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1/*
2 * storage_common.c -- Common definitions for mass storage functionality
3 *
4 * Copyright (C) 2003-2008 Alan Stern
5 * Copyeight (C) 2009 Samsung Electronics
6 * Author: Michal Nazarewicz (m.nazarewicz@samsung.com)
7 *
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.
12 *
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.
17 *
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
21 */
22
23
24/*
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.
33 */
34
35/*
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.
40 *
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.
45 *
46 * When FSG_NO_OTG is defined fsg_otg_desc won't be defined.
47 */
48
49/*
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.
53 */
54
55
56#include <linux/usb/storage.h>
57#include <scsi/scsi.h>
58#include <asm/unaligned.h>
59
60
61/*
62 * Thanks to NetChip Technologies for donating this product ID.
63 *
64 * DO NOT REUSE THESE IDs with any other driver!! Ever!!
65 * Instead: allocate your own, using normal USB-IF procedures.
66 */
67#define FSG_VENDOR_ID 0x0525 /* NetChip */
68#define FSG_PRODUCT_ID 0xa4a5 /* Linux-USB File-backed Storage Gadget */
69
70
71/*-------------------------------------------------------------------------*/
72
73
74#ifndef DEBUG
75#undef VERBOSE_DEBUG
76#undef DUMP_MSGS
77#endif /* !DEBUG */
78
79#ifdef VERBOSE_DEBUG
80#define VLDBG LDBG
81#else
82#define VLDBG(lun, fmt, args...) do { } while (0)
83#endif /* VERBOSE_DEBUG */
84
85#define LDBG(lun, fmt, args...) dev_dbg (&(lun)->dev, fmt, ## args)
86#define LERROR(lun, fmt, args...) dev_err (&(lun)->dev, fmt, ## args)
87#define LWARN(lun, fmt, args...) dev_warn(&(lun)->dev, fmt, ## args)
88#define LINFO(lun, fmt, args...) dev_info(&(lun)->dev, fmt, ## args)
89
90/*
91 * Keep those macros in sync with those in
92 * include/linux/usb/composite.h or else GCC will complain. If they
93 * are identical (the same names of arguments, white spaces in the
94 * same places) GCC will allow redefinition otherwise (even if some
95 * white space is removed or added) warning will be issued.
96 *
97 * Those macros are needed here because File Storage Gadget does not
98 * include the composite.h header. For composite gadgets those macros
99 * are redundant since composite.h is included any way.
100 *
101 * One could check whether those macros are already defined (which
102 * would indicate composite.h had been included) or not (which would
103 * indicate we were in FSG) but this is not done because a warning is
104 * desired if definitions here differ from the ones in composite.h.
105 *
106 * We want the definitions to match and be the same in File Storage
107 * Gadget as well as Mass Storage Function (and so composite gadgets
108 * using MSF). If someone changes them in composite.h it will produce
109 * a warning in this file when building MSF.
