On Wed, 25 Jan 2012 13:16:24 -0500
Steve Dickson <SteveD@xxxxxxxxxx> wrote:
> Hey Jeff,
>
> Commit inline...
>
> On 01/23/2012 03:02 PM, Jeff Layton wrote:
> > This can happen if nfsd is shut down and restarted. If that occurs,
> > then reopen the pipe so we're not waiting for data on the defunct
> > pipe.
> >
> > Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
> > ---
> > utils/nfsdcld/nfsdcld.c | 84 +++++++++++++++++++++++++++++++++++++++++-----
> > 1 files changed, 74 insertions(+), 10 deletions(-)
> >
> > diff --git a/utils/nfsdcld/nfsdcld.c b/utils/nfsdcld/nfsdcld.c
> > index b0c08e2..0dc5b37 100644
> > --- a/utils/nfsdcld/nfsdcld.c
> > +++ b/utils/nfsdcld/nfsdcld.c
> > @@ -57,6 +57,8 @@ struct cld_client {
> >
> > /* global variables */
> > static char *pipepath = DEFAULT_CLD_PATH;
> > +static int inotify_fd = -1;
> > +static struct event pipedir_event;
> >
> > static struct option longopts[] =
> > {
> > @@ -68,8 +70,10 @@ static struct option longopts[] =
> > { NULL, 0, 0, 0 },
> > };
> >
> > +
> > /* forward declarations */
> > static void cldcb(int UNUSED(fd), short which, void *data);
> > +static void cld_pipe_reopen(struct cld_client *clnt);
> >
> > static void
> > usage(char *progname)
> > @@ -80,10 +84,62 @@ usage(char *progname)
> >
> > #define INOTIFY_EVENT_MAX (sizeof(struct inotify_event) + NAME_MAX)
> >
> > +static void
> > +cld_inotify_cb(int UNUSED(fd), short which, void *data)
> > +{
> > + int ret, oldfd;
> > + char evbuf[INOTIFY_EVENT_MAX];
> > + char *dirc = NULL, *pname;
> > + struct inotify_event *event = (struct inotify_event *)evbuf;
> > + struct cld_client *clnt = data;
> > +
> > + if (which != EV_READ)
> > + return;
> > +
> > + dirc = strndup(pipepath, PATH_MAX);
> > + if (!dirc) {
> > + xlog_err("%s: unable to allocate memory", __func__);
> > + goto out;
> > + }
> > +
> > + ret = read(inotify_fd, evbuf, INOTIFY_EVENT_MAX);
> > + if (ret < 0) {
> > + xlog_err("%s: read from inotify fd failed: %m", __func__);
> > + goto out;
> > + }
> > +
> > + /* check to see if we have a filename in the evbuf */
> > + if (!event->len)
> > + goto out;
> > +
> > + pname = basename(dirc);
> > +
> > + /* does the filename match our pipe? */
> > + if (strncmp(pname, event->name, event->len))
> > + goto out;
> > +
> > + /*
> > + * reopen the pipe. The old fd is not closed until the new one is
> > + * opened, so we know they should be different if the reopen is
> > + * successful.
> > + */
> > + oldfd = clnt->cl_fd;
> > + do {
> > + cld_pipe_reopen(clnt);
> > + } while (oldfd == clnt->cl_fd);
> Doesn't this have a potential for an infinite loop?
>
> steved.
Yes. If reopening the new pipe continually fails then it will loop
forever.
> > +
> > + /* readd the event for the cl_event pipe */
> > + event_add(&clnt->cl_event, NULL);
> > +
> > +out:
> > + event_add(&pipedir_event, NULL);
> > + free(dirc);
> > +}
> > +
> > static int
> > cld_pipe_open(struct cld_client *clnt)
> > {
> > - int ifd, wat;
> > + int wat;
> > ssize_t ret;
> > char *dirc, *dname;
> > char event[INOTIFY_EVENT_MAX];
> > @@ -97,16 +153,16 @@ cld_pipe_open(struct cld_client *clnt)
> >
> > dname = dirname(dirc);
> >
> > - ifd = inotify_init();
> > - if (ifd < 0) {
> > + inotify_fd = inotify_init();
> > + if (inotify_fd < 0) {
> > xlog_err("%s: inotify_init failed: %m", __func__);
> > goto out_free;
> > }
> >
> > - wat = inotify_add_watch(ifd, dname, IN_CREATE);
> > + wat = inotify_add_watch(inotify_fd, dname, IN_CREATE);
> > if (wat < 0) {
> > xlog_err("%s: inotify_add_watch failed: %m", __func__);
> > - goto out;
> > + goto out_err;
> > }
> >
> > for (;;) {
> > @@ -117,24 +173,31 @@ cld_pipe_open(struct cld_client *clnt)
> > else if (errno != ENOENT) {
> > xlog_err("%s: unable to open %s: %m", __func__,
> > pipepath);
> > - goto out;
> > + goto out_err;
> > }
> > - ret = read(ifd, event, INOTIFY_EVENT_MAX);
> > + ret = read(inotify_fd, event, INOTIFY_EVENT_MAX);
> > if (ret < 0) {
> > xlog_err("%s: read from inotify fd failed: %m",
> > __func__);
> > - goto out;
> > + goto out_err;
> > }
> > }
> >
> > + /* set event for the pipe reads */
> > event_set(&clnt->cl_event, clnt->cl_fd, EV_READ, cldcb, clnt);
> > event_add(&clnt->cl_event, NULL);
> >
> > -out:
> > - close(ifd);
> > + /* another event for inotify read */
> > + event_set(&pipedir_event, inotify_fd, EV_READ, cld_inotify_cb, clnt);
> > + event_add(&pipedir_event, NULL);
> > +
> > out_free:
> > free(dirc);
> > return clnt->cl_fd;
> > +
> > +out_err:
> > + close(inotify_fd);
> > + goto out_free;
> > }
> >
> > static void
> > @@ -142,6 +205,7 @@ cld_pipe_reopen(struct cld_client *clnt)
> > {
> > int fd;
> >
> > + xlog(D_GENERAL, "%s: reopening pipe", __func__);
> > fd = open(pipepath, O_RDWR, 0);
> > if (fd < 0) {
> > xlog_warn("%s: Re-opening of %s failed: %m",
> > -- 1.7.7.5
--
Jeff Layton <jlayton@xxxxxxxxxx>
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