From ee443996a35c1e04f210cafd43d5a98d41e46085 Mon Sep 17 00:00:00 2001 From: Eric Van Hensbergen Date: Wed, 5 Mar 2008 07:08:09 -0600 Subject: 9p: Documentation updates The kernel-doc comments of much of the 9p system have been in disarray since reorganization. This patch fixes those problems, adds additional documentation and a template book which collects the 9p information. Signed-off-by: Eric Van Hensbergen --- net/9p/conv.c | 128 ++++++++++++++++++++++++++++++++++++++++- net/9p/error.c | 11 +++- net/9p/fcprint.c | 8 +++ net/9p/mod.c | 7 +-- net/9p/trans_fd.c | 146 ++++++++++++++++++++++++++++++++++++++++------- net/9p/trans_virtio.c | 155 ++++++++++++++++++++++++++++++++++++++++++++++---- net/9p/util.c | 32 +++++++++-- 7 files changed, 441 insertions(+), 46 deletions(-) (limited to 'net/9p') diff --git a/net/9p/conv.c b/net/9p/conv.c index 3fe35d532c87..44547201f5bc 100644 --- a/net/9p/conv.c +++ b/net/9p/conv.c @@ -197,7 +197,7 @@ static void buf_get_qid(struct cbuf *bufp, struct p9_qid *qid) /** * p9_size_wstat - calculate the size of a variable length stat struct - * @stat: metadata (stat) structure + * @wstat: metadata (stat) structure * @dotu: non-zero if 9P2000.u * */ @@ -511,6 +511,12 @@ p9_create_common(struct cbuf *bufp, u32 size, u8 id) return fc; } +/** + * p9_set_tag - set the tag field of an &p9_fcall structure + * @fc: fcall structure to set tag within + * @tag: tag id to set + */ + void p9_set_tag(struct p9_fcall *fc, u16 tag) { fc->tag = tag; @@ -518,6 +524,12 @@ void p9_set_tag(struct p9_fcall *fc, u16 tag) } EXPORT_SYMBOL(p9_set_tag); +/** + * p9_create_tversion - allocates and creates a T_VERSION request + * @msize: requested maximum data size + * @version: version string to negotiate + * + */ struct p9_fcall *p9_create_tversion(u32 msize, char *version) { int size; @@ -542,6 +554,16 @@ error: } EXPORT_SYMBOL(p9_create_tversion); +/** + * p9_create_tauth - allocates and creates a T_AUTH request + * @afid: handle to use for authentication protocol + * @uname: user name attempting to authenticate + * @aname: mount specifier for remote server + * @n_uname: numeric id for user attempting to authneticate + * @dotu: 9P2000.u extension flag + * + */ + struct p9_fcall *p9_create_tauth(u32 afid, char *uname, char *aname, u32 n_uname, int dotu) { @@ -580,6 +602,18 @@ error: } EXPORT_SYMBOL(p9_create_tauth); +/** + * p9_create_tattach - allocates and creates a T_ATTACH request + * @fid: handle to use for the new mount point + * @afid: handle to use for authentication protocol + * @uname: user name attempting to attach + * @aname: mount specifier for remote server + * @n_uname: numeric id for user attempting to attach + * @n_uname: numeric id for user attempting to attach + * @dotu: 9P2000.u extension flag + * + */ + struct p9_fcall * p9_create_tattach(u32 fid, u32 afid, char *uname, char *aname, u32 n_uname, int dotu) @@ -616,6 +650,12 @@ error: } EXPORT_SYMBOL(p9_create_tattach); +/** + * p9_create_tflush - allocates and creates a T_FLUSH request + * @oldtag: tag id for the transaction we are attempting to cancel + * + */ + struct p9_fcall *p9_create_tflush(u16 oldtag) { int size; @@ -639,6 +679,15 @@ error: } EXPORT_SYMBOL(p9_create_tflush); +/** + * p9_create_twalk - allocates and creates a T_FLUSH request + * @fid: handle we are traversing from + * @newfid: a new handle for this transaction + * @nwname: number of path elements to traverse + * @wnames: array of path elements + * + */ + struct p9_fcall *p9_create_twalk(u32 fid, u32 newfid, u16 nwname, char **wnames) { @@ -677,6 +726,13 @@ error: } EXPORT_SYMBOL(p9_create_twalk); +/** + * p9_create_topen - allocates and creates a T_OPEN request + * @fid: handle we are trying to open + * @mode: what mode we are trying to open the file in + * + */ + struct p9_fcall *p9_create_topen(u32 fid, u8 mode) { int size; @@ -701,6 +757,19 @@ error: } EXPORT_SYMBOL(p9_create_topen); +/** + * p9_create_tcreate - allocates and creates a T_CREATE request + * @fid: handle of directory we are trying to create in + * @name: name of the file we are trying to create + * @perm: permissions for the file we are trying to create + * @mode: what mode we are trying to open the file in + * @extension: 9p2000.u extension string (for special files) + * @dotu: 9p2000.u enabled flag + * + * Note: Plan 9 create semantics include opening the resulting file + * which is why mode is included. + */ + struct p9_fcall *p9_create_tcreate(u32 fid, char *name, u32 perm, u8 mode, char *extension, int dotu) { @@ -736,6 +805,13 @@ error: } EXPORT_SYMBOL(p9_create_tcreate); +/** + * p9_create_tread - allocates and creates a T_READ request + * @fid: handle of the file we are trying to read + * @offset: offset to start reading from + * @count: how many bytes to read + */ + struct p9_fcall *p9_create_tread(u32 fid, u64 offset, u32 count) { int size; @@ -761,6 +837,17 @@ error: } EXPORT_SYMBOL(p9_create_tread); +/** + * p9_create_twrite - allocates and creates a T_WRITE request from the kernel + * @fid: handle of the file we are trying to write + * @offset: offset to start writing at + * @count: how many bytes to write + * @data: data to write + * + * This function will create a requst with data buffers from the kernel + * such as the page cache. + */ + struct p9_fcall *p9_create_twrite(u32 fid, u64 offset, u32 count, const char *data) { @@ -794,6 +881,16 @@ error: } EXPORT_SYMBOL(p9_create_twrite); +/** + * p9_create_twrite_u - allocates and creates a T_WRITE request from userspace + * @fid: handle of the file we are trying to write + * @offset: offset to start writing at + * @count: how many bytes to write + * @data: data to write + * + * This function will create a request with data buffers from userspace + */ + struct p9_fcall *p9_create_twrite_u(u32 fid, u64 offset, u32 count, const char __user *data) { @@ -827,6 +924,14 @@ error: } EXPORT_SYMBOL(p9_create_twrite_u); +/** + * p9_create_tclunk - allocate a request to forget about a file handle + * @fid: handle of the file we closing or forgetting about + * + * clunk is used both to close open files and to discard transient handles + * which may be created during meta-data operations and hierarchy traversal. + */ + struct p9_fcall *p9_create_tclunk(u32 fid) { int size; @@ -850,6 +955,12 @@ error: } EXPORT_SYMBOL(p9_create_tclunk); +/** + * p9_create_tremove - allocate and create a request to remove a file + * @fid: handle of the file or directory we are removing + * + */ + struct p9_fcall *p9_create_tremove(u32 fid) { int size; @@ -873,6 +984,12 @@ error: } EXPORT_SYMBOL(p9_create_tremove); +/** + * p9_create_tstat - allocate and populate a request for attributes + * @fid: handle of the file or directory we are trying to get the attributes of + * + */ + struct p9_fcall *p9_create_tstat(u32 fid) { int size; @@ -896,6 +1013,14 @@ error: } EXPORT_SYMBOL(p9_create_tstat); +/** + * p9_create_tstat - allocate and populate a request to change attributes + * @fid: handle of the file or directory we are trying to change + * @wstat: &p9_stat structure with attributes we wish to set + * @dotu: 9p2000.u enabled flag + * + */ + struct p9_fcall *p9_create_twstat(u32 fid, struct p9_wstat *wstat, int dotu) { @@ -922,3 +1047,4 @@ error: return fc; } EXPORT_SYMBOL(p9_create_twstat); + diff --git a/net/9p/error.c b/net/9p/error.c index 64104b9cb422..388770c3631e 100644 --- a/net/9p/error.c +++ b/net/9p/error.c @@ -33,6 +33,13 @@ #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; @@ -177,8 +184,7 @@ static struct errormap errmap[] = { }; /** - * p9_error_init - preload - * @errstr: error string + * p9_error_init - preload mappings into hash list * */ @@ -206,6 +212,7 @@ EXPORT_SYMBOL(p9_error_init); /** * errstr2errno - convert error string to error number * @errstr: error string + * @len: length of error string * */ diff --git a/net/9p/fcprint.c b/net/9p/fcprint.c index 40244fbd9b0d..53dd8e28dd8a 100644 --- a/net/9p/fcprint.c +++ b/net/9p/fcprint.c @@ -142,6 +142,14 @@ p9_printdata(char *buf, int buflen, u8 *data, int datalen) return p9_dumpdata(buf, buflen, data, datalen < 16?datalen:16); } +/** + * p9_printfcall - decode and print a protocol structure into a buffer + * @buf: buffer to deposit decoded structure into + * @buflen: available space in buffer + * @fc: protocol rpc structure of type &p9_fcall + * @extended: whether or not session is operating with extended protocol + */ + int p9_printfcall(char *buf, int buflen, struct p9_fcall *fc, int extended) { diff --git a/net/9p/mod.c b/net/9p/mod.c index c285aab2af04..c6d9695949e0 100644 --- a/net/9p/mod.c +++ b/net/9p/mod.c @@ -39,9 +39,6 @@ module_param_named(debug, p9_debug_level, uint, 0); MODULE_PARM_DESC(debug, "9P debugging level"); #endif -extern int p9_mux_global_init(void); -extern void p9_mux_global_exit(void); - /* * Dynamic Transport Registration Routines * @@ -52,7 +49,7 @@ static struct p9_trans_module *v9fs_default_transport; /** * v9fs_register_trans - register a new transport with 9p - * @m - structure describing the transport module and entry points + * @m: structure describing the transport module and entry points * */ void v9fs_register_trans(struct p9_trans_module *m) @@ -65,7 +62,7 @@ EXPORT_SYMBOL(v9fs_register_trans); /** * v9fs_match_trans - match transport versus registered transports - * @arg: string identifying transport + * @name: string identifying transport * */ struct p9_trans_module *v9fs_match_trans(const substring_t *name) diff --git a/net/9p/trans_fd.c b/net/9p/trans_fd.c index f624dff76852..c6eda999fa7d 100644 --- a/net/9p/trans_fd.c +++ b/net/9p/trans_fd.c @@ -47,12 +47,29 @@ #define SCHED_TIMEOUT 10 #define MAXPOLLWADDR 2 +/** + * struct p9_fd_opts - per-transport options + * @rfd: file descriptor for