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>
57 #include <linux/usb/storage.h>
61 * Thanks to NetChip Technologies for donating this product ID.
63 * DO NOT REUSE THESE IDs with any other driver!! Ever!!
64 * Instead: allocate your own, using normal USB-IF procedures.
66 #define FSG_VENDOR_ID 0x0525 /* NetChip */
67 #define FSG_PRODUCT_ID 0xa4a5 /* Linux-USB File-backed Storage Gadget */
70 /*-------------------------------------------------------------------------*/
81 #define VLDBG(lun, fmt, args...) do { } while (0)
82 #endif /* VERBOSE_DEBUG */
84 #define LDBG(lun, fmt, args...) dev_dbg (&(lun)->dev, fmt, ## args)
85 #define LERROR(lun, fmt, args...) dev_err (&(lun)->dev, fmt, ## args)
86 #define LWARN(lun, fmt, args...) dev_warn(&(lun)->dev, fmt, ## args)
87 #define LINFO(lun, fmt, args...) dev_info(&(lun)->dev, fmt, ## args)
90 * Keep those macros in sync with those in
91 * include/linux/usb/composite.h or else GCC will complain. If they
92 * are identical (the same names of arguments, white spaces in the
93 * same places) GCC will allow redefinition otherwise (even if some
94 * white space is removed or added) warning will be issued.
96 * Those macros are needed here because File Storage Gadget does not
97 * include the composite.h header. For composite gadgets those macros
98 * are redundant since composite.h is included any way.
100 * One could check whether those macros are already defined (which
101 * would indicate composite.h had been included) or not (which would
102 * indicate we were in FSG) but this is not done because a warning is
103 * desired if definitions here differ from the ones in composite.h.
105 * We want the definitions to match and be the same in File Storage
106 * Gadget as well as Mass Storage Function (and so composite gadgets
107 * using MSF). If someone changes them in composite.h it will produce
108 * a warning in this file when building MSF.
110 #define DBG(d, fmt, args...) dev_dbg(&(d)->gadget->dev , fmt , ## args)
111 #define VDBG(d, fmt, args...) dev_vdbg(&(d)->gadget->dev , fmt , ## args)
112 #define ERROR(d, fmt, args...) dev_err(&(d)->gadget->dev , fmt , ## args)
113 #define WARNING(d, fmt, args...) dev_warn(&(d)->gadget->dev , fmt , ## args)
114 #define INFO(d, fmt, args...) dev_info(&(d)->gadget->dev , fmt , ## args)
120 # define dump_msg(fsg, /* const char * */ label, \
121 /* const u8 * */ buf, /* unsigned */ length) do { \
122 if (length < 512) { \
123 DBG(fsg, "%s, length %u:\n", label, length); \
124 print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, \
125 16, 1, buf, length, 0); \
129 # define dump_cdb(fsg) do { } while (0)
133 # define dump_msg(fsg, /* const char * */ label, \
134 /* const u8 * */ buf, /* unsigned */ length) do { } while (0)
136 # ifdef VERBOSE_DEBUG
138 # define dump_cdb(fsg) \
139 print_hex_dump(KERN_DEBUG, "SCSI CDB: ", DUMP_PREFIX_NONE, \
140 16, 1, (fsg)->cmnd, (fsg)->cmnd_size, 0) \
144 # define dump_cdb(fsg) do { } while (0)
146 # endif /* VERBOSE_DEBUG */
148 #endif /* DUMP_MSGS */
