1 files changed, 156 insertions, 67 deletions

diff --git a/fs/coda/file.c b/fs/coda/file.c
index 380b798f8443..a390b5d21196 100644
--- a/fs/coda/file.c
+++ b/fs/coda/file.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * File operations for Coda.
  * Original version: (C) 1996 Peter Braam 
@@ -7,109 +8,176 @@
  * to the Coda project. Contact Peter Braam <coda@cs.cmu.edu>.
  */
 
+#include <linux/refcount.h>
 #include <linux/types.h>
 #include <linux/kernel.h>
 #include <linux/time.h>
 #include <linux/file.h>
 #include <linux/fs.h>
+#include <linux/pagemap.h>
 #include <linux/stat.h>
 #include <linux/cred.h>
 #include <linux/errno.h>
 #include <linux/spinlock.h>
 #include <linux/string.h>
 #include <linux/slab.h>
-#include <asm/uaccess.h>
+#include <linux/uaccess.h>
+#include <linux/uio.h>
+#include <linux/splice.h>
 
 #include <linux/coda.h>
-#include <linux/coda_psdev.h>
-
+#include "coda_psdev.h"
 #include "coda_linux.h"
 #include "coda_int.h"
 
+struct coda_vm_ops {
+	refcount_t refcnt;
+	struct file *coda_file;
+	const struct vm_operations_struct *host_vm_ops;
+	struct vm_operations_struct vm_ops;
+};
+
 static ssize_t
-coda_file_read(struct file *coda_file, char __user *buf, size_t count, loff_t *ppos)
+coda_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
 {
-	struct coda_file_info *cfi;
-	struct file *host_file;
+	struct file *coda_file = iocb->ki_filp;
+	struct inode *coda_inode = file_inode(coda_file);
+	struct coda_file_info *cfi = coda_ftoc(coda_file);
+	loff_t ki_pos = iocb->ki_pos;
+	size_t count = iov_iter_count(to);
+	ssize_t ret;
 
-	cfi = CODA_FTOC(coda_file);
-	BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
-	host_file = cfi->cfi_container;
+	ret = venus_access_intent(coda_inode->i_sb, coda_i2f(coda_inode),
+				  &cfi->cfi_access_intent,
+				  count, ki_pos, CODA_ACCESS_TYPE_READ);
+	if (ret)
+		goto finish_read;
 
-	if (!host_file->f_op || !host_file->f_op->read)
-		return -EINVAL;
+	ret = vfs_iter_read(cfi->cfi_container, to, &iocb->ki_pos, 0);
 
-	return host_file->f_op->read(host_file, buf, count, ppos);
+finish_read:
+	venus_access_intent(coda_inode->i_sb, coda_i2f(coda_inode),
+			    &cfi->cfi_access_intent,
+			    count, ki_pos, CODA_ACCESS_TYPE_READ_FINISH);
+	return ret;
 }
 
 static ssize_t
-coda_file_splice_read(struct file *coda_file, loff_t *ppos,
-		      struct pipe_inode_info *pipe, size_t count,
-		      unsigned int flags)
+coda_file_write_iter(struct kiocb *iocb, struct iov_iter *to)
 {
-	ssize_t (*splice_read)(struct file *, loff_t *,
-			       struct pipe_inode_info *, size_t, unsigned int);
-	struct coda_file_info *cfi;
-	struct file *host_file;
+	struct file *coda_file = iocb->ki_filp;
+	struct inode *coda_inode = file_inode(coda_file);
+	struct coda_file_info *cfi = coda_ftoc(coda_file);
+	struct file *host_file = cfi->cfi_container;
+	loff_t ki_pos = iocb->ki_pos;
+	size_t count = iov_iter_count(to);
+	ssize_t ret;
 
-	cfi = CODA_FTOC(coda_file);
-	BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
-	host_file = cfi->cfi_container;
+	ret = venus_access_intent(coda_inode->i_sb, coda_i2f(coda_inode),
+				  &cfi->cfi_access_intent,
+				  count, ki_pos, CODA_ACCESS_TYPE_WRITE);
+	if (ret)
+		goto finish_write;
 
-	splice_read = host_file->f_op->splice_read;
-	if (!splice_read)
-		splice_read = default_file_splice_read;
+	inode_lock(coda_inode);
+	ret = vfs_iter_write(cfi->cfi_container, to, &iocb->ki_pos, 0);
+	coda_inode->i_size = file_inode(host_file)->i_size;
+	coda_inode->i_blocks = (coda_inode->i_size + 511) >> 9;
+	inode_set_mtime_to_ts(coda_inode, inode_set_ctime_current(coda_inode));
+	inode_unlock(coda_inode);
 
