* [PATCH v2] nvmet: add cgroup_path to charge namespace I/O to a cgroup
@ 2026-09-22 6:51 yupeng
2026-09-22 7:00 ` Maurizio Lombardi
0 siblings, 1 reply; 2+ messages in thread
From: yupeng @ 2026-09-22 6:51 UTC (permalink / raw)
To: Christoph Hellwig, Sagi Grimberg, Chaitanya Kulkarni
Cc: Tejun Heo, Johannes Weiner, Michal Koutný,
Josef Bacik, Jens Axboe, cgroups, linux-block, linux-nvme,
linux-kernel, Peng Yu
From: Peng Yu <yupeng0921@gmail.com>
Scenario:
* Create multiple nvmet subsystems/namespaces.
* The namespaces are backed by different LVM logical volumes.
* Some of the logical volumes share the same physical volumes.
* The subsystems are exported to different users.
* We should provide each user a specific iops/bps quota, thus a noisy
neighbor won't impact the performance of other logical volumes.
Implementation:
* Add a `cgroup_path` attribute under the nvmet namespace folder, e.g.:
/sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:bdev/namespaces/1/cgroup_path
* We can write a cgroup path to it, then that cgroup will control
the IOs used by the namespace.
* Write an empty string to clear it.
* The cgroup_path could be modified when the namespace is disabled.
* Support both block device backed namespaces and file backed namespaces.
* Only the direct io scenario is supported, enabling a namespace that
has both cgroup_path and buffered_io set fails with -EINVAL.
Test:
1 Load kernel modules.
sudo modprobe brd rd_nr=2 rd_size=1048576
sudo modprobe nvmet
sudo modprobe nvmet_tcp
sudo modprobe nvme_tcp
2 The two brd devices are used for a bdev backed namespace and a file
backed namespace, remember their major/minor.
lsblk --noheadings --nodeps --output NAME,MAJ:MIN,SIZE /dev/ram0 /dev/ram1
ram0 1:0 1G
ram1 1:1 1G
3 Enable the io controller and create two cgroups, one for the bdev
backed namespace, another for the file backed namespace.
echo "+io" | sudo tee /sys/fs/cgroup/cgroup.subtree_control
sudo mkdir -p /sys/fs/cgroup/nvmet-bdev
sudo mkdir -p /sys/fs/cgroup/nvmet-file
4 Create a file system and a file on ram0.
sudo mkfs.ext4 /dev/ram0
sudo mkdir -p /mnt/nvmet-file
sudo mount -o noatime /dev/ram0 /mnt/nvmet-file
sudo dd if=/dev/zero of=/mnt/nvmet-file/ns.img bs=1M count=512 oflag=direct
5 Create the bdev backed subsystem and namespace.
sudo mkdir -p /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:bdev/namespaces/1
echo 1 | sudo tee /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:bdev/attr_allow_any_host
echo /dev/ram1 | sudo tee /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:bdev/namespaces/1/device_path
echo /nvmet-bdev | sudo tee /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:bdev/namespaces/1/cgroup_path
echo 1 | sudo tee /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:bdev/namespaces/1/enable
6 Create the file backed subsystem and namespace.
sudo mkdir -p /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:file/namespaces/1
echo 1 | sudo tee /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:file/attr_allow_any_host
echo /mnt/nvmet-file/ns.img | sudo tee /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:file/namespaces/1/device_path
echo /nvmet-file | sudo tee /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:file/namespaces/1/cgroup_path
echo 1 | sudo tee /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:file/namespaces/1/enable
7 Export the two subsystems to 127.0.0.1.
sudo mkdir -p /sys/kernel/config/nvmet/ports/1
echo ipv4 | sudo tee /sys/kernel/config/nvmet/ports/1/addr_adrfam
echo tcp | sudo tee /sys/kernel/config/nvmet/ports/1/addr_trtype
echo 127.0.0.1 | sudo tee /sys/kernel/config/nvmet/ports/1/addr_traddr
echo 4420 | sudo tee /sys/kernel/config/nvmet/ports/1/addr_trsvcid
sudo ln -s /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:bdev /sys/kernel/config/nvmet/ports/1/subsystems/nqn.2026-09.io.test01:bdev
sudo ln -s /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:file /sys/kernel/config/nvmet/ports/1/subsystems/nqn.2026-09.io.test01:file
8 Connect the two subsystems from 127.0.0.1.
sudo nvme connect -t tcp -a 127.0.0.1 -s 4420 -n nqn.2026-09.io.test01:bdev
sudo nvme connect -t tcp -a 127.0.0.1 -s 4420 -n nqn.2026-09.io.test01:file
sudo udevadm settle
9 Set riops to 20k and run fio.
echo "1:1 riops=20000 wiops=max rbps=max wbps=max" | sudo tee /sys/fs/cgroup/nvmet-bdev/io.max
echo "1:0 riops=20000 wiops=max rbps=max wbps=max" | sudo tee /sys/fs/cgroup/nvmet-file/io.max
sudo fio --name=t --filename=/dev/nvme0n1 --rw=randread --bs=4k --iodepth=32 --numjobs=1 \
--direct=1 --ioengine=libaio --time_based --runtime=10 --ramp_time=3 \
--group_reporting 2>/dev/null | grep -E '^ +(read|write): IOPS'
read: IOPS=20.0k, BW=78.1MiB/s (81.9MB/s)(781MiB/10001msec)
sudo fio --name=t --filename=/dev/nvme1n1 --rw=randread --bs=4k --iodepth=32 --numjobs=1 \
--direct=1 --ioengine=libaio --time_based --runtime=10 --ramp_time=3 \
--group_reporting 2>/dev/null | grep -E '^ +(read|write): IOPS'
read: IOPS=20.0k, BW=78.1MiB/s (81.9MB/s)(781MiB/10001msec)
10 Set rbps to 100M and run fio.
echo "1:1 riops=max wiops=max rbps=104857600 wbps=max" | sudo tee /sys/fs/cgroup/nvmet-bdev/io.max
echo "1:0 riops=max wiops=max rbps=104857600 wbps=max" | sudo tee /sys/fs/cgroup/nvmet-file/io.max
sudo fio --name=t --filename=/dev/nvme0n1 --rw=read --bs=1M --iodepth=32 --numjobs=1 \
--direct=1 --ioengine=libaio --time_based --runtime=10 --ramp_time=3 \
--group_reporting 2>/dev/null | grep -E '^ +(read|write): IOPS'
read: IOPS=97, BW=100MiB/s (105MB/s)(1033MiB/10304msec)
sudo fio --name=t --filename=/dev/nvme1n1 --rw=read --bs=1M --iodepth=32 --numjobs=1 \
--direct=1 --ioengine=libaio --time_based --runtime=10 --ramp_time=3 \
--group_reporting 2>/dev/null | grep -E '^ +(read|write): IOPS'
read: IOPS=97, BW=100MiB/s (105MB/s)(1031MiB/10297msec)
