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linux/drivers/usb/gadget/f_mass_storage.c
Roger Quadros 3c624d4962 usb: gadget: f_mass_storage: If 'ro'/'cdrom' specified, open file as read-only 
If we don't need Write access then attempt to open backing file in Read Only
mode instead of bailing out too soon.

Signed-off-by: Roger Quadros <roger.quadros@nokia.com>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-13 16:40:59 -07:00

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/*
* f_mass_storage.c -- Mass Storage USB Composite Function
*
* Copyright (C) 2003-2008 Alan Stern
* Copyright (C) 2009 Samsung Electronics
* Author: Michal Nazarewicz <m.nazarewicz@samsung.com>
* 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 Mass Storage Function 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 composite
* function for a USB device, it also illustrates a technique of
* double-buffering for increased throughput.
*
* Function supports multiple logical units (LUNs). Backing storage
* for each LUN is provided by a regular file or a block device.
* Access for each LUN can be limited to read-only. Moreover, the
* function can indicate that LUN is removable and/or CD-ROM. (The
* later implies read-only access.)
*
* MSF is configured by specifying a fsg_config structure. It has the
* following fields:
*
* nluns Number of LUNs function have (anywhere from 1
* to FSG_MAX_LUNS which is 8).
* luns An array of LUN configuration values. This
* should be filled for each LUN that
* function will include (ie. for "nluns"
* LUNs). Each element of the array has
* the following fields:
* ->filename The path to the backing file for the LUN.
* Required if LUN is not marked as
* removable.
* ->ro Flag specifying access to the LUN shall be
* read-only. This is implied if CD-ROM
* emulation is enabled as well as when
* it was impossible to open "filename"
* in R/W mode.
* ->removable Flag specifying that LUN shall be indicated as
* being removable.
* ->cdrom Flag specifying that LUN shall be reported as
* being a CD-ROM.
* ->nofua Flag specifying that FUA flag in SCSI WRITE(10,12)
* commands for this LUN shall be ignored.
*
* lun_name_format A printf-like format for names of the LUN
* devices. This determines how the
* directory in sysfs will be named.
* Unless you are using several MSFs in
* a single gadget (as opposed to single
* MSF in many configurations) you may
* leave it as NULL (in which case
* "lun%d" will be used). In the format
* you can use "%d" to index LUNs for
* MSF's with more than one LUN. (Beware
* that there is only one integer given
* as an argument for the format and
* specifying invalid format may cause
* unspecified behaviour.)
* thread_name Name of the kernel thread process used by the
* MSF. You can safely set it to NULL
* (in which case default "file-storage"
* will be used).
*
* vendor_name
* product_name
* release Information used as a reply to INQUIRY
* request. To use default set to NULL,
* NULL, 0xffff respectively. The first
* field should be 8 and the second 16
* characters or less.
*
* can_stall Set to permit function to halt bulk endpoints.
* Disabled on some USB devices known not
* to work correctly. You should set it
* to true.
*
* If "removable" is not set for a LUN then a backing file must be
* specified. If it is set, then NULL filename means the LUN's medium
* is not loaded (an empty string as "filename" in the fsg_config
* structure causes error). 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.
*
*
* MSF includes support for module parameters. If gadget using it
* decides to use it, the following module parameters will be
* available:
*
* file=filename[,filename...]
* Names of the files or block devices used for
* backing storage.
* ro=b[,b...] Default false, boolean for read-only access.
* removable=b[,b...]
* Default true, boolean for removable media.
* cdrom=b[,b...] Default false, boolean for whether to emulate
* a CD-ROM drive.
* nofua=b[,b...] Default false, booleans for ignore FUA flag
* in SCSI WRITE(10,12) commands
* 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.
*
* The module parameters may be prefixed with some string. You need
* to consult gadget's documentation or source to verify whether it is
* using those module parameters and if it does what are the prefixes
* (look for FSG_MODULE_PARAMETERS() macro usage, what's inside it is
* the prefix).
*
*
* Requirements are modest; only a bulk-in and a bulk-out endpoint are
* needed. 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.
*
*
* The pathnames of the backing files and the ro settings are
* available in the attribute files "file" and "ro" in the lun<n> (or
* to be more precise in a directory which name comes from
* "lun_name_format" option!) 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.
*
* When a LUN receive an "eject" SCSI request (Start/Stop Unit),
* if the LUN is removable, the backing file is released to simulate
* ejection.
*
*
* This function is heavily based on "File-backed Storage Gadget" by
* Alan Stern which in turn 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 MSF 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. At of this moment, MSF
* provides no way to deregister the gadget when thread dies -- maybe
* a callback functions is needed.
*
* To provide maximum throughput, the driver uses a circular pipeline of
* buffer heads (struct fsg_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 <linux/usb/composite.h>
#include "gadget_chips.h"
/*------------------------------------------------------------------------*/
#define FSG_DRIVER_DESC "Mass Storage Function"
#define FSG_DRIVER_VERSION "2009/09/11"
static const char fsg_string_interface[] = "Mass Storage";
#define FSG_NO_INTR_EP 1
#define FSG_NO_DEVICE_STRINGS 1
#define FSG_NO_OTG 1
#define FSG_NO_INTR_EP 1
#include "storage_common.c"
/*-------------------------------------------------------------------------*/
struct fsg_dev;
struct fsg_common;
/* FSF callback functions */
struct fsg_operations {
/*
* Callback function to call when thread exits. If no
* callback is set or it returns value lower then zero MSF
* will force eject all LUNs it operates on (including those
* marked as non-removable or with prevent_medium_removal flag
* set).
*/
int (*thread_exits)(struct fsg_common *common);
/*
* Called prior to ejection. Negative return means error,
* zero means to continue with ejection, positive means not to
* eject.
*/
int (*pre_eject)(struct fsg_common *common,
struct fsg_lun *lun, int num);
/*
* Called after ejection. Negative return means error, zero
* or positive is just a success.
*/
int (*post_eject)(struct fsg_common *common,
struct fsg_lun *lun, int num);
};
/* Data shared by all the FSG instances. */
struct fsg_common {
struct usb_gadget *gadget;
struct fsg_dev *fsg, *new_fsg;
wait_queue_head_t fsg_wait;
/* filesem protects: backing files in use */
struct rw_semaphore filesem;
/* lock protects: state, all the req_busy's */
spinlock_t lock;
struct usb_ep *ep0; /* Copy of gadget->ep0 */
struct usb_request *ep0req; /* Copy of cdev->req */
unsigned int ep0_req_tag;
struct fsg_buffhd *next_buffhd_to_fill;
struct fsg_buffhd *next_buffhd_to_drain;
struct fsg_buffhd buffhds[FSG_NUM_BUFFERS];
int cmnd_size;
u8 cmnd[MAX_COMMAND_SIZE];
unsigned int nluns;
unsigned int lun;
struct fsg_lun *luns;
struct fsg_lun *curlun;
unsigned int bulk_out_maxpacket;
enum fsg_state state; /* For exception handling */
unsigned int exception_req_tag;
enum data_direction data_dir;
u32 data_size;
u32 data_size_from_cmnd;
u32 tag;
u32 residue;
u32 usb_amount_left;
unsigned int can_stall:1;
unsigned int free_storage_on_release:1;
unsigned int phase_error:1;
unsigned int short_packet_received:1;
unsigned int bad_lun_okay:1;
unsigned int running:1;
int thread_wakeup_needed;
struct completion thread_notifier;
struct task_struct *thread_task;
/* Callback functions. */
const struct fsg_operations *ops;
/* Gadget's private data. */
void *private_data;
/*
* Vendor (8 chars), product (16 chars), release (4
* hexadecimal digits) and NUL byte
*/
char inquiry_string[8 + 16 + 4 + 1];
struct kref ref;
};
struct fsg_config {
unsigned nluns;
struct fsg_lun_config {
const char *filename;
char ro;
char removable;
char cdrom;
char nofua;
} luns[FSG_MAX_LUNS];
const char *lun_name_format;
const char *thread_name;
/* Callback functions. */
const struct fsg_operations *ops;
/* Gadget's private data. */
void *private_data;
const char *vendor_name; /* 8 characters or less */
const char *product_name; /* 16 characters or less */
u16 release;
char can_stall;
};
struct fsg_dev {
struct usb_function function;
struct usb_gadget *gadget; /* Copy of cdev->gadget */
struct fsg_common *common;
u16 interface_number;
unsigned int bulk_in_enabled:1;
unsigned int bulk_out_enabled:1;
unsigned long atomic_bitflags;
#define IGNORE_BULK_OUT 0
struct usb_ep *bulk_in;
struct usb_ep *bulk_out;
};
static inline int __fsg_is_set(struct fsg_common *common,
const char *func, unsigned line)
{
if (common->fsg)
return 1;
ERROR(common, "common->fsg is NULL in %s at %u\n", func, line);
WARN_ON(1);
return 0;
}
#define fsg_is_set(common) likely(__fsg_is_set(common, __func__, __LINE__))
static inline struct fsg_dev *fsg_from_func(struct usb_function *f)
{
return container_of(f, struct fsg_dev, function);
}
typedef void (*fsg_routine_t)(struct fsg_dev *);
static int exception_in_progress(struct fsg_common *common)
{
return common->state > FSG_STATE_IDLE;
}
/*-------------------------------------------------------------------------*/
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;
DBG(fsg, "%s set halt\n", name);
return usb_ep_set_halt(ep);
}
/*-------------------------------------------------------------------------*/
/* These routines may be called in process context or in_irq */
/* Caller must hold fsg->lock */
static void wakeup_thread(struct fsg_common *common)
{
/* Tell the main thread that something has happened */
common->thread_wakeup_needed = 1;
if (common->thread_task)
wake_up_process(common->thread_task);
}
static void raise_exception(struct fsg_common *common, enum fsg_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(&common->lock, flags);
if (common->state <= new_state) {
common->exception_req_tag = common->ep0_req_tag;
common->state = new_state;
if (common->thread_task)
send_sig_info(SIGUSR1, SEND_SIG_FORCED,
common->thread_task);
}
spin_unlock_irqrestore(&common->lock, flags);
}
/*-------------------------------------------------------------------------*/
static int ep0_queue(struct fsg_common *common)
{
int rc;
rc = usb_ep_queue(common->ep0, common->ep0req, GFP_ATOMIC);
common->ep0->driver_data = common;
if (rc != 0 && rc != -ESHUTDOWN) {
/* We can't do much more than wait for a reset */
WARNING(common, "error in submission: %s --> %d\n",
common->ep0->name, rc);
}
return rc;
}
/*-------------------------------------------------------------------------*/
/* Completion handlers. These always run in_irq. */
static void bulk_in_complete(struct usb_ep *ep, struct usb_request *req)
{
struct fsg_common *common = ep->driver_data;
struct fsg_buffhd *bh = req->context;
if (req->status || req->actual != req->length)
DBG(common, "%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(&common->lock);
bh->inreq_busy = 0;
bh->state = BUF_STATE_EMPTY;
wakeup_thread(common);
spin_unlock(&common->lock);
}
static void bulk_out_complete(struct usb_ep *ep, struct usb_request *req)
{
struct fsg_common *common = ep->driver_data;
struct fsg_buffhd *bh = req->context;
dump_msg(common, "bulk-out", req->buf, req->actual);
if (req->status || req->actual != req->length)
DBG(common, "%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(&common->lock);
bh->outreq_busy = 0;
bh->state = BUF_STATE_FULL;
wakeup_thread(common);
spin_unlock(&common->lock);
}
static int fsg_setup(struct usb_function *f,
const struct usb_ctrlrequest *ctrl)
{
struct fsg_dev *fsg = fsg_from_func(f);
struct usb_request *req = fsg->common->ep0req;
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_is_set(fsg->common))
return -EOPNOTSUPP;
++fsg->common->ep0_req_tag; /* Record arrival of a new request */
req->context = NULL;
req->length = 0;
dump_msg(fsg, "ep0-setup", (u8 *) ctrl, sizeof(*ctrl));
switch (ctrl->bRequest) {
case USB_BULK_RESET_REQUEST:
if (ctrl->bRequestType !=
(USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE))
break;
if (w_index != fsg->interface_number || w_value != 0)
return -EDOM;
/*
* Raise an exception to stop the current operation
* and reinitialize our state.
