xref: /linux/drivers/scsi/sg.c (revision d8327c784b51b57dac2c26cfad87dce0d68dfd98)
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 = 30533;	/* 2 digits for each component */
22 #define SG_VERSION_STR "3.5.33"
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/config.h>
32 #include <linux/module.h>
33 
34 #include <linux/fs.h>
35 #include <linux/kernel.h>
36 #include <linux/sched.h>
37 #include <linux/string.h>
38 #include <linux/mm.h>
39 #include <linux/errno.h>
40 #include <linux/mtio.h>
41 #include <linux/ioctl.h>
42 #include <linux/fcntl.h>
43 #include <linux/init.h>
44 #include <linux/poll.h>
45 #include <linux/smp_lock.h>
46 #include <linux/moduleparam.h>
47 #include <linux/devfs_fs_kernel.h>
48 #include <linux/cdev.h>
49 #include <linux/seq_file.h>
50 #include <linux/blkdev.h>
51 #include <linux/delay.h>
52 #include <linux/scatterlist.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 = "20050908";
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 #define SG_SECTOR_SZ 512
100 #define SG_SECTOR_MSK (SG_SECTOR_SZ - 1)
101 
102 #define SG_DEV_ARR_LUMP 32	/* amount to over allocate sg_dev_arr by */
103 
104 static int sg_add(struct class_device *, struct class_interface *);
105 static void sg_remove(struct class_device *, struct class_interface *);
106 
107 static DEFINE_RWLOCK(sg_dev_arr_lock);	/* Also used to lock
108 							   file descriptor list for device */
109 
110 static struct class_interface sg_interface = {
111 	.add		= sg_add,
112 	.remove		= sg_remove,
113 };
114 
115 typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
116 	unsigned short k_use_sg; /* Count of kernel scatter-gather pieces */
117 	unsigned short sglist_len; /* size of malloc'd scatter-gather list ++ */
118 	unsigned bufflen;	/* Size of (aggregate) data buffer */
119 	unsigned b_malloc_len;	/* actual len malloc'ed in buffer */
120 	struct scatterlist *buffer;/* scatter list */
121 	char dio_in_use;	/* 0->indirect IO (or mmap), 1->dio */
122 	unsigned char cmd_opcode; /* first byte of command */
123 } Sg_scatter_hold;
124 
125 struct sg_device;		/* forward declarations */
126 struct sg_fd;
127 
128 typedef struct sg_request {	/* SG_MAX_QUEUE requests outstanding per file */
129 	struct sg_request *nextrp;	/* NULL -> tail request (slist) */
130 	struct sg_fd *parentfp;	/* NULL -> not in use */
131 	Sg_scatter_hold data;	/* hold buffer, perhaps scatter list */
132 	sg_io_hdr_t header;	/* scsi command+info, see <scsi/sg.h> */
133 	unsigned char sense_b[SCSI_SENSE_BUFFERSIZE];
134 	char res_used;		/* 1 -> using reserve buffer, 0 -> not ... */
135 	char orphan;		/* 1 -> drop on sight, 0 -> normal */
136 	char sg_io_owned;	/* 1 -> packet belongs to SG_IO */
137 	volatile char done;	/* 0->before bh, 1->before read, 2->read */
138 } Sg_request;
139 
140 typedef struct sg_fd {		/* holds the state of a file descriptor */
141 	struct sg_fd *nextfp;	/* NULL when last opened fd on this device */
142 	struct sg_device *parentdp;	/* owning device */
143 	wait_queue_head_t read_wait;	/* queue read until command done */
144 	rwlock_t rq_list_lock;	/* protect access to list in req_arr */
145 	int timeout;		/* defaults to SG_DEFAULT_TIMEOUT      */
146 	int timeout_user;	/* defaults to SG_DEFAULT_TIMEOUT_USER */
147 	Sg_scatter_hold reserve;	/* buffer held for this file descriptor */
148 	unsigned save_scat_len;	/* original length of trunc. scat. element */
149 	Sg_request *headrp;	/* head of request slist, NULL->empty */
150 	struct fasync_struct *async_qp;	/* used by asynchronous notification */
151 	Sg_request req_arr[SG_MAX_QUEUE];	/* used as singly-linked list */
152 	char low_dma;		/* as in parent but possibly overridden to 1 */
153 	char force_packid;	/* 1 -> pack_id input to read(), 0 -> ignored */
154 	volatile char closed;	/* 1 -> fd closed but request(s) outstanding */
155 	char cmd_q;		/* 1 -> allow command queuing, 0 -> don't */
156 	char next_cmd_len;	/* 0 -> automatic (def), >0 -> use on next write() */
157 	char keep_orphan;	/* 0 -> drop orphan (def), 1 -> keep for read() */
158 	char mmap_called;	/* 0 -> mmap() never called on this fd */
159 } Sg_fd;
160 
161 typedef struct sg_device { /* holds the state of each scsi generic device */
162 	struct scsi_device *device;
163 	wait_queue_head_t o_excl_wait;	/* queue open() when O_EXCL in use */
164 	int sg_tablesize;	/* adapter's max scatter-gather table size */
165 	Sg_fd *headfp;		/* first open fd belonging to this device */
166 	volatile char detached;	/* 0->attached, 1->detached pending removal */
167 	volatile char exclude;	/* opened for exclusive access */
168 	char sgdebug;		/* 0->off, 1->sense, 9->dump dev, 10-> all devs */
169 	struct gendisk *disk;
170 	struct cdev * cdev;	/* char_dev [sysfs: /sys/cdev/major/sg<n>] */
171 } Sg_device;
172 
173 static int sg_fasync(int fd, struct file *filp, int mode);
174 /* tasklet or soft irq callback */
175 static void sg_cmd_done(void *data, char *sense, int result, int resid);
176 static int sg_start_req(Sg_request * srp);
177 static void sg_finish_rem_req(Sg_request * srp);
178 static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
179 static int sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp,
180 			 int tablesize);
181 static ssize_t sg_new_read(Sg_fd * sfp, char __user *buf, size_t count,
182 			   Sg_request * srp);
183 static ssize_t sg_new_write(Sg_fd * sfp, const char __user *buf, size_t count,
184 			    int blocking, int read_only, Sg_request ** o_srp);
185 static int sg_common_write(Sg_fd * sfp, Sg_request * srp,
186 			   unsigned char *cmnd, int timeout, int blocking);
187 static int sg_u_iovec(sg_io_hdr_t * hp, int sg_num, int ind,
188 		      int wr_xf, int *countp, unsigned char __user **up);
189 static int sg_write_xfer(Sg_request * srp);
190 static int sg_read_xfer(Sg_request * srp);
191 static int sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer);
192 static void sg_remove_scat(Sg_scatter_hold * schp);
193 static void sg_build_reserve(Sg_fd * sfp, int req_size);
194 static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
195 static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
196 static struct page *sg_page_malloc(int rqSz, int lowDma, int *retSzp);
197 static void sg_page_free(struct page *page, int size);
198 static Sg_fd *sg_add_sfp(Sg_device * sdp, int dev);
199 static int sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp);
200 static void __sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp);
201 static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id);
202 static Sg_request *sg_add_request(Sg_fd * sfp);
203 static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
204 static int sg_res_in_use(Sg_fd * sfp);
205 static int sg_allow_access(unsigned char opcode, char dev_type);
206 static int sg_build_direct(Sg_request * srp, Sg_fd * sfp, int dxfer_len);
207 static Sg_device *sg_get_dev(int dev);
208 #ifdef CONFIG_SCSI_PROC_FS
209 static int sg_last_dev(void);
210 #endif
211 
212 static Sg_device **sg_dev_arr = NULL;
213 static int sg_dev_max;
214 static int sg_nr_dev;
215 
216 #define SZ_SG_HEADER sizeof(struct sg_header)
217 #define SZ_SG_IO_HDR sizeof(sg_io_hdr_t)
218 #define SZ_SG_IOVEC sizeof(sg_iovec_t)
219 #define SZ_SG_REQ_INFO sizeof(sg_req_info_t)
220 
221 static int
222 sg_open(struct inode *inode, struct file *filp)
223 {
224 	int dev = iminor(inode);
225 	int flags = filp->f_flags;
226 	struct request_queue *q;
227 	Sg_device *sdp;
228 	Sg_fd *sfp;
229 	int res;
230 	int retval;
231 
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 		return -ENXIO;
237 	if (sdp->detached)
238 		return -ENODEV;
239 
240 	/* This driver's module count bumped by fops_get in <linux/fs.h> */
241 	/* Prevent the device driver from vanishing while we sleep */
242 	retval = scsi_device_get(sdp->device);
243 	if (retval)
244 		return retval;
245 
246 	if (!((flags & O_NONBLOCK) ||
247 	      scsi_block_when_processing_errors(sdp->device))) {
248 		retval = -ENXIO;
249 		/* we are in error recovery for this device */
250 		goto error_out;
251 	}
252 
253 	if (flags & O_EXCL) {
254 		if (O_RDONLY == (flags & O_ACCMODE)) {
255 			retval = -EPERM; /* Can't lock it with read only access */
256 			goto error_out;
257 		}
258 		if (sdp->headfp && (flags & O_NONBLOCK)) {
259 			retval = -EBUSY;
260 			goto error_out;
261 		}
262 		res = 0;
263 		__wait_event_interruptible(sdp->o_excl_wait,
264 			((sdp->headfp || sdp->exclude) ? 0 : (sdp->exclude = 1)), res);
265 		if (res) {
266 			retval = res;	/* -ERESTARTSYS because signal hit process */
267 			goto error_out;
268 		}
269 	} else if (sdp->exclude) {	/* some other fd has an exclusive lock on dev */
270 		if (flags & O_NONBLOCK) {
271 			retval = -EBUSY;
272 			goto error_out;
273 		}
274 		res = 0;
275 		__wait_event_interruptible(sdp->o_excl_wait, (!sdp->exclude),
276 					   res);
277 		if (res) {
278 			retval = res;	/* -ERESTARTSYS because signal hit process */
279 			goto error_out;
280 		}
281 	}
282 	if (sdp->detached) {
283 		retval = -ENODEV;
284 		goto error_out;
285 	}
286 	if (!sdp->headfp) {	/* no existing opens on this device */
287 		sdp->sgdebug = 0;
288 		q = sdp->device->request_queue;
289 		sdp->sg_tablesize = min(q->max_hw_segments,
290 					q->max_phys_segments);
291 	}
292 	if ((sfp = sg_add_sfp(sdp, dev)))
293 		filp->private_data = sfp;
294 	else {
295 		if (flags & O_EXCL)
296 			sdp->exclude = 0;	/* undo if error */
297 		retval = -ENOMEM;
298 		goto error_out;
299 	}
300 	return 0;
301 
302       error_out:
303 	scsi_device_put(sdp->device);
304 	return retval;
305 }
306 
307 /* Following function was formerly called 'sg_close' */
308 static int
309 sg_release(struct inode *inode, struct file *filp)
310 {
311 	Sg_device *sdp;
312 	Sg_fd *sfp;
313 
314 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
315 		return -ENXIO;
316 	SCSI_LOG_TIMEOUT(3, printk("sg_release: %s\n", sdp->disk->disk_name));
317 	sg_fasync(-1, filp, 0);	/* remove filp from async notification list */
318 	if (0 == sg_remove_sfp(sdp, sfp)) {	/* Returns 1 when sdp gone */
319 		if (!sdp->detached) {
320 			scsi_device_put(sdp->device);
321 		}
322 		sdp->exclude = 0;
323 		wake_up_interruptible(&sdp->o_excl_wait);
324 	}
325 	return 0;
326 }
327 
328 static ssize_t
329 sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
330 {
331 	Sg_device *sdp;
332 	Sg_fd *sfp;
333 	Sg_request *srp;
334 	int req_pack_id = -1;
335 	sg_io_hdr_t *hp;
336 	struct sg_header *old_hdr = NULL;
337 	int retval = 0;
338 
339 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
340 		return -ENXIO;
341 	SCSI_LOG_TIMEOUT(3, printk("sg_read: %s, count=%d\n",
342 				   sdp->disk->disk_name, (int) count));
343 
344 	if (!access_ok(VERIFY_WRITE, buf, count))
345 		return -EFAULT;
346 	if (sfp->force_packid && (count >= SZ_SG_HEADER)) {
347 		old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
348 		if (!old_hdr)
349 			return -ENOMEM;
350 		if (__copy_from_user(old_hdr, buf, SZ_SG_HEADER)) {
351 			retval = -EFAULT;
352 			goto free_old_hdr;
353 		}
354 		if (old_hdr->reply_len < 0) {
355 			if (count >= SZ_SG_IO_HDR) {
356 				sg_io_hdr_t *new_hdr;
357 				new_hdr = kmalloc(SZ_SG_IO_HDR, GFP_KERNEL);
358 				if (!new_hdr) {
359 					retval = -ENOMEM;
360 					goto free_old_hdr;
361 				}
362 				retval =__copy_from_user
363 				    (new_hdr, buf, SZ_SG_IO_HDR);
364 				req_pack_id = new_hdr->pack_id;
365 				kfree(new_hdr);
366 				if (retval) {
367 					retval = -EFAULT;
368 					goto free_old_hdr;
369 				}
370 			}
371 		} else
372 			req_pack_id = old_hdr->pack_id;
373 	}
374 	srp = sg_get_rq_mark(sfp, req_pack_id);
375 	if (!srp) {		/* now wait on packet to arrive */
376 		if (sdp->detached) {
377 			retval = -ENODEV;
378 			goto free_old_hdr;
379 		}
380 		if (filp->f_flags & O_NONBLOCK) {
381 			retval = -EAGAIN;
382 			goto free_old_hdr;
383 		}
384 		while (1) {
385 			retval = 0; /* following macro beats race condition */
386 			__wait_event_interruptible(sfp->read_wait,
387 				(sdp->detached ||
388 				(srp = sg_get_rq_mark(sfp, req_pack_id))),
