xref: /openbmc/linux/drivers/scsi/sg.c (revision 22246614)
1 /*
2  *  History:
3  *  Started: Aug 9 by Lawrence Foard (entropy@world.std.com),
4  *           to allow user process control of SCSI devices.
5  *  Development Sponsored by Killy Corp. NY NY
6  *
7  * Original driver (sg.c):
8  *        Copyright (C) 1992 Lawrence Foard
9  * Version 2 and 3 extensions to driver:
10  *        Copyright (C) 1998 - 2005 Douglas Gilbert
11  *
12  *  Modified  19-JAN-1998  Richard Gooch <rgooch@atnf.csiro.au>  Devfs support
13  *
14  * This program is free software; you can redistribute it and/or modify
15  * it under the terms of the GNU General Public License as published by
16  * the Free Software Foundation; either version 2, or (at your option)
17  * any later version.
18  *
19  */
20 
21 static int sg_version_num = 30534;	/* 2 digits for each component */
22 #define SG_VERSION_STR "3.5.34"
23 
24 /*
25  *  D. P. Gilbert (dgilbert@interlog.com, dougg@triode.net.au), notes:
26  *      - scsi logging is available via SCSI_LOG_TIMEOUT macros. First
27  *        the kernel/module needs to be built with CONFIG_SCSI_LOGGING
28  *        (otherwise the macros compile to empty statements).
29  *
30  */
31 #include <linux/module.h>
32 
33 #include <linux/fs.h>
34 #include <linux/kernel.h>
35 #include <linux/sched.h>
36 #include <linux/string.h>
37 #include <linux/mm.h>
38 #include <linux/errno.h>
39 #include <linux/mtio.h>
40 #include <linux/ioctl.h>
41 #include <linux/fcntl.h>
42 #include <linux/init.h>
43 #include <linux/poll.h>
44 #include <linux/moduleparam.h>
45 #include <linux/cdev.h>
46 #include <linux/idr.h>
47 #include <linux/seq_file.h>
48 #include <linux/blkdev.h>
49 #include <linux/delay.h>
50 #include <linux/scatterlist.h>
51 #include <linux/blktrace_api.h>
52 
53 #include "scsi.h"
54 #include <scsi/scsi_dbg.h>
55 #include <scsi/scsi_host.h>
56 #include <scsi/scsi_driver.h>
57 #include <scsi/scsi_ioctl.h>
58 #include <scsi/sg.h>
59 
60 #include "scsi_logging.h"
61 
62 #ifdef CONFIG_SCSI_PROC_FS
63 #include <linux/proc_fs.h>
64 static char *sg_version_date = "20061027";
65 
66 static int sg_proc_init(void);
67 static void sg_proc_cleanup(void);
68 #endif
69 
70 #define SG_ALLOW_DIO_DEF 0
71 #define SG_ALLOW_DIO_CODE /* compile out by commenting this define */
72 
73 #define SG_MAX_DEVS 32768
74 
75 /*
76  * Suppose you want to calculate the formula muldiv(x,m,d)=int(x * m / d)
77  * Then when using 32 bit integers x * m may overflow during the calculation.
78  * Replacing muldiv(x) by muldiv(x)=((x % d) * m) / d + int(x / d) * m
79  * calculates the same, but prevents the overflow when both m and d
80  * are "small" numbers (like HZ and USER_HZ).
81  * Of course an overflow is inavoidable if the result of muldiv doesn't fit
82  * in 32 bits.
83  */
84 #define MULDIV(X,MUL,DIV) ((((X % DIV) * MUL) / DIV) + ((X / DIV) * MUL))
85 
86 #define SG_DEFAULT_TIMEOUT MULDIV(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
87 
88 int sg_big_buff = SG_DEF_RESERVED_SIZE;
89 /* N.B. This variable is readable and writeable via
90    /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
91    of this size (or less if there is not enough memory) will be reserved
92    for use by this file descriptor. [Deprecated usage: this variable is also
93    readable via /proc/sys/kernel/sg-big-buff if the sg driver is built into
94    the kernel (i.e. it is not a module).] */
95 static int def_reserved_size = -1;	/* picks up init parameter */
96 static int sg_allow_dio = SG_ALLOW_DIO_DEF;
97 
98 static int scatter_elem_sz = SG_SCATTER_SZ;
99 static int scatter_elem_sz_prev = SG_SCATTER_SZ;
100 
101 #define SG_SECTOR_SZ 512
102 #define SG_SECTOR_MSK (SG_SECTOR_SZ - 1)
103 
104 static int sg_add(struct device *, struct class_interface *);
105 static void sg_remove(struct device *, struct class_interface *);
106 
107 static DEFINE_IDR(sg_index_idr);
108 static DEFINE_RWLOCK(sg_index_lock);	/* Also used to lock
109 							   file descriptor list for device */
110 
111 static struct class_interface sg_interface = {
112 	.add_dev	= sg_add,
113 	.remove_dev	= sg_remove,
114 };
115 
116 typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
117 	unsigned short k_use_sg; /* Count of kernel scatter-gather pieces */
118 	unsigned sglist_len; /* size of malloc'd scatter-gather list ++ */
119 	unsigned bufflen;	/* Size of (aggregate) data buffer */
120 	unsigned b_malloc_len;	/* actual len malloc'ed in buffer */
121 	struct scatterlist *buffer;/* scatter list */
122 	char dio_in_use;	/* 0->indirect IO (or mmap), 1->dio */
123 	unsigned char cmd_opcode; /* first byte of command */
124 } Sg_scatter_hold;
125 
126 struct sg_device;		/* forward declarations */
127 struct sg_fd;
128 
129 typedef struct sg_request {	/* SG_MAX_QUEUE requests outstanding per file */
130 	struct sg_request *nextrp;	/* NULL -> tail request (slist) */
131 	struct sg_fd *parentfp;	/* NULL -> not in use */
132 	Sg_scatter_hold data;	/* hold buffer, perhaps scatter list */
133 	sg_io_hdr_t header;	/* scsi command+info, see <scsi/sg.h> */
134 	unsigned char sense_b[SCSI_SENSE_BUFFERSIZE];
135 	char res_used;		/* 1 -> using reserve buffer, 0 -> not ... */
136 	char orphan;		/* 1 -> drop on sight, 0 -> normal */
137 	char sg_io_owned;	/* 1 -> packet belongs to SG_IO */
138 	volatile char done;	/* 0->before bh, 1->before read, 2->read */
139 } Sg_request;
140 
141 typedef struct sg_fd {		/* holds the state of a file descriptor */
142 	struct sg_fd *nextfp;	/* NULL when last opened fd on this device */
143 	struct sg_device *parentdp;	/* owning device */
144 	wait_queue_head_t read_wait;	/* queue read until command done */
145 	rwlock_t rq_list_lock;	/* protect access to list in req_arr */
146 	int timeout;		/* defaults to SG_DEFAULT_TIMEOUT      */
147 	int timeout_user;	/* defaults to SG_DEFAULT_TIMEOUT_USER */
148 	Sg_scatter_hold reserve;	/* buffer held for this file descriptor */
149 	unsigned save_scat_len;	/* original length of trunc. scat. element */
150 	Sg_request *headrp;	/* head of request slist, NULL->empty */
151 	struct fasync_struct *async_qp;	/* used by asynchronous notification */
152 	Sg_request req_arr[SG_MAX_QUEUE];	/* used as singly-linked list */
153 	char low_dma;		/* as in parent but possibly overridden to 1 */
154 	char force_packid;	/* 1 -> pack_id input to read(), 0 -> ignored */
155 	volatile char closed;	/* 1 -> fd closed but request(s) outstanding */
156 	char cmd_q;		/* 1 -> allow command queuing, 0 -> don't */
157 	char next_cmd_len;	/* 0 -> automatic (def), >0 -> use on next write() */
158 	char keep_orphan;	/* 0 -> drop orphan (def), 1 -> keep for read() */
159 	char mmap_called;	/* 0 -> mmap() never called on this fd */
160 } Sg_fd;
161 
162 typedef struct sg_device { /* holds the state of each scsi generic device */
163 	struct scsi_device *device;
164 	wait_queue_head_t o_excl_wait;	/* queue open() when O_EXCL in use */
165 	int sg_tablesize;	/* adapter's max scatter-gather table size */
166 	u32 index;		/* device index number */
167 	Sg_fd *headfp;		/* first open fd belonging to this device */
168 	volatile char detached;	/* 0->attached, 1->detached pending removal */
169 	volatile char exclude;	/* opened for exclusive access */
170 	char sgdebug;		/* 0->off, 1->sense, 9->dump dev, 10-> all devs */
171 	struct gendisk *disk;
172 	struct cdev * cdev;	/* char_dev [sysfs: /sys/cdev/major/sg<n>] */
173 } Sg_device;
174 
175 static int sg_fasync(int fd, struct file *filp, int mode);
176 /* tasklet or soft irq callback */
177 static void sg_cmd_done(void *data, char *sense, int result, int resid);
178 static int sg_start_req(Sg_request * srp);
179 static void sg_finish_rem_req(Sg_request * srp);
180 static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
181 static int sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp,
182 			 int tablesize);
183 static ssize_t sg_new_read(Sg_fd * sfp, char __user *buf, size_t count,
184 			   Sg_request * srp);
185 static ssize_t sg_new_write(Sg_fd * sfp, const char __user *buf, size_t count,
186 			    int blocking, int read_only, Sg_request ** o_srp);
187 static int sg_common_write(Sg_fd * sfp, Sg_request * srp,
188 			   unsigned char *cmnd, int timeout, int blocking);
189 static int sg_u_iovec(sg_io_hdr_t * hp, int sg_num, int ind,
190 		      int wr_xf, int *countp, unsigned char __user **up);
191 static int sg_write_xfer(Sg_request * srp);
192 static int sg_read_xfer(Sg_request * srp);
193 static int sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer);
194 static void sg_remove_scat(Sg_scatter_hold * schp);
195 static void sg_build_reserve(Sg_fd * sfp, int req_size);
196 static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
197 static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
198 static struct page *sg_page_malloc(int rqSz, int lowDma, int *retSzp);
199 static void sg_page_free(struct page *page, int size);
200 static Sg_fd *sg_add_sfp(Sg_device * sdp, int dev);
201 static int sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp);
202 static void __sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp);
203 static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id);
204 static Sg_request *sg_add_request(Sg_fd * sfp);
205 static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
206 static int sg_res_in_use(Sg_fd * sfp);
207 static int sg_allow_access(unsigned char opcode, char dev_type);
208 static int sg_build_direct(Sg_request * srp, Sg_fd * sfp, int dxfer_len);
209 static Sg_device *sg_get_dev(int dev);
210 #ifdef CONFIG_SCSI_PROC_FS
211 static int sg_last_dev(void);
212 #endif
213 
214 #define SZ_SG_HEADER sizeof(struct sg_header)
215 #define SZ_SG_IO_HDR sizeof(sg_io_hdr_t)
216 #define SZ_SG_IOVEC sizeof(sg_iovec_t)
217 #define SZ_SG_REQ_INFO sizeof(sg_req_info_t)
218 
219 static int
220 sg_open(struct inode *inode, struct file *filp)
221 {
222 	int dev = iminor(inode);
223 	int flags = filp->f_flags;
224 	struct request_queue *q;
225 	Sg_device *sdp;
226 	Sg_fd *sfp;
227 	int res;
228 	int retval;
229 
230 	nonseekable_open(inode, filp);
231 	SCSI_LOG_TIMEOUT(3, printk("sg_open: dev=%d, flags=0x%x\n", dev, flags));
232 	sdp = sg_get_dev(dev);
233 	if ((!sdp) || (!sdp->device))
234 		return -ENXIO;
235 	if (sdp->detached)
236 		return -ENODEV;
237 
238 	/* This driver's module count bumped by fops_get in <linux/fs.h> */
239 	/* Prevent the device driver from vanishing while we sleep */
240 	retval = scsi_device_get(sdp->device);
241 	if (retval)
242 		return retval;
243 
244 	if (!((flags & O_NONBLOCK) ||
245 	      scsi_block_when_processing_errors(sdp->device))) {
246 		retval = -ENXIO;
247 		/* we are in error recovery for this device */
248 		goto error_out;
249 	}
250 
251 	if (flags & O_EXCL) {
252 		if (O_RDONLY == (flags & O_ACCMODE)) {
253 			retval = -EPERM; /* Can't lock it with read only access */
254 			goto error_out;
255 		}
