xref: /openbmc/linux/drivers/scsi/sg.c (revision f15cbe6f1a4b4d9df59142fc8e4abb973302cf44)
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 #include <linux/smp_lock.h>
53 
54 #include "scsi.h"
55 #include <scsi/scsi_dbg.h>
56 #include <scsi/scsi_host.h>
57 #include <scsi/scsi_driver.h>
58 #include <scsi/scsi_ioctl.h>
59 #include <scsi/sg.h>
60 
61 #include "scsi_logging.h"
62 
63 #ifdef CONFIG_SCSI_PROC_FS
64 #include <linux/proc_fs.h>
65 static char *sg_version_date = "20061027";
66 
67 static int sg_proc_init(void);
68 static void sg_proc_cleanup(void);
69 #endif
70 
71 #define SG_ALLOW_DIO_DEF 0
72 #define SG_ALLOW_DIO_CODE /* compile out by commenting this define */
73 
74 #define SG_MAX_DEVS 32768
75 
76 /*
77  * Suppose you want to calculate the formula muldiv(x,m,d)=int(x * m / d)
78  * Then when using 32 bit integers x * m may overflow during the calculation.
79  * Replacing muldiv(x) by muldiv(x)=((x % d) * m) / d + int(x / d) * m
80  * calculates the same, but prevents the overflow when both m and d
81  * are "small" numbers (like HZ and USER_HZ).
82  * Of course an overflow is inavoidable if the result of muldiv doesn't fit
83  * in 32 bits.
84  */
85 #define MULDIV(X,MUL,DIV) ((((X % DIV) * MUL) / DIV) + ((X / DIV) * MUL))
86 
87 #define SG_DEFAULT_TIMEOUT MULDIV(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
88 
89 int sg_big_buff = SG_DEF_RESERVED_SIZE;
90 /* N.B. This variable is readable and writeable via
91    /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
92    of this size (or less if there is not enough memory) will be reserved
93    for use by this file descriptor. [Deprecated usage: this variable is also
94    readable via /proc/sys/kernel/sg-big-buff if the sg driver is built into
95    the kernel (i.e. it is not a module).] */
96 static int def_reserved_size = -1;	/* picks up init parameter */
97 static int sg_allow_dio = SG_ALLOW_DIO_DEF;
98 
99 static int scatter_elem_sz = SG_SCATTER_SZ;
100 static int scatter_elem_sz_prev = SG_SCATTER_SZ;
101 
102 #define SG_SECTOR_SZ 512
103 #define SG_SECTOR_MSK (SG_SECTOR_SZ - 1)
104 
105 static int sg_add(struct device *, struct class_interface *);
106 static void sg_remove(struct device *, struct class_interface *);
107 
108 static DEFINE_IDR(sg_index_idr);
109 static DEFINE_RWLOCK(sg_index_lock);	/* Also used to lock
110 							   file descriptor list for device */
111 
112 static struct class_interface sg_interface = {
113 	.add_dev	= sg_add,
114 	.remove_dev	= sg_remove,
115 };
116 
117 typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
118 	unsigned short k_use_sg; /* Count of kernel scatter-gather pieces */
119 	unsigned sglist_len; /* size of malloc'd scatter-gather list ++ */
120 	unsigned bufflen;	/* Size of (aggregate) data buffer */
121 	unsigned b_malloc_len;	/* actual len malloc'ed in buffer */
122 	struct scatterlist *buffer;/* scatter list */
123 	char dio_in_use;	/* 0->indirect IO (or mmap), 1->dio */
124 	unsigned char cmd_opcode; /* first byte of command */
125 } Sg_scatter_hold;
126 
127 struct sg_device;		/* forward declarations */
128 struct sg_fd;
129 
130 typedef struct sg_request {	/* SG_MAX_QUEUE requests outstanding per file */
131 	struct sg_request *nextrp;	/* NULL -> tail request (slist) */
132 	struct sg_fd *parentfp;	/* NULL -> not in use */
133 	Sg_scatter_hold data;	/* hold buffer, perhaps scatter list */
134 	sg_io_hdr_t header;	/* scsi command+info, see <scsi/sg.h> */
135 	unsigned char sense_b[SCSI_SENSE_BUFFERSIZE];
136 	char res_used;		/* 1 -> using reserve buffer, 0 -> not ... */
137 	char orphan;		/* 1 -> drop on sight, 0 -> normal */
138 	char sg_io_owned;	/* 1 -> packet belongs to SG_IO */
139 	volatile char done;	/* 0->before bh, 1->before read, 2->read */
140 } Sg_request;
141 
142 typedef struct sg_fd {		/* holds the state of a file descriptor */
143 	struct sg_fd *nextfp;	/* NULL when last opened fd on this device */
144 	struct sg_device *parentdp;	/* owning device */
145 	wait_queue_head_t read_wait;	/* queue read until command done */
146 	rwlock_t rq_list_lock;	/* protect access to list in req_arr */
147 	int timeout;		/* defaults to SG_DEFAULT_TIMEOUT      */
148 	int timeout_user;	/* defaults to SG_DEFAULT_TIMEOUT_USER */
149 	Sg_scatter_hold reserve;	/* buffer held for this file descriptor */
150 	unsigned save_scat_len;	/* original length of trunc. scat. element */
151 	Sg_request *headrp;	/* head of request slist, NULL->empty */
152 	struct fasync_struct *async_qp;	/* used by asynchronous notification */
153 	Sg_request req_arr[SG_MAX_QUEUE];	/* used as singly-linked list */
154 	char low_dma;		/* as in parent but possibly overridden to 1 */
155 	char force_packid;	/* 1 -> pack_id input to read(), 0 -> ignored */
156 	volatile char closed;	/* 1 -> fd closed but request(s) outstanding */
157 	char cmd_q;		/* 1 -> allow command queuing, 0 -> don't */
158 	char next_cmd_len;	/* 0 -> automatic (def), >0 -> use on next write() */
159 	char keep_orphan;	/* 0 -> drop orphan (def), 1 -> keep for read() */
160 	char mmap_called;	/* 0 -> mmap() never called on this fd */
161 } Sg_fd;
162 
163 typedef struct sg_device { /* holds the state of each scsi generic device */
164 	struct scsi_device *device;
165 	wait_queue_head_t o_excl_wait;	/* queue open() when O_EXCL in use */
166 	int sg_tablesize;	/* adapter's max scatter-gather table size */
167 	u32 index;		/* device index number */
168 	Sg_fd *headfp;		/* first open fd belonging to this device */
169 	volatile char detached;	/* 0->attached, 1->detached pending removal */
170 	volatile char exclude;	/* opened for exclusive access */
171 	char sgdebug;		/* 0->off, 1->sense, 9->dump dev, 10-> all devs */
172 	struct gendisk *disk;
173 	struct cdev * cdev;	/* char_dev [sysfs: /sys/cdev/major/sg<n>] */
174 } Sg_device;
175 
176 static int sg_fasync(int fd, struct file *filp, int mode);
177 /* tasklet or soft irq callback */
178 static void sg_cmd_done(void *data, char *sense, int result, int resid);
179 static int sg_start_req(Sg_request * srp);
180 static void sg_finish_rem_req(Sg_request * srp);
181 static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
182 static int sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp,
183 			 int tablesize);
184 static ssize_t sg_new_read(Sg_fd * sfp, char __user *buf, size_t count,
185 			   Sg_request * srp);
186 static ssize_t sg_new_write(Sg_fd *sfp, struct file *file,
187 			const char __user *buf, size_t count, int blocking,
188 			int read_only, Sg_request **o_srp);
189 static int sg_common_write(Sg_fd * sfp, Sg_request * srp,
190 			   unsigned char *cmnd, int timeout, int blocking);
191 static int sg_u_iovec(sg_io_hdr_t * hp, int sg_num, int ind,
192 		      int wr_xf, int *countp, unsigned char __user **up);
193 static int sg_write_xfer(Sg_request * srp);
194 static int sg_read_xfer(Sg_request * srp);
195 static int sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer);
196 static void sg_remove_scat(Sg_scatter_hold * schp);
197 static void sg_build_reserve(Sg_fd * sfp, int req_size);
198 static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
199 static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
200 static struct page *sg_page_malloc(int rqSz, int lowDma, int *retSzp);
201 static void sg_page_free(struct page *page, int size);
202 static Sg_fd *sg_add_sfp(Sg_device * sdp, int dev);
203 static int sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp);
204 static void __sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp);
205 static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id);
206 static Sg_request *sg_add_request(Sg_fd * sfp);
207 static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
208 static int sg_res_in_use(Sg_fd * sfp);
209 static int sg_build_direct(Sg_request * srp, Sg_fd * sfp, int dxfer_len);
210 static Sg_device *sg_get_dev(int dev);
211 #ifdef CONFIG_SCSI_PROC_FS
212 static int sg_last_dev(void);
213 #endif
214 
215 #define SZ_SG_HEADER sizeof(struct sg_header)
216 #define SZ_SG_IO_HDR sizeof(sg_io_hdr_t)
217 #define SZ_SG_IOVEC sizeof(sg_iovec_t)
218 #define SZ_SG_REQ_INFO sizeof(sg_req_info_t)
219 
220 static int
221 sg_open(struct inode *inode, struct file *filp)
222 {
223 	int dev = iminor(inode);
224 	int flags = filp->f_flags;
225 	struct request_queue *q;
226 	Sg_device *sdp;
227 	Sg_fd *sfp;
228 	int res;
229 	int retval;
230 
231 	lock_kernel();
232 	nonseekable_open(inode, filp);
233 	SCSI_LOG_TIMEOUT(3, printk("sg_open: dev=%d, flags=0x%x\n", dev, flags));
234 	sdp = sg_get_dev(dev);
235 	if ((!sdp) || (!sdp->device)) {
236 		unlock_kernel();
237 		return -ENXIO;
238 	}
239 	if (sdp->detached) {
240 		unlock_kernel();
241 		return -ENODEV;
242 	}
243 
244 	/* This driver's module count bumped by fops_get in <linux/fs.h> */
245 	/* Prevent the device driver from vanishing while we sleep */
246 	retval = scsi_device_get(sdp->device);
247 	if (retval) {
248 		unlock_kernel();
249 		return retval;
250 	}
251 
252 	if (!((flags & O_NONBLOCK) ||
253 	      scsi_block_when_processing_errors(sdp->device))) {
254 		retval = -ENXIO;
255 		/* we are in error recovery for this device */
256 		goto error_out;
257 	}
258 
259 	if (flags & O_EXCL) {
260 		if (O_RDONLY == (flags & O_ACCMODE)) {
261 			retval = -EPERM; /* Can't lock it with read only access */
262 			goto error_out;
263 		}
264 		if (sdp->headfp && (flags & O_NONBLOCK)) {
265 			retval = -EBUSY;
266 			goto error_out;
267 		}
268 		res = 0;
269 		__wait_event_interruptible(sdp->o_excl_wait,
270 			((sdp->headfp || sdp->exclude) ? 0 : (sdp->exclude = 1)), res);
271 		if (res) {
272 			retval = res;	/* -ERESTARTSYS because signal hit process */
273 			goto error_out;
274 		}
275 	} else if (sdp->exclude) {	/* some other fd has an exclusive lock on dev */
276 		if (flags & O_NONBLOCK) {
277 			retval = -EBUSY;
278 			goto error_out;
279 		}
280 		res = 0;
281 		__wait_event_interruptible(sdp->o_excl_wait, (!sdp->exclude),
282 					   res);
283 		if (res) {
284 			retval = res;	/* -ERESTARTSYS because signal hit process */
285 			goto error_out;
286 		}
287 	}
288 	if (sdp->detached) {
289 		retval = -ENODEV;
290 		goto error_out;
291 	}
292 	if (!sdp->headfp) {	/* no existing opens on this device */
293 		sdp->sgdebug = 0;
294 		q = sdp->device->request_queue;
295 		sdp->sg_tablesize = min(q->max_hw_segments,
296 					q->max_phys_segments);
297 	}
298 	if ((sfp = sg_add_sfp(sdp, dev)))
299 		filp->private_data = sfp;
300 	else {
301 		if (flags & O_EXCL)
302 			sdp->exclude = 0;	/* undo if error */
303 		retval = -ENOMEM;
304 		goto error_out;
305 	}
306 	unlock_kernel();
307 	return 0;
308 
309       error_out:
310 	scsi_device_put(sdp->device);
311 	unlock_kernel();
312 	return retval;
313 }
314 
315 /* Following function was formerly called 'sg_close' */
316 static int
317 sg_release(struct inode *inode, struct file *filp)
318 {
319 	Sg_device *sdp;
320 	Sg_fd *sfp;
321 
322 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