11 Set wiops to 20k and run fio.
echo "1:1 riops=max wiops=20000 rbps=max wbps=max" | sudo tee /sys/fs/cgroup/nvmet-bdev/io.max
echo "1:0 riops=max wiops=20000 rbps=max wbps=max" | sudo tee /sys/fs/cgroup/nvmet-file/io.max
sudo fio --name=t --filename=/dev/nvme0n1 --rw=randwrite --bs=4k --iodepth=32 --numjobs=1 \
--direct=1 --ioengine=libaio --time_based --runtime=10 --ramp_time=3 \
--group_reporting 2>/dev/null | grep -E '^ +(read|write): IOPS'
write: IOPS=20.0k, BW=78.1MiB/s (81.9MB/s)(781MiB/10001msec); 0 zone resets
sudo fio --name=t --filename=/dev/nvme1n1 --rw=randwrite --bs=4k --iodepth=32 --numjobs=1 \
--direct=1 --ioengine=libaio --time_based --runtime=10 --ramp_time=3 \
--group_reporting 2>/dev/null | grep -E '^ +(read|write): IOPS'
write: IOPS=20.0k, BW=78.1MiB/s (81.9MB/s)(781MiB/10001msec); 0 zone resets
12 Set wbps to 100M and run fio.
echo "1:1 riops=max wiops=max rbps=max wbps=104857600" | sudo tee /sys/fs/cgroup/nvmet-bdev/io.max
echo "1:0 riops=max wiops=max rbps=max wbps=104857600" | sudo tee /sys/fs/cgroup/nvmet-file/io.max
sudo fio --name=t --filename=/dev/nvme0n1 --rw=write --bs=1M --iodepth=32 --numjobs=1 \
--direct=1 --ioengine=libaio --time_based --runtime=10 --ramp_time=3 \
--group_reporting 2>/dev/null | grep -E '^ +(read|write): IOPS'
write: IOPS=97, BW=100MiB/s (105MB/s)(1031MiB/10305msec); 0 zone resets
sudo fio --name=t --filename=/dev/nvme1n1 --rw=write --bs=1M --iodepth=32 --numjobs=1 \
--direct=1 --ioengine=libaio --time_based --runtime=10 --ramp_time=3 \
--group_reporting 2>/dev/null | grep -E '^ +(read|write): IOPS'
write: IOPS=97, BW=100MiB/s (105MB/s)(1032MiB/10297msec); 0 zone resets
13 Cleanup the environment.
sudo nvme disconnect -n nqn.2026-09.io.test01:bdev
sudo nvme disconnect -n nqn.2026-09.io.test01:file
sudo udevadm settle
sudo rm -f /sys/kernel/config/nvmet/ports/1/subsystems/nqn.2026-09.io.test01:bdev
sudo rm -f /sys/kernel/config/nvmet/ports/1/subsystems/nqn.2026-09.io.test01:file
sudo rmdir /sys/kernel/config/nvmet/ports/1
echo 0 | sudo tee /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:bdev/namespaces/1/enable
sudo rmdir /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:bdev/namespaces/1
sudo rmdir /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:bdev
echo 0 | sudo tee /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:file/namespaces/1/enable
sudo rmdir /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:file/namespaces/1
sudo rmdir /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:file
sudo umount /mnt/nvmet-file
sudo rmdir /mnt/nvmet-file
sudo modprobe -r brd
sudo rmdir /sys/fs/cgroup/nvmet-bdev
sudo rmdir /sys/fs/cgroup/nvmet-file
sudo rmmod nvme_tcp
sudo rmmod nvmet_tcp
sudo rmmod nvmet
Signed-off-by: Peng Yu <yupeng0921@gmail.com>
Assisted-by: Claude:claude-fable-5 [Claude Code]
Assisted-by: Claude:claude-opus-5 [Claude Code]
---
drivers/nvme/target/configfs.c | 59 ++++++++++++++++++++++++
drivers/nvme/target/core.c | 75 +++++++++++++++++++++++++++++++
drivers/nvme/target/io-cmd-bdev.c | 18 +++++++-
drivers/nvme/target/io-cmd-file.c | 21 ++++++++-
drivers/nvme/target/nvmet.h | 47 +++++++++++++++++++
drivers/nvme/target/zns.c | 1 +
6 files changed, 218 insertions(+), 3 deletions(-)
diff --git a/drivers/nvme/target/configfs.c b/drivers/nvme/target/configfs.c
index 6286e38436dd..829b92d04ad4 100644
--- a/drivers/nvme/target/configfs.c
+++ b/drivers/nvme/target/configfs.c
@@ -561,6 +561,62 @@ static ssize_t nvmet_ns_device_path_store(struct config_item *item,
CONFIGFS_ATTR(nvmet_ns_, device_path);
+#ifdef CONFIG_BLK_CGROUP
+static ssize_t nvmet_ns_cgroup_path_show(struct config_item *item, char *page)
+{
+ struct nvmet_ns *ns = to_nvmet_ns(item);
+ struct nvmet_subsys *subsys = ns->subsys;
+ ssize_t ret;
+
+ mutex_lock(&subsys->lock);
+ ret = snprintf(page, PAGE_SIZE, "%s\n", ns->cgroup_path ?: "");
+ mutex_unlock(&subsys->lock);
+ return ret;
+}
+
+static ssize_t nvmet_ns_cgroup_path_store(struct config_item *item,
+ const char *page, size_t count)
+{
+ struct nvmet_ns *ns = to_nvmet_ns(item);
+ struct nvmet_subsys *subsys = ns->subsys;
+ size_t len;
+ int ret = count;
+
+ mutex_lock(&subsys->lock);
+
+ if (ns->enabled) {
+ ret = -EBUSY;
+ goto out_unlock;
+ }
+
+ len = strcspn(page, "\n");
+ if (!len) {
+ /* An empty write clears the association. */
+ kfree(ns->cgroup_path);
+ ns->cgroup_path = NULL;
+ goto out_unlock;
+ }
+
+ if (page[0] != '/' || len >= PATH_MAX) {
+ ret = -EINVAL;
+ goto out_unlock;
+ }
+
+ kfree(ns->cgroup_path);
+ ns->cgroup_path = kmemdup_nul(page, len, GFP_KERNEL);
+ if (!ns->cgroup_path) {
+ ret = -ENOMEM;
+ goto out_unlock;
+ }
+
+out_unlock:
+ mutex_unlock(&subsys->lock);
+ return ret;
+}
+
+CONFIGFS_ATTR(nvmet_ns_, cgroup_path);
+#endif /* CONFIG_BLK_CGROUP */
+
#ifdef CONFIG_PCI_P2PDMA
static ssize_t nvmet_ns_p2pmem_show(struct config_item *item, char *page)
{
@@ -833,6 +889,9 @@ static struct configfs_attribute *nvmet_ns_attrs[] = {
&nvmet_ns_attr_buffered_io,
&nvmet_ns_attr_revalidate_size,
&nvmet_ns_attr_resv_enable,
+#ifdef CONFIG_BLK_CGROUP
+ &nvmet_ns_attr_cgroup_path,
+#endif
#ifdef CONFIG_PCI_P2PDMA
&nvmet_ns_attr_p2pmem,
#endif
diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c
index 43871a8f56ca..3e4972513c3e 100644
--- a/drivers/nvme/target/core.c
+++ b/drivers/nvme/target/core.c
@@ -4,6 +4,7 @@
* Copyright (c) 2015-2016 HGST, a Western Digital Company.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <linux/cgroup.h>
#include <linux/hex.h>
#include <linux/module.h>
#include <linux/random.h>
@@ -474,8 +475,77 @@ void nvmet_put_namespace(struct nvmet_ns *ns)
percpu_ref_put(&ns->ref);
}
+#ifdef CONFIG_BLK_CGROUP
+static int nvmet_blkcg_ns_enable(struct nvmet_ns *ns)
+{
+ struct cgroup_subsys_state *css;
+ struct cgroup *cgrp;
+
+ if (!ns->cgroup_path)
+ return 0;
+
+ /*
+ * Buffered writes will be handled by a separate thread,
+ * these IOs have no namespace/cgroup information at that time,
+ * so we don't support buffered io.
