From 044c7768841f1ef39f951972d3c1e6537a535030 Mon Sep 17 00:00:00 2001 From: Eric Van Hensbergen Date: Mon, 13 Oct 2008 18:45:23 -0500 Subject: [PATCH] 9p: eliminate callback complexity The current trans_fd rpc mechanisms use a dynamic callback mechanism which introduces a lot of complexity which only accomodates a single special case. This patch removes much of that complexity in favor of a simple exception mechanism to deal with flushes. Signed-off-by: Eric Van Hensbergen --- net/9p/trans_fd.c | 149 ++++++++++++++++++++-------------------------- 1 file changed, 66 insertions(+), 83 deletions(-) diff --git a/net/9p/trans_fd.c b/net/9p/trans_fd.c index dbb057d7fa5..180163b3e8f 100644 --- a/net/9p/trans_fd.c +++ b/net/9p/trans_fd.c @@ -105,9 +105,6 @@ enum { Flushed, }; -struct p9_req; -typedef void (*p9_conn_req_callback)(struct p9_req *req, void *a); - /** * struct p9_req - fd mux encoding of an rpc transaction * @lock: protects req_list @@ -115,8 +112,6 @@ typedef void (*p9_conn_req_callback)(struct p9_req *req, void *a); * @tcall: request &p9_fcall structure * @rcall: response &p9_fcall structure * @err: error state - * @cb: callback for when response is received - * @cba: argument to pass to callback * @flush: flag to indicate RPC has been flushed * @req_list: list link for higher level objects to chain requests * @m: connection this request was issued on @@ -130,8 +125,6 @@ struct p9_req { struct p9_fcall *tcall; struct p9_fcall *rcall; int err; - p9_conn_req_callback cb; - void *cba; int flush; struct list_head req_list; struct p9_conn *m; @@ -231,6 +224,65 @@ static void p9_mux_poll_stop(struct p9_conn *m) spin_unlock_irqrestore(&p9_poll_lock, flags); } +static void p9_mux_free_request(struct p9_conn *m, struct p9_req *req) +{ + p9_mux_put_tag(m, req->tag); + kfree(req); +} + +static void p9_conn_rpc_cb(struct p9_req *req); + +static void p9_mux_flush_cb(struct p9_req *freq) +{ + int tag; + struct p9_conn *m = freq->m; + struct p9_req *req, *rreq, *rptr; + + P9_DPRINTK(P9_DEBUG_MUX, "mux %p tc %p rc %p err %d oldtag %d\n", m, + freq->tcall, freq->rcall, freq->err, + freq->tcall->params.tflush.oldtag); + + spin_lock(&m->lock); + tag = freq->tcall->params.tflush.oldtag; + req = NULL; + list_for_each_entry_safe(rreq, rptr, &m->req_list, req_list) { + if (rreq->tag == tag) { + req = rreq; + list_del(&req->req_list); + break; + } + } + spin_unlock(&m->lock); + + if (req) { + spin_lock(&req->lock); + req->flush = Flushed; + spin_unlock(&req->lock); + + p9_conn_rpc_cb(req); + } + + kfree(freq->tcall); + kfree(freq->rcall); + p9_mux_free_request(m, freq); +} + +static void p9_conn_rpc_cb(struct p9_req *req) +{ + P9_DPRINTK(P9_DEBUG_MUX, "req %p\n", req); + + if (req->tcall->id == P9_TFLUSH) { /* flush callback */ + P9_DPRINTK(P9_DEBUG_MUX, "flush req %p\n", req); + p9_mux_flush_cb(req); + } else { /* normal wakeup path */ + P9_DPRINTK(P9_DEBUG_MUX, "normal req %p\n", req); + if (req->flush != None && !req->err) + req->err = -ERESTARTSYS; + + wake_up(&req->wqueue); + } +} + /** * p9_conn_cancel - cancel all pending requests with error * @m: mux data @@ -259,10 +311,7 @@ void p9_conn_cancel(struct p9_conn *m, int err) if (!req->err) req->err = err; - if (req->cb) - (*req->cb) (req, req->cba); - else - kfree(req->rcall); + p9_conn_rpc_cb(req); } } @@ -472,12 +521,8 @@ static void p9_read_work(struct work_struct *work) req->rcall = rcall; process_request(m, req); - if (req->flush != Flushing) { - if (req->cb) - (*req->cb) (req, req->cba); - else - kfree(req->rcall); - } + if (req->flush != Flushing) + p9_conn_rpc_cb(req); } else { if (err >= 0 && rcall->id != P9_RFLUSH) P9_DPRINTK(P9_DEBUG_ERROR, @@ -786,14 +831,10 @@ static void p9_poll_mux(struct p9_conn *m) * * @m: mux data * @tc: request to be sent - * @cb: callback function to call when response is received - * @cba: parameter to pass to the callback function * */ -static struct p9_req *p9_send_request(struct p9_conn *m, - struct p9_fcall *tc, - p9_conn_req_callback cb, void *cba) +static struct p9_req *p9_send_request(struct p9_conn *m, struct p9_fcall *tc) { int n; struct p9_req *req; @@ -835,8 +876,6 @@ static struct p9_req *p9_send_request(struct p9_conn *m, req->tcall = tc; req->rcall = NULL; req->err = 0; - req->cb = cb; - req->cba = cba; req->flush = None; spin_lock(&m->lock); @@ -854,51 +893,6 @@ static struct p9_req *p9_send_request(struct p9_conn *m, return req; } -static void p9_mux_free_request(struct p9_conn *m, struct p9_req *req) -{ - p9_mux_put_tag(m, req->tag); - kfree(req); -} - -static void p9_mux_flush_cb(struct p9_req *freq, void *a) -{ - int tag; - struct p9_conn *m; - struct p9_req *req, *rreq, *rptr; - - m = a; - P9_DPRINTK(P9_DEBUG_MUX, "mux %p tc %p rc %p err %d oldtag %d\n", m, - freq->tcall, freq->rcall, freq->err, - freq->tcall->params.tflush.oldtag); - - spin_lock(&m->lock); - tag = freq->tcall->params.tflush.oldtag; - req = NULL; - list_for_each_entry_safe(rreq, rptr, &m->req_list, req_list) { - if (rreq->tag == tag) { - req = rreq; - list_del(&req->req_list); - break; - } - } - spin_unlock(&m->lock); - - if (req) { - spin_lock(&req->lock); - req->flush = Flushed; - spin_unlock(&req->lock); - - if (req->cb) - (*req->cb) (req, req->cba); - else - kfree(req->rcall); - } - - kfree(freq->tcall); - kfree(freq->rcall); - p9_mux_free_request(m, freq); -} - static int p9_mux_flush_request(struct p9_conn *m, struct p9_req *req) { @@ -928,8 +922,7 @@ p9_mux_flush_request(struct p9_conn *m, struct p9_req *req) list_del(&rreq->req_list); req->flush = Flushed; spin_unlock(&m->lock); - if (req->cb) - (*req->cb) (req, req->cba); + p9_conn_rpc_cb(req); return 0; } } @@ -937,20 +930,10 @@ p9_mux_flush_request(struct p9_conn *m, struct p9_req *req) clear_thread_flag(TIF_SIGPENDING); fc = p9_create_tflush(req->tag); - p9_send_request(m, fc, p9_mux_flush_cb, m); + p9_send_request(m, fc); return 1; } -static void p9_conn_rpc_cb(struct p9_req *req, void *a) -{ - P9_DPRINTK(P9_DEBUG_MUX, "req %p arg %p\n", req, a); - - if (req->flush != None && !req->err) - req->err = -ERESTARTSYS; - - wake_up(&req->wqueue); -} - /** * p9_fd_rpc- sends 9P request and waits until a response is available. * The function can be interrupted. @@ -978,7 +961,7 @@ p9_fd_rpc(struct p9_client *client, struct p9_fcall *tc, struct p9_fcall **rc) clear_thread_flag(TIF_SIGPENDING); } - req = p9_send_request(m, tc, p9_conn_rpc_cb, NULL); + req = p9_send_request(m, tc); if (IS_ERR(req)) { err = PTR_ERR(req); P9_DPRINTK(P9_DEBUG_MUX, "error %d\n", err); -- 2.41.0