From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops There's some internal state that ftrace_ops needs to have set, but since it can be declared outside of the ftrace.c code, it calls ftrace_ops_init() on the ops in every global function. The issue is that if two tasks call it on the same ops at the same time it is possible to have the initialization of one corrupt the initialization of the other call. Create a ops_mutex to use to synchronize every initialization of the ftrace_ops. The mutex is taken within checking the ftrace_ops flag that states it was initializied but the flag is checked again after the mutex has been taken. Checking first outside the mutex allows it to shortcut having to take the mutex. But then the check needs to be done again after the mute is taken in case of races. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock") Reported-by: sashiko-bot@kernel.org Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/ Signed-off-by: Steven Rostedt --- net/9p/Kconfig | 63 ++ net/9p/Makefile | 29 + net/9p/client.c | 2212 +++++++++++++++++++++++++++++++++++++++++++++++++ net/9p/error.c | 227 +++++ net/9p/mod.c | 212 +++++ net/9p/protocol.c | 800 ++++++++++++++++++ net/9p/protocol.h | 19 + net/9p/trans_common.c | 24 + net/9p/trans_common.h | 7 + net/9p/trans_fd.c | 1093 ++++++++++++++++++++++++ net/9p/trans_rdma.c | 684 +++++++++++++++ net/9p/trans_usbg.c | 969 ++++++++++++++++++++++ net/9p/trans_virtio.c | 842 +++++++++++++++++++ net/9p/trans_xen.c | 607 ++++++++++++++ 14 files changed, 7788 insertions(+) create mode 100644 net/9p/Kconfig create mode 100644 net/9p/Makefile create mode 100644 net/9p/client.c create mode 100644 net/9p/error.c create mode 100644 net/9p/mod.c create mode 100644 net/9p/protocol.c create mode 100644 net/9p/protocol.h create mode 100644 net/9p/trans_common.c create mode 100644 net/9p/trans_common.h create mode 100644 net/9p/trans_fd.c create mode 100644 net/9p/trans_rdma.c create mode 100644 net/9p/trans_usbg.c create mode 100644 net/9p/trans_virtio.c create mode 100644 net/9p/trans_xen.c (limited to 'net/9p') diff --git a/net/9p/Kconfig b/net/9p/Kconfig new file mode 100644 index 000000000..22f8c1678 --- /dev/null +++ b/net/9p/Kconfig @@ -0,0 +1,63 @@ +# SPDX-License-Identifier: GPL-2.0-only +# +# 9P protocol configuration +# + +menuconfig NET_9P + tristate "Plan 9 Resource Sharing Support (9P2000)" + select NETFS_SUPPORT + help + If you say Y here, you will get experimental support for + Plan 9 resource sharing via the 9P2000 protocol. + + See for more information. + + If unsure, say N. + +if NET_9P + +config NET_9P_FD + default NET_9P + imply INET + imply UNIX + tristate "9P FD Transport" + help + This builds support for transports over TCP, Unix sockets and + filedescriptors. + +config NET_9P_VIRTIO + depends on VIRTIO + tristate "9P Virtio Transport" + help + This builds support for a transports between + guest partitions and a host partition. + +config NET_9P_XEN + depends on XEN + select XEN_XENBUS_FRONTEND + tristate "9P Xen Transport" + help + This builds support for a transport for 9pfs between + two Xen domains. + +config NET_9P_USBG + tristate "9P USB Gadget Transport" + depends on USB_GADGET + select CONFIGFS_FS + select USB_LIBCOMPOSITE + help + This builds support for a transport for 9pfs over + usb gadget. + +config NET_9P_RDMA + depends on INET && INFINIBAND && INFINIBAND_ADDR_TRANS + tristate "9P RDMA Transport (Experimental)" + help + This builds support for an RDMA transport. + +config NET_9P_DEBUG + bool "Debug information" + help + Say Y if you want the 9P subsystem to log debug information. + +endif diff --git a/net/9p/Makefile b/net/9p/Makefile new file mode 100644 index 000000000..22794a451 --- /dev/null +++ b/net/9p/Makefile @@ -0,0 +1,29 @@ +# SPDX-License-Identifier: GPL-2.0 +obj-$(CONFIG_NET_9P) := 9pnet.o +obj-$(CONFIG_NET_9P_FD) += 9pnet_fd.o +obj-$(CONFIG_NET_9P_XEN) += 9pnet_xen.o +obj-$(CONFIG_NET_9P_VIRTIO) += 9pnet_virtio.o +obj-$(CONFIG_NET_9P_RDMA) += 9pnet_rdma.o +obj-$(CONFIG_NET_9P_USBG) += 9pnet_usbg.o + +9pnet-objs := \ + mod.o \ + client.o \ + error.o \ + protocol.o \ + trans_common.o \ + +9pnet_fd-objs := \ + trans_fd.o \ + +9pnet_virtio-objs := \ + trans_virtio.o \ + +9pnet_xen-objs := \ + trans_xen.o \ + +9pnet_rdma-objs := \ + trans_rdma.o \ + +9pnet_usbg-objs := \ + trans_usbg.o \ diff --git a/net/9p/client.c b/net/9p/client.c new file mode 100644 index 000000000..ef64546c6 --- /dev/null +++ b/net/9p/client.c @@ -0,0 +1,2212 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * 9P Client + * + * Copyright (C) 2008 by Eric Van Hensbergen + * Copyright (C) 2007 by Latchesar Ionkov + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "protocol.h" + +#define CREATE_TRACE_POINTS +#include + +/* Client Option Parsing (code inspired by NFS code) + * - a little lazy - parse all client options + */ + +inline int p9_is_proto_dotl(struct p9_client *clnt) +{ + return clnt->proto_version == p9_proto_2000L; +} +EXPORT_SYMBOL(p9_is_proto_dotl); + +inline int p9_is_proto_dotu(struct p9_client *clnt) +{ + return clnt->proto_version == p9_proto_2000u; +} +EXPORT_SYMBOL(p9_is_proto_dotu); + +int p9_show_client_options(struct seq_file *m, struct p9_client *clnt) +{ + if (clnt->msize != DEFAULT_MSIZE) + seq_printf(m, ",msize=%u", clnt->msize); + seq_printf(m, ",trans=%s", clnt->trans_mod->name); + + switch (clnt->proto_version) { + case p9_proto_legacy: + seq_puts(m, ",noextend"); + break; + case p9_proto_2000u: + seq_puts(m, ",version=9p2000.u"); + break; + case p9_proto_2000L: + /* Default */ + break; + } + + if (clnt->trans_mod->show_options) + return clnt->trans_mod->show_options(m, clnt); + return 0; +} +EXPORT_SYMBOL(p9_show_client_options); + +/* Some error codes are taken directly from the server replies, + * make sure they are valid. + */ +static int safe_errno(int err) +{ + if (err > 0 || err < -MAX_ERRNO) { + p9_debug(P9_DEBUG_ERROR, "Invalid error code %d\n", err); + return -EPROTO; + } + return err; +} + +static int apply_client_options(struct p9_client *clnt, struct fs_context *fc) +{ + struct v9fs_context *ctx = fc->fs_private; + + clnt->msize = ctx->client_opts.msize; + clnt->trans_mod = ctx->client_opts.trans_mod; + ctx->client_opts.trans_mod = NULL; + clnt->proto_version = ctx->client_opts.proto_version; + + return 0; +} + +static int p9_fcall_init(struct p9_client *c, struct p9_fcall *fc, + int alloc_msize) +{ + if (likely(c->fcall_cache) && alloc_msize == c->msize) { + fc->sdata = kmem_cache_alloc(c->fcall_cache, GFP_NOFS); + fc->cache = c->fcall_cache; + if (!fc->sdata && c->trans_mod->supports_vmalloc) { + fc->sdata = kvmalloc(alloc_msize, GFP_NOFS); + fc->cache = NULL; + } + } else { + if (c->trans_mod->supports_vmalloc) + fc->sdata = kvmalloc(alloc_msize, GFP_NOFS); + else + fc->sdata = kmalloc(alloc_msize, GFP_NOFS); + fc->cache = NULL; + } + if (!fc->sdata) + return -ENOMEM; + fc->capacity = alloc_msize; + fc->id = 0; + fc->tag = P9_NOTAG; + return 0; +} + +void p9_fcall_fini(struct p9_fcall *fc) +{ + /* sdata can be NULL for interrupted requests in trans_rdma, + * and kmem_cache_free does not do NULL-check for us + */ + if (unlikely(!fc->sdata)) + return; + + if (fc->cache) + kmem_cache_free(fc->cache, fc->sdata); + else + kvfree(fc->sdata); +} +EXPORT_SYMBOL(p9_fcall_fini); + +static struct kmem_cache *p9_req_cache; + +/** + * p9_tag_alloc - Allocate a new request. + * @c: Client session. + * @type: Transaction type. + * @t_size: Buffer size for holding this request + * (automatic calculation by format template if 0). + * @r_size: Buffer size for holding server's reply on this request + * (automatic calculation by format template if 0). + * @fmt: Format template for assembling 9p request message + * (see p9pdu_vwritef). + * @ap: Variable arguments to be fed to passed format template + * (see p9pdu_vwritef). + * + * Context: Process context. + * Return: Pointer to new request. + */ +static struct p9_req_t * +p9_tag_alloc(struct p9_client *c, int8_t type, uint t_size, uint r_size, + const char *fmt, va_list ap) +{ + struct p9_req_t *req = kmem_cache_alloc(p9_req_cache, GFP_NOFS); + int alloc_tsize; + int alloc_rsize; + int tag; + va_list apc; + + va_copy(apc, ap); + alloc_tsize = min_t(size_t, c->msize, + t_size ?: p9_msg_buf_size(c, type, fmt, apc)); + va_end(apc); + + alloc_rsize = min_t(size_t, c->msize, + r_size ?: p9_msg_buf_size(c, type + 1, fmt, ap)); + + if (!req) + return ERR_PTR(-ENOMEM); + + if (p9_fcall_init(c, &req->tc, alloc_tsize)) + goto free_req; + if (p9_fcall_init(c, &req->rc, alloc_rsize)) + goto free; + + p9pdu_reset(&req->tc); + p9pdu_reset(&req->rc); + req->t_err = 0; + req->status = REQ_STATUS_ALLOC; + /* refcount needs to be set to 0 before inserting into the idr + * so p9_tag_lookup does not accept a request that is not fully + * initialized. refcount_set to 2 below will mark request ready. + */ + refcount_set(&req->refcount, 0); + init_waitqueue_head(&req->wq); + INIT_LIST_HEAD(&req->req_list); + + idr_preload(GFP_NOFS); + spin_lock_irq(&c->lock); + if (type == P9_TVERSION) + tag = idr_alloc(&c->reqs, req, P9_NOTAG, P9_NOTAG + 1, + GFP_NOWAIT); + else + tag = idr_alloc(&c->reqs, req, 0, P9_NOTAG, GFP_NOWAIT); + req->tc.tag = tag; + spin_unlock_irq(&c->lock); + idr_preload_end(); + if (tag < 0) + goto free; + + /* Init ref to two because in the general case there is one ref + * that is put asynchronously by a writer thread, one ref + * temporarily given by p9_tag_lookup and put by p9_client_cb + * in the recv thread, and one ref put by p9_req_put in the + * main thread. The only exception is virtio that does not use + * p9_tag_lookup but does not have a writer thread either + * (the write happens synchronously in the request/zc_request + * callback), so p9_client_cb eats the second ref there + * as the pointer is duplicated directly by virtqueue_add_sgs() + */ + refcount_set(&req->refcount, 2); + + return req; + +free: + p9_fcall_fini(&req->tc); + p9_fcall_fini(&req->rc); +free_req: + kmem_cache_free(p9_req_cache, req); + return ERR_PTR(-ENOMEM); +} + +/** + * p9_tag_lookup - Look up a request by tag. + * @c: Client session. + * @tag: Transaction ID. + * + * Context: Any context. + * Return: A request, or %NULL if there is no request with that tag. + */ +struct p9_req_t *p9_tag_lookup(struct p9_client *c, u16 tag) +{ + struct p9_req_t *req; + + rcu_read_lock(); +again: + req = idr_find(&c->reqs, tag); + if (req) { + /* We have to be careful with the req found under rcu_read_lock + * Thanks to SLAB_TYPESAFE_BY_RCU we can safely try to get the + * ref again without corrupting other data, then check again + * that the tag matches once we have the ref + */ + if (!p9_req_try_get(req)) + goto again; + if (req->tc.tag != tag) { + p9_req_put(c, req); + goto again; + } + } + rcu_read_unlock(); + + return req; +} +EXPORT_SYMBOL(p9_tag_lookup); + +/** + * p9_tag_remove - Remove a tag. + * @c: Client session. + * @r: Request of reference. + * + * Context: Any context. + */ +static void p9_tag_remove(struct p9_client *c, struct p9_req_t *r) +{ + unsigned long flags; + u16 tag = r->tc.tag; + + p9_debug(P9_DEBUG_MUX, "freeing clnt %p req %p tag: %d\n", c, r, tag); + spin_lock_irqsave(&c->lock, flags); + idr_remove(&c->reqs, tag); + spin_unlock_irqrestore(&c->lock, flags); +} + +int p9_req_put(struct p9_client *c, struct p9_req_t *r) +{ + if (refcount_dec_and_test(&r->refcount)) { + p9_tag_remove(c, r); + + p9_fcall_fini(&r->tc); + p9_fcall_fini(&r->rc); + kmem_cache_free(p9_req_cache, r); + return 1; + } + return 0; +} +EXPORT_SYMBOL(p9_req_put); + +/** + * p9_tag_cleanup - cleans up tags structure and reclaims resources + * @c: v9fs client struct + * + * This frees resources associated with the tags structure + * + */ +static void p9_tag_cleanup(struct p9_client *c) +{ + struct p9_req_t *req; + int id; + + rcu_read_lock(); + idr_for_each_entry(&c->reqs, req, id) { + pr_info("Tag %d still in use\n", id); + if (p9_req_put(c, req) == 0) + pr_warn("Packet with tag %d has still references", + req->tc.tag); + } + rcu_read_unlock(); +} + +/** + * p9_client_cb - call back from transport to client + * @c: client state + * @req: request received + * @status: request status, one of REQ_STATUS_* + * + */ +void p9_client_cb(struct p9_client *c, struct p9_req_t *req, int status) +{ + p9_debug(P9_DEBUG_MUX, " tag %d\n", req->tc.tag); + + /* This barrier is needed to make sure any change made to req before + * the status change is visible to another thread + */ + smp_wmb(); + WRITE_ONCE(req->status, status); + + wake_up(&req->wq); + p9_debug(P9_DEBUG_MUX, "wakeup: %d\n", req->tc.tag); + p9_req_put(c, req); +} +EXPORT_SYMBOL(p9_client_cb); + +/** + * p9_parse_header - parse header arguments out of a packet + * @pdu: packet to parse + * @size: size of packet + * @type: type of request + * @tag: tag of packet + * @rewind: set if we need to rewind offset afterwards + */ + +int +p9_parse_header(struct p9_fcall *pdu, int32_t *size, int8_t *type, + int16_t *tag, int rewind) +{ + s8 r_type; + s16 r_tag; + s32 r_size; + int offset = pdu->offset; + int err; + + pdu->offset = 0; + + err = p9pdu_readf(pdu, 0, "dbw", &r_size, &r_type, &r_tag); + if (err) + goto rewind_and_exit; + + if (type) + *type = r_type; + if (tag) + *tag = r_tag; + if (size) + *size = r_size; + + if (pdu->size != r_size || r_size < 7) { + err = -EINVAL; + goto rewind_and_exit; + } + + pdu->id = r_type; + pdu->tag = r_tag; + + p9_debug(P9_DEBUG_9P, "<<< size=%d type: %d tag: %d\n", + pdu->size, pdu->id, pdu->tag); + +rewind_and_exit: + if (rewind) + pdu->offset = offset; + return err; +} +EXPORT_SYMBOL(p9_parse_header); + +/** + * p9_check_errors - check 9p packet for error return and process it + * @c: current client instance + * @req: request to parse and check for error conditions + * + * returns error code if one is discovered, otherwise returns 0 + * + * this will have to be more complicated if we have multiple + * error packet types + */ + +static int p9_check_errors(struct p9_client *c, struct p9_req_t *req) +{ + s8 type; + int err; + int ecode; + + err = p9_parse_header(&req->rc, NULL, &type, NULL, 0); + if (req->rc.size > req->rc.capacity && !req->rc.zc) { + pr_err("requested packet size too big: %d does not fit %zu (type=%d)\n", + req->rc.size, req->rc.capacity, req->rc.id); + return -EIO; + } + /* dump the response from server + * This should be after check errors which poplulate pdu_fcall. + */ + trace_9p_protocol_dump(c, &req->rc); + if (err) { + p9_debug(P9_DEBUG_ERROR, "couldn't parse header %d\n", err); + return err; + } + if (type != P9_RERROR && type != P9_RLERROR) + return 0; + + if (!p9_is_proto_dotl(c)) { + char *ename = NULL; + + err = p9pdu_readf(&req->rc, c->proto_version, "s?d", + &ename, &ecode); + if (err) { + kfree(ename); + goto out_err; + } + + if (p9_is_proto_dotu(c) && ecode < 512) + err = -ecode; + + if (!err) { + err = p9_errstr2errno(ename, strlen(ename)); + + p9_debug(P9_DEBUG_9P, "<<< RERROR (%d) %s\n", + -ecode, ename); + } + kfree(ename); + } else { + err = p9pdu_readf(&req->rc, c->proto_version, "d", &ecode); + if (err) + goto out_err; + err = -ecode; + + p9_debug(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode); + } + + return err; + +out_err: + p9_debug(P9_DEBUG_ERROR, "couldn't parse error%d\n", err); + + return err; +} + +static struct p9_req_t * +p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...); + +/** + * p9_client_flush - flush (cancel) a request + * @c: client state + * @oldreq: request to cancel + * + * This sents a flush for a particular request and links + * the flush request to the original request. The current + * code only supports a single flush request although the protocol + * allows for multiple flush requests to be sent for a single request. + * + */ + +static int p9_client_flush(struct p9_client *c, struct p9_req_t *oldreq) +{ + struct p9_req_t *req; + s16 oldtag; + int err; + + err = p9_parse_header(&oldreq->tc, NULL, NULL, &oldtag, 1); + if (err) + return err; + + p9_debug(P9_DEBUG_9P, ">>> TFLUSH tag %d\n", oldtag); + + req = p9_client_rpc(c, P9_TFLUSH, "w", oldtag); + if (IS_ERR(req)) + return PTR_ERR(req); + + /* if we haven't received a response for oldreq, + * remove it from the list + */ + if (READ_ONCE(oldreq->status) == REQ_STATUS_SENT) { + if (c->trans_mod->cancelled) + c->trans_mod->cancelled(c, oldreq); + } + + p9_req_put(c, req); + return 0; +} + +static struct p9_req_t *p9_client_prepare_req(struct p9_client *c, + int8_t type, uint t_size, uint r_size, + const char *fmt, va_list ap) +{ + int err; + struct p9_req_t *req; + va_list apc; + + p9_debug(P9_DEBUG_MUX, "client %p op %d\n", c, type); + + /* we allow for any status other than disconnected */ + if (c->status == Disconnected) + return ERR_PTR(-EIO); + + /* if status is begin_disconnected we allow only clunk request */ + if (c->status == BeginDisconnect && type != P9_TCLUNK) + return ERR_PTR(-EIO); + + va_copy(apc, ap); + req = p9_tag_alloc(c, type, t_size, r_size, fmt, apc); + va_end(apc); + if (IS_ERR(req)) + return req; + + /* marshall the data */ + p9pdu_prepare(&req->tc, req->tc.tag, type); + err = p9pdu_vwritef(&req->tc, c->proto_version, fmt, ap); + if (err) + goto reterr; + p9pdu_finalize(c, &req->tc); + trace_9p_client_req(c, type, req->tc.tag); + return req; +reterr: + p9_req_put(c, req); + /* We have to put also the 2nd reference as it won't be used */ + p9_req_put(c, req); + return ERR_PTR(err); +} + +/** + * p9_client_rpc - issue a request and wait for a response + * @c: client session + * @type: type of request + * @fmt: protocol format string (see protocol.c) + * + * Returns request structure (which client must free using p9_req_put) + */ + +static struct p9_req_t * +p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...) +{ + va_list ap; + int sigpending, err; + unsigned long flags; + struct p9_req_t *req; + /* Passing zero for tsize/rsize to p9_client_prepare_req() tells it to + * auto determine an appropriate (small) request/response size + * according to actual message data being sent. Currently RDMA + * transport is excluded from this response message size optimization, + * as it would not cope with it, due to its pooled response buffers + * (using an optimized request size for RDMA as well though). + */ + const uint tsize = 0; + const uint rsize = c->trans_mod->pooled_rbuffers ? c->msize : 0; + + va_start(ap, fmt); + req = p9_client_prepare_req(c, type, tsize, rsize, fmt, ap); + va_end(ap); + if (IS_ERR(req)) + return req; + + req->tc.zc = false; + req->rc.zc = false; + + if (signal_pending(current)) { + sigpending = 1; + clear_thread_flag(TIF_SIGPENDING); + } else { + sigpending = 0; + } + + err = c->trans_mod->request(c, req); + if (err < 0) { + /* write won't happen */ + p9_req_put(c, req); + if (err != -ERESTARTSYS && err != -EFAULT) + c->status = Disconnected; + goto recalc_sigpending; + } +again: + /* Wait for the response */ + err = io_wait_event_killable(req->wq, + READ_ONCE(req->status) >= REQ_STATUS_RCVD); + + /* Make sure our req is coherent with regard to updates in other + * threads - echoes to wmb() in the callback + */ + smp_rmb(); + + if (err == -ERESTARTSYS && c->status == Connected && + type == P9_TFLUSH) { + if (fatal_signal_pending(current)) + goto recalc_sigpending; + sigpending = 1; + clear_thread_flag(TIF_SIGPENDING); + goto again; + } + + if (READ_ONCE(req->status) == REQ_STATUS_ERROR) { + p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err); + err = req->t_err; + } + if (err == -ERESTARTSYS && c->status == Connected) { + p9_debug(P9_DEBUG_MUX, "flushing\n"); + sigpending = 1; + clear_thread_flag(TIF_SIGPENDING); + + if (c->trans_mod->cancel(c, req)) + p9_client_flush(c, req); + + /* if we received the response anyway, don't signal error */ + if (READ_ONCE(req->status) == REQ_STATUS_RCVD) + err = 0; + } +recalc_sigpending: + if (sigpending) { + spin_lock_irqsave(¤t->sighand->siglock, flags); + recalc_sigpending(); + spin_unlock_irqrestore(¤t->sighand->siglock, flags); + } + if (err < 0) + goto reterr; + + err = p9_check_errors(c, req); + trace_9p_client_res(c, type, req->rc.tag, err); + if (!err) + return req; +reterr: + p9_req_put(c, req); + return ERR_PTR(safe_errno(err)); +} + +/** + * p9_client_zc_rpc - issue a request and wait for a response + * @c: client session + * @type: type of request + * @uidata: destination for zero copy read + * @uodata: source for zero copy write + * @inlen: read buffer size + * @olen: write buffer size + * @in_hdrlen: reader header size, This is the size of response protocol data + * @fmt: protocol format string (see protocol.c) + * + * Returns request structure (which client must free using p9_req_put) + */ +static struct p9_req_t *p9_client_zc_rpc(struct p9_client *c, int8_t type, + struct iov_iter *uidata, + struct iov_iter *uodata, + int inlen, int olen, int in_hdrlen, + const char *fmt, ...) +{ + va_list ap; + int sigpending, err; + unsigned long flags; + struct p9_req_t *req; + + va_start(ap, fmt); + /* We allocate a inline protocol data of only 4k bytes. + * The actual content is passed in zero-copy fashion. + */ + req = p9_client_prepare_req(c, type, P9_ZC_HDR_SZ, P9_ZC_HDR_SZ, fmt, ap); + va_end(ap); + if (IS_ERR(req)) + return req; + + req->tc.zc = true; + req->rc.zc = true; + + if (signal_pending(current)) { + sigpending = 1; + clear_thread_flag(TIF_SIGPENDING); + } else { + sigpending = 0; + } + + err = c->trans_mod->zc_request(c, req, uidata, uodata, + inlen, olen, in_hdrlen); + if (err < 0) { + if (err == -EIO) + c->status = Disconnected; + if (err != -ERESTARTSYS) + goto recalc_sigpending; + } + if (READ_ONCE(req->status) == REQ_STATUS_ERROR) { + p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err); + err = req->t_err; + } + if (err == -ERESTARTSYS && c->status == Connected) { + p9_debug(P9_DEBUG_MUX, "flushing\n"); + sigpending = 1; + clear_thread_flag(TIF_SIGPENDING); + + if (c->trans_mod->cancel(c, req)) + p9_client_flush(c, req); + + /* if we received the response anyway, don't signal error */ + if (READ_ONCE(req->status) == REQ_STATUS_RCVD) + err = 0; + } +recalc_sigpending: + if (sigpending) { + spin_lock_irqsave(¤t->sighand->siglock, flags); + recalc_sigpending(); + spin_unlock_irqrestore(¤t->sighand->siglock, flags); + } + if (err < 0) + goto reterr; + + err = p9_check_errors(c, req); + trace_9p_client_res(c, type, req->rc.tag, err); + if (!err) + return req; +reterr: + p9_req_put(c, req); + return ERR_PTR(safe_errno(err)); +} + +static struct p9_fid *p9_fid_create(struct p9_client *clnt) +{ + int ret; + struct p9_fid *fid; + + p9_debug(P9_DEBUG_FID, "clnt %p\n", clnt); + fid = kzalloc_obj(*fid); + if (!fid) + return NULL; + + fid->mode = -1; + fid->uid = current_fsuid(); + fid->clnt = clnt; + refcount_set(&fid->count, 1); + + idr_preload(GFP_KERNEL); + spin_lock_irq(&clnt->lock); + ret = idr_alloc_u32(&clnt->fids, fid, &fid->fid, P9_NOFID - 1, + GFP_NOWAIT); + spin_unlock_irq(&clnt->lock); + idr_preload_end(); + if (!ret) { + trace_9p_fid_ref(fid, P9_FID_REF_CREATE); + return fid; + } + + kfree(fid); + return NULL; +} + +static void p9_fid_destroy(struct p9_fid *fid) +{ + struct p9_client *clnt; + unsigned long flags; + + p9_debug(P9_DEBUG_FID, "fid %d\n", fid->fid); + trace_9p_fid_ref(fid, P9_FID_REF_DESTROY); + clnt = fid->clnt; + spin_lock_irqsave(&clnt->lock, flags); + idr_remove(&clnt->fids, fid->fid); + spin_unlock_irqrestore(&clnt->lock, flags); + kvfree(fid->rdir); + kfree(fid); +} + +/* We also need to export tracepoint symbols for tracepoint_enabled() */ +EXPORT_TRACEPOINT_SYMBOL(9p_fid_ref); + +void do_trace_9p_fid_get(struct p9_fid *fid) +{ + trace_9p_fid_ref(fid, P9_FID_REF_GET); +} +EXPORT_SYMBOL(do_trace_9p_fid_get); + +void do_trace_9p_fid_put(struct p9_fid *fid) +{ + trace_9p_fid_ref(fid, P9_FID_REF_PUT); +} +EXPORT_SYMBOL(do_trace_9p_fid_put); + +static int p9_client_version(struct p9_client *c) +{ + int err; + struct