xref: /linux/drivers/scsi/sg.c (revision 60b2737de1b1ddfdb90f3ba622634eb49d6f3603)
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 
53 #include "scsi.h"
54 #include <scsi/scsi_dbg.h>
55 #include <scsi/scsi_host.h>
56 #include <scsi/scsi_driver.h>
57 #include <scsi/scsi_ioctl.h>
58 #include <scsi/sg.h>
59 
60 #include "scsi_logging.h"
61 
62 #ifdef CONFIG_SCSI_PROC_FS
63 #include <linux/proc_fs.h>
64 static char *sg_version_date = "20050328";
65 
66 static int sg_proc_init(void);
67 static void sg_proc_cleanup(void);
68 #endif
69 
70 #ifndef LINUX_VERSION_CODE
71 #include <linux/version.h>
72 #endif				/* LINUX_VERSION_CODE */
73 
74 #define SG_ALLOW_DIO_DEF 0
75 #define SG_ALLOW_DIO_CODE /* compile out by commenting this define */
76 
77 #define SG_MAX_DEVS 32768
78 
79 /*
80  * Suppose you want to calculate the formula muldiv(x,m,d)=int(x * m / d)
81  * Then when using 32 bit integers x * m may overflow during the calculation.
82  * Replacing muldiv(x) by muldiv(x)=((x % d) * m) / d + int(x / d) * m
83  * calculates the same, but prevents the overflow when both m and d
84  * are "small" numbers (like HZ and USER_HZ).
85  * Of course an overflow is inavoidable if the result of muldiv doesn't fit
86  * in 32 bits.
87  */
88 #define MULDIV(X,MUL,DIV) ((((X % DIV) * MUL) / DIV) + ((X / DIV) * MUL))
89 
90 #define SG_DEFAULT_TIMEOUT MULDIV(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
91 
92 int sg_big_buff = SG_DEF_RESERVED_SIZE;
93 /* N.B. This variable is readable and writeable via
94    /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
95    of this size (or less if there is not enough memory) will be reserved
96    for use by this file descriptor. [Deprecated usage: this variable is also
97    readable via /proc/sys/kernel/sg-big-buff if the sg driver is built into
98    the kernel (i.e. it is not a module).] */
99 static int def_reserved_size = -1;	/* picks up init parameter */
100 static int sg_allow_dio = SG_ALLOW_DIO_DEF;
101 
102 #define SG_SECTOR_SZ 512
103 #define SG_SECTOR_MSK (SG_SECTOR_SZ - 1)
104 
105 #define SG_DEV_ARR_LUMP 32	/* amount to over allocate sg_dev_arr by */
106 
107 static int sg_add(struct class_device *);
108 static void sg_remove(struct class_device *);
109 
110 static Scsi_Request *dummy_cmdp;	/* only used for sizeof */
111 
112 static DEFINE_RWLOCK(sg_dev_arr_lock);	/* Also used to lock
113 							   file descriptor list for device */
114 
115 static struct class_interface sg_interface = {
116 	.add		= sg_add,
117 	.remove		= sg_remove,
118 };
119 
120 typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
121 	unsigned short k_use_sg; /* Count of kernel scatter-gather pieces */
122 	unsigned short sglist_len; /* size of malloc'd scatter-gather list ++ */
123 	unsigned bufflen;	/* Size of (aggregate) data buffer */
124 	unsigned b_malloc_len;	/* actual len malloc'ed in buffer */
125 	void *buffer;		/* Data buffer or scatter list (k_use_sg>0) */
126 	char dio_in_use;	/* 0->indirect IO (or mmap), 1->dio */
127 	unsigned char cmd_opcode; /* first byte of command */
128 } Sg_scatter_hold;
129 
130 struct sg_device;		/* forward declarations */
131 struct sg_fd;
132 
133 typedef struct sg_request {	/* SG_MAX_QUEUE requests outstanding per file */
134 	Scsi_Request *my_cmdp;	/* != 0  when request with lower levels */
135 	struct sg_request *nextrp;	/* NULL -> tail request (slist) */
136 	struct sg_fd *parentfp;	/* NULL -> not in use */
137 	Sg_scatter_hold data;	/* hold buffer, perhaps scatter list */
138 	sg_io_hdr_t header;	/* scsi command+info, see <scsi/sg.h> */
139 	unsigned char sense_b[sizeof (dummy_cmdp->sr_sense_buffer)];
140 	char res_used;		/* 1 -> using reserve buffer, 0 -> not ... */
141 	char orphan;		/* 1 -> drop on sight, 0 -> normal */
142 	char sg_io_owned;	/* 1 -> packet belongs to SG_IO */
143 	volatile char done;	/* 0->before bh, 1->before read, 2->read */
144 } Sg_request;
145 
146 typedef struct sg_fd {		/* holds the state of a file descriptor */
147 	struct sg_fd *nextfp;	/* NULL when last opened fd on this device */
148 	struct sg_device *parentdp;	/* owning device */
149 	wait_queue_head_t read_wait;	/* queue read until command done */
150 	rwlock_t rq_list_lock;	/* protect access to list in req_arr */
151 	int timeout;		/* defaults to SG_DEFAULT_TIMEOUT      */
152 	int timeout_user;	/* defaults to SG_DEFAULT_TIMEOUT_USER */
153 	Sg_scatter_hold reserve;	/* buffer held for this file descriptor */
154 	unsigned save_scat_len;	/* original length of trunc. scat. element */
155 	Sg_request *headrp;	/* head of request slist, NULL->empty */
156 	struct fasync_struct *async_qp;	/* used by asynchronous notification */
157 	Sg_request req_arr[SG_MAX_QUEUE];	/* used as singly-linked list */
158 	char low_dma;		/* as in parent but possibly overridden to 1 */
159 	char force_packid;	/* 1 -> pack_id input to read(), 0 -> ignored */
160 	volatile char closed;	/* 1 -> fd closed but request(s) outstanding */
161 	char cmd_q;		/* 1 -> allow command queuing, 0 -> don't */
162 	char next_cmd_len;	/* 0 -> automatic (def), >0 -> use on next write() */
163 	char keep_orphan;	/* 0 -> drop orphan (def), 1 -> keep for read() */
164 	char mmap_called;	/* 0 -> mmap() never called on this fd */
165 } Sg_fd;
166 
167 typedef struct sg_device { /* holds the state of each scsi generic device */
168 	struct scsi_device *device;
169 	wait_queue_head_t o_excl_wait;	/* queue open() when O_EXCL in use */
170 	int sg_tablesize;	/* adapter's max scatter-gather table size */
171 	Sg_fd *headfp;		/* first open fd belonging to this device */
172 	volatile char detached;	/* 0->attached, 1->detached pending removal */
173 	volatile char exclude;	/* opened for exclusive access */
174 	char sgdebug;		/* 0->off, 1->sense, 9->dump dev, 10-> all devs */
175 	struct gendisk *disk;
176 	struct cdev * cdev;	/* char_dev [sysfs: /sys/cdev/major/sg<n>] */
177 } Sg_device;
178 
179 static int sg_fasync(int fd, struct file *filp, int mode);
180 static void sg_cmd_done(Scsi_Cmnd * SCpnt);	/* tasklet or soft irq callback */
181 static int sg_start_req(Sg_request * srp);
182 static void sg_finish_rem_req(Sg_request * srp);
183 static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
184 static int sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp,
185 			 int tablesize);
186 static ssize_t sg_new_read(Sg_fd * sfp, char __user *buf, size_t count,
187 			   Sg_request * srp);
188 static ssize_t sg_new_write(Sg_fd * sfp, const char __user *buf, size_t count,
189 			    int blocking, int read_only, Sg_request ** o_srp);
190 static int sg_common_write(Sg_fd * sfp, Sg_request * srp,
191 			   unsigned char *cmnd, int timeout, int blocking);
192 static int sg_u_iovec(sg_io_hdr_t * hp, int sg_num, int ind,
193 		      int wr_xf, int *countp, unsigned char __user **up);
194 static int sg_write_xfer(Sg_request * srp);
195 static int sg_read_xfer(Sg_request * srp);
196 static int sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer);
197 static void sg_remove_scat(Sg_scatter_hold * schp);
198 static void sg_build_reserve(Sg_fd * sfp, int req_size);
199 static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
200 static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
201 static char *sg_page_malloc(int rqSz, int lowDma, int *retSzp);
202 static void sg_page_free(char *buff, int size);
203 static Sg_fd *sg_add_sfp(Sg_device * sdp, int dev);
204 static int sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp);
205 static void __sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp);
206 static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id);
207 static Sg_request *sg_add_request(Sg_fd * sfp);
208 static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
209 static int sg_res_in_use(Sg_fd * sfp);
210 static int sg_allow_access(unsigned char opcode, char dev_type);
211 static int sg_build_direct(Sg_request * srp, Sg_fd * sfp, int dxfer_len);
212 static Sg_device *sg_get_dev(int dev);
213 static inline unsigned char *sg_scatg2virt(const struct scatterlist *sclp);
214 #ifdef CONFIG_SCSI_PROC_FS
215 static int sg_last_dev(void);
216 #endif
217 
218 static Sg_device **sg_dev_arr = NULL;
219 static int sg_dev_max;
220 static int sg_nr_dev;
221 
222 #define SZ_SG_HEADER sizeof(struct sg_header)
223 #define SZ_SG_IO_HDR sizeof(sg_io_hdr_t)
224 #define SZ_SG_IOVEC sizeof(sg_iovec_t)
225 #define SZ_SG_REQ_INFO sizeof(sg_req_info_t)
226 
227 static int
228 sg_open(struct inode *inode, struct file *filp)
229 {
230 	int dev = iminor(inode);
231 	int flags = filp->f_flags;
232 	Sg_device *sdp;
233 	Sg_fd *sfp;
234 	int res;
235 	int retval;
236 
237 	nonseekable_open(inode, filp);
238 	SCSI_LOG_TIMEOUT(3, printk("sg_open: dev=%d, flags=0x%x\n", dev, flags));
239 	sdp = sg_get_dev(dev);
240 	if ((!sdp) || (!sdp->device))
241 		return -ENXIO;
242 	if (sdp->detached)
243 		return -ENODEV;
244 
245 	/* This driver's module count bumped by fops_get in <linux/fs.h> */
246 	/* Prevent the device driver from vanishing while we sleep */
247 	retval = scsi_device_get(sdp->device);
248 	if (retval)
249 		return retval;
250 
251 	if (!((flags & O_NONBLOCK) ||
252 	      scsi_block_when_processing_errors(sdp->device))) {
253 		retval = -ENXIO;
254 		/* we are in error recovery for this device */
255 		goto error_out;
256 	}
257 
258 	if (flags & O_EXCL) {
259 		if (O_RDONLY == (flags & O_ACCMODE)) {
260 			retval = -EPERM; /* Can't lock it with read only access */
261 			goto error_out;
262 		}
263 		if (sdp->headfp && (flags & O_NONBLOCK)) {
264 			retval = -EBUSY;
265 			goto error_out;
266 		}
267 		res = 0;
268 		__wait_event_interruptible(sdp->o_excl_wait,
269 			((sdp->headfp || sdp->exclude) ? 0 : (sdp->exclude = 1)), res);
270 		if (res) {
271 			retval = res;	/* -ERESTARTSYS because signal hit process */
272 			goto error_out;
273 		}
274 	} else if (sdp->exclude) {	/* some other fd has an exclusive lock on dev */
275 		if (flags & O_NONBLOCK) {
276 			retval = -EBUSY;
277 			goto error_out;
278 		}
279 		res = 0;
280 		__wait_event_interruptible(sdp->o_excl_wait, (!sdp->exclude),
281 					   res);
282 		if (res) {
283 			retval = res;	/* -ERESTARTSYS because signal hit process */