reading (trans=fd) + * @wfd: file descriptor for writing (trans=fd) + * @port: port to connect to (trans=tcp) + * + */ + struct p9_fd_opts { int rfd; int wfd; u16 port; }; + +/** + * 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; @@ -90,10 +107,24 @@ enum { }; struct p9_req; - typedef void (*p9_conn_req_callback)(struct p9_req *req, void *a); + +/** + * struct p9_req - fd mux encoding of an rpc transaction + * @lock: protects req_list + * @tag: numeric tag for rpc transaction + * @tcall: request &p9_fcall structure + * @rcall: response &p9_fcall structure + * @err: error state + * @cb: callback for when response is received + * @cba: argument to pass to callback + * @flush: flag to indicate RPC has been flushed + * @req_list: list link for higher level objects to chain requests + * + */ + struct p9_req { - spinlock_t lock; /* protect request structure */ + spinlock_t lock; int tag; struct p9_fcall *tcall; struct p9_fcall *rcall; @@ -104,7 +135,39 @@ struct p9_req { struct list_head req_list; }; -struct p9_mux_poll_task; +struct p9_mux_poll_task { + struct task_struct *task; + struct list_head mux_list; + int muxnum; +}; + +/** + * struct p9_conn - fd mux connection state information + * @lock: protects mux_list (?) + * @mux_list: list link for mux to manage multiple connections (?) + * @poll_task: task polling on this connection + * @msize: maximum size for connection (dup) + * @extended: 9p2000.u flag (dup) + * @trans: reference to transport instance for this connection + * @tagpool: id accounting for transactions + * @err: error state + * @equeue: event wait_q (?) + * @req_list: accounting for requests which have been sent + * @unsent_req_list: accounting for requests that haven't been sent + * @rcall: current response &p9_fcall structure + * @rpos: read position in current frame + * @rbuf: current read buffer + * @wpos: write position for current frame + * @wsize: amount of data to write for current frame + * @wbuf: current write buffer + * @poll_wait: array of wait_q's for various worker threads + * @poll_waddr: ???? + * @pt: poll state + * @rq: current read work + * @wq: current write work + * @wsched: ???? + * + */ struct p9_conn { spinlock_t lock; /* protect lock structure */ @@ -132,11 +195,16 @@ struct p9_conn { unsigned long wsched; }; -struct p9_mux_poll_task { - struct task_struct *task; - struct list_head mux_list; - int muxnum; -}; +/** + * struct p9_mux_rpc - fd mux rpc accounting structure + * @m: connection this request was issued on + * @err: error state + * @tcall: request &p9_fcall + * @rcall: response &p9_fcall + * @wqueue: wait queue that client is blocked on for this rpc + * + * Bug: isn't this information duplicated elsewhere like &p9_req + */ struct p9_mux_rpc { struct p9_conn *m; @@ -207,10 +275,12 @@ static void p9_mux_put_tag(struct p9_conn *m, u16 tag) /** * p9_mux_calc_poll_procs - calculates the number of polling procs - * based on the number of mounted v9fs filesystems. + * @muxnum: number of mounts * + * Calculation is based on the number of mounted v9fs filesystems. * The current implementation returns sqrt of the number of mounts. */ + static int p9_mux_calc_poll_procs(int muxnum) { int n; @@ -331,12 +401,11 @@ static void p9_mux_poll_stop(struct p9_conn *m) /** * p9_conn_create - allocate and initialize the per-session mux data - * Creates the polling task if this is the first session. + * @trans: transport structure * - * @trans - transport structure - * @msize - maximum message size - * @extended - extended flag + * Note: Creates the polling task if this is the first session. */ + static struct p9_conn *p9_conn_create(struct p9_trans *trans) { int i, n; @@ -406,7 +475,10 @@ static struct p9_conn *p9_conn_create(struct p9_trans *trans) /** * p9_mux_destroy - cancels all pending requests and frees mux resources + * @m: mux to destroy + * */ + static void p9_conn_destroy(struct p9_conn *m) { P9_DPRINTK(P9_DEBUG_MUX, "mux %p prev %p next %p\n", m, @@ -429,9 +501,14 @@ static void p9_conn_destroy(struct p9_conn *m) } /** - * p9_pollwait - called by files poll operation to add v9fs-poll task - * to files wait queue + * 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) { @@ -462,7 +539,10 @@ p9_pollwait(struct file *filp, wait_queue_head_t *wait_address, poll_table *p) /** * 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) { int n; @@ -499,9 +579,14 @@ static void p9_poll_mux(struct p9_conn *m) } /** - * p9_poll_proc - polls all v9fs transports for new events and queues - * the appropriate work to the work queue + * p9_poll_proc - poll worker thread + * @a: thread state and arguments + * + * polls all v9fs transports for new events and queues the appropriate + * work to the work queue + * */ + static int p9_poll_proc(void *a) { struct p9_conn *m, *mtmp; @@ -527,7 +612,10 @@ static int p9_poll_proc(void *a) /** * 