+ */
+ if (ns->buffered_io) {
+ pr_err("cgroup_path is not supported with buffered_io: %s\n",
+ ns->device_path);
+ return -EINVAL;
+ }
+
+ cgrp = cgroup_get_from_path(ns->cgroup_path);
+ if (IS_ERR(cgrp)) {
+ pr_err("failed to resolve cgroup path %s: %ld\n",
+ ns->cgroup_path, PTR_ERR(cgrp));
+ return PTR_ERR(cgrp);
+ }
+
+ css = cgroup_get_e_css(cgrp, &io_cgrp_subsys);
+ if (!css || css->cgroup != cgrp) {
+ pr_err("the io controller is not enabled in cgroup %s\n",
+ ns->cgroup_path);
+ if (css)
+ css_put(css);
+ cgroup_put(cgrp);
+ return -EINVAL;
+ }
+ ns->blkcg_css = css;
+ cgroup_put(cgrp);
+ return 0;
+}
+
+static void nvmet_blkcg_ns_disable(struct nvmet_ns *ns)
+{
+ if (ns->blkcg_css) {
+ css_put(ns->blkcg_css);
+ ns->blkcg_css = NULL;
+ }
+}
+
+static void nvmet_blkcg_ns_free(struct nvmet_ns *ns)
+{
+ kfree(ns->cgroup_path);
+}
+#else
+static inline int nvmet_blkcg_ns_enable(struct nvmet_ns *ns)
+{
+ return 0;
+}
+
+static inline void nvmet_blkcg_ns_disable(struct nvmet_ns *ns)
+{
+}
+
+static inline void nvmet_blkcg_ns_free(struct nvmet_ns *ns)
+{
+}
+#endif /* CONFIG_BLK_CGROUP */
+
static void nvmet_ns_dev_disable(struct nvmet_ns *ns)
{
+ nvmet_blkcg_ns_disable(ns);
nvmet_bdev_ns_disable(ns);
nvmet_file_ns_disable(ns);
}
@@ -602,6 +672,10 @@ int nvmet_ns_enable(struct nvmet_ns *ns)
if (ret)
goto out_unlock;
+ ret = nvmet_blkcg_ns_enable(ns);
+ if (ret)
+ goto out_dev_disable;
+
ret = nvmet_p2pmem_ns_enable(ns);
if (ret)
goto out_dev_disable;
@@ -699,6 +773,7 @@ void nvmet_ns_free(struct nvmet_ns *ns)
up_write(&nvmet_ana_sem);
kfree(ns->device_path);
+ nvmet_blkcg_ns_free(ns);
kfree(ns);
}
diff --git a/drivers/nvme/target/io-cmd-bdev.c b/drivers/nvme/target/io-cmd-bdev.c
index f2d9e8901df4..0014e5ef2853 100644
--- a/drivers/nvme/target/io-cmd-bdev.c
+++ b/drivers/nvme/target/io-cmd-bdev.c
@@ -297,6 +297,7 @@ static void nvmet_bdev_execute_rw(struct nvmet_req *req)
bio = bio_alloc(req->ns->bdev, bio_max_segs(sg_cnt), opf,
GFP_KERNEL);
}
+ nvmet_blkcg_set_bio(req->ns, bio);
bio->bi_iter.bi_sector = sector;
bio->bi_private = req;
bio->bi_end_io = nvmet_bio_done;
@@ -322,6 +323,7 @@ static void nvmet_bdev_execute_rw(struct nvmet_req *req)
bio = bio_alloc(req->ns->bdev, bio_max_segs(sg_cnt),
opf, GFP_KERNEL);
+ nvmet_blkcg_set_bio(req->ns, bio);
bio->bi_iter.bi_sector = sector;
bio_chain(bio, prev);
@@ -358,6 +360,7 @@ static void nvmet_bdev_execute_flush(struct nvmet_req *req)
bio_init(bio, req->ns->bdev, req->inline_bvec,
ARRAY_SIZE(req->inline_bvec), REQ_OP_WRITE | REQ_PREFLUSH);
+ nvmet_blkcg_set_bio(req->ns, bio);
bio->bi_private = req;
bio->bi_end_io = nvmet_bio_done;
@@ -366,10 +369,16 @@ static void nvmet_bdev_execute_flush(struct nvmet_req *req)
u16 nvmet_bdev_flush(struct nvmet_req *req)
{
+ bool associated;
+ int ret;
+
if (!bdev_write_cache(req->ns->bdev))
return 0;
- if (blkdev_issue_flush(req->ns->bdev))
+ associated = nvmet_blkcg_begin(req->ns);
+ ret = blkdev_issue_flush(req->ns->bdev);
+ nvmet_blkcg_end(associated);
+ if (ret)
return NVME_SC_INTERNAL | NVME_STATUS_DNR;
return 0;
}
@@ -380,9 +389,11 @@ static void nvmet_bdev_execute_discard(struct nvmet_req *req)
struct nvme_dsm_range range;
struct bio *bio = NULL;
sector_t nr_sects;
+ bool associated;
int i;
u16 status = NVME_SC_SUCCESS;
+ associated = nvmet_blkcg_begin(ns);
for (i = 0; i <= le32_to_cpu(req->cmd->dsm.nr); i++) {
status = nvmet_copy_from_sgl(req, i * sizeof(range), &range,
sizeof(range));
@@ -394,6 +405,7 @@ static void nvmet_bdev_execute_discard(struct nvmet_req *req)
nvmet_lba_to_sect(ns, range.slba), nr_sects,
GFP_KERNEL, &bio);
}
+ nvmet_blkcg_end(associated);
if (bio) {
bio->bi_private = req;
@@ -431,6 +443,7 @@ static void nvmet_bdev_execute_write_zeroes(struct nvmet_req *req)
struct bio *bio = NULL;
sector_t sector;
sector_t nr_sector;
+ bool associated;
int ret;
if (!nvmet_check_transfer_len(req, 0))
@@ -440,8 +453,11 @@ static void nvmet_bdev_execute_write_zeroes(struct nvmet_req *req)
nr_sector = (((sector_t)le16_to_cpu(write_zeroes->length) + 1) <<
(req->ns->blksize_shift - 9));
+ associated = nvmet_blkcg_begin(req->ns);
ret = __blkdev_issue_zeroout(req->ns->bdev, sector, nr_sector,
GFP_KERNEL, &bio, 0);
+ nvmet_blkcg_end(associated);
+
if (bio) {
bio->bi_private = req;
bio->bi_end_io = nvmet_bio_done;
diff --git a/drivers/nvme/target/io-cmd-file.c b/drivers/nvme/target/io-cmd-file.c
index 0b22d183f927..570e65259ad8 100644
--- a/drivers/nvme/target/io-cmd-file.c
+++ b/drivers/nvme/target/io-cmd-file.c
@@ -79,6 +79,8 @@ static ssize_t nvmet_file_submit_bvec(struct nvmet_req *req, loff_t pos,
struct kiocb *iocb = &req->f.iocb;
ssize_t (*call_iter)(struct kiocb *iocb, struct iov_iter *iter);
struct iov_iter iter;
+ bool associated;
+ ssize_t ret;
int rw;
if (req->cmd->rw.opcode == nvme_cmd_write) {
@@ -97,7 +99,10 @@ static ssize_t nvmet_file_submit_bvec(struct nvmet_req *req, loff_t pos,
iocb->ki_filp = req->ns->file;
