queue-6.6/smb-client-handle-dfs-tcons-in-cifs_construct_tcon.patch

   1 From 4a5ba0e0bfe552ac7451f57e304f6343c3d87f89 Mon Sep 17 00:00:00 2001
   2 From: Paulo Alcantara <pc@manguebit.com>
   3 Date: Mon, 1 Apr 2024 22:44:08 -0300
   4 Subject: smb: client: handle DFS tcons in cifs_construct_tcon()
   5
   6 From: Paulo Alcantara <pc@manguebit.com>
   7
   8 commit 4a5ba0e0bfe552ac7451f57e304f6343c3d87f89 upstream.
   9
  10 The tcons created by cifs_construct_tcon() on multiuser mounts must
  11 also be able to failover and refresh DFS referrals, so set the
  12 appropriate fields in order to get a full DFS tcon.  They could be
  13 shared among different superblocks later, too.
  14
  15 Cc: stable@vger.kernel.org # 6.4+
  16 Reported-by: kernel test robot <lkp@intel.com>
  17 Closes: https://lore.kernel.org/oe-kbuild-all/202404021518.3Xu2VU4s-lkp@intel.com/
  18 Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
  19 Signed-off-by: Steve French <stfrench@microsoft.com>
  20 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  21 ---
  22  fs/smb/client/connect.c |   30 ++++++++++++++++++++++++++++++
  23  1 file changed, 30 insertions(+)
  24
  25 --- a/fs/smb/client/connect.c
  26 +++ b/fs/smb/client/connect.c
  27 @@ -3988,6 +3988,7 @@ cifs_construct_tcon(struct cifs_sb_info
  28         struct cifs_ses *ses;
  29         struct cifs_tcon *tcon = NULL;
  30         struct smb3_fs_context *ctx;
  31 +       char *origin_fullpath = NULL;
  32
  33         ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
  34         if (ctx == NULL)
  35 @@ -4011,6 +4012,7 @@ cifs_construct_tcon(struct cifs_sb_info
  36         ctx->sign = master_tcon->ses->sign;
  37         ctx->seal = master_tcon->seal;
  38         ctx->witness = master_tcon->use_witness;
  39 +       ctx->dfs_root_ses = master_tcon->ses->dfs_root_ses;
  40
  41         rc = cifs_set_vol_auth(ctx, master_tcon->ses);
  42         if (rc) {
  43 @@ -4030,12 +4032,39 @@ cifs_construct_tcon(struct cifs_sb_info
  44                 goto out;
  45         }
  46
  47 +#ifdef CONFIG_CIFS_DFS_UPCALL
  48 +       spin_lock(&master_tcon->tc_lock);
  49 +       if (master_tcon->origin_fullpath) {
  50 +               spin_unlock(&master_tcon->tc_lock);
  51 +               origin_fullpath = dfs_get_path(cifs_sb, cifs_sb->ctx->source);
  52 +               if (IS_ERR(origin_fullpath)) {
  53 +                       tcon = ERR_CAST(origin_fullpath);
  54 +                       origin_fullpath = NULL;
  55 +                       cifs_put_smb_ses(ses);
  56 +                       goto out;
  57 +               }
  58 +       } else {
  59 +               spin_unlock(&master_tcon->tc_lock);
  60 +       }
  61 +#endif
  62 +
  63         tcon = cifs_get_tcon(ses, ctx);
  64         if (IS_ERR(tcon)) {
  65                 cifs_put_smb_ses(ses);
  66                 goto out;
  67         }
  68
  69 +#ifdef CONFIG_CIFS_DFS_UPCALL
  70 +       if (origin_fullpath) {
  71 +               spin_lock(&tcon->tc_lock);
  72 +               tcon->origin_fullpath = origin_fullpath;
  73 +               spin_unlock(&tcon->tc_lock);
  74 +               origin_fullpath = NULL;
  75 +               queue_delayed_work(dfscache_wq, &tcon->dfs_cache_work,
  76 +                                  dfs_cache_get_ttl() * HZ);
  77 +       }
  78 +#endif
  79 +
  80  #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
  81         if (cap_unix(ses))
  82                 reset_cifs_unix_caps(0, tcon, NULL, ctx);
  83 @@ -4044,6 +4073,7 @@ cifs_construct_tcon(struct cifs_sb_info
  84  out:
  85         kfree(ctx->username);
  86         kfree_sensitive(ctx->password);
  87 +       kfree(origin_fullpath);
  88         kfree(ctx);
  89
  90         return tcon;