diff mbox

[V9fs-developer,V2] 9p: readdir implementation for 9p2000.L

Message ID 20100506092243.26009.1078.stgit@localhost.localdomain (mailing list archive)
State Superseded, archived
Delegated to: Eric Van Hensbergen
Headers show

Commit Message

Sripathi Kodi May 6, 2010, 9:22 a.m. UTC
None
diff mbox

Patch

diff --git a/fs/9p/vfs_dir.c b/fs/9p/vfs_dir.c
index 13ce197..2dffff8 100644
--- a/fs/9p/vfs_dir.c
+++ b/fs/9p/vfs_dir.c
@@ -86,29 +86,19 @@  static void p9stat_init(struct p9_wstat *stbuf)
 }
 
 /**
- * v9fs_dir_readdir - read a directory
+ * v9fs_alloc_rdir_buf - Allocate buffer used for read and readdir
  * @filp: opened file structure
- * @dirent: directory structure ???
- * @filldir: function to populate directory structure ???
+ * @buflen: Length in bytes of buffer to allocate
  *
  */
 
-static int v9fs_dir_readdir(struct file *filp, void *dirent, filldir_t filldir)
+static int v9fs_alloc_rdir_buf(struct file *filp, int buflen)
 {
-	int over;
-	struct p9_wstat st;
-	int err = 0;
-	struct p9_fid *fid;
-	int buflen;
-	int reclen = 0;
 	struct p9_rdir *rdir;
+	struct p9_fid *fid;
+	int err = 0;
 
-	P9_DPRINTK(P9_DEBUG_VFS, "name %s\n", filp->f_path.dentry->d_name.name);
 	fid = filp->private_data;
-
-	buflen = fid->clnt->msize - P9_IOHDRSZ;
-
-	/* allocate rdir on demand */
 	if (!fid->rdir) {
 		rdir = kmalloc(sizeof(struct p9_rdir) + buflen, GFP_KERNEL);
 
@@ -127,6 +117,36 @@  static int v9fs_dir_readdir(struct file *filp, void *dirent, filldir_t filldir)
 		spin_unlock(&filp->f_dentry->d_lock);
 		kfree(rdir);
 	}
+exit:
+	return err;
+}
+
+/**
+ * v9fs_dir_readdir - read a directory
+ * @filp: opened file structure
+ * @dirent: directory structure ???
+ * @filldir: function to populate directory structure ???
+ *
+ */
+
+static int v9fs_dir_readdir(struct file *filp, void *dirent, filldir_t filldir)
+{
+	int over;
+	struct p9_wstat st;
+	int err = 0;
+	struct p9_fid *fid;
+	int buflen;
+	int reclen = 0;
+	struct p9_rdir *rdir;
+
+	P9_DPRINTK(P9_DEBUG_VFS, "name %s\n", filp->f_path.dentry->d_name.name);
+	fid = filp->private_data;
+
+	buflen = fid->clnt->msize - P9_IOHDRSZ;
+
+	err = v9fs_alloc_rdir_buf(filp, buflen);
+	if (err)
+		goto exit;
 	rdir = (struct p9_rdir *) fid->rdir;
 
 	err = mutex_lock_interruptible(&rdir->mutex);
@@ -175,6 +195,88 @@  exit:
 	return err;
 }
 
+/**
+ * v9fs_dir_readdir_dotl - read a directory
+ * @filp: opened file structure
+ * @dirent: buffer to fill dirent structures
+ * @filldir: function to populate dirent structures
+ *
+ */
+static int v9fs_dir_readdir_dotl(struct file *filp, void *dirent,
+						filldir_t filldir)
+{
+	int over;
+	int err = 0;
+	struct p9_fid *fid;
+	int buflen;
+	struct p9_rdir *rdir;
+	struct p9_dirent curdirent;
+	u64 oldoffset = 0;
+
+	P9_DPRINTK(P9_DEBUG_VFS, "name %s\n", filp->f_path.dentry->d_name.name);
+	fid = filp->private_data;
+
+	buflen = fid->clnt->msize - P9_IOHDRSZ;
+
+	err = v9fs_alloc_rdir_buf(filp, buflen);
+	if (err)
+		goto exit;
+	rdir = (struct p9_rdir *) fid->rdir;
+
+	err = mutex_lock_interruptible(&rdir->mutex);
+	if (err)
+		return err;
+
+	while (err == 0) {
+		if (rdir->tail == rdir->head) {
+			err = p9_client_readdir(fid, rdir->buf, buflen,
+								filp->f_pos);
+			if (err <= 0)
+				goto unlock_and_exit;
+
+			rdir->head = 0;
+			rdir->tail = err;
+		}
+
+		while (rdir->head < rdir->tail) {
+
+			err = p9dirent_read(rdir->buf + rdir->head,
+						buflen - rdir->head, &curdirent,
+						fid->clnt->proto_version);
+			if (err < 0) {
+				P9_DPRINTK(P9_DEBUG_VFS, "returned %d\n", err);
+				err = -EIO;
+				goto unlock_and_exit;
+			}
+
+			/* d_off in dirent structure tracks the offset into
+			 * the next dirent in the dir. However, filldir()
+			 * expects offset into the current dirent. Hence
+			 * while calling filldir send the offset from the
+			 * previous dirent structure.
+			 */
+			over = filldir(dirent, curdirent.d_name,
+					strlen(curdirent.d_name),
+					oldoffset, curdirent.d_ino,
+					curdirent.d_type);
+			oldoffset = curdirent.d_off;
+
+			if (over) {
+				err = 0;
+				goto unlock_and_exit;
+			}
+
+			filp->f_pos = curdirent.d_off;
+			rdir->head += err;
+		}
+	}
+
+unlock_and_exit:
+	mutex_unlock(&rdir->mutex);
+exit:
+	return err;
+}
+
 