iocb->ki_flags = ki_flags | iocb->ki_filp->f_iocb_flags;
- return call_iter(iocb, &iter);
+ associated = nvmet_blkcg_begin(req->ns);
+ ret = call_iter(iocb, &iter);
+ nvmet_blkcg_end(associated);
+ return ret;
}
static void nvmet_file_io_done(struct kiocb *iocb, long ret)
@@ -251,7 +256,13 @@ static void nvmet_file_execute_rw(struct nvmet_req *req)
u16 nvmet_file_flush(struct nvmet_req *req)
{
- return errno_to_nvme_status(req, vfs_fsync(req->ns->file, 1));
+ bool associated;
+ int ret;
+
+ associated = nvmet_blkcg_begin(req->ns);
+ ret = vfs_fsync(req->ns->file, 1);
+ nvmet_blkcg_end(associated);
+ return errno_to_nvme_status(req, ret);
}
static void nvmet_file_flush_work(struct work_struct *w)
@@ -274,10 +285,12 @@ static void nvmet_file_execute_discard(struct nvmet_req *req)
int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE;
struct nvme_dsm_range range;
loff_t offset, len;
+ bool associated;
u16 status = 0;
int ret;
int i;
+ associated = nvmet_blkcg_begin(req->ns);
for (i = 0; i <= le32_to_cpu(req->cmd->dsm.nr); i++) {
status = nvmet_copy_from_sgl(req, i * sizeof(range), &range,
sizeof(range));
@@ -300,6 +313,7 @@ static void nvmet_file_execute_discard(struct nvmet_req *req)
break;
}
}
+ nvmet_blkcg_end(associated);
nvmet_req_complete(req, status);
}
@@ -336,6 +350,7 @@ static void nvmet_file_write_zeroes_work(struct work_struct *w)
int mode = FALLOC_FL_ZERO_RANGE | FALLOC_FL_KEEP_SIZE;
loff_t offset;
loff_t len;
+ bool associated;
int ret;
offset = le64_to_cpu(write_zeroes->slba) << req->ns->blksize_shift;
@@ -347,7 +362,9 @@ static void nvmet_file_write_zeroes_work(struct work_struct *w)
return;
}
+ associated = nvmet_blkcg_begin(req->ns);
ret = vfs_fallocate(req->ns->file, mode, offset, len);
+ nvmet_blkcg_end(associated);
nvmet_req_complete(req, ret < 0 ? errno_to_nvme_status(req, ret) : 0);
}
diff --git a/drivers/nvme/target/nvmet.h b/drivers/nvme/target/nvmet.h
index dbda55895f4f..1ef7be97a244 100644
--- a/drivers/nvme/target/nvmet.h
+++ b/drivers/nvme/target/nvmet.h
@@ -21,6 +21,7 @@
#include <linux/radix-tree.h>
#include <linux/t10-pi.h>
#include <linux/kfifo.h>
+#include <linux/kthread.h>
#define NVMET_DEFAULT_VS NVME_VS(2, 1, 0)
@@ -115,6 +116,16 @@ struct nvmet_ns {
struct nvmet_subsys *subsys;
const char *device_path;
+#ifdef CONFIG_BLK_CGROUP
+ const char *cgroup_path;
+ /*
+ * Resolved from ->cgroup_path when the namespace is enabled and
+ * released when it is disabled, so it has the same lifetime and
+ * visibility rules as ->bdev and ->file.
+ */
+ struct cgroup_subsys_state *blkcg_css;
+#endif
+
struct config_group device_group;
struct config_group group;
@@ -732,6 +743,42 @@ void nvmet_bdev_execute_zone_mgmt_recv(struct nvmet_req *req);
void nvmet_bdev_execute_zone_mgmt_send(struct nvmet_req *req);
void nvmet_bdev_execute_zone_append(struct nvmet_req *req);
+#ifdef CONFIG_BLK_CGROUP
+static inline void nvmet_blkcg_set_bio(struct nvmet_ns *ns, struct bio *bio)
+{
+ if (ns->blkcg_css)
+ bio_associate_blkg_from_css(bio, ns->blkcg_css);
+}
+
+static inline bool nvmet_blkcg_begin(struct nvmet_ns *ns)
+{
+ if (!ns->blkcg_css || !in_task() || !(current->flags & PF_KTHREAD))
+ return false;
+
+ kthread_associate_blkcg(ns->blkcg_css);
+ return true;
+}
+
+static inline void nvmet_blkcg_end(bool associated)
+{
+ if (associated)
+ kthread_associate_blkcg(NULL);
+}
+#else
+static inline void nvmet_blkcg_set_bio(struct nvmet_ns *ns, struct bio *bio)
+{
+}
+
+static inline bool nvmet_blkcg_begin(struct nvmet_ns *ns)
+{
+ return false;
+}
+
+static inline void nvmet_blkcg_end(bool associated)
+{
+}
+#endif /* CONFIG_BLK_CGROUP */
+
static inline u32 nvmet_rw_data_len(struct nvmet_req *req)
{
return ((u32)le16_to_cpu(req->cmd->rw.length) + 1) <<
diff --git a/drivers/nvme/target/zns.c b/drivers/nvme/target/zns.c
index 23a17c02abee..1de1f0e1ef1c 100644
--- a/drivers/nvme/target/zns.c
+++ b/drivers/nvme/target/zns.c
@@ -580,6 +580,7 @@ void nvmet_bdev_execute_zone_append(struct nvmet_req *req)
bio = bio_alloc(req->ns->bdev, req->sg_cnt, opf, GFP_KERNEL);
}
+ nvmet_blkcg_set_bio(req->ns, bio);
bio->bi_end_io = nvmet_bdev_zone_append_bio_done;
bio->bi_iter.bi_sector = sect;
bio->bi_private = req;
--
2.53.0
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [PATCH v2] nvmet: add cgroup_path to charge namespace I/O to a cgroup
2026-09-22 6:51 [PATCH v2] nvmet: add cgroup_path to charge namespace I/O to a cgroup yupeng
@ 2026-09-22 7:00 ` Maurizio Lombardi
0 siblings, 0 replies; 2+ messages in thread
From: Maurizio Lombardi @ 2026-09-22 7:00 UTC (permalink / raw)
To: yupeng, Christoph Hellwig, Sagi Grimberg, Chaitanya Kulkarni
Cc: Tejun Heo, Johannes Weiner, Michal Koutný,
Josef Bacik, Jens Axboe, cgroups, linux-block, linux-nvme,
linux-kernel
On Tue Sep 22, 2026 at 8:51 AM CEST, yupeng wrote:
> From: Peng Yu <yupeng0921@gmail.com>
>
> Scenario:
> * Create multiple nvmet subsystems/namespaces.
