aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorGravatar Lars Hjemli <hjemli@gmail.com>2006-12-12 06:53:50 (JST)
committerGravatar Lars Hjemli <hjemli@gmail.com>2006-12-12 06:53:50 (JST)
commitfbaf1171b4e343929dd43ecac7cd9d1c692b84ec (patch)
tree40b7007b2e1e85f2e91e052b33555df2e9fb5e14
parent44923f8953c66dc9b852316b655ab3b5aec9478e (diff)
downloadcgit-fbaf1171b4e343929dd43ecac7cd9d1c692b84ec.zip
cgit-fbaf1171b4e343929dd43ecac7cd9d1c692b84ec.tar.gz
Don't truncate valid cachefiles
An embarrassing thinko in cgit_check_cache() would truncate valid cachefiles in the following situation: 1) process A notices a missing/expired cachefile 2) process B gets scheduled, locks, fills and unlocks the cachefile 3) process A gets scheduled, locks the cachefile, notices that the cachefile now exist/is not expired anymore, and continues to overwrite it with an empty lockfile. Thanks to Linus for noticing (again). Signed-off-by: Lars Hjemli <hjemli@gmail.com>
-rw-r--r--cache.c5
-rw-r--r--cgit.c14
-rw-r--r--cgit.h1
3 files changed, 16 insertions, 4 deletions
diff --git a/cache.c b/cache.c
index 2e1ef8c..b947a34 100644
--- a/cache.c
+++ b/cache.c
@@ -99,6 +99,11 @@ int cache_unlock(struct cacheitem *item)
99 return (rename(fmt("%s.lock", item->name), item->name) == 0); 99 return (rename(fmt("%s.lock", item->name), item->name) == 0);
100} 100}
101 101
102int cache_cancel_lock(struct cacheitem *item)
103{
104 return (unlink(fmt("%s.lock", item->name)) == 0);
105}
106
102int cache_expired(struct cacheitem *item) 107int cache_expired(struct cacheitem *item)
103{ 108{
104 if (item->ttl < 0) 109 if (item->ttl < 0)
diff --git a/cgit.c b/cgit.c
index d1abaa0..0f72f2d 100644
--- a/cgit.c
+++ b/cgit.c
@@ -61,13 +61,19 @@ static void cgit_check_cache(struct cacheitem *item)
61 sleep(1); 61 sleep(1);
62 goto top; 62 goto top;
63 } 63 }
64 if (!cache_exist(item)) 64 if (!cache_exist(item)) {
65 cgit_fill_cache(item); 65 cgit_fill_cache(item);
66 cache_unlock(item); 66 cache_unlock(item);
67 } else {
68 cache_cancel_lock(item);
69 }
67 } else if (cache_expired(item) && cache_lock(item)) { 70 } else if (cache_expired(item) && cache_lock(item)) {
68 if (cache_expired(item)) 71 if (cache_expired(item)) {
69 cgit_fill_cache(item); 72 cgit_fill_cache(item);
70 cache_unlock(item); 73 cache_unlock(item);
74 } else {
75 cache_cancel_lock(item);
76 }
71 } 77 }
72} 78}
73 79
diff --git a/cgit.h b/cgit.h
index c1dcc97..c9554a7 100644
--- a/cgit.h
+++ b/cgit.h
@@ -66,6 +66,7 @@ extern int cgit_parse_query(char *txt, configfn fn);
66extern void cache_prepare(struct cacheitem *item); 66extern void cache_prepare(struct cacheitem *item);
67extern int cache_lock(struct cacheitem *item); 67extern int cache_lock(struct cacheitem *item);
68extern int cache_unlock(struct cacheitem *item); 68extern int cache_unlock(struct cacheitem *item);
69extern int cache_cancel_lock(struct cacheitem *item);
69extern int cache_exist(struct cacheitem *item); 70extern int cache_exist(struct cacheitem *item);
70extern int cache_expired(struct cacheitem *item); 71extern int cache_expired(struct cacheitem *item);
71 72