[PATCH] v9fs: zero copy implementation

Performance enhancement reducing the number of copies in the data and
stat paths.
Signed-off-by: Latchesar Ionkov <lucho@ionkov.net>
Cc: Eric Van Hensbergen <ericvh@ericvh.myip.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

fs/9p/9p.h

@@ -3,6 +3,7 @@
  *
  * 9P protocol definitions.
  *
+ *  Copyright (C) 2005 by Latchesar Ionkov <lucho@ionkov.net>
  *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
  *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
  *
@@ -102,10 +103,16 @@ enum {
 
 #define V9FS_NOTAG	(u16)(~0)
 #define V9FS_NOFID	(u32)(~0)
+#define V9FS_MAXWELEM	16
 
 /* ample room for Twrite/Rread header (iounit) */
 #define V9FS_IOHDRSZ	24
 
+struct v9fs_str {
+	u16 len;
+	char *str;
+};
+
 /* qids are the unique ID for a file (like an inode */
 struct v9fs_qid {
 	u8 type;
@@ -115,6 +122,29 @@ struct v9fs_qid {
 
 /* Plan 9 file metadata (stat) structure */
 struct v9fs_stat {
+	u16 size;
+	u16 type;
+	u32 dev;
+	struct v9fs_qid qid;
+	u32 mode;
+	u32 atime;
+	u32 mtime;
+	u64 length;
+	struct v9fs_str name;
+	struct v9fs_str uid;
+	struct v9fs_str gid;
+	struct v9fs_str muid;
+	struct v9fs_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 similar to v9fs_stat, but the strings don't point to
+   the same memory block and should be freed separately
+*/
+struct v9fs_wstat {
 	u16 size;
 	u16 type;
 	u32 dev;
@@ -131,25 +161,24 @@ struct v9fs_stat {
 	u32 n_uid;		/* 9p2000.u extensions */
 	u32 n_gid;		/* 9p2000.u extensions */
 	u32 n_muid;		/* 9p2000.u extensions */
-	char data[0];
 };
 
 /* Structures for Protocol Operations */
 
 struct Tversion {
 	u32 msize;
-	char *version;
+	struct v9fs_str version;
 };
 
 struct Rversion {
 	u32 msize;
-	char *version;
+	struct v9fs_str version;
 };
 
 struct Tauth {
 	u32 afid;
-	char *uname;
-	char *aname;
+	struct v9fs_str uname;
+	struct v9fs_str aname;
 };
 
 struct Rauth {
@@ -157,12 +186,12 @@ struct Rauth {
 };
 
 struct Rerror {
-	char *error;
+	struct v9fs_str error;
 	u32 errno;		/* 9p2000.u extension */
 };
 
 struct Tflush {
-	u32 oldtag;
+	u16 oldtag;
 };
 
 struct Rflush {
@@ -171,8 +200,8 @@ struct Rflush {
 struct Tattach {
 	u32 fid;
 	u32 afid;
-	char *uname;
-	char *aname;
+	struct v9fs_str uname;
+	struct v9fs_str aname;
 };
 
 struct Rattach {
@@ -182,13 +211,13 @@ struct Rattach {
 struct Twalk {
 	u32 fid;
 	u32 newfid;
-	u32 nwname;
-	char **wnames;
+	u16 nwname;
+	struct v9fs_str wnames[16];
 };
 
 struct Rwalk {
-	u32 nwqid;
-	struct v9fs_qid *wqids;
+	u16 nwqid;
+	struct v9fs_qid wqids[16];
 };
 
 struct Topen {
@@ -203,7 +232,7 @@ struct Ropen {
 
 struct Tcreate {
 	u32 fid;
-	char *name;
+	struct v9fs_str name;
 	u32 perm;
 	u8 mode;
 };
@@ -254,12 +283,12 @@ struct Tstat {
 };
 
 struct Rstat {
-	struct v9fs_stat *stat;
+	struct v9fs_stat stat;
 };
 
 struct Twstat {
 	u32 fid;
-	struct v9fs_stat *stat;
+	struct v9fs_stat stat;
 };
 
 struct Rwstat {
@@ -274,6 +303,7 @@ struct v9fs_fcall {
 	u32 size;
 	u8 id;
 	u16 tag;
+	void *sdata;
 
 	union {
 		struct Tversion tversion;
@@ -306,10 +336,12 @@ struct v9fs_fcall {
 	} params;
 };
 