> * The namespaces are backed by different LVM logical volumes.
> * Some of the logical volumes share the same physical volumes.
> * The subsystems are exported to different users.
> * We should provide each user a specific iops/bps quota, thus a noisy
> neighbor won't impact the performance of other logical volumes.
>
> Implementation:
> * Add a `cgroup_path` attribute under the nvmet namespace folder, e.g.:
> /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:bdev/namespaces/1/cgroup_path
> * We can write a cgroup path to it, then that cgroup will control
> the IOs used by the namespace.
> * Write an empty string to clear it.
> * The cgroup_path could be modified when the namespace is disabled.
> * Support both block device backed namespaces and file backed namespaces.
> * Only the direct io scenario is supported, enabling a namespace that
> has both cgroup_path and buffered_io set fails with -EINVAL.
>
> Test:
> 1 Load kernel modules.
> sudo modprobe brd rd_nr=2 rd_size=1048576
> sudo modprobe nvmet
> sudo modprobe nvmet_tcp
> sudo modprobe nvme_tcp
>
> 2 The two brd devices are used for a bdev backed namespace and a file
> backed namespace, remember their major/minor.
> lsblk --noheadings --nodeps --output NAME,MAJ:MIN,SIZE /dev/ram0 /dev/ram1
> ram0 1:0 1G
> ram1 1:1 1G
>
> 3 Enable the io controller and create two cgroups, one for the bdev
> backed namespace, another for the file backed namespace.
> echo "+io" | sudo tee /sys/fs/cgroup/cgroup.subtree_control
> sudo mkdir -p /sys/fs/cgroup/nvmet-bdev
> sudo mkdir -p /sys/fs/cgroup/nvmet-file
>
> 4 Create a file system and a file on ram0.
> sudo mkfs.ext4 /dev/ram0
> sudo mkdir -p /mnt/nvmet-file
> sudo mount -o noatime /dev/ram0 /mnt/nvmet-file
> sudo dd if=/dev/zero of=/mnt/nvmet-file/ns.img bs=1M count=512 oflag=direct
>
> 5 Create the bdev backed subsystem and namespace.
> sudo mkdir -p /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:bdev/namespaces/1
> echo 1 | sudo tee /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:bdev/attr_allow_any_host
> echo /dev/ram1 | sudo tee /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:bdev/namespaces/1/device_path
> echo /nvmet-bdev | sudo tee /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:bdev/namespaces/1/cgroup_path
> echo 1 | sudo tee /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:bdev/namespaces/1/enable
>
> 6 Create the file backed subsystem and namespace.
> sudo mkdir -p /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:file/namespaces/1
> echo 1 | sudo tee /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:file/attr_allow_any_host
> echo /mnt/nvmet-file/ns.img | sudo tee /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:file/namespaces/1/device_path
> echo /nvmet-file | sudo tee /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:file/namespaces/1/cgroup_path
> echo 1 | sudo tee /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:file/namespaces/1/enable
>
> 7 Export the two subsystems to 127.0.0.1.
> sudo mkdir -p /sys/kernel/config/nvmet/ports/1
> echo ipv4 | sudo tee /sys/kernel/config/nvmet/ports/1/addr_adrfam
> echo tcp | sudo tee /sys/kernel/config/nvmet/ports/1/addr_trtype
> echo 127.0.0.1 | sudo tee /sys/kernel/config/nvmet/ports/1/addr_traddr
> echo 4420 | sudo tee /sys/kernel/config/nvmet/ports/1/addr_trsvcid
> sudo ln -s /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:bdev /sys/kernel/config/nvmet/ports/1/subsystems/nqn.2026-09.io.test01:bdev
> sudo ln -s /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:file /sys/kernel/config/nvmet/ports/1/subsystems/nqn.2026-09.io.test01:file
>
> 8 Connect the two subsystems from 127.0.0.1.
> sudo nvme connect -t tcp -a 127.0.0.1 -s 4420 -n nqn.2026-09.io.test01:bdev
> sudo nvme connect -t tcp -a 127.0.0.1 -s 4420 -n nqn.2026-09.io.test01:file
> sudo udevadm settle
>
> 9 Set riops to 20k and run fio.
> echo "1:1 riops=20000 wiops=max rbps=max wbps=max" | sudo tee /sys/fs/cgroup/nvmet-bdev/io.max
> echo "1:0 riops=20000 wiops=max rbps=max wbps=max" | sudo tee /sys/fs/cgroup/nvmet-file/io.max
>
> sudo fio --name=t --filename=/dev/nvme0n1 --rw=randread --bs=4k --iodepth=32 --numjobs=1 \
> --direct=1 --ioengine=libaio --time_based --runtime=10 --ramp_time=3 \
> --group_reporting 2>/dev/null | grep -E '^ +(read|write): IOPS'
> read: IOPS=20.0k, BW=78.1MiB/s (81.9MB/s)(781MiB/10001msec)
>
> sudo fio --name=t --filename=/dev/nvme1n1 --rw=randread --bs=4k --iodepth=32 --numjobs=1 \
> --direct=1 --ioengine=libaio --time_based --runtime=10 --ramp_time=3 \
> --group_reporting 2>/dev/null | grep -E '^ +(read|write): IOPS'
> read: IOPS=20.0k, BW=78.1MiB/s (81.9MB/s)(781MiB/10001msec)
>
> 10 Set rbps to 100M and run fio.
> echo "1:1 riops=max wiops=max rbps=104857600 wbps=max" | sudo tee /sys/fs/cgroup/nvmet-bdev/io.max
> echo "1:0 riops=max wiops=max rbps=104857600 wbps=max" | sudo tee /sys/fs/cgroup/nvmet-file/io.max
>
> sudo fio --name=t --filename=/dev/nvme0n1 --rw=read --bs=1M --iodepth=32 --numjobs=1 \
> --direct=1 --ioengine=libaio --time_based --runtime=10 --ramp_time=3 \
> --group_reporting 2>/dev/null | grep -E '^ +(read|write): IOPS'
> read: IOPS=97, BW=100MiB/s (105MB/s)(1033MiB/10304msec)
>
> sudo fio --name=t --filename=/dev/nvme1n1 --rw=read --bs=1M --iodepth=32 --numjobs=1 \
> --direct=1 --ioengine=libaio --time_based --runtime=10 --ramp_time=3 \
> --group_reporting 2>/dev/null | grep -E '^ +(read|write): IOPS'
> read: IOPS=97, BW=100MiB/s (105MB/s)(1031MiB/10297msec)
>
> 11 Set wiops to 20k and run fio.
> echo "1:1 riops=max wiops=20000 rbps=max wbps=max" | sudo tee /sys/fs/cgroup/nvmet-bdev/io.max
> echo "1:0 riops=max wiops=20000 rbps=max wbps=max" | sudo tee /sys/fs/cgroup/nvmet-file/io.max
>
> sudo fio --name=t --filename=/dev/nvme0n1 --rw=randwrite --bs=4k --iodepth=32 --numjobs=1 \
> --direct=1 --ioengine=libaio --time_based --runtime=10 --ramp_time=3 \
> --group_reporting 2>/dev/null | grep -E '^ +(read|write): IOPS'
> write: IOPS=20.0k, BW=78.1MiB/s (81.9MB/s)(781MiB/10001msec); 0 zone resets
>
> sudo fio --name=t --filename=/dev/nvme1n1 --rw=randwrite --bs=4k --iodepth=32 --numjobs=1 \
> --direct=1 --ioengine=libaio --time_based --runtime=10 --ramp_time=3 \
> --group_reporting 2>/dev/null | grep -E '^ +(read|write): IOPS'
> write: IOPS=20.0k, BW=78.1MiB/s (81.9MB/s)(781MiB/10001msec); 0 zone resets
>
> 12 Set wbps to 100M and run fio.
