--- zzzz-none-000/linux-3.10.107/fs/9p/vfs_dir.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/fs/9p/vfs_dir.c	2021-02-04 17:41:59.000000000 +0000
@@ -33,6 +33,7 @@
 #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>
 
@@ -42,7 +43,6 @@
 
 /**
  * struct p9_rdir - readdir accounting
- * @mutex: mutex protecting readdir
  * @head: start offset of current dirread buffer
  * @tail: end offset of current dirread buffer
  * @buf: dirread buffer
@@ -101,41 +101,48 @@
 }
 
 /**
- * v9fs_dir_readdir - read a directory
- * @filp: opened file structure
- * @dirent: directory structure ???
- * @filldir: function to populate directory structure ???
+ * 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 *filp, void *dirent, filldir_t filldir)
+static int v9fs_dir_readdir(struct file *file, struct dir_context *ctx)
 {
-	int over;
+	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 %s\n", filp->f_path.dentry->d_name.name);
-	fid = filp->private_data;
+	p9_debug(P9_DEBUG_VFS, "name %pD\n", file);
+	fid = file->private_data;
 
 	buflen = fid->clnt->msize - P9_IOHDRSZ;
 
-	rdir = v9fs_alloc_rdir_buf(filp, buflen);
+	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) {
-			err = v9fs_file_readn(filp, rdir->buf, NULL,
-							buflen, filp->f_pos);
-			if (err <= 0)
+			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 = err;
+			rdir->tail = n;
 		}
 		while (rdir->head < rdir->tail) {
 			p9stat_init(&st);
@@ -148,51 +155,45 @@
 			}
 			reclen = st.size+2;
 
-			over = filldir(dirent, st.name, strlen(st.name),
-			    filp->f_pos, v9fs_qid2ino(&st.qid), dt_type(&st));
-
+			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;
-			filp->f_pos += reclen;
+			ctx->pos += reclen;
 		}
 	}
 }
 
 /**
- * v9fs_dir_readdir_dotl - read a directory
- * @filp: opened file structure
- * @dirent: buffer to fill dirent structures
- * @filldir: function to populate dirent structures
+ * 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 *filp, void *dirent,
-						filldir_t filldir)
+static int v9fs_dir_readdir_dotl(struct file *file, struct dir_context *ctx)
 {
-	int over;
 	int err = 0;
 	struct p9_fid *fid;
 	int buflen;
 	struct p9_rdir *rdir;
 	struct p9_dirent curdirent;
-	u64 oldoffset = 0;
 
-	p9_debug(P9_DEBUG_VFS, "name %s\n", filp->f_path.dentry->d_name.name);
-	fid = filp->private_data;
+	p9_debug(P9_DEBUG_VFS, "name %pD\n", file);
+	fid = file->private_data;
 
 	buflen = fid->clnt->msize - P9_READDIRHDRSZ;
 
-	rdir = v9fs_alloc_rdir_buf(filp, buflen);
+	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,
-						filp->f_pos);
+						ctx->pos);
 			if (err <= 0)
 				return err;
 
@@ -210,22 +211,13 @@
 				return -EIO;
 			}
 
-			/* 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, v9fs_qid2ino(&curdirent.qid),
-					curdirent.d_type);
-			oldoffset = curdirent.d_off;
-
-			if (over)
+			if (!dir_emit(ctx, curdirent.d_name,
+				      strlen(curdirent.d_name),
+				      v9fs_qid2ino(&curdirent.qid),
+				      curdirent.d_type))
 				return 0;
 
-			filp->f_pos = curdirent.d_off;
+			ctx->pos = curdirent.d_off;
 			rdir->head += err;
 		}
 	}
@@ -254,7 +246,7 @@
 const struct file_operations v9fs_dir_operations = {
 	.read = generic_read_dir,
 	.llseek = generic_file_llseek,
-	.readdir = v9fs_dir_readdir,
+	.iterate = v9fs_dir_readdir,
 	.open = v9fs_file_open,
 	.release = v9fs_dir_release,
 };
@@ -262,7 +254,7 @@
 const struct file_operations v9fs_dir_operations_dotl = {
 	.read = generic_read_dir,
 	.llseek = generic_file_llseek,
-	.readdir = v9fs_dir_readdir_dotl,
+	.iterate = v9fs_dir_readdir_dotl,
 	.open = v9fs_file_open,
 	.release = v9fs_dir_release,
         .fsync = v9fs_file_fsync_dotl,