*/
DBG(fsg, "bulk reset request\n");
raise_exception(fsg->common, FSG_STATE_RESET);
return DELAYED_STATUS;
case USB_BULK_GET_MAX_LUN_REQUEST:
if (ctrl->bRequestType !=
(USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE))
break;
if (w_index != fsg->interface_number || w_value != 0)
return -EDOM;
VDBG(fsg, "get max LUN\n");
*(u8 *)req->buf = fsg->common->nluns - 1;
/* Respond with data/status */
req->length = min((u16)1, w_length);
return ep0_queue(fsg->common);
}
VDBG(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 -EOPNOTSUPP;
}
/*-------------------------------------------------------------------------*/
/* 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 fsg_buffer_state *state)
{
int rc;
if (ep == fsg->bulk_in)
dump_msg(fsg, "bulk-in", req->buf, req->length);
spin_lock_irq(&fsg->common->lock);
*pbusy = 1;
*state = BUF_STATE_BUSY;
spin_unlock_irq(&fsg->common->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))
WARNING(fsg, "error in submission: %s --> %d\n",
ep->name, rc);
}
}
static bool start_in_transfer(struct fsg_common *common, struct fsg_buffhd *bh)
{
if (!fsg_is_set(common))
return false;
start_transfer(common->fsg, common->fsg->bulk_in,
bh->inreq, &bh->inreq_busy, &bh->state);
return true;
}
static bool start_out_transfer(struct fsg_common *common, struct fsg_buffhd *bh)
{
if (!fsg_is_set(common))
return false;
start_transfer(common->fsg, common->fsg->bulk_out,
bh->outreq, &bh->outreq_busy, &bh->state);
return true;
}
static int sleep_thread(struct fsg_common *common)
{
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 (common->thread_wakeup_needed)
break;
schedule();
}
__set_current_state(TASK_RUNNING);
common->thread_wakeup_needed = 0;
return rc;
}
/*-------------------------------------------------------------------------*/
static int do_read(struct fsg_common *common)
{
struct fsg_lun *curlun = common->curlun;
u32 lba;
struct fsg_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 (common->cmnd[0] == READ_6)
lba = get_unaligned_be24(&common->cmnd[1]);
else {
lba = get_unaligned_be32(&common->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 ((common->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 = common->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(amount_left, FSG_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 = common->next_buffhd_to_fill;
while (bh->state != BUF_STATE_EMPTY) {
rc = sleep_thread(common);
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;
common->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;
if (!start_in_transfer(common, bh))
/* Don't know what to do if common->fsg is NULL */
return -EIO;
common->next_buffhd_to_fill = bh->next;
}
return -EIO; /* No default reply */
}
/*-------------------------------------------------------------------------*/
static int do_write(struct fsg_common *common)
{
struct fsg_lun *curlun = common->curlun;
u32 lba;
struct fsg_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 (common->cmnd[0] == WRITE_6)
lba = get_unaligned_be24(&common->cmnd[1]);
else {
lba = get_unaligned_be32(&common->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 (common->cmnd[1] & ~0x18) {
curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
return -EINVAL;
}
if (!curlun->nofua && (common->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 = common->data_size_from_cmnd;
amount_left_to_write = common->data_size_from_cmnd;
while (amount_left_to_write > 0) {
/* Queue a request for more data from the host */
bh = common->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, FSG_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;
common->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 = amount;
bh->outreq->short_not_ok = 1;
if (!start_out_transfer(common, bh))
/* Dunno what to do if common->fsg is NULL */
return -EIO;
common->next_buffhd_to_fill = bh->next;
continue;
}
/* Write the received data to the backing file */
bh = common->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();
common->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 */
}
file_offset += nwritten;
amount_left_to_write -= nwritten;
common->residue -= nwritten;
/* If an error occurred, report it and its position */
if (nwritten < amount) {
curlun->sense_data = SS_WRITE_ERROR;
curlun->sense_data_info = file_offset >> 9;
curlun->info_valid = 1;
break;
}
/* Did the host decide to stop early? */
if (bh->outreq->actual != bh->outreq->length) {
common->short_packet_received = 1;
break;
}
continue;
}
/* Wait for something to happen */
rc = sleep_thread(common);
if (rc)
return rc;
}
return -EIO; /* No default reply */
}
/*-------------------------------------------------------------------------*/
static int do_synchronize_cache(struct fsg_common *common)
{
struct fsg_lun *curlun = common->curlun;
int rc;
/* We ignore the requested LBA and write out all file's
* dirty data buffers. */
rc = fsg_lun_fsync_sub(curlun);
if (rc)
curlun->sense_data = SS_WRITE_ERROR;
return 0;
}
/*-------------------------------------------------------------------------*/
static void invalidate_sub(struct fsg_lun *curlun)
{
struct file *filp = curlun->filp;
struct inode *inode = filp->f_path.dentry->d_inode;
unsigned long rc;
rc = invalidate_mapping_pages(inode->i_mapping, 0, -1);
VLDBG(curlun, "invalidate_mapping_pages -> %ld\n", rc);
}
static int do_verify(struct fsg_common *common)
{
struct fsg_lun *curlun = common->curlun;
u32 lba;
u32 verification_length;
struct fsg_buffhd *bh = common->next_buffhd_to_fill;
loff_t file_offset, file_offset_tmp;
u32 amount_left;
unsigned int amount;
ssize_t nread;
/*
* Get the starting Logical Block Address and check that it's
* not too big.
*/
lba = get_unaligned_be32(&common->cmnd[2]);
if (lba >= curlun->num_sectors) {
curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
return -EINVAL;
}
/*
* We allow DPO (Disable Page Out = don't save data in the
* cache) but we don't implement it.
*/
if (common->cmnd[1] & ~0x10) {
curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
return -EINVAL;
}
verification_length = get_unaligned_be16(&common->cmnd[7]);
if (unlikely(verification_length == 0))
return -EIO; /* No default reply */
/* Prepare to carry out the file verify */
amount_left = verification_length << 9;
file_offset = ((loff_t) lba) << 9;
/* Write out all the dirty buffers before invalidating them */
fsg_lun_fsync_sub(curlun);
if (signal_pending(current))
return -EINTR;
invalidate_sub(curlun);
if (signal_pending(current))
return -EINTR;
/* Just try to read the requested blocks */
while (amount_left > 0) {
/*
* Figure out how much we need to read:
* Try to read the remaining amount, but not more than
* the buffer size.
* And don't try to read past the end of the file.
* If this means reading 0 then we were asked to read
* past the end of file.
