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path: root/drivers/usb/gadget/storage_common.c
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Diffstat (limited to 'drivers/usb/gadget/storage_common.c')
-rw-r--r--drivers/usb/gadget/storage_common.c778
1 files changed, 778 insertions, 0 deletions
diff --git a/drivers/usb/gadget/storage_common.c b/drivers/usb/gadget/storage_common.c
new file mode 100644
index 000000000000..868d8ee86756
--- /dev/null
+++ b/drivers/usb/gadget/storage_common.c
@@ -0,0 +1,778 @@
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_serial -- product's serial
30 * - fsg_string_config -- name of the configuration
31 * - fsg_string_interface -- name of the interface
32 * The first four are only needed when FSG_DESCRIPTORS_DEVICE_STRINGS
33 * macro is defined prior to including this file.
34 */
35
36/*
37 * When FSG_NO_INTR_EP is defined fsg_fs_intr_in_desc and
38 * fsg_hs_intr_in_desc objects as well as
39 * FSG_FS_FUNCTION_PRE_EP_ENTRIES and FSG_HS_FUNCTION_PRE_EP_ENTRIES
40 * macros are not defined.
41 *
42 * When FSG_NO_DEVICE_STRINGS is defined FSG_STRING_MANUFACTURER,
43 * FSG_STRING_PRODUCT, FSG_STRING_SERIAL and FSG_STRING_CONFIG are not
44 * defined (as well as corresponding entries in string tables are
45 * missing) and FSG_STRING_INTERFACE has value of zero.
46 *
47 * When FSG_NO_OTG is defined fsg_otg_desc won't be defined.
48 */
49
50/*
51 * When FSG_BUFFHD_STATIC_BUFFER is defined when this file is included
52 * the fsg_buffhd structure's buf field will be an array of FSG_BUFLEN
53 * characters rather then a pointer to void.
54 */
55
56
57#include <asm/unaligned.h>
58
59
60/* Thanks to NetChip Technologies for donating this product ID.
61 *
62 * DO NOT REUSE THESE IDs with any other driver!! Ever!!
63 * Instead: allocate your own, using normal USB-IF procedures. */
64#define FSG_VENDOR_ID 0x0525 /* NetChip */
65#define FSG_PRODUCT_ID 0xa4a5 /* Linux-USB File-backed Storage Gadget */
66
67
68/*-------------------------------------------------------------------------*/
69
70
71#ifndef DEBUG
72#undef VERBOSE_DEBUG
73#undef DUMP_MSGS
74#endif /* !DEBUG */
75
76#ifdef VERBOSE_DEBUG
77#define VLDBG LDBG
78#else
79#define VLDBG(lun, fmt, args...) do { } while (0)
80#endif /* VERBOSE_DEBUG */
81
82#define LDBG(lun, fmt, args...) dev_dbg (&(lun)->dev, fmt, ## args)
83#define LERROR(lun, fmt, args...) dev_err (&(lun)->dev, fmt, ## args)
84#define LWARN(lun, fmt, args...) dev_warn(&(lun)->dev, fmt, ## args)
85#define LINFO(lun, fmt, args...) dev_info(&(lun)->dev, fmt, ## args)
86
87/* Keep those macros in sync with thos in
88 * include/linux/ubs/composite.h or else GCC will complain. If they
89 * are identical (the same names of arguments, white spaces in the
90 * same places) GCC will allow redefinition otherwise (even if some
91 * white space is removed or added) warning will be issued. No
92 * checking if those symbols is defined is performed because warning
93 * is desired when those macros were defined by someone else to mean
94 * something else. */
95#define DBG(d, fmt, args...) dev_dbg(&(d)->gadget->dev , fmt , ## args)
96#define VDBG(d, fmt, args...) dev_vdbg(&(d)->gadget->dev , fmt , ## args)
97#define ERROR(d, fmt, args...) dev_err(&(d)->gadget->dev , fmt , ## args)