p9_req_t *req; + char *version = NULL; + int msize; + + p9_debug(P9_DEBUG_9P, ">>> TVERSION msize %d protocol %d\n", + c->msize, c->proto_version); + + switch (c->proto_version) { + case p9_proto_2000L: + req = p9_client_rpc(c, P9_TVERSION, "ds", + c->msize, "9P2000.L"); + break; + case p9_proto_2000u: + req = p9_client_rpc(c, P9_TVERSION, "ds", + c->msize, "9P2000.u"); + break; + case p9_proto_legacy: + req = p9_client_rpc(c, P9_TVERSION, "ds", + c->msize, "9P2000"); + break; + default: + return -EINVAL; + } + + if (IS_ERR(req)) + return PTR_ERR(req); + + err = p9pdu_readf(&req->rc, c->proto_version, "ds", &msize, &version); + if (err) { + p9_debug(P9_DEBUG_9P, "version error %d\n", err); + trace_9p_protocol_dump(c, &req->rc); + goto error; + } + + p9_debug(P9_DEBUG_9P, "<<< RVERSION msize %d %s\n", msize, version); + if (!strncmp(version, "9P2000.L", 8)) { + c->proto_version = p9_proto_2000L; + } else if (!strncmp(version, "9P2000.u", 8)) { + c->proto_version = p9_proto_2000u; + } else if (!strncmp(version, "9P2000", 6)) { + c->proto_version = p9_proto_legacy; + } else { + p9_debug(P9_DEBUG_ERROR, + "server returned an unknown version: %s\n", version); + err = -EREMOTEIO; + goto error; + } + + if (msize < 4096) { + p9_debug(P9_DEBUG_ERROR, + "server returned a msize < 4096: %d\n", msize); + err = -EREMOTEIO; + goto error; + } + if (msize < c->msize) + c->msize = msize; + +error: + kfree(version); + p9_req_put(c, req); + + return err; +} + +struct p9_client *p9_client_create(struct fs_context *fc) +{ + int err; + static atomic_t seqno = ATOMIC_INIT(0); + struct p9_client *clnt; + char *client_id; + char *cache_name; + + clnt = kmalloc_obj(*clnt); + if (!clnt) + return ERR_PTR(-ENOMEM); + + clnt->trans_mod = NULL; + clnt->trans = NULL; + clnt->fcall_cache = NULL; + + client_id = utsname()->nodename; + memcpy(clnt->name, client_id, strlen(client_id) + 1); + + spin_lock_init(&clnt->lock); + idr_init(&clnt->fids); + idr_init(&clnt->reqs); + + err = apply_client_options(clnt, fc); + if (err) + goto free_client; + + if (!clnt->trans_mod) + clnt->trans_mod = v9fs_get_default_trans(); + + if (!clnt->trans_mod) { + err = -EPROTONOSUPPORT; + p9_debug(P9_DEBUG_ERROR, + "No transport defined or default transport\n"); + goto free_client; + } + + p9_debug(P9_DEBUG_MUX, "clnt %p trans %p msize %d protocol %d\n", + clnt, clnt->trans_mod, clnt->msize, clnt->proto_version); + + err = clnt->trans_mod->create(clnt, fc); + if (err) + goto put_trans; + + if (clnt->msize > clnt->trans_mod->maxsize) { + clnt->msize = clnt->trans_mod->maxsize; + pr_info("Limiting 'msize' to %d as this is the maximum " + "supported by transport %s\n", + clnt->msize, clnt->trans_mod->name + ); + } + + if (clnt->msize < 4096) { + p9_debug(P9_DEBUG_ERROR, + "Please specify a msize of at least 4k\n"); + err = -EINVAL; + goto close_trans; + } + + err = p9_client_version(clnt); + if (err) + goto close_trans; + + cache_name = kasprintf(GFP_KERNEL, + "9p-fcall-cache-%u", atomic_inc_return(&seqno)); + if (!cache_name) { + err = -ENOMEM; + goto close_trans; + } + + /* P9_HDRSZ + 4 is the smallest packet header we can have that is + * followed by data accessed from userspace by read + */ + clnt->fcall_cache = + kmem_cache_create_usercopy(cache_name, clnt->msize, + 0, 0, P9_HDRSZ + 4, + clnt->msize - (P9_HDRSZ + 4), + NULL); + + kfree(cache_name); + return clnt; + +close_trans: + clnt->trans_mod->close(clnt); +put_trans: + v9fs_put_trans(clnt->trans_mod); +free_client: + kfree(clnt); + return ERR_PTR(err); +} +EXPORT_SYMBOL(p9_client_create); + +void p9_client_destroy(struct p9_client *clnt) +{ + struct p9_fid *fid; + int id; + + p9_debug(P9_DEBUG_MUX, "clnt %p\n", clnt); + + if (clnt->trans_mod) + clnt->trans_mod->close(clnt); + + v9fs_put_trans(clnt->trans_mod); + + idr_for_each_entry(&clnt->fids, fid, id) { + pr_info("Found fid %d not clunked\n", fid->fid); + p9_fid_destroy(fid); + } + + p9_tag_cleanup(clnt); + + kmem_cache_destroy(clnt->fcall_cache); + kfree(clnt); +} +EXPORT_SYMBOL(p9_client_destroy); + +void p9_client_disconnect(struct p9_client *clnt) +{ + p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt); + clnt->status = Disconnected; +} +EXPORT_SYMBOL(p9_client_disconnect); + +void p9_client_begin_disconnect(struct p9_client *clnt) +{ + p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt); + clnt->status = BeginDisconnect; +} +EXPORT_SYMBOL(p9_client_begin_disconnect); + +struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid, + const char *uname, kuid_t n_uname, + const char *aname) +{ + int err; + struct p9_req_t *req; + struct p9_fid *fid; + struct p9_qid qid; + + p9_debug(P9_DEBUG_9P, ">>> TATTACH afid %d uname %s aname %s\n", + afid ? afid->fid : -1, uname, aname); + fid = p9_fid_create(clnt); + if (!fid) { + err = -ENOMEM; + goto error; + } + fid->uid = n_uname; + + req = p9_client_rpc(clnt, P9_TATTACH, "ddss?u", fid->fid, + afid ? afid->fid : P9_NOFID, uname, aname, n_uname); + if (IS_ERR(req)) { + err = PTR_ERR(req); + goto error; + } + + err = p9pdu_readf(&req->rc, clnt->proto_version, "Q", &qid); + if (err) { + trace_9p_protocol_dump(clnt, &req->rc); + p9_req_put(clnt, req); + goto error; + } + + p9_debug(P9_DEBUG_9P, "<<< RATTACH qid %x.%llx.%x\n", + qid.type, qid.path, qid.version); + + memmove(&fid->qid, &qid, sizeof(struct p9_qid)); + + p9_req_put(clnt, req); + return fid; + +error: + if (fid) + p9_fid_destroy(fid); + return ERR_PTR(err); +} +EXPORT_SYMBOL(p9_client_attach); + +struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname, + const unsigned char * const *wnames, int clone) +{ + int err; + struct p9_client *clnt; + struct p9_fid *fid; + struct p9_qid *wqids; + struct p9_req_t *req; + u16 nwqids, count; + + wqids = NULL; + clnt = oldfid->clnt; + if (clone) { + fid = p9_fid_create(clnt); + if (!fid) { + err = -ENOMEM; + goto error; + } + + fid->uid = oldfid->uid; + } else { + fid = oldfid; + } + + p9_debug(P9_DEBUG_9P, ">>> TWALK fids %d,%d nwname %ud wname[0] %s\n", + oldfid->fid, fid->fid, nwname, wnames ? wnames[0] : NULL); + req = p9_client_rpc(clnt, P9_TWALK, "ddT", oldfid->fid, fid->fid, + nwname, wnames); + if (IS_ERR(req)) { + err = PTR_ERR(req); + goto error; + } + + err = p9pdu_readf(&req->rc, clnt->proto_version, "R", &nwqids, &wqids); + if (err) { + trace_9p_protocol_dump(clnt, &req->rc); + p9_req_put(clnt, req); + goto clunk_fid; + } + p9_req_put(clnt, req); + + p9_debug(P9_DEBUG_9P, "<<< RWALK nwqid %d:\n", nwqids); + + if (nwqids != nwname) { + err = -ENOENT; + goto clunk_fid; + } + + for (count = 0; count < nwqids; count++) + p9_debug(P9_DEBUG_9P, "<<< [%d] %x.%llx.%x\n", + count, wqids[count].type, + wqids[count].path, + wqids[count].version); + + if (nwname) + memmove(&fid->qid, &wqids[nwqids - 1], sizeof(struct p9_qid)); + else + memmove(&fid->qid, &oldfid->qid, sizeof(struct p9_qid)); + + kfree(wqids); + return fid; + +clunk_fid: + kfree(wqids); + if (fid != oldfid) + p9_fid_put(fid); + fid = NULL; + +error: + if (fid && fid != oldfid) + p9_fid_destroy(fid); + + return ERR_PTR(err); +} +EXPORT_SYMBOL(p9_client_walk); + +int p9_client_open(struct p9_fid *fid, int mode) +{ + int err; + struct p9_client *clnt; + struct p9_req_t *req; + struct p9_qid qid; + int iounit; + + clnt = fid->clnt; + p9_debug(P9_DEBUG_9P, ">>> %s fid %d mode %d\n", + p9_is_proto_dotl(clnt) ? "TLOPEN" : "TOPEN", fid->fid, mode); + + if (fid->mode != -1) + return -EINVAL; + + if (p9_is_proto_dotl(clnt)) + req = p9_client_rpc(clnt, P9_TLOPEN, "dd", fid->fid, mode & P9L_MODE_MASK); + else + req = p9_client_rpc(clnt, P9_TOPEN, "db", fid->fid, mode & P9L_MODE_MASK); + if (IS_ERR(req)) { + err = PTR_ERR(req); + goto error; + } + + err = p9pdu_readf(&req->rc, clnt->proto_version, "Qd", &qid, &iounit); + if (err) { + trace_9p_protocol_dump(clnt, &req->rc); + goto free_and_error; + } + + p9_debug(P9_DEBUG_9P, "<<< %s qid %x.%llx.%x iounit %x\n", + p9_is_proto_dotl(clnt) ? "RLOPEN" : "ROPEN", qid.type, + qid.path, qid.version, iounit); + + memmove(&fid->qid, &qid, sizeof(struct p9_qid)); + fid->mode = mode; + fid->iounit = iounit; + +free_and_error: + p9_req_put(clnt, req); +error: + return err; +} +EXPORT_SYMBOL(p9_client_open); + +int p9_client_create_dotl(struct p9_fid *ofid, const char *name, u32 flags, + u32 mode, kgid_t gid, struct p9_qid *qid) +{ + int err; + struct p9_client *clnt; + struct p9_req_t *req; + int iounit; + + p9_debug(P9_DEBUG_9P, + ">>> TLCREATE fid %d name %s flags %d mode %d gid %d\n", + ofid->fid, name, flags, mode, + from_kgid(&init_user_ns, gid)); + clnt = ofid->clnt; + + if (ofid->mode != -1) + return -EINVAL; + + req = p9_client_rpc(clnt, P9_TLCREATE, "dsddg", ofid->fid, name, flags, + mode & P9L_MODE_MASK, gid); + if (IS_ERR(req)) { + err = PTR_ERR(req); + goto error; + } + + err = p9pdu_readf(&req->rc, clnt->proto_version, "Qd", qid, &iounit); + if (err) { + trace_9p_protocol_dump(clnt, &req->rc); + goto free_and_error; + } + + p9_debug(P9_DEBUG_9P, "<<< RLCREATE qid %x.%llx.%x iounit %x\n", + qid->type, qid->path, qid->version, iounit); + + memmove(&ofid->qid, qid, sizeof(struct p9_qid)); + ofid->mode = flags; + ofid->iounit = iounit; + +free_and_error: + p9_req_put(clnt, req); +error: + return err; +} +EXPORT_SYMBOL(p9_client_create_dotl); + +int p9_client_fcreate(struct p9_fid *fid, const char *name, u32 perm, int mode, + char *extension) +{ + int err; + struct p9_client *clnt; + struct p9_req_t *req; + struct p9_qid qid; + int iounit; + + p9_debug(P9_DEBUG_9P, ">>> TCREATE fid %d name %s perm %d mode %d\n", + fid->fid, name, perm, mode); + clnt = fid->clnt; + + if (fid->mode != -1) + return -EINVAL; + + req = p9_client_rpc(clnt, P9_TCREATE, "dsdb?s", fid->fid, name, perm, + mode & P9L_MODE_MASK, extension); + if (IS_ERR(req)) { + err = PTR_ERR(req); + goto error; + } + + err = p9pdu_readf(&req->rc, clnt->proto_version, "Qd", &qid, &iounit); + if (err) { + trace_9p_protocol_dump(clnt, &req->rc); + goto free_and_error; + } + + p9_debug(P9_DEBUG_9P, "<<< RCREATE qid %x.%llx.%x iounit %x\n", + qid.type, qid.path, qid.version, iounit); + + memmove(&fid->qid, &qid, sizeof(struct p9_qid)); + fid->mode = mode; + fid->iounit = iounit; + +free_and_error: + p9_req_put(clnt, req); +error: + return err; +} +EXPORT_SYMBOL(p9_client_fcreate); + +int p9_client_symlink(struct p9_fid *dfid, const char *name, + const char *symtgt, kgid_t gid, struct p9_qid *qid) +{ + int err; + struct p9_client *clnt; + struct p9_req_t *req; + + p9_debug(P9_DEBUG_9P, ">>> TSYMLINK dfid %d name %s symtgt %s\n", + dfid->fid, name, symtgt); + clnt = dfid->clnt; + + req = p9_client_rpc(clnt, P9_TSYMLINK, "dssg", dfid->fid, name, symtgt, + gid); + if (IS_ERR(req)) { + err = PTR_ERR(req); + goto error; + } + + err = p9pdu_readf(&req->rc, clnt->proto_version, "Q", qid); + if (err) { + trace_9p_protocol_dump(clnt, &req->rc); + goto free_and_error; + } + + p9_debug(P9_DEBUG_9P, "<<< RSYMLINK qid %x.%llx.%x\n", + qid->type, qid->path, qid->version); + +free_and_error: + p9_req_put(clnt, req); +error: + return err; +} +EXPORT_SYMBOL(p9_client_symlink); + +int p9_client_link(struct p9_fid *dfid, struct p9_fid *oldfid, const char *newname) +{ + struct p9_client *clnt; + struct p9_req_t *req; + + p9_debug(P9_DEBUG_9P, ">>> TLINK dfid %d oldfid %d newname %s\n", + dfid->fid, oldfid->fid, newname); + clnt = dfid->clnt; + req = p9_client_rpc(clnt, P9_TLINK, "dds", dfid->fid, oldfid->fid, + newname); + if (IS_ERR(req)) + return PTR_ERR(req); + + p9_debug(P9_DEBUG_9P, "<<< RLINK\n"); + p9_req_put(clnt, req); + return 0; +} +EXPORT_SYMBOL(p9_client_link); + +int p9_client_fsync(struct p9_fid *fid, int datasync) +{ + int err = 0; + struct p9_client *clnt; + struct p9_req_t *req; + + p9_debug(P9_DEBUG_9P, ">>> TFSYNC fid %d datasync:%d\n", + fid->fid, datasync); + clnt = fid->clnt; + + req = p9_client_rpc(clnt, P9_TFSYNC, "dd", fid->fid, datasync); + if (IS_ERR(req)) { + err = PTR_ERR(req); + goto error; + } + + p9_debug(P9_DEBUG_9P, "<<< RFSYNC fid %d\n", fid->fid); + + p9_req_put(clnt, req); + +error: + return err; +} +EXPORT_SYMBOL(p9_client_fsync); + +int p9_client_clunk(struct p9_fid *fid) +{ + int err = 0; + struct p9_client *clnt; + struct p9_req_t *req; + int retries = 0; + +again: + p9_debug(P9_DEBUG_9P, ">>> TCLUNK fid %d (try %d)\n", + fid->fid, retries); + clnt = fid->clnt; + + req = p9_client_rpc(clnt, P9_TCLUNK, "d", fid->fid); + if (IS_ERR(req)) { + err = PTR_ERR(req); + goto error; + } + + p9_debug(P9_DEBUG_9P, "<<< RCLUNK fid %d\n", fid->fid); + + p9_req_put(clnt, req); +error: + /* Fid is not valid even after a failed clunk + * If interrupted, retry once then give up and + * leak fid until umount. + */ + if (err == -ERESTARTSYS) { + if (retries++ == 0) + goto again; + } else { + p9_fid_destroy(fid); + } + return err; +} +EXPORT_SYMBOL(p9_client_clunk); + +int p9_client_remove(struct p9_fid *fid) +{ + int err = 0; + struct p9_client *clnt; + struct p9_req_t *req; + + p9_debug(P9_DEBUG_9P, ">>> TREMOVE fid %d\n", fid->fid); + clnt = fid->clnt; + + req = p9_client_rpc(clnt, P9_TREMOVE, "d", fid->fid); + if (IS_ERR(req)) { + err = PTR_ERR(req); + goto error; + } + + p9_debug(P9_DEBUG_9P, "<<< RREMOVE fid %d\n", fid->fid); + + p9_req_put(clnt, req); +error: + if (err == -ERESTARTSYS) + p9_fid_put(fid); + else + p9_fid_destroy(fid); + return err; +} +EXPORT_SYMBOL(p9_client_remove); + +int p9_client_unlinkat(struct p9_fid *dfid, const char *name, int flags) +{ + int err = 0; + struct p9_req_t *req; + struct p9_client *clnt; + + p9_debug(P9_DEBUG_9P, ">>> TUNLINKAT fid %d %s %d\n", + dfid->fid, name, flags); + + clnt = dfid->clnt; + req = p9_client_rpc(clnt, P9_TUNLINKAT, "dsd", dfid->fid, name, flags); + if (IS_ERR(req)) { + err = PTR_ERR(req); + goto error; + } + p9_debug(P9_DEBUG_9P, "<<< RUNLINKAT fid %d %s\n", dfid->fid, name); + + p9_req_put(clnt, req); +error: + return err; +} +EXPORT_SYMBOL(p9_client_unlinkat); + +int +p9_client_read(struct p9_fid *fid, u64 offset, struct iov_iter *to, int *err) +{ + int total = 0; + *err = 0; + + while (iov_iter_count(to)) { + int count; + + count = p9_client_read_once(fid, offset, to, err); + if (!count || *err) + break; + offset += count; + total += count; + } + return total; +} +EXPORT_SYMBOL(p9_client_read); + +int +p9_client_read_once(struct p9_fid *fid, u64 offset, struct iov_iter *to, + int *err) +{ + struct p9_client *clnt = fid->clnt; + struct p9_req_t *req; + int count = iov_iter_count(to); + u32 rsize, received; + bool non_zc = false; + char *dataptr; + + *err = 0; + p9_debug(P9_DEBUG_9P, ">>> TREAD fid %d offset %llu %zu\n", + fid->fid, offset, iov_iter_count(to)); + + rsize = fid->iounit; + if (!rsize || rsize > clnt->msize - P9_IOHDRSZ) + rsize = clnt->msize - P9_IOHDRSZ; + + if (count < rsize) + rsize = count; + + /* Don't bother zerocopy for small IO (< 1024) */ + if (clnt->trans_mod->zc_request && rsize > 1024) { + /* response header len is 11 + * PDU Header(7) + IO Size (4) + */ + req = p9_client_zc_rpc(clnt, P9_TREAD, to, NULL, rsize, + 0, 11, "dqd", fid->fid, + offset, rsize); + } else { + non_zc = true; + req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset, + rsize); + } + if (IS_ERR(req)) { + *err = PTR_ERR(req); + if (!non_zc) + iov_iter_revert(to, count - iov_iter_count(to)); + return 0; + } + + *err = p9pdu_readf(&req->rc, clnt->proto_version, + "D", &received, &dataptr); + if (*err) { + if (!non_zc) + iov_iter_revert(to, count - iov_iter_count(to)); + trace_9p_protocol_dump(clnt, &req->rc); + p9_req_put(clnt, req); + return 0; + } + if (rsize < received) { + pr_err("bogus RREAD count (%u > %u)\n", received, rsize); + *err = -EIO; + p9_req_put(clnt, req); + return 0; + } + + p9_debug(P9_DEBUG_9P, "<<< RREAD count %u\n", received); + + if (non_zc) { + int n = copy_to_iter(dataptr, received, to); + + if (n != received) { + *err = -EFAULT; + p9_req_put(clnt, req); + return n; + } + } else { + iov_iter_revert(to, count - received - iov_iter_count(to)); + } + p9_req_put(clnt, req); + return received; +} +EXPORT_SYMBOL(p9_client_read_once); + +int +p9_client_write(struct p9_fid *fid, u64 offset, struct iov_iter *from, int *err) +{ + struct p9_client *clnt = fid->clnt; + struct p9_req_t *req; + int total = 0; + *err = 0; + + while (iov_iter_count(from)) { + size_t count = iov_iter_count(from); + u32 rsize = fid->iounit; + u32 written; + + if (!rsize || rsize > clnt->msize - P9_IOHDRSZ) + rsize = clnt->msize - P9_IOHDRSZ; + + if (count < rsize) + rsize = count; + + p9_debug(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %u (/%zu)\n", + fid->fid, offset, rsize, count); + + /* Don't bother zerocopy for small IO (< 1024) */ + if (clnt->trans_mod->zc_request && rsize > 1024) { + req = p9_client_zc_rpc(clnt, P9_TWRITE, NULL, from, 0, + rsize, P9_ZC_HDR_SZ, "dqd", + fid->fid, offset, rsize); + } else { + req = p9_client_rpc(clnt, P9_TWRITE, "dqV", fid->fid, + offset, rsize, from); + } + if (IS_ERR(req)) { + iov_iter_revert(from, count - iov_iter_count(from)); + *err = PTR_ERR(req); + break; + } + + *err = p9pdu_readf(&req->rc, clnt->proto_version, "d", &written); + if (*err) { + iov_iter_revert(from, count - iov_iter_count(from)); + trace_9p_protocol_dump(clnt, &req->rc); + p9_req_put(clnt, req); + break; + } + if (rsize < written) { + pr_err("bogus RWRITE count (%u > %u)\n", written, rsize); + *err = -EIO; + iov_iter_revert(from, count - iov_iter_count(from)); + p9_req_put(clnt, req); + break; + } + + p9_debug(P9_DEBUG_9P, "<<< RWRITE count %u\n", written); + + p9_req_put(clnt, req); + iov_iter_revert(from, count - written - iov_iter_count(from)); + total += written; + offset += written; + } + return total; +} +EXPORT_SYMBOL(p9_client_write); + +void +p9_client_write_subreq(struct netfs_io_subrequest *subreq) +{ + struct netfs_io_request *wreq = subreq->rreq; + struct p9_fid *fid = wreq->netfs_priv; + struct p9_client *clnt = fid->clnt; + struct p9_req_t *req; + unsigned long long start = subreq->start + subreq->transferred; + int written, len = subreq->len - subreq->transferred; + int err; + + p9_debug(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu len %d\n", + fid->fid, start, len); + + /* Don't bother zerocopy for small IO (< 1024) */ + if (clnt->trans_mod->zc_request && len > 1024) { + req = p9_client_zc_rpc(clnt, P9_TWRITE, NULL, &subreq->io_iter, + 0, wreq->len, P9_ZC_HDR_SZ, "dqd", + fid->fid, start, len); + } else { + req = p9_client_rpc(clnt, P9_TWRITE, "dqV", fid->fid, + start, len, &subreq->io_iter); + } + if (IS_ERR(req)) { + netfs_write_subrequest_terminated(subreq, PTR_ERR(req)); + return; + } + + err = p9pdu_readf(&req->rc, clnt->proto_version, "d", &written); + if (err) { + trace_9p_protocol_dump(clnt, &req->rc); + p9_req_put(clnt, req); + netfs_write_subrequest_terminated(subreq, err); + return; + } + + if (written > len) { + pr_err("bogus RWRITE count (%d > %u)\n", written, len); + written = -EIO; + } + + p9_debug(P9_DEBUG_9P, "<<< RWRITE count %d\n", len); + + p9_req_put(clnt, req); + netfs_write_subrequest_terminated(subreq, written); +} +EXPORT_SYMBOL(p9_client_write_subreq); + +struct p9_wstat *p9_client_stat(struct p9_fid *fid) +{ + int err; + struct p9_client *clnt; + struct p9_wstat *ret; + struct p9_req_t *req; + u16 ignored; + + p9_debug(P9_DEBUG_9P, ">>> TSTAT fid %d\n", fid->fid); + + ret = kmalloc_obj(*ret); + if (!ret) + return ERR_PTR(-ENOMEM); + + clnt = fid->clnt; + + req = p9_client_rpc(clnt, P9_TSTAT, "d", fid->fid); + if (IS_ERR(req)) { + err = PTR_ERR(req); + goto error; + } + + err = p9pdu_readf(&req->rc, clnt->proto_version, "wS", &ignored, ret); + if (err) { + trace_9p_protocol_dump(clnt, &req->rc); + p9_req_put(clnt, req); + goto error; + } + + p9_debug(P9_DEBUG_9P, + "<<< RSTAT sz=%x type=%x dev=%x qid=%x.%llx.%x\n" + "<<< mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n" + "<<< name=%s uid=%s gid=%s muid=%s extension=(%s)\n" + "<<< uid=%d gid=%d n_muid=%d\n", + ret->size, ret->type, ret->dev, ret->qid.type, ret->qid.path, + ret->qid.version, ret->mode, + ret->atime, ret->mtime, ret->length, + ret->name, ret->uid, ret->gid, ret->muid, ret->extension, + from_kuid(&init_user_ns, ret->n_uid), + from_kgid(&init_user_ns, ret->n_gid), + from_kuid(&init_user_ns, ret->n_muid)); + + p9_req_put(clnt, req); + return ret; + +error: + kfree(ret); + return ERR_PTR(err); +} +EXPORT_SYMBOL(p9_client_stat); + +struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid, + u64 request_mask) +{ + int err; + struct p9_client *clnt; + struct p9_stat_dotl *ret; + struct p9_req_t *req; + + p9_debug(P9_DEBUG_9P, ">>> TGETATTR fid %d, request_mask %lld\n", + fid->fid, request_mask); + + ret = kmalloc_obj(*ret); + if (!ret) + return ERR_PTR(-ENOMEM); + + clnt = fid->clnt; + + req = p9_client_rpc(clnt, P9_TGETATTR, "dq", fid->fid, request_mask); + if (IS_ERR(req)) { + err = PTR_ERR(req); + goto error; + } + + err = p9pdu_readf(&req->rc, clnt->proto_version, "A", ret); + if (err) { + trace_9p_protocol_dump(clnt, &req->rc); + p9_req_put(clnt, req); + goto error; + } + + p9_debug(P9_DEBUG_9P, "<<< RGETATTR st_result_mask=%lld\n" + "<<< qid=%x.%llx.%x\n" + "<<< st_mode=%8.8x st_nlink=%llu\n" + "<<< st_uid=%d st_gid=%d\n" + "<<< st_rdev=%llx st_size=%llx st_blksize=%llu st_blocks=%llu\n" + "<<< st_atime_sec=%lld st_atime_nsec=%lld\n" + "<<< st_mtime_sec=%lld st_mtime_nsec=%lld\n" + "<<< st_ctime_sec=%lld st_ctime_nsec=%lld\n" + "<<< st_btime_sec=%lld st_btime_nsec=%lld\n" + "<<< st_gen=%lld st_data_version=%lld\n", + ret->st_result_mask, + ret->qid.type, ret->qid.path, ret->qid.version, + ret->st_mode, ret->st_nlink, + from_kuid(&init_user_ns, ret->st_uid), + from_kgid(&init_user_ns, ret->st_gid), + ret->st_rdev, ret->st_size, ret->st_blksize, ret->st_blocks, + ret->st_atime_sec, ret->st_atime_nsec, + ret->st_mtime_sec, ret->st_mtime_nsec, + ret->st_ctime_sec, ret->st_ctime_nsec, + ret->st_btime_sec, ret->st_btime_nsec, + ret->st_gen, ret->st_data_version); + + p9_req_put(clnt, req); + return ret; + +error: + kfree(ret); + return ERR_PTR(err); +} +EXPORT_SYMBOL(p9_client_getattr_dotl); + +static int p9_client_statsize(struct p9_wstat *wst, int proto_version) +{ + int ret; + + /* NOTE: size shouldn't include its own length */ + /* size[2] type[2] dev[4] qid[13] */ + /* mode[4] atime[4] mtime[4] length[8]*/ + /* name[s] uid[s] gid[s] muid[s] */ + ret = 2 + 4 + 13 + 4 + 4 + 4 + 8 + 2 + 2 + 2 + 2; + + if (wst->name) + ret += strlen(wst->name); + if (wst->uid) + ret += strlen(wst->uid); + if (wst->gid) + ret += strlen(wst->gid); + if (wst->muid) + ret += strlen(wst->muid); + + if (proto_version == p9_proto_2000u || + proto_version == p9_proto_2000L) { + /* extension[s] n_uid[4] n_gid[4] n_muid[4] */ + ret += 2 + 4 + 4 + 4; + if (wst->extension) + ret += strlen(wst->extension); + } + + return ret; +} + +int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst) +{ + int err = 0; + struct p9_req_t *req; + struct p9_client *clnt; + + clnt = fid->clnt; + wst->size = p9_client_statsize(wst, clnt->proto_version); + p9_debug(P9_DEBUG_9P, ">>> TWSTAT fid %d\n", + fid->fid); + p9_debug(P9_DEBUG_9P, + " sz=%x type=%x dev=%x qid=%x.%llx.