*/
amount = min(amount_left, FSG_BUFLEN);
amount = min((loff_t)amount,
curlun->file_length - file_offset);
if (amount == 0) {
curlun->sense_data =
SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
curlun->sense_data_info = file_offset >> 9;
curlun->info_valid = 1;
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 verify: %d\n", (int)nread);
nread = 0;
} else if (nread < amount) {
LDBG(curlun, "partial file verify: %d/%u\n",
(int)nread, amount);
nread -= nread & 511; /* Round down to a sector */
}
if (nread == 0) {
curlun->sense_data = SS_UNRECOVERED_READ_ERROR;
curlun->sense_data_info = file_offset >> 9;
curlun->info_valid = 1;
break;
}
file_offset += nread;
amount_left -= nread;
}
return 0;
}
/*-------------------------------------------------------------------------*/
static int do_inquiry(struct fsg_common *common, struct fsg_buffhd *bh)
{
struct fsg_lun *curlun = common->curlun;
u8 *buf = (u8 *) bh->buf;
if (!curlun) { /* Unsupported LUNs are okay */
common->bad_lun_okay = 1;
memset(buf, 0, 36);
buf[0] = 0x7f; /* Unsupported, no device-type */
buf[4] = 31; /* Additional length */
return 36;
}
buf[0] = curlun->cdrom ? TYPE_ROM : TYPE_DISK;
buf[1] = curlun->removable ? 0x80 : 0;
buf[2] = 2; /* ANSI SCSI level 2 */
buf[3] = 2; /* SCSI-2 INQUIRY data format */
buf[4] = 31; /* Additional length */
buf[5] = 0; /* No special options */
buf[6] = 0;
buf[7] = 0;
memcpy(buf + 8, common->inquiry_string, sizeof common->inquiry_string);
return 36;
}
static int do_request_sense(struct fsg_common *common, struct fsg_buffhd *bh)
{
struct fsg_lun *curlun = common->curlun;
u8 *buf = (u8 *) bh->buf;
u32 sd, sdinfo;
int valid;
/*
* From the SCSI-2 spec., section 7.9 (Unit attention condition):
*
* If a REQUEST SENSE command is received from an initiator
* with a pending unit attention condition (before the target
* generates the contingent allegiance condition), then the
* target shall either:
* a) report any pending sense data and preserve the unit
* attention condition on the logical unit, or,
* b) report the unit attention condition, may discard any
* pending sense data, and clear the unit attention
* condition on the logical unit for that initiator.
*
* FSG normally uses option a); enable this code to use option b).
*/
#if 0
if (curlun && curlun->unit_attention_data != SS_NO_SENSE) {
curlun->sense_data = curlun->unit_attention_data;
curlun->unit_attention_data = SS_NO_SENSE;
}
#endif
if (!curlun) { /* Unsupported LUNs are okay */
common->bad_lun_okay = 1;
sd = SS_LOGICAL_UNIT_NOT_SUPPORTED;
sdinfo = 0;
valid = 0;
} else {
sd = curlun->sense_data;
sdinfo = curlun->sense_data_info;
valid = curlun->info_valid << 7;
curlun->sense_data = SS_NO_SENSE;
curlun->sense_data_info = 0;
curlun->info_valid = 0;
}
memset(buf, 0, 18);
buf[0] = valid | 0x70; /* Valid, current error */
buf[2] = SK(sd);
put_unaligned_be32(sdinfo, &buf[3]); /* Sense information */
buf[7] = 18 - 8; /* Additional sense length */
buf[12] = ASC(sd);
buf[13] = ASCQ(sd);
return 18;
}
static int do_read_capacity(struct fsg_common *common, struct fsg_buffhd *bh)
{
struct fsg_lun *curlun = common->curlun;
u32 lba = get_unaligned_be32(&common->cmnd[2]);
int pmi = common->cmnd[8];
u8 *buf = (u8 *)bh->buf;
/* Check the PMI and LBA fields */
if (pmi > 1 || (pmi == 0 && lba != 0)) {
curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
return -EINVAL;
}
put_unaligned_be32(curlun->num_sectors - 1, &buf[0]);
/* Max logical block */
put_unaligned_be32(512, &buf[4]); /* Block length */
return 8;
}
static int do_read_header(struct fsg_common *common, struct fsg_buffhd *bh)
{
struct fsg_lun *curlun = common->curlun;
int msf = common->cmnd[1] & 0x02;
u32 lba = get_unaligned_be32(&common->cmnd[2]);
u8 *buf = (u8 *)bh->buf;
if (common->cmnd[1] & ~0x02) { /* Mask away MSF */
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;
}
memset(buf, 0, 8);
buf[0] = 0x01; /* 2048 bytes of user data, rest is EC */
store_cdrom_address(&buf[4], msf, lba);
return 8;
}
static int do_read_toc(struct fsg_common *common, struct fsg_buffhd *bh)
{
struct fsg_lun *curlun = common->curlun;
int msf = common->cmnd[1] & 0x02;
int start_track = common->cmnd[6];
u8 *buf = (u8 *)bh->buf;
if ((common->cmnd[1] & ~0x02) != 0 || /* Mask away MSF */
start_track > 1) {
curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
return -EINVAL;
}
memset(buf, 0, 20);
buf[1] = (20-2); /* TOC data length */
buf[2] = 1; /* First track number */
buf[3] = 1; /* Last track number */
buf[5] = 0x16; /* Data track, copying allowed */
buf[6] = 0x01; /* Only track is number 1 */
store_cdrom_address(&buf[8], msf, 0);
buf[13] = 0x16; /* Lead-out track is data */
buf[14] = 0xAA; /* Lead-out track number */
store_cdrom_address(&buf[16], msf, curlun->num_sectors);
return 20;
}
static int do_mode_sense(struct fsg_common *common, struct fsg_buffhd *bh)
{
struct fsg_lun *curlun = common->curlun;
int mscmnd = common->cmnd[0];
u8 *buf = (u8 *) bh->buf;
u8 *buf0 = buf;
int pc, page_code;
int changeable_values, all_pages;
int valid_page = 0;
int len, limit;
if ((common->cmnd[1] & ~0x08) != 0) { /* Mask away DBD */
curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
return -EINVAL;
}
pc = common->cmnd[2] >> 6;
page_code = common->cmnd[2] & 0x3f;
if (pc == 3) {
curlun->sense_data = SS_SAVING_PARAMETERS_NOT_SUPPORTED;
return -EINVAL;
}
changeable_values = (pc == 1);
all_pages = (page_code == 0x3f);
/*
* Write the mode parameter header. Fixed values are: default
* medium type, no cache control (DPOFUA), and no block descriptors.
* The only variable value is the WriteProtect bit. We will fill in
* the mode data length later.
*/
memset(buf, 0, 8);
if (mscmnd == MODE_SENSE) {
buf[2] = (curlun->ro ? 0x80 : 0x00); /* WP, DPOFUA */
buf += 4;
limit = 255;
} else { /* MODE_SENSE_10 */
buf[3] = (curlun->ro ? 0x80 : 0x00); /* WP, DPOFUA */
buf += 8;
limit = 65535; /* Should really be FSG_BUFLEN */
}
/* No block descriptors */
/*
* The mode pages, in numerical order. The only page we support
* is the Caching page.
*/
if (page_code == 0x08 || all_pages) {
valid_page = 1;
buf[0] = 0x08; /* Page code */
buf[1] = 10; /* Page length */
memset(buf+2, 0, 10); /* None of the fields are changeable */
if (!changeable_values) {
buf[2] = 0x04; /* Write cache enable, */
/* Read cache not disabled */
/* No cache retention priorities */
put_unaligned_be16(0xffff, &buf[4]);
/* Don't disable prefetch */
/* Minimum prefetch = 0 */
put_unaligned_be16(0xffff, &buf[8]);
/* Maximum prefetch */
put_unaligned_be16(0xffff, &buf[10]);
/* Maximum prefetch ceiling */
}
buf += 12;
}
/*
* Check that a valid page was requested and the mode data length
* isn't too long.
*/
len = buf - buf0;
if (!valid_page || len > limit) {
curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
return -EINVAL;
}
/* Store the mode data length */
if (mscmnd == MODE_SENSE)
buf0[0] = len - 1;
else
put_unaligned_be16(len - 2, buf0);
return len;
}
static int do_start_stop(struct fsg_common *common)
{
struct fsg_lun *curlun = common->curlun;
int loej, start;
if (!curlun) {
return -EINVAL;
} else if (!curlun->removable) {
curlun->sense_data = SS_INVALID_COMMAND;
return -EINVAL;
} else if ((common->cmnd[1] & ~0x01) != 0 || /* Mask away Immed */
(common->cmnd[4] & ~0x03) != 0) { /* Mask LoEj, Start */
curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
return -EINVAL;
}
loej = common->cmnd[4] & 0x02;
start = common->cmnd[4] & 0x01;
/*
* Our emulation doesn't support mounting; the medium is
* available for use as soon as it is loaded.