110 */
111#define DBG(d, fmt, args...) dev_dbg(&(d)->gadget->dev , fmt , ## args)
112#define VDBG(d, fmt, args...) dev_vdbg(&(d)->gadget->dev , fmt , ## args)
113#define ERROR(d, fmt, args...) dev_err(&(d)->gadget->dev , fmt , ## args)
114#define WARNING(d, fmt, args...) dev_warn(&(d)->gadget->dev , fmt , ## args)
115#define INFO(d, fmt, args...) dev_info(&(d)->gadget->dev , fmt , ## args)
116
117
118
119#ifdef DUMP_MSGS
120
121# define dump_msg(fsg, /* const char * */ label, \
122 /* const u8 * */ buf, /* unsigned */ length) do { \
123 if (length < 512) { \
124 DBG(fsg, "%s, length %u:\n", label, length); \
125 print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, \
126 16, 1, buf, length, 0); \
127 } \
128} while (0)
129
130# define dump_cdb(fsg) do { } while (0)
131
132#else
133
134# define dump_msg(fsg, /* const char * */ label, \
135 /* const u8 * */ buf, /* unsigned */ length) do { } while (0)
136
137# ifdef VERBOSE_DEBUG
138
139# define dump_cdb(fsg) \
140 print_hex_dump(KERN_DEBUG, "SCSI CDB: ", DUMP_PREFIX_NONE, \
141 16, 1, (fsg)->cmnd, (fsg)->cmnd_size, 0) \
142
143# else
144
145# define dump_cdb(fsg) do { } while (0)
146
147# endif /* VERBOSE_DEBUG */
148
149#endif /* DUMP_MSGS */
150
151
152
153
154
155/*-------------------------------------------------------------------------*/
156
157/* Bulk-only data structures */
158
159/* Command Block Wrapper */
160struct fsg_bulk_cb_wrap {
161 __le32 Signature; /* Contains 'USBC' */
162 u32 Tag; /* Unique per command id */
163 __le32 DataTransferLength; /* Size of the data */
164 u8 Flags; /* Direction in bit 7 */
165 u8 Lun; /* LUN (normally 0) */
166 u8 Length; /* Of the CDB, <= MAX_COMMAND_SIZE */
167 u8 CDB[16]; /* Command Data Block */
168};
169
170#define USB_BULK_CB_WRAP_LEN 31
171#define USB_BULK_CB_SIG 0x43425355 /* Spells out USBC */
172#define USB_BULK_IN_FLAG 0x80
173
174/* Command Status Wrapper */
175struct bulk_cs_wrap {
176 __le32 Signature; /* Should = 'USBS' */
177 u32 Tag; /* Same as original command */
178 __le32 Residue; /* Amount not transferred */
179 u8 Status; /* See below */
180};
181
182#define USB_BULK_CS_WRAP_LEN 13
183#define USB_BULK_CS_SIG 0x53425355 /* Spells out 'USBS' */
184#define USB_STATUS_PASS 0
185#define USB_STATUS_FAIL 1
186#define USB_STATUS_PHASE_ERROR 2
187
188/* Bulk-only class specific requests */
189#define USB_BULK_RESET_REQUEST 0xff
190#define USB_BULK_GET_MAX_LUN_REQUEST 0xfe
191
192
193/* CBI Interrupt data structure */
194struct interrupt_data {
195 u8 bType;
196 u8 bValue;
197};
198
199#define CBI_INTERRUPT_DATA_LEN 2
200
201/* CBI Accept Device-Specific Command request */
202#define USB_CBI_ADSC_REQUEST 0x00
203
204
205/* Length of a SCSI Command Data Block */
206#define MAX_COMMAND_SIZE 16
207
208/* SCSI Sense Key/Additional Sense Code/ASC Qualifier values */
209#define SS_NO_SENSE 0
210#define SS_COMMUNICATION_FAILURE 0x040800
211#define SS_INVALID_COMMAND 0x052000
212#define SS_INVALID_FIELD_IN_CDB 0x052400
213#define SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE 0x052100
214#define SS_LOGICAL_UNIT_NOT_SUPPORTED 0x052500
215#define SS_MEDIUM_NOT_PRESENT 0x023a00
216#define SS_MEDIUM_REMOVAL_PREVENTED 0x055302
217#define SS_NOT_READY_TO_READY_TRANSITION 0x062800
218#define SS_RESET_OCCURRED 0x062900
219#define SS_SAVING_PARAMETERS_NOT_SUPPORTED 0x053900
220#define SS_UNRECOVERED_READ_ERROR 0x031100
221#define SS_WRITE_ERROR 0x030c02
222#define SS_WRITE_PROTECTED 0x072700
223
224#define SK(x) ((u8) ((x) >> 16)) /* Sense Key byte, etc. */
225#define ASC(x) ((u8) ((x) >> 8))
226#define ASCQ(x) ((u8) (x))
227
228
