jbd2: get rid of open coded allocation retry loop

insert_revoke_hash does an open coded endless allocation loop if journal_oom_retry is true. It doesn't implement any allocation fallback strategy between the retries, though. The memory allocator doesn't know about the never fail requirement so it cannot potentially help to move on with the allocation (e.g. use memory reserves). Get rid of the retry loop and use __GFP_NOFAIL instead. We will lose the debugging message but I am not sure it is anyhow helpful. Do the same for journal_alloc_journal_head which is doing a similar thing. Signed-off-by: Michal Hocko <[email protected]> Signed-off-by: Theodore Ts'o <[email protected]>
josf · Jun 15, 2015 · 7b506b1 · 7b506b1
1 parent b03a2f7
commit 7b506b1
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Showing 2 changed files with 7 additions and 14 deletions.
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
@@ -2377,10 +2377,8 @@ static struct journal_head *journal_alloc_journal_head(void)
 	if (!ret) {
 		jbd_debug(1, "out of memory for journal_head\n");
 		pr_notice_ratelimited("ENOMEM in %s, retrying.\n", __func__);
-		while (!ret) {
-			yield();
-			ret = kmem_cache_zalloc(jbd2_journal_head_cache, GFP_NOFS);
-		}
+		ret = kmem_cache_zalloc(jbd2_journal_head_cache,
+				GFP_NOFS | __GFP_NOFAIL);
 	}
 	return ret;
 }

diff --git a/fs/jbd2/revoke.c b/fs/jbd2/revoke.c
@@ -141,11 +141,13 @@ static int insert_revoke_hash(journal_t *journal, unsigned long long blocknr,
 {
 	struct list_head *hash_list;
 	struct jbd2_revoke_record_s *record;
+	gfp_t gfp_mask = GFP_NOFS;
 
-repeat:
-	record = kmem_cache_alloc(jbd2_revoke_record_cache, GFP_NOFS);
+	if (journal_oom_retry)
+		gfp_mask |= __GFP_NOFAIL;
+	record = kmem_cache_alloc(jbd2_revoke_record_cache, gfp_mask);
 	if (!record)
-		goto oom;
+		return -ENOMEM;
 
 	record->sequence = seq;
 	record->blocknr = blocknr;
@@ -154,13 +156,6 @@ static int insert_revoke_hash(journal_t *journal, unsigned long long blocknr,
 	list_add(&record->hash, hash_list);
 	spin_unlock(&journal->j_revoke_lock);
 	return 0;
-
-oom:
-	if (!journal_oom_retry)
-		return -ENOMEM;
-	jbd_debug(1, "ENOMEM in %s, retrying\n", __func__);
-	yield();
-	goto repeat;
 }
 
 /* Find a revoke record in the journal's hash table. */