--- zzzz-none-000/linux-3.10.107/fs/9p/vfs_file.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/fs/9p/vfs_file.c	2021-02-04 17:41:59.000000000 +0000
@@ -36,6 +36,8 @@
 #include <linux/utsname.h>
 #include <asm/uaccess.h>
 #include <linux/idr.h>
+#include <linux/uio.h>
+#include <linux/slab.h>
 #include <net/9p/9p.h>
 #include <net/9p/client.h>
 
@@ -45,6 +47,7 @@
 #include "cache.h"
 
 static const struct vm_operations_struct v9fs_file_vm_ops;
+static const struct vm_operations_struct v9fs_mmap_file_vm_ops;
 
 /**
  * v9fs_file_open - open a file (or directory)
@@ -71,7 +74,7 @@
 					v9fs_proto_dotu(v9ses));
 	fid = file->private_data;
 	if (!fid) {
-		fid = v9fs_fid_clone(file->f_path.dentry);
+		fid = v9fs_fid_clone(file_dentry(file));
 		if (IS_ERR(fid))
 			return PTR_ERR(fid);
 
@@ -87,7 +90,8 @@
 
 	file->private_data = fid;
 	mutex_lock(&v9inode->v_mutex);
-	if (v9ses->cache && !v9inode->writeback_fid &&
+	if ((v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) &&
+	    !v9inode->writeback_fid &&
 	    ((file->f_flags & O_ACCMODE) != O_RDONLY)) {
 		/*
 		 * clone a fid and add it to writeback_fid
@@ -96,7 +100,7 @@
 		 * because we want write after unlink usecase
 		 * to work.
 		 */
-		fid = v9fs_writeback_fid(file->f_path.dentry);
+		fid = v9fs_writeback_fid(file_dentry(file));
 		if (IS_ERR(fid)) {
 			err = PTR_ERR(fid);
 			mutex_unlock(&v9inode->v_mutex);
@@ -105,10 +109,8 @@
 		v9inode->writeback_fid = (void *) fid;
 	}
 	mutex_unlock(&v9inode->v_mutex);
-#ifdef CONFIG_9P_FSCACHE
-	if (v9ses->cache)
+	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
 		v9fs_cache_inode_set_cookie(inode, file);
-#endif
 	return 0;
 out_error:
 	p9_client_clunk(file->private_data);
@@ -149,7 +151,7 @@
 {
 	struct p9_flock flock;
 	struct p9_fid *fid;
-	uint8_t status;
+	uint8_t status = P9_LOCK_ERROR;
 	int res = 0;
 	unsigned char fl_type;
 
@@ -159,7 +161,7 @@
 	if ((fl->fl_flags & FL_POSIX) != FL_POSIX)
 		BUG();
 
-	res = posix_lock_file_wait(filp, fl);
+	res = locks_lock_file_wait(filp, fl);
 	if (res < 0)
 		goto out;
 
@@ -183,7 +185,7 @@
 	else
 		flock.length = fl->fl_end - fl->fl_start + 1;
 	flock.proc_id = fl->fl_pid;
-	flock.client_id = utsname()->nodename;
+	flock.client_id = fid->clnt->name;
 	if (IS_SETLKW(cmd))
 		flock.flags = P9_LOCK_FLAGS_BLOCK;
 
@@ -194,7 +196,7 @@
 	for (;;) {
 		res = p9_client_lock_dotl(fid, &flock, &status);
 		if (res < 0)
-			break;
+			goto out_unlock;
 
 		if (status != P9_LOCK_BLOCKED)
 			break;
@@ -212,14 +214,16 @@
 	case P9_LOCK_BLOCKED:
 		res = -EAGAIN;
 		break;
+	default:
+		WARN_ONCE(1, "unknown lock status code: %d\n", status);
+		/* fallthough */
 	case P9_LOCK_ERROR:
 	case P9_LOCK_GRACE:
 		res = -ENOLCK;
 		break;
-	default:
-		BUG();
 	}
 
