lkml.org 
[lkml]   [2013]   [Aug]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v2 18/20] mm, hugetlb: clean-up error handling in hugetlb_cow()
Date
Current code include 'Caller expects lock to be held' in every error path.
We can clean-up it as we do error handling in one place.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 7e9a651..8743e5c 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -2500,6 +2500,7 @@ static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma,
int outside_reserve = 0;
long chg;
bool use_reserve = false;
+ int ret = 0;
unsigned long mmun_start; /* For mmu_notifiers */
unsigned long mmun_end; /* For mmu_notifiers */

@@ -2524,10 +2525,8 @@ retry_avoidcopy:
* anon_vma prepared.
*/
if (unlikely(anon_vma_prepare(vma))) {
- page_cache_release(old_page);
- /* Caller expects lock to be held */
- spin_lock(&mm->page_table_lock);
- return VM_FAULT_OOM;
+ ret = VM_FAULT_OOM;
+ goto out_old_page;
}

/*
@@ -2546,11 +2545,8 @@ retry_avoidcopy:
if (!outside_reserve) {
chg = vma_needs_reservation(h, vma, address);
if (chg == -ENOMEM) {
- page_cache_release(old_page);
-
- /* Caller expects lock to be held */
- spin_lock(&mm->page_table_lock);
- return VM_FAULT_OOM;
+ ret = VM_FAULT_OOM;
+ goto out_old_page;
}
use_reserve = !chg;
}
@@ -2584,9 +2580,8 @@ retry_avoidcopy:
WARN_ON_ONCE(1);
}

- /* Caller expects lock to be held */
- spin_lock(&mm->page_table_lock);
- return VM_FAULT_SIGBUS;
+ ret = VM_FAULT_SIGBUS;
+ goto out_lock;
}

copy_user_huge_page(new_page, old_page, address, vma,
@@ -2617,11 +2612,12 @@ retry_avoidcopy:
spin_unlock(&mm->page_table_lock);
mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
page_cache_release(new_page);
+out_old_page:
page_cache_release(old_page);
-
+out_lock:
/* Caller expects lock to be held */
spin_lock(&mm->page_table_lock);
- return 0;
+ return ret;
}

/* Return the pagecache page at a given address within a VMA */
--
1.7.9.5


\
 
 \ /
  Last update: 2013-08-09 11:41    [W:0.284 / U:0.388 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site