284 			goto error_out;
285 		}
286 	}
287 	if (sdp->detached) {
288 		retval = -ENODEV;
289 		goto error_out;
290 	}
291 	if (!sdp->headfp) {	/* no existing opens on this device */
292 		sdp->sgdebug = 0;
293 		sdp->sg_tablesize = sdp->device->host->sg_tablesize;
294 	}
295 	if ((sfp = sg_add_sfp(sdp, dev)))
296 		filp->private_data = sfp;
297 	else {
298 		if (flags & O_EXCL)
299 			sdp->exclude = 0;	/* undo if error */
300 		retval = -ENOMEM;
301 		goto error_out;
302 	}
303 	return 0;
304 
305       error_out:
306 	scsi_device_put(sdp->device);
307 	return retval;
308 }
309 
310 /* Following function was formerly called 'sg_close' */
311 static int
312 sg_release(struct inode *inode, struct file *filp)
313 {
314 	Sg_device *sdp;
315 	Sg_fd *sfp;
316 
317 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
318 		return -ENXIO;
319 	SCSI_LOG_TIMEOUT(3, printk("sg_release: %s\n", sdp->disk->disk_name));
320 	sg_fasync(-1, filp, 0);	/* remove filp from async notification list */
321 	if (0 == sg_remove_sfp(sdp, sfp)) {	/* Returns 1 when sdp gone */
322 		if (!sdp->detached) {
323 			scsi_device_put(sdp->device);
324 		}
325 		sdp->exclude = 0;
326 		wake_up_interruptible(&sdp->o_excl_wait);
327 	}
328 	return 0;
329 }
330 
331 static ssize_t
332 sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
333 {
334 	Sg_device *sdp;
335 	Sg_fd *sfp;
336 	Sg_request *srp;
337 	int req_pack_id = -1;
338 	sg_io_hdr_t *hp;
339 	struct sg_header *old_hdr = NULL;
340 	int retval = 0;
341 
342 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
343 		return -ENXIO;
344 	SCSI_LOG_TIMEOUT(3, printk("sg_read: %s, count=%d\n",
345 				   sdp->disk->disk_name, (int) count));
346 	if (!access_ok(VERIFY_WRITE, buf, count))
347 		return -EFAULT;
348 	if (sfp->force_packid && (count >= SZ_SG_HEADER)) {
349 		old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
350 		if (!old_hdr)
351 			return -ENOMEM;
352 		if (__copy_from_user(old_hdr, buf, SZ_SG_HEADER)) {
353 			retval = -EFAULT;
354 			goto free_old_hdr;
355 		}
356 		if (old_hdr->reply_len < 0) {
357 			if (count >= SZ_SG_IO_HDR) {
358 				sg_io_hdr_t *new_hdr;
359 				new_hdr = kmalloc(SZ_SG_IO_HDR, GFP_KERNEL);
360 				if (!new_hdr) {
361 					retval = -ENOMEM;
362 					goto free_old_hdr;
363 				}
364 				retval =__copy_from_user
365 				    (new_hdr, buf, SZ_SG_IO_HDR);
366 				req_pack_id = new_hdr->pack_id;
367 				kfree(new_hdr);
368 				if (retval) {
369 					retval = -EFAULT;
370 					goto free_old_hdr;
371 				}
372 			}
373 		} else
374 			req_pack_id = old_hdr->pack_id;
375 	}
376 	srp = sg_get_rq_mark(sfp, req_pack_id);
377 	if (!srp) {		/* now wait on packet to arrive */
378 		if (sdp->detached) {
379 			retval = -ENODEV;
380 			goto free_old_hdr;
381 		}
382 		if (filp->f_flags & O_NONBLOCK) {
383 			retval = -EAGAIN;
384 			goto free_old_hdr;
385 		}
386 		while (1) {
387 			retval = 0; /* following macro beats race condition */
388 			__wait_event_interruptible(sfp->read_wait,
389 				(sdp->detached ||
390 				(srp = sg_get_rq_mark(sfp, req_pack_id))),
391 				retval);
392 			if (sdp->detached) {
393 				retval = -ENODEV;
394 				goto free_old_hdr;
395 			}
396 			if (0 == retval)
397 				break;
398 
399 			/* -ERESTARTSYS as signal hit process */
400 			goto free_old_hdr;
401 		}
402 	}
403 	if (srp->header.interface_id != '\0') {
404 		retval = sg_new_read(sfp, buf, count, srp);
405 		goto free_old_hdr;
406 	}
407 
408 	hp = &srp->header;
409 	if (old_hdr == NULL) {
410 		old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
411 		if (! old_hdr) {
412 			retval = -ENOMEM;
413 			goto free_old_hdr;
414 		}
415 	}
416 	memset(old_hdr, 0, SZ_SG_HEADER);
417 	old_hdr->reply_len = (int) hp->timeout;
418 	old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
419 	old_hdr->pack_id = hp->pack_id;
420 	old_hdr->twelve_byte =
421 	    ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
422 	old_hdr->target_status = hp->masked_status;
423 	old_hdr->host_status = hp->host_status;
424 	old_hdr->driver_status = hp->driver_status;
425 	if ((CHECK_CONDITION & hp->masked_status) ||
426 	    (DRIVER_SENSE & hp->driver_status))
427 		memcpy(old_hdr->sense_buffer, srp->sense_b,
428 		       sizeof (old_hdr->sense_buffer));
429 	switch (hp->host_status) {
430 	/* This setup of 'result' is for backward compatibility and is best
431 	   ignored by the user who should use target, host + driver status */
432 	case DID_OK:
433 	case DID_PASSTHROUGH:
434 	case DID_SOFT_ERROR:
435 		old_hdr->result = 0;
436 		break;
437 	case DID_NO_CONNECT:
438 	case DID_BUS_BUSY:
439 	case DID_TIME_OUT:
440 		old_hdr->result = EBUSY;
441 		break;
442 	case DID_BAD_TARGET:
443 	case DID_ABORT:
444 	case DID_PARITY:
445 	case DID_RESET:
446 	case DID_BAD_INTR:
447 		old_hdr->result = EIO;
448 		break;
449 	case DID_ERROR:
450 		old_hdr->result = (srp->sense_b[0] == 0 &&
451 				  hp->masked_status == GOOD) ? 0 : EIO;
452 		break;
453 	default:
454 		old_hdr->result = EIO;
455 		break;
456 	}
457 
458 	/* Now copy the result back to the user buffer.  */
459 	if (count >= SZ_SG_HEADER) {
460 		if (__copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
461 			retval = -EFAULT;
462 			goto free_old_hdr;
463 		}
464 		buf += SZ_SG_HEADER;
465 		if (count > old_hdr->reply_len)
466 			count = old_hdr->reply_len;
467 		if (count > SZ_SG_HEADER) {
468 			if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
469 				retval = -EFAULT;
470 				goto free_old_hdr;
471 			}
472 		}
473 	} else
474 		count = (old_hdr->result == 0) ? 0 : -EIO;
475 	sg_finish_rem_req(srp);
476 	retval = count;
477 free_old_hdr:
478 	if (old_hdr)
479 		kfree(old_hdr);
480 	return retval;
481 }
482 
483 static ssize_t
484 sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
485 {
486 	sg_io_hdr_t *hp = &srp->header;
487 	int err = 0;
488 	int len;
489 
490 	if (count < SZ_SG_IO_HDR) {
491 		err = -EINVAL;
492 		goto err_out;
493 	}
494 	hp->sb_len_wr = 0;
495 	if ((hp->mx_sb_len > 0) && hp->sbp) {
496 		if ((CHECK_CONDITION & hp->masked_status) ||
497 		    (DRIVER_SENSE & hp->driver_status)) {
498 			int sb_len = sizeof (dummy_cmdp->sr_sense_buffer);
499 			sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
500 			len = 8 + (int) srp->sense_b[7];	/* Additional sense length field */
501 			len = (len > sb_len) ? sb_len : len;
502 			if (copy_to_user(hp->sbp, srp->sense_b, len)) {
503 				err = -EFAULT;
504 				goto err_out;
505 			}
506 			hp->sb_len_wr = len;
507 		}
508 	}
509 	if (hp->masked_status || hp->host_status || hp->driver_status)
510 		hp->info |= SG_INFO_CHECK;
511 	if (copy_to_user(buf, hp, SZ_SG_IO_HDR)) {
512 		err = -EFAULT;
513 		goto err_out;
514 	}
515 	err = sg_read_xfer(srp);
516       err_out:
517 	sg_finish_rem_req(srp);
518 	return (0 == err) ? count : err;
519 }
520 
521 static ssize_t
522 sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
523 {
524 	int mxsize, cmd_size, k;
525 	int input_size, blocking;
526 	unsigned char opcode;
527 	Sg_device *sdp;
528 	Sg_fd *sfp;
529 	Sg_request *srp;
530 	struct sg_header old_hdr;
531 	sg_io_hdr_t *hp;
532 	unsigned char cmnd[sizeof (dummy_cmdp->sr_cmnd)];
533 
534 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
535 		return -ENXIO;
536 	SCSI_LOG_TIMEOUT(3, printk("sg_write: %s, count=%d\n",
537 				   sdp->disk->disk_name, (int) count));
538 	if (sdp->detached)
539 		return -ENODEV;
540 	if (!((filp->f_flags & O_NONBLOCK) ||
541 	      scsi_block_when_processing_errors(sdp->device)))
542 		return -ENXIO;
543 
544 	if (!access_ok(VERIFY_READ, buf, count))
545 		return -EFAULT;	/* protects following copy_from_user()s + get_user()s */
546 	if (count < SZ_SG_HEADER)
547 		return -EIO;
548 	if (__copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
549 		return -EFAULT;
550 	blocking = !(filp->f_flags & O_NONBLOCK);
551 	if (old_hdr.reply_len < 0)
552 		return sg_new_write(sfp, buf, count, blocking, 0, NULL);
553 	if (count < (SZ_SG_HEADER + 6))
554 		return -EIO;	/* The minimum scsi command length is 6 bytes. */
555 
556 	if (!(srp = sg_add_request(sfp))) {
557 		SCSI_LOG_TIMEOUT(1, printk("sg_write: queue full\n"));
558 		return -EDOM;
559 	}
560 	buf += SZ_SG_HEADER;
561 	__get_user(opcode, buf);
562 	if (sfp->next_cmd_len > 0) {
563 		if (sfp->next_cmd_len > MAX_COMMAND_SIZE) {
564 			SCSI_LOG_TIMEOUT(1, printk("sg_write: command length too long\n"));
565 			sfp->next_cmd_len = 0;
566 			sg_remove_request(sfp, srp);
567 			return -EIO;
568 		}
569 		cmd_size = sfp->next_cmd_len;
570 		sfp->next_cmd_len = 0;	/* reset so only this write() effected */
571 	} else {
572 		cmd_size = COMMAND_SIZE(opcode);	/* based on SCSI command group */
573 		if ((opcode >= 0xc0) && old_hdr.twelve_byte)
574 			cmd_size = 12;
575 	}
576 	SCSI_LOG_TIMEOUT(4, printk(
577 		"sg_write:   scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
578 /* Determine buffer size.  */
579 	input_size = count - cmd_size;
580 	mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
581 	mxsize -= SZ_SG_HEADER;
582 	input_size -= SZ_SG_HEADER;
583 	if (input_size < 0) {
584 		sg_remove_request(sfp, srp);
585 		return -EIO;	/* User did not pass enough bytes for this command. */
586 	}
587 	hp = &srp->header;
588 	hp->interface_id = '\0';	/* indicator of old interface tunnelled */
589 	hp->cmd_len = (unsigned char) cmd_size;
590 	hp->iovec_count = 0;
591 	hp->mx_sb_len = 0;
592 	if (input_size > 0)
593 		hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
594 		    SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
595 	else
596 		hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
597 	hp->dxfer_len = mxsize;
598 	hp->dxferp = (char __user *)buf + cmd_size;
599 	hp->sbp = NULL;
600 	hp->timeout = old_hdr.reply_len;	/* structure abuse ... */
601 	hp->flags = input_size;	/* structure abuse ... */
602 	hp->pack_id = old_hdr.pack_id;
603 	hp->usr_ptr = NULL;
604 	if (__copy_from_user(cmnd, buf, cmd_size))
605 		return -EFAULT;
606 	/*
607 	 * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
608 	 * but is is possible that the app intended SG_DXFER_TO_DEV, because there
609 	 * is a non-zero input_size, so emit a warning.