389 				retval);
390 			if (sdp->detached) {
391 				retval = -ENODEV;
392 				goto free_old_hdr;
393 			}
394 			if (0 == retval)
395 				break;
396 
397 			/* -ERESTARTSYS as signal hit process */
398 			goto free_old_hdr;
399 		}
400 	}
401 	if (srp->header.interface_id != '\0') {
402 		retval = sg_new_read(sfp, buf, count, srp);
403 		goto free_old_hdr;
404 	}
405 
406 	hp = &srp->header;
407 	if (old_hdr == NULL) {
408 		old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
409 		if (! old_hdr) {
410 			retval = -ENOMEM;
411 			goto free_old_hdr;
412 		}
413 	}
414 	memset(old_hdr, 0, SZ_SG_HEADER);
415 	old_hdr->reply_len = (int) hp->timeout;
416 	old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
417 	old_hdr->pack_id = hp->pack_id;
418 	old_hdr->twelve_byte =
419 	    ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
420 	old_hdr->target_status = hp->masked_status;
421 	old_hdr->host_status = hp->host_status;
422 	old_hdr->driver_status = hp->driver_status;
423 	if ((CHECK_CONDITION & hp->masked_status) ||
424 	    (DRIVER_SENSE & hp->driver_status))
425 		memcpy(old_hdr->sense_buffer, srp->sense_b,
426 		       sizeof (old_hdr->sense_buffer));
427 	switch (hp->host_status) {
428 	/* This setup of 'result' is for backward compatibility and is best
429 	   ignored by the user who should use target, host + driver status */
430 	case DID_OK:
431 	case DID_PASSTHROUGH:
432 	case DID_SOFT_ERROR:
433 		old_hdr->result = 0;
434 		break;
435 	case DID_NO_CONNECT:
436 	case DID_BUS_BUSY:
437 	case DID_TIME_OUT:
438 		old_hdr->result = EBUSY;
439 		break;
440 	case DID_BAD_TARGET:
441 	case DID_ABORT:
442 	case DID_PARITY:
443 	case DID_RESET:
444 	case DID_BAD_INTR:
445 		old_hdr->result = EIO;
446 		break;
447 	case DID_ERROR:
448 		old_hdr->result = (srp->sense_b[0] == 0 &&
449 				  hp->masked_status == GOOD) ? 0 : EIO;
450 		break;
451 	default:
452 		old_hdr->result = EIO;
453 		break;
454 	}
455 
456 	/* Now copy the result back to the user buffer.  */
457 	if (count >= SZ_SG_HEADER) {
458 		if (__copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
459 			retval = -EFAULT;
460 			goto free_old_hdr;
461 		}
462 		buf += SZ_SG_HEADER;
463 		if (count > old_hdr->reply_len)
464 			count = old_hdr->reply_len;
465 		if (count > SZ_SG_HEADER) {
466 			if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
467 				retval = -EFAULT;
468 				goto free_old_hdr;
469 			}
470 		}
471 	} else
472 		count = (old_hdr->result == 0) ? 0 : -EIO;
473 	sg_finish_rem_req(srp);
474 	retval = count;
475 free_old_hdr:
476 	kfree(old_hdr);
477 	return retval;
478 }
479 
480 static ssize_t
481 sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
482 {
483 	sg_io_hdr_t *hp = &srp->header;
484 	int err = 0;
485 	int len;
486 
487 	if (count < SZ_SG_IO_HDR) {
488 		err = -EINVAL;
489 		goto err_out;
490 	}
491 	hp->sb_len_wr = 0;
492 	if ((hp->mx_sb_len > 0) && hp->sbp) {
493 		if ((CHECK_CONDITION & hp->masked_status) ||
494 		    (DRIVER_SENSE & hp->driver_status)) {
495 			int sb_len = SCSI_SENSE_BUFFERSIZE;
496 			sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
497 			len = 8 + (int) srp->sense_b[7];	/* Additional sense length field */
498 			len = (len > sb_len) ? sb_len : len;
499 			if (copy_to_user(hp->sbp, srp->sense_b, len)) {
500 				err = -EFAULT;
501 				goto err_out;
502 			}
503 			hp->sb_len_wr = len;
504 		}
505 	}
506 	if (hp->masked_status || hp->host_status || hp->driver_status)
507 		hp->info |= SG_INFO_CHECK;
508 	if (copy_to_user(buf, hp, SZ_SG_IO_HDR)) {
509 		err = -EFAULT;
510 		goto err_out;
511 	}
512 	err = sg_read_xfer(srp);
513       err_out:
514 	sg_finish_rem_req(srp);
515 	return (0 == err) ? count : err;
516 }
517 
518 static ssize_t
519 sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
520 {
521 	int mxsize, cmd_size, k;
522 	int input_size, blocking;
523 	unsigned char opcode;
524 	Sg_device *sdp;
525 	Sg_fd *sfp;
526 	Sg_request *srp;
527 	struct sg_header old_hdr;
528 	sg_io_hdr_t *hp;
529 	unsigned char cmnd[MAX_COMMAND_SIZE];
530 
531 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
532 		return -ENXIO;
533 	SCSI_LOG_TIMEOUT(3, printk("sg_write: %s, count=%d\n",
534 				   sdp->disk->disk_name, (int) count));
535 	if (sdp->detached)
536 		return -ENODEV;
537 	if (!((filp->f_flags & O_NONBLOCK) ||
538 	      scsi_block_when_processing_errors(sdp->device)))
539 		return -ENXIO;
540 
541 	if (!access_ok(VERIFY_READ, buf, count))
542 		return -EFAULT;	/* protects following copy_from_user()s + get_user()s */
543 	if (count < SZ_SG_HEADER)
544 		return -EIO;
545 	if (__copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
546 		return -EFAULT;
547 	blocking = !(filp->f_flags & O_NONBLOCK);
548 	if (old_hdr.reply_len < 0)
549 		return sg_new_write(sfp, buf, count, blocking, 0, NULL);
550 	if (count < (SZ_SG_HEADER + 6))
551 		return -EIO;	/* The minimum scsi command length is 6 bytes. */
552 
553 	if (!(srp = sg_add_request(sfp))) {
554 		SCSI_LOG_TIMEOUT(1, printk("sg_write: queue full\n"));
555 		return -EDOM;
556 	}
557 	buf += SZ_SG_HEADER;
558 	__get_user(opcode, buf);
559 	if (sfp->next_cmd_len > 0) {
560 		if (sfp->next_cmd_len > MAX_COMMAND_SIZE) {
561 			SCSI_LOG_TIMEOUT(1, printk("sg_write: command length too long\n"));
562 			sfp->next_cmd_len = 0;
563 			sg_remove_request(sfp, srp);
564 			return -EIO;
565 		}
566 		cmd_size = sfp->next_cmd_len;
567 		sfp->next_cmd_len = 0;	/* reset so only this write() effected */
568 	} else {
569 		cmd_size = COMMAND_SIZE(opcode);	/* based on SCSI command group */
570 		if ((opcode >= 0xc0) && old_hdr.twelve_byte)
571 			cmd_size = 12;
572 	}
573 	SCSI_LOG_TIMEOUT(4, printk(
574 		"sg_write:   scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
575 /* Determine buffer size.  */
576 	input_size = count - cmd_size;
577 	mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
578 	mxsize -= SZ_SG_HEADER;
579 	input_size -= SZ_SG_HEADER;
580 	if (input_size < 0) {
581 		sg_remove_request(sfp, srp);
582 		return -EIO;	/* User did not pass enough bytes for this command. */
583 	}
584 	hp = &srp->header;
585 	hp->interface_id = '\0';	/* indicator of old interface tunnelled */
586 	hp->cmd_len = (unsigned char) cmd_size;
587 	hp->iovec_count = 0;
588 	hp->mx_sb_len = 0;
589 	if (input_size > 0)
590 		hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
591 		    SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
592 	else
593 		hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
594 	hp->dxfer_len = mxsize;
595 	hp->dxferp = (char __user *)buf + cmd_size;
596 	hp->sbp = NULL;
597 	hp->timeout = old_hdr.reply_len;	/* structure abuse ... */
598 	hp->flags = input_size;	/* structure abuse ... */
599 	hp->pack_id = old_hdr.pack_id;
600 	hp->usr_ptr = NULL;
601 	if (__copy_from_user(cmnd, buf, cmd_size))
602 		return -EFAULT;
603 	/*
604 	 * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
605 	 * but is is possible that the app intended SG_DXFER_TO_DEV, because there
606 	 * is a non-zero input_size, so emit a warning.
607 	 */
608 	if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV)
609 		if (printk_ratelimit())
610 			printk(KERN_WARNING
611 			       "sg_write: data in/out %d/%d bytes for SCSI command 0x%x--"
612 			       "guessing data in;\n" KERN_WARNING "   "
613 			       "program %s not setting count and/or reply_len properly\n",
614 			       old_hdr.reply_len - (int)SZ_SG_HEADER,
615 			       input_size, (unsigned int) cmnd[0],
616 			       current->comm);
617 	k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
618 	return (k < 0) ? k : count;
619 }
620 
621 static ssize_t
622 sg_new_write(Sg_fd * sfp, const char __user *buf, size_t count,
623 	     int blocking, int read_only, Sg_request ** o_srp)
624 {
625 	int k;
626 	Sg_request *srp;
627 	sg_io_hdr_t *hp;
628 	unsigned char cmnd[MAX_COMMAND_SIZE];
629 	int timeout;
630 	unsigned long ul_timeout;
631 
632 	if (count < SZ_SG_IO_HDR)
633 		return -EINVAL;
634 	if (!access_ok(VERIFY_READ, buf, count))
635 		return -EFAULT; /* protects following copy_from_user()s + get_user()s */
636 
637 	sfp->cmd_q = 1;	/* when sg_io_hdr seen, set command queuing on */
638 	if (!(srp = sg_add_request(sfp))) {
639 		SCSI_LOG_TIMEOUT(1, printk("sg_new_write: queue full\n"));
640 		return -EDOM;
641 	}
642 	hp = &srp->header;
643 	if (__copy_from_user(hp, buf, SZ_SG_IO_HDR)) {
644 		sg_remove_request(sfp, srp);
645 		return -EFAULT;
646 	}
647 	if (hp->interface_id != 'S') {
648 		sg_remove_request(sfp, srp);
649 		return -ENOSYS;
650 	}
651 	if (hp->flags & SG_FLAG_MMAP_IO) {
652 		if (hp->dxfer_len > sfp->reserve.bufflen) {
653 			sg_remove_request(sfp, srp);
654 			return -ENOMEM;	/* MMAP_IO size must fit in reserve buffer */
655 		}
656 		if (hp->flags & SG_FLAG_DIRECT_IO) {
657 			sg_remove_request(sfp, srp);
658 			return -EINVAL;	/* either MMAP_IO or DIRECT_IO (not both) */
659 		}
660 		if (sg_res_in_use(sfp)) {
661 			sg_remove_request(sfp, srp);
662 			return -EBUSY;	/* reserve buffer already being used */
663 		}
664 	}
665 	ul_timeout = msecs_to_jiffies(srp->header.timeout);
666 	timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
667 	if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
668 		sg_remove_request(sfp, srp);
669 		return -EMSGSIZE;
670 	}
671 	if (!access_ok(VERIFY_READ, hp->cmdp, hp->cmd_len)) {
672 		sg_remove_request(sfp, srp);
673 		return -EFAULT;	/* protects following copy_from_user()s + get_user()s */
674 	}
675 	if (__copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
676 		sg_remove_request(sfp, srp);
677 		return -EFAULT;
678 	}
679 	if (read_only &&
680 	    (!sg_allow_access(cmnd[0], sfp->parentdp->device->type))) {
681 		sg_remove_request(sfp, srp);
682 		return -EPERM;
683 	}
684 	k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
685 	if (k < 0)
686 		return k;
687 	if (o_srp)
688 		*o_srp = srp;
689 	return count;
690 }
691 
692 static int
693 sg_common_write(Sg_fd * sfp, Sg_request * srp,
694 		unsigned char *cmnd, int timeout, int blocking)
695 {
696 	int k, data_dir;
697 	Sg_device *sdp = sfp->parentdp;
698 	sg_io_hdr_t *hp = &srp->header;
699 
700 	srp->data.cmd_opcode = cmnd[0];	/* hold opcode of command */
701 	hp->status = 0;
702 	hp->masked_status = 0;
703 	hp->msg_status = 0;
704 	hp->info = 0;
705 	hp->host_status = 0;
706 	hp->driver_status = 0;
707 	hp->resid = 0;
708 	SCSI_LOG_TIMEOUT(4, printk("sg_common_write:  scsi opcode=0x%02x, cmd_size=%d\n",
709 			  (int) cmnd[0], (int) hp->cmd_len));
710 
711 	if ((k = sg_start_req(srp))) {
712 		SCSI_LOG_TIMEOUT(1, printk("sg_write: start_req err=%d\n", k));
713 		sg_finish_rem_req(srp);
714 		return k;	/* probably out of space --> ENOMEM */
715 	}
716 	if ((k = sg_write_xfer(srp))) {
717 		SCSI_LOG_TIMEOUT(1, printk("sg_write: write_xfer, bad address\n"));
718 		sg_finish_rem_req(srp);
719 		return k;
720 	}
721 	if (sdp->detached) {
722 		sg_finish_rem_req(srp);
723 		return -ENODEV;
724 	}
725 
726 	switch (hp->dxfer_direction) {
727 	case SG_DXFER_TO_FROM_DEV:
728 	case SG_DXFER_FROM_DEV:
729 		data_dir = DMA_FROM_DEVICE;
730 		break;
731 	case SG_DXFER_TO_DEV:
732 		data_dir = DMA_TO_DEVICE;
733 		break;
734 	case SG_DXFER_UNKNOWN:
735 		data_dir = DMA_BIDIRECTIONAL;
736 		break;
737 	default:
738 		data_dir = DMA_NONE;
739 		break;
740 	}
741 	hp->duration = jiffies_to_msecs(jiffies);
742 /* Now send everything of to mid-level. The next time we hear about this
743    packet is when sg_cmd_done() is called (i.e. a callback). */
744 	if (scsi_execute_async(sdp->device, cmnd, hp->cmd_len, data_dir, srp->data.buffer,
745 				hp->dxfer_len, srp->data.k_use_sg, timeout,
746 				SG_DEFAULT_RETRIES, srp, sg_cmd_done,
747 				GFP_ATOMIC)) {
748 		SCSI_LOG_TIMEOUT(1, printk("sg_write: scsi_execute_async failed\n"));
749 		/*
750 		 * most likely out of mem, but could also be a bad map
751 		 */
752 		return -ENOMEM;
753 	} else
754 		return 0;
755 }
756 
757 static int
758 sg_srp_done(Sg_request *srp, Sg_fd *sfp)
759 {
760 	unsigned long iflags;
761 	int done;
762 