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) { int n, err; @@ -638,7 +726,10 @@ static void process_request(struct p9_conn *m, struct p9_req *req) /** * 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) { int n, err; @@ -793,7 +884,9 @@ error: * @tc: request to be sent * @cb: callback function to call when response is received * @cba: parameter to pass to the callback function + * */ + static struct p9_req *p9_send_request(struct p9_conn *m, struct p9_fcall *tc, p9_conn_req_callback cb, void *cba) @@ -961,10 +1054,12 @@ p9_conn_rpc_cb(struct p9_req *req, void *a) /** * p9_fd_rpc- sends 9P request and waits until a response is available. * The function can be interrupted. - * @m: mux data + * @t: transport data * @tc: request to be sent * @rc: pointer where a pointer to the response is stored + * */ + int p9_fd_rpc(struct p9_trans *t, struct p9_fcall *tc, struct p9_fcall **rc) { @@ -1041,8 +1136,10 @@ p9_fd_rpc(struct p9_trans *t, struct p9_fcall *tc, struct p9_fcall **rc) * @m: mux data * @tc: request to be sent * @cb: callback function to be called when response arrives - * @cba: value to pass to the callback function + * @a: value to pass to the callback function + * */ + int p9_conn_rpcnb(struct p9_conn *m, struct p9_fcall *tc, p9_conn_req_callback cb, void *a) { @@ -1065,7 +1162,9 @@ int p9_conn_rpcnb(struct p9_conn *m, struct p9_fcall *tc, * p9_conn_cancel - cancel all pending requests with error * @m: mux data * @err: error code + * */ + void p9_conn_cancel(struct p9_conn *m, int err) { struct p9_req *req, *rtmp; @@ -1099,7 +1198,7 @@ void p9_conn_cancel(struct p9_conn *m, int err) /** * v9fs_parse_options - parse mount options into session structure * @options: options string passed from mount - * @v9ses: existing v9fs session information + * @opts: transport-specific structure to parse options into * */ @@ -1193,11 +1292,12 @@ static int p9_socket_open(struct p9_trans *trans, struct socket *csocket) /** * p9_fd_read- read from a fd - * @v9ses: session information + * @trans: transport instance state * @v: buffer to receive data into * @len: size of receive buffer * */ + static int p9_fd_read(struct p9_trans *trans, void *v, int len) { int ret; @@ -1220,11 +1320,12 @@ static int p9_fd_read(struct p9_trans *trans, void *v, int len) /** * p9_fd_write - write to a socket - * @v9ses: session information + * @trans: transport instance state * @v: buffer to send data from * @len: size of send buffer * */ + static int p9_fd_write(struct p9_trans *trans, void *v, int len) { int ret; @@ -1296,6 +1397,7 @@ end: * @trans: private socket structure * */ + static void p9_fd_close(struct p9_trans *trans) { struct p9_trans_fd *ts; diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c index de7a9f532edc..0bab1f23590e 100644 --- a/net/9p/trans_virtio.c +++ b/net/9p/trans_virtio.c @@ -55,23 +55,69 @@ static int chan_index; #define P9_INIT_MAXTAG 16 -#define REQ_STATUS_IDLE 0 -#define REQ_STATUS_SENT 1 -#define REQ_STATUS_RCVD 2 -#define REQ_STATUS_FLSH 3 + +/** + * enum p9_req_status_t - virtio request status + * @REQ_STATUS_IDLE: request slot unused + * @REQ_STATUS_SENT: request sent to server + * @REQ_STATUS_RCVD: response received from server + * @REQ_STATUS_FLSH: request has been flushed + * + * The @REQ_STATUS_IDLE state is used to mark a request slot as unused + * but use is actually tracked by the idpool structure which handles tag + * id allocation. + * + */ + +enum p9_req_status_t { + REQ_STATUS_IDLE, + REQ_STATUS_SENT, + REQ_STATUS_RCVD, + REQ_STATUS_FLSH, +}; + +/** + * struct p9_req_t - virtio request slots + * @status: status of this request slot + * @wq: wait_queue for the client to block on for this request + * + * The virtio transport uses an array to track outstanding requests + * instead of a list. While this may incurr overhead during initial + * allocation or expansion, it makes request lookup much easier as the + * tag id is a index into an array. (We use tag+1 so that we can accomodate + * the -1 tag for the T_VERSION request). + * This also has the nice effect of only having to allocate wait_queues + * once, instead of constantly allocating and freeing them. Its possible + * other resources could benefit from this scheme as well. + * + */ struct p9_req_t { int status; wait_queue_head_t *wq; }; -/* We keep all per-channel information in a structure. +/** + * struct virtio_chan - per-instance transport information + * @initialized: whether the channel is initialized + * @inuse: whether the channel is in use + * @lock: protects multiple elements within this structure + * @vdev: virtio dev associated with this channel + * @vq: virtio queue associated with this channel + * @tagpool: accounting for tag ids (and request slots) + * @reqs: array of request slots + * @max_tag: current number of request_slots allocated + * @sg: scatter gather list which is used to pack a