610 	 */
611 	if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV)
612 		if (printk_ratelimit())
613 			printk(KERN_WARNING
614 			       "sg_write: data in/out %d/%d bytes for SCSI command 0x%x--"
615 			       "guessing data in;\n" KERN_WARNING "   "
616 			       "program %s not setting count and/or reply_len properly\n",
617 			       old_hdr.reply_len - (int)SZ_SG_HEADER,
618 			       input_size, (unsigned int) cmnd[0],
619 			       current->comm);
620 	k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
621 	return (k < 0) ? k : count;
622 }
623 
624 static ssize_t
625 sg_new_write(Sg_fd * sfp, const char __user *buf, size_t count,
626 	     int blocking, int read_only, Sg_request ** o_srp)
627 {
628 	int k;
629 	Sg_request *srp;
630 	sg_io_hdr_t *hp;
631 	unsigned char cmnd[sizeof (dummy_cmdp->sr_cmnd)];
632 	int timeout;
633 	unsigned long ul_timeout;
634 
635 	if (count < SZ_SG_IO_HDR)
636 		return -EINVAL;
637 	if (!access_ok(VERIFY_READ, buf, count))
638 		return -EFAULT; /* protects following copy_from_user()s + get_user()s */
639 
640 	sfp->cmd_q = 1;	/* when sg_io_hdr seen, set command queuing on */
641 	if (!(srp = sg_add_request(sfp))) {
642 		SCSI_LOG_TIMEOUT(1, printk("sg_new_write: queue full\n"));
643 		return -EDOM;
644 	}
645 	hp = &srp->header;
646 	if (__copy_from_user(hp, buf, SZ_SG_IO_HDR)) {
647 		sg_remove_request(sfp, srp);
648 		return -EFAULT;
649 	}
650 	if (hp->interface_id != 'S') {
651 		sg_remove_request(sfp, srp);
652 		return -ENOSYS;
653 	}
654 	if (hp->flags & SG_FLAG_MMAP_IO) {
655 		if (hp->dxfer_len > sfp->reserve.bufflen) {
656 			sg_remove_request(sfp, srp);
657 			return -ENOMEM;	/* MMAP_IO size must fit in reserve buffer */
658 		}
659 		if (hp->flags & SG_FLAG_DIRECT_IO) {
660 			sg_remove_request(sfp, srp);
661 			return -EINVAL;	/* either MMAP_IO or DIRECT_IO (not both) */
662 		}
663 		if (sg_res_in_use(sfp)) {
664 			sg_remove_request(sfp, srp);
665 			return -EBUSY;	/* reserve buffer already being used */
666 		}
667 	}
668 	ul_timeout = msecs_to_jiffies(srp->header.timeout);
669 	timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
670 	if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
671 		sg_remove_request(sfp, srp);
672 		return -EMSGSIZE;
673 	}
674 	if (!access_ok(VERIFY_READ, hp->cmdp, hp->cmd_len)) {
675 		sg_remove_request(sfp, srp);
676 		return -EFAULT;	/* protects following copy_from_user()s + get_user()s */
677 	}
678 	if (__copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
679 		sg_remove_request(sfp, srp);
680 		return -EFAULT;
681 	}
682 	if (read_only &&
683 	    (!sg_allow_access(cmnd[0], sfp->parentdp->device->type))) {
684 		sg_remove_request(sfp, srp);
685 		return -EPERM;
686 	}
687 	k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
688 	if (k < 0)
689 		return k;
690 	if (o_srp)
691 		*o_srp = srp;
692 	return count;
693 }
694 
695 static int
696 sg_common_write(Sg_fd * sfp, Sg_request * srp,
697 		unsigned char *cmnd, int timeout, int blocking)
698 {
699 	int k;
700 	Scsi_Request *SRpnt;
701 	Sg_device *sdp = sfp->parentdp;
702 	sg_io_hdr_t *hp = &srp->header;
703 	request_queue_t *q;
704 
705 	srp->data.cmd_opcode = cmnd[0];	/* hold opcode of command */
706 	hp->status = 0;
707 	hp->masked_status = 0;
708 	hp->msg_status = 0;
709 	hp->info = 0;
710 	hp->host_status = 0;
711 	hp->driver_status = 0;
712 	hp->resid = 0;
713 	SCSI_LOG_TIMEOUT(4, printk("sg_common_write:  scsi opcode=0x%02x, cmd_size=%d\n",
714 			  (int) cmnd[0], (int) hp->cmd_len));
715 
716 	if ((k = sg_start_req(srp))) {
717 		SCSI_LOG_TIMEOUT(1, printk("sg_write: start_req err=%d\n", k));
718 		sg_finish_rem_req(srp);
719 		return k;	/* probably out of space --> ENOMEM */
720 	}
721 	if ((k = sg_write_xfer(srp))) {
722 		SCSI_LOG_TIMEOUT(1, printk("sg_write: write_xfer, bad address\n"));
723 		sg_finish_rem_req(srp);
724 		return k;
725 	}
726 	if (sdp->detached) {
727 		sg_finish_rem_req(srp);
728 		return -ENODEV;
729 	}
730 	SRpnt = scsi_allocate_request(sdp->device, GFP_ATOMIC);
731 	if (SRpnt == NULL) {
732 		SCSI_LOG_TIMEOUT(1, printk("sg_write: no mem\n"));
733 		sg_finish_rem_req(srp);
734 		return -ENOMEM;
735 	}
736 
737 	srp->my_cmdp = SRpnt;
738 	q = SRpnt->sr_device->request_queue;
739 	SRpnt->sr_request->rq_disk = sdp->disk;
740 	SRpnt->sr_sense_buffer[0] = 0;
741 	SRpnt->sr_cmd_len = hp->cmd_len;
742 	SRpnt->sr_use_sg = srp->data.k_use_sg;
743 	SRpnt->sr_sglist_len = srp->data.sglist_len;
744 	SRpnt->sr_bufflen = srp->data.bufflen;
745 	SRpnt->sr_underflow = 0;
746 	SRpnt->sr_buffer = srp->data.buffer;
747 	switch (hp->dxfer_direction) {
748 	case SG_DXFER_TO_FROM_DEV:
749 	case SG_DXFER_FROM_DEV:
750 		SRpnt->sr_data_direction = DMA_FROM_DEVICE;
751 		break;
752 	case SG_DXFER_TO_DEV:
753 		SRpnt->sr_data_direction = DMA_TO_DEVICE;
754 		break;
755 	case SG_DXFER_UNKNOWN:
756 		SRpnt->sr_data_direction = DMA_BIDIRECTIONAL;
757 		break;
758 	default:
759 		SRpnt->sr_data_direction = DMA_NONE;
760 		break;
761 	}
762 	SRpnt->upper_private_data = srp;
763 	srp->data.k_use_sg = 0;
764 	srp->data.sglist_len = 0;
765 	srp->data.bufflen = 0;
766 	srp->data.buffer = NULL;
767 	hp->duration = jiffies_to_msecs(jiffies);
768 /* Now send everything of to mid-level. The next time we hear about this
769    packet is when sg_cmd_done() is called (i.e. a callback). */
770 	scsi_do_req(SRpnt, (void *) cmnd,
771 		    (void *) SRpnt->sr_buffer, hp->dxfer_len,
772 		    sg_cmd_done, timeout, SG_DEFAULT_RETRIES);
773 	/* dxfer_len overwrites SRpnt->sr_bufflen, hence need for b_malloc_len */
774 	return 0;
775 }
776 
777 static int
778 sg_srp_done(Sg_request *srp, Sg_fd *sfp)
779 {
780 	unsigned long iflags;
781 	int done;
782 
783 	read_lock_irqsave(&sfp->rq_list_lock, iflags);
784 	done = srp->done;
785 	read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
786 	return done;
787 }
788 
789 static int
790 sg_ioctl(struct inode *inode, struct file *filp,
791 	 unsigned int cmd_in, unsigned long arg)
792 {
793 	void __user *p = (void __user *)arg;
794 	int __user *ip = p;
795 	int result, val, read_only;
796 	Sg_device *sdp;
797 	Sg_fd *sfp;
798 	Sg_request *srp;
799 	unsigned long iflags;
800 
801 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
802 		return -ENXIO;
803 	SCSI_LOG_TIMEOUT(3, printk("sg_ioctl: %s, cmd=0x%x\n",
804 				   sdp->disk->disk_name, (int) cmd_in));
805 	read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
806 
807 	switch (cmd_in) {
808 	case SG_IO:
809 		{
810 			int blocking = 1;	/* ignore O_NONBLOCK flag */
811 
812 			if (sdp->detached)
813 				return -ENODEV;
814 			if (!scsi_block_when_processing_errors(sdp->device))
815 				return -ENXIO;
816 			if (!access_ok(VERIFY_WRITE, p, SZ_SG_IO_HDR))
817 				return -EFAULT;
818 			result =
819 			    sg_new_write(sfp, p, SZ_SG_IO_HDR,
820 					 blocking, read_only, &srp);
821 			if (result < 0)
822 				return result;
823 			srp->sg_io_owned = 1;
824 			while (1) {
825 				result = 0;	/* following macro to beat race condition */
826 				__wait_event_interruptible(sfp->read_wait,
827 					(sdp->detached || sfp->closed || sg_srp_done(srp, sfp)),
828 							   result);
829 				if (sdp->detached)
830 					return -ENODEV;
831 				if (sfp->closed)
832 					return 0;	/* request packet dropped already */
833 				if (0 == result)
834 					break;
835 				srp->orphan = 1;
836 				return result;	/* -ERESTARTSYS because signal hit process */
837 			}
838 			write_lock_irqsave(&sfp->rq_list_lock, iflags);
839 			srp->done = 2;
840 			write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
841 			result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
842 			return (result < 0) ? result : 0;
843 		}
844 	case SG_SET_TIMEOUT:
845 		result = get_user(val, ip);
846 		if (result)
847 			return result;
848 		if (val < 0)
849 			return -EIO;
850 		if (val >= MULDIV (INT_MAX, USER_HZ, HZ))
851 		    val = MULDIV (INT_MAX, USER_HZ, HZ);
852 		sfp->timeout_user = val;
853 		sfp->timeout = MULDIV (val, HZ, USER_HZ);
854 
855 		return 0;
856 	case SG_GET_TIMEOUT:	/* N.B. User receives timeout as return value */
857 				/* strange ..., for backward compatibility */
858 		return sfp->timeout_user;
859 	case SG_SET_FORCE_LOW_DMA:
860 		result = get_user(val, ip);
861 		if (result)
862 			return result;
863 		if (val) {
864 			sfp->low_dma = 1;
865 			if ((0 == sfp->low_dma) && (0 == sg_res_in_use(sfp))) {
866 				val = (int) sfp->reserve.bufflen;
867 				sg_remove_scat(&sfp->reserve);
868 				sg_build_reserve(sfp, val);
869 			}
870 		} else {
871 			if (sdp->detached)
872 				return -ENODEV;
873 			sfp->low_dma = sdp->device->host->unchecked_isa_dma;
874 		}
875 		return 0;
876 	case SG_GET_LOW_DMA:
877 		return put_user((int) sfp->low_dma, ip);
878 	case SG_GET_SCSI_ID:
879 		if (!access_ok(VERIFY_WRITE, p, sizeof (sg_scsi_id_t)))
880 			return -EFAULT;
881 		else {
882 			sg_scsi_id_t __user *sg_idp = p;
883 
884 			if (sdp->detached)
885 				return -ENODEV;
886 			__put_user((int) sdp->device->host->host_no,
887 				   &sg_idp->host_no);
888 			__put_user((int) sdp->device->channel,
889 				   &sg_idp->channel);
890 			__put_user((int) sdp->device->id, &sg_idp->scsi_id);
891 			__put_user((int) sdp->device->lun, &sg_idp->lun);
892 			__put_user((int) sdp->device->type, &sg_idp->scsi_type);
893 			__put_user((short) sdp->device->host->cmd_per_lun,
894 				   &sg_idp->h_cmd_per_lun);
895 			__put_user((short) sdp->device->queue_depth,
896 				   &sg_idp->d_queue_depth);
897 			__put_user(0, &sg_idp->unused[0]);
898 			__put_user(0, &sg_idp->unused[1]);
899 			return 0;
900 		}
901 	case SG_SET_FORCE_PACK_ID:
902 		result = get_user(val, ip);
903 		if (result)
904 			return result;
905 		sfp->force_packid = val ? 1 : 0;
906 		return 0;
907 	case SG_GET_PACK_ID:
908 		if (!access_ok(VERIFY_WRITE, ip, sizeof (int)))
909 			return -EFAULT;
910 		read_lock_irqsave(&sfp->rq_list_lock, iflags);
911 		for (srp = sfp->headrp; srp; srp = srp->nextrp) {
912 			if ((1 == srp->done) && (!srp->sg_io_owned)) {
913 				read_unlock_irqrestore(&sfp->rq_list_lock,
914 						       iflags);
915 				__put_user(srp->header.pack_id, ip);
916 				return 0;
917 			}
918 		}
919 		read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
920 		__put_user(-1, ip);
921 		return 0;
922 	case SG_GET_NUM_WAITING:
923 		read_lock_irqsave(&sfp->rq_list_lock, iflags);
924 		for (val = 0, srp = sfp->headrp; srp; srp = srp->nextrp) {
925 			if ((1 == srp->done) && (!srp->sg_io_owned))
926 				++val;
927 		}
928 		read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
929 		return put_user(val, ip);
930 	case SG_GET_SG_TABLESIZE:
931 		return put_user(sdp->sg_tablesize, ip);
932 	case SG_SET_RESERVED_SIZE:
933 		result = get_user(val, ip);
934 		if (result)
935 			return result;
936                 if (val < 0)
937                         return -EINVAL;
938 		if (val != sfp->reserve.bufflen) {
939 			if (sg_res_in_use(sfp) || sfp->mmap_called)
940 				return -EBUSY;
941 			sg_remove_scat(&sfp->reserve);
942 			sg_build_reserve(sfp, val);
943 		}
944 		return 0;
945 	case SG_GET_RESERVED_SIZE:
946 		val = (int) sfp->reserve.bufflen;
947 		return put_user(val, ip);
948 	case SG_SET_COMMAND_Q:
949 		result = get_user(val, ip);
950 		if (result)
951 			return result;
952 		sfp->cmd_q = val ? 1 : 0;
953 		return 0;
954 	case SG_GET_COMMAND_Q:
955 		return put_user((int) sfp->cmd_q, ip);
956 	case SG_SET_KEEP_ORPHAN:
957 		result = get_user(val, ip);
958 		if (result)
959 			return result;
960 		sfp->keep_orphan = val;
961 		return 0;
962 	case SG_GET_KEEP_ORPHAN:
963 		return put_user((int) sfp->keep_orphan, ip);
964 	case SG_NEXT_CMD_LEN:
965 		result = get_user(val, ip);
966 		if (result)
967 			return result;
968 		sfp->next_cmd_len = (val > 0) ? val : 0;
969 		return 0;
970 	case SG_GET_VERSION_NUM:
971 		return put_user(sg_version_num, ip);
972 	case SG_GET_ACCESS_COUNT:
973 		/* faked - we don't have a real access count anymore */
974 		val = (sdp->device ? 1 : 0);
975 		return put_user(val, ip);
976 	case SG_GET_REQUEST_TABLE:
977 		if (!access_ok(VERIFY_WRITE, p, SZ_SG_REQ_INFO * SG_MAX_QUEUE))
978 			return -EFAULT;
979 		else {
980 			sg_req_info_t *rinfo;
981 			unsigned int ms;
982 
983 			rinfo = kmalloc(SZ_SG_REQ_INFO * SG_MAX_QUEUE,
984 								GFP_KERNEL);
985 			if (!rinfo)
986 				return -ENOMEM;
987 			read_lock_irqsave(&sfp->rq_list_lock, iflags);
988 			for (srp = sfp->headrp, val = 0; val < SG_MAX_QUEUE;
989 			     ++val, srp = srp ? srp->nextrp : srp) {
990 				memset(&rinfo[val], 0, SZ_SG_REQ_INFO);
991 				if (srp) {
992 					rinfo[val].req_state = srp->done + 1;
993 					rinfo[val].problem =
994 					    srp->header.masked_status &
995 					    srp->header.host_status &
996 					    srp->header.driver_status;
997 					if (srp->done)
998 						rinfo[val].duration =
999 							srp->header.duration;
1000 					else {
1001 						ms = jiffies_to_msecs(jiffies);
1002 						rinfo[val].duration =
1003 						    (ms > srp->header.duration) ?
