2 * storage_common.c -- Common definitions for mass storage functionality
4 * Copyright (C) 2003-2008 Alan Stern
5 * Copyeight (C) 2009 Samsung Electronics
6 * Author: Michal Nazarewicz (m.nazarewicz@samsung.com)
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
25 * This file requires the following identifiers used in USB strings to
26 * be defined (each of type pointer to char):
27 * - fsg_string_manufacturer -- name of the manufacturer
28 * - fsg_string_product -- name of the product
29 * - fsg_string_config -- name of the configuration
30 * - fsg_string_interface -- name of the interface
31 * The first four are only needed when FSG_DESCRIPTORS_DEVICE_STRINGS
32 * macro is defined prior to including this file.
36 * When FSG_NO_INTR_EP is defined fsg_fs_intr_in_desc and
37 * fsg_hs_intr_in_desc objects as well as
38 * FSG_FS_FUNCTION_PRE_EP_ENTRIES and FSG_HS_FUNCTION_PRE_EP_ENTRIES
39 * macros are not defined.
41 * When FSG_NO_DEVICE_STRINGS is defined FSG_STRING_MANUFACTURER,
42 * FSG_STRING_PRODUCT, FSG_STRING_SERIAL and FSG_STRING_CONFIG are not
43 * defined (as well as corresponding entries in string tables are
44 * missing) and FSG_STRING_INTERFACE has value of zero.
46 * When FSG_NO_OTG is defined fsg_otg_desc won't be defined.
50 * When FSG_BUFFHD_STATIC_BUFFER is defined when this file is included
51 * the fsg_buffhd structure's buf field will be an array of FSG_BUFLEN
52 * characters rather then a pointer to void.
56 #include <asm/unaligned.h>
60 * Thanks to NetChip Technologies for donating this product ID.
62 * DO NOT REUSE THESE IDs with any other driver!! Ever!!
63 * Instead: allocate your own, using normal USB-IF procedures.
65 #define FSG_VENDOR_ID 0x0525 /* NetChip */
66 #define FSG_PRODUCT_ID 0xa4a5 /* Linux-USB File-backed Storage Gadget */
69 /*-------------------------------------------------------------------------*/
80 #define VLDBG(lun, fmt, args...) do { } while (0)
81 #endif /* VERBOSE_DEBUG */
83 #define LDBG(lun, fmt, args...) dev_dbg (&(lun)->dev, fmt, ## args)
84 #define LERROR(lun, fmt, args...) dev_err (&(lun)->dev, fmt, ## args)
85 #define LWARN(lun, fmt, args...) dev_warn(&(lun)->dev, fmt, ## args)
86 #define LINFO(lun, fmt, args...) dev_info(&(lun)->dev, fmt, ## args)
89 * Keep those macros in sync with those in
90 * include/linux/usb/composite.h or else GCC will complain. If they
91 * are identical (the same names of arguments, white spaces in the
92 * same places) GCC will allow redefinition otherwise (even if some
93 * white space is removed or added) warning will be issued.
95 * Those macros are needed here because File Storage Gadget does not
96 * include the composite.h header. For composite gadgets those macros
97 * are redundant since composite.h is included any way.
99 * One could check whether those macros are already defined (which
100 * would indicate composite.h had been included) or not (which would
101 * indicate we were in FSG) but this is not done because a warning is
102 * desired if definitions here differ from the ones in composite.h.
104 * We want the definitions to match and be the same in File Storage
105 * Gadget as well as Mass Storage Function (and so composite gadgets
106 * using MSF). If someone changes them in composite.h it will produce
107 * a warning in this file when building MSF.