323 		return -ENXIO;
324 	SCSI_LOG_TIMEOUT(3, printk("sg_release: %s\n", sdp->disk->disk_name));
325 	sg_fasync(-1, filp, 0);	/* remove filp from async notification list */
326 	if (0 == sg_remove_sfp(sdp, sfp)) {	/* Returns 1 when sdp gone */
327 		if (!sdp->detached) {
328 			scsi_device_put(sdp->device);
329 		}
330 		sdp->exclude = 0;
331 		wake_up_interruptible(&sdp->o_excl_wait);
332 	}
333 	return 0;
334 }
335 
336 static ssize_t
337 sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
338 {
339 	Sg_device *sdp;
340 	Sg_fd *sfp;
341 	Sg_request *srp;
342 	int req_pack_id = -1;
343 	sg_io_hdr_t *hp;
344 	struct sg_header *old_hdr = NULL;
345 	int retval = 0;
346 
347 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
348 		return -ENXIO;
349 	SCSI_LOG_TIMEOUT(3, printk("sg_read: %s, count=%d\n",
350 				   sdp->disk->disk_name, (int) count));
351 
352 	if (!access_ok(VERIFY_WRITE, buf, count))
353 		return -EFAULT;
354 	if (sfp->force_packid && (count >= SZ_SG_HEADER)) {
355 		old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
356 		if (!old_hdr)
357 			return -ENOMEM;
358 		if (__copy_from_user(old_hdr, buf, SZ_SG_HEADER)) {
359 			retval = -EFAULT;
360 			goto free_old_hdr;
361 		}
362 		if (old_hdr->reply_len < 0) {
363 			if (count >= SZ_SG_IO_HDR) {
364 				sg_io_hdr_t *new_hdr;
365 				new_hdr = kmalloc(SZ_SG_IO_HDR, GFP_KERNEL);
366 				if (!new_hdr) {
367 					retval = -ENOMEM;
368 					goto free_old_hdr;
369 				}
370 				retval =__copy_from_user
371 				    (new_hdr, buf, SZ_SG_IO_HDR);
372 				req_pack_id = new_hdr->pack_id;
373 				kfree(new_hdr);
374 				if (retval) {
375 					retval = -EFAULT;
376 					goto free_old_hdr;
377 				}
378 			}
379 		} else
380 			req_pack_id = old_hdr->pack_id;
381 	}
382 	srp = sg_get_rq_mark(sfp, req_pack_id);
383 	if (!srp) {		/* now wait on packet to arrive */
384 		if (sdp->detached) {
385 			retval = -ENODEV;
386 			goto free_old_hdr;
387 		}
388 		if (filp->f_flags & O_NONBLOCK) {
389 			retval = -EAGAIN;
390 			goto free_old_hdr;
391 		}
392 		while (1) {
393 			retval = 0; /* following macro beats race condition */
394 			__wait_event_interruptible(sfp->read_wait,
395 				(sdp->detached ||
396 				(srp = sg_get_rq_mark(sfp, req_pack_id))),
397 				retval);
398 			if (sdp->detached) {
399 				retval = -ENODEV;
400 				goto free_old_hdr;
401 			}
402 			if (0 == retval)
403 				break;
404 
405 			/* -ERESTARTSYS as signal hit process */
406 			goto free_old_hdr;
407 		}
408 	}
409 	if (srp->header.interface_id != '\0') {
410 		retval = sg_new_read(sfp, buf, count, srp);
411 		goto free_old_hdr;
412 	}
413 
414 	hp = &srp->header;
415 	if (old_hdr == NULL) {
416 		old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
417 		if (! old_hdr) {
418 			retval = -ENOMEM;
419 			goto free_old_hdr;
420 		}
421 	}
422 	memset(old_hdr, 0, SZ_SG_HEADER);
423 	old_hdr->reply_len = (int) hp->timeout;
424 	old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
425 	old_hdr->pack_id = hp->pack_id;
426 	old_hdr->twelve_byte =
427 	    ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
428 	old_hdr->target_status = hp->masked_status;
429 	old_hdr->host_status = hp->host_status;
430 	old_hdr->driver_status = hp->driver_status;
431 	if ((CHECK_CONDITION & hp->masked_status) ||
432 	    (DRIVER_SENSE & hp->driver_status))
433 		memcpy(old_hdr->sense_buffer, srp->sense_b,
434 		       sizeof (old_hdr->sense_buffer));
435 	switch (hp->host_status) {
436 	/* This setup of 'result' is for backward compatibility and is best
437 	   ignored by the user who should use target, host + driver status */
438 	case DID_OK:
439 	case DID_PASSTHROUGH:
440 	case DID_SOFT_ERROR:
441 		old_hdr->result = 0;
442 		break;
443 	case DID_NO_CONNECT:
444 	case DID_BUS_BUSY:
445 	case DID_TIME_OUT:
446 		old_hdr->result = EBUSY;
447 		break;
448 	case DID_BAD_TARGET:
449 	case DID_ABORT:
450 	case DID_PARITY:
451 	case DID_RESET:
452 	case DID_BAD_INTR:
453 		old_hdr->result = EIO;
454 		break;
455 	case DID_ERROR:
456 		old_hdr->result = (srp->sense_b[0] == 0 &&
457 				  hp->masked_status == GOOD) ? 0 : EIO;
458 		break;
459 	default:
460 		old_hdr->result = EIO;
461 		break;
462 	}
463 
464 	/* Now copy the result back to the user buffer.  */
465 	if (count >= SZ_SG_HEADER) {
466 		if (__copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
467 			retval = -EFAULT;
468 			goto free_old_hdr;
469 		}
470 		buf += SZ_SG_HEADER;
471 		if (count > old_hdr->reply_len)
472 			count = old_hdr->reply_len;
473 		if (count > SZ_SG_HEADER) {
474 			if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
475 				retval = -EFAULT;
476 				goto free_old_hdr;
477 			}
478 		}
479 	} else
480 		count = (old_hdr->result == 0) ? 0 : -EIO;
481 	sg_finish_rem_req(srp);
482 	retval = count;
483 free_old_hdr:
484 	kfree(old_hdr);
485 	return retval;
486 }
487 
488 static ssize_t
489 sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
490 {
491 	sg_io_hdr_t *hp = &srp->header;
492 	int err = 0;
493 	int len;
494 
495 	if (count < SZ_SG_IO_HDR) {
496 		err = -EINVAL;
497 		goto err_out;
498 	}
499 	hp->sb_len_wr = 0;
500 	if ((hp->mx_sb_len > 0) && hp->sbp) {
501 		if ((CHECK_CONDITION & hp->masked_status) ||
502 		    (DRIVER_SENSE & hp->driver_status)) {
503 			int sb_len = SCSI_SENSE_BUFFERSIZE;
504 			sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
505 			len = 8 + (int) srp->sense_b[7];	/* Additional sense length field */
506 			len = (len > sb_len) ? sb_len : len;
507 			if (copy_to_user(hp->sbp, srp->sense_b, len)) {
508 				err = -EFAULT;
509 				goto err_out;
510 			}
511 			hp->sb_len_wr = len;
512 		}
513 	}
514 	if (hp->masked_status || hp->host_status || hp->driver_status)
515 		hp->info |= SG_INFO_CHECK;
516 	if (copy_to_user(buf, hp, SZ_SG_IO_HDR)) {
517 		err = -EFAULT;
518 		goto err_out;
519 	}
520 	err = sg_read_xfer(srp);
521       err_out:
522 	sg_finish_rem_req(srp);
523 	return (0 == err) ? count : err;
524 }
525 
526 static ssize_t
527 sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
528 {
529 	int mxsize, cmd_size, k;
530 	int input_size, blocking;
531 	unsigned char opcode;
532 	Sg_device *sdp;
533 	Sg_fd *sfp;
534 	Sg_request *srp;
535 	struct sg_header old_hdr;
536 	sg_io_hdr_t *hp;
537 	unsigned char cmnd[MAX_COMMAND_SIZE];
538 
539 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
540 		return -ENXIO;
541 	SCSI_LOG_TIMEOUT(3, printk("sg_write: %s, count=%d\n",
542 				   sdp->disk->disk_name, (int) count));
543 	if (sdp->detached)
544 		return -ENODEV;
545 	if (!((filp->f_flags & O_NONBLOCK) ||
546 	      scsi_block_when_processing_errors(sdp->device)))
547 		return -ENXIO;
548 
549 	if (!access_ok(VERIFY_READ, buf, count))
550 		return -EFAULT;	/* protects following copy_from_user()s + get_user()s */
551 	if (count < SZ_SG_HEADER)
552 		return -EIO;
553 	if (__copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
554 		return -EFAULT;
555 	blocking = !(filp->f_flags & O_NONBLOCK);
556 	if (old_hdr.reply_len < 0)
557 		return sg_new_write(sfp, filp, buf, count, blocking, 0, NULL);
558 	if (count < (SZ_SG_HEADER + 6))
559 		return -EIO;	/* The minimum scsi command length is 6 bytes. */
560 
561 	if (!(srp = sg_add_request(sfp))) {
562 		SCSI_LOG_TIMEOUT(1, printk("sg_write: queue full\n"));
563 		return -EDOM;
564 	}
565 	buf += SZ_SG_HEADER;
566 	__get_user(opcode, buf);
567 	if (sfp->next_cmd_len > 0) {
568 		if (sfp->next_cmd_len > MAX_COMMAND_SIZE) {
569 			SCSI_LOG_TIMEOUT(1, printk("sg_write: command length too long\n"));
570 			sfp->next_cmd_len = 0;
571 			sg_remove_request(sfp, srp);
572 			return -EIO;
573 		}
574 		cmd_size = sfp->next_cmd_len;
575 		sfp->next_cmd_len = 0;	/* reset so only this write() effected */
576 	} else {
577 		cmd_size = COMMAND_SIZE(opcode);	/* based on SCSI command group */
578 		if ((opcode >= 0xc0) && old_hdr.twelve_byte)
579 			cmd_size = 12;
580 	}
581 	SCSI_LOG_TIMEOUT(4, printk(
582 		"sg_write:   scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
583 /* Determine buffer size.  */
584 	input_size = count - cmd_size;
585 	mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
586 	mxsize -= SZ_SG_HEADER;
587 	input_size -= SZ_SG_HEADER;
588 	if (input_size < 0) {
589 		sg_remove_request(sfp, srp);
590 		return -EIO;	/* User did not pass enough bytes for this command. */
591 	}
592 	hp = &srp->header;
593 	hp->interface_id = '\0';	/* indicator of old interface tunnelled */
594 	hp->cmd_len = (unsigned char) cmd_size;
595 	hp->iovec_count = 0;
596 	hp->mx_sb_len = 0;
597 	if (input_size > 0)
598 		hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
599 		    SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
600 	else
601 		hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
602 	hp->dxfer_len = mxsize;
603 	hp->dxferp = (char __user *)buf + cmd_size;
604 	hp->sbp = NULL;
605 	hp->timeout = old_hdr.reply_len;	/* structure abuse ... */
606 	hp->flags = input_size;	/* structure abuse ... */
607 	hp->pack_id = old_hdr.pack_id;
608 	hp->usr_ptr = NULL;
609 	if (__copy_from_user(cmnd, buf, cmd_size))
610 		return -EFAULT;
611 	/*
612 	 * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
613 	 * but is is possible that the app intended SG_DXFER_TO_DEV, because there
614 	 * is a non-zero input_size, so emit a warning.
615 	 */
616 	if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
617 		static char cmd[TASK_COMM_LEN];
618 		if (strcmp(current->comm, cmd) && printk_ratelimit()) {
619 			printk(KERN_WARNING
620 			       "sg_write: data in/out %d/%d bytes for SCSI command 0x%x--"
621 			       "guessing data in;\n" KERN_WARNING "   "
622 			       "program %s not setting count and/or reply_len properly\n",
623 			       old_hdr.reply_len - (int)SZ_SG_HEADER,
624 			       input_size, (unsigned int) cmnd[0],
625 			       current->comm);
626 			strcpy(cmd, current->comm);
627 		}
628 	}
629 	k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
630 	return (k < 0) ? k : count;
631 }
632 
633 static ssize_t
634 sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
635 		 size_t count, int blocking, int read_only,
636 		 Sg_request **o_srp)
637 {
638 	int k;
639 	Sg_request *srp;
640 	sg_io_hdr_t *hp;
641 	unsigned char cmnd[MAX_COMMAND_SIZE];
642 	int timeout;
643 	unsigned long ul_timeout;
644 
645 	if (count < SZ_SG_IO_HDR)
646 		return -EINVAL;
647 	if (!access_ok(VERIFY_READ, buf, count))
648 		return -EFAULT; /* protects following copy_from_user()s + get_user()s */
649 
650 	sfp->cmd_q = 1;	/* when sg_io_hdr seen, set command queuing on */
651 	if (!(srp = sg_add_request(sfp))) {
652 		SCSI_LOG_TIMEOUT(1, printk("sg_new_write: queue full\n"));
653 		return -EDOM;
654 	}
655 	hp = &srp->header;
656 	if (__copy_from_user(hp, buf, SZ_SG_IO_HDR)) {
657 		sg_remove_request(sfp, srp);
658 		return -EFAULT;
659 	}
660 	if (hp->interface_id != 'S') {
661 		sg_remove_request(sfp, srp);
662 		return -ENOSYS;
663 	}