154 /*-------------------------------------------------------------------------*/
156 /* SCSI device types */
157 #define TYPE_DISK 0x00
158 #define TYPE_CDROM 0x05
160 /* Bulk-only data structures */
162 /* Command Block Wrapper */
163 struct fsg_bulk_cb_wrap {
164 __le32 Signature; /* Contains 'USBC' */
165 u32 Tag; /* Unique per command id */
166 __le32 DataTransferLength; /* Size of the data */
167 u8 Flags; /* Direction in bit 7 */
168 u8 Lun; /* LUN (normally 0) */
169 u8 Length; /* Of the CDB, <= MAX_COMMAND_SIZE */
170 u8 CDB[16]; /* Command Data Block */
173 #define USB_BULK_CB_WRAP_LEN 31
174 #define USB_BULK_CB_SIG 0x43425355 /* Spells out USBC */
175 #define USB_BULK_IN_FLAG 0x80
177 /* Command Status Wrapper */
178 struct bulk_cs_wrap {
179 __le32 Signature; /* Should = 'USBS' */
180 u32 Tag; /* Same as original command */
181 __le32 Residue; /* Amount not transferred */
182 u8 Status; /* See below */
185 #define USB_BULK_CS_WRAP_LEN 13
186 #define USB_BULK_CS_SIG 0x53425355 /* Spells out 'USBS' */
187 #define USB_STATUS_PASS 0
188 #define USB_STATUS_FAIL 1
189 #define USB_STATUS_PHASE_ERROR 2
191 /* Bulk-only class specific requests */
192 #define USB_BULK_RESET_REQUEST 0xff
193 #define USB_BULK_GET_MAX_LUN_REQUEST 0xfe
196 /* CBI Interrupt data structure */
197 struct interrupt_data {
202 #define CBI_INTERRUPT_DATA_LEN 2
204 /* CBI Accept Device-Specific Command request */
205 #define USB_CBI_ADSC_REQUEST 0x00
208 /* Length of a SCSI Command Data Block */
209 #define MAX_COMMAND_SIZE 16
211 /* SCSI commands that we recognize */
212 #define SC_FORMAT_UNIT 0x04
213 #define SC_INQUIRY 0x12
214 #define SC_MODE_SELECT_6 0x15
215 #define SC_MODE_SELECT_10 0x55
216 #define SC_MODE_SENSE_6 0x1a
217 #define SC_MODE_SENSE_10 0x5a
218 #define SC_PREVENT_ALLOW_MEDIUM_REMOVAL 0x1e
219 #define SC_READ_6 0x08
220 #define SC_READ_10 0x28
221 #define SC_READ_12 0xa8
222 #define SC_READ_CAPACITY 0x25
223 #define SC_READ_FORMAT_CAPACITIES 0x23
224 #define SC_READ_HEADER 0x44
225 #define SC_READ_TOC 0x43
226 #define SC_RELEASE 0x17
227 #define SC_REQUEST_SENSE 0x03
228 #define SC_RESERVE 0x16
229 #define SC_SEND_DIAGNOSTIC 0x1d
230 #define SC_START_STOP_UNIT 0x1b
231 #define SC_SYNCHRONIZE_CACHE 0x35
232 #define SC_TEST_UNIT_READY 0x00
233 #define SC_VERIFY 0x2f
234 #define SC_WRITE_6 0x0a
235 #define SC_WRITE_10 0x2a
236 #define SC_WRITE_12 0xaa
238 /* SCSI Sense Key/Additional Sense Code/ASC Qualifier values */
239 #define SS_NO_SENSE 0
240 #define SS_COMMUNICATION_FAILURE 0x040800
241 #define SS_INVALID_COMMAND 0x052000
242 #define SS_INVALID_FIELD_IN_CDB 0x052400
243 #define SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE 0x052100
244 #define SS_LOGICAL_UNIT_NOT_SUPPORTED 0x052500
245 #define SS_MEDIUM_NOT_PRESENT 0x023a00
246 #define SS_MEDIUM_REMOVAL_PREVENTED 0x055302
247 #define SS_NOT_READY_TO_READY_TRANSITION 0x062800
248 #define SS_RESET_OCCURRED 0x062900
249 #define SS_SAVING_PARAMETERS_NOT_SUPPORTED 0x053900
250 #define SS_UNRECOVERED_READ_ERROR 0x031100