109 #define DBG(d, fmt, args...) dev_dbg(&(d)->gadget->dev , fmt , ## args)
110 #define VDBG(d, fmt, args...) dev_vdbg(&(d)->gadget->dev , fmt , ## args)
111 #define ERROR(d, fmt, args...) dev_err(&(d)->gadget->dev , fmt , ## args)
112 #define WARNING(d, fmt, args...) dev_warn(&(d)->gadget->dev , fmt , ## args)
113 #define INFO(d, fmt, args...) dev_info(&(d)->gadget->dev , fmt , ## args)
119 # define dump_msg(fsg, /* const char * */ label, \
120 /* const u8 * */ buf, /* unsigned */ length) do { \
121 if (length < 512) { \
122 DBG(fsg, "%s, length %u:\n", label, length); \
123 print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, \
124 16, 1, buf, length, 0); \
128 # define dump_cdb(fsg) do { } while (0)
132 # define dump_msg(fsg, /* const char * */ label, \
133 /* const u8 * */ buf, /* unsigned */ length) do { } while (0)
135 # ifdef VERBOSE_DEBUG
137 # define dump_cdb(fsg) \
138 print_hex_dump(KERN_DEBUG, "SCSI CDB: ", DUMP_PREFIX_NONE, \
139 16, 1, (fsg)->cmnd, (fsg)->cmnd_size, 0) \
143 # define dump_cdb(fsg) do { } while (0)
145 # endif /* VERBOSE_DEBUG */
147 #endif /* DUMP_MSGS */
153 /*-------------------------------------------------------------------------*/
155 /* SCSI device types */
156 #define TYPE_DISK 0x00
157 #define TYPE_CDROM 0x05
159 /* USB protocol value = the transport method */
160 #define USB_PR_CBI 0x00 /* Control/Bulk/Interrupt */
161 #define USB_PR_CB 0x01 /* Control/Bulk w/o interrupt */
162 #define USB_PR_BULK 0x50 /* Bulk-only */
164 /* USB subclass value = the protocol encapsulation */
165 #define USB_SC_RBC 0x01 /* Reduced Block Commands (flash) */
166 #define USB_SC_8020 0x02 /* SFF-8020i, MMC-2, ATAPI (CD-ROM) */
167 #define USB_SC_QIC 0x03 /* QIC-157 (tape) */
168 #define USB_SC_UFI 0x04 /* UFI (floppy) */
169 #define USB_SC_8070 0x05 /* SFF-8070i (removable) */
170 #define USB_SC_SCSI 0x06 /* Transparent SCSI */
172 /* Bulk-only data structures */
174 /* Command Block Wrapper */
175 struct fsg_bulk_cb_wrap {
176 __le32 Signature; /* Contains 'USBC' */
177 u32 Tag; /* Unique per command id */
178 __le32 DataTransferLength; /* Size of the data */
179 u8 Flags; /* Direction in bit 7 */
180 u8 Lun; /* LUN (normally 0) */
181 u8 Length; /* Of the CDB, <= MAX_COMMAND_SIZE */
182 u8 CDB[16]; /* Command Data Block */
185 #define USB_BULK_CB_WRAP_LEN 31
186 #define USB_BULK_CB_SIG 0x43425355 /* Spells out USBC */
187 #define USB_BULK_IN_FLAG 0x80
189 /* Command Status Wrapper */
190 struct bulk_cs_wrap {
191 __le32 Signature; /* Should = 'USBS' */
192 u32 Tag; /* Same as original command */
193 __le32 Residue; /* Amount not transferred */
194 u8 Status; /* See below */
197 #define USB_BULK_CS_WRAP_LEN 13
198 #define USB_BULK_CS_SIG 0x53425355 /* Spells out 'USBS' */
199 #define USB_STATUS_PASS 0
200 #define USB_STATUS_FAIL 1
201 #define USB_STATUS_PHASE_ERROR 2
203 /* Bulk-only class specific requests */
204 #define USB_BULK_RESET_REQUEST 0xff
205 #define USB_BULK_GET_MAX_LUN_REQUEST 0xfe
208 /* CBI Interrupt data structure */
209 struct interrupt_data {
214 #define CBI_INTERRUPT_DATA_LEN 2
216 /* CBI Accept Device-Specific Command request */