664 	if (hp->flags & SG_FLAG_MMAP_IO) {
665 		if (hp->dxfer_len > sfp->reserve.bufflen) {
666 			sg_remove_request(sfp, srp);
667 			return -ENOMEM;	/* MMAP_IO size must fit in reserve buffer */
668 		}
669 		if (hp->flags & SG_FLAG_DIRECT_IO) {
670 			sg_remove_request(sfp, srp);
671 			return -EINVAL;	/* either MMAP_IO or DIRECT_IO (not both) */
672 		}
673 		if (sg_res_in_use(sfp)) {
674 			sg_remove_request(sfp, srp);
675 			return -EBUSY;	/* reserve buffer already being used */
676 		}
677 	}
678 	ul_timeout = msecs_to_jiffies(srp->header.timeout);
679 	timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
680 	if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
681 		sg_remove_request(sfp, srp);
682 		return -EMSGSIZE;
683 	}
684 	if (!access_ok(VERIFY_READ, hp->cmdp, hp->cmd_len)) {
685 		sg_remove_request(sfp, srp);
686 		return -EFAULT;	/* protects following copy_from_user()s + get_user()s */
687 	}
688 	if (__copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
689 		sg_remove_request(sfp, srp);
690 		return -EFAULT;
691 	}
692 	if (read_only && !blk_verify_command(file, cmnd)) {
693 		sg_remove_request(sfp, srp);
694 		return -EPERM;
695 	}
696 	k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
697 	if (k < 0)
698 		return k;
699 	if (o_srp)
700 		*o_srp = srp;
701 	return count;
702 }
703 
704 static int
705 sg_common_write(Sg_fd * sfp, Sg_request * srp,
706 		unsigned char *cmnd, int timeout, int blocking)
707 {
708 	int k, data_dir;
709 	Sg_device *sdp = sfp->parentdp;
710 	sg_io_hdr_t *hp = &srp->header;
711 
712 	srp->data.cmd_opcode = cmnd[0];	/* hold opcode of command */
713 	hp->status = 0;
714 	hp->masked_status = 0;
715 	hp->msg_status = 0;
716 	hp->info = 0;
717 	hp->host_status = 0;
718 	hp->driver_status = 0;
719 	hp->resid = 0;
720 	SCSI_LOG_TIMEOUT(4, printk("sg_common_write:  scsi opcode=0x%02x, cmd_size=%d\n",
721 			  (int) cmnd[0], (int) hp->cmd_len));
722 
723 	if ((k = sg_start_req(srp))) {
724 		SCSI_LOG_TIMEOUT(1, printk("sg_common_write: start_req err=%d\n", k));
725 		sg_finish_rem_req(srp);
726 		return k;	/* probably out of space --> ENOMEM */
727 	}
728 	if ((k = sg_write_xfer(srp))) {
729 		SCSI_LOG_TIMEOUT(1, printk("sg_common_write: write_xfer, bad address\n"));
730 		sg_finish_rem_req(srp);
731 		return k;
732 	}
733 	if (sdp->detached) {
734 		sg_finish_rem_req(srp);
735 		return -ENODEV;
736 	}
737 
738 	switch (hp->dxfer_direction) {
739 	case SG_DXFER_TO_FROM_DEV:
740 	case SG_DXFER_FROM_DEV:
741 		data_dir = DMA_FROM_DEVICE;
742 		break;
743 	case SG_DXFER_TO_DEV:
744 		data_dir = DMA_TO_DEVICE;
745 		break;
746 	case SG_DXFER_UNKNOWN:
747 		data_dir = DMA_BIDIRECTIONAL;
748 		break;
749 	default:
750 		data_dir = DMA_NONE;
751 		break;
752 	}
753 	hp->duration = jiffies_to_msecs(jiffies);
754 /* Now send everything of to mid-level. The next time we hear about this
755    packet is when sg_cmd_done() is called (i.e. a callback). */
756 	if (scsi_execute_async(sdp->device, cmnd, hp->cmd_len, data_dir, srp->data.buffer,
757 				hp->dxfer_len, srp->data.k_use_sg, timeout,
758 				SG_DEFAULT_RETRIES, srp, sg_cmd_done,
759 				GFP_ATOMIC)) {
760 		SCSI_LOG_TIMEOUT(1, printk("sg_common_write: scsi_execute_async failed\n"));
761 		/*
762 		 * most likely out of mem, but could also be a bad map
763 		 */
764 		sg_finish_rem_req(srp);
765 		return -ENOMEM;
766 	} else
767 		return 0;
768 }
769 
770 static int
771 sg_srp_done(Sg_request *srp, Sg_fd *sfp)
772 {
773 	unsigned long iflags;
774 	int done;
775 
776 	read_lock_irqsave(&sfp->rq_list_lock, iflags);
777 	done = srp->done;
778 	read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
779 	return done;
780 }
781 
782 static int
783 sg_ioctl(struct inode *inode, struct file *filp,
784 	 unsigned int cmd_in, unsigned long arg)
785 {
786 	void __user *p = (void __user *)arg;
787 	int __user *ip = p;
788 	int result, val, read_only;
789 	Sg_device *sdp;
790 	Sg_fd *sfp;
791 	Sg_request *srp;
792 	unsigned long iflags;
793 
794 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
795 		return -ENXIO;
796 	SCSI_LOG_TIMEOUT(3, printk("sg_ioctl: %s, cmd=0x%x\n",
797 				   sdp->disk->disk_name, (int) cmd_in));
798 	read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
799 
800 	switch (cmd_in) {
801 	case SG_IO:
802 		{
803 			int blocking = 1;	/* ignore O_NONBLOCK flag */
804 
805 			if (sdp->detached)
806 				return -ENODEV;
807 			if (!scsi_block_when_processing_errors(sdp->device))
808 				return -ENXIO;
809 			if (!access_ok(VERIFY_WRITE, p, SZ_SG_IO_HDR))
810 				return -EFAULT;
811 			result =
812 			    sg_new_write(sfp, filp, p, SZ_SG_IO_HDR,
813 					 blocking, read_only, &srp);
814 			if (result < 0)
815 				return result;
816 			srp->sg_io_owned = 1;
817 			while (1) {
818 				result = 0;	/* following macro to beat race condition */
819 				__wait_event_interruptible(sfp->read_wait,
820 					(sdp->detached || sfp->closed || sg_srp_done(srp, sfp)),
821 							   result);
822 				if (sdp->detached)
823 					return -ENODEV;
824 				if (sfp->closed)
825 					return 0;	/* request packet dropped already */
826 				if (0 == result)
827 					break;
828 				srp->orphan = 1;
829 				return result;	/* -ERESTARTSYS because signal hit process */
830 			}
831 			write_lock_irqsave(&sfp->rq_list_lock, iflags);
832 			srp->done = 2;
833 			write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
834 			result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
835 			return (result < 0) ? result : 0;
836 		}
837 	case SG_SET_TIMEOUT:
838 		result = get_user(val, ip);
839 		if (result)
840 			return result;
841 		if (val < 0)
842 			return -EIO;
843 		if (val >= MULDIV (INT_MAX, USER_HZ, HZ))
844 		    val = MULDIV (INT_MAX, USER_HZ, HZ);
845 		sfp->timeout_user = val;
846 		sfp->timeout = MULDIV (val, HZ, USER_HZ);
847 
848 		return 0;
849 	case SG_GET_TIMEOUT:	/* N.B. User receives timeout as return value */
850 				/* strange ..., for backward compatibility */
851 		return sfp->timeout_user;
852 	case SG_SET_FORCE_LOW_DMA:
853 		result = get_user(val, ip);
854 		if (result)
855 			return result;
856 		if (val) {
857 			sfp->low_dma = 1;
858 			if ((0 == sfp->low_dma) && (0 == sg_res_in_use(sfp))) {
859 				val = (int) sfp->reserve.bufflen;
860 				sg_remove_scat(&sfp->reserve);
861 				sg_build_reserve(sfp, val);
862 			}
863 		} else {
864 			if (sdp->detached)
865 				return -ENODEV;
866 			sfp->low_dma = sdp->device->host->unchecked_isa_dma;
867 		}
868 		return 0;
869 	case SG_GET_LOW_DMA:
870 		return put_user((int) sfp->low_dma, ip);
871 	case SG_GET_SCSI_ID:
872 		if (!access_ok(VERIFY_WRITE, p, sizeof (sg_scsi_id_t)))
873 			return -EFAULT;
874 		else {
875 			sg_scsi_id_t __user *sg_idp = p;
876 
877 			if (sdp->detached)
878 				return -ENODEV;
879 			__put_user((int) sdp->device->host->host_no,
880 				   &sg_idp->host_no);
881 			__put_user((int) sdp->device->channel,
882 				   &sg_idp->channel);
883 			__put_user((int) sdp->device->id, &sg_idp->scsi_id);
884 			__put_user((int) sdp->device->lun, &sg_idp->lun);
885 			__put_user((int) sdp->device->type, &sg_idp->scsi_type);
886 			__put_user((short) sdp->device->host->cmd_per_lun,
887 				   &sg_idp->h_cmd_per_lun);
888 			__put_user((short) sdp->device->queue_depth,
889 				   &sg_idp->d_queue_depth);
890 			__put_user(0, &sg_idp->unused[0]);
891 			__put_user(0, &sg_idp->unused[1]);
892 			return 0;
893 		}
894 	case SG_SET_FORCE_PACK_ID:
895 		result = get_user(val, ip);
896 		if (result)
897 			return result;
898 		sfp->force_packid = val ? 1 : 0;
899 		return 0;
900 	case SG_GET_PACK_ID:
901 		if (!access_ok(VERIFY_WRITE, ip, sizeof (int)))
902 			return -EFAULT;
903 		read_lock_irqsave(&sfp->rq_list_lock, iflags);
904 		for (srp = sfp->headrp; srp; srp = srp->nextrp) {
905 			if ((1 == srp->done) && (!srp->sg_io_owned)) {
906 				read_unlock_irqrestore(&sfp->rq_list_lock,
907 						       iflags);
908 				__put_user(srp->header.pack_id, ip);
909 				return 0;
910 			}
911 		}
912 		read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
913 		__put_user(-1, ip);
914 		return 0;
915 	case SG_GET_NUM_WAITING:
916 		read_lock_irqsave(&sfp->rq_list_lock, iflags);
917 		for (val = 0, srp = sfp->headrp; srp; srp = srp->nextrp) {
918 			if ((1 == srp->done) && (!srp->sg_io_owned))
919 				++val;
920 		}
921 		read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
922 		return put_user(val, ip);
923 	case SG_GET_SG_TABLESIZE:
924 		return put_user(sdp->sg_tablesize, ip);
925 	case SG_SET_RESERVED_SIZE:
926 		result = get_user(val, ip);
927 		if (result)
928 			return result;
929                 if (val < 0)
930                         return -EINVAL;
931 		val = min_t(int, val,
932 				sdp->device->request_queue->max_sectors * 512);
933 		if (val != sfp->reserve.bufflen) {
934 			if (sg_res_in_use(sfp) || sfp->mmap_called)
935 				return -EBUSY;
936 			sg_remove_scat(&sfp->reserve);
937 			sg_build_reserve(sfp, val);
938 		}
939 		return 0;
940 	case SG_GET_RESERVED_SIZE:
941 		val = min_t(int, sfp->reserve.bufflen,
942 				sdp->device->request_queue->max_sectors * 512);
943 		return put_user(val, ip);
944 	case SG_SET_COMMAND_Q:
945 		result = get_user(val, ip);
946 		if (result)
947 			return result;
948 		sfp->cmd_q = val ? 1 : 0;
949 		return 0;
950 	case SG_GET_COMMAND_Q:
951 		return put_user((int) sfp->cmd_q, ip);
952 	case SG_SET_KEEP_ORPHAN:
953 		result = get_user(val, ip);
954 		if (result)
955 			return result;
956 		sfp->keep_orphan = val;
957 		return 0;
958 	case SG_GET_KEEP_ORPHAN:
959 		return put_user((int) sfp->keep_orphan, ip);
960 	case SG_NEXT_CMD_LEN:
961 		result = get_user(val, ip);
962 		if (result)
963 			return result;
964 		sfp->next_cmd_len = (val > 0) ? val : 0;
965 		return 0;
966 	case SG_GET_VERSION_NUM:
967 		return put_user(sg_version_num, ip);
968 	case SG_GET_ACCESS_COUNT:
969 		/* faked - we don't have a real access count anymore */
970 		val = (sdp->device ? 1 : 0);
971 		return put_user(val, ip);
972 	case SG_GET_REQUEST_TABLE:
973 		if (!access_ok(VERIFY_WRITE, p, SZ_SG_REQ_INFO * SG_MAX_QUEUE))
974 			return -EFAULT;
975 		else {
976 			sg_req_info_t *rinfo;
977 			unsigned int ms;
978 
979 			rinfo = kmalloc(SZ_SG_REQ_INFO * SG_MAX_QUEUE,
980 								GFP_KERNEL);
981 			if (!rinfo)
982 				return -ENOMEM;
983 			read_lock_irqsave(&sfp->rq_list_lock, iflags);
984 			for (srp = sfp->headrp, val = 0; val < SG_MAX_QUEUE;
985 			     ++val, srp = srp ? srp->nextrp : srp) {
986 				memset(&rinfo[val], 0, SZ_SG_REQ_INFO);
987 				if (srp) {
988 					rinfo[val].req_state = srp->done + 1;
989 					rinfo[val].problem =
990 					    srp->header.masked_status &
991 					    srp->header.host_status &
992 					    srp->header.driver_status;
993 					if (srp->done)
994 						rinfo[val].duration =
995 							srp->header.duration;
996 					else {
997 						ms = jiffies_to_msecs(jiffies);
998 						rinfo[val].duration =
999 						    (ms > srp->header.duration) ?