229/*-------------------------------------------------------------------------*/
230
231
232struct fsg_lun {
233 struct file *filp;
234 loff_t file_length;
235 loff_t num_sectors;
236
237 unsigned int initially_ro:1;
238 unsigned int ro:1;
239 unsigned int removable:1;
240 unsigned int cdrom:1;
241 unsigned int prevent_medium_removal:1;
242 unsigned int registered:1;
243 unsigned int info_valid:1;
244 unsigned int nofua:1;
245
246 u32 sense_data;
247 u32 sense_data_info;
248 u32 unit_attention_data;
249
250 struct device dev;
251};
252
253#define fsg_lun_is_open(curlun) ((curlun)->filp != NULL)
254
255static struct fsg_lun *fsg_lun_from_dev(struct device *dev)
256{
257 return container_of(dev, struct fsg_lun, dev);
258}
259
260
261/* Big enough to hold our biggest descriptor */
262#define EP0_BUFSIZE 256
263#define DELAYED_STATUS (EP0_BUFSIZE + 999) /* An impossibly large value */
264
265/* Number of buffers we will use. 2 is enough for double-buffering */
266#define FSG_NUM_BUFFERS 2
267
268/* Default size of buffer length. */
269#define FSG_BUFLEN ((u32)16384)
270
271/* Maximal number of LUNs supported in mass storage function */
272#define FSG_MAX_LUNS 8
273
274enum fsg_buffer_state {
275 BUF_STATE_EMPTY = 0,
276 BUF_STATE_FULL,
277 BUF_STATE_BUSY
278};
279
280struct fsg_buffhd {
281#ifdef FSG_BUFFHD_STATIC_BUFFER
282 char buf[FSG_BUFLEN];
283#else
284 void *buf;
285#endif
286 enum fsg_buffer_state state;
287 struct fsg_buffhd *next;
288
289 /*
290 * The NetChip 2280 is faster, and handles some protocol faults
291 * better, if we don't submit any short bulk-out read requests.
292 * So we will record the intended request length here.
293 */
294 unsigned int bulk_out_intended_length;
295
296 struct usb_request *inreq;
297 int inreq_busy;
298 struct usb_request *outreq;
299 int outreq_busy;
300};
301
302enum fsg_state {
303 /* This one isn't used anywhere */
304 FSG_STATE_COMMAND_PHASE = -10,
305 FSG_STATE_DATA_PHASE,
306 FSG_STATE_STATUS_PHASE,
307
308 FSG_STATE_IDLE = 0,
309 FSG_STATE_ABORT_BULK_OUT,
310 FSG_STATE_RESET,
311 FSG_STATE_INTERFACE_CHANGE,
312 FSG_STATE_CONFIG_CHANGE,
313 FSG_STATE_DISCONNECT,
314 FSG_STATE_EXIT,
315 FSG_STATE_TERMINATED
316};
317
318enum data_direction {
319 DATA_DIR_UNKNOWN = 0,
320 DATA_DIR_FROM_HOST,
321 DATA_DIR_TO_HOST,
322 DATA_DIR_NONE
323};
324
325
326/*-------------------------------------------------------------------------*/
327
328
329static inline u32 get_unaligned_be24(u8 *buf)
330{
331 return 0xffffff & (u32) get_unaligned_be32(buf - 1);
332}
333
334
335/*-------------------------------------------------------------------------*/
336
337
338enum {
339#ifndef FSG_NO_DEVICE_STRINGS
340 FSG_STRING_MANUFACTURER = 1,
341 FSG_STRING_PRODUCT,
342 FSG_STRING_SERIAL,
343 FSG_STRING_CONFIG,
344#endif
345 FSG_STRING_INTERFACE
346};
347
348
349#ifndef FSG_NO_OTG
350static struct usb_otg_descriptor
351fsg_otg_desc = {
352 .bLength = sizeof fsg_otg_desc,
353 .bDescriptorType = USB_DT_OTG,
354
355 .bmAttributes = USB_OTG_SRP,
356};
357#endif
358
359/* There is only one interface. */
360
361static struct usb_interface_descriptor
362fsg_intf_desc = {
363 .bLength = sizeof fsg_intf_desc,
364 .bDescriptorType = USB_DT_INTERFACE,
365
366 .bNumEndpoints = 2, /* Adjusted during fsg_bind() */
367 .bInterfaceClass = USB_CLASS_MASS_STORAGE,
368 .bInterfaceSubClass = USB_SC_SCSI, /* Adjusted during fsg_bind() */
369 .bInterfaceProtocol = USB_PR_BULK, /* Adjusted during fsg_bind() */
370 .iInterface = FSG_STRING_INTERFACE,
371};
372
373/*
374 * Three full-speed endpoint descriptors: bulk-in, bulk-out, and
375 * interrupt-in.
