318d106300
Add a global variable, cgit_max_lock_attemps, to avoid the possibility of infinite loops when failing to acquire a lockfile. This could happen on broken setups or under crazy server load. Incidentally, this also fixes a lurking bug in cache_lock() where an uninitialized returnvalue was used. Signed-off-by: Lars Hjemli <hjemli@gmail.com>
108 rader
2.3 KiB
C
108 rader
2.3 KiB
C
/* cache.c: cache management
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*
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* Copyright (C) 2006 Lars Hjemli
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*
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* Licensed under GNU General Public License v2
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* (see COPYING for full license text)
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*/
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#include "cgit.h"
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const int NOLOCK = -1;
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void cache_prepare(struct cacheitem *item)
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{
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if (!cgit_query_repo) {
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item->name = xstrdup(fmt("%s/index.html", cgit_cache_root));
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item->ttl = cgit_cache_root_ttl;
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} else if (!cgit_query_page) {
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item->name = xstrdup(fmt("%s/%s/index.html", cgit_cache_root,
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cgit_query_repo));
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item->ttl = cgit_cache_repo_ttl;
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} else {
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item->name = xstrdup(fmt("%s/%s/%s/%s.html", cgit_cache_root,
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cgit_query_repo, cgit_query_page,
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cgit_querystring));
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if (cgit_query_has_symref)
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item->ttl = cgit_cache_dynamic_ttl;
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else if (cgit_query_has_sha1)
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item->ttl = cgit_cache_static_ttl;
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else
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item->ttl = cgit_cache_repo_ttl;
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}
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}
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int cache_exist(struct cacheitem *item)
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{
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if (stat(item->name, &item->st)) {
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item->st.st_mtime = 0;
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return 0;
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}
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return 1;
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}
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int cache_create_dirs()
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{
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char *path;
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if (!cgit_query_repo)
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return 0;
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path = fmt("%s/%s", cgit_cache_root, cgit_query_repo);
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if (mkdir(path, S_IRWXU) && errno!=EEXIST)
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return 0;
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if (cgit_query_page) {
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path = fmt("%s/%s/%s", cgit_cache_root, cgit_query_repo,
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cgit_query_page);
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if (mkdir(path, S_IRWXU) && errno!=EEXIST)
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return 0;
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}
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return 1;
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}
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int cache_refill_overdue(const char *lockfile)
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{
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struct stat st;
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if (stat(lockfile, &st))
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return 0;
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else
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return (time(NULL) - st.st_mtime > cgit_cache_max_create_time);
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}
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int cache_lock(struct cacheitem *item)
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{
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int i = 0;
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char *lockfile = fmt("%s.lock", item->name);
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top:
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if (++i > cgit_max_lock_attempts)
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die("cache_lock: unable to lock %s: %s",
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item->name, strerror(errno));
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item->fd = open(lockfile, O_WRONLY|O_CREAT|O_EXCL, S_IRUSR|S_IWUSR);
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if (item->fd == NOLOCK && errno == ENOENT && cache_create_dirs())
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goto top;
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if (item->fd == NOLOCK && errno == EEXIST &&
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cache_refill_overdue(lockfile) && !unlink(lockfile))
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goto top;
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return (item->fd > 0);
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}
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int cache_unlock(struct cacheitem *item)
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{
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close(item->fd);
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return (rename(fmt("%s.lock", item->name), item->name) == 0);
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}
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int cache_expired(struct cacheitem *item)
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{
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if (item->ttl < 0)
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return 0;
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return item->st.st_mtime + item->ttl * 60 < time(NULL);
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}
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