libceph: allocate the locator string with GFP_NOFAIL

calc_target() isn't supposed to fail with anything but POOL_DNE, in
which case we report that the pool doesn't exist and fail the request
with -ENOENT.  Doing this for -ENOMEM is at the very least confusing
and also harmful -- as the preceding requests complete, a short-lived
locator string allocation is likely to succeed after a wait.

(We used to call ceph_object_locator_to_pg() for a pi lookup.  In
theory that could fail with -ENOENT, hence the "ret != -ENOENT" warning
being removed.)

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

3 files changed, 13 insertions, 24 deletions

diff --git a/include/linux/ceph/osdmap.h b/include/linux/ceph/osdmap.h
index e71fb222c7c3..5675b1f09bc5 100644
--- a/include/linux/ceph/osdmap.h
+++ b/include/linux/ceph/osdmap.h
@@ -279,10 +279,10 @@ bool ceph_osds_changed(const struct ceph_osds *old_acting,
                        const struct ceph_osds *new_acting,
                        bool any_change);
 
-int __ceph_object_locator_to_pg(struct ceph_pg_pool_info *pi,
-                                const struct ceph_object_id *oid,
-                                const struct ceph_object_locator *oloc,
-                                struct ceph_pg *raw_pgid);
+void __ceph_object_locator_to_pg(struct ceph_pg_pool_info *pi,
+                                 const struct ceph_object_id *oid,
+                                 const struct ceph_object_locator *oloc,
+                                 struct ceph_pg *raw_pgid);
 int ceph_object_locator_to_pg(struct ceph_osdmap *osdmap,
                               const struct ceph_object_id *oid,
                               const struct ceph_object_locator *oloc,
diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c
index 05c4d27d25fe..f2584fe1246f 100644
--- a/net/ceph/osd_client.c
+++ b/net/ceph/osd_client.c
@@ -1430,7 +1430,6 @@ static enum calc_target_result calc_target(struct ceph_osd_client *osdc,
         bool recovery_deletes = ceph_osdmap_flag(osdc,
                                                  CEPH_OSDMAP_RECOVERY_DELETES);
         enum calc_target_result ct_res;
-        int ret;
 
         t->epoch = osdc->osdmap->epoch;
         pi = ceph_pg_pool_by_id(osdc->osdmap, t->base_oloc.pool);
@@ -1466,14 +1465,7 @@ static enum calc_target_result calc_target(struct ceph_osd_client *osdc,
                 }
         }
 
-        ret = __ceph_object_locator_to_pg(pi, &t->target_oid, &t->target_oloc,
-                                          &pgid);
-        if (ret) {
-                WARN_ON(ret != -ENOENT);
-                t->osd = CEPH_HOMELESS_OSD;
-                ct_res = CALC_TARGET_POOL_DNE;
-                goto out;
-        }
+        __ceph_object_locator_to_pg(pi, &t->target_oid, &t->target_oloc, &pgid);
         last_pgid.pool = pgid.pool;
         last_pgid.seed = ceph_stable_mod(pgid.seed, t->pg_num, t->pg_num_mask);
 
diff --git a/net/ceph/osdmap.c b/net/ceph/osdmap.c
index 9645ffd6acfb..a7494f623451 100644
--- a/net/ceph/osdmap.c
+++ b/net/ceph/osdmap.c
@@ -2145,10 +2145,10 @@ bool ceph_osds_changed(const struct ceph_osds *old_acting,
  * Should only be called with target_oid and target_oloc (as opposed to
  * base_oid and base_oloc), since tiering isn't taken into account.
  */
-int __ceph_object_locator_to_pg(struct ceph_pg_pool_info *pi,
-                                const struct ceph_object_id *oid,
-                                const struct ceph_object_locator *oloc,
-                                struct ceph_pg *raw_pgid)
+void __ceph_object_locator_to_pg(struct ceph_pg_pool_info *pi,
+                                 const struct ceph_object_id *oid,
+                                 const struct ceph_object_locator *oloc,
+                                 struct ceph_pg *raw_pgid)
 {
         WARN_ON(pi->id != oloc->pool);
 
@@ -2164,11 +2164,8 @@ int __ceph_object_locator_to_pg(struct ceph_pg_pool_info *pi,
                 int nsl = oloc->pool_ns->len;
                 size_t total = nsl + 1 + oid->name_len;
 
-                if (total > sizeof(stack_buf)) {
-                        buf = kmalloc(total, GFP_NOIO);
-                        if (!buf)
-                                return -ENOMEM;
-                }
+                if (total > sizeof(stack_buf))
+                        buf = kmalloc(total, GFP_NOIO | __GFP_NOFAIL);
                 memcpy(buf, oloc->pool_ns->str, nsl);
                 buf[nsl] = '\037';
                 memcpy(buf + nsl + 1, oid->name, oid->name_len);
@@ -2180,7 +2177,6 @@ int __ceph_object_locator_to_pg(struct ceph_pg_pool_info *pi,
                      oid->name, nsl, oloc->pool_ns->str,
                      raw_pgid->pool, raw_pgid->seed);
         }
-        return 0;
 }
 
 int ceph_object_locator_to_pg(struct ceph_osdmap *osdmap,
@@ -2194,7 +2190,8 @@ int ceph_object_locator_to_pg(struct ceph_osdmap *osdmap,
         if (!pi)
                 return -ENOENT;
 
-        return __ceph_object_locator_to_pg(pi, oid, oloc, raw_pgid);
+        __ceph_object_locator_to_pg(pi, oid, oloc, raw_pgid);
+        return 0;
 }
 EXPORT_SYMBOL(ceph_object_locator_to_pg);