%x\n" + " mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n" + " name=%s uid=%s gid=%s muid=%s extension=(%s)\n" + " uid=%d gid=%d n_muid=%d\n", + wst->size, wst->type, wst->dev, wst->qid.type, + wst->qid.path, wst->qid.version, + wst->mode, wst->atime, wst->mtime, wst->length, + wst->name, wst->uid, wst->gid, wst->muid, wst->extension, + from_kuid(&init_user_ns, wst->n_uid), + from_kgid(&init_user_ns, wst->n_gid), + from_kuid(&init_user_ns, wst->n_muid)); + + req = p9_client_rpc(clnt, P9_TWSTAT, "dwS", + fid->fid, wst->size + 2, wst); + if (IS_ERR(req)) { + err = PTR_ERR(req); + goto error; + } + + p9_debug(P9_DEBUG_9P, "<<< RWSTAT fid %d\n", fid->fid); + + p9_req_put(clnt, req); +error: + return err; +} +EXPORT_SYMBOL(p9_client_wstat); + +int p9_client_setattr(struct p9_fid *fid, struct p9_iattr_dotl *p9attr) +{ + int err = 0; + struct p9_req_t *req; + struct p9_client *clnt; + + clnt = fid->clnt; + p9_debug(P9_DEBUG_9P, ">>> TSETATTR fid %d\n", fid->fid); + p9_debug(P9_DEBUG_9P, " valid=%x mode=%x uid=%d gid=%d size=%lld\n", + p9attr->valid, p9attr->mode, + from_kuid(&init_user_ns, p9attr->uid), + from_kgid(&init_user_ns, p9attr->gid), + p9attr->size); + p9_debug(P9_DEBUG_9P, " atime_sec=%lld atime_nsec=%lld\n", + p9attr->atime_sec, p9attr->atime_nsec); + p9_debug(P9_DEBUG_9P, " mtime_sec=%lld mtime_nsec=%lld\n", + p9attr->mtime_sec, p9attr->mtime_nsec); + + req = p9_client_rpc(clnt, P9_TSETATTR, "dI", fid->fid, p9attr); + + if (IS_ERR(req)) { + err = PTR_ERR(req); + goto error; + } + p9_debug(P9_DEBUG_9P, "<<< RSETATTR fid %d\n", fid->fid); + p9_req_put(clnt, req); +error: + return err; +} +EXPORT_SYMBOL(p9_client_setattr); + +int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb) +{ + int err; + struct p9_req_t *req; + struct p9_client *clnt; + + clnt = fid->clnt; + + p9_debug(P9_DEBUG_9P, ">>> TSTATFS fid %d\n", fid->fid); + + req = p9_client_rpc(clnt, P9_TSTATFS, "d", fid->fid); + if (IS_ERR(req)) { + err = PTR_ERR(req); + goto error; + } + + err = p9pdu_readf(&req->rc, clnt->proto_version, "ddqqqqqqd", &sb->type, + &sb->bsize, &sb->blocks, &sb->bfree, &sb->bavail, + &sb->files, &sb->ffree, &sb->fsid, &sb->namelen); + if (err) { + trace_9p_protocol_dump(clnt, &req->rc); + p9_req_put(clnt, req); + goto error; + } + + p9_debug(P9_DEBUG_9P, + "<<< RSTATFS fid %d type 0x%x bsize %u blocks %llu bfree %llu bavail %llu files %llu ffree %llu fsid %llu namelen %u\n", + fid->fid, sb->type, sb->bsize, sb->blocks, sb->bfree, + sb->bavail, sb->files, sb->ffree, sb->fsid, sb->namelen); + + p9_req_put(clnt, req); +error: + return err; +} +EXPORT_SYMBOL(p9_client_statfs); + +int p9_client_rename(struct p9_fid *fid, + struct p9_fid *newdirfid, const char *name) +{ + int err = 0; + struct p9_req_t *req; + struct p9_client *clnt; + + clnt = fid->clnt; + + p9_debug(P9_DEBUG_9P, ">>> TRENAME fid %d newdirfid %d name %s\n", + fid->fid, newdirfid->fid, name); + + req = p9_client_rpc(clnt, P9_TRENAME, "dds", fid->fid, + newdirfid->fid, name); + if (IS_ERR(req)) { + err = PTR_ERR(req); + goto error; + } + + p9_debug(P9_DEBUG_9P, "<<< RRENAME fid %d\n", fid->fid); + + p9_req_put(clnt, req); +error: + return err; +} +EXPORT_SYMBOL(p9_client_rename); + +int p9_client_renameat(struct p9_fid *olddirfid, const char *old_name, + struct p9_fid *newdirfid, const char *new_name) +{ + int err = 0; + struct p9_req_t *req; + struct p9_client *clnt; + + clnt = olddirfid->clnt; + + p9_debug(P9_DEBUG_9P, + ">>> TRENAMEAT olddirfid %d old name %s newdirfid %d new name %s\n", + olddirfid->fid, old_name, newdirfid->fid, new_name); + + req = p9_client_rpc(clnt, P9_TRENAMEAT, "dsds", olddirfid->fid, + old_name, newdirfid->fid, new_name); + if (IS_ERR(req)) { + err = PTR_ERR(req); + goto error; + } + + p9_debug(P9_DEBUG_9P, "<<< RRENAMEAT newdirfid %d new name %s\n", + newdirfid->fid, new_name); + + p9_req_put(clnt, req); +error: + return err; +} +EXPORT_SYMBOL(p9_client_renameat); + +/* An xattrwalk without @attr_name gives the fid for the lisxattr namespace + */ +struct p9_fid *p9_client_xattrwalk(struct p9_fid *file_fid, + const char *attr_name, u64 *attr_size) +{ + int err; + struct p9_req_t *req; + struct p9_client *clnt; + struct p9_fid *attr_fid; + + clnt = file_fid->clnt; + attr_fid = p9_fid_create(clnt); + if (!attr_fid) { + err = -ENOMEM; + goto error; + } + p9_debug(P9_DEBUG_9P, + ">>> TXATTRWALK file_fid %d, attr_fid %d name '%s'\n", + file_fid->fid, attr_fid->fid, attr_name); + + req = p9_client_rpc(clnt, P9_TXATTRWALK, "dds", + file_fid->fid, attr_fid->fid, attr_name); + if (IS_ERR(req)) { + err = PTR_ERR(req); + goto error; + } + err = p9pdu_readf(&req->rc, clnt->proto_version, "q", attr_size); + if (err) { + trace_9p_protocol_dump(clnt, &req->rc); + p9_req_put(clnt, req); + goto clunk_fid; + } + p9_req_put(clnt, req); + p9_debug(P9_DEBUG_9P, "<<< RXATTRWALK fid %d size %llu\n", + attr_fid->fid, *attr_size); + return attr_fid; +clunk_fid: + p9_fid_put(attr_fid); + attr_fid = NULL; +error: + if (attr_fid && attr_fid != file_fid) + p9_fid_destroy(attr_fid); + + return ERR_PTR(err); +} +EXPORT_SYMBOL_GPL(p9_client_xattrwalk); + +int p9_client_xattrcreate(struct p9_fid *fid, const char *name, + u64 attr_size, int flags) +{ + int err = 0; + struct p9_req_t *req; + struct p9_client *clnt; + + p9_debug(P9_DEBUG_9P, + ">>> TXATTRCREATE fid %d name %s size %llu flag %d\n", + fid->fid, name, attr_size, flags); + clnt = fid->clnt; + req = p9_client_rpc(clnt, P9_TXATTRCREATE, "dsqd", + fid->fid, name, attr_size, flags); + if (IS_ERR(req)) { + err = PTR_ERR(req); + goto error; + } + p9_debug(P9_DEBUG_9P, "<<< RXATTRCREATE fid %d\n", fid->fid); + p9_req_put(clnt, req); +error: + return err; +} +EXPORT_SYMBOL_GPL(p9_client_xattrcreate); + +int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset) +{ + int err, non_zc = 0; + u32 rsize; + struct p9_client *clnt; + struct p9_req_t *req; + char *dataptr; + struct kvec kv = {.iov_base = data, .iov_len = count}; + struct iov_iter to; + + iov_iter_kvec(&to, ITER_DEST, &kv, 1, count); + + p9_debug(P9_DEBUG_9P, ">>> TREADDIR fid %d offset %llu count %u\n", + fid->fid, offset, count); + + clnt = fid->clnt; + + rsize = fid->iounit; + if (!rsize || rsize > clnt->msize - P9_READDIRHDRSZ) + rsize = clnt->msize - P9_READDIRHDRSZ; + + if (count < rsize) + rsize = count; + + /* Don't bother zerocopy for small IO (< 1024) */ + if (clnt->trans_mod->zc_request && rsize > 1024) { + /* response header len is 11 + * PDU Header(7) + IO Size (4) + */ + req = p9_client_zc_rpc(clnt, P9_TREADDIR, &to, NULL, rsize, 0, + 11, "dqd", fid->fid, offset, rsize); + } else { + non_zc = 1; + req = p9_client_rpc(clnt, P9_TREADDIR, "dqd", fid->fid, + offset, rsize); + } + if (IS_ERR(req)) { + err = PTR_ERR(req); + goto error; + } + + err = p9pdu_readf(&req->rc, clnt->proto_version, "D", &count, &dataptr); + if (err) { + trace_9p_protocol_dump(clnt, &req->rc); + goto free_and_error; + } + if (rsize < count) { + pr_err("bogus RREADDIR count (%u > %u)\n", count, rsize); + err = -EIO; + goto free_and_error; + } + + p9_debug(P9_DEBUG_9P, "<<< RREADDIR count %u\n", count); + + if (non_zc) + memmove(data, dataptr, count); + + p9_req_put(clnt, req); + return count; + +free_and_error: + p9_req_put(clnt, req); +error: + return err; +} +EXPORT_SYMBOL(p9_client_readdir); + +int p9_client_mknod_dotl(struct p9_fid *fid, const char *name, int mode, + dev_t rdev, kgid_t gid, struct p9_qid *qid) +{ + int err; + struct p9_client *clnt; + struct p9_req_t *req; + + clnt = fid->clnt; + p9_debug(P9_DEBUG_9P, + ">>> TMKNOD fid %d name %s mode %d major %d minor %d\n", + fid->fid, name, mode, MAJOR(rdev), MINOR(rdev)); + req = p9_client_rpc(clnt, P9_TMKNOD, "dsdddg", fid->fid, name, mode, + MAJOR(rdev), MINOR(rdev), gid); + if (IS_ERR(req)) + return PTR_ERR(req); + + err = p9pdu_readf(&req->rc, clnt->proto_version, "Q", qid); + if (err) { + trace_9p_protocol_dump(clnt, &req->rc); + goto error; + } + p9_debug(P9_DEBUG_9P, "<<< RMKNOD qid %x.%llx.%x\n", + qid->type, qid->path, qid->version); + +error: + p9_req_put(clnt, req); + return err; +} +EXPORT_SYMBOL(p9_client_mknod_dotl); + +int p9_client_mkdir_dotl(struct p9_fid *fid, const char *name, int mode, + kgid_t gid, struct p9_qid *qid) +{ + int err; + struct p9_client *clnt; + struct p9_req_t *req; + + clnt = fid->clnt; + p9_debug(P9_DEBUG_9P, ">>> TMKDIR fid %d name %s mode %d gid %d\n", + fid->fid, name, mode, from_kgid(&init_user_ns, gid)); + req = p9_client_rpc(clnt, P9_TMKDIR, "dsdg", + fid->fid, name, mode, gid); + if (IS_ERR(req)) + return PTR_ERR(req); + + err = p9pdu_readf(&req->rc, clnt->proto_version, "Q", qid); + if (err) { + trace_9p_protocol_dump(clnt, &req->rc); + goto error; + } + p9_debug(P9_DEBUG_9P, "<<< RMKDIR qid %x.%llx.%x\n", qid->type, + qid->path, qid->version); + +error: + p9_req_put(clnt, req); + return err; +} +EXPORT_SYMBOL(p9_client_mkdir_dotl); + +int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status) +{ + int err; + struct p9_client *clnt; + struct p9_req_t *req; + + clnt = fid->clnt; + p9_debug(P9_DEBUG_9P, + ">>> TLOCK fid %d type %i flags %d start %lld length %lld proc_id %d client_id %s\n", + fid->fid, flock->type, flock->flags, flock->start, + flock->length, flock->proc_id, flock->client_id); + + req = p9_client_rpc(clnt, P9_TLOCK, "dbdqqds", fid->fid, flock->type, + flock->flags, flock->start, flock->length, + flock->proc_id, flock->client_id); + + if (IS_ERR(req)) + return PTR_ERR(req); + + err = p9pdu_readf(&req->rc, clnt->proto_version, "b", status); + if (err) { + trace_9p_protocol_dump(clnt, &req->rc); + goto error; + } + p9_debug(P9_DEBUG_9P, "<<< RLOCK status %i\n", *status); +error: + p9_req_put(clnt, req); + return err; +} +EXPORT_SYMBOL(p9_client_lock_dotl); + +int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *glock) +{ + int err; + struct p9_client *clnt; + struct p9_req_t *req; + + clnt = fid->clnt; + p9_debug(P9_DEBUG_9P, + ">>> TGETLOCK fid %d, type %i start %lld length %lld proc_id %d client_id %s\n", + fid->fid, glock->type, glock->start, glock->length, + glock->proc_id, glock->client_id); + + req = p9_client_rpc(clnt, P9_TGETLOCK, "dbqqds", fid->fid, + glock->type, glock->start, glock->length, + glock->proc_id, glock->client_id); + + if (IS_ERR(req)) + return PTR_ERR(req); + + err = p9pdu_readf(&req->rc, clnt->proto_version, "bqqds", &glock->type, + &glock->start, &glock->length, &glock->proc_id, + &glock->client_id); + if (err) { + trace_9p_protocol_dump(clnt, &req->rc); + goto error; + } + p9_debug(P9_DEBUG_9P, + "<<< RGETLOCK type %i start %lld length %lld proc_id %d client_id %s\n", + glock->type, glock->start, glock->length, + glock->proc_id, glock->client_id); +error: + p9_req_put(clnt, req); + return err; +} +EXPORT_SYMBOL(p9_client_getlock_dotl); + +int p9_client_readlink(struct p9_fid *fid, char **target) +{ + int err; + struct p9_client *clnt; + struct p9_req_t *req; + + clnt = fid->clnt; + p9_debug(P9_DEBUG_9P, ">>> TREADLINK fid %d\n", fid->fid); + + req = p9_client_rpc(clnt, P9_TREADLINK, "d", fid->fid); + if (IS_ERR(req)) + return PTR_ERR(req); + + err = p9pdu_readf(&req->rc, clnt->proto_version, "s", target); + if (err) { + trace_9p_protocol_dump(clnt, &req->rc); + goto error; + } + p9_debug(P9_DEBUG_9P, "<<< RREADLINK target %s\n", *target); +error: + p9_req_put(clnt, req); + return err; +} +EXPORT_SYMBOL(p9_client_readlink); + +int __init p9_client_init(void) +{ + p9_req_cache = KMEM_CACHE(p9_req_t, SLAB_TYPESAFE_BY_RCU); + return p9_req_cache ? 0 : -ENOMEM; +} + +void __exit p9_client_exit(void) +{ + kmem_cache_destroy(p9_req_cache); +} diff --git a/net/9p/error.c b/net/9p/error.c new file mode 100644 index 000000000..8ba8afc91 --- /dev/null +++ b/net/9p/error.c @@ -0,0 +1,227 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Error string handling + * + * Plan 9 uses error strings, Unix uses error numbers. These functions + * try to help manage that and provide for dynamically adding error + * mappings. + * + * Copyright (C) 2004 by Eric Van Hensbergen + * Copyright (C) 2002 by Ron Minnich + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#include +#include + +/** + * struct errormap - map string errors from Plan 9 to Linux numeric ids + * @name: string sent over 9P + * @val: numeric id most closely representing @name + * @namelen: length of string + * @list: hash-table list for string lookup + */ +struct errormap { + char *name; + int val; + + int namelen; + struct hlist_node list; +}; + +#define ERRHASH_BITS 5 +static DEFINE_HASHTABLE(hash_errmap, ERRHASH_BITS); + +/* FixMe - reduce to a reasonable size */ +static struct errormap errmap[] = { + {"Operation not permitted", EPERM}, + {"wstat prohibited", EPERM}, + {"No such file or directory", ENOENT}, + {"directory entry not found", ENOENT}, + {"file not found", ENOENT}, + {"Interrupted system call", EINTR}, + {"Input/output error", EIO}, + {"No such device or address", ENXIO}, + {"Argument list too long", E2BIG}, + {"Bad file descriptor", EBADF}, + {"Resource temporarily unavailable", EAGAIN}, + {"Cannot allocate memory", ENOMEM}, + {"Permission denied", EACCES}, + {"Bad address", EFAULT}, + {"Block device required", ENOTBLK}, + {"Device or resource busy", EBUSY}, + {"File exists", EEXIST}, + {"Invalid cross-device link", EXDEV}, + {"No such device", ENODEV}, + {"Not a directory", ENOTDIR}, + {"Is a directory", EISDIR}, + {"Invalid argument", EINVAL}, + {"Too many open files in system", ENFILE}, + {"Too many open files", EMFILE}, + {"Text file busy", ETXTBSY}, + {"File too large", EFBIG}, + {"No space left on device", ENOSPC}, + {"Illegal seek", ESPIPE}, + {"Read-only file system", EROFS}, + {"Too many links", EMLINK}, + {"Broken pipe", EPIPE}, + {"Numerical argument out of domain", EDOM}, + {"Numerical result out of range", ERANGE}, + {"Resource deadlock avoided", EDEADLK}, + {"File name too long", ENAMETOOLONG}, + {"No locks available", ENOLCK}, + {"Function not implemented", ENOSYS}, + {"Directory not empty", ENOTEMPTY}, + {"Too many levels of symbolic links", ELOOP}, + {"No message of desired type", ENOMSG}, + {"Identifier removed", EIDRM}, + {"No data available", ENODATA}, + {"Machine is not on the network", ENONET}, + {"Package not installed", ENOPKG}, + {"Object is remote", EREMOTE}, + {"Link has been severed", ENOLINK}, + {"Communication error on send", ECOMM}, + {"Protocol error", EPROTO}, + {"Bad message", EBADMSG}, + {"File descriptor in bad state", EBADFD}, + {"Streams pipe error", ESTRPIPE}, + {"Too many users", EUSERS}, + {"Socket operation on non-socket", ENOTSOCK}, + {"Message too long", EMSGSIZE}, + {"Protocol not available", ENOPROTOOPT}, + {"Protocol not supported", EPROTONOSUPPORT}, + {"Socket type not supported", ESOCKTNOSUPPORT}, + {"Operation not supported", EOPNOTSUPP}, + {"Protocol family not supported", EPFNOSUPPORT}, + {"Network is down", ENETDOWN}, + {"Network is unreachable", ENETUNREACH}, + {"Network dropped connection on reset", ENETRESET}, + {"Software caused connection abort", ECONNABORTED}, + {"Connection reset by peer", ECONNRESET}, + {"No buffer space available", ENOBUFS}, + {"Transport endpoint is already connected", EISCONN}, + {"Transport endpoint is not connected", ENOTCONN}, + {"Cannot send after transport endpoint shutdown", ESHUTDOWN}, + {"Connection timed out", ETIMEDOUT}, + {"Connection refused", ECONNREFUSED}, + {"Host is down", EHOSTDOWN}, + {"No route to host", EHOSTUNREACH}, + {"Operation already in progress", EALREADY}, + {"Operation now in progress", EINPROGRESS}, + {"Is a named type file", EISNAM}, + {"Remote I/O error", EREMOTEIO}, + {"Disk quota exceeded", EDQUOT}, +/* errors from fossil, vacfs, and u9fs */ + {"fid unknown or out of range", EBADF}, + {"permission denied", EACCES}, + {"file does not exist", ENOENT}, + {"authentication failed", ECONNREFUSED}, + {"bad offset in directory read", ESPIPE}, + {"bad use of fid", EBADF}, + {"wstat can't convert between files and directories", EPERM}, + {"directory is not empty", ENOTEMPTY}, + {"file exists", EEXIST}, + {"file already exists", EEXIST}, + {"file or directory already exists", EEXIST}, + {"fid already in use", EBADF}, + {"file in use", ETXTBSY}, + {"i/o error", EIO}, + {"file already open for I/O", ETXTBSY}, + {"illegal mode", EINVAL}, + {"illegal name", ENAMETOOLONG}, + {"not a directory", ENOTDIR}, + {"not a member of proposed group", EPERM}, + {"not owner", EACCES}, + {"only owner can change group in wstat", EACCES}, + {"read only file system", EROFS}, + {"no access to special file", EPERM}, + {"i/o count too large", EIO}, + {"unknown group", EINVAL}, + {"unknown user", EINVAL}, + {"bogus wstat buffer", EPROTO}, + {"exclusive use file already open", EAGAIN}, + {"corrupted directory entry", EIO}, + {"corrupted file entry", EIO}, + {"corrupted block label", EIO}, + {"corrupted meta data", EIO}, + {"illegal offset", EINVAL}, + {"illegal path element", ENOENT}, + {"root of file system is corrupted", EIO}, + {"corrupted super block", EIO}, + {"protocol botch", EPROTO}, + {"file system is full", ENOSPC}, + {"file is in use", EAGAIN}, + {"directory entry is not allocated", ENOENT}, + {"file is read only", EROFS}, + {"file has been removed", EIDRM}, + {"only support truncation to zero length", EPERM}, + {"cannot remove root", EPERM}, + {"file too big", EFBIG}, + {"venti i/o error", EIO}, + /* these are not errors */ + {"u9fs rhostsauth: no authentication required", 0}, + {"u9fs authnone: no authentication required", 0}, + {NULL, -1} +}; + +/** + * p9_error_init - preload mappings into hash list + * + */ + +int p9_error_init(void) +{ + struct errormap *c; + u32 hash; + + /* load initial error map into hash table */ + for (c = errmap; c->name; c++) { + c->namelen = strlen(c->name); + hash = jhash(c->name, c->namelen, 0); + INIT_HLIST_NODE(&c->list); + hash_add(hash_errmap, &c->list, hash); + } + + return 1; +} +EXPORT_SYMBOL(p9_error_init); + +/** + * p9_errstr2errno - convert error string to error number + * @errstr: error string + * @len: length of error string + * + */ + +int p9_errstr2errno(char *errstr, int len) +{ + int errno; + struct errormap *c; + u32 hash; + + errno = 0; + c = NULL; + hash = jhash(errstr, len, 0); + hash_for_each_possible(hash_errmap, c, list, hash) { + if (c->namelen == len && !memcmp(c->name, errstr, len)) { + errno = c->val; + break; + } + } + + if (errno == 0) { + /* TODO: if error isn't found, add it dynamically */ + errstr[len] = 0; + pr_err("%s: server reported unknown error %s\n", + __func__, errstr); + errno = ESERVERFAULT; + } + + return -errno; +} +EXPORT_SYMBOL(p9_errstr2errno); diff --git a/net/9p/mod.c b/net/9p/mod.c new file mode 100644 index 000000000..85160b52d --- /dev/null +++ b/net/9p/mod.c @@ -0,0 +1,212 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * 9P entry point + * + * Copyright (C) 2007 by Latchesar Ionkov + * Copyright (C) 2004 by Eric Van Hensbergen + * Copyright (C) 2002 by Ron Minnich + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#ifdef CONFIG_NET_9P_DEBUG +unsigned int p9_debug_level; /* feature-rific global debug level */ +EXPORT_SYMBOL(p9_debug_level); +module_param_named(debug, p9_debug_level, uint, 0); +MODULE_PARM_DESC(debug, "9P debugging level"); + +void _p9_debug(enum p9_debug_flags level, const char *func, + const char *fmt, ...) +{ + struct va_format vaf; + va_list args; + + if ((p9_debug_level & level) != level) + return; + + va_start(args, fmt); + + vaf.fmt = fmt; + vaf.va = &args; + + if (level == P9_DEBUG_9P) + pr_notice("(%8.8d) %pV", task_pid_nr(current), &vaf); + else + pr_notice("-- %s (%d): %pV", func, task_pid_nr(current), &vaf); + + va_end(args); +} +EXPORT_SYMBOL(_p9_debug); +#endif + +/* Dynamic Transport Registration Routines */ + +static DEFINE_SPINLOCK(v9fs_trans_lock); +static LIST_HEAD(v9fs_trans_list); + +/** + * v9fs_register_trans - register a new transport with 9p + * @m: structure describing the transport module and entry points + * + */ +void v9fs_register_trans(struct p9_trans_module *m) +{ + spin_lock(&v9fs_trans_lock); + list_add_tail(&m->list, &v9fs_trans_list); + spin_unlock(&v9fs_trans_lock); +} +EXPORT_SYMBOL(v9fs_register_trans); + +/** + * v9fs_unregister_trans - unregister a 9p transport + * @m: the transport to remove + * + */ +void v9fs_unregister_trans(struct p9_trans_module *m) +{ + spin_lock(&v9fs_trans_lock); + list_del_init(&m->list); + spin_unlock(&v9fs_trans_lock); +} +EXPORT_SYMBOL(v9fs_unregister_trans); + +static struct p9_trans_module *_p9_get_trans_by_name(const char *s) +{ + struct p9_trans_module *t, *found = NULL; + + spin_lock(&v9fs_trans_lock); + + list_for_each_entry(t, &v9fs_trans_list, list) + if (strcmp(t->name, s) == 0 && + try_module_get(t->owner)) { + found = t; + break; + } + + spin_unlock(&v9fs_trans_lock); + + return found; +} + +/** + * v9fs_get_trans_by_name - get transport with the matching name + * @s: string identifying transport + * + */ +struct p9_trans_module *v9fs_get_trans_by_name(const char *s) +{ + struct p9_trans_module *found = NULL; + + found = _p9_get_trans_by_name(s); + +#ifdef CONFIG_MODULES + if (!found) { + request_module("9p-%s", s); + found = _p9_get_trans_by_name(s); + } +#endif + + return found; +} +EXPORT_SYMBOL(v9fs_get_trans_by_name); + +static const char * const v9fs_default_transports[] = { + "virtio", "tcp", "fd", "unix", "xen", "rdma", +}; + +/** + * v9fs_get_default_trans - get the default transport + * + */ + +struct p9_trans_module *v9fs_get_default_trans(void) +{ + struct p9_trans_module *t, *found = NULL; + int i; + + spin_lock(&v9fs_trans_lock); + + list_for_each_entry(t, &v9fs_trans_list, list) + if (t->def && try_module_get(t->owner)) { + found = t; + break; + } + + if (!found) + list_for_each_entry(t, &v9fs_trans_list, list) + if (try_module_get(t->owner)) { + found = t; + break; + } + + spin_unlock(&v9fs_trans_lock); + + for (i = 0; !found && i < ARRAY_SIZE(v9fs_default_transports); i++) + found = v9fs_get_trans_by_name(v9fs_default_transports[i]); + + return found; +} +EXPORT_SYMBOL(v9fs_get_default_trans); + +/** + * v9fs_put_trans - put trans + * @m: transport to put + * + */ +void v9fs_put_trans(struct p9_trans_module *m) +{ + if (m) + module_put(m->owner); +} +EXPORT_SYMBOL(v9fs_put_trans); + +/** + * init_p9 - Initialize module + * + */ +static int __init init_p9(void) +{ + int ret; + + ret = p9_client_init(); + if (ret) + return ret; + + p9_error_init(); + pr_info("Installing 9P2000 support\n"); + + return ret; +} + +/** + * exit_p9 - shutdown module + * + */ + +static void __exit exit_p9(void) +{ + pr_info("Unloading 9P2000 support\n"); + + p9_client_exit(); +} + +module_init(init_p9) +module_exit(exit_p9) + +MODULE_AUTHOR("Latchesar Ionkov "); +MODULE_AUTHOR("Eric Van Hensbergen "); +MODULE_AUTHOR("Ron Minnich "); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Plan 9 Resource Sharing Support (9P2000)"); diff --git a/net/9p/protocol.c b/net/9p/protocol.c new file mode 100644 index 000000000..67b0586d8 --- /dev/null +++ b/net/9p/protocol.c @@ -0,0 +1,800 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * 9P Protocol Support Code + * + * Copyright (C) 2008 by Eric Van Hensbergen + * + * Base on code from Anthony Liguori + * Copyright (C) 2008 by IBM, Corp. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "protocol.h" + +#include + +/* len[2] text[len] */ +#define P9_STRLEN(s) \ + (2 + min_t(size_t, s ? strlen(s) : 0, USHRT_MAX)) + +/** + * p9_msg_buf_size - Returns a buffer size sufficiently large to hold the + * intended 9p message. + * @c: client + * @type: message type + * @fmt: format template for assembling request message + * (see p9pdu_vwritef) + * @ap: variable arguments to be fed to passed format template + * (see p9pdu_vwritef) + * + * Note: Even for response types (P9_R*) the format template and variable + * arguments must always be for the originating request type (P9_T*). + */ +size_t p9_msg_buf_size(struct p9_client *c, enum p9_msg_t type, + const char *fmt, va_list ap) +{ + /* size[4] type[1] tag[2] */ + const int hdr = 4 + 1 + 2; + /* ename[s] errno[4] */ + const int rerror_size = hdr + P9_ERRMAX + 4; + /* ecode[4] */ + const int rlerror_size = hdr + 4; + const int err_size = + c->proto_version == p9_proto_2000L ? rlerror_size : rerror_size; + + static_assert(NAME_MAX <= 4*1024, "p9_msg_buf_size() currently assumes " + "a max. allowed directory entry name length of 4k"); + + switch (type) { + + /* message types not used at all */ + case P9_TERROR: + case P9_TLERROR: + case P9_TAUTH: + case P9_RAUTH: + BUG(); + + /* variable length & potentially large message types */ + case P9_TATTACH: + BUG_ON(strcmp("ddss?u", fmt)); + va_arg(ap, int32_t); + va_arg(ap, int32_t); + { + const char *uname = va_arg(ap, const char *); + const char *aname = va_arg(ap, const char *); + /* fid[4] afid[4] uname[s] aname[s] n_uname[4] */ + return hdr + 4 + 4 + P9_STRLEN(uname) + P9_STRLEN(aname) + 4; + } + case P9_TWALK: + BUG_ON(strcmp("ddT", fmt)); + va_arg(ap, int32_t); + va_arg(ap, int32_t); + { + uint i, nwname = va_arg(ap, int); + size_t wname_all; + const char **wnames = va_arg(ap, const char **); + for (i = 0, wname_all = 0; i < nwname; ++i) { + wname_all += P9_STRLEN(wnames[i]); + } + /* fid[4] newfid[4] nwname[2] nwname*(wname[s]) */ + return hdr + 4 + 4 + 2 + wname_all; + } + case P9_RWALK: + BUG_ON(strcmp("ddT", fmt)); + va_arg(ap, int32_t); + va_arg(ap, int32_t); + { + uint nwname = va_arg(ap, int); + /* nwqid[2] nwqid*(wqid[13]) */ + return max_t(size_t, hdr + 2 + nwname * 13, err_size); + } + case P9_TCREATE: + BUG_ON(strcmp("dsdb?s", fmt)); + va_arg(ap, int32_t); + { + const char *name = va_arg(ap, const char *); + if (c->proto_version == p9_proto_legacy) { + /* fid[4] name[s] perm[4] mode[1] */ + return hdr + 4 + P9_STRLEN(name) + 4 + 1; + } else { + va_arg(ap, int32_t); + va_arg(ap, int); + { + const char *ext = va_arg(ap, const char *); + /* fid[4] name[s] perm[4] mode[1] extension[s] */ + return hdr + 4 + P9_STRLEN(name) + 4 + 1 + P9_STRLEN(ext); + } + } + } + case P9_TLCREATE: + BUG_ON(strcmp("dsddg", fmt)); + va_arg(ap, int32_t); + { + const char *name = va_arg(ap, const char *); + /* fid[4] name[s] flags[4] mode[4] gid[4] */ + return hdr + 4 + P9_STRLEN(name) + 4 + 4 + 4; + } + case P9_RREAD: + case P9_RREADDIR: + BUG_ON(strcmp("dqd", fmt)); + va_arg(ap, int32_t); + va_arg(ap, int64_t); + { + const int32_t count = va_arg(ap, int32_t); + /* count[4] data[count] */ + return max_t(size_t, hdr + 4 + count, err_size); + } + case P9_TWRITE: + BUG_ON(strcmp("dqV", fmt)); + va_arg(ap, int32_t); + va_arg(ap, int64_t); + { + const int32_t count = va_arg(ap, int32_t); + /* fid[4] offset[8] count[4] data[count] */ + return hdr + 4 + 8 + 4 + count; + } + case P9_TRENAMEAT: + BUG_ON(strcmp("dsds", fmt)); + va_arg(ap, int32_t); + { + const char *oldname, *newname; + oldname = va_arg(ap, const char *); + va_arg(ap, int32_t); + newname = va_arg(ap, const char *); + /* olddirfid[4] oldname[s] newdirfid[4] newname[s] */ + return hdr + 4 + P9_STRLEN(oldname) + 4 + P9_STRLEN(newname); + } + case P9_TSYMLINK: + BUG_ON(strcmp("dssg", fmt)); + va_arg(ap, int32_t); + { + const char *name = va_arg(ap, const char *); + const char *symtgt = va_arg(ap, const char *); + /* fid[4] name[s] symtgt[s] gid[4] */ + return hdr + 4 + P9_STRLEN(name) + P9_STRLEN(symtgt) + 4; + } + + case P9_RERROR: + return rerror_size; + case P9_RLERROR: + return rlerror_size; + + /* small message types */ + case P9_TWSTAT: + case P9_RSTAT: + case P9_RREADLINK: + case P9_TXATTRWALK: + case P9_TXATTRCREATE: + case P9_TLINK: + case P9_TMKDIR: + case P9_TMKNOD: + case P9_TRENAME: + case P9_TUNLINKAT: + case P9_TLOCK: + return 8 * 1024; + + /* tiny message types */ + default: + return 4 * 1024; + + } +} + +static int +p9pdu_writef(struct p9_fcall *pdu, int proto_version, const char *fmt, ...); + +void p9stat_free(struct p9_wstat *stbuf) +{ + kfree(stbuf->name); + stbuf->name = NULL; + kfree(stbuf->uid); + stbuf->uid = NULL; + kfree(stbuf->gid); + stbuf->gid = NULL; + kfree(stbuf->muid); + stbuf->muid = NULL; + kfree(stbuf->extension); + stbuf->extension = NULL; +} +EXPORT_SYMBOL(p9stat_free); + +size_t pdu_read(struct p9_fcall *pdu, void *data, size_t size) +{ + size_t len = min(pdu->size - pdu->offset, size); + + memcpy(data, &pdu->sdata[pdu->offset], len); + pdu->offset += len; + return size - len; +} + +static size_t pdu_write(struct p9_fcall *pdu, const void *data, size_t size) +{ + size_t len = min(pdu->capacity - pdu->size, size); + + memcpy(&pdu->sdata[pdu->size], data, len); + pdu->size += len; + return size - len; +} + +static size_t +pdu_write_u(struct p9_fcall *pdu, struct iov_iter *from, size_t size) +{ + size_t len = min(pdu->capacity - pdu->size, size); + + if (!copy_from_iter_full(&pdu->sdata[pdu->size], len, from)) + len = 0; + + pdu->size += len; + return size - len; +} + +/* b - int8_t + * w - int16_t + * d - int32_t + * q - int64_t + * s - string + * u - numeric uid + * g - numeric gid + * S - stat + * Q - qid + * D - data blob (int32_t size followed by void *, results are not freed) + * T - array of strings (int16_t count, followed by strings) + * R - array of qids (int16_t count, followed by qids) + * A - stat for 9p2000.L (p9_stat_dotl) + * ? - if optional = 1, continue parsing + */ + +static int +p9pdu_vreadf(struct p9_fcall *pdu, int proto_version, const char *fmt, + va_list ap) +{ + const char *ptr; + int errcode = 0; + + for (ptr = fmt; *ptr; ptr++) { + switch (*ptr) { + case 'b':{ + int8_t *val = va_arg(ap, int8_t *); + if (pdu_read(pdu, val, sizeof(*val))) { + errcode = -EFAULT; + break; + } + } + break; + case 'w':{ + int16_t *val = va_arg(ap, int16_t *); + __le16 le_val; + if (pdu_read(pdu, &le_val, sizeof(le_val))) { + errcode = -EFAULT; + break; + } + *val = le16_to_cpu(le_val); + } + break; + case 'd':{ + int32_t *val = va_arg(ap, int32_t *); + __le32 le_val; + if (pdu_read(pdu, &le_val, sizeof(le_val))) { + errcode = -EFAULT; + break; + } + *val = le32_to_cpu(le_val); + } + break; + case 'q':{ + int64_t *val = va_arg(ap, int64_t *); + __le64 le_val; + if (pdu_read(pdu, &le_val, sizeof(le_val))) { + errcode = -EFAULT; + break; + } + *val = le64_to_cpu(le_val); + } + break; + case 's':{ + char **sptr = va_arg(ap, char **); + uint16_t len; + + errcode = p9pdu_readf(pdu, proto_version, + "w", &len); + if (errcode) + break; + + *sptr = kmalloc(len + 1, GFP_NOFS); + if (*sptr == NULL) { + errcode = -ENOMEM; + break; + } + if (pdu_read(pdu, *sptr, len)) { + errcode = -EFAULT; + kfree(*sptr); + *sptr = NULL; + } else + (*sptr)[len] = 0; + } + break; + case 'u': { + kuid_t *uid = va_arg(ap, kuid_t *); + __le32 le_val; + if (pdu_read(pdu, &le_val, sizeof(le_val))) { + errcode = -EFAULT; + break; + } + *uid = make_kuid(&init_user_ns, + le32_to_cpu(le_val)); + } break; + case 'g': { + kgid_t *gid = va_arg(ap, kgid_t *); + __le32 le_val; + if (pdu_read(pdu, &le_val, sizeof(le_val))) { + errcode = -EFAULT; + break; + } + *gid = make_kgid(&init_user_ns, + le32_to_cpu(le_val)); + } break; + case 'Q':{ + struct p9_qid *qid = + va_arg(ap, struct p9_qid *); + + errcode = p9pdu_readf(pdu, proto_version, "bdq", + &qid->type, &qid->version, + &qid->path); + } + break; + case 'S':{ + struct p9_wstat *stbuf = + va_arg(ap, struct p9_wstat *); + + memset(stbuf, 0, sizeof(struct p9_wstat)); + stbuf->n_uid = stbuf->n_muid = INVALID_UID; + stbuf->n_gid = INVALID_GID; + + errcode = + p9pdu_readf(pdu, proto_version, + "wwdQdddqssss?sugu", + &stbuf->size, &stbuf->type, + &stbuf->dev, &stbuf->qid, + &stbuf->mode, &stbuf->atime, + &stbuf->mtime, &stbuf->length, + &stbuf->name, &stbuf->uid, + &stbuf->gid, &stbuf->muid, + &stbuf->extension, + &stbuf->n_uid, &stbuf->n_gid, + &stbuf->n_muid); + if (errcode) + p9stat_free(stbuf); + } + break; + case 'D':{ + uint32_t *count = va_arg(ap, uint32_t *); + void **data = va_arg(ap, void **); + + errcode = + p9pdu_readf(pdu, proto_version, "d", count); + if (!errcode) { + *count = + min_t(uint32_t, *count, + pdu->size - pdu->offset); + *data = &pdu->sdata[pdu->offset]; + } + } + break; + case 'T':{ + uint16_t *nwname = va_arg(ap, uint16_t *); + char ***wnames = va_arg(ap, char ***); + + *wnames = NULL; + + errcode = p9pdu_readf(pdu, proto_version, + "w", nwname); + if (!errcode) { + *wnames = + kmalloc_array(*nwname, + sizeof(char *), + GFP_NOFS); + if (!*wnames) + errcode = -ENOMEM; + else + (*wnames)[0] = NULL; + } + + if (!errcode) { + int i; + + for (i = 0; i < *nwname; i++) { + errcode = + p9pdu_readf(pdu, + proto_version, + "s", + &(*wnames)[i]); + if (errcode) { + (*wnames)[i] = NULL; + break; + } + } + } + + if (errcode) { + if (*wnames) { + int i; + + for (i = 0; i < *nwname; i++) { + if (!(*wnames)[i]) + break; + kfree((*wnames)[i]); + } + kfree(*wnames); + *wnames = NULL; + } + } + } + break; + case 'R':{ + uint16_t *nwqid = va_arg(ap, uint16_t *); + struct p9_qid **wqids = + va_arg(ap, struct p9_qid **); + + *wqids = NULL; + + errcode = + p9pdu_readf(pdu, proto_version, "w", nwqid); + if (!errcode) { + *wqids = + kmalloc_objs(struct p9_qid, *nwqid, + GFP_NOFS); + if (*wqids == NULL) + errcode = -ENOMEM; + } + + if (!errcode) { + int i; + + for (i = 0; i < *nwqid; i++) { + errcode = + p9pdu_readf(pdu, + proto_version, + "Q", + &(*wqids)[i]); + if (errcode) + break; + } + } + + if (errcode) { + kfree(*wqids); + *wqids = NULL; + } + } + break; + case 'A': { + struct p9_stat_dotl *stbuf = + va_arg(ap, struct p9_stat_dotl *); + + memset(stbuf, 0, sizeof(struct p9_stat_dotl)); + errcode = + p9pdu_readf(pdu, proto_version, + "qQdugqqqqqqqqqqqqqqq", + &stbuf->st_result_mask, + &stbuf->qid, + &stbuf->st_mode, + &stbuf->st_uid, &stbuf->st_gid, + &stbuf->st_nlink, + &stbuf->st_rdev, &stbuf->st_size, + &stbuf->st_blksize, &stbuf->st_blocks, + &stbuf->st_atime_sec, + &stbuf->st_atime_nsec, + &stbuf->st_mtime_sec, + &stbuf->st_mtime_nsec, + &stbuf->st_ctime_sec, + &stbuf->st_ctime_nsec, + &stbuf->st_btime_sec, + &stbuf->st_btime_nsec, + &stbuf->st_gen, + &stbuf->st_data_version); + } + break; + case '?': + if ((proto_version != p9_proto_2000u) && + (proto_version != p9_proto_2000L)) + return 0; + break; + default: + BUG(); + break; + } + + if (errcode) + break; + } + + return errcode; +} + +int +p9pdu_vwritef(struct p9_fcall *pdu, int proto_version, const char *fmt, + va_list ap) +{ + const char *ptr; + int errcode = 0; + + for (ptr = fmt; *ptr; ptr++) { + switch (*ptr) { + case 'b':{ + int8_t val = va_arg(ap, int); + if (pdu_write(pdu, &val, sizeof(val))) + errcode = -EFAULT; + } + break; + case 'w':{ + __le16 val = cpu_to_le16(va_arg(ap, int)); + if (pdu_write(pdu, &val, sizeof(val))) + errcode = -EFAULT; + } + break; + case 'd':{ + __le32 val = cpu_to_le32(va_arg(ap, int32_t)); + if (pdu_write(pdu, &val, sizeof(val))) + errcode = -EFAULT; + } + break; + case 'q':{ + __le64 val = cpu_to_le64(va_arg(ap, int64_t)); + if (pdu_write(pdu, &val, sizeof(val))) + errcode = -EFAULT; + } + break; + case 's':{ + const char *sptr = va_arg(ap, const char *); + uint16_t len = 0; + if (sptr) + len = min_t(size_t, strlen(sptr), + USHRT_MAX); + + errcode = p9pdu_writef(pdu, proto_version, + "w", len); + if (!errcode && pdu_write(pdu, sptr, len)) + errcode = -EFAULT; + } + break; + case 'u': { + kuid_t uid = va_arg(ap, kuid_t); + __le32 val = cpu_to_le32( + from_kuid(&init_user_ns, uid)); + if (pdu_write(pdu, &val, sizeof(val))) + errcode = -EFAULT; + } break; + case 'g': { + kgid_t gid = va_arg(ap, kgid_t); + __le32 val = cpu_to_le32( + from_kgid(&init_user_ns, gid)); + if (pdu_write(pdu, &val, sizeof(val))) + errcode = -EFAULT; + } break; + case 'Q':{ + const struct p9_qid *qid = + va_arg(ap, const struct p9_qid *); + errcode = + p9pdu_writef(pdu, proto_version, "bdq", + qid->type, qid->version, + qid->path); + } break; + case 'S':{ + const struct p9_wstat *stbuf = + va_arg(ap, const struct p9_wstat *); + errcode = + p9pdu_writef(pdu, proto_version, + "wwdQdddqssss?sugu", + stbuf->size, stbuf->type, + stbuf->dev, &stbuf->qid, + stbuf->mode, stbuf->atime, + stbuf->mtime, stbuf->length, + stbuf->name, stbuf->uid, + stbuf->gid, stbuf->muid, + stbuf->extension, stbuf->n_uid, + stbuf->n_gid, stbuf->n_muid); + } break; + case 'V':{ + uint32_t count = va_arg(ap, uint32_t); + struct iov_iter *from = + va_arg(ap, struct iov_iter *); + errcode = p9pdu_writef(pdu, proto_version, "d", + count); + if (!errcode && pdu_write_u(pdu, from, count)) + errcode = -EFAULT; + } + break; + case 'T':{ + uint16_t nwname = va_arg(ap, int); + const char **wnames = va_arg(ap, const char **); + + errcode = p9pdu_writef(pdu, proto_version, "w", + nwname); + if (!errcode) { + int i; + + for (i = 0; i < nwname; i++) { + errcode = + p9pdu_writef(pdu, + proto_version, + "s", + wnames[i]); + if (errcode) + break; + } + } + } + break; + case 'R':{ + uint16_t nwqid = va_arg(ap, int); + struct p9_qid *wqids = + va_arg(ap, struct p9_qid *); + + errcode = p9pdu_writef(pdu, proto_version, "w", + nwqid); + if (!errcode) { + int i; + + for (i = 0; i < nwqid; i++) { + errcode = + p9pdu_writef(pdu, + proto_version, + "Q", + &wqids[i]); + if (errcode) + break; + } + } + } + break; + case 'I':{ + struct p9_iattr_dotl *p9attr = va_arg(ap, + struct p9_iattr_dotl *); + + errcode = p9pdu_writef(pdu, proto_version, + "ddugqqqqq", + p9attr->valid, + p9attr->mode, + p9attr->uid, + p9attr->gid, + p9attr->size, + p9attr->atime_sec, + p9attr->atime_nsec, + p9attr->mtime_sec, + p9attr->mtime_nsec); + } + break; + case '?': + if ((proto_version != p9_proto_2000u) && + (proto_version != p9_proto_2000L)) + return 0; + break; + default: + BUG(); + break; + } + + if (errcode) + break; + } + + return errcode; +} + +int p9pdu_readf(struct p9_fcall *pdu, int proto_version, const char *fmt, ...) +{ + va_list ap; + int ret; + + va_start(ap, fmt); + ret = p9pdu_vreadf(pdu, proto_version, fmt, ap); + va_end(ap); + + return ret; +} + +static int +p9pdu_writef(struct p9_fcall *pdu, int proto_version, const char *fmt, ...) +{ + va_list ap; + int ret; + + va_start(ap, fmt); + ret = p9pdu_vwritef(pdu, proto_version, fmt, ap); + va_end(ap); + + return ret; +} + +int p9stat_read(struct p9_client *clnt, char *buf, int len, struct p9_wstat *st) +{ + struct p9_fcall fake_pdu; + int ret; + + fake_pdu.size = len; + fake_pdu.capacity = len; + fake_pdu.sdata = buf; + fake_pdu.offset = 0; + + ret = p9pdu_readf(&fake_pdu, clnt->proto_version, "S", st); + if (ret) { + p9_debug(P9_DEBUG_9P, "<<< p9stat_read failed: %d\n", ret); + trace_9p_protocol_dump(clnt, &fake_pdu); + return ret; + } + + return fake_pdu.offset; +} +EXPORT_SYMBOL(p9stat_read); + +int p9pdu_prepare(struct p9_fcall *pdu, int16_t tag, int8_t type) +{ + pdu->id = type; + return p9pdu_writef(pdu, 0, "dbw", 0, type, tag); +} + +int p9pdu_finalize(struct p9_client *clnt, struct p9_fcall *pdu) +{ + int size = pdu->size; + int err; + + pdu->size = 0; + err = p9pdu_writef(pdu, 0, "d", size); + pdu->size = size; + + trace_9p_protocol_dump(clnt, pdu); + p9_debug(P9_DEBUG_9P, ">>> size=%d type: %d tag: %d\n", + pdu->size, pdu->id, pdu->tag); + + return err; +} + +void p9pdu_reset(struct p9_fcall *pdu) +{ + pdu->offset = 0; + pdu->size = 0; +} + +int p9dirent_read(struct p9_client *clnt, char *buf, int len, + struct p9_dirent *dirent) +{ + struct p9_fcall fake_pdu; + int ret; + char *nameptr; + + fake_pdu.size = len; + fake_pdu.capacity = len; + fake_pdu.sdata = buf; + fake_pdu.offset = 0; + + ret = p9pdu_readf(&fake_pdu, clnt->proto_version, "Qqbs", &dirent->qid, + &dirent->d_off, &dirent->d_type, &nameptr); + if (ret) { + p9_debug(P9_DEBUG_9P, "<<< p9dirent_read failed: %d\n", ret); + trace_9p_protocol_dump(clnt, &fake_pdu); + return ret; + } + + ret = strscpy(dirent->d_name, nameptr, sizeof(dirent->d_name)); + if (ret < 0) { + p9_debug(P9_DEBUG_ERROR, + "On the wire dirent name too long: %s\n", + nameptr); + kfree(nameptr); + return ret; + } + kfree(nameptr); + + return fake_pdu.offset; +} +EXPORT_SYMBOL(p9dirent_read); diff --git a/net/9p/protocol.h b/net/9p/protocol.h new file mode 100644 index 000000000..ad2283d1f --- /dev/null +++ b/net/9p/protocol.h @@ -0,0 +1,19 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * 9P Protocol Support Code + * + * Copyright (C) 2008 by Eric Van Hensbergen + * + * Base on code from Anthony Liguori + * Copyright (C) 2008 by IBM, Corp. + */ + +size_t p9_msg_buf_size(struct p9_client *c, enum p9_msg_t type, + const char *fmt, va_list ap); +int p9pdu_vwritef(struct p9_fcall *pdu, int proto_version, const char *fmt, + va_list ap); +int p9pdu_readf(struct p9_fcall *pdu, int proto_version, const char *fmt, ...); +int p9pdu_prepare(struct p9_fcall *pdu, int16_t tag, int8_t type); +int p9pdu_finalize(struct p9_client *clnt, struct p9_fcall *pdu); +void p9pdu_reset(struct p9_fcall *pdu); +size_t pdu_read(struct p9_fcall *pdu, void *data, size_t size); diff --git a/net/9p/trans_common.c b/net/9p/trans_common.c new file mode 100644 index 000000000..c827f6945 --- /dev/null +++ b/net/9p/trans_common.c @@ -0,0 +1,24 @@ +// SPDX-License-Identifier: LGPL-2.1 +/* + * Copyright IBM Corporation, 2010 + * Author Venkateswararao Jujjuri + */ + +#include +#include +#include "trans_common.h" + +/** + * p9_release_pages - Release pages after the transaction. + * @pages: array of pages to be put + * @nr_pages: size of array + */ +void p9_release_pages(struct page **pages, int nr_pages) +{ + int i; + + for (i = 0; i < nr_pages; i++) + if (pages[i]) + put_page(pages[i]); +} +EXPORT_SYMBOL(p9_release_pages); diff --git a/net/9p/trans_common.h b/net/9p/trans_common.h new file mode 100644 index 000000000..32134db6a --- /dev/null +++ b/net/9p/trans_common.h @@ -0,0 +1,7 @@ +/* SPDX-License-Identifier: LGPL-2.1 */ +/* + * Copyright IBM Corporation, 2010 + * Author Venkateswararao Jujjuri + */ + +void p9_release_pages(struct page **pages, int nr_pages); diff --git a/net/9p/trans_fd.c b/net/9p/trans_fd.c new file mode 100644 index 000000000..eb685b52a --- /dev/null +++ b/net/9p/trans_fd.c @@ -0,0 +1,1093 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Fd transport layer. Includes deprecated socket layer. + * + * Copyright (C) 2006 by Russ Cox + * Copyright (C) 2004-2005 by Latchesar Ionkov + * Copyright (C) 2004-2008 by Eric Van Hensbergen + * Copyright (C) 1997-2002 by Ron Minnich + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include /* killme */ + +#define MAX_SOCK_BUF (1024*1024) +#define MAXPOLLWADDR 2 + +static struct p9_trans_module p9_tcp_trans; +static struct p9_trans_module p9_fd_trans; + +enum { + Rworksched = 1, /* read work scheduled or running */ + Rpending = 2, /* can read */ + Wworksched = 4, /* write work scheduled or running */ + Wpending = 8, /* can write */ +}; + +struct p9_poll_wait { + struct p9_conn *conn; + wait_queue_entry_t wait; + wait_queue_head_t *wait_addr; +}; + +/** + * struct p9_conn - fd mux connection state information + * @mux_list: list link for mux to manage multiple connections (?) + * @client: reference to client instance for this connection + * @err: error state + * @req_lock: lock protecting req_list and requests statuses + * @req_list: accounting for requests which have been sent + * @unsent_req_list: accounting for requests that haven't been sent + * @rreq: read request + * @wreq: write request + * @tmp_buf: temporary buffer to read in header + * @rc: temporary fcall for reading current frame + * @wpos: write position for current frame + * @wsize: amount of data to write for current frame + * @wbuf: current write buffer + * @poll_pending_link: pending links to be polled per conn + * @poll_wait: array of wait_q's for various worker threads + * @pt: poll state + * @rq: current read work + * @wq: current write work + * @wsched: ???? + * + */ + +struct p9_conn { + struct list_head mux_list; + struct p9_client *client; + int err; + spinlock_t req_lock; + struct list_head req_list; + struct list_head unsent_req_list; + struct p9_req_t *rreq; + struct p9_req_t *wreq; + char tmp_buf[P9_HDRSZ]; + struct p9_fcall rc; + int wpos; + int wsize; + char *wbuf; + struct list_head poll_pending_link; + struct p9_poll_wait poll_wait[MAXPOLLWADDR]; + poll_table pt; + struct work_struct rq; + struct work_struct wq; + unsigned long wsched; +}; + +/** + * struct p9_trans_fd - transport state + * @rd: reference to file to read from + * @wr: reference of file to write to + * @conn: connection state reference + * + */ + +struct p9_trans_fd { + struct file *rd; + struct file *wr; + struct p9_conn conn; +}; + +static void p9_poll_workfn(struct work_struct *work); + +static DEFINE_SPINLOCK(p9_poll_lock); +static LIST_HEAD(p9_poll_pending_list); +static DECLARE_WORK(p9_poll_work, p9_poll_workfn); + +static unsigned int p9_ipport_resv_min = P9_DEF_MIN_RESVPORT; +static unsigned int p9_ipport_resv_max = P9_DEF_MAX_RESVPORT; + +static void p9_mux_poll_stop(struct p9_conn *m) +{ + unsigned long flags; + int i; + + for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) { + struct p9_poll_wait *pwait = &m->poll_wait[i]; + + if (pwait->wait_addr) { + remove_wait_queue(pwait->wait_addr, &pwait->wait); + pwait->wait_addr = NULL; + } + } + + spin_lock_irqsave(&p9_poll_lock, flags); + list_del_init(&m->poll_pending_link); + spin_unlock_irqrestore(&p9_poll_lock, flags); + + flush_work(&p9_poll_work); +} + +/** + * p9_conn_cancel - cancel all pending requests with error + * @m: mux data + * @err: error code + * + */ + +static void p9_conn_cancel(struct p9_conn *m, int err) +{ + struct p9_req_t *req, *rtmp; + LIST_HEAD(cancel_list); + + p9_debug(P9_DEBUG_ERROR, "mux %p err %d\n", m, err); + + spin_lock(&m->req_lock); + + if (READ_ONCE(m->err)) { + spin_unlock(&m->req_lock); + return; + } + + WRITE_ONCE(m->err, err); + ASSERT_EXCLUSIVE_WRITER(m->err); + + list_for_each_entry_safe(req, rtmp, &m->req_list, req_list) { + list_move(&req->req_list, &cancel_list); + WRITE_ONCE(req->status, REQ_STATUS_ERROR); + } + list_for_each_entry_safe(req, rtmp, &m->unsent_req_list, req_list) { + list_move(&req->req_list, &cancel_list); + WRITE_ONCE(req->status, REQ_STATUS_ERROR); + } + + spin_unlock(&m->req_lock); + + list_for_each_entry_safe(req, rtmp, &cancel_list, req_list) { + p9_debug(P9_DEBUG_ERROR, "call back req %p\n", req); + list_del(&req->req_list); + if (!req->t_err) + req->t_err = err; + p9_client_cb(m->client, req, REQ_STATUS_ERROR); + } +} + +static __poll_t +p9_fd_poll(struct p9_client *client, struct poll_table_struct *pt, int *err) +{ + __poll_t ret; + struct p9_trans_fd *ts = NULL; + + if (client && client->status == Connected) + ts = client->trans; + + if (!ts) { + if (err) + *err = -EREMOTEIO; + return EPOLLERR; + } + + ret = vfs_poll(ts->rd, pt); + if (ts->rd != ts->wr) + ret = (ret & ~EPOLLOUT) | (vfs_poll(ts->wr, pt) & ~EPOLLIN); + return ret; +} + +/** + * p9_fd_read- read from a fd + * @client: client instance + * @v: buffer to receive data into + * @len: size of receive buffer + * + */ + +static int p9_fd_read(struct p9_client *client, void *v, int len) +{ + int ret; + struct p9_trans_fd *ts = NULL; + loff_t pos; + + if (client && client->status != Disconnected) + ts = client->trans; + + if (!ts) + return -EREMOTEIO; + + if (!(ts->rd->f_flags & O_NONBLOCK)) + p9_debug(P9_DEBUG_ERROR, "blocking read ...\n"); + + pos = ts->rd->f_pos; + ret = kernel_read(ts->rd, v, len, &pos); + if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN) + client->status = Disconnected; + return ret; +} + +/** + * p9_read_work - called when there is some data to be read from a transport + * @work: container of work to be done + * + */ + +static void p9_read_work(struct work_struct *work) +{ + __poll_t n; + int err; + struct p9_conn *m; + + m = container_of(work, struct p9_conn, rq); + + if (READ_ONCE(m->err) < 0) + return; + + p9_debug(P9_DEBUG_TRANS, "start mux %p pos %zd\n", m, m->rc.offset); + + if (!m->rc.sdata) { + m->rc.sdata = m->tmp_buf; + m->rc.offset = 0; + m->rc.capacity = P9_HDRSZ; /* start by reading header */ + } + + clear_bit(Rpending, &m->wsched); + p9_debug(P9_DEBUG_TRANS, "read mux %p pos %zd size: %zd = %zd\n", + m, m->rc.offset, m->rc.capacity, + m->rc.capacity - m->rc.offset); + err = p9_fd_read(m->client, m->rc.sdata + m->rc.offset, + m->rc.capacity - m->rc.offset); + p9_debug(P9_DEBUG_TRANS, "mux %p got %d bytes\n", m, err); + if (err == -EAGAIN) + goto end_clear; + + if (err <= 0) + goto error; + + m->rc.offset += err; + + /* header read in */ + if ((!m->rreq) && (m->rc.offset == m->rc.capacity)) { + p9_debug(P9_DEBUG_TRANS, "got new header\n"); + + /* Header size */ + m->rc.size = P9_HDRSZ; + err = p9_parse_header(&m->rc, &m->rc.size, NULL, NULL, 0); + if (err) { + p9_debug(P9_DEBUG_ERROR, + "error parsing header: %d\n", err); + goto error; + } + + p9_debug(P9_DEBUG_TRANS, + "mux %p pkt: size: %d bytes tag: %d\n", + m, m->rc.size, m->rc.tag); + + m->rreq = p9_tag_lookup(m->client, m->rc.tag); + if (!m->rreq || (m->rreq->status != REQ_STATUS_SENT)) { + p9_debug(P9_DEBUG_ERROR, "Unexpected packet tag %d\n", + m->rc.tag); + err = -EIO; + goto error; + } + + if (m->rc.size > m->rreq->rc.capacity) { + p9_debug(P9_DEBUG_ERROR, + "requested packet size too big: %d for tag %d with capacity %zd\n", + m->rc.size, m->rc.tag, m->rreq->rc.capacity); + err = -EIO; + goto error; + } + + if (!m->rreq->rc.sdata) { + p9_debug(P9_DEBUG_ERROR, + "No recv fcall for tag %d (req %p), disconnecting!