98#define WARNING(d, fmt, args...) dev_warn(&(d)->gadget->dev , fmt , ## args)
99#define INFO(d, fmt, args...) dev_info(&(d)->gadget->dev , fmt , ## args)
100
101
102
103#ifdef DUMP_MSGS
104
105# define dump_msg(fsg, /* const char * */ label, \
106 /* const u8 * */ buf, /* unsigned */ length) do { \
107 if (length < 512) { \
108 DBG(fsg, "%s, length %u:\n", label, length); \
109 print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, \
110 16, 1, buf, length, 0); \
111 } \
112} while (0)
113
114# define dump_cdb(fsg) do { } while (0)
115
116#else
117
118# define dump_msg(fsg, /* const char * */ label, \
119 /* const u8 * */ buf, /* unsigned */ length) do { } while (0)
120
121# ifdef VERBOSE_DEBUG
122
123# define dump_cdb(fsg) \
124 print_hex_dump(KERN_DEBUG, "SCSI CDB: ", DUMP_PREFIX_NONE, \
125 16, 1, (fsg)->cmnd, (fsg)->cmnd_size, 0) \
126
127# else
128
129# define dump_cdb(fsg) do { } while (0)
130
131# endif /* VERBOSE_DEBUG */
132
133#endif /* DUMP_MSGS */
134
135
136
137
138
139/*-------------------------------------------------------------------------*/
140
141/* SCSI device types */
142#define TYPE_DISK 0x00
143#define TYPE_CDROM 0x05
144
145/* USB protocol value = the transport method */
146#define USB_PR_CBI 0x00 /* Control/Bulk/Interrupt */
147#define USB_PR_CB 0x01 /* Control/Bulk w/o interrupt */
148#define USB_PR_BULK 0x50 /* Bulk-only */
149
150/* USB subclass value = the protocol encapsulation */
151#define USB_SC_RBC 0x01 /* Reduced Block Commands (flash) */
152#define USB_SC_8020 0x02 /* SFF-8020i, MMC-2, ATAPI (CD-ROM) */
153#define USB_SC_QIC 0x03 /* QIC-157 (tape) */
154#define USB_SC_UFI 0x04 /* UFI (floppy) */
155#define USB_SC_8070 0x05 /* SFF-8070i (removable) */
156#define USB_SC_SCSI 0x06 /* Transparent SCSI */
157
158/* Bulk-only data structures */
159
160/* Command Block Wrapper */
161struct fsg_bulk_cb_wrap {
162 __le32 Signature; /* Contains 'USBC' */
163 u32 Tag; /* Unique per command id */
164 __le32 DataTransferLength; /* Size of the data */
165 u8 Flags; /* Direction in bit 7 */
166 u8 Lun; /* LUN (normally 0) */
167 u8 Length; /* Of the CDB, <= MAX_COMMAND_SIZE */
168 u8 CDB[16]; /* Command Data Block */
169};
170
171#define USB_BULK_CB_WRAP_LEN 31
172#define USB_BULK_CB_SIG 0x43425355 /* Spells out USBC */
173#define USB_BULK_IN_FLAG 0x80
174
175/* Command Status Wrapper */
176struct bulk_cs_wrap {
177 __le32 Signature; /* Should = 'USBS' */
178 u32 Tag; /* Same as original command */
179 __le32 Residue; /* Amount not transferred */
180 u8 Status; /* See below */
181};
182
183#define USB_BULK_CS_WRAP_LEN 13
184#define USB_BULK_CS_SIG 0x53425355 /* Spells out 'USBS' */
185#define USB_STATUS_PASS 0
186#define USB_STATUS_FAIL 1
187#define USB_STATUS_PHASE_ERROR 2
188
189/* Bulk-only class specific requests */
190#define USB_BULK_RESET_REQUEST 0xff
191#define USB_BULK_GET_MAX_LUN_REQUEST 0xfe
192
193
194/* CBI Interrupt data structure */
195struct interrupt_data {
196 u8 bType;
197 u8 bValue;
198};
199
200#define CBI_INTERRUPT_DATA_LEN 2
201
202/* CBI Accept Device-Specific Command request */
203#define USB_CBI_ADSC_REQUEST 0x00
204
205
206/* Length of a SCSI Command Data Block */
207#define MAX_COMMAND_SIZE 16
208
