Fixed MTP to work with TWRP

fs/ncpfs/file.c

@@ -0,0 +1,296 @@
+/*
+ *  file.c
+ *
+ *  Copyright (C) 1995, 1996 by Volker Lendecke
+ *  Modified 1997 Peter Waltenberg, Bill Hawes, David Woodhouse for 2.1 dcache
+ *
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <asm/uaccess.h>
+
+#include <linux/time.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/fcntl.h>
+#include <linux/stat.h>
+#include <linux/mm.h>
+#include <linux/vmalloc.h>
+#include <linux/sched.h>
+
+#include "ncp_fs.h"
+
+static int ncp_fsync(struct file *file, loff_t start, loff_t end, int datasync)
+{
+	return filemap_write_and_wait_range(file->f_mapping, start, end);
+}
+
+/*
+ * Open a file with the specified read/write mode.
+ */
+int ncp_make_open(struct inode *inode, int right)
+{
+	int error;
+	int access;
+
+	error = -EINVAL;
+	if (!inode) {
+		pr_err("%s: got NULL inode\n", __func__);
+		goto out;
+	}
+
+	ncp_dbg(1, "opened=%d, volume # %u, dir entry # %u\n",
+		atomic_read(&NCP_FINFO(inode)->opened), 
+		NCP_FINFO(inode)->volNumber, 
+		NCP_FINFO(inode)->dirEntNum);
+	error = -EACCES;
+	mutex_lock(&NCP_FINFO(inode)->open_mutex);
+	if (!atomic_read(&NCP_FINFO(inode)->opened)) {
+		struct ncp_entry_info finfo;
+		int result;
+
+		/* tries max. rights */
+		finfo.access = O_RDWR;
+		result = ncp_open_create_file_or_subdir(NCP_SERVER(inode),
+					inode, NULL, OC_MODE_OPEN,
+					0, AR_READ | AR_WRITE, &finfo);
+		if (!result)
+			goto update;
+		/* RDWR did not succeeded, try readonly or writeonly as requested */
+		switch (right) {
+			case O_RDONLY:
+				finfo.access = O_RDONLY;
+				result = ncp_open_create_file_or_subdir(NCP_SERVER(inode),
+					inode, NULL, OC_MODE_OPEN,
+					0, AR_READ, &finfo);
+				break;
+			case O_WRONLY:
+				finfo.access = O_WRONLY;
+				result = ncp_open_create_file_or_subdir(NCP_SERVER(inode),
+					inode, NULL, OC_MODE_OPEN,
+					0, AR_WRITE, &finfo);
+				break;
+		}
+		if (result) {
+			ncp_vdbg("failed, result=%d\n", result);
+			goto out_unlock;
+		}
+		/*
+		 * Update the inode information.
+		 */
+	update:
+		ncp_update_inode(inode, &finfo);
+		atomic_set(&NCP_FINFO(inode)->opened, 1);
+	}
+
+	access = NCP_FINFO(inode)->access;
+	ncp_vdbg("file open, access=%x\n", access);
+	if (access == right || access == O_RDWR) {
+		atomic_inc(&NCP_FINFO(inode)->opened);
+		error = 0;
+	}
+
+out_unlock:
+	mutex_unlock(&NCP_FINFO(inode)->open_mutex);
+out:
+	return error;
+}
+
+static ssize_t
+ncp_file_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
+{
+	struct dentry *dentry = file->f_path.dentry;
+	struct inode *inode = dentry->d_inode;
+	size_t already_read = 0;
+	off_t pos;
+	size_t bufsize;
+	int error;
+	void* freepage;
+	size_t freelen;
+
+	ncp_dbg(1, "enter %pd2\n", dentry);
+
+	pos = *ppos;
+
+	if ((ssize_t) count < 0) {
+		return -EINVAL;
+	}
+	if (!count)
+		return 0;
+	if (pos > inode->i_sb->s_maxbytes)
+		return 0;
+	if (pos + count > inode->i_sb->s_maxbytes) {
+		count = inode->i_sb->s_maxbytes - pos;
+	}
+
+	error = ncp_make_open(inode, O_RDONLY);
+	if (error) {
+		ncp_dbg(1, "open failed, error=%d\n", error);
+		return error;
+	}
+
+	bufsize = NCP_SERVER(inode)->buffer_size;
+
+	error = -EIO;
+	freelen = ncp_read_bounce_size(bufsize);
+	freepage = vmalloc(freelen);
+	if (!freepage)
+		goto outrel;
+	error = 0;
+	/* First read in as much as possible for each bufsize. */
+	while (already_read < count) {
+		int read_this_time;
+		size_t to_read = min_t(unsigned int,
