src/patches/suse-2.6.27.39/patches.suse/dm-mpath-accept-failed-paths

   1 From: Hannes Reinecke <hare@suse.de>
   2 Subject: Accept failed paths for multipath maps
   3 References: bnc#458037,bnc#458393
   4
   5 The multipath kernel module is rejecting any map with an invalid
   6 device. However, as the multipathd is processing the events serially
   7 it will try to push a map with invalid devices if more than one
   8 device failed at the same time.
   9 So we can as well accept those maps and make sure to mark the
  10 paths as down.
  11
  12 Signed-off-by: Hannes Reinecke <hare@suse.de>
  13
  14 ---
  15  drivers/md/dm-mpath.c |   66 ++++++++++++++++++++++++++++++++++++++++----------
  16  drivers/md/dm-mpath.h |    1
  17  drivers/md/dm-table.c |    3 ++
  18  drivers/md/dm.c       |    4 +++
  19  4 files changed, 61 insertions(+), 13 deletions(-)
  20
  21 --- a/drivers/md/dm-mpath.c
  22 +++ b/drivers/md/dm-mpath.c
  23 @@ -141,7 +141,8 @@ static void deactivate_path(struct work_
  24         struct pgpath *pgpath =
  25                 container_of(work, struct pgpath, deactivate_path);
  26
  27 -       blk_abort_queue(pgpath->path.dev->bdev->bd_disk->queue);
  28 +       if (pgpath->path.dev)
  29 +               blk_abort_queue(pgpath->path.dev->bdev->bd_disk->queue);
  30  }
  31
  32  static struct priority_group *alloc_priority_group(void)
  33 @@ -253,6 +254,11 @@ static int __choose_path_in_pg(struct mu
  34
  35         m->current_pgpath = path_to_pgpath(path);
  36
  37 +       if (!m->current_pgpath->path.dev) {
  38 +               m->current_pgpath = NULL;
  39 +               return -ENODEV;
  40 +       }
  41 +
  42         if (m->current_pg != pg)
  43                 __switch_pg(m, m->current_pgpath);
  44
  45 @@ -576,6 +582,7 @@ static struct pgpath *parse_path(struct
  46  {
  47         int r;
  48         struct pgpath *p;
  49 +       char *path;
  50         struct multipath *m = ti->private;
  51
  52         /* we need at least a path arg */
  53 @@ -588,14 +595,37 @@ static struct pgpath *parse_path(struct
  54         if (!p)
  55                 return NULL;
  56
  57 -       r = dm_get_device(ti, shift(as), ti->begin, ti->len,
  58 +       path = shift(as);
  59 +       r = dm_get_device(ti, path, ti->begin, ti->len,
  60                           dm_table_get_mode(ti->table), &p->path.dev);
  61         if (r) {
  62 -               ti->error = "error getting device";
  63 -               goto bad;
  64 +               unsigned major, minor;
  65 +
  66 +               /* Try to add a failed device */
  67 +               if (r == -ENXIO && sscanf(path, "%u:%u", &major, &minor) == 2) {
  68 +                       dev_t dev;
  69 +
  70 +                       /* Extract the major/minor numbers */
  71 +                       dev = MKDEV(major, minor);
  72 +                       if (MAJOR(dev) != major || MINOR(dev) != minor) {
  73 +                               /* Nice try, didn't work */
  74 +                               DMWARN("Invalid device path %s", path);
  75 +                               ti->error = "error converting devnum";
  76 +                               goto bad;
  77 +                       }
  78 +                       DMWARN("adding disabled device %d:%d", major, minor);
  79 +                       p->path.dev = NULL;
  80 +                       format_dev_t(p->path.pdev, dev);
  81 +                       p->is_active = 0;
  82 +               } else {
  83 +                       ti->error = "error getting device";
  84 +                       goto bad;
  85 +               }
  86 +       } else {
  87 +               memcpy(p->path.pdev, p->path.dev->name, 16);
  88         }
  89
  90 -       if (m->hw_handler_name) {
  91 +       if (m->hw_handler_name && p->path.dev) {
  92                 struct request_queue *q = bdev_get_queue(p->path.dev->bdev);
  93
  94                 r = scsi_dh_attach(q, m->hw_handler_name);
  95 @@ -891,7 +921,7 @@ static int fail_path(struct pgpath *pgpa
  96         if (!pgpath->is_active)
  97                 goto out;
  98
  99 -       DMWARN("Failing path %s.", pgpath->path.dev->name);
 100 +       DMWARN("Failing path %s.", pgpath->path.pdev);
 101
 102         pgpath->pg->ps.type->fail_path(&pgpath->pg->ps, &pgpath->path);
 103         pgpath->is_active = 0;
 104 @@ -903,7 +933,7 @@ static int fail_path(struct pgpath *pgpa
 105                 m->current_pgpath = NULL;
 106
 107         dm_path_uevent(DM_UEVENT_PATH_FAILED, m->ti,
 108 -                     pgpath->path.dev->name, m->nr_valid_paths);
 109 +                      pgpath->path.pdev, m->nr_valid_paths);
 110
 111         queue_work(kmultipathd, &m->trigger_event);
 112         queue_work(kmultipathd, &pgpath->deactivate_path);
 113 @@ -928,6 +958,12 @@ static int reinstate_path(struct pgpath
 114         if (pgpath->is_active)