\n", + m->rc.tag, m->rreq); + p9_req_put(m->client, m->rreq); + m->rreq = NULL; + err = -EIO; + goto error; + } + m->rc.sdata = m->rreq->rc.sdata; + memcpy(m->rc.sdata, m->tmp_buf, m->rc.capacity); + m->rc.capacity = m->rc.size; + } + + /* packet is read in + * not an else because some packets (like clunk) have no payload + */ + if ((m->rreq) && (m->rc.offset == m->rc.capacity)) { + p9_debug(P9_DEBUG_TRANS, "got new packet\n"); + m->rreq->rc.size = m->rc.offset; + spin_lock(&m->req_lock); + if (m->rreq->status == REQ_STATUS_SENT) { + list_del(&m->rreq->req_list); + p9_client_cb(m->client, m->rreq, REQ_STATUS_RCVD); + } else if (m->rreq->status == REQ_STATUS_FLSHD) { + /* Ignore replies associated with a cancelled request. */ + p9_debug(P9_DEBUG_TRANS, + "Ignore replies associated with a cancelled request\n"); + } else { + spin_unlock(&m->req_lock); + p9_debug(P9_DEBUG_ERROR, + "Request tag %d errored out while we were reading the reply\n", + m->rc.tag); + err = -EIO; + goto error; + } + spin_unlock(&m->req_lock); + m->rc.sdata = NULL; + m->rc.offset = 0; + m->rc.capacity = 0; + p9_req_put(m->client, m->rreq); + m->rreq = NULL; + } + +end_clear: + clear_bit(Rworksched, &m->wsched); + + if (!list_empty(&m->req_list)) { + if (test_and_clear_bit(Rpending, &m->wsched)) + n = EPOLLIN; + else + n = p9_fd_poll(m->client, NULL, NULL); + + if ((n & EPOLLIN) && !test_and_set_bit(Rworksched, &m->wsched)) { + p9_debug(P9_DEBUG_TRANS, "sched read work %p\n", m); + schedule_work(&m->rq); + } + } + + return; +error: + p9_conn_cancel(m, err); + clear_bit(Rworksched, &m->wsched); +} + +/** + * p9_fd_write - write to a socket + * @client: client instance + * @v: buffer to send data from + * @len: size of send buffer + * + */ + +static int p9_fd_write(struct p9_client *client, void *v, int len) +{ + ssize_t ret; + struct p9_trans_fd *ts = NULL; + + if (client && client->status != Disconnected) + ts = client->trans; + + if (!ts) + return -EREMOTEIO; + + if (!(ts->wr->f_flags & O_NONBLOCK)) + p9_debug(P9_DEBUG_ERROR, "blocking write ...\n"); + + ret = kernel_write(ts->wr, v, len, &ts->wr->f_pos); + if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN) + client->status = Disconnected; + return ret; +} + +/** + * p9_write_work - called when a transport can send some data + * @work: container for work to be done + * + */ + +static void p9_write_work(struct work_struct *work) +{ + __poll_t n; + int err; + struct p9_conn *m; + struct p9_req_t *req; + + m = container_of(work, struct p9_conn, wq); + + if (READ_ONCE(m->err) < 0) { + clear_bit(Wworksched, &m->wsched); + return; + } + + if (!m->wsize) { + spin_lock(&m->req_lock); + if (list_empty(&m->unsent_req_list)) { + clear_bit(Wworksched, &m->wsched); + spin_unlock(&m->req_lock); + return; + } + + req = list_entry(m->unsent_req_list.next, struct p9_req_t, + req_list); + WRITE_ONCE(req->status, REQ_STATUS_SENT); + p9_debug(P9_DEBUG_TRANS, "move req %p\n", req); + list_move_tail(&req->req_list, &m->req_list); + + m->wbuf = req->tc.sdata; + m->wsize = req->tc.size; + m->wpos = 0; + p9_req_get(req); + m->wreq = req; + spin_unlock(&m->req_lock); + } + + p9_debug(P9_DEBUG_TRANS, "mux %p pos %d size %d\n", + m, m->wpos, m->wsize); + clear_bit(Wpending, &m->wsched); + err = p9_fd_write(m->client, m->wbuf + m->wpos, m->wsize - m->wpos); + p9_debug(P9_DEBUG_TRANS, "mux %p sent %d bytes\n", m, err); + if (err == -EAGAIN) + goto end_clear; + + + if (err < 0) + goto error; + else if (err == 0) { + err = -EREMOTEIO; + goto error; + } + + m->wpos += err; + if (m->wpos == m->wsize) { + m->wpos = m->wsize = 0; + p9_req_put(m->client, m->wreq); + m->wreq = NULL; + } + +end_clear: + clear_bit(Wworksched, &m->wsched); + + if (m->wsize || !list_empty(&m->unsent_req_list)) { + if (test_and_clear_bit(Wpending, &m->wsched)) + n = EPOLLOUT; + else + n = p9_fd_poll(m->client, NULL, NULL); + + if ((n & EPOLLOUT) && + !test_and_set_bit(Wworksched, &m->wsched)) { + p9_debug(P9_DEBUG_TRANS, "sched write work %p\n", m); + schedule_work(&m->wq); + } + } + + return; + +error: + p9_conn_cancel(m, err); + clear_bit(Wworksched, &m->wsched); +} + +static int p9_pollwake(wait_queue_entry_t *wait, unsigned int mode, int sync, void *key) +{ + struct p9_poll_wait *pwait = + container_of(wait, struct p9_poll_wait, wait); + struct p9_conn *m = pwait->conn; + unsigned long flags; + + spin_lock_irqsave(&p9_poll_lock, flags); + if (list_empty(&m->poll_pending_link)) + list_add_tail(&m->poll_pending_link, &p9_poll_pending_list); + spin_unlock_irqrestore(&p9_poll_lock, flags); + + schedule_work(&p9_poll_work); + return 1; +} + +/** + * p9_pollwait - add poll task to the wait queue + * @filp: file pointer being polled + * @wait_address: wait_q to block on + * @p: poll state + * + * called by files poll operation to add v9fs-poll task to files wait queue + */ + +static void +p9_pollwait(struct file *filp, wait_queue_head_t *wait_address, poll_table *p) +{ + struct p9_conn *m = container_of(p, struct p9_conn, pt); + struct p9_poll_wait *pwait = NULL; + int i; + + for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) { + if (m->poll_wait[i].wait_addr == NULL) { + pwait = &m->poll_wait[i]; + break; + } + } + + if (!pwait) { + p9_debug(P9_DEBUG_ERROR, "not enough wait_address slots\n"); + return; + } + + pwait->conn = m; + pwait->wait_addr = wait_address; + init_waitqueue_func_entry(&pwait->wait, p9_pollwake); + add_wait_queue(wait_address, &pwait->wait); +} + +/** + * p9_conn_create - initialize the per-session mux data + * @client: client instance + * + * Note: Creates the polling task if this is the first session. + */ + +static void p9_conn_create(struct p9_client *client) +{ + __poll_t n; + struct p9_trans_fd *ts = client->trans; + struct p9_conn *m = &ts->conn; + + p9_debug(P9_DEBUG_TRANS, "client %p msize %d\n", client, client->msize); + + INIT_LIST_HEAD(&m->mux_list); + m->client = client; + + spin_lock_init(&m->req_lock); + INIT_LIST_HEAD(&m->req_list); + INIT_LIST_HEAD(&m->unsent_req_list); + INIT_WORK(&m->rq, p9_read_work); + INIT_WORK(&m->wq, p9_write_work); + INIT_LIST_HEAD(&m->poll_pending_link); + init_poll_funcptr(&m->pt, p9_pollwait); + + n = p9_fd_poll(client, &m->pt, NULL); + if (n & EPOLLIN) { + p9_debug(P9_DEBUG_TRANS, "mux %p can read\n", m); + set_bit(Rpending, &m->wsched); + } + + if (n & EPOLLOUT) { + p9_debug(P9_DEBUG_TRANS, "mux %p can write\n", m); + set_bit(Wpending, &m->wsched); + } +} + +/** + * p9_poll_mux - polls a mux and schedules read or write works if necessary + * @m: connection to poll + * + */ + +static void p9_poll_mux(struct p9_conn *m) +{ + __poll_t n; + int err = -ECONNRESET; + + if (READ_ONCE(m->err) < 0) + return; + + n = p9_fd_poll(m->client, NULL, &err); + if (n & (EPOLLERR | EPOLLHUP | EPOLLNVAL)) { + p9_debug(P9_DEBUG_TRANS, "error mux %p err %d\n", m, n); + p9_conn_cancel(m, err); + } + + if (n & EPOLLIN) { + set_bit(Rpending, &m->wsched); + p9_debug(P9_DEBUG_TRANS, "mux %p can read\n", m); + if (!test_and_set_bit(Rworksched, &m->wsched)) { + p9_debug(P9_DEBUG_TRANS, "sched read work %p\n", m); + schedule_work(&m->rq); + } + } + + if (n & EPOLLOUT) { + set_bit(Wpending, &m->wsched); + p9_debug(P9_DEBUG_TRANS, "mux %p can write\n", m); + if ((m->wsize || !list_empty(&m->unsent_req_list)) && + !test_and_set_bit(Wworksched, &m->wsched)) { + p9_debug(P9_DEBUG_TRANS, "sched write work %p\n", m); + schedule_work(&m->wq); + } + } +} + +/** + * p9_fd_request - send 9P request + * The function can sleep until the request is scheduled for sending. + * The function can be interrupted. Return from the function is not + * a guarantee that the request is sent successfully. + * + * @client: client instance + * @req: request to be sent + * + */ + +static int p9_fd_request(struct p9_client *client, struct p9_req_t *req) +{ + int err; + struct p9_trans_fd *ts = client->trans; + struct p9_conn *m = &ts->conn; + + p9_debug(P9_DEBUG_TRANS, "mux %p task %p tcall %p id %d\n", + m, current, &req->tc, req->tc.id); + + spin_lock(&m->req_lock); + + err = READ_ONCE(m->err); + if (err < 0) { + spin_unlock(&m->req_lock); + return err; + } + + WRITE_ONCE(req->status, REQ_STATUS_UNSENT); + list_add_tail(&req->req_list, &m->unsent_req_list); + spin_unlock(&m->req_lock); + + p9_poll_mux(m); + + return 0; +} + +static int p9_fd_cancel(struct p9_client *client, struct p9_req_t *req) +{ + struct p9_trans_fd *ts = client->trans; + struct p9_conn *m = &ts->conn; + int ret = 1; + + p9_debug(P9_DEBUG_TRANS, "client %p req %p\n", client, req); + + spin_lock(&m->req_lock); + + if (req->status == REQ_STATUS_UNSENT) { + list_del(&req->req_list); + WRITE_ONCE(req->status, REQ_STATUS_FLSHD); + p9_req_put(client, req); + ret = 0; + } + spin_unlock(&m->req_lock); + + return ret; +} + +static int p9_fd_cancelled(struct p9_client *client, struct p9_req_t *req) +{ + struct p9_trans_fd *ts = client->trans; + struct p9_conn *m = &ts->conn; + + p9_debug(P9_DEBUG_TRANS, "client %p req %p\n", client, req); + + spin_lock(&m->req_lock); + /* Ignore cancelled request if status changed since the request was + * processed in p9_client_flush() + */ + if (req->status != REQ_STATUS_SENT) { + spin_unlock(&m->req_lock); + return 0; + } + + /* we haven't received a response for oldreq, + * remove it from the list. + */ + list_del(&req->req_list); + WRITE_ONCE(req->status, REQ_STATUS_FLSHD); + spin_unlock(&m->req_lock); + + p9_req_put(client, req); + + return 0; +} + +static int p9_fd_show_options(struct seq_file *m, struct p9_client *clnt) +{ + if (clnt->trans_mod == &p9_tcp_trans) { + if (clnt->trans_opts.tcp.port != P9_FD_PORT) + seq_printf(m, ",port=%u", clnt->trans_opts.tcp.port); + } else if (clnt->trans_mod == &p9_fd_trans) { + if (clnt->trans_opts.fd.rfd != ~0) + seq_printf(m, ",rfd=%u", clnt->trans_opts.fd.rfd); + if (clnt->trans_opts.fd.wfd != ~0) + seq_printf(m, ",wfd=%u", clnt->trans_opts.fd.wfd); + } + return 0; +} + +static int p9_fd_open(struct p9_client *client, int rfd, int wfd) +{ + struct p9_trans_fd *ts = kzalloc_obj(struct p9_trans_fd); + if (!ts) + return -ENOMEM; + + ts->rd = fget(rfd); + if (!ts->rd) + goto out_free_ts; + if (!(ts->rd->f_mode & FMODE_READ)) + goto out_put_rd; + /* Prevent workers from hanging on IO when fd is a pipe. + * It's technically possible for userspace or concurrent mounts to + * modify this flag concurrently, which will likely result in a + * broken filesystem. However, just having bad flags here should + * not crash the kernel or cause any other sort of bug, so mark this + * particular data race as intentional so that tooling (like KCSAN) + * can allow it and detect further problems. + */ + data_race(ts->rd->f_flags |= O_NONBLOCK); + ts->wr = fget(wfd); + if (!ts->wr) + goto out_put_rd; + if (!(ts->wr->f_mode & FMODE_WRITE)) + goto out_put_wr; + data_race(ts->wr->f_flags |= O_NONBLOCK); + + client->trans = ts; + client->status = Connected; + + return 0; + +out_put_wr: + fput(ts->wr); +out_put_rd: + fput(ts->rd); +out_free_ts: + kfree(ts); + return -EIO; +} + +static int p9_socket_open(struct p9_client *client, struct socket *csocket) +{ + struct p9_trans_fd *p; + struct file *file; + + p = kzalloc_obj(struct p9_trans_fd); + if (!p) { + sock_release(csocket); + return -ENOMEM; + } + + csocket->sk->sk_allocation = GFP_NOIO; + csocket->sk->sk_use_task_frag = false; + file = sock_alloc_file(csocket, 0, NULL); + if (IS_ERR(file)) { + pr_err("%s (%d): failed to map fd\n", + __func__, task_pid_nr(current)); + kfree(p); + return PTR_ERR(file); + } + + get_file(file); + p->wr = p->rd = file; + client->trans = p; + client->status = Connected; + + p->rd->f_flags |= O_NONBLOCK; + + p9_conn_create(client); + return 0; +} + +/** + * p9_conn_destroy - cancels all pending requests of mux + * @m: mux to destroy + * + */ + +static void p9_conn_destroy(struct p9_conn *m) +{ + p9_debug(P9_DEBUG_TRANS, "mux %p prev %p next %p\n", + m, m->mux_list.prev, m->mux_list.next); + + p9_mux_poll_stop(m); + cancel_work_sync(&m->rq); + if (m->rreq) { + p9_req_put(m->client, m->rreq); + m->rreq = NULL; + } + cancel_work_sync(&m->wq); + if (m->wreq) { + p9_req_put(m->client, m->wreq); + m->wreq = NULL; + } + + p9_conn_cancel(m, -ECONNRESET); + + m->client = NULL; +} + +/** + * p9_fd_close - shutdown file descriptor transport + * @client: client instance + * + */ + +static void p9_fd_close(struct p9_client *client) +{ + struct p9_trans_fd *ts; + + if (!client) + return; + + ts = client->trans; + if (!ts) + return; + + client->status = Disconnected; + + p9_conn_destroy(&ts->conn); + + if (ts->rd) + fput(ts->rd); + if (ts->wr) + fput(ts->wr); + + kfree(ts); +} + +static int p9_bind_privport(struct socket *sock) +{ + struct sockaddr_storage stor = { 0 }; + int port, err = -EINVAL; + + stor.ss_family = sock->ops->family; + if (stor.ss_family == AF_INET) + ((struct sockaddr_in *)&stor)->sin_addr.s_addr = htonl(INADDR_ANY); + else + ((struct sockaddr_in6 *)&stor)->sin6_addr = in6addr_any; + for (port = p9_ipport_resv_max; port >= p9_ipport_resv_min; port--) { + if (stor.ss_family == AF_INET) + ((struct sockaddr_in *)&stor)->sin_port = htons((ushort)port); + else + ((struct sockaddr_in6 *)&stor)->sin6_port = htons((ushort)port); + err = kernel_bind(sock, (struct sockaddr_unsized *)&stor, sizeof(stor)); + if (err != -EADDRINUSE) + break; + } + return err; +} + +static int +p9_fd_create_tcp(struct p9_client *client, struct fs_context *fc) +{ + const char *addr = fc->source; + struct v9fs_context *ctx = fc->fs_private; + int err; + char port_str[6]; + struct socket *csocket; + struct sockaddr_storage stor = { 0 }; + struct p9_fd_opts opts; + + /* opts are already parsed in context */ + opts = ctx->fd_opts; + + if (!addr) + return -EINVAL; + + sprintf(port_str, "%u", opts.port); + err = inet_pton_with_scope(current->nsproxy->net_ns, AF_UNSPEC, addr, + port_str, &stor); + if (err < 0) + return err; + + csocket = NULL; + + client->trans_opts.tcp.port = opts.port; + client->trans_opts.tcp.privport = opts.privport; + err = __sock_create(current->nsproxy->net_ns, stor.ss_family, + SOCK_STREAM, IPPROTO_TCP, &csocket, 1); + if (err) { + pr_err("%s (%d): problem creating socket\n", + __func__, task_pid_nr(current)); + return err; + } + + if (opts.privport) { + err = p9_bind_privport(csocket); + if (err < 0) { + pr_err("%s (%d): problem binding to privport\n", + __func__, task_pid_nr(current)); + sock_release(csocket); + return err; + } + } + + err = READ_ONCE(csocket->ops)->connect(csocket, + (struct sockaddr_unsized *)&stor, + sizeof(stor), 0); + if (err < 0) { + pr_err("%s (%d): problem connecting socket to %s\n", + __func__, task_pid_nr(current), addr); + sock_release(csocket); + return err; + } + + return p9_socket_open(client, csocket); +} + +static int +p9_fd_create_unix(struct p9_client *client, struct fs_context *fc) +{ + const char *addr = fc->source; + int err; + struct socket *csocket; + struct sockaddr_un sun_server; + + csocket = NULL; + + if (!addr || !strlen(addr)) + return -EINVAL; + + sun_server.sun_family = PF_UNIX; + if (strscpy(sun_server.sun_path, addr) < 0) { + pr_err("%s (%d): address too long: %s\n", + __func__, task_pid_nr(current), addr); + return -ENAMETOOLONG; + } + err = __sock_create(current->nsproxy->net_ns, PF_UNIX, + SOCK_STREAM, 0, &csocket, 1); + if (err < 0) { + pr_err("%s (%d): problem creating socket\n", + __func__, task_pid_nr(current)); + + return err; + } + err = READ_ONCE(csocket->ops)->connect(csocket, (struct sockaddr_unsized *)&sun_server, + sizeof(struct sockaddr_un) - 1, 0); + if (err < 0) { + pr_err("%s (%d): problem connecting socket: %s: %d\n", + __func__, task_pid_nr(current), addr, err); + sock_release(csocket); + return err; + } + + return p9_socket_open(client, csocket); +} + +static int +p9_fd_create(struct p9_client *client, struct fs_context *fc) +{ + struct v9fs_context *ctx = fc->fs_private; + struct p9_fd_opts opts = ctx->fd_opts; + int err; + + client->trans_opts.fd.rfd = opts.rfd; + client->trans_opts.fd.wfd = opts.wfd; + + if (opts.rfd == ~0 || opts.wfd == ~0) { + pr_err("Insufficient options for proto=fd\n"); + return -ENOPROTOOPT; + } + + err = p9_fd_open(client, opts.rfd, opts.wfd); + if (err < 0) + return err; + + p9_conn_create(client); + + return 0; +} + +static struct p9_trans_module p9_tcp_trans = { + .name = "tcp", + .maxsize = MAX_SOCK_BUF, + .pooled_rbuffers = false, + .def = false, + .supports_vmalloc = true, + .create = p9_fd_create_tcp, + .close = p9_fd_close, + .request = p9_fd_request, + .cancel = p9_fd_cancel, + .cancelled = p9_fd_cancelled, + .show_options = p9_fd_show_options, + .owner = THIS_MODULE, +}; +MODULE_ALIAS_9P("tcp"); + +static struct p9_trans_module p9_unix_trans = { + .name = "unix", + .maxsize = MAX_SOCK_BUF, + .def = false, + .supports_vmalloc = true, + .create = p9_fd_create_unix, + .close = p9_fd_close, + .request = p9_fd_request, + .cancel = p9_fd_cancel, + .cancelled = p9_fd_cancelled, + .show_options = p9_fd_show_options, + .owner = THIS_MODULE, +}; +MODULE_ALIAS_9P("unix"); + +static struct p9_trans_module p9_fd_trans = { + .name = "fd", + .maxsize = MAX_SOCK_BUF, + .def = false, + .supports_vmalloc = true, + .create = p9_fd_create, + .close = p9_fd_close, + .request = p9_fd_request, + .cancel = p9_fd_cancel, + .cancelled = p9_fd_cancelled, + .show_options = p9_fd_show_options, + .owner = THIS_MODULE, +}; +MODULE_ALIAS_9P("fd"); + +/** + * p9_poll_workfn - poll worker thread + * @work: work queue + * + * polls all v9fs transports for new events and queues the appropriate + * work to the work queue + * + */ + +static void p9_poll_workfn(struct work_struct *work) +{ + unsigned long flags; + + p9_debug(P9_DEBUG_TRANS, "start %p\n", current); + + spin_lock_irqsave(&p9_poll_lock, flags); + while (!list_empty(&p9_poll_pending_list)) { + struct p9_conn *conn = list_first_entry(&p9_poll_pending_list, + struct p9_conn, + poll_pending_link); + list_del_init(&conn->poll_pending_link); + spin_unlock_irqrestore(&p9_poll_lock, flags); + + p9_poll_mux(conn); + + spin_lock_irqsave(&p9_poll_lock, flags); + } + spin_unlock_irqrestore(&p9_poll_lock, flags); + + p9_debug(P9_DEBUG_TRANS, "finish\n"); +} + +static int __init p9_trans_fd_init(void) +{ + v9fs_register_trans(&p9_tcp_trans); + v9fs_register_trans(&p9_unix_trans); + v9fs_register_trans(&p9_fd_trans); + + return 0; +} + +static void __exit p9_trans_fd_exit(void) +{ + flush_work(&p9_poll_work); + v9fs_unregister_trans(&p9_tcp_trans); + v9fs_unregister_trans(&p9_unix_trans); + v9fs_unregister_trans(&p9_fd_trans); +} + +module_init(p9_trans_fd_init); +module_exit(p9_trans_fd_exit); + +MODULE_AUTHOR("Eric Van Hensbergen "); +MODULE_DESCRIPTION("Filedescriptor Transport for 9P"); +MODULE_LICENSE("GPL"); diff --git a/net/9p/trans_rdma.c b/net/9p/trans_rdma.c new file mode 100644 index 000000000..b4274f10f --- /dev/null +++ b/net/9p/trans_rdma.c @@ -0,0 +1,684 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * RDMA transport layer based on the trans_fd.c implementation. + * + * Copyright (C) 2008 by Tom Tucker + * Copyright (C) 2006 by Russ Cox + * Copyright (C) 2004-2005 by Latchesar Ionkov + * Copyright (C) 2004-2008 by Eric Van Hensbergen + * Copyright (C) 1997-2002 by Ron Minnich + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define P9_RDMA_SEND_SGE 4 +#define P9_RDMA_RECV_SGE 4 +#define P9_RDMA_IRD 0 +#define P9_RDMA_ORD 0 +#define P9_RDMA_MAXSIZE (1024*1024) /* 1MB */ + +/** + * struct p9_trans_rdma - RDMA transport instance + * + * @state: tracks the transport state machine for connection setup and tear down + * @cm_id: The RDMA CM ID + * @pd: Protection Domain pointer + * @qp: Queue Pair pointer + * @cq: Completion Queue pointer + * @timeout: Number of uSecs to wait for connection management events + * @privport: Whether a privileged port may be used + * @port: The port to use + * @sq_depth: The depth of the Send Queue + * @sq_sem: Semaphore for the SQ + * @rq_depth: The depth of the Receive Queue. + * @rq_sem: Semaphore for the RQ + * @excess_rc : Amount of posted Receive Contexts without a pending request. + * See rdma_request() + * @addr: The remote peer's address + * @req_lock: Protects the active request list + * @cm_done: Completion event for connection management tracking + */ +struct p9_trans_rdma { + enum { + P9_RDMA_INIT, + P9_RDMA_ADDR_RESOLVED, + P9_RDMA_ROUTE_RESOLVED, + P9_RDMA_CONNECTED, + P9_RDMA_FLUSHING, + P9_RDMA_CLOSING, + P9_RDMA_CLOSED, + } state; + struct rdma_cm_id *cm_id; + struct ib_pd *pd; + struct ib_qp *qp; + struct ib_cq *cq; + long timeout; + bool privport; + u16 port; + int sq_depth; + struct semaphore sq_sem; + int rq_depth; + struct semaphore rq_sem; + atomic_t excess_rc; + struct sockaddr_in addr; + spinlock_t req_lock; + + struct completion cm_done; +}; + +struct p9_rdma_req; + +/** + * struct p9_rdma_context - Keeps track of in-process WR + * + * @cqe: completion queue entry + * @busa: Bus address to unmap when the WR completes + * @req: Keeps track of requests (send) + * @rc: Keepts track of replies (receive) + */ +struct p9_rdma_context { + struct ib_cqe cqe; + dma_addr_t busa; + union { + struct p9_req_t *req; + struct p9_fcall rc; + }; +}; + +static int p9_rdma_show_options(struct seq_file *m, struct p9_client *clnt) +{ + struct p9_trans_rdma *rdma = clnt->trans; + + if (rdma->port != P9_RDMA_PORT) + seq_printf(m, ",port=%u", rdma->port); + if (rdma->sq_depth != P9_RDMA_SQ_DEPTH) + seq_printf(m, ",sq=%u", rdma->sq_depth); + if (rdma->rq_depth != P9_RDMA_RQ_DEPTH) + seq_printf(m, ",rq=%u", rdma->rq_depth); + if (rdma->timeout != P9_RDMA_TIMEOUT) + seq_printf(m, ",timeout=%lu", rdma->timeout); + if (rdma->privport) + seq_puts(m, ",privport"); + return 0; +} + +static int +p9_cm_event_handler(struct rdma_cm_id *id, struct rdma_cm_event *event) +{ + struct p9_client *c = id->context; + struct p9_trans_rdma *rdma = c->trans; + unsigned long flags; + + switch (event->event) { + case RDMA_CM_EVENT_ADDR_RESOLVED: + spin_lock_irqsave(&rdma->req_lock, flags); + BUG_ON(rdma->state != P9_RDMA_INIT); + rdma->state = P9_RDMA_ADDR_RESOLVED; + spin_unlock_irqrestore(&rdma->req_lock, flags); + break; + + case RDMA_CM_EVENT_ROUTE_RESOLVED: + spin_lock_irqsave(&rdma->req_lock, flags); + BUG_ON(rdma->state != P9_RDMA_ADDR_RESOLVED); + rdma->state = P9_RDMA_ROUTE_RESOLVED; + spin_unlock_irqrestore(&rdma->req_lock, flags); + break; + + case RDMA_CM_EVENT_ESTABLISHED: + spin_lock_irqsave(&rdma->req_lock, flags); + BUG_ON(rdma->state != P9_RDMA_ROUTE_RESOLVED); + rdma->state = P9_RDMA_CONNECTED; + spin_unlock_irqrestore(&rdma->req_lock, flags); + break; + + case RDMA_CM_EVENT_DISCONNECTED: + if (rdma) { + spin_lock_irqsave(&rdma->req_lock, flags); + rdma->state = P9_RDMA_CLOSED; + spin_unlock_irqrestore(&rdma->req_lock, flags); + } + c->status = Disconnected; + break; + + case RDMA_CM_EVENT_TIMEWAIT_EXIT: + break; + + case RDMA_CM_EVENT_ADDR_CHANGE: + case RDMA_CM_EVENT_ROUTE_ERROR: + case RDMA_CM_EVENT_DEVICE_REMOVAL: + case RDMA_CM_EVENT_MULTICAST_JOIN: + case RDMA_CM_EVENT_MULTICAST_ERROR: + case RDMA_CM_EVENT_REJECTED: + case RDMA_CM_EVENT_CONNECT_REQUEST: + case RDMA_CM_EVENT_CONNECT_RESPONSE: + case RDMA_CM_EVENT_CONNECT_ERROR: + case RDMA_CM_EVENT_ADDR_ERROR: + case RDMA_CM_EVENT_UNREACHABLE: + c->status = Disconnected; + rdma_disconnect(rdma->cm_id); + break; + default: + BUG(); + } + complete(&rdma->cm_done); + return 0; +} + +static void +recv_done(struct ib_cq *cq, struct ib_wc *wc) +{ + struct p9_client *client = cq->cq_context; + struct p9_trans_rdma *rdma = client->trans; + struct p9_rdma_context *c = + container_of(wc->wr_cqe, struct p9_rdma_context, cqe); + struct p9_req_t *req; + int err = 0; + int16_t tag; + unsigned long flags; + + req = NULL; + ib_dma_unmap_single(rdma->cm_id->device, c->busa, client->msize, + DMA_FROM_DEVICE); + + if (wc->status != IB_WC_SUCCESS) + goto err_out; + + c->rc.size = wc->byte_len; + err = p9_parse_header(&c->rc, NULL, NULL, &tag, 1); + if (err) + goto err_out; + + req = p9_tag_lookup(client, tag); + if (!req) + goto err_out; + + /* Check that we have not yet received a reply for this request. + */ + if (unlikely(req->rc.sdata)) { + pr_err("Duplicate reply for request %d", tag); + goto err_out; + } + + req->rc.size = c->rc.size; + req->rc.sdata = c->rc.sdata; + p9_client_cb(client, req, REQ_STATUS_RCVD); + + out: + up(&rdma->rq_sem); + kfree(c); + return; + + err_out: + p9_debug(P9_DEBUG_ERROR, "req %p err %d status %d\n", + req, err, wc->status); + spin_lock_irqsave(&rdma->req_lock, flags); + if (rdma->state < P9_RDMA_FLUSHING) + rdma->state = P9_RDMA_FLUSHING; + spin_unlock_irqrestore(&rdma->req_lock, flags); + client->status = Disconnected; + goto out; +} + +static void +send_done(struct ib_cq *cq, struct ib_wc *wc) +{ + struct p9_client *client = cq->cq_context; + struct p9_trans_rdma *rdma = client->trans; + struct p9_rdma_context *c = + container_of(wc->wr_cqe, struct p9_rdma_context, cqe); + + ib_dma_unmap_single(rdma->cm_id->device, + c->busa, c->req->tc.size, + DMA_TO_DEVICE); + up(&rdma->sq_sem); + p9_req_put(client, c->req); + kfree(c); +} + +static void qp_event_handler(struct ib_event *event, void *context) +{ + p9_debug(P9_DEBUG_ERROR, "QP event %d context %p\n", + event->event, context); +} + +static void rdma_destroy_trans(struct p9_trans_rdma *rdma) +{ + if (!rdma) + return; + + if (rdma->qp && !IS_ERR(rdma->qp)) + ib_destroy_qp(rdma->qp); + + if (rdma->pd && !IS_ERR(rdma->pd)) + ib_dealloc_pd(rdma->pd); + + if (rdma->cq && !IS_ERR(rdma->cq)) + ib_free_cq(rdma->cq); + + if (rdma->cm_id && !IS_ERR(rdma->cm_id)) + rdma_destroy_id(rdma->cm_id); + + kfree(rdma); +} + +static int +post_recv(struct p9_client *client, struct p9_rdma_context *c) +{ + struct p9_trans_rdma *rdma = client->trans; + struct ib_recv_wr wr; + struct ib_sge sge; + int ret; + + c->busa = ib_dma_map_single(rdma->cm_id->device, + c->rc.sdata, client->msize, + DMA_FROM_DEVICE); + if (ib_dma_mapping_error(rdma->cm_id->device, c->busa)) + goto error; + + c->cqe.done = recv_done; + + sge.addr = c->busa; + sge.length = client->msize; + sge.lkey = rdma->pd->local_dma_lkey; + + wr.next = NULL; + wr.wr_cqe = &c->cqe; + wr.sg_list = &sge; + wr.num_sge = 1; + + ret = ib_post_recv(rdma->qp, &wr, NULL); + if (ret) + ib_dma_unmap_single(rdma->cm_id->device, c->busa, + client->msize, DMA_FROM_DEVICE); + return ret; + + error: + p9_debug(P9_DEBUG_ERROR, "EIO\n"); + return -EIO; +} + +static int rdma_request(struct p9_client *client, struct p9_req_t *req) +{ + struct p9_trans_rdma *rdma = client->trans; + struct ib_send_wr wr; + struct ib_sge sge; + int err = 0; + unsigned long flags; + struct p9_rdma_context *c = NULL; + struct p9_rdma_context *rpl_context = NULL; + + /* When an error occurs between posting the recv and the send, + * there will be a receive context posted without a pending request. + * Since there is no way to "un-post" it, we remember it and skip + * post_recv() for the next request. + * So here, + * see if we are this `next request' and need to absorb an excess rc. + * If yes, then drop and free our own, and do not recv_post(). + **/ + if (unlikely(atomic_read(&rdma->excess_rc) > 0)) { + if ((atomic_sub_return(1, &rdma->excess_rc) >= 0)) { + /* Got one! */ + p9_fcall_fini(&req->rc); + req->rc.sdata = NULL; + goto dont_need_post_recv; + } else { + /* We raced and lost. */ + atomic_inc(&rdma->excess_rc); + } + } + + /* Allocate an fcall for the reply */ + rpl_context = kmalloc_obj(*rpl_context, GFP_NOFS); + if (!rpl_context) { + err = -ENOMEM; + goto recv_error; + } + rpl_context->rc.sdata = req->rc.sdata; + + /* + * Post a receive buffer for this request. We need to ensure + * there is a reply buffer available for every outstanding + * request. A flushed request can result in no reply for an + * outstanding request, so we must keep a count to avoid + * overflowing the RQ. + */ + if (down_interruptible(&rdma->rq_sem)) { + err = -EINTR; + goto recv_error; + } + + err = post_recv(client, rpl_context); + if (err) { + p9_debug(P9_DEBUG_ERROR, "POST RECV failed: %d\n", err); + goto recv_error; + } + /* remove posted receive buffer from request structure */ + req->rc.sdata = NULL; + +dont_need_post_recv: + /* Post the request */ + c = kmalloc_obj(*c, GFP_NOFS); + if (!c) { + err = -ENOMEM; + goto send_error; + } + c->req = req; + + c->busa = ib_dma_map_single(rdma->cm_id->device, + c->req->tc.sdata, c->req->tc.size, + DMA_TO_DEVICE); + if (ib_dma_mapping_error(rdma->cm_id->device, c->busa)) { + err = -EIO; + goto send_error; + } + + c->cqe.done = send_done; + + sge.addr = c->busa; + sge.length = c->req->tc.size; + sge.lkey = rdma->pd->local_dma_lkey; + + wr.next = NULL; + wr.wr_cqe = &c->cqe; + wr.opcode = IB_WR_SEND; + wr.send_flags = IB_SEND_SIGNALED; + wr.sg_list = &sge; + wr.num_sge = 1; + + if (down_interruptible(&rdma->sq_sem)) { + err = -EINTR; + goto dma_unmap; + } + + /* Mark request as `sent' *before* we actually send it, + * because doing if after could erase the REQ_STATUS_RCVD + * status in case of a very fast reply. + */ + WRITE_ONCE(req->status, REQ_STATUS_SENT); + err = ib_post_send(rdma->qp, &wr, NULL); + if (err) + goto dma_unmap; + + /* Success */ + return 0; + +dma_unmap: + ib_dma_unmap_single(rdma->cm_id->device, c->busa, + c->req->tc.size, DMA_TO_DEVICE); + /* Handle errors that happened during or while preparing the send: */ + send_error: + WRITE_ONCE(req->status, REQ_STATUS_ERROR); + kfree(c); + p9_debug(P9_DEBUG_ERROR, "Error %d in rdma_request()\n", err); + + /* Ach. + * We did recv_post(), but not send. We have one recv_post in excess. + */ + atomic_inc(&rdma->excess_rc); + return err; + + /* Handle errors that happened during or while preparing post_recv(): */ + recv_error: + kfree(rpl_context); + spin_lock_irqsave(&rdma->req_lock, flags); + if (err != -EINTR && rdma->state < P9_RDMA_CLOSING) { + rdma->state = P9_RDMA_CLOSING; + spin_unlock_irqrestore(&rdma->req_lock, flags); + rdma_disconnect(rdma->cm_id); + } else + spin_unlock_irqrestore(&rdma->req_lock, flags); + return err; +} + +static void rdma_close(struct p9_client *client) +{ + struct p9_trans_rdma *rdma; + + if (!client) + return; + + rdma = client->trans; + if (!rdma) + return; + + client->status = Disconnected; + rdma_disconnect(rdma->cm_id); + rdma_destroy_trans(rdma); +} + +/** + * alloc_rdma - Allocate and initialize the rdma transport structure + * @opts: Mount options structure + */ +static struct p9_trans_rdma *alloc_rdma(struct p9_rdma_opts *opts) +{ + struct p9_trans_rdma *rdma; + + rdma = kzalloc_obj(struct p9_trans_rdma); + if (!rdma) + return NULL; + + rdma->port = opts->port; + rdma->privport = opts->privport; + rdma->sq_depth = opts->sq_depth; + rdma->rq_depth = opts->rq_depth; + rdma->timeout = opts->timeout; + spin_lock_init(&rdma->req_lock); + init_completion(&rdma->cm_done); + sema_init(&rdma->sq_sem, rdma->sq_depth); + sema_init(&rdma->rq_sem, rdma->rq_depth); + atomic_set(&rdma->excess_rc, 0); + + return rdma; +} + +static int rdma_cancel(struct p9_client *client, struct p9_req_t *req) +{ + /* Nothing to do here. + * We will take care of it (if we have to) in rdma_cancelled() + */ + return 1; +} + +/* A request has been fully flushed without a reply. + * That means we have posted one buffer in excess. + */ +static int rdma_cancelled(struct p9_client *client, struct p9_req_t *req) +{ + struct p9_trans_rdma *rdma = client->trans; + atomic_inc(&rdma->excess_rc); + return 0; +} + +static int p9_rdma_bind_privport(struct p9_trans_rdma *rdma) +{ + struct sockaddr_in cl = { + .sin_family = AF_INET, + .sin_addr.s_addr = htonl(INADDR_ANY), + }; + int port, err = -EINVAL; + + for (port = P9_DEF_MAX_RESVPORT; port >= P9_DEF_MIN_RESVPORT; port--) { + cl.sin_port = htons((ushort)port); + err = rdma_bind_addr(rdma->cm_id, (struct sockaddr *)&cl); + if (err != -EADDRINUSE) + break; + } + return err; +} + +/** + * rdma_create_trans - Transport method for creating a transport instance + * @client: client instance + * @fc: The filesystem context + */ +static int +rdma_create_trans(struct p9_client *client, struct fs_context *fc) +{ + const char *addr = fc->source; + struct v9fs_context *ctx = fc->fs_private; + struct p9_rdma_opts opts = ctx->rdma_opts; + int err; + struct p9_trans_rdma *rdma; + struct rdma_conn_param conn_param; + struct ib_qp_init_attr qp_attr; + + if (addr == NULL) + return -EINVAL; + + /* options are already parsed, in the fs context */ + opts = ctx->rdma_opts; + + /* Create and initialize the RDMA transport structure */ + rdma = alloc_rdma(&opts); + if (!rdma) + return -ENOMEM; + + /* Create the RDMA CM ID */ + rdma->cm_id = rdma_create_id(&init_net, p9_cm_event_handler, client, + RDMA_PS_TCP, IB_QPT_RC); + if (IS_ERR(rdma->cm_id)) + goto error; + + /* Associate the client with the transport */ + client->trans = rdma; + + /* Bind to a privileged port if we need to */ + if (opts.privport) { + err = p9_rdma_bind_privport(rdma); + if (err < 0) { + pr_err("%s (%d): problem binding to privport: %d\n", + __func__, task_pid_nr(current), -err); + goto error; + } + } + + /* Resolve the server's address */ + rdma->addr.sin_family = AF_INET; + rdma->addr.sin_addr.s_addr = in_aton(addr); + rdma->addr.sin_port = htons(opts.port); + err = rdma_resolve_addr(rdma->cm_id, NULL, + (struct sockaddr *)&rdma->addr, + rdma->timeout); + if (err) + goto error; + err = wait_for_completion_interruptible(&rdma->cm_done); + if (err || (rdma->state != P9_RDMA_ADDR_RESOLVED)) + goto error; + + /* Resolve the route to the server */ + err = rdma_resolve_route(rdma->cm_id, rdma->timeout); + if (err) + goto error; + err = wait_for_completion_interruptible(&rdma->cm_done); + if (err || (rdma->state != P9_RDMA_ROUTE_RESOLVED)) + goto error; + + /* Create the Completion Queue */ + rdma->cq = ib_alloc_cq_any(rdma->cm_id->device, client, + opts.sq_depth + opts.rq_depth + 1, + IB_POLL_SOFTIRQ); + if (IS_ERR(rdma->cq)) + goto error; + + /* Create the Protection Domain */ + rdma->pd = ib_alloc_pd(rdma->cm_id->device, 0); + if (IS_ERR(rdma->pd)) + goto error; + + /* Create the Queue Pair */ + memset(&qp_attr, 0, sizeof qp_attr); + qp_attr.event_handler = qp_event_handler; + qp_attr.qp_context = client; + qp_attr.cap.max_send_wr = opts.sq_depth; + qp_attr.cap.max_recv_wr = opts.rq_depth; + qp_attr.cap.max_send_sge = P9_RDMA_SEND_SGE; + qp_attr.cap.max_recv_sge = P9_RDMA_RECV_SGE; + qp_attr.sq_sig_type = IB_SIGNAL_REQ_WR; + qp_attr.qp_type = IB_QPT_RC; + qp_attr.send_cq = rdma->cq; + qp_attr.recv_cq = rdma->cq; + err = rdma_create_qp(rdma->cm_id, rdma->pd, &qp_attr); + if (err) + goto error; + rdma->qp = rdma->cm_id->qp; + + /* Request a connection */ + memset(&conn_param, 0, sizeof(conn_param)); + conn_param.private_data = NULL; + conn_param.private_data_len = 0; + conn_param.responder_resources = P9_RDMA_IRD; + conn_param.initiator_depth = P9_RDMA_ORD; + err = rdma_connect(rdma->cm_id, &conn_param); + if (err) + goto error; + err = wait_for_completion_interruptible(&rdma->cm_done); + if (err || (rdma->state != P9_RDMA_CONNECTED)) + goto error; + + client->status = Connected; + + return 0; + +error: + rdma_destroy_trans(rdma); + return -ENOTCONN; +} + +static struct p9_trans_module p9_rdma_trans = { + .name = "rdma", + .maxsize = P9_RDMA_MAXSIZE, + .pooled_rbuffers = true, + .def = false, + .supports_vmalloc = false, + .owner = THIS_MODULE, + .create = rdma_create_trans, + .close = rdma_close, + .request = rdma_request, + .cancel = rdma_cancel, + .cancelled = rdma_cancelled, + .show_options = p9_rdma_show_options, +}; + +/** + * p9_trans_rdma_init - Register the 9P RDMA transport driver + */ +static int __init p9_trans_rdma_init(void) +{ + v9fs_register_trans(&p9_rdma_trans); + return 0; +} + +static void __exit p9_trans_rdma_exit(void) +{ + v9fs_unregister_trans(&p9_rdma_trans); +} + +module_init(p9_trans_rdma_init); +module_exit(p9_trans_rdma_exit); +MODULE_ALIAS_9P("rdma"); + +MODULE_AUTHOR("Tom Tucker "); +MODULE_DESCRIPTION("RDMA Transport for 9P"); +MODULE_LICENSE("Dual BSD/GPL"); diff --git a/net/9p/trans_usbg.c b/net/9p/trans_usbg.c new file mode 100644 index 000000000..419cda13a --- /dev/null +++ b/net/9p/trans_usbg.c @@ -0,0 +1,969 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * trans_usbg.c - USB peripheral usb9pfs configuration driver and transport. + * + * Copyright (C) 2024 Michael Grzeschik + */ + +/* Gadget usb9pfs only needs two bulk endpoints, and will use the usb9pfs + * transport to mount host exported filesystem via usb gadget. + */ + +/* +--------------------------+ | +--------------------------+ + * | 9PFS mounting client | | | 9PFS exporting server | + * SW | | | | | + * | (this:trans_usbg) | | |(e.g. diod or nfs-ganesha)| + * +-------------^------------+ | +-------------^------------+ + * | | | + * ------------------|------------------------------------|------------- + * | | | + * +-------------v------------+ | +-------------v------------+ + * | | | | | + * HW | USB Device Controller <---------> USB Host Controller | + * | | | | | + * +--------------------------+ | +--------------------------+ + */ + +#include +#include +#include +#include +#include +#include + +#include +#include +#include + +#define DEFAULT_BUFLEN 16384 + +struct f_usb9pfs { + struct p9_client *client; + + /* 9p request lock for en/dequeue */ + spinlock_t lock; + + struct usb_request *in_req; + struct usb_request *out_req; + + struct usb_ep *in_ep; + struct usb_ep *out_ep; + + struct completion send; + struct completion received; + + unsigned int buflen; + + struct usb_function function; +}; + +static inline struct f_usb9pfs *func_to_usb9pfs(struct usb_function *f) +{ + return container_of(f, struct f_usb9pfs, function); +} + +struct f_usb9pfs_opts { + struct usb_function_instance func_inst; + unsigned int buflen; + + struct f_usb9pfs_dev *dev; + + /* Read/write access to configfs attributes is handled by configfs. + * + * This is to protect the data from concurrent access by read/write + * and create symlink/remove symlink. + */ + struct mutex lock; + int refcnt; +}; + +struct f_usb9pfs_dev { + struct f_usb9pfs *usb9pfs; + struct f_usb9pfs_opts *opts; + char tag[41]; + bool inuse; + + struct list_head usb9pfs_instance; +}; + +static DEFINE_MUTEX(usb9pfs_lock); +static struct list_head usbg_instance_list; + +static int usb9pfs_queue_tx(struct f_usb9pfs *usb9pfs, struct p9_req_t *p9_tx_req, + gfp_t gfp_flags) +{ + struct usb_composite_dev *cdev = usb9pfs->function.config->cdev; + struct usb_request *req = usb9pfs->in_req; + int ret; + + if (!(p9_tx_req->tc.size % usb9pfs->in_ep->maxpacket)) + req->zero = 1; + + req->buf = p9_tx_req->tc.sdata; + req->length = p9_tx_req->tc.size; + req->context = p9_tx_req; + + dev_dbg(&cdev->gadget->dev, "%s usb9pfs send --> %d/%d, zero: %d\n", + usb9pfs->in_ep->name, req->actual, req->length, req->zero); + + ret = usb_ep_queue(usb9pfs->in_ep, req, gfp_flags); + if (ret) + req->context = NULL; + + dev_dbg(&cdev->gadget->dev, "tx submit --> %d\n", ret); + + return ret; +} + +static int usb9pfs_queue_rx(struct f_usb9pfs *usb9pfs, struct usb_request *req, + gfp_t gfp_flags) +{ + struct usb_composite_dev *cdev = usb9pfs->function.config->cdev; + int ret; + + ret = usb_ep_queue(usb9pfs->out_ep, req, gfp_flags); + + dev_dbg(&cdev->gadget->dev, "rx submit --> %d\n", ret); + + return ret; +} + +static int usb9pfs_transmit(struct f_usb9pfs *usb9pfs, struct p9_req_t *p9_req) +{ + int ret = 0; + + guard(spinlock_irqsave)(&usb9pfs->lock); + + ret = usb9pfs_queue_tx(usb9pfs, p9_req, GFP_ATOMIC); + if (ret) + return ret; + + list_del(&p9_req->req_list); + + p9_req_get(p9_req); + + return ret; +} + +static void usb9pfs_tx_complete(struct usb_ep *ep, struct usb_request *req) +{ + struct f_usb9pfs *usb9pfs = ep->driver_data; + struct usb_composite_dev *cdev = usb9pfs->function.config->cdev; + struct p9_req_t *p9_tx_req = req->context; + unsigned long flags; + + /* reset zero packages */ + req->zero = 0; + + if (req->status) { + dev_err(&cdev->gadget->dev, "%s usb9pfs complete --> %d, %d/%d\n", + ep->name, req->status, req->actual, req->length); + return; + } + + dev_dbg(&cdev->gadget->dev, "%s usb9pfs complete --> %d, %d/%d\n", + ep->name, req->status, req->actual, req->length); + + spin_lock_irqsave(&usb9pfs->lock, flags); + WRITE_ONCE(p9_tx_req->status, REQ_STATUS_SENT); + + p9_req_put(usb9pfs->client, p9_tx_req); + + req->context = NULL; + + spin_unlock_irqrestore(&usb9pfs->lock, flags); + + complete(&usb9pfs->send); +} + +static struct p9_req_t *usb9pfs_rx_header(struct f_usb9pfs *usb9pfs, void *buf) +{ + struct p9_req_t *p9_rx_req; + struct p9_fcall rc; + int ret; + + /* start by reading header */ + rc.sdata = buf; + rc.offset = 0; + rc.capacity = P9_HDRSZ; + rc.size = P9_HDRSZ; + + p9_debug(P9_DEBUG_TRANS, "mux %p got %zu bytes\n", usb9pfs, + rc.capacity - rc.offset); + + ret = p9_parse_header(&rc, &rc.size, NULL, NULL, 0); + if (ret) { + p9_debug(P9_DEBUG_ERROR, + "error parsing header: %d\n", ret); + return NULL; + } + + p9_debug(P9_DEBUG_TRANS, + "mux %p pkt: size: %d bytes tag: %d\n", + usb9pfs, rc.size, rc.tag); + + p9_rx_req = p9_tag_lookup(usb9pfs->client, rc.tag); + if (!p9_rx_req || p9_rx_req->status != REQ_STATUS_SENT) { + p9_debug(P9_DEBUG_ERROR, "Unexpected packet tag %d\n", rc.tag); + return NULL; + } + + if (rc.size > p9_rx_req->rc.capacity) { + p9_debug(P9_DEBUG_ERROR, + "requested packet size too big: %d for tag %d with capacity %zd\n", + rc.size, rc.tag, p9_rx_req->rc.capacity); + p9_req_put(usb9pfs->client, p9_rx_req); + return NULL; + } + + if (!p9_rx_req->rc.sdata) { + p9_debug(P9_DEBUG_ERROR, + "No recv fcall for tag %d (req %p), disconnecting!\n", + rc.tag, p9_rx_req); + p9_req_put(usb9pfs->client, p9_rx_req); + return NULL; + } + + return p9_rx_req; +} + +static void usb9pfs_rx_complete(struct usb_ep *ep, struct usb_request *req) +{ + struct f_usb9pfs *usb9pfs = ep->driver_data; + struct usb_composite_dev *cdev = usb9pfs->function.config->cdev; + struct p9_req_t *p9_rx_req; + unsigned int req_size = req->actual; + int status = REQ_STATUS_RCVD; + + if (req->status) { + dev_err(&cdev->gadget->dev, "%s usb9pfs complete --> %d, %d/%d\n", + ep->name, req->status, req->actual, req->length); + return; + } + + p9_rx_req = usb9pfs_rx_header(usb9pfs, req->buf); + if (!p9_rx_req) + return; + + if (req_size > p9_rx_req->rc.capacity) { + dev_err(&cdev->gadget->dev, + "%s received data size %u exceeds buffer capacity %zu\n", + ep->name, req_size, p9_rx_req->rc.capacity); + req_size = 0; + status = REQ_STATUS_ERROR; + } + + memcpy(p9_rx_req->rc.sdata, req->buf, req_size); + + p9_rx_req->rc.size = req_size; + + p9_client_cb(usb9pfs->client, p9_rx_req, status); + p9_req_put(usb9pfs->client, p9_rx_req); + + complete(&usb9pfs->received); +} + +static void disable_ep(struct usb_composite_dev *cdev, struct usb_ep *ep) +{ + int value; + + value = usb_ep_disable(ep); + if (value < 0) + dev_info(&cdev->gadget->dev, + "disable %s --> %d\n", ep->name, value); +} + +static void disable_usb9pfs(struct f_usb9pfs *usb9pfs) +{ + struct usb_composite_dev *cdev = + usb9pfs->function.config->cdev; + + if (usb9pfs->in_req) { + usb_ep_free_request(usb9pfs->in_ep, usb9pfs->in_req); + usb9pfs->in_req = NULL; + } + + if (usb9pfs->out_req) { + usb_ep_free_request(usb9pfs->out_ep, usb9pfs->out_req); + usb9pfs->out_req = NULL; + } + + disable_ep(cdev, usb9pfs->in_ep); + disable_ep(cdev, usb9pfs->out_ep); + dev_dbg(&cdev->gadget->dev, "%s disabled\n", + usb9pfs->function.name); +} + +static int alloc_requests(struct usb_composite_dev *cdev, + struct f_usb9pfs *usb9pfs) +{ + int ret; + + usb9pfs->in_req = usb_ep_alloc_request(usb9pfs->in_ep, GFP_ATOMIC); + if (!usb9pfs->in_req) { + ret = -ENOENT; + goto fail; + } + + usb9pfs->out_req = alloc_ep_req(usb9pfs->out_ep, usb9pfs->buflen); + if (!usb9pfs->out_req) { + ret = -ENOENT; + goto fail_in; + } + + usb9pfs->in_req->complete = usb9pfs_tx_complete; + usb9pfs->out_req->complete = usb9pfs_rx_complete; + + /* length will be set in complete routine */ + usb9pfs->in_req->context = usb9pfs; + usb9pfs->out_req->context = usb9pfs; + + return 0; + +fail_in: + usb_ep_free_request(usb9pfs->in_ep, usb9pfs->in_req); +fail: + return ret; +} + +static int enable_endpoint(struct usb_composite_dev *cdev, + struct f_usb9pfs *usb9pfs, struct usb_ep *ep) +{ + int ret; + + ret = config_ep_by_speed(cdev->gadget, &usb9pfs->function, ep); + if (ret) + return ret; + + ret = usb_ep_enable(ep); + if (ret < 0) + return ret; + + ep->driver_data = usb9pfs; + + return 0; +} + +static int +enable_usb9pfs(struct usb_composite_dev *cdev, struct f_usb9pfs *usb9pfs) +{ + struct p9_client *client; + int ret = 0; + + ret = enable_endpoint(cdev, usb9pfs, usb9pfs->in_ep); + if (ret) + goto out; + + ret = enable_endpoint(cdev, usb9pfs, usb9pfs->out_ep); + if (ret) + goto disable_in; + + ret = alloc_requests(cdev, usb9pfs); + if (ret) + goto disable_out; + + client = usb9pfs->client; + if (client) + client->status = Connected; + + dev_dbg(&cdev->gadget->dev, "%s enabled\n", usb9pfs->function.name); + return 0; + +disable_out: + usb_ep_disable(usb9pfs->out_ep); +disable_in: + usb_ep_disable(usb9pfs->in_ep); +out: + return ret; +} + +static int p9_usbg_create(struct p9_client *client, struct fs_context *fc) +{ + const char *devname = fc->source; + struct f_usb9pfs_dev *dev; + struct f_usb9pfs *usb9pfs; + int ret = -ENOENT; + int found = 0; + + if (!devname) + return -EINVAL; + + guard(mutex)(&usb9pfs_lock); + + list_for_each_entry(dev, &usbg_instance_list, usb9pfs_instance) { + if (!strncmp(devname, dev->tag, strlen(devname))) { + if (!dev->inuse) { + dev->inuse = true; + found = 1; + break; + } + ret = -EBUSY; + break; + } + } + + if (!found) { + pr_err("no channels available for device %s\n", devname); + return ret; + } + + usb9pfs = dev->usb9pfs; + if (!usb9pfs) + return -EINVAL; + + client->trans = (void *)usb9pfs; + if (!usb9pfs->in_req) + client->status = Disconnected; + else + client->status = Connected; + usb9pfs->client = client; + + client->trans_mod->maxsize = usb9pfs->buflen; + + complete(&usb9pfs->received); + + return 0; +} + +static void usb9pfs_clear_tx(struct f_usb9pfs *usb9pfs) +{ + struct p9_req_t *req; + + guard(spinlock_irqsave)(&usb9pfs->lock); + + req = usb9pfs->in_req->context; + if (!req) + return; + + if (!req->t_err) + req->t_err = -ECONNRESET; + + p9_client_cb(usb9pfs->client, req, REQ_STATUS_ERROR); +} + +static void p9_usbg_close(struct p9_client *client) +{ + struct f_usb9pfs *usb9pfs; + struct f_usb9pfs_dev *dev; + struct f_usb9pfs_opts *opts; + + if (!client) + return; + + usb9pfs = client->trans; + if (!usb9pfs) + return; + + client->status = Disconnected; + + usb9pfs_clear_tx(usb9pfs); + + opts = container_of(usb9pfs->function.fi, + struct f_usb9pfs_opts, func_inst); + + dev = opts->dev; + + mutex_lock(&usb9pfs_lock); + dev->inuse = false; + mutex_unlock(&usb9pfs_lock); +} + +static int p9_usbg_request(struct p9_client *client, struct p9_req_t *p9_req) +{ + struct f_usb9pfs *usb9pfs = client->trans; + int ret; + + if (client->status != Connected) + return -EBUSY; + + ret = wait_for_completion_killable(&usb9pfs->received); + if (ret) + return ret; + + ret = usb9pfs_transmit(usb9pfs, p9_req); + if (ret) + return ret; + + ret = wait_for_completion_killable(&usb9pfs->send); + if (ret) + return ret; + + return usb9pfs_queue_rx(usb9pfs, usb9pfs->out_req, GFP_ATOMIC); +} + +static int p9_usbg_cancel(struct p9_client *client, struct p9_req_t *req) +{ + struct f_usb9pfs *usb9pfs = client->trans; + int