[PATCH] RDMA/srpt: Make slab cache names unique

Bart Van Assche
2024-10-04T17:38:25Z

Since commit 4c39529663b9 ("slab: Warn on duplicate cache names when
DEBUG_VM=y"), slab complains about duplicate cache names. Hence this
patch that makes cache names unique.

Reported-by: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Closes: https://lore.kernel.org/linux-block/xpe6bea7rakpyoyfvspvin2dsozjmjtjktpph7rep3h25tv7fb@ooz4cu5z6bq6/
Fixes: 5dabcd0456d7 ("RDMA/srpt: Add support for immediate data")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
drivers/infiniband/ulp/srpt/ib_srpt.c | 32 ++++++++++++++++++++++-----
drivers/infiniband/ulp/srpt/ib_srpt.h | 6 +++++
2 files changed, 32 insertions(+), 6 deletions(-)

diff --git a/drivers/infiniband/ulp/srpt/ib_srpt.c b/drivers/infiniband/ulp/srpt/ib_srpt.c
index 9632afbd727b..4cb462074f00 100644
--- a/drivers/infiniband/ulp/srpt/ib_srpt.c
+++ b/drivers/infiniband/ulp/srpt/ib_srpt.c
@@ -41,6 +41,7 @@
#include <linux/string.h>
#include <linux/delay.h>
#include <linux/atomic.h>
+#include <linux/idr.h>
#include <linux/inet.h>
#include <rdma/ib_cache.h>
#include <scsi/scsi_proto.h>
@@ -68,6 +69,7 @@ MODULE_LICENSE("Dual BSD/GPL");
static u64 srpt_service_guid;
static DEFINE_SPINLOCK(srpt_dev_lock); /* Protects srpt_dev_list. */
static LIST_HEAD(srpt_dev_list); /* List of srpt_device structures. */
+static DEFINE_IDA(cache_ida);

static unsigned srp_max_req_size = DEFAULT_MAX_REQ_SIZE;
module_param(srp_max_req_size, int, 0444);
@@ -2120,12 +2122,14 @@ static void srpt_release_channel_work(struct work_struct *w)
ch->rsp_buf_cache, DMA_TO_DEVICE);

kmem_cache_destroy(ch->rsp_buf_cache);
+ ida_free(&cache_ida, ch->rsp_buf_cache_idx);

srpt_free_ioctx_ring((struct srpt_ioctx **)ch->ioctx_recv_ring,
sdev, ch->rq_size,
ch->req_buf_cache, DMA_FROM_DEVICE);

kmem_cache_destroy(ch->req_buf_cache);
+ ida_free(&cache_ida, ch->req_buf_cache_idx);

kref_put(&ch->kref, srpt_free_ch);
}
@@ -2164,6 +2168,7 @@ static int srpt_cm_req_recv(struct srpt_device *const sdev,
u32 it_iu_len;
int i, tag_num, tag_size, ret;
struct srpt_tpg *stpg;
+ char cache_name[32];

WARN_ON_ONCE(irqs_disabled());

@@ -2245,8 +2250,11 @@ static int srpt_cm_req_recv(struct srpt_device *const sdev,
INIT_LIST_HEAD(&ch->cmd_wait_list);
ch->max_rsp_size = ch->sport->port_attrib.srp_max_rsp_size;

- ch->rsp_buf_cache = kmem_cache_create("srpt-rsp-buf", ch->max_rsp_size,
- 512, 0, NULL);
+ ch->rsp_buf_cache_idx = ida_alloc(&cache_ida, GFP_KERNEL);
+ snprintf(cache_name, sizeof(cache_name), "srpt-rsp-buf-%u",
+ ch->rsp_buf_cache_idx);
+ ch->rsp_buf_cache =
+ kmem_cache_create(cache_name, ch->max_rsp_size, 512, 0, NULL);
if (!ch->rsp_buf_cache)
goto free_ch;

@@ -2280,8 +2288,11 @@ static int srpt_cm_req_recv(struct srpt_device *const sdev,
alignment_offset = round_up(imm_data_offset, 512) -
imm_data_offset;
req_sz = alignment_offset + imm_data_offset + srp_max_req_size;
- ch->req_buf_cache = kmem_cache_create("srpt-req-buf", req_sz,
- 512, 0, NULL);
+ ch->req_buf_cache_idx = ida_alloc(&cache_ida, GFP_KERNEL);
+ snprintf(cache_name, sizeof(cache_name), "srpt-req-buf-%u",
+ ch->req_buf_cache_idx);
+ ch->req_buf_cache =
+ kmem_cache_create(cache_name, req_sz, 512, 0, NULL);
if (!ch->req_buf_cache)
goto free_rsp_ring;

