linux/drivers/usb/gadget/storage_common.c
Linus Torvalds a0e881b7c1 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull second vfs pile from Al Viro:
 "The stuff in there: fsfreeze deadlock fixes by Jan (essentially, the
  deadlock reproduced by xfstests 068), symlink and hardlink restriction
  patches, plus assorted cleanups and fixes.

  Note that another fsfreeze deadlock (emergency thaw one) is *not*
  dealt with - the series by Fernando conflicts a lot with Jan's, breaks
  userland ABI (FIFREEZE semantics gets changed) and trades the deadlock
  for massive vfsmount leak; this is going to be handled next cycle.
  There probably will be another pull request, but that stuff won't be
  in it."

Fix up trivial conflicts due to unrelated changes next to each other in
drivers/{staging/gdm72xx/usb_boot.c, usb/gadget/storage_common.c}

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (54 commits)
  delousing target_core_file a bit
  Documentation: Correct s_umount state for freeze_fs/unfreeze_fs
  fs: Remove old freezing mechanism
  ext2: Implement freezing
  btrfs: Convert to new freezing mechanism
  nilfs2: Convert to new freezing mechanism
  ntfs: Convert to new freezing mechanism
  fuse: Convert to new freezing mechanism
  gfs2: Convert to new freezing mechanism
  ocfs2: Convert to new freezing mechanism
  xfs: Convert to new freezing code
  ext4: Convert to new freezing mechanism
  fs: Protect write paths by sb_start_write - sb_end_write
  fs: Skip atime update on frozen filesystem
  fs: Add freezing handling to mnt_want_write() / mnt_drop_write()
  fs: Improve filesystem freezing handling
  switch the protection of percpu_counter list to spinlock
  nfsd: Push mnt_want_write() outside of i_mutex
  btrfs: Push mnt_want_write() outside of i_mutex
  fat: Push mnt_want_write() outside of i_mutex
  ...
2012-08-01 10:26:23 -07:00

894 lines
24 KiB
C

/*
* storage_common.c -- Common definitions for mass storage functionality
*
* Copyright (C) 2003-2008 Alan Stern
* Copyeight (C) 2009 Samsung Electronics
* Author: Michal Nazarewicz (mina86@mina86.com)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*/
/*
* This file requires the following identifiers used in USB strings to
* be defined (each of type pointer to char):
* - fsg_string_manufacturer -- name of the manufacturer
* - fsg_string_product -- name of the product
* - fsg_string_config -- name of the configuration
* - fsg_string_interface -- name of the interface
* The first four are only needed when FSG_DESCRIPTORS_DEVICE_STRINGS
* macro is defined prior to including this file.
*/
/*
* When FSG_NO_INTR_EP is defined fsg_fs_intr_in_desc and
* fsg_hs_intr_in_desc objects as well as
* FSG_FS_FUNCTION_PRE_EP_ENTRIES and FSG_HS_FUNCTION_PRE_EP_ENTRIES
* macros are not defined.
*
* When FSG_NO_DEVICE_STRINGS is defined FSG_STRING_MANUFACTURER,
* FSG_STRING_PRODUCT, FSG_STRING_SERIAL and FSG_STRING_CONFIG are not
* defined (as well as corresponding entries in string tables are
* missing) and FSG_STRING_INTERFACE has value of zero.
*
* When FSG_NO_OTG is defined fsg_otg_desc won't be defined.
*/
/*
* When USB_GADGET_DEBUG_FILES is defined the module param num_buffers
* sets the number of pipeline buffers (length of the fsg_buffhd array).
* The valid range of num_buffers is: num >= 2 && num <= 4.
*/
#include <linux/usb/storage.h>
#include <scsi/scsi.h>
#include <asm/unaligned.h>
/*
* Thanks to NetChip Technologies for donating this product ID.
*
* DO NOT REUSE THESE IDs with any other driver!! Ever!!
* Instead: allocate your own, using normal USB-IF procedures.
