From 51eaefb49449152d10309fcc1b1fb804fa685fa4 Mon Sep 17 00:00:00 2001 From: Thomas Lamprecht Date: Tue, 11 Jan 2022 08:13:17 +0100 Subject: [PATCH] cherry-pick "blk-cgroup: always terminate io.stat lines" Signed-off-by: Thomas Lamprecht --- ...group-always-terminate-io.stat-lines.patch | 138 ++++++++++++++++++ 1 file changed, 138 insertions(+) create mode 100644 patches/kernel/0010-blk-cgroup-always-terminate-io.stat-lines.patch diff --git a/patches/kernel/0010-blk-cgroup-always-terminate-io.stat-lines.patch b/patches/kernel/0010-blk-cgroup-always-terminate-io.stat-lines.patch new file mode 100644 index 0000000..f560745 --- /dev/null +++ b/patches/kernel/0010-blk-cgroup-always-terminate-io.stat-lines.patch @@ -0,0 +1,138 @@ +From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 +From: Wolfgang Bumiller +Date: Mon, 10 Jan 2022 16:34:57 +0100 +Subject: [PATCH] blk-cgroup: always terminate io.stat lines + +With the removal of seq_get_buf in blkcg_print_one_stat, we +cannot make adding the newline conditional on there being +relevant stats because the name was already written out +unconditionally. +Otherwise we may end up with multiple device names in one +line which is confusing and doesn't follow the nested-keyed +file format. + +Signed-off-by: Wolfgang Bumiller +Fixes: 252c651a4c85 ("blk-cgroup: stop using seq_get_buf") +Signed-off-by: Thomas Lamprecht +--- + block/blk-cgroup.c | 9 ++------- + block/blk-iocost.c | 5 ++--- + block/blk-iolatency.c | 6 ++---- + include/linux/blk-cgroup.h | 2 +- + 4 files changed, 7 insertions(+), 15 deletions(-) + +diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c +index 0eec59e4df65..38c62a44905a 100644 +--- a/block/blk-cgroup.c ++++ b/block/blk-cgroup.c +@@ -887,7 +887,6 @@ static void blkcg_print_one_stat(struct blkcg_gq *blkg, struct seq_file *s) + { + struct blkg_iostat_set *bis = &blkg->iostat; + u64 rbytes, wbytes, rios, wios, dbytes, dios; +- bool has_stats = false; + const char *dname; + unsigned seq; + int i; +@@ -913,14 +912,12 @@ static void blkcg_print_one_stat(struct blkcg_gq *blkg, struct seq_file *s) + } while (u64_stats_fetch_retry(&bis->sync, seq)); + + if (rbytes || wbytes || rios || wios) { +- has_stats = true; + seq_printf(s, "rbytes=%llu wbytes=%llu rios=%llu wios=%llu dbytes=%llu dios=%llu", + rbytes, wbytes, rios, wios, + dbytes, dios); + } + + if (blkcg_debug_stats && atomic_read(&blkg->use_delay)) { +- has_stats = true; + seq_printf(s, " use_delay=%d delay_nsec=%llu", + atomic_read(&blkg->use_delay), + atomic64_read(&blkg->delay_nsec)); +@@ -932,12 +929,10 @@ static void blkcg_print_one_stat(struct blkcg_gq *blkg, struct seq_file *s) + if (!blkg->pd[i] || !pol->pd_stat_fn) + continue; + +- if (pol->pd_stat_fn(blkg->pd[i], s)) +- has_stats = true; ++ pol->pd_stat_fn(blkg->pd[i], s); + } + +- if (has_stats) +- seq_printf(s, "\n"); ++ seq_puts(s, "\n"); + } + + static int blkcg_print_stat(struct seq_file *sf, void *v) +diff --git a/block/blk-iocost.c b/block/blk-iocost.c +index eb7b0d6bd11f..381c28f9561e 100644 +--- a/block/blk-iocost.c ++++ b/block/blk-iocost.c +@@ -2995,13 +2995,13 @@ static void ioc_pd_free(struct blkg_policy_data *pd) + kfree(iocg); + } + +-static bool ioc_pd_stat(struct blkg_policy_data *pd, struct seq_file *s) ++static void ioc_pd_stat(struct blkg_policy_data *pd, struct seq_file *s) + { + struct ioc_gq *iocg = pd_to_iocg(pd); + struct ioc *ioc = iocg->ioc; + + if (!ioc->enabled) +- return false; ++ return; + + if (iocg->level == 0) { + unsigned vp10k = DIV64_U64_ROUND_CLOSEST( +@@ -3017,7 +3017,6 @@ static bool ioc_pd_stat(struct blkg_policy_data *pd, struct seq_file *s) + iocg->last_stat.wait_us, + iocg->last_stat.indebt_us, + iocg->last_stat.indelay_us); +- return true; + } + + static u64 ioc_weight_prfill(struct seq_file *sf, struct blkg_policy_data *pd, +diff --git a/block/blk-iolatency.c b/block/blk-iolatency.c +index c0545f9da549..9e0c83223e04 100644 +--- a/block/blk-iolatency.c ++++ b/block/blk-iolatency.c +@@ -913,17 +913,16 @@ static bool iolatency_ssd_stat(struct iolatency_grp *iolat, struct seq_file *s) + (unsigned long long)stat.ps.missed, + (unsigned long long)stat.ps.total, + iolat->rq_depth.max_depth); +- return true; + } + +-static bool iolatency_pd_stat(struct blkg_policy_data *pd, struct seq_file *s) ++static void iolatency_pd_stat(struct blkg_policy_data *pd, struct seq_file *s) + { + struct iolatency_grp *iolat = pd_to_lat(pd); + unsigned long long avg_lat; + unsigned long long cur_win; + + if (!blkcg_debug_stats) +- return false; ++ return; + + if (iolat->ssd) + return iolatency_ssd_stat(iolat, s); +@@ -936,7 +935,6 @@ static bool iolatency_pd_stat(struct blkg_policy_data *pd, struct seq_file *s) + else + seq_printf(s, " depth=%u avg_lat=%llu win=%llu", + iolat->rq_depth.max_depth, avg_lat, cur_win); +- return true; + } + + static struct blkg_policy_data *iolatency_pd_alloc(gfp_t gfp, +diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h +index b4de2010fba5..132e05ed6935 100644 +--- a/include/linux/blk-cgroup.h ++++ b/include/linux/blk-cgroup.h +@@ -152,7 +152,7 @@ typedef void (blkcg_pol_online_pd_fn)(struct blkg_policy_data *pd); + typedef void (blkcg_pol_offline_pd_fn)(struct blkg_policy_data *pd); + typedef void (blkcg_pol_free_pd_fn)(struct blkg_policy_data *pd); + typedef void (blkcg_pol_reset_pd_stats_fn)(struct blkg_policy_data *pd); +-typedef bool (blkcg_pol_stat_pd_fn)(struct blkg_policy_data *pd, ++typedef void (blkcg_pol_stat_pd_fn)(struct blkg_policy_data *pd, + struct seq_file *s); + + struct blkcg_policy {