1000 						    (ms - srp->header.duration) : 0;
1001 					}
1002 					rinfo[val].orphan = srp->orphan;
1003 					rinfo[val].sg_io_owned =
1004 							srp->sg_io_owned;
1005 					rinfo[val].pack_id =
1006 							srp->header.pack_id;
1007 					rinfo[val].usr_ptr =
1008 							srp->header.usr_ptr;
1009 				}
1010 			}
1011 			read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1012 			result = __copy_to_user(p, rinfo,
1013 						SZ_SG_REQ_INFO * SG_MAX_QUEUE);
1014 			result = result ? -EFAULT : 0;
1015 			kfree(rinfo);
1016 			return result;
1017 		}
1018 	case SG_EMULATED_HOST:
1019 		if (sdp->detached)
1020 			return -ENODEV;
1021 		return put_user(sdp->device->host->hostt->emulated, ip);
1022 	case SG_SCSI_RESET:
1023 		if (sdp->detached)
1024 			return -ENODEV;
1025 		if (filp->f_flags & O_NONBLOCK) {
1026 			if (scsi_host_in_recovery(sdp->device->host))
1027 				return -EBUSY;
1028 		} else if (!scsi_block_when_processing_errors(sdp->device))
1029 			return -EBUSY;
1030 		result = get_user(val, ip);
1031 		if (result)
1032 			return result;
1033 		if (SG_SCSI_RESET_NOTHING == val)
1034 			return 0;
1035 		switch (val) {
1036 		case SG_SCSI_RESET_DEVICE:
1037 			val = SCSI_TRY_RESET_DEVICE;
1038 			break;
1039 		case SG_SCSI_RESET_TARGET:
1040 			val = SCSI_TRY_RESET_TARGET;
1041 			break;
1042 		case SG_SCSI_RESET_BUS:
1043 			val = SCSI_TRY_RESET_BUS;
1044 			break;
1045 		case SG_SCSI_RESET_HOST:
1046 			val = SCSI_TRY_RESET_HOST;
1047 			break;
1048 		default:
1049 			return -EINVAL;
1050 		}
1051 		if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1052 			return -EACCES;
1053 		return (scsi_reset_provider(sdp->device, val) ==
1054 			SUCCESS) ? 0 : -EIO;
1055 	case SCSI_IOCTL_SEND_COMMAND:
1056 		if (sdp->detached)
1057 			return -ENODEV;
1058 		if (read_only) {
1059 			unsigned char opcode = WRITE_6;
1060 			Scsi_Ioctl_Command __user *siocp = p;
1061 
1062 			if (copy_from_user(&opcode, siocp->data, 1))
1063 				return -EFAULT;
1064 			if (!blk_verify_command(filp, &opcode))
1065 				return -EPERM;
1066 		}
1067 		return sg_scsi_ioctl(filp, sdp->device->request_queue, NULL, p);
1068 	case SG_SET_DEBUG:
1069 		result = get_user(val, ip);
1070 		if (result)
1071 			return result;
1072 		sdp->sgdebug = (char) val;
1073 		return 0;
1074 	case SCSI_IOCTL_GET_IDLUN:
1075 	case SCSI_IOCTL_GET_BUS_NUMBER:
1076 	case SCSI_IOCTL_PROBE_HOST:
1077 	case SG_GET_TRANSFORM:
1078 		if (sdp->detached)
1079 			return -ENODEV;
1080 		return scsi_ioctl(sdp->device, cmd_in, p);
1081 	case BLKSECTGET:
1082 		return put_user(sdp->device->request_queue->max_sectors * 512,
1083 				ip);
1084 	case BLKTRACESETUP:
1085 		return blk_trace_setup(sdp->device->request_queue,
1086 				       sdp->disk->disk_name,
1087 				       sdp->device->sdev_gendev.devt,
1088 				       (char *)arg);
1089 	case BLKTRACESTART:
1090 		return blk_trace_startstop(sdp->device->request_queue, 1);
1091 	case BLKTRACESTOP:
1092 		return blk_trace_startstop(sdp->device->request_queue, 0);
1093 	case BLKTRACETEARDOWN:
1094 		return blk_trace_remove(sdp->device->request_queue);
1095 	default:
1096 		if (read_only)
1097 			return -EPERM;	/* don't know so take safe approach */
1098 		return scsi_ioctl(sdp->device, cmd_in, p);
1099 	}
1100 }
1101 
1102 #ifdef CONFIG_COMPAT
1103 static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1104 {
1105 	Sg_device *sdp;
1106 	Sg_fd *sfp;
1107 	struct scsi_device *sdev;
1108 
1109 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1110 		return -ENXIO;
1111 
1112 	sdev = sdp->device;
1113 	if (sdev->host->hostt->compat_ioctl) {
1114 		int ret;
1115 
1116 		ret = sdev->host->hostt->compat_ioctl(sdev, cmd_in, (void __user *)arg);
1117 
1118 		return ret;
1119 	}
1120 
1121 	return -ENOIOCTLCMD;
1122 }
1123 #endif
1124 
1125 static unsigned int
1126 sg_poll(struct file *filp, poll_table * wait)
1127 {
1128 	unsigned int res = 0;
1129 	Sg_device *sdp;
1130 	Sg_fd *sfp;
1131 	Sg_request *srp;
1132 	int count = 0;
1133 	unsigned long iflags;
1134 
1135 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp))
1136 	    || sfp->closed)
1137 		return POLLERR;
1138 	poll_wait(filp, &sfp->read_wait, wait);
1139 	read_lock_irqsave(&sfp->rq_list_lock, iflags);
1140 	for (srp = sfp->headrp; srp; srp = srp->nextrp) {
1141 		/* if any read waiting, flag it */
1142 		if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1143 			res = POLLIN | POLLRDNORM;
1144 		++count;
1145 	}
1146 	read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1147 
1148 	if (sdp->detached)
1149 		res |= POLLHUP;
1150 	else if (!sfp->cmd_q) {
1151 		if (0 == count)
1152 			res |= POLLOUT | POLLWRNORM;
1153 	} else if (count < SG_MAX_QUEUE)
1154 		res |= POLLOUT | POLLWRNORM;
1155 	SCSI_LOG_TIMEOUT(3, printk("sg_poll: %s, res=0x%x\n",
1156 				   sdp->disk->disk_name, (int) res));
1157 	return res;
1158 }
1159 
1160 static int
1161 sg_fasync(int fd, struct file *filp, int mode)
1162 {
1163 	int retval;
1164 	Sg_device *sdp;
1165 	Sg_fd *sfp;
1166 
1167 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1168 		return -ENXIO;
1169 	SCSI_LOG_TIMEOUT(3, printk("sg_fasync: %s, mode=%d\n",
1170 				   sdp->disk->disk_name, mode));
1171 
1172 	retval = fasync_helper(fd, filp, mode, &sfp->async_qp);
1173 	return (retval < 0) ? retval : 0;
1174 }
1175 
1176 static int
1177 sg_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
1178 {
1179 	Sg_fd *sfp;
1180 	unsigned long offset, len, sa;
1181 	Sg_scatter_hold *rsv_schp;
1182 	struct scatterlist *sg;
1183 	int k;
1184 
1185 	if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1186 		return VM_FAULT_SIGBUS;
1187 	rsv_schp = &sfp->reserve;
1188 	offset = vmf->pgoff << PAGE_SHIFT;
1189 	if (offset >= rsv_schp->bufflen)
1190 		return VM_FAULT_SIGBUS;
1191 	SCSI_LOG_TIMEOUT(3, printk("sg_vma_fault: offset=%lu, scatg=%d\n",
1192 				   offset, rsv_schp->k_use_sg));
1193 	sg = rsv_schp->buffer;
1194 	sa = vma->vm_start;
1195 	for (k = 0; (k < rsv_schp->k_use_sg) && (sa < vma->vm_end);
1196 	     ++k, sg = sg_next(sg)) {
1197 		len = vma->vm_end - sa;
1198 		len = (len < sg->length) ? len : sg->length;
1199 		if (offset < len) {
1200 			struct page *page;
1201 			page = virt_to_page(page_address(sg_page(sg)) + offset);
1202 			get_page(page);	/* increment page count */
1203 			vmf->page = page;
1204 			return 0; /* success */
1205 		}
1206 		sa += len;
1207 		offset -= len;
1208 	}
1209 
1210 	return VM_FAULT_SIGBUS;
1211 }
1212 
1213 static struct vm_operations_struct sg_mmap_vm_ops = {
1214 	.fault = sg_vma_fault,
1215 };
1216 
1217 static int
1218 sg_mmap(struct file *filp, struct vm_area_struct *vma)
1219 {
1220 	Sg_fd *sfp;
1221 	unsigned long req_sz, len, sa;
1222 	Sg_scatter_hold *rsv_schp;
1223 	int k;
1224 	struct scatterlist *sg;
1225 
1226 	if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1227 		return -ENXIO;
1228 	req_sz = vma->vm_end - vma->vm_start;
1229 	SCSI_LOG_TIMEOUT(3, printk("sg_mmap starting, vm_start=%p, len=%d\n",
1230 				   (void *) vma->vm_start, (int) req_sz));
1231 	if (vma->vm_pgoff)
1232 		return -EINVAL;	/* want no offset */
1233 	rsv_schp = &sfp->reserve;
1234 	if (req_sz > rsv_schp->bufflen)
1235 		return -ENOMEM;	/* cannot map more than reserved buffer */
1236 
1237 	sa = vma->vm_start;
1238 	sg = rsv_schp->buffer;
1239 	for (k = 0; (k < rsv_schp->k_use_sg) && (sa < vma->vm_end);
1240 	     ++k, sg = sg_next(sg)) {
1241 		len = vma->vm_end - sa;
1242 		len = (len < sg->length) ? len : sg->length;
1243 		sa += len;
1244 	}
1245 
1246 	sfp->mmap_called = 1;
1247 	vma->vm_flags |= VM_RESERVED;
1248 	vma->vm_private_data = sfp;
1249 	vma->vm_ops = &sg_mmap_vm_ops;
1250 	return 0;
1251 }
1252 
1253 /* This function is a "bottom half" handler that is called by the
1254  * mid level when a command is completed (or has failed). */
1255 static void
1256 sg_cmd_done(void *data, char *sense, int result, int resid)
1257 {
1258 	Sg_request *srp = data;
1259 	Sg_device *sdp = NULL;
1260 	Sg_fd *sfp;
1261 	unsigned long iflags;
1262 	unsigned int ms;
1263 
1264 	if (NULL == srp) {
1265 		printk(KERN_ERR "sg_cmd_done: NULL request\n");
1266 		return;
1267 	}
1268 	sfp = srp->parentfp;
1269 	if (sfp)
1270 		sdp = sfp->parentdp;
1271 	if ((NULL == sdp) || sdp->detached) {
1272 		printk(KERN_INFO "sg_cmd_done: device detached\n");
1273 		return;
1274 	}
1275 
1276 
1277 	SCSI_LOG_TIMEOUT(4, printk("sg_cmd_done: %s, pack_id=%d, res=0x%x\n",
1278 		sdp->disk->disk_name, srp->header.pack_id, result));
1279 	srp->header.resid = resid;
1280 	ms = jiffies_to_msecs(jiffies);
1281 	srp->header.duration = (ms > srp->header.duration) ?
1282 				(ms - srp->header.duration) : 0;
1283 	if (0 != result) {
1284 		struct scsi_sense_hdr sshdr;
1285 
1286 		memcpy(srp->sense_b, sense, sizeof (srp->sense_b));
1287 		srp->header.status = 0xff & result;
1288 		srp->header.masked_status = status_byte(result);
1289 		srp->header.msg_status = msg_byte(result);
1290 		srp->header.host_status = host_byte(result);
1291 		srp->header.driver_status = driver_byte(result);
1292 		if ((sdp->sgdebug > 0) &&
1293 		    ((CHECK_CONDITION == srp->header.masked_status) ||
1294 		     (COMMAND_TERMINATED == srp->header.masked_status)))
1295 			__scsi_print_sense("sg_cmd_done", sense,
1296 					   SCSI_SENSE_BUFFERSIZE);
1297 
1298 		/* Following if statement is a patch supplied by Eric Youngdale */
1299 		if (driver_byte(result) != 0
1300 		    && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
1301 		    && !scsi_sense_is_deferred(&sshdr)
1302 		    && sshdr.sense_key == UNIT_ATTENTION
1303 		    && sdp->device->removable) {
1304 			/* Detected possible disc change. Set the bit - this */
1305 			/* may be used if there are filesystems using this device */
1306 			sdp->device->changed = 1;
1307 		}
1308 	}
1309 	/* Rely on write phase to clean out srp status values, so no "else" */
1310 
1311 	if (sfp->closed) {	/* whoops this fd already released, cleanup */
1312 		SCSI_LOG_TIMEOUT(1, printk("sg_cmd_done: already closed, freeing ...\n"));
1313 		sg_finish_rem_req(srp);
1314 		srp = NULL;
1315 		if (NULL == sfp->headrp) {
1316 			SCSI_LOG_TIMEOUT(1, printk("sg_cmd_done: already closed, final cleanup\n"));
1317 			if (0 == sg_remove_sfp(sdp, sfp)) {	/* device still present */
1318 				scsi_device_put(sdp->device);
1319 			}
1320 			sfp = NULL;
1321 		}
1322 	} else if (srp && srp->orphan) {
1323 		if (sfp->keep_orphan)
1324 			srp->sg_io_owned = 0;
1325 		else {
1326 			sg_finish_rem_req(srp);
1327 			srp = NULL;
1328 		}
1329 	}
1330 	if (sfp && srp) {
1331 		/* Now wake up any sg_read() that is waiting for this packet. */
1332 		kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1333 		write_lock_irqsave(&sfp->rq_list_lock, iflags);
1334 		srp->done = 1;
1335 		wake_up_interruptible(&sfp->read_wait);
1336 		write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1337 	}
1338 }
1339 
1340 static struct file_operations sg_fops = {
1341 	.owner = THIS_MODULE,
1342 	.read = sg_read,
1343 	.write = sg_write,
1344 	.poll = sg_poll,
1345 	.ioctl = sg_ioctl,
1346 #ifdef CONFIG_COMPAT
1347 	.compat_ioctl = sg_compat_ioctl,
1348 #endif
1349 	.open = sg_open,
1350 	.mmap = sg_mmap,
1351 	.release = sg_release,
1352 	.fasync = sg_fasync,
1353 };
1354 
1355 static struct class *sg_sysfs_class;
1356 
1357 static int sg_sysfs_valid = 0;
1358 
1359 static Sg_device *sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1360 {
1361 	struct request_queue *q = scsidp->request_queue;
1362 	Sg_device *sdp;
1363 	unsigned long iflags;
1364 	int error;
1365 	u32 k;
1366 
1367 	sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1368 	if (!sdp) {
1369 		printk(KERN_WARNING "kmalloc Sg_device failure\n");
1370 		return ERR_PTR(-ENOMEM);
1371 	}
1372 	error = -ENOMEM;
1373 	if (!idr_pre_get(&sg_index_idr, GFP_KERNEL)) {
1374 		printk(KERN_WARNING "idr expansion Sg_device failure\n");
1375 		goto out;
1376 	}
1377 
1378 	write_lock_irqsave(&sg_index_lock, iflags);
1379 	error = idr_get_new(&sg_index_idr, sdp, &k);
1380 	write_unlock_irqrestore(&sg_index_lock, iflags);
1381 
1382 	if (error) {
1383 		printk(KERN_WARNING "idr allocation Sg_device failure: %d\n",
1384 		       error);
1385 		goto out;
1386 	}
1387 
1388 	if (unlikely(k >= SG_MAX_DEVS))
1389 		goto overflow;
1390 
1391 	SCSI_LOG_TIMEOUT(3, printk("sg_alloc: dev=%d \n", k));
1392 	sprintf(disk->disk_name, "sg%d", k);
1393 	disk->first_minor = k;
1394 	sdp->disk = disk;
1395 	sdp->device = scsidp;
1396 	init_waitqueue_head(&sdp->o_excl_wait);
1397 	sdp->sg_tablesize = min(q->max_hw_segments, q->max_phys_segments);
1398 	sdp->index = k;
1399 
1400 	error = 0;
1401  out:
1402 	if (error) {
1403 		kfree(sdp);
1404 		return ERR_PTR(error);
1405 	}
1406 	return sdp;
1407 
1408  overflow:
1409 	sdev_printk(KERN_WARNING, scsidp,
1410 		    "Unable to attach sg device type=%d, minor "
1411 		    "number exceeds %d\n", scsidp->type, SG_MAX_DEVS - 1);
1412 	error = -ENODEV;
1413 	goto out;
1414 }
1415 
1416 static int
1417 sg_add(struct device *cl_dev, struct class_interface *cl_intf)
1418 {
1419 	struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1420 	struct gendisk *disk;
1421 	Sg_device *sdp = NULL;
1422 	struct cdev * cdev = NULL;
1423 	int error;
1424 	unsigned long iflags;
1425 
1426 	disk = alloc_disk(1);
1427 	if (!disk) {
1428 		printk(KERN_WARNING "alloc_disk failed\n");
1429 		return -ENOMEM;
1430 	}
1431 	disk->major = SCSI_GENERIC_MAJOR;
1432 
1433 	error = -ENOMEM;
1434 	cdev = cdev_alloc();
1435 	if (!cdev) {
1436 		printk(KERN_WARNING "cdev_alloc failed\n");