217 #define USB_CBI_ADSC_REQUEST 0x00
220 /* Length of a SCSI Command Data Block */
221 #define MAX_COMMAND_SIZE 16
223 /* SCSI commands that we recognize */
224 #define SC_FORMAT_UNIT 0x04
225 #define SC_INQUIRY 0x12
226 #define SC_MODE_SELECT_6 0x15
227 #define SC_MODE_SELECT_10 0x55
228 #define SC_MODE_SENSE_6 0x1a
229 #define SC_MODE_SENSE_10 0x5a
230 #define SC_PREVENT_ALLOW_MEDIUM_REMOVAL 0x1e
231 #define SC_READ_6 0x08
232 #define SC_READ_10 0x28
233 #define SC_READ_12 0xa8
234 #define SC_READ_CAPACITY 0x25
235 #define SC_READ_FORMAT_CAPACITIES 0x23
236 #define SC_READ_HEADER 0x44
237 #define SC_READ_TOC 0x43
238 #define SC_RELEASE 0x17
239 #define SC_REQUEST_SENSE 0x03
240 #define SC_RESERVE 0x16
241 #define SC_SEND_DIAGNOSTIC 0x1d
242 #define SC_START_STOP_UNIT 0x1b
243 #define SC_SYNCHRONIZE_CACHE 0x35
244 #define SC_TEST_UNIT_READY 0x00
245 #define SC_VERIFY 0x2f
246 #define SC_WRITE_6 0x0a
247 #define SC_WRITE_10 0x2a
248 #define SC_WRITE_12 0xaa
250 /* SCSI Sense Key/Additional Sense Code/ASC Qualifier values */
251 #define SS_NO_SENSE 0
252 #define SS_COMMUNICATION_FAILURE 0x040800
253 #define SS_INVALID_COMMAND 0x052000
254 #define SS_INVALID_FIELD_IN_CDB 0x052400
255 #define SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE 0x052100
256 #define SS_LOGICAL_UNIT_NOT_SUPPORTED 0x052500
257 #define SS_MEDIUM_NOT_PRESENT 0x023a00
258 #define SS_MEDIUM_REMOVAL_PREVENTED 0x055302
259 #define SS_NOT_READY_TO_READY_TRANSITION 0x062800
260 #define SS_RESET_OCCURRED 0x062900
261 #define SS_SAVING_PARAMETERS_NOT_SUPPORTED 0x053900
262 #define SS_UNRECOVERED_READ_ERROR 0x031100
263 #define SS_WRITE_ERROR 0x030c02
264 #define SS_WRITE_PROTECTED 0x072700
266 #define SK(x) ((u8) ((x) >> 16)) /* Sense Key byte, etc. */
267 #define ASC(x) ((u8) ((x) >> 8))
268 #define ASCQ(x) ((u8) (x))
271 /*-------------------------------------------------------------------------*/
279 unsigned int initially_ro:1;
281 unsigned int removable:1;
282 unsigned int cdrom:1;
283 unsigned int prevent_medium_removal:1;
284 unsigned int registered:1;
285 unsigned int info_valid:1;
286 unsigned int nofua:1;
290 u32 unit_attention_data;
295 #define fsg_lun_is_open(curlun) ((curlun)->filp != NULL)
297 static struct fsg_lun *fsg_lun_from_dev(struct device *dev)
299 return container_of(dev, struct fsg_lun, dev);
303 /* Big enough to hold our biggest descriptor */
304 #define EP0_BUFSIZE 256
305 #define DELAYED_STATUS (EP0_BUFSIZE + 999) /* An impossibly large value */
307 /* Number of buffers we will use. 2 is enough for double-buffering */
308 #define FSG_NUM_BUFFERS 2
310 /* Default size of buffer length. */
311 #define FSG_BUFLEN ((u32)16384)
313 /* Maximal number of LUNs supported in mass storage function */
314 #define FSG_MAX_LUNS 8
316 enum fsg_buffer_state {
323 #ifdef FSG_BUFFHD_STATIC_BUFFER
324 char buf[FSG_BUFLEN];
328 enum fsg_buffer_state state;
329 struct fsg_buffhd *next;
332 * The NetChip 2280 is faster, and handles some protocol faults
333 * better, if we don't submit any short bulk-out read requests.
334 * So we will record the intended request length here.
