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
  ...

fs/9p/v9fs.c

@@ -30,8 +30,8 @@
 #include <linux/parser.h>
 #include <linux/idr.h>
 #include <net/9p/9p.h>
-#include <net/9p/transport.h>
 #include <net/9p/client.h>
+#include <net/9p/transport.h>
 #include "v9fs.h"
 #include "v9fs_vfs.h"
 
@@ -234,7 +234,7 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
 	if (!v9ses->clnt->dotu)
 		v9ses->flags &= ~V9FS_EXTENDED;
 
-	v9ses->maxdata = v9ses->clnt->msize;
+	v9ses->maxdata = v9ses->clnt->msize - P9_IOHDRSZ;
 
 	/* for legacy mode, fall back to V9FS_ACCESS_ANY */
 	if (!v9fs_extended(v9ses) &&

fs/9p/v9fs_vfs.h

@@ -46,9 +46,11 @@ extern struct dentry_operations v9fs_cached_dentry_operations;
 
 struct inode *v9fs_get_inode(struct super_block *sb, int mode);
 ino_t v9fs_qid2ino(struct p9_qid *qid);
-void v9fs_stat2inode(struct p9_stat *, struct inode *, struct super_block *);
+void v9fs_stat2inode(struct p9_wstat *, 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_inode2stat(struct inode *inode, struct p9_stat *stat);
+void v9fs_inode2stat(struct inode *inode, struct p9_wstat *stat);
 void v9fs_dentry_release(struct dentry *);
 int v9fs_uflags2omode(int uflags, int extended);
+
+ssize_t v9fs_file_readn(struct file *, char *, char __user *, u32, u64);

fs/9p/vfs_addr.c

@@ -38,7 +38,6 @@
 
 #include "v9fs.h"
 #include "v9fs_vfs.h"
-#include "fid.h"
 
 /**
  * v9fs_vfs_readpage - read an entire page in from 9P
@@ -53,14 +52,12 @@ static int v9fs_vfs_readpage(struct file *filp, struct page *page)
 	int retval;
 	loff_t offset;
 	char *buffer;
-	struct p9_fid *fid;
 
 	P9_DPRINTK(P9_DEBUG_VFS, "\n");
-	fid = filp->private_data;
 	buffer = kmap(page);
 	offset = page_offset(page);
 
-	retval = p9_client_readn(fid, buffer, offset, PAGE_CACHE_SIZE);
+	retval = v9fs_file_readn(filp, buffer, NULL, offset, PAGE_CACHE_SIZE);
 	if (retval < 0)
 		goto done;
 

fs/9p/vfs_dir.c

@@ -45,7 +45,7 @@
  *
  */
 
-static inline int dt_type(struct p9_stat *mistat)
+static inline int dt_type(struct p9_wstat *mistat)
 {
 	unsigned long perm = mistat->mode;
 	int rettype = DT_REG;
@@ -69,32 +69,58 @@ static inline int dt_type(struct p9_stat *mistat)
 static int v9fs_dir_readdir(struct file *filp, void *dirent, filldir_t filldir)
 {
 	int over;
+	struct p9_wstat st;
+	int err;
 	struct p9_fid *fid;
-	struct v9fs_session_info *v9ses;
-	struct inode *inode;
-	struct p9_stat *st;
+	int buflen;
+	char *statbuf;
+	int n, i = 0;
 
 	P9_DPRINTK(P9_DEBUG_VFS, "name %s\n", filp->f_path.dentry->d_name.name);
-	inode = filp->f_path.dentry->d_inode;
-	v9ses = v9fs_inode2v9ses(inode);
 	fid = filp->private_data;
-	while ((st = p9_client_dirread(fid, filp->f_pos)) != NULL) {
-		if (IS_ERR(st))
-			return PTR_ERR(st);
 