-#define V9FS_FCALLHDRSZ (sizeof(struct v9fs_fcall) + \
-	sizeof(struct v9fs_stat) + 16*sizeof(struct v9fs_qid) + 16)
+#define PRINT_FCALL_ERROR(s, fcall) dprintk(DEBUG_ERROR, "%s: %.*s\n", s, \
+	fcall?fcall->params.rerror.error.len:0, \
+	fcall?fcall->params.rerror.error.str:"");
 
-#define FCALL_ERROR(fcall) (fcall ? fcall->params.rerror.error : "")
+char *v9fs_str_copy(char *buf, int buflen, struct v9fs_str *str);
+int v9fs_str_compare(char *buf, struct v9fs_str *str);
 
 int v9fs_t_version(struct v9fs_session_info *v9ses, u32 msize,
 		   char *version, struct v9fs_fcall **rcall);
@@ -325,7 +357,7 @@ int v9fs_t_stat(struct v9fs_session_info *v9ses, u32 fid,
 		struct v9fs_fcall **rcall);
 
 int v9fs_t_wstat(struct v9fs_session_info *v9ses, u32 fid,
-		 struct v9fs_stat *stat, struct v9fs_fcall **rcall);
+		 struct v9fs_wstat *wstat, struct v9fs_fcall **rcall);
 
 int v9fs_t_walk(struct v9fs_session_info *v9ses, u32 fid, u32 newfid,
 		char *name, struct v9fs_fcall **rcall);
@@ -343,4 +375,5 @@ int v9fs_t_read(struct v9fs_session_info *v9ses, u32 fid,
 		u64 offset, u32 count, struct v9fs_fcall **rcall);
 
 int v9fs_t_write(struct v9fs_session_info *v9ses, u32 fid, u64 offset,
-		 u32 count, void *data, struct v9fs_fcall **rcall);
+		 u32 count, const char __user * data,
+		 struct v9fs_fcall **rcall);

fs/9p/Makefile

 obj-$(CONFIG_9P_FS) := 9p2000.o
 
 9p2000-objs := \
+	trans_fd.o \
+	trans_sock.o \
+	mux.o \
+	9p.o \
+	conv.o \
 	vfs_super.o \
 	vfs_inode.o \
 	vfs_file.o \
 	vfs_dir.o \
 	vfs_dentry.o \
 	error.o \
-	mux.o \
-	trans_fd.o \
-	trans_sock.o \
-	9p.o \
-	conv.o \
 	v9fs.o \
 	fid.o
 

fs/9p/conv.h

 /*
  * linux/fs/9p/conv.h
  *
- * 9P protocol conversion definitions
+ * 9P protocol conversion definitions.
  *
+ *  Copyright (C) 2005 by Latchesar Ionkov <lucho@ionkov.net>
  *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
  *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
  *
@@ -25,11 +26,26 @@
  */
 
 int v9fs_deserialize_stat(void *buf, u32 buflen, struct v9fs_stat *stat,
-	u32 statlen, int extended);
-int v9fs_serialize_fcall(struct v9fs_fcall *tcall, void *buf, u32 buflen,
 	int extended);
 int v9fs_deserialize_fcall(void *buf, u32 buflen, struct v9fs_fcall *rcall,
-	int rcalllen, int extended);
+	int extended);
+
+void v9fs_set_tag(struct v9fs_fcall *fc, u16 tag);
 
-/* this one is actually in error.c right now */
-int v9fs_errstr2errno(char *errstr);
+struct v9fs_fcall *v9fs_create_tversion(u32 msize, char *version);
+struct v9fs_fcall *v9fs_create_tauth(u32 afid, char *uname, char *aname);
+struct v9fs_fcall *v9fs_create_tattach(u32 fid, u32 afid, char *uname,
+	char *aname);
+struct v9fs_fcall *v9fs_create_tflush(u16 oldtag);
+struct v9fs_fcall *v9fs_create_twalk(u32 fid, u32 newfid, u16 nwname,
+	char **wnames);
+struct v9fs_fcall *v9fs_create_topen(u32 fid, u8 mode);
+struct v9fs_fcall *v9fs_create_tcreate(u32 fid, char *name, u32 perm, u8 mode);
+struct v9fs_fcall *v9fs_create_tread(u32 fid, u64 offset, u32 count);
+struct v9fs_fcall *v9fs_create_twrite(u32 fid, u64 offset, u32 count,
+	const char __user *data);
+struct v9fs_fcall *v9fs_create_tclunk(u32 fid);
+struct v9fs_fcall *v9fs_create_tremove(u32 fid);
+struct v9fs_fcall *v9fs_create_tstat(u32 fid);
+struct v9fs_fcall *v9fs_create_twstat(u32 fid, struct v9fs_wstat *wstat,
+	int extended);

fs/9p/debug.h

@@ -51,16 +51,23 @@ do { \
 #if DEBUG_DUMP_PKT
 static inline void dump_data(const unsigned char *data, unsigned int datalen)
 {
-	int i, j;
-	int len = datalen;
+	int i, n;
+	char buf[5*8];
 
