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.
> +
> + /* 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
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