patches/kernel/0009-blk-cgroup-always-terminate-io.stat-lines.patch

   1 From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
   2 From: Wolfgang Bumiller <w.bumiller@proxmox.com>
   3 Date: Tue, 11 Jan 2022 09:31:59 +0100
   4 Subject: [PATCH] blk-cgroup: always terminate io.stat lines
   5
   6 With the removal of seq_get_buf in blkcg_print_one_stat, we
   7 cannot make adding the newline conditional on there being
   8 relevant stats because the name was already written out
   9 unconditionally.
  10 Otherwise we may end up with multiple device names in one
  11 line which is confusing and doesn't follow the nested-keyed
  12 file format.
  13
  14 Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
  15 Fixes: 252c651a4c85 ("blk-cgroup: stop using seq_get_buf")
  16 Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
  17 ---
  18  block/blk-cgroup.c         | 9 ++-------
  19  block/blk-iocost.c         | 5 ++---
  20  block/blk-iolatency.c      | 8 +++-----
  21  include/linux/blk-cgroup.h | 2 +-
  22  4 files changed, 8 insertions(+), 16 deletions(-)
  23
  24 diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
  25 index 07a2524e6efd..fd09c20a5543 100644
  26 --- a/block/blk-cgroup.c
  27 +++ b/block/blk-cgroup.c
  28 @@ -887,7 +887,6 @@ static void blkcg_print_one_stat(struct blkcg_gq *blkg, struct seq_file *s)
  29  {
  30         struct blkg_iostat_set *bis = &blkg->iostat;
  31         u64 rbytes, wbytes, rios, wios, dbytes, dios;
  32 -       bool has_stats = false;
  33         const char *dname;
  34         unsigned seq;
  35         int i;
  36 @@ -913,14 +912,12 @@ static void blkcg_print_one_stat(struct blkcg_gq *blkg, struct seq_file *s)
  37         } while (u64_stats_fetch_retry(&bis->sync, seq));
  38
  39         if (rbytes || wbytes || rios || wios) {
  40 -               has_stats = true;
  41                 seq_printf(s, "rbytes=%llu wbytes=%llu rios=%llu wios=%llu dbytes=%llu dios=%llu",
  42                         rbytes, wbytes, rios, wios,
  43                         dbytes, dios);
  44         }
  45
  46         if (blkcg_debug_stats && atomic_read(&blkg->use_delay)) {
  47 -               has_stats = true;
  48                 seq_printf(s, " use_delay=%d delay_nsec=%llu",
  49                         atomic_read(&blkg->use_delay),
  50                         atomic64_read(&blkg->delay_nsec));
  51 @@ -932,12 +929,10 @@ static void blkcg_print_one_stat(struct blkcg_gq *blkg, struct seq_file *s)
  52                 if (!blkg->pd[i] || !pol->pd_stat_fn)
  53                         continue;
  54
  55 -               if (pol->pd_stat_fn(blkg->pd[i], s))
  56 -                       has_stats = true;
  57 +               pol->pd_stat_fn(blkg->pd[i], s);
  58         }
  59
  60 -       if (has_stats)
  61 -               seq_printf(s, "\n");
  62 +       seq_puts(s, "\n");
  63  }
  64
  65  static int blkcg_print_stat(struct seq_file *sf, void *v)
  66 diff --git a/block/blk-iocost.c b/block/blk-iocost.c
  67 index 10851493940c..21db328c0bcc 100644
  68 --- a/block/blk-iocost.c
  69 +++ b/block/blk-iocost.c
  70 @@ -3005,13 +3005,13 @@ static void ioc_pd_free(struct blkg_policy_data *pd)
  71         kfree(iocg);
  72  }
  73
  74 -static bool ioc_pd_stat(struct blkg_policy_data *pd, struct seq_file *s)
  75 +static void ioc_pd_stat(struct blkg_policy_data *pd, struct seq_file *s)
  76  {
  77         struct ioc_gq *iocg = pd_to_iocg(pd);
  78         struct ioc *ioc = iocg->ioc;
  79
  80         if (!ioc->enabled)
  81 -               return false;
  82 +               return;
  83
  84         if (iocg->level == 0) {
  85                 unsigned vp10k = DIV64_U64_ROUND_CLOSEST(
  86 @@ -3027,7 +3027,6 @@ static bool ioc_pd_stat(struct blkg_policy_data *pd, struct seq_file *s)
  87                         iocg->last_stat.wait_us,
  88                         iocg->last_stat.indebt_us,
  89                         iocg->last_stat.indelay_us);
  90 -       return true;
  91  }
  92
  93  static u64 ioc_weight_prfill(struct seq_file *sf, struct blkg_policy_data *pd,
  94 diff --git a/block/blk-iolatency.c b/block/blk-iolatency.c
  95 index c0545f9da549..d33460f3d43d 100644
  96 --- a/block/blk-iolatency.c
  97 +++ b/block/blk-iolatency.c
  98 @@ -890,7 +890,7 @@ static int iolatency_print_limit(struct seq_file *sf, void *v)
  99         return 0;
 100  }
 101
 102 -static bool iolatency_ssd_stat(struct iolatency_grp *iolat, struct seq_file *s)
 103 +static void iolatency_ssd_stat(struct iolatency_grp *iolat, struct seq_file *s)
 104  {
 105         struct latency_stat stat;
 106         int cpu;
 107 @@ -913,17 +913,16 @@ static bool iolatency_ssd_stat(struct iolatency_grp *iolat, struct seq_file *s)
 108                         (unsigned long long)stat.ps.missed,
 109                         (unsigned long long)stat.ps.total,
 110                         iolat->rq_depth.max_depth);
 111 -       return true;
 112  }
 113
 114 -static bool iolatency_pd_stat(struct blkg_policy_data *pd, struct seq_file *s)
 115 +static void iolatency_pd_stat(struct blkg_policy_data *pd, struct seq_file *s)
 116  {
 117         struct iolatency_grp *iolat = pd_to_lat(pd);
 118         unsigned long long avg_lat;
 119         unsigned long long cur_win;
 120
 121         if (!blkcg_debug_stats)
 122 -               return false;
 123 +               return;
 124
 125         if (iolat->ssd)
 126                 return iolatency_ssd_stat(iolat, s);
 127 @@ -936,7 +935,6 @@ static bool iolatency_pd_stat(struct blkg_policy_data *pd, struct seq_file *s)
 128         else
 129                 seq_printf(s, " depth=%u avg_lat=%llu win=%llu",
 130                         iolat->rq_depth.max_depth, avg_lat, cur_win);
 131 -       return true;
 132  }
 133
 134  static struct blkg_policy_data *iolatency_pd_alloc(gfp_t gfp,
 135 diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h
 136 index bc5c04d711bb..618359e3beca 100644
 137 --- a/include/linux/blk-cgroup.h
 138 +++ b/include/linux/blk-cgroup.h
 139 @@ -153,7 +153,7 @@ typedef void (blkcg_pol_online_pd_fn)(struct blkg_policy_data *pd);
 140  typedef void (blkcg_pol_offline_pd_fn)(struct blkg_policy_data *pd);
 141  typedef void (blkcg_pol_free_pd_fn)(struct blkg_policy_data *pd);
 142  typedef void (blkcg_pol_reset_pd_stats_fn)(struct blkg_policy_data *pd);
 143 -typedef bool (blkcg_pol_stat_pd_fn)(struct blkg_policy_data *pd,
 144 +typedef void (blkcg_pol_stat_pd_fn)(struct blkg_policy_data *pd,
 145                                 struct seq_file *s);
 146
 147  struct blkcg_policy {