> echo "1:1 riops=max wiops=max rbps=max wbps=104857600" | sudo tee /sys/fs/cgroup/nvmet-bdev/io.max
> echo "1:0 riops=max wiops=max rbps=max wbps=104857600" | sudo tee /sys/fs/cgroup/nvmet-file/io.max
>
> sudo fio --name=t --filename=/dev/nvme0n1 --rw=write --bs=1M --iodepth=32 --numjobs=1 \
> --direct=1 --ioengine=libaio --time_based --runtime=10 --ramp_time=3 \
> --group_reporting 2>/dev/null | grep -E '^ +(read|write): IOPS'
> write: IOPS=97, BW=100MiB/s (105MB/s)(1031MiB/10305msec); 0 zone resets
>
> sudo fio --name=t --filename=/dev/nvme1n1 --rw=write --bs=1M --iodepth=32 --numjobs=1 \
> --direct=1 --ioengine=libaio --time_based --runtime=10 --ramp_time=3 \
> --group_reporting 2>/dev/null | grep -E '^ +(read|write): IOPS'
> write: IOPS=97, BW=100MiB/s (105MB/s)(1032MiB/10297msec); 0 zone resets
>
> 13 Cleanup the environment.
> sudo nvme disconnect -n nqn.2026-09.io.test01:bdev
> sudo nvme disconnect -n nqn.2026-09.io.test01:file
> sudo udevadm settle
>
> sudo rm -f /sys/kernel/config/nvmet/ports/1/subsystems/nqn.2026-09.io.test01:bdev
> sudo rm -f /sys/kernel/config/nvmet/ports/1/subsystems/nqn.2026-09.io.test01:file
> sudo rmdir /sys/kernel/config/nvmet/ports/1
>
> echo 0 | sudo tee /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:bdev/namespaces/1/enable
> sudo rmdir /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:bdev/namespaces/1
> sudo rmdir /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:bdev
>
> echo 0 | sudo tee /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:file/namespaces/1/enable
> sudo rmdir /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:file/namespaces/1
> sudo rmdir /sys/kernel/config/nvmet/subsystems/nqn.2026-09.io.test01:file
>
> sudo umount /mnt/nvmet-file
> sudo rmdir /mnt/nvmet-file
> sudo modprobe -r brd
>
> sudo rmdir /sys/fs/cgroup/nvmet-bdev
> sudo rmdir /sys/fs/cgroup/nvmet-file
>
> sudo rmmod nvme_tcp
> sudo rmmod nvmet_tcp
> sudo rmmod nvmet
IMO the commit message should just explain the problem and its fix.
All those test details and commands belong to a cover letter.
Maurizio
>
> Signed-off-by: Peng Yu <yupeng0921@gmail.com>
> Assisted-by: Claude:claude-fable-5 [Claude Code]
> Assisted-by: Claude:claude-opus-5 [Claude Code]
> ---
> drivers/nvme/target/configfs.c | 59 ++++++++++++++++++++++++
> drivers/nvme/target/core.c | 75 +++++++++++++++++++++++++++++++
> drivers/nvme/target/io-cmd-bdev.c | 18 +++++++-
> drivers/nvme/target/io-cmd-file.c | 21 ++++++++-
> drivers/nvme/target/nvmet.h | 47 +++++++++++++++++++
> drivers/nvme/target/zns.c | 1 +
> 6 files changed, 218 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/nvme/target/configfs.c b/drivers/nvme/target/configfs.c
> index 6286e38436dd..829b92d04ad4 100644
> --- a/drivers/nvme/target/configfs.c
> +++ b/drivers/nvme/target/configfs.c
> @@ -561,6 +561,62 @@ static ssize_t nvmet_ns_device_path_store(struct config_item *item,
>
> CONFIGFS_ATTR(nvmet_ns_, device_path);
>
> +#ifdef CONFIG_BLK_CGROUP
> +static ssize_t nvmet_ns_cgroup_path_show(struct config_item *item, char *page)
> +{
> + struct nvmet_ns *ns = to_nvmet_ns(item);
> + struct nvmet_subsys *subsys = ns->subsys;
> + ssize_t ret;
> +
> + mutex_lock(&subsys->lock);
> + ret = snprintf(page, PAGE_SIZE, "%s\n", ns->cgroup_path ?: "");
> + mutex_unlock(&subsys->lock);
> + return ret;
> +}
> +
> +static ssize_t nvmet_ns_cgroup_path_store(struct config_item *item,
> + const char *page, size_t count)
> +{
> + struct nvmet_ns *ns = to_nvmet_ns(item);
> + struct nvmet_subsys *subsys = ns->subsys;
> + size_t len;
> + int ret = count;
> +
> + mutex_lock(&subsys->lock);
> +
> + if (ns->enabled) {
> + ret = -EBUSY;
> + goto out_unlock;
> + }
> +
> + len = strcspn(page, "\n");
> + if (!len) {
> + /* An empty write clears the association. */
> + kfree(ns->cgroup_path);
> + ns->cgroup_path = NULL;
> + goto out_unlock;
> + }
> +
> + if (page[0] != '/' || len >= PATH_MAX) {
> + ret = -EINVAL;
> + goto out_unlock;
> + }
> +
> + kfree(ns->cgroup_path);
> + ns->cgroup_path = kmemdup_nul(page, len, GFP_KERNEL);
> + if (!ns->cgroup_path) {
> + ret = -ENOMEM;
> + goto out_unlock;
> + }
> +
> +out_unlock:
> + mutex_unlock(&subsys->lock);
> + return ret;
> +}
> +
> +CONFIGFS_ATTR(nvmet_ns_, cgroup_path);
> +#endif /* CONFIG_BLK_CGROUP */
> +
> #ifdef CONFIG_PCI_P2PDMA
> static ssize_t nvmet_ns_p2pmem_show(struct config_item *item, char *page)
> {
> @@ -833,6 +889,9 @@ static struct configfs_attribute *nvmet_ns_attrs[] = {
> &nvmet_ns_attr_buffered_io,
> &nvmet_ns_attr_revalidate_size,
> &nvmet_ns_attr_resv_enable,
> +#ifdef CONFIG_BLK_CGROUP
> + &nvmet_ns_attr_cgroup_path,
> +#endif
> #ifdef CONFIG_PCI_P2PDMA
> &nvmet_ns_attr_p2pmem,
> #endif
> diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c
> index 43871a8f56ca..3e4972513c3e 100644
> --- a/drivers/nvme/target/core.c
> +++ b/drivers/nvme/target/core.c
> @@ -4,6 +4,7 @@
> * Copyright (c) 2015-2016 HGST, a Western Digital Company.