-		over = filldir(dirent, st->name.str, st->name.len, filp->f_pos,
-			v9fs_qid2ino(&st->qid), dt_type(st));
+	buflen = fid->clnt->msize - P9_IOHDRSZ;
+	statbuf = kmalloc(buflen, GFP_KERNEL);
+	if (!statbuf)
+		return -ENOMEM;
 
-		if (over)
+	while (1) {
+		err = v9fs_file_readn(filp, statbuf, NULL, buflen,
+								fid->rdir_fpos);
+		if (err <= 0)
 			break;
 
-		filp->f_pos += st->size;
-		kfree(st);
-		st = NULL;
+		n = err;
+		while (i < n) {
+			err = p9stat_read(statbuf + i, buflen-i, &st,
+							fid->clnt->dotu);
+			if (err) {
+				P9_DPRINTK(P9_DEBUG_VFS, "returned %d\n", err);
+				err = -EIO;
+				p9stat_free(&st);
+				goto free_and_exit;
+			}
+
+			i += st.size+2;
+			fid->rdir_fpos += st.size+2;
+
+			over = filldir(dirent, st.name, strlen(st.name),
+			    filp->f_pos, v9fs_qid2ino(&st.qid), dt_type(&st));
+
+			filp->f_pos += st.size+2;
+
+			p9stat_free(&st);
+
+			if (over) {
+				err = 0;
+				goto free_and_exit;
+			}
+		}
 	}
 
-	kfree(st);
-	return 0;
+free_and_exit:
+	kfree(statbuf);
+	return err;
 }
 
 

fs/9p/vfs_file.c

@@ -120,23 +120,72 @@ static int v9fs_file_lock(struct file *filp, int cmd, struct file_lock *fl)
 }
 
 /**
- * v9fs_file_read - read from a file
+ * v9fs_file_readn - read from a file
  * @filp: file pointer to read
  * @data: data buffer to read data into
+ * @udata: user data buffer to read data into
  * @count: size of buffer
  * @offset: offset at which to read data
  *
  */
+
+ssize_t
+v9fs_file_readn(struct file *filp, char *data, char __user *udata, u32 count,
+	       u64 offset)
+{
+	int n, total;
+	struct p9_fid *fid = filp->private_data;
+
+	P9_DPRINTK(P9_DEBUG_VFS, "fid %d offset %llu count %d\n", fid->fid,
+					(long long unsigned) offset, count);
+
+	n = 0;
+	total = 0;
+	do {
+		n = p9_client_read(fid, data, udata, offset, count);
+		if (n <= 0)
+			break;
+
+		if (data)
+			data += n;
+		if (udata)
+			udata += n;
+
+		offset += n;
+		count -= n;
+		total += n;
+	} while (count > 0 && n == (fid->clnt->msize - P9_IOHDRSZ));
+
+	if (n < 0)
+		total = n;
+
+	return total;
+}
+
+/**
+ * v9fs_file_read - read from a file
+ * @filp: file pointer to read
+ * @udata: user data buffer to read data into
+ * @count: size of buffer
+ * @offset: offset at which to read data
+ *
+ */
+
 static ssize_t
-v9fs_file_read(struct file *filp, char __user * data, size_t count,
+v9fs_file_read(struct file *filp, char __user *udata, size_t count,
 	       loff_t * offset)
 {
 	int ret;
 	struct p9_fid *fid;
 
-	P9_DPRINTK(P9_DEBUG_VFS, "\n");
+	P9_DPRINTK(P9_DEBUG_VFS, "count %d offset %lld\n", count, *offset);
 	fid = filp->private_data;
-	ret = p9_client_uread(fid, data, *offset, count);
+
+	if (count > (fid->clnt->msize - P9_IOHDRSZ))
+		ret = v9fs_file_readn(filp, NULL, udata, count, *offset);
+	else
+		ret = p9_client_read(fid, NULL, udata, *offset, count);
+
 	if (ret > 0)
 		*offset += ret;
 
