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// SPDX-License-Identifier: GPL-2.0+
/*
* storage_common.c -- Common definitions for mass storage functionality
*
* Copyright (C) 2003-2008 Alan Stern
* Copyeight (C) 2009 Samsung Electronics
* Author: Michal Nazarewicz (mina86@mina86.com)
*/
/*
* This file requires the following identifiers used in USB strings to
* be defined (each of type pointer to char):
* - fsg_string_interface -- name of the interface
*/
/*
* When USB_GADGET_DEBUG_FILES is defined the module param num_buffers
* sets the number of pipeline buffers (length of the fsg_buffhd array).
* The valid range of num_buffers is: num >= 2 && num <= 4.
*/
#include <linux/module.h>
#include <linux/blkdev.h>
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/usb/composite.h>
#include "storage_common.h"
/* There is only one interface. */
struct usb_interface_descriptor fsg_intf_desc = {
.bLength = sizeof fsg_intf_desc,
.bDescriptorType = USB_DT_INTERFACE,
.bNumEndpoints = 2, /* Adjusted during fsg_bind() */
.bInterfaceClass = USB_CLASS_MASS_STORAGE,
.bInterfaceSubClass = USB_SC_SCSI, /* Adjusted during fsg_bind() */
.bInterfaceProtocol = USB_PR_BULK, /* Adjusted during fsg_bind() */
.iInterface = FSG_STRING_INTERFACE,
};
EXPORT_SYMBOL_GPL(fsg_intf_desc);
/*
* Three full-speed endpoint descriptors: bulk-in, bulk-out, and
* interrupt-in.
*/
struct usb_endpoint_descriptor fsg_fs_bulk_in_desc = {
.bLength = USB_DT_ENDPOINT_SIZE,
.bDescriptorType = USB_DT_ENDPOINT,
.bEndpointAddress = USB_DIR_IN,
.bmAttributes = USB_ENDPOINT_XFER_BULK,
/* wMaxPacketSize set by autoconfiguration */
};
EXPORT_SYMBOL_GPL(fsg_fs_bulk_in_desc);
struct usb_endpoint_descriptor fsg_fs_bulk_out_desc = {
.bLength = USB_DT_ENDPOINT_SIZE,
.bDescriptorType = USB_DT_ENDPOINT,
.bEndpointAddress = USB_DIR_OUT,
.bmAttributes = USB_ENDPOINT_XFER_BULK,
/* wMaxPacketSize set by autoconfiguration */
};
EXPORT_SYMBOL_GPL(fsg_fs_bulk_out_desc);
struct usb_descriptor_header *fsg_fs_function[] = {
(struct usb_descriptor_header *) &fsg_intf_desc,
(struct usb_descriptor_header *) &fsg_fs_bulk_in_desc,
(struct usb_descriptor_header *) &fsg_fs_bulk_out_desc,
NULL,
};
EXPORT_SYMBOL_GPL(fsg_fs_function);
/*
* USB 2.0 devices need to expose both high speed and full speed
* descriptors, unless they only run at full speed.
*
* That means alternate endpoint descriptors (bigger packets).
*/
struct usb_endpoint_descriptor fsg_hs_bulk_in_desc = {
.bLength = USB_DT_ENDPOINT_SIZE,
.bDescriptorType = USB_DT_ENDPOINT,
/* bEndpointAddress copied from fs_bulk_in_desc during fsg_bind() */
.bmAttributes = USB_ENDPOINT_XFER_BULK,
.wMaxPacketSize = cpu_to_le16(512),
};
EXPORT_SYMBOL_GPL(fsg_hs_bulk_in_desc);
struct usb_endpoint_descriptor fsg_hs_bulk_out_desc = {
.bLength = USB_DT_ENDPOINT_SIZE,
.bDescriptorType = USB_DT_ENDPOINT,
/* bEndpointAddress copied from fs_bulk_out_desc during fsg_bind() */
.bmAttributes = USB_ENDPOINT_XFER_BULK,
.wMaxPacketSize = cpu_to_le16(512),
.bInterval = 1, /* NAK every 1 uframe */
};
EXPORT_SYMBOL_GPL(fsg_hs_bulk_out_desc);
struct usb_descriptor_header *fsg_hs_function[] = {
(struct usb_descriptor_header *) &fsg_intf_desc,
(struct usb_descriptor_header *) &fsg_hs_bulk_in_desc,
(struct usb_descriptor_header *) &fsg_hs_bulk_out_desc,
NULL,
};
EXPORT_SYMBOL_GPL(fsg_hs_function);
struct usb_endpoint_descriptor fsg_ss_bulk_in_desc = {
.bLength = USB_DT_ENDPOINT_SIZE,
.bDescriptorType = USB_DT_ENDPOINT,
/* bEndpointAddress copied from fs_bulk_in_desc during fsg_bind() */
.bmAttributes = USB_ENDPOINT_XFER_BULK,
