From: Ilya Dryomov <idryomov@gmail.com>
Date: Wed, 23 May 2018 14:46:53 +0200
Subject: libceph: allocate the locator string with GFP_NOFAIL
Git-commit: a86f009f106cba322c608785e09c8b5be8ffe8bb
Patch-mainline: v4.18-rc1
References: FATE#324714

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>
Acked-by: Luis Henriques <lhenriques@suse.com>
---
 include/linux/ceph/osdmap.h |    8 ++++----
 net/ceph/osd_client.c       |   10 +---------
 net/ceph/osdmap.c           |   19 ++++++++-----------
 3 files changed, 13 insertions(+), 24 deletions(-)

--- a/include/linux/ceph/osdmap.h
+++ b/include/linux/ceph/osdmap.h
@@ -283,10 +283,10 @@ void ceph_calc_file_object_mapping(struc
 				   u64 off, u64 len,
 				   u64 *objno, u64 *objoff, u32 *xlen);
 
-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,
--- a/net/ceph/osd_client.c
+++ b/net/ceph/osd_client.c
@@ -1364,7 +1364,6 @@ static enum calc_target_result calc_targ
 	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);
@@ -1400,14 +1399,7 @@ static enum calc_target_result calc_targ
 		}
 	}
 
-	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);
 
--- a/net/ceph/osdmap.c
+++ b/net/ceph/osdmap.c
@@ -2181,10 +2181,10 @@ EXPORT_SYMBOL(ceph_calc_file_object_mapp
  * 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);
 
@@ -2200,11 +2200,8 @@ int __ceph_object_locator_to_pg(struct c
 		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);
@@ -2216,7 +2213,6 @@ int __ceph_object_locator_to_pg(struct c
 		     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,
@@ -2230,7 +2226,8 @@ int ceph_object_locator_to_pg(struct cep
 	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);