@@ -156,19 +205,38 @@ static ssize_t
 v9fs_file_write(struct file *filp, const char __user * data,
 		size_t count, loff_t * offset)
 {
-	int ret;
+	int n, rsize, total = 0;
 	struct p9_fid *fid;
+	struct p9_client *clnt;
 	struct inode *inode = filp->f_path.dentry->d_inode;
+	int origin = *offset;
 
 	P9_DPRINTK(P9_DEBUG_VFS, "data %p count %d offset %x\n", data,
 		(int)count, (int)*offset);
 
 	fid = filp->private_data;
-	ret = p9_client_uwrite(fid, data, *offset, count);
-	if (ret > 0) {
-		invalidate_inode_pages2_range(inode->i_mapping, *offset,
-								*offset+ret);
-		*offset += ret;
+	clnt = fid->clnt;
+
+	rsize = fid->iounit;
+	if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
+		rsize = clnt->msize - P9_IOHDRSZ;
+
+	do {
+		if (count < rsize)
+			rsize = count;
+
+		n = p9_client_write(fid, NULL, data+total, *offset+total,
+									rsize);
+		if (n <= 0)
+			break;
+		count -= n;
+		total += n;
+	} while (count > 0);
+
+	if (total > 0) {
+		invalidate_inode_pages2_range(inode->i_mapping, origin,
+								origin+total);
+		*offset += total;
 	}
 
 	if (*offset > inode->i_size) {
@@ -176,7 +244,10 @@ v9fs_file_write(struct file *filp, const char __user * data,
 		inode->i_blocks = (inode->i_size + 512 - 1) >> 9;
 	}
 
-	return ret;
+	if (n < 0)
+		return n;
+
+	return total;
 }
 
 static const struct file_operations v9fs_cached_file_operations = {

fs/9p/vfs_inode.c

@@ -334,7 +334,7 @@ v9fs_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
 {
 	int err, umode;
 	struct inode *ret;
-	struct p9_stat *st;
+	struct p9_wstat *st;
 
 	ret = NULL;
 	st = p9_client_stat(fid);
@@ -417,6 +417,8 @@ v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
 	struct p9_fid *dfid, *ofid, *fid;
 	struct inode *inode;
 
+	P9_DPRINTK(P9_DEBUG_VFS, "name %s\n", dentry->d_name.name);
+
 	err = 0;
 	ofid = NULL;
 	fid = NULL;
@@ -424,6 +426,7 @@ v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
 	dfid = v9fs_fid_clone(dentry->d_parent);
 	if (IS_ERR(dfid)) {
 		err = PTR_ERR(dfid);
+		P9_DPRINTK(P9_DEBUG_VFS, "fid clone failed %d\n", err);
 		dfid = NULL;
 		goto error;
 	}
@@ -432,18 +435,22 @@ v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
 	ofid = p9_client_walk(dfid, 0, NULL, 1);
 	if (IS_ERR(ofid)) {
 		err = PTR_ERR(ofid);
+		P9_DPRINTK(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
 		ofid = NULL;
 		goto error;
 	}
 
 	err = p9_client_fcreate(ofid, name, perm, mode, extension);
-	if (err < 0)
+	if (err < 0) {
+		P9_DPRINTK(P9_DEBUG_VFS, "p9_client_fcreate failed %d\n", err);
 		goto error;
+	}
 
 	/* now walk from the parent so we can get unopened fid */
 	fid = p9_client_walk(dfid, 1, &name, 0);
 	if (IS_ERR(fid)) {
 		err = PTR_ERR(fid);
+		P9_DPRINTK(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
 		fid = NULL;
 		goto error;
 	} else
@@ -453,6 +460,7 @@ v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
 	inode = v9fs_inode_from_fid(v9ses, fid, dir->i_sb);
 	if (IS_ERR(inode)) {
 		err = PTR_ERR(inode);
+		P9_DPRINTK(P9_DEBUG_VFS, "inode creation failed %d\n", err);
 		goto error;
 	}
 