376 */
377
378static struct usb_endpoint_descriptor
379fsg_fs_bulk_in_desc = {
380 .bLength = USB_DT_ENDPOINT_SIZE,
381 .bDescriptorType = USB_DT_ENDPOINT,
382
383 .bEndpointAddress = USB_DIR_IN,
384 .bmAttributes = USB_ENDPOINT_XFER_BULK,
385 /* wMaxPacketSize set by autoconfiguration */
386};
387
388static struct usb_endpoint_descriptor
389fsg_fs_bulk_out_desc = {
390 .bLength = USB_DT_ENDPOINT_SIZE,
391 .bDescriptorType = USB_DT_ENDPOINT,
392
393 .bEndpointAddress = USB_DIR_OUT,
394 .bmAttributes = USB_ENDPOINT_XFER_BULK,
395 /* wMaxPacketSize set by autoconfiguration */
396};
397
398#ifndef FSG_NO_INTR_EP
399
400static struct usb_endpoint_descriptor
401fsg_fs_intr_in_desc = {
402 .bLength = USB_DT_ENDPOINT_SIZE,
403 .bDescriptorType = USB_DT_ENDPOINT,
404
405 .bEndpointAddress = USB_DIR_IN,
406 .bmAttributes = USB_ENDPOINT_XFER_INT,
407 .wMaxPacketSize = cpu_to_le16(2),
408 .bInterval = 32, /* frames -> 32 ms */
409};
410
411#ifndef FSG_NO_OTG
412# define FSG_FS_FUNCTION_PRE_EP_ENTRIES 2
413#else
414# define FSG_FS_FUNCTION_PRE_EP_ENTRIES 1
415#endif
416
417#endif
418
419static struct usb_descriptor_header *fsg_fs_function[] = {
420#ifndef FSG_NO_OTG
421 (struct usb_descriptor_header *) &fsg_otg_desc,
422#endif
423 (struct usb_descriptor_header *) &fsg_intf_desc,
424 (struct usb_descriptor_header *) &fsg_fs_bulk_in_desc,
425 (struct usb_descriptor_header *) &fsg_fs_bulk_out_desc,
426#ifndef FSG_NO_INTR_EP
427 (struct usb_descriptor_header *) &fsg_fs_intr_in_desc,
428#endif
429 NULL,
430};
431
432
433/*
434 * USB 2.0 devices need to expose both high speed and full speed
435 * descriptors, unless they only run at full speed.
436 *
437 * That means alternate endpoint descriptors (bigger packets)
438 * and a "device qualifier" ... plus more construction options
439 * for the configuration descriptor.