1004 						    (ms - srp->header.duration) : 0;
1005 					}
1006 					rinfo[val].orphan = srp->orphan;
1007 					rinfo[val].sg_io_owned =
1008 							srp->sg_io_owned;
1009 					rinfo[val].pack_id =
1010 							srp->header.pack_id;
1011 					rinfo[val].usr_ptr =
1012 							srp->header.usr_ptr;
1013 				}
1014 			}
1015 			read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1016 			result = __copy_to_user(p, rinfo,
1017 						SZ_SG_REQ_INFO * SG_MAX_QUEUE);
1018 			result = result ? -EFAULT : 0;
1019 			kfree(rinfo);
1020 			return result;
1021 		}
1022 	case SG_EMULATED_HOST:
1023 		if (sdp->detached)
1024 			return -ENODEV;
1025 		return put_user(sdp->device->host->hostt->emulated, ip);
1026 	case SG_SCSI_RESET:
1027 		if (sdp->detached)
1028 			return -ENODEV;
1029 		if (filp->f_flags & O_NONBLOCK) {
1030 			if (test_bit(SHOST_RECOVERY,
1031 				     &sdp->device->host->shost_state))
1032 				return -EBUSY;
1033 		} else if (!scsi_block_when_processing_errors(sdp->device))
1034 			return -EBUSY;
1035 		result = get_user(val, ip);
1036 		if (result)
1037 			return result;
1038 		if (SG_SCSI_RESET_NOTHING == val)
1039 			return 0;
1040 		switch (val) {
1041 		case SG_SCSI_RESET_DEVICE:
1042 			val = SCSI_TRY_RESET_DEVICE;
1043 			break;
1044 		case SG_SCSI_RESET_BUS:
1045 			val = SCSI_TRY_RESET_BUS;
1046 			break;
1047 		case SG_SCSI_RESET_HOST:
1048 			val = SCSI_TRY_RESET_HOST;
1049 			break;
1050 		default:
1051 			return -EINVAL;
1052 		}
1053 		if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1054 			return -EACCES;
1055 		return (scsi_reset_provider(sdp->device, val) ==
1056 			SUCCESS) ? 0 : -EIO;
1057 	case SCSI_IOCTL_SEND_COMMAND:
1058 		if (sdp->detached)
1059 			return -ENODEV;
1060 		if (read_only) {
1061 			unsigned char opcode = WRITE_6;
1062 			Scsi_Ioctl_Command __user *siocp = p;
1063 
1064 			if (copy_from_user(&opcode, siocp->data, 1))
1065 				return -EFAULT;
1066 			if (!sg_allow_access(opcode, sdp->device->type))
1067 				return -EPERM;
1068 		}
1069 		return scsi_ioctl_send_command(sdp->device, p);
1070 	case SG_SET_DEBUG:
1071 		result = get_user(val, ip);
1072 		if (result)
1073 			return result;
1074 		sdp->sgdebug = (char) val;
1075 		return 0;
1076 	case SCSI_IOCTL_GET_IDLUN:
1077 	case SCSI_IOCTL_GET_BUS_NUMBER:
1078 	case SCSI_IOCTL_PROBE_HOST:
1079 	case SG_GET_TRANSFORM:
1080 		if (sdp->detached)
1081 			return -ENODEV;
1082 		return scsi_ioctl(sdp->device, cmd_in, p);
1083 	default:
1084 		if (read_only)
1085 			return -EPERM;	/* don't know so take safe approach */
1086 		return scsi_ioctl(sdp->device, cmd_in, p);
1087 	}
1088 }
1089 
1090 #ifdef CONFIG_COMPAT
1091 static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1092 {
1093 	Sg_device *sdp;
1094 	Sg_fd *sfp;
1095 	struct scsi_device *sdev;
1096 
1097 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1098 		return -ENXIO;
1099 
1100 	sdev = sdp->device;
1101 	if (sdev->host->hostt->compat_ioctl) {
1102 		int ret;
1103 
1104 		ret = sdev->host->hostt->compat_ioctl(sdev, cmd_in, (void __user *)arg);
1105 
1106 		return ret;
1107 	}
1108 
1109 	return -ENOIOCTLCMD;
1110 }
1111 #endif
1112 
1113 static unsigned int
1114 sg_poll(struct file *filp, poll_table * wait)
1115 {
1116 	unsigned int res = 0;
1117 	Sg_device *sdp;
1118 	Sg_fd *sfp;
1119 	Sg_request *srp;
1120 	int count = 0;
1121 	unsigned long iflags;
1122 
1123 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp))
1124 	    || sfp->closed)
1125 		return POLLERR;
1126 	poll_wait(filp, &sfp->read_wait, wait);
1127 	read_lock_irqsave(&sfp->rq_list_lock, iflags);
1128 	for (srp = sfp->headrp; srp; srp = srp->nextrp) {
1129 		/* if any read waiting, flag it */
1130 		if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1131 			res = POLLIN | POLLRDNORM;
1132 		++count;
1133 	}
1134 	read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1135 
1136 	if (sdp->detached)
1137 		res |= POLLHUP;
1138 	else if (!sfp->cmd_q) {
1139 		if (0 == count)
1140 			res |= POLLOUT | POLLWRNORM;
1141 	} else if (count < SG_MAX_QUEUE)
1142 		res |= POLLOUT | POLLWRNORM;
1143 	SCSI_LOG_TIMEOUT(3, printk("sg_poll: %s, res=0x%x\n",
1144 				   sdp->disk->disk_name, (int) res));
1145 	return res;
1146 }
1147 
1148 static int
1149 sg_fasync(int fd, struct file *filp, int mode)
1150 {
1151 	int retval;
1152 	Sg_device *sdp;
1153 	Sg_fd *sfp;
1154 
1155 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1156 		return -ENXIO;
1157 	SCSI_LOG_TIMEOUT(3, printk("sg_fasync: %s, mode=%d\n",
1158 				   sdp->disk->disk_name, mode));
1159 
1160 	retval = fasync_helper(fd, filp, mode, &sfp->async_qp);
1161 	return (retval < 0) ? retval : 0;
1162 }
1163 
1164 static inline unsigned char *
1165 sg_scatg2virt(const struct scatterlist *sclp)
1166 {
1167 	return (sclp && sclp->page) ?
1168 	    (unsigned char *) page_address(sclp->page) + sclp->offset : NULL;
1169 }
1170 
1171 /* When startFinish==1 increments page counts for pages other than the
1172    first of scatter gather elements obtained from __get_free_pages().