1437 		goto out;
1438 	}
1439 	cdev->owner = THIS_MODULE;
1440 	cdev->ops = &sg_fops;
1441 
1442 	sdp = sg_alloc(disk, scsidp);
1443 	if (IS_ERR(sdp)) {
1444 		printk(KERN_WARNING "sg_alloc failed\n");
1445 		error = PTR_ERR(sdp);
1446 		goto out;
1447 	}
1448 
1449 	error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), 1);
1450 	if (error)
1451 		goto cdev_add_err;
1452 
1453 	sdp->cdev = cdev;
1454 	if (sg_sysfs_valid) {
1455 		struct device *sg_class_member;
1456 
1457 		sg_class_member = device_create_drvdata(sg_sysfs_class,
1458 							cl_dev->parent,
1459 							MKDEV(SCSI_GENERIC_MAJOR,
1460 							      sdp->index),
1461 							sdp,
1462 							"%s", disk->disk_name);
1463 		if (IS_ERR(sg_class_member)) {
1464 			printk(KERN_ERR "sg_add: "
1465 			       "device_create failed\n");
1466 			error = PTR_ERR(sg_class_member);
1467 			goto cdev_add_err;
1468 		}
1469 		error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1470 					  &sg_class_member->kobj, "generic");
1471 		if (error)
1472 			printk(KERN_ERR "sg_add: unable to make symlink "
1473 					"'generic' back to sg%d\n", sdp->index);
1474 	} else
1475 		printk(KERN_WARNING "sg_add: sg_sys Invalid\n");
1476 
1477 	sdev_printk(KERN_NOTICE, scsidp,
1478 		    "Attached scsi generic sg%d type %d\n", sdp->index,
1479 		    scsidp->type);
1480 
1481 	dev_set_drvdata(cl_dev, sdp);
1482 
1483 	return 0;
1484 
1485 cdev_add_err:
1486 	write_lock_irqsave(&sg_index_lock, iflags);
1487 	idr_remove(&sg_index_idr, sdp->index);
1488 	write_unlock_irqrestore(&sg_index_lock, iflags);
1489 	kfree(sdp);
1490 
1491 out:
1492 	put_disk(disk);
1493 	if (cdev)
1494 		cdev_del(cdev);
1495 	return error;
1496 }
1497 
1498 static void
1499 sg_remove(struct device *cl_dev, struct class_interface *cl_intf)
1500 {
1501 	struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1502 	Sg_device *sdp = dev_get_drvdata(cl_dev);
1503 	unsigned long iflags;
1504 	Sg_fd *sfp;
1505 	Sg_fd *tsfp;
1506 	Sg_request *srp;
1507 	Sg_request *tsrp;
1508 	int delay;
1509 
1510 	if (!sdp)
1511 		return;
1512 
1513 	delay = 0;
1514 	write_lock_irqsave(&sg_index_lock, iflags);
1515 	if (sdp->headfp) {
1516 		sdp->detached = 1;
1517 		for (sfp = sdp->headfp; sfp; sfp = tsfp) {
1518 			tsfp = sfp->nextfp;
1519 			for (srp = sfp->headrp; srp; srp = tsrp) {
1520 				tsrp = srp->nextrp;
1521 				if (sfp->closed || (0 == sg_srp_done(srp, sfp)))
1522 					sg_finish_rem_req(srp);
1523 			}
1524 			if (sfp->closed) {
1525 				scsi_device_put(sdp->device);
1526 				__sg_remove_sfp(sdp, sfp);
1527 			} else {
1528 				delay = 1;
1529 				wake_up_interruptible(&sfp->read_wait);
1530 				kill_fasync(&sfp->async_qp, SIGPOLL,
1531 					    POLL_HUP);
1532 			}
1533 		}
1534 		SCSI_LOG_TIMEOUT(3, printk("sg_remove: dev=%d, dirty\n", sdp->index));
1535 		if (NULL == sdp->headfp) {
1536 			idr_remove(&sg_index_idr, sdp->index);
1537 		}
1538 	} else {	/* nothing active, simple case */
1539 		SCSI_LOG_TIMEOUT(3, printk("sg_remove: dev=%d\n", sdp->index));
1540 		idr_remove(&sg_index_idr, sdp->index);
1541 	}
1542 	write_unlock_irqrestore(&sg_index_lock, iflags);
1543 
1544 	sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1545 	device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index));
1546 	cdev_del(sdp->cdev);
1547 	sdp->cdev = NULL;
1548 	put_disk(sdp->disk);
1549 	sdp->disk = NULL;
1550 	if (NULL == sdp->headfp)
1551 		kfree(sdp);
1552 
1553 	if (delay)
1554 		msleep(10);	/* dirty detach so delay device destruction */
1555 }
1556 
1557 module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR);
1558 module_param_named(def_reserved_size, def_reserved_size, int,
1559 		   S_IRUGO | S_IWUSR);
1560 module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1561 
1562 MODULE_AUTHOR("Douglas Gilbert");
1563 MODULE_DESCRIPTION("SCSI generic (sg) driver");
1564 MODULE_LICENSE("GPL");
1565 MODULE_VERSION(SG_VERSION_STR);
1566 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1567 
1568 MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element "
1569                 "size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
1570 MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1571 MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1572 
1573 static int __init
1574 init_sg(void)
1575 {
1576 	int rc;
1577 
1578 	if (scatter_elem_sz < PAGE_SIZE) {
1579 		scatter_elem_sz = PAGE_SIZE;
1580 		scatter_elem_sz_prev = scatter_elem_sz;
1581 	}
1582 	if (def_reserved_size >= 0)
1583 		sg_big_buff = def_reserved_size;
1584 	else
1585 		def_reserved_size = sg_big_buff;
1586 
1587 	rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1588 				    SG_MAX_DEVS, "sg");
1589 	if (rc)
1590 		return rc;
1591         sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
1592         if ( IS_ERR(sg_sysfs_class) ) {
1593 		rc = PTR_ERR(sg_sysfs_class);
1594 		goto err_out;
1595         }
1596 	sg_sysfs_valid = 1;
1597 	rc = scsi_register_interface(&sg_interface);
1598 	if (0 == rc) {
1599 #ifdef CONFIG_SCSI_PROC_FS
1600 		sg_proc_init();
1601 #endif				/* CONFIG_SCSI_PROC_FS */
1602 		return 0;
1603 	}
1604 	class_destroy(sg_sysfs_class);
1605 err_out:
1606 	unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1607 	return rc;
1608 }
1609 
1610 static void __exit
1611 exit_sg(void)
1612 {
1613 #ifdef CONFIG_SCSI_PROC_FS
1614 	sg_proc_cleanup();
1615 #endif				/* CONFIG_SCSI_PROC_FS */
1616 	scsi_unregister_interface(&sg_interface);
1617 	class_destroy(sg_sysfs_class);
1618 	sg_sysfs_valid = 0;
1619 	unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1620 				 SG_MAX_DEVS);
1621 	idr_destroy(&sg_index_idr);
1622 }
1623 
1624 static int
1625 sg_start_req(Sg_request * srp)
1626 {
1627 	int res;
1628 	Sg_fd *sfp = srp->parentfp;
1629 	sg_io_hdr_t *hp = &srp->header;
1630 	int dxfer_len = (int) hp->dxfer_len;
1631 	int dxfer_dir = hp->dxfer_direction;
1632 	Sg_scatter_hold *req_schp = &srp->data;
1633 	Sg_scatter_hold *rsv_schp = &sfp->reserve;
1634 
1635 	SCSI_LOG_TIMEOUT(4, printk("sg_start_req: dxfer_len=%d\n", dxfer_len));
1636 	if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1637 		return 0;
1638 	if (sg_allow_dio && (hp->flags & SG_FLAG_DIRECT_IO) &&
1639 	    (dxfer_dir != SG_DXFER_UNKNOWN) && (0 == hp->iovec_count) &&
1640 	    (!sfp->parentdp->device->host->unchecked_isa_dma)) {
1641 		res = sg_build_direct(srp, sfp, dxfer_len);
1642 		if (res <= 0)	/* -ve -> error, 0 -> done, 1 -> try indirect */
1643 			return res;
1644 	}
1645 	if ((!sg_res_in_use(sfp)) && (dxfer_len <= rsv_schp->bufflen))
1646 		sg_link_reserve(sfp, srp, dxfer_len);
1647 	else {
1648 		res = sg_build_indirect(req_schp, sfp, dxfer_len);
1649 		if (res) {
1650 			sg_remove_scat(req_schp);
1651 			return res;
1652 		}
1653 	}
1654 	return 0;
1655 }
1656 
1657 static void
1658 sg_finish_rem_req(Sg_request * srp)
1659 {
1660 	Sg_fd *sfp = srp->parentfp;
1661 	Sg_scatter_hold *req_schp = &srp->data;
1662 
1663 	SCSI_LOG_TIMEOUT(4, printk("sg_finish_rem_req: res_used=%d\n", (int) srp->res_used));
1664 	if (srp->res_used)
1665 		sg_unlink_reserve(sfp, srp);
1666 	else
1667 		sg_remove_scat(req_schp);
1668 	sg_remove_request(sfp, srp);
1669 }
1670 
1671 static int
1672 sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1673 {
1674 	int sg_bufflen = tablesize * sizeof(struct scatterlist);
1675 	gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1676 
1677 	/*
1678 	 * TODO: test without low_dma, we should not need it since
1679 	 * the block layer will bounce the buffer for us
1680 	 *
1681 	 * XXX(hch): we shouldn't need GFP_DMA for the actual S/G list.
1682 	 */
1683 	if (sfp->low_dma)
1684 		 gfp_flags |= GFP_DMA;
1685 	schp->buffer = kzalloc(sg_bufflen, gfp_flags);
1686 	if (!schp->buffer)
1687 		return -ENOMEM;
1688 	sg_init_table(schp->buffer, tablesize);
1689 	schp->sglist_len = sg_bufflen;
1690 	return tablesize;	/* number of scat_gath elements allocated */
1691 }
1692 
1693 #ifdef SG_ALLOW_DIO_CODE
1694 /* vvvvvvvv  following code borrowed from st driver's direct IO vvvvvvvvv */
1695 	/* TODO: hopefully we can use the generic block layer code */
1696 
1697 /* Pin down user pages and put them into a scatter gather list. Returns <= 0 if
1698    - mapping of all pages not successful
1699    (i.e., either completely successful or fails)
1700 */
1701 static int
1702 st_map_user_pages(struct scatterlist *sgl, const unsigned int max_pages,
1703 	          unsigned long uaddr, size_t count, int rw)
1704 {
1705 	unsigned long end = (uaddr + count + PAGE_SIZE - 1) >> PAGE_SHIFT;
1706 	unsigned long start = uaddr >> PAGE_SHIFT;
1707 	const int nr_pages = end - start;
1708 	int res, i, j;
1709 	struct page **pages;
1710 
1711 	/* User attempted Overflow! */
1712 	if ((uaddr + count) < uaddr)
1713 		return -EINVAL;
1714 
1715 	/* Too big */
1716         if (nr_pages > max_pages)
1717 		return -ENOMEM;
1718 
1719 	/* Hmm? */
1720 	if (count == 0)
1721 		return 0;
1722 
1723 	if ((pages = kmalloc(max_pages * sizeof(*pages), GFP_ATOMIC)) == NULL)
1724 		return -ENOMEM;
1725 
1726         /* Try to fault in all of the necessary pages */
1727 	down_read(&current->mm->mmap_sem);
1728         /* rw==READ means read from drive, write into memory area */
1729 	res = get_user_pages(
1730 		current,
1731 		current->mm,
1732 		uaddr,
1733 		nr_pages,
1734 		rw == READ,
1735 		0, /* don't force */
1736 		pages,
1737 		NULL);
1738 	up_read(&current->mm->mmap_sem);
1739 
1740 	/* Errors and no page mapped should return here */
1741 	if (res < nr_pages)
1742 		goto out_unmap;
1743 
1744         for (i=0; i < nr_pages; i++) {
1745                 /* FIXME: flush superflous for rw==READ,
1746                  * probably wrong function for rw==WRITE
1747                  */
1748 		flush_dcache_page(pages[i]);
1749 		/* ?? Is locking needed? I don't think so */
1750 		/* if (TestSetPageLocked(pages[i]))
1751 		   goto out_unlock; */
1752         }
1753 
1754 	sg_set_page(sgl, pages[0], 0, uaddr & ~PAGE_MASK);
1755 	if (nr_pages > 1) {
1756 		sgl[0].length = PAGE_SIZE - sgl[0].offset;
1757 		count -= sgl[0].length;
1758 		for (i=1; i < nr_pages ; i++)
1759 			sg_set_page(&sgl[i], pages[i], count < PAGE_SIZE ? count : PAGE_SIZE, 0);
1760 	}
1761 	else {
1762 		sgl[0].length = count;
1763 	}
1764 
1765 	kfree(pages);
1766 	return nr_pages;
1767 
1768  out_unmap:
1769 	if (res > 0) {
1770 		for (j=0; j < res; j++)
1771 			page_cache_release(pages[j]);
1772 		res = 0;
1773 	}
1774 	kfree(pages);
1775 	return res;
1776 }
1777 
1778 
1779 /* And unmap them... */
1780 static int
1781 st_unmap_user_pages(struct scatterlist *sgl, const unsigned int nr_pages,
1782 		    int dirtied)
1783 {
1784 	int i;
1785 
1786 	for (i=0; i < nr_pages; i++) {
1787 		struct page *page = sg_page(&sgl[i]);
1788 
1789 		if (dirtied)
1790 			SetPageDirty(page);
1791 		/* unlock_page(page); */
1792 		/* FIXME: cache flush missing for rw==READ
1793 		 * FIXME: call the correct reference counting function
1794 		 */
1795 		page_cache_release(page);
1796 	}
1797 
1798 	return 0;
1799 }
1800 
1801 /* ^^^^^^^^  above code borrowed from st driver's direct IO ^^^^^^^^^ */
1802 #endif
1803 
1804 
1805 /* Returns: -ve -> error, 0 -> done, 1 -> try indirect */
1806 static int
1807 sg_build_direct(Sg_request * srp, Sg_fd * sfp, int dxfer_len)
1808 {
1809 #ifdef SG_ALLOW_DIO_CODE
1810 	sg_io_hdr_t *hp = &srp->header;
1811 	Sg_scatter_hold *schp = &srp->data;
1812 	int sg_tablesize = sfp->parentdp->sg_tablesize;
1813 	int mx_sc_elems, res;
1814 	struct scsi_device *sdev = sfp->parentdp->device;
1815 
1816 	if (((unsigned long)hp->dxferp &
1817 			queue_dma_alignment(sdev->request_queue)) != 0)
1818 		return 1;
1819 
1820 	mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1821         if (mx_sc_elems <= 0) {
1822                 return 1;
1823         }
1824 	res = st_map_user_pages(schp->buffer, mx_sc_elems,
1825 				(unsigned long)hp->dxferp, dxfer_len,
1826 				(SG_DXFER_TO_DEV == hp->dxfer_direction) ? 1 : 0);
1827 	if (res <= 0) {
1828 		sg_remove_scat(schp);
1829 		return 1;
1830 	}
1831 	schp->k_use_sg = res;
1832 	schp->dio_in_use = 1;
1833 	hp->info |= SG_INFO_DIRECT_IO;
1834 	return 0;
1835 #else
1836 	return 1;
1837 #endif
1838 }
1839 
1840 static int
1841 sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1842 {
1843 	struct scatterlist *sg;
1844 	int ret_sz = 0, k, rem_sz, num, mx_sc_elems;
1845 	int sg_tablesize = sfp->parentdp->sg_tablesize;
1846 	int blk_size = buff_size;
1847 	struct page *p = NULL;
1848 
1849 	if (blk_size < 0)
1850 		return -EFAULT;
1851 	if (0 == blk_size)
1852 		++blk_size;	/* don't know why */
1853 /* round request up to next highest SG_SECTOR_SZ byte boundary */
1854 	blk_size = (blk_size + SG_SECTOR_MSK) & (~SG_SECTOR_MSK);
1855 	SCSI_LOG_TIMEOUT(4, printk("sg_build_indirect: buff_size=%d, blk_size=%d\n",
1856 				   buff_size, blk_size));
1857 
1858 	/* N.B. ret_sz carried into this block ... */
1859 	mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1860 	if (mx_sc_elems < 0)
1861 		return mx_sc_elems;	/* most likely -ENOMEM */
1862 
1863 	num = scatter_elem_sz;
1864 	if (unlikely(num != scatter_elem_sz_prev)) {
1865 		if (num < PAGE_SIZE) {
1866 			scatter_elem_sz = PAGE_SIZE;
1867 			scatter_elem_sz_prev = PAGE_SIZE;
1868 		} else
1869 			scatter_elem_sz_prev = num;
1870 	}
1871 	for (k = 0, sg = schp->buffer, rem_sz = blk_size;
1872 	     (rem_sz > 0) && (k < mx_sc_elems);
1873 	     ++k, rem_sz -= ret_sz, sg = sg_next(sg)) {
1874 
1875 		num = (rem_sz > scatter_elem_sz_prev) ?