440 */
441static struct usb_endpoint_descriptor
442fsg_hs_bulk_in_desc = {
443 .bLength = USB_DT_ENDPOINT_SIZE,
444 .bDescriptorType = USB_DT_ENDPOINT,
445
446 /* bEndpointAddress copied from fs_bulk_in_desc during fsg_bind() */
447 .bmAttributes = USB_ENDPOINT_XFER_BULK,
448 .wMaxPacketSize = cpu_to_le16(512),
449};
450
451static struct usb_endpoint_descriptor
452fsg_hs_bulk_out_desc = {
453 .bLength = USB_DT_ENDPOINT_SIZE,
454 .bDescriptorType = USB_DT_ENDPOINT,
455
456 /* bEndpointAddress copied from fs_bulk_out_desc during fsg_bind() */
457 .bmAttributes = USB_ENDPOINT_XFER_BULK,
458 .wMaxPacketSize = cpu_to_le16(512),
459 .bInterval = 1, /* NAK every 1 uframe */
460};
461
462#ifndef FSG_NO_INTR_EP
463
464static struct usb_endpoint_descriptor
465fsg_hs_intr_in_desc = {
466 .bLength = USB_DT_ENDPOINT_SIZE,
467 .bDescriptorType = USB_DT_ENDPOINT,
468
469 /* bEndpointAddress copied from fs_intr_in_desc during fsg_bind() */
470 .bmAttributes = USB_ENDPOINT_XFER_INT,
471 .wMaxPacketSize = cpu_to_le16(2),
472 .bInterval = 9, /* 2**(9-1) = 256 uframes -> 32 ms */
473};
474
475#ifndef FSG_NO_OTG
476# define FSG_HS_FUNCTION_PRE_EP_ENTRIES 2
477#else
478# define FSG_HS_FUNCTION_PRE_EP_ENTRIES 1
479#endif
480
481#endif
482
483static struct usb_descriptor_header *fsg_hs_function[] = {
484#ifndef FSG_NO_OTG
485 (struct usb_descriptor_header *) &fsg_otg_desc,
486#endif
487 (struct usb_descriptor_header *) &fsg_intf_desc,
488 (struct usb_descriptor_header *) &fsg_hs_bulk_in_desc,
489 (struct usb_descriptor_header *) &fsg_hs_bulk_out_desc,
490#ifndef FSG_NO_INTR_EP
491 (struct usb_descriptor_header *) &fsg_hs_intr_in_desc,
492#endif
493 NULL,
494};
495
496/* Maxpacket and other transfer characteristics vary by speed. */
497static __maybe_unused struct usb_endpoint_descriptor *
498fsg_ep_desc(struct usb_gadget *g, struct usb_endpoint_descriptor *fs,
499 struct usb_endpoint_descriptor *hs)
500{
501 if (gadget_is_dualspeed(g) && g->speed == USB_SPEED_HIGH)
502 return hs;
503 return fs;
504}
505
506
507/* Static strings, in UTF-8 (for simplicity we use only ASCII characters) */
508static struct usb_string fsg_strings[] = {
509#ifndef FSG_NO_DEVICE_STRINGS
510 {FSG_STRING_MANUFACTURER, fsg_string_manufacturer},
511 {FSG_STRING_PRODUCT, fsg_string_product},
512 {FSG_STRING_SERIAL, ""},
513 {FSG_STRING_CONFIG, fsg_string_config},
514#endif
515 {FSG_STRING_INTERFACE, fsg_string_interface},
516 {}
517};
518
519static struct usb_gadget_strings fsg_stringtab = {
520 .language = 0x0409, /* en-us */
521 .strings = fsg_strings,
522};
523
524
525 /*-------------------------------------------------------------------------*/
526
527/*
528 * If the next two routines are called while the gadget is registered,
529 * the caller must own fsg->filesem for writing.
530 */
531
532static int fsg_lun_open(struct fsg_lun *curlun, const char *filename)
533{
534 int ro;
535 struct file *filp = NULL;
536 int rc = -EINVAL;
537 struct inode *inode = NULL;
538 loff_t size;
539 loff_t num_sectors;
540 loff_t min_sectors;
541
542 /* R/W if we can, R/O if we must */
543 ro = curlun->initially_ro;
544 if (!ro) {
545 filp = filp_open(filename, O_RDWR | O_LARGEFILE, 0);
546 if (PTR_ERR(filp) == -EROFS || PTR_ERR(filp) == -EACCES)
547 ro = 1;
548 }
549 if (ro)
550 filp = filp_open(filename, O_RDONLY | O_LARGEFILE, 0);
551 if (IS_ERR(filp)) {
552 LINFO(curlun, "unable to open backing file: %s\n", filename);
553 return PTR_ERR(filp);
554 }
555
556 if (!(filp->f_mode & FMODE_WRITE))
557 ro = 1;
558
559 if (filp->f_path.dentry)
560 inode = filp->f_path.dentry->d_inode;
561 if (!inode || (!S_ISREG(inode->i_mode) && !S_ISBLK(inode->i_mode))) {
562 LINFO(curlun, "invalid file type: %s\n", filename);
563 goto out;
564 }
565
566 /*
567 * If we can't read the file, it's no good.
