9p: move dirread to fs layer

Currently reading a directory is implemented in the client code.
This function is not actually a wire operation, but a meta operation 
which calls read operations and processes the results.

This patch moves this functionality to the fs layer and calls component
wire operations instead of constructing their packets.  This provides a 
cleaner separation and will help when we reorganize the client functions
and protocol processing methods.
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

fs/9p/vfs_dir.c

@@ -69,32 +69,54 @@ 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_stat 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, fid->rdir_fpos,
+									buflen);
+		if (err <= 0)
 			break;
 
-		filp->f_pos += st->size;
-		kfree(st);
-		st = NULL;
+		n = err;
+		while (i < n) {
+			err = p9_deserialize_stat(statbuf + i, buflen-i, &st,
+							fid->clnt->dotu);
+			if (!err) {
+				err = -EIO;
+				goto free_and_exit;
+			}
+
+			i += err;
+			fid->rdir_fpos += err;
+
+			over = filldir(dirent, st.name.str, st.name.len,
+			    filp->f_pos, v9fs_qid2ino(&st.qid), dt_type(&st));
+
+			filp->f_pos += st.size;
+
+			if (over) {
+				err = 0;
+				goto free_and_exit;
+			}
+		}
 	}
 
-	kfree(st);
-	return 0;
+free_and_exit:
+	kfree(statbuf);
+	return err;
 }
 
 

include/net/9p/client.h

@@ -163,8 +163,6 @@ 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
  *
@@ -181,8 +179,6 @@ 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 */
 };
@@ -207,7 +203,6 @@ int p9_client_write(struct p9_fid *fid, char *data, const char __user *udata,
 							u64 offset, u32 count);
 struct p9_stat *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);

net/9p/client.c

@@ -559,8 +559,6 @@ static struct p9_fid *p9_fid_create(struct p9_client *clnt)
 	memset(&fid->qid, 0, sizeof(struct p9_qid));
 	fid->mode = -1;
 	fid->rdir_fpos = 0;
-	fid->rdir_pos = 0;
-	fid->rdir_fcall = NULL;
 	fid->uid = current->fsuid;
 	fid->clnt = clnt;
 	fid->aux = NULL;
@@ -586,7 +584,6 @@ static void p9_fid_destroy(struct p9_fid *fid)
 	spin_lock(&clnt->lock);
 	list_del(&fid->flist);
 	spin_unlock(&clnt->lock);
-	kfree(fid->rdir_fcall);
 	kfree(fid);
 }
 
@@ -1261,103 +1258,3 @@ int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
 	return err;
 }
 EXPORT_SYMBOL(p9_client_wstat);
-
-struct p9_stat *p9_client_dirread(struct p9_fid *fid, u64 offset)
-{
-	int err, n, m;
-	struct p9_fcall *tc, *rc;
-	struct p9_client *clnt;
-	struct p9_stat st, *ret;
-
-	P9_DPRINTK(P9_DEBUG_9P, "fid %d offset %llu\n", fid->fid,
-						(long long unsigned) offset);
-	err = 0;
-	tc = NULL;
-	rc = NULL;
-	ret = NULL;
-	clnt = fid->clnt;
-
-	/* if the offset is below or above the current response, free it */
-	if (offset < fid->rdir_fpos || (fid->rdir_fcall &&
-		offset >= fid->rdir_fpos+fid->rdir_fcall->params.rread.count)) {
-		fid->rdir_pos = 0;
-		if (fid->rdir_fcall)
-			fid->rdir_fpos += fid->rdir_fcall->params.rread.count;
-
-		kfree(fid->rdir_fcall);
-		fid->rdir_fcall = NULL;
-		if (offset < fid->rdir_fpos)
-			fid->rdir_fpos = 0;
-	}
-
-	if (!fid->rdir_fcall) {
-		n = fid->iounit;
-		if (!n || n > clnt->msize-P9_IOHDRSZ)
-			n = clnt->msize - P9_IOHDRSZ;
-
-		while (1) {
-			if (fid->rdir_fcall) {
-				fid->rdir_fpos +=
-					fid->rdir_fcall->params.rread.count;
-				kfree(fid->rdir_fcall);
-				fid->rdir_fcall = NULL;
-			}
-
-			tc = p9_create_tread(fid->fid, fid->rdir_fpos, n);
-			if (IS_ERR(tc)) {
-				err = PTR_ERR(tc);
-				tc = NULL;
-				goto error;
-			}
-
-			err = p9_client_rpc(clnt, tc, &rc);
-			if (err)
-				goto error;
-
-			n = rc->params.rread.count;
-			if (n == 0)
-				goto done;
-
-			fid->rdir_fcall = rc;
-			rc = NULL;
-			if (offset >= fid->rdir_fpos &&
-						offset < fid->rdir_fpos+n)
-				break;
-		}
-
-		fid->rdir_pos = 0;
-	}
-
-	m = offset - fid->rdir_fpos;
-	if (m < 0)
-		goto done;
-
-	n = p9_deserialize_stat(fid->rdir_fcall->params.rread.data + m,
-		fid->rdir_fcall->params.rread.count - m, &st, clnt->dotu);
-
-	if (!n) {
-		err = -EIO;
-		goto error;
-	}
-
-	fid->rdir_pos += n;
-	st.size = n;
-	ret = p9_clone_stat(&st, clnt->dotu);
-	if (IS_ERR(ret)) {
-		err = PTR_ERR(ret);
-		ret = NULL;
-		goto error;
-	}
-
-done:
-	kfree(tc);
-	kfree(rc);
-	return ret;
-
-error:
-	kfree(tc);
-	kfree(rc);
-	kfree(ret);
-	return ERR_PTR(err);
-}
-EXPORT_SYMBOL(p9_client_dirread);