@@ -2479,6 +2490,7 @@ static int srpt_cm_req_recv(struct srpt_device *const sdev,

free_recv_cache:
kmem_cache_destroy(ch->req_buf_cache);
+ ida_free(&cache_ida, ch->req_buf_cache_idx);

free_rsp_ring:
srpt_free_ioctx_ring((struct srpt_ioctx **)ch->ioctx_ring,
@@ -2487,6 +2499,7 @@ static int srpt_cm_req_recv(struct srpt_device *const sdev,

free_rsp_cache:
kmem_cache_destroy(ch->rsp_buf_cache);
+ ida_free(&cache_ida, ch->rsp_buf_cache_idx);

free_ch:
if (rdma_cm_id)
@@ -3056,6 +3069,7 @@ static void srpt_free_srq(struct srpt_device *sdev)
sdev->srq_size, sdev->req_buf_cache,
DMA_FROM_DEVICE);
kmem_cache_destroy(sdev->req_buf_cache);
+ ida_free(&cache_ida, sdev->req_buf_cache_idx);
sdev->srq = NULL;
}

@@ -3070,6 +3084,7 @@ static int srpt_alloc_srq(struct srpt_device *sdev)
};
struct ib_device *device = sdev->device;
struct ib_srq *srq;
+ char cache_name[32];
int i;

WARN_ON_ONCE(sdev->srq);
@@ -3082,8 +3097,11 @@ static int srpt_alloc_srq(struct srpt_device *sdev)
pr_debug("create SRQ #wr= %d max_allow=%d dev= %s\n", sdev->srq_size,
sdev->device->attrs.max_srq_wr, dev_name(&device->dev));

- sdev->req_buf_cache = kmem_cache_create("srpt-srq-req-buf",
- srp_max_req_size, 0, 0, NULL);
+ sdev->req_buf_cache_idx = ida_alloc(&cache_ida, GFP_KERNEL);
+ snprintf(cache_name, sizeof(cache_name), "srpt-srq-req-buf-%u",
+ sdev->req_buf_cache_idx);
+ sdev->req_buf_cache =
+ kmem_cache_create(cache_name, srp_max_req_size, 0, 0, NULL);
if (!sdev->req_buf_cache)
goto free_srq;

@@ -3106,6 +3124,7 @@ static int srpt_alloc_srq(struct srpt_device *sdev)

free_cache:
kmem_cache_destroy(sdev->req_buf_cache);
+ ida_free(&cache_ida, sdev->req_buf_cache_idx);

free_srq:
ib_destroy_srq(srq);
@@ -3926,6 +3945,7 @@ static void __exit srpt_cleanup_module(void)
rdma_destroy_id(rdma_cm_id);
ib_unregister_client(&srpt_client);
target_unregister_template(&srpt_template);
+ ida_destroy(&cache_ida);
}

module_init(srpt_init_module);
diff --git a/drivers/infiniband/ulp/srpt/ib_srpt.h b/drivers/infiniband/ulp/srpt/ib_srpt.h
index 4c46b301eea1..6d10cd7c9f21 100644
--- a/drivers/infiniband/ulp/srpt/ib_srpt.h
+++ b/drivers/infiniband/ulp/srpt/ib_srpt.h
@@ -276,6 +276,8 @@ enum rdma_ch_state {
* @state: channel state. See also enum rdma_ch_state.
* @using_rdma_cm: Whether the RDMA/CM or IB/CM is used for this channel.
* @processing_wait_list: Whether or not cmd_wait_list is being processed.
+ * @rsp_buf_cache_idx: @rsp_buf_cache index for slab.
+ * @req_buf_cache_idx: @req_buf_cache index for slab.
* @rsp_buf_cache: kmem_cache for @ioctx_ring.
* @ioctx_ring: Send ring.
* @req_buf_cache: kmem_cache for @ioctx_recv_ring.
@@ -316,6 +318,8 @@ struct srpt_rdma_ch {
u16 imm_data_offset;
spinlock_t spinlock;
enum rdma_ch_state state;
+ int rsp_buf_cache_idx;
+ int req_buf_cache_idx;
struct kmem_cache *rsp_buf_cache;
struct srpt_send_ioctx **ioctx_ring;
struct kmem_cache *req_buf_cache;
@@ -443,6 +447,7 @@ struct srpt_port {
* @srq_size: SRQ size.
* @sdev_mutex: Serializes use_srq changes.
* @use_srq: Whether or not to use SRQ.
+ * @req_buf_cache_idx: @req_buf_cache index for slab.
* @req_buf_cache: kmem_cache for @ioctx_ring buffers.
* @ioctx_ring: Per-HCA SRQ.
* @event_handler: Per-HCA asynchronous IB event handler.
@@ -459,6 +464,7 @@ struct srpt_device {
int srq_size;
struct mutex sdev_mutex;
bool use_srq;
+ int req_buf_cache_idx;
struct kmem_cache *req_buf_cache;
struct srpt_recv_ioctx **ioctx_ring;
struct ib_event_handler event_handler;