*/
if (start) {
if (!fsg_lun_is_open(curlun)) {
curlun->sense_data = SS_MEDIUM_NOT_PRESENT;
return -EINVAL;
}
return 0;
}
/* Are we allowed to unload the media? */
if (curlun->prevent_medium_removal) {
LDBG(curlun, "unload attempt prevented\n");
curlun->sense_data = SS_MEDIUM_REMOVAL_PREVENTED;
return -EINVAL;
}
if (!loej)
return 0;
/* Simulate an unload/eject */
if (common->ops && common->ops->pre_eject) {
int r = common->ops->pre_eject(common, curlun,
curlun - common->luns);
if (unlikely(r < 0))
return r;
else if (r)
return 0;
}
up_read(&common->filesem);
down_write(&common->filesem);
fsg_lun_close(curlun);
up_write(&common->filesem);
down_read(&common->filesem);
return common->ops && common->ops->post_eject
? min(0, common->ops->post_eject(common, curlun,
curlun - common->luns))
: 0;
}
static int do_prevent_allow(struct fsg_common *common)
{
struct fsg_lun *curlun = common->curlun;
int prevent;
if (!common->curlun) {
return -EINVAL;
} else if (!common->curlun->removable) {
common->curlun->sense_data = SS_INVALID_COMMAND;
return -EINVAL;
}
prevent = common->cmnd[4] & 0x01;
if ((common->cmnd[4] & ~0x01) != 0) { /* Mask away Prevent */
curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
return -EINVAL;
}
if (curlun->prevent_medium_removal && !prevent)
fsg_lun_fsync_sub(curlun);
curlun->prevent_medium_removal = prevent;
return 0;
}
static int do_read_format_capacities(struct fsg_common *common,
struct fsg_buffhd *bh)
{
struct fsg_lun *curlun = common->curlun;
u8 *buf = (u8 *) bh->buf;
buf[0] = buf[1] = buf[2] = 0;
buf[3] = 8; /* Only the Current/Maximum Capacity Descriptor */
buf += 4;
put_unaligned_be32(curlun->num_sectors, &buf[0]);
/* Number of blocks */
put_unaligned_be32(512, &buf[4]); /* Block length */
buf[4] = 0x02; /* Current capacity */
return 12;
}
static int do_mode_select(struct fsg_common *common, struct fsg_buffhd *bh)
{
struct fsg_lun *curlun = common->curlun;
/* We don't support MODE SELECT */
if (curlun)
curlun->sense_data = SS_INVALID_COMMAND;
return -EINVAL;
}
/*-------------------------------------------------------------------------*/
static int halt_bulk_in_endpoint(struct fsg_dev *fsg)
{
int rc;
rc = fsg_set_halt(fsg, fsg->bulk_in);
if (rc == -EAGAIN)
VDBG(fsg, "delayed bulk-in endpoint halt\n");
while (rc != 0) {
if (rc != -EAGAIN) {
WARNING(fsg, "usb_ep_set_halt -> %d\n", rc);
rc = 0;
break;
}
/* Wait for a short time and then try again */
if (msleep_interruptible(100) != 0)
return -EINTR;
rc = usb_ep_set_halt(fsg->bulk_in);
}
return rc;
}
static int wedge_bulk_in_endpoint(struct fsg_dev *fsg)
{
int rc;
DBG(fsg, "bulk-in set wedge\n");
rc = usb_ep_set_wedge(fsg->bulk_in);
if (rc == -EAGAIN)
VDBG(fsg, "delayed bulk-in endpoint wedge\n");
while (rc != 0) {
if (rc != -EAGAIN) {
WARNING(fsg, "usb_ep_set_wedge -> %d\n", rc);
rc = 0;
break;
}
/* Wait for a short time and then try again */
if (msleep_interruptible(100) != 0)
return -EINTR;
rc = usb_ep_set_wedge(fsg->bulk_in);
}
return rc;
}
static int throw_away_data(struct fsg_common *common)
{
struct fsg_buffhd *bh;
u32 amount;
int rc;
for (bh = common->next_buffhd_to_drain;
bh->state != BUF_STATE_EMPTY || common->usb_amount_left > 0;
bh = common->next_buffhd_to_drain) {
/* Throw away the data in a filled buffer */
if (bh->state == BUF_STATE_FULL) {
smp_rmb();
bh->state = BUF_STATE_EMPTY;
common->next_buffhd_to_drain = bh->next;
/* A short packet or an error ends everything */
if (bh->outreq->actual != bh->outreq->length ||
bh->outreq->status != 0) {
raise_exception(common,
FSG_STATE_ABORT_BULK_OUT);
return -EINTR;
}
continue;
}
/* Try to submit another request if we need one */
bh = common->next_buffhd_to_fill;
if (bh->state == BUF_STATE_EMPTY
&& common->usb_amount_left > 0) {
amount = min(common->usb_amount_left, FSG_BUFLEN);
/*
* amount is always divisible by 512, hence by
* the bulk-out maxpacket size.
*/
bh->outreq->length = amount;
bh->outreq->short_not_ok = 1;
if (!start_out_transfer(common, bh))
/* Dunno what to do if common->fsg is NULL */
return -EIO;
common->next_buffhd_to_fill = bh->next;
common->usb_amount_left -= amount;
continue;
}
/* Otherwise wait for something to happen */
rc = sleep_thread(common);
if (rc)
return rc;
}
return 0;
}
static int finish_reply(struct fsg_common *common)
{
struct fsg_buffhd *bh = common->next_buffhd_to_fill;
int rc = 0;
switch (common->data_dir) {
case DATA_DIR_NONE:
break; /* Nothing to send */
/*
* If we don't know whether the host wants to read or write,
* this must be CB or CBI with an unknown command. We mustn't
* try to send or receive any data. So stall both bulk pipes
* if we can and wait for a reset.
*/
case DATA_DIR_UNKNOWN:
if (!common->can_stall) {
/* Nothing */
} else if (fsg_is_set(common)) {
fsg_set_halt(common->fsg, common->fsg->bulk_out);
rc = halt_bulk_in_endpoint(common->fsg);
} else {
/* Don't know what to do if common->fsg is NULL */
rc = -EIO;
}
break;
/* All but the last buffer of data must have already been sent */
case DATA_DIR_TO_HOST:
if (common->data_size == 0) {
/* Nothing to send */
/* Don't know what to do if common->fsg is NULL */
} else if (!fsg_is_set(common)) {
rc = -EIO;
/* If there's no residue, simply send the last buffer */
} else if (common->residue == 0) {
bh->inreq->zero = 0;
if (!start_in_transfer(common, bh))
return -EIO;
common->next_buffhd_to_fill = bh->next;
/*
* For Bulk-only, mark the end of the data with a short
* packet. If we are allowed to stall, halt the bulk-in
* endpoint. (Note: This violates the Bulk-Only Transport
* specification, which requires us to pad the data if we
* don't halt the endpoint. Presumably nobody will mind.)
*/
} else {
bh->inreq->zero = 1;
if (!start_in_transfer(common, bh))
rc = -EIO;
common->next_buffhd_to_fill = bh->next;
if (common->can_stall)
rc = halt_bulk_in_endpoint(common->fsg);
}
break;
/*
* We have processed all we want from the data the host has sent.
* There may still be outstanding bulk-out requests.
*/
case DATA_DIR_FROM_HOST:
if (common->residue == 0) {
/* Nothing to receive */
/* Did the host stop sending unexpectedly early? */
} else if (common->short_packet_received) {
raise_exception(common, FSG_STATE_ABORT_BULK_OUT);
rc = -EINTR;
/*
* We haven't processed all the incoming data. Even though
* we may be allowed to stall, doing so would cause a race.
* The controller may already have ACK'ed all the remaining
* bulk-out packets, in which case the host wouldn't see a
* STALL. Not realizing the endpoint was halted, it wouldn't
* clear the halt -- leading to problems later on.
*/
#if 0
} else if (common->can_stall) {
if (fsg_is_set(common))
fsg_set_halt(common->fsg,
common->fsg->bulk_out);
raise_exception(common, FSG_STATE_ABORT_BULK_OUT);
rc = -EINTR;
#endif
/*
* We can't stall. Read in the excess data and throw it
* all away.
*/
} else {
rc = throw_away_data(common);
}
break;
}
return rc;
}
static int send_status(struct fsg_common *common)
{
struct fsg_lun *curlun = common->curlun;
struct fsg_buffhd *bh;
struct bulk_cs_wrap *csw;
int rc;
u8 status = USB_STATUS_PASS;
u32 sd, sdinfo = 0;
/* Wait for the next buffer to become available */
bh = common->next_buffhd_to_fill;
while (bh->state != BUF_STATE_EMPTY) {
rc = sleep_thread(common);
if (rc)
return rc;
}
if (curlun) {
sd = curlun->sense_data;
sdinfo = curlun->sense_data_info;
} else if (common->bad_lun_okay)
sd = SS_NO_SENSE;
else
sd = SS_LOGICAL_UNIT_NOT_SUPPORTED;
if (common->phase_error) {
DBG(common, "sending phase-error status\n");
status = USB_STATUS_PHASE_ERROR;
sd = SS_INVALID_COMMAND;
} else if (sd != SS_NO_SENSE) {
DBG(common, "sending command-failure status\n");
status = USB_STATUS_FAIL;
VDBG(common, " sense data: SK x%02x, ASC x%02x, ASCQ x%02x;"
" info x%x\n",
SK(sd), ASC(sd), ASCQ(sd), sdinfo);
}
/* Store and send the Bulk-only CSW */
csw = (void *)bh->buf;
csw->Signature = cpu_to_le32(USB_BULK_CS_SIG);
csw->Tag = common->tag;
csw->Residue = cpu_to_le32(common->residue);
csw->Status = status;
bh->inreq->length = USB_BULK_CS_WRAP_LEN;
bh->inreq->zero = 0;
if (!start_in_transfer(common, bh))
/* Don't know what to do if common->fsg is NULL */
return -EIO;
common->next_buffhd_to_fill = bh->next;
return 0;
}
/*-------------------------------------------------------------------------*/
/*
* Check whether the command is properly formed and whether its data size
* and direction agree with the values we already have.
*/
static int check_command(struct fsg_common *common, int cmnd_size,
enum data_direction data_dir, unsigned int mask,
int needs_medium, const char *name)
{
int i;
int lun = common->cmnd[1] >> 5;
static const char dirletter[4] = {'u', 'o', 'i', 'n'};
char hdlen[20];
struct fsg_lun *curlun;
hdlen[0] = 0;
if (common->data_dir != DATA_DIR_UNKNOWN)
sprintf(hdlen, ", H%c=%u", dirletter[(int) common->data_dir],
common->data_size);
VDBG(common, "SCSI command: %s; Dc=%d, D%c=%u; Hc=%d%s\n",
name, cmnd_size, dirletter[(int) data_dir],
common->data_size_from_cmnd, common->cmnd_size, hdlen);
/*
* We can't reply at all until we know the correct data direction
* and size.
*/
if (common->data_size_from_cmnd == 0)
data_dir = DATA_DIR_NONE;
if (common->data_size < common->data_size_from_cmnd) {
/*
* Host data size < Device data size is a phase error.
* Carry out the command, but only transfer as much as
* we are allowed.
*/
common->data_size_from_cmnd = common->data_size;
common->phase_error = 1;
}
common->residue = common->data_size;
common->usb_amount_left = common->data_size;
/* Conflicting data directions is a phase error */
if (common->data_dir != data_dir && common->data_size_from_cmnd > 0) {
common->phase_error = 1;
return -EINVAL;
}
/* Verify the length of the command itself */
if (cmnd_size != common->cmnd_size) {
/*
* Special case workaround: There are plenty of buggy SCSI
* implementations. Many have issues with cbw->Length
* field passing a wrong command size. For those cases we
* always try to work around the problem by using the length
* sent by the host side provided it is at least as large
* as the correct command length.
* Examples of such cases would be MS-Windows, which issues
* REQUEST SENSE with cbw->Length == 12 where it should
* be 6, and xbox360 issuing INQUIRY, TEST UNIT READY and
* REQUEST SENSE with cbw->Length == 10 where it should
* be 6 as well.