336 unsigned int bulk_out_intended_length;
338 struct usb_request *inreq;
340 struct usb_request *outreq;
345 /* This one isn't used anywhere */
346 FSG_STATE_COMMAND_PHASE = -10,
347 FSG_STATE_DATA_PHASE,
348 FSG_STATE_STATUS_PHASE,
351 FSG_STATE_ABORT_BULK_OUT,
353 FSG_STATE_INTERFACE_CHANGE,
354 FSG_STATE_CONFIG_CHANGE,
355 FSG_STATE_DISCONNECT,
360 enum data_direction {
361 DATA_DIR_UNKNOWN = 0,
368 /*-------------------------------------------------------------------------*/
371 static inline u32 get_unaligned_be24(u8 *buf)
373 return 0xffffff & (u32) get_unaligned_be32(buf - 1);
377 /*-------------------------------------------------------------------------*/
381 #ifndef FSG_NO_DEVICE_STRINGS
382 FSG_STRING_MANUFACTURER = 1,
392 static struct usb_otg_descriptor
394 .bLength = sizeof fsg_otg_desc,
395 .bDescriptorType = USB_DT_OTG,
397 .bmAttributes = USB_OTG_SRP,
401 /* There is only one interface. */
403 static struct usb_interface_descriptor
405 .bLength = sizeof fsg_intf_desc,
406 .bDescriptorType = USB_DT_INTERFACE,
408 .bNumEndpoints = 2, /* Adjusted during fsg_bind() */
409 .bInterfaceClass = USB_CLASS_MASS_STORAGE,
410 .bInterfaceSubClass = USB_SC_SCSI, /* Adjusted during fsg_bind() */
411 .bInterfaceProtocol = USB_PR_BULK, /* Adjusted during fsg_bind() */
412 .iInterface = FSG_STRING_INTERFACE,
416 * Three full-speed endpoint descriptors: bulk-in, bulk-out, and
420 static struct usb_endpoint_descriptor
421 fsg_fs_bulk_in_desc = {
422 .bLength = USB_DT_ENDPOINT_SIZE,
423 .bDescriptorType = USB_DT_ENDPOINT,
425 .bEndpointAddress = USB_DIR_IN,
426 .bmAttributes = USB_ENDPOINT_XFER_BULK,
427 /* wMaxPacketSize set by autoconfiguration */
430 static struct usb_endpoint_descriptor
431 fsg_fs_bulk_out_desc = {
432 .bLength = USB_DT_ENDPOINT_SIZE,
433 .bDescriptorType = USB_DT_ENDPOINT,
435 .bEndpointAddress = USB_DIR_OUT,
436 .bmAttributes = USB_ENDPOINT_XFER_BULK,
437 /* wMaxPacketSize set by autoconfiguration */
440 #ifndef FSG_NO_INTR_EP
442 static struct usb_endpoint_descriptor
443 fsg_fs_intr_in_desc = {
444 .bLength = USB_DT_ENDPOINT_SIZE,
445 .bDescriptorType = USB_DT_ENDPOINT,
447 .bEndpointAddress = USB_DIR_IN,
448 .bmAttributes = USB_ENDPOINT_XFER_INT,
449 .wMaxPacketSize = cpu_to_le16(2),
450 .bInterval = 32, /* frames -> 32 ms */
454 # define FSG_FS_FUNCTION_PRE_EP_ENTRIES 2
456 # define FSG_FS_FUNCTION_PRE_EP_ENTRIES 1
461 static struct usb_descriptor_header *fsg_fs_function[] = {
463 (struct usb_descriptor_header *) &fsg_otg_desc,
465 (struct usb_descriptor_header *) &fsg_intf_desc,
466 (struct usb_descriptor_header *) &fsg_fs_bulk_in_desc,
467 (struct usb_descriptor_header *) &fsg_fs_bulk_out_desc,
468 #ifndef FSG_NO_INTR_EP
469 (struct usb_descriptor_header *) &fsg_fs_intr_in_desc,
476 * USB 2.0 devices need to expose both high speed and full speed
477 * descriptors, unless they only run at full speed.
479 * That means alternate endpoint descriptors (bigger packets)
480 * and a "device qualifier" ... plus more construction options
481 * for the configuration descriptor.
