523 строки
13 KiB
C
523 строки
13 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* storage_common.c -- Common definitions for mass storage functionality
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*
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* Copyright (C) 2003-2008 Alan Stern
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* Copyeight (C) 2009 Samsung Electronics
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* Author: Michal Nazarewicz (mina86@mina86.com)
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*/
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/*
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* This file requires the following identifiers used in USB strings to
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* be defined (each of type pointer to char):
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* - fsg_string_interface -- name of the interface
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*/
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/*
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* When USB_GADGET_DEBUG_FILES is defined the module param num_buffers
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* sets the number of pipeline buffers (length of the fsg_buffhd array).
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* The valid range of num_buffers is: num >= 2 && num <= 4.
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*/
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#include <linux/module.h>
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#include <linux/blkdev.h>
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#include <linux/file.h>
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#include <linux/fs.h>
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#include <linux/usb/composite.h>
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#include "storage_common.h"
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/* There is only one interface. */
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struct usb_interface_descriptor fsg_intf_desc = {
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.bLength = sizeof fsg_intf_desc,
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.bDescriptorType = USB_DT_INTERFACE,
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.bNumEndpoints = 2, /* Adjusted during fsg_bind() */
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.bInterfaceClass = USB_CLASS_MASS_STORAGE,
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.bInterfaceSubClass = USB_SC_SCSI, /* Adjusted during fsg_bind() */
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.bInterfaceProtocol = USB_PR_BULK, /* Adjusted during fsg_bind() */
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.iInterface = FSG_STRING_INTERFACE,
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};
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EXPORT_SYMBOL_GPL(fsg_intf_desc);
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/*
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* Three full-speed endpoint descriptors: bulk-in, bulk-out, and
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* interrupt-in.
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*/
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struct usb_endpoint_descriptor fsg_fs_bulk_in_desc = {
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.bLength = USB_DT_ENDPOINT_SIZE,
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.bDescriptorType = USB_DT_ENDPOINT,
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.bEndpointAddress = USB_DIR_IN,
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.bmAttributes = USB_ENDPOINT_XFER_BULK,
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/* wMaxPacketSize set by autoconfiguration */
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};
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EXPORT_SYMBOL_GPL(fsg_fs_bulk_in_desc);
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struct usb_endpoint_descriptor fsg_fs_bulk_out_desc = {
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.bLength = USB_DT_ENDPOINT_SIZE,
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.bDescriptorType = USB_DT_ENDPOINT,
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.bEndpointAddress = USB_DIR_OUT,
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.bmAttributes = USB_ENDPOINT_XFER_BULK,
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/* wMaxPacketSize set by autoconfiguration */
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};
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EXPORT_SYMBOL_GPL(fsg_fs_bulk_out_desc);
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struct usb_descriptor_header *fsg_fs_function[] = {
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(struct usb_descriptor_header *) &fsg_intf_desc,
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(struct usb_descriptor_header *) &fsg_fs_bulk_in_desc,
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(struct usb_descriptor_header *) &fsg_fs_bulk_out_desc,
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NULL,
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};
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EXPORT_SYMBOL_GPL(fsg_fs_function);
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/*
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* USB 2.0 devices need to expose both high speed and full speed
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* descriptors, unless they only run at full speed.
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*
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* That means alternate endpoint descriptors (bigger packets).