+out_unlock:
 	/*
 	 * incase server returned error for lock request, revert
 	 * it locally
@@ -227,7 +231,8 @@
 	if (res < 0 && fl->fl_type != F_UNLCK) {
 		fl_type = fl->fl_type;
 		fl->fl_type = F_UNLCK;
-		res = posix_lock_file_wait(filp, fl);
+		/* Even if this fails we want to return the remote error */
+		locks_lock_file_wait(filp, fl);
 		fl->fl_type = fl_type;
 	}
 out:
@@ -260,7 +265,7 @@
 	else
 		glock.length = fl->fl_end - fl->fl_start + 1;
 	glock.proc_id = fl->fl_pid;
-	glock.client_id = utsname()->nodename;
+	glock.client_id = fid->clnt->name;
 
 	res = p9_client_getlock_dotl(fid, &glock);
 	if (res < 0)
@@ -285,6 +290,7 @@
 			fl->fl_end = glock.start + glock.length - 1;
 		fl->fl_pid = glock.proc_id;
 	}
+	kfree(glock.client_id);
 	return res;
 }
 
@@ -301,8 +307,8 @@
 	struct inode *inode = file_inode(filp);
 	int ret = -ENOLCK;
 
-	p9_debug(P9_DEBUG_VFS, "filp: %p cmd:%d lock: %p name: %s\n",
-		 filp, cmd, fl, filp->f_path.dentry->d_name.name);
+	p9_debug(P9_DEBUG_VFS, "filp: %p cmd:%d lock: %p name: %pD\n",
+		 filp, cmd, fl, filp);
 
 	/* No mandatory locks */
 	if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK)
@@ -337,8 +343,8 @@
 	struct inode *inode = file_inode(filp);
 	int ret = -ENOLCK;
 
-	p9_debug(P9_DEBUG_VFS, "filp: %p cmd:%d lock: %p name: %s\n",
-		 filp, cmd, fl, filp->f_path.dentry->d_name.name);
+	p9_debug(P9_DEBUG_VFS, "filp: %p cmd:%d lock: %p name: %pD\n",
+		 filp, cmd, fl, filp);
 
 	/* No mandatory locks */
 	if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK)
@@ -352,9 +358,6 @@
 		invalidate_mapping_pages(&inode->i_data, 0, -1);
 	}
 	/* Convert flock to posix lock */
-	fl->fl_owner = (fl_owner_t)filp;
-	fl->fl_start = 0;
-	fl->fl_end = OFFSET_MAX;
 	fl->fl_flags |= FL_POSIX;
 	fl->fl_flags ^= FL_FLOCK;
 
@@ -367,63 +370,6 @@
 }
 
 /**
- * v9fs_fid_readn - read from a fid
- * @fid: fid to read
- * @data: data buffer to read data into
- * @udata: user data buffer to read data into
- * @count: size of buffer
- * @offset: offset at which to read data
- *
- */
-ssize_t
-v9fs_fid_readn(struct p9_fid *fid, char *data, char __user *udata, u32 count,
-	       u64 offset)
-{
-	int n, total, size;
-
-	p9_debug(P9_DEBUG_VFS, "fid %d offset %llu count %d\n",
-		 fid->fid, (long long unsigned)offset, count);
-	n = 0;
-	total = 0;
-	size = fid->iounit ? fid->iounit : fid->clnt->msize - P9_IOHDRSZ;
-	do {
-		n = p9_client_read(fid, data, udata, offset, count);
-		if (n <= 0)
-			break;
-
-		if (data)
-			data += n;
-		if (udata)
-			udata += n;
-
-		offset += n;
-		count -= n;
-		total += n;
-	} while (count > 0 && n == size);
-
-	if (n < 0)
-		total = n;
-
-	return total;
-}
-
-/**
- * v9fs_file_readn - read from a file
- * @filp: file pointer to read
- * @data: data buffer to read data into
- * @udata: user data buffer to read data into
- * @count: size of buffer
- * @offset: offset at which to read data
- *
- */
-ssize_t
-v9fs_file_readn(struct file *filp, char *data, char __user *udata, u32 count,
-	       u64 offset)
-{
-	return v9fs_fid_readn(filp->private_data, data, udata, count, offset);
-}
-
-/**
  * v9fs_file_read - read from a file
  * @filp: file pointer to read
  * @udata: user data buffer to read data into
@@ -433,71 +379,22 @@
  */
 
