src/patches/suse-2.6.27.31/patches.fixes/nfsd-06-sunrpc-cache-retry-cache-lookups-that-return-ETIMEDO.patch

   1 Patch-mainline: submitted 04aug2009
   2 References: bnc#498708
   3 From: NeilBrown <neilb@suse.de>
   4 Date: Tue, 4 Aug 2009 15:06:38 +1000
   5 Subject: [PATCH 08/12] sunrpc/cache: retry cache lookups that return -ETIMEDOUT
   6
   7 If cache_check returns -ETIMEDOUT, then the cache item is not
   8 up-to-date, but there is no pending upcall.
   9 This could mean the data is not available, or it could mean that the
  10 good data has been stored in a new cache item.
  11
  12 So re-do the lookup and if that returns a new item, proceed using that
  13 item.
  14
  15 Signed-off-by: NeilBrown <neilb@suse.de>
  16
  17 ---
  18  fs/nfsd/export.c          |   18 ++++++++++++++++++
  19  net/sunrpc/svcauth_unix.c |   22 ++++++++++++++++++++--
  20  2 files changed, 38 insertions(+), 2 deletions(-)
  21
  22 --- linux-2.6.27-SLE11_BRANCH.orig/fs/nfsd/export.c
  23 +++ linux-2.6.27-SLE11_BRANCH/fs/nfsd/export.c
  24 @@ -796,9 +796,18 @@ exp_find_key(svc_client *clp, int fsid_t
  25         memcpy(key.ek_fsid, fsidv, key_len(fsid_type));
  26
  27         ek = svc_expkey_lookup(&key);
  28 + again:
  29         if (ek == NULL)
  30                 return ERR_PTR(-ENOMEM);
  31         err = cache_check(&svc_expkey_cache, &ek->h, reqp);
  32 +       if (err == -ETIMEDOUT) {
  33 +               struct svc_expkey *prev_ek = ek;
  34 +               ek = svc_expkey_lookup(&key);
  35 +               if (ek != prev_ek)
  36 +                       goto again;
  37 +               if (ek)
  38 +                       cache_put(&ek->h, &svc_expkey_cache);
  39 +       }
  40         if (err)
  41                 return ERR_PTR(err);
  42         return ek;
  43 @@ -870,9 +879,18 @@ static svc_export *exp_get_by_name(svc_c
  44         key.ex_path.dentry = dentry;
  45
  46         exp = svc_export_lookup(&key);
  47 + retry:
  48         if (exp == NULL)
  49                 return ERR_PTR(-ENOMEM);
  50         err = cache_check(&svc_export_cache, &exp->h, reqp);
  51 +       if (err == -ETIMEDOUT) {
  52 +               struct svc_export *prev_exp = exp;
  53 +               exp = svc_export_lookup(&key);
  54 +               if (exp != prev_exp)
  55 +                       goto retry;
  56 +               if (exp)
  57 +                       cache_put(&exp->h, &svc_export_cache);
  58 +       }
  59         if (err)
  60                 return ERR_PTR(err);
  61         return exp;
  62 --- linux-2.6.27-SLE11_BRANCH.orig/net/sunrpc/svcauth_unix.c
  63 +++ linux-2.6.27-SLE11_BRANCH/net/sunrpc/svcauth_unix.c
  64 @@ -659,8 +659,10 @@ static int unix_gid_find(uid_t uid, stru
  65                          struct svc_rqst *rqstp)
  66  {
  67         struct unix_gid *ug = unix_gid_lookup(uid);
  68 +       struct unix_gid *prevug;
  69         if (!ug)
  70                 return -EAGAIN;
  71 + retry:
  72         switch (cache_check(&unix_gid_cache, &ug->h, &rqstp->rq_chandle)) {
  73         case -ENOENT:
  74                 *gip = NULL;
  75 @@ -669,6 +671,13 @@ static int unix_gid_find(uid_t uid, stru
  76                 *gip = ug->gi;
  77                 get_group_info(*gip);
  78                 return 0;
  79 +       case -ETIMEDOUT:
  80 +               prevug = ug;
  81 +               ug = unix_gid_lookup(uid);
  82 +               if (ug != prevug)
  83 +                       goto retry;
  84 +               if (ug)
  85 +                       cache_put(&ug->h, &unix_gid_cache);
  86         default:
  87                 return -EAGAIN;
  88         }
  89 @@ -679,7 +688,7 @@ svcauth_unix_set_client(struct svc_rqst
  90  {
  91         struct sockaddr_in *sin;
  92         struct sockaddr_in6 *sin6, sin6_storage;
  93 -       struct ip_map *ipm;
  94 +       struct ip_map *ipm, *prev_ipm;
  95
  96         switch (rqstp->rq_addr.ss_family) {
  97         case AF_INET:
  98 @@ -704,14 +713,23 @@ svcauth_unix_set_client(struct svc_rqst
  99                 ipm = ip_map_lookup(rqstp->rq_server->sv_program->pg_class,
 100                                     &sin6->sin6_addr);
 101
 102 + retry:
 103         if (ipm == NULL)
 104                 return SVC_DENIED;
 105
 106         switch (cache_check(&ip_map_cache, &ipm->h, &rqstp->rq_chandle)) {
 107                 default:
 108                         BUG();
 109 -               case -EAGAIN:
 110                 case -ETIMEDOUT:
 111 +                       prev_ipm = ipm;
 112 +                       ipm = ip_map_lookup(rqstp->rq_server->sv_program->pg_class,
 113 +                                           &sin6->sin6_addr);
 114 +                       if (ipm != prev_ipm)
 115 +                               goto retry;
 116 +                       if (ipm)
 117 +                               cache_put(&ipm->h, &ip_map_cache);
 118 +
 119 +               case -EAGAIN:
 120                         return SVC_DROP;
 121                 case -ENOENT:
 122                         return SVC_DENIED;