251 #define SS_WRITE_ERROR 0x030c02
252 #define SS_WRITE_PROTECTED 0x072700
254 #define SK(x) ((u8) ((x) >> 16)) /* Sense Key byte, etc. */
255 #define ASC(x) ((u8) ((x) >> 8))
256 #define ASCQ(x) ((u8) (x))
259 /*-------------------------------------------------------------------------*/
267 unsigned int initially_ro:1;
269 unsigned int removable:1;
270 unsigned int cdrom:1;
271 unsigned int prevent_medium_removal:1;
272 unsigned int registered:1;
273 unsigned int info_valid:1;
274 unsigned int nofua:1;
278 u32 unit_attention_data;
283 #define fsg_lun_is_open(curlun) ((curlun)->filp != NULL)
285 static struct fsg_lun *fsg_lun_from_dev(struct device *dev)
287 return container_of(dev, struct fsg_lun, dev);
291 /* Big enough to hold our biggest descriptor */
292 #define EP0_BUFSIZE 256
293 #define DELAYED_STATUS (EP0_BUFSIZE + 999) /* An impossibly large value */
295 /* Number of buffers we will use. 2 is enough for double-buffering */
296 #define FSG_NUM_BUFFERS 2
298 /* Default size of buffer length. */
299 #define FSG_BUFLEN ((u32)16384)
301 /* Maximal number of LUNs supported in mass storage function */
302 #define FSG_MAX_LUNS 8
304 enum fsg_buffer_state {
311 #ifdef FSG_BUFFHD_STATIC_BUFFER
312 char buf[FSG_BUFLEN];
316 enum fsg_buffer_state state;
317 struct fsg_buffhd *next;
320 * The NetChip 2280 is faster, and handles some protocol faults
321 * better, if we don't submit any short bulk-out read requests.
322 * So we will record the intended request length here.
324 unsigned int bulk_out_intended_length;
326 struct usb_request *inreq;
328 struct usb_request *outreq;
333 /* This one isn't used anywhere */
334 FSG_STATE_COMMAND_PHASE = -10,
335 FSG_STATE_DATA_PHASE,
336 FSG_STATE_STATUS_PHASE,
339 FSG_STATE_ABORT_BULK_OUT,
341 FSG_STATE_INTERFACE_CHANGE,
342 FSG_STATE_CONFIG_CHANGE,
343 FSG_STATE_DISCONNECT,
348 enum data_direction {
349 DATA_DIR_UNKNOWN = 0,
356 /*-------------------------------------------------------------------------*/
359 static inline u32 get_unaligned_be24(u8 *buf)
361 return 0xffffff & (u32) get_unaligned_be32(buf - 1);
365 /*-------------------------------------------------------------------------*/
369 #ifndef FSG_NO_DEVICE_STRINGS
370 FSG_STRING_MANUFACTURER = 1,
380 static struct usb_otg_descriptor
382 .bLength = sizeof fsg_otg_desc,
383 .bDescriptorType = USB_DT_OTG,
385 .bmAttributes = USB_OTG_SRP,
389 /* There is only one interface. */
391 static struct usb_interface_descriptor
393 .bLength = sizeof fsg_intf_desc,
394 .bDescriptorType = USB_DT_INTERFACE,
396 .bNumEndpoints = 2, /* Adjusted during fsg_bind() */
397 .bInterfaceClass = USB_CLASS_MASS_STORAGE,
398 .bInterfaceSubClass = USB_SC_SCSI, /* Adjusted during fsg_bind() */
399 .bInterfaceProtocol = USB_PR_BULK, /* Adjusted during fsg_bind() */
400 .iInterface = FSG_STRING_INTERFACE,
404 * Three full-speed endpoint descriptors: bulk-in, bulk-out, and
408 static struct usb_endpoint_descriptor
409 fsg_fs_bulk_in_desc = {
410 .bLength = USB_DT_ENDPOINT_SIZE,
411 .bDescriptorType = USB_DT_ENDPOINT,