 static ssize_t
-v9fs_file_read(struct file *filp, char __user *udata, size_t count,
-	       loff_t * offset)
+v9fs_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
 {
-	int ret;
-	struct p9_fid *fid;
-	size_t size;
+	struct p9_fid *fid = iocb->ki_filp->private_data;
+	int ret, err = 0;
 
-	p9_debug(P9_DEBUG_VFS, "count %zu offset %lld\n", count, *offset);
-	fid = filp->private_data;
+	p9_debug(P9_DEBUG_VFS, "count %zu offset %lld\n",
+		 iov_iter_count(to), iocb->ki_pos);
 
-	size = fid->iounit ? fid->iounit : fid->clnt->msize - P9_IOHDRSZ;
-	if (count > size)
-		ret = v9fs_file_readn(filp, NULL, udata, count, *offset);
-	else
-		ret = p9_client_read(fid, NULL, udata, *offset, count);
-
-	if (ret > 0)
-		*offset += ret;
+	ret = p9_client_read(fid, iocb->ki_pos, to, &err);
+	if (!ret)
+		return err;
 
+	iocb->ki_pos += ret;
 	return ret;
 }
 
-ssize_t
-v9fs_file_write_internal(struct inode *inode, struct p9_fid *fid,
-			 const char __user *data, size_t count,
-			 loff_t *offset, int invalidate)
-{
-	int n;
-	loff_t i_size;
-	size_t total = 0;
-	struct p9_client *clnt;
-	loff_t origin = *offset;
-	unsigned long pg_start, pg_end;
-
-	p9_debug(P9_DEBUG_VFS, "data %p count %d offset %x\n",
-		 data, (int)count, (int)*offset);
-
-	clnt = fid->clnt;
-	do {
-		n = p9_client_write(fid, NULL, data+total, origin+total, count);
-		if (n <= 0)
-			break;
-		count -= n;
-		total += n;
-	} while (count > 0);
-
-	if (invalidate && (total > 0)) {
-		pg_start = origin >> PAGE_CACHE_SHIFT;
-		pg_end = (origin + total - 1) >> PAGE_CACHE_SHIFT;
-		if (inode->i_mapping && inode->i_mapping->nrpages)
-			invalidate_inode_pages2_range(inode->i_mapping,
-						      pg_start, pg_end);
-		*offset += total;
-		i_size = i_size_read(inode);
-		if (*offset > i_size) {
-			inode_add_bytes(inode, *offset - i_size);
-			i_size_write(inode, *offset);
-		}
-	}
-	if (n < 0)
-		return n;
-
-	return total;
-}
-
 /**
  * v9fs_file_write - write to a file
  * @filp: file pointer to write
@@ -507,35 +404,39 @@
  *
  */
 static ssize_t
-v9fs_file_write(struct file *filp, const char __user * data,
-		size_t count, loff_t *offset)
+v9fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
 {
-	ssize_t retval = 0;
-	loff_t origin = *offset;
-
-
-	retval = generic_write_checks(filp, &origin, &count, 0);
-	if (retval)
-		goto out;
+	struct file *file = iocb->ki_filp;
+	ssize_t retval;
+	loff_t origin;
+	int err = 0;
 
-	retval = -EINVAL;
-	if ((ssize_t) count < 0)
-		goto out;
-	retval = 0;
-	if (!count)
-		goto out;
+	retval = generic_write_checks(iocb, from);
+	if (retval <= 0)
+		return retval;
 
