diff mbox series

[v15,15/22] xfs: Handle krealloc errors in xlog_recover_add_to_cont_trans

Message ID 20210218165348.4754-16-allison.henderson@oracle.com (mailing list archive)
State New
Headers show
Series xfs: Delayed Attributes | expand

Commit Message

Allison Henderson Feb. 18, 2021, 4:53 p.m. UTC
Because xattrs can be over a page in size, we need to handle possible
krealloc errors to avoid warnings

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 | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

Comments

Darrick J. Wong Feb. 26, 2021, 5:06 a.m. UTC | #1
On Thu, Feb 18, 2021 at 09:53:41AM -0700, Allison Henderson wrote:
> Because xattrs can be over a page in size, we need to handle possible
> krealloc errors to avoid warnings
> 
> 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 | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c
> index 97f3130..295a5c6 100644
> --- a/fs/xfs/xfs_log_recover.c
> +++ b/fs/xfs/xfs_log_recover.c
> @@ -2061,7 +2061,10 @@ 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)
> +		return -ENOMEM;

Given that we update i_addr anyway, perhaps this should fall back to
kmem_alloc_large+memcpy to avoid introducing another failure point?

--D

> +
>  	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
>
Allison Henderson Feb. 27, 2021, 12:57 a.m. UTC | #2
On 2/25/21 10:06 PM, Darrick J. Wong wrote:
> On Thu, Feb 18, 2021 at 09:53:41AM -0700, Allison Henderson wrote:
>> Because xattrs can be over a page in size, we need to handle possible
>> krealloc errors to avoid warnings
>>
>> 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 | 5 ++++-
>>   1 file changed, 4 insertions(+), 1 deletion(-)
>>
>> diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c
>> index 97f3130..295a5c6 100644
>> --- a/fs/xfs/xfs_log_recover.c
>> +++ b/fs/xfs/xfs_log_recover.c
>> @@ -2061,7 +2061,10 @@ 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)
>> +		return -ENOMEM;
> 
> Given that we update i_addr anyway, perhaps this should fall back to
> kmem_alloc_large+memcpy to avoid introducing another failure point?
Sure, I can add that in. Thx!

Allison
> 
> --D
> 
>> +
>>   	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
>>
diff mbox series

Patch

diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c
index 97f3130..295a5c6 100644
--- a/fs/xfs/xfs_log_recover.c
+++ b/fs/xfs/xfs_log_recover.c
@@ -2061,7 +2061,10 @@  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)
+		return -ENOMEM;
+
 	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;