413 .bEndpointAddress = USB_DIR_IN,
414 .bmAttributes = USB_ENDPOINT_XFER_BULK,
415 /* wMaxPacketSize set by autoconfiguration */
418 static struct usb_endpoint_descriptor
419 fsg_fs_bulk_out_desc = {
420 .bLength = USB_DT_ENDPOINT_SIZE,
421 .bDescriptorType = USB_DT_ENDPOINT,
423 .bEndpointAddress = USB_DIR_OUT,
424 .bmAttributes = USB_ENDPOINT_XFER_BULK,
425 /* wMaxPacketSize set by autoconfiguration */
428 #ifndef FSG_NO_INTR_EP
430 static struct usb_endpoint_descriptor
431 fsg_fs_intr_in_desc = {
432 .bLength = USB_DT_ENDPOINT_SIZE,
433 .bDescriptorType = USB_DT_ENDPOINT,
435 .bEndpointAddress = USB_DIR_IN,
436 .bmAttributes = USB_ENDPOINT_XFER_INT,
437 .wMaxPacketSize = cpu_to_le16(2),
438 .bInterval = 32, /* frames -> 32 ms */
442 # define FSG_FS_FUNCTION_PRE_EP_ENTRIES 2
444 # define FSG_FS_FUNCTION_PRE_EP_ENTRIES 1
449 static struct usb_descriptor_header *fsg_fs_function[] = {
451 (struct usb_descriptor_header *) &fsg_otg_desc,
453 (struct usb_descriptor_header *) &fsg_intf_desc,
454 (struct usb_descriptor_header *) &fsg_fs_bulk_in_desc,
455 (struct usb_descriptor_header *) &fsg_fs_bulk_out_desc,
456 #ifndef FSG_NO_INTR_EP
457 (struct usb_descriptor_header *) &fsg_fs_intr_in_desc,
464 * USB 2.0 devices need to expose both high speed and full speed
465 * descriptors, unless they only run at full speed.
467 * That means alternate endpoint descriptors (bigger packets)
468 * and a "device qualifier" ... plus more construction options
469 * for the configuration descriptor.
471 static struct usb_endpoint_descriptor
472 fsg_hs_bulk_in_desc = {
473 .bLength = USB_DT_ENDPOINT_SIZE,
474 .bDescriptorType = USB_DT_ENDPOINT,
476 /* bEndpointAddress copied from fs_bulk_in_desc during fsg_bind() */
477 .bmAttributes = USB_ENDPOINT_XFER_BULK,
478 .wMaxPacketSize = cpu_to_le16(512),
481 static struct usb_endpoint_descriptor
482 fsg_hs_bulk_out_desc = {
483 .bLength = USB_DT_ENDPOINT_SIZE,
484 .bDescriptorType = USB_DT_ENDPOINT,
486 /* bEndpointAddress copied from fs_bulk_out_desc during fsg_bind() */
487 .bmAttributes = USB_ENDPOINT_XFER_BULK,
488 .wMaxPacketSize = cpu_to_le16(512),
489 .bInterval = 1, /* NAK every 1 uframe */
492 #ifndef FSG_NO_INTR_EP
494 static struct usb_endpoint_descriptor
495 fsg_hs_intr_in_desc = {
496 .bLength = USB_DT_ENDPOINT_SIZE,
497 .bDescriptorType = USB_DT_ENDPOINT,
499 /* bEndpointAddress copied from fs_intr_in_desc during fsg_bind() */
500 .bmAttributes = USB_ENDPOINT_XFER_INT,
501 .wMaxPacketSize = cpu_to_le16(2),
502 .bInterval = 9, /* 2**(9-1) = 256 uframes -> 32 ms */
506 # define FSG_HS_FUNCTION_PRE_EP_ENTRIES 2
508 # define FSG_HS_FUNCTION_PRE_EP_ENTRIES 1
513 static struct usb_descriptor_header *fsg_hs_function[] = {
515 (struct usb_descriptor_header *) &fsg_otg_desc,
517 (struct usb_descriptor_header *) &fsg_intf_desc,
518 (struct usb_descriptor_header *) &fsg_hs_bulk_in_desc,
519 (struct usb_descriptor_header *) &fsg_hs_bulk_out_desc,
520 #ifndef FSG_NO_INTR_EP
521 (struct usb_descriptor_header *) &fsg_hs_intr_in_desc,