*/
#define FSG_VENDOR_ID 0x0525 /* NetChip */
#define FSG_PRODUCT_ID 0xa4a5 /* Linux-USB File-backed Storage Gadget */
/*-------------------------------------------------------------------------*/
#ifndef DEBUG
#undef VERBOSE_DEBUG
#undef DUMP_MSGS
#endif /* !DEBUG */
#ifdef VERBOSE_DEBUG
#define VLDBG LDBG
#else
#define VLDBG(lun, fmt, args...) do { } while (0)
#endif /* VERBOSE_DEBUG */
#define LDBG(lun, fmt, args...) dev_dbg (&(lun)->dev, fmt, ## args)
#define LERROR(lun, fmt, args...) dev_err (&(lun)->dev, fmt, ## args)
#define LWARN(lun, fmt, args...) dev_warn(&(lun)->dev, fmt, ## args)
#define LINFO(lun, fmt, args...) dev_info(&(lun)->dev, fmt, ## args)
/*
* Keep those macros in sync with those in
* include/linux/usb/composite.h or else GCC will complain. If they
* are identical (the same names of arguments, white spaces in the
* same places) GCC will allow redefinition otherwise (even if some
* white space is removed or added) warning will be issued.
*
* Those macros are needed here because File Storage Gadget does not
* include the composite.h header. For composite gadgets those macros
* are redundant since composite.h is included any way.
*
* One could check whether those macros are already defined (which
* would indicate composite.h had been included) or not (which would
* indicate we were in FSG) but this is not done because a warning is
* desired if definitions here differ from the ones in composite.h.
*
* We want the definitions to match and be the same in File Storage
* Gadget as well as Mass Storage Function (and so composite gadgets
* using MSF). If someone changes them in composite.h it will produce
* a warning in this file when building MSF.
*/
#define DBG(d, fmt, args...) dev_dbg(&(d)->gadget->dev , fmt , ## args)
#define VDBG(d, fmt, args...) dev_vdbg(&(d)->gadget->dev , fmt , ## args)
#define ERROR(d, fmt, args...) dev_err(&(d)->gadget->dev , fmt , ## args)
#define WARNING(d, fmt, args...) dev_warn(&(d)->gadget->dev , fmt , ## args)
#define INFO(d, fmt, args...) dev_info(&(d)->gadget->dev , fmt , ## args)
#ifdef DUMP_MSGS
# define dump_msg(fsg, /* const char * */ label, \
/* const u8 * */ buf, /* unsigned */ length) do { \
if (length < 512) { \
DBG(fsg, "%s, length %u:\n", label, length); \
print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, \
16, 1, buf, length, 0); \
} \
} while (0)
# define dump_cdb(fsg) do { } while (0)
#else
# define dump_msg(fsg, /* const char * */ label, \
/* const u8 * */ buf, /* unsigned */ length) do { } while (0)
# ifdef VERBOSE_DEBUG
# define dump_cdb(fsg) \
print_hex_dump(KERN_DEBUG, "SCSI CDB: ", DUMP_PREFIX_NONE, \
16, 1, (fsg)->cmnd, (fsg)->cmnd_size, 0) \
# else
# define dump_cdb(fsg) do { } while (0)
# endif /* VERBOSE_DEBUG */
#endif /* DUMP_MSGS */
/*-------------------------------------------------------------------------*/
/* CBI Interrupt data structure */
struct interrupt_data {
u8 bType;
u8 bValue;
};
#define CBI_INTERRUPT_DATA_LEN 2
/* CBI Accept Device-Specific Command request */
