hi:
I have some questions about this patch.
>
> 2009/8/31 Michał Nazarewicz <m.nazarewicz@xxxxxxxxxxx>:
>> Copied file_storage.c to f_mass_storage.c which will be used as
>> template for the mass storage composite function.
>>
>> Signed-off-by: Michal Nazarewicz <mnazarewicz@xxxxxxxxxxx>
>> ---
>> drivers/usb/gadget/f_mass_storage.c | 3713
>> +++++++++++++++++++++++++++++++++++
>> 1 files changed, 3713 insertions(+), 0 deletions(-)
>> create mode 100644 drivers/usb/gadget/f_mass_storage.c
>>
>> diff --git a/drivers/usb/gadget/f_mass_storage.c
>> b/drivers/usb/gadget/f_mass_storage.c
>> new file mode 100644
>> index 0000000..d1d463c
>> --- /dev/null
>> +++ b/drivers/usb/gadget/f_mass_storage.c
>> @@ -0,0 +1,3713 @@
>> +/*
>> + * file_storage.c -- File-backed USB Storage Gadget, for USB development
>> + *
>> + * Copyright (C) 2003-2008 Alan Stern
>> + * Copyeight (C) 2009 Samsung Electronics
>> + * Author: Michal Nazarewicz (m.nazarewicz@xxxxxxxxxxx)
>> + * All rights reserved.
>> + *
>> + * Redistribution and use in source and binary forms, with or without
>> + * modification, are permitted provided that the following conditions
>> + * are met:
>> + * 1. Redistributions of source code must retain the above copyright
>> + * notice, this list of conditions, and the following disclaimer,
>> + * without modification.
>> + * 2. Redistributions in binary form must reproduce the above copyright
>> + * notice, this list of conditions and the following disclaimer in the
>> + * documentation and/or other materials provided with the distribution.
>> + * 3. The names of the above-listed copyright holders may not be used
>> + * to endorse or promote products derived from this software without
>> + * specific prior written permission.
>> + *
>> + * ALTERNATIVELY, this software may be distributed under the terms of the
>> + * GNU General Public License ("GPL") as published by the Free Software
>> + * Foundation, either version 2 of that License or (at your option) any
>> + * later version.
>> + *
>> + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
>> + * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
>> TO,
>> + * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
>> + * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
>> + * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
>> + * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
>> + * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
>> + * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
>> + * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
>> + * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
>> + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
>> + */
>> +
>> +
>> +/*
>> + * The File-backed Storage Gadget acts as a USB Mass Storage device,
>> + * appearing to the host as a disk drive or as a CD-ROM drive. In addition
>> + * to providing an example of a genuinely useful gadget driver for a USB
>> + * device, it also illustrates a technique of double-buffering for
>> increased
>> + * throughput. Last but not least, it gives an easy way to probe the
>> + * behavior of the Mass Storage drivers in a USB host.
>> + *
>> + * Backing storage is provided by a regular file or a block device,
>> specified
>> + * by the "file" module parameter. Access can be limited to read-only by
>> + * setting the optional "ro" module parameter. (For CD-ROM emulation,
>> + * access is always read-only.) The gadget will indicate that it has
>> + * removable media if the optional "removable" module parameter is set.
>> + *
>> + * The gadget supports the Control-Bulk (CB), Control-Bulk-Interrupt (CBI),
>> + * and Bulk-Only (also known as Bulk-Bulk-Bulk or BBB) transports, selected
>> + * by the optional "transport" module parameter. It also supports the
>> + * following protocols: RBC (0x01), ATAPI or SFF-8020i (0x02), QIC-157
>> (0c03),
>> + * UFI (0x04), SFF-8070i (0x05), and transparent SCSI (0x06), selected by
>> + * the optional "protocol" module parameter. In addition, the default
>> + * Vendor ID, Product ID, and release number can be overridden.
>> + *
>> + * There is support for multiple logical units (LUNs), each of which has
>> + * its own backing file. The number of LUNs can be set using the optional
>> + * "luns" module parameter (anywhere from 1 to 8), and the corresponding
>> + * files are specified using comma-separated lists for "file" and "ro".
>> + * The default number of LUNs is taken from the number of "file" elements;
>> + * it is 1 if "file" is not given. If "removable" is not set then a
>> backing
>> + * file must be specified for each LUN. If it is set, then an unspecified
>> + * or empty backing filename means the LUN's medium is not loaded. Ideally
>> + * each LUN would be settable independently as a disk drive or a CD-ROM
>> + * drive, but currently all LUNs have to be the same type. The CD-ROM
>> + * emulation includes a single data track and no audio tracks; hence there
>> + * need be only one backing file per LUN. Note also that the CD-ROM block
>> + * length is set to 512 rather than the more common value 2048.
>> + *
>> + * Requirements are modest; only a bulk-in and a bulk-out endpoint are
>> + * needed (an interrupt-out endpoint is also needed for CBI). The memory
>> + * requirement amounts to two 16K buffers, size configurable by a
>> parameter.
>> + * Support is included for both full-speed and high-speed operation.
>> + *
>> + * Note that the driver is slightly non-portable in that it assumes a
>> + * single memory/DMA buffer will be useable for bulk-in, bulk-out, and
>> + * interrupt-in endpoints. With most device controllers this isn't an
>> + * issue, but there may be some with hardware restrictions that prevent
>> + * a buffer from being used by more than one endpoint.
>> + *
>> + * Module options:
>> + *
>> + * file=filename[,filename...]
>> + * Required if "removable" is not set, names of
>> + * the files or block devices used for
>> + * backing storage
>> + * ro=b[,b...] Default false, booleans for read-only access
>> + * removable Default false, boolean for removable media
>> + * luns=N Default N = number of filenames, number of
>> + * LUNs to support
>> + * stall Default determined according to the type of
>> + * USB device controller (usually
>> true),
>> + * boolean to permit the driver to halt
>> + * bulk endpoints
>> + * cdrom Default false, boolean for whether to
>> emulate
>> + * a CD-ROM drive
>> + * transport=XXX Default BBB, transport name (CB, CBI, or
>> BBB)
>> + * protocol=YYY Default SCSI, protocol name (RBC, 8020 or
>> + * ATAPI, QIC, UFI, 8070, or SCSI;
>> + * also 1 - 6)
>> + * vendor=0xVVVV Default 0x0525 (NetChip), USB Vendor ID
>> + * product=0xPPPP Default 0xa4a5 (FSG), USB Product ID
>> + * release=0xRRRR Override the USB release number (bcdDevice)
>> + * buflen=N Default N=16384, buffer size used (will be
>> + * rounded down to a multiple of
>> + * PAGE_CACHE_SIZE)
>> + *
>> + * If CONFIG_USB_FILE_STORAGE_TEST is not set, only the "file", "ro",
>> + * "removable", "luns", "stall", and "cdrom" options are available; default
>> + * values are used for everything else.
>> + *
>> + * The pathnames of the backing files and the ro settings are available in
>> + * the attribute files "file" and "ro" in the lun<n> subdirectory of the
>> + * gadget's sysfs directory. If the "removable" option is set, writing to
>> + * these files will simulate ejecting/loading the medium (writing an empty
>> + * line means eject) and adjusting a write-enable tab. Changes to the ro
>> + * setting are not allowed when the medium is loaded or if CD-ROM emulation
>> + * is being used.
>> + *
>> + * This gadget driver is heavily based on "Gadget Zero" by David Brownell.
