On Mon, Mar 4, 2024 at 2:02 AM Xiubo Li <xiubli@xxxxxxxxxx> wrote: > > > On 3/2/24 00:16, Ilya Dryomov wrote: > > On Thu, Feb 29, 2024 at 5:22 AM <xiubli@xxxxxxxxxx> wrote: > >> From: Xiubo Li <xiubli@xxxxxxxxxx> > >> > >> The osd code has remove cursor initilizing code and this will make > >> the sparse read state into a infinite loop. We should initialize > >> the cursor just before each sparse-read in messnger v2. > >> > >> Cc: stable@xxxxxxxxxxxxxxx > >> URL: https://tracker.ceph.com/issues/64607 > >> Fixes: 8e46a2d068c9 ("libceph: just wait for more data to be available on the socket") > >> Reported-by: Luis Henriques <lhenriques@xxxxxxx> > >> Signed-off-by: Xiubo Li <xiubli@xxxxxxxxxx> > >> --- > >> net/ceph/messenger_v2.c | 3 +++ > >> 1 file changed, 3 insertions(+) > >> > >> diff --git a/net/ceph/messenger_v2.c b/net/ceph/messenger_v2.c > >> index a0ca5414b333..7ae0f80100f4 100644 > >> --- a/net/ceph/messenger_v2.c > >> +++ b/net/ceph/messenger_v2.c > >> @@ -2025,6 +2025,7 @@ static int prepare_sparse_read_cont(struct ceph_connection *con) > >> static int prepare_sparse_read_data(struct ceph_connection *con) > >> { > >> struct ceph_msg *msg = con->in_msg; > >> + u64 len = con->in_msg->sparse_read_total ? : data_len(con->in_msg); > > Hi Xiubo, > > > > Why is sparse_read_total being tested here? Isn't this function > > supposed to be called only for sparse reads, after the state is set to > > IN_S_PREPARE_SPARSE_DATA based on a similar test: > > > > if (msg->sparse_read_total) > > con->v2.in_state = IN_S_PREPARE_SPARSE_DATA; > > else > > con->v2.in_state = IN_S_PREPARE_READ_DATA; > > Then the patch could be simplified and just be: > > diff --git a/net/ceph/messenger_v2.c b/net/ceph/messenger_v2.c > index a0ca5414b333..ab3ab130a911 100644 > --- a/net/ceph/messenger_v2.c > +++ b/net/ceph/messenger_v2.c > @@ -2034,6 +2034,9 @@ static int prepare_sparse_read_data(struct > ceph_connection *con) > if (!con_secure(con)) > con->in_data_crc = -1; > > + ceph_msg_data_cursor_init(&con->v2.in_cursor, con->in_msg, > + con->in_msg->sparse_read_total); > + > reset_in_kvecs(con); > con->v2.in_state = IN_S_PREPARE_SPARSE_DATA_CONT; > con->v2.data_len_remain = data_len(msg); > > Else where should we do the test like this ? Hi Xiubo, I suspect you copied this test from prepare_message_data() in msgr1, where that function is called unconditionally for all reads. In msgr2, prepare_sparse_read_data() is called conditionally, so the test just seems bogus. That said, CephFS is the only user of sparse read code, so you should know better at this point ;) Thanks, Ilya