.wMaxPacketSize = cpu_to_le16(1024),
};
EXPORT_SYMBOL_GPL(fsg_ss_bulk_in_desc);
struct usb_ss_ep_comp_descriptor fsg_ss_bulk_in_comp_desc = {
.bLength = sizeof(fsg_ss_bulk_in_comp_desc),
.bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
/*.bMaxBurst = DYNAMIC, */
};
EXPORT_SYMBOL_GPL(fsg_ss_bulk_in_comp_desc);
struct usb_endpoint_descriptor fsg_ss_bulk_out_desc = {
.bLength = USB_DT_ENDPOINT_SIZE,
.bDescriptorType = USB_DT_ENDPOINT,
/* bEndpointAddress copied from fs_bulk_out_desc during fsg_bind() */
.bmAttributes = USB_ENDPOINT_XFER_BULK,
.wMaxPacketSize = cpu_to_le16(1024),
};
EXPORT_SYMBOL_GPL(fsg_ss_bulk_out_desc);
struct usb_ss_ep_comp_descriptor fsg_ss_bulk_out_comp_desc = {
.bLength = sizeof(fsg_ss_bulk_in_comp_desc),
.bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
/*.bMaxBurst = DYNAMIC, */
};
EXPORT_SYMBOL_GPL(fsg_ss_bulk_out_comp_desc);
struct usb_descriptor_header *fsg_ss_function[] = {
(struct usb_descriptor_header *) &fsg_intf_desc,
(struct usb_descriptor_header *) &fsg_ss_bulk_in_desc,
(struct usb_descriptor_header *) &fsg_ss_bulk_in_comp_desc,
(struct usb_descriptor_header *) &fsg_ss_bulk_out_desc,
(struct usb_descriptor_header *) &fsg_ss_bulk_out_comp_desc,
NULL,
};
EXPORT_SYMBOL_GPL(fsg_ss_function);
/*-------------------------------------------------------------------------*/
/*
* If the next two routines are called while the gadget is registered,
* the caller must own fsg->filesem for writing.
*/
void fsg_lun_close(struct fsg_lun *curlun)
{
if (curlun->filp) {
LDBG(curlun, "close backing file\n");
fput(curlun->filp);
curlun->filp = NULL;
}
}
EXPORT_SYMBOL_GPL(fsg_lun_close);
int fsg_lun_open(struct fsg_lun *curlun, const char *filename)
{
int ro;
struct file *filp = NULL;
int rc = -EINVAL;
struct inode *inode = NULL;
loff_t size;
loff_t num_sectors;
loff_t min_sectors;
unsigned int blkbits;
unsigned int blksize;
/* R/W if we can, R/O if we must */
ro = curlun->initially_ro;
if (!ro) {
filp = filp_open(filename, O_RDWR | O_LARGEFILE, 0);
if (PTR_ERR(filp) == -EROFS || PTR_ERR(filp) == -EACCES)
ro = 1;
}
if (ro)
filp = filp_open(filename, O_RDONLY | O_LARGEFILE, 0);
if (IS_ERR(filp)) {
LINFO(curlun, "unable to open backing file: %s\n", filename);
return PTR_ERR(filp);
}
if (!(filp->f_mode & FMODE_WRITE))
ro = 1;
inode = filp->f_mapping->host;
if ((!S_ISREG(inode->i_mode) && !S_ISBLK(inode->i_mode))) {
LINFO(curlun, "invalid file type: %s\n", filename);
goto out;
}
/*
* If we can't read the file, it's no good.
* If we can't write the file, use it read-only.
*/
if (!(filp->f_mode & FMODE_CAN_READ)) {
LINFO(curlun, "file not readable: %s\n", filename);
goto out;
}
if (!(filp->f_mode & FMODE_CAN_WRITE))
ro = 1;
size = i_size_read(inode);
if (size < 0) {
LINFO(curlun, "unable to find file size: %s\n", filename);
rc = (int) size;
goto out;
}
if (curlun->cdrom) {
blksize = 2048;
blkbits = 11;
} else if (S_ISBLK(inode->i_mode)) {
blksize = bdev_logical_block_size(I_BDEV(inode));
blkbits = blksize_bits(blksize);
} else {
blksize = 512;
blkbits = 9;
}
num_sectors = size >> blkbits; /* File size in logic-block-size blocks */
min_sectors = 1;
if (curlun->cdrom) {
min_sectors = 300; /* Smallest track is 300 frames */
if (num_sectors >= 256*60*75) {
num_sectors = 256*60*75 - 1;
LINFO(curlun, "file too big: %s\n", filename);
LINFO(curlun, "using only first %d blocks\n",
(int) num_sectors);
}
}
if (num_sectors < min_sectors) {
LINFO(curlun, "file too small: %s\n", filename);
rc = -ETOOSMALL;
goto out;
}
if (
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