@@ -734,7 +742,7 @@ v9fs_vfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
 	int err;
 	struct v9fs_session_info *v9ses;
 	struct p9_fid *fid;
-	struct p9_stat *st;
+	struct p9_wstat *st;
 
 	P9_DPRINTK(P9_DEBUG_VFS, "dentry: %p\n", dentry);
 	err = -EPERM;
@@ -815,10 +823,9 @@ static int v9fs_vfs_setattr(struct dentry *dentry, struct iattr *iattr)
  */
 
 void
-v9fs_stat2inode(struct p9_stat *stat, struct inode *inode,
+v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
 	struct super_block *sb)
 {
-	int n;
 	char ext[32];
 	struct v9fs_session_info *v9ses = sb->s_fs_info;
 
@@ -842,11 +849,7 @@ v9fs_stat2inode(struct p9_stat *stat, struct inode *inode,
 		int major = -1;
 		int minor = -1;
 
-		n = stat->extension.len;
-		if (n > sizeof(ext)-1)
-			n = sizeof(ext)-1;
-		memmove(ext, stat->extension.str, n);
-		ext[n] = 0;
+		strncpy(ext, stat->extension, sizeof(ext));
 		sscanf(ext, "%c %u %u", &type, &major, &minor);
 		switch (type) {
 		case 'c':
@@ -857,10 +860,11 @@ v9fs_stat2inode(struct p9_stat *stat, struct inode *inode,
 			break;
 		default:
 			P9_DPRINTK(P9_DEBUG_ERROR,
-				"Unknown special type %c (%.*s)\n", type,
-				stat->extension.len, stat->extension.str);
+				"Unknown special type %c %s\n", type,
+				stat->extension);
 		};
 		inode->i_rdev = MKDEV(major, minor);
+		init_special_inode(inode, inode->i_mode, inode->i_rdev);
 	} else
 		inode->i_rdev = 0;
 
@@ -904,7 +908,7 @@ static int v9fs_readlink(struct dentry *dentry, char *buffer, int buflen)
 
 	struct v9fs_session_info *v9ses;
 	struct p9_fid *fid;
-	struct p9_stat *st;
+	struct p9_wstat *st;
 
 	P9_DPRINTK(P9_DEBUG_VFS, " %s\n", dentry->d_name.name);
 	retval = -EPERM;
@@ -926,15 +930,10 @@ static int v9fs_readlink(struct dentry *dentry, char *buffer, int buflen)
 	}
 
 	/* copy extension buffer into buffer */
-	if (st->extension.len < buflen)
-		buflen = st->extension.len + 1;
-
-	memmove(buffer, st->extension.str, buflen - 1);
-	buffer[buflen-1] = 0;
+	strncpy(buffer, st->extension, buflen);
 
 	P9_DPRINTK(P9_DEBUG_VFS,
-		"%s -> %.*s (%s)\n", dentry->d_name.name, st->extension.len,
-		st->extension.str, buffer);
+		"%s -> %s (%s)\n", dentry->d_name.name, st->extension, buffer);
 
 	retval = buflen;
 

fs/9p/vfs_super.c

@@ -111,7 +111,7 @@ static int v9fs_get_sb(struct file_system_type *fs_type, int flags,
 	struct inode *inode = NULL;
 	struct dentry *root = NULL;
 	struct v9fs_session_info *v9ses = NULL;
-	struct p9_stat *st = NULL;
+	struct p9_wstat *st = NULL;
 	int mode = S_IRWXUGO | S_ISVTX;
 	uid_t uid = current->fsuid;
 	gid_t gid = current->fsgid;
@@ -161,10 +161,14 @@ static int v9fs_get_sb(struct file_system_type *fs_type, int flags,
 
 	sb->s_root = root;
 	root->d_inode->i_ino = v9fs_qid2ino(&st->qid);
+
 	v9fs_stat2inode(st, root->d_inode, sb);
+
 	v9fs_fid_add(root, fid);
+	p9stat_free(st);
 	kfree(st);
 
