Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs

* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs: (26 commits)
  9p: add more conservative locking
  9p: fix oops in protocol stat parsing error path.
  9p: fix device file handling
  9p: Improve debug support
  9p: eliminate depricated conv functions
  9p: rework client code to use new protocol support functions
  9p: remove unnecessary tag field from p9_req_t structure
  9p: remove 9p fcall debug prints
  9p: add new protocol support code
  9p: encapsulate version function
  9p: move dirread to fs layer
  9p: adjust 9p vfs write operation
  9p: move readn meta-function from client to fs layer
  9p: consolidate read/write functions
  9p: drop broken unused error path from p9_conn_create()
  9p: make rpc code common and rework flush code
  9p: use the rcall structure passed in the request in trans_fd read_work
  9p: apply common request code to trans_fd
  9p: apply common tagpool handling to trans_fd
  9p: move request management to client code
  ...

3 files changed, 138 insertions, 160 deletions

diff --git a/include/net/9p/9p.h b/include/net/9p/9p.h
index fb163e2e0de6..d2c60c73619d 100644
--- a/include/net/9p/9p.h
+++ b/include/net/9p/9p.h
@@ -27,8 +27,6 @@
 #ifndef NET_9P_H
 #define NET_9P_H
 
-#ifdef CONFIG_NET_9P_DEBUG
-
 /**
  * enum p9_debug_flags - bits for mount time debug parameter
  * @P9_DEBUG_ERROR: more verbose error messages including original error string
@@ -39,6 +37,7 @@
  * @P9_DEBUG_TRANS: transport tracing
  * @P9_DEBUG_SLABS: memory management tracing
  * @P9_DEBUG_FCALL: verbose dump of protocol messages
+ * @P9_DEBUG_FID: fid allocation/deallocation tracking
  *
  * These flags are passed at mount time to turn on various levels of
  * verbosity and tracing which will be output to the system logs.
@@ -53,24 +52,27 @@ enum p9_debug_flags {
         P9_DEBUG_TRANS =        (1<<6),
         P9_DEBUG_SLABS =        (1<<7),
         P9_DEBUG_FCALL =        (1<<8),
+        P9_DEBUG_FID =          (1<<9),
+        P9_DEBUG_PKT =          (1<<10),
 };
 
 extern unsigned int p9_debug_level;
 
+#ifdef CONFIG_NET_9P_DEBUG
 #define P9_DPRINTK(level, format, arg...) \
 do {  \
-        if ((p9_debug_level & level) == level) \
-                printk(KERN_NOTICE "-- %s (%d): " \
-                format , __func__, task_pid_nr(current) , ## arg); \
+        if ((p9_debug_level & level) == level) {\
+                if (level == P9_DEBUG_9P) \
+                        printk(KERN_NOTICE "(%8.8d) " \
+                        format , task_pid_nr(current) , ## arg); \
+                else \
+                        printk(KERN_NOTICE "-- %s (%d): " \
+                        format , __func__, task_pid_nr(current) , ## arg); \
+        } \
 } while (0)
 
-#define PRINT_FCALL_ERROR(s, fcall) P9_DPRINTK(P9_DEBUG_ERROR,   \
-        "%s: %.*s\n", s, fcall?fcall->params.rerror.error.len:0, \
-        fcall?fcall->params.rerror.error.str:"");
-
 #else
 #define P9_DPRINTK(level, format, arg...)  do { } while (0)
-#define PRINT_FCALL_ERROR(s, fcall) do { } while (0)
 #endif
 
 #define P9_EPRINTK(level, format, arg...) \
@@ -325,33 +327,6 @@ struct p9_qid {
  * See Also: http://plan9.bell-labs.com/magic/man2html/2/stat
  */
 
-struct p9_stat {
-        u16 size;
-        u16 type;
-        u32 dev;
-        struct p9_qid qid;
-        u32 mode;
-        u32 atime;
-        u32 mtime;
-        u64 length;
-        struct p9_str name;
-        struct p9_str uid;
-        struct p9_str gid;
-        struct p9_str muid;
-        struct p9_str extension;        /* 9p2000.u extensions */
-        u32 n_uid;                      /* 9p2000.u extensions */
-        u32 n_gid;                      /* 9p2000.u extensions */
-        u32 n_muid;                     /* 9p2000.u extensions */
-};
-
-/*
- * file metadata (stat) structure used to create Twstat message
- * The is identical to &p9_stat, but the strings don't point to
- * the same memory block and should be freed separately
- *
- * See Also: http://plan9.bell-labs.com/magic/man2html/2/stat
- */
-
 struct p9_wstat {
         u16 size;
         u16 type;
@@ -493,12 +468,12 @@ struct p9_tstat {
 };
 
