This patch add an ability to set a blkio cgroup for an iscsi target. When a new client is connected, the kernel creates two kernel threads and run all io requests from them, this means that we can set a blkio group for these threads and set io limits via this group.
Here is an exampe how this works: $ TGT_PATH=/sys/kernel/config/target/iscsi/iqn.2014-06.com.vstorage\:test $ CG_PATH=/sys/fs/cgroup/blkio/system.slice/vstorage-iscsi/ # create a group $ mkdir -p $CG_PATH # set cgroup for iscsi target $ bash -c 'echo $$ > $CG_PATH/tasks && echo 1 > $TGT_PATH/tpgt_1/param/BlkioCgroup' $ cat $TGT_PATH/tpgt_1/param/BlkioCgroup /system.slice/vstorage-iscsi # attach iscsi target $ IQN=iqn.2014-06.com.vstorage:test $ iscsiadm -m node -T $IQN -l Logging in to [iface: default, target: iqn.2014-06.com.vstorage:test, portal: 10.94.120.187,3260] (multiple) Login to [iface: default, target: iqn.2014-06.com.vstorage:test, portal: 10.94.120.187,3260] successful. # check that iscsi threads in the required cgroup $ ps -C iscsi_ttx PID TTY TIME CMD 4097 ? 00:00:00 iscsi_ttx $ cat /proc/4097/cgroup | grep blkio 1:blkio:/system.slice/vstorage-iscsi # set io limits for a target backing store device $ ploop list ploop15810 /mnt/vstorage/vols/iscsi/iqn.2014-06.com.vstorage:test/lun1/ploop $ ls -l /dev/ploop15810 brw-rw---- 1 root disk 182, 252960 Mar 14 00:59 /dev/ploop15810 $ echo "182:252960 6291456" > $CG_PATH/blkio.throttle.read_bps_device # check that limits work as expected $ dd if=/dev/sda of=/dev/null bs=10M count=10 10+0 records in 10+0 records out 104857600 bytes (105 MB) copied, 17.3534 s, 6.0 MB/s Signed-off-by: Andrei Vagin <ava...@openvz.org> --- drivers/target/iscsi/iscsi_target_configfs.c | 46 ++++++++++++++++++++++++++++ drivers/target/iscsi/iscsi_target_login.c | 34 +++++++++++++++++++- drivers/target/iscsi/iscsi_target_tpg.c | 36 ++++++++++++++++++++++ drivers/target/iscsi/iscsi_target_tpg.h | 2 ++ include/target/iscsi/iscsi_target_core.h | 2 ++ kernel/cgroup.c | 1 + 6 files changed, 120 insertions(+), 1 deletion(-) diff --git a/drivers/target/iscsi/iscsi_target_configfs.c b/drivers/target/iscsi/iscsi_target_configfs.c index e6631ab..6d754cf 100644 --- a/drivers/target/iscsi/iscsi_target_configfs.c +++ b/drivers/target/iscsi/iscsi_target_configfs.c @@ -1412,6 +1412,51 @@ TPG_PARAM_ATTR(IFMarkInt, S_IRUGO | S_IWUSR); DEF_TPG_PARAM(OFMarkInt); TPG_PARAM_ATTR(OFMarkInt, S_IRUGO | S_IWUSR); +static ssize_t iscsi_tpg_param_show_BlkioCgroup( + struct se_portal_group *se_tpg, + char *page) +{ + struct iscsi_portal_group *tpg = container_of(se_tpg, + struct iscsi_portal_group, tpg_se_tpg); + ssize_t rb; + + if (iscsit_get_tpg(tpg) < 0) + return -EINVAL; + + rb = iscsit_ta_tpg_show_blkcg(tpg, page); + iscsit_put_tpg(tpg); + return rb; +} + +static ssize_t iscsi_tpg_param_store_BlkioCgroup( + struct se_portal_group *se_tpg, + const char *page, + size_t count) +{ + struct iscsi_portal_group *tpg = container_of(se_tpg, + struct iscsi_portal_group, tpg_se_tpg); + u32 val; + int ret; + + if (iscsit_get_tpg(tpg) < 