256 		if (sdp->headfp && (flags & O_NONBLOCK)) {
257 			retval = -EBUSY;
258 			goto error_out;
259 		}
260 		res = 0;
261 		__wait_event_interruptible(sdp->o_excl_wait,
262 			((sdp->headfp || sdp->exclude) ? 0 : (sdp->exclude = 1)), res);
263 		if (res) {
264 			retval = res;	/* -ERESTARTSYS because signal hit process */
265 			goto error_out;
266 		}
267 	} else if (sdp->exclude) {	/* some other fd has an exclusive lock on dev */
268 		if (flags & O_NONBLOCK) {
269 			retval = -EBUSY;
270 			goto error_out;
271 		}
272 		res = 0;
273 		__wait_event_interruptible(sdp->o_excl_wait, (!sdp->exclude),
274 					   res);
275 		if (res) {
276 			retval = res;	/* -ERESTARTSYS because signal hit process */
277 			goto error_out;
278 		}
279 	}
280 	if (sdp->detached) {
281 		retval = -ENODEV;
282 		goto error_out;
283 	}
284 	if (!sdp->headfp) {	/* no existing opens on this device */
285 		sdp->sgdebug = 0;
286 		q = sdp->device->request_queue;
287 		sdp->sg_tablesize = min(q->max_hw_segments,
288 					q->max_phys_segments);
289 	}
290 	if ((sfp = sg_add_sfp(sdp, dev)))
291 		filp->private_data = sfp;
292 	else {
293 		if (flags & O_EXCL)
294 			sdp->exclude = 0;	/* undo if error */
295 		retval = -ENOMEM;
296 		goto error_out;
297 	}
298 	return 0;
299 
300       error_out:
301 	scsi_device_put(sdp->device);
302 	return retval;
303 }
304 
305 /* Following function was formerly called 'sg_close' */
306 static int
307 sg_release(struct inode *inode, struct file *filp)
308 {
309 	Sg_device *sdp;
310 	Sg_fd *sfp;
311 
312 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
313 		return -ENXIO;
314 	SCSI_LOG_TIMEOUT(3, printk("sg_release: %s\n", sdp->disk->disk_name));
315 	sg_fasync(-1, filp, 0);	/* remove filp from async notification list */
316 	if (0 == sg_remove_sfp(sdp, sfp)) {	/* Returns 1 when sdp gone */
317 		if (!sdp->detached) {
318 			scsi_device_put(sdp->device);
319 		}
320 		sdp->exclude = 0;
321 		wake_up_interruptible(&sdp->o_excl_wait);
322 	}
323 	return 0;
324 }
325 
326 static ssize_t
327 sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
328 {
329 	Sg_device *sdp;
330 	Sg_fd *sfp;
331 	Sg_request *srp;
332 	int req_pack_id = -1;
333 	sg_io_hdr_t *hp;
334 	struct sg_header *old_hdr = NULL;
335 	int retval = 0;
336 
337 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
338 		return -ENXIO;
339 	SCSI_LOG_TIMEOUT(3, printk("sg_read: %s, count=%d\n",
340 				   sdp->disk->disk_name, (int) count));
341 
342 	if (!access_ok(VERIFY_WRITE, buf, count))
343 		return -EFAULT;
344 	if (sfp->force_packid && (count >= SZ_SG_HEADER)) {
345 		old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
346 		if (!old_hdr)
347 			return -ENOMEM;
348 		if (__copy_from_user(old_hdr, buf, SZ_SG_HEADER)) {
349 			retval = -EFAULT;
350 			goto free_old_hdr;
351 		}
352 		if (old_hdr->reply_len < 0) {
353 			if (count >= SZ_SG_IO_HDR) {
354 				sg_io_hdr_t *new_hdr;
355 				new_hdr = kmalloc(SZ_SG_IO_HDR, GFP_KERNEL);
356 				if (!new_hdr) {
357 					retval = -ENOMEM;
358 					goto free_old_hdr;
359 				}
360 				retval =__copy_from_user
361 				    (new_hdr, buf, SZ_SG_IO_HDR);
362 				req_pack_id = new_hdr->pack_id;
363 				kfree(new_hdr);
364 				if (retval) {
365 					retval = -EFAULT;
366 					goto free_old_hdr;
367 				}
368 			}
369 		} else
370 			req_pack_id = old_hdr->pack_id;
371 	}
372 	srp = sg_get_rq_mark(sfp, req_pack_id);
373 	if (!srp) {		/* now wait on packet to arrive */
374 		if (sdp->detached) {
375 			retval = -ENODEV;
376 			goto free_old_hdr;
377 		}
378 		if (filp->f_flags & O_NONBLOCK) {
379 			retval = -EAGAIN;
380 			goto free_old_hdr;
381 		}
382 		while (1) {
383 			retval = 0; /* following macro beats race condition */
384 			__wait_event_interruptible(sfp->read_wait,
385 				(sdp->detached ||
386 				(srp = sg_get_rq_mark(sfp, req_pack_id))),
387 				retval);
388 			if (sdp->detached) {
389 				retval = -ENODEV;
390 				goto free_old_hdr;
391 			}
392 			if (0 == retval)
393 				break;
394 
395 			/* -ERESTARTSYS as signal hit process */
396 			goto free_old_hdr;
397 		}
398 	}
399 	if (srp->header.interface_id != '\0') {
400 		retval = sg_new_read(sfp, buf, count, srp);
401 		goto free_old_hdr;
402 	}
403 
404 	hp = &srp->header;
405 	if (old_hdr == NULL) {
406 		old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
407 		if (! old_hdr) {
408 			retval = -ENOMEM;
409 			goto free_old_hdr;
410 		}
411 	}
412 	memset(old_hdr, 0, SZ_SG_HEADER);
413 	old_hdr->reply_len = (int) hp->timeout;
414 	old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
415 	old_hdr->pack_id = hp->pack_id;
416 	old_hdr->twelve_byte =
417 	    ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
418 	old_hdr->target_status = hp->masked_status;
419 	old_hdr->host_status = hp->host_status;
420 	old_hdr->driver_status = hp->driver_status;
421 	if ((CHECK_CONDITION & hp->masked_status) ||
422 	    (DRIVER_SENSE & hp->driver_status))
423 		memcpy(old_hdr->sense_buffer, srp->sense_b,
424 		       sizeof (old_hdr->sense_buffer));
425 	switch (hp->host_status) {
426 	/* This setup of 'result' is for backward compatibility and is best
427 	   ignored by the user who should use target, host + driver status */
428 	case DID_OK:
429 	case DID_PASSTHROUGH:
430 	case DID_SOFT_ERROR:
431 		old_hdr->result = 0;
432 		break;
433 	case DID_NO_CONNECT:
434 	case DID_BUS_BUSY:
435 	case DID_TIME_OUT:
436 		old_hdr->result = EBUSY;
437 		break;
438 	case DID_BAD_TARGET:
439 	case DID_ABORT:
440 	case DID_PARITY:
441 	case DID_RESET:
442 	case DID_BAD_INTR:
443 		old_hdr->result = EIO;
444 		break;
445 	case DID_ERROR:
446 		old_hdr->result = (srp->sense_b[0] == 0 &&
447 				  hp->masked_status == GOOD) ? 0 : EIO;
448 		break;
449 	default:
450 		old_hdr->result = EIO;
451 		break;
452 	}
453 
454 	/* Now copy the result back to the user buffer.  */
455 	if (count >= SZ_SG_HEADER) {
456 		if (__copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
457 			retval = -EFAULT;
458 			goto free_old_hdr;
459 		}
460 		buf += SZ_SG_HEADER;
461 		if (count > old_hdr->reply_len)
462 			count = old_hdr->reply_len;
463 		if (count > SZ_SG_HEADER) {
464 			if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
465 				retval = -EFAULT;
466 				goto free_old_hdr;
467 			}
468 		}
469 	} else
470 		count = (old_hdr->result == 0) ? 0 : -EIO;
471 	sg_finish_rem_req(srp);
472 	retval = count;
473 free_old_hdr:
474 	kfree(old_hdr);
475 	return retval;
476 }
477 
478 static ssize_t
479 sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
480 {
481 	sg_io_hdr_t *hp = &srp->header;
482 	int err = 0;
483 	int len;
484 
485 	if (count < SZ_SG_IO_HDR) {
486 		err = -EINVAL;
487 		goto err_out;
488 	}
489 	hp->sb_len_wr = 0;
490 	if ((hp->mx_sb_len > 0) && hp->sbp) {
491 		if ((CHECK_CONDITION & hp->masked_status) ||
492 		    (DRIVER_SENSE & hp->driver_status)) {
493 			int sb_len = SCSI_SENSE_BUFFERSIZE;
494 			sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
495 			len = 8 + (int) srp->sense_b[7];	/* Additional sense length field */
496 			len = (len > sb_len) ? sb_len : len;
497 			if (copy_to_user(hp->sbp, srp->sense_b, len)) {
498 				err = -EFAULT;
499 				goto err_out;
500 			}
501 			hp->sb_len_wr = len;
502 		}
503 	}
504 	if (hp->masked_status || hp->host_status || hp->driver_status)
505 		hp->info |= SG_INFO_CHECK;
506 	if (copy_to_user(buf, hp, SZ_SG_IO_HDR)) {
507 		err = -EFAULT;
508 		goto err_out;
509 	}
510 	err = sg_read_xfer(srp);
511       err_out:
512 	sg_finish_rem_req(srp);
513 	return (0 == err) ? count : err;
514 }
515 
516 static ssize_t
517 sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
518 {
519 	int mxsize, cmd_size, k;
520 	int input_size, blocking;
521 	unsigned char opcode;
522 	Sg_device *sdp;
523 	Sg_fd *sfp;
524 	Sg_request *srp;
525 	struct sg_header old_hdr;
526 	sg_io_hdr_t *hp;
527 	unsigned char cmnd[MAX_COMMAND_SIZE];
528 
529 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
530 		return -ENXIO;
531 	SCSI_LOG_TIMEOUT(3, printk("sg_write: %s, count=%d\n",
532 				   sdp->disk->disk_name, (int) count));
533 	if (sdp->detached)
534 		return -ENODEV;
535 	if (!((filp->f_flags & O_NONBLOCK) ||
536 	      scsi_block_when_processing_errors(sdp->device)))
537 		return -ENXIO;
538 
539 	if (!access_ok(VERIFY_READ, buf, count))
540 		return -EFAULT;	/* protects following copy_from_user()s + get_user()s */
541 	if (count < SZ_SG_HEADER)
542 		return -EIO;
543 	if (__copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
544 		return -EFAULT;
545 	blocking = !(filp->f_flags & O_NONBLOCK);
546 	if (old_hdr.reply_len < 0)
547 		return sg_new_write(sfp, buf, count, blocking, 0, NULL);
548 	if (count < (SZ_SG_HEADER + 6))
549 		return -EIO;	/* The minimum scsi command length is 6 bytes. */
550 
551 	if (!(srp = sg_add_request(sfp))) {
552 		SCSI_LOG_TIMEOUT(1, printk("sg_write: queue full\n"));
553 		return -EDOM;
554 	}
555 	buf += SZ_SG_HEADER;
556 	__get_user(opcode, buf);
557 	if (sfp->next_cmd_len > 0) {
558 		if (sfp->next_cmd_len > MAX_COMMAND_SIZE) {
559 			SCSI_LOG_TIMEOUT(1, printk("sg_write: command length too long\n"));
560 			sfp->next_cmd_len = 0;
561 			sg_remove_request(sfp, srp);
562 			return -EIO;
563 		}
564 		cmd_size = sfp->next_cmd_len;
565 		sfp->next_cmd_len = 0;	/* reset so only this write() effected */
566 	} else {
567 		cmd_size = COMMAND_SIZE(opcode);	/* based on SCSI command group */
568 		if ((opcode >= 0xc0) && old_hdr.twelve_byte)
569 			cmd_size = 12;
570 	}
571 	SCSI_LOG_TIMEOUT(4, printk(
572 		"sg_write:   scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
573 /* Determine buffer size.  */
574 	input_size = count - cmd_size;
575 	mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
576 	mxsize -= SZ_SG_HEADER;
577 	input_size -= SZ_SG_HEADER;
578 	if (input_size < 0) {
579 		sg_remove_request(sfp, srp);
580 		return -EIO;	/* User did not pass enough bytes for this command. */
581 	}
582 	hp = &srp->header;
583 	hp->interface_id = '\0';	/* indicator of old interface tunnelled */
584 	hp->cmd_len = (unsigned char) cmd_size;
585 	hp->iovec_count = 0;
586 	hp->mx_sb_len = 0;
587 	if (input_size > 0)
588 		hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
589 		    SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
590 	else
591 		hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
592 	hp->dxfer_len = mxsize;
593 	hp->dxferp = (char __user *)buf + cmd_size;
594 	hp->sbp = NULL;
595 	hp->timeout = old_hdr.reply_len;	/* structure abuse ... */
596 	hp->flags = input_size;	/* structure abuse ... */
597 	hp->pack_id = old_hdr.pack_id;
598 	hp->usr_ptr = NULL;
599 	if (__copy_from_user(cmnd, buf, cmd_size))
600 		return -EFAULT;
601 	/*
602 	 * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
603 	 * but is is possible that the app intended SG_DXFER_TO_DEV, because there
604 	 * is a non-zero input_size, so emit a warning.