-	return splice_read(host_file, ppos, pipe, count, flags);
+finish_write:
+	venus_access_intent(coda_inode->i_sb, coda_i2f(coda_inode),
+			    &cfi->cfi_access_intent,
+			    count, ki_pos, CODA_ACCESS_TYPE_WRITE_FINISH);
+	return ret;
 }
 
 static ssize_t
-coda_file_write(struct file *coda_file, const char __user *buf, size_t count, loff_t *ppos)
+coda_file_splice_read(struct file *coda_file, loff_t *ppos,
+		      struct pipe_inode_info *pipe,
+		      size_t len, unsigned int flags)
 {
-	struct inode *host_inode, *coda_inode = file_inode(coda_file);
-	struct coda_file_info *cfi;
-	struct file *host_file;
+	struct inode *coda_inode = file_inode(coda_file);
+	struct coda_file_info *cfi = coda_ftoc(coda_file);
+	struct file *in = cfi->cfi_container;
+	loff_t ki_pos = *ppos;
 	ssize_t ret;
 
-	cfi = CODA_FTOC(coda_file);
-	BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
-	host_file = cfi->cfi_container;
+	ret = venus_access_intent(coda_inode->i_sb, coda_i2f(coda_inode),
+				  &cfi->cfi_access_intent,
+				  len, ki_pos, CODA_ACCESS_TYPE_READ);
+	if (ret)
+		goto finish_read;
 
-	if (!host_file->f_op || !host_file->f_op->write)
-		return -EINVAL;
+	ret = vfs_splice_read(in, ppos, pipe, len, flags);
 
-	host_inode = file_inode(host_file);
-	file_start_write(host_file);
-	mutex_lock(&coda_inode->i_mutex);
+finish_read:
+	venus_access_intent(coda_inode->i_sb, coda_i2f(coda_inode),
+			    &cfi->cfi_access_intent,
+			    len, ki_pos, CODA_ACCESS_TYPE_READ_FINISH);
+	return ret;
+}
 
-	ret = host_file->f_op->write(host_file, buf, count, ppos);
+static void
+coda_vm_open(struct vm_area_struct *vma)
+{
+	struct coda_vm_ops *cvm_ops =
+		container_of(vma->vm_ops, struct coda_vm_ops, vm_ops);
 
-	coda_inode->i_size = host_inode->i_size;
-	coda_inode->i_blocks = (coda_inode->i_size + 511) >> 9;
-	coda_inode->i_mtime = coda_inode->i_ctime = CURRENT_TIME_SEC;
-	mutex_unlock(&coda_inode->i_mutex);
-	file_end_write(host_file);
+	refcount_inc(&cvm_ops->refcnt);
 
-	return ret;
+	if (cvm_ops->host_vm_ops && cvm_ops->host_vm_ops->open)
+		cvm_ops->host_vm_ops->open(vma);
+}
+
+static void
+coda_vm_close(struct vm_area_struct *vma)
+{
+	struct coda_vm_ops *cvm_ops =
+		container_of(vma->vm_ops, struct coda_vm_ops, vm_ops);
+
+	if (cvm_ops->host_vm_ops && cvm_ops->host_vm_ops->close)
+		cvm_ops->host_vm_ops->close(vma);
+
+	if (refcount_dec_and_test(&cvm_ops->refcnt)) {
+		vma->vm_ops = cvm_ops->host_vm_ops;
+		fput(cvm_ops->coda_file);
+		kfree(cvm_ops);
+	}
 }
 
 static int
 coda_file_mmap(struct file *coda_file, struct vm_area_struct *vma)
 {
-	struct coda_file_info *cfi;
+	struct inode *coda_inode = file_inode(coda_file);
+	struct coda_file_info *cfi = coda_ftoc(coda_file);
+	struct file *host_file = cfi->cfi_container;
+	struct inode *host_inode = file_inode(host_file);
 	struct coda_inode_info *cii;
-	struct file *host_file;
-	struct inode *coda_inode, *host_inode;
-
-	cfi = CODA_FTOC(coda_file);
-	BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
-	host_file = cfi->cfi_container;
+	struct coda_vm_ops *cvm_ops;
+	loff_t ppos;
+	size_t count;
+	int ret;
 
-	if (!host_file->f_op || !host_file->f_op->mmap)
+	if (!can_mmap_file(host_file))
 		return -ENODEV;
 