1876 		      scatter_elem_sz_prev : rem_sz;
1877 		p = sg_page_malloc(num, sfp->low_dma, &ret_sz);
1878 		if (!p)
1879 			return -ENOMEM;
1880 
1881 		if (num == scatter_elem_sz_prev) {
1882 			if (unlikely(ret_sz > scatter_elem_sz_prev)) {
1883 				scatter_elem_sz = ret_sz;
1884 				scatter_elem_sz_prev = ret_sz;
1885 			}
1886 		}
1887 		sg_set_page(sg, p, (ret_sz > num) ? num : ret_sz, 0);
1888 
1889 		SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k=%d, num=%d, "
1890 				 "ret_sz=%d\n", k, num, ret_sz));
1891 	}		/* end of for loop */
1892 
1893 	schp->k_use_sg = k;
1894 	SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k_use_sg=%d, "
1895 			 "rem_sz=%d\n", k, rem_sz));
1896 
1897 	schp->bufflen = blk_size;
1898 	if (rem_sz > 0)	/* must have failed */
1899 		return -ENOMEM;
1900 
1901 	return 0;
1902 }
1903 
1904 static int
1905 sg_write_xfer(Sg_request * srp)
1906 {
1907 	sg_io_hdr_t *hp = &srp->header;
1908 	Sg_scatter_hold *schp = &srp->data;
1909 	struct scatterlist *sg = schp->buffer;
1910 	int num_xfer = 0;
1911 	int j, k, onum, usglen, ksglen, res;
1912 	int iovec_count = (int) hp->iovec_count;
1913 	int dxfer_dir = hp->dxfer_direction;
1914 	unsigned char *p;
1915 	unsigned char __user *up;
1916 	int new_interface = ('\0' == hp->interface_id) ? 0 : 1;
1917 
1918 	if ((SG_DXFER_UNKNOWN == dxfer_dir) || (SG_DXFER_TO_DEV == dxfer_dir) ||
1919 	    (SG_DXFER_TO_FROM_DEV == dxfer_dir)) {
1920 		num_xfer = (int) (new_interface ? hp->dxfer_len : hp->flags);
1921 		if (schp->bufflen < num_xfer)
1922 			num_xfer = schp->bufflen;
1923 	}
1924 	if ((num_xfer <= 0) || (schp->dio_in_use) ||
1925 	    (new_interface
1926 	     && ((SG_FLAG_NO_DXFER | SG_FLAG_MMAP_IO) & hp->flags)))
1927 		return 0;
1928 
1929 	SCSI_LOG_TIMEOUT(4, printk("sg_write_xfer: num_xfer=%d, iovec_count=%d, k_use_sg=%d\n",
1930 			  num_xfer, iovec_count, schp->k_use_sg));
1931 	if (iovec_count) {
1932 		onum = iovec_count;
1933 		if (!access_ok(VERIFY_READ, hp->dxferp, SZ_SG_IOVEC * onum))
1934 			return -EFAULT;
1935 	} else
1936 		onum = 1;
1937 
1938 	ksglen = sg->length;
1939 	p = page_address(sg_page(sg));
1940 	for (j = 0, k = 0; j < onum; ++j) {
1941 		res = sg_u_iovec(hp, iovec_count, j, 1, &usglen, &up);
1942 		if (res)
1943 			return res;
1944 
1945 		for (; p; sg = sg_next(sg), ksglen = sg->length,
1946 		     p = page_address(sg_page(sg))) {
1947 			if (usglen <= 0)
1948 				break;
1949 			if (ksglen > usglen) {
1950 				if (usglen >= num_xfer) {
1951 					if (__copy_from_user(p, up, num_xfer))
1952 						return -EFAULT;
1953 					return 0;
1954 				}
1955 				if (__copy_from_user(p, up, usglen))
1956 					return -EFAULT;
1957 				p += usglen;
1958 				ksglen -= usglen;
1959 				break;
1960 			} else {
1961 				if (ksglen >= num_xfer) {
1962 					if (__copy_from_user(p, up, num_xfer))
1963 						return -EFAULT;
1964 					return 0;
1965 				}
1966 				if (__copy_from_user(p, up, ksglen))
1967 					return -EFAULT;
1968 				up += ksglen;
1969 				usglen -= ksglen;
1970 			}
1971 			++k;
1972 			if (k >= schp->k_use_sg)
1973 				return 0;
1974 		}
1975 	}
1976 
1977 	return 0;
1978 }
1979 
1980 static int
1981 sg_u_iovec(sg_io_hdr_t * hp, int sg_num, int ind,
1982 	   int wr_xf, int *countp, unsigned char __user **up)
1983 {
1984 	int num_xfer = (int) hp->dxfer_len;
1985 	unsigned char __user *p = hp->dxferp;
1986 	int count;
1987 
1988 	if (0 == sg_num) {
1989 		if (wr_xf && ('\0' == hp->interface_id))
1990 			count = (int) hp->flags;	/* holds "old" input_size */
1991 		else
1992 			count = num_xfer;
1993 	} else {
1994 		sg_iovec_t iovec;
1995 		if (__copy_from_user(&iovec, p + ind*SZ_SG_IOVEC, SZ_SG_IOVEC))
1996 			return -EFAULT;
1997 		p = iovec.iov_base;
1998 		count = (int) iovec.iov_len;
1999 	}
2000 	if (!access_ok(wr_xf ? VERIFY_READ : VERIFY_WRITE, p, count))
2001 		return -EFAULT;
2002 	if (up)
2003 		*up = p;
2004 	if (countp)
2005 		*countp = count;
2006 	return 0;
2007 }
2008 
2009 static void
2010 sg_remove_scat(Sg_scatter_hold * schp)
2011 {
2012 	SCSI_LOG_TIMEOUT(4, printk("sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
2013 	if (schp->buffer && (schp->sglist_len > 0)) {
2014 		struct scatterlist *sg = schp->buffer;
2015 
2016 		if (schp->dio_in_use) {
2017 #ifdef SG_ALLOW_DIO_CODE
2018 			st_unmap_user_pages(sg, schp->k_use_sg, TRUE);
2019 #endif
2020 		} else {
2021 			int k;
2022 
2023 			for (k = 0; (k < schp->k_use_sg) && sg_page(sg);
2024 			     ++k, sg = sg_next(sg)) {
2025 				SCSI_LOG_TIMEOUT(5, printk(
2026 				    "sg_remove_scat: k=%d, pg=0x%p, len=%d\n",
2027 				    k, sg_page(sg), sg->length));
2028 				sg_page_free(sg_page(sg), sg->length);
2029 			}
2030 		}
2031 		kfree(schp->buffer);
2032 	}
2033 	memset(schp, 0, sizeof (*schp));
2034 }
2035 
2036 static int
2037 sg_read_xfer(Sg_request * srp)
2038 {
2039 	sg_io_hdr_t *hp = &srp->header;
2040 	Sg_scatter_hold *schp = &srp->data;
2041 	struct scatterlist *sg = schp->buffer;
2042 	int num_xfer = 0;
2043 	int j, k, onum, usglen, ksglen, res;
2044 	int iovec_count = (int) hp->iovec_count;
2045 	int dxfer_dir = hp->dxfer_direction;
2046 	unsigned char *p;
2047 	unsigned char __user *up;
2048 	int new_interface = ('\0' == hp->interface_id) ? 0 : 1;
2049 
2050 	if ((SG_DXFER_UNKNOWN == dxfer_dir) || (SG_DXFER_FROM_DEV == dxfer_dir)
2051 	    || (SG_DXFER_TO_FROM_DEV == dxfer_dir)) {
2052 		num_xfer = hp->dxfer_len;
2053 		if (schp->bufflen < num_xfer)
2054 			num_xfer = schp->bufflen;
2055 	}
2056 	if ((num_xfer <= 0) || (schp->dio_in_use) ||
2057 	    (new_interface
2058 	     && ((SG_FLAG_NO_DXFER | SG_FLAG_MMAP_IO) & hp->flags)))
2059 		return 0;
2060 
2061 	SCSI_LOG_TIMEOUT(4, printk("sg_read_xfer: num_xfer=%d, iovec_count=%d, k_use_sg=%d\n",
2062 			  num_xfer, iovec_count, schp->k_use_sg));
2063 	if (iovec_count) {
2064 		onum = iovec_count;
2065 		if (!access_ok(VERIFY_READ, hp->dxferp, SZ_SG_IOVEC * onum))
2066 			return -EFAULT;
2067 	} else
2068 		onum = 1;
2069 
2070 	p = page_address(sg_page(sg));
2071 	ksglen = sg->length;
2072 	for (j = 0, k = 0; j < onum; ++j) {
2073 		res = sg_u_iovec(hp, iovec_count, j, 0, &usglen, &up);
2074 		if (res)
2075 			return res;
2076 
2077 		for (; p; sg = sg_next(sg), ksglen = sg->length,
2078 		     p = page_address(sg_page(sg))) {
2079 			if (usglen <= 0)
2080 				break;
2081 			if (ksglen > usglen) {
2082 				if (usglen >= num_xfer) {
2083 					if (__copy_to_user(up, p, num_xfer))
2084 						return -EFAULT;
2085 					return 0;
2086 				}
2087 				if (__copy_to_user(up, p, usglen))
2088 					return -EFAULT;
2089 				p += usglen;
2090 				ksglen -= usglen;
2091 				break;
2092 			} else {
2093 				if (ksglen >= num_xfer) {
2094 					if (__copy_to_user(up, p, num_xfer))
2095 						return -EFAULT;
2096 					return 0;
2097 				}
2098 				if (__copy_to_user(up, p, ksglen))
2099 					return -EFAULT;
2100 				up += ksglen;
2101 				usglen -= ksglen;
2102 			}
2103 			++k;
2104 			if (k >= schp->k_use_sg)
2105 				return 0;
2106 		}
2107 	}
2108 
2109 	return 0;
2110 }
2111 
2112 static int
2113 sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
2114 {
2115 	Sg_scatter_hold *schp = &srp->data;
2116 	struct scatterlist *sg = schp->buffer;
2117 	int k, num;
2118 
2119 	SCSI_LOG_TIMEOUT(4, printk("sg_read_oxfer: num_read_xfer=%d\n",
2120 				   num_read_xfer));
2121 	if ((!outp) || (num_read_xfer <= 0))
2122 		return 0;
2123 
2124 	for (k = 0; (k < schp->k_use_sg) && sg_page(sg); ++k, sg = sg_next(sg)) {
2125 		num = sg->length;
2126 		if (num > num_read_xfer) {
2127 			if (__copy_to_user(outp, page_address(sg_page(sg)),
2128 					   num_read_xfer))
2129 				return -EFAULT;
2130 			break;
2131 		} else {
2132 			if (__copy_to_user(outp, page_address(sg_page(sg)),
2133 					   num))
2134 				return -EFAULT;
2135 			num_read_xfer -= num;
2136 			if (num_read_xfer <= 0)
2137 				break;
2138 			outp += num;
2139 		}
2140 	}
2141 
2142 	return 0;
2143 }
2144 
2145 static void
2146 sg_build_reserve(Sg_fd * sfp, int req_size)
2147 {
2148 	Sg_scatter_hold *schp = &sfp->reserve;
2149 
2150 	SCSI_LOG_TIMEOUT(4, printk("sg_build_reserve: req_size=%d\n", req_size));
2151 	do {
2152 		if (req_size < PAGE_SIZE)
2153 			req_size = PAGE_SIZE;
2154 		if (0 == sg_build_indirect(schp, sfp, req_size))
2155 			return;
2156 		else
2157 			sg_remove_scat(schp);
2158 		req_size >>= 1;	/* divide by 2 */
2159 	} while (req_size > (PAGE_SIZE / 2));
2160 }
2161 
2162 static void
2163 sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
2164 {
2165 	Sg_scatter_hold *req_schp = &srp->data;
2166 	Sg_scatter_hold *rsv_schp = &sfp->reserve;
2167 	struct scatterlist *sg = rsv_schp->buffer;
2168 	int k, num, rem;
2169 
2170 	srp->res_used = 1;
2171 	SCSI_LOG_TIMEOUT(4, printk("sg_link_reserve: size=%d\n", size));
2172 	rem = size;
2173 
2174 	for (k = 0; k < rsv_schp->k_use_sg; ++k, sg = sg_next(sg)) {
2175 		num = sg->length;
2176 		if (rem <= num) {
2177 			sfp->save_scat_len = num;
2178 			sg->length = rem;
2179 			req_schp->k_use_sg = k + 1;
2180 			req_schp->sglist_len = rsv_schp->sglist_len;
2181 			req_schp->buffer = rsv_schp->buffer;
2182 
2183 			req_schp->bufflen = size;
2184 			req_schp->b_malloc_len = rsv_schp->b_malloc_len;
2185 			break;
2186 		} else
2187 			rem -= num;
2188 	}
2189 
2190 	if (k >= rsv_schp->k_use_sg)
2191 		SCSI_LOG_TIMEOUT(1, printk("sg_link_reserve: BAD size\n"));
2192 }
2193 
2194 static void
2195 sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
2196 {
2197 	Sg_scatter_hold *req_schp = &srp->data;
2198 	Sg_scatter_hold *rsv_schp = &sfp->reserve;
2199 
2200 	SCSI_LOG_TIMEOUT(4, printk("sg_unlink_reserve: req->k_use_sg=%d\n",
2201 				   (int) req_schp->k_use_sg));
2202 	if ((rsv_schp->k_use_sg > 0) && (req_schp->k_use_sg > 0)) {
2203 		struct scatterlist *sg = rsv_schp->buffer;
2204 
2205 		if (sfp->save_scat_len > 0)
2206 			(sg + (req_schp->k_use_sg - 1))->length =
2207 			    (unsigned) sfp->save_scat_len;
2208 		else
2209 			SCSI_LOG_TIMEOUT(1, printk ("sg_unlink_reserve: BAD save_scat_len\n"));
2210 	}
2211 	req_schp->k_use_sg = 0;
2212 	req_schp->bufflen = 0;
2213 	req_schp->buffer = NULL;
2214 	req_schp->sglist_len = 0;
2215 	sfp->save_scat_len = 0;
2216 	srp->res_used = 0;
2217 }
2218 
2219 static Sg_request *
2220 sg_get_rq_mark(Sg_fd * sfp, int pack_id)
2221 {
2222 	Sg_request *resp;
2223 	unsigned long iflags;
2224 
2225 	write_lock_irqsave(&sfp->rq_list_lock, iflags);
2226 	for (resp = sfp->headrp; resp; resp = resp->nextrp) {
2227 		/* look for requests that are ready + not SG_IO owned */
2228 		if ((1 == resp->done) && (!resp->sg_io_owned) &&
2229 		    ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
2230 			resp->done = 2;	/* guard against other readers */
2231 			break;
2232 		}
2233 	}