request (protected?) + * + * 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. + * */ + static struct virtio_chan { - bool initialized; /* channel is initialized */ - bool inuse; /* channel is in use */ + bool initialized; + bool inuse; spinlock_t lock; @@ -86,7 +132,19 @@ static struct virtio_chan { struct scatterlist sg[VIRTQUEUE_NUM]; } channels[MAX_9P_CHAN]; -/* Lookup requests by tag */ +/** + * p9_lookup_tag - Lookup requests by tag + * @c: virtio channel to lookup tag within + * @tag: numeric id for transaction + * + * this is a simple array lookup, but will grow the + * request_slots as necessary to accomodate transaction + * ids which did not previously have a slot. + * + * Bugs: there is currently no upper limit on request slots set + * here, but that should be constrained by the id accounting. + */ + static struct p9_req_t *p9_lookup_tag(struct virtio_chan *c, u16 tag) { /* This looks up the original request by tag so we know which @@ -130,6 +188,15 @@ static unsigned int rest_of_page(void *data) return PAGE_SIZE - ((unsigned long)data % PAGE_SIZE); } +/** + * p9_virtio_close - reclaim resources of a channel + * @trans: transport state + * + * This reclaims a channel by freeing its resources and + * reseting its inuse flag. + * + */ + static void p9_virtio_close(struct p9_trans *trans) { struct virtio_chan *chan = trans->priv; @@ -151,6 +218,19 @@ static void p9_virtio_close(struct p9_trans *trans) kfree(trans); } +/** + * 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; @@ -169,6 +249,20 @@ static void req_done(struct virtqueue *vq) spin_unlock_irqrestore(&chan->lock, flags); } +/** + * 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) @@ -189,6 +283,14 @@ pack_sg_list(struct scatterlist *sg, int start, int limit, char *data, return index-start; } +/** + * p9_virtio_rpc - issue a request and wait for a response + * @t: transport state + * @tc: &p9_fcall request to transmit + * @rc: &p9_fcall to put reponse into + * + */ + static int p9_virtio_rpc(struct p9_trans *t, struct p9_fcall *tc, struct p9_fcall **rc) { @@ -263,6 +365,16 @@ p9_virtio_rpc(struct p9_trans *t, struct p9_fcall *tc, struct p9_fcall **rc) return 0; } +/** + * p9_virtio_probe - probe for existence of 9P virtio channels + * @vdev: virtio device to probe + * + * This probes for existing virtio channels. At present only + * a single channel is in use, so in the future more work may need + * to be done here. + * + */ + static int p9_virtio_probe(struct virtio_device *vdev) { int err; @@ -307,11 +419,28 @@ fail: return err; } -/* This sets up a transport channel for 9p communication. Right now + +/** + * p9_virtio_create - allocate a new virtio channel + * @devname: string identifying the channel to connect to (unused) + * @args: args passed from sys_mount() for per-transport options (unused) + * @msize: requested maximum packet size + * @extended: 9p2000.u enabled flag + * + * This sets up a transport channel for 9p communication. Right now * we only match the first available channel, but eventually we couldlook 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. */ + * mount has a channel open at a time. + * + * Bugs: doesn't allow identification of a specific channel + * to allocate, channels are allocated sequentially. This was + * a pragmatic decision to get things rolling, but ideally some + * way of identifying the channel to attach to would be nice + * if we are going to support multiple channels. + * + */ + static struct p9_trans * p9_virtio_create(const char *devname, char *args, int msize, unsigned char extended) @@ -360,6 +489,12 @@ p9_virtio_create(const char *devname, char *args, int msize, return trans; } +/** + * 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; diff --git a/net/9p/util.c b/net/9p/util.c index ef7215565d88..4d5646045330 100644 --- a/net/9p/util.c +++ b/net/9p/util.c @@ -32,11 +32,23 @@ #include #include +/** + * struct p9_idpool - per-connection accounting for tag idpool + * @lock: protects the pool + * @pool: idr to allocate tag id from + * + */ + struct p9_idpool { spinlock_t lock; struct idr pool; }; +/** + * p9_idpool_create - create a new per-connection id pool + * + */ + struct p9_idpool *p9_idpool_create(void) { struct p9_idpool *p; @@ -52,6 +64,11 @@ struct p9_idpool *p9_idpool_create(void) } EXPORT_SYMBOL(p9_idpool_create); +/** + * p9_idpool_destroy - create a new per-connection id pool + * @p: idpool to destory + */ + void p9_idpool_destroy(struct p9_idpool *p) { idr_destroy(&p->pool); @@ -61,9 +78,9 @@ EXPORT_SYMBOL(p9_idpool_destroy); /** * p9_idpool_get - allocate numeric id from pool - * @p - pool to allocate from + * @p: pool to allocate from * - * XXX - This seems to be an awful generic function, should it be in idr.c with + * Bugs: This seems to be an awful generic function, should it be in idr.c with * the lock included in struct