 struct p9_rstat {
-        struct p9_stat stat;
+        struct p9_wstat stat;
 };
 
 struct p9_twstat {
         u32 fid;
-        struct p9_stat stat;
+        struct p9_wstat stat;
 };
 
 struct p9_rwstat {
@@ -509,8 +484,9 @@ struct p9_rwstat {
  * @size: prefixed length of the structure
  * @id: protocol operating identifier of type &p9_msg_t
  * @tag: transaction id of the request
+ * @offset: used by marshalling routines to track currentposition in buffer
+ * @capacity: used by marshalling routines to track total capacity
  * @sdata: payload
- * @params: per-operation parameters
  *
  * &p9_fcall represents the structure for all 9P RPC
  * transactions.  Requests are packaged into fcalls, and reponses
@@ -523,68 +499,15 @@ struct p9_fcall {
         u32 size;
         u8 id;
         u16 tag;
-        void *sdata;
-
-        union {
-                struct p9_tversion tversion;
-                struct p9_rversion rversion;
-                struct p9_tauth tauth;
-                struct p9_rauth rauth;
-                struct p9_rerror rerror;
-                struct p9_tflush tflush;
-                struct p9_rflush rflush;
-                struct p9_tattach tattach;
-                struct p9_rattach rattach;
-                struct p9_twalk twalk;
-                struct p9_rwalk rwalk;
-                struct p9_topen topen;
-                struct p9_ropen ropen;
-                struct p9_tcreate tcreate;
-                struct p9_rcreate rcreate;
-                struct p9_tread tread;
-                struct p9_rread rread;
-                struct p9_twrite twrite;
-                struct p9_rwrite rwrite;
-                struct p9_tclunk tclunk;
-                struct p9_rclunk rclunk;
-                struct p9_tremove tremove;
-                struct p9_rremove rremove;
-                struct p9_tstat tstat;
-                struct p9_rstat rstat;
-                struct p9_twstat twstat;
-                struct p9_rwstat rwstat;
-        } params;
+
+        size_t offset;
+        size_t capacity;
+
+        uint8_t *sdata;
 };
 
 struct p9_idpool;
 
-int p9_deserialize_stat(void *buf, u32 buflen, struct p9_stat *stat,
-        int dotu);
-int p9_deserialize_fcall(void *buf, u32 buflen, struct p9_fcall *fc, int dotu);
-void p9_set_tag(struct p9_fcall *fc, u16 tag);
-struct p9_fcall *p9_create_tversion(u32 msize, char *version);
-struct p9_fcall *p9_create_tattach(u32 fid, u32 afid, char *uname,
-        char *aname, u32 n_uname, int dotu);
-struct p9_fcall *p9_create_tauth(u32 afid, char *uname, char *aname,
-        u32 n_uname, int dotu);
-struct p9_fcall *p9_create_tflush(u16 oldtag);
-struct p9_fcall *p9_create_twalk(u32 fid, u32 newfid, u16 nwname,
-        char **wnames);
-struct p9_fcall *p9_create_topen(u32 fid, u8 mode);
-struct p9_fcall *p9_create_tcreate(u32 fid, char *name, u32 perm, u8 mode,
-        char *extension, int dotu);
-struct p9_fcall *p9_create_tread(u32 fid, u64 offset, u32 count);
-struct p9_fcall *p9_create_twrite(u32 fid, u64 offset, u32 count,
-        const char *data);
-struct p9_fcall *p9_create_twrite_u(u32 fid, u64 offset, u32 count,
-        const char __user *data);
-struct p9_fcall *p9_create_tclunk(u32 fid);
-struct p9_fcall *p9_create_tremove(u32 fid);
-struct p9_fcall *p9_create_tstat(u32 fid);
-struct p9_fcall *p9_create_twstat(u32 fid, struct p9_wstat *wstat,
-        int dotu);
-
-int p9_printfcall(char *buf, int buflen, struct p9_fcall *fc, int dotu);
 int p9_errstr2errno(char *errstr, int len);
 
 struct p9_idpool *p9_idpool_create(void);
diff --git a/include/net/9p/client.h b/include/net/9p/client.h
index c936dd14de41..1f17f3d93727 100644
--- a/include/net/9p/client.h
+++ b/include/net/9p/client.h
@@ -26,6 +26,87 @@
 #ifndef NET_9P_CLIENT_H
 #define NET_9P_CLIENT_H
 