1173    When startFinish==0 decrements ... */
1174 static void
1175 sg_rb_correct4mmap(Sg_scatter_hold * rsv_schp, int startFinish)
1176 {
1177 	void *page_ptr;
1178 	struct page *page;
1179 	int k, m;
1180 
1181 	SCSI_LOG_TIMEOUT(3, printk("sg_rb_correct4mmap: startFinish=%d, scatg=%d\n",
1182 				   startFinish, rsv_schp->k_use_sg));
1183 	/* N.B. correction _not_ applied to base page of each allocation */
1184 	if (rsv_schp->k_use_sg) {	/* reserve buffer is a scatter gather list */
1185 		struct scatterlist *sclp = rsv_schp->buffer;
1186 
1187 		for (k = 0; k < rsv_schp->k_use_sg; ++k, ++sclp) {
1188 			for (m = PAGE_SIZE; m < sclp->length; m += PAGE_SIZE) {
1189 				page_ptr = sg_scatg2virt(sclp) + m;
1190 				page = virt_to_page(page_ptr);
1191 				if (startFinish)
1192 					get_page(page);
1193 				else {
1194 					if (page_count(page) > 0)
1195 						__put_page(page);
1196 				}
1197 			}
1198 		}
1199 	} else {		/* reserve buffer is just a single allocation */
1200 		for (m = PAGE_SIZE; m < rsv_schp->bufflen; m += PAGE_SIZE) {
1201 			page_ptr = (unsigned char *) rsv_schp->buffer + m;
1202 			page = virt_to_page(page_ptr);
1203 			if (startFinish)
1204 				get_page(page);
1205 			else {
1206 				if (page_count(page) > 0)
1207 					__put_page(page);
1208 			}
1209 		}
1210 	}
1211 }
1212 
1213 static struct page *
1214 sg_vma_nopage(struct vm_area_struct *vma, unsigned long addr, int *type)
1215 {
1216 	Sg_fd *sfp;
1217 	struct page *page = NOPAGE_SIGBUS;
1218 	void *page_ptr = NULL;
1219 	unsigned long offset;
1220 	Sg_scatter_hold *rsv_schp;
1221 
1222 	if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1223 		return page;
1224 	rsv_schp = &sfp->reserve;
1225 	offset = addr - vma->vm_start;
1226 	if (offset >= rsv_schp->bufflen)
1227 		return page;
1228 	SCSI_LOG_TIMEOUT(3, printk("sg_vma_nopage: offset=%lu, scatg=%d\n",
1229 				   offset, rsv_schp->k_use_sg));
1230 	if (rsv_schp->k_use_sg) {	/* reserve buffer is a scatter gather list */
1231 		int k;
1232 		unsigned long sa = vma->vm_start;
1233 		unsigned long len;
1234 		struct scatterlist *sclp = rsv_schp->buffer;
1235 
1236 		for (k = 0; (k < rsv_schp->k_use_sg) && (sa < vma->vm_end);
1237 		     ++k, ++sclp) {
1238 			len = vma->vm_end - sa;
1239 			len = (len < sclp->length) ? len : sclp->length;
1240 			if (offset < len) {
1241 				page_ptr = sg_scatg2virt(sclp) + offset;
1242 				page = virt_to_page(page_ptr);
1243 				get_page(page);	/* increment page count */
1244 				break;
1245 			}
1246 			sa += len;
1247 			offset -= len;
1248 		}
1249 	} else {		/* reserve buffer is just a single allocation */
1250 		page_ptr = (unsigned char *) rsv_schp->buffer + offset;
1251 		page = virt_to_page(page_ptr);
1252 		get_page(page);	/* increment page count */
1253 	}
1254 	if (type)
1255 		*type = VM_FAULT_MINOR;
1256 	return page;
1257 }
1258 
1259 static struct vm_operations_struct sg_mmap_vm_ops = {
1260 	.nopage = sg_vma_nopage,
1261 };
1262 
1263 static int
1264 sg_mmap(struct file *filp, struct vm_area_struct *vma)
1265 {
1266 	Sg_fd *sfp;
1267 	unsigned long req_sz;
1268 	Sg_scatter_hold *rsv_schp;
1269 
1270 	if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1271 		return -ENXIO;
1272 	req_sz = vma->vm_end - vma->vm_start;
1273 	SCSI_LOG_TIMEOUT(3, printk("sg_mmap starting, vm_start=%p, len=%d\n",
1274 				   (void *) vma->vm_start, (int) req_sz));
1275 	if (vma->vm_pgoff)
1276 		return -EINVAL;	/* want no offset */
1277 	rsv_schp = &sfp->reserve;
1278 	if (req_sz > rsv_schp->bufflen)
1279 		return -ENOMEM;	/* cannot map more than reserved buffer */
1280 
1281 	if (rsv_schp->k_use_sg) { /* reserve buffer is a scatter gather list */
1282 		int k;
1283 		unsigned long sa = vma->vm_start;
1284 		unsigned long len;
1285 		struct scatterlist *sclp = rsv_schp->buffer;
1286 
1287 		for (k = 0; (k < rsv_schp->k_use_sg) && (sa < vma->vm_end);
1288 		     ++k, ++sclp) {
1289 			if (0 != sclp->offset)
1290 				return -EFAULT;	/* non page aligned memory ?? */
1291 			len = vma->vm_end - sa;
1292 			len = (len < sclp->length) ? len : sclp->length;
1293 			sa += len;
1294 		}
1295 	} else {	/* reserve buffer is just a single allocation */
1296 		if ((unsigned long) rsv_schp->buffer & (PAGE_SIZE - 1))
1297 			return -EFAULT;	/* non page aligned memory ?? */
1298 	}
1299 	if (0 == sfp->mmap_called) {
1300 		sg_rb_correct4mmap(rsv_schp, 1);	/* do only once per fd lifetime */
1301 		sfp->mmap_called = 1;
1302 	}
1303 	vma->vm_flags |= (VM_RESERVED | VM_IO);
1304 	vma->vm_private_data = sfp;
1305 	vma->vm_ops = &sg_mmap_vm_ops;
1306 	return 0;
1307 }
1308 
1309 /* This function is a "bottom half" handler that is called by the
1310  * mid level when a command is completed (or has failed). */
1311 static void
1312 sg_cmd_done(Scsi_Cmnd * SCpnt)
1313 {
1314 	Scsi_Request *SRpnt = NULL;
1315 	Sg_device *sdp = NULL;
1316 	Sg_fd *sfp;
1317 	Sg_request *srp = NULL;
1318 	unsigned long iflags;
1319 	unsigned int ms;
1320 
1321 	if (SCpnt && (SRpnt = SCpnt->sc_request))
1322 		srp = (Sg_request *) SRpnt->upper_private_data;
1323 	if (NULL == srp) {
1324 		printk(KERN_ERR "sg_cmd_done: NULL request\n");
1325 		if (SRpnt)
1326 			scsi_release_request(SRpnt);
1327 		return;
1328 	}
1329 	sfp = srp->parentfp;
1330 	if (sfp)
1331 		sdp = sfp->parentdp;
1332 	if ((NULL == sdp) || sdp->detached) {
1333 		printk(KERN_INFO "sg_cmd_done: device detached\n");
1334 		scsi_release_request(SRpnt);
1335 		return;
1336 	}
1337 
1338 	/* First transfer ownership of data buffers to sg_device object. */
1339 	srp->data.k_use_sg = SRpnt->sr_use_sg;
1340 	srp->data.sglist_len = SRpnt->sr_sglist_len;
1341 	srp->data.bufflen = SRpnt->sr_bufflen;
1342 	srp->data.buffer = SRpnt->sr_buffer;
1343 	/* now clear out request structure */
1344 	SRpnt->sr_use_sg = 0;
1345 	SRpnt->sr_sglist_len = 0;
1346 	SRpnt->sr_bufflen = 0;
1347 	SRpnt->sr_buffer = NULL;
1348 	SRpnt->sr_underflow = 0;
1349 	SRpnt->sr_request->rq_disk = NULL; /* "sg" _disowns_ request blk */
1350 
1351 	srp->my_cmdp = NULL;
1352 
1353 	SCSI_LOG_TIMEOUT(4, printk("sg_cmd_done: %s, pack_id=%d, res=0x%x\n",
1354 		sdp->disk->disk_name, srp->header.pack_id, (int) SRpnt->sr_result));
1355 	srp->header.resid = SCpnt->resid;
1356 	ms = jiffies_to_msecs(jiffies);
1357 	srp->header.duration = (ms > srp->header.duration) ?
1358 				(ms - srp->header.duration) : 0;
1359 	if (0 != SRpnt->sr_result) {
1360 		struct scsi_sense_hdr sshdr;
1361 
1362 		memcpy(srp->sense_b, SRpnt->sr_sense_buffer,
1363 		       sizeof (srp->sense_b));
1364 		srp->header.status = 0xff & SRpnt->sr_result;
1365 		srp->header.masked_status = status_byte(SRpnt->sr_result);
1366 		srp->header.msg_status = msg_byte(SRpnt->sr_result);
1367 		srp->header.host_status = host_byte(SRpnt->sr_result);
1368 		srp->header.driver_status = driver_byte(SRpnt->sr_result);
1369 		if ((sdp->sgdebug > 0) &&
1370 		    ((CHECK_CONDITION == srp->header.masked_status) ||
1371 		     (COMMAND_TERMINATED == srp->header.masked_status)))
1372 			scsi_print_req_sense("sg_cmd_done", SRpnt);
1373 
1374 		/* Following if statement is a patch supplied by Eric Youngdale */
1375 		if (driver_byte(SRpnt->sr_result) != 0
1376 		    && scsi_command_normalize_sense(SCpnt, &sshdr)
1377 		    && !scsi_sense_is_deferred(&sshdr)
1378 		    && sshdr.sense_key == UNIT_ATTENTION
1379 		    && sdp->device->removable) {
1380 			/* Detected possible disc change. Set the bit - this */
1381 			/* may be used if there are filesystems using this device */
1382 			sdp->device->changed = 1;
1383 		}
1384 	}
1385 	/* Rely on write phase to clean out srp status values, so no "else" */
1386 
1387 	scsi_release_request(SRpnt);
1388 	SRpnt = NULL;
1389 	if (sfp->closed) {	/* whoops this fd already released, cleanup */
1390 		SCSI_LOG_TIMEOUT(1, printk("sg_cmd_done: already closed, freeing ...\n"));
1391 		sg_finish_rem_req(srp);
1392 		srp = NULL;
1393 		if (NULL == sfp->headrp) {
1394 			SCSI_LOG_TIMEOUT(1, printk("sg...bh: already closed, final cleanup\n"));
1395 			if (0 == sg_remove_sfp(sdp, sfp)) {	/* device still present */
1396 				scsi_device_put(sdp->device);
1397 			}
1398 			sfp = NULL;
1399 		}
1400 	} else if (srp && srp->orphan) {
1401 		if (sfp->keep_orphan)
1402 			srp->sg_io_owned = 0;
1403 		else {
1404 			sg_finish_rem_req(srp);
1405 			srp = NULL;
1406 		}
1407 	}
1408 	if (sfp && srp) {
1409 		/* Now wake up any sg_read() that is waiting for this packet. */
1410 		kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1411 		write_lock_irqsave(&sfp->rq_list_lock, iflags);
1412 		srp->done = 1;
1413 		wake_up_interruptible(&sfp->read_wait);
1414 		write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1415 	}
1416 }
1417 
1418 static struct file_operations sg_fops = {
1419 	.owner = THIS_MODULE,
1420 	.read = sg_read,
1421 	.write = sg_write,
1422 	.poll = sg_poll,
1423 	.ioctl = sg_ioctl,
1424 #ifdef CONFIG_COMPAT
1425 	.compat_ioctl = sg_compat_ioctl,
1426 #endif
1427 	.open = sg_open,
1428 	.mmap = sg_mmap,
1429 	.release = sg_release,
1430 	.fasync = sg_fasync,
1431 };
1432 
1433 static struct class *sg_sysfs_class;
1434 
1435 static int sg_sysfs_valid = 0;
1436 
1437 static int sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1438 {
1439 	Sg_device *sdp;
1440 	unsigned long iflags;
1441 	void *old_sg_dev_arr = NULL;
1442 	int k, error;
1443 
1444 	sdp = kmalloc(sizeof(Sg_device), GFP_KERNEL);
1445 	if (!sdp) {
1446 		printk(KERN_WARNING "kmalloc Sg_device failure\n");
1447 		return -ENOMEM;
1448 	}
1449 
1450 	write_lock_irqsave(&sg_dev_arr_lock, iflags);
1451 	if (unlikely(sg_nr_dev >= sg_dev_max)) {	/* try to resize */
1452 		Sg_device **tmp_da;
1453 		int tmp_dev_max = sg_nr_dev + SG_DEV_ARR_LUMP;
1454 		write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1455 
1456 		tmp_da = kmalloc(tmp_dev_max * sizeof(Sg_device *), GFP_KERNEL);
1457 		if (unlikely(!tmp_da))
1458 			goto expand_failed;
1459 
1460 		write_lock_irqsave(&sg_dev_arr_lock, iflags);