568 * If we can't write the file, use it read-only.
569 */
570 if (!filp->f_op || !(filp->f_op->read || filp->f_op->aio_read)) {
571 LINFO(curlun, "file not readable: %s\n", filename);
572 goto out;
573 }
574 if (!(filp->f_op->write || filp->f_op->aio_write))
575 ro = 1;
576
577 size = i_size_read(inode->i_mapping->host);
578 if (size < 0) {
579 LINFO(curlun, "unable to find file size: %s\n", filename);
580 rc = (int) size;
581 goto out;
582 }
583 num_sectors = size >> 9; /* File size in 512-byte blocks */
584 min_sectors = 1;
585 if (curlun->cdrom) {
586 num_sectors &= ~3; /* Reduce to a multiple of 2048 */
587 min_sectors = 300*4; /* Smallest track is 300 frames */
588 if (num_sectors >= 256*60*75*4) {
589 num_sectors = (256*60*75 - 1) * 4;
590 LINFO(curlun, "file too big: %s\n", filename);
591 LINFO(curlun, "using only first %d blocks\n",
592 (int) num_sectors);
593 }
594 }
595 if (num_sectors < min_sectors) {
596 LINFO(curlun, "file too small: %s\n", filename);
597 rc = -ETOOSMALL;
598 goto out;
599 }
600
601 get_file(filp);
602 curlun->ro = ro;
603 curlun->filp = filp;
604 curlun->file_length = size;
605 curlun->num_sectors = num_sectors;
606 LDBG(curlun, "open backing file: %s\n", filename);
607 rc = 0;
608
609out:
610 filp_close(filp, current->files);
611 return rc;
612}
613
614
615static void fsg_lun_close(struct fsg_lun *curlun)
616{
617 if (curlun->filp) {
618 LDBG(curlun, "close backing file\n");
619 fput(curlun->filp);
620 curlun->filp = NULL;
621 }
622}
623
624
625/*-------------------------------------------------------------------------*/
626
627/*
628 * Sync the file data, don't bother with the metadata.
629 * This code was copied from fs/buffer.c:sys_fdatasync().
630 */
631static int fsg_lun_fsync_sub(struct fsg_lun *curlun)
632{
633 struct file *filp = curlun->filp;
634
635 if (curlun->ro || !filp)
636 return 0;
637 return vfs_fsync(filp, 1);
638}
639
640static void store_cdrom_address(u8 *dest, int msf, u32 addr)
641{
642 if (msf) {
643 /* Convert to Minutes-Seconds-Frames */
644 addr >>= 2; /* Convert to 2048-byte frames */
645 addr += 2*75; /* Lead-in occupies 2 seconds */
646 dest[3] = addr % 75; /* Frames */
647 addr /= 75;
648 dest[2] = addr % 60; /* Seconds */
649 addr /= 60;
650 dest[1] = addr; /* Minutes */
651 dest[0] = 0; /* Reserved */
652 } else {
653 /* Absolute sector */
654 put_unaligned_be32(addr, dest);
655 }
656}
657
658
659/*-------------------------------------------------------------------------*/
660
661
662static ssize_t fsg_show_ro(struct device *dev, struct device_attribute *attr,
663 char *buf)
664{
665 struct fsg_lun *curlun = fsg_lun_from_dev(dev);
666
667 return sprintf(buf, "%d\n", fsg_lun_is_open(curlun)
668 ? curlun->ro
669 : curlun->initially_ro);
670}
671
672static ssize_t fsg_show_nofua(struct device *dev, struct device_attribute *attr,
673 char *buf)
674{
675 struct fsg_lun *curlun = fsg_lun_from_dev(dev);
676