763 	read_lock_irqsave(&sfp->rq_list_lock, iflags);
764 	done = srp->done;
765 	read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
766 	return done;
767 }
768 
769 static int
770 sg_ioctl(struct inode *inode, struct file *filp,
771 	 unsigned int cmd_in, unsigned long arg)
772 {
773 	void __user *p = (void __user *)arg;
774 	int __user *ip = p;
775 	int result, val, read_only;
776 	Sg_device *sdp;
777 	Sg_fd *sfp;
778 	Sg_request *srp;
779 	unsigned long iflags;
780 
781 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
782 		return -ENXIO;
783 	SCSI_LOG_TIMEOUT(3, printk("sg_ioctl: %s, cmd=0x%x\n",
784 				   sdp->disk->disk_name, (int) cmd_in));
785 	read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
786 
787 	switch (cmd_in) {
788 	case SG_IO:
789 		{
790 			int blocking = 1;	/* ignore O_NONBLOCK flag */
791 
792 			if (sdp->detached)
793 				return -ENODEV;
794 			if (!scsi_block_when_processing_errors(sdp->device))
795 				return -ENXIO;
796 			if (!access_ok(VERIFY_WRITE, p, SZ_SG_IO_HDR))
797 				return -EFAULT;
798 			result =
799 			    sg_new_write(sfp, p, SZ_SG_IO_HDR,
800 					 blocking, read_only, &srp);
801 			if (result < 0)
802 				return result;
803 			srp->sg_io_owned = 1;
804 			while (1) {
805 				result = 0;	/* following macro to beat race condition */
806 				__wait_event_interruptible(sfp->read_wait,
807 					(sdp->detached || sfp->closed || sg_srp_done(srp, sfp)),
808 							   result);
809 				if (sdp->detached)
810 					return -ENODEV;
811 				if (sfp->closed)
812 					return 0;	/* request packet dropped already */
813 				if (0 == result)
814 					break;
815 				srp->orphan = 1;
816 				return result;	/* -ERESTARTSYS because signal hit process */
817 			}
818 			write_lock_irqsave(&sfp->rq_list_lock, iflags);
819 			srp->done = 2;
820 			write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
821 			result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
822 			return (result < 0) ? result : 0;
823 		}
824 	case SG_SET_TIMEOUT:
825 		result = get_user(val, ip);
826 		if (result)
827 			return result;
828 		if (val < 0)
829 			return -EIO;
830 		if (val >= MULDIV (INT_MAX, USER_HZ, HZ))
831 		    val = MULDIV (INT_MAX, USER_HZ, HZ);
832 		sfp->timeout_user = val;
833 		sfp->timeout = MULDIV (val, HZ, USER_HZ);
834 
835 		return 0;
836 	case SG_GET_TIMEOUT:	/* N.B. User receives timeout as return value */
837 				/* strange ..., for backward compatibility */
838 		return sfp->timeout_user;
839 	case SG_SET_FORCE_LOW_DMA:
840 		result = get_user(val, ip);
841 		if (result)
842 			return result;
843 		if (val) {
844 			sfp->low_dma = 1;
845 			if ((0 == sfp->low_dma) && (0 == sg_res_in_use(sfp))) {
846 				val = (int) sfp->reserve.bufflen;
847 				sg_remove_scat(&sfp->reserve);
848 				sg_build_reserve(sfp, val);
849 			}
850 		} else {
851 			if (sdp->detached)
852 				return -ENODEV;
853 			sfp->low_dma = sdp->device->host->unchecked_isa_dma;
854 		}
855 		return 0;
856 	case SG_GET_LOW_DMA:
857 		return put_user((int) sfp->low_dma, ip);
858 	case SG_GET_SCSI_ID:
859 		if (!access_ok(VERIFY_WRITE, p, sizeof (sg_scsi_id_t)))
860 			return -EFAULT;
861 		else {
862 			sg_scsi_id_t __user *sg_idp = p;
863 
864 			if (sdp->detached)
865 				return -ENODEV;
866 			__put_user((int) sdp->device->host->host_no,
867 				   &sg_idp->host_no);
868 			__put_user((int) sdp->device->channel,
869 				   &sg_idp->channel);
870 			__put_user((int) sdp->device->id, &sg_idp->scsi_id);
871 			__put_user((int) sdp->device->lun, &sg_idp->lun);
872 			__put_user((int) sdp->device->type, &sg_idp->scsi_type);
873 			__put_user((short) sdp->device->host->cmd_per_lun,
874 				   &sg_idp->h_cmd_per_lun);
875 			__put_user((short) sdp->device->queue_depth,
876 				   &sg_idp->d_queue_depth);
877 			__put_user(0, &sg_idp->unused[0]);
878 			__put_user(0, &sg_idp->unused[1]);
879 			return 0;
880 		}
881 	case SG_SET_FORCE_PACK_ID:
882 		result = get_user(val, ip);
883 		if (result)
884 			return result;
885 		sfp->force_packid = val ? 1 : 0;
886 		return 0;
887 	case SG_GET_PACK_ID:
888 		if (!access_ok(VERIFY_WRITE, ip, sizeof (int)))
889 			return -EFAULT;
890 		read_lock_irqsave(&sfp->rq_list_lock, iflags);
891 		for (srp = sfp->headrp; srp; srp = srp->nextrp) {
892 			if ((1 == srp->done) && (!srp->sg_io_owned)) {
893 				read_unlock_irqrestore(&sfp->rq_list_lock,
894 						       iflags);
895 				__put_user(srp->header.pack_id, ip);
896 				return 0;
897 			}
898 		}
899 		read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
900 		__put_user(-1, ip);
901 		return 0;
902 	case SG_GET_NUM_WAITING:
903 		read_lock_irqsave(&sfp->rq_list_lock, iflags);
904 		for (val = 0, srp = sfp->headrp; srp; srp = srp->nextrp) {
905 			if ((1 == srp->done) && (!srp->sg_io_owned))
906 				++val;
907 		}
908 		read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
909 		return put_user(val, ip);
910 	case SG_GET_SG_TABLESIZE:
911 		return put_user(sdp->sg_tablesize, ip);
912 	case SG_SET_RESERVED_SIZE:
913 		result = get_user(val, ip);
914 		if (result)
915 			return result;
916                 if (val < 0)
917                         return -EINVAL;
918 		if (val != sfp->reserve.bufflen) {
919 			if (sg_res_in_use(sfp) || sfp->mmap_called)
920 				return -EBUSY;
921 			sg_remove_scat(&sfp->reserve);
922 			sg_build_reserve(sfp, val);
923 		}
924 		return 0;
925 	case SG_GET_RESERVED_SIZE:
926 		val = (int) sfp->reserve.bufflen;
927 		return put_user(val, ip);
928 	case SG_SET_COMMAND_Q:
929 		result = get_user(val, ip);
930 		if (result)
931 			return result;
932 		sfp->cmd_q = val ? 1 : 0;
933 		return 0;
934 	case SG_GET_COMMAND_Q:
935 		return put_user((int) sfp->cmd_q, ip);
936 	case SG_SET_KEEP_ORPHAN:
937 		result = get_user(val, ip);
938 		if (result)
939 			return result;
940 		sfp->keep_orphan = val;
941 		return 0;
942 	case SG_GET_KEEP_ORPHAN:
943 		return put_user((int) sfp->keep_orphan, ip);
944 	case SG_NEXT_CMD_LEN:
945 		result = get_user(val, ip);
946 		if (result)
947 			return result;
948 		sfp->next_cmd_len = (val > 0) ? val : 0;
949 		return 0;
950 	case SG_GET_VERSION_NUM:
951 		return put_user(sg_version_num, ip);
952 	case SG_GET_ACCESS_COUNT:
953 		/* faked - we don't have a real access count anymore */
954 		val = (sdp->device ? 1 : 0);
955 		return put_user(val, ip);
956 	case SG_GET_REQUEST_TABLE:
957 		if (!access_ok(VERIFY_WRITE, p, SZ_SG_REQ_INFO * SG_MAX_QUEUE))
958 			return -EFAULT;
959 		else {
960 			sg_req_info_t *rinfo;
961 			unsigned int ms;
962 
963 			rinfo = kmalloc(SZ_SG_REQ_INFO * SG_MAX_QUEUE,
964 								GFP_KERNEL);
965 			if (!rinfo)
966 				return -ENOMEM;
967 			read_lock_irqsave(&sfp->rq_list_lock, iflags);
968 			for (srp = sfp->headrp, val = 0; val < SG_MAX_QUEUE;
969 			     ++val, srp = srp ? srp->nextrp : srp) {
970 				memset(&rinfo[val], 0, SZ_SG_REQ_INFO);
971 				if (srp) {
972 					rinfo[val].req_state = srp->done + 1;
973 					rinfo[val].problem =
974 					    srp->header.masked_status &
975 					    srp->header.host_status &
976 					    srp->header.driver_status;
977 					if (srp->done)
978 						rinfo[val].duration =
979 							srp->header.duration;
980 					else {
981 						ms = jiffies_to_msecs(jiffies);
982 						rinfo[val].duration =
983 						    (ms > srp->header.duration) ?
984 						    (ms - srp->header.duration) : 0;
985 					}
986 					rinfo[val].orphan = srp->orphan;
987 					rinfo[val].sg_io_owned =
988 							srp->sg_io_owned;
989 					rinfo[val].pack_id =
990 							srp->header.pack_id;
991 					rinfo[val].usr_ptr =
992 							srp->header.usr_ptr;
993 				}
994 			}
995 			read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
996 			result = __copy_to_user(p, rinfo,
997 						SZ_SG_REQ_INFO * SG_MAX_QUEUE);
998 			result = result ? -EFAULT : 0;
999 			kfree(rinfo);
1000 			return result;
1001 		}
1002 	case SG_EMULATED_HOST:
1003 		if (sdp->detached)
1004 			return -ENODEV;
1005 		return put_user(sdp->device->host->hostt->emulated, ip);
1006 	case SG_SCSI_RESET:
1007 		if (sdp->detached)
1008 			return -ENODEV;
1009 		if (filp->f_flags & O_NONBLOCK) {
1010 			if (scsi_host_in_recovery(sdp->device->host))
1011 				return -EBUSY;
1012 		} else if (!scsi_block_when_processing_errors(sdp->device))
1013 			return -EBUSY;
1014 		result = get_user(val, ip);
1015 		if (result)
1016 			return result;
1017 		if (SG_SCSI_RESET_NOTHING == val)
1018 			return 0;
1019 		switch (val) {
1020 		case SG_SCSI_RESET_DEVICE:
1021 			val = SCSI_TRY_RESET_DEVICE;
1022 			break;
1023 		case SG_SCSI_RESET_BUS:
1024 			val = SCSI_TRY_RESET_BUS;
1025 			break;
1026 		case SG_SCSI_RESET_HOST:
1027 			val = SCSI_TRY_RESET_HOST;
1028 			break;
1029 		default:
1030 			return -EINVAL;
1031 		}
1032 		if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1033 			return -EACCES;
1034 		return (scsi_reset_provider(sdp->device, val) ==
1035 			SUCCESS) ? 0 : -EIO;
1036 	case SCSI_IOCTL_SEND_COMMAND:
1037 		if (sdp->detached)
1038 			return -ENODEV;
1039 		if (read_only) {
1040 			unsigned char opcode = WRITE_6;
1041 			Scsi_Ioctl_Command __user *siocp = p;
1042 
1043 			if (copy_from_user(&opcode, siocp->data, 1))
1044 				return -EFAULT;
1045 			if (!sg_allow_access(opcode, sdp->device->type))
1046 				return -EPERM;
1047 		}
1048 		return scsi_ioctl_send_command(sdp->device, p);
1049 	case SG_SET_DEBUG:
1050 		result = get_user(val, ip);
1051 		if (result)
1052 			return result;
1053 		sdp->sgdebug = (char) val;
1054 		return 0;
1055 	case SCSI_IOCTL_GET_IDLUN:
1056 	case SCSI_IOCTL_GET_BUS_NUMBER:
1057 	case SCSI_IOCTL_PROBE_HOST:
1058 	case SG_GET_TRANSFORM:
1059 		if (sdp->detached)
1060 			return -ENODEV;
1061 		return scsi_ioctl(sdp->device, cmd_in, p);
1062 	default:
1063 		if (read_only)
1064 			return -EPERM;	/* don't know so take safe approach */
1065 		return scsi_ioctl(sdp->device, cmd_in, p);
1066 	}
1067 }
1068 
1069 #ifdef CONFIG_COMPAT
1070 static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1071 {
1072 	Sg_device *sdp;
1073 	Sg_fd *sfp;
1074 	struct scsi_device *sdev;
1075 
1076 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1077 		return -ENXIO;
1078 
1079 	sdev = sdp->device;
1080 	if (sdev->host->hostt->compat_ioctl) {
1081 		int ret;
1082 
1083 		ret = sdev->host->hostt->compat_ioctl(sdev, cmd_in, (void __user *)arg);
1084 
1085 		return ret;
1086 	}
1087 
1088 	return -ENOIOCTLCMD;
1089 }
1090 #endif
1091 
1092 static unsigned int
1093 sg_poll(struct file *filp, poll_table * wait)
1094 {
1095 	unsigned int res = 0;
1096 	Sg_device *sdp;
1097 	Sg_fd *sfp;
1098 	Sg_request *srp;
1099 	int count = 0;
1100 	unsigned long iflags;
1101 
1102 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp))
1103 	    || sfp->closed)
1104 		return POLLERR;
1105 	poll_wait(filp, &sfp->read_wait, wait);
1106 	read_lock_irqsave(&sfp->rq_list_lock, iflags);
1107 	for (srp = sfp->headrp; srp; srp = srp->nextrp) {
1108 		/* if any read waiting, flag it */
1109 		if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1110 			res = POLLIN | POLLRDNORM;
1111 		++count;
1112 	}
1113 	read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1114 
1115 	if (sdp->detached)
1116 		res |= POLLHUP;
1117 	else if (!sfp->cmd_q) {
1118 		if (0 == count)
1119 			res |= POLLOUT | POLLWRNORM;
1120 	} else if (count < SG_MAX_QUEUE)
1121 		res |= POLLOUT | POLLWRNORM;
1122 	SCSI_LOG_TIMEOUT(3, printk("sg_poll: %s, res=0x%x\n",
1123 				   sdp->disk->disk_name, (int) res));
1124 	return res;
1125 }
1126 
1127 static int
1128 sg_fasync(int fd, struct file *filp, int mode)
1129 {
1130 	int retval;
1131 	Sg_device *sdp;
1132 	Sg_fd *sfp;
1133 
1134 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1135 		return -ENXIO;
1136 	SCSI_LOG_TIMEOUT(3, printk("sg_fasync: %s, mode=%d\n",
1137 				   sdp->disk->disk_name, mode));
1138 
1139 	retval = fasync_helper(fd, filp, mode, &sfp->async_qp);
1140 	return (retval < 0) ? retval : 0;
1141 }
1142 
1143 /* When startFinish==1 increments page counts for pages other than the
1144    first of scatter gather elements obtained from alloc_pages().
