Jeff Layton <jlayton@xxxxxxxxxx> writes:
> On Wed, 2022-03-30 at 15:04 -0400, Jeff Layton wrote:
>> When we do an unchecked create, we optimistically pre-create an inode
>> and populate it, including its fscrypt context. It's possible though
>> that we'll end up opening an existing inode, in which case the
>> precreated inode will have a crypto context that doesn't match the
>> existing data.
>>
>> If we're issuing an O_CREAT open and find an existing inode, just
>> discard the precreated inode and create a new one to ensure the context
>> is properly set.
>>
>> Cc: Luís Henriques <lhenriques@xxxxxxx>
>> Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
>> ---
>> fs/ceph/mds_client.c | 10 ++++++++--
>> 1 file changed, 8 insertions(+), 2 deletions(-)
>>
>> diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
>> index 840a60b812fc..b03128fdbb07 100644
>> --- a/fs/ceph/mds_client.c
>> +++ b/fs/ceph/mds_client.c
>> @@ -3504,13 +3504,19 @@ static void handle_reply(struct ceph_mds_session *session, struct ceph_msg *msg)
>> /* Must find target inode outside of mutexes to avoid deadlocks */
>> rinfo = &req->r_reply_info;
>> if ((err >= 0) && rinfo->head->is_target) {
>> - struct inode *in;
>> + struct inode *in = xchg(&req->r_new_inode, NULL);
>> struct ceph_vino tvino = {
>> .ino = le64_to_cpu(rinfo->targeti.in->ino),
>> .snap = le64_to_cpu(rinfo->targeti.in->snapid)
>> };
>>
>> - in = ceph_get_inode(mdsc->fsc->sb, tvino, xchg(&req->r_new_inode, NULL));
>> + /* If we ended up opening an existing inode, discard r_new_inode */
>> + if (req->r_op == CEPH_MDS_OP_CREATE && !req->r_reply_info.has_create_ino) {
>> + iput(in);
>> + in = NULL;
>> + }
>> +
>> + in = ceph_get_inode(mdsc->fsc->sb, tvino, in);
>> if (IS_ERR(in)) {
>> err = PTR_ERR(in);
>> mutex_lock(&session->s_mutex);
>
> Forgot to mention that this one is for the fscrypt pile. This patch
> fixes generic/595 for me.
Wow! I must say it: the issue is very far from the places I was looking
at. Thanks!
Reviewed-and-tested-by: Luís Henriques <lhenriques@xxxxxxx>
Cheers,
--
Luís