+P9_DPRINTK(P9_DEBUG_VFS, " return simple set mount\n");
 	return simple_set_mnt(mnt, sb);
 
 release_sb:

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);

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 */

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);

net/9p/Makefile

@@ -4,10 +4,9 @@ obj-$(CONFIG_NET_9P_VIRTIO) += 9pnet_virtio.o
 9pnet-objs := \
 	mod.o \
 	client.o \
-	conv.o \
 	error.o \
-	fcprint.o \
 	util.o \
+	protocol.o \
 	trans_fd.o \
 
 9pnet_virtio-objs := \

net/9p/fcprint.c

-/*
- *  net/9p/fcprint.c
- *
- *  Print 9P call.
- *
- *  Copyright (C) 2005 by Latchesar Ionkov <lucho@ionkov.net>
- *
- *  This program is free software; you can redistribute it and/or modify
- *  it under the terms of the GNU General Public License version 2
- *  as published by the Free Software Foundation.
- *
- *  This program is distributed in the hope that it will be useful,
- *  but WITHOUT ANY WARRANTY; without even the implied warranty of
- *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *  GNU General Public License for more details.
- *
- *  You should have received a copy of the GNU General Public License
- *  along with this program; if not, write to:
- *  Free Software Foundation
- *  51 Franklin Street, Fifth Floor
- *  Boston, MA  02111-1301  USA
- *
- */
-#include <linux/module.h>
-#include <linux/errno.h>
-#include <linux/fs.h>
-#include <linux/idr.h>
-#include <net/9p/9p.h>
-
-#ifdef CONFIG_NET_9P_DEBUG
-
-static int
-p9_printqid(char *buf, int buflen, struct p9_qid *q)
-{
-	int n;
-	char b[10];
-
-	n = 0;
-	if (q->type & P9_QTDIR)
-		b[n++] = 'd';
-	if (q->type & P9_QTAPPEND)
-		b[n++] = 'a';
-	if (q->type & P9_QTAUTH)
-		b[n++] = 'A';
-	if (q->type & P9_QTEXCL)
-		b[n++] = 'l';
-	if (q->type & P9_QTTMP)
-		b[n++] = 't';
-	if (q->type & P9_QTSYMLINK)
-		b[n++] = 'L';
-	b[n] = '\0';
-
-	return scnprintf(buf, buflen, "(%.16llx %x %s)",
-					(long long int) q->path, q->version, b);
-}
-
-static int
-p9_printperm(char *buf, int buflen, int perm)
-{
-	int n;
-	char b[15];
-
-	n = 0;
-	if (perm & P9_DMDIR)
-		b[n++] = 'd';
-	if (perm & P9_DMAPPEND)
-		b[n++] = 'a';
-	if (perm & P9_DMAUTH)
-		b[n++] = 'A';
-	if (perm & P9_DMEXCL)
-		b[n++] = 'l';
-	if (perm & P9_DMTMP)
-		b[n++] = 't';
-	if (perm & P9_DMDEVICE)
-		b[n++] = 'D';
-	if (perm & P9_DMSOCKET)
-		b[n++] = 'S';
-	if (perm & P9_DMNAMEDPIPE)
-		b[n++] = 'P';
-	if (perm & P9_DMSYMLINK)
-		b[n++] = 'L';
-	b[n] = '\0';
-
-	return scnprintf(buf, buflen, "%s%03o", b, perm&077);
-}
-
-static int
-p9_printstat(char *buf, int buflen, struct p9_stat *st, int extended)
-{
-	int n;
-
-	n = scnprintf(buf, buflen, "'%.*s' '%.*s'", st->name.len,
-		st->name.str, st->uid.len, st->uid.str);
-	if (extended)
-		n += scnprintf(buf+n, buflen-n, "(%d)", st->n_uid);
-
-	n += scnprintf(buf+n, buflen-n, " '%.*s'", st->gid.len, st->gid.str);
-	if (extended)
-		n += scnprintf(buf+n, buflen-n, "(%d)", st->n_gid);
-
-	n += scnprintf(buf+n, buflen-n, " '%.*s'", st->muid.len, st->muid.str);
-	if (extended)
-		n += scnprintf(buf+n, buflen-n, "(%d)", st->n_muid);
-
-	n += scnprintf(buf+n, buflen-n, " q ");
-	n += p9_printqid(buf+n, buflen-n, &st->qid);
-	n += scnprintf(buf+n, buflen-n, " m ");
-	n += p9_printperm(buf+n, buflen-n, st->mode);
-	n += scnprintf(buf+n, buflen-n, " at %d mt %d l %lld",
