hulk inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/ICA1GK -------------------------------- Create a bpf iter target for the 'diskstats' interface, to which the bpf prog can attach. Signed-off-by: GONG Ruiqi <gongruiqi1@huawei.com> --- block/Makefile | 1 + block/bpf-rvi.c | 224 ++++++++++++++++++++++++++++++++++++++++++++++++ block/genhd.c | 3 +- 3 files changed, 226 insertions(+), 2 deletions(-) create mode 100644 block/bpf-rvi.c diff --git a/block/Makefile b/block/Makefile index bfba1d2afc0e..400731b162c0 100644 --- a/block/Makefile +++ b/block/Makefile @@ -41,3 +41,4 @@ obj-$(CONFIG_BLK_INLINE_ENCRYPTION) += blk-crypto.o blk-crypto-profile.o \ obj-$(CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK) += blk-crypto-fallback.o obj-$(CONFIG_BLOCK_HOLDER_DEPRECATED) += holder.o obj-$(CONFIG_BLK_IO_HIERARCHY_STATS) += blk-io-hierarchy/ +obj-$(CONFIG_BPF_RVI) += bpf-rvi.o diff --git a/block/bpf-rvi.c b/block/bpf-rvi.c new file mode 100644 index 000000000000..f6b56f3085f7 --- /dev/null +++ b/block/bpf-rvi.c @@ -0,0 +1,224 @@ +#include <linux/blkdev.h> +#include <linux/init.h> +#include <linux/seq_file.h> +#include <linux/part_stat.h> +#include <linux/pid_namespace.h> +#include <linux/bpf.h> + +#include "blk-mq.h" +#include "blk-cgroup.h" + +/* + * Diskstats + */ + +struct diskstats_seq_priv { + struct class_dev_iter iter; // must be the first, + // to let us reuse disk_seqf_next() + struct blkcg *task_blkcg; +}; + +/* + * Basically the same with disk_seqf_start() but without allocating iter and + * then overwriting seqf->private, which points to priv_data->target_private + * in bpf_iter case (see prepare_seq_file()), and is needed to retrieve + * struct bpf_iter_priv_data. Here we allocate iter via setting + * .seq_priv_size and turning priv_data->target_private into iter. + */ +static void *bpf_disk_seqf_start(struct seq_file *seqf, loff_t *pos) +{ + loff_t skip = *pos; + struct diskstats_seq_priv *priv = seqf->private; + struct class_dev_iter *iter; + struct device *dev; + struct task_struct *reaper = get_current_level1_reaper(); + + priv->task_blkcg = css_to_blkcg(task_css(reaper ?: current, io_cgrp_id)); + if (reaper) + put_task_struct(reaper); + + iter = &priv->iter; + class_dev_iter_init(iter, &block_class, NULL, &disk_type); + do { + dev = class_dev_iter_next(iter); + if (!dev) + return NULL; + } while (skip--); + + return dev_to_disk(dev); +} + +/* + * Similar to the difference between {bpf_,}disk_seqf_start, + * here we don't free iter. + */ +static void bpf_disk_seqf_stop(struct seq_file *seqf, void *v) +{ + struct diskstats_seq_priv *priv = seqf->private; + struct class_dev_iter *iter = &priv->iter; + + /* stop is called even after start failed :-( */ + if (iter) + class_dev_iter_exit(iter); +} + +/* Same with disk_seqf_next() */ +static void *bpf_disk_seqf_next(struct seq_file *seqf, void *v, loff_t *pos) +{ + struct device *dev; + + (*pos)++; + dev = class_dev_iter_next(seqf->private); + if (dev) + return dev_to_disk(dev); + + return NULL; +} + +struct bpf_iter__diskstats { + __bpf_md_ptr(struct bpf_iter_meta *, meta); + __bpf_md_ptr(struct block_device *, bd); + __bpf_md_ptr(struct disk_stats *, native_stat); + unsigned int inflight __aligned(8); + __bpf_md_ptr(struct blkcg *, task_blkcg); +}; + +DEFINE_BPF_ITER_FUNC(diskstats, struct bpf_iter_meta *meta, + struct block_device *bd, struct disk_stats *native_stat, + uint inflight, + struct blkcg *task_blkcg) + +static int native_diskstats_show(struct seq_file *seqf, struct block_device *hd, + struct disk_stats *stat, unsigned int inflight) +{ + seq_printf(seqf, "%4d %7d %pg " + "%lu %lu %lu %u " + "%lu %lu %lu %u " + "%u %u %u " + "%lu %lu %lu %u " + "%lu %u" + "\n", + MAJOR(hd->bd_dev), MINOR(hd->bd_dev), hd, + stat->ios[STAT_READ], + stat->merges[STAT_READ], + stat->sectors[STAT_READ], + (unsigned int)div_u64(stat->nsecs[STAT_READ], + NSEC_PER_MSEC), + stat->ios[STAT_WRITE], + stat->merges[STAT_WRITE], + stat->sectors[STAT_WRITE], + (unsigned int)div_u64(stat->nsecs[STAT_WRITE], + NSEC_PER_MSEC), + inflight, + jiffies_to_msecs(stat->io_ticks), + (unsigned int)div_u64(stat->nsecs[STAT_READ] + + stat->nsecs[STAT_WRITE] + + stat->nsecs[STAT_DISCARD] + + stat->nsecs[STAT_FLUSH], + NSEC_PER_MSEC), + stat->ios[STAT_DISCARD], + stat->merges[STAT_DISCARD], + stat->sectors[STAT_DISCARD], + (unsigned int)div_u64(stat->nsecs[STAT_DISCARD], + NSEC_PER_MSEC), + stat->ios[STAT_FLUSH], + (unsigned int)div_u64(stat->nsecs[STAT_FLUSH], + NSEC_PER_MSEC) + ); + return 0; +} + +static int __diskstats_show(struct seq_file *seqf, struct block_device *hd, + struct disk_stats *stat, unsigned int inflight) +{ + struct bpf_iter__diskstats ctx; + struct bpf_iter_meta meta; + struct bpf_prog *prog; + struct diskstats_seq_priv *priv = seqf->private; + + meta.seq = seqf; + prog = bpf_iter_get_info(&meta, false); + if (!prog) + return native_diskstats_show(seqf, hd, stat, inflight); + + ctx.meta = &meta; + ctx.bd = hd; + ctx.native_stat = stat; + ctx.inflight = inflight; + ctx.task_blkcg = priv->task_blkcg; + return bpf_iter_run_prog(prog, &ctx); +} + +/* The only function that becomes extern from static. Don't bother to place it in header file. */ +void part_stat_read_all(struct block_device *part, struct disk_stats *stat); + +static int diskstats_show(struct seq_file *seqf, void *v) +{ + struct gendisk *gp = v; + struct block_device *hd; + unsigned int inflight; + struct disk_stats stat; + unsigned long idx; + int ret = 0; + + rcu_read_lock(); + xa_for_each(&gp->part_tbl, idx, hd) { + if (bdev_is_partition(hd) && !bdev_nr_sectors(hd)) + continue; + if (queue_is_mq(gp->queue)) + inflight = blk_mq_in_flight(gp->queue, hd); + else + inflight = part_in_flight(hd); + + if (inflight) { + part_stat_lock(); + update_io_ticks(hd, jiffies, true); + part_stat_unlock(); + } + part_stat_read_all(hd, &stat); + ret = __diskstats_show(seqf, hd, &stat, inflight); + if (ret) + break; + } + rcu_read_unlock(); + + return ret; +} + +static const struct seq_operations bpf_diskstats_op = { + .start = bpf_disk_seqf_start, + .next = bpf_disk_seqf_next, + .stop = bpf_disk_seqf_stop, + .show = diskstats_show +}; + +static const struct bpf_iter_seq_info diskstats_seq_info = { + .seq_ops = &bpf_diskstats_op, + .init_seq_private = NULL, + .fini_seq_private = NULL, + .seq_priv_size = sizeof(struct diskstats_seq_priv), +}; + +static struct bpf_iter_reg diskstats_reg_info = { + .target = "diskstats", + .ctx_arg_info_size = 2, + .ctx_arg_info = { + { offsetof(struct bpf_iter__diskstats, bd), + PTR_TO_BTF_ID }, + { offsetof(struct bpf_iter__diskstats, native_stat), + PTR_TO_BTF_ID }, + }, + .seq_info = &diskstats_seq_info, +}; + +BTF_ID_LIST(btf_diststats_ids) +BTF_ID(struct, block_device) +BTF_ID(struct, disk_stats) + +static int __init diskstats_iter_init(void) +{ + diskstats_reg_info.ctx_arg_info[0].btf_id = btf_diststats_ids[0]; + diskstats_reg_info.ctx_arg_info[1].btf_id = btf_diststats_ids[1]; + return bpf_iter_reg_target(&diskstats_reg_info); +} +late_initcall(diskstats_iter_init); diff --git a/block/genhd.c b/block/genhd.c index 61d340aa30f4..0fc39e2ae0b8 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -97,8 +97,7 @@ bool set_capacity_and_notify(struct gendisk *disk, sector_t size) } EXPORT_SYMBOL_GPL(set_capacity_and_notify); -static void part_stat_read_all(struct block_device *part, - struct disk_stats *stat) +void part_stat_read_all(struct block_device *part, struct disk_stats *stat) { int cpu; -- 2.25.1