>> + * The driver's SCSI command interface was based on the "Information
>> + * technology - Small Computer System Interface - 2" document from
>> + * X3T9.2 Project 375D, Revision 10L, 7-SEP-93, available at
>> + * <http://www.t10.org/ftp/t10/drafts/s2/s2-r10l.pdf>. The single
>> exception
>> + * is opcode 0x23 (READ FORMAT CAPACITIES), which was based on the
>> + * "Universal Serial Bus Mass Storage Class UFI Command Specification"
>> + * document, Revision 1.0, December 14, 1998, available at
>> + * <http://www.usb.org/developers/devclass_docs/usbmass-ufi10.pdf>.
>> + */
>> +
>> +
>> +/*
>> + * Driver Design
>> + *
>> + * The FSG driver is fairly straightforward. There is a main kernel
>> + * thread that handles most of the work. Interrupt routines field
>> + * callbacks from the controller driver: bulk- and interrupt-request
>> + * completion notifications, endpoint-0 events, and disconnect events.
>> + * Completion events are passed to the main thread by wakeup calls. Many
>> + * ep0 requests are handled at interrupt time, but SetInterface,
>> + * SetConfiguration, and device reset requests are forwarded to the
>> + * thread in the form of "exceptions" using SIGUSR1 signals (since they
>> + * should interrupt any ongoing file I/O operations).
>> + *
>> + * The thread's main routine implements the standard command/data/status
>> + * parts of a SCSI interaction. It and its subroutines are full of tests
>> + * for pending signals/exceptions -- all this polling is necessary since
>> + * the kernel has no setjmp/longjmp equivalents. (Maybe this is an
>> + * indication that the driver really wants to be running in userspace.)
>> + * An important point is that so long as the thread is alive it keeps an
>> + * open reference to the backing file. This will prevent unmounting
>> + * the backing file's underlying filesystem and could cause problems
>> + * during system shutdown, for example. To prevent such problems, the
>> + * thread catches INT, TERM, and KILL signals and converts them into
>> + * an EXIT exception.
>> + *
>> + * In normal operation the main thread is started during the gadget's
>> + * fsg_bind() callback and stopped during fsg_unbind(). But it can also
>> + * exit when it receives a signal, and there's no point leaving the
>> + * gadget running when the thread is dead. So just before the thread
>> + * exits, it deregisters the gadget driver. This makes things a little
>> + * tricky: The driver is deregistered at two places, and the exiting
>> + * thread can indirectly call fsg_unbind() which in turn can tell the
>> + * thread to exit. The first problem is resolved through the use of the
>> + * REGISTERED atomic bitflag; the driver will only be deregistered once.
>> + * The second problem is resolved by having fsg_unbind() check
>> + * fsg->state; it won't try to stop the thread if the state is already
>> + * STOR_STATE_TERMINATED.
>> + *
>> + * To provide maximum throughput, the driver uses a circular pipeline of
>> + * buffer heads (struct stor_buffhd). In principle the pipeline can be
>> + * arbitrarily long; in practice the benefits don't justify having more
>> + * than 2 stages (i.e., double buffering). But it helps to think of the
>> + * pipeline as being a long one. Each buffer head contains a bulk-in and
>> + * a bulk-out request pointer (since the buffer can be used for both
>> + * output and input -- directions always are given from the host's
>> + * point of view) as well as a pointer to the buffer and various state
>> + * variables.
>> + *
>> + * Use of the pipeline follows a simple protocol. There is a variable
>> + * (fsg->next_buffhd_to_fill) that points to the next buffer head to use.
>> + * At any time that buffer head may still be in use from an earlier
>> + * request, so each buffer head has a state variable indicating whether
>> + * it is EMPTY, FULL, or BUSY. Typical use involves waiting for the
>> + * buffer head to be EMPTY, filling the buffer either by file I/O or by
>> + * USB I/O (during which the buffer head is BUSY), and marking the buffer
>> + * head FULL when the I/O is complete. Then the buffer will be emptied
>> + * (again possibly by USB I/O, during which it is marked BUSY) and
>> + * finally marked EMPTY again (possibly by a completion routine).
>> + *
>> + * A module parameter tells the driver to avoid stalling the bulk
>> + * endpoints wherever the transport specification allows. This is
>> + * necessary for some UDCs like the SuperH, which cannot reliably clear a
>> + * halt on a bulk endpoint. However, under certain circumstances the
>> + * Bulk-only specification requires a stall. In such cases the driver
>> + * will halt the endpoint and set a flag indicating that it should clear
>> + * the halt in software during the next device reset. Hopefully this
>> + * will permit everything to work correctly. Furthermore, although the
>> + * specification allows the bulk-out endpoint to halt when the host sends
>> + * too much data, implementing this would cause an unavoidable race.
>> + * The driver will always use the "no-stall" approach for OUT transfers.
>> + *
>> + * One subtle point concerns sending status-stage responses for ep0
>> + * requests. Some of these requests, such as device reset, can involve
>> + * interrupting an ongoing file I/O operation, which might take an
>> + * arbitrarily long time. During that delay the host might give up on
>> + * the original ep0 request and issue a new one. When that happens the
>> + * driver should not notify the host about completion of the original
>> + * request, as the host will no longer be waiting for it. So the driver
>> + * assigns to each ep0 request a unique tag, and it keeps track of the
>> + * tag value of the request associated with a long-running exception
>> + * (device-reset, interface-change, or configuration-change). When the
>> + * exception handler is finished, the status-stage response is submitted
>> + * only if the current ep0 request tag is equal to the exception request
>> + * tag. Thus only the most recently received ep0 request will get a
>> + * status-stage response.
>> + *
>> + * Warning: This driver source file is too long. It ought to be split up
>> + * into a header file plus about 3 separate .c files, to handle the details
>> + * of the Gadget, USB Mass Storage, and SCSI protocols.
>> + */
>> +
>> +
>> +/* #define VERBOSE_DEBUG */
>> +/* #define DUMP_MSGS */
>> +
>> +
>> +#include <linux/blkdev.h>
>> +#include <linux/completion.h>
>> +#include <linux/dcache.h>
>> +#include <linux/delay.h>
>> +#include <linux/device.h>
>> +#include <linux/fcntl.h>
>> +#include <linux/file.h>
>> +#include <linux/fs.h>
>> +#include <linux/kref.h>
>> +#include <linux/kthread.h>
>> +#include <linux/limits.h>
>> +#include <linux/rwsem.h>
>> +#include <linux/slab.h>
>> +#include <linux/spinlock.h>
>> +#include <linux/string.h>
>> +#include <linux/freezer.h>
>> +#include <linux/utsname.h>
>> +
>> +#include <linux/usb/ch9.h>
>> +#include <linux/usb/gadget.h>
>> +
>> +#include "gadget_chips.h"
>> +
>> +
>> +
>> +/*-------------------------------------------------------------------------*/
>> +
>> +#define DRIVER_DESC "File-backed Storage Gadget"
>> +#define DRIVER_NAME "g_file_storage"
>> +#define DRIVER_VERSION "20 November 2008"
>> +
>> +static char stor_string_manufacturer[64];
>> +static const char stor_string_product[] = DRIVER_DESC;
>> +static char stor_string_serial[13];
>> +static char stor_string_config[] = "Self Powered";
>> +static const char stor_string_interface[] = "Mass Storage";
>> +
>> +MODULE_DESCRIPTION(DRIVER_DESC);
>> +MODULE_AUTHOR("Alan Stern");
>> +MODULE_LICENSE("Dual BSD/GPL");
>> +
>> +/*
>> + * This driver assumes self-powered hardware and has no way for users to
>> + * trigger remote wakeup. It uses autoconfiguration to select endpoints
>> + * and endpoint addresses.