-		st->atime, st->mtime, (long long int) st->length);
-
-	if (extended)
-		n += scnprintf(buf+n, buflen-n, " ext '%.*s'",
-			st->extension.len, st->extension.str);
-
-	return n;
-}
-
-static int
-p9_dumpdata(char *buf, int buflen, u8 *data, int datalen)
-{
-	int i, n;
-
-	i = n = 0;
-	while (i < datalen) {
-		n += scnprintf(buf + n, buflen - n, "%02x", data[i]);
-		if (i%4 == 3)
-			n += scnprintf(buf + n, buflen - n, " ");
-		if (i%32 == 31)
-			n += scnprintf(buf + n, buflen - n, "\n");
-
-		i++;
-	}
-	n += scnprintf(buf + n, buflen - n, "\n");
-
-	return n;
-}
-
-static int
-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)
-{
-	int i, ret, type, tag;
-
-	if (!fc)
-		return scnprintf(buf, buflen, "<NULL>");
-
-	type = fc->id;
-	tag = fc->tag;
-
-	ret = 0;
-	switch (type) {
-	case P9_TVERSION:
-		ret += scnprintf(buf+ret, buflen-ret,
-				"Tversion tag %u msize %u version '%.*s'", tag,
-				fc->params.tversion.msize,
-				fc->params.tversion.version.len,
-				fc->params.tversion.version.str);
-		break;
-
-	case P9_RVERSION:
-		ret += scnprintf(buf+ret, buflen-ret,
-				"Rversion tag %u msize %u version '%.*s'", tag,
-				fc->params.rversion.msize,
-				fc->params.rversion.version.len,
-				fc->params.rversion.version.str);
-		break;
-
-	case P9_TAUTH:
-		ret += scnprintf(buf+ret, buflen-ret,
-			"Tauth tag %u afid %d uname '%.*s' aname '%.*s'", tag,
-			fc->params.tauth.afid, fc->params.tauth.uname.len,
-			fc->params.tauth.uname.str, fc->params.tauth.aname.len,
-			fc->params.tauth.aname.str);
-		break;
-
-	case P9_RAUTH:
-		ret += scnprintf(buf+ret, buflen-ret, "Rauth tag %u qid ", tag);
-		p9_printqid(buf+ret, buflen-ret, &fc->params.rauth.qid);
-		break;
-
-	case P9_TATTACH:
-		ret += scnprintf(buf+ret, buflen-ret,
-		 "Tattach tag %u fid %d afid %d uname '%.*s' aname '%.*s'", tag,
-		 fc->params.tattach.fid, fc->params.tattach.afid,
-		 fc->params.tattach.uname.len, fc->params.tattach.uname.str,
-		 fc->params.tattach.aname.len, fc->params.tattach.aname.str);
-		break;
-
-	case P9_RATTACH:
-		ret += scnprintf(buf+ret, buflen-ret, "Rattach tag %u qid ",
-									tag);
-		p9_printqid(buf+ret, buflen-ret, &fc->params.rattach.qid);
-		break;
-
-	case P9_RERROR:
-		ret += scnprintf(buf+ret, buflen-ret,
-				"Rerror tag %u ename '%.*s'", tag,
-				fc->params.rerror.error.len,
-				fc->params.rerror.error.str);
-		if (extended)
-			ret += scnprintf(buf+ret, buflen-ret, " ecode %d\n",
-				fc->params.rerror.errno);
-		break;
-
-	case P9_TFLUSH:
-		ret += scnprintf(buf+ret, buflen-ret, "Tflush tag %u oldtag %u",
-			tag, fc->params.tflush.oldtag);
-		break;
-
-	case P9_RFLUSH:
-		ret += scnprintf(buf+ret, buflen-ret, "Rflush tag %u", tag);
-		break;
-
-	case P9_TWALK:
-		ret += scnprintf(buf+ret, buflen-ret,
-			"Twalk tag %u fid %d newfid %d nwname %d", tag,
-			fc->params.twalk.fid, fc->params.twalk.newfid,
-			fc->params.twalk.nwname);
-		for (i = 0; i < fc->params.twalk.nwname; i++)
-			ret += scnprintf(buf+ret, buflen-ret, " '%.*s'",
-				fc->params.twalk.wnames[i].len,
-				fc->params.twalk.wnames[i].str);
-		break;
-
-	case P9_RWALK:
-		ret += scnprintf(buf+ret, buflen-ret, "Rwalk tag %u nwqid %d",
-			tag, fc->params.rwalk.nwqid);
-		for (i = 0; i < fc->params.rwalk.nwqid; i++)
-			ret += p9_printqid(buf+ret, buflen-ret,
-				&fc->params.rwalk.wqids[i]);