605 	 */
606 	if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
607 		static char cmd[TASK_COMM_LEN];
608 		if (strcmp(current->comm, cmd) && printk_ratelimit()) {
609 			printk(KERN_WARNING
610 			       "sg_write: data in/out %d/%d bytes for SCSI command 0x%x--"
611 			       "guessing data in;\n" KERN_WARNING "   "
612 			       "program %s not setting count and/or reply_len properly\n",
613 			       old_hdr.reply_len - (int)SZ_SG_HEADER,
614 			       input_size, (unsigned int) cmnd[0],
615 			       current->comm);
616 			strcpy(cmd, current->comm);
617 		}
618 	}
619 	k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
620 	return (k < 0) ? k : count;
621 }
622 
623 static ssize_t
624 sg_new_write(Sg_fd * sfp, const char __user *buf, size_t count,
625 	     int blocking, int read_only, Sg_request ** o_srp)
626 {
627 	int k;
628 	Sg_request *srp;
629 	sg_io_hdr_t *hp;
630 	unsigned char cmnd[MAX_COMMAND_SIZE];
631 	int timeout;
632 	unsigned long ul_timeout;
633 
634 	if (count < SZ_SG_IO_HDR)
635 		return -EINVAL;
636 	if (!access_ok(VERIFY_READ, buf, count))
637 		return -EFAULT; /* protects following copy_from_user()s + get_user()s */
638 
639 	sfp->cmd_q = 1;	/* when sg_io_hdr seen, set command queuing on */
640 	if (!(srp = sg_add_request(sfp))) {
641 		SCSI_LOG_TIMEOUT(1, printk("sg_new_write: queue full\n"));
642 		return -EDOM;
643 	}
644 	hp = &srp->header;
645 	if (__copy_from_user(hp, buf, SZ_SG_IO_HDR)) {
646 		sg_remove_request(sfp, srp);
647 		return -EFAULT;
648 	}
649 	if (hp->interface_id != 'S') {
650 		sg_remove_request(sfp, srp);
651 		return -ENOSYS;
652 	}
653 	if (hp->flags & SG_FLAG_MMAP_IO) {
654 		if (hp->dxfer_len > sfp->reserve.bufflen) {
655 			sg_remove_request(sfp, srp);
656 			return -ENOMEM;	/* MMAP_IO size must fit in reserve buffer */
657 		}
658 		if (hp->flags & SG_FLAG_DIRECT_IO) {
659 			sg_remove_request(sfp, srp);
660 			return -EINVAL;	/* either MMAP_IO or DIRECT_IO (not both) */
661 		}
662 		if (sg_res_in_use(sfp)) {
663 			sg_remove_request(sfp, srp);
664 			return -EBUSY;	/* reserve buffer already being used */
665 		}
666 	}
667 	ul_timeout = msecs_to_jiffies(srp->header.timeout);
668 	timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
669 	if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
670 		sg_remove_request(sfp, srp);
671 		return -EMSGSIZE;
672 	}
673 	if (!access_ok(VERIFY_READ, hp->cmdp, hp->cmd_len)) {
674 		sg_remove_request(sfp, srp);
675 		return -EFAULT;	/* protects following copy_from_user()s + get_user()s */
676 	}
677 	if (__copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
678 		sg_remove_request(sfp, srp);
679 		return -EFAULT;
680 	}
681 	if (read_only &&
682 	    (!sg_allow_access(cmnd[0], sfp->parentdp->device->type))) {
683 		sg_remove_request(sfp, srp);
684 		return -EPERM;
685 	}
686 	k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
687 	if (k < 0)
688 		return k;
689 	if (o_srp)
690 		*o_srp = srp;
691 	return count;
692 }
693 
694 static int
695 sg_common_write(Sg_fd * sfp, Sg_request * srp,
696 		unsigned char *cmnd, int timeout, int blocking)
697 {
698 	int k, data_dir;
699 	Sg_device *sdp = sfp->parentdp;
700 	sg_io_hdr_t *hp = &srp->header;
701 
702 	srp->data.cmd_opcode = cmnd[0];	/* hold opcode of command */
703 	hp->status = 0;
704 	hp->masked_status = 0;
705 	hp->msg_status = 0;
706 	hp->info = 0;
707 	hp->host_status = 0;
708 	hp->driver_status = 0;
709 	hp->resid = 0;
710 	SCSI_LOG_TIMEOUT(4, printk("sg_common_write:  scsi opcode=0x%02x, cmd_size=%d\n",
711 			  (int) cmnd[0], (int) hp->cmd_len));
712 
713 	if ((k = sg_start_req(srp))) {
714 		SCSI_LOG_TIMEOUT(1, printk("sg_common_write: start_req err=%d\n", k));
715 		sg_finish_rem_req(srp);
716 		return k;	/* probably out of space --> ENOMEM */
717 	}
718 	if ((k = sg_write_xfer(srp))) {
719 		SCSI_LOG_TIMEOUT(1, printk("sg_common_write: write_xfer, bad address\n"));
720 		sg_finish_rem_req(srp);
721 		return k;
722 	}
723 	if (sdp->detached) {
724 		sg_finish_rem_req(srp);
725 		return -ENODEV;
726 	}
727 
728 	switch (hp->dxfer_direction) {
729 	case SG_DXFER_TO_FROM_DEV:
730 	case SG_DXFER_FROM_DEV:
731 		data_dir = DMA_FROM_DEVICE;
732 		break;
733 	case SG_DXFER_TO_DEV:
734 		data_dir = DMA_TO_DEVICE;
735 		break;
736 	case SG_DXFER_UNKNOWN:
737 		data_dir = DMA_BIDIRECTIONAL;
738 		break;
739 	default:
740 		data_dir = DMA_NONE;
741 		break;
742 	}
743 	hp->duration = jiffies_to_msecs(jiffies);
744 /* Now send everything of to mid-level. The next time we hear about this
745    packet is when sg_cmd_done() is called (i.e. a callback). */
746 	if (scsi_execute_async(sdp->device, cmnd, hp->cmd_len, data_dir, srp->data.buffer,
747 				hp->dxfer_len, srp->data.k_use_sg, timeout,
748 				SG_DEFAULT_RETRIES, srp, sg_cmd_done,
749 				GFP_ATOMIC)) {
750 		SCSI_LOG_TIMEOUT(1, printk("sg_common_write: scsi_execute_async failed\n"));
751 		/*
752 		 * most likely out of mem, but could also be a bad map
753 		 */
754 		sg_finish_rem_req(srp);
755 		return -ENOMEM;
756 	} else
757 		return 0;
758 }
759 
760 static int
761 sg_srp_done(Sg_request *srp, Sg_fd *sfp)
762 {
763 	unsigned long iflags;
764 	int done;
765 
766 	read_lock_irqsave(&sfp->rq_list_lock, iflags);
767 	done = srp->done;
768 	read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
769 	return done;
770 }
771 
772 static int
773 sg_ioctl(struct inode *inode, struct file *filp,
774 	 unsigned int cmd_in, unsigned long arg)
775 {
776 	void __user *p = (void __user *)arg;
777 	int __user *ip = p;
778 	int result, val, read_only;
779 	Sg_device *sdp;
780 	Sg_fd *sfp;
781 	Sg_request *srp;
782 	unsigned long iflags;
783 
784 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
785 		return -ENXIO;
786 	SCSI_LOG_TIMEOUT(3, printk("sg_ioctl: %s, cmd=0x%x\n",
787 				   sdp->disk->disk_name, (int) cmd_in));
788 	read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
789 
790 	switch (cmd_in) {
791 	case SG_IO:
792 		{
793 			int blocking = 1;	/* ignore O_NONBLOCK flag */
794 
795 			if (sdp->detached)
796 				return -ENODEV;
797 			if (!scsi_block_when_processing_errors(sdp->device))
798 				return -ENXIO;
799 			if (!access_ok(VERIFY_WRITE, p, SZ_SG_IO_HDR))
800 				return -EFAULT;
801 			result =
802 			    sg_new_write(sfp, p, SZ_SG_IO_HDR,
803 					 blocking, read_only, &srp);
804 			if (result < 0)
805 				return result;
806 			srp->sg_io_owned = 1;
807 			while (1) {
808 				result = 0;	/* following macro to beat race condition */
809 				__wait_event_interruptible(sfp->read_wait,
810 					(sdp->detached || sfp->closed || sg_srp_done(srp, sfp)),
811 							   result);
812 				if (sdp->detached)
813 					return -ENODEV;
814 				if (sfp->closed)
815 					return 0;	/* request packet dropped already */
816 				if (0 == result)
817 					break;
818 				srp->orphan = 1;
819 				return result;	/* -ERESTARTSYS because signal hit process */
820 			}
821 			write_lock_irqsave(&sfp->rq_list_lock, iflags);
822 			srp->done = 2;
823 			write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
824 			result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
825 			return (result < 0) ? result : 0;
826 		}
827 	case SG_SET_TIMEOUT:
828 		result = get_user(val, ip);
829 		if (result)
830 			return result;
831 		if (val < 0)
832 			return -EIO;
833 		if (val >= MULDIV (INT_MAX, USER_HZ, HZ))
834 		    val = MULDIV (INT_MAX, USER_HZ, HZ);
835 		sfp->timeout_user = val;
836 		sfp->timeout = MULDIV (val, HZ, USER_HZ);
837 
838 		return 0;
839 	case SG_GET_TIMEOUT:	/* N.B. User receives timeout as return value */
840 				/* strange ..., for backward compatibility */
841 		return sfp->timeout_user;
842 	case SG_SET_FORCE_LOW_DMA:
843 		result = get_user(val, ip);
844 		if (result)
845 			return result;
846 		if (val) {
847 			sfp->low_dma = 1;
848 			if ((0 == sfp->low_dma) && (0 == sg_res_in_use(sfp))) {
849 				val = (int) sfp->reserve.bufflen;
850 				sg_remove_scat(&sfp->reserve);
851 				sg_build_reserve(sfp, val);
852 			}
853 		} else {
854 			if (sdp->detached)
855 				return -ENODEV;
856 			sfp->low_dma = sdp->device->host->unchecked_isa_dma;
857 		}
858 		return 0;
859 	case SG_GET_LOW_DMA:
860 		return put_user((int) sfp->low_dma, ip);
861 	case SG_GET_SCSI_ID:
862 		if (!access_ok(VERIFY_WRITE, p, sizeof (sg_scsi_id_t)))
863 			return -EFAULT;
864 		else {
865 			sg_scsi_id_t __user *sg_idp = p;
866 
867 			if (sdp->detached)
868 				return -ENODEV;
869 			__put_user((int) sdp->device->host->host_no,
870 				   &sg_idp->host_no);
871 			__put_user((int) sdp->device->channel,
872 				   &sg_idp->channel);
873 			__put_user((int) sdp->device->id, &sg_idp->scsi_id);
874 			__put_user((int) sdp->device->lun, &sg_idp->lun);
875 			__put_user((int) sdp->device->type, &sg_idp->scsi_type);
876 			__put_user((short) sdp->device->host->cmd_per_lun,
877 				   &sg_idp->h_cmd_per_lun);
878 			__put_user((short) sdp->device->queue_depth,
879 				   &sg_idp->d_queue_depth);
880 			__put_user(0, &sg_idp->unused[0]);
881 			__put_user(0, &sg_idp->unused[1]);
882 			return 0;
883 		}
884 	case SG_SET_FORCE_PACK_ID:
885 		result = get_user(val, ip);
886 		if (result)
887 			return result;
888 		sfp->force_packid = val ? 1 : 0;
889 		return 0;
890 	case SG_GET_PACK_ID:
891 		if (!access_ok(VERIFY_WRITE, ip, sizeof (int)))
892 			return -EFAULT;
893 		read_lock_irqsave(&sfp->rq_list_lock, iflags);
894 		for (srp = sfp->headrp; srp; srp = srp->nextrp) {
895 			if ((1 == srp->done) && (!srp->sg_io_owned)) {
896 				read_unlock_irqrestore(&sfp->rq_list_lock,
897 						       iflags);
898 				__put_user(srp->header.pack_id, ip);
899 				return 0;
900 			}
901 		}
902 		read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
903 		__put_user(-1, ip);
904 		return 0;
905 	case SG_GET_NUM_WAITING:
906 		read_lock_irqsave(&sfp->rq_list_lock, iflags);
907 		for (val = 0, srp = sfp->headrp; srp; srp = srp->nextrp) {
908 			if ((1 == srp->done) && (!srp->sg_io_owned))
909 				++val;
910 		}
911 		read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
912 		return put_user(val, ip);
913 	case SG_GET_SG_TABLESIZE:
914 		return put_user(sdp->sg_tablesize, ip);
915 	case SG_SET_RESERVED_SIZE:
916 		result = get_user(val, ip);
917 		if (result)
918 			return result;
919                 if (val < 0)
920                         return -EINVAL;
921 		val = min_t(int, val,
922 				sdp->device->request_queue->max_sectors * 512);
923 		if (val != sfp->reserve.bufflen) {
924 			if (sg_res_in_use(sfp) || sfp->mmap_called)
925 				return -EBUSY;
926 			sg_remove_scat(&sfp->reserve);
927 			sg_build_reserve(sfp, val);
928 		}
929 		return 0;
930 	case SG_GET_RESERVED_SIZE:
931 		val = min_t(int, sfp->reserve.bufflen,
932 				sdp->device->request_queue->max_sectors * 512);
933 		return put_user(val, ip);
934 	case SG_SET_COMMAND_Q:
935 		result = get_user(val, ip);
936 		if (result)
937 			return result;
938 		sfp->cmd_q = val ? 1 : 0;
939 		return 0;
940 	case SG_GET_COMMAND_Q:
941 		return put_user((int) sfp->cmd_q, ip);
942 	case SG_SET_KEEP_ORPHAN:
943 		result = get_user(val, ip);
944 		if (result)
945 			return result;
946 		sfp->keep_orphan = val;
947 		return 0;
948 	case SG_GET_KEEP_ORPHAN:
949 		return put_user((int) sfp->keep_orphan, ip);
950 	case SG_NEXT_CMD_LEN:
951 		result = get_user(val, ip);
952 		if (result)
953 			return result;
954 		sfp->next_cmd_len = (val > 0) ? val : 0;
955 		return 0;
956 	case SG_GET_VERSION_NUM:
957 		return put_user(sg_version_num, ip);
958 	case SG_GET_ACCESS_COUNT:
959 		/* faked - we don't have a real access count anymore */
960 		val = (sdp->device ? 1 : 0);
961 		return put_user(val, ip);
962 	case SG_GET_REQUEST_TABLE:
963 		if (!access_ok(VERIFY_WRITE, p, SZ_SG_REQ_INFO * SG_MAX_QUEUE))
964 			return -EFAULT;
965 		else {
966 			sg_req_info_t *rinfo;
967 			unsigned int ms;
968 
969 			rinfo = kmalloc(SZ_SG_REQ_INFO * SG_MAX_QUEUE,
970 								GFP_KERNEL);
971 			if (!rinfo)
972 				return -ENOMEM;
973 			read_lock_irqsave(&sfp->rq_list_lock, iflags);
974 			for (srp = sfp->headrp, val = 0; val < SG_MAX_QUEUE;
975 			     ++val, srp = srp ? srp->nextrp : srp) {
976 				memset(&rinfo[val], 0, SZ_SG_REQ_INFO);
977 				if (srp) {
978 					rinfo[val].req_state = srp->done + 1;
979 					rinfo[val].problem =
980 					    srp->header.masked_status &
981 					    srp->header.host_status &
982 					    srp->header.driver_status;
983 					if (srp->done)
984 						rinfo[val].duration =
985 							srp->header.duration;
986 					else {
987 						ms = jiffies_to_msecs(jiffies);
988 						rinfo[val].duration =
989 						    (ms > srp->header.duration) ?
