target/linux/layerscape/patches-5.4/303-core-0004-cgroup-bfq-revert-bfq.weight-symlink-change.patch

   1 From b7f71899fbdba1cac6773a62ed4ea841b7eda6b0 Mon Sep 17 00:00:00 2001
   2 From: Jens Axboe <axboe@kernel.dk>
   3 Date: Mon, 10 Jun 2019 03:35:41 -0600
   4 Subject: [PATCH] cgroup/bfq: revert bfq.weight symlink change
   5
   6 There's some discussion on how to do this the best, and Tejun prefers
   7 that BFQ just create the file itself instead of having cgroups support
   8 a symlink feature.
   9
  10 Hence revert commit 54b7b868e826 and 19e9da9e86c4 for 5.2, and this
  11 can be done properly for 5.3.
  12
  13 Signed-off-by: Jens Axboe <axboe@kernel.dk>
  14 (cherry picked from commit cf8929885de318c0bf73438c9e5dde59d6536f7c)
  15 Signed-off-by: Li Yang <leoyang.li@nxp.com>
  16 ---
  17  include/linux/cgroup-defs.h |  3 ---
  18  kernel/cgroup/cgroup.c      | 33 ++++-----------------------------
  19  2 files changed, 4 insertions(+), 32 deletions(-)
  20
  21 --- a/include/linux/cgroup-defs.h
  22 +++ b/include/linux/cgroup-defs.h
  23 @@ -106,8 +106,6 @@ enum {
  24         CFTYPE_WORLD_WRITABLE   = (1 << 4),     /* (DON'T USE FOR NEW FILES) S_IWUGO */
  25         CFTYPE_DEBUG            = (1 << 5),     /* create when cgroup_debug */
  26
  27 -       CFTYPE_SYMLINKED        = (1 << 6),     /* pointed to by symlink too */
  28 -
  29         /* internal flags, do not use outside cgroup core proper */
  30         __CFTYPE_ONLY_ON_DFL    = (1 << 16),    /* only on default hierarchy */
  31         __CFTYPE_NOT_ON_DFL     = (1 << 17),    /* not on default hierarchy */
  32 @@ -546,7 +544,6 @@ struct cftype {
  33          * end of cftype array.
  34          */
  35         char name[MAX_CFTYPE_NAME];
  36 -       char link_name[MAX_CFTYPE_NAME];
  37         unsigned long private;
  38
  39         /*
  40 --- a/kernel/cgroup/cgroup.c
  41 +++ b/kernel/cgroup/cgroup.c
  42 @@ -1465,8 +1465,8 @@ struct cgroup *task_cgroup_from_root(str
  43
  44  static struct kernfs_syscall_ops cgroup_kf_syscall_ops;
  45
  46 -static char *cgroup_fill_name(struct cgroup *cgrp, const struct cftype *cft,
  47 -                             char *buf, bool write_link_name)
  48 +static char *cgroup_file_name(struct cgroup *cgrp, const struct cftype *cft,
  49 +                             char *buf)
  50  {
  51         struct cgroup_subsys *ss = cft->ss;
  52
  53 @@ -1476,26 +1476,13 @@ static char *cgroup_fill_name(struct cgr
  54
  55                 snprintf(buf, CGROUP_FILE_NAME_MAX, "%s%s.%s",
  56                          dbg, cgroup_on_dfl(cgrp) ? ss->name : ss->legacy_name,
  57 -                        write_link_name ? cft->link_name : cft->name);
  58 +                        cft->name);
  59         } else {
  60 -               strscpy(buf, write_link_name ? cft->link_name : cft->name,
  61 -                       CGROUP_FILE_NAME_MAX);
  62 +               strscpy(buf, cft->name, CGROUP_FILE_NAME_MAX);
  63         }
  64         return buf;
  65  }
  66
  67 -static char *cgroup_file_name(struct cgroup *cgrp, const struct cftype *cft,
  68 -                             char *buf)
  69 -{
  70 -       return cgroup_fill_name(cgrp, cft, buf, false);
  71 -}
  72 -
  73 -static char *cgroup_link_name(struct cgroup *cgrp, const struct cftype *cft,
  74 -                             char *buf)
  75 -{
  76 -       return cgroup_fill_name(cgrp, cft, buf, true);
  77 -}
  78 -
  79  /**
  80   * cgroup_file_mode - deduce file mode of a control file
  81   * @cft: the control file in question
  82 @@ -1654,9 +1641,6 @@ static void cgroup_rm_file(struct cgroup
  83         }
  84
  85         kernfs_remove_by_name(cgrp->kn, cgroup_file_name(cgrp, cft, name));
  86 -       if (cft->flags & CFTYPE_SYMLINKED)
  87 -               kernfs_remove_by_name(cgrp->kn,
  88 -                                     cgroup_link_name(cgrp, cft, name));
  89  }
  90
  91  /**
  92 @@ -3887,7 +3871,6 @@ static int cgroup_add_file(struct cgroup
  93  {
  94         char name[CGROUP_FILE_NAME_MAX];
  95         struct kernfs_node *kn;
  96 -       struct kernfs_node *kn_link;
  97         struct lock_class_key *key = NULL;
  98         int ret;
  99
 100 @@ -3918,14 +3901,6 @@ static int cgroup_add_file(struct cgroup
 101                 spin_unlock_irq(&cgroup_file_kn_lock);
 102         }
 103
 104 -       if (cft->flags & CFTYPE_SYMLINKED) {
 105 -               kn_link = kernfs_create_link(cgrp->kn,
 106 -                                            cgroup_link_name(cgrp, cft, name),
 107 -                                            kn);
 108 -               if (IS_ERR(kn_link))
 109 -                       return PTR_ERR(kn_link);
 110 -       }
 111 -
 112         return 0;
 113  }
 114