> */
> #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
> +#include <linux/cgroup.h>
> #include <linux/hex.h>
> #include <linux/module.h>
> #include <linux/random.h>
> @@ -474,8 +475,77 @@ void nvmet_put_namespace(struct nvmet_ns *ns)
> percpu_ref_put(&ns->ref);
> }
>
> +#ifdef CONFIG_BLK_CGROUP
> +static int nvmet_blkcg_ns_enable(struct nvmet_ns *ns)
> +{
> + struct cgroup_subsys_state *css;
> + struct cgroup *cgrp;
> +
> + if (!ns->cgroup_path)
> + return 0;
> +
> + /*
> + * Buffered writes will be handled by a separate thread,
> + * these IOs have no namespace/cgroup information at that time,
> + * so we don't support buffered io.
> + */
> + if (ns->buffered_io) {
> + pr_err("cgroup_path is not supported with buffered_io: %s\n",
> + ns->device_path);
> + return -EINVAL;
> + }
> +
> + cgrp = cgroup_get_from_path(ns->cgroup_path);
> + if (IS_ERR(cgrp)) {
> + pr_err("failed to resolve cgroup path %s: %ld\n",
> + ns->cgroup_path, PTR_ERR(cgrp));
> + return PTR_ERR(cgrp);
> + }
> +
> + css = cgroup_get_e_css(cgrp, &io_cgrp_subsys);
> + if (!css || css->cgroup != cgrp) {
> + pr_err("the io controller is not enabled in cgroup %s\n",
> + ns->cgroup_path);
> + if (css)
> + css_put(css);
> + cgroup_put(cgrp);
> + return -EINVAL;
> + }
> + ns->blkcg_css = css;
> + cgroup_put(cgrp);
> + return 0;
> +}
> +
> +static void nvmet_blkcg_ns_disable(struct nvmet_ns *ns)
> +{
> + if (ns->blkcg_css) {
> + css_put(ns->blkcg_css);
> + ns->blkcg_css = NULL;
> + }
> +}
> +
> +static void nvmet_blkcg_ns_free(struct nvmet_ns *ns)
> +{
> + kfree(ns->cgroup_path);
> +}
> +#else
> +static inline int nvmet_blkcg_ns_enable(struct nvmet_ns *ns)
> +{
> + return 0;
> +}
> +
> +static inline void nvmet_blkcg_ns_disable(struct nvmet_ns *ns)
> +{
> +}
> +
> +static inline void nvmet_blkcg_ns_free(struct nvmet_ns *ns)
> +{
> +}
> +#endif /* CONFIG_BLK_CGROUP */
> +
> static void nvmet_ns_dev_disable(struct nvmet_ns *ns)
> {
> + nvmet_blkcg_ns_disable(ns);
> nvmet_bdev_ns_disable(ns);
> nvmet_file_ns_disable(ns);
> }
> @@ -602,6 +672,10 @@ int nvmet_ns_enable(struct nvmet_ns *ns)
> if (ret)
> goto out_unlock;
>
> + ret = nvmet_blkcg_ns_enable(ns);
> + if (ret)
> + goto out_dev_disable;
> +
> ret = nvmet_p2pmem_ns_enable(ns);
> if (ret)
> goto out_dev_disable;
> @@ -699,6 +773,7 @@ void nvmet_ns_free(struct nvmet_ns *ns)
> up_write(&nvmet_ana_sem);
>
> kfree(ns->device_path);
> + nvmet_blkcg_ns_free(ns);
> kfree(ns);
> }
>
> diff --git a/drivers/nvme/target/io-cmd-bdev.c b/drivers/nvme/target/io-cmd-bdev.c
> index f2d9e8901df4..0014e5ef2853 100644
> --- a/drivers/nvme/target/io-cmd-bdev.c
> +++ b/drivers/nvme/target/io-cmd-bdev.c
> @@ -297,6 +297,7 @@ static void nvmet_bdev_execute_rw(struct nvmet_req *req)
> bio = bio_alloc(req->ns->bdev, bio_max_segs(sg_cnt), opf,
> GFP_KERNEL);
> }
> + nvmet_blkcg_set_bio(req->ns, bio);
> bio->bi_iter.bi_sector = sector;
> bio->bi_private = req;
> bio->bi_end_io = nvmet_bio_done;
> @@ -322,6 +323,7 @@ static void nvmet_bdev_execute_rw(struct nvmet_req *req)
>
> bio = bio_alloc(req->ns->bdev, bio_max_segs(sg_cnt),
> opf, GFP_KERNEL);
> + nvmet_blkcg_set_bio(req->ns, bio);
> bio->bi_iter.bi_sector = sector;
>
> bio_chain(bio, prev);
> @@ -358,6 +360,7 @@ static void nvmet_bdev_execute_flush(struct nvmet_req *req)
>
> bio_init(bio, req->ns->bdev, req->inline_bvec,
> ARRAY_SIZE(req->inline_bvec), REQ_OP_WRITE | REQ_PREFLUSH);
> + nvmet_blkcg_set_bio(req->ns, bio);
> bio->bi_private = req;
> bio->bi_end_io = nvmet_bio_done;
>
> @@ -366,10 +369,16 @@ static void nvmet_bdev_execute_flush(struct nvmet_req *req)
>
> u16 nvmet_bdev_flush(struct nvmet_req *req)
> {
> + bool associated;
> + int ret;
> +
> if (!bdev_write_cache(req->ns->bdev))
> return 0;
>
> - if (blkdev_issue_flush(req->ns->bdev))
> + associated = nvmet_blkcg_begin(req->ns);
> + ret = blkdev_issue_flush(req->ns->bdev);
> + nvmet_blkcg_end(associated);
> + if (ret)
> return NVME_SC_INTERNAL | NVME_STATUS_DNR;
> return 0;
> }
> @@ -380,9 +389,11 @@ static void nvmet_bdev_execute_discard(struct nvmet_req *req)
> struct nvme_dsm_range range;
> struct bio *bio = NULL;
> sector_t nr_sects;
> + bool associated;
> int i;
> u16 status = NVME_SC_SUCCESS;
>
> + associated = nvmet_blkcg_begin(ns);
> for (i = 0; i <= le32_to_cpu(req->cmd->dsm.nr); i++) {
> status = nvmet_copy_from_sgl(req, i * sizeof(range), &range,
> sizeof(range));
> @@ -394,6 +405,7 @@ static void nvmet_bdev_execute_discard(struct nvmet_req *req)
> nvmet_lba_to_sect(ns, range.slba), nr_sects,
> GFP_KERNEL, &bio);
> }
> + nvmet_blkcg_end(associated);
>
> if (bio) {
> bio->bi_private = req;
> @@ -431,6 +443,7 @@ static void nvmet_bdev_execute_write_zeroes(struct nvmet_req *req)
> struct bio *bio = NULL;
> sector_t sector;
> sector_t nr_sector;
> + bool associated;
> int ret;
>
> if (!nvmet_check_transfer_len(req, 0))
> @@ -440,8 +453,11 @@ static void nvmet_bdev_execute_write_zeroes(struct nvmet_req *req)
> nr_sector = (((sector_t)le16_to_cpu(write_zeroes->length) + 1) <<
> (req->ns->blksize_shift - 9));
>
> + associated = nvmet_blkcg_begin(req->ns);
> ret = __blkdev_issue_zeroout(req->ns->bdev, sector, nr_sector,
> GFP_KERNEL, &bio, 0);
> + nvmet_blkcg_end(associated);
> +
> if (bio) {
> bio->bi_private = req;
> bio->bi_end_io = nvmet_bio_done;
> diff --git a/drivers/nvme/target/io-cmd-file.c b/drivers/nvme/target/io-cmd-file.c