483 static struct usb_endpoint_descriptor
484 fsg_hs_bulk_in_desc = {
485 .bLength = USB_DT_ENDPOINT_SIZE,
486 .bDescriptorType = USB_DT_ENDPOINT,
488 /* bEndpointAddress copied from fs_bulk_in_desc during fsg_bind() */
489 .bmAttributes = USB_ENDPOINT_XFER_BULK,
490 .wMaxPacketSize = cpu_to_le16(512),
493 static struct usb_endpoint_descriptor
494 fsg_hs_bulk_out_desc = {
495 .bLength = USB_DT_ENDPOINT_SIZE,
496 .bDescriptorType = USB_DT_ENDPOINT,
498 /* bEndpointAddress copied from fs_bulk_out_desc during fsg_bind() */
499 .bmAttributes = USB_ENDPOINT_XFER_BULK,
500 .wMaxPacketSize = cpu_to_le16(512),
501 .bInterval = 1, /* NAK every 1 uframe */
504 #ifndef FSG_NO_INTR_EP
506 static struct usb_endpoint_descriptor
507 fsg_hs_intr_in_desc = {
508 .bLength = USB_DT_ENDPOINT_SIZE,
509 .bDescriptorType = USB_DT_ENDPOINT,
511 /* bEndpointAddress copied from fs_intr_in_desc during fsg_bind() */
512 .bmAttributes = USB_ENDPOINT_XFER_INT,
513 .wMaxPacketSize = cpu_to_le16(2),
514 .bInterval = 9, /* 2**(9-1) = 256 uframes -> 32 ms */
518 # define FSG_HS_FUNCTION_PRE_EP_ENTRIES 2
520 # define FSG_HS_FUNCTION_PRE_EP_ENTRIES 1
525 static struct usb_descriptor_header *fsg_hs_function[] = {
527 (struct usb_descriptor_header *) &fsg_otg_desc,
529 (struct usb_descriptor_header *) &fsg_intf_desc,
530 (struct usb_descriptor_header *) &fsg_hs_bulk_in_desc,
531 (struct usb_descriptor_header *) &fsg_hs_bulk_out_desc,
532 #ifndef FSG_NO_INTR_EP
533 (struct usb_descriptor_header *) &fsg_hs_intr_in_desc,
538 /* Maxpacket and other transfer characteristics vary by speed. */
539 static struct usb_endpoint_descriptor *
540 fsg_ep_desc(struct usb_gadget *g, struct usb_endpoint_descriptor *fs,
541 struct usb_endpoint_descriptor *hs)
543 if (gadget_is_dualspeed(g) && g->speed == USB_SPEED_HIGH)
549 /* Static strings, in UTF-8 (for simplicity we use only ASCII characters) */
550 static struct usb_string fsg_strings[] = {
551 #ifndef FSG_NO_DEVICE_STRINGS
552 {FSG_STRING_MANUFACTURER, fsg_string_manufacturer},
553 {FSG_STRING_PRODUCT, fsg_string_product},
554 {FSG_STRING_SERIAL, ""},
555 {FSG_STRING_CONFIG, fsg_string_config},
557 {FSG_STRING_INTERFACE, fsg_string_interface},
561 static struct usb_gadget_strings fsg_stringtab = {
562 .language = 0x0409, /* en-us */
563 .strings = fsg_strings,
567 /*-------------------------------------------------------------------------*/
570 * If the next two routines are called while the gadget is registered,
571 * the caller must own fsg->filesem for writing.
574 static int fsg_lun_open(struct fsg_lun *curlun, const char *filename)
577 struct file *filp = NULL;
579 struct inode *inode = NULL;
584 /* R/W if we can, R/O if we must */
585 ro = curlun->initially_ro;
587 filp = filp_open(filename, O_RDWR | O_LARGEFILE, 0);
588 if (-EROFS == PTR_ERR(filp))
592 filp = filp_open(filename, O_RDONLY | O_LARGEFILE, 0);
594 LINFO(curlun, "unable to open backing file: %s\n", filename);
595 return PTR_ERR(filp);
598 if (!(filp->f_mode & FMODE_WRITE))
601 if (filp->f_path.dentry)
602 inode = filp->f_path.dentry->d_inode;
603 if (inode && S_ISBLK(inode->i_mode)) {
604 if (bdev_read_only(inode->i_bdev))
606 } else if (!inode || !S_ISREG(inode->i_mode)) {
607 LINFO(curlun, "invalid file type: %s\n", filename);
612 * If we can't read the file, it's no good.
613 * If we can't write the file, use it read-only.
615 if (!filp->f_op || !(filp->f_op->read || filp->f_op->aio_read)) {
616 LINFO(curlun, "file not readable: %s\n", filename);
619 if (!(filp->f_op->write || filp->f_op->aio_write))
622 size = i_size_read(inode->i_mapping->host);
624 LINFO(curlun, "unable to find file size: %s\n", filename);
628 num_sectors = size >> 9; /* File size in 512-byte blocks */
631 num_sectors &= ~3; /* Reduce to a multiple of 2048 */
632 min_sectors = 300*4; /* Smallest track is 300 frames */
633 if (num_sectors >= 256*60*75*4) {
634 num_sectors = (256*60*75 - 1) * 4;
635 LINFO(curlun, "file too big: %s\n", filename);
636 LINFO(curlun, "using only first %d blocks\n",
640 if (num_sectors < min_sectors) {
641 LINFO(curlun, "file too small: %s\n", filename);
649 curlun->file_length = size;
650 curlun->num_sectors = num_sectors;
651 LDBG(curlun, "open backing file: %s\n", filename);
655 filp_close(filp, current->files);
660 static void fsg_lun_close(struct fsg_lun *curlun)
663 LDBG(curlun, "close backing file\n");
670 /*-------------------------------------------------------------------------*/
673 * Sync the file data, don't bother with the metadata.
