src/patches/suse-2.6.27.25/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 diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
  15 index 510fd26..95feacd 100644
  16 --- a/drivers/md/dm-mpath.c
  17 +++ b/drivers/md/dm-mpath.c
  18 @@ -141,7 +141,8 @@ static void deactivate_path(struct work_struct *work)
  19         struct pgpath *pgpath =
  20                 container_of(work, struct pgpath, deactivate_path);
  21
  22 -       blk_abort_queue(pgpath->path.dev->bdev->bd_disk->queue);
  23 +       if (pgpath->path.dev)
  24 +               blk_abort_queue(pgpath->path.dev->bdev->bd_disk->queue);
  25  }
  26
  27  static struct priority_group *alloc_priority_group(void)
  28 @@ -253,6 +254,11 @@ static int __choose_path_in_pg(struct multipath *m, struct priority_group *pg,
  29
  30         m->current_pgpath = path_to_pgpath(path);
  31
  32 +       if (!m->current_pgpath->path.dev) {
  33 +               m->current_pgpath = NULL;
  34 +               return -ENODEV;
  35 +       }
  36 +
  37         if (m->current_pg != pg)
  38                 __switch_pg(m, m->current_pgpath);
  39
  40 @@ -570,6 +576,7 @@ static struct pgpath *parse_path(struct arg_set *as, struct path_selector *ps,
  41  {
  42         int r;
  43         struct pgpath *p;
  44 +       char *path;
  45         struct multipath *m = ti->private;
  46
  47         /* we need at least a path arg */
  48 @@ -582,14 +589,37 @@ static struct pgpath *parse_path(struct arg_set *as, struct path_selector *ps,
  49         if (!p)
  50                 return NULL;
  51
  52 -       r = dm_get_device(ti, shift(as), ti->begin, ti->len,
  53 +       path = shift(as);
  54 +       r = dm_get_device(ti, path, ti->begin, ti->len,
  55                           dm_table_get_mode(ti->table), &p->path.dev);
  56         if (r) {
  57 -               ti->error = "error getting device";
  58 -               goto bad;
  59 +               unsigned major, minor;
  60 +
  61 +               /* Try to add a failed device */
  62 +               if (r == -ENXIO && sscanf(path, "%u:%u", &major, &minor) == 2) {
  63 +                       dev_t dev;
  64 +
  65 +                       /* Extract the major/minor numbers */
  66 +                       dev = MKDEV(major, minor);
  67 +                       if (MAJOR(dev) != major || MINOR(dev) != minor) {
  68 +                               /* Nice try, didn't work */
  69 +                               DMWARN("Invalid device path %s", path);
  70 +                               ti->error = "error converting devnum";
  71 +                               goto bad;
  72 +                       }
  73 +                       DMWARN("adding disabled device %d:%d", major, minor);
  74 +                       p->path.dev = NULL;
  75 +                       format_dev_t(p->path.pdev, dev);
  76 +                       p->is_active = 0;
  77 +               } else {
  78 +                       ti->error = "error getting device";
  79 +                       goto bad;
  80 +               }
  81 +       } else {
  82 +               memcpy(p->path.pdev, p->path.dev->name, 16);
  83         }
  84
  85 -       if (m->hw_handler_name) {
  86 +       if (m->hw_handler_name && p->path.dev) {
  87                 struct request_queue *q = bdev_get_queue(p->path.dev->bdev);
  88
  89                 r = scsi_dh_attach(q, m->hw_handler_name);
  90 @@ -880,7 +910,7 @@ static int fail_path(struct pgpath *pgpath)
  91         if (!pgpath->is_active)
  92                 goto out;
  93
  94 -       DMWARN("Failing path %s.", pgpath->path.dev->name);
  95 +       DMWARN("Failing path %s.", pgpath->path.pdev);
  96
  97         pgpath->pg->ps.type->fail_path(&pgpath->pg->ps, &pgpath->path);
  98         pgpath->is_active = 0;
  99 @@ -892,7 +922,7 @@ static int fail_path(struct pgpath *pgpath)
 100                 m->current_pgpath = NULL;
 101
 102         dm_path_uevent(DM_UEVENT_PATH_FAILED, m->ti,
 103 -                     pgpath->path.dev->name, m->nr_valid_paths);
 104 +                      pgpath->path.pdev, m->nr_valid_paths);
 105
 106         queue_work(kmultipathd, &m->trigger_event);
 107         queue_work(kmultipathd, &pgpath->deactivate_path);
 108 @@ -917,6 +947,12 @@ static int reinstate_path(struct pgpath *pgpath)
 109         if (pgpath->is_active)
 110                 goto out;
 111
 112 +       if (!pgpath->path.dev) {
 113 +               DMWARN("Cannot reinstate disabled path %s", pgpath->path.pdev);
 114 +               r = -ENODEV;
 115 +               goto out;
 116 +       }
 117 +
 118         if (!pgpath->pg->ps.type->reinstate_path) {
 119                 DMWARN("Reinstate path not supported by path selector %s",
 120                        pgpath->pg->ps.type->name);
 121 @@ -935,7 +971,7 @@ static int reinstate_path(struct pgpath *pgpath)