1145    When startFinish==0 decrements ... */
1146 static void
1147 sg_rb_correct4mmap(Sg_scatter_hold * rsv_schp, int startFinish)
1148 {
1149 	struct scatterlist *sg = rsv_schp->buffer;
1150 	struct page *page;
1151 	int k, m;
1152 
1153 	SCSI_LOG_TIMEOUT(3, printk("sg_rb_correct4mmap: startFinish=%d, scatg=%d\n",
1154 				   startFinish, rsv_schp->k_use_sg));
1155 	/* N.B. correction _not_ applied to base page of each allocation */
1156 	for (k = 0; k < rsv_schp->k_use_sg; ++k, ++sg) {
1157 		for (m = PAGE_SIZE; m < sg->length; m += PAGE_SIZE) {
1158 			page = sg->page;
1159 			if (startFinish)
1160 				get_page(page);
1161 			else {
1162 				if (page_count(page) > 0)
1163 					__put_page(page);
1164 			}
1165 		}
1166 	}
1167 }
1168 
1169 static struct page *
1170 sg_vma_nopage(struct vm_area_struct *vma, unsigned long addr, int *type)
1171 {
1172 	Sg_fd *sfp;
1173 	struct page *page = NOPAGE_SIGBUS;
1174 	unsigned long offset, len, sa;
1175 	Sg_scatter_hold *rsv_schp;
1176 	struct scatterlist *sg;
1177 	int k;
1178 
1179 	if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1180 		return page;
1181 	rsv_schp = &sfp->reserve;
1182 	offset = addr - vma->vm_start;
1183 	if (offset >= rsv_schp->bufflen)
1184 		return page;
1185 	SCSI_LOG_TIMEOUT(3, printk("sg_vma_nopage: offset=%lu, scatg=%d\n",
1186 				   offset, rsv_schp->k_use_sg));
1187 	sg = rsv_schp->buffer;
1188 	sa = vma->vm_start;
1189 	for (k = 0; (k < rsv_schp->k_use_sg) && (sa < vma->vm_end);
1190 	     ++k, ++sg) {
1191 		len = vma->vm_end - sa;
1192 		len = (len < sg->length) ? len : sg->length;
1193 		if (offset < len) {
1194 			page = sg->page;
1195 			get_page(page);	/* increment page count */
1196 			break;
1197 		}
1198 		sa += len;
1199 		offset -= len;
1200 	}
1201 
1202 	if (type)
1203 		*type = VM_FAULT_MINOR;
1204 	return page;
1205 }
1206 
1207 static struct vm_operations_struct sg_mmap_vm_ops = {
1208 	.nopage = sg_vma_nopage,
1209 };
1210 
1211 static int
1212 sg_mmap(struct file *filp, struct vm_area_struct *vma)
1213 {
1214 	Sg_fd *sfp;
1215 	unsigned long req_sz, len, sa;
1216 	Sg_scatter_hold *rsv_schp;
1217 	int k;
1218 	struct scatterlist *sg;
1219 
1220 	if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1221 		return -ENXIO;
1222 	req_sz = vma->vm_end - vma->vm_start;
1223 	SCSI_LOG_TIMEOUT(3, printk("sg_mmap starting, vm_start=%p, len=%d\n",
1224 				   (void *) vma->vm_start, (int) req_sz));
1225 	if (vma->vm_pgoff)
1226 		return -EINVAL;	/* want no offset */
1227 	rsv_schp = &sfp->reserve;
1228 	if (req_sz > rsv_schp->bufflen)
1229 		return -ENOMEM;	/* cannot map more than reserved buffer */
1230 
1231 	sa = vma->vm_start;
1232 	sg = rsv_schp->buffer;
1233 	for (k = 0; (k < rsv_schp->k_use_sg) && (sa < vma->vm_end);
1234 	     ++k, ++sg) {
1235 		len = vma->vm_end - sa;
1236 		len = (len < sg->length) ? len : sg->length;
1237 		sa += len;
1238 	}
1239 
1240 	if (0 == sfp->mmap_called) {
1241 		sg_rb_correct4mmap(rsv_schp, 1);	/* do only once per fd lifetime */
1242 		sfp->mmap_called = 1;
1243 	}
1244 	vma->vm_flags |= VM_RESERVED;
1245 	vma->vm_private_data = sfp;
1246 	vma->vm_ops = &sg_mmap_vm_ops;
1247 	return 0;
1248 }
1249 
1250 /* This function is a "bottom half" handler that is called by the
1251  * mid level when a command is completed (or has failed). */
1252 static void
1253 sg_cmd_done(void *data, char *sense, int result, int resid)
1254 {
1255 	Sg_request *srp = data;
1256 	Sg_device *sdp = NULL;
1257 	Sg_fd *sfp;
1258 	unsigned long iflags;
1259 	unsigned int ms;
1260 
1261 	if (NULL == srp) {
1262 		printk(KERN_ERR "sg_cmd_done: NULL request\n");
1263 		return;
1264 	}
1265 	sfp = srp->parentfp;
1266 	if (sfp)
1267 		sdp = sfp->parentdp;
1268 	if ((NULL == sdp) || sdp->detached) {
1269 		printk(KERN_INFO "sg_cmd_done: device detached\n");
1270 		return;
1271 	}
1272 
1273 
1274 	SCSI_LOG_TIMEOUT(4, printk("sg_cmd_done: %s, pack_id=%d, res=0x%x\n",
1275 		sdp->disk->disk_name, srp->header.pack_id, result));
1276 	srp->header.resid = resid;
1277 	ms = jiffies_to_msecs(jiffies);
1278 	srp->header.duration = (ms > srp->header.duration) ?
1279 				(ms - srp->header.duration) : 0;
1280 	if (0 != result) {
1281 		struct scsi_sense_hdr sshdr;
1282 
1283 		memcpy(srp->sense_b, sense, sizeof (srp->sense_b));
1284 		srp->header.status = 0xff & result;
1285 		srp->header.masked_status = status_byte(result);
1286 		srp->header.msg_status = msg_byte(result);
1287 		srp->header.host_status = host_byte(result);
1288 		srp->header.driver_status = driver_byte(result);
1289 		if ((sdp->sgdebug > 0) &&
1290 		    ((CHECK_CONDITION == srp->header.masked_status) ||
1291 		     (COMMAND_TERMINATED == srp->header.masked_status)))
1292 			__scsi_print_sense("sg_cmd_done", sense,
1293 					   SCSI_SENSE_BUFFERSIZE);
1294 
1295 		/* Following if statement is a patch supplied by Eric Youngdale */
1296 		if (driver_byte(result) != 0
1297 		    && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
1298 		    && !scsi_sense_is_deferred(&sshdr)
1299 		    && sshdr.sense_key == UNIT_ATTENTION
1300 		    && sdp->device->removable) {
1301 			/* Detected possible disc change. Set the bit - this */
1302 			/* may be used if there are filesystems using this device */
1303 			sdp->device->changed = 1;
1304 		}
1305 	}
1306 	/* Rely on write phase to clean out srp status values, so no "else" */
1307 
1308 	if (sfp->closed) {	/* whoops this fd already released, cleanup */
1309 		SCSI_LOG_TIMEOUT(1, printk("sg_cmd_done: already closed, freeing ...\n"));
1310 		sg_finish_rem_req(srp);
1311 		srp = NULL;
1312 		if (NULL == sfp->headrp) {
1313 			SCSI_LOG_TIMEOUT(1, printk("sg...bh: already closed, final cleanup\n"));
1314 			if (0 == sg_remove_sfp(sdp, sfp)) {	/* device still present */
1315 				scsi_device_put(sdp->device);
1316 			}
1317 			sfp = NULL;
1318 		}
1319 	} else if (srp && srp->orphan) {
1320 		if (sfp->keep_orphan)
1321 			srp->sg_io_owned = 0;
1322 		else {
1323 			sg_finish_rem_req(srp);
1324 			srp = NULL;
1325 		}
1326 	}
1327 	if (sfp && srp) {
1328 		/* Now wake up any sg_read() that is waiting for this packet. */
1329 		kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1330 		write_lock_irqsave(&sfp->rq_list_lock, iflags);
1331 		srp->done = 1;
1332 		wake_up_interruptible(&sfp->read_wait);
1333 		write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1334 	}
1335 }
1336 
1337 static struct file_operations sg_fops = {
1338 	.owner = THIS_MODULE,
1339 	.read = sg_read,
1340 	.write = sg_write,
1341 	.poll = sg_poll,
1342 	.ioctl = sg_ioctl,
1343 #ifdef CONFIG_COMPAT
1344 	.compat_ioctl = sg_compat_ioctl,
1345 #endif
1346 	.open = sg_open,
1347 	.mmap = sg_mmap,
1348 	.release = sg_release,
1349 	.fasync = sg_fasync,
1350 };
1351 
1352 static struct class *sg_sysfs_class;
1353 
1354 static int sg_sysfs_valid = 0;
1355 
1356 static int sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1357 {
1358 	struct request_queue *q = scsidp->request_queue;
1359 	Sg_device *sdp;
1360 	unsigned long iflags;
1361 	void *old_sg_dev_arr = NULL;
1362 	int k, error;
1363 
1364 	sdp = kmalloc(sizeof(Sg_device), GFP_KERNEL);
1365 	if (!sdp) {
1366 		printk(KERN_WARNING "kmalloc Sg_device failure\n");
1367 		return -ENOMEM;
1368 	}
1369 
1370 	write_lock_irqsave(&sg_dev_arr_lock, iflags);
1371 	if (unlikely(sg_nr_dev >= sg_dev_max)) {	/* try to resize */
1372 		Sg_device **tmp_da;
1373 		int tmp_dev_max = sg_nr_dev + SG_DEV_ARR_LUMP;
1374 		write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1375 
1376 		tmp_da = kmalloc(tmp_dev_max * sizeof(Sg_device *), GFP_KERNEL);
1377 		if (unlikely(!tmp_da))
1378 			goto expand_failed;
1379 
1380 		write_lock_irqsave(&sg_dev_arr_lock, iflags);
1381 		memset(tmp_da, 0, tmp_dev_max * sizeof(Sg_device *));
1382 		memcpy(tmp_da, sg_dev_arr, sg_dev_max * sizeof(Sg_device *));
1383 		old_sg_dev_arr = sg_dev_arr;
1384 		sg_dev_arr = tmp_da;
1385 		sg_dev_max = tmp_dev_max;
1386 	}
1387 
1388 	for (k = 0; k < sg_dev_max; k++)
1389 		if (!sg_dev_arr[k])
1390 			break;
1391 	if (unlikely(k >= SG_MAX_DEVS))
1392 		goto overflow;
1393 
1394 	memset(sdp, 0, sizeof(*sdp));
1395 	SCSI_LOG_TIMEOUT(3, printk("sg_alloc: dev=%d \n", k));
1396 	sprintf(disk->disk_name, "sg%d", k);
1397 	disk->first_minor = k;
1398 	sdp->disk = disk;
1399 	sdp->device = scsidp;
1400 	init_waitqueue_head(&sdp->o_excl_wait);
1401 	sdp->sg_tablesize = min(q->max_hw_segments, q->max_phys_segments);
1402 
1403 	sg_nr_dev++;
1404 	sg_dev_arr[k] = sdp;
1405 	write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1406 	error = k;
1407 
1408  out:
1409 	if (error < 0)
1410 		kfree(sdp);
1411 	kfree(old_sg_dev_arr);
1412 	return error;
1413 
1414  expand_failed:
1415 	printk(KERN_WARNING "sg_alloc: device array cannot be resized\n");
1416 	error = -ENOMEM;
1417 	goto out;
1418 
1419  overflow:
1420 	write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1421 	sdev_printk(KERN_WARNING, scsidp,
1422 		    "Unable to attach sg device type=%d, minor "
1423 		    "number exceeds %d\n", scsidp->type, SG_MAX_DEVS - 1);
1424 	error = -ENODEV;
1425 	goto out;
1426 }
1427 
1428 static int
1429 sg_add(struct class_device *cl_dev, struct class_interface *cl_intf)
1430 {
1431 	struct scsi_device *scsidp = to_scsi_device(cl_dev->dev);
1432 	struct gendisk *disk;
1433 	Sg_device *sdp = NULL;
1434 	struct cdev * cdev = NULL;
1435 	int error, k;
1436 
1437 	disk = alloc_disk(1);
1438 	if (!disk) {
1439 		printk(KERN_WARNING "alloc_disk failed\n");
1440 		return -ENOMEM;
1441 	}
1442 	disk->major = SCSI_GENERIC_MAJOR;
1443 
1444 	error = -ENOMEM;
1445 	cdev = cdev_alloc();
1446 	if (!cdev) {
1447 		printk(KERN_WARNING "cdev_alloc failed\n");
1448 		goto out;
1449 	}
1450 	cdev->owner = THIS_MODULE;
1451 	cdev->ops = &sg_fops;
1452 
1453 	error = sg_alloc(disk, scsidp);
1454 	if (error < 0) {
1455 		printk(KERN_WARNING "sg_alloc failed\n");
1456 		goto out;
1457 	}
1458 	k = error;
1459 	sdp = sg_dev_arr[k];
1460 
1461 	devfs_mk_cdev(MKDEV(SCSI_GENERIC_MAJOR, k),
1462 			S_IFCHR | S_IRUSR | S_IWUSR | S_IRGRP,
1463 			"%s/generic", scsidp->devfs_name);
1464 	error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, k), 1);
1465 	if (error) {
1466 		devfs_remove("%s/generic", scsidp->devfs_name);
1467 		goto out;
1468 	}
1469 	sdp->cdev = cdev;
1470 	if (sg_sysfs_valid) {
1471 		struct class_device * sg_class_member;
1472 
1473 		sg_class_member = class_device_create(sg_sysfs_class, NULL,
1474 				MKDEV(SCSI_GENERIC_MAJOR, k),
1475 				cl_dev->dev, "%s",
1476 				disk->disk_name);
1477 		if (IS_ERR(sg_class_member))
1478 			printk(KERN_WARNING "sg_add: "
1479 				"class_device_create failed\n");
1480 		class_set_devdata(sg_class_member, sdp);
1481 		error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1482 					  &sg_class_member->kobj, "generic");
1483 		if (error)
1484 			printk(KERN_ERR "sg_add: unable to make symlink "
1485 					"'generic' back to sg%d\n", k);
1486 	} else
1487 		printk(KERN_WARNING "sg_add: sg_sys INvalid\n");
1488 
1489 	sdev_printk(KERN_NOTICE, scsidp,
1490 		    "Attached scsi generic sg%d type %d\n", k,scsidp->type);
1491 