*/
if (cmnd_size <= common->cmnd_size) {
DBG(common, "%s is buggy! Expected length %d "
"but we got %d\n", name,
cmnd_size, common->cmnd_size);
cmnd_size = common->cmnd_size;
} else {
common->phase_error = 1;
return -EINVAL;
}
}
/* Check that the LUN values are consistent */
if (common->lun != lun)
DBG(common, "using LUN %d from CBW, not LUN %d from CDB\n",
common->lun, lun);
/* Check the LUN */
if (common->lun >= 0 && common->lun < common->nluns) {
curlun = &common->luns[common->lun];
common->curlun = curlun;
if (common->cmnd[0] != REQUEST_SENSE) {
curlun->sense_data = SS_NO_SENSE;
curlun->sense_data_info = 0;
curlun->info_valid = 0;
}
} else {
common->curlun = NULL;
curlun = NULL;
common->bad_lun_okay = 0;
/*
* INQUIRY and REQUEST SENSE commands are explicitly allowed
* to use unsupported LUNs; all others may not.
*/
if (common->cmnd[0] != INQUIRY &&
common->cmnd[0] != REQUEST_SENSE) {
DBG(common, "unsupported LUN %d\n", common->lun);
return -EINVAL;
}
}
/*
* If a unit attention condition exists, only INQUIRY and
* REQUEST SENSE commands are allowed; anything else must fail.
*/
if (curlun && curlun->unit_attention_data != SS_NO_SENSE &&
common->cmnd[0] != INQUIRY &&
common->cmnd[0] != REQUEST_SENSE) {
curlun->sense_data = curlun->unit_attention_data;
curlun->unit_attention_data = SS_NO_SENSE;
return -EINVAL;
}
/* Check that only command bytes listed in the mask are non-zero */
common->cmnd[1] &= 0x1f; /* Mask away the LUN */
for (i = 1; i < cmnd_size; ++i) {
if (common->cmnd[i] && !(mask & (1 << i))) {
if (curlun)
curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
return -EINVAL;
}
}
/* If the medium isn't mounted and the command needs to access
* it, return an error. */
if (curlun && !fsg_lun_is_open(curlun) && needs_medium) {
curlun->sense_data = SS_MEDIUM_NOT_PRESENT;
return -EINVAL;
}
return 0;
}
static int do_scsi_command(struct fsg_common *common)
{
struct fsg_buffhd *bh;
int rc;
int reply = -EINVAL;
int i;
static char unknown[16];
dump_cdb(common);
/* Wait for the next buffer to become available for data or status */
bh = common->next_buffhd_to_fill;
common->next_buffhd_to_drain = bh;
while (bh->state != BUF_STATE_EMPTY) {
rc = sleep_thread(common);
if (rc)
return rc;
}
common->phase_error = 0;
common->short_packet_received = 0;
down_read(&common->filesem); /* We're using the backing file */
switch (common->cmnd[0]) {
case INQUIRY:
common->data_size_from_cmnd = common->cmnd[4];
reply = check_command(common, 6, DATA_DIR_TO_HOST,
(1<<4), 0,
"INQUIRY");
if (reply == 0)
reply = do_inquiry(common, bh);
break;
case MODE_SELECT:
common->data_size_from_cmnd = common->cmnd[4];
reply = check_command(common, 6, DATA_DIR_FROM_HOST,
(1<<1) | (1<<4), 0,
"MODE SELECT(6)");
if (reply == 0)
reply = do_mode_select(common, bh);
break;
case MODE_SELECT_10:
common->data_size_from_cmnd =
get_unaligned_be16(&common->cmnd[7]);
reply = check_command(common, 10, DATA_DIR_FROM_HOST,
(1<<1) | (3<<7), 0,
"MODE SELECT(10)");
if (reply == 0)
reply = do_mode_select(common, bh);
break;
case MODE_SENSE:
common->data_size_from_cmnd = common->cmnd[4];
reply = check_command(common, 6, DATA_DIR_TO_HOST,
(1<<1) | (1<<2) | (1<<4), 0,
"MODE SENSE(6)");
if (reply == 0)
reply = do_mode_sense(common, bh);
break;
case MODE_SENSE_10:
common->data_size_from_cmnd =
get_unaligned_be16(&common->cmnd[7]);
reply = check_command(common, 10, DATA_DIR_TO_HOST,
(1<<1) | (1<<2) | (3<<7), 0,
"MODE SENSE(10)");
if (reply == 0)
reply = do_mode_sense(common, bh);
break;
case ALLOW_MEDIUM_REMOVAL:
common->data_size_from_cmnd = 0;
reply = check_command(common, 6, DATA_DIR_NONE,
(1<<4), 0,
"PREVENT-ALLOW MEDIUM REMOVAL");
if (reply == 0)
reply = do_prevent_allow(common);
break;
case READ_6:
i = common->cmnd[4];
common->data_size_from_cmnd = (i == 0 ? 256 : i) << 9;
reply = check_command(common, 6, DATA_DIR_TO_HOST,
(7<<1) | (1<<4), 1,
"READ(6)");
if (reply == 0)
reply = do_read(common);
break;
case READ_10:
common->data_size_from_cmnd =
get_unaligned_be16(&common->cmnd[7]) << 9;
reply = check_command(common, 10, DATA_DIR_TO_HOST,
(1<<1) | (0xf<<2) | (3<<7), 1,
"READ(10)");
if (reply == 0)
reply = do_read(common);
break;
case READ_12:
common->data_size_from_cmnd =
get_unaligned_be32(&common->cmnd[6]) << 9;
reply = check_command(common, 12, DATA_DIR_TO_HOST,
(1<<1) | (0xf<<2) | (0xf<<6), 1,
"READ(12)");
if (reply == 0)
reply = do_read(common);
break;
case READ_CAPACITY:
common->data_size_from_cmnd = 8;
reply = check_command(common, 10, DATA_DIR_TO_HOST,
(0xf<<2) | (1<<8), 1,
"READ CAPACITY");
if (reply == 0)
reply = do_read_capacity(common, bh);
break;
case READ_HEADER:
if (!common->curlun || !common->curlun->cdrom)
goto unknown_cmnd;
common->data_size_from_cmnd =
get_unaligned_be16(&common->cmnd[7]);
reply = check_command(common, 10, DATA_DIR_TO_HOST,
(3<<7) | (0x1f<<1), 1,
"READ HEADER");
if (reply == 0)
reply = do_read_header(common, bh);
break;
case READ_TOC:
if (!common->curlun || !common->curlun->cdrom)
goto unknown_cmnd;
common->data_size_from_cmnd =
get_unaligned_be16(&common->cmnd[7]);
reply = check_command(common, 10, DATA_DIR_TO_HOST,
(7<<6) | (1<<1), 1,
"READ TOC");
if (reply == 0)
reply = do_read_toc(common, bh);
break;
case READ_FORMAT_CAPACITIES:
common->data_size_from_cmnd =
get_unaligned_be16(&common->cmnd[7]);
reply = check_command(common, 10, DATA_DIR_TO_HOST,
(3<<7), 1,
"READ FORMAT CAPACITIES");
if (reply == 0)
reply = do_read_format_capacities(common, bh);
break;
case REQUEST_SENSE:
common->data_size_from_cmnd = common->cmnd[4];
reply = check_command(common, 6, DATA_DIR_TO_HOST,
(1<<4), 0,
"REQUEST SENSE");
if (reply == 0)
reply = do_request_sense(common, bh);
break;
case START_STOP:
common->data_size_from_cmnd = 0;
reply = check_command(common, 6, DATA_DIR_NONE,
(1<<1) | (1<<4), 0,
"START-STOP UNIT");
if (reply == 0)
reply = do_start_stop(common);
break;
case SYNCHRONIZE_CACHE:
common->data_size_from_cmnd = 0;
reply = check_command(common, 10, DATA_DIR_NONE,
(0xf<<2) | (3<<7), 1,
"SYNCHRONIZE CACHE");
if (reply == 0)
reply = do_synchronize_cache(common);
break;
case TEST_UNIT_READY:
common->data_size_from_cmnd = 0;
reply = check_command(common, 6, DATA_DIR_NONE,
0, 1,
"TEST UNIT READY");
break;
/*
* Although optional, this command is used by MS-Windows. We
* support a minimal version: BytChk must be 0.
*/
case VERIFY:
common->data_size_from_cmnd = 0;
reply = check_command(common, 10, DATA_DIR_NONE,
(1<<1) | (0xf<<2) | (3<<7), 1,
"VERIFY");
if (reply == 0)
reply = do_verify(common);
break;
case WRITE_6:
i = common->cmnd[4];
common->data_size_from_cmnd = (i == 0 ? 256 : i) << 9;
reply = check_command(common, 6, DATA_DIR_FROM_HOST,
(7<<1) | (1<<4), 1,
"WRITE(6)");
if (reply == 0)
reply = do_write(common);
break;
case WRITE_10:
common->data_size_from_cmnd =
get_unaligned_be16(&common->cmnd[7]) << 9;
reply = check_command(common, 10, DATA_DIR_FROM_HOST,
(1<<1) | (0xf<<2) | (3<<7), 1,
"WRITE(10)");
if (reply == 0)
reply = do_write(common);
break;
case WRITE_12:
common->data_size_from_cmnd =
get_unaligned_be32(&common->cmnd[6]) << 9;
reply = check_command(common, 12, DATA_DIR_FROM_HOST,
(1<<1) | (0xf<<2) | (0xf<<6), 1,
"WRITE(12)");
if (reply == 0)
reply = do_write(common);
break;
/*
* Some mandatory commands that we recognize but don't implement.
* They don't mean much in this setting. It's left as an exercise
* for anyone interested to implement RESERVE and RELEASE in terms
* of Posix locks.