#define USB_CBI_ADSC_REQUEST 0x00
/* Length of a SCSI Command Data Block */
#define MAX_COMMAND_SIZE 16
/* SCSI Sense Key/Additional Sense Code/ASC Qualifier values */
#define SS_NO_SENSE 0
#define SS_COMMUNICATION_FAILURE 0x040800
#define SS_INVALID_COMMAND 0x052000
#define SS_INVALID_FIELD_IN_CDB 0x052400
#define SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE 0x052100
#define SS_LOGICAL_UNIT_NOT_SUPPORTED 0x052500
#define SS_MEDIUM_NOT_PRESENT 0x023a00
#define SS_MEDIUM_REMOVAL_PREVENTED 0x055302
#define SS_NOT_READY_TO_READY_TRANSITION 0x062800
#define SS_RESET_OCCURRED 0x062900
#define SS_SAVING_PARAMETERS_NOT_SUPPORTED 0x053900
#define SS_UNRECOVERED_READ_ERROR 0x031100
#define SS_WRITE_ERROR 0x030c02
#define SS_WRITE_PROTECTED 0x072700
#define SK(x) ((u8) ((x) >> 16)) /* Sense Key byte, etc. */
#define ASC(x) ((u8) ((x) >> 8))
#define ASCQ(x) ((u8) (x))
/*-------------------------------------------------------------------------*/
struct fsg_lun {
struct file *filp;
loff_t file_length;
loff_t num_sectors;
unsigned int initially_ro:1;
unsigned int ro:1;
unsigned int removable:1;
unsigned int cdrom:1;
unsigned int prevent_medium_removal:1;
unsigned int registered:1;
unsigned int info_valid:1;
unsigned int nofua:1;
u32 sense_data;
u32 sense_data_info;
u32 unit_attention_data;
unsigned int blkbits; /* Bits of logical block size of bound block device */
unsigned int blksize; /* logical block size of bound block device */
struct device dev;
};
#define fsg_lun_is_open(curlun) ((curlun)->filp != NULL)
static struct fsg_lun *fsg_lun_from_dev(struct device *dev)
{
return container_of(dev, struct fsg_lun, dev);
}
/* Big enough to hold our biggest descriptor */
#define EP0_BUFSIZE 256
#define DELAYED_STATUS (EP0_BUFSIZE + 999) /* An impossibly large value */
#ifdef CONFIG_USB_GADGET_DEBUG_FILES
static unsigned int fsg_num_buffers = CONFIG_USB_GADGET_STORAGE_NUM_BUFFERS;
module_param_named(num_buffers, fsg_num_buffers, uint, S_IRUGO);
MODULE_PARM_DESC(num_buffers, "Number of pipeline buffers");
#else
/*
* Number of buffers we will use.
* 2 is usually enough for good buffering pipeline
*/
#define fsg_num_buffers CONFIG_USB_GADGET_STORAGE_NUM_BUFFERS
#endif /* CONFIG_USB_DEBUG */
/* check if fsg_num_buffers is within a valid range */
static inline int fsg_num_buffers_validate(void)
{
if (fsg_num_buffers >= 2 && fsg_num_buffers <= 4)
return 0;
pr_err("fsg_num_buffers %u is out of range (%d to %d)\n",
fsg_num_buffers, 2 ,4);
return -EINVAL;
}
/* Default size of buffer length. */
#define FSG_BUFLEN ((u32)16384)
/* Maximal number of LUNs supported in mass storage function */
#define FSG_MAX_LUNS 8
enum fsg_buffer_state {
BUF_STATE_EMPTY = 0,
BUF_STATE_FULL,
BUF_STATE_BUSY
};
struct fsg_buffhd {
void *buf;
enum fsg_buffer_state state;
struct fsg_buffhd *next;
/*
* The NetChip 2280 is faster, and handles some protocol faults
* better, if we don't submit any short bulk-out read requests.
* So we will record the intended request length here.