990 						    (ms - srp->header.duration) : 0;
991 					}
992 					rinfo[val].orphan = srp->orphan;
993 					rinfo[val].sg_io_owned =
994 							srp->sg_io_owned;
995 					rinfo[val].pack_id =
996 							srp->header.pack_id;
997 					rinfo[val].usr_ptr =
998 							srp->header.usr_ptr;
999 				}
1000 			}
1001 			read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1002 			result = __copy_to_user(p, rinfo,
1003 						SZ_SG_REQ_INFO * SG_MAX_QUEUE);
1004 			result = result ? -EFAULT : 0;
1005 			kfree(rinfo);
1006 			return result;
1007 		}
1008 	case SG_EMULATED_HOST:
1009 		if (sdp->detached)
1010 			return -ENODEV;
1011 		return put_user(sdp->device->host->hostt->emulated, ip);
1012 	case SG_SCSI_RESET:
1013 		if (sdp->detached)
1014 			return -ENODEV;
1015 		if (filp->f_flags & O_NONBLOCK) {
1016 			if (scsi_host_in_recovery(sdp->device->host))
1017 				return -EBUSY;
1018 		} else if (!scsi_block_when_processing_errors(sdp->device))
1019 			return -EBUSY;
1020 		result = get_user(val, ip);
1021 		if (result)
1022 			return result;
1023 		if (SG_SCSI_RESET_NOTHING == val)
1024 			return 0;
1025 		switch (val) {
1026 		case SG_SCSI_RESET_DEVICE:
1027 			val = SCSI_TRY_RESET_DEVICE;
1028 			break;
1029 		case SG_SCSI_RESET_BUS:
1030 			val = SCSI_TRY_RESET_BUS;
1031 			break;
1032 		case SG_SCSI_RESET_HOST:
1033 			val = SCSI_TRY_RESET_HOST;
1034 			break;
1035 		default:
1036 			return -EINVAL;
1037 		}
1038 		if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1039 			return -EACCES;
1040 		return (scsi_reset_provider(sdp->device, val) ==
1041 			SUCCESS) ? 0 : -EIO;
1042 	case SCSI_IOCTL_SEND_COMMAND:
1043 		if (sdp->detached)
1044 			return -ENODEV;
1045 		if (read_only) {
1046 			unsigned char opcode = WRITE_6;
1047 			Scsi_Ioctl_Command __user *siocp = p;
1048 
1049 			if (copy_from_user(&opcode, siocp->data, 1))
1050 				return -EFAULT;
1051 			if (!sg_allow_access(opcode, sdp->device->type))
1052 				return -EPERM;
1053 		}
1054 		return sg_scsi_ioctl(filp, sdp->device->request_queue, NULL, p);
1055 	case SG_SET_DEBUG:
1056 		result = get_user(val, ip);
1057 		if (result)
1058 			return result;
1059 		sdp->sgdebug = (char) val;
1060 		return 0;
1061 	case SCSI_IOCTL_GET_IDLUN:
1062 	case SCSI_IOCTL_GET_BUS_NUMBER:
1063 	case SCSI_IOCTL_PROBE_HOST:
1064 	case SG_GET_TRANSFORM:
1065 		if (sdp->detached)
1066 			return -ENODEV;
1067 		return scsi_ioctl(sdp->device, cmd_in, p);
1068 	case BLKSECTGET:
1069 		return put_user(sdp->device->request_queue->max_sectors * 512,
1070 				ip);
1071 	case BLKTRACESETUP:
1072 		return blk_trace_setup(sdp->device->request_queue,
1073 				       sdp->disk->disk_name,
1074 				       sdp->device->sdev_gendev.devt,
1075 				       (char *)arg);
1076 	case BLKTRACESTART:
1077 		return blk_trace_startstop(sdp->device->request_queue, 1);
1078 	case BLKTRACESTOP:
1079 		return blk_trace_startstop(sdp->device->request_queue, 0);
1080 	case BLKTRACETEARDOWN:
1081 		return blk_trace_remove(sdp->device->request_queue);
1082 	default:
1083 		if (read_only)
1084 			return -EPERM;	/* don't know so take safe approach */
1085 		return scsi_ioctl(sdp->device, cmd_in, p);
1086 	}
1087 }
1088 
1089 #ifdef CONFIG_COMPAT
1090 static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1091 {
1092 	Sg_device *sdp;
1093 	Sg_fd *sfp;
1094 	struct scsi_device *sdev;
1095 
1096 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1097 		return -ENXIO;
1098 
1099 	sdev = sdp->device;
1100 	if (sdev->host->hostt->compat_ioctl) {
1101 		int ret;
1102 
1103 		ret = sdev->host->hostt->compat_ioctl(sdev, cmd_in, (void __user *)arg);
1104 
1105 		return ret;
1106 	}
1107 
1108 	return -ENOIOCTLCMD;
1109 }
1110 #endif
1111 
1112 static unsigned int
1113 sg_poll(struct file *filp, poll_table * wait)
1114 {
1115 	unsigned int res = 0;
1116 	Sg_device *sdp;
1117 	Sg_fd *sfp;
1118 	Sg_request *srp;
1119 	int count = 0;
1120 	unsigned long iflags;
1121 
1122 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp))
1123 	    || sfp->closed)
1124 		return POLLERR;
1125 	poll_wait(filp, &sfp->read_wait, wait);
1126 	read_lock_irqsave(&sfp->rq_list_lock, iflags);
1127 	for (srp = sfp->headrp; srp; srp = srp->nextrp) {
1128 		/* if any read waiting, flag it */
1129 		if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1130 			res = POLLIN | POLLRDNORM;
1131 		++count;
1132 	}
1133 	read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1134 
1135 	if (sdp->detached)
1136 		res |= POLLHUP;
1137 	else if (!sfp->cmd_q) {
1138 		if (0 == count)
1139 			res |= POLLOUT | POLLWRNORM;
1140 	} else if (count < SG_MAX_QUEUE)
1141 		res |= POLLOUT | POLLWRNORM;
1142 	SCSI_LOG_TIMEOUT(3, printk("sg_poll: %s, res=0x%x\n",
1143 				   sdp->disk->disk_name, (int) res));
1144 	return res;
1145 }
1146 
1147 static int
1148 sg_fasync(int fd, struct file *filp, int mode)
1149 {
1150 	int retval;
1151 	Sg_device *sdp;
1152 	Sg_fd *sfp;
1153 
1154 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1155 		return -ENXIO;
1156 	SCSI_LOG_TIMEOUT(3, printk("sg_fasync: %s, mode=%d\n",
1157 				   sdp->disk->disk_name, mode));
1158 
1159 	retval = fasync_helper(fd, filp, mode, &sfp->async_qp);
1160 	return (retval < 0) ? retval : 0;
1161 }
1162 
1163 static int
1164 sg_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
1165 {
1166 	Sg_fd *sfp;
1167 	unsigned long offset, len, sa;
1168 	Sg_scatter_hold *rsv_schp;
1169 	struct scatterlist *sg;
1170 	int k;
1171 
1172 	if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1173 		return VM_FAULT_SIGBUS;
1174 	rsv_schp = &sfp->reserve;
1175 	offset = vmf->pgoff << PAGE_SHIFT;
1176 	if (offset >= rsv_schp->bufflen)
1177 		return VM_FAULT_SIGBUS;
1178 	SCSI_LOG_TIMEOUT(3, printk("sg_vma_fault: offset=%lu, scatg=%d\n",
1179 				   offset, rsv_schp->k_use_sg));
1180 	sg = rsv_schp->buffer;
1181 	sa = vma->vm_start;
1182 	for (k = 0; (k < rsv_schp->k_use_sg) && (sa < vma->vm_end);
1183 	     ++k, sg = sg_next(sg)) {
1184 		len = vma->vm_end - sa;
1185 		len = (len < sg->length) ? len : sg->length;
1186 		if (offset < len) {
1187 			struct page *page;
1188 			page = virt_to_page(page_address(sg_page(sg)) + offset);
1189 			get_page(page);	/* increment page count */
1190 			vmf->page = page;
1191 			return 0; /* success */
1192 		}
1193 		sa += len;
1194 		offset -= len;
1195 	}
1196 
1197 	return VM_FAULT_SIGBUS;
1198 }
1199 
1200 static struct vm_operations_struct sg_mmap_vm_ops = {
1201 	.fault = sg_vma_fault,
1202 };
1203 
1204 static int
1205 sg_mmap(struct file *filp, struct vm_area_struct *vma)
1206 {
1207 	Sg_fd *sfp;
1208 	unsigned long req_sz, len, sa;
1209 	Sg_scatter_hold *rsv_schp;
1210 	int k;
1211 	struct scatterlist *sg;
1212 
1213 	if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1214 		return -ENXIO;
1215 	req_sz = vma->vm_end - vma->vm_start;
1216 	SCSI_LOG_TIMEOUT(3, printk("sg_mmap starting, vm_start=%p, len=%d\n",
1217 				   (void *) vma->vm_start, (int) req_sz));
1218 	if (vma->vm_pgoff)
1219 		return -EINVAL;	/* want no offset */
1220 	rsv_schp = &sfp->reserve;
1221 	if (req_sz > rsv_schp->bufflen)
1222 		return -ENOMEM;	/* cannot map more than reserved buffer */
1223 
1224 	sa = vma->vm_start;
1225 	sg = rsv_schp->buffer;
1226 	for (k = 0; (k < rsv_schp->k_use_sg) && (sa < vma->vm_end);
1227 	     ++k, sg = sg_next(sg)) {
1228 		len = vma->vm_end - sa;
1229 		len = (len < sg->length) ? len : sg->length;
1230 		sa += len;
1231 	}
1232 
1233 	sfp->mmap_called = 1;
1234 	vma->vm_flags |= VM_RESERVED;
1235 	vma->vm_private_data = sfp;
1236 	vma->vm_ops = &sg_mmap_vm_ops;
1237 	return 0;
1238 }
1239 
1240 /* This function is a "bottom half" handler that is called by the
1241  * mid level when a command is completed (or has failed). */
1242 static void
1243 sg_cmd_done(void *data, char *sense, int result, int resid)
1244 {
1245 	Sg_request *srp = data;
1246 	Sg_device *sdp = NULL;
1247 	Sg_fd *sfp;
1248 	unsigned long iflags;
1249 	unsigned int ms;
1250 
1251 	if (NULL == srp) {
1252 		printk(KERN_ERR "sg_cmd_done: NULL request\n");
1253 		return;
1254 	}
1255 	sfp = srp->parentfp;
1256 	if (sfp)
1257 		sdp = sfp->parentdp;
1258 	if ((NULL == sdp) || sdp->detached) {
1259 		printk(KERN_INFO "sg_cmd_done: device detached\n");
1260 		return;
1261 	}
1262 
1263 
1264 	SCSI_LOG_TIMEOUT(4, printk("sg_cmd_done: %s, pack_id=%d, res=0x%x\n",
1265 		sdp->disk->disk_name, srp->header.pack_id, result));
1266 	srp->header.resid = resid;
1267 	ms = jiffies_to_msecs(jiffies);
1268 	srp->header.duration = (ms > srp->header.duration) ?
1269 				(ms - srp->header.duration) : 0;
1270 	if (0 != result) {
1271 		struct scsi_sense_hdr sshdr;
1272 
1273 		memcpy(srp->sense_b, sense, sizeof (srp->sense_b));
1274 		srp->header.status = 0xff & result;
1275 		srp->header.masked_status = status_byte(result);
1276 		srp->header.msg_status = msg_byte(result);
1277 		srp->header.host_status = host_byte(result);
1278 		srp->header.driver_status = driver_byte(result);
1279 		if ((sdp->sgdebug > 0) &&
1280 		    ((CHECK_CONDITION == srp->header.masked_status) ||
1281 		     (COMMAND_TERMINATED == srp->header.masked_status)))
1282 			__scsi_print_sense("sg_cmd_done", sense,
1283 					   SCSI_SENSE_BUFFERSIZE);
1284 
1285 		/* Following if statement is a patch supplied by Eric Youngdale */
1286 		if (driver_byte(result) != 0
1287 		    && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
1288 		    && !scsi_sense_is_deferred(&sshdr)
1289 		    && sshdr.sense_key == UNIT_ATTENTION
1290 		    && sdp->device->removable) {
1291 			/* Detected possible disc change. Set the bit - this */
1292 			/* may be used if there are filesystems using this device */
1293 			sdp->device->changed = 1;
1294 		}
1295 	}
1296 	/* Rely on write phase to clean out srp status values, so no "else" */
1297 
1298 	if (sfp->closed) {	/* whoops this fd already released, cleanup */
1299 		SCSI_LOG_TIMEOUT(1, printk("sg_cmd_done: already closed, freeing ...\n"));
1300 		sg_finish_rem_req(srp);
1301 		srp = NULL;
1302 		if (NULL == sfp->headrp) {
1303 			SCSI_LOG_TIMEOUT(1, printk("sg_cmd_done: already closed, final cleanup\n"));
1304 			if (0 == sg_remove_sfp(sdp, sfp)) {	/* device still present */
1305 				scsi_device_put(sdp->device);
1306 			}
1307 			sfp = NULL;
1308 		}
1309 	} else if (srp && srp->orphan) {
1310 		if (sfp->keep_orphan)
1311 			srp->sg_io_owned = 0;
1312 		else {
1313 			sg_finish_rem_req(srp);
1314 			srp = NULL;
1315 		}
1316 	}
1317 	if (sfp && srp) {
1318 		/* Now wake up any sg_read() that is waiting for this packet. */
1319 		kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1320 		write_lock_irqsave(&sfp->rq_list_lock, iflags);
1321 		srp->done = 1;
1322 		wake_up_interruptible(&sfp->read_wait);
1323 		write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1324 	}
1325 }
1326 
1327 static struct file_operations sg_fops = {
1328 	.owner = THIS_MODULE,
1329 	.read = sg_read,
1330 	.write = sg_write,
1331 	.poll = sg_poll,
1332 	.ioctl = sg_ioctl,
1333 #ifdef CONFIG_COMPAT
1334 	.compat_ioctl = sg_compat_ioctl,
1335 #endif
1336 	.open = sg_open,
1337 	.mmap = sg_mmap,
1338 	.release = sg_release,
1339 	.fasync = sg_fasync,
1340 };
1341 
1342 static struct class *sg_sysfs_class;
1343 
1344 static int sg_sysfs_valid = 0;
1345 
1346 static Sg_device *sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1347 {
1348 	struct request_queue *q = scsidp->request_queue;
1349 	Sg_device *sdp;
1350 	unsigned long iflags;
1351 	int error;
1352 	u32 k;
1353 
1354 	sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1355 	if (!sdp) {
1356 		printk(KERN_WARNING "kmalloc Sg_device failure\n");
1357 		return ERR_PTR(-ENOMEM);
1358 	}
1359 	error = -ENOMEM;
1360 	if (!idr_pre_get(&sg_index_idr, GFP_KERNEL)) {
1361 		printk(KERN_WARNING "idr expansion Sg_device failure\n");
1362 		goto out;
1363 	}
1364 
1365 	write_lock_irqsave(&sg_index_lock, iflags);
1366 	error = idr_get_new(&sg_index_idr, sdp, &k);
1367 	write_unlock_irqrestore(&sg_index_lock, iflags);
1368 
1369 	if (error) {
1370 		printk(KERN_WARNING "idr allocation Sg_device failure: %d\n",
1371 		       error);
1372 		goto out;
1373 	}
1374 
1375 	if (unlikely(k >= SG_MAX_DEVS))
1376 		goto overflow;
1377 
1378 	SCSI_LOG_TIMEOUT(3, printk("sg_alloc: dev=%d \n", k));
1379 	sprintf(disk->disk_name, "sg%d", k);
1380 	disk->first_minor = k;
1381 	sdp->disk = disk;
1382 	sdp->device = scsidp;
1383 	init_waitqueue_head(&sdp->o_excl_wait);
1384 	sdp->sg_tablesize = min(q->max_hw_segments, q->max_phys_segments);
1385 	sdp->index = k;
1386 
1387 	error = 0;
1388  out:
1389 	if (error) {
1390 		kfree(sdp);
1391 		return ERR_PTR(error);
1392 	}
1393 	return sdp;
1394 
1395  overflow:
1396 	sdev_printk(KERN_WARNING, scsidp,
1397 		    "Unable to attach sg device type=%d, minor "
1398 		    "number exceeds %d\n", scsidp->type, SG_MAX_DEVS - 1);
1399 	error = -ENODEV;
1400 	goto out;
1401 }
1402 
1403 static int
1404 sg_add(struct device *cl_dev, struct class_interface *cl_intf)
1405 {
1406 	struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1407 	struct gendisk *disk;
1408 	Sg_device *sdp = NULL;
1409 	struct cdev * cdev = NULL;
1410 	int error;
1411 	unsigned long iflags;
1412 
1413 	disk = alloc_disk(1);
1414 	if (!disk) {
1415 		printk(KERN_WARNING "alloc_disk failed\n");
1416 		return -ENOMEM;
1417 	}
1418 	disk->major = SCSI_GENERIC_MAJOR;
1419 
1420 	error = -ENOMEM;
1421 	cdev = cdev_alloc();
1422 	if (!cdev) {
1423 		printk(KERN_WARNING "cdev_alloc failed\n");
1424 		goto out;
1425 	}