-	printk(KERN_DEBUG "data ");
-	for (i = 0; i < len; i += 4) {
-		for (j = 0; (j < 4) && (i + j < len); j++)
-			printk(KERN_DEBUG "%02x", data[i + j]);
-		printk(KERN_DEBUG " ");
+	n = 0;
+	i = 0;
+	while (i < datalen) {
+		n += snprintf(buf+n, sizeof(buf)-n, "%02x", data[i++]);
+		if (i%4 == 0)
+			n += snprintf(buf+n, sizeof(buf)-n, " ");
+
+		if (i%16 == 0) {
+			dprintk(DEBUG_ERROR, "%s\n", buf);
+			n = 0;
+		}
 	}
-	printk(KERN_DEBUG "\n");
+
+	dprintk(DEBUG_ERROR, "%s\n", buf);
 }
 #else				/* DEBUG_DUMP_PKT */
 static inline void dump_data(const unsigned char *data, unsigned int datalen)

fs/9p/error.c

@@ -33,7 +33,6 @@
 
 #include <linux/list.h>
 #include <linux/jhash.h>
-#include <linux/string.h>
 
 #include "debug.h"
 #include "error.h"
@@ -55,7 +54,8 @@ int v9fs_error_init(void)
 
 	/* load initial error map into hash table */
 	for (c = errmap; c->name != NULL; c++) {
-		bucket = jhash(c->name, strlen(c->name), 0) % ERRHASHSZ;
+		c->namelen = strlen(c->name);
+		bucket = jhash(c->name, c->namelen, 0) % ERRHASHSZ;
 		INIT_HLIST_NODE(&c->list);
 		hlist_add_head(&c->list, &hash_errmap[bucket]);
 	}
@@ -69,15 +69,15 @@ int v9fs_error_init(void)
  *
  */
 
-int v9fs_errstr2errno(char *errstr)
+int v9fs_errstr2errno(char *errstr, int len)
 {
 	int errno = 0;
 	struct hlist_node *p = NULL;
 	struct errormap *c = NULL;
-	int bucket = jhash(errstr, strlen(errstr), 0) % ERRHASHSZ;
+	int bucket = jhash(errstr, len, 0) % ERRHASHSZ;
 
 	hlist_for_each_entry(c, p, &hash_errmap[bucket], list) {
-		if (!strcmp(c->name, errstr)) {
+		if (c->namelen==len && !memcmp(c->name, errstr, len)) {
 			errno = c->val;
 			break;
 		}

fs/9p/error.h

@@ -36,6 +36,7 @@ struct errormap {
 	char *name;
 	int val;
 
+	int namelen;
 	struct hlist_node list;
 };
 
@@ -175,4 +176,4 @@ static struct errormap errmap[] = {
 };
 
 extern int v9fs_error_init(void);
-extern int v9fs_errstr2errno(char *errstr);
+extern int v9fs_errstr2errno(char *errstr, int len);

fs/9p/fid.c

@@ -31,9 +31,6 @@
 #include "v9fs.h"
 #include "9p.h"
 #include "v9fs_vfs.h"
-#include "transport.h"
-#include "mux.h"
-#include "conv.h"
 #include "fid.h"
 
 /**

fs/9p/mux.c

@@ -35,8 +35,8 @@
 #include "debug.h"
 #include "v9fs.h"
 #include "9p.h"
-#include "transport.h"
 #include "conv.h"
+#include "transport.h"
 #include "mux.h"
 
 #define ERREQFLUSH	1
@@ -74,6 +74,7 @@ struct v9fs_mux_data {
 	wait_queue_head_t equeue;
 	struct list_head req_list;
 	struct list_head unsent_req_list;
+	struct v9fs_fcall *rcall;
 	int rpos;
 	char *rbuf;
 	int wpos;
@@ -101,11 +102,15 @@ struct v9fs_mux_rpc {
 	wait_queue_head_t wqueue;
 };
 