*/
unsigned int bulk_out_intended_length;
struct usb_request *inreq;
int inreq_busy;
struct usb_request *outreq;
int outreq_busy;
};
enum fsg_state {
/* This one isn't used anywhere */
FSG_STATE_COMMAND_PHASE = -10,
FSG_STATE_DATA_PHASE,
FSG_STATE_STATUS_PHASE,
FSG_STATE_IDLE = 0,
FSG_STATE_ABORT_BULK_OUT,
FSG_STATE_RESET,
FSG_STATE_INTERFACE_CHANGE,
FSG_STATE_CONFIG_CHANGE,
FSG_STATE_DISCONNECT,
FSG_STATE_EXIT,
FSG_STATE_TERMINATED
};
enum data_direction {
DATA_DIR_UNKNOWN = 0,
DATA_DIR_FROM_HOST,
DATA_DIR_TO_HOST,
DATA_DIR_NONE
};
/*-------------------------------------------------------------------------*/
static inline u32 get_unaligned_be24(u8 *buf)
{
return 0xffffff & (u32) get_unaligned_be32(buf - 1);
}
/*-------------------------------------------------------------------------*/
enum {
#ifndef FSG_NO_DEVICE_STRINGS
FSG_STRING_MANUFACTURER = 1,
FSG_STRING_PRODUCT,
FSG_STRING_SERIAL,
FSG_STRING_CONFIG,
#endif
FSG_STRING_INTERFACE
};
#ifndef FSG_NO_OTG
static struct usb_otg_descriptor
fsg_otg_desc = {
.bLength = sizeof fsg_otg_desc,
.bDescriptorType = USB_DT_OTG,
.bmAttributes = USB_OTG_SRP,
};
#endif
/* There is only one interface. */
static struct usb_interface_descriptor
fsg_intf_desc = {
.bLength = sizeof fsg_intf_desc,
.bDescriptorType = USB_DT_INTERFACE,
.bNumEndpoints = 2, /* Adjusted during fsg_bind() */
.bInterfaceClass = USB_CLASS_MASS_STORAGE,
.bInterfaceSubClass = USB_SC_SCSI, /* Adjusted during fsg_bind() */
.bInterfaceProtocol = USB_PR_BULK, /* Adjusted during fsg_bind() */
.iInterface = FSG_STRING_INTERFACE,
};
/*
* Three full-speed endpoint descriptors: bulk-in, bulk-out, and
* interrupt-in.
*/
static struct usb_endpoint_descriptor
fsg_fs_bulk_in_desc = {
.bLength = USB_DT_ENDPOINT_SIZE,
.bDescriptorType = USB_DT_ENDPOINT,
.bEndpointAddress = USB_DIR_IN,
.bmAttributes = USB_ENDPOINT_XFER_BULK,
/* wMaxPacketSize set by autoconfiguration */
};
static struct usb_endpoint_descriptor
fsg_fs_bulk_out_desc = {
.bLength = USB_DT_ENDPOINT_SIZE,
.bDescriptorType = USB_DT_ENDPOINT,
.bEndpointAddress = USB_DIR_OUT,
.bmAttributes = USB_ENDPOINT_XFER_BULK,
/* wMaxPacketSize set by autoconfiguration */
};
#ifndef FSG_NO_INTR_EP
static struct usb_endpoint_descriptor
fsg_fs_intr_in_desc = {
.bLength = USB_DT_ENDPOINT_SIZE,
.bDescriptorType = USB_DT_ENDPOINT,
.bEndpointAddress = USB_DIR_IN,
.bmAttributes = USB_ENDPOINT_XFER_INT,
.wMaxPacketSize = cpu_to_le16(2),
.bInterval = 32, /* frames -> 32 ms */
};
#ifndef FSG_NO_OTG
# define FSG_FS_FUNCTION_PRE_EP_ENTRIES 2
#else
# define FSG_FS_FUNCTION_PRE_EP_ENTRIES 1
#endif
#endif
static struct usb_descriptor_header *fsg_fs_function[] = {
#ifndef FSG_NO_OTG
(struct usb_descriptor_header *) &fsg_otg_desc,
#endif
(struct usb_descriptor_header *) &fsg_intf_desc,
(struct usb_descriptor_header *) &fsg_fs_bulk_in_desc,
(struct usb_descriptor_header *) &fsg_fs_bulk_out_desc,
#ifndef FSG_NO_INTR_EP
(struct usb_descriptor_header *) &fsg_fs_intr_in_desc,
#endif
NULL,
};
/*
* USB 2.0 devices need to expose both high speed and full speed
* descriptors, unless they only run at full speed.
*
* That means alternate endpoint descriptors (bigger packets)
* and a "device qualifier" ... plus more construction options
* for the configuration descriptor.