209/* SCSI commands that we recognize */
210#define SC_FORMAT_UNIT 0x04
211#define SC_INQUIRY 0x12
212#define SC_MODE_SELECT_6 0x15
213#define SC_MODE_SELECT_10 0x55
214#define SC_MODE_SENSE_6 0x1a
215#define SC_MODE_SENSE_10 0x5a
216#define SC_PREVENT_ALLOW_MEDIUM_REMOVAL 0x1e
217#define SC_READ_6 0x08
218#define SC_READ_10 0x28
219#define SC_READ_12 0xa8
220#define SC_READ_CAPACITY 0x25
221#define SC_READ_FORMAT_CAPACITIES 0x23
222#define SC_READ_HEADER 0x44
223#define SC_READ_TOC 0x43
224#define SC_RELEASE 0x17
225#define SC_REQUEST_SENSE 0x03
226#define SC_RESERVE 0x16
227#define SC_SEND_DIAGNOSTIC 0x1d
228#define SC_START_STOP_UNIT 0x1b
229#define SC_SYNCHRONIZE_CACHE 0x35
230#define SC_TEST_UNIT_READY 0x00
231#define SC_VERIFY 0x2f
232#define SC_WRITE_6 0x0a
233#define SC_WRITE_10 0x2a
234#define SC_WRITE_12 0xaa
235
236/* SCSI Sense Key/Additional Sense Code/ASC Qualifier values */
237#define SS_NO_SENSE 0
238#define SS_COMMUNICATION_FAILURE 0x040800
239#define SS_INVALID_COMMAND 0x052000
240#define SS_INVALID_FIELD_IN_CDB 0x052400
241#define SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE 0x052100
242#define SS_LOGICAL_UNIT_NOT_SUPPORTED 0x052500
243#define SS_MEDIUM_NOT_PRESENT 0x023a00
244#define SS_MEDIUM_REMOVAL_PREVENTED 0x055302
245#define SS_NOT_READY_TO_READY_TRANSITION 0x062800
246#define SS_RESET_OCCURRED 0x062900
247#define SS_SAVING_PARAMETERS_NOT_SUPPORTED 0x053900
248#define SS_UNRECOVERED_READ_ERROR 0x031100
249#define SS_WRITE_ERROR 0x030c02
250#define SS_WRITE_PROTECTED 0x072700
251
252#define SK(x) ((u8) ((x) >> 16)) /* Sense Key byte, etc. */
253#define ASC(x) ((u8) ((x) >> 8))
254#define ASCQ(x) ((u8) (x))
255
256
257/*-------------------------------------------------------------------------*/
258
259
260struct fsg_lun {
261 struct file *filp;
262 loff_t file_length;
263 loff_t num_sectors;
264
265 unsigned int initially_ro:1;
266 unsigned int ro:1;
267 unsigned int removable:1;
268 unsigned int cdrom:1;
269 unsigned int prevent_medium_removal:1;
270 unsigned int registered:1;
271 unsigned int info_valid:1;
272
273 u32 sense_data;
274 u32 sense_data_info;
275 u32 unit_attention_data;
276
277 struct device dev;
278};
279
280#define fsg_lun_is_open(curlun) ((curlun)->filp != NULL)
281
282static struct fsg_lun *fsg_lun_from_dev(struct device *dev)
283{
284 return container_of(dev, struct fsg_lun, dev);
285}
286
287
288/* Big enough to hold our biggest descriptor */
289#define EP0_BUFSIZE 256
290#define DELAYED_STATUS (EP0_BUFSIZE + 999) /* An impossibly large value */
291
292/* Number of buffers we will use. 2 is enough for double-buffering */
293#define FSG_NUM_BUFFERS 2
294
295/* Default size of buffer length. */
296#define FSG_BUFLEN ((u32)16384)
297
298/* Maximal number of LUNs supported in mass storage function */
299#define FSG_MAX_LUNS 8
300
301enum fsg_buffer_state {
302 BUF_STATE_EMPTY = 0,
303 BUF_STATE_FULL,
304 BUF_STATE_BUSY
305};
306
307struct fsg_buffhd {
308#ifdef FSG_BUFFHD_STATIC_BUFFER
309 char buf[FSG_BUFLEN];
310#else
311 void *buf;
312#endif
313 enum fsg_buffer_state state;
314 struct fsg_buffhd *next;
315
316 /* The NetChip 2280 is faster, and handles some protocol faults
317 * better, if we don't submit any short bulk-out read requests.