1461 		memset(tmp_da, 0, tmp_dev_max * sizeof(Sg_device *));
1462 		memcpy(tmp_da, sg_dev_arr, sg_dev_max * sizeof(Sg_device *));
1463 		old_sg_dev_arr = sg_dev_arr;
1464 		sg_dev_arr = tmp_da;
1465 		sg_dev_max = tmp_dev_max;
1466 	}
1467 
1468 	for (k = 0; k < sg_dev_max; k++)
1469 		if (!sg_dev_arr[k])
1470 			break;
1471 	if (unlikely(k >= SG_MAX_DEVS))
1472 		goto overflow;
1473 
1474 	memset(sdp, 0, sizeof(*sdp));
1475 	SCSI_LOG_TIMEOUT(3, printk("sg_alloc: dev=%d \n", k));
1476 	sprintf(disk->disk_name, "sg%d", k);
1477 	disk->first_minor = k;
1478 	sdp->disk = disk;
1479 	sdp->device = scsidp;
1480 	init_waitqueue_head(&sdp->o_excl_wait);
1481 	sdp->sg_tablesize = scsidp->host ? scsidp->host->sg_tablesize : 0;
1482 
1483 	sg_nr_dev++;
1484 	sg_dev_arr[k] = sdp;
1485 	write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1486 	error = k;
1487 
1488  out:
1489 	if (error < 0)
1490 		kfree(sdp);
1491 	kfree(old_sg_dev_arr);
1492 	return error;
1493 
1494  expand_failed:
1495 	printk(KERN_WARNING "sg_alloc: device array cannot be resized\n");
1496 	error = -ENOMEM;
1497 	goto out;
1498 
1499  overflow:
1500 	write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1501 	printk(KERN_WARNING
1502 	       "Unable to attach sg device <%d, %d, %d, %d> type=%d, minor "
1503 	       "number exceeds %d\n", scsidp->host->host_no, scsidp->channel,
1504 	       scsidp->id, scsidp->lun, scsidp->type, SG_MAX_DEVS - 1);
1505 	error = -ENODEV;
1506 	goto out;
1507 }
1508 
1509 static int
1510 sg_add(struct class_device *cl_dev)
1511 {
1512 	struct scsi_device *scsidp = to_scsi_device(cl_dev->dev);
1513 	struct gendisk *disk;
1514 	Sg_device *sdp = NULL;
1515 	struct cdev * cdev = NULL;
1516 	int error, k;
1517 
1518 	disk = alloc_disk(1);
1519 	if (!disk) {
1520 		printk(KERN_WARNING "alloc_disk failed\n");
1521 		return -ENOMEM;
1522 	}
1523 	disk->major = SCSI_GENERIC_MAJOR;
1524 
1525 	error = -ENOMEM;
1526 	cdev = cdev_alloc();
1527 	if (!cdev) {
1528 		printk(KERN_WARNING "cdev_alloc failed\n");
1529 		goto out;
1530 	}
1531 	cdev->owner = THIS_MODULE;
1532 	cdev->ops = &sg_fops;
1533 
1534 	error = sg_alloc(disk, scsidp);
1535 	if (error < 0) {
1536 		printk(KERN_WARNING "sg_alloc failed\n");
1537 		goto out;
1538 	}
1539 	k = error;
1540 	sdp = sg_dev_arr[k];
1541 
1542 	devfs_mk_cdev(MKDEV(SCSI_GENERIC_MAJOR, k),
1543 			S_IFCHR | S_IRUSR | S_IWUSR | S_IRGRP,
1544 			"%s/generic", scsidp->devfs_name);
1545 	error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, k), 1);
1546 	if (error) {
1547 		devfs_remove("%s/generic", scsidp->devfs_name);
1548 		goto out;
1549 	}
1550 	sdp->cdev = cdev;
1551 	if (sg_sysfs_valid) {
1552 		struct class_device * sg_class_member;
1553 
1554 		sg_class_member = class_device_create(sg_sysfs_class,
1555 				MKDEV(SCSI_GENERIC_MAJOR, k),
1556 				cl_dev->dev, "%s",
1557 				disk->disk_name);
1558 		if (IS_ERR(sg_class_member))
1559 			printk(KERN_WARNING "sg_add: "
1560 				"class_device_create failed\n");
1561 		class_set_devdata(sg_class_member, sdp);
1562 		error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1563 					  &sg_class_member->kobj, "generic");
1564 		if (error)
1565 			printk(KERN_ERR "sg_add: unable to make symlink "
1566 					"'generic' back to sg%d\n", k);
1567 	} else
1568 		printk(KERN_WARNING "sg_add: sg_sys INvalid\n");
1569 
1570 	printk(KERN_NOTICE
1571 	       "Attached scsi generic sg%d at scsi%d, channel"
1572 	       " %d, id %d, lun %d,  type %d\n", k,
1573 	       scsidp->host->host_no, scsidp->channel, scsidp->id,
1574 	       scsidp->lun, scsidp->type);
1575 
1576 	return 0;
1577 
1578 out:
1579 	put_disk(disk);
1580 	if (cdev)
1581 		cdev_del(cdev);
1582 	return error;
1583 }
1584 
1585 static void
1586 sg_remove(struct class_device *cl_dev)
1587 {
1588 	struct scsi_device *scsidp = to_scsi_device(cl_dev->dev);
1589 	Sg_device *sdp = NULL;
1590 	unsigned long iflags;
1591 	Sg_fd *sfp;
1592 	Sg_fd *tsfp;
1593 	Sg_request *srp;
1594 	Sg_request *tsrp;
1595 	int k, delay;
1596 
1597 	if (NULL == sg_dev_arr)
1598 		return;
1599 	delay = 0;
1600 	write_lock_irqsave(&sg_dev_arr_lock, iflags);
1601 	for (k = 0; k < sg_dev_max; k++) {
1602 		sdp = sg_dev_arr[k];
1603 		if ((NULL == sdp) || (sdp->device != scsidp))
1604 			continue;	/* dirty but lowers nesting */
1605 		if (sdp->headfp) {
1606 			sdp->detached = 1;
1607 			for (sfp = sdp->headfp; sfp; sfp = tsfp) {
1608 				tsfp = sfp->nextfp;
1609 				for (srp = sfp->headrp; srp; srp = tsrp) {
1610 					tsrp = srp->nextrp;
1611 					if (sfp->closed || (0 == sg_srp_done(srp, sfp)))
1612 						sg_finish_rem_req(srp);
1613 				}
1614 				if (sfp->closed) {
1615 					scsi_device_put(sdp->device);
1616 					__sg_remove_sfp(sdp, sfp);
1617 				} else {
1618 					delay = 1;
1619 					wake_up_interruptible(&sfp->read_wait);
1620 					kill_fasync(&sfp->async_qp, SIGPOLL,
1621 						    POLL_HUP);
1622 				}
1623 			}
1624 			SCSI_LOG_TIMEOUT(3, printk("sg_detach: dev=%d, dirty\n", k));
1625 			if (NULL == sdp->headfp) {
1626 				sg_dev_arr[k] = NULL;
1627 			}
1628 		} else {	/* nothing active, simple case */
1629 			SCSI_LOG_TIMEOUT(3, printk("sg_detach: dev=%d\n", k));
1630 			sg_dev_arr[k] = NULL;
1631 		}
1632 		sg_nr_dev--;
1633 		break;
1634 	}
1635 	write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1636 
1637 	if (sdp) {
1638 		sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1639 		class_device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, k));
1640 		cdev_del(sdp->cdev);
1641 		sdp->cdev = NULL;
1642 		devfs_remove("%s/generic", scsidp->devfs_name);
1643 		put_disk(sdp->disk);
1644 		sdp->disk = NULL;
1645 		if (NULL == sdp->headfp)
1646 			kfree((char *) sdp);
1647 	}
1648 
1649 	if (delay)
1650 		msleep(10);	/* dirty detach so delay device destruction */
1651 }
1652 
1653 /* Set 'perm' (4th argument) to 0 to disable module_param's definition
1654  * of sysfs parameters (which module_param doesn't yet support).
1655  * Sysfs parameters defined explicitly below.
1656  */
1657 module_param_named(def_reserved_size, def_reserved_size, int, S_IRUGO);
1658 module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1659 
1660 MODULE_AUTHOR("Douglas Gilbert");
1661 MODULE_DESCRIPTION("SCSI generic (sg) driver");
1662 MODULE_LICENSE("GPL");
1663 MODULE_VERSION(SG_VERSION_STR);
1664 
1665 MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1666 MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1667 
1668 static int __init
1669 init_sg(void)
1670 {
1671 	int rc;
1672 
1673 	if (def_reserved_size >= 0)
1674 		sg_big_buff = def_reserved_size;
1675 
1676 	rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1677 				    SG_MAX_DEVS, "sg");
1678 	if (rc)
1679 		return rc;
1680         sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
1681         if ( IS_ERR(sg_sysfs_class) ) {
1682 		rc = PTR_ERR(sg_sysfs_class);
1683 		goto err_out;
1684         }
1685 	sg_sysfs_valid = 1;
1686 	rc = scsi_register_interface(&sg_interface);
1687 	if (0 == rc) {
1688 #ifdef CONFIG_SCSI_PROC_FS
1689 		sg_proc_init();
1690 #endif				/* CONFIG_SCSI_PROC_FS */
1691 		return 0;
1692 	}
1693 	class_destroy(sg_sysfs_class);
1694 err_out:
1695 	unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1696 	return rc;
1697 }
1698 
1699 static void __exit
1700 exit_sg(void)
1701 {
1702 #ifdef CONFIG_SCSI_PROC_FS
1703 	sg_proc_cleanup();
1704 #endif				/* CONFIG_SCSI_PROC_FS */
1705 	scsi_unregister_interface(&sg_interface);
1706 	class_destroy(sg_sysfs_class);
1707 	sg_sysfs_valid = 0;
1708 	unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1709 				 SG_MAX_DEVS);
1710 	if (sg_dev_arr != NULL) {
1711 		kfree((char *) sg_dev_arr);
1712 		sg_dev_arr = NULL;
1713 	}
1714 	sg_dev_max = 0;
1715 }
1716 
1717 static int
1718 sg_start_req(Sg_request * srp)
1719 {
1720 	int res;
1721 	Sg_fd *sfp = srp->parentfp;
1722 	sg_io_hdr_t *hp = &srp->header;
1723 	int dxfer_len = (int) hp->dxfer_len;
1724 	int dxfer_dir = hp->dxfer_direction;
1725 	Sg_scatter_hold *req_schp = &srp->data;
1726 	Sg_scatter_hold *rsv_schp = &sfp->reserve;
1727 
1728 	SCSI_LOG_TIMEOUT(4, printk("sg_start_req: dxfer_len=%d\n", dxfer_len));
1729 	if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1730 		return 0;
1731 	if (sg_allow_dio && (hp->flags & SG_FLAG_DIRECT_IO) &&
1732 	    (dxfer_dir != SG_DXFER_UNKNOWN) && (0 == hp->iovec_count) &&
1733 	    (!sfp->parentdp->device->host->unchecked_isa_dma)) {
1734 		res = sg_build_direct(srp, sfp, dxfer_len);
1735 		if (res <= 0)	/* -ve -> error, 0 -> done, 1 -> try indirect */
1736 			return res;
1737 	}
1738 	if ((!sg_res_in_use(sfp)) && (dxfer_len <= rsv_schp->bufflen))
1739 		sg_link_reserve(sfp, srp, dxfer_len);
1740 	else {
1741 		res = sg_build_indirect(req_schp, sfp, dxfer_len);
1742 		if (res) {
1743 			sg_remove_scat(req_schp);
1744 			return res;
1745 		}
1746 	}
1747 	return 0;
1748 }
1749 
1750 static void
1751 sg_finish_rem_req(Sg_request * srp)
1752 {
1753 	Sg_fd *sfp = srp->parentfp;
1754 	Sg_scatter_hold *req_schp = &srp->data;
1755 
1756 	SCSI_LOG_TIMEOUT(4, printk("sg_finish_rem_req: res_used=%d\n", (int) srp->res_used));
1757 	if (srp->res_used)
1758 		sg_unlink_reserve(sfp, srp);
1759 	else
1760 		sg_remove_scat(req_schp);
1761 	sg_remove_request(sfp, srp);
1762 }
1763 
1764 static int
1765 sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1766 {
1767 	int ret_sz;
1768 	int elem_sz = sizeof (struct scatterlist);
1769 	int sg_bufflen = tablesize * elem_sz;
1770 	int mx_sc_elems = tablesize;
1771 
1772 	schp->buffer = sg_page_malloc(sg_bufflen, sfp->low_dma, &ret_sz);
1773 	if (!schp->buffer)
1774 		return -ENOMEM;
1775 	else if (ret_sz != sg_bufflen) {
1776 		sg_bufflen = ret_sz;
1777 		mx_sc_elems = sg_bufflen / elem_sz;
1778 	}
1779 	schp->sglist_len = sg_bufflen;
1780 	memset(schp->buffer, 0, sg_bufflen);
1781 	return mx_sc_elems;	/* number of scat_gath elements allocated */
1782 }
1783 
1784 #ifdef SG_ALLOW_DIO_CODE