*/
static struct usb_endpoint_descriptor
fsg_hs_bulk_in_desc = {
.bLength = USB_DT_ENDPOINT_SIZE,
.bDescriptorType = USB_DT_ENDPOINT,
/* bEndpointAddress copied from fs_bulk_in_desc during fsg_bind() */
.bmAttributes = USB_ENDPOINT_XFER_BULK,
.wMaxPacketSize = cpu_to_le16(512),
};
static struct usb_endpoint_descriptor
fsg_hs_bulk_out_desc = {
.bLength = USB_DT_ENDPOINT_SIZE,
.bDescriptorType = USB_DT_ENDPOINT,
/* bEndpointAddress copied from fs_bulk_out_desc during fsg_bind() */
.bmAttributes = USB_ENDPOINT_XFER_BULK,
.wMaxPacketSize = cpu_to_le16(512),
.bInterval = 1, /* NAK every 1 uframe */
};
#ifndef FSG_NO_INTR_EP
static struct usb_endpoint_descriptor
fsg_hs_intr_in_desc = {
.bLength = USB_DT_ENDPOINT_SIZE,
.bDescriptorType = USB_DT_ENDPOINT,
/* bEndpointAddress copied from fs_intr_in_desc during fsg_bind() */
.bmAttributes = USB_ENDPOINT_XFER_INT,
.wMaxPacketSize = cpu_to_le16(2),
.bInterval = 9, /* 2**(9-1) = 256 uframes -> 32 ms */
};
#ifndef FSG_NO_OTG
# define FSG_HS_FUNCTION_PRE_EP_ENTRIES 2
#else
# define FSG_HS_FUNCTION_PRE_EP_ENTRIES 1
#endif
#endif
static struct usb_descriptor_header *fsg_hs_function[] = {
#ifndef FSG_NO_OTG
(struct usb_descriptor_header *) &fsg_otg_desc,
#endif
(struct usb_descriptor_header *) &fsg_intf_desc,
(struct usb_descriptor_header *) &fsg_hs_bulk_in_desc,
(struct usb_descriptor_header *) &fsg_hs_bulk_out_desc,
#ifndef FSG_NO_INTR_EP
(struct usb_descriptor_header *) &fsg_hs_intr_in_desc,
#endif
NULL,
};
static struct usb_endpoint_descriptor
fsg_ss_bulk_in_desc = {
.bLength = USB_DT_ENDPOINT_SIZE,
.bDescriptorType = USB_DT_ENDPOINT,
/* bEndpointAddress copied from fs_bulk_in_desc during fsg_bind() */
.bmAttributes = USB_ENDPOINT_XFER_BULK,
.wMaxPacketSize = cpu_to_le16(1024),
};
static struct usb_ss_ep_comp_descriptor fsg_ss_bulk_in_comp_desc = {
.bLength = sizeof(fsg_ss_bulk_in_comp_desc),
.bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
/*.bMaxBurst = DYNAMIC, */
};
static struct usb_endpoint_descriptor
fsg_ss_bulk_out_desc = {
.bLength = USB_DT_ENDPOINT_SIZE,
.bDescriptorType = USB_DT_ENDPOINT,
/* bEndpointAddress copied from fs_bulk_out_desc during fsg_bind() */
.bmAttributes = USB_ENDPOINT_XFER_BULK,
.wMaxPacketSize = cpu_to_le16(1024),
};
static struct usb_ss_ep_comp_descriptor fsg_ss_bulk_out_comp_desc = {
.bLength = sizeof(fsg_ss_bulk_in_comp_desc),
.bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
/*.bMaxBurst = DYNAMIC, */
};
#ifndef FSG_NO_INTR_EP
static struct usb_endpoint_descriptor
fsg_ss_intr_in_desc = {
.bLength = USB_DT_ENDPOINT_SIZE,
.bDescriptorType = USB_DT_ENDPOINT,
/* bEndpointAddress copied from fs_intr_in_desc during fsg_bind() */
.bmAttributes = USB_ENDPOINT_XFER_INT,
.wMaxPacketSize = cpu_to_le16(2),
.bInterval = 9, /* 2**(9-1) = 256 uframes -> 32 ms */
};
static struct usb_ss_ep_comp_descriptor fsg_ss_intr_in_comp_desc = {
.bLength = sizeof(fsg_ss_bulk_in_comp_desc),
.bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
.wBytesPerInterval = cpu_to_le16(2),
};
#ifndef FSG_NO_OTG
# define FSG_SS_FUNCTION_PRE_EP_ENTRIES 2
#else
# define FSG_SS_FUNCTION_PRE_EP_ENTRIES 1
#endif
#endif
static __maybe_unused struct usb_ext_cap_descriptor fsg_ext_cap_desc = {
.bLength = USB_DT_USB_EXT_CAP_SIZE,
.bDescriptorType = USB_DT_DEVICE_CAPABILITY,
.bDevCapabilityType = USB_CAP_TYPE_EXT,
.bmAttributes = cpu_to_le32(USB_LPM_SUPPORT),
};
static __maybe_unused struct usb_ss_cap_descriptor fsg_ss_cap_desc = {
.bLength = USB_DT_USB_SS_CAP_SIZE,
.bDescriptorType = USB_DT_DEVICE_CAPABILITY,
.bDevCapabilityType = USB_SS_CAP_TYPE,
/* .bmAttributes = LTM is not supported yet */
.wSpeedSupported = cpu_to_le16(USB_LOW_SPEED_OPERATION
| USB_FULL_SPEED_OPERATION
| USB_HIGH_SPEED_OPERATION
| USB_5GBPS_OPERATION),
.bFunctionalitySupport = USB_LOW_SPEED_OPERATION,
.bU1devExitLat = USB_DEFAULT_U1_DEV_EXIT_LAT,
.bU2DevExitLat = cpu_to_le16(USB_DEFAULT_U2_DEV_EXIT_LAT),
};
static __maybe_unused struct usb_bos_descriptor fsg_bos_desc = {
.bLength = USB_DT_BOS_SIZE,
.bDescriptorType = USB_DT_BOS,
.wTotalLength = cpu_to_le16(USB_DT_BOS_SIZE
+ USB_DT_USB_EXT_CAP_SIZE
+ USB_DT_USB_SS_CAP_SIZE),
.bNumDeviceCaps = 2,
};
static struct usb_descriptor_header *fsg_ss_function[] = {
#ifndef FSG_NO_OTG
(struct usb_descriptor_header *) &fsg_otg_desc,
#endif
(struct usb_descriptor_header *) &fsg_intf_desc,
(struct usb_descriptor_header *) &fsg_ss_bulk_in_desc,
(struct usb_descriptor_header *) &fsg_ss_bulk_in_comp_desc,
(struct usb_descriptor_header *) &fsg_ss_bulk_out_desc,
(struct usb_descriptor_header *) &fsg_ss_bulk_out_comp_desc,
#ifndef FSG_NO_INTR_EP
(struct usb_descriptor_header *) &fsg_ss_intr_in_desc,
(struct usb_descriptor_header *) &fsg_ss_intr_in_comp_desc,
#endif
NULL,
};
/* Maxpacket and other transfer characteristics vary by speed. */
static __maybe_unused struct usb_endpoint_descriptor *
fsg_ep_desc(struct usb_gadget *g, struct usb_endpoint_descriptor *fs,
struct usb_endpoint_descriptor *hs,
struct usb_endpoint_descriptor *ss)
{
if (gadget_is_superspeed(g) && g->speed == USB_SPEED_SUPER)
return ss;
else if (gadget_is_dualspeed(g) && g->speed == USB_SPEED_HIGH)
return hs;
return fs;
}
/* Static strings, in UTF-8 (for simplicity we use only ASCII characters) */
static struct usb_string fsg_strings[] = {
#ifndef FSG_NO_DEVICE_STRINGS
{FSG_STRING_MANUFACTURER, fsg_string_manufacturer},
{FSG_STRING_PRODUCT, fsg_string_product},
{FSG_STRING_SERIAL, ""},
{FSG_STRING_CONFIG, fsg_string_config},
#endif
{FSG_STRING_INTERFACE, fsg_string_interface},
{}
};
static struct usb_gadget_strings fsg_stringtab = {
.language = 0x0409, /* en-us */
.strings = fsg_strings,
};
/*-------------------------------------------------------------------------*/
/*
* If the next two routines are called while the gadget is registered,
* the caller must own fsg->filesem for writing.