2234 	write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2235 	return resp;
2236 }
2237 
2238 #ifdef CONFIG_SCSI_PROC_FS
2239 static Sg_request *
2240 sg_get_nth_request(Sg_fd * sfp, int nth)
2241 {
2242 	Sg_request *resp;
2243 	unsigned long iflags;
2244 	int k;
2245 
2246 	read_lock_irqsave(&sfp->rq_list_lock, iflags);
2247 	for (k = 0, resp = sfp->headrp; resp && (k < nth);
2248 	     ++k, resp = resp->nextrp) ;
2249 	read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2250 	return resp;
2251 }
2252 #endif
2253 
2254 /* always adds to end of list */
2255 static Sg_request *
2256 sg_add_request(Sg_fd * sfp)
2257 {
2258 	int k;
2259 	unsigned long iflags;
2260 	Sg_request *resp;
2261 	Sg_request *rp = sfp->req_arr;
2262 
2263 	write_lock_irqsave(&sfp->rq_list_lock, iflags);
2264 	resp = sfp->headrp;
2265 	if (!resp) {
2266 		memset(rp, 0, sizeof (Sg_request));
2267 		rp->parentfp = sfp;
2268 		resp = rp;
2269 		sfp->headrp = resp;
2270 	} else {
2271 		if (0 == sfp->cmd_q)
2272 			resp = NULL;	/* command queuing disallowed */
2273 		else {
2274 			for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2275 				if (!rp->parentfp)
2276 					break;
2277 			}
2278 			if (k < SG_MAX_QUEUE) {
2279 				memset(rp, 0, sizeof (Sg_request));
2280 				rp->parentfp = sfp;
2281 				while (resp->nextrp)
2282 					resp = resp->nextrp;
2283 				resp->nextrp = rp;
2284 				resp = rp;
2285 			} else
2286 				resp = NULL;
2287 		}
2288 	}
2289 	if (resp) {
2290 		resp->nextrp = NULL;
2291 		resp->header.duration = jiffies_to_msecs(jiffies);
2292 	}
2293 	write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2294 	return resp;
2295 }
2296 
2297 /* Return of 1 for found; 0 for not found */
2298 static int
2299 sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2300 {
2301 	Sg_request *prev_rp;
2302 	Sg_request *rp;
2303 	unsigned long iflags;
2304 	int res = 0;
2305 
2306 	if ((!sfp) || (!srp) || (!sfp->headrp))
2307 		return res;
2308 	write_lock_irqsave(&sfp->rq_list_lock, iflags);
2309 	prev_rp = sfp->headrp;
2310 	if (srp == prev_rp) {
2311 		sfp->headrp = prev_rp->nextrp;
2312 		prev_rp->parentfp = NULL;
2313 		res = 1;
2314 	} else {
2315 		while ((rp = prev_rp->nextrp)) {
2316 			if (srp == rp) {
2317 				prev_rp->nextrp = rp->nextrp;
2318 				rp->parentfp = NULL;
2319 				res = 1;
2320 				break;
2321 			}
2322 			prev_rp = rp;
2323 		}
2324 	}
2325 	write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2326 	return res;
2327 }
2328 
2329 #ifdef CONFIG_SCSI_PROC_FS
2330 static Sg_fd *
2331 sg_get_nth_sfp(Sg_device * sdp, int nth)
2332 {
2333 	Sg_fd *resp;
2334 	unsigned long iflags;
2335 	int k;
2336 
2337 	read_lock_irqsave(&sg_index_lock, iflags);
2338 	for (k = 0, resp = sdp->headfp; resp && (k < nth);
2339 	     ++k, resp = resp->nextfp) ;
2340 	read_unlock_irqrestore(&sg_index_lock, iflags);
2341 	return resp;
2342 }
2343 #endif
2344 
2345 static Sg_fd *
2346 sg_add_sfp(Sg_device * sdp, int dev)
2347 {
2348 	Sg_fd *sfp;
2349 	unsigned long iflags;
2350 	int bufflen;
2351 
2352 	sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2353 	if (!sfp)
2354 		return NULL;
2355 
2356 	init_waitqueue_head(&sfp->read_wait);
2357 	rwlock_init(&sfp->rq_list_lock);
2358 
2359 	sfp->timeout = SG_DEFAULT_TIMEOUT;
2360 	sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2361 	sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2362 	sfp->low_dma = (SG_DEF_FORCE_LOW_DMA == 0) ?
2363 	    sdp->device->host->unchecked_isa_dma : 1;
2364 	sfp->cmd_q = SG_DEF_COMMAND_Q;
2365 	sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2366 	sfp->parentdp = sdp;
2367 	write_lock_irqsave(&sg_index_lock, iflags);
2368 	if (!sdp->headfp)
2369 		sdp->headfp = sfp;
2370 	else {			/* add to tail of existing list */
2371 		Sg_fd *pfp = sdp->headfp;
2372 		while (pfp->nextfp)
2373 			pfp = pfp->nextfp;
2374 		pfp->nextfp = sfp;
2375 	}
2376 	write_unlock_irqrestore(&sg_index_lock, iflags);
2377 	SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp: sfp=0x%p\n", sfp));
2378 	if (unlikely(sg_big_buff != def_reserved_size))
2379 		sg_big_buff = def_reserved_size;
2380 
2381 	bufflen = min_t(int, sg_big_buff,
2382 			sdp->device->request_queue->max_sectors * 512);
2383 	sg_build_reserve(sfp, bufflen);
2384 	SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp:   bufflen=%d, k_use_sg=%d\n",
2385 			   sfp->reserve.bufflen, sfp->reserve.k_use_sg));
2386 	return sfp;
2387 }
2388 
2389 static void
2390 __sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp)
2391 {
2392 	Sg_fd *fp;
2393 	Sg_fd *prev_fp;
2394 
2395 	prev_fp = sdp->headfp;
2396 	if (sfp == prev_fp)
2397 		sdp->headfp = prev_fp->nextfp;
2398 	else {
2399 		while ((fp = prev_fp->nextfp)) {
2400 			if (sfp == fp) {
2401 				prev_fp->nextfp = fp->nextfp;
2402 				break;
2403 			}
2404 			prev_fp = fp;
2405 		}
2406 	}
2407 	if (sfp->reserve.bufflen > 0) {
2408 		SCSI_LOG_TIMEOUT(6,
2409 			printk("__sg_remove_sfp:    bufflen=%d, k_use_sg=%d\n",
2410 			(int) sfp->reserve.bufflen, (int) sfp->reserve.k_use_sg));
2411 		sg_remove_scat(&sfp->reserve);
2412 	}
2413 	sfp->parentdp = NULL;
2414 	SCSI_LOG_TIMEOUT(6, printk("__sg_remove_sfp:    sfp=0x%p\n", sfp));
2415 	kfree(sfp);
2416 }
2417 
2418 /* Returns 0 in normal case, 1 when detached and sdp object removed */
2419 static int
2420 sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp)
2421 {
2422 	Sg_request *srp;
2423 	Sg_request *tsrp;
2424 	int dirty = 0;
2425 	int res = 0;
2426 
2427 	for (srp = sfp->headrp; srp; srp = tsrp) {
2428 		tsrp = srp->nextrp;
2429 		if (sg_srp_done(srp, sfp))
2430 			sg_finish_rem_req(srp);
2431 		else
2432 			++dirty;
2433 	}
2434 	if (0 == dirty) {
2435 		unsigned long iflags;
2436 
2437 		write_lock_irqsave(&sg_index_lock, iflags);
2438 		__sg_remove_sfp(sdp, sfp);
2439 		if (sdp->detached && (NULL == sdp->headfp)) {
2440 			idr_remove(&sg_index_idr, sdp->index);
2441 			kfree(sdp);
2442 			res = 1;
2443 		}
2444 		write_unlock_irqrestore(&sg_index_lock, iflags);
2445 	} else {
2446 		/* MOD_INC's to inhibit unloading sg and associated adapter driver */
2447 		/* only bump the access_count if we actually succeeded in
2448 		 * throwing another counter on the host module */
2449 		scsi_device_get(sdp->device);	/* XXX: retval ignored? */
2450 		sfp->closed = 1;	/* flag dirty state on this fd */
2451 		SCSI_LOG_TIMEOUT(1, printk("sg_remove_sfp: worrisome, %d writes pending\n",
2452 				  dirty));
2453 	}
2454 	return res;
2455 }
2456 
2457 static int
2458 sg_res_in_use(Sg_fd * sfp)
2459 {
2460 	const Sg_request *srp;
2461 	unsigned long iflags;
2462 
2463 	read_lock_irqsave(&sfp->rq_list_lock, iflags);
2464 	for (srp = sfp->headrp; srp; srp = srp->nextrp)
2465 		if (srp->res_used)
2466 			break;
2467 	read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2468 	return srp ? 1 : 0;
2469 }
2470 
2471 /* The size fetched (value output via retSzp) set when non-NULL return */
2472 static struct page *
2473 sg_page_malloc(int rqSz, int lowDma, int *retSzp)
2474 {
2475 	struct page *resp = NULL;
2476 	gfp_t page_mask;
2477 	int order, a_size;
2478 	int resSz;
2479 
2480 	if ((rqSz <= 0) || (NULL == retSzp))
2481 		return resp;
2482 
2483 	if (lowDma)
2484 		page_mask = GFP_ATOMIC | GFP_DMA | __GFP_COMP | __GFP_NOWARN;
2485 	else
2486 		page_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN;
2487 
2488 	for (order = 0, a_size = PAGE_SIZE; a_size < rqSz;
2489 	     order++, a_size <<= 1) ;
2490 	resSz = a_size;		/* rounded up if necessary */
2491 	resp = alloc_pages(page_mask, order);
2492 	while ((!resp) && order) {
2493 		--order;
2494 		a_size >>= 1;	/* divide by 2, until PAGE_SIZE */
2495 		resp =  alloc_pages(page_mask, order);	/* try half */
2496 		resSz = a_size;
2497 	}
2498 	if (resp) {
2499 		if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2500 			memset(page_address(resp), 0, resSz);
2501 		*retSzp = resSz;
2502 	}
2503 	return resp;
2504 }
2505 
2506 static void
2507 sg_page_free(struct page *page, int size)
2508 {
2509 	int order, a_size;
2510 
2511 	if (!page)
2512 		return;
2513 	for (order = 0, a_size = PAGE_SIZE; a_size < size;
2514 	     order++, a_size <<= 1) ;
2515 	__free_pages(page, order);
2516 }
2517 
2518 #ifdef CONFIG_SCSI_PROC_FS
2519 static int
2520 sg_idr_max_id(int id, void *p, void *data)
2521 {
2522 	int *k = data;
2523 
2524 	if (*k < id)
2525 		*k = id;
2526 
2527 	return 0;
2528 }
2529 
2530 static int
2531 sg_last_dev(void)
2532 {
2533 	int k = -1;
2534 	unsigned long iflags;
2535 
2536 	read_lock_irqsave(&sg_index_lock, iflags);
2537 	idr_for_each(&sg_index_idr, sg_idr_max_id, &k);
2538 	read_unlock_irqrestore(&sg_index_lock, iflags);
2539 	return k + 1;		/* origin 1 */
2540 }
2541 #endif
2542 
2543 static Sg_device *
2544 sg_get_dev(int dev)
2545 {
2546 	Sg_device *sdp;
2547 	unsigned long iflags;
2548 
2549 	read_lock_irqsave(&sg_index_lock, iflags);
2550 	sdp = idr_find(&sg_index_idr, dev);
2551 	read_unlock_irqrestore(&sg_index_lock, iflags);
2552 
2553 	return sdp;
2554 }
2555 
2556 #ifdef CONFIG_SCSI_PROC_FS
2557 
2558 static struct proc_dir_entry *sg_proc_sgp = NULL;
2559 
2560 static char sg_proc_sg_dirname[] = "scsi/sg";
2561 
2562 static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2563 
2564 static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2565 static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2566 			          size_t count, loff_t *off);
2567 static struct file_operations adio_fops = {
2568 	/* .owner, .read and .llseek added in sg_proc_init() */
2569 	.open = sg_proc_single_open_adio,
2570 	.write = sg_proc_write_adio,
2571 	.release = single_release,
2572 };
2573 
2574 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2575 static ssize_t sg_proc_write_dressz(struct file *filp,
2576 		const char __user *buffer, size_t count, loff_t *off);
2577 static struct file_operations dressz_fops = {
2578 	.open = sg_proc_single_open_dressz,
2579 	.write = sg_proc_write_dressz,
2580 	.release = single_release,
2581 };
2582 
2583 static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2584 static int sg_proc_single_open_version(struct inode *inode, struct file *file);
2585 static struct file_operations version_fops = {
2586 	.open = sg_proc_single_open_version,
2587 	.release = single_release,
2588 };
2589 
2590 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2591 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file);
2592 static struct file_operations devhdr_fops = {
2593 	.open = sg_proc_single_open_devhdr,
2594 	.release = single_release,
2595 };
2596 
2597 static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2598 static int sg_proc_open_dev(struct inode *inode, struct file *file);