674 * This code was copied from fs/buffer.c:sys_fdatasync().
676 static int fsg_lun_fsync_sub(struct fsg_lun *curlun)
678 struct file *filp = curlun->filp;
680 if (curlun->ro || !filp)
682 return vfs_fsync(filp, 1);
685 static void store_cdrom_address(u8 *dest, int msf, u32 addr)
688 /* Convert to Minutes-Seconds-Frames */
689 addr >>= 2; /* Convert to 2048-byte frames */
690 addr += 2*75; /* Lead-in occupies 2 seconds */
691 dest[3] = addr % 75; /* Frames */
693 dest[2] = addr % 60; /* Seconds */
695 dest[1] = addr; /* Minutes */
696 dest[0] = 0; /* Reserved */
698 /* Absolute sector */
699 put_unaligned_be32(addr, dest);
704 /*-------------------------------------------------------------------------*/
707 static ssize_t fsg_show_ro(struct device *dev, struct device_attribute *attr,
710 struct fsg_lun *curlun = fsg_lun_from_dev(dev);
712 return sprintf(buf, "%d\n", fsg_lun_is_open(curlun)
714 : curlun->initially_ro);
717 static ssize_t fsg_show_nofua(struct device *dev, struct device_attribute *attr,
720 struct fsg_lun *curlun = fsg_lun_from_dev(dev);
722 return sprintf(buf, "%u\n", curlun->nofua);
725 static ssize_t fsg_show_file(struct device *dev, struct device_attribute *attr,
728 struct fsg_lun *curlun = fsg_lun_from_dev(dev);
729 struct rw_semaphore *filesem = dev_get_drvdata(dev);
734 if (fsg_lun_is_open(curlun)) { /* Get the complete pathname */
735 p = d_path(&curlun->filp->f_path, buf, PAGE_SIZE - 1);
741 buf[rc] = '\n'; /* Add a newline */
744 } else { /* No file, return 0 bytes */
753 static ssize_t fsg_store_ro(struct device *dev, struct device_attribute *attr,
754 const char *buf, size_t count)
757 struct fsg_lun *curlun = fsg_lun_from_dev(dev);
758 struct rw_semaphore *filesem = dev_get_drvdata(dev);
761 if (strict_strtoul(buf, 2, &ro))
765 * Allow the write-enable status to change only while the
766 * backing file is closed.
769 if (fsg_lun_is_open(curlun)) {
770 LDBG(curlun, "read-only status change prevented\n");
774 curlun->initially_ro = ro;
775 LDBG(curlun, "read-only status set to %d\n", curlun->ro);
781 static ssize_t fsg_store_nofua(struct device *dev,
782 struct device_attribute *attr,
783 const char *buf, size_t count)
785 struct fsg_lun *curlun = fsg_lun_from_dev(dev);
788 if (strict_strtoul(buf, 2, &nofua))
791 /* Sync data when switching from async mode to sync */
792 if (!nofua && curlun->nofua)
793 fsg_lun_fsync_sub(curlun);
795 curlun->nofua = nofua;
800 static ssize_t fsg_store_file(struct device *dev, struct device_attribute *attr,
801 const char *buf, size_t count)
803 struct fsg_lun *curlun = fsg_lun_from_dev(dev);
804 struct rw_semaphore *filesem = dev_get_drvdata(dev);
807 if (curlun->prevent_medium_removal && fsg_lun_is_open(curlun)) {
808 LDBG(curlun, "eject attempt prevented\n");
809 return -EBUSY; /* "Door is locked" */
812 /* Remove a trailing newline */
813 if (count > 0 && buf[count-1] == '\n')
814 ((char *) buf)[count-1] = 0; /* Ugh! */
816 /* Eject current medium */
818 if (fsg_lun_is_open(curlun)) {
819 fsg_lun_close(curlun);
820 curlun->unit_attention_data = SS_MEDIUM_NOT_PRESENT;
823 /* Load new medium */
824 if (count > 0 && buf[0]) {
825 rc = fsg_lun_open(curlun, buf);
827 curlun->unit_attention_data =
828 SS_NOT_READY_TO_READY_TRANSITION;
831 return (rc < 0 ? rc : count);