+extern int v9fs_errstr2errno(char *str, int len);
+
 static int v9fs_poll_proc(void *);
 static void v9fs_read_work(void *);
 static void v9fs_write_work(void *);
 static void v9fs_pollwait(struct file *filp, wait_queue_head_t * wait_address,
 			  poll_table * p);
+static u16 v9fs_mux_get_tag(struct v9fs_mux_data *);
+static void v9fs_mux_put_tag(struct v9fs_mux_data *, u16);
 
 static DECLARE_MUTEX(v9fs_mux_task_lock);
 static struct workqueue_struct *v9fs_mux_wq;
@@ -166,8 +171,9 @@ static void v9fs_mux_poll_start(struct v9fs_mux_data *m)
 			if (v9fs_mux_poll_tasks[i].task == NULL) {
 				vpt = &v9fs_mux_poll_tasks[i];
 				dprintk(DEBUG_MUX, "create proc %p\n", vpt);
-				vpt->task = kthread_create(v9fs_poll_proc,
-					vpt, "v9fs-poll");
+				vpt->task =
+				    kthread_create(v9fs_poll_proc, vpt,
+						   "v9fs-poll");
 				INIT_LIST_HEAD(&vpt->mux_list);
 				vpt->muxnum = 0;
 				v9fs_mux_poll_task_num++;
@@ -253,7 +259,7 @@ struct v9fs_mux_data *v9fs_mux_init(struct v9fs_transport *trans, int msize,
 	struct v9fs_mux_data *m, *mtmp;
 
 	dprintk(DEBUG_MUX, "transport %p msize %d\n", trans, msize);
-	m = kmalloc(sizeof(struct v9fs_mux_data) + 2 * msize, GFP_KERNEL);
+	m = kmalloc(sizeof(struct v9fs_mux_data), GFP_KERNEL);
 	if (!m)
 		return ERR_PTR(-ENOMEM);
 
@@ -268,10 +274,11 @@ struct v9fs_mux_data *v9fs_mux_init(struct v9fs_transport *trans, int msize,
 	init_waitqueue_head(&m->equeue);
 	INIT_LIST_HEAD(&m->req_list);
 	INIT_LIST_HEAD(&m->unsent_req_list);
+	m->rcall = NULL;
 	m->rpos = 0;
-	m->rbuf = (char *)m + sizeof(struct v9fs_mux_data);
+	m->rbuf = NULL;
 	m->wpos = m->wsize = 0;
-	m->wbuf = m->rbuf + msize;
+	m->wbuf = NULL;
 	INIT_WORK(&m->rq, v9fs_read_work, m);
 	INIT_WORK(&m->wq, v9fs_write_work, m);
 	m->wsched = 0;
@@ -427,29 +434,6 @@ static int v9fs_poll_proc(void *a)
 	return 0;
 }
 
-static inline int v9fs_write_req(struct v9fs_mux_data *m, struct v9fs_req *req)
-{
-	int n;
-
-	list_move_tail(&req->req_list, &m->req_list);
-	n = v9fs_serialize_fcall(req->tcall, m->wbuf, m->msize, *m->extended);
-	if (n < 0) {
-		req->err = n;
-		list_del(&req->req_list);
-		if (req->cb) {
-			spin_unlock(&m->lock);
-			(*req->cb) (req->cba, req->tcall, req->rcall, req->err);
-			req->cb = NULL;
-			spin_lock(&m->lock);
-		} else
-			kfree(req->rcall);
-
-		kfree(req);
-	}
-
-	return n;
-}
-
 /**
  * v9fs_write_work - called when a transport can send some data
  */
@@ -457,7 +441,7 @@ static void v9fs_write_work(void *a)
 {
 	int n, err;
 	struct v9fs_mux_data *m;
-	struct v9fs_req *req, *rtmp;
+	struct v9fs_req *req;
 
 	m = a;
 
@@ -472,17 +456,15 @@ static void v9fs_write_work(void *a)
 			return;
 		}
 
-		err = 0;
 		spin_lock(&m->lock);
-		list_for_each_entry_safe(req, rtmp, &m->unsent_req_list,
-					 req_list) {
-			err = v9fs_write_req(m, req);
-			if (err > 0)
-				break;
-		}
-
-		m->wsize = err;
+		req =
+		    list_entry(m->unsent_req_list.next, struct v9fs_req,
+			       req_list);
+		list_move_tail(&req->req_list, &m->req_list);
+		m->wbuf = req->tcall->sdata;
+		m->wsize = req->tcall->size;
 		m->wpos = 0;
+		dump_data(m->wbuf, m->wsize);
 		spin_unlock(&m->lock);
 	}
 