-	coda_inode = file_inode(coda_file);
-	host_inode = file_inode(host_file);
+	if (WARN_ON(coda_file != vma->vm_file))
+		return -EIO;
+
+	count = vma->vm_end - vma->vm_start;
+	ppos = vma->vm_pgoff * PAGE_SIZE;
+
+	ret = venus_access_intent(coda_inode->i_sb, coda_i2f(coda_inode),
+				  &cfi->cfi_access_intent,
+				  count, ppos, CODA_ACCESS_TYPE_MMAP);
+	if (ret)
+		return ret;
+
+	cvm_ops = kmalloc(sizeof(struct coda_vm_ops), GFP_KERNEL);
+	if (!cvm_ops)
+		return -ENOMEM;
 
 	cii = ITOC(coda_inode);
 	spin_lock(&cii->c_lock);
@@ -121,6 +189,7 @@ coda_file_mmap(struct file *coda_file, struct vm_area_struct *vma)
 	 * the container file on us! */
 	else if (coda_inode->i_mapping != host_inode->i_mapping) {
 		spin_unlock(&cii->c_lock);
+		kfree(cvm_ops);
 		return -EBUSY;
 	}
 
@@ -129,7 +198,29 @@ coda_file_mmap(struct file *coda_file, struct vm_area_struct *vma)
 	cfi->cfi_mapcount++;
 	spin_unlock(&cii->c_lock);
 
-	return host_file->f_op->mmap(host_file, vma);
+	vma->vm_file = get_file(host_file);
+	ret = vfs_mmap(vma->vm_file, vma);
+
+	if (ret) {
+		/* if vfs_mmap fails, our caller will put host_file so we
+		 * should drop the reference to the coda_file that we got.
+		 */
+		fput(coda_file);
+		kfree(cvm_ops);
+	} else {
+		/* here we add redirects for the open/close vm_operations */
+		cvm_ops->host_vm_ops = vma->vm_ops;
+		if (vma->vm_ops)
+			cvm_ops->vm_ops = *vma->vm_ops;
+
+		cvm_ops->vm_ops.open = coda_vm_open;
+		cvm_ops->vm_ops.close = coda_vm_close;
+		cvm_ops->coda_file = coda_file;
+		refcount_set(&cvm_ops->refcnt, 1);
+
+		vma->vm_ops = &cvm_ops->vm_ops;
+	}
+	return ret;
 }
 
 int coda_open(struct inode *coda_inode, struct file *coda_file)
@@ -159,6 +250,8 @@ int coda_open(struct inode *coda_inode, struct file *coda_file)
 	cfi->cfi_magic = CODA_MAGIC;
 	cfi->cfi_mapcount = 0;
 	cfi->cfi_container = host_file;
+	/* assume access intents are supported unless we hear otherwise */
+	cfi->cfi_access_intent = true;
 
 	BUG_ON(coda_file->private_data != NULL);
 	coda_file->private_data = cfi;
@@ -172,12 +265,10 @@ int coda_release(struct inode *coda_inode, struct file *coda_file)
 	struct coda_file_info *cfi;
 	struct coda_inode_info *cii;
 	struct inode *host_inode;
-	int err;
 
-	cfi = CODA_FTOC(coda_file);
-	BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
+	cfi = coda_ftoc(coda_file);
 
-	err = venus_close(coda_inode->i_sb, coda_i2f(coda_inode),
+	venus_close(coda_inode->i_sb, coda_i2f(coda_inode),
 			  coda_flags, coda_file->f_cred->fsuid);
 
 	host_inode = file_inode(cfi->cfi_container);
@@ -215,28 +306,26 @@ int coda_fsync(struct file *coda_file, loff_t start, loff_t end, int datasync)
 	err = filemap_write_and_wait_range(coda_inode->i_mapping, start, end);
 	if (err)
 		return err;
-	mutex_lock(&coda_inode->i_mutex);
+	inode_lock(coda_inode);
 
-	cfi = CODA_FTOC(coda_file);
-	BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
+	cfi = coda_ftoc(coda_file);
 	host_file = cfi->cfi_container;
 
 	err = vfs_fsync(host_file, datasync);
 	if (!err && !datasync)
 		err = venus_fsync(coda_inode->i_sb, coda_i2f(coda_inode));
-	mutex_unlock(&coda_inode->i_mutex);
+	inode_unlock(coda_inode);
 
 	return err;
 }
 
 const struct file_operations coda_file_operations = {
 	.llseek		= generic_file_llseek,
-	.read		= coda_file_read,
-	.write		= coda_file_write,
+	.read_iter	= coda_file_read_iter,
+	.write_iter	= coda_file_write_iter,
 	.mmap		= coda_file_mmap,
 	.open		= coda_open,
 	.release	= coda_release,
 	.fsync		= coda_fsync,
 	.splice_read	= coda_file_splice_read,
 };
-