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-rw-r--r--drivers/block/loop.c22
-rw-r--r--drivers/block/rnbd/rnbd-clt.c13
-rw-r--r--drivers/block/ublk_drv.c32
-rw-r--r--drivers/block/zloop.c8
4 files changed, 53 insertions, 22 deletions
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 272bc608e528..32a3a5b13802 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -1082,7 +1082,7 @@ static int loop_configure(struct loop_device *lo, blk_mode_t mode,
/* Order wrt reading lo_state in loop_validate_file(). */
wmb();
- lo->lo_state = Lo_bound;
+ WRITE_ONCE(lo->lo_state, Lo_bound);
if (part_shift)
lo->lo_flags |= LO_FLAGS_PARTSCAN;
partscan = lo->lo_flags & LO_FLAGS_PARTSCAN;
@@ -1179,7 +1179,7 @@ static void __loop_clr_fd(struct loop_device *lo)
if (!part_shift)
set_bit(GD_SUPPRESS_PART_SCAN, &lo->lo_disk->state);
mutex_lock(&lo->lo_mutex);
- lo->lo_state = Lo_unbound;
+ WRITE_ONCE(lo->lo_state, Lo_unbound);
mutex_unlock(&lo->lo_mutex);
/*
@@ -1218,7 +1218,7 @@ static int loop_clr_fd(struct loop_device *lo)
lo->lo_flags |= LO_FLAGS_AUTOCLEAR;
if (disk_openers(lo->lo_disk) == 1)
- lo->lo_state = Lo_rundown;
+ WRITE_ONCE(lo->lo_state, Lo_rundown);
loop_global_unlock(lo, true);
return 0;
@@ -1743,7 +1743,7 @@ static void lo_release(struct gendisk *disk)
mutex_lock(&lo->lo_mutex);
if (lo->lo_state == Lo_bound && (lo->lo_flags & LO_FLAGS_AUTOCLEAR))
- lo->lo_state = Lo_rundown;
+ WRITE_ONCE(lo->lo_state, Lo_rundown);
need_clear = (lo->lo_state == Lo_rundown);
mutex_unlock(&lo->lo_mutex);
@@ -1858,7 +1858,7 @@ static blk_status_t loop_queue_rq(struct blk_mq_hw_ctx *hctx,
blk_mq_start_request(rq);
- if (lo->lo_state != Lo_bound)
+ if (data_race(READ_ONCE(lo->lo_state)) != Lo_bound)
return BLK_STS_IOERR;
switch (req_op(rq)) {
@@ -2016,7 +2016,7 @@ static int loop_add(int i)
lo->worker_tree = RB_ROOT;
INIT_LIST_HEAD(&lo->idle_worker_list);
timer_setup(&lo->timer, loop_free_idle_workers_timer, TIMER_DEFERRABLE);
- lo->lo_state = Lo_unbound;
+ WRITE_ONCE(lo->lo_state, Lo_unbound);
err = mutex_lock_killable(&loop_ctl_mutex);
if (err)
@@ -2174,7 +2174,7 @@ static int loop_control_remove(int idx)
goto mark_visible;
}
/* Mark this loop device as no more bound, but not quite unbound yet */
- lo->lo_state = Lo_deleting;
+ WRITE_ONCE(lo->lo_state, Lo_deleting);
mutex_unlock(&lo->lo_mutex);
loop_remove(lo);
@@ -2197,8 +2197,12 @@ static int loop_control_get_free(int idx)
if (ret)
return ret;
idr_for_each_entry(&loop_index_idr, lo, id) {
- /* Hitting a race results in creating a new loop device which is harmless. */
- if (lo->idr_visible && data_race(lo->lo_state) == Lo_unbound)
+ /*
+ * Hitting a race results in creating a new loop device
+ * which is harmless.
+ */
+ if (lo->idr_visible &&
+ data_race(READ_ONCE(lo->lo_state)) == Lo_unbound)
goto found;
}
mutex_unlock(&loop_ctl_mutex);
diff --git a/drivers/block/rnbd/rnbd-clt.c b/drivers/block/rnbd/rnbd-clt.c
index f1409e54010a..d1c354636315 100644
--- a/drivers/block/rnbd/rnbd-clt.c
+++ b/drivers/block/rnbd/rnbd-clt.c
@@ -1423,9 +1423,11 @@ static struct rnbd_clt_dev *init_dev(struct rnbd_clt_session *sess,
goto out_alloc;
}
- ret = ida_alloc_max(&index_ida, (1 << (MINORBITS - RNBD_PART_BITS)) - 1,
- GFP_KERNEL);
- if (ret < 0) {
+ dev->clt_device_id = ida_alloc_max(&index_ida,
+ (1 << (MINORBITS - RNBD_PART_BITS)) - 1,
+ GFP_KERNEL);
+ if (dev->clt_device_id < 0) {
+ ret = dev->clt_device_id;
pr_err("Failed to initialize device '%s' from session %s, allocating idr failed, err: %d\n",
pathname, sess->sessname, ret);
goto out_queues;
@@ -1434,10 +1436,9 @@ static struct rnbd_clt_dev *init_dev(struct rnbd_clt_session *sess,
dev->pathname = kstrdup(pathname, GFP_KERNEL);
if (!dev->pathname) {
ret = -ENOMEM;
- goto out_queues;
+ goto out_ida;
}
- dev->clt_device_id = ret;
dev->sess = sess;
dev->access_mode = access_mode;
dev->nr_poll_queues = nr_poll_queues;
@@ -1453,6 +1454,8 @@ static struct rnbd_clt_dev *init_dev(struct rnbd_clt_session *sess,