+/* Number of requests per row */
+#define P9_ROW_MAXTAG 255
+
+/**
+ * enum p9_trans_status - different states of underlying transports
+ * @Connected: transport is connected and healthy
+ * @Disconnected: transport has been disconnected
+ * @Hung: transport is connected by wedged
+ *
+ * This enumeration details the various states a transport
+ * instatiation can be in.
+ */
+
+enum p9_trans_status {
+        Connected,
+        Disconnected,
+        Hung,
+};
+
+/**
+ * enum p9_req_status_t - virtio request status
+ * @REQ_STATUS_IDLE: request slot unused
+ * @REQ_STATUS_ALLOC: request has been allocated but not sent
+ * @REQ_STATUS_UNSENT: request waiting to be sent
+ * @REQ_STATUS_SENT: request sent to server
+ * @REQ_STATUS_FLSH: a flush has been sent for this request
+ * @REQ_STATUS_RCVD: response received from server
+ * @REQ_STATUS_FLSHD: request has been flushed
+ * @REQ_STATUS_ERROR: request encountered an error on the client side
+ *
+ * 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_ALLOC,
+        REQ_STATUS_UNSENT,
+        REQ_STATUS_SENT,
+        REQ_STATUS_FLSH,
+        REQ_STATUS_RCVD,
+        REQ_STATUS_FLSHD,
+        REQ_STATUS_ERROR,
+};
+
+/**
+ * struct p9_req_t - request slots
+ * @status: status of this request slot
+ * @t_err: transport error
+ * @flush_tag: tag of request being flushed (for flush requests)
+ * @wq: wait_queue for the client to block on for this request
+ * @tc: the request fcall structure
+ * @rc: the response fcall structure
+ * @aux: transport specific data (provided for trans_fd migration)
+ * @req_list: link for higher level objects to chain requests
+ *
+ * Transport use 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;
+        int t_err;
+        u16 flush_tag;
+        wait_queue_head_t *wq;
+        struct p9_fcall *tc;
+        struct p9_fcall *rc;
+        void *aux;
+
+        struct list_head req_list;
+};
+
 /**
  * struct p9_client - per client instance state
  * @lock: protect @fidlist
@@ -36,9 +117,20 @@
  * @conn: connection state information used by trans_fd
  * @fidpool: fid handle accounting for session
  * @fidlist: List of active fid handles
+ * @tagpool - transaction id accounting for session
+ * @reqs - 2D array of requests
+ * @max_tag - current maximum tag id allocated
  *
  * The client structure is used to keep track of various per-client
  * state that has been instantiated.
+ * In order to minimize per-transaction overhead we use a
+ * simple array to lookup requests instead of a hash table
+ * or linked list.  In order to support larger number of
+ * transactions, we make this a 2D array, allocating new rows
+ * when we need to grow the total number of the transactions.
+ *
+ * Each row is 256 requests and we'll support up to 256 rows for
+ * a total of 64k concurrent requests per session.
  *
  * Bugs: duplicated data and potentially unnecessary elements.
  */
@@ -48,11 +140,16 @@ struct p9_client {
         int msize;
         unsigned char dotu;
         struct p9_trans_module *trans_mod;
-        struct p9_trans *trans;
+        enum p9_trans_status status;
+        void *trans;
         struct p9_conn *conn;
 
         struct p9_idpool *fidpool;
         struct list_head fidlist;
+
+        struct p9_idpool *tagpool;
+        struct p9_req_t *reqs[P9_ROW_MAXTAG];
+        int max_tag;
 };
 
 /**
@@ -65,8 +162,6 @@ struct p9_client {
  * @uid: the numeric uid of the local user who owns this handle
  * @aux: transport specific information (unused?)
  * @rdir_fpos: tracks offset of file position when reading directory contents
- * @rdir_pos: (unused?)
- * @rdir_fcall: holds response of last directory read request
  * @flist: per-client-instance fid tracking
  * @dlist: per-dentry fid tracking
  *
@@ -83,8 +178,6 @@ struct p9_fid {
         void *aux;
 