0) + return -EINVAL; + + ret = kstrtou32(page, 0, &val); + if (ret) + goto out; + ret = iscsit_ta_tpg_set_blkcg(tpg, val); + if (ret < 0) + goto out; + + iscsit_put_tpg(tpg); + return count; +out: + iscsit_put_tpg(tpg); + return ret; +} + +TPG_PARAM_ATTR(BlkioCgroup, S_IRUGO | S_IWUSR); + static struct configfs_attribute *lio_target_tpg_param_attrs[] = { &iscsi_tpg_param_AuthMethod.attr, &iscsi_tpg_param_HeaderDigest.attr, @@ -1434,6 +1479,7 @@ static struct configfs_attribute *lio_target_tpg_param_attrs[] = { &iscsi_tpg_param_OFMarker.attr, &iscsi_tpg_param_IFMarkInt.attr, &iscsi_tpg_param_OFMarkInt.attr, + &iscsi_tpg_param_BlkioCgroup.attr, NULL, }; diff --git a/drivers/target/iscsi/iscsi_target_login.c b/drivers/target/iscsi/iscsi_target_login.c index c20b561..4f59416 100644 --- a/drivers/target/iscsi/iscsi_target_login.c +++ b/drivers/target/iscsi/iscsi_target_login.c @@ -20,6 +20,7 @@ #include <linux/string.h> #include <linux/kthread.h> #include <linux/idr.h> +#include <linux/cgroup.h> #include <scsi/iscsi_proto.h> #include <target/target_core_base.h> #include <target/target_core_fabric.h> @@ -712,8 +713,18 @@ static void iscsi_post_login_start_timers(struct iscsi_conn *conn) int iscsit_start_kthreads(struct iscsi_conn *conn) { + struct iscsi_portal_group *tpg = conn->tpg; + struct cgroup_subsys_state *blk_css = NULL; int ret = 0; + if (iscsit_get_tpg(tpg) < 0) + return -EINVAL; + if (tpg->blk_css) { + blk_css = tpg->blk_css; + css_get(blk_css); + } + iscsit_put_tpg(tpg); + spin_lock(&iscsit_global->ts_bitmap_lock); conn->bitmap_id = bitmap_find_free_region(iscsit_global->ts_bitmap, ISCSIT_BITMAP_BITS, get_order(1)); @@ -722,7 +733,8 @@ int iscsit_start_kthreads(struct iscsi_conn *conn) if (conn->bitmap_id < 0) { pr_err("bitmap_find_free_region() failed for" " iscsit_start_kthreads()\n"); - return -ENOMEM; + ret = -ENOMEM; + goto put_blk_css; } conn->tx_thread = kthread_run(iscsi_target_tx_thread, conn, @@ -732,6 +744,11 @@ int iscsit_start_kthreads(struct iscsi_conn *conn) ret = PTR_ERR(conn->tx_thread); goto out_bitmap; } + if (blk_css) { + ret = cgroup_kernel_attach(blk_css->cgroup, conn->tx_thread); + if (ret < 0) + goto out_tx; + } conn->tx_thread_active = true; conn->rx_thread = kthread_run(iscsi_target_rx_thread, conn, @@ -741,9 +758,21 @@ int iscsit_start_kthreads(struct iscsi_conn *conn) ret = PTR_ERR(conn->rx_thread); goto out_tx; } + if (blk_css) { + ret = cgroup_kernel_attach(blk_css->cgroup, conn->rx_thread); + if (ret < 0) + goto out_rx; + } conn->rx_thread_active = true; + if (blk_css) + css_put(blk_css); + return 0; +out_rx: + send_sig(SIGINT, conn->rx_thread, 1); + kthread_stop(conn->rx_thread); + conn->rx_thread_active = false; out_tx: send_sig(SIGINT, conn->tx_thread, 1); kthread_stop(conn->tx_thread); @@ -753,6 +782,9 @@ out_bitmap: bitmap_release_region(iscsit_global->ts_bitmap, conn->bitmap_id, get_order(1)); spin_unlock(&iscsit_global->ts_bitmap_lock); +put_blk_css: + if (blk_css) + css_put(blk_css); return ret; } diff --git