-		break;
-
-	case P9_TOPEN:
-		ret += scnprintf(buf+ret, buflen-ret,
-			"Topen tag %u fid %d mode %d", tag,
-			fc->params.topen.fid, fc->params.topen.mode);
-		break;
-
-	case P9_ROPEN:
-		ret += scnprintf(buf+ret, buflen-ret, "Ropen tag %u", tag);
-		ret += p9_printqid(buf+ret, buflen-ret, &fc->params.ropen.qid);
-		ret += scnprintf(buf+ret, buflen-ret, " iounit %d",
-			fc->params.ropen.iounit);
-		break;
-
-	case P9_TCREATE:
-		ret += scnprintf(buf+ret, buflen-ret,
-			"Tcreate tag %u fid %d name '%.*s' perm ", tag,
-			fc->params.tcreate.fid, fc->params.tcreate.name.len,
-			fc->params.tcreate.name.str);
-
-		ret += p9_printperm(buf+ret, buflen-ret,
-						fc->params.tcreate.perm);
-		ret += scnprintf(buf+ret, buflen-ret, " mode %d",
-			fc->params.tcreate.mode);
-		break;
-
-	case P9_RCREATE:
-		ret += scnprintf(buf+ret, buflen-ret, "Rcreate tag %u", tag);
-		ret += p9_printqid(buf+ret, buflen-ret,
-						&fc->params.rcreate.qid);
-		ret += scnprintf(buf+ret, buflen-ret, " iounit %d",
-			fc->params.rcreate.iounit);
-		break;
-
-	case P9_TREAD:
-		ret += scnprintf(buf+ret, buflen-ret,
-			"Tread tag %u fid %d offset %lld count %u", tag,
-			fc->params.tread.fid,
-			(long long int) fc->params.tread.offset,
-			fc->params.tread.count);
-		break;
-
-	case P9_RREAD:
-		ret += scnprintf(buf+ret, buflen-ret,
-			"Rread tag %u count %u data ", tag,
-			fc->params.rread.count);
-		ret += p9_printdata(buf+ret, buflen-ret, fc->params.rread.data,
-			fc->params.rread.count);
-		break;
-
-	case P9_TWRITE:
-		ret += scnprintf(buf+ret, buflen-ret,
-			"Twrite tag %u fid %d offset %lld count %u data ",
-			tag, fc->params.twrite.fid,
-			(long long int) fc->params.twrite.offset,
-			fc->params.twrite.count);
-		ret += p9_printdata(buf+ret, buflen-ret, fc->params.twrite.data,
-			fc->params.twrite.count);
-		break;
-
-	case P9_RWRITE:
-		ret += scnprintf(buf+ret, buflen-ret, "Rwrite tag %u count %u",
-			tag, fc->params.rwrite.count);
-		break;
-
-	case P9_TCLUNK:
-		ret += scnprintf(buf+ret, buflen-ret, "Tclunk tag %u fid %d",
-			tag, fc->params.tclunk.fid);
-		break;
-
-	case P9_RCLUNK:
-		ret += scnprintf(buf+ret, buflen-ret, "Rclunk tag %u", tag);
-		break;
-
-	case P9_TREMOVE:
-		ret += scnprintf(buf+ret, buflen-ret, "Tremove tag %u fid %d",
-			tag, fc->params.tremove.fid);
-		break;
-
-	case P9_RREMOVE:
-		ret += scnprintf(buf+ret, buflen-ret, "Rremove tag %u", tag);
-		break;
-
-	case P9_TSTAT:
-		ret += scnprintf(buf+ret, buflen-ret, "Tstat tag %u fid %d",
-			tag, fc->params.tstat.fid);
-		break;
-
-	case P9_RSTAT:
-		ret += scnprintf(buf+ret, buflen-ret, "Rstat tag %u ", tag);
-		ret += p9_printstat(buf+ret, buflen-ret, &fc->params.rstat.stat,
-			extended);
-		break;
-
-	case P9_TWSTAT:
-		ret += scnprintf(buf+ret, buflen-ret, "Twstat tag %u fid %d ",
-			tag, fc->params.twstat.fid);
-		ret += p9_printstat(buf+ret, buflen-ret,
-					&fc->params.twstat.stat, extended);
-		break;
-
-	case P9_RWSTAT:
-		ret += scnprintf(buf+ret, buflen-ret, "Rwstat tag %u", tag);
-		break;
-
-	default:
-		ret += scnprintf(buf+ret, buflen-ret, "unknown type %d", type);
-		break;
-	}
-
-	return ret;
-}
-#else
-int
-p9_printfcall(char *buf, int buflen, struct p9_fcall *fc, int extended)
-{
-	return 0;
-}
-#endif /* CONFIG_NET_9P_DEBUG */
-EXPORT_SYMBOL(p9_printfcall);
-