1426 	cdev->owner = THIS_MODULE;
1427 	cdev->ops = &sg_fops;
1428 
1429 	sdp = sg_alloc(disk, scsidp);
1430 	if (IS_ERR(sdp)) {
1431 		printk(KERN_WARNING "sg_alloc failed\n");
1432 		error = PTR_ERR(sdp);
1433 		goto out;
1434 	}
1435 
1436 	error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), 1);
1437 	if (error)
1438 		goto cdev_add_err;
1439 
1440 	sdp->cdev = cdev;
1441 	if (sg_sysfs_valid) {
1442 		struct device *sg_class_member;
1443 
1444 		sg_class_member = device_create(sg_sysfs_class, cl_dev->parent,
1445 						MKDEV(SCSI_GENERIC_MAJOR,
1446 						      sdp->index),
1447 						"%s", disk->disk_name);
1448 		if (IS_ERR(sg_class_member)) {
1449 			printk(KERN_ERR "sg_add: "
1450 			       "device_create failed\n");
1451 			error = PTR_ERR(sg_class_member);
1452 			goto cdev_add_err;
1453 		}
1454 		dev_set_drvdata(sg_class_member, sdp);
1455 		error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1456 					  &sg_class_member->kobj, "generic");
1457 		if (error)
1458 			printk(KERN_ERR "sg_add: unable to make symlink "
1459 					"'generic' back to sg%d\n", sdp->index);
1460 	} else
1461 		printk(KERN_WARNING "sg_add: sg_sys Invalid\n");
1462 
1463 	sdev_printk(KERN_NOTICE, scsidp,
1464 		    "Attached scsi generic sg%d type %d\n", sdp->index,
1465 		    scsidp->type);
1466 
1467 	dev_set_drvdata(cl_dev, sdp);
1468 
1469 	return 0;
1470 
1471 cdev_add_err:
1472 	write_lock_irqsave(&sg_index_lock, iflags);
1473 	idr_remove(&sg_index_idr, sdp->index);
1474 	write_unlock_irqrestore(&sg_index_lock, iflags);
1475 	kfree(sdp);
1476 
1477 out:
1478 	put_disk(disk);
1479 	if (cdev)
1480 		cdev_del(cdev);
1481 	return error;
1482 }
1483 
1484 static void
1485 sg_remove(struct device *cl_dev, struct class_interface *cl_intf)
1486 {
1487 	struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1488 	Sg_device *sdp = dev_get_drvdata(cl_dev);
1489 	unsigned long iflags;
1490 	Sg_fd *sfp;
1491 	Sg_fd *tsfp;
1492 	Sg_request *srp;
1493 	Sg_request *tsrp;
1494 	int delay;
1495 
1496 	if (!sdp)
1497 		return;
1498 
1499 	delay = 0;
1500 	write_lock_irqsave(&sg_index_lock, iflags);
1501 	if (sdp->headfp) {
1502 		sdp->detached = 1;
1503 		for (sfp = sdp->headfp; sfp; sfp = tsfp) {
1504 			tsfp = sfp->nextfp;
1505 			for (srp = sfp->headrp; srp; srp = tsrp) {
1506 				tsrp = srp->nextrp;
1507 				if (sfp->closed || (0 == sg_srp_done(srp, sfp)))
1508 					sg_finish_rem_req(srp);
1509 			}
1510 			if (sfp->closed) {
1511 				scsi_device_put(sdp->device);
1512 				__sg_remove_sfp(sdp, sfp);
1513 			} else {
1514 				delay = 1;
1515 				wake_up_interruptible(&sfp->read_wait);
1516 				kill_fasync(&sfp->async_qp, SIGPOLL,
1517 					    POLL_HUP);
1518 			}
1519 		}
1520 		SCSI_LOG_TIMEOUT(3, printk("sg_remove: dev=%d, dirty\n", sdp->index));
1521 		if (NULL == sdp->headfp) {
1522 			idr_remove(&sg_index_idr, sdp->index);
1523 		}
1524 	} else {	/* nothing active, simple case */
1525 		SCSI_LOG_TIMEOUT(3, printk("sg_remove: dev=%d\n", sdp->index));
1526 		idr_remove(&sg_index_idr, sdp->index);
1527 	}
1528 	write_unlock_irqrestore(&sg_index_lock, iflags);
1529 
1530 	sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1531 	device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index));
1532 	cdev_del(sdp->cdev);
1533 	sdp->cdev = NULL;
1534 	put_disk(sdp->disk);
1535 	sdp->disk = NULL;
1536 	if (NULL == sdp->headfp)
1537 		kfree(sdp);
1538 
1539 	if (delay)
1540 		msleep(10);	/* dirty detach so delay device destruction */
1541 }
1542 
1543 module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR);
1544 module_param_named(def_reserved_size, def_reserved_size, int,
1545 		   S_IRUGO | S_IWUSR);
1546 module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1547 
1548 MODULE_AUTHOR("Douglas Gilbert");
1549 MODULE_DESCRIPTION("SCSI generic (sg) driver");
1550 MODULE_LICENSE("GPL");
1551 MODULE_VERSION(SG_VERSION_STR);
1552 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1553 
1554 MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element "
1555                 "size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
1556 MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1557 MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1558 
1559 static int __init
1560 init_sg(void)
1561 {
1562 	int rc;
1563 
1564 	if (scatter_elem_sz < PAGE_SIZE) {
1565 		scatter_elem_sz = PAGE_SIZE;
1566 		scatter_elem_sz_prev = scatter_elem_sz;
1567 	}
1568 	if (def_reserved_size >= 0)
1569 		sg_big_buff = def_reserved_size;
1570 	else
1571 		def_reserved_size = sg_big_buff;
1572 
1573 	rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1574 				    SG_MAX_DEVS, "sg");
1575 	if (rc)
1576 		return rc;
1577         sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
1578         if ( IS_ERR(sg_sysfs_class) ) {
1579 		rc = PTR_ERR(sg_sysfs_class);
1580 		goto err_out;
1581         }
1582 	sg_sysfs_valid = 1;
1583 	rc = scsi_register_interface(&sg_interface);
1584 	if (0 == rc) {
1585 #ifdef CONFIG_SCSI_PROC_FS
1586 		sg_proc_init();
1587 #endif				/* CONFIG_SCSI_PROC_FS */
1588 		return 0;
1589 	}
1590 	class_destroy(sg_sysfs_class);
1591 err_out:
1592 	unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1593 	return rc;
1594 }
1595 
1596 static void __exit
1597 exit_sg(void)
1598 {
1599 #ifdef CONFIG_SCSI_PROC_FS
1600 	sg_proc_cleanup();
1601 #endif				/* CONFIG_SCSI_PROC_FS */
1602 	scsi_unregister_interface(&sg_interface);
1603 	class_destroy(sg_sysfs_class);
1604 	sg_sysfs_valid = 0;
1605 	unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1606 				 SG_MAX_DEVS);
1607 	idr_destroy(&sg_index_idr);
1608 }
1609 
1610 static int
1611 sg_start_req(Sg_request * srp)
1612 {
1613 	int res;
1614 	Sg_fd *sfp = srp->parentfp;
1615 	sg_io_hdr_t *hp = &srp->header;
1616 	int dxfer_len = (int) hp->dxfer_len;
1617 	int dxfer_dir = hp->dxfer_direction;
1618 	Sg_scatter_hold *req_schp = &srp->data;
1619 	Sg_scatter_hold *rsv_schp = &sfp->reserve;
1620 
1621 	SCSI_LOG_TIMEOUT(4, printk("sg_start_req: dxfer_len=%d\n", dxfer_len));
1622 	if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1623 		return 0;
1624 	if (sg_allow_dio && (hp->flags & SG_FLAG_DIRECT_IO) &&
1625 	    (dxfer_dir != SG_DXFER_UNKNOWN) && (0 == hp->iovec_count) &&
1626 	    (!sfp->parentdp->device->host->unchecked_isa_dma)) {
1627 		res = sg_build_direct(srp, sfp, dxfer_len);
1628 		if (res <= 0)	/* -ve -> error, 0 -> done, 1 -> try indirect */
1629 			return res;
1630 	}
1631 	if ((!sg_res_in_use(sfp)) && (dxfer_len <= rsv_schp->bufflen))
1632 		sg_link_reserve(sfp, srp, dxfer_len);
1633 	else {
1634 		res = sg_build_indirect(req_schp, sfp, dxfer_len);
1635 		if (res) {
1636 			sg_remove_scat(req_schp);
1637 			return res;
1638 		}
1639 	}
1640 	return 0;
1641 }
1642 
1643 static void
1644 sg_finish_rem_req(Sg_request * srp)
1645 {
1646 	Sg_fd *sfp = srp->parentfp;
1647 	Sg_scatter_hold *req_schp = &srp->data;
1648 
1649 	SCSI_LOG_TIMEOUT(4, printk("sg_finish_rem_req: res_used=%d\n", (int) srp->res_used));
1650 	if (srp->res_used)
1651 		sg_unlink_reserve(sfp, srp);
1652 	else
1653 		sg_remove_scat(req_schp);
1654 	sg_remove_request(sfp, srp);
1655 }
1656 
1657 static int
1658 sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1659 {
1660 	int sg_bufflen = tablesize * sizeof(struct scatterlist);
1661 	gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1662 
1663 	/*
1664 	 * TODO: test without low_dma, we should not need it since
1665 	 * the block layer will bounce the buffer for us
1666 	 *
1667 	 * XXX(hch): we shouldn't need GFP_DMA for the actual S/G list.
1668 	 */
1669 	if (sfp->low_dma)
1670 		 gfp_flags |= GFP_DMA;
1671 	schp->buffer = kzalloc(sg_bufflen, gfp_flags);
1672 	if (!schp->buffer)
1673 		return -ENOMEM;
1674 	sg_init_table(schp->buffer, tablesize);
1675 	schp->sglist_len = sg_bufflen;
1676 	return tablesize;	/* number of scat_gath elements allocated */
1677 }
1678 
1679 #ifdef SG_ALLOW_DIO_CODE
1680 /* vvvvvvvv  following code borrowed from st driver's direct IO vvvvvvvvv */
1681 	/* TODO: hopefully we can use the generic block layer code */
1682 
1683 /* Pin down user pages and put them into a scatter gather list. Returns <= 0 if
1684    - mapping of all pages not successful
1685    (i.e., either completely successful or fails)
1686 */
1687 static int
1688 st_map_user_pages(struct scatterlist *sgl, const unsigned int max_pages,
1689 	          unsigned long uaddr, size_t count, int rw)
1690 {
1691 	unsigned long end = (uaddr + count + PAGE_SIZE - 1) >> PAGE_SHIFT;
1692 	unsigned long start = uaddr >> PAGE_SHIFT;
1693 	const int nr_pages = end - start;
1694 	int res, i, j;
1695 	struct page **pages;
1696 
1697 	/* User attempted Overflow! */
1698 	if ((uaddr + count) < uaddr)
1699 		return -EINVAL;
1700 
1701 	/* Too big */
1702         if (nr_pages > max_pages)
1703 		return -ENOMEM;
1704 
1705 	/* Hmm? */
1706 	if (count == 0)
1707 		return 0;
1708 
1709 	if ((pages = kmalloc(max_pages * sizeof(*pages), GFP_ATOMIC)) == NULL)
1710 		return -ENOMEM;
1711 
1712         /* Try to fault in all of the necessary pages */
1713 	down_read(&current->mm->mmap_sem);
1714         /* rw==READ means read from drive, write into memory area */
1715 	res = get_user_pages(
1716 		current,
1717 		current->mm,
1718 		uaddr,
1719 		nr_pages,
1720 		rw == READ,
1721 		0, /* don't force */
1722 		pages,
1723 		NULL);
1724 	up_read(&current->mm->mmap_sem);
1725 
1726 	/* Errors and no page mapped should return here */
1727 	if (res < nr_pages)
1728 		goto out_unmap;
1729 
1730         for (i=0; i < nr_pages; i++) {
1731                 /* FIXME: flush superflous for rw==READ,
1732                  * probably wrong function for rw==WRITE
1733                  */
1734 		flush_dcache_page(pages[i]);
1735 		/* ?? Is locking needed? I don't think so */
1736 		/* if (TestSetPageLocked(pages[i]))
1737 		   goto out_unlock; */
1738         }
1739 
1740 	sg_set_page(sgl, pages[0], 0, uaddr & ~PAGE_MASK);
1741 	if (nr_pages > 1) {
1742 		sgl[0].length = PAGE_SIZE - sgl[0].offset;
1743 		count -= sgl[0].length;
1744 		for (i=1; i < nr_pages ; i++)
1745 			sg_set_page(&sgl[i], pages[i], count < PAGE_SIZE ? count : PAGE_SIZE, 0);
1746 	}
1747 	else {
1748 		sgl[0].length = count;
1749 	}
1750 
1751 	kfree(pages);
1752 	return nr_pages;
1753 
1754  out_unmap:
1755 	if (res > 0) {
1756 		for (j=0; j < res; j++)
1757 			page_cache_release(pages[j]);
1758 		res = 0;
1759 	}
1760 	kfree(pages);
1761 	return res;
1762 }
1763 
1764 
1765 /* And unmap them... */
1766 static int
1767 st_unmap_user_pages(struct scatterlist *sgl, const unsigned int nr_pages,
1768 		    int dirtied)
1769 {
1770 	int i;
1771 
1772 	for (i=0; i < nr_pages; i++) {
1773 		struct page *page = sg_page(&sgl[i]);
1774 
1775 		if (dirtied)
1776 			SetPageDirty(page);
1777 		/* unlock_page(page); */
1778 		/* FIXME: cache flush missing for rw==READ
1779 		 * FIXME: call the correct reference counting function
1780 		 */
1781 		page_cache_release(page);
1782 	}
1783 
1784 	return 0;
1785 }
1786 
1787 /* ^^^^^^^^  above code borrowed from st driver's direct IO ^^^^^^^^^ */
1788 #endif
1789 
1790 
1791 /* Returns: -ve -> error, 0 -> done, 1 -> try indirect */
1792 static int
1793 sg_build_direct(Sg_request * srp, Sg_fd * sfp, int dxfer_len)
1794 {
1795 #ifdef SG_ALLOW_DIO_CODE
1796 	sg_io_hdr_t *hp = &srp->header;
1797 	Sg_scatter_hold *schp = &srp->data;
1798 	int sg_tablesize = sfp->parentdp->sg_tablesize;
1799 	int mx_sc_elems, res;
1800 	struct scsi_device *sdev = sfp->parentdp->device;
1801 
1802 	if (((unsigned long)hp->dxferp &
1803 			queue_dma_alignment(sdev->request_queue)) != 0)
1804 		return 1;
1805 
1806 	mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1807         if (mx_sc_elems <= 0) {
1808                 return 1;
1809         }
1810 	res = st_map_user_pages(schp->buffer, mx_sc_elems,
1811 				(unsigned long)hp->dxferp, dxfer_len,
1812 				(SG_DXFER_TO_DEV == hp->dxfer_direction) ? 1 : 0);
1813 	if (res <= 0) {
1814 		sg_remove_scat(schp);
1815 		return 1;
1816 	}
1817 	schp->k_use_sg = res;
1818 	schp->dio_in_use = 1;
1819 	hp->info |= SG_INFO_DIRECT_IO;
1820 	return 0;
1821 #else
1822 	return 1;
1823 #endif
1824 }
1825 
1826 static int
1827 sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1828 {
1829 	struct scatterlist *sg;
1830 	int ret_sz = 0, k, rem_sz, num, mx_sc_elems;
1831 	int sg_tablesize = sfp->parentdp->sg_tablesize;
1832 	int blk_size = buff_size;
1833 	struct page *p = NULL;
1834 
1835 	if (blk_size < 0)
1836 		return -EFAULT;
1837 	if (0 == blk_size)
1838 		++blk_size;	/* don't know why */
1839 /* round request up to next highest SG_SECTOR_SZ byte boundary */
1840 	blk_size = (blk_size + SG_SECTOR_MSK) & (~SG_SECTOR_MSK);
1841 	SCSI_LOG_TIMEOUT(4, printk("sg_build_indirect: buff_size=%d, blk_size=%d\n",
1842 				   buff_size, blk_size));
1843 
1844 	/* N.B. ret_sz carried into this block ... */
1845 	mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1846 	if (mx_sc_elems < 0)
1847 		return mx_sc_elems;	/* most likely -ENOMEM */
1848 
1849 	num = scatter_elem_sz;
1850 	if (unlikely(num != scatter_elem_sz_prev)) {
1851 		if (num < PAGE_SIZE) {
1852 			scatter_elem_sz = PAGE_SIZE;
1853 			scatter_elem_sz_prev = PAGE_SIZE;
1854 		} else
1855 			scatter_elem_sz_prev = num;
1856 	}
1857 	for (k = 0, sg = schp->buffer, rem_sz = blk_size;
1858 	     (rem_sz > 0) && (k < mx_sc_elems);
1859 	     ++k, rem_sz -= ret_sz, sg = sg_next(sg)) {
1860 
1861 		num = (rem_sz > scatter_elem_sz_prev) ?
