[PATCH v21 04/13] xfs: Handle krealloc errors in xlog_recover_add_to_cont_trans

[Allison Henderson <allison.henderson@oracle.com>]

Because xattrs can be over a page in size, we need to handle possible
krealloc errors to avoid warnings.  If the allocation does fail, fall
back to kmem_alloc_large, with a memcpy.

The warning:
   WARNING: CPU: 1 PID: 20255 at mm/page_alloc.c:3446
                 get_page_from_freelist+0x100b/0x1690

is caused when sizes larger that a page are allocated with the
__GFP_NOFAIL flag option.  We encounter this error now because attr
values can be up to 64k in size.  So we cannot use __GFP_NOFAIL, and
we need to handle the error code if the allocation fails.

Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
---
 fs/xfs/xfs_log_recover.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c
index ec4ccae..6ab467b 100644
--- a/fs/xfs/xfs_log_recover.c
+++ b/fs/xfs/xfs_log_recover.c
@@ -2062,7 +2062,15 @@ xlog_recover_add_to_cont_trans(
 	old_ptr = item->ri_buf[item->ri_cnt-1].i_addr;
 	old_len = item->ri_buf[item->ri_cnt-1].i_len;
 
-	ptr = krealloc(old_ptr, len + old_len, GFP_KERNEL | __GFP_NOFAIL);
+	ptr = krealloc(old_ptr, len + old_len, GFP_KERNEL);
+	if (ptr == NULL) {
+		ptr = kmem_alloc_large(len + old_len, KM_ZERO);
+		if (ptr == NULL)
+			return -ENOMEM;
+
+		memcpy(ptr, old_ptr, old_len);
+	}
+
 	memcpy(&ptr[old_len], dp, len);
 	item->ri_buf[item->ri_cnt-1].i_len += len;
 	item->ri_buf[item->ri_cnt-1].i_addr = ptr;
-- 
2.7.4