From 1de7ce2b94fd02cba8e2fb0b2b6f341c5f920ce3 Mon Sep 17 00:00:00 2001
From: Michal Hocko <mhocko@suse.cz>
Date: Sun, 5 Jul 2015 12:33:44 -0400
Subject: [PATCH] ext4: replace open coded nofail allocation in
ext4_free_blocks()
commit 7444a072c387a93ebee7066e8aee776954ab0e41 upstream.
ext4_free_blocks is looping around the allocation request and mimics
__GFP_NOFAIL behavior without any allocation fallback strategy. Let's
remove the open coded loop and replace it with __GFP_NOFAIL. Without the
flag the allocator has no way to find out never-fail requirement and
cannot help in any way.
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
[bwh: Backported to 3.2:
- Adjust context
- s/ext4_free_data_cachep/ext4_free_ext_cachep/]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
fs/ext4/mballoc.c | 16 +++++-----------
1 file changed, 5 insertions(+), 11 deletions(-)
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 5baa7ba79091..7c03826bde26 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -4720,18 +4720,12 @@ void ext4_free_blocks(handle_t *handle, struct inode *inode,
/*
* blocks being freed are metadata. these blocks shouldn't
* be used until this transaction is committed
+ *
+ * We use __GFP_NOFAIL because ext4_free_blocks() is not allowed
+ * to fail.
*/
- retry:
- new_entry = kmem_cache_alloc(ext4_free_ext_cachep, GFP_NOFS);
- if (!new_entry) {
- /*
- * We use a retry loop because
- * ext4_free_blocks() is not allowed to fail.
- */
- cond_resched();
- congestion_wait(BLK_RW_ASYNC, HZ/50);
- goto retry;
- }
+ new_entry = kmem_cache_alloc(ext4_free_ext_cachep,
+ GFP_NOFS|__GFP_NOFAIL);
new_entry->start_cluster = bit;
new_entry->group = block_group;
new_entry->count = count_clusters;
--
2.30.9