*/
static void fsg_lun_close(struct fsg_lun *curlun)
{
if (curlun->filp) {
LDBG(curlun, "close backing file\n");
fput(curlun->filp);
curlun->filp = NULL;
}
}
static int fsg_lun_open(struct fsg_lun *curlun, const char *filename)
{
int ro;
struct file *filp = NULL;
int rc = -EINVAL;
struct inode *inode = NULL;
loff_t size;
loff_t num_sectors;
loff_t min_sectors;
unsigned int blkbits;
unsigned int blksize;
/* R/W if we can, R/O if we must */
ro = curlun->initially_ro;
if (!ro) {
filp = filp_open(filename, O_RDWR | O_LARGEFILE, 0);
if (PTR_ERR(filp) == -EROFS || PTR_ERR(filp) == -EACCES)
ro = 1;
}
if (ro)
filp = filp_open(filename, O_RDONLY | O_LARGEFILE, 0);
if (IS_ERR(filp)) {
LINFO(curlun, "unable to open backing file: %s\n", filename);
return PTR_ERR(filp);
}
if (!(filp->f_mode & FMODE_WRITE))
ro = 1;
inode = filp->f_path.dentry->d_inode;
if ((!S_ISREG(inode->i_mode) && !S_ISBLK(inode->i_mode))) {
LINFO(curlun, "invalid file type: %s\n", filename);
goto out;
}
/*
* If we can't read the file, it's no good.
* If we can't write the file, use it read-only.
*/
if (!(filp->f_op->read || filp->f_op->aio_read)) {
LINFO(curlun, "file not readable: %s\n", filename);
goto out;
}
if (!(filp->f_op->write || filp->f_op->aio_write))
ro = 1;
size = i_size_read(inode->i_mapping->host);
if (size < 0) {
LINFO(curlun, "unable to find file size: %s\n", filename);
rc = (int) size;
goto out;
}
if (curlun->cdrom) {
blksize = 2048;
blkbits = 11;
} else if (inode->i_bdev) {
blksize = bdev_logical_block_size(inode->i_bdev);
blkbits = blksize_bits(blksize);
} else {
blksize = 512;
blkbits = 9;
}
num_sectors = size >> blkbits; /* File size in logic-block-size blocks */
min_sectors = 1;
if (curlun->cdrom) {
min_sectors = 300; /* Smallest track is 300 frames */
if (num_sectors >= 256*60*75) {
num_sectors = 256*60*75 - 1;
LINFO(curlun, "file too big: %s\n", filename);
LINFO(curlun, "using only first %d blocks\n",
(int) num_sectors);
}
}
if (num_sectors < min_sectors) {
LINFO(curlun, "file too small: %s\n", filename);
rc = -ETOOSMALL;
goto out;
}
if (fsg_lun_is_open(curlun))
fsg_lun_close(curlun);
curlun->blksize = blksize;
curlun->blkbits = blkbits;
curlun->ro = ro;
curlun->filp = filp;
curlun->file_length = size;
curlun->num_sectors = num_sectors;
LDBG(curlun, "open backing file: %s\n", filename);
return 0;
out:
fput(filp);
return rc;
}
/*-------------------------------------------------------------------------*/
/*
* Sync the file data, don't bother with the metadata.
* This code was copied from fs/buffer.c:sys_fdatasync().
