From: Lars Ellenberg Date: Wed, 1 Sep 2010 12:39:30 +0000 (+0200) Subject: drbd: implicitly create unconfigured devices on sync-after dependencies X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=ef50a3e34f93a067ada541346be3175e924331a2;p=openwrt%2Fstaging%2Fblogic.git drbd: implicitly create unconfigured devices on sync-after dependencies If pacemaker (for example) decided to initialize minor devices not in the exact sync-after dependency order, the configuration partially failed with an error "The sync-after minor number is invalid". (Bugz. #322) We can avoid that by implicitly creating unconfigured minor devices, if others depend on them. Signed-off-by: Philipp Reisner Signed-off-by: Lars Ellenberg --- diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c index d066190f997a..e0061a906ba8 100644 --- a/drivers/block/drbd/drbd_nl.c +++ b/drivers/block/drbd/drbd_nl.c @@ -413,6 +413,39 @@ int drbd_set_role(struct drbd_conf *mdev, enum drbd_role new_role, int force) return r; } +static struct drbd_conf *ensure_mdev(int minor, int create) +{ + struct drbd_conf *mdev; + + if (minor >= minor_count) + return NULL; + + mdev = minor_to_mdev(minor); + + if (!mdev && create) { + struct gendisk *disk = NULL; + mdev = drbd_new_device(minor); + + spin_lock_irq(&drbd_pp_lock); + if (minor_table[minor] == NULL) { + minor_table[minor] = mdev; + disk = mdev->vdisk; + mdev = NULL; + } /* else: we lost the race */ + spin_unlock_irq(&drbd_pp_lock); + + if (disk) /* we won the race above */ + /* in case we ever add a drbd_delete_device(), + * don't forget the del_gendisk! */ + add_disk(disk); + else /* we lost the race above */ + drbd_free_mdev(mdev); + + mdev = minor_to_mdev(minor); + } + + return mdev; +} static int drbd_nl_primary(struct drbd_conf *mdev, struct drbd_nl_cfg_req *nlp, struct drbd_nl_cfg_reply *reply) @@ -1713,6 +1746,12 @@ static int drbd_nl_syncer_conf(struct drbd_conf *mdev, struct drbd_nl_cfg_req *n } #undef AL_MAX + /* to avoid spurious errors when configuring minors before configuring + * the minors they depend on: if necessary, first create the minor we + * depend on */ + if (sc.after >= 0) + ensure_mdev(sc.after, 1); + /* most sanity checks done, try to assign the new sync-after * dependency. need to hold the global lock in there, * to avoid a race in the dependency loop check. */ @@ -2080,40 +2119,6 @@ out: return 0; } -static struct drbd_conf *ensure_mdev(struct drbd_nl_cfg_req *nlp) -{ - struct drbd_conf *mdev; - - if (nlp->drbd_minor >= minor_count) - return NULL; - - mdev = minor_to_mdev(nlp->drbd_minor); - - if (!mdev && (nlp->flags & DRBD_NL_CREATE_DEVICE)) { - struct gendisk *disk = NULL; - mdev = drbd_new_device(nlp->drbd_minor); - - spin_lock_irq(&drbd_pp_lock); - if (minor_table[nlp->drbd_minor] == NULL) { - minor_table[nlp->drbd_minor] = mdev; - disk = mdev->vdisk; - mdev = NULL; - } /* else: we lost the race */ - spin_unlock_irq(&drbd_pp_lock); - - if (disk) /* we won the race above */ - /* in case we ever add a drbd_delete_device(), - * don't forget the del_gendisk! */ - add_disk(disk); - else /* we lost the race above */ - drbd_free_mdev(mdev); - - mdev = minor_to_mdev(nlp->drbd_minor); - } - - return mdev; -} - struct cn_handler_struct { int (*function)(struct drbd_conf *, struct drbd_nl_cfg_req *, @@ -2174,7 +2179,8 @@ static void drbd_connector_callback(struct cn_msg *req, struct netlink_skb_parms goto fail; } - mdev = ensure_mdev(nlp); + mdev = ensure_mdev(nlp->drbd_minor, + (nlp->flags & DRBD_NL_CREATE_DEVICE)); if (!mdev) { retcode = ERR_MINOR_INVALID; goto fail;