1492 	return 0;
1493 
1494 out:
1495 	put_disk(disk);
1496 	if (cdev)
1497 		cdev_del(cdev);
1498 	return error;
1499 }
1500 
1501 static void
1502 sg_remove(struct class_device *cl_dev, struct class_interface *cl_intf)
1503 {
1504 	struct scsi_device *scsidp = to_scsi_device(cl_dev->dev);
1505 	Sg_device *sdp = NULL;
1506 	unsigned long iflags;
1507 	Sg_fd *sfp;
1508 	Sg_fd *tsfp;
1509 	Sg_request *srp;
1510 	Sg_request *tsrp;
1511 	int k, delay;
1512 
1513 	if (NULL == sg_dev_arr)
1514 		return;
1515 	delay = 0;
1516 	write_lock_irqsave(&sg_dev_arr_lock, iflags);
1517 	for (k = 0; k < sg_dev_max; k++) {
1518 		sdp = sg_dev_arr[k];
1519 		if ((NULL == sdp) || (sdp->device != scsidp))
1520 			continue;	/* dirty but lowers nesting */
1521 		if (sdp->headfp) {
1522 			sdp->detached = 1;
1523 			for (sfp = sdp->headfp; sfp; sfp = tsfp) {
1524 				tsfp = sfp->nextfp;
1525 				for (srp = sfp->headrp; srp; srp = tsrp) {
1526 					tsrp = srp->nextrp;
1527 					if (sfp->closed || (0 == sg_srp_done(srp, sfp)))
1528 						sg_finish_rem_req(srp);
1529 				}
1530 				if (sfp->closed) {
1531 					scsi_device_put(sdp->device);
1532 					__sg_remove_sfp(sdp, sfp);
1533 				} else {
1534 					delay = 1;
1535 					wake_up_interruptible(&sfp->read_wait);
1536 					kill_fasync(&sfp->async_qp, SIGPOLL,
1537 						    POLL_HUP);
1538 				}
1539 			}
1540 			SCSI_LOG_TIMEOUT(3, printk("sg_detach: dev=%d, dirty\n", k));
1541 			if (NULL == sdp->headfp) {
1542 				sg_dev_arr[k] = NULL;
1543 			}
1544 		} else {	/* nothing active, simple case */
1545 			SCSI_LOG_TIMEOUT(3, printk("sg_detach: dev=%d\n", k));
1546 			sg_dev_arr[k] = NULL;
1547 		}
1548 		sg_nr_dev--;
1549 		break;
1550 	}
1551 	write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1552 
1553 	if (sdp) {
1554 		sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1555 		class_device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, k));
1556 		cdev_del(sdp->cdev);
1557 		sdp->cdev = NULL;
1558 		devfs_remove("%s/generic", scsidp->devfs_name);
1559 		put_disk(sdp->disk);
1560 		sdp->disk = NULL;
1561 		if (NULL == sdp->headfp)
1562 			kfree((char *) sdp);
1563 	}
1564 
1565 	if (delay)
1566 		msleep(10);	/* dirty detach so delay device destruction */
1567 }
1568 
1569 /* Set 'perm' (4th argument) to 0 to disable module_param's definition
1570  * of sysfs parameters (which module_param doesn't yet support).
1571  * Sysfs parameters defined explicitly below.
1572  */
1573 module_param_named(def_reserved_size, def_reserved_size, int, S_IRUGO);
1574 module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1575 
1576 MODULE_AUTHOR("Douglas Gilbert");
1577 MODULE_DESCRIPTION("SCSI generic (sg) driver");
1578 MODULE_LICENSE("GPL");
1579 MODULE_VERSION(SG_VERSION_STR);
1580 
1581 MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1582 MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1583 
1584 static int __init
1585 init_sg(void)
1586 {
1587 	int rc;
1588 
1589 	if (def_reserved_size >= 0)
1590 		sg_big_buff = def_reserved_size;
1591 
1592 	rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1593 				    SG_MAX_DEVS, "sg");
1594 	if (rc)
1595 		return rc;
1596         sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
1597         if ( IS_ERR(sg_sysfs_class) ) {
1598 		rc = PTR_ERR(sg_sysfs_class);
1599 		goto err_out;
1600         }
1601 	sg_sysfs_valid = 1;
1602 	rc = scsi_register_interface(&sg_interface);
1603 	if (0 == rc) {
1604 #ifdef CONFIG_SCSI_PROC_FS
1605 		sg_proc_init();
1606 #endif				/* CONFIG_SCSI_PROC_FS */
1607 		return 0;
1608 	}
1609 	class_destroy(sg_sysfs_class);
1610 err_out:
1611 	unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1612 	return rc;
1613 }
1614 
1615 static void __exit
1616 exit_sg(void)
1617 {
1618 #ifdef CONFIG_SCSI_PROC_FS
1619 	sg_proc_cleanup();
1620 #endif				/* CONFIG_SCSI_PROC_FS */
1621 	scsi_unregister_interface(&sg_interface);
1622 	class_destroy(sg_sysfs_class);
1623 	sg_sysfs_valid = 0;
1624 	unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1625 				 SG_MAX_DEVS);
1626 	kfree((char *)sg_dev_arr);
1627 	sg_dev_arr = NULL;
1628 	sg_dev_max = 0;
1629 }
1630 
1631 static int
1632 sg_start_req(Sg_request * srp)
1633 {
1634 	int res;
1635 	Sg_fd *sfp = srp->parentfp;
1636 	sg_io_hdr_t *hp = &srp->header;
1637 	int dxfer_len = (int) hp->dxfer_len;
1638 	int dxfer_dir = hp->dxfer_direction;
1639 	Sg_scatter_hold *req_schp = &srp->data;
1640 	Sg_scatter_hold *rsv_schp = &sfp->reserve;
1641 
1642 	SCSI_LOG_TIMEOUT(4, printk("sg_start_req: dxfer_len=%d\n", dxfer_len));
1643 	if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1644 		return 0;
1645 	if (sg_allow_dio && (hp->flags & SG_FLAG_DIRECT_IO) &&
1646 	    (dxfer_dir != SG_DXFER_UNKNOWN) && (0 == hp->iovec_count) &&
1647 	    (!sfp->parentdp->device->host->unchecked_isa_dma)) {
1648 		res = sg_build_direct(srp, sfp, dxfer_len);
1649 		if (res <= 0)	/* -ve -> error, 0 -> done, 1 -> try indirect */
1650 			return res;
1651 	}
1652 	if ((!sg_res_in_use(sfp)) && (dxfer_len <= rsv_schp->bufflen))
1653 		sg_link_reserve(sfp, srp, dxfer_len);
1654 	else {
1655 		res = sg_build_indirect(req_schp, sfp, dxfer_len);
1656 		if (res) {
1657 			sg_remove_scat(req_schp);
1658 			return res;
1659 		}
1660 	}
1661 	return 0;
1662 }
1663 
1664 static void
1665 sg_finish_rem_req(Sg_request * srp)
1666 {
1667 	Sg_fd *sfp = srp->parentfp;
1668 	Sg_scatter_hold *req_schp = &srp->data;
1669 
1670 	SCSI_LOG_TIMEOUT(4, printk("sg_finish_rem_req: res_used=%d\n", (int) srp->res_used));
1671 	if (srp->res_used)
1672 		sg_unlink_reserve(sfp, srp);
1673 	else
1674 		sg_remove_scat(req_schp);
1675 	sg_remove_request(sfp, srp);
1676 }
1677 
1678 static int
1679 sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1680 {
1681 	int sg_bufflen = tablesize * sizeof(struct scatterlist);
1682 	gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1683 
1684 	/*
1685 	 * TODO: test without low_dma, we should not need it since
1686 	 * the block layer will bounce the buffer for us
1687 	 *
1688 	 * XXX(hch): we shouldn't need GFP_DMA for the actual S/G list.
1689 	 */
1690 	if (sfp->low_dma)
1691 		 gfp_flags |= GFP_DMA;
1692 	schp->buffer = kzalloc(sg_bufflen, gfp_flags);
1693 	if (!schp->buffer)
1694 		return -ENOMEM;
1695 	schp->sglist_len = sg_bufflen;
1696 	return tablesize;	/* number of scat_gath elements allocated */
1697 }
1698 
1699 #ifdef SG_ALLOW_DIO_CODE
1700 /* vvvvvvvv  following code borrowed from st driver's direct IO vvvvvvvvv */
1701 	/* TODO: hopefully we can use the generic block layer code */
1702 
1703 /* Pin down user pages and put them into a scatter gather list. Returns <= 0 if
1704    - mapping of all pages not successful
1705    (i.e., either completely successful or fails)
1706 */
1707 static int
1708 st_map_user_pages(struct scatterlist *sgl, const unsigned int max_pages,
1709 	          unsigned long uaddr, size_t count, int rw)
1710 {
1711 	unsigned long end = (uaddr + count + PAGE_SIZE - 1) >> PAGE_SHIFT;
1712 	unsigned long start = uaddr >> PAGE_SHIFT;
1713 	const int nr_pages = end - start;
1714 	int res, i, j;
1715 	struct page **pages;
1716 
1717 	/* User attempted Overflow! */
1718 	if ((uaddr + count) < uaddr)
1719 		return -EINVAL;
1720 
1721 	/* Too big */
1722         if (nr_pages > max_pages)
1723 		return -ENOMEM;
1724 
1725 	/* Hmm? */
1726 	if (count == 0)
1727 		return 0;
1728 
1729 	if ((pages = kmalloc(max_pages * sizeof(*pages), GFP_ATOMIC)) == NULL)
1730 		return -ENOMEM;
1731 
1732         /* Try to fault in all of the necessary pages */
1733 	down_read(&current->mm->mmap_sem);
1734         /* rw==READ means read from drive, write into memory area */
1735 	res = get_user_pages(
1736 		current,
1737 		current->mm,
1738 		uaddr,
1739 		nr_pages,
1740 		rw == READ,
1741 		0, /* don't force */
1742 		pages,
1743 		NULL);
1744 	up_read(&current->mm->mmap_sem);
1745 
1746 	/* Errors and no page mapped should return here */
1747 	if (res < nr_pages)
1748 		goto out_unmap;
1749 
1750         for (i=0; i < nr_pages; i++) {
1751                 /* FIXME: flush superflous for rw==READ,
1752                  * probably wrong function for rw==WRITE
1753                  */
1754 		flush_dcache_page(pages[i]);
1755 		/* ?? Is locking needed? I don't think so */
1756 		/* if (TestSetPageLocked(pages[i]))
1757 		   goto out_unlock; */
1758         }
1759 
1760 	sgl[0].page = pages[0];
1761 	sgl[0].offset = uaddr & ~PAGE_MASK;
1762 	if (nr_pages > 1) {
1763 		sgl[0].length = PAGE_SIZE - sgl[0].offset;
1764 		count -= sgl[0].length;
1765 		for (i=1; i < nr_pages ; i++) {
1766 			sgl[i].page = pages[i];
1767 			sgl[i].length = count < PAGE_SIZE ? count : PAGE_SIZE;
1768 			count -= PAGE_SIZE;
1769 		}
1770 	}
1771 	else {
1772 		sgl[0].length = count;
1773 	}
1774 
1775 	kfree(pages);
1776 	return nr_pages;
1777 
1778  out_unmap:
1779 	if (res > 0) {
1780 		for (j=0; j < res; j++)
1781 			page_cache_release(pages[j]);
1782 		res = 0;
1783 	}
1784 	kfree(pages);
1785 	return res;
1786 }
1787 
1788 
1789 /* And unmap them... */
1790 static int
1791 st_unmap_user_pages(struct scatterlist *sgl, const unsigned int nr_pages,
1792 		    int dirtied)
1793 {
1794 	int i;
1795 
1796 	for (i=0; i < nr_pages; i++) {
1797 		struct page *page = sgl[i].page;
1798 
1799 		if (dirtied)
1800 			SetPageDirty(page);
1801 		/* unlock_page(page); */
1802 		/* FIXME: cache flush missing for rw==READ
1803 		 * FIXME: call the correct reference counting function
1804 		 */
1805 		page_cache_release(page);
1806 	}
1807 
1808 	return 0;
1809 }
1810 
1811 /* ^^^^^^^^  above code borrowed from st driver's direct IO ^^^^^^^^^ */
1812 #endif
1813 
1814 
1815 /* Returns: -ve -> error, 0 -> done, 1 -> try indirect */
1816 static int
1817 sg_build_direct(Sg_request * srp, Sg_fd * sfp, int dxfer_len)
1818 {
1819 #ifdef SG_ALLOW_DIO_CODE
1820 	sg_io_hdr_t *hp = &srp->header;
1821 	Sg_scatter_hold *schp = &srp->data;
1822 	int sg_tablesize = sfp->parentdp->sg_tablesize;
1823 	int mx_sc_elems, res;
1824 	struct scsi_device *sdev = sfp->parentdp->device;
1825 
1826 	if (((unsigned long)hp->dxferp &
1827 			queue_dma_alignment(sdev->request_queue)) != 0)
1828 		return 1;
1829 
1830 	mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1831         if (mx_sc_elems <= 0) {
1832                 return 1;
1833         }
1834 	res = st_map_user_pages(schp->buffer, mx_sc_elems,
1835 				(unsigned long)hp->dxferp, dxfer_len,
1836 				(SG_DXFER_TO_DEV == hp->dxfer_direction) ? 1 : 0);
1837 	if (res <= 0)
1838 		return 1;
1839 	schp->k_use_sg = res;
1840 	schp->dio_in_use = 1;
1841 	hp->info |= SG_INFO_DIRECT_IO;
1842 	return 0;
1843 #else
1844 	return 1;
1845 #endif
1846 }
1847 
1848 static int
1849 sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1850 {
1851 	struct scatterlist *sg;
1852 	int ret_sz = 0, k, rem_sz, num, mx_sc_elems;
1853 	int sg_tablesize = sfp->parentdp->sg_tablesize;
1854 	int blk_size = buff_size;
1855 	struct page *p = NULL;
1856 
1857 	if ((blk_size < 0) || (!sfp))
1858 		return -EFAULT;
1859 	if (0 == blk_size)
1860 		++blk_size;	/* don't know why */