ret = 1; + + p9_debug(P9_DEBUG_TRANS, "client %p req %p\n", client, req); + + guard(spinlock_irqsave)(&usb9pfs->lock); + + if (req->status == REQ_STATUS_UNSENT) { + list_del(&req->req_list); + WRITE_ONCE(req->status, REQ_STATUS_FLSHD); + p9_req_put(client, req); + ret = 0; + } + + return ret; +} + +static struct p9_trans_module p9_usbg_trans = { + .name = "usbg", + .create = p9_usbg_create, + .close = p9_usbg_close, + .request = p9_usbg_request, + .cancel = p9_usbg_cancel, + .supports_vmalloc = false, + .owner = THIS_MODULE, +}; + +/*-------------------------------------------------------------------------*/ + +#define USB_PROTOCOL_9PFS 0x09 + +static struct usb_interface_descriptor usb9pfs_intf = { + .bLength = sizeof(usb9pfs_intf), + .bDescriptorType = USB_DT_INTERFACE, + + .bNumEndpoints = 2, + .bInterfaceClass = USB_CLASS_VENDOR_SPEC, + .bInterfaceSubClass = USB_SUBCLASS_VENDOR_SPEC, + .bInterfaceProtocol = USB_PROTOCOL_9PFS, + + /* .iInterface = DYNAMIC */ +}; + +/* full speed support: */ + +static struct usb_endpoint_descriptor fs_usb9pfs_source_desc = { + .bLength = USB_DT_ENDPOINT_SIZE, + .bDescriptorType = USB_DT_ENDPOINT, + + .bEndpointAddress = USB_DIR_IN, + .bmAttributes = USB_ENDPOINT_XFER_BULK, +}; + +static struct usb_endpoint_descriptor fs_usb9pfs_sink_desc = { + .bLength = USB_DT_ENDPOINT_SIZE, + .bDescriptorType = USB_DT_ENDPOINT, + + .bEndpointAddress = USB_DIR_OUT, + .bmAttributes = USB_ENDPOINT_XFER_BULK, +}; + +static struct usb_descriptor_header *fs_usb9pfs_descs[] = { + (struct usb_descriptor_header *)&usb9pfs_intf, + (struct usb_descriptor_header *)&fs_usb9pfs_sink_desc, + (struct usb_descriptor_header *)&fs_usb9pfs_source_desc, + NULL, +}; + +/* high speed support: */ + +static struct usb_endpoint_descriptor hs_usb9pfs_source_desc = { + .bLength = USB_DT_ENDPOINT_SIZE, + .bDescriptorType = USB_DT_ENDPOINT, + + .bmAttributes = USB_ENDPOINT_XFER_BULK, + .wMaxPacketSize = cpu_to_le16(512), +}; + +static struct usb_endpoint_descriptor hs_usb9pfs_sink_desc = { + .bLength = USB_DT_ENDPOINT_SIZE, + .bDescriptorType = USB_DT_ENDPOINT, + + .bmAttributes = USB_ENDPOINT_XFER_BULK, + .wMaxPacketSize = cpu_to_le16(512), +}; + +static struct usb_descriptor_header *hs_usb9pfs_descs[] = { + (struct usb_descriptor_header *)&usb9pfs_intf, + (struct usb_descriptor_header *)&hs_usb9pfs_source_desc, + (struct usb_descriptor_header *)&hs_usb9pfs_sink_desc, + NULL, +}; + +/* super speed support: */ + +static struct usb_endpoint_descriptor ss_usb9pfs_source_desc = { + .bLength = USB_DT_ENDPOINT_SIZE, + .bDescriptorType = USB_DT_ENDPOINT, + + .bmAttributes = USB_ENDPOINT_XFER_BULK, + .wMaxPacketSize = cpu_to_le16(1024), +}; + +static struct usb_ss_ep_comp_descriptor ss_usb9pfs_source_comp_desc = { + .bLength = USB_DT_SS_EP_COMP_SIZE, + .bDescriptorType = USB_DT_SS_ENDPOINT_COMP, + .bMaxBurst = 0, + .bmAttributes = 0, + .wBytesPerInterval = 0, +}; + +static struct usb_endpoint_descriptor ss_usb9pfs_sink_desc = { + .bLength = USB_DT_ENDPOINT_SIZE, + .bDescriptorType = USB_DT_ENDPOINT, + + .bmAttributes = USB_ENDPOINT_XFER_BULK, + .wMaxPacketSize = cpu_to_le16(1024), +}; + +static struct usb_ss_ep_comp_descriptor ss_usb9pfs_sink_comp_desc = { + .bLength = USB_DT_SS_EP_COMP_SIZE, + .bDescriptorType = USB_DT_SS_ENDPOINT_COMP, + .bMaxBurst = 0, + .bmAttributes = 0, + .wBytesPerInterval = 0, +}; + +static struct usb_descriptor_header *ss_usb9pfs_descs[] = { + (struct usb_descriptor_header *)&usb9pfs_intf, + (struct usb_descriptor_header *)&ss_usb9pfs_source_desc, + (struct usb_descriptor_header *)&ss_usb9pfs_source_comp_desc, + (struct usb_descriptor_header *)&ss_usb9pfs_sink_desc, + (struct usb_descriptor_header *)&ss_usb9pfs_sink_comp_desc, + NULL, +}; + +/* function-specific strings: */ +static struct usb_string strings_usb9pfs[] = { + [0].s = "usb9pfs input to output", + { } /* end of list */ +}; + +static struct usb_gadget_strings stringtab_usb9pfs = { + .language = 0x0409, /* en-us */ + .strings = strings_usb9pfs, +}; + +static struct usb_gadget_strings *usb9pfs_strings[] = { + &stringtab_usb9pfs, + NULL, +}; + +/*-------------------------------------------------------------------------*/ + +static int usb9pfs_func_bind(struct usb_configuration *c, + struct usb_function *f) +{ + struct f_usb9pfs *usb9pfs = func_to_usb9pfs(f); + struct f_usb9pfs_opts *opts; + struct usb_composite_dev *cdev = c->cdev; + int ret; + int id; + + /* allocate interface ID(s) */ + id = usb_interface_id(c, f); + if (id < 0) + return id; + usb9pfs_intf.bInterfaceNumber = id; + + id = usb_string_id(cdev); + if (id < 0) + return id; + strings_usb9pfs[0].id = id; + usb9pfs_intf.iInterface = id; + + /* allocate endpoints */ + usb9pfs->in_ep = usb_ep_autoconfig(cdev->gadget, + &fs_usb9pfs_source_desc); + if (!usb9pfs->in_ep) + goto autoconf_fail; + + usb9pfs->out_ep = usb_ep_autoconfig(cdev->gadget, + &fs_usb9pfs_sink_desc); + if (!usb9pfs->out_ep) + goto autoconf_fail; + + /* support high speed hardware */ + hs_usb9pfs_source_desc.bEndpointAddress = + fs_usb9pfs_source_desc.bEndpointAddress; + hs_usb9pfs_sink_desc.bEndpointAddress = + fs_usb9pfs_sink_desc.bEndpointAddress; + + /* support super speed hardware */ + ss_usb9pfs_source_desc.bEndpointAddress = + fs_usb9pfs_source_desc.bEndpointAddress; + ss_usb9pfs_sink_desc.bEndpointAddress = + fs_usb9pfs_sink_desc.bEndpointAddress; + + ret = usb_assign_descriptors(f, fs_usb9pfs_descs, hs_usb9pfs_descs, + ss_usb9pfs_descs, ss_usb9pfs_descs); + if (ret) + return ret; + + opts = container_of(f->fi, struct f_usb9pfs_opts, func_inst); + opts->dev->usb9pfs = usb9pfs; + + dev_dbg(&cdev->gadget->dev, "%s speed %s: IN/%s, OUT/%s\n", + (gadget_is_superspeed(c->cdev->gadget) ? "super" : + (gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full")), + f->name, usb9pfs->in_ep->name, usb9pfs->out_ep->name); + + return 0; + +autoconf_fail: + ERROR(cdev, "%s: can't autoconfigure on %s\n", + f->name, cdev->gadget->name); + return -ENODEV; +} + +static void usb9pfs_func_unbind(struct usb_configuration *c, + struct usb_function *f) +{ + struct f_usb9pfs *usb9pfs = func_to_usb9pfs(f); + + disable_usb9pfs(usb9pfs); +} + +static void usb9pfs_free_func(struct usb_function *f) +{ + struct f_usb9pfs *usb9pfs = func_to_usb9pfs(f); + struct f_usb9pfs_opts *opts; + + kfree(usb9pfs); + + opts = container_of(f->fi, struct f_usb9pfs_opts, func_inst); + + mutex_lock(&opts->lock); + opts->refcnt--; + mutex_unlock(&opts->lock); + + usb_free_all_descriptors(f); +} + +static int usb9pfs_set_alt(struct usb_function *f, + unsigned int intf, unsigned int alt) +{ + struct f_usb9pfs *usb9pfs = func_to_usb9pfs(f); + struct usb_composite_dev *cdev = f->config->cdev; + + return enable_usb9pfs(cdev, usb9pfs); +} + +static void usb9pfs_disable(struct usb_function *f) +{ + struct f_usb9pfs *usb9pfs = func_to_usb9pfs(f); + + usb9pfs_clear_tx(usb9pfs); +} + +static struct usb_function *usb9pfs_alloc(struct usb_function_instance *fi) +{ + struct f_usb9pfs_opts *usb9pfs_opts; + struct f_usb9pfs *usb9pfs; + + usb9pfs = kzalloc_obj(*usb9pfs); + if (!usb9pfs) + return ERR_PTR(-ENOMEM); + + spin_lock_init(&usb9pfs->lock); + + init_completion(&usb9pfs->send); + init_completion(&usb9pfs->received); + + usb9pfs_opts = container_of(fi, struct f_usb9pfs_opts, func_inst); + + mutex_lock(&usb9pfs_opts->lock); + usb9pfs_opts->refcnt++; + mutex_unlock(&usb9pfs_opts->lock); + + usb9pfs->buflen = usb9pfs_opts->buflen; + + usb9pfs->function.name = "usb9pfs"; + usb9pfs->function.bind = usb9pfs_func_bind; + usb9pfs->function.unbind = usb9pfs_func_unbind; + usb9pfs->function.set_alt = usb9pfs_set_alt; + usb9pfs->function.disable = usb9pfs_disable; + usb9pfs->function.strings = usb9pfs_strings; + + usb9pfs->function.free_func = usb9pfs_free_func; + + return &usb9pfs->function; +} + +static inline struct f_usb9pfs_opts *to_f_usb9pfs_opts(struct config_item *item) +{ + return container_of(to_config_group(item), struct f_usb9pfs_opts, + func_inst.group); +} + +static inline struct f_usb9pfs_opts *fi_to_f_usb9pfs_opts(struct usb_function_instance *fi) +{ + return container_of(fi, struct f_usb9pfs_opts, func_inst); +} + +static void usb9pfs_attr_release(struct config_item *item) +{ + struct f_usb9pfs_opts *usb9pfs_opts = to_f_usb9pfs_opts(item); + + usb_put_function_instance(&usb9pfs_opts->func_inst); +} + +static const struct configfs_item_operations usb9pfs_item_ops = { + .release = usb9pfs_attr_release, +}; + +static ssize_t f_usb9pfs_opts_buflen_show(struct config_item *item, char *page) +{ + struct f_usb9pfs_opts *opts = to_f_usb9pfs_opts(item); + int ret; + + mutex_lock(&opts->lock); + ret = sysfs_emit(page, "%d\n", opts->buflen); + mutex_unlock(&opts->lock); + + return ret; +} + +static ssize_t f_usb9pfs_opts_buflen_store(struct config_item *item, + const char *page, size_t len) +{ + struct f_usb9pfs_opts *opts = to_f_usb9pfs_opts(item); + int ret; + u32 num; + + guard(mutex)(&opts->lock); + + if (opts->refcnt) + return -EBUSY; + + ret = kstrtou32(page, 0, &num); + if (ret) + return ret; + + opts->buflen = num; + + return len; +} + +CONFIGFS_ATTR(f_usb9pfs_opts_, buflen); + +static struct configfs_attribute *usb9pfs_attrs[] = { + &f_usb9pfs_opts_attr_buflen, + NULL, +}; + +static const struct config_item_type usb9pfs_func_type = { + .ct_item_ops = &usb9pfs_item_ops, + .ct_attrs = usb9pfs_attrs, + .ct_owner = THIS_MODULE, +}; + +static struct f_usb9pfs_dev *_usb9pfs_do_find_dev(const char *tag) +{ + struct f_usb9pfs_dev *usb9pfs_dev; + + if (!tag) + return NULL; + + list_for_each_entry(usb9pfs_dev, &usbg_instance_list, usb9pfs_instance) { + if (strcmp(usb9pfs_dev->tag, tag) == 0) + return usb9pfs_dev; + } + + return NULL; +} + +static int usb9pfs_tag_instance(struct f_usb9pfs_dev *dev, const char *tag) +{ + struct f_usb9pfs_dev *existing; + int ret = 0; + + guard(mutex)(&usb9pfs_lock); + + existing = _usb9pfs_do_find_dev(tag); + if (!existing) + strscpy(dev->tag, tag, ARRAY_SIZE(dev->tag)); + else if (existing != dev) + ret = -EBUSY; + + return ret; +} + +static int usb9pfs_set_inst_tag(struct usb_function_instance *fi, const char *tag) +{ + if (strlen(tag) >= sizeof_field(struct f_usb9pfs_dev, tag)) + return -ENAMETOOLONG; + return usb9pfs_tag_instance(fi_to_f_usb9pfs_opts(fi)->dev, tag); +} + +static void usb9pfs_free_instance(struct usb_function_instance *fi) +{ + struct f_usb9pfs_opts *usb9pfs_opts = + container_of(fi, struct f_usb9pfs_opts, func_inst); + struct f_usb9pfs_dev *dev = usb9pfs_opts->dev; + + mutex_lock(&usb9pfs_lock); + list_del(&dev->usb9pfs_instance); + mutex_unlock(&usb9pfs_lock); + + kfree(usb9pfs_opts); +} + +static struct usb_function_instance *usb9pfs_alloc_instance(void) +{ + struct f_usb9pfs_opts *usb9pfs_opts; + struct f_usb9pfs_dev *dev; + + usb9pfs_opts = kzalloc_obj(*usb9pfs_opts); + if (!usb9pfs_opts) + return ERR_PTR(-ENOMEM); + + mutex_init(&usb9pfs_opts->lock); + + usb9pfs_opts->func_inst.set_inst_name = usb9pfs_set_inst_tag; + usb9pfs_opts->func_inst.free_func_inst = usb9pfs_free_instance; + + usb9pfs_opts->buflen = DEFAULT_BUFLEN; + + dev = kzalloc_obj(*dev); + if (!dev) { + kfree(usb9pfs_opts); + return ERR_PTR(-ENOMEM); + } + + usb9pfs_opts->dev = dev; + dev->opts = usb9pfs_opts; + + config_group_init_type_name(&usb9pfs_opts->func_inst.group, "", + &usb9pfs_func_type); + + mutex_lock(&usb9pfs_lock); + list_add_tail(&dev->usb9pfs_instance, &usbg_instance_list); + mutex_unlock(&usb9pfs_lock); + + return &usb9pfs_opts->func_inst; +} +DECLARE_USB_FUNCTION(usb9pfs, usb9pfs_alloc_instance, usb9pfs_alloc); + +static int __init usb9pfs_modinit(void) +{ + int ret; + + INIT_LIST_HEAD(&usbg_instance_list); + + ret = usb_function_register(&usb9pfsusb_func); + if (!ret) + v9fs_register_trans(&p9_usbg_trans); + + return ret; +} + +static void __exit usb9pfs_modexit(void) +{ + usb_function_unregister(&usb9pfsusb_func); + v9fs_unregister_trans(&p9_usbg_trans); +} + +module_init(usb9pfs_modinit); +module_exit(usb9pfs_modexit); + +MODULE_ALIAS_9P("usbg"); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("USB gadget 9pfs transport"); +MODULE_AUTHOR("Michael Grzeschik"); diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c new file mode 100644 index 000000000..b0d0094ec --- /dev/null +++ b/net/9p/trans_virtio.c @@ -0,0 +1,842 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * The Virtio 9p transport driver + * + * This is a block based transport driver based on the lguest block driver + * code. + * + * Copyright (C) 2007, 2008 Eric Van Hensbergen, IBM Corporation + * + * Based on virtio console driver + * Copyright (C) 2006, 2007 Rusty Russell, IBM Corporation + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "trans_common.h" + +#define VIRTQUEUE_NUM 128 + +/* a single mutex to manage channel initialization and attachment */ +static DEFINE_MUTEX(virtio_9p_lock); +static DECLARE_WAIT_QUEUE_HEAD(vp_wq); +static atomic_t vp_pinned = ATOMIC_INIT(0); + +/** + * struct virtio_chan - per-instance transport information + * @inuse: whether the channel is in use + * @lock: protects multiple elements within this structure + * @client: client instance + * @vdev: virtio dev associated with this channel + * @vq: virtio queue associated with this channel + * @ring_bufs_avail: flag to indicate there is some available in the ring buf + * @vc_wq: wait queue for waiting for thing to be added to ring buf + * @p9_max_pages: maximum number of pinned pages + * @sg: scatter gather list which is used to pack a request (protected?) + * @chan_list: linked list of channels + * + * We keep all per-channel information in a structure. + * This structure is allocated within the devices dev->mem space. + * A pointer to the structure will get put in the transport private. + * + */ + +struct virtio_chan { + bool inuse; + + spinlock_t lock; + + struct p9_client *client; + struct virtio_device *vdev; + struct virtqueue *vq; + int ring_bufs_avail; + wait_queue_head_t *vc_wq; + /* This is global limit. Since we don't have a global structure, + * will be placing it in each channel. + */ + unsigned long p9_max_pages; + /* Scatterlist: can be too big for stack. */ + struct scatterlist sg[VIRTQUEUE_NUM]; + /** + * @tag: name to identify a mount null terminated + */ + char *tag; + + struct list_head chan_list; +}; + +static struct list_head virtio_chan_list; + +/* How many bytes left in this page. */ +static unsigned int rest_of_page(void *data) +{ + return PAGE_SIZE - offset_in_page(data); +} + +/** + * p9_virtio_close - reclaim resources of a channel + * @client: client instance + * + * This reclaims a channel by freeing its resources and + * resetting its inuse flag. + * + */ + +static void p9_virtio_close(struct p9_client *client) +{ + struct virtio_chan *chan = client->trans; + + mutex_lock(&virtio_9p_lock); + if (chan) + chan->inuse = false; + mutex_unlock(&virtio_9p_lock); +} + +/** + * req_done - callback which signals activity from the server + * @vq: virtio queue activity was received on + * + * This notifies us that the server has triggered some activity + * on the virtio channel - most likely a response to request we + * sent. Figure out which requests now have responses and wake up + * those threads. + * + * Bugs: could do with some additional sanity checking, but appears to work. + * + */ + +static void req_done(struct virtqueue *vq) +{ + struct virtio_chan *chan = vq->vdev->priv; + unsigned int len; + struct p9_req_t *req; + bool need_wakeup = false; + unsigned long flags; + + p9_debug(P9_DEBUG_TRANS, ": request done\n"); + + spin_lock_irqsave(&chan->lock, flags); + while ((req = virtqueue_get_buf(chan->vq, &len)) != NULL) { + if (!chan->ring_bufs_avail) { + chan->ring_bufs_avail = 1; + need_wakeup = true; + } + + if (len) { + req->rc.size = len; + p9_client_cb(chan->client, req, REQ_STATUS_RCVD); + } + } + spin_unlock_irqrestore(&chan->lock, flags); + /* Wakeup if anyone waiting for VirtIO ring space. */ + if (need_wakeup) + wake_up(chan->vc_wq); +} + +/** + * pack_sg_list - pack a scatter gather list from a linear buffer + * @sg: scatter/gather list to pack into + * @start: which segment of the sg_list to start at + * @limit: maximum segment to pack data to + * @data: data to pack into scatter/gather list + * @count: amount of data to pack into the scatter/gather list + * + * sg_lists have multiple segments of various sizes. This will pack + * arbitrary data into an existing scatter gather list, segmenting the + * data as necessary within constraints. + * + */ + +static int pack_sg_list(struct scatterlist *sg, int start, + int limit, char *data, int count) +{ + int s; + int index = start; + + while (count) { + s = rest_of_page(data); + if (s > count) + s = count; + BUG_ON(index >= limit); + /* Make sure we don't terminate early. */ + sg_unmark_end(&sg[index]); + sg_set_buf(&sg[index++], data, s); + count -= s; + data += s; + } + if (index-start) + sg_mark_end(&sg[index - 1]); + return index-start; +} + +/* We don't currently allow canceling of virtio requests */ +static int p9_virtio_cancel(struct p9_client *client, struct p9_req_t *req) +{ + return 1; +} + +/* Reply won't come, so drop req ref */ +static int p9_virtio_cancelled(struct p9_client *client, struct p9_req_t *req) +{ + p9_req_put(client, req); + return 0; +} + +/** + * pack_sg_list_p - Just like pack_sg_list. Instead of taking a buffer, + * this takes a list of pages. + * @sg: scatter/gather list to pack into + * @start: which segment of the sg_list to start at + * @limit: maximum number of pages in sg list. + * @pdata: a list of pages to add into sg. + * @nr_pages: number of pages to pack into the scatter/gather list + * @offs: amount of data in the beginning of first page _not_ to pack + * @count: amount of data to pack into the scatter/gather list + */ +static int +pack_sg_list_p(struct scatterlist *sg, int start, int limit, + struct page **pdata, int nr_pages, size_t offs, int count) +{ + int i = 0, s; + int data_off = offs; + int index = start; + + BUG_ON(nr_pages > (limit - start)); + /* + * if the first page doesn't start at + * page boundary find the offset + */ + while (nr_pages) { + s = PAGE_SIZE - data_off; + if (s > count) + s = count; + BUG_ON(index >= limit); + /* Make sure we don't terminate early. */ + sg_unmark_end(&sg[index]); + sg_set_page(&sg[index++], pdata[i++], s, data_off); + data_off = 0; + count -= s; + nr_pages--; + } + + if (index-start) + sg_mark_end(&sg[index - 1]); + return index - start; +} + +/** + * p9_virtio_request - issue a request + * @client: client instance issuing the request + * @req: request to be issued + * + */ + +static int +p9_virtio_request(struct p9_client *client, struct p9_req_t *req) +{ + int err; + int in, out, out_sgs, in_sgs; + unsigned long flags; + struct virtio_chan *chan = client->trans; + struct scatterlist *sgs[2]; + + p9_debug(P9_DEBUG_TRANS, "9p debug: virtio request\n"); + + WRITE_ONCE(req->status, REQ_STATUS_SENT); +req_retry: + spin_lock_irqsave(&chan->lock, flags); + + out_sgs = in_sgs = 0; + /* Handle out VirtIO ring buffers */ + out = pack_sg_list(chan->sg, 0, + VIRTQUEUE_NUM, req->tc.sdata, req->tc.size); + if (out) + sgs[out_sgs++] = chan->sg; + + in = pack_sg_list(chan->sg, out, + VIRTQUEUE_NUM, req->rc.sdata, req->rc.capacity); + if (in) + sgs[out_sgs + in_sgs++] = chan->sg + out; + + err = virtqueue_add_sgs(chan->vq, sgs, out_sgs, in_sgs, req, + GFP_ATOMIC); + if (err < 0) { + if (err == -ENOSPC) { + chan->ring_bufs_avail = 0; + spin_unlock_irqrestore(&chan->lock, flags); + err = io_wait_event_killable(*chan->vc_wq, + chan->ring_bufs_avail); + if (err == -ERESTARTSYS) + return err; + + p9_debug(P9_DEBUG_TRANS, "Retry virtio request\n"); + goto req_retry; + } else { + spin_unlock_irqrestore(&chan->lock, flags); + p9_debug(P9_DEBUG_TRANS, + "virtio rpc add_sgs returned failure\n"); + return -EIO; + } + } + virtqueue_kick(chan->vq); + spin_unlock_irqrestore(&chan->lock, flags); + + p9_debug(P9_DEBUG_TRANS, "virtio request kicked\n"); + return 0; +} + +static int p9_get_mapped_pages(struct virtio_chan *chan, + struct page ***pages, + struct iov_iter *data, + int count, + size_t *offs, + int *need_drop) +{ + int nr_pages; + int err; + + if (!iov_iter_count(data)) + return 0; + + if (!iov_iter_is_kvec(data)) { + int n; + /* + * We allow only p9_max_pages pinned. We wait for the + * Other zc request to finish here + */ + if (atomic_read(&vp_pinned) >= chan->p9_max_pages) { + err = io_wait_event_killable(vp_wq, + (atomic_read(&vp_pinned) < chan->p9_max_pages)); + if (err == -ERESTARTSYS) + return err; + } + n = iov_iter_get_pages_alloc2(data, pages, count, offs); + if (n < 0) + return n; + *need_drop = 1; + nr_pages = DIV_ROUND_UP(n + *offs, PAGE_SIZE); + atomic_add(nr_pages, &vp_pinned); + return n; + } else { + /* kernel buffer, no need to pin pages */ + int index; + size_t len; + void *p; + + /* we'd already checked that it's non-empty */ + while (1) { + len = iov_iter_single_seg_count(data); + if (likely(len)) { + p = data->kvec->iov_base + data->iov_offset; + break; + } + iov_iter_advance(data, 0); + } + if (len > count) + len = count; + + nr_pages = DIV_ROUND_UP((unsigned long)p + len, PAGE_SIZE) - + (unsigned long)p / PAGE_SIZE; + + *pages = kmalloc_objs(struct page *, nr_pages, GFP_NOFS); + if (!