v4.19.13 snapshot.
diff --git a/fs/9p/vfs_dir.c b/fs/9p/vfs_dir.c
new file mode 100644
index 0000000..48db9a9
--- /dev/null
+++ b/fs/9p/vfs_dir.c
@@ -0,0 +1,250 @@
+/*
+ * linux/fs/9p/vfs_dir.c
+ *
+ * This file contains vfs directory ops for the 9P2000 protocol.
+ *
+ * Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
+ * Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
+ *
+ * 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/file.h>
+#include <linux/stat.h>
+#include <linux/string.h>
+#include <linux/sched.h>
+#include <linux/inet.h>
+#include <linux/idr.h>
+#include <linux/slab.h>
+#include <linux/uio.h>
+#include <net/9p/9p.h>
+#include <net/9p/client.h>
+
+#include "v9fs.h"
+#include "v9fs_vfs.h"
+#include "fid.h"
+
+/**
+ * struct p9_rdir - readdir accounting
+ * @head: start offset of current dirread buffer
+ * @tail: end offset of current dirread buffer
+ * @buf: dirread buffer
+ *
+ * private structure for keeping track of readdir
+ * allocated on demand
+ */
+
+struct p9_rdir {
+ int head;
+ int tail;
+ uint8_t buf[];
+};
+
+/**
+ * dt_type - return file type
+ * @mistat: mistat structure
+ *
+ */
+
+static inline int dt_type(struct p9_wstat *mistat)
+{
+ unsigned long perm = mistat->mode;
+ int rettype = DT_REG;
+
+ if (perm & P9_DMDIR)
+ rettype = DT_DIR;
+ if (perm & P9_DMSYMLINK)
+ rettype = DT_LNK;
+
+ return rettype;
+}
+
+/**
+ * v9fs_alloc_rdir_buf - Allocate buffer used for read and readdir
+ * @filp: opened file structure
+ * @buflen: Length in bytes of buffer to allocate
+ *
+ */
+
+static struct p9_rdir *v9fs_alloc_rdir_buf(struct file *filp, int buflen)
+{
+ struct p9_fid *fid = filp->private_data;
+ if (!fid->rdir)
+ fid->rdir = kzalloc(sizeof(struct p9_rdir) + buflen, GFP_KERNEL);
+ return fid->rdir;
+}
+
+/**
+ * v9fs_dir_readdir - iterate through a directory
+ * @file: opened file structure
+ * @ctx: actor we feed the entries to
+ *
+ */
+
+static int v9fs_dir_readdir(struct file *file, struct dir_context *ctx)
+{
+ bool over;
+ struct p9_wstat st;
+ int err = 0;
+ struct p9_fid *fid;
+ int buflen;
+ int reclen = 0;
+ struct p9_rdir *rdir;
+ struct kvec kvec;
+
+ p9_debug(P9_DEBUG_VFS, "name %pD\n", file);
+ fid = file->private_data;
+
+ buflen = fid->clnt->msize - P9_IOHDRSZ;
+
+ rdir = v9fs_alloc_rdir_buf(file, buflen);
+ if (!rdir)
+ return -ENOMEM;
+ kvec.iov_base = rdir->buf;
+ kvec.iov_len = buflen;
+
+ while (1) {
+ if (rdir->tail == rdir->head) {
+ struct iov_iter to;
+ int n;
+ iov_iter_kvec(&to, READ | ITER_KVEC, &kvec, 1, buflen);
+ n = p9_client_read(file->private_data, ctx->pos, &to,
+ &err);
+ if (err)
+ return err;
+ if (n == 0)
+ return 0;
+
+ rdir->head = 0;
+ rdir->tail = n;
+ }
+ while (rdir->head < rdir->tail) {
+ err = p9stat_read(fid->clnt, rdir->buf + rdir->head,
+ rdir->tail - rdir->head, &st);
+ if (err) {
+ p9_debug(P9_DEBUG_VFS, "returned %d\n", err);
+ return -EIO;
+ }
+ reclen = st.size+2;
+
+ over = !dir_emit(ctx, st.name, strlen(st.name),
+ v9fs_qid2ino(&st.qid), dt_type(&st));
+ p9stat_free(&st);
+ if (over)
+ return 0;
+
+ rdir->head += reclen;
+ ctx->pos += reclen;
+ }
+ }
+}
+
+/**
+ * v9fs_dir_readdir_dotl - iterate through a directory
+ * @file: opened file structure
+ * @ctx: actor we feed the entries to
+ *
+ */
+static int v9fs_dir_readdir_dotl(struct file *file, struct dir_context *ctx)
+{
+ int err = 0;
+ struct p9_fid *fid;
+ int buflen;
+ struct p9_rdir *rdir;
+ struct p9_dirent curdirent;
+
+ p9_debug(P9_DEBUG_VFS, "name %pD\n", file);
+ fid = file->private_data;
+
+ buflen = fid->clnt->msize - P9_READDIRHDRSZ;
+
+ rdir = v9fs_alloc_rdir_buf(file, buflen);
+ if (!rdir)
+ return -ENOMEM;
+
+ while (1) {
+ if (rdir->tail == rdir->head) {
+ err = p9_client_readdir(fid, rdir->buf, buflen,
+ ctx->pos);
+ if (err <= 0)
+ return err;
+
+ rdir->head = 0;
+ rdir->tail = err;
+ }
+
+ while (rdir->head < rdir->tail) {
+
+ err = p9dirent_read(fid->clnt, rdir->buf + rdir->head,
+ rdir->tail - rdir->head,
+ &curdirent);
+ if (err < 0) {
+ p9_debug(P9_DEBUG_VFS, "returned %d\n", err);
+ return -EIO;
+ }
+
+ if (!dir_emit(ctx, curdirent.d_name,
+ strlen(curdirent.d_name),
+ v9fs_qid2ino(&curdirent.qid),
+ curdirent.d_type))
+ return 0;
+
+ ctx->pos = curdirent.d_off;
+ rdir->head += err;
+ }
+ }
+}
+
+
+/**
+ * v9fs_dir_release - close a directory
+ * @inode: inode of the directory
+ * @filp: file pointer to a directory
+ *
+ */
+
+int v9fs_dir_release(struct inode *inode, struct file *filp)
+{
+ struct p9_fid *fid;
+
+ fid = filp->private_data;
+ p9_debug(P9_DEBUG_VFS, "inode: %p filp: %p fid: %d\n",
+ inode, filp, fid ? fid->fid : -1);
+ if (fid)
+ p9_client_clunk(fid);
+ return 0;
+}
+
+const struct file_operations v9fs_dir_operations = {
+ .read = generic_read_dir,
+ .llseek = generic_file_llseek,
+ .iterate_shared = v9fs_dir_readdir,
+ .open = v9fs_file_open,
+ .release = v9fs_dir_release,
+};
+
+const struct file_operations v9fs_dir_operations_dotl = {
+ .read = generic_read_dir,
+ .llseek = generic_file_llseek,
+ .iterate_shared = v9fs_dir_readdir_dotl,
+ .open = v9fs_file_open,
+ .release = v9fs_dir_release,
+ .fsync = v9fs_file_fsync_dotl,
+};