[PATCH 3/3] debuginfod: When retrieving files from cache, update atime manually

["Jan Alexander Steffens (heftig)" <heftig@archlinux.org>]

The cache cleaning logic requires atime to be correct (strictatime) but
most users on Linux only have relatime or even noatime.

Attempt to update the atime manually so that the cache works properly.

Signed-off-by: Jan Alexander Steffens (heftig) <heftig@archlinux.org>
---
 debuginfod/debuginfod-client.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/debuginfod/debuginfod-client.c b/debuginfod/debuginfod-client.c
index 1a2d7573..484dc7b3 100644
--- a/debuginfod/debuginfod-client.c
+++ b/debuginfod/debuginfod-client.c
@@ -618,6 +618,19 @@ path_escape (const char *src, char *dest)
   dest[q] = '\0';
 }
 
+/* Attempt to update the atime */
+static void
+update_atime (int fd)
+{
+  struct timespec tvs[2];
+
+  tvs[0].tv_sec = tvs[1].tv_sec = 0;
+  tvs[0].tv_nsec = UTIME_NOW;
+  tvs[1].tv_nsec = UTIME_OMIT;
+
+  (void) futimens (fd, tvs);  /* best effort */
+}
+
 /* Attempt to read an ELF/DWARF section with name SECTION from FD and write
    it to a separate file in the debuginfod cache.  If successful the absolute
    path of the separate file containing SECTION will be stored in USR_PATH.
@@ -761,6 +774,7 @@ extract_section (int fd, const char *section, char *fd_path, char **usr_path)
 	    *usr_path = sec_path;
 	  else
 	    free (sec_path);
+	  update_atime(fd);
 	  rc = sec_fd;
 	  goto out2;
 	}
@@ -1098,6 +1112,7 @@ debuginfod_query_server (debuginfod_client *c,
                 }
             }
           /* Success!!!! */
+          update_atime(fd);
           rc = fd;
           goto out;
         }
-- 
2.40.0