idr? */ @@ -94,9 +111,10 @@ EXPORT_SYMBOL(p9_idpool_get); /** * p9_idpool_put - release numeric id from pool - * @p - pool to allocate from + * @id: numeric id which is being released + * @p: pool to release id into * - * XXX - This seems to be an awful generic function, should it be in idr.c with + * Bugs: This seems to be an awful generic function, should it be in idr.c with * the lock included in struct idr? */ @@ -111,11 +129,13 @@ EXPORT_SYMBOL(p9_idpool_put); /** * p9_idpool_check - check if the specified id is available - * @id - id to check - * @p - pool + * @id: id to check + * @p: pool to check */ + int p9_idpool_check(int id, struct p9_idpool *p) { return idr_find(&p->pool, id) != NULL; } EXPORT_SYMBOL(p9_idpool_check); + -- cgit v1.2.3 From bb8ffdfc3e3b32ad9fcdb8da289088d3b22794e5 Mon Sep 17 00:00:00 2001 From: Eric Van Hensbergen Date: Fri, 7 Mar 2008 10:53:53 -0600 Subject: 9p: propagate parse_option changes to client and transports Propagate changes that were made to the parse_options code to the other parse options pieces present in the other modules. Looks like the client parse options was probably corrupting the parse string and causing problems for others. Signed-off-by: Eric Van Hensbergen --- net/9p/client.c | 30 +++++++++++++++++++++++------- net/9p/trans_fd.c | 29 ++++++++++++++++++++++------- 2 files changed, 45 insertions(+), 14 deletions(-) (limited to 'net/9p') diff --git a/net/9p/client.c b/net/9p/client.c index 84e087e24146..553c34e9f296 100644 --- a/net/9p/client.c +++ b/net/9p/client.c @@ -64,21 +64,30 @@ static match_table_t tokens = { * @options: options string passed from mount * @v9ses: existing v9fs session information * + * Return 0 upon success, -ERRNO upon failure */ -static void parse_opts(char *options, struct p9_client *clnt) +static int parse_opts(char *opts, struct p9_client *clnt) { + char *options; char *p; substring_t args[MAX_OPT_ARGS]; int option; - int ret; + int ret = 0; clnt->trans_mod = v9fs_default_trans(); clnt->dotu = 1; clnt->msize = 8192; - if (!options) - return; + if (!opts) + return 0; + + options = kstrdup(opts, GFP_KERNEL); + if (!options) { + P9_DPRINTK(P9_DEBUG_ERROR, + "failed to allocate copy of option string\n"); + return -ENOMEM; + } while ((p = strsep(&options, ",")) != NULL) { int token; @@ -86,10 +95,11 @@ static void parse_opts(char *options, struct p9_client *clnt) continue; token = match_token(p, tokens, args); if (token < Opt_trans) { - ret = match_int(&args[0], &option); - if (ret < 0) { + int r = match_int(&args[0], &option); + if (r < 0) { P9_DPRINTK(P9_DEBUG_ERROR, "integer field, but no integer?\n"); + ret = r; continue; } } @@ -107,6 +117,8 @@ static void parse_opts(char *options, struct p9_client *clnt) continue; } } + kfree(options); + return ret; } @@ -138,6 +150,7 @@ struct p9_client *p9_client_create(const char *dev_name, char *options) if (!clnt) return ERR_PTR(-ENOMEM); + clnt->trans = NULL; spin_lock_init(&clnt->lock); INIT_LIST_HEAD(&clnt->fidlist); clnt->fidpool = p9_idpool_create(); @@ -147,7 +160,10 @@ struct p9_client *p9_client_create(const char *dev_name, char *options) goto error; } - parse_opts(options, clnt); + err = parse_opts(options, clnt); + if (err < 0) + goto error; + if (clnt->trans_mod == NULL) { err = -EPROTONOSUPPORT; P9_DPRINTK(P9_DEBUG_ERROR, diff --git a/net/9p/trans_fd.c b/net/9p/trans_fd.c index c6eda999fa7d..97b103b70499 100644 --- a/net/9p/trans_fd.c +++ b/net/9p/trans_fd.c @@ -1196,35 +1196,46 @@ void p9_conn_cancel(struct p9_conn *m, int err) } /** - * v9fs_parse_options - parse mount options into session structure + * parse_options - parse mount options into session structure * @options: options string passed from mount * @opts: transport-specific structure to parse options into * + * Returns 0 upon success, -ERRNO upon failure */ -static void parse_opts(char *options, struct p9_fd_opts *opts) +static int parse_opts(char *params, struct p9_fd_opts *opts) { char *p; substring_t args[MAX_OPT_ARGS]; int option; + char *options; int ret; opts->port = P9_PORT; opts->rfd = ~0; opts->wfd = ~0; - if (!options) - return; + if (!params) + return 0; + + options = kstrdup(params, GFP_KERNEL); + if (!options) { + P9_DPRINTK(P9_DEBUG_ERROR, + "failed to allocate copy of option string\n"); + return -ENOMEM; + } while ((p = strsep(&options, ",")) != NULL) { int token; + int r; if (!*p) continue; token = match_token(p, tokens, args); - ret = match_int(&args[0], &option); - if (ret < 0) { + r = match_int(&args[0], &option); + if (r < 0) { P9_DPRINTK(P9_DEBUG_ERROR, "integer field, but no integer?