1 files changed, 254 insertions, 0 deletions
diff --git a/fs/9p/vfs_dir.c b/fs/9p/vfs_dir.c
new file mode 100644
index 0000000000..4102759a5c
--- /dev/null
+++ b/fs/9p/vfs_dir.c
@@ -0,0 +1,254 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * 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>
+ */
+
+#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/slab.h>
+#include <linux/uio.h>
+#include <linux/fscache.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;
+	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, ITER_DEST, &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 <= 0) {
+				p9_debug(P9_DEBUG_VFS, "returned %d\n", err);
+				return -EIO;
+			}
+
+			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 += err;
+			ctx->pos += err;
+		}
+	}
+}
+
+/**
+ * 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 or a file
+ * @inode: inode of the directory or file
+ * @filp: file pointer to a directory or file
+ *
+ */
+
+int v9fs_dir_release(struct inode *inode, struct file *filp)
+{
+	struct v9fs_inode *v9inode = V9FS_I(inode);
+	struct p9_fid *fid;
+	__le32 version;
+	loff_t i_size;
+	int retval = 0, put_err;
+
+	fid = filp->private_data;
+	p9_debug(P9_DEBUG_VFS, "inode: %p filp: %p fid: %d\n",
+		 inode, filp, fid ? fid->fid : -1);
+
+	if (fid) {
+		if ((S_ISREG(inode->i_mode)) && (filp->f_mode & FMODE_WRITE))
+			retval = filemap_fdatawrite(inode->i_mapping);
+
+		spin_lock(&inode->i_lock);
+		hlist_del(&fid->ilist);
+		spin_unlock(&inode->i_lock);
+		put_err = p9_fid_put(fid);
+		retval = retval < 0 ? retval : put_err;
+	}
+
+	if ((filp->f_mode & FMODE_WRITE)) {
+		version = cpu_to_le32(v9inode->qid.version);
+		i_size = i_size_read(inode);
+		fscache_unuse_cookie(v9fs_inode_cookie(v9inode),
+				     &version, &i_size);
+	} else {
+		fscache_unuse_cookie(v9fs_inode_cookie(v9inode), NULL, NULL);
+	}
+	return retval;
+}
+
+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,
+};