 /**
  * v9fs_dir_release - close a directory
@@ -206,7 +308,7 @@  const struct file_operations v9fs_dir_operations = {
 const struct file_operations v9fs_dir_operations_dotl = {
 	.read = generic_read_dir,
 	.llseek = generic_file_llseek,
-	.readdir = v9fs_dir_readdir,
+	.readdir = v9fs_dir_readdir_dotl,
 	.open = v9fs_file_open,
 	.release = v9fs_dir_release,
 };
diff --git a/include/net/9p/9p.h b/include/net/9p/9p.h
index 156c26b..991dc20 100644
--- a/include/net/9p/9p.h
+++ b/include/net/9p/9p.h
@@ -133,6 +133,8 @@  enum p9_msg_t {
 	P9_RSTATFS,
 	P9_TRENAME = 20,
 	P9_RRENAME,
+	P9_TREADDIR = 40,
+	P9_RREADDIR,
 	P9_TVERSION = 100,
 	P9_RVERSION,
 	P9_TAUTH = 102,
diff --git a/include/net/9p/client.h b/include/net/9p/client.h
index 7dd3ed8..cd6de1c 100644
--- a/include/net/9p/client.h
+++ b/include/net/9p/client.h
@@ -195,6 +195,21 @@  struct p9_fid {
 	struct list_head dlist;	/* list of all fids attached to a dentry */
 };
 
+/**
+ * struct p9_dirent - directory entry structure
+ * @d_ino: inode number
+ * @d_off: offset to the next dirent
+ * @d_type: type of file
+ * @d_name: file name
+ */
+
+struct p9_dirent {
+	u64 d_ino;
+	u64 d_off;
+	unsigned char d_type;
+	char d_name[256];
+};
+
 int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb);
 int p9_client_rename(struct p9_fid *fid, struct p9_fid *newdirfid, char *name);
 int p9_client_version(struct p9_client *);
@@ -217,6 +232,9 @@  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);
+int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset);
+int p9dirent_read(char *buf, int len, struct p9_dirent *dirent,
+							int proto_version);
 struct p9_wstat *p9_client_stat(struct p9_fid *fid);
 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst);
 
diff --git a/net/9p/client.c b/net/9p/client.c
index 8596aa7..8b7f82a 100644
--- a/net/9p/client.c
+++ b/net/9p/client.c
@@ -1431,3 +1431,50 @@  error:
 }
 EXPORT_SYMBOL(p9_client_rename);
 
+int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset)
+{
+	int err, rsize, total;
+	struct p9_client *clnt;
+	struct p9_req_t *req;
+	char *dataptr;
+
+	P9_DPRINTK(P9_DEBUG_9P, ">>> TREADDIR fid %d offset %llu count %d\n",
+				fid->fid, (long long unsigned) offset, count);
+
+	err = 0;
+	clnt = fid->clnt;
+	total = 0;
+
+	rsize = fid->iounit;
+	if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
+		rsize = clnt->msize - P9_IOHDRSZ;
+
+	if (count < rsize)
+		rsize = count;
+
+	req = p9_client_rpc(clnt, P9_TREADDIR, "dqd", fid->fid, offset, rsize);
+	if (IS_ERR(req)) {
+		err = PTR_ERR(req);
+		goto error;
+	}
+
+	err = p9pdu_readf(req->rc, clnt->proto_version, "D", &count, &dataptr);
+	if (err) {
+		p9pdu_dump(1, req->rc);
+		goto free_and_error;
+	}
+
+	P9_DPRINTK(P9_DEBUG_9P, "<<< RREADDIR count %d\n", count);
+
+	if (data)
+		memmove(data, dataptr, count);
+
+	p9_free_req(clnt, req);
+	return count;
+
+free_and_error:
+	p9_free_req(clnt, req);
+error:
+	return err;
+}
+EXPORT_SYMBOL(p9_client_readdir);
diff --git a/net/9p/protocol.c b/net/9p/protocol.c
index d6bc02f..c2ff445 100644
--- a/net/9p/protocol.c
+++ b/net/9p/protocol.c
@@ -579,3 +579,30 @@  void p9pdu_reset(struct p9_fcall *pdu)
 	pdu->offset = 0;
 	pdu->size = 0;
 }
+
+int p9dirent_read(char *buf, int len, struct p9_dirent *dirent,
+						int proto_version)
+{
+	struct p9_fcall fake_pdu;
+	int ret;
+	char *nameptr;
+
+	fake_pdu.size = len;
+	fake_pdu.capacity = len;
+	fake_pdu.sdata = buf;
+	fake_pdu.offset = 0;
+
+	ret = p9pdu_readf(&fake_pdu, proto_version, "qqbs", &dirent->d_ino,
+			&dirent->d_off, &dirent->d_type, &nameptr);
+	if (ret) {
+		P9_DPRINTK(P9_DEBUG_9P, "<<< p9dirent_read failed: %d\n", ret);
+		p9pdu_dump(1, &fake_pdu);
+		goto out;
+	}
+
+	strcpy(dirent->d_name, nameptr);
+
+out:
+	return fake_pdu.offset;
+}
+EXPORT_SYMBOL(p9dirent_read);