH v3 05/12] refs: manage lifetime of packed refs cache via reference counting Michael Haggerty
2013-06-20 8:37 ` [PATCH v3 06/12] do_for_each_entry(): increment the packed refs cache refcount Michael Haggerty
2013-06-20 8:37 ` Michael Haggerty [this message]
2013-06-20 8:37 ` [PATCH v3 08/12] Extract a struct stat_data from cache_entry Michael Haggerty
2013-06-20 8:37 ` [PATCH v3 09/12] add a stat_validity struct Michael Haggerty
2013-06-20 8:37 ` [PATCH v3 10/12] get_packed_ref_cache: reload packed-refs file when it changes Michael Haggerty
2013-06-20 8:37 ` [PATCH v3 11/12] for_each_ref: load all loose refs before packed refs Michael Haggerty
2013-06-20 8:37 ` [PATCH v3 12/12] refs: do not invalidate the packed-refs cache unnecessarily Michael Haggerty
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