1861 /* round request up to next highest SG_SECTOR_SZ byte boundary */
1862 	blk_size = (blk_size + SG_SECTOR_MSK) & (~SG_SECTOR_MSK);
1863 	SCSI_LOG_TIMEOUT(4, printk("sg_build_indirect: buff_size=%d, blk_size=%d\n",
1864 				   buff_size, blk_size));
1865 
1866 	/* N.B. ret_sz carried into this block ... */
1867 	mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1868 	if (mx_sc_elems < 0)
1869 		return mx_sc_elems;	/* most likely -ENOMEM */
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) {
1874 
1875 		num = (rem_sz > SG_SCATTER_SZ) ? SG_SCATTER_SZ : rem_sz;
1876 		p = sg_page_malloc(num, sfp->low_dma, &ret_sz);
1877 		if (!p)
1878 			return -ENOMEM;
1879 
1880 		sg->page = p;
1881 		sg->length = ret_sz;
1882 
1883 		SCSI_LOG_TIMEOUT(5, printk("sg_build_build: k=%d, a=0x%p, len=%d\n",
1884 				  k, p, ret_sz));
1885 	}		/* end of for loop */
1886 
1887 	schp->k_use_sg = k;
1888 	SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k_use_sg=%d, rem_sz=%d\n", k, rem_sz));
1889 
1890 	schp->bufflen = blk_size;
1891 	if (rem_sz > 0)	/* must have failed */
1892 		return -ENOMEM;
1893 
1894 	return 0;
1895 }
1896 
1897 static int
1898 sg_write_xfer(Sg_request * srp)
1899 {
1900 	sg_io_hdr_t *hp = &srp->header;
1901 	Sg_scatter_hold *schp = &srp->data;
1902 	struct scatterlist *sg = schp->buffer;
1903 	int num_xfer = 0;
1904 	int j, k, onum, usglen, ksglen, res;
1905 	int iovec_count = (int) hp->iovec_count;
1906 	int dxfer_dir = hp->dxfer_direction;
1907 	unsigned char *p;
1908 	unsigned char __user *up;
1909 	int new_interface = ('\0' == hp->interface_id) ? 0 : 1;
1910 
1911 	if ((SG_DXFER_UNKNOWN == dxfer_dir) || (SG_DXFER_TO_DEV == dxfer_dir) ||
1912 	    (SG_DXFER_TO_FROM_DEV == dxfer_dir)) {
1913 		num_xfer = (int) (new_interface ? hp->dxfer_len : hp->flags);
1914 		if (schp->bufflen < num_xfer)
1915 			num_xfer = schp->bufflen;
1916 	}
1917 	if ((num_xfer <= 0) || (schp->dio_in_use) ||
1918 	    (new_interface
1919 	     && ((SG_FLAG_NO_DXFER | SG_FLAG_MMAP_IO) & hp->flags)))
1920 		return 0;
1921 
1922 	SCSI_LOG_TIMEOUT(4, printk("sg_write_xfer: num_xfer=%d, iovec_count=%d, k_use_sg=%d\n",
1923 			  num_xfer, iovec_count, schp->k_use_sg));
1924 	if (iovec_count) {
1925 		onum = iovec_count;
1926 		if (!access_ok(VERIFY_READ, hp->dxferp, SZ_SG_IOVEC * onum))
1927 			return -EFAULT;
1928 	} else
1929 		onum = 1;
1930 
1931 	ksglen = sg->length;
1932 	p = page_address(sg->page);
1933 	for (j = 0, k = 0; j < onum; ++j) {
1934 		res = sg_u_iovec(hp, iovec_count, j, 1, &usglen, &up);
1935 		if (res)
1936 			return res;
1937 
1938 		for (; p; ++sg, ksglen = sg->length,
1939 		     p = page_address(sg->page)) {
1940 			if (usglen <= 0)
1941 				break;
1942 			if (ksglen > usglen) {
1943 				if (usglen >= num_xfer) {
1944 					if (__copy_from_user(p, up, num_xfer))
1945 						return -EFAULT;
1946 					return 0;
1947 				}
1948 				if (__copy_from_user(p, up, usglen))
1949 					return -EFAULT;
1950 				p += usglen;
1951 				ksglen -= usglen;
1952 				break;
1953 			} else {
1954 				if (ksglen >= num_xfer) {
1955 					if (__copy_from_user(p, up, num_xfer))
1956 						return -EFAULT;
1957 					return 0;
1958 				}
1959 				if (__copy_from_user(p, up, ksglen))
1960 					return -EFAULT;
1961 				up += ksglen;
1962 				usglen -= ksglen;
1963 			}
1964 			++k;
1965 			if (k >= schp->k_use_sg)
1966 				return 0;
1967 		}
1968 	}
1969 
1970 	return 0;
1971 }
1972 
1973 static int
1974 sg_u_iovec(sg_io_hdr_t * hp, int sg_num, int ind,
1975 	   int wr_xf, int *countp, unsigned char __user **up)
1976 {
1977 	int num_xfer = (int) hp->dxfer_len;
1978 	unsigned char __user *p = hp->dxferp;
1979 	int count;
1980 
1981 	if (0 == sg_num) {
1982 		if (wr_xf && ('\0' == hp->interface_id))
1983 			count = (int) hp->flags;	/* holds "old" input_size */
1984 		else
1985 			count = num_xfer;
1986 	} else {
1987 		sg_iovec_t iovec;
1988 		if (__copy_from_user(&iovec, p + ind*SZ_SG_IOVEC, SZ_SG_IOVEC))
1989 			return -EFAULT;
1990 		p = iovec.iov_base;
1991 		count = (int) iovec.iov_len;
1992 	}
1993 	if (!access_ok(wr_xf ? VERIFY_READ : VERIFY_WRITE, p, count))
1994 		return -EFAULT;
1995 	if (up)
1996 		*up = p;
1997 	if (countp)
1998 		*countp = count;
1999 	return 0;
2000 }
2001 
2002 static void
2003 sg_remove_scat(Sg_scatter_hold * schp)
2004 {
2005 	SCSI_LOG_TIMEOUT(4, printk("sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
2006 	if (schp->buffer && (schp->sglist_len > 0)) {
2007 		struct scatterlist *sg = schp->buffer;
2008 
2009 		if (schp->dio_in_use) {
2010 #ifdef SG_ALLOW_DIO_CODE
2011 			st_unmap_user_pages(sg, schp->k_use_sg, TRUE);
2012 #endif
2013 		} else {
2014 			int k;
2015 
2016 			for (k = 0; (k < schp->k_use_sg) && sg->page;
2017 			     ++k, ++sg) {
2018 				SCSI_LOG_TIMEOUT(5, printk(
2019 				    "sg_remove_scat: k=%d, a=0x%p, len=%d\n",
2020 				    k, sg->page, sg->length));
2021 				sg_page_free(sg->page, sg->length);
2022 			}
2023 		}
2024 		kfree(schp->buffer);
2025 	}
2026 	memset(schp, 0, sizeof (*schp));
2027 }
2028 
2029 static int
2030 sg_read_xfer(Sg_request * srp)
2031 {
2032 	sg_io_hdr_t *hp = &srp->header;
2033 	Sg_scatter_hold *schp = &srp->data;
2034 	struct scatterlist *sg = schp->buffer;
2035 	int num_xfer = 0;
2036 	int j, k, onum, usglen, ksglen, res;
2037 	int iovec_count = (int) hp->iovec_count;
2038 	int dxfer_dir = hp->dxfer_direction;
2039 	unsigned char *p;
2040 	unsigned char __user *up;
2041 	int new_interface = ('\0' == hp->interface_id) ? 0 : 1;
2042 
2043 	if ((SG_DXFER_UNKNOWN == dxfer_dir) || (SG_DXFER_FROM_DEV == dxfer_dir)
2044 	    || (SG_DXFER_TO_FROM_DEV == dxfer_dir)) {
2045 		num_xfer = hp->dxfer_len;
2046 		if (schp->bufflen < num_xfer)
2047 			num_xfer = schp->bufflen;
2048 	}
2049 	if ((num_xfer <= 0) || (schp->dio_in_use) ||
2050 	    (new_interface
2051 	     && ((SG_FLAG_NO_DXFER | SG_FLAG_MMAP_IO) & hp->flags)))
2052 		return 0;
2053 
2054 	SCSI_LOG_TIMEOUT(4, printk("sg_read_xfer: num_xfer=%d, iovec_count=%d, k_use_sg=%d\n",
2055 			  num_xfer, iovec_count, schp->k_use_sg));
2056 	if (iovec_count) {
2057 		onum = iovec_count;
2058 		if (!access_ok(VERIFY_READ, hp->dxferp, SZ_SG_IOVEC * onum))
2059 			return -EFAULT;
2060 	} else
2061 		onum = 1;
2062 
2063 	p = page_address(sg->page);
2064 	ksglen = sg->length;
2065 	for (j = 0, k = 0; j < onum; ++j) {
2066 		res = sg_u_iovec(hp, iovec_count, j, 0, &usglen, &up);
2067 		if (res)
2068 			return res;
2069 
2070 		for (; p; ++sg, ksglen = sg->length,
2071 		     p = page_address(sg->page)) {
2072 			if (usglen <= 0)
2073 				break;
2074 			if (ksglen > usglen) {
2075 				if (usglen >= num_xfer) {
2076 					if (__copy_to_user(up, p, num_xfer))
2077 						return -EFAULT;
2078 					return 0;
2079 				}
2080 				if (__copy_to_user(up, p, usglen))
2081 					return -EFAULT;
2082 				p += usglen;
2083 				ksglen -= usglen;
2084 				break;
2085 			} else {
2086 				if (ksglen >= num_xfer) {
2087 					if (__copy_to_user(up, p, num_xfer))
2088 						return -EFAULT;
2089 					return 0;
2090 				}
2091 				if (__copy_to_user(up, p, ksglen))
2092 					return -EFAULT;
2093 				up += ksglen;
2094 				usglen -= ksglen;
2095 			}
2096 			++k;
2097 			if (k >= schp->k_use_sg)
2098 				return 0;
2099 		}
2100 	}
2101 
2102 	return 0;
2103 }
2104 
2105 static int
2106 sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
2107 {
2108 	Sg_scatter_hold *schp = &srp->data;
2109 	struct scatterlist *sg = schp->buffer;
2110 	int k, num;
2111 
2112 	SCSI_LOG_TIMEOUT(4, printk("sg_read_oxfer: num_read_xfer=%d\n",
2113 				   num_read_xfer));
2114 	if ((!outp) || (num_read_xfer <= 0))
2115 		return 0;
2116 
2117 	for (k = 0; (k < schp->k_use_sg) && sg->page; ++k, ++sg) {
2118 		num = sg->length;
2119 		if (num > num_read_xfer) {
2120 			if (__copy_to_user(outp, page_address(sg->page),
2121 					   num_read_xfer))
2122 				return -EFAULT;
2123 			break;
2124 		} else {
2125 			if (__copy_to_user(outp, page_address(sg->page),
2126 					   num))
2127 				return -EFAULT;
2128 			num_read_xfer -= num;
2129 			if (num_read_xfer <= 0)
2130 				break;
2131 			outp += num;
2132 		}
2133 	}
2134 
2135 	return 0;
2136 }
2137 
2138 static void
2139 sg_build_reserve(Sg_fd * sfp, int req_size)
2140 {
2141 	Sg_scatter_hold *schp = &sfp->reserve;
2142 
2143 	SCSI_LOG_TIMEOUT(4, printk("sg_build_reserve: req_size=%d\n", req_size));
2144 	do {
2145 		if (req_size < PAGE_SIZE)
2146 			req_size = PAGE_SIZE;
2147 		if (0 == sg_build_indirect(schp, sfp, req_size))
2148 			return;
2149 		else
2150 			sg_remove_scat(schp);
2151 		req_size >>= 1;	/* divide by 2 */
2152 	} while (req_size > (PAGE_SIZE / 2));
2153 }
2154 
2155 static void
2156 sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
2157 {
2158 	Sg_scatter_hold *req_schp = &srp->data;
2159 	Sg_scatter_hold *rsv_schp = &sfp->reserve;
2160 	struct scatterlist *sg = rsv_schp->buffer;
2161 	int k, num, rem;
2162 
2163 	srp->res_used = 1;
2164 	SCSI_LOG_TIMEOUT(4, printk("sg_link_reserve: size=%d\n", size));
2165 	rem = size;
2166 
2167 	for (k = 0; k < rsv_schp->k_use_sg; ++k, ++sg) {
2168 		num = sg->length;
2169 		if (rem <= num) {
2170 			sfp->save_scat_len = num;
2171 			sg->length = rem;
2172 			req_schp->k_use_sg = k + 1;
2173 			req_schp->sglist_len = rsv_schp->sglist_len;
2174 			req_schp->buffer = rsv_schp->buffer;
2175 
2176 			req_schp->bufflen = size;
2177 			req_schp->b_malloc_len = rsv_schp->b_malloc_len;
2178 			break;
2179 		} else
2180 			rem -= num;
2181 	}
2182 
2183 	if (k >= rsv_schp->k_use_sg)
2184 		SCSI_LOG_TIMEOUT(1, printk("sg_link_reserve: BAD size\n"));
2185 }
2186 
2187 static void
2188 sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
2189 {
2190 	Sg_scatter_hold *req_schp = &srp->data;
2191 	Sg_scatter_hold *rsv_schp = &sfp->reserve;
2192 
2193 	SCSI_LOG_TIMEOUT(4, printk("sg_unlink_reserve: req->k_use_sg=%d\n",
2194 				   (int) req_schp->k_use_sg));
2195 	if ((rsv_schp->k_use_sg > 0) && (req_schp->k_use_sg > 0)) {
2196 		struct scatterlist *sg = rsv_schp->buffer;
2197 
2198 		if (sfp->save_scat_len > 0)
2199 			(sg + (req_schp->k_use_sg - 1))->length =
2200 			    (unsigned) sfp->save_scat_len;
2201 		else
2202 			SCSI_LOG_TIMEOUT(1, printk ("sg_unlink_reserve: BAD save_scat_len\n"));
2203 	}
2204 	req_schp->k_use_sg = 0;
2205 	req_schp->bufflen = 0;
2206 	req_schp->buffer = NULL;
2207 	req_schp->sglist_len = 0;
2208 	sfp->save_scat_len = 0;
2209 	srp->res_used = 0;
2210 }
2211 
2212 static Sg_request *
2213 sg_get_rq_mark(Sg_fd * sfp, int pack_id)
2214 {
2215 	Sg_request *resp;
2216 	unsigned long iflags;
2217 
2218 	write_lock_irqsave(&sfp->rq_list_lock, iflags);
2219 	for (resp = sfp->headrp; resp; resp = resp->nextrp) {
2220 		/* look for requests that are ready + not SG_IO owned */
2221 		if ((1 == resp->done) && (!resp->sg_io_owned) &&
2222 		    ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
2223 			resp->done = 2;	/* guard against other readers */
2224 			break;
2225 		}
2226 	}
2227 	write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2228 	return resp;
2229 }
2230 
2231 #ifdef CONFIG_SCSI_PROC_FS
2232 static Sg_request *
2233 sg_get_nth_request(Sg_fd * sfp, int nth)
