On Fri, 16 Mar 2012 18:09:25 +0300 Pavel Shilovsky <[email protected]> wrote:
> by making it as unsigned integer and surround access with req_lock > from server structure. > > Signed-off-by: Pavel Shilovsky <[email protected]> > --- > fs/cifs/cifs_debug.c | 3 +-- > fs/cifs/cifsglob.h | 21 ++++++++++++++++++++- > fs/cifs/cifssmb.c | 6 +++--- > fs/cifs/connect.c | 10 +++++----- > fs/cifs/transport.c | 45 +++++++++++++++++++++++---------------------- > 5 files changed, 52 insertions(+), 33 deletions(-) > > diff --git a/fs/cifs/cifs_debug.c b/fs/cifs/cifs_debug.c > index 24b3dfc..573b899 100644 > --- a/fs/cifs/cifs_debug.c > +++ b/fs/cifs/cifs_debug.c > @@ -171,8 +171,7 @@ static int cifs_debug_data_proc_show(struct seq_file *m, > void *v) > seq_printf(m, "TCP status: %d\n\tLocal Users To " > "Server: %d SecMode: 0x%x Req On Wire: %d", > server->tcpStatus, server->srv_count, > - server->sec_mode, > - atomic_read(&server->inFlight)); > + server->sec_mode, in_flight(server)); > > #ifdef CONFIG_CIFS_STATS2 > seq_printf(m, " In Send: %d In MaxReq Wait: %d", > diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h > index d47d20a..fb78bc9 100644 > --- a/fs/cifs/cifsglob.h > +++ b/fs/cifs/cifsglob.h > @@ -250,7 +250,8 @@ struct TCP_Server_Info { > bool noblocksnd; /* use blocking sendmsg */ > bool noautotune; /* do not autotune send buf sizes */ > bool tcp_nodelay; > - atomic_t inFlight; /* number of requests on the wire to server */ > + unsigned int in_flight; /* number of requests on the wire to server */ > + spinlock_t req_lock; /* protect the value above */ > struct mutex srv_mutex; > struct task_struct *tsk; > char server_GUID[16]; > @@ -303,6 +304,24 @@ struct TCP_Server_Info { > #endif > }; > > +static inline unsigned int > +in_flight(struct TCP_Server_Info *server) > +{ > + unsigned int num; > + spin_lock(&server->req_lock); > + num = server->in_flight; > + spin_unlock(&server->req_lock); > + return num; > +} > + > +static inline void > +dec_in_flight(struct TCP_Server_Info *server) > +{ > + spin_lock(&server->req_lock); > + server->in_flight--; > + spin_unlock(&server->req_lock); > +} > + > /* > * Macros to allow the TCP_Server_Info->net field and related code to drop > out > * when CONFIG_NET_NS isn't set. > diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c > index cd66b76..d7cbcfa 100644 > --- a/fs/cifs/cifssmb.c > +++ b/fs/cifs/cifssmb.c > @@ -721,7 +721,7 @@ cifs_echo_callback(struct mid_q_entry *mid) > struct TCP_Server_Info *server = mid->callback_data; > > DeleteMidQEntry(mid); > - atomic_dec(&server->inFlight); > + dec_in_flight(server); > wake_up(&server->request_q); > } > > @@ -1674,7 +1674,7 @@ cifs_readv_callback(struct mid_q_entry *mid) > > queue_work(system_nrt_wq, &rdata->work); > DeleteMidQEntry(mid); > - atomic_dec(&server->inFlight); > + dec_in_flight(server); > wake_up(&server->request_q); > } > > @@ -2115,7 +2115,7 @@ cifs_writev_callback(struct mid_q_entry *mid) > > queue_work(system_nrt_wq, &wdata->work); > DeleteMidQEntry(mid); > - atomic_dec(&tcon->ses->server->inFlight); > + dec_in_flight(tcon->ses->server); > wake_up(&tcon->ses->server->request_q); > } > > diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c > index 03f71fb..a7627f2 100644 > --- a/fs/cifs/connect.c > +++ b/fs/cifs/connect.c > @@ -643,14 +643,14 @@ static void clean_demultiplex_info(struct > TCP_Server_Info *server) > wake_up_all(&server->response_q); > > /* Check if we have blocked requests that need to free. */ > - spin_lock(&GlobalMid_Lock); > - if (atomic_read(&server->inFlight) >= server->maxReq) > - atomic_set(&server->inFlight, server->maxReq - 1); > + spin_lock(&server->req_lock); > + if (server->in_flight >= server->maxReq) > + server->in_flight = server->maxReq - 1; > /* > * We do not want to set the max_pending too low or we could end up > * with the counter going negative. > */ > - spin_unlock(&GlobalMid_Lock); > + spin_unlock(&server->req_lock); > /* > * Although there should not be any requests blocked on this queue it > * can not hurt to be paranoid and try to wake up requests that may > @@ -1905,7 +1905,7 @@ cifs_get_tcp_session(struct smb_vol *volume_info) > tcp_ses->noblocksnd = volume_info->noblocksnd; > tcp_ses->noautotune = volume_info->noautotune; > tcp_ses->tcp_nodelay = volume_info->sockopt_tcp_nodelay; > - atomic_set(&tcp_ses->inFlight, 0); > + tcp_ses->in_flight = 0; > tcp_ses->maxReq = 1; /* enough to send negotiate request */ > init_waitqueue_head(&tcp_ses->response_q); > init_waitqueue_head(&tcp_ses->request_q); > diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c > index 99a27cf..e2673aa 100644 > --- a/fs/cifs/transport.c > +++ b/fs/cifs/transport.c > @@ -254,28 +254,29 @@ smb_send(struct