Re: [PATCH] ceph:Fix error handling in the function down_reply

From: Ilya Dryomov
Date: Mon Nov 09 2015 - 05:29:27 EST


On Mon, Nov 9, 2015 at 11:15 AM, Yan, Zheng <zyan@xxxxxxxxxx> wrote:
>
>> On Nov 9, 2015, at 11:11, Nicholas Krause <xerofoify@xxxxxxxxx> wrote:
>>
>> This fixes error handling in the function down_reply in order to
>> properly check and jump to the goto label, out_err for this
>> particular function if a error code is returned by any function
>> called in down_reply and therefore make checking be included
>> for the call to ceph_update_snap_trace in order to comply with
>> these error handling checks/paths.
>>
>> Signed-off-by: Nicholas Krause <xerofoify@xxxxxxxxx>
>> ---
>> fs/ceph/mds_client.c | 11 +++++++----
>> 1 file changed, 7 insertions(+), 4 deletions(-)
>>
>> diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
>> index 51cb02d..0b01f94 100644
>> --- a/fs/ceph/mds_client.c
>> +++ b/fs/ceph/mds_client.c
>> @@ -2495,14 +2495,17 @@ static void handle_reply(struct ceph_mds_session *session, struct ceph_msg *msg)
>> realm = NULL;
>> if (rinfo->snapblob_len) {
>> down_write(&mdsc->snap_rwsem);
>> - ceph_update_snap_trace(mdsc, rinfo->snapblob,
>> - rinfo->snapblob + rinfo->snapblob_len,
>> - le32_to_cpu(head->op) == CEPH_MDS_OP_RMSNAP,
>> - &realm);
>> + err = ceph_update_snap_trace(mdsc, rinfo->snapblob,
>> + rinfo->snapblob + rinfo->snapblob_len,
>> + le32_to_cpu(head->op) == CEPH_MDS_OP_RMSNAP,
>> + &realm);
>> downgrade_write(&mdsc->snap_rwsem);
>> } else {
>> down_read(&mdsc->snap_rwsem);
>> }
>> +
>> + if (err)
>> + goto out_err;
>>
>> /* insert trace into our cache */
>> mutex_lock(&req->r_fill_mutex);
>
> Applied, thanks

This looks to me like it'd leave snap_rwsem locked for read? Also, the
name of the function in question is handle_reply(), not down_reply().

I'll revert testing.

Thanks,

Ilya
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