>> + */
>> +
>> +
>> +/*-------------------------------------------------------------------------*/
>> +
>> +
>> +/*
>> + * Kbuild is not very cooperative with respect to linking separately
>> + * compiled library objects into one module. So for now we won't use
>> + * separate compilation ... ensuring init/exit sections work to shrink
>> + * the runtime footprint, and giving us at least some parts of what
>> + * a "gcc --combine ... part1.c part2.c part3.c ... " build would.
>> + */
>> +#include "usbstring.c"
>> +#include "config.c"
>> +#include "epautoconf.c"
>> +
>> +#define STOR_DESCRIPTORS_DEVICE_STRINGS 1
>> +#define STOR_DESCRIPTORS_INTR_EP 1
>> +
>> +#include "storage_common.c"
>> +
>> +
>> +/* Encapsulate the module parameter settings */
>> +
>> +static struct {
>> + char *file[STORAGE_MAX_LUNS];
>> + int ro[STORAGE_MAX_LUNS];
>> + unsigned int num_filenames;
>> + unsigned int num_ros;
>> + unsigned int nluns;
>> +
>> + int removable;
>> + int can_stall;
>> + int cdrom;
>> +
>> + char *transport_parm;
>> + char *protocol_parm;
>> + unsigned short vendor;
>> + unsigned short product;
>> + unsigned short release;
>> + unsigned int buflen;
>> +
>> + int transport_type;
>> + char *transport_name;
>> + int protocol_type;
>> + char *protocol_name;
>> +
>> +} mod_data = { // Default values
>> + .transport_parm = "BBB",
>> + .protocol_parm = "SCSI",
>> + .removable = 0,
>> + .can_stall = 1,
>> + .cdrom = 0,
>> + .vendor = STORAGE_VENDOR_ID,
>> + .product = STORAGE_PRODUCT_ID,
>> + .release = 0xffff, // Use controller chip type
>> + .buflen = 16384,
>> + };
>> +
>> +
>> +module_param_array_named(file, mod_data.file, charp,
>> &mod_data.num_filenames,
>> + S_IRUGO);
>> +MODULE_PARM_DESC(file, "names of backing files or devices");
>> +
>> +module_param_array_named(ro, mod_data.ro, bool, &mod_data.num_ros,
>> S_IRUGO);
>> +MODULE_PARM_DESC(ro, "true to force read-only");
>> +
>> +module_param_named(luns, mod_data.nluns, uint, S_IRUGO);
>> +MODULE_PARM_DESC(luns, "number of LUNs");
>> +
>> +module_param_named(removable, mod_data.removable, bool, S_IRUGO);
>> +MODULE_PARM_DESC(removable, "true to simulate removable media");
>> +
>> +module_param_named(stall, mod_data.can_stall, bool, S_IRUGO);
>> +MODULE_PARM_DESC(stall, "false to prevent bulk stalls");
>> +
>> +module_param_named(cdrom, mod_data.cdrom, bool, S_IRUGO);
>> +MODULE_PARM_DESC(cdrom, "true to emulate cdrom instead of disk");
>> +
>> +
>> +/* In the non-TEST version, only the module parameters listed above
>> + * are available. */
>> +#ifdef CONFIG_USB_FILE_STORAGE_TEST
>> +
>> +module_param_named(transport, mod_data.transport_parm, charp, S_IRUGO);
>> +MODULE_PARM_DESC(transport, "type of transport (BBB, CBI, or CB)");
>> +
>> +module_param_named(protocol, mod_data.protocol_parm, charp, S_IRUGO);
>> +MODULE_PARM_DESC(protocol, "type of protocol (RBC, 8020, QIC, UFI, "
>> + "8070, or SCSI)");
>> +
>> +module_param_named(vendor, mod_data.vendor, ushort, S_IRUGO);
>> +MODULE_PARM_DESC(vendor, "USB Vendor ID");
>> +
>> +module_param_named(product, mod_data.product, ushort, S_IRUGO);
>> +MODULE_PARM_DESC(product, "USB Product ID");
>> +
>> +module_param_named(release, mod_data.release, ushort, S_IRUGO);
>> +MODULE_PARM_DESC(release, "USB release number");
>> +
>> +module_param_named(buflen, mod_data.buflen, uint, S_IRUGO);
>> +MODULE_PARM_DESC(buflen, "I/O buffer size");
>> +
>> +#endif /* CONFIG_USB_FILE_STORAGE_TEST */
>> +
>> +
>> +/*
>> + * These definitions will permit the compiler to avoid generating code for
>> + * parts of the driver that aren't used in the non-TEST version. Even gcc
>> + * can recognize when a test of a constant expression yields a dead code
>> + * path.
>> + */
>> +
>> +#ifdef CONFIG_USB_FILE_STORAGE_TEST
>> +
>> +#define transport_is_bbb() (mod_data.transport_type == USB_PR_BULK)
>> +#define transport_is_cbi() (mod_data.transport_type == USB_PR_CBI)
>> +#define protocol_is_scsi() (mod_data.protocol_type == USB_SC_SCSI)
>> +
>> +#else
>> +
>> +#define transport_is_bbb() 1
>> +#define transport_is_cbi() 0
>> +#define protocol_is_scsi() 1
>> +
>> +#endif /* CONFIG_USB_FILE_STORAGE_TEST */
>> +
>> +
>> +struct fsg_dev {
>> + /* lock protects: state, all the req_busy's, and cbbuf_cmnd */
>> + spinlock_t lock;
>> + struct usb_gadget *gadget;
>> +
>> + /* filesem protects: backing files in use */
>> + struct rw_semaphore filesem;
>> +
>> + /* reference counting: wait until all LUNs are released */
>> + struct kref ref;
>> +
>> + struct usb_ep *ep0; // Handy copy of gadget->ep0
>> + struct usb_request *ep0req; // For control responses
>> + unsigned int ep0_req_tag;
>> + const char *ep0req_name;
>> +
>> + struct usb_request *intreq; // For interrupt responses
>> + int intreq_busy;
>> + struct stor_buffhd *intr_buffhd;
>> +
>> + unsigned int bulk_out_maxpacket;
>> + enum stor_state state; // For exception handling
>> + unsigned int exception_req_tag;
>> +
>> + u8 config, new_config;
>> +
>> + unsigned int running : 1;
>> + unsigned int bulk_in_enabled : 1;
>> + unsigned int bulk_out_enabled : 1;
>> + unsigned int intr_in_enabled : 1;
>> + unsigned int phase_error : 1;
>> + unsigned int short_packet_received : 1;
>> + unsigned int bad_lun_okay : 1;
>> +
>> + unsigned long atomic_bitflags;
>> +#define REGISTERED 0
>> +#define IGNORE_BULK_OUT 1
>> +#define SUSPENDED 2
>> +
>> + struct usb_ep *bulk_in;
>> + struct usb_ep *bulk_out;
>> + struct usb_ep *intr_in;
>> +
>> + struct stor_buffhd *next_buffhd_to_fill;
>> + struct stor_buffhd *next_buffhd_to_drain;
>> + struct stor_buffhd buffhds[STORAGE_NUM_BUFFERS];
>> +
>> + int thread_wakeup_needed;
>> + struct completion thread_notifier;