318 * So we will record the intended request length here. */
319 unsigned int bulk_out_intended_length;
320
321 struct usb_request *inreq;
322 int inreq_busy;
323 struct usb_request *outreq;
324 int outreq_busy;
325};
326
327enum fsg_state {
328 /* This one isn't used anywhere */
329 FSG_STATE_COMMAND_PHASE = -10,
330 FSG_STATE_DATA_PHASE,
331 FSG_STATE_STATUS_PHASE,
332
333 FSG_STATE_IDLE = 0,
334 FSG_STATE_ABORT_BULK_OUT,
335 FSG_STATE_RESET,
336 FSG_STATE_INTERFACE_CHANGE,
337 FSG_STATE_CONFIG_CHANGE,
338 FSG_STATE_DISCONNECT,
339 FSG_STATE_EXIT,
340 FSG_STATE_TERMINATED
341};
342
343enum data_direction {
344 DATA_DIR_UNKNOWN = 0,
345 DATA_DIR_FROM_HOST,
346 DATA_DIR_TO_HOST,
347 DATA_DIR_NONE
348};
349
350
351/*-------------------------------------------------------------------------*/
352
353
354static inline u32 get_unaligned_be24(u8 *buf)
355{
356 return 0xffffff & (u32) get_unaligned_be32(buf - 1);
357}
358
359
360/*-------------------------------------------------------------------------*/
361
362
363enum {
364#ifndef FSG_NO_DEVICE_STRINGS
365 FSG_STRING_MANUFACTURER = 1,
366 FSG_STRING_PRODUCT,
367 FSG_STRING_SERIAL,
368 FSG_STRING_CONFIG,
369#endif
370 FSG_STRING_INTERFACE
371};
372
373
374#ifndef FSG_NO_OTG
375static struct usb_otg_descriptor
376fsg_otg_desc = {
377 .bLength = sizeof fsg_otg_desc,
378 .bDescriptorType = USB_DT_OTG,
379
380 .bmAttributes = USB_OTG_SRP,
381};
382#endif
383
384/* There is only one interface. */
385
386static struct usb_interface_descriptor
387fsg_intf_desc = {
388 .bLength = sizeof fsg_intf_desc,
389 .bDescriptorType = USB_DT_INTERFACE,
390
391 .bNumEndpoints = 2, /* Adjusted during fsg_bind() */
392 .bInterfaceClass = USB_CLASS_MASS_STORAGE,
393 .bInterfaceSubClass = USB_SC_SCSI, /* Adjusted during fsg_bind() */
394 .bInterfaceProtocol = USB_PR_BULK, /* Adjusted during fsg_bind() */
395 .iInterface = FSG_STRING_INTERFACE,
396};
397
398/* Three full-speed endpoint descriptors: bulk-in, bulk-out,
399 * and interrupt-in. */
400
401static struct usb_endpoint_descriptor
402fsg_fs_bulk_in_desc = {
403 .bLength = USB_DT_ENDPOINT_SIZE,
404 .bDescriptorType = USB_DT_ENDPOINT,
405
406 .bEndpointAddress = USB_DIR_IN,
407 .bmAttributes = USB_ENDPOINT_XFER_BULK,
408 /* wMaxPacketSize set by autoconfiguration */
409};
410
411static struct usb_endpoint_descriptor
412fsg_fs_bulk_out_desc = {
413 .bLength = USB_DT_ENDPOINT_SIZE,
414 .bDescriptorType = USB_DT_ENDPOINT,
415
416 .bEndpointAddress = USB_DIR_OUT,
417 .bmAttributes = USB_ENDPOINT_XFER_BULK,
418 /* wMaxPacketSize set by autoconfiguration */
419};
420
421#ifndef FSG_NO_INTR_EP
422
423static struct usb_endpoint_descriptor
424fsg_fs_intr_in_desc = {
425 .bLength = USB_DT_ENDPOINT_SIZE,
426 .bDescriptorType = USB_DT_ENDPOINT,
427
428 .bEndpointAddress = USB_DIR_IN,
429 .bmAttributes = USB_ENDPOINT_XFER_INT,
430 .wMaxPacketSize = cpu_to_le16(2),
431 .bInterval = 32, /* frames -> 32 ms */
432};
433
434#ifndef FSG_NO_OTG
435# define FSG_FS_FUNCTION_PRE_EP_ENTRIES 2
436#else
437# define FSG_FS_FUNCTION_PRE_EP_ENTRIES 1
438#endif
439
440#endif
441
442static struct usb_descriptor_header *fsg_fs_function[] = {
443#ifndef FSG_NO_OTG
444 (struct usb_descriptor_header *) &fsg_otg_desc,
445#endif
446 (struct usb_descriptor_header *) &fsg_intf_desc,
447 (struct usb_descriptor_header *) &fsg_fs_bulk_in_desc,
448 (struct usb_descriptor_header *) &fsg_fs_bulk_out_desc,
449#ifndef FSG_NO_INTR_EP
450 (struct usb_descriptor_header *) &fsg_fs_intr_in_desc,
451#endif
452 NULL,
453};
454
455
456/*
457 * USB 2.0 devices need to expose both high speed and full speed
458 * descriptors, unless they only run at full speed.
