nvme-pci: align io queue count with allocted nvme_queue in nvme_probe

Since commit 147b27e4bd08 ("nvme-pci: allocate device queues storage
space at probe"), nvme_alloc_queue does not alloc the nvme queues
itself anymore.

If the write/poll_queues module parameters are changed at runtime to
values larger than the number of allocated queues in nvme_probe,
nvme_alloc_queue will access unallocated memory.

Add a new nr_allocated_queues member to struct nvme_dev to record how
many queues were alloctated in nvme_probe to avoid using more than the
allocated queues after a reset following a change to the
write/poll_queues module parameters.

Also add nr_write_queues and nr_poll_queues members to allow refreshing
the number of write and poll queues based on a change to the module
parameters when resetting the controller.

Fixes: 147b27e4bd08 ("nvme-pci: allocate device queues storage space at probe")
Signed-off-by: Weiping Zhang <zhangweiping@didiglobal.com>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
[hch: add nvme_max_io_queues, update the commit message]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index b945e9a89883ad9d376420d4b48a13975a71a67e..b0978ac554d5df5b891cff6a6f935077cd565391 100644 (file)
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -128,6 +128,9 @@ struct nvme_dev {
        dma_addr_t host_mem_descs_dma;
        struct nvme_host_mem_buf_desc *host_mem_descs;
        void **host_mem_desc_bufs;
+       unsigned int nr_allocated_queues;
+       unsigned int nr_write_queues;
+       unsigned int nr_poll_queues;
 };
 
 static int io_queue_depth_set(const char *val, const struct kernel_param *kp)
@@ -208,25 +211,14 @@ struct nvme_iod {
        struct scatterlist *sg;
 };
 
-static unsigned int max_io_queues(void)
+static inline unsigned int nvme_dbbuf_size(struct nvme_dev *dev)
 {
-       return num_possible_cpus() + write_queues + poll_queues;
-}
-
-static unsigned int max_queue_count(void)
-{
-       /* IO queues + admin queue */
-       return 1 + max_io_queues();
-}
-
-static inline unsigned int nvme_dbbuf_size(u32 stride)
-{
-       return (max_queue_count() * 8 * stride);
+       return dev->nr_allocated_queues * 8 * dev->db_stride;
 }
 
 static int nvme_dbbuf_dma_alloc(struct nvme_dev *dev)
 {
-       unsigned int mem_size = nvme_dbbuf_size(dev->db_stride);
+       unsigned int mem_size = nvme_dbbuf_size(dev);
 
        if (dev->dbbuf_dbs)
                return 0;
@@ -251,7 +243,7 @@ static int nvme_dbbuf_dma_alloc(struct nvme_dev *dev)
 
 static void nvme_dbbuf_dma_free(struct nvme_dev *dev)
 {
-       unsigned int mem_size = nvme_dbbuf_size(dev->db_stride);
+       unsigned int mem_size = nvme_dbbuf_size(dev);
 
        if (dev->dbbuf_dbs) {
                dma_free_coherent(dev->dev, mem_size,
@@ -1981,7 +1973,7 @@ static int nvme_setup_host_mem(struct nvme_dev *dev)
 static void nvme_calc_irq_sets(struct irq_affinity *affd, unsigned int nrirqs)
 {
        struct nvme_dev *dev = affd->priv;
-       unsigned int nr_read_queues;
+       unsigned int nr_read_queues, nr_write_queues = dev->nr_write_queues;
 
        /*
         * If there is no interupt available for queues, ensure that
@@ -1997,12 +1989,12 @@ static void nvme_calc_irq_sets(struct irq_affinity *affd, unsigned int nrirqs)
        if (!nrirqs) {
                nrirqs = 1;
                nr_read_queues = 0;
-       } else if (nrirqs == 1 || !write_queues) {
+       } else if (nrirqs == 1 || !nr_write_queues) {
                nr_read_queues = 0;
-       } else if (write_queues >= nrirqs) {
+       } else if (nr_write_queues >= nrirqs) {
                nr_read_queues = 1;
        } else {
-               nr_read_queues = nrirqs - write_queues;
+               nr_read_queues = nrirqs - nr_write_queues;
        }
 
        dev->io_queues[HCTX_TYPE_DEFAULT] = nrirqs - nr_read_queues;
@@ -2026,7 +2018,7 @@ static int nvme_setup_irqs(struct nvme_dev *dev, unsigned int nr_io_queues)
         * Poll queues don't need interrupts, but we need at least one IO
         * queue left over for non-polled IO.
         */
-       this_p_queues = poll_queues;
+       this_p_queues = dev->nr_poll_queues;
        if (this_p_queues >= nr_io_queues) {
                this_p_queues = nr_io_queues - 1;
                irq_queues = 1;
@@ -2056,14 +2048,25 @@ static void nvme_disable_io_queues(struct nvme_dev *dev)
                __nvme_disable_io_queues(dev, nvme_admin_delete_cq);
 }
 
+static unsigned int nvme_max_io_queues(struct nvme_dev *dev)
+{
+       return num_possible_cpus() + dev->nr_write_queues + dev->nr_poll_queues;
+}
+
 static int nvme_setup_io_queues(struct nvme_dev *dev)
 {
        struct nvme_queue *adminq = &dev->queues[0];
        struct pci_dev *pdev = to_pci_dev(dev->dev);
-       int result, nr_io_queues;
+       unsigned int nr_io_queues;
        unsigned long size;
+       int result;
 
-       nr_io_queues = max_io_queues();
+       /*
+        * Sample the module parameters once at reset time so that we have
+        * stable values to work with.
+        */
+       dev->nr_write_queues = write_queues;
+       dev->nr_poll_queues = poll_queues;
 
        /*
         * If tags are shared with admin queue (Apple bug), then
@@ -2071,6 +2074,9 @@ static int nvme_setup_io_queues(struct nvme_dev *dev)
         */
        if (dev->ctrl.quirks & NVME_QUIRK_SHARED_TAGS)
                nr_io_queues = 1;
+       else
+               nr_io_queues = min(nvme_max_io_queues(dev),
+                                  dev->nr_allocated_queues - 1);
 
        result = nvme_set_queue_count(&dev->ctrl, &nr_io_queues);
        if (result < 0)
@@ -2745,8 +2751,11 @@ static int nvme_probe(struct pci_dev *pdev, const struct pci_device_id *id)
        if (!dev)
                return -ENOMEM;
 
-       dev->queues = kcalloc_node(max_queue_count(), sizeof(struct nvme_queue),
-                                       GFP_KERNEL, node);
+       dev->nr_write_queues = write_queues;
+       dev->nr_poll_queues = poll_queues;
+       dev->nr_allocated_queues = nvme_max_io_queues(dev) + 1;
+       dev->queues = kcalloc_node(dev->nr_allocated_queues,
+                       sizeof(struct nvme_queue), GFP_KERNEL, node);
        if (!dev->queues)
                goto free;