\n"); + ret = r; continue; } switch (token) { @@ -1241,6 +1252,8 @@ static void parse_opts(char *options, struct p9_fd_opts *opts) continue; } } + kfree(options); + return 0; } static int p9_fd_open(struct p9_trans *trans, int rfd, int wfd) @@ -1430,7 +1443,9 @@ p9_trans_create_tcp(const char *addr, char *args, int msize, unsigned char dotu) struct p9_fd_opts opts; struct p9_trans_fd *p; - parse_opts(args, &opts); + err = parse_opts(args, &opts); + if (err < 0) + return ERR_PTR(err); csocket = NULL; trans = kmalloc(sizeof(struct p9_trans), GFP_KERNEL); -- cgit v1.2.3 From c1549497e903a1ffa1c5808337a987180e480e7a Mon Sep 17 00:00:00 2001 From: Josef 'Jeff' Sipek Date: Fri, 7 Mar 2008 11:39:13 -0600 Subject: 9p: use struct mutex instead of struct semaphore Replace semaphores protecting use flags with a mutex. Signed-off-by: Josef 'Jeff' Sipek Acked-by: Eric Van Hensbergen --- net/9p/trans_virtio.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) (limited to 'net/9p') diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c index 0bab1f23590e..d23ed60483c3 100644 --- a/net/9p/trans_virtio.c +++ b/net/9p/trans_virtio.c @@ -49,7 +49,7 @@ #define VIRTQUEUE_NUM 128 /* a single mutex to manage channel initialization and attachment */ -static DECLARE_MUTEX(virtio_9p_lock); +static DEFINE_MUTEX(virtio_9p_lock); /* global which tracks highest initialized channel */ static int chan_index; @@ -211,9 +211,9 @@ static void p9_virtio_close(struct p9_trans *trans) chan->max_tag = 0; spin_unlock_irqrestore(&chan->lock, flags); - down(&virtio_9p_lock); + mutex_lock(&virtio_9p_lock); chan->inuse = false; - up(&virtio_9p_lock); + mutex_unlock(&virtio_9p_lock); kfree(trans); } @@ -381,10 +381,10 @@ static int p9_virtio_probe(struct virtio_device *vdev) struct virtio_chan *chan; int index; - down(&virtio_9p_lock); + mutex_lock(&virtio_9p_lock); index = chan_index++; chan = &channels[index]; - up(&virtio_9p_lock); + mutex_unlock(&virtio_9p_lock); if (chan_index > MAX_9P_CHAN) { printk(KERN_ERR "9p: virtio: Maximum channels exceeded\n"); @@ -413,9 +413,9 @@ static int p9_virtio_probe(struct virtio_device *vdev) out_free_vq: vdev->config->del_vq(chan->vq); fail: - down(&virtio_9p_lock); + mutex_lock(&virtio_9p_lock); chan_index--; - up(&virtio_9p_lock); + mutex_unlock(&virtio_9p_lock); return err; } @@ -449,7 +449,7 @@ p9_virtio_create(const char *devname, char *args, int msize, struct virtio_chan *chan = channels; int index = 0; - down(&virtio_9p_lock); + mutex_lock(&virtio_9p_lock); while (index < MAX_9P_CHAN) { if (chan->initialized && !chan->inuse) { chan->inuse = true; @@ -459,7 +459,7 @@ p9_virtio_create(const char *devname, char *args, int msize, chan = &channels[index]; } } - up(&virtio_9p_lock); + mutex_unlock(&virtio_9p_lock); if (index >= MAX_9P_CHAN) { printk(KERN_ERR "9p: no channels available\n"); -- cgit v1.2.3 From 728fc4ef17748042d9c71144aa339ed9c68e8b01 Mon Sep 17 00:00:00 2001 From: Josef 'Jeff' Sipek Date: Fri, 7 Mar 2008 11:40:33 -0600 Subject: 9p: Correct fidpool creation failure in p9_client_create On error, p9_idpool_create returns an ERR_PTR-encoded errno. Signed-off-by: Josef 'Jeff' Sipek Acked-by: Eric Van Hensbergen --- net/9p/client.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/9p') diff --git a/net/9p/client.c b/net/9p/client.c index 553c34e9f296..2ffe40cf2f01 100644 --- a/net/9p/client.c +++ b/net/9p/client.c @@ -154,7 +154,7 @@ struct p9_client *p9_client_create(const char *dev_name, char *options) spin_lock_init(&clnt->lock); INIT_LIST_HEAD(&clnt->fidlist); clnt->fidpool = p9_idpool_create(); - if (!clnt->fidpool) { + if (IS_ERR(clnt->fidpool)) { err = PTR_ERR(clnt->fidpool); clnt->fidpool = NULL; goto error; -- cgit v1.2.3 From d0c447180bfcb1db8d59e6ddb10f0346bd7d29e9 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Sat, 3 May 2008 17:29:50 -0500 Subject: 9p: fix flags length in net Some files in the net/9p directory uses "int" for flags. This can cause hard to find bugs on some architectures. This patch converts the flags to use "long" instead. This bug was discovered by doing an allyesconfig make on the -rt kernel where checks are done to ensure all flags are of size sizeof(long). Signed-off-by: Steven Rostedt Acked-by: Eric Van Hensbergen --- net/9p/trans_virtio.c | 2 +- net/9p/util.c | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-) (limited to 'net/9p') diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c index d23ed60483c3..42adc052b149 100644 --- a/net/9p/trans_virtio.c +++ b/net/9p/trans_virtio.c @@ -201,7 +201,7 @@ static void p9_virtio_close(struct p9_trans *trans) { struct virtio_chan *chan = trans->priv; int count; - unsigned int flags; + unsigned long flags; spin_lock_irqsave(&chan->lock, flags); p9_idpool_destroy(chan->tagpool); diff --git a/net/9p/util.c b/net/9p/util.c index 4d5646045330..958fc58cd1ff 100644 --- a/net/9p/util.c +++ b/net/9p/util.c @@ -88,7 +88,7 @@ int p9_idpool_get(struct p9_idpool *p) { int i = 0; int error; - unsigned int flags; + unsigned long flags; retry: if (idr_pre_get(&p->pool, GFP_KERNEL) == 0) @@ -120,7 +120,7 @@ EXPORT_SYMBOL(p9_idpool_get); void p9_idpool_put(int id, struct p9_idpool *p) { - unsigned int flags; + unsigned long flags; spin_lock_irqsave(&p->lock, flags); idr_remove(&p->pool, id); spin_unlock_irqrestore(&p->lock, flags); -- cgit v1.2.3 From 332c421e67045343de74e644cdf389f559f0d83f Mon Sep 17 00:00:00 2001 From: Eric Van Hensbergen Date: Sat, 3 May 2008 17:29:26 -0500 Subject: 9p: make cryptic unknown error from server less scary Right now when we get an error string from the server that we can't map we report a cryptic error that actually makes it look like we are reporting a problem with the client. This changes the text of the log message to clarify where the error is coming from. Signed-off-by: Eric Van Hensbergen --- net/9p/error.