>> + struct task_struct *thread_task;
>> +
>> + int cmnd_size;
>> + u8 cmnd[MAX_COMMAND_SIZE];
>> + enum stor_data_direction data_dir;
>> + u32 data_size;
>> + u32 data_size_from_cmnd;
>> + u32 tag;
>> + unsigned int lun;
>> + u32 residue;
>> + u32 usb_amount_left;
>> +
>> + /* The CB protocol offers no way for a host to know when a command
>> + * has completed. As a result the next command may arrive early,
>> + * and we will still have to handle it. For that reason we need
>> + * a buffer to store new commands when using CB (or CBI, which
>> + * does not oblige a host to wait for command completion either). */
>> + int cbbuf_cmnd_size;
>> + u8 cbbuf_cmnd[MAX_COMMAND_SIZE];
>> +
>> + unsigned int nluns;
>> + struct storage_lun *luns;
>> + struct storage_lun *curlun;
>> +};
>> +
>> +typedef void (*fsg_routine_t)(struct fsg_dev *);
>> +
>> +static int exception_in_progress(struct fsg_dev *fsg)
>> +{
>> + return (fsg->state > STOR_STATE_IDLE);
>> +}
>> +
>> +/* Make bulk-out requests be divisible by the maxpacket size */
>> +static void set_bulk_out_req_length(struct fsg_dev *fsg,
>> + struct stor_buffhd *bh, unsigned int length)
>> +{
>> + unsigned int rem;
>> +
>> + bh->bulk_out_intended_length = length;
>> + rem = length % fsg->bulk_out_maxpacket;
>> + if (rem > 0)
>> + length += fsg->bulk_out_maxpacket - rem;
>> + bh->outreq->length = length;
>> +}
>> +
>> +static struct fsg_dev *the_fsg;
>> +static struct usb_gadget_driver fsg_driver;
>> +
>> +
>> +/*-------------------------------------------------------------------------*/
>> +
>> +static inline void dump_cdb(struct fsg_dev *fsg)
>> +{
>> +#if defined DUMP_MSGS || !defined VERBOSE_DEBUG
>> + print_hex_dump(KERN_DEBUG, "SCSI CDB: ", DUMP_PREFIX_NONE,
>> + 16, 1, fsg->cmnd, fsg->cmnd_size, 0);
>> +#endif
>> +}
>> +
>> +
>> +static int fsg_set_halt(struct fsg_dev *fsg, struct usb_ep *ep)
>> +{
>> + const char *name;
>> +
>> + if (ep == fsg->bulk_in)
>> + name = "bulk-in";
>> + else if (ep == fsg->bulk_out)
>> + name = "bulk-out";
>> + else
>> + name = ep->name;
>> + SDBG(fsg, "%s set halt\n", name);
>> + return usb_ep_set_halt(ep);
>> +}
>> +
>> +
>> +/*-------------------------------------------------------------------------*/
>> +
>> +/*
>> + * DESCRIPTORS ... most are static, but strings and (full) configuration
>> + * descriptors are built on demand. Also the (static) config and interface
>> + * descriptors are adjusted during fsg_bind().
>> + */
>> +
>> +/* Some of the descriptors are defined in storage_common.c file. */
>> +
>> +/* There is only one configuration. */
>> +#define CONFIG_VALUE 1
>> +
>> +static struct usb_device_descriptor
>> +device_desc = {
>> + .bLength = sizeof device_desc,
>> + .bDescriptorType = USB_DT_DEVICE,
>> +
>> + .bcdUSB = cpu_to_le16(0x0200),
>> + .bDeviceClass = USB_CLASS_PER_INTERFACE,
>> +
>> + /* The next three values can be overridden by module parameters */
>> + .idVendor = cpu_to_le16(STORAGE_VENDOR_ID),
>> + .idProduct = cpu_to_le16(STORAGE_PRODUCT_ID),
>> + .bcdDevice = cpu_to_le16(0xffff),
>> +
>> + .iManufacturer = STOR_STRING_MANUFACTURER,
>> + .iProduct = STOR_STRING_PRODUCT,
>> + .iSerialNumber = STOR_STRING_SERIAL,
>> + .bNumConfigurations = 1,
>> +};
>> +
>> +static struct usb_config_descriptor
>> +config_desc = {
>> + .bLength = sizeof config_desc,
>> + .bDescriptorType = USB_DT_CONFIG,
>> +
>> + /* wTotalLength computed by usb_gadget_config_buf() */
>> + .bNumInterfaces = 1,
>> + .bConfigurationValue = CONFIG_VALUE,
>> + .iConfiguration = STOR_STRING_CONFIG,
>> + .bmAttributes = USB_CONFIG_ATT_ONE |
>> USB_CONFIG_ATT_SELFPOWER,
>> + .bMaxPower = CONFIG_USB_GADGET_VBUS_DRAW / 2,
>> +};
>> +
>> +
>> +static struct usb_qualifier_descriptor
>> +dev_qualifier = {
>> + .bLength = sizeof dev_qualifier,
>> + .bDescriptorType = USB_DT_DEVICE_QUALIFIER,
>> +
>> + .bcdUSB = cpu_to_le16(0x0200),
>> + .bDeviceClass = USB_CLASS_PER_INTERFACE,
>> +
>> + .bNumConfigurations = 1,
>> +};
>> +
>> +
>> +
>> +/*
>> + * Config descriptors must agree with the code that sets configurations
>> + * and with code managing interfaces and their altsettings. They must
>> + * also handle different speeds and other-speed requests.
>> + */
>> +static int populate_config_buf(struct usb_gadget *gadget,
>> + u8 *buf, u8 type, unsigned index)
>> +{
>> + enum usb_device_speed speed = gadget->speed;
>> + int len;
>> + const struct usb_descriptor_header **function;
>> +
>> + if (index > 0)
>> + return -EINVAL;
>> +
>> + if (gadget_is_dualspeed(gadget) && type ==
>> USB_DT_OTHER_SPEED_CONFIG)
>> + speed = (USB_SPEED_FULL + USB_SPEED_HIGH) - speed;
>> + if (gadget_is_dualspeed(gadget) && speed == USB_SPEED_HIGH)
>> + function = stor_hs_function;
>> + else
>> + function = stor_fs_function;
>> +
>> + /* for now, don't advertise srp-only devices */
>> + if (!gadget_is_otg(gadget))
>> + function++;
>> +
>> + len = usb_gadget_config_buf(&config_desc, buf, EP0_BUFSIZE,
>> function);
>> + ((struct usb_config_descriptor *) buf)->bDescriptorType = type;
>> + return len;
>> +}
>> +
>> +
>> +/*-------------------------------------------------------------------------*/
>> +
>> +/* These routines may be called in process context or in_irq */
>> +
>> +/* Caller must hold fsg->lock */
>> +static void wakeup_thread(struct fsg_dev *fsg)
>> +{
>> + /* Tell the main thread that something has happened */
>> + fsg->thread_wakeup_needed = 1;
>> + if (fsg->thread_task)
>> + wake_up_process(fsg->thread_task);
>> +}
>> +
>> +
>> +static void raise_exception(struct fsg_dev *fsg, enum stor_state new_state)
>> +{
>> + unsigned long flags;
>> +
>> + /* Do nothing if a higher-priority exception is already in progress.