return dev;
+out_ida:
+ ida_free(&index_ida, dev->clt_device_id);
out_queues:
kfree(dev->hw_queues);
out_alloc:
diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index df9831783a13..cfd2132410dd 100644
--- a/drivers/block/ublk_drv.c
+++ b/drivers/block/ublk_drv.c
@@ -1080,12 +1080,20 @@ static inline struct ublk_uring_cmd_pdu *ublk_get_uring_cmd_pdu(
return io_uring_cmd_to_pdu(ioucmd, struct ublk_uring_cmd_pdu);
}
+static void ublk_end_request(struct request *req, blk_status_t error)
+{
+ local_bh_disable();
+ blk_mq_end_request(req, error);
+ local_bh_enable();
+}
+
/* todo: handle partial completion */
static inline void __ublk_complete_rq(struct request *req, struct ublk_io *io,
bool need_map)
{
unsigned int unmapped_bytes;
blk_status_t res = BLK_STS_OK;
+ bool requeue;
/* failed read IO if nothing is read */
if (!io->res && req_op(req) == REQ_OP_READ)
@@ -1117,14 +1125,30 @@ static inline void __ublk_complete_rq(struct request *req, struct ublk_io *io,
if (unlikely(unmapped_bytes < io->res))
io->res = unmapped_bytes;
- if (blk_update_request(req, BLK_STS_OK, io->res))
+ /*
+ * Run bio->bi_end_io() with softirqs disabled. If the final fput
+ * happens off this path, then that will prevent ublk's blkdev_release()
+ * from being called on current's task work, see fput() implementation.
+ *
+ * Otherwise, ublk server may not provide forward progress in case of
+ * reading the partition table from bdev_open() with disk->open_mutex
+ * held, and causes dead lock as we could already be holding
+ * disk->open_mutex here.
+ *
+ * Preferably we would not be doing IO with a mutex held that is also
+ * used for release, but this work-around will suffice for now.
+ */
+ local_bh_disable();
+ requeue = blk_update_request(req, BLK_STS_OK, io->res);
+ local_bh_enable();
+ if (requeue)
blk_mq_requeue_request(req, true);
else if (likely(!blk_should_fake_timeout(req->q)))
__blk_mq_end_request(req, BLK_STS_OK);
return;
exit:
- blk_mq_end_request(req, res);
+ ublk_end_request(req, res);
}
static struct io_uring_cmd *__ublk_prep_compl_io_cmd(struct ublk_io *io,
@@ -1164,7 +1188,7 @@ static inline void __ublk_abort_rq(struct ublk_queue *ubq,
if (ublk_nosrv_dev_should_queue_io(ubq->dev))
blk_mq_requeue_request(rq, false);
else
- blk_mq_end_request(rq, BLK_STS_IOERR);
+ ublk_end_request(rq, BLK_STS_IOERR);
}
static void
@@ -1209,7 +1233,7 @@ __ublk_do_auto_buf_reg(const struct ublk_queue *ubq, struct request *req,
ublk_auto_buf_reg_fallback(ubq, req->tag);
return AUTO_BUF_REG_FALLBACK;
}
- blk_mq_end_request(req, BLK_STS_IOERR);
+ ublk_end_request(req, BLK_STS_IOERR);
return AUTO_BUF_REG_FAIL;
}
diff --git a/drivers/block/zloop.c b/drivers/block/zloop.c
index 77bd6081b244..8e334f5025fc 100644
--- a/drivers/block/zloop.c
+++ b/drivers/block/zloop.c
@@ -697,7 +697,7 @@ static blk_status_t zloop_queue_rq(struct blk_mq_hw_ctx *hctx,
struct zloop_cmd *cmd = blk_mq_rq_to_pdu(rq);
struct zloop_device *zlo = rq->q->queuedata;
- if (zlo->state == Zlo_deleting)
+ if (data_race(READ_ONCE(zlo->state)) == Zlo_deleting)
return BLK_STS_IOERR;
/*
@@ -1002,7 +1002,7 @@ static int zloop_ctl_add(struct zloop_options *opts)
ret = -ENOMEM;
goto out;
}
- zlo->state = Zlo_creating;
+ WRITE_ONCE(zlo->state, Zlo_creating);
ret = mutex_lock_killable(&zloop_ctl_mutex);
if (ret)
@@ -1113,7 +1113,7 @@ static int zloop_ctl_add(struct zloop_options *opts)
}
mutex_lock(&zloop_ctl_mutex);
- zlo->state = Zlo_live;
+ WRITE_ONCE(zlo->state, Zlo_live);
mutex_unlock(&zloop_ctl_mutex);
pr_info("zloop: device %d, %u zones of %llu MiB, %u B block size\n",
@@ -1177,7 +1177,7 @@ static int zloop_ctl_remove(struct zloop_options *opts)
ret = -EINVAL;
} else {
idr_remove(&zloop_index_idr, zlo->id);
- zlo->state = Zlo_deleting;
+ WRITE_ONCE(zlo->state, Zlo_deleting);
}
mutex_unlock(&zloop_ctl_mutex);
generated by cgit v1.2.3 (git 2.0.4) at 2025-12-23 22:52:01 +0000