diff options
Diffstat (limited to 'drivers/staging/ccg/storage_common.c')
| -rw-r--r-- | drivers/staging/ccg/storage_common.c | 893 |
1 files changed, 893 insertions, 0 deletions
diff --git a/drivers/staging/ccg/storage_common.c b/drivers/staging/ccg/storage_common.c new file mode 100644 index 000000000000..8d9bcd8207c8 --- /dev/null +++ b/drivers/staging/ccg/storage_common.c @@ -0,0 +1,893 @@ +/* + * 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); +} |