2234 {
2235 	Sg_request *resp;
2236 	unsigned long iflags;
2237 	int k;
2238 
2239 	read_lock_irqsave(&sfp->rq_list_lock, iflags);
2240 	for (k = 0, resp = sfp->headrp; resp && (k < nth);
2241 	     ++k, resp = resp->nextrp) ;
2242 	read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2243 	return resp;
2244 }
2245 #endif
2246 
2247 /* always adds to end of list */
2248 static Sg_request *
2249 sg_add_request(Sg_fd * sfp)
2250 {
2251 	int k;
2252 	unsigned long iflags;
2253 	Sg_request *resp;
2254 	Sg_request *rp = sfp->req_arr;
2255 
2256 	write_lock_irqsave(&sfp->rq_list_lock, iflags);
2257 	resp = sfp->headrp;
2258 	if (!resp) {
2259 		memset(rp, 0, sizeof (Sg_request));
2260 		rp->parentfp = sfp;
2261 		resp = rp;
2262 		sfp->headrp = resp;
2263 	} else {
2264 		if (0 == sfp->cmd_q)
2265 			resp = NULL;	/* command queuing disallowed */
2266 		else {
2267 			for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2268 				if (!rp->parentfp)
2269 					break;
2270 			}
2271 			if (k < SG_MAX_QUEUE) {
2272 				memset(rp, 0, sizeof (Sg_request));
2273 				rp->parentfp = sfp;
2274 				while (resp->nextrp)
2275 					resp = resp->nextrp;
2276 				resp->nextrp = rp;
2277 				resp = rp;
2278 			} else
2279 				resp = NULL;
2280 		}
2281 	}
2282 	if (resp) {
2283 		resp->nextrp = NULL;
2284 		resp->header.duration = jiffies_to_msecs(jiffies);
2285 	}
2286 	write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2287 	return resp;
2288 }
2289 
2290 /* Return of 1 for found; 0 for not found */
2291 static int
2292 sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2293 {
2294 	Sg_request *prev_rp;
2295 	Sg_request *rp;
2296 	unsigned long iflags;
2297 	int res = 0;
2298 
2299 	if ((!sfp) || (!srp) || (!sfp->headrp))
2300 		return res;
2301 	write_lock_irqsave(&sfp->rq_list_lock, iflags);
2302 	prev_rp = sfp->headrp;
2303 	if (srp == prev_rp) {
2304 		sfp->headrp = prev_rp->nextrp;
2305 		prev_rp->parentfp = NULL;
2306 		res = 1;
2307 	} else {
2308 		while ((rp = prev_rp->nextrp)) {
2309 			if (srp == rp) {
2310 				prev_rp->nextrp = rp->nextrp;
2311 				rp->parentfp = NULL;
2312 				res = 1;
2313 				break;
2314 			}
2315 			prev_rp = rp;
2316 		}
2317 	}
2318 	write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2319 	return res;
2320 }
2321 
2322 #ifdef CONFIG_SCSI_PROC_FS
2323 static Sg_fd *
2324 sg_get_nth_sfp(Sg_device * sdp, int nth)
2325 {
2326 	Sg_fd *resp;
2327 	unsigned long iflags;
2328 	int k;
2329 
2330 	read_lock_irqsave(&sg_dev_arr_lock, iflags);
2331 	for (k = 0, resp = sdp->headfp; resp && (k < nth);
2332 	     ++k, resp = resp->nextfp) ;
2333 	read_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2334 	return resp;
2335 }
2336 #endif
2337 
2338 static Sg_fd *
2339 sg_add_sfp(Sg_device * sdp, int dev)
2340 {
2341 	Sg_fd *sfp;
2342 	unsigned long iflags;
2343 
2344 	sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2345 	if (!sfp)
2346 		return NULL;
2347 
2348 	init_waitqueue_head(&sfp->read_wait);
2349 	rwlock_init(&sfp->rq_list_lock);
2350 
2351 	sfp->timeout = SG_DEFAULT_TIMEOUT;
2352 	sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2353 	sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2354 	sfp->low_dma = (SG_DEF_FORCE_LOW_DMA == 0) ?
2355 	    sdp->device->host->unchecked_isa_dma : 1;
2356 	sfp->cmd_q = SG_DEF_COMMAND_Q;
2357 	sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2358 	sfp->parentdp = sdp;
2359 	write_lock_irqsave(&sg_dev_arr_lock, iflags);
2360 	if (!sdp->headfp)
2361 		sdp->headfp = sfp;
2362 	else {			/* add to tail of existing list */
2363 		Sg_fd *pfp = sdp->headfp;
2364 		while (pfp->nextfp)
2365 			pfp = pfp->nextfp;
2366 		pfp->nextfp = sfp;
2367 	}
2368 	write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2369 	SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp: sfp=0x%p\n", sfp));
2370 	sg_build_reserve(sfp, sg_big_buff);
2371 	SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp:   bufflen=%d, k_use_sg=%d\n",
2372 			   sfp->reserve.bufflen, sfp->reserve.k_use_sg));
2373 	return sfp;
2374 }
2375 
2376 static void
2377 __sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp)
2378 {
2379 	Sg_fd *fp;
2380 	Sg_fd *prev_fp;
2381 
2382 	prev_fp = sdp->headfp;
2383 	if (sfp == prev_fp)
2384 		sdp->headfp = prev_fp->nextfp;
2385 	else {
2386 		while ((fp = prev_fp->nextfp)) {
2387 			if (sfp == fp) {
2388 				prev_fp->nextfp = fp->nextfp;
2389 				break;
2390 			}
2391 			prev_fp = fp;
2392 		}
2393 	}
2394 	if (sfp->reserve.bufflen > 0) {
2395 		SCSI_LOG_TIMEOUT(6,
2396 			printk("__sg_remove_sfp:    bufflen=%d, k_use_sg=%d\n",
2397 			(int) sfp->reserve.bufflen, (int) sfp->reserve.k_use_sg));
2398 		if (sfp->mmap_called)
2399 			sg_rb_correct4mmap(&sfp->reserve, 0);	/* undo correction */
2400 		sg_remove_scat(&sfp->reserve);
2401 	}
2402 	sfp->parentdp = NULL;
2403 	SCSI_LOG_TIMEOUT(6, printk("__sg_remove_sfp:    sfp=0x%p\n", sfp));
2404 	kfree(sfp);
2405 }
2406 
2407 /* Returns 0 in normal case, 1 when detached and sdp object removed */
2408 static int
2409 sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp)
2410 {
2411 	Sg_request *srp;
2412 	Sg_request *tsrp;
2413 	int dirty = 0;
2414 	int res = 0;
2415 
2416 	for (srp = sfp->headrp; srp; srp = tsrp) {
2417 		tsrp = srp->nextrp;
2418 		if (sg_srp_done(srp, sfp))
2419 			sg_finish_rem_req(srp);
2420 		else
2421 			++dirty;
2422 	}
2423 	if (0 == dirty) {
2424 		unsigned long iflags;
2425 
2426 		write_lock_irqsave(&sg_dev_arr_lock, iflags);
2427 		__sg_remove_sfp(sdp, sfp);
2428 		if (sdp->detached && (NULL == sdp->headfp)) {
2429 			int k, maxd;
2430 
2431 			maxd = sg_dev_max;
2432 			for (k = 0; k < maxd; ++k) {
2433 				if (sdp == sg_dev_arr[k])
2434 					break;
2435 			}
2436 			if (k < maxd)
2437 				sg_dev_arr[k] = NULL;
2438 			kfree((char *) sdp);
2439 			res = 1;
2440 		}
2441 		write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2442 	} else {
2443 		/* MOD_INC's to inhibit unloading sg and associated adapter driver */
2444 		/* only bump the access_count if we actually succeeded in
2445 		 * throwing another counter on the host module */
2446 		scsi_device_get(sdp->device);	/* XXX: retval ignored? */
2447 		sfp->closed = 1;	/* flag dirty state on this fd */
2448 		SCSI_LOG_TIMEOUT(1, printk("sg_remove_sfp: worrisome, %d writes pending\n",
2449 				  dirty));
2450 	}
2451 	return res;
2452 }
2453 
2454 static int
2455 sg_res_in_use(Sg_fd * sfp)
2456 {
2457 	const Sg_request *srp;
2458 	unsigned long iflags;
2459 
2460 	read_lock_irqsave(&sfp->rq_list_lock, iflags);
2461 	for (srp = sfp->headrp; srp; srp = srp->nextrp)
2462 		if (srp->res_used)
2463 			break;
2464 	read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2465 	return srp ? 1 : 0;
2466 }
2467 
2468 /* If retSzp==NULL want exact size or fail */
2469 static struct page *
2470 sg_page_malloc(int rqSz, int lowDma, int *retSzp)
2471 {
2472 	struct page *resp = NULL;
2473 	gfp_t page_mask;
2474 	int order, a_size;
2475 	int resSz = rqSz;
2476 
2477 	if (rqSz <= 0)
2478 		return resp;
2479 
2480 	if (lowDma)
2481 		page_mask = GFP_ATOMIC | GFP_DMA | __GFP_NOWARN;
2482 	else
2483 		page_mask = GFP_ATOMIC | __GFP_NOWARN;
2484 
2485 	for (order = 0, a_size = PAGE_SIZE; a_size < rqSz;
2486 	     order++, a_size <<= 1) ;
2487 	resp = alloc_pages(page_mask, order);
2488 	while ((!resp) && order && retSzp) {
2489 		--order;
2490 		a_size >>= 1;	/* divide by 2, until PAGE_SIZE */
2491 		resp =  alloc_pages(page_mask, order);	/* try half */
2492 		resSz = a_size;
2493 	}
2494 	if (resp) {
2495 		if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2496 			memset(page_address(resp), 0, resSz);
2497 		if (retSzp)
2498 			*retSzp = resSz;
2499 	}
2500 	return resp;
2501 }
2502 
2503 static void
2504 sg_page_free(struct page *page, int size)
2505 {
2506 	int order, a_size;
2507 
2508 	if (!page)
2509 		return;
2510 	for (order = 0, a_size = PAGE_SIZE; a_size < size;
2511 	     order++, a_size <<= 1) ;
2512 	__free_pages(page, order);
2513 }
2514 
2515 #ifndef MAINTENANCE_IN_CMD
2516 #define MAINTENANCE_IN_CMD 0xa3
2517 #endif
2518 
2519 static unsigned char allow_ops[] = { TEST_UNIT_READY, REQUEST_SENSE,
2520 	INQUIRY, READ_CAPACITY, READ_BUFFER, READ_6, READ_10, READ_12,
2521 	READ_16, MODE_SENSE, MODE_SENSE_10, LOG_SENSE, REPORT_LUNS,
2522 	SERVICE_ACTION_IN, RECEIVE_DIAGNOSTIC, READ_LONG, MAINTENANCE_IN_CMD
2523 };
2524 
2525 static int
2526 sg_allow_access(unsigned char opcode, char dev_type)
2527 {
2528 	int k;
2529 
2530 	if (TYPE_SCANNER == dev_type)	/* TYPE_ROM maybe burner */
2531 		return 1;
2532 	for (k = 0; k < sizeof (allow_ops); ++k) {
2533 		if (opcode == allow_ops[k])
2534 			return 1;
2535 	}
2536 	return 0;
2537 }
2538 
2539 #ifdef CONFIG_SCSI_PROC_FS
2540 static int
2541 sg_last_dev(void)
2542 {
2543 	int k;
2544 	unsigned long iflags;
2545 
2546 	read_lock_irqsave(&sg_dev_arr_lock, iflags);
2547 	for (k = sg_dev_max - 1; k >= 0; --k)
2548 		if (sg_dev_arr[k] && sg_dev_arr[k]->device)
2549 			break;
2550 	read_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2551 	return k + 1;		/* origin 1 */
2552 }
2553 #endif
2554 
2555 static Sg_device *
2556 sg_get_dev(int dev)
2557 {
2558 	Sg_device *sdp = NULL;
2559 	unsigned long iflags;
2560 
2561 	if (sg_dev_arr && (dev >= 0)) {
2562 		read_lock_irqsave(&sg_dev_arr_lock, iflags);
2563 		if (dev < sg_dev_max)
2564 			sdp = sg_dev_arr[dev];
2565 		read_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2566 	}
2567 	return sdp;
2568 }
2569 
2570 #ifdef CONFIG_SCSI_PROC_FS
2571 
2572 static struct proc_dir_entry *sg_proc_sgp = NULL;
2573 
2574 static char sg_proc_sg_dirname[] = "scsi/sg";
2575 
2576 static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2577 
2578 static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2579 static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2580 			          size_t count, loff_t *off);
2581 static struct file_operations adio_fops = {
2582 	/* .owner, .read and .llseek added in sg_proc_init() */
2583 	.open = sg_proc_single_open_adio,
2584 	.write = sg_proc_write_adio,
2585 	.release = single_release,
2586 };
2587 
2588 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2589 static ssize_t sg_proc_write_dressz(struct file *filp,
2590 		const char __user *buffer, size_t count, loff_t *off);
2591 static struct file_operations dressz_fops = {
2592 	.open = sg_proc_single_open_dressz,
2593 	.write = sg_proc_write_dressz,
2594 	.release = single_release,
2595 };
2596 
2597 static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2598 static int sg_proc_single_open_version(struct inode *inode, struct file *file);
2599 static struct file_operations version_fops = {
2600 	.open = sg_proc_single_open_version,
2601 	.release = single_release,
2602 };
2603 
2604 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2605 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file);
2606 static struct file_operations devhdr_fops = {
2607 	.open = sg_proc_single_open_devhdr,
2608 	.release = single_release,
2609 };
2610 
2611 static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2612 static int sg_proc_open_dev(struct inode *inode, struct file *file);