1785 /* vvvvvvvv  following code borrowed from st driver's direct IO vvvvvvvvv */
1786 	/* hopefully this generic code will moved to a library */
1787 
1788 /* Pin down user pages and put them into a scatter gather list. Returns <= 0 if
1789    - mapping of all pages not successful
1790    - any page is above max_pfn
1791    (i.e., either completely successful or fails)
1792 */
1793 static int
1794 st_map_user_pages(struct scatterlist *sgl, const unsigned int max_pages,
1795 	          unsigned long uaddr, size_t count, int rw,
1796 	          unsigned long max_pfn)
1797 {
1798 	int res, i, j;
1799 	unsigned int nr_pages;
1800 	struct page **pages;
1801 
1802 	nr_pages = ((uaddr & ~PAGE_MASK) + count + ~PAGE_MASK) >> PAGE_SHIFT;
1803 
1804 	/* User attempted Overflow! */
1805 	if ((uaddr + count) < uaddr)
1806 		return -EINVAL;
1807 
1808 	/* Too big */
1809         if (nr_pages > max_pages)
1810 		return -ENOMEM;
1811 
1812 	/* Hmm? */
1813 	if (count == 0)
1814 		return 0;
1815 
1816 	if ((pages = kmalloc(max_pages * sizeof(*pages), GFP_ATOMIC)) == NULL)
1817 		return -ENOMEM;
1818 
1819         /* Try to fault in all of the necessary pages */
1820 	down_read(&current->mm->mmap_sem);
1821         /* rw==READ means read from drive, write into memory area */
1822 	res = get_user_pages(
1823 		current,
1824 		current->mm,
1825 		uaddr,
1826 		nr_pages,
1827 		rw == READ,
1828 		0, /* don't force */
1829 		pages,
1830 		NULL);
1831 	up_read(&current->mm->mmap_sem);
1832 
1833 	/* Errors and no page mapped should return here */
1834 	if (res < nr_pages)
1835 		goto out_unmap;
1836 
1837         for (i=0; i < nr_pages; i++) {
1838                 /* FIXME: flush superflous for rw==READ,
1839                  * probably wrong function for rw==WRITE
1840                  */
1841 		flush_dcache_page(pages[i]);
1842 		if (page_to_pfn(pages[i]) > max_pfn)
1843 			goto out_unlock;
1844 		/* ?? Is locking needed? I don't think so */
1845 		/* if (TestSetPageLocked(pages[i]))
1846 		   goto out_unlock; */
1847         }
1848 
1849 	/* Populate the scatter/gather list */
1850 	sgl[0].page = pages[0];
1851 	sgl[0].offset = uaddr & ~PAGE_MASK;
1852 	if (nr_pages > 1) {
1853 		sgl[0].length = PAGE_SIZE - sgl[0].offset;
1854 		count -= sgl[0].length;
1855 		for (i=1; i < nr_pages ; i++) {
1856 			sgl[i].offset = 0;
1857 			sgl[i].page = pages[i];
1858 			sgl[i].length = count < PAGE_SIZE ? count : PAGE_SIZE;
1859 			count -= PAGE_SIZE;
1860 		}
1861 	}
1862 	else {
1863 		sgl[0].length = count;
1864 	}
1865 
1866 	kfree(pages);
1867 	return nr_pages;
1868 
1869  out_unlock:
1870 	/* for (j=0; j < i; j++)
1871 	   unlock_page(pages[j]); */
1872 	res = 0;
1873  out_unmap:
1874 	if (res > 0)
1875 		for (j=0; j < res; j++)
1876 			page_cache_release(pages[j]);
1877 	kfree(pages);
1878 	return res;
1879 }
1880 
1881 
1882 /* And unmap them... */
1883 static int
1884 st_unmap_user_pages(struct scatterlist *sgl, const unsigned int nr_pages,
1885 		    int dirtied)
1886 {
1887 	int i;
1888 
1889 	for (i=0; i < nr_pages; i++) {
1890 		if (dirtied && !PageReserved(sgl[i].page))
1891 			SetPageDirty(sgl[i].page);
1892 		/* unlock_page(sgl[i].page); */
1893 		/* FIXME: cache flush missing for rw==READ
1894 		 * FIXME: call the correct reference counting function
1895 		 */
1896 		page_cache_release(sgl[i].page);
1897 	}
1898 
1899 	return 0;
1900 }
1901 
1902 /* ^^^^^^^^  above code borrowed from st driver's direct IO ^^^^^^^^^ */
1903 #endif
1904 
1905 
1906 /* Returns: -ve -> error, 0 -> done, 1 -> try indirect */
1907 static int
1908 sg_build_direct(Sg_request * srp, Sg_fd * sfp, int dxfer_len)
1909 {
1910 #ifdef SG_ALLOW_DIO_CODE
1911 	sg_io_hdr_t *hp = &srp->header;
1912 	Sg_scatter_hold *schp = &srp->data;
1913 	int sg_tablesize = sfp->parentdp->sg_tablesize;
1914 	struct scatterlist *sgl;
1915 	int mx_sc_elems, res;
1916 	struct scsi_device *sdev = sfp->parentdp->device;
1917 
1918 	if (((unsigned long)hp->dxferp &
1919 			queue_dma_alignment(sdev->request_queue)) != 0)
1920 		return 1;
1921 	mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1922         if (mx_sc_elems <= 0) {
1923                 return 1;
1924         }
1925 	sgl = (struct scatterlist *)schp->buffer;
1926 	res = st_map_user_pages(sgl, mx_sc_elems, (unsigned long)hp->dxferp, dxfer_len,
1927 				(SG_DXFER_TO_DEV == hp->dxfer_direction) ? 1 : 0, ULONG_MAX);
1928 	if (res <= 0)
1929 		return 1;
1930 	schp->k_use_sg = res;
1931 	schp->dio_in_use = 1;
1932 	hp->info |= SG_INFO_DIRECT_IO;
1933 	return 0;
1934 #else
1935 	return 1;
1936 #endif
1937 }
1938 
1939 static int
1940 sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1941 {
1942 	int ret_sz;
1943 	int blk_size = buff_size;
1944 	unsigned char *p = NULL;
1945 
1946 	if ((blk_size < 0) || (!sfp))
1947 		return -EFAULT;
1948 	if (0 == blk_size)
1949 		++blk_size;	/* don't know why */
1950 /* round request up to next highest SG_SECTOR_SZ byte boundary */
1951 	blk_size = (blk_size + SG_SECTOR_MSK) & (~SG_SECTOR_MSK);
1952 	SCSI_LOG_TIMEOUT(4, printk("sg_build_indirect: buff_size=%d, blk_size=%d\n",
1953 				   buff_size, blk_size));
1954 	if (blk_size <= SG_SCATTER_SZ) {
1955 		p = sg_page_malloc(blk_size, sfp->low_dma, &ret_sz);
1956 		if (!p)
1957 			return -ENOMEM;
1958 		if (blk_size == ret_sz) {	/* got it on the first attempt */
1959 			schp->k_use_sg = 0;
1960 			schp->buffer = p;
1961 			schp->bufflen = blk_size;
1962 			schp->b_malloc_len = blk_size;
1963 			return 0;
1964 		}
1965 	} else {
1966 		p = sg_page_malloc(SG_SCATTER_SZ, sfp->low_dma, &ret_sz);
1967 		if (!p)
1968 			return -ENOMEM;
1969 	}
1970 /* Want some local declarations, so start new block ... */
1971 	{			/* lets try and build a scatter gather list */
1972 		struct scatterlist *sclp;
1973 		int k, rem_sz, num;
1974 		int mx_sc_elems;
1975 		int sg_tablesize = sfp->parentdp->sg_tablesize;
1976 		int first = 1;
1977 
1978 		/* N.B. ret_sz carried into this block ... */
1979 		mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1980 		if (mx_sc_elems < 0)
1981 			return mx_sc_elems;	/* most likely -ENOMEM */
1982 
1983 		for (k = 0, sclp = schp->buffer, rem_sz = blk_size;
1984 		     (rem_sz > 0) && (k < mx_sc_elems);
1985 		     ++k, rem_sz -= ret_sz, ++sclp) {
1986 			if (first)
1987 				first = 0;
1988 			else {
1989 				num =
1990 				    (rem_sz >
1991 				     SG_SCATTER_SZ) ? SG_SCATTER_SZ : rem_sz;
1992 				p = sg_page_malloc(num, sfp->low_dma, &ret_sz);
1993 				if (!p)
1994 					break;
1995 			}
1996 			sclp->page = virt_to_page(p);
1997 			sclp->offset = offset_in_page(p);
1998 			sclp->length = ret_sz;
1999 
2000 			SCSI_LOG_TIMEOUT(5, printk("sg_build_build: k=%d, a=0x%p, len=%d\n",
2001 					  k, sg_scatg2virt(sclp), ret_sz));
2002 		}		/* end of for loop */
2003 		schp->k_use_sg = k;
2004 		SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k_use_sg=%d, rem_sz=%d\n", k, rem_sz));
2005 		schp->bufflen = blk_size;
2006 		if (rem_sz > 0)	/* must have failed */
2007 			return -ENOMEM;
2008 	}
2009 	return 0;
2010 }
2011 
2012 static int
2013 sg_write_xfer(Sg_request * srp)
2014 {
2015 	sg_io_hdr_t *hp = &srp->header;
2016 	Sg_scatter_hold *schp = &srp->data;
2017 	int num_xfer = 0;
2018 	int j, k, onum, usglen, ksglen, res;
2019 	int iovec_count = (int) hp->iovec_count;
2020 	int dxfer_dir = hp->dxfer_direction;
2021 	unsigned char *p;
2022 	unsigned char __user *up;
2023 	int new_interface = ('\0' == hp->interface_id) ? 0 : 1;
2024 
2025 	if ((SG_DXFER_UNKNOWN == dxfer_dir) || (SG_DXFER_TO_DEV == dxfer_dir) ||
2026 	    (SG_DXFER_TO_FROM_DEV == dxfer_dir)) {
2027 		num_xfer = (int) (new_interface ? hp->dxfer_len : hp->flags);
2028 		if (schp->bufflen < num_xfer)
2029 			num_xfer = schp->bufflen;
2030 	}
2031 	if ((num_xfer <= 0) || (schp->dio_in_use) ||
2032 	    (new_interface
2033 	     && ((SG_FLAG_NO_DXFER | SG_FLAG_MMAP_IO) & hp->flags)))
2034 		return 0;
2035 
2036 	SCSI_LOG_TIMEOUT(4, printk("sg_write_xfer: num_xfer=%d, iovec_count=%d, k_use_sg=%d\n",
2037 			  num_xfer, iovec_count, schp->k_use_sg));
2038 	if (iovec_count) {
2039 		onum = iovec_count;
2040 		if (!access_ok(VERIFY_READ, hp->dxferp, SZ_SG_IOVEC * onum))
2041 			return -EFAULT;
2042 	} else
2043 		onum = 1;
2044 
2045 	if (0 == schp->k_use_sg) {	/* kernel has single buffer */
2046 		for (j = 0, p = schp->buffer; j < onum; ++j) {
2047 			res = sg_u_iovec(hp, iovec_count, j, 1, &usglen, &up);
2048 			if (res)
2049 				return res;
2050 			usglen = (num_xfer > usglen) ? usglen : num_xfer;
2051 			if (__copy_from_user(p, up, usglen))
2052 				return -EFAULT;
2053 			p += usglen;
2054 			num_xfer -= usglen;
2055 			if (num_xfer <= 0)
2056 				return 0;
2057 		}
2058 	} else {		/* kernel using scatter gather list */
2059 		struct scatterlist *sclp = (struct scatterlist *) schp->buffer;
2060 
2061 		ksglen = (int) sclp->length;
2062 		p = sg_scatg2virt(sclp);
2063 		for (j = 0, k = 0; j < onum; ++j) {
2064 			res = sg_u_iovec(hp, iovec_count, j, 1, &usglen, &up);
2065 			if (res)
2066 				return res;
2067 
2068 			for (; p; ++sclp, ksglen = (int) sclp->length,
2069 				  p = sg_scatg2virt(sclp)) {
2070 				if (usglen <= 0)
2071 					break;
2072 				if (ksglen > usglen) {
2073 					if (usglen >= num_xfer) {
2074 						if (__copy_from_user
2075 						    (p, up, num_xfer))
2076 							return -EFAULT;
2077 						return 0;
2078 					}
2079 					if (__copy_from_user(p, up, usglen))
2080 						return -EFAULT;
2081 					p += usglen;
2082 					ksglen -= usglen;
2083 					break;
2084 				} else {
2085 					if (ksglen >= num_xfer) {
2086 						if (__copy_from_user
2087 						    (p, up, num_xfer))
2088 							return -EFAULT;
2089 						return 0;
2090 					}
2091 					if (__copy_from_user(p, up, 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_u_iovec(sg_io_hdr_t * hp, int sg_num, int ind,
2107 	   int wr_xf, int *countp, unsigned char __user **up)
2108 {
2109 	int num_xfer = (int) hp->dxfer_len;
2110 	unsigned char __user *p = hp->dxferp;