459 *
460 * That means alternate endpoint descriptors (bigger packets)
461 * and a "device qualifier" ... plus more construction options
462 * for the config descriptor.
463 */
464static struct usb_endpoint_descriptor
465fsg_hs_bulk_in_desc = {
466 .bLength = USB_DT_ENDPOINT_SIZE,
467 .bDescriptorType = USB_DT_ENDPOINT,
468
469 /* bEndpointAddress copied from fs_bulk_in_desc during fsg_bind() */
470 .bmAttributes = USB_ENDPOINT_XFER_BULK,
471 .wMaxPacketSize = cpu_to_le16(512),
472};
473
474static struct usb_endpoint_descriptor
475fsg_hs_bulk_out_desc = {
476 .bLength = USB_DT_ENDPOINT_SIZE,
477 .bDescriptorType = USB_DT_ENDPOINT,
478
479 /* bEndpointAddress copied from fs_bulk_out_desc during fsg_bind() */
480 .bmAttributes = USB_ENDPOINT_XFER_BULK,
481 .wMaxPacketSize = cpu_to_le16(512),
482 .bInterval = 1, /* NAK every 1 uframe */
483};
484
485#ifndef FSG_NO_INTR_EP
486
487static struct usb_endpoint_descriptor
488fsg_hs_intr_in_desc = {
489 .bLength = USB_DT_ENDPOINT_SIZE,
490 .bDescriptorType = USB_DT_ENDPOINT,
491
492 /* bEndpointAddress copied from fs_intr_in_desc during fsg_bind() */
493 .bmAttributes = USB_ENDPOINT_XFER_INT,
494 .wMaxPacketSize = cpu_to_le16(2),
495 .bInterval = 9, /* 2**(9-1) = 256 uframes -> 32 ms */
496};
497
498#ifndef FSG_NO_OTG
499# define FSG_HS_FUNCTION_PRE_EP_ENTRIES 2
500#else
501# define FSG_HS_FUNCTION_PRE_EP_ENTRIES 1
502#endif
503
504#endif
505
506static struct usb_descriptor_header *fsg_hs_function[] = {
507#ifndef FSG_NO_OTG
508 (struct usb_descriptor_header *) &fsg_otg_desc,
509#endif
510 (struct usb_descriptor_header *) &fsg_intf_desc,
511 (struct usb_descriptor_header *) &fsg_hs_bulk_in_desc,
512 (struct usb_descriptor_header *) &fsg_hs_bulk_out_desc,
513#ifndef FSG_NO_INTR_EP
514 (struct usb_descriptor_header *) &fsg_hs_intr_in_desc,
515#endif
516 NULL,
517};
518
519/* Maxpacket and other transfer characteristics vary by speed. */
520static struct usb_endpoint_descriptor *
521fsg_ep_desc(struct usb_gadget *g, struct usb_endpoint_descriptor *fs,
522 struct usb_endpoint_descriptor *hs)
523{
524 if (gadget_is_dualspeed(g) && g->speed == USB_SPEED_HIGH)
525 return hs;
526 return fs;
527}
528
529
530/* Static strings, in UTF-8 (for simplicity we use only ASCII characters) */
531static struct usb_string fsg_strings[] = {
532#ifndef FSG_NO_DEVICE_STRINGS
533 {FSG_STRING_MANUFACTURER, fsg_string_manufacturer},
534 {FSG_STRING_PRODUCT, fsg_string_product},
535 {FSG_STRING_SERIAL, fsg_string_serial},
536 {FSG_STRING_CONFIG, fsg_string_config},
537#endif
538 {FSG_STRING_INTERFACE, fsg_string_interface},
539 {}
540};
541
542static struct usb_gadget_strings fsg_stringtab = {
543 .language = 0x0409, /* en-us */
544 .strings = fsg_strings,
545};
546
547
548 /*-------------------------------------------------------------------------*/
