From 2800528713cd32a4d12d7e17c14eba34eb8a4ec2 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Tue, 14 Apr 2009 14:59:24 +1000 Subject: [PATCH] Wait for POLLPRI on /proc or /sys files. From 2.6.30, /proc/mounts and various /sys files will probably always returns 'readable' to select, so we will need to wait on POLLPRI to get the 'new data is available' signal. When using select, this corresponds to an 'exception', so adjust calls to select accordingly. In one case we sometimes wait on a socket and sometime on /proc/mounts, so we need to test which. Signed-off-by: NeilBrown --- Monitor.c | 2 +- mdstat.c | 14 ++++++++++++-- monitor.c | 2 +- 3 files changed, 14 insertions(+), 4 deletions(-) diff --git a/Monitor.c b/Monitor.c index af53129..2677f7b 100644 --- a/Monitor.c +++ b/Monitor.c @@ -706,7 +706,7 @@ int WaitClean(char *dev, int verbose) if (sysfs_match_word(buf, clean_states) <= 4) break; FD_SET(state_fd, &fds); - rv = select(state_fd + 1, &fds, NULL, NULL, &tm); + rv = select(state_fd + 1, NULL, NULL, &fds, &tm); if (rv < 0 && errno != EINTR) break; lseek(state_fd, 0, SEEK_SET); diff --git a/mdstat.c b/mdstat.c index ebdfc67..8de51cf 100644 --- a/mdstat.c +++ b/mdstat.c @@ -280,8 +280,18 @@ void mdstat_wait_fd(int fd, const sigset_t *sigmask) FD_ZERO(&rfds); if (mdstat_fd >= 0) FD_SET(mdstat_fd, &fds); - if (fd >= 0) - FD_SET(fd, &rfds); + if (fd >= 0) { + struct stat stb; + fstat(fd, &stb); + if ((stb.st_mode & S_IFMT) == S_IFREG) + /* Must be a /proc or /sys fd, so expect + * POLLPRI + * i.e. an 'exceptional' event. + */ + FD_SET(fd, &fds); + else + FD_SET(fd, &rfds); + } if (mdstat_fd > maxfd) maxfd = mdstat_fd; diff --git a/monitor.c b/monitor.c index 3388d31..66fea80 100644 --- a/monitor.c +++ b/monitor.c @@ -498,7 +498,7 @@ static int wait_and_act(struct supertype *container, int nowait) sigprocmask(SIG_UNBLOCK, NULL, &set); sigdelset(&set, SIGUSR1); monitor_loop_cnt |= 1; - rv = pselect(maxfd+1, &rfds, NULL, NULL, NULL, &set); + rv = pselect(maxfd+1, NULL, NULL, &rfds, NULL, &set); monitor_loop_cnt += 1; if (rv == -1 && errno == EINTR) rv = 0;