@@ -526,24 +508,23 @@ static void v9fs_write_work(void *a)
 static void process_request(struct v9fs_mux_data *m, struct v9fs_req *req)
 {
 	int ecode, tag;
-	char *ename;
+	struct v9fs_str *ename;
 
 	tag = req->tag;
 	if (req->rcall->id == RERROR && !req->err) {
 		ecode = req->rcall->params.rerror.errno;
-		ename = req->rcall->params.rerror.error;
+		ename = &req->rcall->params.rerror.error;
 
-		dprintk(DEBUG_MUX, "Rerror %s\n", ename);
+		dprintk(DEBUG_MUX, "Rerror %.*s\n", ename->len, ename->str);
 
 		if (*m->extended)
 			req->err = -ecode;
 
 		if (!req->err) {
-			req->err = v9fs_errstr2errno(ename);
+			req->err = v9fs_errstr2errno(ename->str, ename->len);
 
 			if (!req->err) {	/* string match failed */
-				dprintk(DEBUG_ERROR, "unknown error: %s\n",
-					ename);
+				PRINT_FCALL_ERROR("unknown error", req->rcall);
 			}
 
 			if (!req->err)
@@ -565,8 +546,7 @@ static void process_request(struct v9fs_mux_data *m, struct v9fs_req *req)
 	} else
 		kfree(req->rcall);
 
-	if (tag != V9FS_NOTAG)
-		v9fs_put_idpool(tag, &m->tidpool);
+	v9fs_mux_put_tag(m, tag);
 
 	wake_up(&m->equeue);
 	kfree(req);
@@ -577,10 +557,11 @@ static void process_request(struct v9fs_mux_data *m, struct v9fs_req *req)
  */
 static void v9fs_read_work(void *a)
 {
-	int n, err, rcallen;
+	int n, err;
 	struct v9fs_mux_data *m;
 	struct v9fs_req *req, *rptr, *rreq;
 	struct v9fs_fcall *rcall;
+	char *rbuf;
 
 	m = a;
 
@@ -589,6 +570,19 @@ static void v9fs_read_work(void *a)
 
 	rcall = NULL;
 	dprintk(DEBUG_MUX, "start mux %p pos %d\n", m, m->rpos);
+
+	if (!m->rcall) {
+		m->rcall =
+		    kmalloc(sizeof(struct v9fs_fcall) + m->msize, GFP_KERNEL);
+		if (!m->rcall) {
+			err = -ENOMEM;
+			goto error;
+		}
+
+		m->rbuf = (char *)m->rcall + sizeof(struct v9fs_fcall);
+		m->rpos = 0;
+	}
+
 	clear_bit(Rpending, &m->wsched);
 	err = m->trans->read(m->trans, m->rbuf + m->rpos, m->msize - m->rpos);
 	dprintk(DEBUG_MUX, "mux %p got %d bytes\n", m, err);
@@ -613,21 +607,32 @@ static void v9fs_read_work(void *a)
 		if (m->rpos < n)
 			break;
 
-		rcallen = n + V9FS_FCALLHDRSZ;
-		rcall = kmalloc(rcallen, GFP_KERNEL);
-		if (!rcall) {
-			err = -ENOMEM;
+		dump_data(m->rbuf, n);
+		err =
+		    v9fs_deserialize_fcall(m->rbuf, n, m->rcall, *m->extended);
+		if (err < 0) {
 			goto error;
 		}
 
-		dump_data(m->rbuf, n);
-		err = v9fs_deserialize_fcall(m->rbuf, n, rcall, rcallen,
-					     *m->extended);
-		if (err < 0) {
-			kfree(rcall);
+		rcall = m->rcall;
+		rbuf = m->rbuf;
+		if (m->rpos > n) {
+			m->rcall = kmalloc(sizeof(struct v9fs_fcall) + m->msize,
+					   GFP_KERNEL);
+			if (!m->rcall) {
+				err = -ENOMEM;
 				goto error;
 			}
 
+			m->rbuf = (char *)m->rcall + sizeof(struct v9fs_fcall);
+			memmove(m->rbuf, rbuf + n, m->rpos - n);
+			m->rpos -= n;
+		} else {
+			m->rcall = NULL;
+			m->rbuf = NULL;
+			m->rpos = 0;
+		}
+
 		dprintk(DEBUG_MUX, "mux %p fcall id %d tag %d\n", m, rcall->id,
 			rcall->tag);
 