*/
static int fsg_lun_fsync_sub(struct fsg_lun *curlun)
{
struct file *filp = curlun->filp;
if (curlun->ro || !filp)
return 0;
return vfs_fsync(filp, 1);
}
static void store_cdrom_address(u8 *dest, int msf, u32 addr)
{
if (msf) {
/* Convert to Minutes-Seconds-Frames */
addr >>= 2; /* Convert to 2048-byte frames */
addr += 2*75; /* Lead-in occupies 2 seconds */
dest[3] = addr % 75; /* Frames */
addr /= 75;
dest[2] = addr % 60; /* Seconds */
addr /= 60;
dest[1] = addr; /* Minutes */
dest[0] = 0; /* Reserved */
} else {
/* Absolute sector */
put_unaligned_be32(addr, dest);
}
}
/*-------------------------------------------------------------------------*/
static ssize_t fsg_show_ro(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct fsg_lun *curlun = fsg_lun_from_dev(dev);
return sprintf(buf, "%d\n", fsg_lun_is_open(curlun)
? curlun->ro
: curlun->initially_ro);
}
static ssize_t fsg_show_nofua(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct fsg_lun *curlun = fsg_lun_from_dev(dev);
return sprintf(buf, "%u\n", curlun->nofua);
}
static ssize_t fsg_show_file(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct fsg_lun *curlun = fsg_lun_from_dev(dev);
struct rw_semaphore *filesem = dev_get_drvdata(dev);
char *p;
ssize_t rc;
down_read(filesem);
if (fsg_lun_is_open(curlun)) { /* Get the complete pathname */
p = d_path(&curlun->filp->f_path, buf, PAGE_SIZE - 1);
if (IS_ERR(p))
rc = PTR_ERR(p);
else {
rc = strlen(p);
memmove(buf, p, rc);
buf[rc] = '\n'; /* Add a newline */
buf[++rc] = 0;
}
} else { /* No file, return 0 bytes */
*buf = 0;
rc = 0;
}
up_read(filesem);
return rc;
}
static ssize_t fsg_store_ro(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
ssize_t rc;
struct fsg_lun *curlun = fsg_lun_from_dev(dev);
struct rw_semaphore *filesem = dev_get_drvdata(dev);
unsigned ro;
rc = kstrtouint(buf, 2, &ro);
if (rc)
return rc;
/*
* Allow the write-enable status to change only while the
* backing file is closed.
*/
down_read(filesem);
if (fsg_lun_is_open(curlun)) {
LDBG(curlun, "read-only status change prevented\n");
rc = -EBUSY;
} else {
curlun->ro = ro;
curlun->initially_ro = ro;
LDBG(curlun, "read-only status set to %d\n", curlun->ro);
rc = count;
}
up_read(filesem);
return rc;
}
static ssize_t fsg_store_nofua(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct fsg_lun *curlun = fsg_lun_from_dev(dev);
unsigned nofua;
int ret;
ret = kstrtouint(buf, 2, &nofua);
if (ret)
return ret;
/* Sync data when switching from async mode to sync */
if (!nofua && curlun->nofua)
fsg_lun_fsync_sub(curlun);
curlun->nofua = nofua;
return count;
}
static ssize_t fsg_store_file(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct fsg_lun *curlun = fsg_lun_from_dev(dev);
struct rw_semaphore *filesem = dev_get_drvdata(dev);
int rc = 0;
if (curlun->prevent_medium_removal && fsg_lun_is_open(curlun)) {
LDBG(curlun, "eject attempt prevented\n");
return -EBUSY; /* "Door is locked" */
}
/* Remove a trailing newline */
if (count > 0 && buf[count-1] == '\n')
((char *) buf)[count-1] = 0; /* Ugh! */
/* Load new medium */
down_write(filesem);
if (count > 0 && buf[0]) {
/* fsg_lun_open() will close existing file if any. */
rc = fsg_lun_open(curlun, buf);
if (rc == 0)
curlun->unit_attention_data =
SS_NOT_READY_TO_READY_TRANSITION;
} else if (fsg_lun_is_open(curlun)) {
fsg_lun_close(curlun);
curlun->unit_attention_data = SS_MEDIUM_NOT_PRESENT;
}
up_write(filesem);
return (rc < 0 ? rc : count);
}