+				     bufsize - (pos % bufsize),
+				     count - already_read);
+
+		error = ncp_read_bounce(NCP_SERVER(inode),
+			 	NCP_FINFO(inode)->file_handle,
+				pos, to_read, buf, &read_this_time, 
+				freepage, freelen);
+		if (error) {
+			error = -EIO;	/* NW errno -> Linux errno */
+			break;
+		}
+		pos += read_this_time;
+		buf += read_this_time;
+		already_read += read_this_time;
+
+		if (read_this_time != to_read) {
+			break;
+		}
+	}
+	vfree(freepage);
+
+	*ppos = pos;
+
+	file_accessed(file);
+
+	ncp_dbg(1, "exit %pd2\n", dentry);
+outrel:
+	ncp_inode_close(inode);		
+	return already_read ? already_read : error;
+}
+
+static ssize_t
+ncp_file_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
+{
+	struct dentry *dentry = file->f_path.dentry;
+	struct inode *inode = dentry->d_inode;
+	size_t already_written = 0;
+	off_t pos;
+	size_t bufsize;
+	int errno;
+	void* bouncebuffer;
+
+	ncp_dbg(1, "enter %pd2\n", dentry);
+	if ((ssize_t) count < 0)
+		return -EINVAL;
+	pos = *ppos;
+	if (file->f_flags & O_APPEND) {
+		pos = i_size_read(inode);
+	}
+
+	if (pos + count > MAX_NON_LFS && !(file->f_flags&O_LARGEFILE)) {
+		if (pos >= MAX_NON_LFS) {
+			return -EFBIG;
+		}
+		if (count > MAX_NON_LFS - (u32)pos) {
+			count = MAX_NON_LFS - (u32)pos;
+		}
+	}
+	if (pos >= inode->i_sb->s_maxbytes) {
+		if (count || pos > inode->i_sb->s_maxbytes) {
+			return -EFBIG;
+		}
+	}
+	if (pos + count > inode->i_sb->s_maxbytes) {
+		count = inode->i_sb->s_maxbytes - pos;
+	}
+	
+	if (!count)
+		return 0;
+	errno = ncp_make_open(inode, O_WRONLY);
+	if (errno) {
+		ncp_dbg(1, "open failed, error=%d\n", errno);
+		return errno;
+	}
+	bufsize = NCP_SERVER(inode)->buffer_size;
+
+	already_written = 0;
+
+	errno = file_update_time(file);
+	if (errno)
+		goto outrel;
+
+	bouncebuffer = vmalloc(bufsize);
+	if (!bouncebuffer) {
+		errno = -EIO;	/* -ENOMEM */
+		goto outrel;
+	}
+	while (already_written < count) {
+		int written_this_time;
+		size_t to_write = min_t(unsigned int,
+				      bufsize - (pos % bufsize),
+				      count - already_written);
+
+		if (copy_from_user(bouncebuffer, buf, to_write)) {
+			errno = -EFAULT;
+			break;
+		}
+		if (ncp_write_kernel(NCP_SERVER(inode), 
+		    NCP_FINFO(inode)->file_handle,
+		    pos, to_write, bouncebuffer, &written_this_time) != 0) {
+			errno = -EIO;
+			break;
+		}
+		pos += written_this_time;
+		buf += written_this_time;
+		already_written += written_this_time;
+
+		if (written_this_time != to_write) {
+			break;
+		}
+	}
+	vfree(bouncebuffer);
+
+	*ppos = pos;
+
+	if (pos > i_size_read(inode)) {
+		mutex_lock(&inode->i_mutex);
+		if (pos > i_size_read(inode))
+			i_size_write(inode, pos);
+		mutex_unlock(&inode->i_mutex);
+	}
+	ncp_dbg(1, "exit %pd2\n", dentry);
+outrel:
+	ncp_inode_close(inode);		
+	return already_written ? already_written : errno;
+}
+
+static int ncp_release(struct inode *inode, struct file *file) {
+	if (ncp_make_closed(inode)) {
+		ncp_dbg(1, "failed to close\n");
+	}
+	return 0;
+}
+
+const struct file_operations ncp_file_operations =
+{
+	.llseek		= generic_file_llseek,
+	.read		= ncp_file_read,
+	.write		= ncp_file_write,
+	.unlocked_ioctl	= ncp_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl	= ncp_compat_ioctl,
+#endif
+	.mmap		= ncp_mmap,
+	.release	= ncp_release,
+	.fsync		= ncp_fsync,
+};
+
+const struct inode_operations ncp_file_inode_operations =
+{
+	.setattr	= ncp_notify_change,
+};