diff --git a/common/dotlock.c b/common/dotlock.c index cd8e95066..3d948f718 100644 --- a/common/dotlock.c +++ b/common/dotlock.c @@ -526,7 +526,7 @@ maybe_deadlock (dotlock_t h) has been created on the same node. */ #ifdef HAVE_POSIX_SYSTEM static int -read_lockfile (dotlock_t h, int *same_node ) +read_lockfile (dotlock_t h, int *same_node, int *r_fd) { char buffer_space[10+1+70+1]; /* 70 is just an estimated value; node names are usually shorter. */ @@ -579,7 +579,11 @@ read_lockfile (dotlock_t h, int *same_node ) nread += res; } while (res && nread != expected_len); - close(fd); + + if (r_fd) + *r_fd = fd; + else + close(fd); if (nread < 11) { @@ -1027,13 +1031,12 @@ dotlock_take_unix (dotlock_t h, long timeout) const char *maybe_dead=""; int same_node; int saveerrno; + int fd; again: if (h->use_o_excl) { /* No hardlink support - use open(O_EXCL). */ - int fd; - do { my_set_errno (0); @@ -1103,7 +1106,7 @@ dotlock_take_unix (dotlock_t h, long timeout) } /* Check for stale lock files. */ - if ( (pid = read_lockfile (h, &same_node)) == -1 ) + if ( (pid = read_lockfile (h, &same_node, &fd)) == -1 ) { if ( errno != ENOENT ) { @@ -1119,18 +1122,30 @@ dotlock_take_unix (dotlock_t h, long timeout) { my_info_0 ("Oops: lock already held by us\n"); h->locked = 1; + + close (fd); return 0; /* okay */ } else if ( same_node && kill (pid, 0) && errno == ESRCH ) { - /* Note: It is unlikely that we get a race here unless a pid is - reused too fast or a new process with the same pid as the one - of the stale file tries to lock right at the same time as we. */ + struct stat sb; + + /* Check if it's unlocked during examining the lockfile. */ + if (fstat (fd, &sb) || sb.st_nlink == 0) + { + /* It's gone already. */ + close (fd); + goto again; + } + + close (fd); + my_info_1 (_("removing stale lockfile (created by %d)\n"), pid); unlink (h->lockname); goto again; } + close (fd); if (lastpid == -1) lastpid = pid; ownerchanged = (pid != lastpid); @@ -1277,7 +1292,7 @@ dotlock_release_unix (dotlock_t h) int pid, same_node; int saveerrno; - pid = read_lockfile (h, &same_node); + pid = read_lockfile (h, &same_node, NULL); if ( pid == -1 ) { saveerrno = errno;