a/drivers/target/iscsi/iscsi_target_tpg.c b/drivers/target/iscsi/iscsi_target_tpg.c index 2426b0b..792d3ee 100644 --- a/drivers/target/iscsi/iscsi_target_tpg.c +++ b/drivers/target/iscsi/iscsi_target_tpg.c @@ -16,6 +16,7 @@ * GNU General Public License for more details. ******************************************************************************/ +#include <linux/cgroup.h> #include <target/target_core_base.h> #include <target/target_core_fabric.h> #include <target/target_core_configfs.h> @@ -303,6 +304,9 @@ int iscsit_tpg_del_portal_group( list_del(&tpg->tpg_list); spin_unlock(&tiqn->tiqn_tpg_lock); + if (tpg->blk_css) + css_put(tpg->blk_css); + pr_debug("CORE[%s]_TPG[%hu] - Deleted iSCSI Target Portal Group\n", tiqn->tiqn, tpg->tpgt); @@ -896,3 +900,35 @@ int iscsit_ta_tpg_enabled_sendtargets( return 0; } + +int iscsit_ta_tpg_set_blkcg(struct iscsi_portal_group *tpg, u32 flag) +{ + struct cgroup_subsys_state *css; + + if (flag != 1) + return -EINVAL; + + css = task_get_css(current, blkio_subsys_id); + if (tpg->blk_css) + css_put(tpg->blk_css); + tpg->blk_css = css; + + return 0; +} + +int iscsit_ta_tpg_show_blkcg(struct iscsi_portal_group *tpg, char *page) +{ + int rb; + + if (tpg->blk_css) { + rb = cgroup_path(tpg->blk_css->cgroup, page, PAGE_SIZE - 1); + if (rb == 0) + rb = strlen(page); + page[rb] = '\n'; + page[rb + 1] = 0; + rb++; + } else + rb = 0; + + return rb; +} diff --git a/drivers/target/iscsi/iscsi_target_tpg.h b/drivers/target/iscsi/iscsi_target_tpg.h index b2f49c0..416b929 100644 --- a/drivers/target/iscsi/iscsi_target_tpg.h +++ b/drivers/target/iscsi/iscsi_target_tpg.h @@ -40,5 +40,7 @@ extern int iscsit_ta_demo_mode_discovery(struct iscsi_portal_group *, u32); extern int iscsit_ta_default_erl(struct iscsi_portal_group *, u32); extern int iscsit_ta_t10_pi(struct iscsi_portal_group *, u32); extern int iscsit_ta_tpg_enabled_sendtargets(struct iscsi_portal_group *, u32); +extern int iscsit_ta_tpg_set_blkcg(struct iscsi_portal_group *tpg, u32 flag); +extern int iscsit_ta_tpg_show_blkcg(struct iscsi_portal_group *tpg, char *page); #endif /* ISCSI_TARGET_TPG_H */ diff --git a/include/target/iscsi/iscsi_target_core.h b/include/target/iscsi/iscsi_target_core.h index 3e3b2f9..83eb63b 100644 --- a/include/target/iscsi/iscsi_target_core.h +++ b/include/target/iscsi/iscsi_target_core.h @@ -838,6 +838,8 @@ struct iscsi_portal_group { struct iscsi_tiqn *tpg_tiqn; struct list_head tpg_gnp_list; struct list_head tpg_list; + + struct cgroup_subsys_state *blk_css; } ____cacheline_aligned; struct iscsi_wwn_stat_grps { diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 11c547f..0fbb37e 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -5924,6 +5924,7 @@ int cgroup_kernel_attach(struct cgroup *cgrp, struct task_struct *tsk) mutex_unlock(&cgroup_mutex); return ret; } +EXPORT_SYMBOL_GPL(cgroup_kernel_attach); void cgroup_kernel_close(struct cgroup *cgrp) { -- 1.8.3.1 _______________________________________________ Devel mailing list Devel@openvz.org https://lists.openvz.org/mailman/listinfo/devel