*/
case FORMAT_UNIT:
case RELEASE:
case RESERVE:
case SEND_DIAGNOSTIC:
/* Fall through */
default:
unknown_cmnd:
common->data_size_from_cmnd = 0;
sprintf(unknown, "Unknown x%02x", common->cmnd[0]);
reply = check_command(common, common->cmnd_size,
DATA_DIR_UNKNOWN, 0xff, 0, unknown);
if (reply == 0) {
common->curlun->sense_data = SS_INVALID_COMMAND;
reply = -EINVAL;
}
break;
}
up_read(&common->filesem);
if (reply == -EINTR || signal_pending(current))
return -EINTR;
/* Set up the single reply buffer for finish_reply() */
if (reply == -EINVAL)
reply = 0; /* Error reply length */
if (reply >= 0 && common->data_dir == DATA_DIR_TO_HOST) {
reply = min((u32)reply, common->data_size_from_cmnd);
bh->inreq->length = reply;
bh->state = BUF_STATE_FULL;
common->residue -= reply;
} /* Otherwise it's already set */
return 0;
}
/*-------------------------------------------------------------------------*/
static int received_cbw(struct fsg_dev *fsg, struct fsg_buffhd *bh)
{
struct usb_request *req = bh->outreq;
struct fsg_bulk_cb_wrap *cbw = req->buf;
struct fsg_common *common = fsg->common;
/* Was this a real packet? Should it be ignored? */
if (req->status || test_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags))
return -EINVAL;
/* Is the CBW valid? */
if (req->actual != USB_BULK_CB_WRAP_LEN ||
cbw->Signature != cpu_to_le32(
USB_BULK_CB_SIG)) {
DBG(fsg, "invalid CBW: len %u sig 0x%x\n",
req->actual,
le32_to_cpu(cbw->Signature));
/*
* The Bulk-only spec says we MUST stall the IN endpoint
* (6.6.1), so it's unavoidable. It also says we must
* retain this state until the next reset, but there's
* no way to tell the controller driver it should ignore
* Clear-Feature(HALT) requests.
*
* We aren't required to halt the OUT endpoint; instead
* we can simply accept and discard any data received
* until the next reset.
*/
wedge_bulk_in_endpoint(fsg);
set_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags);
return -EINVAL;
}
/* Is the CBW meaningful? */
if (cbw->Lun >= FSG_MAX_LUNS || cbw->Flags & ~USB_BULK_IN_FLAG ||
cbw->Length <= 0 || cbw->Length > MAX_COMMAND_SIZE) {
DBG(fsg, "non-meaningful CBW: lun = %u, flags = 0x%x, "
"cmdlen %u\n",
cbw->Lun, cbw->Flags, cbw->Length);
/*
* We can do anything we want here, so let's stall the
* bulk pipes if we are allowed to.
*/
if (common->can_stall) {
fsg_set_halt(fsg, fsg->bulk_out);
halt_bulk_in_endpoint(fsg);
}
return -EINVAL;
}
/* Save the command for later */
common->cmnd_size = cbw->Length;
memcpy(common->cmnd, cbw->CDB, common->cmnd_size);
if (cbw->Flags & USB_BULK_IN_FLAG)
common->data_dir = DATA_DIR_TO_HOST;
else
common->data_dir = DATA_DIR_FROM_HOST;
common->data_size = le32_to_cpu(cbw->DataTransferLength);
if (common->data_size == 0)
common->data_dir = DATA_DIR_NONE;
common->lun = cbw->Lun;
common->tag = cbw->Tag;
return 0;
}
static int get_next_command(struct fsg_common *common)
{
struct fsg_buffhd *bh;
int rc = 0;
/* Wait for the next buffer to become available */
bh = common->next_buffhd_to_fill;
while (bh->state != BUF_STATE_EMPTY) {
rc = sleep_thread(common);
if (rc)
return rc;
}
/* Queue a request to read a Bulk-only CBW */
bh->outreq->length = USB_BULK_CB_WRAP_LEN;
bh->outreq->short_not_ok = 0;
if (!start_out_transfer(common, bh))
/* Don't know what to do if common->fsg is NULL */
return -EIO;
/*
* 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(common);
if (rc)
return rc;
}
smp_rmb();
rc = fsg_is_set(common) ? received_cbw(common->fsg, bh) : -EIO;
bh->state = BUF_STATE_EMPTY;
return rc;
}
/*-------------------------------------------------------------------------*/
static int enable_endpoint(struct fsg_common *common, struct usb_ep *ep,
const struct usb_endpoint_descriptor *d)
{
int rc;
ep->driver_data = common;
rc = usb_ep_enable(ep, d);
if (rc)
ERROR(common, "can't enable %s, result %d\n", ep->name, rc);
return rc;
}
static int alloc_request(struct fsg_common *common, struct usb_ep *ep,
struct usb_request **preq)
{
*preq = usb_ep_alloc_request(ep, GFP_ATOMIC);
if (*preq)
return 0;
ERROR(common, "can't allocate request for %s\n", ep->name);
return -ENOMEM;
}
/* Reset interface setting and re-init endpoint state (toggle etc). */
static int do_set_interface(struct fsg_common *common, struct fsg_dev *new_fsg)
{
const struct usb_endpoint_descriptor *d;
struct fsg_dev *fsg;
int i, rc = 0;
if (common->running)
DBG(common, "reset interface\n");
reset:
/* Deallocate the requests */
if (common->fsg) {
fsg = common->fsg;
for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
struct fsg_buffhd *bh = &common->buffhds[i];
if (bh->inreq) {
usb_ep_free_request(fsg->bulk_in, bh->inreq);
bh->inreq = NULL;
}
if (bh->outreq) {
usb_ep_free_request(fsg->bulk_out, bh->outreq);
bh->outreq = NULL;
}
}
/* Disable the endpoints */
if (fsg->bulk_in_enabled) {
usb_ep_disable(fsg->bulk_in);
fsg->bulk_in_enabled = 0;
}
if (fsg->bulk_out_enabled) {
usb_ep_disable(fsg->bulk_out);
fsg->bulk_out_enabled = 0;
}
common->fsg = NULL;
wake_up(&common->fsg_wait);
}
common->running = 0;
if (!new_fsg || rc)
return rc;
common->fsg = new_fsg;
fsg = common->fsg;
/* Enable the endpoints */
d = fsg_ep_desc(common->gadget,
&fsg_fs_bulk_in_desc, &fsg_hs_bulk_in_desc);
rc = enable_endpoint(common, fsg->bulk_in, d);
if (rc)
goto reset;
fsg->bulk_in_enabled = 1;
d = fsg_ep_desc(common->gadget,
&fsg_fs_bulk_out_desc, &fsg_hs_bulk_out_desc);
rc = enable_endpoint(common, fsg->bulk_out, d);
if (rc)
goto reset;
fsg->bulk_out_enabled = 1;
common->bulk_out_maxpacket = le16_to_cpu(d->wMaxPacketSize);
clear_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags);
/* Allocate the requests */
for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
struct fsg_buffhd *bh = &common->buffhds[i];
rc = alloc_request(common, fsg->bulk_in, &bh->inreq);
if (rc)
goto reset;
rc = alloc_request(common, fsg->bulk_out, &bh->outreq);
if (rc)
goto reset;
bh->inreq->buf = bh->outreq->buf = bh->buf;
bh->inreq->context = bh->outreq->context = bh;
bh->inreq->complete = bulk_in_complete;
bh->outreq->complete = bulk_out_complete;
}
common->running = 1;
for (i = 0; i < common->nluns; ++i)
common->luns[i].unit_attention_data = SS_RESET_OCCURRED;
return rc;
}
/****************************** ALT CONFIGS ******************************/
static int fsg_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
{
struct fsg_dev *fsg = fsg_from_func(f);
fsg->common->new_fsg = fsg;
raise_exception(fsg->common, FSG_STATE_CONFIG_CHANGE);
return 0;
}
static void fsg_disable(struct usb_function *f)
{
struct fsg_dev *fsg = fsg_from_func(f);
fsg->common->new_fsg = NULL;
raise_exception(fsg->common, FSG_STATE_CONFIG_CHANGE);
}
/*-------------------------------------------------------------------------*/
static void handle_exception(struct fsg_common *common)
{
siginfo_t info;
int i;
struct fsg_buffhd *bh;
enum fsg_state old_state;
struct fsg_lun *curlun;
unsigned int exception_req_tag;
/*
* Clear the existing signals. Anything but SIGUSR1 is converted
* into a high-priority EXIT exception.
*/
for (;;) {
int sig =
dequeue_signal_lock(current, &current->blocked, &info);
if (!sig)
break;
if (sig != SIGUSR1) {
if (common->state < FSG_STATE_EXIT)
DBG(common, "Main thread exiting on signal\n");
raise_exception(common, FSG_STATE_EXIT);
}
}
/* Cancel all the pending transfers */
if (likely(common->fsg)) {
for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
bh = &common->buffhds[i];
if (bh->inreq_busy)
usb_ep_dequeue(common->fsg->bulk_in, bh->inreq);
if (bh->outreq_busy)
usb_ep_dequeue(common->fsg->bulk_out,
bh->outreq);
}
/* Wait until everything is idle */
for (;;) {
int num_active = 0;
for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
bh = &common->buffhds[i];
num_active += bh->inreq_busy + bh->outreq_busy;
}
if (num_active == 0)
break;
if (sleep_thread(common))
return;
}
/* Clear out the controller's fifos */
if (common->fsg->bulk_in_enabled)
usb_ep_fifo_flush(common->fsg->bulk_in);
if (common->fsg->bulk_out_enabled)
usb_ep_fifo_flush(common->fsg->bulk_out);
}
/*
* Reset the I/O buffer states and pointers, the SCSI
* state, and the exception. Then invoke the handler.
