[PATCH v22 07/16] xfs: Handle krealloc errors in xlog_recover_add_to_cont_trans

Allison Henderson
2021-07-27T06:21:19Z

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>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
---
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 12118d5..1212fa1 100644
--- a/fs/xfs/xfs_log_recover.c
+++ b/fs/xfs/xfs_log_recover.c
@@ -2088,7 +2088,15 @@ 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