*pages) + return -ENOMEM; + + *need_drop = 0; + p -= (*offs = offset_in_page(p)); + for (index = 0; index < nr_pages; index++) { + if (is_vmalloc_addr(p)) + (*pages)[index] = vmalloc_to_page(p); + else + (*pages)[index] = kmap_to_page(p); + p += PAGE_SIZE; + } + iov_iter_advance(data, len); + return len; + } +} + +static void handle_rerror(struct p9_req_t *req, int in_hdr_len, + size_t offs, struct page **pages) +{ + unsigned size, n; + void *to = req->rc.sdata + in_hdr_len; + + // Fits entirely into the static data? Nothing to do. + if (req->rc.size < in_hdr_len || !pages) + return; + + // Really long error message? Tough, truncate the reply. Might get + // rejected (we can't be arsed to adjust the size encoded in header, + // or string size for that matter), but it wouldn't be anything valid + // anyway. + if (unlikely(req->rc.size > P9_ZC_HDR_SZ)) + req->rc.size = P9_ZC_HDR_SZ; + + // data won't span more than two pages + size = req->rc.size - in_hdr_len; + n = PAGE_SIZE - offs; + if (size > n) { + memcpy_from_page(to, *pages++, offs, n); + offs = 0; + to += n; + size -= n; + } + memcpy_from_page(to, *pages, offs, size); +} + +/** + * p9_virtio_zc_request - issue a zero copy request + * @client: client instance issuing the request + * @req: request to be issued + * @uidata: user buffer that should be used for zero copy read + * @uodata: user buffer that should be used for zero copy write + * @inlen: read buffer size + * @outlen: write buffer size + * @in_hdr_len: reader header size, This is the size of response protocol data + * + */ +static int +p9_virtio_zc_request(struct p9_client *client, struct p9_req_t *req, + struct iov_iter *uidata, struct iov_iter *uodata, + int inlen, int outlen, int in_hdr_len) +{ + int in, out, err, out_sgs, in_sgs; + unsigned long flags; + int in_nr_pages = 0, out_nr_pages = 0; + struct page **in_pages = NULL, **out_pages = NULL; + struct virtio_chan *chan = client->trans; + struct scatterlist *sgs[4]; + size_t offs = 0; + int need_drop = 0; + int kicked = 0; + + p9_debug(P9_DEBUG_TRANS, "virtio request\n"); + + if (uodata) { + __le32 sz; + int n = p9_get_mapped_pages(chan, &out_pages, uodata, + outlen, &offs, &need_drop); + if (n < 0) { + err = n; + goto err_out; + } + out_nr_pages = DIV_ROUND_UP(n + offs, PAGE_SIZE); + if (n != outlen) { + __le32 v = cpu_to_le32(n); + memcpy(&req->tc.sdata[req->tc.size - 4], &v, 4); + outlen = n; + } + /* The size field of the message must include the length of the + * header and the length of the data. We didn't actually know + * the length of the data until this point so add it in now. + */ + sz = cpu_to_le32(req->tc.size + outlen); + memcpy(&req->tc.sdata[0], &sz, sizeof(sz)); + } else if (uidata) { + int n = p9_get_mapped_pages(chan, &in_pages, uidata, + inlen, &offs, &need_drop); + if (n < 0) { + err = n; + goto err_out; + } + in_nr_pages = DIV_ROUND_UP(n + offs, PAGE_SIZE); + if (n != inlen) { + __le32 v = cpu_to_le32(n); + memcpy(&req->tc.sdata[req->tc.size - 4], &v, 4); + inlen = n; + } + } + WRITE_ONCE(req->status, REQ_STATUS_SENT); +req_retry_pinned: + spin_lock_irqsave(&chan->lock, flags); + + out_sgs = in_sgs = 0; + + /* out data */ + out = pack_sg_list(chan->sg, 0, + VIRTQUEUE_NUM, req->tc.sdata, req->tc.size); + + if (out) + sgs[out_sgs++] = chan->sg; + + if (out_pages) { + sgs[out_sgs++] = chan->sg + out; + out += pack_sg_list_p(chan->sg, out, VIRTQUEUE_NUM, + out_pages, out_nr_pages, offs, outlen); + } + + /* + * Take care of in data + * For example TREAD have 11. + * 11 is the read/write header = PDU Header(7) + IO Size (4). + * Arrange in such a way that server places header in the + * allocated memory and payload onto the user buffer. + */ + in = pack_sg_list(chan->sg, out, + VIRTQUEUE_NUM, req->rc.sdata, in_hdr_len); + if (in) + sgs[out_sgs + in_sgs++] = chan->sg + out; + + if (in_pages) { + sgs[out_sgs + in_sgs++] = chan->sg + out + in; + pack_sg_list_p(chan->sg, out + in, VIRTQUEUE_NUM, + in_pages, in_nr_pages, offs, inlen); + } + + BUG_ON(out_sgs + in_sgs > ARRAY_SIZE(sgs)); + err = virtqueue_add_sgs(chan->vq, sgs, out_sgs, in_sgs, req, + GFP_ATOMIC); + if (err < 0) { + if (err == -ENOSPC) { + chan->ring_bufs_avail = 0; + spin_unlock_irqrestore(&chan->lock, flags); + err = io_wait_event_killable(*chan->vc_wq, + chan->ring_bufs_avail); + if (err == -ERESTARTSYS) + goto err_out; + + p9_debug(P9_DEBUG_TRANS, "Retry virtio request\n"); + goto req_retry_pinned; + } else { + spin_unlock_irqrestore(&chan->lock, flags); + p9_debug(P9_DEBUG_TRANS, + "virtio rpc add_sgs returned failure\n"); + err = -EIO; + goto err_out; + } + } + virtqueue_kick(chan->vq); + spin_unlock_irqrestore(&chan->lock, flags); + kicked = 1; + p9_debug(P9_DEBUG_TRANS, "virtio request kicked\n"); + err = io_wait_event_killable(req->wq, + READ_ONCE(req->status) >= REQ_STATUS_RCVD); + /* + * Make sure our req is coherent with regard to updates in other + * threads - echoes to wmb() in the callback + */ + smp_rmb(); + // RERROR needs reply (== error string) in static data + if (READ_ONCE(req->status) == REQ_STATUS_RCVD && + unlikely(req->rc.sdata[4] == P9_RERROR)) + handle_rerror(req, in_hdr_len, offs, in_pages); + + /* + * Non kernel buffers are pinned, unpin them + */ +err_out: + if (need_drop) { + if (in_pages) { + p9_release_pages(in_pages, in_nr_pages); + atomic_sub(in_nr_pages, &vp_pinned); + } + if (out_pages) { + p9_release_pages(out_pages, out_nr_pages); + atomic_sub(out_nr_pages, &vp_pinned); + } + /* wakeup anybody waiting for slots to pin pages */ + wake_up(&vp_wq); + } + kvfree(in_pages); + kvfree(out_pages); + if (!kicked) { + /* reply won't come */ + p9_req_put(client, req); + } + return err; +} + +static ssize_t p9_mount_tag_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct virtio_chan *chan; + struct virtio_device *vdev; + int tag_len; + + vdev = dev_to_virtio(dev); + chan = vdev->priv; + tag_len = strlen(chan->tag); + + memcpy(buf, chan->tag, tag_len + 1); + + return tag_len + 1; +} + +static DEVICE_ATTR(mount_tag, 0444, p9_mount_tag_show, NULL); + +/** + * p9_virtio_probe - probe for existence of 9P virtio channels + * @vdev: virtio device to probe + * + * This probes for existing virtio channels. + * + */ + +static int p9_virtio_probe(struct virtio_device *vdev) +{ + __u16 tag_len; + char *tag; + int err; + struct virtio_chan *chan; + + if (!vdev->config->get) { + dev_err(&vdev->dev, "%s failure: config access disabled\n", + __func__); + return -EINVAL; + } + + chan = kmalloc_obj(struct virtio_chan); + if (!chan) { + pr_err("Failed to allocate virtio 9P channel\n"); + err = -ENOMEM; + goto fail; + } + + chan->vdev = vdev; + + /* We expect one virtqueue, for requests. */ + chan->vq = virtio_find_single_vq(vdev, req_done, "requests"); + if (IS_ERR(chan->vq)) { + err = PTR_ERR(chan->vq); + goto out_free_chan; + } + chan->vq->vdev->priv = chan; + spin_lock_init(&chan->lock); + + sg_init_table(chan->sg, VIRTQUEUE_NUM); + + chan->inuse = false; + if (virtio_has_feature(vdev, VIRTIO_9P_MOUNT_TAG)) { + virtio_cread(vdev, struct virtio_9p_config, tag_len, &tag_len); + } else { + err = -EINVAL; + goto out_free_vq; + } + tag = kzalloc(tag_len + 1, GFP_KERNEL); + if (!tag) { + err = -ENOMEM; + goto out_free_vq; + } + + virtio_cread_bytes(vdev, offsetof(struct virtio_9p_config, tag), + tag, tag_len); + chan->tag = tag; + err = sysfs_create_file(&(vdev->dev.kobj), &dev_attr_mount_tag.attr); + if (err) { + goto out_free_tag; + } + chan->vc_wq = kmalloc_obj(wait_queue_head_t); + if (!chan->vc_wq) { + err = -ENOMEM; + goto out_remove_file; + } + init_waitqueue_head(chan->vc_wq); + chan->ring_bufs_avail = 1; + /* Ceiling limit to avoid denial of service attacks */ + chan->p9_max_pages = nr_free_buffer_pages()/4; + + virtio_device_ready(vdev); + + mutex_lock(&virtio_9p_lock); + list_add_tail(&chan->chan_list, &virtio_chan_list); + mutex_unlock(&virtio_9p_lock); + + /* Let udev rules use the new mount_tag attribute. */ + kobject_uevent(&(vdev->dev.kobj), KOBJ_CHANGE); + + return 0; + +out_remove_file: + sysfs_remove_file(&vdev->dev.kobj, &dev_attr_mount_tag.attr); +out_free_tag: + kfree(tag); +out_free_vq: + vdev->config->del_vqs(vdev); +out_free_chan: + kfree(chan); +fail: + return err; +} + + +/** + * p9_virtio_create - allocate a new virtio channel + * @client: client instance invoking this transport + * @fc: the filesystem context + * + * This sets up a transport channel for 9p communication. Right now + * we only match the first available channel, but eventually we could look up + * alternate channels by matching devname versus a virtio_config entry. + * We use a simple reference count mechanism to ensure that only a single + * mount has a channel open at a time. + * + */ + +static int +p9_virtio_create(struct p9_client *client, struct fs_context *fc) +{ + const char *devname = fc->source; + struct virtio_chan *chan; + int ret = -ENOENT; + int found = 0; + + if (devname == NULL) + return -EINVAL; + + mutex_lock(&virtio_9p_lock); + list_for_each_entry(chan, &virtio_chan_list, chan_list) { + if (!strcmp(devname, chan->tag)) { + if (!chan->inuse) { + chan->inuse = true; + found = 1; + break; + } + ret = -EBUSY; + } + } + mutex_unlock(&virtio_9p_lock); + + if (!found) { + pr_err("no channels available for device %s\n", devname); + return ret; + } + + client->trans = (void *)chan; + client->status = Connected; + chan->client = client; + + return 0; +} + +/** + * p9_virtio_remove - clean up resources associated with a virtio device + * @vdev: virtio device to remove + * + */ + +static void p9_virtio_remove(struct virtio_device *vdev) +{ + struct virtio_chan *chan = vdev->priv; + unsigned long warning_time; + + mutex_lock(&virtio_9p_lock); + + /* Remove self from list so we don't get new users. */ + list_del(&chan->chan_list); + warning_time = jiffies; + + /* Wait for existing users to close. */ + while (chan->inuse) { + mutex_unlock(&virtio_9p_lock); + msleep(250); + if (time_after(jiffies, warning_time + 10 * HZ)) { + dev_emerg(&vdev->dev, + "p9_virtio_remove: waiting for device in use.\n"); + warning_time = jiffies; + } + mutex_lock(&virtio_9p_lock); + } + + mutex_unlock(&virtio_9p_lock); + + virtio_reset_device(vdev); + vdev->config->del_vqs(vdev); + + sysfs_remove_file(&(vdev->dev.kobj), &dev_attr_mount_tag.attr); + kobject_uevent(&(vdev->dev.kobj), KOBJ_CHANGE); + kfree(chan->tag); + kfree(chan->vc_wq); + kfree(chan); + +} + +static struct virtio_device_id id_table[] = { + { VIRTIO_ID_9P, VIRTIO_DEV_ANY_ID }, + { 0 }, +}; + +static unsigned int features[] = { + VIRTIO_9P_MOUNT_TAG, +}; + +/* The standard "struct lguest_driver": */ +static struct virtio_driver p9_virtio_drv = { + .feature_table = features, + .feature_table_size = ARRAY_SIZE(features), + .driver.name = KBUILD_MODNAME, + .id_table = id_table, + .probe = p9_virtio_probe, + .remove = p9_virtio_remove, +}; + +static struct p9_trans_module p9_virtio_trans = { + .name = "virtio", + .create = p9_virtio_create, + .close = p9_virtio_close, + .request = p9_virtio_request, + .zc_request = p9_virtio_zc_request, + .cancel = p9_virtio_cancel, + .cancelled = p9_virtio_cancelled, + /* + * We leave one entry for input and one entry for response + * headers. We also skip one more entry to accommodate, address + * that are not at page boundary, that can result in an extra + * page in zero copy. + */ + .maxsize = PAGE_SIZE * (VIRTQUEUE_NUM - 3), + .pooled_rbuffers = false, + .def = true, + .supports_vmalloc = false, + .owner = THIS_MODULE, +}; + +/* The standard init function */ +static int __init p9_virtio_init(void) +{ + int rc; + + INIT_LIST_HEAD(&virtio_chan_list); + + v9fs_register_trans(&p9_virtio_trans); + rc = register_virtio_driver(&p9_virtio_drv); + if (rc) + v9fs_unregister_trans(&p9_virtio_trans); + + return rc; +} + +static void __exit p9_virtio_cleanup(void) +{ + unregister_virtio_driver(&p9_virtio_drv); + v9fs_unregister_trans(&p9_virtio_trans); +} + +module_init(p9_virtio_init); +module_exit(p9_virtio_cleanup); +MODULE_ALIAS_9P("virtio"); + +MODULE_DEVICE_TABLE(virtio, id_table); +MODULE_AUTHOR("Eric Van Hensbergen "); +MODULE_DESCRIPTION("Virtio 9p Transport"); +MODULE_LICENSE("GPL"); diff --git a/net/9p/trans_xen.c b/net/9p/trans_xen.c new file mode 100644 index 000000000..f9fb2db7a --- /dev/null +++ b/net/9p/trans_xen.c @@ -0,0 +1,607 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * linux/fs/9p/trans_xen + * + * Xen transport layer. + * + * Copyright (C) 2017 by Stefano Stabellini + */ + +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#include + +#define XEN_9PFS_NUM_RINGS 2 +#define XEN_9PFS_RING_ORDER 9 +#define XEN_9PFS_RING_SIZE(ring) XEN_FLEX_RING_SIZE(ring->intf->ring_order) + +struct xen_9pfs_header { + uint32_t size; + uint8_t id; + uint16_t tag; + + /* uint8_t sdata[]; */ +} __attribute__((packed)); + +/* One per ring, more than one per 9pfs share */ +struct xen_9pfs_dataring { + struct xen_9pfs_front_priv *priv; + + struct xen_9pfs_data_intf *intf; + grant_ref_t ref; + int evtchn; + int irq; + /* protect a ring from concurrent accesses */ + spinlock_t lock; + + struct xen_9pfs_data data; + wait_queue_head_t wq; + struct work_struct work; +}; + +/* One per 9pfs share */ +struct xen_9pfs_front_priv { + struct list_head list; + struct xenbus_device *dev; + char *tag; + struct p9_client *client; + + struct xen_9pfs_dataring *rings; +}; + +static LIST_HEAD(xen_9pfs_devs); +static DEFINE_RWLOCK(xen_9pfs_lock); + +/* We don't currently allow canceling of requests */ +static int p9_xen_cancel(struct p9_client *client, struct p9_req_t *req) +{ + return 1; +} + +static int p9_xen_create(struct p9_client *client, struct fs_context *fc) +{ + const char *addr = fc->source; + struct xen_9pfs_front_priv *priv; + + if (addr == NULL) + return -EINVAL; + + read_lock(&xen_9pfs_lock); + list_for_each_entry(priv, &xen_9pfs_devs, list) { + if (!strcmp(priv->tag, addr)) { + priv->client = client; + read_unlock(&xen_9pfs_lock); + return 0; + } + } + read_unlock(&xen_9pfs_lock); + return -EINVAL; +} + +static void p9_xen_close(struct p9_client *client) +{ + struct xen_9pfs_front_priv *priv; + + read_lock(&xen_9pfs_lock); + list_for_each_entry(priv, &xen_9pfs_devs, list) { + if (priv->client == client) { + priv->client = NULL; + read_unlock(&xen_9pfs_lock); + return; + } + } + read_unlock(&xen_9pfs_lock); +} + +static bool p9_xen_write_todo(struct xen_9pfs_dataring *ring, RING_IDX size) +{ + RING_IDX cons, prod; + + cons = ring->intf->out_cons; + prod = ring->intf->out_prod; + virt_mb(); + + return XEN_9PFS_RING_SIZE(ring) - + xen_9pfs_queued(prod, cons, XEN_9PFS_RING_SIZE(ring)) >= size; +} + +static int p9_xen_request(struct p9_client *client, struct p9_req_t *p9_req) +{ + struct xen_9pfs_front_priv *priv; + RING_IDX cons, prod, masked_cons, masked_prod; + unsigned long flags; + u32 size = p9_req->tc.size; + struct xen_9pfs_dataring *ring; + int num; + + read_lock(&xen_9pfs_lock); + list_for_each_entry(priv, &xen_9pfs_devs, list) { + if (priv->client == client) + break; + } + read_unlock(&xen_9pfs_lock); + if (list_entry_is_head(priv, &xen_9pfs_devs, list)) + return -EINVAL; + + num = p9_req->tc.tag % XEN_9PFS_NUM_RINGS; + ring = &priv->rings[num]; + +again: + while (io_wait_event_killable(ring->wq, + p9_xen_write_todo(ring, size)) != 0) + ; + + spin_lock_irqsave(&ring->lock, flags); + cons = ring->intf->out_cons; + prod = ring->intf->out_prod; + virt_mb(); + + if (XEN_9PFS_RING_SIZE(ring) - + xen_9pfs_queued(prod, cons, XEN_9PFS_RING_SIZE(ring)) < size) { + spin_unlock_irqrestore(&ring->lock, flags); + goto again; + } + + masked_prod = xen_9pfs_mask(prod, XEN_9PFS_RING_SIZE(ring)); + masked_cons = xen_9pfs_mask(cons, XEN_9PFS_RING_SIZE(ring)); + + xen_9pfs_write_packet(ring->data.out, p9_req->tc.sdata, size, + &masked_prod, masked_cons, + XEN_9PFS_RING_SIZE(ring)); + + WRITE_ONCE(p9_req->status, REQ_STATUS_SENT); + virt_wmb(); /* write ring before updating pointer */ + prod += size; + ring->intf->out_prod = prod; + spin_unlock_irqrestore(&ring->lock, flags); + notify_remote_via_irq(ring->irq); + p9_req_put(client, p9_req); + + return 0; +} + +static void p9_xen_response(struct work_struct *work) +{ + struct xen_9pfs_front_priv *priv; + struct xen_9pfs_dataring *ring; + RING_IDX cons, prod, masked_cons, masked_prod; + struct xen_9pfs_header h; + struct p9_req_t *req; + int status; + + ring = container_of(work, struct xen_9pfs_dataring, work); + priv = ring->priv; + + while (1) { + cons = ring->intf->in_cons; + prod = ring->intf->in_prod; + virt_rmb(); + + if (xen_9pfs_queued(prod, cons, XEN_9PFS_RING_SIZE(ring)) < + sizeof(h)) { + notify_remote_via_irq(ring->irq); + return; + } + + masked_prod = xen_9pfs_mask(prod, XEN_9PFS_RING_SIZE(ring)); + masked_cons = xen_9pfs_mask(cons, XEN_9PFS_RING_SIZE(ring)); + + /* First, read just the header */ + xen_9pfs_read_packet(&h, ring->data.in, sizeof(h), + masked_prod, &masked_cons, + XEN_9PFS_RING_SIZE(ring)); + + req = p9_tag_lookup(priv->client, h.tag); + if (!req || req->status != REQ_STATUS_SENT) { + dev_warn(&priv->dev->dev, "Wrong req tag=%x\n", h.tag); + cons += h.size; + virt_mb(); + ring->intf->in_cons = cons; + continue; + } + + if (h.size > req->rc.capacity) { + dev_warn(&priv->dev->dev, + "requested packet size too big: %d for tag %d with capacity %zd\n", + h.size, h.tag, req->rc.capacity); + WRITE_ONCE(req->status, REQ_STATUS_ERROR); + goto recv_error; + } + + req->rc.size = h.size; + req->rc.id = h.id; + req->rc.tag = h.tag; + req->rc.offset = 0; + + masked_cons = xen_9pfs_mask(cons, XEN_9PFS_RING_SIZE(ring)); + /* Then, read the whole packet (including the header) */ + xen_9pfs_read_packet(req->rc.sdata, ring->data.in, h.size, + masked_prod, &masked_cons, + XEN_9PFS_RING_SIZE(ring)); + +recv_error: + virt_mb(); + cons += h.size; + ring->intf->in_cons = cons; + + status = (req->status != REQ_STATUS_ERROR) ? + REQ_STATUS_RCVD : REQ_STATUS_ERROR; + + p9_client_cb(priv->client, req, status); + } +} + +static irqreturn_t xen_9pfs_front_event_handler(int irq, void *r) +{ + struct xen_9pfs_dataring *ring = r; + + if (!ring || !ring->priv->client) { + /* ignore spurious interrupt */ + return IRQ_HANDLED; + } + + wake_up_interruptible(&ring->wq); + schedule_work(&ring->work); + + return IRQ_HANDLED; +} + +static struct p9_trans_module p9_xen_trans = { + .name = "xen", + .maxsize = 1 << (XEN_9PFS_RING_ORDER + XEN_PAGE_SHIFT - 2), + .pooled_rbuffers = false, + .def = true, + .supports_vmalloc = false, + .create = p9_xen_create, + .close = p9_xen_close, + .request = p9_xen_request, + .cancel = p9_xen_cancel, + .owner = THIS_MODULE, +}; + +static const struct xenbus_device_id xen_9pfs_front_ids[] = { + { "9pfs" }, + { "" } +}; + +static void xen_9pfs_front_free(struct xen_9pfs_front_priv *priv) +{ + int i, j; + + if (priv->rings) { + for (i = 0; i < XEN_9PFS_NUM_RINGS; i++) { + struct xen_9pfs_dataring *ring = &priv->rings[i]; + + cancel_work_sync(&ring->work); + + if (!ring->intf) + break; + if (ring->irq >= 0) { + unbind_from_irqhandler(ring->irq, ring); + ring->irq = -1; + } + if (ring->data.in) { + for (j = 0; j < (1 << ring->intf->ring_order); + j++) { + grant_ref_t ref; + + ref = ring->intf->ref[j]; + gnttab_end_foreign_access(ref, NULL); + ring->intf->ref[j] = INVALID_GRANT_REF; + } + free_pages_exact(ring->data.in, + 1UL << (ring->intf->ring_order + + XEN_PAGE_SHIFT)); + ring->data.in = NULL; + ring->data.out = NULL; + } + if (ring->ref != INVALID_GRANT_REF) { + gnttab_end_foreign_access(ring->ref, NULL); + ring->ref = INVALID_GRANT_REF; + } + free_page((unsigned long)ring->intf); + ring->intf = NULL; + } + kfree(priv->rings); + } + kfree(priv->tag); + kfree(priv); +} + +static void xen_9pfs_front_remove(struct xenbus_device *dev) +{ + struct xen_9pfs_front_priv *priv; + + write_lock(&xen_9pfs_lock); + priv = dev_get_drvdata(&dev->dev); + if (priv == NULL) { + write_unlock(&xen_9pfs_lock); + return; + } + dev_set_drvdata(&dev->dev, NULL); + list_del(&priv->list); + write_unlock(&xen_9pfs_lock); + + xen_9pfs_front_free(priv); +} + +static int xen_9pfs_front_alloc_dataring(struct xenbus_device *dev, + struct xen_9pfs_dataring *ring, + unsigned int order) +{ + int i = 0; + int ret = -ENOMEM; + void *bytes = NULL; + + ring->intf = NULL; + ring->data.in = NULL; + ring->data.out = NULL; + ring->ref = INVALID_GRANT_REF; + ring->irq = -1; + + init_waitqueue_head(&ring->wq); + spin_lock_init(&ring->lock); + INIT_WORK(&ring->work, p9_xen_response); + + ring->intf = (struct xen_9pfs_data_intf *)get_zeroed_page(GFP_KERNEL); + if (!ring->intf) + return ret; + ret = gnttab_grant_foreign_access(dev->otherend_id, + virt_to_gfn(ring->intf), 0); + if (ret < 0) + goto out; + ring->ref = ret; + bytes = alloc_pages_exact(1UL << (order + XEN_PAGE_SHIFT), + GFP_KERNEL | __GFP_ZERO); + if (!bytes) { + ret = -ENOMEM; + goto out; + } + for (; i < (1 << order); i++) { + ret = gnttab_grant_foreign_access( + dev->otherend_id, virt_to_gfn(bytes) + i, 0); + if (ret < 0) + goto out; + ring->intf->ref[i] = ret; + } + ring->intf->ring_order = order; + ring->data.in = bytes; + ring->data.out = bytes + XEN_FLEX_RING_SIZE(order); + + ret = xenbus_alloc_evtchn(dev, &ring->evtchn); + if (ret) + goto out; + ring->irq = bind_evtchn_to_irqhandler(ring->evtchn, + xen_9pfs_front_event_handler, + 0, "xen_9pfs-frontend", ring); + if (ring->irq >= 0) + return 0; + + xenbus_free_evtchn(dev, ring->evtchn); + ret = ring->irq; +out: + if (bytes) { + for (i--; i >= 0; i--) + gnttab_end_foreign_access(ring->intf->ref[i], NULL); + free_pages_exact(bytes, 1UL << (order + XEN_PAGE_SHIFT)); + ring->data.in = NULL; + ring->data.out = NULL; + } + if (ring->ref != INVALID_GRANT_REF) { + gnttab_end_foreign_access(ring->ref, NULL); + ring->ref = INVALID_GRANT_REF; + } + if (ring->intf) { + free_page((unsigned long)ring->intf); + ring->intf = NULL; + } + ring->irq = -1; + return ret; +} + +static int xen_9pfs_front_init(struct xenbus_device *dev) +{ + int ret, i; + struct xenbus_transaction xbt; + struct xen_9pfs_front_priv *priv; + char *versions, *v, *token; + bool version_1 = false; + unsigned int max_rings, max_ring_order, len = 0, version; + + versions = xenbus_read(XBT_NIL, dev->otherend, "versions", &len); + if (IS_ERR(versions)) + return PTR_ERR(versions); + for (v = versions; (token = strsep(&v, ",")); ) { + if (!*token) + continue; + + ret = kstrtouint(token, 10, &version); + if (ret) { + kfree(versions); + return ret; + } + if (version == 1) + version_1 = true; + } + kfree(versions); + if (!version_1) + return -EINVAL; + + max_rings = xenbus_read_unsigned(dev->otherend, "max-rings", 0); + if (max_rings < XEN_9PFS_NUM_RINGS) + return -EINVAL; + max_ring_order = xenbus_read_unsigned(dev->otherend, + "max-ring-page-order", 0); + if (max_ring_order > XEN_9PFS_RING_ORDER) + max_ring_order = XEN_9PFS_RING_ORDER; + if (p9_xen_trans.maxsize > XEN_FLEX_RING_SIZE(max_ring_order)) + p9_xen_trans.maxsize = XEN_FLEX_RING_SIZE(max_ring_order) / 2; + + priv = kzalloc_obj(*priv); + if (!priv) + return -ENOMEM; + priv->dev = dev; + priv->rings = kzalloc_objs(*priv->rings, XEN_9PFS_NUM_RINGS); + if (!priv->rings) { + kfree(priv); + return -ENOMEM; + } + + for (i = 0; i < XEN_9PFS_NUM_RINGS; i++) { + priv->rings[i].priv = priv; + ret = xen_9pfs_front_alloc_dataring(dev, &priv->rings[i], + max_ring_order); + if (ret < 0) + goto error; + } + + again: + ret = xenbus_transaction_start(&xbt); + if (ret) { + xenbus_dev_fatal(dev, ret, "starting transaction"); + goto error; + } + ret = xenbus_printf(xbt, dev->nodename, "version", "%u", 1); + if (ret) + goto error_xenbus; + ret = xenbus_printf(xbt, dev->nodename, "num-rings", "%u", + XEN_9PFS_NUM_RINGS); + if (ret) + goto error_xenbus; + + for (i = 0; i < XEN_9PFS_NUM_RINGS; i++) { + char str[16]; + + BUILD_BUG_ON(XEN_9PFS_NUM_RINGS > 9); + sprintf(str, "ring-ref%d", i); + ret = xenbus_printf(xbt, dev->nodename, str, "%d", + priv->rings[i].ref); + if (ret) + goto error_xenbus; + + sprintf(str, "event-channel-%d", i); + ret = xenbus_printf(xbt, dev->nodename, str, "%u", + priv->rings[i].evtchn); + if (ret) + goto error_xenbus; + } + priv->tag = xenbus_read(xbt, dev->nodename, "tag", NULL); + if (IS_ERR(priv->tag)) { + ret = PTR_ERR(priv->tag); + goto error_xenbus; + } + ret = xenbus_transaction_end(xbt, 0); + if (ret) { + if (ret == -EAGAIN) + goto again; + xenbus_dev_fatal(dev, ret, "completing transaction"); + goto error; + } + + write_lock(&xen_9pfs_lock); + dev_set_drvdata(&dev->dev, priv); + list_add_tail(&priv->list, &xen_9pfs_devs); + write_unlock(&xen_9pfs_lock); + + xenbus_switch_state(dev, XenbusStateInitialised); + return 0; + + error_xenbus: + xenbus_transaction_end(xbt, 1); + xenbus_dev_fatal(dev, ret, "writing xenstore"); + error: + xen_9pfs_front_free(priv); + return ret; +} + +static int xen_9pfs_front_probe(struct xenbus_device *dev, + const struct xenbus_device_id *id) +{ + return 0; +} + +static int xen_9pfs_front_resume(struct xenbus_device *dev) +{ + dev_warn(&dev->dev, "suspend/resume unsupported\n"); + return 0; +} + +static void xen_9pfs_front_changed(struct xenbus_device *dev, + enum xenbus_state backend_state) +{ + switch (backend_state) { + case XenbusStateReconfiguring: + case XenbusStateReconfigured: + case XenbusStateInitialising: + case XenbusStateInitialised: + case XenbusStateUnknown: + break; + + case XenbusStateInitWait: + if (dev->state != XenbusStateInitialising) + break; + + xen_9pfs_front_init(dev); + break; + + case XenbusStateConnected: + xenbus_switch_state(dev, XenbusStateConnected); + break; + + case XenbusStateClosed: + if (dev->state == XenbusStateClosed) + break; + fallthrough; /* Missed the backend's CLOSING state */ + case XenbusStateClosing: + xenbus_frontend_closed(dev); + break; + } +} + +static struct xenbus_driver xen_9pfs_front_driver = { + .ids = xen_9pfs_front_ids, + .probe = xen_9pfs_front_probe, + .remove = xen_9pfs_front_remove, + .resume = xen_9pfs_front_resume, + .otherend_changed = xen_9pfs_front_changed, +}; + +static int __init p9_trans_xen_init(void) +{ + int rc; + + if (!xen_domain()) + return -ENODEV; + + pr_info("Initialising Xen transport for 9pfs\n"); + + v9fs_register_trans(&p9_xen_trans); + rc = xenbus_register_frontend(&xen_9pfs_front_driver); + if (rc) + v9fs_unregister_trans(&p9_xen_trans); + + return rc; +} +module_init(p9_trans_xen_init); +MODULE_ALIAS_9P("xen"); + +static void __exit p9_trans_xen_exit(void) +{ + v9fs_unregister_trans(&p9_xen_trans); + return xenbus_unregister_driver(&xen_9pfs_front_driver); +} +module_exit(p9_trans_xen_exit); + +MODULE_ALIAS("xen:9pfs"); +MODULE_AUTHOR("Stefano Stabellini "); +MODULE_DESCRIPTION("Xen Transport for 9P"); +MODULE_LICENSE("GPL"); -- cgit v1.3.1