On Tue, Nov 08, 2016 at 11:05:01AM +0800, tang.wenjun3@xxxxxxxxxx wrote:
Thanks.
ACK
-Ben
> From: 10144149 <tang.wenjun3@xxxxxxxxxx>
>
> Deadlock occurred in uev_add_path() when &vecs->lock would lock twice in uev_update_path()
> ---
> multipathd/main.c | 54 ++++++++++++++++++++++++++++++------------------------
> multipathd/main.h | 1 +
> 2 files changed, 31 insertions(+), 24 deletions(-)
>
> diff --git a/multipathd/main.c b/multipathd/main.c
> index d6f081f..e74d124 100644
> --- a/multipathd/main.c
> +++ b/multipathd/main.c
> @@ -611,7 +611,7 @@ static int
> uev_add_path (struct uevent *uev, struct vectors * vecs)
> {
> struct path *pp;
> - int ret = 0, i;
> + int ret = 0;
> struct config *conf;
>
> condlog(2, "%s: add path (uevent)", uev->kernel);
> @@ -628,32 +628,11 @@ uev_add_path (struct uevent *uev, struct vectors * vecs)
> pthread_testcancel();
> pp = find_path_by_dev(vecs->pathvec, uev->kernel);
> if (pp) {
> - int r;
> -
> condlog(0, "%s: spurious uevent, path already in pathvec",
> uev->kernel);
> if (!pp->mpp && !strlen(pp->wwid)) {
> condlog(3, "%s: reinitialize path", uev->kernel);
> - udev_device_unref(pp->udev);
> - pp->udev = udev_device_ref(uev->udev);
> - conf = get_multipath_config();
> - r = pathinfo(pp, conf,
> - DI_ALL | DI_BLACKLIST);
> - put_multipath_config(conf);
> - if (r == PATHINFO_OK)
> - ret = ev_add_path(pp, vecs);
> - else if (r == PATHINFO_SKIPPED) {
> - condlog(3, "%s: remove blacklisted path",
> - uev->kernel);
> - i = find_slot(vecs->pathvec, (void *)pp);
> - if (i != -1)
> - vector_del_slot(vecs->pathvec, i);
> - free_path(pp);
> - } else {
> - condlog(0, "%s: failed to reinitialize path",
> - uev->kernel);
> - ret = 1;
> - }
> + ret = ev_add_path_with_pathinfo(uev->udev, pp, vecs);
> }
> }
> lock_cleanup_pop(vecs->lock);
> @@ -693,6 +672,33 @@ uev_add_path (struct uevent *uev, struct vectors * vecs)
> return ret;
> }
>
> +int
> +ev_add_path_with_pathinfo (struct udev_device *udevice, struct path * pp, struct vectors * vecs)
> +{
> + int r;
> + int ret = 0, i;
> + struct config *conf;
> +
> + udev_device_unref(pp->udev);
> + pp->udev = udev_device_ref(udevice);
> + conf = get_multipath_config();
> + r = pathinfo(pp, conf, DI_ALL | DI_BLACKLIST);
> + put_multipath_config(conf);
> + if (r == PATHINFO_OK)
> + ret = ev_add_path(pp, vecs);
> + else if (r == PATHINFO_SKIPPED) {
> + condlog(3, "%s: remove blacklisted path", pp->dev);
> + i = find_slot(vecs->pathvec, (void *)pp);
> + if (i != -1)
> + vector_del_slot(vecs->pathvec, i);
> + free_path(pp);
> + } else {
> + condlog(0, "%s: failed to reinitialize path", pp->dev);
> + ret = 1;
> + }
> + return ret;
> +}
> +
> /*
> * returns:
> * 0: added
> @@ -995,7 +1001,7 @@ uev_update_path (struct uevent *uev, struct vectors * vecs)
> }
>
> if (pp->initialized == INIT_REQUESTED_UDEV)
> - retval = uev_add_path(uev, vecs);
> + retval = ev_add_path_with_pathinfo(uev->udev, pp, vecs);
> else if (mpp && ro >= 0) {
> condlog(2, "%s: update path write_protect to '%d' (uevent)", uev->kernel, ro);
>
> diff --git a/multipathd/main.h b/multipathd/main.h
> index f72580d..d3cd145 100644
> --- a/multipathd/main.h
> +++ b/multipathd/main.h
> @@ -23,6 +23,7 @@ const char * daemon_status(void);
> int need_to_delay_reconfig (struct vectors *);
> int reconfigure (struct vectors *);
> int ev_add_path (struct path *, struct vectors *);
> +int ev_add_path_with_pathinfo (struct udev_device *, struct path *, struct vectors *);
> int ev_remove_path (struct path *, struct vectors *);
> int ev_add_map (char *, char *, struct vectors *);
> int ev_remove_map (char *, char *, int, struct vectors *);
> --
> 2.8.1.windows.1
--
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