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*/
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struct usb_endpoint_descriptor fsg_hs_bulk_in_desc = {
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.bLength = USB_DT_ENDPOINT_SIZE,
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.bDescriptorType = USB_DT_ENDPOINT,
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/* bEndpointAddress copied from fs_bulk_in_desc during fsg_bind() */
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.bmAttributes = USB_ENDPOINT_XFER_BULK,
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.wMaxPacketSize = cpu_to_le16(512),
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};
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EXPORT_SYMBOL_GPL(fsg_hs_bulk_in_desc);
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struct usb_endpoint_descriptor fsg_hs_bulk_out_desc = {
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.bLength = USB_DT_ENDPOINT_SIZE,
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.bDescriptorType = USB_DT_ENDPOINT,
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/* bEndpointAddress copied from fs_bulk_out_desc during fsg_bind() */
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.bmAttributes = USB_ENDPOINT_XFER_BULK,
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.wMaxPacketSize = cpu_to_le16(512),
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.bInterval = 1, /* NAK every 1 uframe */
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};
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EXPORT_SYMBOL_GPL(fsg_hs_bulk_out_desc);
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struct usb_descriptor_header *fsg_hs_function[] = {
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(struct usb_descriptor_header *) &fsg_intf_desc,
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(struct usb_descriptor_header *) &fsg_hs_bulk_in_desc,
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(struct usb_descriptor_header *) &fsg_hs_bulk_out_desc,
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NULL,
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};
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EXPORT_SYMBOL_GPL(fsg_hs_function);
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struct usb_endpoint_descriptor fsg_ss_bulk_in_desc = {
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.bLength = USB_DT_ENDPOINT_SIZE,
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.bDescriptorType = USB_DT_ENDPOINT,
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/* bEndpointAddress copied from fs_bulk_in_desc during fsg_bind() */
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.bmAttributes = USB_ENDPOINT_XFER_BULK,
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.wMaxPacketSize = cpu_to_le16(1024),
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};
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EXPORT_SYMBOL_GPL(fsg_ss_bulk_in_desc);
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struct usb_ss_ep_comp_descriptor fsg_ss_bulk_in_comp_desc = {
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.bLength = sizeof(fsg_ss_bulk_in_comp_desc),
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.bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
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/*.bMaxBurst = DYNAMIC, */
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};
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EXPORT_SYMBOL_GPL(fsg_ss_bulk_in_comp_desc);
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struct usb_endpoint_descriptor fsg_ss_bulk_out_desc = {
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.bLength = USB_DT_ENDPOINT_SIZE,
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.bDescriptorType = USB_DT_ENDPOINT,
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/* bEndpointAddress copied from fs_bulk_out_desc during fsg_bind() */
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.bmAttributes = USB_ENDPOINT_XFER_BULK,
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.wMaxPacketSize = cpu_to_le16(1024),
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};
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EXPORT_SYMBOL_GPL(fsg_ss_bulk_out_desc);
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struct usb_ss_ep_comp_descriptor fsg_ss_bulk_out_comp_desc = {
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.bLength = sizeof(fsg_ss_bulk_in_comp_desc),
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.bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
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/*.bMaxBurst = DYNAMIC, */
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};
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EXPORT_SYMBOL_GPL(fsg_ss_bulk_out_comp_desc);
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struct usb_descriptor_header *fsg_ss_function[] = {
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(struct usb_descriptor_header *) &fsg_intf_desc,
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(struct usb_descriptor_header *) &fsg_ss_bulk_in_desc,
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(struct usb_descriptor_header *) &fsg_ss_bulk_in_comp_desc,
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(struct usb_descriptor_header *) &fsg_ss_bulk_out_desc,
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(struct usb_descriptor_header *) &fsg_ss_bulk_out_comp_desc,
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NULL,
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};
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EXPORT_SYMBOL_GPL(fsg_ss_function);
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/*-------------------------------------------------------------------------*/
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/*
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* If the next two routines are called while the gadget is registered,
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* the caller must own fsg->filesem for writing.
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*/
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void fsg_lun_close(struct fsg_lun *curlun)
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{
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if (curlun->filp) {
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LDBG(curlun, "close backing file\n");
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fput(curlun->filp);
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curlun->filp = NULL;
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}
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}
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EXPORT_SYMBOL_GPL(fsg_lun_close);
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int fsg_lun_open(struct fsg_lun *curlun, const char *filename)
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{
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int ro;
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struct file *filp = NULL;
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int rc = -EINVAL;
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struct inode *inode = NULL;
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loff_t size;
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loff_t num_sectors;
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loff_t min_sectors;
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unsigned int blkbits;
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unsigned int blksize;
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/* R/W if we can, R/O if we must */
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ro = curlun->initially_ro;
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if (!ro) {
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filp = filp_open(filename, O_RDWR | O_LARGEFILE, 0);
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if (PTR_ERR(filp) == -EROFS || PTR_ERR(filp) == -EACCES)
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ro = 1;
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}
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if (ro)
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filp = filp_open(filename, O_RDONLY | O_LARGEFILE, 0);
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if (IS_ERR(filp)) {
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LINFO(curlun, "unable to open backing file: %s\n", filename);
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return PTR_ERR(filp);
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}
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if (!(filp->f_mode & FMODE_WRITE))
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ro = 1;
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inode = file_inode(filp);
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if ((!S_ISREG(inode->i_mode) && !S_ISBLK(inode->i_mode))) {
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LINFO(curlun, "invalid file type: %s\n", filename);
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goto out;
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}
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/*
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* If we can't read the file, it's no good.
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* If we can't write the file, use it read-only.