-	retval = v9fs_file_write_internal(file_inode(filp),
-					filp->private_data,
-					data, count, &origin, 1);
-	/* update offset on successful write */
-	if (retval > 0)
-		*offset = origin;
-out:
-	return retval;
+	origin = iocb->ki_pos;
+	retval = p9_client_write(file->private_data, iocb->ki_pos, from, &err);
+	if (retval > 0) {
+		struct inode *inode = file_inode(file);
+		loff_t i_size;
+		unsigned long pg_start, pg_end;
+		pg_start = origin >> PAGE_CACHE_SHIFT;
+		pg_end = (origin + retval - 1) >> PAGE_CACHE_SHIFT;
+		if (inode->i_mapping && inode->i_mapping->nrpages)
+			invalidate_inode_pages2_range(inode->i_mapping,
+						      pg_start, pg_end);
+		iocb->ki_pos += retval;
+		i_size = i_size_read(inode);
+		if (iocb->ki_pos > i_size) {
+			inode_add_bytes(inode, iocb->ki_pos - i_size);
+			i_size_write(inode, iocb->ki_pos);
+		}
+		return retval;
+	}
+	return err;
 }
 
-
 static int v9fs_file_fsync(struct file *filp, loff_t start, loff_t end,
 			   int datasync)
 {
@@ -583,11 +484,12 @@
 }
 
 static int
-v9fs_file_mmap(struct file *file, struct vm_area_struct *vma)
+v9fs_file_mmap(struct file *filp, struct vm_area_struct *vma)
 {
 	int retval;
 
-	retval = generic_file_mmap(file, vma);
+
+	retval = generic_file_mmap(filp, vma);
 	if (!retval)
 		vma->vm_ops = &v9fs_file_vm_ops;
 
@@ -595,6 +497,43 @@
 }
 
 static int
+v9fs_mmap_file_mmap(struct file *filp, struct vm_area_struct *vma)
+{
+	int retval;
+	struct inode *inode;
+	struct v9fs_inode *v9inode;
+	struct p9_fid *fid;
+
+	inode = file_inode(filp);
+	v9inode = V9FS_I(inode);
+	mutex_lock(&v9inode->v_mutex);
+	if (!v9inode->writeback_fid &&
+	    (vma->vm_flags & VM_WRITE)) {
+		/*
+		 * clone a fid and add it to writeback_fid
+		 * we do it during mmap instead of
+		 * page dirty time via write_begin/page_mkwrite
+		 * because we want write after unlink usecase
+		 * to work.
+		 */
+		fid = v9fs_writeback_fid(file_dentry(filp));
+		if (IS_ERR(fid)) {
+			retval = PTR_ERR(fid);
+			mutex_unlock(&v9inode->v_mutex);
+			return retval;
+		}
+		v9inode->writeback_fid = (void *) fid;
+	}
+	mutex_unlock(&v9inode->v_mutex);
+
+	retval = generic_file_mmap(filp, vma);
+	if (!retval)
+		vma->vm_ops = &v9fs_mmap_file_vm_ops;
+
+	return retval;
+}
+
+static int
 v9fs_vm_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
 	struct v9fs_inode *v9inode;
@@ -624,98 +563,23 @@
 	return VM_FAULT_NOPAGE;
 }
 
