lib: file_wait/try_lock() treats EINTR differently now for timeouts and for actual...

diff --git a/src/lib/file-lock.c b/src/lib/file-lock.c
index d818bad1d2759802dec43f6e4c477600cd8c3b80..1ec858d1b3c2c87ca23b6db4ad9396e0f0e49d14 100644 (file)
--- a/src/lib/file-lock.c
+++ b/src/lib/file-lock.c
@@ -4,6 +4,7 @@
 #include "istream.h"
 #include "file-lock.h"
 
+#include <time.h>
 #include <sys/stat.h>
 #ifdef HAVE_FLOCK
 #  include <sys/file.h>
@@ -144,11 +145,21 @@ const char *file_lock_find(int lock_fd, enum file_lock_method lock_method,
        return file_lock_find_proc_locks(lock_fd);
 }
 
+static bool err_is_lock_timeout(time_t started, unsigned int timeout_secs)
+{
+       /* if EINTR took at least timeout_secs-1 number of seconds,
+          assume it was the alarm. otherwise log EINTR failure.
+          (We most likely don't want to retry EINTR since a signal
+          means somebody wants us to stop blocking). */
+       return errno == EINTR && time(NULL) - started + 1 >= timeout_secs;
+}
+
 static int file_lock_do(int fd, const char *path, int lock_type,
                        enum file_lock_method lock_method,
                        unsigned int timeout_secs, const char **error_r)
 {
        const char *lock_type_str;
+       time_t started = time(NULL);
        int ret;
 
        i_assert(fd != -1);
@@ -188,10 +199,7 @@ static int file_lock_do(int fd, const char *path, int lock_type,
                        return 0;
                }
 
-               if (errno == EINTR) {
-                       /* most likely alarm hit, meaning we timeouted.
-                          even if not, we probably want to be killed
-                          so stop blocking. */
+               if (err_is_lock_timeout(started, timeout_secs)) {
                        errno = EAGAIN;
                        *error_r = t_strdup_printf(
                                "fcntl(%s, %s, F_SETLKW) locking failed: "
@@ -238,7 +246,7 @@ static int file_lock_do(int fd, const char *path, int lock_type,
                                "(File is already locked)", path, lock_type_str);
                        return 0;
                }
-               if (errno == EINTR) {
+               if (err_is_lock_timeout(started, timeout_secs)) {
                        errno = EAGAIN;
                        *error_r = t_strdup_printf("flock(%s, %s) failed: "
                                "Timed out after %u seconds%s",