 115                 goto out;
 116
 117 +       if (!pgpath->path.dev) {
 118 +               DMWARN("Cannot reinstate disabled path %s", pgpath->path.pdev);
 119 +               r = -ENODEV;
 120 +               goto out;
 121 +       }
 122 +
 123         if (!pgpath->pg->ps.type->reinstate_path) {
 124                 DMWARN("Reinstate path not supported by path selector %s",
 125                        pgpath->pg->ps.type->name);
 126 @@ -946,7 +982,7 @@ static int reinstate_path(struct pgpath
 127                 queue_work(kmultipathd, &m->process_queued_ios);
 128
 129         dm_path_uevent(DM_UEVENT_PATH_REINSTATED, m->ti,
 130 -                     pgpath->path.dev->name, m->nr_valid_paths);
 131 +                      pgpath->path.pdev, m->nr_valid_paths);
 132
 133         queue_work(kmultipathd, &m->trigger_event);
 134
 135 @@ -966,6 +1002,9 @@ static int action_dev(struct multipath *
 136         struct pgpath *pgpath;
 137         struct priority_group *pg;
 138
 139 +       if (!dev)
 140 +               return 0;
 141 +
 142         list_for_each_entry(pg, &m->priority_groups, list) {
 143                 list_for_each_entry(pgpath, &pg->pgpaths, list) {
 144                         if (pgpath->path.dev == dev)
 145 @@ -1135,11 +1174,12 @@ static void pg_init_done(struct dm_path
 146
 147  static void activate_path(struct work_struct *work)
 148  {
 149 -       int ret;
 150 +       int ret = SCSI_DH_DEV_OFFLINED;
 151         struct pgpath *pgpath =
 152                 container_of(work, struct pgpath, activate_path);
 153
 154 -       ret = scsi_dh_activate(bdev_get_queue(pgpath->path.dev->bdev));
 155 +       if (pgpath->path.dev)
 156 +               ret = scsi_dh_activate(bdev_get_queue(pgpath->path.dev->bdev));
 157         pg_init_done(&pgpath->path, ret);
 158  }
 159
 160 @@ -1306,7 +1346,7 @@ static int multipath_status(struct dm_ta
 161                                pg->ps.type->info_args);
 162
 163                         list_for_each_entry(p, &pg->pgpaths, list) {
 164 -                               DMEMIT("%s %s %u ", p->path.dev->name,
 165 +                               DMEMIT("%s %s %u ", p->path.pdev,
 166                                        p->is_active ? "A" : "F",
 167                                        p->fail_count);
 168                                 if (pg->ps.type->status)
 169 @@ -1332,7 +1372,7 @@ static int multipath_status(struct dm_ta
 170                                pg->ps.type->table_args);
 171
 172                         list_for_each_entry(p, &pg->pgpaths, list) {
 173 -                               DMEMIT("%s ", p->path.dev->name);
 174 +                               DMEMIT("%s ", p->path.pdev);
 175                                 if (pg->ps.type->status)
 176                                         sz += pg->ps.type->status(&pg->ps,
 177                                               &p->path, type, result + sz,
 178 @@ -1414,7 +1454,7 @@ static int multipath_ioctl(struct dm_tar
 179         if (!m->current_pgpath)
 180                 __choose_pgpath(m, 1 << 19); /* Assume 512KB */
 181
 182 -       if (m->current_pgpath) {
 183 +       if (m->current_pgpath && m->current_pgpath->path.dev) {
 184                 bdev = m->current_pgpath->path.dev->bdev;
 185                 fake_dentry.d_inode = bdev->bd_inode;
 186                 fake_file.f_mode = m->current_pgpath->path.dev->mode;
 187 --- a/drivers/md/dm-mpath.h
 188 +++ b/drivers/md/dm-mpath.h
 189 @@ -12,6 +12,7 @@
 190  struct dm_dev;
 191
 192  struct dm_path {
 193 +       char pdev[16];          /* Requested physical device */
 194         struct dm_dev *dev;     /* Read-only */
 195         void *pscontext;        /* For path-selector use */
 196  };
 197 --- a/drivers/md/dm-table.c
 198 +++ b/drivers/md/dm-table.c
 199 @@ -566,6 +566,9 @@ int dm_get_device(struct dm_target *ti,
 200   */
 201  void dm_put_device(struct dm_target *ti, struct dm_dev *dd)
 202  {
 203 +       if (!dd)
 204 +               return;
 205 +
 206         if (atomic_dec_and_test(&dd->count)) {
 207                 close_dev(dd, ti->table->md);
 208                 list_del(&dd->list);
 209 --- a/drivers/md/dm.c
 210 +++ b/drivers/md/dm.c
 211 @@ -1503,6 +1503,9 @@ static void map_request(struct dm_target
 212         tio->ti = ti;
 213         atomic_inc(&md->pending);
 214
 215 +#if 0
 216 +       /* This might trigger accidentally */
 217 +
 218         /*
 219          * Although submitted requests to the md->queue are checked against
 220          * the table/queue limitations at the submission time, the limitations
 221 @@ -1525,6 +1528,7 @@ static void map_request(struct dm_target
 222                 dm_kill_request(clone, r);
 223                 return;
 224         }
 225 +#endif
 226
 227         r = ti->type->map_rq(ti, clone, &tio->info);
 228         switch (r) {