@@ -642,6 +647,7 @@ static void v9fs_read_work(void *a)
 				process_request(m, req);
 				break;
 			}
+
 		}
 
 		if (!req) {
@@ -652,10 +658,6 @@ static void v9fs_read_work(void *a)
 					m, rcall->id, rcall->tag);
 			kfree(rcall);
 		}
-
-		if (m->rpos > n)
-			memmove(m->rbuf, m->rbuf + n, m->rpos - n);
-		m->rpos -= n;
 	}
 
 	if (!list_empty(&m->req_list)) {
@@ -710,12 +712,13 @@ static struct v9fs_req *v9fs_send_request(struct v9fs_mux_data *m,
 	if (tc->id == TVERSION)
 		n = V9FS_NOTAG;
 	else
-		n = v9fs_get_idpool(&m->tidpool);
+		n = v9fs_mux_get_tag(m);
 
 	if (n < 0)
 		return ERR_PTR(-ENOMEM);
 
-	tc->tag = n;
+	v9fs_set_tag(tc, n);
+
 	req->tag = n;
 	req->tcall = tc;
 	req->rcall = NULL;
@@ -773,9 +776,7 @@ v9fs_mux_flush_cb(void *a, struct v9fs_fcall *tc, struct v9fs_fcall *rc,
 	if (!cb)
 		spin_unlock(&m->lock);
 
-	if (v9fs_check_idpool(tag, &m->tidpool))
-		v9fs_put_idpool(tag, &m->tidpool);
-
+	v9fs_mux_put_tag(m, tag);
 	kfree(tc);
 	kfree(rc);
 }
@@ -787,10 +788,7 @@ v9fs_mux_flush_request(struct v9fs_mux_data *m, struct v9fs_req *req)
 
 	dprintk(DEBUG_MUX, "mux %p req %p tag %d\n", m, req, req->tag);
 
-	fc = kmalloc(sizeof(struct v9fs_fcall), GFP_KERNEL);
-	fc->id = TFLUSH;
-	fc->params.tflush.oldtag = req->tag;
-
+	fc = v9fs_create_tflush(req->tag);
 	v9fs_send_request(m, fc, v9fs_mux_flush_cb, m);
 }
 
@@ -939,3 +937,20 @@ void v9fs_mux_cancel(struct v9fs_mux_data *m, int err)
 
 	wake_up(&m->equeue);
 }
+
+static u16 v9fs_mux_get_tag(struct v9fs_mux_data *m)
+{
+	int tag;
+
+	tag = v9fs_get_idpool(&m->tidpool);
+	if (tag < 0)
+		return V9FS_NOTAG;
+	else
+		return (u16) tag;
+}
+
+static void v9fs_mux_put_tag(struct v9fs_mux_data *m, u16 tag)
+{
+	if (tag != V9FS_NOTAG && v9fs_check_idpool(tag, &m->tidpool))
+		v9fs_put_idpool(tag, &m->tidpool);
+}

fs/9p/trans_sock.c

@@ -110,7 +110,6 @@ static int v9fs_sock_send(struct v9fs_transport *trans, void *v, int len)
 	if (!(ts->filp->f_flags & O_NONBLOCK))
 		dprintk(DEBUG_ERROR, "blocking write ...\n");
 
-	dump_data(v, len);
 	oldfs = get_fs();
 	set_fs(get_ds());
 	ret = vfs_write(ts->filp, (void __user *)v, len, &ts->filp->f_pos);

fs/9p/v9fs.c

@@ -37,7 +37,6 @@
 #include "v9fs_vfs.h"
 #include "transport.h"
 #include "mux.h"
-#include "conv.h"
 
 /* TODO: sysfs or debugfs interface */
 int v9fs_debug_level = 0;	/* feature-rific global debug level  */
@@ -353,7 +352,7 @@ v9fs_session_init(struct v9fs_session_info *v9ses,
 		}
 
