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authorIlya Dryomov <idryomov@gmail.com>2017-04-13 12:17:39 +0200
committerIlya Dryomov <idryomov@gmail.com>2017-05-04 09:19:24 +0200
commite010dd0ada619ed6d3411de7371fba12c1baa48b (patch)
treed7767fd111a68592b4e7fa6498b0c5179cac3e35 /drivers/block
parent3b77faa0495abd07e94119681be8cc66af5e0a3b (diff)
downloadlinux-e010dd0ada619ed6d3411de7371fba12c1baa48b.tar.bz2
rbd: exclusive map option
Support disabling automatic exclusive lock transfers to allow users to be in charge of which node should own the lock while being able to reuse exclusive lock's built-in blacklist/break-lock functionality. Signed-off-by: Ilya Dryomov <idryomov@gmail.com> Reviewed-by: Jason Dillaman <dillaman@redhat.com>
Diffstat (limited to 'drivers/block')
-rw-r--r--drivers/block/rbd.c83
1 files changed, 73 insertions, 10 deletions
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 8babb1a59a0a..3402ff7414c5 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -798,6 +798,7 @@ enum {
Opt_read_only,
Opt_read_write,
Opt_lock_on_read,
+ Opt_exclusive,
Opt_err
};
@@ -810,6 +811,7 @@ static match_table_t rbd_opts_tokens = {
{Opt_read_write, "read_write"},
{Opt_read_write, "rw"}, /* Alternate spelling */
{Opt_lock_on_read, "lock_on_read"},
+ {Opt_exclusive, "exclusive"},
{Opt_err, NULL}
};
@@ -817,11 +819,13 @@ struct rbd_options {
int queue_depth;
bool read_only;
bool lock_on_read;
+ bool exclusive;
};
#define RBD_QUEUE_DEPTH_DEFAULT BLKDEV_MAX_RQ
#define RBD_READ_ONLY_DEFAULT false
#define RBD_LOCK_ON_READ_DEFAULT false
+#define RBD_EXCLUSIVE_DEFAULT false
static int parse_rbd_opts_token(char *c, void *private)
{
@@ -860,6 +864,9 @@ static int parse_rbd_opts_token(char *c, void *private)
case Opt_lock_on_read:
rbd_opts->lock_on_read = true;
break;
+ case Opt_exclusive:
+ rbd_opts->exclusive = true;
+ break;
default:
/* libceph prints "bad option" msg */
return -EINVAL;
@@ -3440,6 +3447,18 @@ again:
ret = rbd_request_lock(rbd_dev);
if (ret == -ETIMEDOUT) {
goto again; /* treat this as a dead client */
+ } else if (ret == -EROFS) {
+ rbd_warn(rbd_dev, "peer will not release lock");
+ /*
+ * If this is rbd_add_acquire_lock(), we want to fail
+ * immediately -- reuse BLACKLISTED flag. Otherwise we
+ * want to block.