677 return sprintf(buf, "%u\n", curlun->nofua);
678}
679
680static ssize_t fsg_show_file(struct device *dev, struct device_attribute *attr,
681 char *buf)
682{
683 struct fsg_lun *curlun = fsg_lun_from_dev(dev);
684 struct rw_semaphore *filesem = dev_get_drvdata(dev);
685 char *p;
686 ssize_t rc;
687
688 down_read(filesem);
689 if (fsg_lun_is_open(curlun)) { /* Get the complete pathname */
690 p = d_path(&curlun->filp->f_path, buf, PAGE_SIZE - 1);
691 if (IS_ERR(p))
692 rc = PTR_ERR(p);
693 else {
694 rc = strlen(p);
695 memmove(buf, p, rc);
696 buf[rc] = '\n'; /* Add a newline */
697 buf[++rc] = 0;
698 }
699 } else { /* No file, return 0 bytes */
700 *buf = 0;
701 rc = 0;
702 }
703 up_read(filesem);
704 return rc;
705}
706
707
708static ssize_t fsg_store_ro(struct device *dev, struct device_attribute *attr,
709 const char *buf, size_t count)
710{
711 ssize_t rc;
712 struct fsg_lun *curlun = fsg_lun_from_dev(dev);
713 struct rw_semaphore *filesem = dev_get_drvdata(dev);
714 unsigned ro;
715
716 rc = kstrtouint(buf, 2, &ro);
717 if (rc)
718 return rc;
719
720 /*
721 * Allow the write-enable status to change only while the
722 * backing file is closed.
723 */
724 down_read(filesem);
725 if (fsg_lun_is_open(curlun)) {
726 LDBG(curlun, "read-only status change prevented\n");
727 rc = -EBUSY;
728 } else {
729 curlun->ro = ro;
730 curlun->initially_ro = ro;
731 LDBG(curlun, "read-only status set to %d\n", curlun->ro);
732 rc = count;
733 }
734 up_read(filesem);
735 return rc;
736}
737
738static ssize_t fsg_store_nofua(struct device *dev,
739 struct device_attribute *attr,
740 const char *buf, size_t count)
741{
742 struct fsg_lun *curlun = fsg_lun_from_dev(dev);
743 unsigned nofua;
744 int ret;
745
746 ret = kstrtouint(buf, 2, &nofua);
747 if (ret)
748 return ret;
749
750 /* Sync data when switching from async mode to sync */
751 if (!nofua && curlun->nofua)
752 fsg_lun_fsync_sub(curlun);
753
754 curlun->nofua = nofua;
755
756 return count;
757}
758
759static ssize_t fsg_store_file(struct device *dev, struct device_attribute *attr,
760 const char *buf, size_t count)
761{
762 struct fsg_lun *curlun = fsg_lun_from_dev(dev);
763 struct rw_semaphore *filesem = dev_get_drvdata(dev);
764 int rc = 0;
765
766 if (curlun->prevent_medium_removal && fsg_lun_is_open(curlun)) {
767 LDBG(curlun, "eject attempt prevented\n");
768 return -EBUSY; /* "Door is locked" */
769 }
770
771 /* Remove a trailing newline */
772 if (count > 0 && buf[count-1] == '\n')
773 ((char *) buf)[count-1] = 0; /* Ugh! */
774
775 /* Eject current medium */
776 down_write(filesem);
777 if (fsg_lun_is_open(curlun)) {
778 fsg_lun_close(curlun);
779 curlun->unit_attention_data = SS_MEDIUM_NOT_PRESENT;
780 }
781
782 /* Load new medium */
783 if (count > 0 && buf[0]) {
784 rc = fsg_lun_open(curlun, buf);
785 if (rc == 0)
786 curlun->unit_attention_data =
787 SS_NOT_READY_TO_READY_TRANSITION;
788 }
789 up_write(filesem);
790 return (rc < 0 ? rc : count);
791}