1862 		      scatter_elem_sz_prev : rem_sz;
1863 		p = sg_page_malloc(num, sfp->low_dma, &ret_sz);
1864 		if (!p)
1865 			return -ENOMEM;
1866 
1867 		if (num == scatter_elem_sz_prev) {
1868 			if (unlikely(ret_sz > scatter_elem_sz_prev)) {
1869 				scatter_elem_sz = ret_sz;
1870 				scatter_elem_sz_prev = ret_sz;
1871 			}
1872 		}
1873 		sg_set_page(sg, p, (ret_sz > num) ? num : ret_sz, 0);
1874 
1875 		SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k=%d, num=%d, "
1876 				 "ret_sz=%d\n", k, num, ret_sz));
1877 	}		/* end of for loop */
1878 
1879 	schp->k_use_sg = k;
1880 	SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k_use_sg=%d, "
1881 			 "rem_sz=%d\n", k, rem_sz));
1882 
1883 	schp->bufflen = blk_size;
1884 	if (rem_sz > 0)	/* must have failed */
1885 		return -ENOMEM;
1886 
1887 	return 0;
1888 }
1889 
1890 static int
1891 sg_write_xfer(Sg_request * srp)
1892 {
1893 	sg_io_hdr_t *hp = &srp->header;
1894 	Sg_scatter_hold *schp = &srp->data;
1895 	struct scatterlist *sg = schp->buffer;
1896 	int num_xfer = 0;
1897 	int j, k, onum, usglen, ksglen, res;
1898 	int iovec_count = (int) hp->iovec_count;
1899 	int dxfer_dir = hp->dxfer_direction;
1900 	unsigned char *p;
1901 	unsigned char __user *up;
1902 	int new_interface = ('\0' == hp->interface_id) ? 0 : 1;
1903 
1904 	if ((SG_DXFER_UNKNOWN == dxfer_dir) || (SG_DXFER_TO_DEV == dxfer_dir) ||
1905 	    (SG_DXFER_TO_FROM_DEV == dxfer_dir)) {
1906 		num_xfer = (int) (new_interface ? hp->dxfer_len : hp->flags);
1907 		if (schp->bufflen < num_xfer)
1908 			num_xfer = schp->bufflen;
1909 	}
1910 	if ((num_xfer <= 0) || (schp->dio_in_use) ||
1911 	    (new_interface
1912 	     && ((SG_FLAG_NO_DXFER | SG_FLAG_MMAP_IO) & hp->flags)))
1913 		return 0;
1914 
1915 	SCSI_LOG_TIMEOUT(4, printk("sg_write_xfer: num_xfer=%d, iovec_count=%d, k_use_sg=%d\n",
1916 			  num_xfer, iovec_count, schp->k_use_sg));
1917 	if (iovec_count) {
1918 		onum = iovec_count;
1919 		if (!access_ok(VERIFY_READ, hp->dxferp, SZ_SG_IOVEC * onum))
1920 			return -EFAULT;
1921 	} else
1922 		onum = 1;
1923 
1924 	ksglen = sg->length;
1925 	p = page_address(sg_page(sg));
1926 	for (j = 0, k = 0; j < onum; ++j) {
1927 		res = sg_u_iovec(hp, iovec_count, j, 1, &usglen, &up);
1928 		if (res)
1929 			return res;
1930 
1931 		for (; p; sg = sg_next(sg), ksglen = sg->length,
1932 		     p = page_address(sg_page(sg))) {
1933 			if (usglen <= 0)
1934 				break;
1935 			if (ksglen > usglen) {
1936 				if (usglen >= num_xfer) {
1937 					if (__copy_from_user(p, up, num_xfer))
1938 						return -EFAULT;
1939 					return 0;
1940 				}
1941 				if (__copy_from_user(p, up, usglen))
1942 					return -EFAULT;
1943 				p += usglen;
1944 				ksglen -= usglen;
1945 				break;
1946 			} else {
1947 				if (ksglen >= num_xfer) {
1948 					if (__copy_from_user(p, up, num_xfer))
1949 						return -EFAULT;
1950 					return 0;
1951 				}
1952 				if (__copy_from_user(p, up, ksglen))
1953 					return -EFAULT;
1954 				up += ksglen;
1955 				usglen -= ksglen;
1956 			}
1957 			++k;
1958 			if (k >= schp->k_use_sg)
1959 				return 0;
1960 		}
1961 	}
1962 
1963 	return 0;
1964 }
1965 
1966 static int
1967 sg_u_iovec(sg_io_hdr_t * hp, int sg_num, int ind,
1968 	   int wr_xf, int *countp, unsigned char __user **up)
1969 {
1970 	int num_xfer = (int) hp->dxfer_len;
1971 	unsigned char __user *p = hp->dxferp;
1972 	int count;
1973 
1974 	if (0 == sg_num) {
1975 		if (wr_xf && ('\0' == hp->interface_id))
1976 			count = (int) hp->flags;	/* holds "old" input_size */
1977 		else
1978 			count = num_xfer;
1979 	} else {
1980 		sg_iovec_t iovec;
1981 		if (__copy_from_user(&iovec, p + ind*SZ_SG_IOVEC, SZ_SG_IOVEC))
1982 			return -EFAULT;
1983 		p = iovec.iov_base;
1984 		count = (int) iovec.iov_len;
1985 	}
1986 	if (!access_ok(wr_xf ? VERIFY_READ : VERIFY_WRITE, p, count))
1987 		return -EFAULT;
1988 	if (up)
1989 		*up = p;
1990 	if (countp)
1991 		*countp = count;
1992 	return 0;
1993 }
1994 
1995 static void
1996 sg_remove_scat(Sg_scatter_hold * schp)
1997 {
1998 	SCSI_LOG_TIMEOUT(4, printk("sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
1999 	if (schp->buffer && (schp->sglist_len > 0)) {
2000 		struct scatterlist *sg = schp->buffer;
2001 
2002 		if (schp->dio_in_use) {
2003 #ifdef SG_ALLOW_DIO_CODE
2004 			st_unmap_user_pages(sg, schp->k_use_sg, TRUE);
2005 #endif
2006 		} else {
2007 			int k;
2008 
2009 			for (k = 0; (k < schp->k_use_sg) && sg_page(sg);
2010 			     ++k, sg = sg_next(sg)) {
2011 				SCSI_LOG_TIMEOUT(5, printk(
2012 				    "sg_remove_scat: k=%d, pg=0x%p, len=%d\n",
2013 				    k, sg_page(sg), sg->length));
2014 				sg_page_free(sg_page(sg), sg->length);
2015 			}
2016 		}
2017 		kfree(schp->buffer);
2018 	}
2019 	memset(schp, 0, sizeof (*schp));
2020 }
2021 
2022 static int
2023 sg_read_xfer(Sg_request * srp)
2024 {
2025 	sg_io_hdr_t *hp = &srp->header;
2026 	Sg_scatter_hold *schp = &srp->data;
2027 	struct scatterlist *sg = schp->buffer;
2028 	int num_xfer = 0;
2029 	int j, k, onum, usglen, ksglen, res;
2030 	int iovec_count = (int) hp->iovec_count;
2031 	int dxfer_dir = hp->dxfer_direction;
2032 	unsigned char *p;
2033 	unsigned char __user *up;
2034 	int new_interface = ('\0' == hp->interface_id) ? 0 : 1;
2035 
2036 	if ((SG_DXFER_UNKNOWN == dxfer_dir) || (SG_DXFER_FROM_DEV == dxfer_dir)
2037 	    || (SG_DXFER_TO_FROM_DEV == dxfer_dir)) {
2038 		num_xfer = hp->dxfer_len;
2039 		if (schp->bufflen < num_xfer)
2040 			num_xfer = schp->bufflen;
2041 	}
2042 	if ((num_xfer <= 0) || (schp->dio_in_use) ||
2043 	    (new_interface
2044 	     && ((SG_FLAG_NO_DXFER | SG_FLAG_MMAP_IO) & hp->flags)))
2045 		return 0;
2046 
2047 	SCSI_LOG_TIMEOUT(4, printk("sg_read_xfer: num_xfer=%d, iovec_count=%d, k_use_sg=%d\n",
2048 			  num_xfer, iovec_count, schp->k_use_sg));
2049 	if (iovec_count) {
2050 		onum = iovec_count;
2051 		if (!access_ok(VERIFY_READ, hp->dxferp, SZ_SG_IOVEC * onum))
2052 			return -EFAULT;
2053 	} else
2054 		onum = 1;
2055 
2056 	p = page_address(sg_page(sg));
2057 	ksglen = sg->length;
2058 	for (j = 0, k = 0; j < onum; ++j) {
2059 		res = sg_u_iovec(hp, iovec_count, j, 0, &usglen, &up);
2060 		if (res)
2061 			return res;
2062 
2063 		for (; p; sg = sg_next(sg), ksglen = sg->length,
2064 		     p = page_address(sg_page(sg))) {
2065 			if (usglen <= 0)
2066 				break;
2067 			if (ksglen > usglen) {
2068 				if (usglen >= num_xfer) {
2069 					if (__copy_to_user(up, p, num_xfer))
2070 						return -EFAULT;
2071 					return 0;
2072 				}
2073 				if (__copy_to_user(up, p, usglen))
2074 					return -EFAULT;
2075 				p += usglen;
2076 				ksglen -= usglen;
2077 				break;
2078 			} else {
2079 				if (ksglen >= num_xfer) {
2080 					if (__copy_to_user(up, p, num_xfer))
2081 						return -EFAULT;
2082 					return 0;
2083 				}
2084 				if (__copy_to_user(up, p, ksglen))
2085 					return -EFAULT;
2086 				up += ksglen;
2087 				usglen -= ksglen;
2088 			}
2089 			++k;
2090 			if (k >= schp->k_use_sg)
2091 				return 0;
2092 		}
2093 	}
2094 
2095 	return 0;
2096 }
2097 
2098 static int
2099 sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
2100 {
2101 	Sg_scatter_hold *schp = &srp->data;
2102 	struct scatterlist *sg = schp->buffer;
2103 	int k, num;
2104 
2105 	SCSI_LOG_TIMEOUT(4, printk("sg_read_oxfer: num_read_xfer=%d\n",
2106 				   num_read_xfer));
2107 	if ((!outp) || (num_read_xfer <= 0))
2108 		return 0;
2109 
2110 	for (k = 0; (k < schp->k_use_sg) && sg_page(sg); ++k, sg = sg_next(sg)) {
2111 		num = sg->length;
2112 		if (num > num_read_xfer) {
2113 			if (__copy_to_user(outp, page_address(sg_page(sg)),
2114 					   num_read_xfer))
2115 				return -EFAULT;
2116 			break;
2117 		} else {
2118 			if (__copy_to_user(outp, page_address(sg_page(sg)),
2119 					   num))
2120 				return -EFAULT;
2121 			num_read_xfer -= num;
2122 			if (num_read_xfer <= 0)
2123 				break;
2124 			outp += num;
2125 		}
2126 	}
2127 
2128 	return 0;
2129 }
2130 
2131 static void
2132 sg_build_reserve(Sg_fd * sfp, int req_size)
2133 {
2134 	Sg_scatter_hold *schp = &sfp->reserve;
2135 
2136 	SCSI_LOG_TIMEOUT(4, printk("sg_build_reserve: req_size=%d\n", req_size));
2137 	do {
2138 		if (req_size < PAGE_SIZE)
2139 			req_size = PAGE_SIZE;
2140 		if (0 == sg_build_indirect(schp, sfp, req_size))
2141 			return;
2142 		else
2143 			sg_remove_scat(schp);
2144 		req_size >>= 1;	/* divide by 2 */
2145 	} while (req_size > (PAGE_SIZE / 2));
2146 }
2147 
2148 static void
2149 sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
2150 {
2151 	Sg_scatter_hold *req_schp = &srp->data;
2152 	Sg_scatter_hold *rsv_schp = &sfp->reserve;
2153 	struct scatterlist *sg = rsv_schp->buffer;
2154 	int k, num, rem;
2155 
2156 	srp->res_used = 1;
2157 	SCSI_LOG_TIMEOUT(4, printk("sg_link_reserve: size=%d\n", size));
2158 	rem = size;
2159 
2160 	for (k = 0; k < rsv_schp->k_use_sg; ++k, sg = sg_next(sg)) {
2161 		num = sg->length;
2162 		if (rem <= num) {
2163 			sfp->save_scat_len = num;
2164 			sg->length = rem;
2165 			req_schp->k_use_sg = k + 1;
2166 			req_schp->sglist_len = rsv_schp->sglist_len;
2167 			req_schp->buffer = rsv_schp->buffer;
2168 
2169 			req_schp->bufflen = size;
2170 			req_schp->b_malloc_len = rsv_schp->b_malloc_len;
2171 			break;
2172 		} else
2173 			rem -= num;
2174 	}
2175 
2176 	if (k >= rsv_schp->k_use_sg)
2177 		SCSI_LOG_TIMEOUT(1, printk("sg_link_reserve: BAD size\n"));
2178 }
2179 
2180 static void
2181 sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
2182 {
2183 	Sg_scatter_hold *req_schp = &srp->data;
2184 	Sg_scatter_hold *rsv_schp = &sfp->reserve;
2185 
2186 	SCSI_LOG_TIMEOUT(4, printk("sg_unlink_reserve: req->k_use_sg=%d\n",
2187 				   (int) req_schp->k_use_sg));
2188 	if ((rsv_schp->k_use_sg > 0) && (req_schp->k_use_sg > 0)) {
2189 		struct scatterlist *sg = rsv_schp->buffer;
2190 
2191 		if (sfp->save_scat_len > 0)
2192 			(sg + (req_schp->k_use_sg - 1))->length =
2193 			    (unsigned) sfp->save_scat_len;
2194 		else
2195 			SCSI_LOG_TIMEOUT(1, printk ("sg_unlink_reserve: BAD save_scat_len\n"));
2196 	}
2197 	req_schp->k_use_sg = 0;
2198 	req_schp->bufflen = 0;
2199 	req_schp->buffer = NULL;
2200 	req_schp->sglist_len = 0;
2201 	sfp->save_scat_len = 0;
2202 	srp->res_used = 0;
2203 }
2204 
2205 static Sg_request *
2206 sg_get_rq_mark(Sg_fd * sfp, int pack_id)
2207 {
2208 	Sg_request *resp;
2209 	unsigned long iflags;
2210 
2211 	write_lock_irqsave(&sfp->rq_list_lock, iflags);
2212 	for (resp = sfp->headrp; resp; resp = resp->nextrp) {
2213 		/* look for requests that are ready + not SG_IO owned */
2214 		if ((1 == resp->done) && (!resp->sg_io_owned) &&
2215 		    ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
2216 			resp->done = 2;	/* guard against other readers */
2217 			break;
2218 		}
2219 	}
2220 	write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2221 	return resp;
2222 }
2223 
2224 #ifdef CONFIG_SCSI_PROC_FS
2225 static Sg_request *
2226 sg_get_nth_request(Sg_fd * sfp, int nth)
2227 {
2228 	Sg_request *resp;