>> + * If a lower-or-equal priority exception is in progress, preempt it
>> + * and notify the main thread by sending it a signal. */
>> + spin_lock_irqsave(&fsg->lock, flags);
>> + if (fsg->state <= new_state) {
>> + fsg->exception_req_tag = fsg->ep0_req_tag;
>> + fsg->state = new_state;
>> + if (fsg->thread_task)
>> + send_sig_info(SIGUSR1, SEND_SIG_FORCED,
>> + fsg->thread_task);
>> + }
>> + spin_unlock_irqrestore(&fsg->lock, flags);
>> +}
>> +
>> +
>> +/*-------------------------------------------------------------------------*/
>> +
>> +/* The disconnect callback and ep0 routines. These always run in_irq,
>> + * except that ep0_queue() is called in the main thread to acknowledge
>> + * completion of various requests: set config, set interface, and
>> + * Bulk-only device reset. */
>> +
>> +static void fsg_disconnect(struct usb_gadget *gadget)
>> +{
>> + struct fsg_dev *fsg = get_gadget_data(gadget);
>> +
>> + SDBG(fsg, "disconnect or port reset\n");
>> + raise_exception(fsg, STOR_STATE_DISCONNECT);
>> +}
>> +
>> +
>> +static int ep0_queue(struct fsg_dev *fsg)
>> +{
>> + int rc;
>> +
>> + rc = usb_ep_queue(fsg->ep0, fsg->ep0req, GFP_ATOMIC);
>> + if (rc != 0 && rc != -ESHUTDOWN) {
>> +
>> + /* We can't do much more than wait for a reset */
>> + SWARN(fsg, "error in submission: %s --> %d\n",
>> + fsg->ep0->name, rc);
>> + }
>> + return rc;
>> +}
>> +
>> +static void ep0_complete(struct usb_ep *ep, struct usb_request *req)
>> +{
>> + struct fsg_dev *fsg = ep->driver_data;
>> +
>> + if (req->actual > 0)
>> + dump_msg(fsg, fsg->ep0req_name, req->buf, req->actual);
>> + if (req->status || req->actual != req->length)
>> + SDBG(fsg, "%s --> %d, %u/%u\n", __func__,
>> + req->status, req->actual, req->length);
>> + if (req->status == -ECONNRESET) // Request was cancelled
>> + usb_ep_fifo_flush(ep);
>> +
>> + if (req->status == 0 && req->context)
>> + ((fsg_routine_t) (req->context))(fsg);
>> +}
>> +
>> +
>> +/*-------------------------------------------------------------------------*/
>> +
>> +/* Bulk and interrupt endpoint completion handlers.
>> + * These always run in_irq. */
>> +
>> +static void bulk_in_complete(struct usb_ep *ep, struct usb_request *req)
>> +{
>> + struct fsg_dev *fsg = ep->driver_data;
>> + struct stor_buffhd *bh = req->context;
>> +
>> + if (req->status || req->actual != req->length)
>> + SDBG(fsg, "%s --> %d, %u/%u\n", __func__,
>> + req->status, req->actual, req->length);
>> + if (req->status == -ECONNRESET) // Request was cancelled
>> + usb_ep_fifo_flush(ep);
>> +
>> + /* Hold the lock while we update the request and buffer states */
>> + smp_wmb();
>> + spin_lock(&fsg->lock);
>> + bh->inreq_busy = 0;
>> + bh->state = BUF_STATE_EMPTY;
>> + wakeup_thread(fsg);
>> + spin_unlock(&fsg->lock);
>> +}
>> +
>> +static void bulk_out_complete(struct usb_ep *ep, struct usb_request *req)
>> +{
>> + struct fsg_dev *fsg = ep->driver_data;
>> + struct stor_buffhd *bh = req->context;
>> +
>> + dump_msg(fsg, "bulk-out", req->buf, req->actual);
>> + if (req->status || req->actual != bh->bulk_out_intended_length)
>> + SDBG(fsg, "%s --> %d, %u/%u\n", __func__,
>> + req->status, req->actual,
>> + bh->bulk_out_intended_length);
>> + if (req->status == -ECONNRESET) // Request was cancelled
>> + usb_ep_fifo_flush(ep);
>> +
>> + /* Hold the lock while we update the request and buffer states */
>> + smp_wmb();
>> + spin_lock(&fsg->lock);
>> + bh->outreq_busy = 0;
>> + bh->state = BUF_STATE_FULL;
>> + wakeup_thread(fsg);
>> + spin_unlock(&fsg->lock);
>> +}
>> +
>> +
>> +#ifdef CONFIG_USB_FILE_STORAGE_TEST
>> +static void intr_in_complete(struct usb_ep *ep, struct usb_request *req)
>> +{
>> + struct fsg_dev *fsg = ep->driver_data;
>> + struct stor_buffhd *bh = req->context;
>> +
>> + if (req->status || req->actual != req->length)
>> + SDBG(fsg, "%s --> %d, %u/%u\n", __func__,
>> + req->status, req->actual, req->length);
>> + if (req->status == -ECONNRESET) // Request was cancelled
>> + usb_ep_fifo_flush(ep);
>> +
>> + /* Hold the lock while we update the request and buffer states */
>> + smp_wmb();
>> + spin_lock(&fsg->lock);
>> + fsg->intreq_busy = 0;
>> + bh->state = BUF_STATE_EMPTY;
>> + wakeup_thread(fsg);
>> + spin_unlock(&fsg->lock);
>> +}
>> +
>> +#else
>> +static void intr_in_complete(struct usb_ep *ep, struct usb_request *req)
>> +{}
>> +#endif /* CONFIG_USB_FILE_STORAGE_TEST */
>> +
>> +
>> +/*-------------------------------------------------------------------------*/
>> +
>> +/* Ep0 class-specific handlers. These always run in_irq. */
>> +
>> +#ifdef CONFIG_USB_FILE_STORAGE_TEST
>> +static void received_cbi_adsc(struct fsg_dev *fsg, struct stor_buffhd *bh)
>> +{
>> + struct usb_request *req = fsg->ep0req;
>> + static u8 cbi_reset_cmnd[6] = {
>> + SC_SEND_DIAGNOSTIC, 4, 0xff, 0xff, 0xff, 0xff};
>> +
>> + /* Error in command transfer? */
>> + if (req->status || req->length != req->actual ||
>> + req->actual < 6 || req->actual > MAX_COMMAND_SIZE) {
>> +
>> + /* Not all controllers allow a protocol stall after
>> + * receiving control-out data, but we'll try anyway. */
>> + fsg_set_halt(fsg, fsg->ep0);
>> + return; // Wait for reset
>> + }
>> +
>> + /* Is it the special reset command? */
>> + if (req->actual >= sizeof cbi_reset_cmnd &&
>> + memcmp(req->buf, cbi_reset_cmnd,
>> + sizeof cbi_reset_cmnd) == 0) {
>> +
>> + /* Raise an exception to stop the current operation
>> + * and reinitialize our state. */
>> + SDBG(fsg, "cbi reset request\n");
>> + raise_exception(fsg, STOR_STATE_RESET);
>> + return;
>> + }
>> +
>> + VSDBG(fsg, "CB[I] accept device-specific command\n");
>> + spin_lock(&fsg->lock);
>> +
>> + /* Save the command for later */
>> + if (fsg->cbbuf_cmnd_size)
>> + SWARN(fsg, "CB[I] overwriting previous command\n");
>> + fsg->cbbuf_cmnd_size = req->actual;
>> + memcpy(fsg->cbbuf_cmnd, req->buf, fsg->cbbuf_cmnd_size);
>> +
>> + wakeup_thread(fsg);
>> + spin_unlock(&fsg->lock);
>> +}
>> +
>> +#else
>> +static void received_cbi_adsc(struct fsg_dev *fsg, struct stor_buffhd *bh)
>> +{}
>> +#endif /* CONFIG_USB_FILE_STORAGE_TEST */
>> +
>> +
>> +static int class_setup_req(struct fsg_dev *fsg,
>> + const struct usb_ctrlrequest *ctrl)
>> +{
>> + struct usb_request *req = fsg->ep0req;
>> + int value = -EOPNOTSUPP;