*/
spin_lock_irq(&common->lock);
for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
bh = &common->buffhds[i];
bh->state = BUF_STATE_EMPTY;
}
common->next_buffhd_to_fill = &common->buffhds[0];
common->next_buffhd_to_drain = &common->buffhds[0];
exception_req_tag = common->exception_req_tag;
old_state = common->state;
if (old_state == FSG_STATE_ABORT_BULK_OUT)
common->state = FSG_STATE_STATUS_PHASE;
else {
for (i = 0; i < common->nluns; ++i) {
curlun = &common->luns[i];
curlun->prevent_medium_removal = 0;
curlun->sense_data = SS_NO_SENSE;
curlun->unit_attention_data = SS_NO_SENSE;
curlun->sense_data_info = 0;
curlun->info_valid = 0;
}
common->state = FSG_STATE_IDLE;
}
spin_unlock_irq(&common->lock);
/* Carry out any extra actions required for the exception */
switch (old_state) {
case FSG_STATE_ABORT_BULK_OUT:
send_status(common);
spin_lock_irq(&common->lock);
if (common->state == FSG_STATE_STATUS_PHASE)
common->state = FSG_STATE_IDLE;
spin_unlock_irq(&common->lock);
break;
case FSG_STATE_RESET:
/*
* In case we were forced against our will to halt a
* bulk endpoint, clear the halt now. (The SuperH UDC
* requires this.)
*/
if (!fsg_is_set(common))
break;
if (test_and_clear_bit(IGNORE_BULK_OUT,
&common->fsg->atomic_bitflags))
usb_ep_clear_halt(common->fsg->bulk_in);
if (common->ep0_req_tag == exception_req_tag)
ep0_queue(common); /* Complete the status stage */
/*
* Technically this should go here, but it would only be
* a waste of time. Ditto for the INTERFACE_CHANGE and
* CONFIG_CHANGE cases.
*/
/* for (i = 0; i < common->nluns; ++i) */
/* common->luns[i].unit_attention_data = */
/* SS_RESET_OCCURRED; */
break;
case FSG_STATE_CONFIG_CHANGE:
do_set_interface(common, common->new_fsg);
break;
case FSG_STATE_EXIT:
case FSG_STATE_TERMINATED:
do_set_interface(common, NULL); /* Free resources */
spin_lock_irq(&common->lock);
common->state = FSG_STATE_TERMINATED; /* Stop the thread */
spin_unlock_irq(&common->lock);
break;
case FSG_STATE_INTERFACE_CHANGE:
case FSG_STATE_DISCONNECT:
case FSG_STATE_COMMAND_PHASE:
case FSG_STATE_DATA_PHASE:
case FSG_STATE_STATUS_PHASE:
case FSG_STATE_IDLE:
break;
}
}
/*-------------------------------------------------------------------------*/
static int fsg_main_thread(void *common_)
{
struct fsg_common *common = common_;
/*
* Allow the thread to be killed by a signal, but set the signal mask
* to block everything but INT, TERM, KILL, and USR1.
*/
allow_signal(SIGINT);
allow_signal(SIGTERM);
allow_signal(SIGKILL);
allow_signal(SIGUSR1);
/* Allow the thread to be frozen */
set_freezable();
/*
* Arrange for userspace references to be interpreted as kernel
* pointers. That way we can pass a kernel pointer to a routine
* that expects a __user pointer and it will work okay.
*/
set_fs(get_ds());
/* The main loop */
while (common->state != FSG_STATE_TERMINATED) {
if (exception_in_progress(common) || signal_pending(current)) {
handle_exception(common);
continue;
}
if (!common->running) {
sleep_thread(common);
continue;
}
if (get_next_command(common))
continue;
spin_lock_irq(&common->lock);
if (!exception_in_progress(common))
common->state = FSG_STATE_DATA_PHASE;
spin_unlock_irq(&common->lock);
if (do_scsi_command(common) || finish_reply(common))
continue;
spin_lock_irq(&common->lock);
if (!exception_in_progress(common))
common->state = FSG_STATE_STATUS_PHASE;
spin_unlock_irq(&common->lock);
if (send_status(common))
continue;
spin_lock_irq(&common->lock);
if (!exception_in_progress(common))
common->state = FSG_STATE_IDLE;
spin_unlock_irq(&common->lock);
}
spin_lock_irq(&common->lock);
common->thread_task = NULL;
spin_unlock_irq(&common->lock);
if (!common->ops || !common->ops->thread_exits
|| common->ops->thread_exits(common) < 0) {
struct fsg_lun *curlun = common->luns;
unsigned i = common->nluns;
down_write(&common->filesem);
for (; i--; ++curlun) {
if (!fsg_lun_is_open(curlun))
continue;
fsg_lun_close(curlun);
curlun->unit_attention_data = SS_MEDIUM_NOT_PRESENT;
}
up_write(&common->filesem);
}
/* Let fsg_unbind() know the thread has exited */
complete_and_exit(&common->thread_notifier, 0);
}
/*************************** DEVICE ATTRIBUTES ***************************/
/* Write permission is checked per LUN in store_*() functions. */
static DEVICE_ATTR(ro, 0644, fsg_show_ro, fsg_store_ro);
static DEVICE_ATTR(nofua, 0644, fsg_show_nofua, fsg_store_nofua);
static DEVICE_ATTR(file, 0644, fsg_show_file, fsg_store_file);
/****************************** FSG COMMON ******************************/
static void fsg_common_release(struct kref *ref);
static void fsg_lun_release(struct device *dev)
{
/* Nothing needs to be done */
}
static inline void fsg_common_get(struct fsg_common *common)
{
kref_get(&common->ref);
}
static inline void fsg_common_put(struct fsg_common *common)
{
kref_put(&common->ref, fsg_common_release);
}
static struct fsg_common *fsg_common_init(struct fsg_common *common,
struct usb_composite_dev *cdev,
struct fsg_config *cfg)
{
struct usb_gadget *gadget = cdev->gadget;
struct fsg_buffhd *bh;
struct fsg_lun *curlun;
struct fsg_lun_config *lcfg;
int nluns, i, rc;
char *pathbuf;
/* Find out how many LUNs there should be */
nluns = cfg->nluns;
if (nluns < 1 || nluns > FSG_MAX_LUNS) {
dev_err(&gadget->dev, "invalid number of LUNs: %u\n", nluns);
return ERR_PTR(-EINVAL);
}
/* Allocate? */
if (!common) {
common = kzalloc(sizeof *common, GFP_KERNEL);
if (!common)
return ERR_PTR(-ENOMEM);
common->free_storage_on_release = 1;
} else {
memset(common, 0, sizeof *common);
common->free_storage_on_release = 0;
}
common->ops = cfg->ops;
common->private_data = cfg->private_data;
common->gadget = gadget;
common->ep0 = gadget->ep0;
common->ep0req = cdev->req;
/* Maybe allocate device-global string IDs, and patch descriptors */
if (fsg_strings[FSG_STRING_INTERFACE].id == 0) {
rc = usb_string_id(cdev);
if (unlikely(rc < 0))
goto error_release;
fsg_strings[FSG_STRING_INTERFACE].id = rc;
fsg_intf_desc.iInterface = rc;
}
/*
* Create the LUNs, open their backing files, and register the
* LUN devices in sysfs.
*/
curlun = kzalloc(nluns * sizeof *curlun, GFP_KERNEL);
if (unlikely(!curlun)) {
rc = -ENOMEM;
goto error_release;
}
common->luns = curlun;
init_rwsem(&common->filesem);
for (i = 0, lcfg = cfg->luns; i < nluns; ++i, ++curlun, ++lcfg) {
curlun->cdrom = !!lcfg->cdrom;
curlun->ro = lcfg->cdrom || lcfg->ro;
curlun->initially_ro = curlun->ro;
curlun->removable = lcfg->removable;
curlun->dev.release = fsg_lun_release;
curlun->dev.parent = &gadget->dev;
/* curlun->dev.driver = &fsg_driver.driver; XXX */
dev_set_drvdata(&curlun->dev, &common->filesem);
dev_set_name(&curlun->dev,
cfg->lun_name_format
? cfg->lun_name_format
: "lun%d",
i);
rc = device_register(&curlun->dev);
if (rc) {
INFO(common, "failed to register LUN%d: %d\n", i, rc);
common->nluns = i;
put_device(&curlun->dev);
goto error_release;
}
rc = device_create_file(&curlun->dev, &dev_attr_ro);
if (rc)
goto error_luns;
rc = device_create_file(&curlun->dev, &dev_attr_file);
if (rc)
goto error_luns;
rc = device_create_file(&curlun->dev, &dev_attr_nofua);
if (rc)
goto error_luns;
if (lcfg->filename) {
rc = fsg_lun_open(curlun, lcfg->filename);
if (rc)
goto error_luns;
} else if (!curlun->removable) {
ERROR(common, "no file given for LUN%d\n", i);
rc = -EINVAL;
goto error_luns;
}
}
common->nluns = nluns;
/* Data buffers cyclic list */
bh = common->buffhds;
i = FSG_NUM_BUFFERS;
goto buffhds_first_it;
do {
bh->next = bh + 1;
++bh;
buffhds_first_it:
bh->buf = kmalloc(FSG_BUFLEN, GFP_KERNEL);
if (unlikely(!bh->buf)) {
rc = -ENOMEM;
goto error_release;
}
} while (--i);
bh->next = common->buffhds;
/* Prepare inquiryString */
if (cfg->release != 0xffff) {
i = cfg->release;
} else {
i = usb_gadget_controller_number(gadget);
if (i >= 0) {
i = 0x0300 + i;
} else {
WARNING(common, "controller '%s' not recognized\n",
gadget->name);
i = 0x0399;
}
}
snprintf(common->inquiry_string, sizeof common->inquiry_string,
"%-8s%-16s%04x", cfg->vendor_name ?: "Linux",
/* Assume product name dependent on the first LUN */
cfg->product_name ?: (common->luns->cdrom
? "File-Stor Gadget"
: "File-CD Gadget"),
i);
/*
* Some peripheral controllers are known not to be able to
* halt bulk endpoints correctly. If one of them is present,
* disable stalls.