         int rdir_fpos;
-        int rdir_pos;
-        struct p9_fcall *rdir_fcall;
         struct list_head flist;
         struct list_head dlist; /* list of all fids attached to a dentry */
 };
@@ -103,15 +196,18 @@ int p9_client_fcreate(struct p9_fid *fid, char *name, u32 perm, int mode,
                                                         char *extension);
 int p9_client_clunk(struct p9_fid *fid);
 int p9_client_remove(struct p9_fid *fid);
-int p9_client_read(struct p9_fid *fid, char *data, u64 offset, u32 count);
-int p9_client_readn(struct p9_fid *fid, char *data, u64 offset, u32 count);
-int p9_client_write(struct p9_fid *fid, char *data, u64 offset, u32 count);
-int p9_client_uread(struct p9_fid *fid, char __user *data, u64 offset,
-                                                                u32 count);
-int p9_client_uwrite(struct p9_fid *fid, const char __user *data, u64 offset,
-                                                                u32 count);
-struct p9_stat *p9_client_stat(struct p9_fid *fid);
+int p9_client_read(struct p9_fid *fid, char *data, char __user *udata,
+                                                        u64 offset, u32 count);
+int p9_client_write(struct p9_fid *fid, char *data, const char __user *udata,
+                                                        u64 offset, u32 count);
+struct p9_wstat *p9_client_stat(struct p9_fid *fid);
 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst);
-struct p9_stat *p9_client_dirread(struct p9_fid *fid, u64 offset);
+
+struct p9_req_t *p9_tag_lookup(struct p9_client *, u16);
+void p9_client_cb(struct p9_client *c, struct p9_req_t *req);
+
+int p9stat_read(char *, int, struct p9_wstat *, int);
+void p9stat_free(struct p9_wstat *);
+
 
 #endif /* NET_9P_CLIENT_H */
diff --git a/include/net/9p/transport.h b/include/net/9p/transport.h
index 3ca737120a90..6d5886efb102 100644
--- a/include/net/9p/transport.h
+++ b/include/net/9p/transport.h
@@ -26,52 +26,6 @@
 #ifndef NET_9P_TRANSPORT_H
 #define NET_9P_TRANSPORT_H
 
-#include <linux/module.h>
-
-/**
- * enum p9_trans_status - different states of underlying transports
- * @Connected: transport is connected and healthy
- * @Disconnected: transport has been disconnected
- * @Hung: transport is connected by wedged
- *
- * This enumeration details the various states a transport
- * instatiation can be in.
- */
-
-enum p9_trans_status {
-        Connected,
-        Disconnected,
-        Hung,
-};
-
-/**
- * struct p9_trans - per-transport state and API
- * @status: transport &p9_trans_status
- * @msize: negotiated maximum packet size (duplicate from client)
- * @extended: negotiated protocol extensions (duplicate from client)
- * @priv: transport private data
- * @close: member function to disconnect and close the transport
- * @rpc: member function to issue a request to the transport
- *
- * This is the basic API for a transport instance.  It is used as
- * a handle by the client to issue requests.  This interface is currently
- * in flux during reorganization.
- *
- * Bugs: there is lots of duplicated data here and its not clear that
- * the member functions need to be per-instance versus per transport
- * module.
- */
-
-struct p9_trans {
-        enum p9_trans_status status;
-        int msize;
-        unsigned char extended;
-        void *priv;
-        void (*close) (struct p9_trans *);
-        int (*rpc) (struct p9_trans *t, struct p9_fcall *tc,
-                                                        struct p9_fcall **rc);
-};
-
 /**
  * struct p9_trans_module - transport module interface
  * @list: used to maintain a list of currently available transports
@@ -79,12 +33,14 @@ struct p9_trans {
  * @maxsize: transport provided maximum packet size
  * @def: set if this transport should be considered the default
  * @create: member function to create a new connection on this transport
+ * @request: member function to issue a request to the transport
+ * @cancel: member function to cancel a request (if it hasn't been sent)
  *
  * This is the basic API for a transport module which is registered by the
  * transport module with the 9P core network module and used by the client
  * to instantiate a new connection on a transport.
  *
- * Bugs: the transport module list isn't protected.
+ * BUGS: the transport module list isn't protected.
  */
 
 struct p9_trans_module {
@@ -92,8 +48,11 @@ struct p9_trans_module {
         char *name;             /* name of transport */
         int maxsize;            /* max message size of transport */
         int def;                /* this transport should be default */
-        struct p9_trans * (*create)(const char *, char *, int, unsigned char);
         struct module *owner;
+        int (*create)(struct p9_client *, const char *, char *);
+        void (*close) (struct p9_client *);
+        int (*request) (struct p9_client *, struct p9_req_t *req);
+        int (*cancel) (struct p9_client *, struct p9_req_t *req);
 };
 
 void v9fs_register_trans(struct p9_trans_module *m);