TCP_Server_Info *server, struct smb_hdr > *smb_buffer, > return smb_sendv(server, &iov, 1); > } > > -static int wait_for_free_request(struct TCP_Server_Info *server, > - const int long_op) > +static int > +wait_for_free_request(struct TCP_Server_Info *server, const int long_op) > { > + spin_lock(&server->req_lock); > + > if (long_op == CIFS_ASYNC_OP) { > /* oplock breaks must not be held up */ > - atomic_inc(&server->inFlight); > + server->in_flight++; > + spin_unlock(&server->req_lock); > return 0; > } > > - spin_lock(&GlobalMid_Lock); > while (1) { > - if (atomic_read(&server->inFlight) >= server->maxReq) { > - spin_unlock(&GlobalMid_Lock); > + if (server->in_flight >= server->maxReq) { > + spin_unlock(&server->req_lock); > cifs_num_waiters_inc(server); > wait_event(server->request_q, > - atomic_read(&server->inFlight) > - < server->maxReq); > + in_flight(server) < server->maxReq); > cifs_num_waiters_dec(server); > - spin_lock(&GlobalMid_Lock); > + spin_lock(&server->req_lock); > } else { > if (server->tcpStatus == CifsExiting) { > - spin_unlock(&GlobalMid_Lock); > + spin_unlock(&server->req_lock); > return -ENOENT; > } > > @@ -284,8 +285,8 @@ static int wait_for_free_request(struct TCP_Server_Info > *server, > > /* update # of requests on the wire to server */ > if (long_op != CIFS_BLOCKING_OP) > - atomic_inc(&server->inFlight); > - spin_unlock(&GlobalMid_Lock); > + server->in_flight++; > + spin_unlock(&server->req_lock); > break; > } > } > @@ -359,7 +360,7 @@ cifs_call_async(struct TCP_Server_Info *server, struct > kvec *iov, > mid = AllocMidQEntry(hdr, server); > if (mid == NULL) { > mutex_unlock(&server->srv_mutex); > - atomic_dec(&server->inFlight); > + dec_in_flight(server); > wake_up(&server->request_q); > return -ENOMEM; > } > @@ -392,7 +393,7 @@ cifs_call_async(struct TCP_Server_Info *server, struct > kvec *iov, > return rc; > out_err: > delete_mid(mid); > - atomic_dec(&server->inFlight); > + dec_in_flight(server); > wake_up(&server->request_q); > return rc; > } > @@ -564,7 +565,7 @@ SendReceive2(const unsigned int xid, struct cifs_ses *ses, > mutex_unlock(&ses->server->srv_mutex); > cifs_small_buf_release(in_buf); > /* Update # of requests on wire to server */ > - atomic_dec(&ses->server->inFlight); > + dec_in_flight(ses->server); > wake_up(&ses->server->request_q); > return rc; > } > @@ -601,7 +602,7 @@ SendReceive2(const unsigned int xid, struct cifs_ses *ses, > midQ->callback = DeleteMidQEntry; > spin_unlock(&GlobalMid_Lock); > cifs_small_buf_release(in_buf); > - atomic_dec(&ses->server->inFlight); > + dec_in_flight(ses->server); > wake_up(&ses->server->request_q); > return rc; > } > @@ -612,7 +613,7 @@ SendReceive2(const unsigned int xid, struct cifs_ses *ses, > > rc = cifs_sync_mid_result(midQ, ses->server); > if (rc != 0) { > - atomic_dec(&ses->server->inFlight); > + dec_in_flight(ses->server); > wake_up(&ses->server->request_q); > return rc; > } > @@ -637,7 +638,7 @@ SendReceive2(const unsigned int xid, struct cifs_ses *ses, > midQ->resp_buf = NULL; > out: > delete_mid(midQ); > - atomic_dec(&ses->server->inFlight); > + dec_in_flight(ses->server); > wake_up(&ses->server->request_q); > > return rc; > @@ -688,7 +689,7 @@ SendReceive(const unsigned int xid, struct cifs_ses *ses, > if (rc) { > mutex_unlock(&ses->server->srv_mutex); > /* Update # of requests on wire to server */ > - atomic_dec(&ses->server->inFlight); > + dec_in_flight(ses->server); > wake_up(&ses->server->request_q); > return rc; > } > @@ -721,7 +722,7 @@ SendReceive(const unsigned int xid, struct cifs_ses *ses, > /* no longer considered to be "in-flight" */ > midQ->callback = DeleteMidQEntry; > spin_unlock(&GlobalMid_Lock); > - atomic_dec(&ses->server->inFlight); > + dec_in_flight(ses->server); > wake_up(&ses->server->request_q); > return rc; > } > @@ -730,7 +731,7 @@ SendReceive(const unsigned int xid, struct cifs_ses *ses, > > rc = cifs_sync_mid_result(midQ, ses->server); > if (rc != 0) { > - atomic_dec(&ses->server->inFlight); > + dec_in_flight(ses->server); > wake_up(&ses->server->request_q); > return rc; > } > @@ -747,7 +748,7 @@ SendReceive(const unsigned int xid, struct cifs_ses *ses, > rc = cifs_check_receive(midQ, ses->server, 0); > out: > delete_mid(midQ); > - atomic_dec(&ses->server->inFlight); > + dec_in_flight(ses->server); > wake_up(&ses->server->request_q); > > return rc; Looks reasonable. It might be a little slower with the extra locking, but it shouldn't make much difference as this is not a terribly hot codepath. This also makes the locking very clear. Reviewed-by: Jeff Layton <[email protected]> -- To unsubscribe from this list: send the line "unsubscribe linux-cifs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