2229 	unsigned long iflags;
2230 	int k;
2231 
2232 	read_lock_irqsave(&sfp->rq_list_lock, iflags);
2233 	for (k = 0, resp = sfp->headrp; resp && (k < nth);
2234 	     ++k, resp = resp->nextrp) ;
2235 	read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2236 	return resp;
2237 }
2238 #endif
2239 
2240 /* always adds to end of list */
2241 static Sg_request *
2242 sg_add_request(Sg_fd * sfp)
2243 {
2244 	int k;
2245 	unsigned long iflags;
2246 	Sg_request *resp;
2247 	Sg_request *rp = sfp->req_arr;
2248 
2249 	write_lock_irqsave(&sfp->rq_list_lock, iflags);
2250 	resp = sfp->headrp;
2251 	if (!resp) {
2252 		memset(rp, 0, sizeof (Sg_request));
2253 		rp->parentfp = sfp;
2254 		resp = rp;
2255 		sfp->headrp = resp;
2256 	} else {
2257 		if (0 == sfp->cmd_q)
2258 			resp = NULL;	/* command queuing disallowed */
2259 		else {
2260 			for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2261 				if (!rp->parentfp)
2262 					break;
2263 			}
2264 			if (k < SG_MAX_QUEUE) {
2265 				memset(rp, 0, sizeof (Sg_request));
2266 				rp->parentfp = sfp;
2267 				while (resp->nextrp)
2268 					resp = resp->nextrp;
2269 				resp->nextrp = rp;
2270 				resp = rp;
2271 			} else
2272 				resp = NULL;
2273 		}
2274 	}
2275 	if (resp) {
2276 		resp->nextrp = NULL;
2277 		resp->header.duration = jiffies_to_msecs(jiffies);
2278 	}
2279 	write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2280 	return resp;
2281 }
2282 
2283 /* Return of 1 for found; 0 for not found */
2284 static int
2285 sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2286 {
2287 	Sg_request *prev_rp;
2288 	Sg_request *rp;
2289 	unsigned long iflags;
2290 	int res = 0;
2291 
2292 	if ((!sfp) || (!srp) || (!sfp->headrp))
2293 		return res;
2294 	write_lock_irqsave(&sfp->rq_list_lock, iflags);
2295 	prev_rp = sfp->headrp;
2296 	if (srp == prev_rp) {
2297 		sfp->headrp = prev_rp->nextrp;
2298 		prev_rp->parentfp = NULL;
2299 		res = 1;
2300 	} else {
2301 		while ((rp = prev_rp->nextrp)) {
2302 			if (srp == rp) {
2303 				prev_rp->nextrp = rp->nextrp;
2304 				rp->parentfp = NULL;
2305 				res = 1;
2306 				break;
2307 			}
2308 			prev_rp = rp;
2309 		}
2310 	}
2311 	write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2312 	return res;
2313 }
2314 
2315 #ifdef CONFIG_SCSI_PROC_FS
2316 static Sg_fd *
2317 sg_get_nth_sfp(Sg_device * sdp, int nth)
2318 {
2319 	Sg_fd *resp;
2320 	unsigned long iflags;
2321 	int k;
2322 
2323 	read_lock_irqsave(&sg_index_lock, iflags);
2324 	for (k = 0, resp = sdp->headfp; resp && (k < nth);
2325 	     ++k, resp = resp->nextfp) ;
2326 	read_unlock_irqrestore(&sg_index_lock, iflags);
2327 	return resp;
2328 }
2329 #endif
2330 
2331 static Sg_fd *
2332 sg_add_sfp(Sg_device * sdp, int dev)
2333 {
2334 	Sg_fd *sfp;
2335 	unsigned long iflags;
2336 	int bufflen;
2337 
2338 	sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2339 	if (!sfp)
2340 		return NULL;
2341 
2342 	init_waitqueue_head(&sfp->read_wait);
2343 	rwlock_init(&sfp->rq_list_lock);
2344 
2345 	sfp->timeout = SG_DEFAULT_TIMEOUT;
2346 	sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2347 	sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2348 	sfp->low_dma = (SG_DEF_FORCE_LOW_DMA == 0) ?
2349 	    sdp->device->host->unchecked_isa_dma : 1;
2350 	sfp->cmd_q = SG_DEF_COMMAND_Q;
2351 	sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2352 	sfp->parentdp = sdp;
2353 	write_lock_irqsave(&sg_index_lock, iflags);
2354 	if (!sdp->headfp)
2355 		sdp->headfp = sfp;
2356 	else {			/* add to tail of existing list */
2357 		Sg_fd *pfp = sdp->headfp;
2358 		while (pfp->nextfp)
2359 			pfp = pfp->nextfp;
2360 		pfp->nextfp = sfp;
2361 	}
2362 	write_unlock_irqrestore(&sg_index_lock, iflags);
2363 	SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp: sfp=0x%p\n", sfp));
2364 	if (unlikely(sg_big_buff != def_reserved_size))
2365 		sg_big_buff = def_reserved_size;
2366 
2367 	bufflen = min_t(int, sg_big_buff,
2368 			sdp->device->request_queue->max_sectors * 512);
2369 	sg_build_reserve(sfp, bufflen);
2370 	SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp:   bufflen=%d, k_use_sg=%d\n",
2371 			   sfp->reserve.bufflen, sfp->reserve.k_use_sg));
2372 	return sfp;
2373 }
2374 
2375 static void
2376 __sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp)
2377 {
2378 	Sg_fd *fp;
2379 	Sg_fd *prev_fp;
2380 
2381 	prev_fp = sdp->headfp;
2382 	if (sfp == prev_fp)
2383 		sdp->headfp = prev_fp->nextfp;
2384 	else {
2385 		while ((fp = prev_fp->nextfp)) {
2386 			if (sfp == fp) {
2387 				prev_fp->nextfp = fp->nextfp;
2388 				break;
2389 			}
2390 			prev_fp = fp;
2391 		}
2392 	}
2393 	if (sfp->reserve.bufflen > 0) {
2394 		SCSI_LOG_TIMEOUT(6,
2395 			printk("__sg_remove_sfp:    bufflen=%d, k_use_sg=%d\n",
2396 			(int) sfp->reserve.bufflen, (int) sfp->reserve.k_use_sg));
2397 		sg_remove_scat(&sfp->reserve);
2398 	}
2399 	sfp->parentdp = NULL;
2400 	SCSI_LOG_TIMEOUT(6, printk("__sg_remove_sfp:    sfp=0x%p\n", sfp));
2401 	kfree(sfp);
2402 }
2403 
2404 /* Returns 0 in normal case, 1 when detached and sdp object removed */
2405 static int
2406 sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp)
2407 {
2408 	Sg_request *srp;
2409 	Sg_request *tsrp;
2410 	int dirty = 0;
2411 	int res = 0;
2412 
2413 	for (srp = sfp->headrp; srp; srp = tsrp) {
2414 		tsrp = srp->nextrp;
2415 		if (sg_srp_done(srp, sfp))
2416 			sg_finish_rem_req(srp);
2417 		else
2418 			++dirty;
2419 	}
2420 	if (0 == dirty) {
2421 		unsigned long iflags;
2422 
2423 		write_lock_irqsave(&sg_index_lock, iflags);
2424 		__sg_remove_sfp(sdp, sfp);
2425 		if (sdp->detached && (NULL == sdp->headfp)) {
2426 			idr_remove(&sg_index_idr, sdp->index);
2427 			kfree(sdp);
2428 			res = 1;
2429 		}
2430 		write_unlock_irqrestore(&sg_index_lock, iflags);
2431 	} else {
2432 		/* MOD_INC's to inhibit unloading sg and associated adapter driver */
2433 		/* only bump the access_count if we actually succeeded in
2434 		 * throwing another counter on the host module */
2435 		scsi_device_get(sdp->device);	/* XXX: retval ignored? */
2436 		sfp->closed = 1;	/* flag dirty state on this fd */
2437 		SCSI_LOG_TIMEOUT(1, printk("sg_remove_sfp: worrisome, %d writes pending\n",
2438 				  dirty));
2439 	}
2440 	return res;
2441 }
2442 
2443 static int
2444 sg_res_in_use(Sg_fd * sfp)
2445 {
2446 	const Sg_request *srp;
2447 	unsigned long iflags;
2448 
2449 	read_lock_irqsave(&sfp->rq_list_lock, iflags);
2450 	for (srp = sfp->headrp; srp; srp = srp->nextrp)
2451 		if (srp->res_used)
2452 			break;
2453 	read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2454 	return srp ? 1 : 0;
2455 }
2456 
2457 /* The size fetched (value output via retSzp) set when non-NULL return */
2458 static struct page *
2459 sg_page_malloc(int rqSz, int lowDma, int *retSzp)
2460 {
2461 	struct page *resp = NULL;
2462 	gfp_t page_mask;
2463 	int order, a_size;
2464 	int resSz;
2465 
2466 	if ((rqSz <= 0) || (NULL == retSzp))
2467 		return resp;
2468 
2469 	if (lowDma)
2470 		page_mask = GFP_ATOMIC | GFP_DMA | __GFP_COMP | __GFP_NOWARN;
2471 	else
2472 		page_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN;
2473 
2474 	for (order = 0, a_size = PAGE_SIZE; a_size < rqSz;
2475 	     order++, a_size <<= 1) ;
2476 	resSz = a_size;		/* rounded up if necessary */
2477 	resp = alloc_pages(page_mask, order);
2478 	while ((!resp) && order) {
2479 		--order;
2480 		a_size >>= 1;	/* divide by 2, until PAGE_SIZE */
2481 		resp =  alloc_pages(page_mask, order);	/* try half */
2482 		resSz = a_size;
2483 	}
2484 	if (resp) {
2485 		if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2486 			memset(page_address(resp), 0, resSz);
2487 		*retSzp = resSz;
2488 	}
2489 	return resp;
2490 }
2491 
2492 static void
2493 sg_page_free(struct page *page, int size)
2494 {
2495 	int order, a_size;
2496 
2497 	if (!page)
2498 		return;
2499 	for (order = 0, a_size = PAGE_SIZE; a_size < size;
2500 	     order++, a_size <<= 1) ;
2501 	__free_pages(page, order);
2502 }
2503 
2504 #ifndef MAINTENANCE_IN_CMD
2505 #define MAINTENANCE_IN_CMD 0xa3
2506 #endif
2507 
2508 static unsigned char allow_ops[] = { TEST_UNIT_READY, REQUEST_SENSE,
2509 	INQUIRY, READ_CAPACITY, READ_BUFFER, READ_6, READ_10, READ_12,
2510 	READ_16, MODE_SENSE, MODE_SENSE_10, LOG_SENSE, REPORT_LUNS,
2511 	SERVICE_ACTION_IN, RECEIVE_DIAGNOSTIC, READ_LONG, MAINTENANCE_IN_CMD
2512 };
2513 
2514 static int
2515 sg_allow_access(unsigned char opcode, char dev_type)
2516 {
2517 	int k;
2518 
2519 	if (TYPE_SCANNER == dev_type)	/* TYPE_ROM maybe burner */
2520 		return 1;
2521 	for (k = 0; k < sizeof (allow_ops); ++k) {
2522 		if (opcode == allow_ops[k])
2523 			return 1;
2524 	}
2525 	return 0;
2526 }
2527 
2528 #ifdef CONFIG_SCSI_PROC_FS
2529 static int
2530 sg_idr_max_id(int id, void *p, void *data)
2531 {
2532 	int *k = data;
2533 
2534 	if (*k < id)
2535 		*k = id;
2536 
2537 	return 0;
2538 }
2539 
2540 static int
2541 sg_last_dev(void)
2542 {
2543 	int k = -1;
2544 	unsigned long iflags;
2545 
2546 	read_lock_irqsave(&sg_index_lock, iflags);
2547 	idr_for_each(&sg_index_idr, sg_idr_max_id, &k);
2548 	read_unlock_irqrestore(&sg_index_lock, iflags);
2549 	return k + 1;		/* origin 1 */
2550 }
2551 #endif
2552 
2553 static Sg_device *
2554 sg_get_dev(int dev)
2555 {
2556 	Sg_device *sdp;
2557 	unsigned long iflags;
2558 
2559 	read_lock_irqsave(&sg_index_lock, iflags);
2560 	sdp = idr_find(&sg_index_idr, dev);
2561 	read_unlock_irqrestore(&sg_index_lock, iflags);
2562 
2563 	return sdp;
2564 }
2565 
2566 #ifdef CONFIG_SCSI_PROC_FS
2567 
2568 static struct proc_dir_entry *sg_proc_sgp = NULL;
2569 
2570 static char sg_proc_sg_dirname[] = "scsi/sg";
2571 
2572 static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2573 
2574 static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2575 static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2576 			          size_t count, loff_t *off);
2577 static struct file_operations adio_fops = {
2578 	/* .owner, .read and .llseek added in sg_proc_init() */
2579 	.open = sg_proc_single_open_adio,
2580 	.write = sg_proc_write_adio,
2581 	.release = single_release,
2582 };
2583 
2584 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2585 static ssize_t sg_proc_write_dressz(struct file *filp,
2586 		const char __user *buffer, size_t count, loff_t *off);
2587 static struct file_operations dressz_fops = {
2588 	.open = sg_proc_single_open_dressz,
2589 	.write = sg_proc_write_dressz,
2590 	.release = single_release,
2591 };
2592 
2593 static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2594 static int sg_proc_single_open_version(struct inode *inode, struct file *file);
2595 static struct file_operations version_fops = {
2596 	.open = sg_proc_single_open_version,
2597 	.release = single_release,
2598 };
2599 
2600 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2601 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file);
2602 static struct file_operations devhdr_fops = {
2603 	.open = sg_proc_single_open_devhdr,
