commit 9b2510924916cdc1e66d879b43f4dc953aac3c83
from: Stefan Sperling <stsp@stsp.name>
via: Thomas Adam <thomas@xteddy.org>
date: Tue Nov 08 20:14:11 2022 UTC

use sub-second precision when checking for objects/pack/ modification

Convert from st.m_time (second-precision time_t) to st.m_tim (struct timespec).
To compensate for the potential case where a filesystem provides resolution
in seconds only, always read the directory if no pack files are known to exist.

Otherwise, there is a race condition when gotd repo_write creates a new pack
and a request arrives for repo_read shortly after. Caught by a regression test
for gotd on empty repositories. Test failure pointed out by Mikhail.

ok op@

commit - c22ed3f5d5d97db3f1d8fc8c649537c9033136f9
commit + 9b2510924916cdc1e66d879b43f4dc953aac3c83
blob - cd9aa4370a65e5d58169777bb0760f75b984b0b1
blob + e78dd4fb4cada73349067798a377d8d17194da2e
--- gotd/privsep_stub.c
+++ gotd/privsep_stub.c
@@ -15,6 +15,7 @@
  */
 
 #include <sys/types.h>
+#include <sys/time.h>
 #include <sys/queue.h>
 #include <sys/tree.h>
 #include <sys/uio.h>
blob - ced490e96ad476ac78d59ed49d235863982116c3
blob + b8032ffd3ffe9dab29beaf3cc57c39a6ef957859
--- lib/got_lib_repository.h
+++ lib/got_lib_repository.h
@@ -65,7 +65,7 @@ struct got_repository {
 	int gitdir_fd;
 
 	struct got_pathlist_head packidx_paths;
-	time_t pack_path_mtime;
+	struct timespec pack_path_mtime;
 
 	/* The pack index cache speeds up search for packed objects. */
 	struct got_packidx *packidx_cache[GOT_PACK_CACHE_SIZE];
blob - 3c735047768978e048588c45a499263ce4d16e37
blob + 5522108b0b638af2088f27d7658bd2a3671def42
--- lib/read_gitconfig_privsep.c
+++ lib/read_gitconfig_privsep.c
@@ -14,6 +14,7 @@
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
+#include <sys/time.h>
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <sys/queue.h>
blob - 59e3126a13e7972046e19f9dbdc2a29da4c031dd
blob + b7acde6c731648b5e05261665578a19822deafd3
--- lib/repository.c
+++ lib/repository.c
@@ -1145,7 +1145,9 @@ refresh_packidx_paths(struct got_repository *repo)
 			err = got_error_from_errno2("stat", objects_pack_dir);
 			goto done;
 		}
-	} else if (sb.st_mtime != repo->pack_path_mtime) {
+	} else if (TAILQ_EMPTY(&repo->packidx_paths) ||
+	    sb.st_mtim.tv_sec != repo->pack_path_mtime.tv_sec ||
+	    sb.st_mtim.tv_nsec != repo->pack_path_mtime.tv_nsec) {
 		purge_packidx_paths(&repo->packidx_paths);
 		err = got_repo_list_packidx(&repo->packidx_paths, repo);
 		if (err)
@@ -1272,7 +1274,8 @@ got_repo_list_packidx(struct got_pathlist_head *packid
 		err = got_error_from_errno("fstat");
 		goto done;
 	}
-	repo->pack_path_mtime = sb.st_mtime;
+	repo->pack_path_mtime.tv_sec = sb.st_mtim.tv_sec;
+	repo->pack_path_mtime.tv_nsec = sb.st_mtim.tv_nsec;
 
 	while ((dent = readdir(packdir)) != NULL) {
 		if (!got_repo_is_packidx_filename(dent->d_name,