 122                 queue_work(kmultipathd, &m->process_queued_ios);
 123
 124         dm_path_uevent(DM_UEVENT_PATH_REINSTATED, m->ti,
 125 -                     pgpath->path.dev->name, m->nr_valid_paths);
 126 +                      pgpath->path.pdev, m->nr_valid_paths);
 127
 128         queue_work(kmultipathd, &m->trigger_event);
 129
 130 @@ -955,6 +991,9 @@ static int action_dev(struct multipath *m, struct dm_dev *dev,
 131         struct pgpath *pgpath;
 132         struct priority_group *pg;
 133
 134 +       if (!dev)
 135 +               return 0;
 136 +
 137         list_for_each_entry(pg, &m->priority_groups, list) {
 138                 list_for_each_entry(pgpath, &pg->pgpaths, list) {
 139                         if (pgpath->path.dev == dev)
 140 @@ -1124,11 +1163,12 @@ static void pg_init_done(struct dm_path *path, int errors)
 141
 142  static void activate_path(struct work_struct *work)
 143  {
 144 -       int ret;
 145 +       int ret = SCSI_DH_DEV_OFFLINED;
 146         struct pgpath *pgpath =
 147                 container_of(work, struct pgpath, activate_path);
 148
 149 -       ret = scsi_dh_activate(bdev_get_queue(pgpath->path.dev->bdev));
 150 +       if (pgpath->path.dev)
 151 +               ret = scsi_dh_activate(bdev_get_queue(pgpath->path.dev->bdev));
 152         pg_init_done(&pgpath->path, ret);
 153  }
 154
 155 @@ -1295,7 +1335,7 @@ static int multipath_status(struct dm_target *ti, status_type_t type,
 156                                pg->ps.type->info_args);
 157
 158                         list_for_each_entry(p, &pg->pgpaths, list) {
 159 -                               DMEMIT("%s %s %u ", p->path.dev->name,
 160 +                               DMEMIT("%s %s %u ", p->path.pdev,
 161                                        p->is_active ? "A" : "F",
 162                                        p->fail_count);
 163                                 if (pg->ps.type->status)
 164 @@ -1321,7 +1361,7 @@ static int multipath_status(struct dm_target *ti, status_type_t type,
 165                                pg->ps.type->table_args);
 166
 167                         list_for_each_entry(p, &pg->pgpaths, list) {
 168 -                               DMEMIT("%s ", p->path.dev->name);
 169 +                               DMEMIT("%s ", p->path.pdev);
 170                                 if (pg->ps.type->status)
 171                                         sz += pg->ps.type->status(&pg->ps,
 172                                               &p->path, type, result + sz,
 173 @@ -1403,7 +1443,7 @@ static int multipath_ioctl(struct dm_target *ti, struct inode *inode,
 174         if (!m->current_pgpath)
 175                 __choose_pgpath(m, 1 << 19); /* Assume 512KB */
 176
 177 -       if (m->current_pgpath) {
 178 +       if (m->current_pgpath && m->current_pgpath->path.dev) {
 179                 bdev = m->current_pgpath->path.dev->bdev;
 180                 fake_dentry.d_inode = bdev->bd_inode;
 181                 fake_file.f_mode = m->current_pgpath->path.dev->mode;
 182 diff --git a/drivers/md/dm-mpath.h b/drivers/md/dm-mpath.h
 183 index e230f71..f97388d 100644
 184 --- a/drivers/md/dm-mpath.h
 185 +++ b/drivers/md/dm-mpath.h
 186 @@ -12,6 +12,7 @@
 187  struct dm_dev;
 188
 189  struct dm_path {
 190 +       char pdev[16];          /* Requested physical device */
 191         struct dm_dev *dev;     /* Read-only */
 192         void *pscontext;        /* For path-selector use */
 193  };
 194 diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
 195 index 1514e84..ee61b82 100644
 196 --- a/drivers/md/dm-table.c
 197 +++ b/drivers/md/dm-table.c
 198 @@ -566,6 +566,9 @@ int dm_get_device(struct dm_target *ti, const char *path, sector_t start,
 199   */
 200  void dm_put_device(struct dm_target *ti, struct dm_dev *dd)
 201  {
 202 +       if (!dd)
 203 +               return;
 204 +
 205         if (atomic_dec_and_test(&dd->count)) {
 206                 close_dev(dd, ti->table->md);
 207                 list_del(&dd->list);
 208 diff --git a/drivers/md/dm.c b/drivers/md/dm.c
 209 index 6783f91..134995e 100644
 210 --- a/drivers/md/dm.c
 211 +++ b/drivers/md/dm.c
 212 @@ -1503,6 +1503,9 @@ static void map_request(struct dm_target *ti, struct request *rq,
 213         tio->ti = ti;
 214         atomic_inc(&md->pending);
 215
 216 +#if 0
 217 +       /* This might trigger accidentally */
 218 +
 219         /*
 220          * Although submitted requests to the md->queue are checked against
 221          * the table/queue limitations at the submission time, the limitations
 222 @@ -1525,6 +1528,7 @@ static void map_request(struct dm_target *ti, struct request *rq,
 223                 dm_kill_request(clone, r);
 224                 return;
 225         }
 226 +#endif
 227
 228         r = ti->type->map_rq(ti, clone, &tio->info);
 229         switch (r) {