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*/
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if (!(filp->f_mode & FMODE_CAN_READ)) {
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LINFO(curlun, "file not readable: %s\n", filename);
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goto out;
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}
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if (!(filp->f_mode & FMODE_CAN_WRITE))
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ro = 1;
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size = i_size_read(inode->i_mapping->host);
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if (size < 0) {
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LINFO(curlun, "unable to find file size: %s\n", filename);
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rc = (int) size;
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goto out;
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}
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if (curlun->cdrom) {
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blksize = 2048;
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blkbits = 11;
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} else if (inode->i_bdev) {
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blksize = bdev_logical_block_size(inode->i_bdev);
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blkbits = blksize_bits(blksize);
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} else {
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blksize = 512;
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blkbits = 9;
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}
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num_sectors = size >> blkbits; /* File size in logic-block-size blocks */
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min_sectors = 1;
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if (curlun->cdrom) {
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min_sectors = 300; /* Smallest track is 300 frames */
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if (num_sectors >= 256*60*75) {
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num_sectors = 256*60*75 - 1;
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LINFO(curlun, "file too big: %s\n", filename);
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LINFO(curlun, "using only first %d blocks\n",
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(int) num_sectors);
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}
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}
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if (num_sectors < min_sectors) {
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LINFO(curlun, "file too small: %s\n", filename);
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rc = -ETOOSMALL;
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goto out;
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}
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if (fsg_lun_is_open(curlun))
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fsg_lun_close(curlun);
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curlun->blksize = blksize;
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curlun->blkbits = blkbits;
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curlun->ro = ro;
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curlun->filp = filp;
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curlun->file_length = size;
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curlun->num_sectors = num_sectors;
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LDBG(curlun, "open backing file: %s\n", filename);
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return 0;
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out:
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fput(filp);
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return rc;
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}
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EXPORT_SYMBOL_GPL(fsg_lun_open);
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/*-------------------------------------------------------------------------*/
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/*
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* Sync the file data, don't bother with the metadata.
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* This code was copied from fs/buffer.c:sys_fdatasync().
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*/
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int fsg_lun_fsync_sub(struct fsg_lun *curlun)
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{
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struct file *filp = curlun->filp;
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if (curlun->ro || !filp)
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return 0;
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return vfs_fsync(filp, 1);
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}
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EXPORT_SYMBOL_GPL(fsg_lun_fsync_sub);
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void store_cdrom_address(u8 *dest, int msf, u32 addr)
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{
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if (msf) {
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/* Convert to Minutes-Seconds-Frames */
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addr >>= 2; /* Convert to 2048-byte frames */
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addr += 2*75; /* Lead-in occupies 2 seconds */
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dest[3] = addr % 75; /* Frames */
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addr /= 75;
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dest[2] = addr % 60; /* Seconds */
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addr /= 60;
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dest[1] = addr; /* Minutes */
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dest[0] = 0; /* Reserved */
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} else {
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/* Absolute sector */
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put_unaligned_be32(addr, dest);
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}
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}
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EXPORT_SYMBOL_GPL(store_cdrom_address);
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/*-------------------------------------------------------------------------*/
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ssize_t fsg_show_ro(struct fsg_lun *curlun, char *buf)
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{
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return sprintf(buf, "%d\n", fsg_lun_is_open(curlun)
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? curlun->ro
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: curlun->initially_ro);
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}
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EXPORT_SYMBOL_GPL(fsg_show_ro);
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ssize_t fsg_show_nofua(struct fsg_lun *curlun, char *buf)
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{
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return sprintf(buf, "%u\n", curlun->nofua);
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}
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EXPORT_SYMBOL_GPL(fsg_show_nofua);
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ssize_t fsg_show_file(struct fsg_lun *curlun, struct rw_semaphore *filesem,
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char *buf)
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{
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char *p;
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ssize_t rc;
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down_read(filesem);
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if (fsg_lun_is_open(curlun)) { /* Get the complete pathname */
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p = file_path(curlun->filp, buf, PAGE_SIZE - 1);
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if (IS_ERR(p))
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rc = PTR_ERR(p);
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else {
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rc = strlen(p);
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memmove(buf, p, rc);
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buf[rc] = '\n'; /* Add a newline */
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buf[++rc] = 0;
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}
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} else { /* No file, return 0 bytes */
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*buf = 0;
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rc = 0;
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}
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up_read(filesem);
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return rc;
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}
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EXPORT_SYMBOL_GPL(fsg_show_file);
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ssize_t fsg_show_cdrom(struct fsg_lun *curlun, char *buf)
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{
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return sprintf(buf, "%u\n", curlun->cdrom);
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}
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EXPORT_SYMBOL_GPL(fsg_show_cdrom);
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ssize_t fsg_show_removable(struct fsg_lun *curlun, char *buf)
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{
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return sprintf(buf, "%u\n", curlun->removable);
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}
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EXPORT_SYMBOL_GPL(fsg_show_removable);
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ssize_t fsg_show_inquiry_string(struct fsg_lun *curlun, char *buf)
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{
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return sprintf(buf, "%s\n", curlun->inquiry_string);
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}
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EXPORT_SYMBOL_GPL(fsg_show_inquiry_string);
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/*
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* The caller must hold fsg->filesem for reading when calling this function.