 		/* Really should check for 9P1 and report error */
-		if (!strcmp(fcall->params.rversion.version, "9P2000.u")) {
+		if (!v9fs_str_compare("9P2000.u", &fcall->params.rversion.version)) {
 			dprintk(DEBUG_9P, "9P2000 UNIX extensions enabled\n");
 			v9ses->extended = 1;
 		} else {

fs/9p/v9fs_vfs.h

@@ -45,9 +45,8 @@ extern struct dentry_operations v9fs_dentry_operations;
 
 struct inode *v9fs_get_inode(struct super_block *sb, int mode);
 ino_t v9fs_qid2ino(struct v9fs_qid *qid);
-void v9fs_mistat2inode(struct v9fs_stat *, struct inode *,
-		       struct super_block *);
+void v9fs_stat2inode(struct v9fs_stat *, struct inode *, struct super_block *);
 int v9fs_dir_release(struct inode *inode, struct file *filp);
 int v9fs_file_open(struct inode *inode, struct file *file);
-void v9fs_inode2mistat(struct inode *inode, struct v9fs_stat *mistat);
+void v9fs_inode2stat(struct inode *inode, struct v9fs_stat *stat);
 void v9fs_dentry_release(struct dentry *);

fs/9p/vfs_dentry.c

@@ -40,7 +40,6 @@
 #include "v9fs.h"
 #include "9p.h"
 #include "v9fs_vfs.h"
-#include "conv.h"
 #include "fid.h"
 
 /**
@@ -108,7 +107,8 @@ void v9fs_dentry_release(struct dentry *dentry)
 			err = v9fs_t_clunk(current_fid->v9ses, current_fid->fid);
 
 			if (err < 0)
-				dprintk(DEBUG_ERROR, "clunk failed: %d\n", err);
+				dprintk(DEBUG_ERROR, "clunk failed: %d name %s\n",
+					err, dentry->d_iname);
 
 			v9fs_fid_destroy(current_fid);
 		}

fs/9p/vfs_dir.c

@@ -37,8 +37,8 @@
 #include "debug.h"
 #include "v9fs.h"
 #include "9p.h"
-#include "v9fs_vfs.h"
 #include "conv.h"
+#include "v9fs_vfs.h"
 #include "fid.h"
 
 /**
@@ -77,17 +77,13 @@ static int v9fs_dir_readdir(struct file *filp, void *dirent, filldir_t filldir)
 	unsigned int i, n, s;
 	int fid = -1;
 	int ret = 0;
-	struct v9fs_stat *mi = NULL;
+	struct v9fs_stat stat;
 	int over = 0;
 
 	dprintk(DEBUG_VFS, "name %s\n", filp->f_dentry->d_name.name);
 
 	fid = file->fid;
 
-	mi = kmalloc(v9ses->maxdata, GFP_KERNEL);
-	if (!mi)
-		return -ENOMEM;
-
 	if (file->rdir_fcall && (filp->f_pos != file->rdir_pos)) {
 		kfree(file->rdir_fcall);
 		file->rdir_fcall = NULL;
@@ -99,18 +95,18 @@ static int v9fs_dir_readdir(struct file *filp, void *dirent, filldir_t filldir)
 		while (i < n) {
 			s = v9fs_deserialize_stat(
 				file->rdir_fcall->params.rread.data + i,
-				n - i, mi, v9ses->maxdata, v9ses->extended);
+				n - i, &stat, v9ses->extended);
 
 			if (s == 0) {
 				dprintk(DEBUG_ERROR,
-					"error while deserializing mistat\n");
+					"error while deserializing stat\n");
 				ret = -EIO;
 				goto FreeStructs;
 			}
 
-			over = filldir(dirent, mi->name, strlen(mi->name),
-				    filp->f_pos, v9fs_qid2ino(&mi->qid),
-				    dt_type(mi));
+			over = filldir(dirent, stat.name.str, stat.name.len,
+				    filp->f_pos, v9fs_qid2ino(&stat.qid),
+				    dt_type(&stat));
 
 			if (over) {
 				file->rdir_fpos = i;
@@ -142,17 +138,17 @@ static int v9fs_dir_readdir(struct file *filp, void *dirent, filldir_t filldir)
 		i = 0;
 		while (i < n) {
 			s = v9fs_deserialize_stat(fcall->params.rread.data + i,
-				n - i, mi, v9ses->maxdata, v9ses->extended);
+				n - i, &stat, v9ses->extended);
 
 			if (s == 0) {
 				dprintk(DEBUG_ERROR,
-					"error while deserializing mistat\n");
+					"error while deserializing stat\n");
 				return -EIO;
 			}
 
-			over = filldir(dirent, mi->name, strlen(mi->name),
-				    filp->f_pos, v9fs_qid2ino(&mi->qid),
-				    dt_type(mi));
+			over = filldir(dirent, stat.name.str, stat.name.len,
+				    filp->f_pos, v9fs_qid2ino(&stat.qid),
+				    dt_type(&stat));
 
 			if (over) {
 				file->rdir_fcall = fcall;
@@ -171,7 +167,6 @@ static int v9fs_dir_readdir(struct file *filp, void *dirent, filldir_t filldir)
 