>> + u16 w_index = le16_to_cpu(ctrl->wIndex);
>> + u16 w_value = le16_to_cpu(ctrl->wValue);
>> + u16 w_length = le16_to_cpu(ctrl->wLength);
>> +
>> + if (!fsg->config)
>> + return value;
>> +
>> + /* Handle Bulk-only class-specific requests */
>> + if (transport_is_bbb()) {
>> + switch (ctrl->bRequest) {
>> +
>> + case USB_BULK_RESET_REQUEST:
>> + if (ctrl->bRequestType != (USB_DIR_OUT |
>> + USB_TYPE_CLASS |
>> USB_RECIP_INTERFACE))
>> + break;
>> + if (w_index != 0 || w_value != 0) {
>> + value = -EDOM;
>> + break;
>> + }
>> +
>> + /* Raise an exception to stop the current operation
>> + * and reinitialize our state. */
>> + SDBG(fsg, "bulk reset request\n");
>> + raise_exception(fsg, STOR_STATE_RESET);
>> + value = DELAYED_STATUS;
>> + break;
>> +
>> + case USB_BULK_GET_MAX_LUN_REQUEST:
>> + if (ctrl->bRequestType != (USB_DIR_IN |
>> + USB_TYPE_CLASS |
>> USB_RECIP_INTERFACE))
>> + break;
>> + if (w_index != 0 || w_value != 0) {
>> + value = -EDOM;
>> + break;
>> + }
>> + VSDBG(fsg, "get max LUN\n");
>> + *(u8 *) req->buf = fsg->nluns - 1;
>> + value = 1;
>> + break;
>> + }
>> + }
>> +
>> + /* Handle CBI class-specific requests */
>> + else {
>> + switch (ctrl->bRequest) {
>> +
>> + case USB_CBI_ADSC_REQUEST:
>> + if (ctrl->bRequestType != (USB_DIR_OUT |
>> + USB_TYPE_CLASS |
>> USB_RECIP_INTERFACE))
>> + break;
>> + if (w_index != 0 || w_value != 0) {
>> + value = -EDOM;
>> + break;
>> + }
>> + if (w_length > MAX_COMMAND_SIZE) {
>> + value = -EOVERFLOW;
>> + break;
>> + }
>> + value = w_length;
>> + fsg->ep0req->context = received_cbi_adsc;
>> + break;
>> + }
>> + }
>> +
>> + if (value == -EOPNOTSUPP)
>> + VSDBG(fsg,
>> + "unknown class-specific control req "
>> + "%02x.%02x v%04x i%04x l%u\n",
>> + ctrl->bRequestType, ctrl->bRequest,
>> + le16_to_cpu(ctrl->wValue), w_index, w_length);
>> + return value;
>> +}
>> +
>> +
>> +/*-------------------------------------------------------------------------*/
>> +
>> +/* Ep0 standard request handlers. These always run in_irq. */
>> +
>> +static int standard_setup_req(struct fsg_dev *fsg,
>> + const struct usb_ctrlrequest *ctrl)
>> +{
>> + struct usb_request *req = fsg->ep0req;
>> + int value = -EOPNOTSUPP;
>> + u16 w_index = le16_to_cpu(ctrl->wIndex);
>> + u16 w_value = le16_to_cpu(ctrl->wValue);
>> +
>> + /* Usually this just stores reply data in the pre-allocated ep0
>> buffer,
>> + * but config change events will also reconfigure hardware. */
>> + switch (ctrl->bRequest) {
>> +
>> + case USB_REQ_GET_DESCRIPTOR:
>> + if (ctrl->bRequestType != (USB_DIR_IN | USB_TYPE_STANDARD |
>> + USB_RECIP_DEVICE))
>> + break;
>> + switch (w_value >> 8) {
>> +
>> + case USB_DT_DEVICE:
>> + VSDBG(fsg, "get device descriptor\n");
>> + value = sizeof device_desc;
>> + memcpy(req->buf, &device_desc, value);
>> + break;
>> + case USB_DT_DEVICE_QUALIFIER:
>> + VSDBG(fsg, "get device qualifier\n");
>> + if (!gadget_is_dualspeed(fsg->gadget))
>> + break;
>> + value = sizeof dev_qualifier;
>> + memcpy(req->buf, &dev_qualifier, value);
>> + break;
>> +
>> + case USB_DT_OTHER_SPEED_CONFIG:
>> + VSDBG(fsg, "get other-speed config descriptor\n");
>> + if (!gadget_is_dualspeed(fsg->gadget))
>> + break;
>> + goto get_config;
>> + case USB_DT_CONFIG:
>> + VSDBG(fsg, "get configuration descriptor\n");
>> +get_config:
>> + value = populate_config_buf(fsg->gadget,
>> + req->buf,
>> + w_value >> 8,
>> + w_value & 0xff);
>> + break;
>> +
>> + case USB_DT_STRING:
>> + VSDBG(fsg, "get string descriptor\n");
>> +
>> + /* wIndex == language code */
>> + value = usb_gadget_get_string(&stor_stringtab,
>> + w_value & 0xff, req->buf);
>> + break;
>> + }
>> + break;
>> +
>> + /* One config, two speeds */
>> + case USB_REQ_SET_CONFIGURATION:
>> + if (ctrl->bRequestType != (USB_DIR_OUT | USB_TYPE_STANDARD |
>> + USB_RECIP_DEVICE))
>> + break;
>> + VSDBG(fsg, "set configuration\n");
>> + if (w_value == CONFIG_VALUE || w_value == 0) {
>> + fsg->new_config = w_value;
>> +
>> + /* Raise an exception to wipe out previous
>> transaction
>> + * state (queued bufs, etc) and set the new config.
>> */
>> + raise_exception(fsg, STOR_STATE_CONFIG_CHANGE);
>> + value = DELAYED_STATUS;
>> + }
>> + break;
>> + case USB_REQ_GET_CONFIGURATION:
>> + if (ctrl->bRequestType != (USB_DIR_IN | USB_TYPE_STANDARD |
>> + USB_RECIP_DEVICE))
>> + break;
>> + VSDBG(fsg, "get configuration\n");
>> + *(u8 *) req->buf = fsg->config;
>> + value = 1;
>> + break;
>> +
>> + case USB_REQ_SET_INTERFACE:
>> + if (ctrl->bRequestType != (USB_DIR_OUT| USB_TYPE_STANDARD |
>> + USB_RECIP_INTERFACE))
>> + break;
>> + if (fsg->config && w_index == 0) {
>> +
>> + /* Raise an exception to wipe out previous
>> transaction
>> + * state (queued bufs, etc) and install the new
>> + * interface altsetting. */
>> + raise_exception(fsg, STOR_STATE_INTERFACE_CHANGE);
>> + value = DELAYED_STATUS;
>> + }
>> + break;
>> + case USB_REQ_GET_INTERFACE:
>> + if (ctrl->bRequestType != (USB_DIR_IN | USB_TYPE_STANDARD |
>> + USB_RECIP_INTERFACE))
>> + break;
>> + if (!fsg->config)
>> + break;
>> + if (w_index != 0) {
>> + value = -EDOM;
>> + break;
>> + }
>> + VSDBG(fsg, "get interface\n");
>> + *(u8 *) req->buf = 0;
>> + value = 1;
>> + break;
>> +
>> + default:
>> + VSDBG(fsg,
>> + "unknown control req %02x.%02x v%04x i%04x l%u\n",
>> + ctrl->bRequestType, ctrl->bRequest,
>> + w_value, w_index, le16_to_cpu(ctrl->wLength));
>> + }
>> +
>> + return value;
>> +}
>> +
>> +
>> +static int fsg_setup(struct usb_gadget *gadget,
>> + const struct usb_ctrlrequest *ctrl)
>> +{
>> + struct fsg_dev *fsg = get_gadget_data(gadget);
>> + int rc;
>> + int w_length = le16_to_cpu(ctrl->wLength);
>> +
>> + ++fsg->ep0_req_tag; // Record arrival of a new request
>> + fsg->ep0req->context = NULL;
>> + fsg->ep0req->length = 0;
>> + dump_msg(fsg, "ep0-setup", (u8 *) ctrl, sizeof(*ctrl));
>> +
>> + if ((ctrl->bRequestType & USB_TYPE_MASK) == USB_TYPE_CLASS)
>> + rc = class_setup_req(fsg, ctrl);
>> + else
>> + rc = standard_setup_req(fsg, ctrl);
>> +
>> + /* Respond with data/status or defer until later? */
>> + if (rc >= 0 && rc != DELAYED_STATUS) {
>> + rc = min(rc, w_length);
>> + fsg->ep0req->length = rc;
>> + fsg->ep0req->zero = rc < w_length;
>> + fsg->ep0req_name = (ctrl->bRequestType & USB_DIR_IN ?