*/
common->can_stall = cfg->can_stall &&
!(gadget_is_at91(common->gadget));
spin_lock_init(&common->lock);
kref_init(&common->ref);
/* Tell the thread to start working */
common->thread_task =
kthread_create(fsg_main_thread, common,
cfg->thread_name ?: "file-storage");
if (IS_ERR(common->thread_task)) {
rc = PTR_ERR(common->thread_task);
goto error_release;
}
init_completion(&common->thread_notifier);
init_waitqueue_head(&common->fsg_wait);
/* Information */
INFO(common, FSG_DRIVER_DESC ", version: " FSG_DRIVER_VERSION "\n");
INFO(common, "Number of LUNs=%d\n", common->nluns);
pathbuf = kmalloc(PATH_MAX, GFP_KERNEL);
for (i = 0, nluns = common->nluns, curlun = common->luns;
i < nluns;
++curlun, ++i) {
char *p = "(no medium)";
if (fsg_lun_is_open(curlun)) {
p = "(error)";
if (pathbuf) {
p = d_path(&curlun->filp->f_path,
pathbuf, PATH_MAX);
if (IS_ERR(p))
p = "(error)";
}
}
LINFO(curlun, "LUN: %s%s%sfile: %s\n",
curlun->removable ? "removable " : "",
curlun->ro ? "read only " : "",
curlun->cdrom ? "CD-ROM " : "",
p);
}
kfree(pathbuf);
DBG(common, "I/O thread pid: %d\n", task_pid_nr(common->thread_task));
wake_up_process(common->thread_task);
return common;
error_luns:
common->nluns = i + 1;
error_release:
common->state = FSG_STATE_TERMINATED; /* The thread is dead */
/* Call fsg_common_release() directly, ref might be not initialised. */
fsg_common_release(&common->ref);
return ERR_PTR(rc);
}
static void fsg_common_release(struct kref *ref)
{
struct fsg_common *common = container_of(ref, struct fsg_common, ref);
/* If the thread isn't already dead, tell it to exit now */
if (common->state != FSG_STATE_TERMINATED) {
raise_exception(common, FSG_STATE_EXIT);
wait_for_completion(&common->thread_notifier);
}
if (likely(common->luns)) {
struct fsg_lun *lun = common->luns;
unsigned i = common->nluns;
/* In error recovery common->nluns may be zero. */
for (; i; --i, ++lun) {
device_remove_file(&lun->dev, &dev_attr_nofua);
device_remove_file(&lun->dev, &dev_attr_ro);
device_remove_file(&lun->dev, &dev_attr_file);
fsg_lun_close(lun);
device_unregister(&lun->dev);
}
kfree(common->luns);
}
{
struct fsg_buffhd *bh = common->buffhds;
unsigned i = FSG_NUM_BUFFERS;
do {
kfree(bh->buf);
} while (++bh, --i);
}
if (common->free_storage_on_release)
kfree(common);
}
/*-------------------------------------------------------------------------*/
static void fsg_unbind(struct usb_configuration *c, struct usb_function *f)
{
struct fsg_dev *fsg = fsg_from_func(f);
struct fsg_common *common = fsg->common;
DBG(fsg, "unbind\n");
if (fsg->common->fsg == fsg) {
fsg->common->new_fsg = NULL;
raise_exception(fsg->common, FSG_STATE_CONFIG_CHANGE);
/* FIXME: make interruptible or killable somehow? */
wait_event(common->fsg_wait, common->fsg != fsg);
}
fsg_common_put(common);
usb_free_descriptors(fsg->function.descriptors);
usb_free_descriptors(fsg->function.hs_descriptors);
kfree(fsg);
}
static int fsg_bind(struct usb_configuration *c, struct usb_function *f)
{
struct fsg_dev *fsg = fsg_from_func(f);
struct usb_gadget *gadget = c->cdev->gadget;
int i;
struct usb_ep *ep;
fsg->gadget = gadget;
/* New interface */
i = usb_interface_id(c, f);
if (i < 0)
return i;
fsg_intf_desc.bInterfaceNumber = i;
fsg->interface_number = i;
/* Find all the endpoints we will use */
ep = usb_ep_autoconfig(gadget, &fsg_fs_bulk_in_desc);
if (!ep)
goto autoconf_fail;
ep->driver_data = fsg->common; /* claim the endpoint */
fsg->bulk_in = ep;
ep = usb_ep_autoconfig(gadget, &fsg_fs_bulk_out_desc);
if (!ep)
goto autoconf_fail;
ep->driver_data = fsg->common; /* claim the endpoint */
fsg->bulk_out = ep;
/* Copy descriptors */
f->descriptors = usb_copy_descriptors(fsg_fs_function);
if (unlikely(!f->descriptors))
return -ENOMEM;
if (gadget_is_dualspeed(gadget)) {
/* Assume endpoint addresses are the same for both speeds */
fsg_hs_bulk_in_desc.bEndpointAddress =
fsg_fs_bulk_in_desc.bEndpointAddress;
fsg_hs_bulk_out_desc.bEndpointAddress =
fsg_fs_bulk_out_desc.bEndpointAddress;
f->hs_descriptors = usb_copy_descriptors(fsg_hs_function);
if (unlikely(!f->hs_descriptors)) {
usb_free_descriptors(f->descriptors);
return -ENOMEM;
}
}
return 0;
autoconf_fail:
ERROR(fsg, "unable to autoconfigure all endpoints\n");
return -ENOTSUPP;
}
/****************************** ADD FUNCTION ******************************/
static struct usb_gadget_strings *fsg_strings_array[] = {
&fsg_stringtab,
NULL,
};
static int fsg_bind_config(struct usb_composite_dev *cdev,
struct usb_configuration *c,
struct fsg_common *common)
{
struct fsg_dev *fsg;
int rc;
fsg = kzalloc(sizeof *fsg, GFP_KERNEL);
if (unlikely(!fsg))
return -ENOMEM;
fsg->function.name = FSG_DRIVER_DESC;
fsg->function.strings = fsg_strings_array;
fsg->function.bind = fsg_bind;
fsg->function.unbind = fsg_unbind;
fsg->function.setup = fsg_setup;
fsg->function.set_alt = fsg_set_alt;
fsg->function.disable = fsg_disable;
fsg->common = common;
/*
* Our caller holds a reference to common structure so we
* don't have to be worry about it being freed until we return
* from this function. So instead of incrementing counter now
* and decrement in error recovery we increment it only when
* call to usb_add_function() was successful.
*/
rc = usb_add_function(c, &fsg->function);
if (unlikely(rc))
kfree(fsg);
else
fsg_common_get(fsg->common);
return rc;
}
static inline int __deprecated __maybe_unused
fsg_add(struct usb_composite_dev *cdev, struct usb_configuration *c,
struct fsg_common *common)
{
return fsg_bind_config(cdev, c, common);
}
/************************* Module parameters *************************/
struct fsg_module_parameters {
char *file[FSG_MAX_LUNS];
int ro[FSG_MAX_LUNS];
int removable[FSG_MAX_LUNS];
int cdrom[FSG_MAX_LUNS];
int nofua[FSG_MAX_LUNS];
unsigned int file_count, ro_count, removable_count, cdrom_count;
unsigned int nofua_count;
unsigned int luns; /* nluns */
int stall; /* can_stall */
};
#define _FSG_MODULE_PARAM_ARRAY(prefix, params, name, type, desc) \
module_param_array_named(prefix ## name, params.name, type, \
&prefix ## params.name ## _count, \
S_IRUGO); \
MODULE_PARM_DESC(prefix ## name, desc)
#define _FSG_MODULE_PARAM(prefix, params, name, type, desc) \
module_param_named(prefix ## name, params.name, type, \
S_IRUGO); \
MODULE_PARM_DESC(prefix ## name, desc)
#define FSG_MODULE_PARAMETERS(prefix, params) \
_FSG_MODULE_PARAM_ARRAY(prefix, params, file, charp, \
"names of backing files or devices"); \
_FSG_MODULE_PARAM_ARRAY(prefix, params, ro, bool, \
"true to force read-only"); \
_FSG_MODULE_PARAM_ARRAY(prefix, params, removable, bool, \
"true to simulate removable media"); \
_FSG_MODULE_PARAM_ARRAY(prefix, params, cdrom, bool, \
"true to simulate CD-ROM instead of disk"); \
_FSG_MODULE_PARAM_ARRAY(prefix, params, nofua, bool, \
"true to ignore SCSI WRITE(10,12) FUA bit"); \
_FSG_MODULE_PARAM(prefix, params, luns, uint, \
"number of LUNs"); \
_FSG_MODULE_PARAM(prefix, params, stall, bool, \
"false to prevent bulk stalls")
static void
fsg_config_from_params(struct fsg_config *cfg,
const struct fsg_module_parameters *params)
{
struct fsg_lun_config *lun;
unsigned i;
/* Configure LUNs */
cfg->nluns =
min(params->luns ?: (params->file_count ?: 1u),
(unsigned)FSG_MAX_LUNS);
for (i = 0, lun = cfg->luns; i < cfg->nluns; ++i, ++lun) {
lun->ro = !!params->ro[i];
lun->cdrom = !!params->cdrom[i];
lun->removable = /* Removable by default */
params->removable_count <= i || params->removable[i];
lun->filename =
params->file_count > i && params->file[i][0]
? params->file[i]
: 0;
}
/* Let MSF use defaults */
cfg->lun_name_format = 0;
cfg->thread_name = 0;
cfg->vendor_name = 0;
cfg->product_name = 0;
cfg->release = 0xffff;
cfg->ops = NULL;
cfg->private_data = NULL;
/* Finalise */
cfg->can_stall = params->stall;
}
static inline struct fsg_common *
fsg_common_from_params(struct fsg_common *common,
struct usb_composite_dev *cdev,
const struct fsg_module_parameters *params)
__attribute__((unused));
static inline struct fsg_common *
fsg_common_from_params(struct fsg_common *common,
struct usb_composite_dev *cdev,
const struct fsg_module_parameters *params)
{
struct fsg_config cfg;
fsg_config_from_params(&cfg, params);
return fsg_common_init(common, cdev, &cfg);
}
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