       FreeStructs:
 	kfree(fcall);
-	kfree(mi);
 	return ret;
 }
 

fs/9p/vfs_file.c

@@ -32,6 +32,7 @@
 #include <linux/string.h>
 #include <linux/smp_lock.h>
 #include <linux/inet.h>
+#include <linux/version.h>
 #include <linux/list.h>
 #include <asm/uaccess.h>
 #include <linux/idr.h>
@@ -117,9 +118,7 @@ int v9fs_file_open(struct inode *inode, struct file *file)
 
 		result = v9fs_t_open(v9ses, newfid, open_mode, &fcall);
 		if (result < 0) {
-			dprintk(DEBUG_ERROR,
-				"open failed, open_mode 0x%x: %s\n", open_mode,
-				FCALL_ERROR(fcall));
+			PRINT_FCALL_ERROR("open failed", fcall);
 			kfree(fcall);
 			return result;
 		}
@@ -256,7 +255,6 @@ v9fs_file_write(struct file *filp, const char __user * data,
 	int result = -EIO;
 	int rsize = 0;
 	int total = 0;
-	char *buf;
 
 	dprintk(DEBUG_VFS, "data %p count %d offset %x\n", data, (int)count,
 		(int)*offset);
@@ -264,28 +262,14 @@ v9fs_file_write(struct file *filp, const char __user * data,
 	if (v9fid->iounit != 0 && rsize > v9fid->iounit)
 		rsize = v9fid->iounit;
 
-	buf = kmalloc(v9ses->maxdata - V9FS_IOHDRSZ, GFP_KERNEL);
-	if (!buf)
-		return -ENOMEM;
-
 	do {
 		if (count < rsize)
 			rsize = count;
 
-		result = copy_from_user(buf, data, rsize);
-		if (result) {
-			dprintk(DEBUG_ERROR, "Problem copying from user\n");
-			kfree(buf);
-			return -EFAULT;
-		}
-
-		dump_data(buf, rsize);
-		result = v9fs_t_write(v9ses, fid, *offset, rsize, buf, &fcall);
+		result = v9fs_t_write(v9ses, fid, *offset, rsize, data, &fcall);
 		if (result < 0) {
-			eprintk(KERN_ERR, "error while writing: %s(%d)\n",
-				FCALL_ERROR(fcall), result);
+			PRINT_FCALL_ERROR("error while writing", fcall);
 			kfree(fcall);
-			kfree(buf);
 			return result;
 		} else
 			*offset += result;
@@ -305,7 +289,6 @@ v9fs_file_write(struct file *filp, const char __user * data,
 		total += result;
 	} while (count);
 
-	kfree(buf);
 	return total;
 }
 

fs/9p/vfs_super.c

@@ -44,7 +44,6 @@
 #include "v9fs.h"
 #include "9p.h"
 #include "v9fs_vfs.h"
-#include "conv.h"
 #include "fid.h"
 
 static void v9fs_clear_inode(struct inode *);
@@ -123,10 +122,11 @@ static struct super_block *v9fs_get_sb(struct file_system_type
 
 	dprintk(DEBUG_VFS, " \n");
 
-	v9ses = kcalloc(1, sizeof(struct v9fs_session_info), GFP_KERNEL);
+	v9ses = kmalloc(sizeof(struct v9fs_session_info), GFP_KERNEL);
 	if (!v9ses)
 		return ERR_PTR(-ENOMEM);
 
+	memset(v9ses, 0, sizeof(struct v9fs_session_info));
 	if ((newfid = v9fs_session_init(v9ses, dev_name, data)) < 0) {
 		dprintk(DEBUG_ERROR, "problem initiating session\n");
 		kfree(v9ses);
@@ -168,10 +168,10 @@ static struct super_block *v9fs_get_sb(struct file_system_type
 			goto put_back_sb;
 		}
 
-		root_fid->qid = fcall->params.rstat.stat->qid;
+		root_fid->qid = fcall->params.rstat.stat.qid;
 		root->d_inode->i_ino =
-		    v9fs_qid2ino(&fcall->params.rstat.stat->qid);
-		v9fs_mistat2inode(fcall->params.rstat.stat, root->d_inode, sb);
+		    v9fs_qid2ino(&fcall->params.rstat.stat.qid);
+		v9fs_stat2inode(&fcall->params.rstat.stat, root->d_inode, sb);
 	}
 
 	kfree(fcall);