From: Ilya Dryomov idryomov@gmail.com
commit f38cb9d9c2045dad16eead4a2e1aedfddd94603b upstream.
Make the "num_lockers can be only 0 or 1" assumption explicit and simplify the API by getting rid of output parameters in preparation for calling get_lock_owner_info() twice before blocklisting.
Signed-off-by: Ilya Dryomov idryomov@gmail.com Reviewed-by: Dongsheng Yang dongsheng.yang@easystack.cn Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/block/rbd.c | 84 +++++++++++++++++++++++++++++++--------------------- 1 file changed, 51 insertions(+), 33 deletions(-)
--- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -3850,10 +3850,17 @@ static void wake_lock_waiters(struct rbd list_splice_tail_init(&rbd_dev->acquiring_list, &rbd_dev->running_list); }
-static int get_lock_owner_info(struct rbd_device *rbd_dev, - struct ceph_locker **lockers, u32 *num_lockers) +static void free_locker(struct ceph_locker *locker) +{ + if (locker) + ceph_free_lockers(locker, 1); +} + +static struct ceph_locker *get_lock_owner_info(struct rbd_device *rbd_dev) { struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc; + struct ceph_locker *lockers; + u32 num_lockers; u8 lock_type; char *lock_tag; int ret; @@ -3862,39 +3869,45 @@ static int get_lock_owner_info(struct rb
ret = ceph_cls_lock_info(osdc, &rbd_dev->header_oid, &rbd_dev->header_oloc, RBD_LOCK_NAME, - &lock_type, &lock_tag, lockers, num_lockers); - if (ret) - return ret; + &lock_type, &lock_tag, &lockers, &num_lockers); + if (ret) { + rbd_warn(rbd_dev, "failed to retrieve lockers: %d", ret); + return ERR_PTR(ret); + }
- if (*num_lockers == 0) { + if (num_lockers == 0) { dout("%s rbd_dev %p no lockers detected\n", __func__, rbd_dev); + lockers = NULL; goto out; }
if (strcmp(lock_tag, RBD_LOCK_TAG)) { rbd_warn(rbd_dev, "locked by external mechanism, tag %s", lock_tag); - ret = -EBUSY; - goto out; + goto err_busy; }
if (lock_type == CEPH_CLS_LOCK_SHARED) { rbd_warn(rbd_dev, "shared lock type detected"); - ret = -EBUSY; - goto out; + goto err_busy; }
- if (strncmp((*lockers)[0].id.cookie, RBD_LOCK_COOKIE_PREFIX, + WARN_ON(num_lockers != 1); + if (strncmp(lockers[0].id.cookie, RBD_LOCK_COOKIE_PREFIX, strlen(RBD_LOCK_COOKIE_PREFIX))) { rbd_warn(rbd_dev, "locked by external mechanism, cookie %s", - (*lockers)[0].id.cookie); - ret = -EBUSY; - goto out; + lockers[0].id.cookie); + goto err_busy; }
out: kfree(lock_tag); - return ret; + return lockers; + +err_busy: + kfree(lock_tag); + ceph_free_lockers(lockers, num_lockers); + return ERR_PTR(-EBUSY); }
static int find_watcher(struct rbd_device *rbd_dev, @@ -3948,51 +3961,56 @@ out: static int rbd_try_lock(struct rbd_device *rbd_dev) { struct ceph_client *client = rbd_dev->rbd_client->client; - struct ceph_locker *lockers; - u32 num_lockers; + struct ceph_locker *locker; int ret;
for (;;) { + locker = NULL; + ret = rbd_lock(rbd_dev); if (ret != -EBUSY) - return ret; + goto out;
/* determine if the current lock holder is still alive */ - ret = get_lock_owner_info(rbd_dev, &lockers, &num_lockers); - if (ret) - return ret; - - if (num_lockers == 0) + locker = get_lock_owner_info(rbd_dev); + if (IS_ERR(locker)) { + ret = PTR_ERR(locker); + locker = NULL; + goto out; + } + if (!locker) goto again;
- ret = find_watcher(rbd_dev, lockers); + ret = find_watcher(rbd_dev, locker); if (ret) goto out; /* request lock or error */
rbd_warn(rbd_dev, "breaking header lock owned by %s%llu", - ENTITY_NAME(lockers[0].id.name)); + ENTITY_NAME(locker->id.name));
ret = ceph_monc_blocklist_add(&client->monc, - &lockers[0].info.addr); + &locker->info.addr); if (ret) { - rbd_warn(rbd_dev, "blocklist of %s%llu failed: %d", - ENTITY_NAME(lockers[0].id.name), ret); + rbd_warn(rbd_dev, "failed to blocklist %s%llu: %d", + ENTITY_NAME(locker->id.name), ret); goto out; }
ret = ceph_cls_break_lock(&client->osdc, &rbd_dev->header_oid, &rbd_dev->header_oloc, RBD_LOCK_NAME, - lockers[0].id.cookie, - &lockers[0].id.name); - if (ret && ret != -ENOENT) + locker->id.cookie, &locker->id.name); + if (ret && ret != -ENOENT) { + rbd_warn(rbd_dev, "failed to break header lock: %d", + ret); goto out; + }
again: - ceph_free_lockers(lockers, num_lockers); + free_locker(locker); }
out: - ceph_free_lockers(lockers, num_lockers); + free_locker(locker); return ret; }