>> + "ep0-in" : "ep0-out");
>> + rc = ep0_queue(fsg);
>> + }
>> +
>> + /* Device either stalls (rc < 0) or reports success */
>> + return rc;
>> +}
>> +
>> +
>> +/*-------------------------------------------------------------------------*/
>> +
>> +/* All the following routines run in process context */
>> +
>> +
>> +/* Use this for bulk or interrupt transfers, not ep0 */
>> +static void start_transfer(struct fsg_dev *fsg, struct usb_ep *ep,
>> + struct usb_request *req, int *pbusy,
>> + enum stor_buffer_state *state)
>> +{
>> + int rc;
>> +
>> + if (ep == fsg->bulk_in)
>> + dump_msg(fsg, "bulk-in", req->buf, req->length);
>> + else if (ep == fsg->intr_in)
>> + dump_msg(fsg, "intr-in", req->buf, req->length);
>> +
>> + spin_lock_irq(&fsg->lock);
>> + *pbusy = 1;
>> + *state = BUF_STATE_BUSY;
>> + spin_unlock_irq(&fsg->lock);
>> + rc = usb_ep_queue(ep, req, GFP_KERNEL);
>> + if (rc != 0) {
>> + *pbusy = 0;
>> + *state = BUF_STATE_EMPTY;
>> +
>> + /* We can't do much more than wait for a reset */
>> +
>> + /* Note: currently the net2280 driver fails zero-length
>> + * submissions if DMA is enabled. */
>> + if (rc != -ESHUTDOWN && !(rc == -EOPNOTSUPP &&
>> + req->length == 0))
>> + SWARN(fsg, "error in submission: %s --> %d\n",
>> + ep->name, rc);
>> + }
>> +}
>> +
>> +
>> +static int sleep_thread(struct fsg_dev *fsg)
>> +{
>> + int rc = 0;
>> +
>> + /* Wait until a signal arrives or we are woken up */
>> + for (;;) {
>> + try_to_freeze();
>> + set_current_state(TASK_INTERRUPTIBLE);
>> + if (signal_pending(current)) {
>> + rc = -EINTR;
>> + break;
>> + }
>> + if (fsg->thread_wakeup_needed)
>> + break;
>> + schedule();
>> + }
>> + __set_current_state(TASK_RUNNING);
>> + fsg->thread_wakeup_needed = 0;
>> + return rc;
>> +}
>> +
>> +
>> +/*-------------------------------------------------------------------------*/
>> +
>> +static int do_read(struct fsg_dev *fsg)
>> +{
>> + struct storage_lun *curlun = fsg->curlun;
>> + u32 lba;
>> + struct stor_buffhd *bh;
>> + int rc;
>> + u32 amount_left;
>> + loff_t file_offset, file_offset_tmp;
>> + unsigned int amount;
>> + unsigned int partial_page;
>> + ssize_t nread;
>> +
>> + /* Get the starting Logical Block Address and check that it's
>> + * not too big */
>> + if (fsg->cmnd[0] == SC_READ_6)
>> + lba = get_unaligned_be24(&fsg->cmnd[1]);
>> + else {
>> + lba = get_unaligned_be32(&fsg->cmnd[2]);
>> +
>> + /* We allow DPO (Disable Page Out = don't save data in the
>> + * cache) and FUA (Force Unit Access = don't read from the
>> + * cache), but we don't implement them. */
>> + if ((fsg->cmnd[1] & ~0x18) != 0) {
>> + curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
>> + return -EINVAL;
>> + }
>> + }
>> + if (lba >= curlun->num_sectors) {
>> + curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
>> + return -EINVAL;
>> + }
>> + file_offset = ((loff_t) lba) << 9;
>> +
>> + /* Carry out the file reads */
>> + amount_left = fsg->data_size_from_cmnd;
>> + if (unlikely(amount_left == 0))
>> + return -EIO; // No default reply
>> +
>> + for (;;) {
>> +
>> + /* Figure out how much we need to read:
>> + * Try to read the remaining amount.
>> + * But don't read more than the buffer size.
>> + * And don't try to read past the end of the file.
>> + * Finally, if we're not at a page boundary, don't read past
>> + * the next page.
>> + * If this means reading 0 then we were asked to read past
>> + * the end of file. */
>> + amount = min((unsigned int) amount_left, mod_data.buflen);
>> + amount = min((loff_t) amount,
>> + curlun->file_length - file_offset);
>> + partial_page = file_offset & (PAGE_CACHE_SIZE - 1);
>> + if (partial_page > 0)
>> + amount = min(amount, (unsigned int) PAGE_CACHE_SIZE
>> -
>> + partial_page);
>> +
>> + /* Wait for the next buffer to become available */
>> + bh = fsg->next_buffhd_to_fill;
>> + while (bh->state != BUF_STATE_EMPTY) {
>> + rc = sleep_thread(fsg);
>> + if (rc)
>> + return rc;
>> + }
>> +
>> + /* If we were asked to read past the end of file,
>> + * end with an empty buffer. */
>> + if (amount == 0) {
>> + curlun->sense_data =
>> +
>> SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
>> + curlun->sense_data_info = file_offset >> 9;
>> + curlun->info_valid = 1;
>> + bh->inreq->length = 0;
>> + bh->state = BUF_STATE_FULL;
>> + break;
>> + }
>> +
>> + /* Perform the read */
>> + file_offset_tmp = file_offset;
>> + nread = vfs_read(curlun->filp,
>> + (char __user *) bh->buf,
>> + amount, &file_offset_tmp);
>> + VLDBG(curlun, "file read %u @ %llu -> %d\n", amount,
>> + (unsigned long long) file_offset,
>> + (int) nread);
>> + if (signal_pending(current))
>> + return -EINTR;
>> +
>> + if (nread < 0) {
>> + LDBG(curlun, "error in file read: %d\n",
>> + (int) nread);
>> + nread = 0;
>> + } else if (nread < amount) {
>> + LDBG(curlun, "partial file read: %d/%u\n",
>> + (int) nread, amount);
>> + nread -= (nread & 511); // Round down to a block
>> + }
>> + file_offset += nread;
>> + amount_left -= nread;
>> + fsg->residue -= nread;
>> + bh->inreq->length = nread;
>> + bh->state = BUF_STATE_FULL;
>> +
>> + /* If an error occurred, report it and its position */
>> + if (nread < amount) {
>> + curlun->sense_data = SS_UNRECOVERED_READ_ERROR;
>> + curlun->sense_data_info = file_offset >> 9;
>> + curlun->info_valid = 1;
>> + break;
>> + }
>> +
>> + if (amount_left == 0)
>> + break; // No more left to read
>> +
>> + /* Send this buffer and go read some more */
>> + bh->inreq->zero = 0;
>> + start_transfer(fsg, fsg->bulk_in, bh->inreq,
>> + &bh->inreq_busy, &bh->state);
>> + fsg->next_buffhd_to_fill = bh->next;
>> + }
>> +
>> + return -EIO; // No default reply
>> +}
>> +
>> +
>> +/*-------------------------------------------------------------------------*/
>> +
>> +static int do_write(struct fsg_dev *fsg)
>> +{
>> + struct storage_lun *curlun = fsg->curlun;
>> + u32 lba;
>> + struct stor_buffhd *bh;
>> + int get_some_more;
>> + u32 amount_left_to_req, amount_left_to_write;
>> + loff_t usb_offset, file_offset, file_offset_tmp;