+ */
+ if (!(rbd_dev->disk->flags & GENHD_FL_UP)) {
+ set_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags);
+ /* wake "rbd map --exclusive" process */
+ wake_requests(rbd_dev, false);
+ }
} else if (ret < 0) {
rbd_warn(rbd_dev, "error requesting lock: %d", ret);
mod_delayed_work(rbd_dev->task_wq, &rbd_dev->lock_dwork,
@@ -3606,9 +3625,15 @@ static int rbd_handle_request_lock(struct rbd_device *rbd_dev, u8 struct_v,
result = 0;
if (rbd_dev->lock_state == RBD_LOCK_STATE_LOCKED) {
- dout("%s rbd_dev %p queueing unlock_work\n", __func__,
- rbd_dev);
- queue_work(rbd_dev->task_wq, &rbd_dev->unlock_work);
+ if (!rbd_dev->opts->exclusive) {
+ dout("%s rbd_dev %p queueing unlock_work\n",
+ __func__, rbd_dev);
+ queue_work(rbd_dev->task_wq,
+ &rbd_dev->unlock_work);
+ } else {
+ /* refuse to release the lock */
+ result = -EROFS;
+ }
}
}
@@ -4073,8 +4098,14 @@ static void rbd_queue_workfn(struct work_struct *work)
if (must_be_locked) {
down_read(&rbd_dev->lock_rwsem);
if (rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED &&
- !test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags))
+ !test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags)) {
+ if (rbd_dev->opts->exclusive) {
+ rbd_warn(rbd_dev, "exclusive lock required");
+ result = -EROFS;
+ goto err_unlock;
+ }
rbd_wait_state_locked(rbd_dev);
+ }
if (test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags)) {
result = -EBLACKLISTED;
goto err_unlock;
@@ -5640,6 +5671,7 @@ static int rbd_add_parse_args(const char *buf,
rbd_opts->read_only = RBD_READ_ONLY_DEFAULT;
rbd_opts->queue_depth = RBD_QUEUE_DEPTH_DEFAULT;
rbd_opts->lock_on_read = RBD_LOCK_ON_READ_DEFAULT;
+ rbd_opts->exclusive = RBD_EXCLUSIVE_DEFAULT;
copts = ceph_parse_options(options, mon_addrs,
mon_addrs + mon_addrs_size - 1,
@@ -5698,6 +5730,33 @@ again:
return ret;
}
+static void rbd_dev_image_unlock(struct rbd_device *rbd_dev)
+{
+ down_write(&rbd_dev->lock_rwsem);
+ if (__rbd_is_lock_owner(rbd_dev))
+ rbd_unlock(rbd_dev);
+ up_write(&rbd_dev->lock_rwsem);
+}
+
+static int rbd_add_acquire_lock(struct rbd_device *rbd_dev)
+{
+ if (!(rbd_dev->header.features & RBD_FEATURE_EXCLUSIVE_LOCK)) {
+ rbd_warn(rbd_dev, "exclusive-lock feature is not enabled");
+ return -EINVAL;
+ }
+
+ /* FIXME: "rbd map --exclusive" should be in interruptible */
+ down_read(&rbd_dev->lock_rwsem);
+ rbd_wait_state_locked(rbd_dev);
+ up_read(&rbd_dev->lock_rwsem);
+ if (test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags)) {
+ rbd_warn(rbd_dev, "failed to acquire exclusive lock");
+ return -EROFS;
+ }
+
+ return 0;
+}
+
/*
* An rbd format 2 image has a unique identifier, distinct from the
* name given to it by the user. Internally, that identifier is
@@ -6141,11 +6200,17 @@ static ssize_t do_rbd_add(struct bus_type *bus,
if (rc)
goto err_out_image_probe;
+ if (rbd_dev->opts->exclusive) {
+ rc = rbd_add_acquire_lock(rbd_dev);
+ if (rc)
+ goto err_out_device_setup;
+ }
+
/* Everything's ready. Announce the disk to the world. */
rc = device_add(&rbd_dev->dev);
if (rc)
- goto err_out_device_setup;
+ goto err_out_image_lock;
add_disk(rbd_dev->disk);
/* see rbd_init_disk() */
@@ -6163,6 +6228,8 @@ out:
module_put(THIS_MODULE);
return rc;
+err_out_image_lock:
+ rbd_dev_image_unlock(rbd_dev);
err_out_device_setup:
rbd_dev_device_release(rbd_dev);
err_out_image_probe:
@@ -6286,11 +6353,7 @@ static ssize_t do_rbd_remove(struct bus_type *bus,
spin_unlock(&rbd_dev_list_lock);
device_del(&rbd_dev->dev);
- down_write(&rbd_dev->lock_rwsem);
- if (__rbd_is_lock_owner(rbd_dev))
- rbd_unlock(rbd_dev);
- up_write(&rbd_dev->lock_rwsem);
-
+ rbd_dev_image_unlock(rbd_dev);
rbd_dev_device_release(rbd_dev);
rbd_dev_image_release(rbd_dev);
rbd_dev_destroy(rbd_dev);