net/9p/mod.c

@@ -29,6 +29,7 @@
 #include <net/9p/9p.h>
 #include <linux/fs.h>
 #include <linux/parser.h>
+#include <net/9p/client.h>
 #include <net/9p/transport.h>
 #include <linux/list.h>
 #include <linux/spinlock.h>

net/9p/protocol.h

+/*
+ * net/9p/protocol.h
+ *
+ * 9P Protocol Support Code
+ *
+ *  Copyright (C) 2008 by Eric Van Hensbergen <ericvh@gmail.com>
+ *
+ *  Base on code from Anthony Liguori <aliguori@us.ibm.com>
+ *  Copyright (C) 2008 by IBM, Corp.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2
+ *  as published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to:
+ *  Free Software Foundation
+ *  51 Franklin Street, Fifth Floor
+ *  Boston, MA  02111-1301  USA
+ *
+ */
+
+int
+p9pdu_vwritef(struct p9_fcall *pdu, int optional, const char *fmt, va_list ap);
+int p9pdu_readf(struct p9_fcall *pdu, int optional, const char *fmt, ...);
+int p9pdu_prepare(struct p9_fcall *pdu, int16_t tag, int8_t type);
+int p9pdu_finalize(struct p9_fcall *pdu);
+void p9pdu_dump(int, struct p9_fcall *);
+void p9pdu_reset(struct p9_fcall *pdu);