* [PATCH AUTOSEL 5.4 440/459] nvmet: Pass lockdep expression to RCU lists
[not found] <20200214160149.11681-1-sashal@kernel.org>
@ 2020-02-14 16:01 ` Sasha Levin
2020-02-14 16:01 ` [PATCH AUTOSEL 5.4 441/459] nvme-pci: remove nvmeq->tags Sasha Levin
1 sibling, 0 replies; 2+ messages in thread
From: Sasha Levin @ 2020-02-14 16:01 UTC (permalink / raw)
To: linux-kernel, stable
Cc: Sasha Levin, kbuild test robot, Amol Grover, linux-nvme,
Keith Busch, Joel Fernandes
From: Amol Grover <frextrite@gmail.com>
[ Upstream commit 4ac76436a6d07dec1c3c766f234aa787a16e8f65 ]
ctrl->subsys->namespaces and subsys->namespaces are traversed with
list_for_each_entry_rcu outside an RCU read-side critical section but
under the protection of ctrl->subsys->lock and subsys->lock respectively.
Hence, add the corresponding lockdep expression to the list traversal
primitive to silence false-positive lockdep warnings, and harden RCU
lists.
Reported-by: kbuild test robot <lkp@intel.com>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Amol Grover <frextrite@gmail.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/nvme/target/core.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c
index 3a67e244e5685..57a4062cbb59e 100644
--- a/drivers/nvme/target/core.c
+++ b/drivers/nvme/target/core.c
@@ -555,7 +555,8 @@ int nvmet_ns_enable(struct nvmet_ns *ns)
} else {
struct nvmet_ns *old;
- list_for_each_entry_rcu(old, &subsys->namespaces, dev_link) {
+ list_for_each_entry_rcu(old, &subsys->namespaces, dev_link,
+ lockdep_is_held(&subsys->lock)) {
BUG_ON(ns->nsid == old->nsid);
if (ns->nsid < old->nsid)
break;
@@ -1174,7 +1175,8 @@ static void nvmet_setup_p2p_ns_map(struct nvmet_ctrl *ctrl,
ctrl->p2p_client = get_device(req->p2p_client);
- list_for_each_entry_rcu(ns, &ctrl->subsys->namespaces, dev_link)
+ list_for_each_entry_rcu(ns, &ctrl->subsys->namespaces, dev_link,
+ lockdep_is_held(&ctrl->subsys->lock))
nvmet_p2pmem_ns_add_p2p(ctrl, ns);
}
--
2.20.1
_______________________________________________
linux-nvme mailing list
linux-nvme@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-nvme
^ permalink raw reply related [flat|nested] 2+ messages in thread
* [PATCH AUTOSEL 5.4 441/459] nvme-pci: remove nvmeq->tags
[not found] <20200214160149.11681-1-sashal@kernel.org>
2020-02-14 16:01 ` [PATCH AUTOSEL 5.4 440/459] nvmet: Pass lockdep expression to RCU lists Sasha Levin
@ 2020-02-14 16:01 ` Sasha Levin
1 sibling, 0 replies; 2+ messages in thread
From: Sasha Levin @ 2020-02-14 16:01 UTC (permalink / raw)
To: linux-kernel, stable
Cc: Keith Busch, Sasha Levin, Edmund Nadolski, Christoph Hellwig, linux-nvme
From: Christoph Hellwig <hch@lst.de>
[ Upstream commit cfa27356f835dc7755192e7b941d4f4851acbcc7 ]
There is no real need to have a pointer to the tagset in
struct nvme_queue, as we only need it in a single place, and that place
can derive the used tagset from the device and qid trivially. This
fixes a problem with stale pointer exposure when tagsets are reset,
and also shrinks the nvme_queue structure. It also matches what most
other transports have done since day 1.
Reported-by: Edmund Nadolski <edmund.nadolski@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/nvme/host/pci.c | 23 ++++++++---------------
1 file changed, 8 insertions(+), 15 deletions(-)
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 14d513087a14b..f34a56d588d31 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -167,7 +167,6 @@ struct nvme_queue {
/* only used for poll queues: */
spinlock_t cq_poll_lock ____cacheline_aligned_in_smp;
volatile struct nvme_completion *cqes;
- struct blk_mq_tags **tags;
dma_addr_t sq_dma_addr;
dma_addr_t cq_dma_addr;
u32 __iomem *q_db;
@@ -377,29 +376,17 @@ static int nvme_admin_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
WARN_ON(hctx_idx != 0);
WARN_ON(dev->admin_tagset.tags[0] != hctx->tags);
- WARN_ON(nvmeq->tags);
hctx->driver_data = nvmeq;
- nvmeq->tags = &dev->admin_tagset.tags[0];
return 0;
}
-static void nvme_admin_exit_hctx(struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx)
-{
- struct nvme_queue *nvmeq = hctx->driver_data;
-
- nvmeq->tags = NULL;
-}
-
static int nvme_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
unsigned int hctx_idx)
{
struct nvme_dev *dev = data;
struct nvme_queue *nvmeq = &dev->queues[hctx_idx + 1];
- if (!nvmeq->tags)
- nvmeq->tags = &dev->tagset.tags[hctx_idx];
-
WARN_ON(dev->tagset.tags[hctx_idx] != hctx->tags);
hctx->driver_data = nvmeq;
return 0;
@@ -950,6 +937,13 @@ static inline void nvme_ring_cq_doorbell(struct nvme_queue *nvmeq)
writel(head, nvmeq->q_db + nvmeq->dev->db_stride);
}
+static inline struct blk_mq_tags *nvme_queue_tagset(struct nvme_queue *nvmeq)
+{
+ if (!nvmeq->qid)
+ return nvmeq->dev->admin_tagset.tags[0];
+ return nvmeq->dev->tagset.tags[nvmeq->qid - 1];
+}
+
static inline void nvme_handle_cqe(struct nvme_queue *nvmeq, u16 idx)
{
volatile struct nvme_completion *cqe = &nvmeq->cqes[idx];
@@ -975,7 +969,7 @@ static inline void nvme_handle_cqe(struct nvme_queue *nvmeq, u16 idx)
return;
}
- req = blk_mq_tag_to_rq(*nvmeq->tags, cqe->command_id);
+ req = blk_mq_tag_to_rq(nvme_queue_tagset(nvmeq), cqe->command_id);
trace_nvme_sq(req, cqe->sq_head, nvmeq->sq_tail);
nvme_end_request(req, cqe->status, cqe->result);
}
@@ -1578,7 +1572,6 @@ static const struct blk_mq_ops nvme_mq_admin_ops = {
.queue_rq = nvme_queue_rq,
.complete = nvme_pci_complete_rq,
.init_hctx = nvme_admin_init_hctx,
- .exit_hctx = nvme_admin_exit_hctx,
.init_request = nvme_init_request,
.timeout = nvme_timeout,
};
--
2.20.1
_______________________________________________
linux-nvme mailing list
linux-nvme@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-nvme
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2020-02-14 16:01 ` [PATCH AUTOSEL 5.4 440/459] nvmet: Pass lockdep expression to RCU lists Sasha Levin
2020-02-14 16:01 ` [PATCH AUTOSEL 5.4 441/459] nvme-pci: remove nvmeq->tags Sasha Levin
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