From: Junio C Hamano <gitster@pobox.com>
Date: Wed, 25 Jun 2014 18:49:48 +0000 (-0700)
Subject: Merge branch 'ym/fix-opportunistic-index-update-race' into maint
X-Git-Tag: v2.0.1~3
X-Git-Url: https://git.lorimer.id.au/gitweb.git/diff_plain/1881d2b88c4b889dcb95782ad4bc5395808438e9

Merge branch 'ym/fix-opportunistic-index-update-race' into maint

"git status", even though it is a read-only operation, tries to
update the index with refreshed lstat(2) info to optimize future
accesses to the working tree opportunistically, but this could
race with a "read-write" operation that modify the index while it
is running.  Detect such a race and avoid overwriting the index.

* ym/fix-opportunistic-index-update-race:
read-cache.c: verify index file before we opportunistically update it
wrapper.c: add xpread() similar to xread()
---

1881d2b88c4b889dcb95782ad4bc5395808438e9
diff --cc builtin/index-pack.c
index 54b089542b,e7a6b537b4..18f57de58b
--- a/builtin/index-pack.c
+++ b/builtin/index-pack.c
@@@ -554,7 -542,7 +554,7 @@@ static void *unpack_data(struct object_
  
  	do {
  		ssize_t n = (len < 64*1024) ? len : 64*1024;
- 		n = pread(get_thread_data()->pack_fd, inbuf, n, from);
 -		n = xpread(pack_fd, inbuf, n, from);
++		n = xpread(get_thread_data()->pack_fd, inbuf, n, from);
  		if (n < 0)
  			die_errno(_("cannot pread pack file"));
  		if (!n)
diff --cc cache.h
index 107ac61b68,9244c387c3..cc46be4e0f
--- a/cache.h
+++ b/cache.h
@@@ -277,8 -277,9 +277,9 @@@ struct index_state 
  	struct cache_time timestamp;
  	unsigned name_hash_initialized : 1,
  		 initialized : 1;
 -	struct hash_table name_hash;
 -	struct hash_table dir_hash;
 +	struct hashmap name_hash;
 +	struct hashmap dir_hash;
+ 	unsigned char sha1[20];
  };
  
  extern struct index_state the_index;