549
550/* If the next two routines are called while the gadget is registered,
551 * the caller must own fsg->filesem for writing. */
552
553static int fsg_lun_open(struct fsg_lun *curlun, const char *filename)
554{
555 int ro;
556 struct file *filp = NULL;
557 int rc = -EINVAL;
558 struct inode *inode = NULL;
559 loff_t size;
560 loff_t num_sectors;
561 loff_t min_sectors;
562
563 /* R/W if we can, R/O if we must */
564 ro = curlun->initially_ro;
565 if (!ro) {
566 filp = filp_open(filename, O_RDWR | O_LARGEFILE, 0);
567 if (-EROFS == PTR_ERR(filp))
568 ro = 1;
569 }
570 if (ro)
571 filp = filp_open(filename, O_RDONLY | O_LARGEFILE, 0);
572 if (IS_ERR(filp)) {
573 LINFO(curlun, "unable to open backing file: %s\n", filename);
574 return PTR_ERR(filp);
575 }
576
577 if (!(filp->f_mode & FMODE_WRITE))
578 ro = 1;
579
580 if (filp->f_path.dentry)
581 inode = filp->f_path.dentry->d_inode;
582 if (inode && S_ISBLK(inode->i_mode)) {
583 if (bdev_read_only(inode->i_bdev))
584 ro = 1;
585 } else if (!inode || !S_ISREG(inode->i_mode)) {
586 LINFO(curlun, "invalid file type: %s\n", filename);
587 goto out;
588 }
589
590 /* If we can't read the file, it's no good.
591 * If we can't write the file, use it read-only. */
592 if (!filp->f_op || !(filp->f_op->read || filp->f_op->aio_read)) {
593 LINFO(curlun, "file not readable: %s\n", filename);
594 goto out;
595 }
596 if (!(filp->f_op->write || filp->f_op->aio_write))
597 ro = 1;
598
599 size = i_size_read(inode->i_mapping->host);
600 if (size < 0) {
601 LINFO(curlun, "unable to find file size: %s\n", filename);
602 rc = (int) size;
603 goto out;
604 }
605 num_sectors = size >> 9; /* File size in 512-byte blocks */
606 min_sectors = 1;
607 if (curlun->cdrom) {
608 num_sectors &= ~3; /* Reduce to a multiple of 2048 */
609 min_sectors = 300*4; /* Smallest track is 300 frames */
610 if (num_sectors >= 256*60*75*4) {
611 num_sectors = (256*60*75 - 1) * 4;
612 LINFO(curlun, "file too big: %s\n", filename);
613 LINFO(curlun, "using only first %d blocks\n",
614 (int) num_sectors);
615 }
616 }
617 if (num_sectors < min_sectors) {
618 LINFO(curlun, "file too small: %s\n", filename);
619 rc = -ETOOSMALL;
620 goto out;
621 }
622
623 get_file(filp);
624 curlun->ro = ro;
625 curlun->filp = filp;
626 curlun->file_length = size;
627 curlun->num_sectors = num_sectors;
628 LDBG(curlun, "open backing file: %s\n", filename);
629 rc = 0;
630
631out:
632 filp_close(filp, current->files);
633 return rc;
634}
635
636
637static void fsg_lun_close(struct fsg_lun *curlun)
638{
639 if (curlun->filp) {
640 LDBG(curlun, "close backing file\n");
641 fput(curlun->filp);
642 curlun->filp = NULL;
643 }
644}
645
646
647/*-------------------------------------------------------------------------*/
648
649/* Sync the file data, don't bother with the metadata.