> index 0b22d183f927..570e65259ad8 100644
> --- a/drivers/nvme/target/io-cmd-file.c
> +++ b/drivers/nvme/target/io-cmd-file.c
> @@ -79,6 +79,8 @@ static ssize_t nvmet_file_submit_bvec(struct nvmet_req *req, loff_t pos,
> struct kiocb *iocb = &req->f.iocb;
> ssize_t (*call_iter)(struct kiocb *iocb, struct iov_iter *iter);
> struct iov_iter iter;
> + bool associated;
> + ssize_t ret;
> int rw;
>
> if (req->cmd->rw.opcode == nvme_cmd_write) {
> @@ -97,7 +99,10 @@ static ssize_t nvmet_file_submit_bvec(struct nvmet_req *req, loff_t pos,
> iocb->ki_filp = req->ns->file;
> iocb->ki_flags = ki_flags | iocb->ki_filp->f_iocb_flags;
>
> - return call_iter(iocb, &iter);
> + associated = nvmet_blkcg_begin(req->ns);
> + ret = call_iter(iocb, &iter);
> + nvmet_blkcg_end(associated);
> + return ret;
> }
>
> static void nvmet_file_io_done(struct kiocb *iocb, long ret)
> @@ -251,7 +256,13 @@ static void nvmet_file_execute_rw(struct nvmet_req *req)
>
> u16 nvmet_file_flush(struct nvmet_req *req)
> {
> - return errno_to_nvme_status(req, vfs_fsync(req->ns->file, 1));
> + bool associated;
> + int ret;
> +
> + associated = nvmet_blkcg_begin(req->ns);
> + ret = vfs_fsync(req->ns->file, 1);
> + nvmet_blkcg_end(associated);
> + return errno_to_nvme_status(req, ret);
> }
>
> static void nvmet_file_flush_work(struct work_struct *w)
> @@ -274,10 +285,12 @@ static void nvmet_file_execute_discard(struct nvmet_req *req)
> int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE;
> struct nvme_dsm_range range;
> loff_t offset, len;
> + bool associated;
> u16 status = 0;
> int ret;
> int i;
>
> + associated = nvmet_blkcg_begin(req->ns);
> for (i = 0; i <= le32_to_cpu(req->cmd->dsm.nr); i++) {
> status = nvmet_copy_from_sgl(req, i * sizeof(range), &range,
> sizeof(range));
> @@ -300,6 +313,7 @@ static void nvmet_file_execute_discard(struct nvmet_req *req)
> break;
> }
> }
> + nvmet_blkcg_end(associated);
>
> nvmet_req_complete(req, status);
> }
> @@ -336,6 +350,7 @@ static void nvmet_file_write_zeroes_work(struct work_struct *w)
> int mode = FALLOC_FL_ZERO_RANGE | FALLOC_FL_KEEP_SIZE;
> loff_t offset;
> loff_t len;
> + bool associated;
> int ret;
>
> offset = le64_to_cpu(write_zeroes->slba) << req->ns->blksize_shift;
> @@ -347,7 +362,9 @@ static void nvmet_file_write_zeroes_work(struct work_struct *w)
> return;
> }
>
> + associated = nvmet_blkcg_begin(req->ns);
> ret = vfs_fallocate(req->ns->file, mode, offset, len);
> + nvmet_blkcg_end(associated);
> nvmet_req_complete(req, ret < 0 ? errno_to_nvme_status(req, ret) : 0);
> }
>
> diff --git a/drivers/nvme/target/nvmet.h b/drivers/nvme/target/nvmet.h
> index dbda55895f4f..1ef7be97a244 100644
> --- a/drivers/nvme/target/nvmet.h
> +++ b/drivers/nvme/target/nvmet.h
> @@ -21,6 +21,7 @@
> #include <linux/radix-tree.h>
> #include <linux/t10-pi.h>
> #include <linux/kfifo.h>
> +#include <linux/kthread.h>
>
> #define NVMET_DEFAULT_VS NVME_VS(2, 1, 0)
>
> @@ -115,6 +116,16 @@ struct nvmet_ns {
> struct nvmet_subsys *subsys;
> const char *device_path;
>
> +#ifdef CONFIG_BLK_CGROUP
> + const char *cgroup_path;
> + /*
> + * Resolved from ->cgroup_path when the namespace is enabled and
> + * released when it is disabled, so it has the same lifetime and
> + * visibility rules as ->bdev and ->file.
> + */
> + struct cgroup_subsys_state *blkcg_css;
> +#endif
> +
> struct config_group device_group;
> struct config_group group;
>
> @@ -732,6 +743,42 @@ void nvmet_bdev_execute_zone_mgmt_recv(struct nvmet_req *req);
> void nvmet_bdev_execute_zone_mgmt_send(struct nvmet_req *req);
> void nvmet_bdev_execute_zone_append(struct nvmet_req *req);
>
> +#ifdef CONFIG_BLK_CGROUP
> +static inline void nvmet_blkcg_set_bio(struct nvmet_ns *ns, struct bio *bio)
> +{
> + if (ns->blkcg_css)
> + bio_associate_blkg_from_css(bio, ns->blkcg_css);
> +}
> +
> +static inline bool nvmet_blkcg_begin(struct nvmet_ns *ns)
> +{
> + if (!ns->blkcg_css || !in_task() || !(current->flags & PF_KTHREAD))
> + return false;
> +
> + kthread_associate_blkcg(ns->blkcg_css);
> + return true;
> +}
> +
> +static inline void nvmet_blkcg_end(bool associated)
> +{
> + if (associated)
> + kthread_associate_blkcg(NULL);
> +}
> +#else
> +static inline void nvmet_blkcg_set_bio(struct nvmet_ns *ns, struct bio *bio)
> +{
> +}
> +
> +static inline bool nvmet_blkcg_begin(struct nvmet_ns *ns)
> +{
> + return false;
> +}
> +
> +static inline void nvmet_blkcg_end(bool associated)
> +{
> +}
> +#endif /* CONFIG_BLK_CGROUP */
> +
> static inline u32 nvmet_rw_data_len(struct nvmet_req *req)
> {
> return ((u32)le16_to_cpu(req->cmd->rw.length) + 1) <<
> diff --git a/drivers/nvme/target/zns.c b/drivers/nvme/target/zns.c
> index 23a17c02abee..1de1f0e1ef1c 100644
> --- a/drivers/nvme/target/zns.c
> +++ b/drivers/nvme/target/zns.c
> @@ -580,6 +580,7 @@ void nvmet_bdev_execute_zone_append(struct nvmet_req *req)
> bio = bio_alloc(req->ns->bdev, req->sg_cnt, opf, GFP_KERNEL);
> }
>
> + nvmet_blkcg_set_bio(req->ns, bio);
> bio->bi_end_io = nvmet_bdev_zone_append_bio_done;
> bio->bi_iter.bi_sector = sect;
> bio->bi_private = req;
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2026-09-22 7:00 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2026-09-22 6:51 [PATCH v2] nvmet: add cgroup_path to charge namespace I/O to a cgroup yupeng
2026-09-22 7:00 ` Maurizio Lombardi
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