526 /* Maxpacket and other transfer characteristics vary by speed. */
527 static struct usb_endpoint_descriptor *
528 fsg_ep_desc(struct usb_gadget *g, struct usb_endpoint_descriptor *fs,
529 struct usb_endpoint_descriptor *hs)
531 if (gadget_is_dualspeed(g) && g->speed == USB_SPEED_HIGH)
537 /* Static strings, in UTF-8 (for simplicity we use only ASCII characters) */
538 static struct usb_string fsg_strings[] = {
539 #ifndef FSG_NO_DEVICE_STRINGS
540 {FSG_STRING_MANUFACTURER, fsg_string_manufacturer},
541 {FSG_STRING_PRODUCT, fsg_string_product},
542 {FSG_STRING_SERIAL, ""},
543 {FSG_STRING_CONFIG, fsg_string_config},
545 {FSG_STRING_INTERFACE, fsg_string_interface},
549 static struct usb_gadget_strings fsg_stringtab = {
550 .language = 0x0409, /* en-us */
551 .strings = fsg_strings,
555 /*-------------------------------------------------------------------------*/
558 * If the next two routines are called while the gadget is registered,
559 * the caller must own fsg->filesem for writing.
562 static int fsg_lun_open(struct fsg_lun *curlun, const char *filename)
565 struct file *filp = NULL;
567 struct inode *inode = NULL;
572 /* R/W if we can, R/O if we must */
573 ro = curlun->initially_ro;
575 filp = filp_open(filename, O_RDWR | O_LARGEFILE, 0);
576 if (-EROFS == PTR_ERR(filp))
580 filp = filp_open(filename, O_RDONLY | O_LARGEFILE, 0);
582 LINFO(curlun, "unable to open backing file: %s\n", filename);
583 return PTR_ERR(filp);
586 if (!(filp->f_mode & FMODE_WRITE))
589 if (filp->f_path.dentry)
590 inode = filp->f_path.dentry->d_inode;
591 if (inode && S_ISBLK(inode->i_mode)) {
592 if (bdev_read_only(inode->i_bdev))
594 } else if (!inode || !S_ISREG(inode->i_mode)) {
595 LINFO(curlun, "invalid file type: %s\n", filename);
600 * If we can't read the file, it's no good.
601 * If we can't write the file, use it read-only.
603 if (!filp->f_op || !(filp->f_op->read || filp->f_op->aio_read)) {
604 LINFO(curlun, "file not readable: %s\n", filename);
607 if (!(filp->f_op->write || filp->f_op->aio_write))
610 size = i_size_read(inode->i_mapping->host);
612 LINFO(curlun, "unable to find file size: %s\n", filename);
616 num_sectors = size >> 9; /* File size in 512-byte blocks */
619 num_sectors &= ~3; /* Reduce to a multiple of 2048 */
620 min_sectors = 300*4; /* Smallest track is 300 frames */
621 if (num_sectors >= 256*60*75*4) {
622 num_sectors = (256*60*75 - 1) * 4;
623 LINFO(curlun, "file too big: %s\n", filename);
624 LINFO(curlun, "using only first %d blocks\n",
628 if (num_sectors < min_sectors) {
629 LINFO(curlun, "file too small: %s\n", filename);
637 curlun->file_length = size;
638 curlun->num_sectors = num_sectors;
639 LDBG(curlun, "open backing file: %s\n", filename);
643 filp_close(filp, current->files);
648 static void fsg_lun_close(struct fsg_lun *curlun)
651 LDBG(curlun, "close backing file\n");
658 /*-------------------------------------------------------------------------*/
661 * Sync the file data, don't bother with the metadata.
662 * This code was copied from fs/buffer.c:sys_fdatasync().