>> + unsigned int amount;
>> + unsigned int partial_page;
>> + ssize_t nwritten;
>> + int rc;
>> +
>> + if (curlun->ro) {
>> + curlun->sense_data = SS_WRITE_PROTECTED;
>> + return -EINVAL;
>> + }
>> + spin_lock(&curlun->filp->f_lock);
>> + curlun->filp->f_flags &= ~O_SYNC; // Default is not to wait
>> + spin_unlock(&curlun->filp->f_lock);
>> +
>> + /* Get the starting Logical Block Address and check that it's
>> + * not too big */
>> + if (fsg->cmnd[0] == SC_WRITE_6)
>> + lba = get_unaligned_be24(&fsg->cmnd[1]);
>> + else {
>> + lba = get_unaligned_be32(&fsg->cmnd[2]);
>> +
>> + /* We allow DPO (Disable Page Out = don't save data in the
>> + * cache) and FUA (Force Unit Access = write directly to the
>> + * medium). We don't implement DPO; we implement FUA by
>> + * performing synchronous output. */
>> + if ((fsg->cmnd[1] & ~0x18) != 0) {
>> + curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
>> + return -EINVAL;
>> + }
>> + if (fsg->cmnd[1] & 0x08) { // FUA
>> + spin_lock(&curlun->filp->f_lock);
>> + curlun->filp->f_flags |= O_SYNC;
>> + spin_unlock(&curlun->filp->f_lock);
>> + }
>> + }
>> + if (lba >= curlun->num_sectors) {
>> + curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
>> + return -EINVAL;
>> + }
>> +
>> + /* Carry out the file writes */
>> + get_some_more = 1;
>> + file_offset = usb_offset = ((loff_t) lba) << 9;
>> + amount_left_to_req = amount_left_to_write =
>> fsg->data_size_from_cmnd;
>> +
>> + while (amount_left_to_write > 0) {
>> +
>> + /* Queue a request for more data from the host */
>> + bh = fsg->next_buffhd_to_fill;
>> + if (bh->state == BUF_STATE_EMPTY && get_some_more) {
>> +
>> + /* Figure out how much we want to get:
>> + * Try to get the remaining amount.
>> + * But don't get more than the buffer size.
>> + * And don't try to go past the end of the file.
>> + * If we're not at a page boundary,
>> + * don't go past the next page.
>> + * If this means getting 0, then we were asked
>> + * to write past the end of file.
>> + * Finally, round down to a block boundary. */
>> + amount = min(amount_left_to_req, mod_data.buflen);
>> + amount = min((loff_t) amount, curlun->file_length -
>> + usb_offset);
>> + partial_page = usb_offset & (PAGE_CACHE_SIZE - 1);
>> + if (partial_page > 0)
>> + amount = min(amount,
>> + (unsigned int) PAGE_CACHE_SIZE - partial_page);
>> +
>> + if (amount == 0) {
>> + get_some_more = 0;
>> + curlun->sense_data =
>> +
>> SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
>> + curlun->sense_data_info = usb_offset >> 9;
>> + curlun->info_valid = 1;
>> + continue;
>> + }
>> + amount -= (amount & 511);
>> + if (amount == 0) {
>> +
>> + /* Why were we were asked to transfer a
>> + * partial block? */
>> + get_some_more = 0;
>> + continue;
>> + }
>> +
>> + /* Get the next buffer */
>> + usb_offset += amount;
>> + fsg->usb_amount_left -= amount;
>> + amount_left_to_req -= amount;
>> + if (amount_left_to_req == 0)
>> + get_some_more = 0;
>> +
>> + /* amount is always divisible by 512, hence by
>> + * the bulk-out maxpacket size */
>> + bh->outreq->length = bh->bulk_out_intended_length =
>> + amount;
>> + bh->outreq->short_not_ok = 1;
>> + start_transfer(fsg, fsg->bulk_out, bh->outreq,
>> + &bh->outreq_busy, &bh->state);
>> + fsg->next_buffhd_to_fill = bh->next;
>> + continue;
>> + }
>> +
>> + /* Write the received data to the backing file */
>> + bh = fsg->next_buffhd_to_drain;
>> + if (bh->state == BUF_STATE_EMPTY && !get_some_more)
>> + break; // We stopped early
>> + if (bh->state == BUF_STATE_FULL) {
>> + smp_rmb();
>> + fsg->next_buffhd_to_drain = bh->next;
>> + bh->state = BUF_STATE_EMPTY;
>> +
>> + /* Did something go wrong with the transfer? */
>> + if (bh->outreq->status != 0) {
>> + curlun->sense_data =
>> SS_COMMUNICATION_FAILURE;
>> + curlun->sense_data_info = file_offset >> 9;
>> + curlun->info_valid = 1;
>> + break;
>> + }
>> +
>> + amount = bh->outreq->actual;
>> + if (curlun->file_length - file_offset < amount) {
>> + LERROR(curlun,
>> + "write %u @ %llu beyond end %llu\n",
>> + amount, (unsigned long long) file_offset,
>> + (unsigned long long) curlun->file_length);
>> + amount = curlun->file_length - file_offset;
>> + }
>> +
>> + /* Perform the write */
>> + file_offset_tmp = file_offset;
>> + nwritten = vfs_write(curlun->filp,
>> + (char __user *) bh->buf,
>> + amount, &file_offset_tmp);
>> + VLDBG(curlun, "file write %u @ %llu -> %d\n",
>> amount,
>> + (unsigned long long) file_offset,
>> + (int) nwritten);
>> + if (signal_pending(current))
>> + return -EINTR; // Interrupted!
>> +
>> + if (nwritten < 0) {
>> + LDBG(curlun, "error in file write: %d\n",
>> + (int) nwritten);
>> + nwritten = 0;
>> + } else if (nwritten < amount) {
>> + LDBG(curlun, "partial file write: %d/%u\n",
>> + (int) nwritten, amount);
>> + nwritten -= (nwritten & 511);
>> + // Round down to a block
>> + ...
sorry for picking this old after reading this patch, I have some questions:
1. when below will be executed?( I temporarily remove that and
program runs well.)
if (req->status == 0 && req->context)
((fsg_routine_t) (req->context))(fsg);
2. in following source code, it is possible process will fall in ****>
loop if the state in start_transfer be EMPTY, when queue failed,
right?
if that really happen, who or when the process will leave ***>?
start_transfer(fsg, fsg->bulk_out, bh->outreq,
&bh->outreq_busy, &bh->state);
/* We will drain the buffer in software, which means we
* can reuse it for the next filling. No need to advance
* next_buffhd_to_fill. */
/* Wait for the CBW to arrive */
********> while (bh->state != BUF_STATE_FULL) {
rc = sleep_thread(fsg);
if (rc)
return rc;
3. in http://www.mail-archive.com/linux-usb-devel@xxxxxxxxxxxxxxxxxxxxx/msg15529.html
, it mentioned about Scsi-backed Storage Gadget, is that
finally realized?
File_backend storage file is quite standard user defined behavior and
it should work on all udc, right?
-
Regards,
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