2599 static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2600 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2601 static void dev_seq_stop(struct seq_file *s, void *v);
2602 static struct file_operations dev_fops = {
2603 	.open = sg_proc_open_dev,
2604 	.release = seq_release,
2605 };
2606 static struct seq_operations dev_seq_ops = {
2607 	.start = dev_seq_start,
2608 	.next  = dev_seq_next,
2609 	.stop  = dev_seq_stop,
2610 	.show  = sg_proc_seq_show_dev,
2611 };
2612 
2613 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2614 static int sg_proc_open_devstrs(struct inode *inode, struct file *file);
2615 static struct file_operations devstrs_fops = {
2616 	.open = sg_proc_open_devstrs,
2617 	.release = seq_release,
2618 };
2619 static struct seq_operations devstrs_seq_ops = {
2620 	.start = dev_seq_start,
2621 	.next  = dev_seq_next,
2622 	.stop  = dev_seq_stop,
2623 	.show  = sg_proc_seq_show_devstrs,
2624 };
2625 
2626 static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2627 static int sg_proc_open_debug(struct inode *inode, struct file *file);
2628 static struct file_operations debug_fops = {
2629 	.open = sg_proc_open_debug,
2630 	.release = seq_release,
2631 };
2632 static struct seq_operations debug_seq_ops = {
2633 	.start = dev_seq_start,
2634 	.next  = dev_seq_next,
2635 	.stop  = dev_seq_stop,
2636 	.show  = sg_proc_seq_show_debug,
2637 };
2638 
2639 
2640 struct sg_proc_leaf {
2641 	const char * name;
2642 	struct file_operations * fops;
2643 };
2644 
2645 static struct sg_proc_leaf sg_proc_leaf_arr[] = {
2646 	{"allow_dio", &adio_fops},
2647 	{"debug", &debug_fops},
2648 	{"def_reserved_size", &dressz_fops},
2649 	{"device_hdr", &devhdr_fops},
2650 	{"devices", &dev_fops},
2651 	{"device_strs", &devstrs_fops},
2652 	{"version", &version_fops}
2653 };
2654 
2655 static int
2656 sg_proc_init(void)
2657 {
2658 	int k, mask;
2659 	int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2660 	struct sg_proc_leaf * leaf;
2661 
2662 	sg_proc_sgp = proc_mkdir(sg_proc_sg_dirname, NULL);
2663 	if (!sg_proc_sgp)
2664 		return 1;
2665 	for (k = 0; k < num_leaves; ++k) {
2666 		leaf = &sg_proc_leaf_arr[k];
2667 		mask = leaf->fops->write ? S_IRUGO | S_IWUSR : S_IRUGO;
2668 		leaf->fops->owner = THIS_MODULE;
2669 		leaf->fops->read = seq_read;
2670 		leaf->fops->llseek = seq_lseek;
2671 		proc_create(leaf->name, mask, sg_proc_sgp, leaf->fops);
2672 	}
2673 	return 0;
2674 }
2675 
2676 static void
2677 sg_proc_cleanup(void)
2678 {
2679 	int k;
2680 	int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2681 
2682 	if (!sg_proc_sgp)
2683 		return;
2684 	for (k = 0; k < num_leaves; ++k)
2685 		remove_proc_entry(sg_proc_leaf_arr[k].name, sg_proc_sgp);
2686 	remove_proc_entry(sg_proc_sg_dirname, NULL);
2687 }
2688 
2689 
2690 static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2691 {
2692 	seq_printf(s, "%d\n", *((int *)s->private));
2693 	return 0;
2694 }
2695 
2696 static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2697 {
2698 	return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2699 }
2700 
2701 static ssize_t
2702 sg_proc_write_adio(struct file *filp, const char __user *buffer,
2703 		   size_t count, loff_t *off)
2704 {
2705 	int num;
2706 	char buff[11];
2707 
2708 	if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2709 		return -EACCES;
2710 	num = (count < 10) ? count : 10;
2711 	if (copy_from_user(buff, buffer, num))
2712 		return -EFAULT;
2713 	buff[num] = '\0';
2714 	sg_allow_dio = simple_strtoul(buff, NULL, 10) ? 1 : 0;
2715 	return count;
2716 }
2717 
2718 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2719 {
2720 	return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2721 }
2722 
2723 static ssize_t
2724 sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2725 		     size_t count, loff_t *off)
2726 {
2727 	int num;
2728 	unsigned long k = ULONG_MAX;
2729 	char buff[11];
2730 
2731 	if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2732 		return -EACCES;
2733 	num = (count < 10) ? count : 10;
2734 	if (copy_from_user(buff, buffer, num))
2735 		return -EFAULT;
2736 	buff[num] = '\0';
2737 	k = simple_strtoul(buff, NULL, 10);
2738 	if (k <= 1048576) {	/* limit "big buff" to 1 MB */
2739 		sg_big_buff = k;
2740 		return count;
2741 	}
2742 	return -ERANGE;
2743 }
2744 
2745 static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2746 {
2747 	seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2748 		   sg_version_date);
2749 	return 0;
2750 }
2751 
2752 static int sg_proc_single_open_version(struct inode *inode, struct file *file)
2753 {
2754 	return single_open(file, sg_proc_seq_show_version, NULL);
2755 }
2756 
2757 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2758 {
2759 	seq_printf(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\t"
2760 		   "online\n");
2761 	return 0;
2762 }
2763 
2764 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file)
2765 {
2766 	return single_open(file, sg_proc_seq_show_devhdr, NULL);
2767 }
2768 
2769 struct sg_proc_deviter {
2770 	loff_t	index;
2771 	size_t	max;
2772 };
2773 
2774 static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2775 {
2776 	struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2777 
2778 	s->private = it;
2779 	if (! it)
2780 		return NULL;
2781 
2782 	it->index = *pos;
2783 	it->max = sg_last_dev();
2784 	if (it->index >= it->max)
2785 		return NULL;
2786 	return it;
2787 }
2788 
2789 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2790 {
2791 	struct sg_proc_deviter * it = s->private;
2792 
2793 	*pos = ++it->index;
2794 	return (it->index < it->max) ? it : NULL;
2795 }
2796 
2797 static void dev_seq_stop(struct seq_file *s, void *v)
2798 {
2799 	kfree(s->private);
2800 }
2801 
2802 static int sg_proc_open_dev(struct inode *inode, struct file *file)
2803 {
2804         return seq_open(file, &dev_seq_ops);
2805 }
2806 
2807 static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2808 {
2809 	struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2810 	Sg_device *sdp;
2811 	struct scsi_device *scsidp;
2812 
2813 	sdp = it ? sg_get_dev(it->index) : NULL;
2814 	if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2815 		seq_printf(s, "%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\n",
2816 			      scsidp->host->host_no, scsidp->channel,
2817 			      scsidp->id, scsidp->lun, (int) scsidp->type,
2818 			      1,
2819 			      (int) scsidp->queue_depth,
2820 			      (int) scsidp->device_busy,
2821 			      (int) scsi_device_online(scsidp));
2822 	else
2823 		seq_printf(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2824 	return 0;
2825 }
2826 
2827 static int sg_proc_open_devstrs(struct inode *inode, struct file *file)
2828 {
2829         return seq_open(file, &devstrs_seq_ops);
2830 }
2831 
2832 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2833 {
2834 	struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2835 	Sg_device *sdp;
2836 	struct scsi_device *scsidp;
2837 
2838 	sdp = it ? sg_get_dev(it->index) : NULL;
2839 	if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2840 		seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2841 			   scsidp->vendor, scsidp->model, scsidp->rev);
2842 	else
2843 		seq_printf(s, "<no active device>\n");
2844 	return 0;
2845 }
2846 
2847 static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2848 {
2849 	int k, m, new_interface, blen, usg;
2850 	Sg_request *srp;
2851 	Sg_fd *fp;
2852 	const sg_io_hdr_t *hp;
2853 	const char * cp;
2854 	unsigned int ms;
2855 
2856 	for (k = 0; (fp = sg_get_nth_sfp(sdp, k)); ++k) {
2857 		seq_printf(s, "   FD(%d): timeout=%dms bufflen=%d "
2858 			   "(res)sgat=%d low_dma=%d\n", k + 1,
2859 			   jiffies_to_msecs(fp->timeout),
2860 			   fp->reserve.bufflen,
2861 			   (int) fp->reserve.k_use_sg,
2862 			   (int) fp->low_dma);
2863 		seq_printf(s, "   cmd_q=%d f_packid=%d k_orphan=%d closed=%d\n",
2864 			   (int) fp->cmd_q, (int) fp->force_packid,
2865 			   (int) fp->keep_orphan, (int) fp->closed);
2866 		for (m = 0; (srp = sg_get_nth_request(fp, m)); ++m) {
2867 			hp = &srp->header;
2868 			new_interface = (hp->interface_id == '\0') ? 0 : 1;
2869 			if (srp->res_used) {
2870 				if (new_interface &&
2871 				    (SG_FLAG_MMAP_IO & hp->flags))
2872 					cp = "     mmap>> ";
2873 				else
2874 					cp = "     rb>> ";
2875 			} else {
2876 				if (SG_INFO_DIRECT_IO_MASK & hp->info)
2877 					cp = "     dio>> ";
2878 				else
2879 					cp = "     ";
2880 			}
2881 			seq_printf(s, cp);
2882 			blen = srp->data.bufflen;
2883 			usg = srp->data.k_use_sg;
2884 			seq_printf(s, srp->done ?
2885 				   ((1 == srp->done) ?  "rcv:" : "fin:")
2886 				   : "act:");
2887 			seq_printf(s, " id=%d blen=%d",
2888 				   srp->header.pack_id, blen);
2889 			if (srp->done)
2890 				seq_printf(s, " dur=%d", hp->duration);
2891 			else {
2892 				ms = jiffies_to_msecs(jiffies);
2893 				seq_printf(s, " t_o/elap=%d/%d",
2894 					(new_interface ? hp->timeout :
2895 						  jiffies_to_msecs(fp->timeout)),
2896 					(ms > hp->duration ? ms - hp->duration : 0));
2897 			}
2898 			seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2899 				   (int) srp->data.cmd_opcode);
2900 		}
2901 		if (0 == m)
2902 			seq_printf(s, "     No requests active\n");
2903 	}
2904 }
2905 
2906 static int sg_proc_open_debug(struct inode *inode, struct file *file)
2907 {
2908         return seq_open(file, &debug_seq_ops);
2909 }
2910 
2911 static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2912 {
2913 	struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2914 	Sg_device *sdp;
2915 
2916 	if (it && (0 == it->index)) {
2917 		seq_printf(s, "max_active_device=%d(origin 1)\n",
2918 			   (int)it->max);
2919 		seq_printf(s, " def_reserved_size=%d\n", sg_big_buff);
2920 	}
2921 	sdp = it ? sg_get_dev(it->index) : NULL;
2922 	if (sdp) {
2923 		struct scsi_device *scsidp = sdp->device;
2924 
2925 		if (NULL == scsidp) {
2926 			seq_printf(s, "device %d detached ??\n",
2927 				   (int)it->index);
2928 			return 0;
2929 		}
2930 
2931 		if (sg_get_nth_sfp(sdp, 0)) {
2932 			seq_printf(s, " >>> device=%s ",
2933 				sdp->disk->disk_name);
2934 			if (sdp->detached)
2935 				seq_printf(s, "detached pending close ");
2936 			else
2937 				seq_printf
2938 				    (s, "scsi%d chan=%d id=%d lun=%d   em=%d",
2939 				     scsidp->host->host_no,
2940 				     scsidp->channel, scsidp->id,
2941 				     scsidp->lun,
2942 				     scsidp->host->hostt->emulated);
2943 			seq_printf(s, " sg_tablesize=%d excl=%d\n",
2944 				   sdp->sg_tablesize, sdp->exclude);
2945 		}
2946 		sg_proc_debug_helper(s, sdp);
2947 	}
2948 	return 0;
2949 }
2950 
2951 #endif				/* CONFIG_SCSI_PROC_FS */
2952 
2953 module_init(init_sg);
2954 module_exit(exit_sg);
2955