2604 	.release = single_release,
2605 };
2606 
2607 static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2608 static int sg_proc_open_dev(struct inode *inode, struct file *file);
2609 static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2610 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2611 static void dev_seq_stop(struct seq_file *s, void *v);
2612 static struct file_operations dev_fops = {
2613 	.open = sg_proc_open_dev,
2614 	.release = seq_release,
2615 };
2616 static struct seq_operations dev_seq_ops = {
2617 	.start = dev_seq_start,
2618 	.next  = dev_seq_next,
2619 	.stop  = dev_seq_stop,
2620 	.show  = sg_proc_seq_show_dev,
2621 };
2622 
2623 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2624 static int sg_proc_open_devstrs(struct inode *inode, struct file *file);
2625 static struct file_operations devstrs_fops = {
2626 	.open = sg_proc_open_devstrs,
2627 	.release = seq_release,
2628 };
2629 static struct seq_operations devstrs_seq_ops = {
2630 	.start = dev_seq_start,
2631 	.next  = dev_seq_next,
2632 	.stop  = dev_seq_stop,
2633 	.show  = sg_proc_seq_show_devstrs,
2634 };
2635 
2636 static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2637 static int sg_proc_open_debug(struct inode *inode, struct file *file);
2638 static struct file_operations debug_fops = {
2639 	.open = sg_proc_open_debug,
2640 	.release = seq_release,
2641 };
2642 static struct seq_operations debug_seq_ops = {
2643 	.start = dev_seq_start,
2644 	.next  = dev_seq_next,
2645 	.stop  = dev_seq_stop,
2646 	.show  = sg_proc_seq_show_debug,
2647 };
2648 
2649 
2650 struct sg_proc_leaf {
2651 	const char * name;
2652 	struct file_operations * fops;
2653 };
2654 
2655 static struct sg_proc_leaf sg_proc_leaf_arr[] = {
2656 	{"allow_dio", &adio_fops},
2657 	{"debug", &debug_fops},
2658 	{"def_reserved_size", &dressz_fops},
2659 	{"device_hdr", &devhdr_fops},
2660 	{"devices", &dev_fops},
2661 	{"device_strs", &devstrs_fops},
2662 	{"version", &version_fops}
2663 };
2664 
2665 static int
2666 sg_proc_init(void)
2667 {
2668 	int k, mask;
2669 	int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2670 	struct sg_proc_leaf * leaf;
2671 
2672 	sg_proc_sgp = proc_mkdir(sg_proc_sg_dirname, NULL);
2673 	if (!sg_proc_sgp)
2674 		return 1;
2675 	for (k = 0; k < num_leaves; ++k) {
2676 		leaf = &sg_proc_leaf_arr[k];
2677 		mask = leaf->fops->write ? S_IRUGO | S_IWUSR : S_IRUGO;
2678 		leaf->fops->owner = THIS_MODULE;
2679 		leaf->fops->read = seq_read;
2680 		leaf->fops->llseek = seq_lseek;
2681 		proc_create(leaf->name, mask, sg_proc_sgp, leaf->fops);
2682 	}
2683 	return 0;
2684 }
2685 
2686 static void
2687 sg_proc_cleanup(void)
2688 {
2689 	int k;
2690 	int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2691 
2692 	if (!sg_proc_sgp)
2693 		return;
2694 	for (k = 0; k < num_leaves; ++k)
2695 		remove_proc_entry(sg_proc_leaf_arr[k].name, sg_proc_sgp);
2696 	remove_proc_entry(sg_proc_sg_dirname, NULL);
2697 }
2698 
2699 
2700 static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2701 {
2702 	seq_printf(s, "%d\n", *((int *)s->private));
2703 	return 0;
2704 }
2705 
2706 static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2707 {
2708 	return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2709 }
2710 
2711 static ssize_t
2712 sg_proc_write_adio(struct file *filp, const char __user *buffer,
2713 		   size_t count, loff_t *off)
2714 {
2715 	int num;
2716 	char buff[11];
2717 
2718 	if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2719 		return -EACCES;
2720 	num = (count < 10) ? count : 10;
2721 	if (copy_from_user(buff, buffer, num))
2722 		return -EFAULT;
2723 	buff[num] = '\0';
2724 	sg_allow_dio = simple_strtoul(buff, NULL, 10) ? 1 : 0;
2725 	return count;
2726 }
2727 
2728 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2729 {
2730 	return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2731 }
2732 
2733 static ssize_t
2734 sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2735 		     size_t count, loff_t *off)
2736 {
2737 	int num;
2738 	unsigned long k = ULONG_MAX;
2739 	char buff[11];
2740 
2741 	if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2742 		return -EACCES;
2743 	num = (count < 10) ? count : 10;
2744 	if (copy_from_user(buff, buffer, num))
2745 		return -EFAULT;
2746 	buff[num] = '\0';
2747 	k = simple_strtoul(buff, NULL, 10);
2748 	if (k <= 1048576) {	/* limit "big buff" to 1 MB */
2749 		sg_big_buff = k;
2750 		return count;
2751 	}
2752 	return -ERANGE;
2753 }
2754 
2755 static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2756 {
2757 	seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2758 		   sg_version_date);
2759 	return 0;
2760 }
2761 
2762 static int sg_proc_single_open_version(struct inode *inode, struct file *file)
2763 {
2764 	return single_open(file, sg_proc_seq_show_version, NULL);
2765 }
2766 
2767 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2768 {
2769 	seq_printf(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\t"
2770 		   "online\n");
2771 	return 0;
2772 }
2773 
2774 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file)
2775 {
2776 	return single_open(file, sg_proc_seq_show_devhdr, NULL);
2777 }
2778 
2779 struct sg_proc_deviter {
2780 	loff_t	index;
2781 	size_t	max;
2782 };
2783 
2784 static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2785 {
2786 	struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2787 
2788 	s->private = it;
2789 	if (! it)
2790 		return NULL;
2791 
2792 	it->index = *pos;
2793 	it->max = sg_last_dev();
2794 	if (it->index >= it->max)
2795 		return NULL;
2796 	return it;
2797 }
2798 
2799 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2800 {
2801 	struct sg_proc_deviter * it = s->private;
2802 
2803 	*pos = ++it->index;
2804 	return (it->index < it->max) ? it : NULL;
2805 }
2806 
2807 static void dev_seq_stop(struct seq_file *s, void *v)
2808 {
2809 	kfree(s->private);
2810 }
2811 
2812 static int sg_proc_open_dev(struct inode *inode, struct file *file)
2813 {
2814         return seq_open(file, &dev_seq_ops);
2815 }
2816 
2817 static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2818 {
2819 	struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2820 	Sg_device *sdp;
2821 	struct scsi_device *scsidp;
2822 
2823 	sdp = it ? sg_get_dev(it->index) : NULL;
2824 	if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2825 		seq_printf(s, "%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\n",
2826 			      scsidp->host->host_no, scsidp->channel,
2827 			      scsidp->id, scsidp->lun, (int) scsidp->type,
2828 			      1,
2829 			      (int) scsidp->queue_depth,
2830 			      (int) scsidp->device_busy,
2831 			      (int) scsi_device_online(scsidp));
2832 	else
2833 		seq_printf(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2834 	return 0;
2835 }
2836 
2837 static int sg_proc_open_devstrs(struct inode *inode, struct file *file)
2838 {
2839         return seq_open(file, &devstrs_seq_ops);
2840 }
2841 
2842 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2843 {
2844 	struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2845 	Sg_device *sdp;
2846 	struct scsi_device *scsidp;
2847 
2848 	sdp = it ? sg_get_dev(it->index) : NULL;
2849 	if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2850 		seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2851 			   scsidp->vendor, scsidp->model, scsidp->rev);
2852 	else
2853 		seq_printf(s, "<no active device>\n");
2854 	return 0;
2855 }
2856 
2857 static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2858 {
2859 	int k, m, new_interface, blen, usg;
2860 	Sg_request *srp;
2861 	Sg_fd *fp;
2862 	const sg_io_hdr_t *hp;
2863 	const char * cp;
2864 	unsigned int ms;
2865 
2866 	for (k = 0; (fp = sg_get_nth_sfp(sdp, k)); ++k) {
2867 		seq_printf(s, "   FD(%d): timeout=%dms bufflen=%d "
2868 			   "(res)sgat=%d low_dma=%d\n", k + 1,
2869 			   jiffies_to_msecs(fp->timeout),
2870 			   fp->reserve.bufflen,
2871 			   (int) fp->reserve.k_use_sg,
2872 			   (int) fp->low_dma);
2873 		seq_printf(s, "   cmd_q=%d f_packid=%d k_orphan=%d closed=%d\n",
2874 			   (int) fp->cmd_q, (int) fp->force_packid,
2875 			   (int) fp->keep_orphan, (int) fp->closed);
2876 		for (m = 0; (srp = sg_get_nth_request(fp, m)); ++m) {
2877 			hp = &srp->header;
2878 			new_interface = (hp->interface_id == '\0') ? 0 : 1;
2879 			if (srp->res_used) {
2880 				if (new_interface &&
2881 				    (SG_FLAG_MMAP_IO & hp->flags))
2882 					cp = "     mmap>> ";
2883 				else
2884 					cp = "     rb>> ";
2885 			} else {
2886 				if (SG_INFO_DIRECT_IO_MASK & hp->info)
2887 					cp = "     dio>> ";
2888 				else
2889 					cp = "     ";
2890 			}
2891 			seq_printf(s, cp);
2892 			blen = srp->data.bufflen;
2893 			usg = srp->data.k_use_sg;
2894 			seq_printf(s, srp->done ?
2895 				   ((1 == srp->done) ?  "rcv:" : "fin:")
2896 				   : "act:");
2897 			seq_printf(s, " id=%d blen=%d",
2898 				   srp->header.pack_id, blen);
2899 			if (srp->done)
2900 				seq_printf(s, " dur=%d", hp->duration);
2901 			else {
2902 				ms = jiffies_to_msecs(jiffies);
2903 				seq_printf(s, " t_o/elap=%d/%d",
2904 					(new_interface ? hp->timeout :
2905 						  jiffies_to_msecs(fp->timeout)),
2906 					(ms > hp->duration ? ms - hp->duration : 0));
2907 			}
2908 			seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2909 				   (int) srp->data.cmd_opcode);
2910 		}
2911 		if (0 == m)
2912 			seq_printf(s, "     No requests active\n");
2913 	}
2914 }
2915 
2916 static int sg_proc_open_debug(struct inode *inode, struct file *file)
2917 {
2918         return seq_open(file, &debug_seq_ops);
2919 }
2920 
2921 static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2922 {
2923 	struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2924 	Sg_device *sdp;
2925 
2926 	if (it && (0 == it->index)) {
2927 		seq_printf(s, "max_active_device=%d(origin 1)\n",
2928 			   (int)it->max);
2929 		seq_printf(s, " def_reserved_size=%d\n", sg_big_buff);
2930 	}
2931 	sdp = it ? sg_get_dev(it->index) : NULL;
2932 	if (sdp) {
2933 		struct scsi_device *scsidp = sdp->device;
2934 
2935 		if (NULL == scsidp) {
2936 			seq_printf(s, "device %d detached ??\n",
2937 				   (int)it->index);
2938 			return 0;
2939 		}
2940 
2941 		if (sg_get_nth_sfp(sdp, 0)) {
2942 			seq_printf(s, " >>> device=%s ",
2943 				sdp->disk->disk_name);
2944 			if (sdp->detached)
2945 				seq_printf(s, "detached pending close ");
2946 			else
2947 				seq_printf
2948 				    (s, "scsi%d chan=%d id=%d lun=%d   em=%d",
2949 				     scsidp->host->host_no,
2950 				     scsidp->channel, scsidp->id,
2951 				     scsidp->lun,
2952 				     scsidp->host->hostt->emulated);
2953 			seq_printf(s, " sg_tablesize=%d excl=%d\n",
2954 				   sdp->sg_tablesize, sdp->exclude);
2955 		}
2956 		sg_proc_debug_helper(s, sdp);
2957 	}
2958 	return 0;
2959 }
2960 
2961 #endif				/* CONFIG_SCSI_PROC_FS */
2962 
2963 module_init(init_sg);
2964 module_exit(exit_sg);
2965