2613 static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2614 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2615 static void dev_seq_stop(struct seq_file *s, void *v);
2616 static struct file_operations dev_fops = {
2617 	.open = sg_proc_open_dev,
2618 	.release = seq_release,
2619 };
2620 static struct seq_operations dev_seq_ops = {
2621 	.start = dev_seq_start,
2622 	.next  = dev_seq_next,
2623 	.stop  = dev_seq_stop,
2624 	.show  = sg_proc_seq_show_dev,
2625 };
2626 
2627 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2628 static int sg_proc_open_devstrs(struct inode *inode, struct file *file);
2629 static struct file_operations devstrs_fops = {
2630 	.open = sg_proc_open_devstrs,
2631 	.release = seq_release,
2632 };
2633 static struct seq_operations devstrs_seq_ops = {
2634 	.start = dev_seq_start,
2635 	.next  = dev_seq_next,
2636 	.stop  = dev_seq_stop,
2637 	.show  = sg_proc_seq_show_devstrs,
2638 };
2639 
2640 static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2641 static int sg_proc_open_debug(struct inode *inode, struct file *file);
2642 static struct file_operations debug_fops = {
2643 	.open = sg_proc_open_debug,
2644 	.release = seq_release,
2645 };
2646 static struct seq_operations debug_seq_ops = {
2647 	.start = dev_seq_start,
2648 	.next  = dev_seq_next,
2649 	.stop  = dev_seq_stop,
2650 	.show  = sg_proc_seq_show_debug,
2651 };
2652 
2653 
2654 struct sg_proc_leaf {
2655 	const char * name;
2656 	struct file_operations * fops;
2657 };
2658 
2659 static struct sg_proc_leaf sg_proc_leaf_arr[] = {
2660 	{"allow_dio", &adio_fops},
2661 	{"debug", &debug_fops},
2662 	{"def_reserved_size", &dressz_fops},
2663 	{"device_hdr", &devhdr_fops},
2664 	{"devices", &dev_fops},
2665 	{"device_strs", &devstrs_fops},
2666 	{"version", &version_fops}
2667 };
2668 
2669 static int
2670 sg_proc_init(void)
2671 {
2672 	int k, mask;
2673 	int num_leaves =
2674 	    sizeof (sg_proc_leaf_arr) / sizeof (sg_proc_leaf_arr[0]);
2675 	struct proc_dir_entry *pdep;
2676 	struct sg_proc_leaf * leaf;
2677 
2678 	sg_proc_sgp = proc_mkdir(sg_proc_sg_dirname, NULL);
2679 	if (!sg_proc_sgp)
2680 		return 1;
2681 	for (k = 0; k < num_leaves; ++k) {
2682 		leaf = &sg_proc_leaf_arr[k];
2683 		mask = leaf->fops->write ? S_IRUGO | S_IWUSR : S_IRUGO;
2684 		pdep = create_proc_entry(leaf->name, mask, sg_proc_sgp);
2685 		if (pdep) {
2686 			leaf->fops->owner = THIS_MODULE,
2687 			leaf->fops->read = seq_read,
2688 			leaf->fops->llseek = seq_lseek,
2689 			pdep->proc_fops = leaf->fops;
2690 		}
2691 	}
2692 	return 0;
2693 }
2694 
2695 static void
2696 sg_proc_cleanup(void)
2697 {
2698 	int k;
2699 	int num_leaves =
2700 	    sizeof (sg_proc_leaf_arr) / sizeof (sg_proc_leaf_arr[0]);
2701 
2702 	if (!sg_proc_sgp)
2703 		return;
2704 	for (k = 0; k < num_leaves; ++k)
2705 		remove_proc_entry(sg_proc_leaf_arr[k].name, sg_proc_sgp);
2706 	remove_proc_entry(sg_proc_sg_dirname, NULL);
2707 }
2708 
2709 
2710 static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2711 {
2712 	seq_printf(s, "%d\n", *((int *)s->private));
2713 	return 0;
2714 }
2715 
2716 static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2717 {
2718 	return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2719 }
2720 
2721 static ssize_t
2722 sg_proc_write_adio(struct file *filp, const char __user *buffer,
2723 		   size_t count, loff_t *off)
2724 {
2725 	int num;
2726 	char buff[11];
2727 
2728 	if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2729 		return -EACCES;
2730 	num = (count < 10) ? count : 10;
2731 	if (copy_from_user(buff, buffer, num))
2732 		return -EFAULT;
2733 	buff[num] = '\0';
2734 	sg_allow_dio = simple_strtoul(buff, NULL, 10) ? 1 : 0;
2735 	return count;
2736 }
2737 
2738 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2739 {
2740 	return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2741 }
2742 
2743 static ssize_t
2744 sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2745 		     size_t count, loff_t *off)
2746 {
2747 	int num;
2748 	unsigned long k = ULONG_MAX;
2749 	char buff[11];
2750 
2751 	if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2752 		return -EACCES;
2753 	num = (count < 10) ? count : 10;
2754 	if (copy_from_user(buff, buffer, num))
2755 		return -EFAULT;
2756 	buff[num] = '\0';
2757 	k = simple_strtoul(buff, NULL, 10);
2758 	if (k <= 1048576) {	/* limit "big buff" to 1 MB */
2759 		sg_big_buff = k;
2760 		return count;
2761 	}
2762 	return -ERANGE;
2763 }
2764 
2765 static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2766 {
2767 	seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2768 		   sg_version_date);
2769 	return 0;
2770 }
2771 
2772 static int sg_proc_single_open_version(struct inode *inode, struct file *file)
2773 {
2774 	return single_open(file, sg_proc_seq_show_version, NULL);
2775 }
2776 
2777 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2778 {
2779 	seq_printf(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\t"
2780 		   "online\n");
2781 	return 0;
2782 }
2783 
2784 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file)
2785 {
2786 	return single_open(file, sg_proc_seq_show_devhdr, NULL);
2787 }
2788 
2789 struct sg_proc_deviter {
2790 	loff_t	index;
2791 	size_t	max;
2792 };
2793 
2794 static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2795 {
2796 	struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2797 
2798 	s->private = it;
2799 	if (! it)
2800 		return NULL;
2801 
2802 	if (NULL == sg_dev_arr)
2803 		return NULL;
2804 	it->index = *pos;
2805 	it->max = sg_last_dev();
2806 	if (it->index >= it->max)
2807 		return NULL;
2808 	return it;
2809 }
2810 
2811 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2812 {
2813 	struct sg_proc_deviter * it = s->private;
2814 
2815 	*pos = ++it->index;
2816 	return (it->index < it->max) ? it : NULL;
2817 }
2818 
2819 static void dev_seq_stop(struct seq_file *s, void *v)
2820 {
2821 	kfree(s->private);
2822 }
2823 
2824 static int sg_proc_open_dev(struct inode *inode, struct file *file)
2825 {
2826         return seq_open(file, &dev_seq_ops);
2827 }
2828 
2829 static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2830 {
2831 	struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2832 	Sg_device *sdp;
2833 	struct scsi_device *scsidp;
2834 
2835 	sdp = it ? sg_get_dev(it->index) : NULL;
2836 	if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2837 		seq_printf(s, "%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\n",
2838 			      scsidp->host->host_no, scsidp->channel,
2839 			      scsidp->id, scsidp->lun, (int) scsidp->type,
2840 			      1,
2841 			      (int) scsidp->queue_depth,
2842 			      (int) scsidp->device_busy,
2843 			      (int) scsi_device_online(scsidp));
2844 	else
2845 		seq_printf(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2846 	return 0;
2847 }
2848 
2849 static int sg_proc_open_devstrs(struct inode *inode, struct file *file)
2850 {
2851         return seq_open(file, &devstrs_seq_ops);
2852 }
2853 
2854 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2855 {
2856 	struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2857 	Sg_device *sdp;
2858 	struct scsi_device *scsidp;
2859 
2860 	sdp = it ? sg_get_dev(it->index) : NULL;
2861 	if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2862 		seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2863 			   scsidp->vendor, scsidp->model, scsidp->rev);
2864 	else
2865 		seq_printf(s, "<no active device>\n");
2866 	return 0;
2867 }
2868 
2869 static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2870 {
2871 	int k, m, new_interface, blen, usg;
2872 	Sg_request *srp;
2873 	Sg_fd *fp;
2874 	const sg_io_hdr_t *hp;
2875 	const char * cp;
2876 	unsigned int ms;
2877 
2878 	for (k = 0; (fp = sg_get_nth_sfp(sdp, k)); ++k) {
2879 		seq_printf(s, "   FD(%d): timeout=%dms bufflen=%d "
2880 			   "(res)sgat=%d low_dma=%d\n", k + 1,
2881 			   jiffies_to_msecs(fp->timeout),
2882 			   fp->reserve.bufflen,
2883 			   (int) fp->reserve.k_use_sg,
2884 			   (int) fp->low_dma);
2885 		seq_printf(s, "   cmd_q=%d f_packid=%d k_orphan=%d closed=%d\n",
2886 			   (int) fp->cmd_q, (int) fp->force_packid,
2887 			   (int) fp->keep_orphan, (int) fp->closed);
2888 		for (m = 0; (srp = sg_get_nth_request(fp, m)); ++m) {
2889 			hp = &srp->header;
2890 			new_interface = (hp->interface_id == '\0') ? 0 : 1;
2891 			if (srp->res_used) {
2892 				if (new_interface &&
2893 				    (SG_FLAG_MMAP_IO & hp->flags))
2894 					cp = "     mmap>> ";
2895 				else
2896 					cp = "     rb>> ";
2897 			} else {
2898 				if (SG_INFO_DIRECT_IO_MASK & hp->info)
2899 					cp = "     dio>> ";
2900 				else
2901 					cp = "     ";
2902 			}
2903 			seq_printf(s, cp);
2904 			blen = srp->data.bufflen;
2905 			usg = srp->data.k_use_sg;
2906 			seq_printf(s, srp->done ?
2907 				   ((1 == srp->done) ?  "rcv:" : "fin:")
2908 				   : "act:");
2909 			seq_printf(s, " id=%d blen=%d",
2910 				   srp->header.pack_id, blen);
2911 			if (srp->done)
2912 				seq_printf(s, " dur=%d", hp->duration);
2913 			else {
2914 				ms = jiffies_to_msecs(jiffies);
2915 				seq_printf(s, " t_o/elap=%d/%d",
2916 					(new_interface ? hp->timeout :
2917 						  jiffies_to_msecs(fp->timeout)),
2918 					(ms > hp->duration ? ms - hp->duration : 0));
2919 			}
2920 			seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2921 				   (int) srp->data.cmd_opcode);
2922 		}
2923 		if (0 == m)
2924 			seq_printf(s, "     No requests active\n");
2925 	}
2926 }
2927 
2928 static int sg_proc_open_debug(struct inode *inode, struct file *file)
2929 {
2930         return seq_open(file, &debug_seq_ops);
2931 }
2932 
2933 static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2934 {
2935 	struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2936 	Sg_device *sdp;
2937 
2938 	if (it && (0 == it->index)) {
2939 		seq_printf(s, "dev_max(currently)=%d max_active_device=%d "
2940 			   "(origin 1)\n", sg_dev_max, (int)it->max);
2941 		seq_printf(s, " def_reserved_size=%d\n", sg_big_buff);
2942 	}
2943 	sdp = it ? sg_get_dev(it->index) : NULL;
2944 	if (sdp) {
2945 		struct scsi_device *scsidp = sdp->device;
2946 
2947 		if (NULL == scsidp) {
2948 			seq_printf(s, "device %d detached ??\n",
2949 				   (int)it->index);
2950 			return 0;
2951 		}
2952 
2953 		if (sg_get_nth_sfp(sdp, 0)) {
2954 			seq_printf(s, " >>> device=%s ",
2955 				sdp->disk->disk_name);
2956 			if (sdp->detached)
2957 				seq_printf(s, "detached pending close ");
2958 			else
2959 				seq_printf
2960 				    (s, "scsi%d chan=%d id=%d lun=%d   em=%d",
2961 				     scsidp->host->host_no,
2962 				     scsidp->channel, scsidp->id,
2963 				     scsidp->lun,
2964 				     scsidp->host->hostt->emulated);
2965 			seq_printf(s, " sg_tablesize=%d excl=%d\n",
2966 				   sdp->sg_tablesize, sdp->exclude);
2967 		}
2968 		sg_proc_debug_helper(s, sdp);
2969 	}
2970 	return 0;
2971 }
2972 
2973 #endif				/* CONFIG_SCSI_PROC_FS */
2974 
2975 module_init(init_sg);
2976 module_exit(exit_sg);
2977 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
2978