-static ssize_t
-v9fs_direct_read(struct file *filp, char __user *udata, size_t count,
-		 loff_t *offsetp)
-{
-	loff_t size, offset;
-	struct inode *inode;
-	struct address_space *mapping;
-
-	offset = *offsetp;
-	mapping = filp->f_mapping;
-	inode = mapping->host;
-	if (!count)
-		return 0;
-	size = i_size_read(inode);
-	if (offset < size)
-		filemap_write_and_wait_range(mapping, offset,
-					     offset + count - 1);
-
-	return v9fs_file_read(filp, udata, count, offsetp);
-}
-
 /**
- * v9fs_cached_file_read - read from a file
+ * v9fs_mmap_file_read - read from a file
  * @filp: file pointer to read
- * @udata: user data buffer to read data into
+ * @data: user data buffer to read data into
  * @count: size of buffer
  * @offset: offset at which to read data
  *
  */
 static ssize_t
-v9fs_cached_file_read(struct file *filp, char __user *data, size_t count,
-		      loff_t *offset)
+v9fs_mmap_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
 {
-	if (filp->f_flags & O_DIRECT)
-		return v9fs_direct_read(filp, data, count, offset);
-	return do_sync_read(filp, data, count, offset);
-}
-
-static ssize_t
-v9fs_direct_write(struct file *filp, const char __user * data,
-		  size_t count, loff_t *offsetp)
-{
-	loff_t offset;
-	ssize_t retval;
-	struct inode *inode;
-	struct address_space *mapping;
-
-	offset = *offsetp;
-	mapping = filp->f_mapping;
-	inode = mapping->host;
-	if (!count)
-		return 0;
-
-	mutex_lock(&inode->i_mutex);
-	retval = filemap_write_and_wait_range(mapping, offset,
-					      offset + count - 1);
-	if (retval)
-		goto err_out;
-	/*
-	 * After a write we want buffered reads to be sure to go to disk to get
-	 * the new data.  We invalidate clean cached page from the region we're
-	 * about to write.  We do this *before* the write so that if we fail
-	 * here we fall back to buffered write
-	 */
-	if (mapping->nrpages) {
-		pgoff_t pg_start = offset >> PAGE_CACHE_SHIFT;
-		pgoff_t pg_end   = (offset + count - 1) >> PAGE_CACHE_SHIFT;
-
-		retval = invalidate_inode_pages2_range(mapping,
-							pg_start, pg_end);
-		/*
-		 * If a page can not be invalidated, fall back
-		 * to buffered write.
-		 */
-		if (retval) {
-			if (retval == -EBUSY)
-				goto buff_write;
-			goto err_out;
-		}
-	}
-	retval = v9fs_file_write(filp, data, count, offsetp);
-err_out:
-	mutex_unlock(&inode->i_mutex);
-	return retval;
-
-buff_write:
-	mutex_unlock(&inode->i_mutex);
-	return do_sync_write(filp, data, count, offsetp);
+	/* TODO: Check if there are dirty pages */
+	return v9fs_file_read_iter(iocb, to);
 }
 
 /**
- * v9fs_cached_file_write - write to a file
+ * v9fs_mmap_file_write - write to a file
  * @filp: file pointer to write
  * @data: data buffer to write data from
  * @count: size of buffer
@@ -723,28 +587,59 @@
  *
  */
 static ssize_t
-v9fs_cached_file_write(struct file *filp, const char __user * data,
-		       size_t count, loff_t *offset)
+v9fs_mmap_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
 {
+	/*
+	 * TODO: invalidate mmaps on filp's inode between
+	 * offset and offset+count
+	 */
+	return v9fs_file_write_iter(iocb, from);
+}
 
-	if (filp->f_flags & O_DIRECT)
-		return v9fs_direct_write(filp, data, count, offset);
-	return do_sync_write(filp, data, count, offset);
+static void v9fs_mmap_vm_close(struct vm_area_struct *vma)
+{
+	struct inode *inode;
+
+	struct writeback_control wbc = {
+		.nr_to_write = LONG_MAX,
+		.sync_mode = WB_SYNC_ALL,
+		.range_start = vma->vm_pgoff * PAGE_SIZE,
+		 /* absolute end, byte at end included */
+		.range_end = vma->vm_pgoff * PAGE_SIZE +
+			(vma->vm_end - vma->vm_start - 1),
+	};
+
+
+	p9_debug(P9_DEBUG_VFS, "9p VMA close, %p, flushing", vma);
+
+	inode = file_inode(vma->vm_file);
+
+	if (!mapping_cap_writeback_dirty(inode->i_mapping))
+		wbc.nr_to_write = 0;
+
+	might_sleep();
+	sync_inode(inode, &wbc);
 }
 