650 * This code was copied from fs/buffer.c:sys_fdatasync(). */
651static int fsg_lun_fsync_sub(struct fsg_lun *curlun)
652{
653 struct file *filp = curlun->filp;
654
655 if (curlun->ro || !filp)
656 return 0;
657 return vfs_fsync(filp, filp->f_path.dentry, 1);
658}
659
660static void store_cdrom_address(u8 *dest, int msf, u32 addr)
661{
662 if (msf) {
663 /* Convert to Minutes-Seconds-Frames */
664 addr >>= 2; /* Convert to 2048-byte frames */
665 addr += 2*75; /* Lead-in occupies 2 seconds */
666 dest[3] = addr % 75; /* Frames */
667 addr /= 75;
668 dest[2] = addr % 60; /* Seconds */
669 addr /= 60;
670 dest[1] = addr; /* Minutes */
671 dest[0] = 0; /* Reserved */
672 } else {
673 /* Absolute sector */
674 put_unaligned_be32(addr, dest);
675 }
676}
677
678
679/*-------------------------------------------------------------------------*/
680
681
682static ssize_t fsg_show_ro(struct device *dev, struct device_attribute *attr,
683 char *buf)
684{
685 struct fsg_lun *curlun = fsg_lun_from_dev(dev);
686
687 return sprintf(buf, "%d\n", fsg_lun_is_open(curlun)
688 ? curlun->ro
689 : curlun->initially_ro);
690}
691
692static ssize_t fsg_show_file(struct device *dev, struct device_attribute *attr,
693 char *buf)
694{
695 struct fsg_lun *curlun = fsg_lun_from_dev(dev);
696 struct rw_semaphore *filesem = dev_get_drvdata(dev);
697 char *p;
698 ssize_t rc;
699
700 down_read(filesem);
701 if (fsg_lun_is_open(curlun)) { /* Get the complete pathname */
702 p = d_path(&curlun->filp->f_path, buf, PAGE_SIZE - 1);
703 if (IS_ERR(p))
704 rc = PTR_ERR(p);
705 else {
706 rc = strlen(p);
707 memmove(buf, p, rc);
708 buf[rc] = '\n'; /* Add a newline */
709 buf[++rc] = 0;
710 }
711 } else { /* No file, return 0 bytes */
712 *buf = 0;
713 rc = 0;
714 }
715 up_read(filesem);
716 return rc;
717}
718
719
720static ssize_t fsg_store_ro(struct device *dev, struct device_attribute *attr,
721 const char *buf, size_t count)
722{
723 ssize_t rc = count;
724 struct fsg_lun *curlun = fsg_lun_from_dev(dev);
725 struct rw_semaphore *filesem = dev_get_drvdata(dev);
726 int i;
727
728 if (sscanf(buf, "%d", &i) != 1)
729 return -EINVAL;
730
731 /* Allow the write-enable status to change only while the backing file
732 * is closed. */
733 down_read(filesem);
734 if (fsg_lun_is_open(curlun)) {
735 LDBG(curlun, "read-only status change prevented\n");
736 rc = -EBUSY;
737 } else {
738 curlun->ro = !!i;
739 curlun->initially_ro = !!i;
740 LDBG(curlun, "read-only status set to %d\n", curlun->ro);
741 }
742 up_read(filesem);
743 return rc;
744}
745
746static ssize_t fsg_store_file(struct device *dev, struct device_attribute *attr,
747 const char *buf, size_t count)
748{
749 struct fsg_lun *curlun = fsg_lun_from_dev(dev);
750 struct rw_semaphore *filesem = dev_get_drvdata(dev);
751 int rc = 0;
752
753 if (curlun->prevent_medium_removal && fsg_lun_is_open(curlun)) {
754 LDBG(curlun, "eject attempt prevented\n");
755 return -EBUSY; /* "Door is locked" */
756 }
757
758 /* Remove a trailing newline */
759 if (count > 0 && buf[count-1] == '\n')
760 ((char *) buf)[count-1] = 0; /* Ugh! */
761
762 /* Eject current medium */
763 down_write(filesem);
764 if (fsg_lun_is_open(curlun)) {
765 fsg_lun_close(curlun);
766 curlun->unit_attention_data = SS_MEDIUM_NOT_PRESENT;
767 }
768
769 /* Load new medium */
770 if (count > 0 && buf[0]) {
771 rc = fsg_lun_open(curlun, buf);
772 if (rc == 0)
773 curlun->unit_attention_data =
774 SS_NOT_READY_TO_READY_TRANSITION;
775 }
776 up_write(filesem);
777 return (rc < 0 ? rc : count);
778}
generated by cgit v1.2.2 (git 2.25.0) at 2025-08-07 08:22:06 -0400