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'net/9p') diff --git a/net/9p/error.c b/net/9p/error.c index 388770c3631e..fdebe4314062 100644 --- a/net/9p/error.c +++ b/net/9p/error.c @@ -237,8 +237,8 @@ int p9_errstr2errno(char *errstr, int len) if (errno == 0) { /* TODO: if error isn't found, add it dynamically */ errstr[len] = 0; - printk(KERN_ERR "%s: errstr :%s: not found\n", __func__, - errstr); + printk(KERN_ERR "%s: server reported unknown error %s\n", + __func__, errstr); errno = 1; } -- cgit v1.2.3 From 887b3ece65be7b643dfdae0d433c91a26a3f437d Mon Sep 17 00:00:00 2001 From: Eric Van Hensbergen Date: Thu, 8 May 2008 20:26:37 -0500 Subject: 9p: fix error path during early mount There was some cleanup issues during early mount which would trigger a kernel bug for certain types of failure. This patch reorganizes the cleanup to get rid of the bad behavior. This also merges the 9pnet and 9pnet_fd modules for the purpose of configuration and initialization. Keeping the fd transport separate from the core 9pnet code seemed like a good idea at the time, but in practice has caused more harm and confusion than good. Signed-off-by: Eric Van Hensbergen --- net/9p/Kconfig | 10 ---------- net/9p/Makefile | 3 --- net/9p/mod.c | 1 + net/9p/trans_fd.c | 29 ++++++++++++++++++++++------- 4 files changed, 23 insertions(+), 20 deletions(-) (limited to 'net/9p') diff --git a/net/9p/Kconfig b/net/9p/Kconfig index bafc50c9e6ff..ff34c5acc130 100644 --- a/net/9p/Kconfig +++ b/net/9p/Kconfig @@ -13,16 +13,6 @@ menuconfig NET_9P If unsure, say N. -config NET_9P_FD - depends on NET_9P - default y if NET_9P - tristate "9P File Descriptor Transports (Experimental)" - help - This builds support for file descriptor transports for 9p - which includes support for TCP/IP, named pipes, or passed - file descriptors. TCP/IP is the default transport for 9p, - so if you are going to use 9p, you'll likely want this. - config NET_9P_VIRTIO depends on NET_9P && EXPERIMENTAL && VIRTIO tristate "9P Virtio Transport (Experimental)" diff --git a/net/9p/Makefile b/net/9p/Makefile index 8a1051101898..519219480db1 100644 --- a/net/9p/Makefile +++ b/net/9p/Makefile @@ -1,5 +1,4 @@ obj-$(CONFIG_NET_9P) := 9pnet.o -obj-$(CONFIG_NET_9P_FD) += 9pnet_fd.o obj-$(CONFIG_NET_9P_VIRTIO) += 9pnet_virtio.o 9pnet-objs := \ @@ -9,8 +8,6 @@ obj-$(CONFIG_NET_9P_VIRTIO) += 9pnet_virtio.o error.o \ fcprint.o \ util.o \ - -9pnet_fd-objs := \ trans_fd.o \ 9pnet_virtio-objs := \ diff --git a/net/9p/mod.c b/net/9p/mod.c index c6d9695949e0..bdee1fb7cc62 100644 --- a/net/9p/mod.c +++ b/net/9p/mod.c @@ -107,6 +107,7 @@ static int __init init_p9(void) p9_error_init(); printk(KERN_INFO "Installing 9P2000 support\n"); + p9_trans_fd_init(); return ret; } diff --git a/net/9p/trans_fd.c b/net/9p/trans_fd.c index 97b103b70499..4507f744f44e 100644 --- a/net/9p/trans_fd.c +++ b/net/9p/trans_fd.c @@ -1433,6 +1433,23 @@ static void p9_fd_close(struct p9_trans *trans) kfree(ts); } +/* + * stolen from NFS - maybe should be made a generic function? + */ +static inline int valid_ipaddr4(const char *buf) +{ + int rc, count, in[4]; + + rc = sscanf(buf, "%d.%d.%d.%d", &in[0], &in[1], &in[2], &in[3]); + if (rc != 4) + return -EINVAL; + for (count = 0; count < 4; count++) { + if (in[count] > 255) + return -EINVAL; + } + return 0; +} + static struct p9_trans * p9_trans_create_tcp(const char *addr, char *args, int msize, unsigned char dotu) { @@ -1447,6 +1464,9 @@ p9_trans_create_tcp(const char *addr, char *args, int msize, unsigned char dotu) if (err < 0) return ERR_PTR(err); + if (valid_ipaddr4(addr) < 0) + return ERR_PTR(-EINVAL); + csocket = NULL; trans = kmalloc(sizeof(struct p9_trans), GFP_KERNEL); if (!trans) @@ -1625,7 +1645,7 @@ static struct p9_trans_module p9_fd_trans = { .create = p9_trans_create_fd, }; -static int __init p9_trans_fd_init(void) +int p9_trans_fd_init(void) { int ret = p9_mux_global_init(); if (ret) { @@ -1639,9 +1659,4 @@ static int __init p9_trans_fd_init(void) return 0; } - -module_init(p9_trans_fd_init); - -MODULE_AUTHOR("Latchesar Ionkov "); -MODULE_AUTHOR("Eric Van Hensbergen "); -MODULE_LICENSE("GPL"); +EXPORT_SYMBOL(p9_trans_fd_init); -- cgit v1.2.3