+
 static const struct vm_operations_struct v9fs_file_vm_ops = {
 	.fault = filemap_fault,
+	.map_pages = filemap_map_pages,
+	.page_mkwrite = v9fs_vm_page_mkwrite,
+};
+
+static const struct vm_operations_struct v9fs_mmap_file_vm_ops = {
+	.close = v9fs_mmap_vm_close,
+	.fault = filemap_fault,
+	.map_pages = filemap_map_pages,
 	.page_mkwrite = v9fs_vm_page_mkwrite,
-	.remap_pages = generic_file_remap_pages,
 };
 
 
 const struct file_operations v9fs_cached_file_operations = {
 	.llseek = generic_file_llseek,
-	.read = v9fs_cached_file_read,
-	.write = v9fs_cached_file_write,
-	.aio_read = generic_file_aio_read,
-	.aio_write = generic_file_aio_write,
+	.read_iter = generic_file_read_iter,
+	.write_iter = generic_file_write_iter,
 	.open = v9fs_file_open,
 	.release = v9fs_dir_release,
 	.lock = v9fs_file_lock,
@@ -754,10 +649,8 @@
 
 const struct file_operations v9fs_cached_file_operations_dotl = {
 	.llseek = generic_file_llseek,
-	.read = v9fs_cached_file_read,
-	.write = v9fs_cached_file_write,
-	.aio_read = generic_file_aio_read,
-	.aio_write = generic_file_aio_write,
+	.read_iter = generic_file_read_iter,
+	.write_iter = generic_file_write_iter,
 	.open = v9fs_file_open,
 	.release = v9fs_dir_release,
 	.lock = v9fs_file_lock_dotl,
@@ -768,8 +661,8 @@
 
 const struct file_operations v9fs_file_operations = {
 	.llseek = generic_file_llseek,
-	.read = v9fs_file_read,
-	.write = v9fs_file_write,
+	.read_iter = v9fs_file_read_iter,
+	.write_iter = v9fs_file_write_iter,
 	.open = v9fs_file_open,
 	.release = v9fs_dir_release,
 	.lock = v9fs_file_lock,
@@ -779,8 +672,8 @@
 
 const struct file_operations v9fs_file_operations_dotl = {
 	.llseek = generic_file_llseek,
-	.read = v9fs_file_read,
-	.write = v9fs_file_write,
+	.read_iter = v9fs_file_read_iter,
+	.write_iter = v9fs_file_write_iter,
 	.open = v9fs_file_open,
 	.release = v9fs_dir_release,
 	.lock = v9fs_file_lock_dotl,
@@ -788,3 +681,26 @@
 	.mmap = generic_file_readonly_mmap,
 	.fsync = v9fs_file_fsync_dotl,
 };
+
+const struct file_operations v9fs_mmap_file_operations = {
+	.llseek = generic_file_llseek,
+	.read_iter = v9fs_mmap_file_read_iter,
+	.write_iter = v9fs_mmap_file_write_iter,
+	.open = v9fs_file_open,
+	.release = v9fs_dir_release,
+	.lock = v9fs_file_lock,
+	.mmap = v9fs_mmap_file_mmap,
+	.fsync = v9fs_file_fsync,
+};
+
+const struct file_operations v9fs_mmap_file_operations_dotl = {
+	.llseek = generic_file_llseek,
+	.read_iter = v9fs_mmap_file_read_iter,
+	.write_iter = v9fs_mmap_file_write_iter,
+	.open = v9fs_file_open,
+	.release = v9fs_dir_release,
+	.lock = v9fs_file_lock_dotl,
+	.flock = v9fs_file_flock_dotl,
+	.mmap = v9fs_mmap_file_mmap,
+	.fsync = v9fs_file_fsync_dotl,
+};