664 static int fsg_lun_fsync_sub(struct fsg_lun *curlun)
666 struct file *filp = curlun->filp;
668 if (curlun->ro || !filp)
670 return vfs_fsync(filp, 1);
673 static void store_cdrom_address(u8 *dest, int msf, u32 addr)
676 /* Convert to Minutes-Seconds-Frames */
677 addr >>= 2; /* Convert to 2048-byte frames */
678 addr += 2*75; /* Lead-in occupies 2 seconds */
679 dest[3] = addr % 75; /* Frames */
681 dest[2] = addr % 60; /* Seconds */
683 dest[1] = addr; /* Minutes */
684 dest[0] = 0; /* Reserved */
686 /* Absolute sector */
687 put_unaligned_be32(addr, dest);
692 /*-------------------------------------------------------------------------*/
695 static ssize_t fsg_show_ro(struct device *dev, struct device_attribute *attr,
698 struct fsg_lun *curlun = fsg_lun_from_dev(dev);
700 return sprintf(buf, "%d\n", fsg_lun_is_open(curlun)
702 : curlun->initially_ro);
705 static ssize_t fsg_show_nofua(struct device *dev, struct device_attribute *attr,
708 struct fsg_lun *curlun = fsg_lun_from_dev(dev);
710 return sprintf(buf, "%u\n", curlun->nofua);
713 static ssize_t fsg_show_file(struct device *dev, struct device_attribute *attr,
716 struct fsg_lun *curlun = fsg_lun_from_dev(dev);
717 struct rw_semaphore *filesem = dev_get_drvdata(dev);
722 if (fsg_lun_is_open(curlun)) { /* Get the complete pathname */
723 p = d_path(&curlun->filp->f_path, buf, PAGE_SIZE - 1);
729 buf[rc] = '\n'; /* Add a newline */
732 } else { /* No file, return 0 bytes */
741 static ssize_t fsg_store_ro(struct device *dev, struct device_attribute *attr,
742 const char *buf, size_t count)
745 struct fsg_lun *curlun = fsg_lun_from_dev(dev);
746 struct rw_semaphore *filesem = dev_get_drvdata(dev);
749 if (strict_strtoul(buf, 2, &ro))
753 * Allow the write-enable status to change only while the
754 * backing file is closed.
757 if (fsg_lun_is_open(curlun)) {
758 LDBG(curlun, "read-only status change prevented\n");
762 curlun->initially_ro = ro;
763 LDBG(curlun, "read-only status set to %d\n", curlun->ro);
769 static ssize_t fsg_store_nofua(struct device *dev,
770 struct device_attribute *attr,
771 const char *buf, size_t count)
773 struct fsg_lun *curlun = fsg_lun_from_dev(dev);
776 if (strict_strtoul(buf, 2, &nofua))
779 /* Sync data when switching from async mode to sync */
780 if (!nofua && curlun->nofua)
781 fsg_lun_fsync_sub(curlun);
783 curlun->nofua = nofua;
788 static ssize_t fsg_store_file(struct device *dev, struct device_attribute *attr,
789 const char *buf, size_t count)
791 struct fsg_lun *curlun = fsg_lun_from_dev(dev);
792 struct rw_semaphore *filesem = dev_get_drvdata(dev);
795 if (curlun->prevent_medium_removal && fsg_lun_is_open(curlun)) {
796 LDBG(curlun, "eject attempt prevented\n");
797 return -EBUSY; /* "Door is locked" */
800 /* Remove a trailing newline */
801 if (count > 0 && buf[count-1] == '\n')
802 ((char *) buf)[count-1] = 0; /* Ugh! */
804 /* Eject current medium */
806 if (fsg_lun_is_open(curlun)) {
807 fsg_lun_close(curlun);
808 curlun->unit_attention_data = SS_MEDIUM_NOT_PRESENT;
811 /* Load new medium */
812 if (count > 0 && buf[0]) {
813 rc = fsg_lun_open(curlun, buf);
815 curlun->unit_attention_data =
816 SS_NOT_READY_TO_READY_TRANSITION;
819 return (rc < 0 ? rc : count);