Commit 4f5db0a5 authored by Justin Erenkrantz's avatar Justin Erenkrantz
Browse files

mod_disk_cache: Retry file rename up to three times to ameliorate race 

condition with htcacheclean removing the directories underneath us.

(Includes tweaks by Justin.)

Suggested by: Graham Leggett
Submitted by: Andreas Steinmetz <ast@domdv.de>
Reviewed by: Justin Erenkrantz


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@231349 13f79535-47bb-0310-9956-ffa450edef68
parent ef5d974d

modules/cache/mod_disk_cache.c

+30 −3
Changes for modules/cache/mod_disk_cache.c: 30 added lines, 3 removed lines.
Original line number Diff line number Diff line
@@ -184,6 +184,33 @@ static void mkdir_structure(disk_cache_conf *conf, const char *file, apr_pool_t 
    }

}



/* htcacheclean may remove directories underneath us.

 * So, we'll try renaming three times at a cost of 0.002 seconds.

 */

static apr_status_t safe_file_rename(disk_cache_conf *conf,

                                     const char *src, const char *dest,

                                     apr_pool_t *pool)

{

    apr_status_t rv;



    rv = apr_file_rename(src, dest, pool);



    if (rv != APR_SUCCESS) {

        int i;



        for (i = 0; i < 2 && rv != APR_SUCCESS; i++) {

            /* 1000 micro-seconds aka 0.001 seconds. */

            apr_sleep(1000);



            mkdir_structure(conf, dest, pool);



            rv = apr_file_rename(src, dest, pool);

        }

    }



    return rv;

}



static apr_status_t file_cache_el_final(disk_cache_object_t *dobj,

                                        request_rec *r)

{
@@ -795,7 +822,8 @@ static apr_status_t store_headers(cache_handle_t *h, request_rec *r, cache_info 


            dobj->tfd = NULL;



            rv = apr_file_rename(dobj->tempfile, dobj->hdrsfile, r->pool);

            rv = safe_file_rename(conf, dobj->tempfile, dobj->hdrsfile,

                                  r->pool);

            if (rv != APR_SUCCESS) {

                ap_log_error(APLOG_MARK, APLOG_DEBUG, rv, r->server,

                    "disk_cache: rename tempfile to varyfile failed: %s -> %s",
@@ -887,8 +915,7 @@ static apr_status_t store_headers(cache_handle_t *h, request_rec *r, cache_info 
        mkdir_structure(conf, dobj->hdrsfile, r->pool);

    }



    rv = apr_file_rename(dobj->tempfile, dobj->hdrsfile, r->pool);



    rv = safe_file_rename(conf, dobj->tempfile, dobj->hdrsfile, r->pool);

    if (rv != APR_SUCCESS) {

        ap_log_error(APLOG_MARK, APLOG_ERR, rv, r->server,

                     "disk_cache: rename tempfile to hdrsfile failed: %s -> %s",