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*/
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static ssize_t _fsg_store_ro(struct fsg_lun *curlun, bool ro)
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{
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if (fsg_lun_is_open(curlun)) {
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LDBG(curlun, "read-only status change prevented\n");
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return -EBUSY;
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}
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curlun->ro = ro;
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curlun->initially_ro = ro;
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LDBG(curlun, "read-only status set to %d\n", curlun->ro);
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return 0;
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}
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ssize_t fsg_store_ro(struct fsg_lun *curlun, struct rw_semaphore *filesem,
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const char *buf, size_t count)
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{
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ssize_t rc;
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bool ro;
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rc = strtobool(buf, &ro);
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if (rc)
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return rc;
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/*
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* Allow the write-enable status to change only while the
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* backing file is closed.
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*/
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down_read(filesem);
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rc = _fsg_store_ro(curlun, ro);
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if (!rc)
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rc = count;
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up_read(filesem);
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return rc;
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}
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EXPORT_SYMBOL_GPL(fsg_store_ro);
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ssize_t fsg_store_nofua(struct fsg_lun *curlun, const char *buf, size_t count)
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{
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bool nofua;
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int ret;
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ret = strtobool(buf, &nofua);
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if (ret)
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return ret;
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/* Sync data when switching from async mode to sync */
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if (!nofua && curlun->nofua)
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fsg_lun_fsync_sub(curlun);
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curlun->nofua = nofua;
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return count;
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}
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EXPORT_SYMBOL_GPL(fsg_store_nofua);
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ssize_t fsg_store_file(struct fsg_lun *curlun, struct rw_semaphore *filesem,
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const char *buf, size_t count)
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{
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int rc = 0;
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if (curlun->prevent_medium_removal && fsg_lun_is_open(curlun)) {
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LDBG(curlun, "eject attempt prevented\n");
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return -EBUSY; /* "Door is locked" */
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}
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/* Remove a trailing newline */
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if (count > 0 && buf[count-1] == '\n')
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((char *) buf)[count-1] = 0; /* Ugh! */
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/* Load new medium */
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down_write(filesem);
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if (count > 0 && buf[0]) {
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/* fsg_lun_open() will close existing file if any. */
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rc = fsg_lun_open(curlun, buf);
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if (rc == 0)
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curlun->unit_attention_data =
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SS_NOT_READY_TO_READY_TRANSITION;
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} else if (fsg_lun_is_open(curlun)) {
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fsg_lun_close(curlun);
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curlun->unit_attention_data = SS_MEDIUM_NOT_PRESENT;
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}
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up_write(filesem);
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return (rc < 0 ? rc : count);
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}
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EXPORT_SYMBOL_GPL(fsg_store_file);
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ssize_t fsg_store_cdrom(struct fsg_lun *curlun, struct rw_semaphore *filesem,
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const char *buf, size_t count)
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{
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bool cdrom;
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int ret;
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ret = strtobool(buf, &cdrom);
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if (ret)
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return ret;
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down_read(filesem);
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ret = cdrom ? _fsg_store_ro(curlun, true) : 0;
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if (!ret) {
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curlun->cdrom = cdrom;
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ret = count;
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}
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up_read(filesem);
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return ret;
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}
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EXPORT_SYMBOL_GPL(fsg_store_cdrom);
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ssize_t fsg_store_removable(struct fsg_lun *curlun, const char *buf,
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size_t count)
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{
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bool removable;
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int ret;
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ret = strtobool(buf, &removable);
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if (ret)
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return ret;
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curlun->removable = removable;
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return count;
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}
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EXPORT_SYMBOL_GPL(fsg_store_removable);
|
|
|
|
ssize_t fsg_store_inquiry_string(struct fsg_lun *curlun, const char *buf,
|
|
size_t count)
|
|
{
|
|
const size_t len = min(count, sizeof(curlun->inquiry_string));
|
|
|
|
if (len == 0 || buf[0] == '\n') {
|
|
curlun->inquiry_string[0] = 0;
|
|
} else {
|
|
snprintf(curlun->inquiry_string,
|
|
sizeof(curlun->inquiry_string), "%-28s", buf);
|
|
if (curlun->inquiry_string[len-1] == '\n')
|
|
curlun->inquiry_string[len-1] = ' ';
|
|
}
|
|
|
|
return count;
|
|
}
|
|
EXPORT_SYMBOL_GPL(fsg_store_inquiry_string);
|
|
|
|
MODULE_LICENSE("GPL");
|