2111 	int count;
2112 
2113 	if (0 == sg_num) {
2114 		if (wr_xf && ('\0' == hp->interface_id))
2115 			count = (int) hp->flags;	/* holds "old" input_size */
2116 		else
2117 			count = num_xfer;
2118 	} else {
2119 		sg_iovec_t iovec;
2120 		if (__copy_from_user(&iovec, p + ind*SZ_SG_IOVEC, SZ_SG_IOVEC))
2121 			return -EFAULT;
2122 		p = iovec.iov_base;
2123 		count = (int) iovec.iov_len;
2124 	}
2125 	if (!access_ok(wr_xf ? VERIFY_READ : VERIFY_WRITE, p, count))
2126 		return -EFAULT;
2127 	if (up)
2128 		*up = p;
2129 	if (countp)
2130 		*countp = count;
2131 	return 0;
2132 }
2133 
2134 static void
2135 sg_remove_scat(Sg_scatter_hold * schp)
2136 {
2137 	SCSI_LOG_TIMEOUT(4, printk("sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
2138 	if (schp->buffer && (schp->sglist_len > 0)) {
2139 		struct scatterlist *sclp = (struct scatterlist *) schp->buffer;
2140 
2141 		if (schp->dio_in_use) {
2142 #ifdef SG_ALLOW_DIO_CODE
2143 			st_unmap_user_pages(sclp, schp->k_use_sg, TRUE);
2144 #endif
2145 		} else {
2146 			int k;
2147 
2148 			for (k = 0; (k < schp->k_use_sg) && sg_scatg2virt(sclp);
2149 			     ++k, ++sclp) {
2150 				SCSI_LOG_TIMEOUT(5, printk(
2151 				    "sg_remove_scat: k=%d, a=0x%p, len=%d\n",
2152 				    k, sg_scatg2virt(sclp), sclp->length));
2153 				sg_page_free(sg_scatg2virt(sclp), sclp->length);
2154 				sclp->page = NULL;
2155 				sclp->offset = 0;
2156 				sclp->length = 0;
2157 			}
2158 		}
2159 		sg_page_free(schp->buffer, schp->sglist_len);
2160 	} else if (schp->buffer)
2161 		sg_page_free(schp->buffer, schp->b_malloc_len);
2162 	memset(schp, 0, sizeof (*schp));
2163 }
2164 
2165 static int
2166 sg_read_xfer(Sg_request * srp)
2167 {
2168 	sg_io_hdr_t *hp = &srp->header;
2169 	Sg_scatter_hold *schp = &srp->data;
2170 	int num_xfer = 0;
2171 	int j, k, onum, usglen, ksglen, res;
2172 	int iovec_count = (int) hp->iovec_count;
2173 	int dxfer_dir = hp->dxfer_direction;
2174 	unsigned char *p;
2175 	unsigned char __user *up;
2176 	int new_interface = ('\0' == hp->interface_id) ? 0 : 1;
2177 
2178 	if ((SG_DXFER_UNKNOWN == dxfer_dir) || (SG_DXFER_FROM_DEV == dxfer_dir)
2179 	    || (SG_DXFER_TO_FROM_DEV == dxfer_dir)) {
2180 		num_xfer = hp->dxfer_len;
2181 		if (schp->bufflen < num_xfer)
2182 			num_xfer = schp->bufflen;
2183 	}
2184 	if ((num_xfer <= 0) || (schp->dio_in_use) ||
2185 	    (new_interface
2186 	     && ((SG_FLAG_NO_DXFER | SG_FLAG_MMAP_IO) & hp->flags)))
2187 		return 0;
2188 
2189 	SCSI_LOG_TIMEOUT(4, printk("sg_read_xfer: num_xfer=%d, iovec_count=%d, k_use_sg=%d\n",
2190 			  num_xfer, iovec_count, schp->k_use_sg));
2191 	if (iovec_count) {
2192 		onum = iovec_count;
2193 		if (!access_ok(VERIFY_READ, hp->dxferp, SZ_SG_IOVEC * onum))
2194 			return -EFAULT;
2195 	} else
2196 		onum = 1;
2197 
2198 	if (0 == schp->k_use_sg) {	/* kernel has single buffer */
2199 		for (j = 0, p = schp->buffer; j < onum; ++j) {
2200 			res = sg_u_iovec(hp, iovec_count, j, 0, &usglen, &up);
2201 			if (res)
2202 				return res;
2203 			usglen = (num_xfer > usglen) ? usglen : num_xfer;
2204 			if (__copy_to_user(up, p, usglen))
2205 				return -EFAULT;
2206 			p += usglen;
2207 			num_xfer -= usglen;
2208 			if (num_xfer <= 0)
2209 				return 0;
2210 		}
2211 	} else {		/* kernel using scatter gather list */
2212 		struct scatterlist *sclp = (struct scatterlist *) schp->buffer;
2213 
2214 		ksglen = (int) sclp->length;
2215 		p = sg_scatg2virt(sclp);
2216 		for (j = 0, k = 0; j < onum; ++j) {
2217 			res = sg_u_iovec(hp, iovec_count, j, 0, &usglen, &up);
2218 			if (res)
2219 				return res;
2220 
2221 			for (; p; ++sclp, ksglen = (int) sclp->length,
2222 				  p = sg_scatg2virt(sclp)) {
2223 				if (usglen <= 0)
2224 					break;
2225 				if (ksglen > usglen) {
2226 					if (usglen >= num_xfer) {
2227 						if (__copy_to_user
2228 						    (up, p, num_xfer))
2229 							return -EFAULT;
2230 						return 0;
2231 					}
2232 					if (__copy_to_user(up, p, usglen))
2233 						return -EFAULT;
2234 					p += usglen;
2235 					ksglen -= usglen;
2236 					break;
2237 				} else {
2238 					if (ksglen >= num_xfer) {
2239 						if (__copy_to_user
2240 						    (up, p, num_xfer))
2241 							return -EFAULT;
2242 						return 0;
2243 					}
2244 					if (__copy_to_user(up, p, ksglen))
2245 						return -EFAULT;
2246 					up += ksglen;
2247 					usglen -= ksglen;
2248 				}
2249 				++k;
2250 				if (k >= schp->k_use_sg)
2251 					return 0;
2252 			}
2253 		}
2254 	}
2255 	return 0;
2256 }
2257 
2258 static int
2259 sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
2260 {
2261 	Sg_scatter_hold *schp = &srp->data;
2262 
2263 	SCSI_LOG_TIMEOUT(4, printk("sg_read_oxfer: num_read_xfer=%d\n",
2264 				   num_read_xfer));
2265 	if ((!outp) || (num_read_xfer <= 0))
2266 		return 0;
2267 	if (schp->k_use_sg > 0) {
2268 		int k, num;
2269 		struct scatterlist *sclp = (struct scatterlist *) schp->buffer;
2270 
2271 		for (k = 0; (k < schp->k_use_sg) && sg_scatg2virt(sclp);
2272 		     ++k, ++sclp) {
2273 			num = (int) sclp->length;
2274 			if (num > num_read_xfer) {
2275 				if (__copy_to_user
2276 				    (outp, sg_scatg2virt(sclp), num_read_xfer))
2277 					return -EFAULT;
2278 				break;
2279 			} else {
2280 				if (__copy_to_user
2281 				    (outp, sg_scatg2virt(sclp), num))
2282 					return -EFAULT;
2283 				num_read_xfer -= num;
2284 				if (num_read_xfer <= 0)
2285 					break;
2286 				outp += num;
2287 			}
2288 		}
2289 	} else {
2290 		if (__copy_to_user(outp, schp->buffer, num_read_xfer))
2291 			return -EFAULT;
2292 	}
2293 	return 0;
2294 }
2295 
2296 static void
2297 sg_build_reserve(Sg_fd * sfp, int req_size)
2298 {
2299 	Sg_scatter_hold *schp = &sfp->reserve;
2300 
2301 	SCSI_LOG_TIMEOUT(4, printk("sg_build_reserve: req_size=%d\n", req_size));
2302 	do {
2303 		if (req_size < PAGE_SIZE)
2304 			req_size = PAGE_SIZE;
2305 		if (0 == sg_build_indirect(schp, sfp, req_size))
2306 			return;
2307 		else
2308 			sg_remove_scat(schp);
2309 		req_size >>= 1;	/* divide by 2 */
2310 	} while (req_size > (PAGE_SIZE / 2));
2311 }
2312 
2313 static void
2314 sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
2315 {
2316 	Sg_scatter_hold *req_schp = &srp->data;
2317 	Sg_scatter_hold *rsv_schp = &sfp->reserve;
2318 
2319 	srp->res_used = 1;
2320 	SCSI_LOG_TIMEOUT(4, printk("sg_link_reserve: size=%d\n", size));
2321 	size = (size + 1) & (~1);	/* round to even for aha1542 */
2322 	if (rsv_schp->k_use_sg > 0) {
2323 		int k, num;
2324 		int rem = size;
2325 		struct scatterlist *sclp =
2326 		    (struct scatterlist *) rsv_schp->buffer;
2327 
2328 		for (k = 0; k < rsv_schp->k_use_sg; ++k, ++sclp) {
2329 			num = (int) sclp->length;
2330 			if (rem <= num) {
2331 				if (0 == k) {
2332 					req_schp->k_use_sg = 0;
2333 					req_schp->buffer = sg_scatg2virt(sclp);
2334 				} else {
2335 					sfp->save_scat_len = num;
2336 					sclp->length = (unsigned) rem;
2337 					req_schp->k_use_sg = k + 1;
2338 					req_schp->sglist_len =
2339 					    rsv_schp->sglist_len;
2340 					req_schp->buffer = rsv_schp->buffer;
2341 				}
2342 				req_schp->bufflen = size;
2343 				req_schp->b_malloc_len = rsv_schp->b_malloc_len;
2344 				break;
2345 			} else
2346 				rem -= num;
2347 		}
2348 		if (k >= rsv_schp->k_use_sg)
2349 			SCSI_LOG_TIMEOUT(1, printk("sg_link_reserve: BAD size\n"));
2350 	} else {
2351 		req_schp->k_use_sg = 0;
2352 		req_schp->bufflen = size;
2353 		req_schp->buffer = rsv_schp->buffer;
2354 		req_schp->b_malloc_len = rsv_schp->b_malloc_len;
2355 	}
2356 }
2357 
2358 static void
2359 sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
2360 {
2361 	Sg_scatter_hold *req_schp = &srp->data;
2362 	Sg_scatter_hold *rsv_schp = &sfp->reserve;
2363 
2364 	SCSI_LOG_TIMEOUT(4, printk("sg_unlink_reserve: req->k_use_sg=%d\n",
2365 				   (int) req_schp->k_use_sg));
2366 	if ((rsv_schp->k_use_sg > 0) && (req_schp->k_use_sg > 0)) {
2367 		struct scatterlist *sclp =
2368 		    (struct scatterlist *) rsv_schp->buffer;
2369 
2370 		if (sfp->save_scat_len > 0)
2371 			(sclp + (req_schp->k_use_sg - 1))->length =
2372 			    (unsigned) sfp->save_scat_len;
2373 		else
2374 			SCSI_LOG_TIMEOUT(1, printk ("sg_unlink_reserve: BAD save_scat_len\n"));
2375 	}
2376 	req_schp->k_use_sg = 0;
2377 	req_schp->bufflen = 0;
2378 	req_schp->buffer = NULL;
2379 	req_schp->sglist_len = 0;
2380 	sfp->save_scat_len = 0;
2381 	srp->res_used = 0;
2382 }
2383 
2384 static Sg_request *
2385 sg_get_rq_mark(Sg_fd * sfp, int pack_id)
2386 {
2387 	Sg_request *resp;
2388 	unsigned long iflags;
2389 
2390 	write_lock_irqsave(&sfp->rq_list_lock, iflags);
2391 	for (resp = sfp->headrp; resp; resp = resp->nextrp) {
2392 		/* look for requests that are ready + not SG_IO owned */
2393 		if ((1 == resp->done) && (!resp->sg_io_owned) &&
2394 		    ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
2395 			resp->done = 2;	/* guard against other readers */
2396 			break;
2397 		}
2398 	}
2399 	write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2400 	return resp;
2401 }
2402 
2403 #ifdef CONFIG_SCSI_PROC_FS
2404 static Sg_request *
2405 sg_get_nth_request(Sg_fd * sfp, int nth)
2406 {
2407 	Sg_request *resp;
2408 	unsigned long iflags;
2409 	int k;
2410 
2411 	read_lock_irqsave(&sfp->rq_list_lock, iflags);
2412 	for (k = 0, resp = sfp->headrp; resp && (k < nth);
2413 	     ++k, resp = resp->nextrp) ;
2414 	read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2415 	return resp;
2416 }
2417 #endif
2418 
2419 /* always adds to end of list */
2420 static Sg_request *
2421 sg_add_request(Sg_fd * sfp)
2422 {
2423 	int k;
2424 	unsigned long iflags;
2425 	Sg_request *resp;
2426 	Sg_request *rp = sfp->req_arr;
2427 
2428 	write_lock_irqsave(&sfp->rq_list_lock, iflags);
2429 	resp = sfp->headrp;
2430 	if (!resp) {
2431 		memset(rp, 0, sizeof (Sg_request));
2432 		rp->parentfp = sfp;
2433 		resp = rp;
2434 		sfp->headrp = resp;
2435 	} else {
2436 		if (0 == sfp->cmd_q)
2437 			resp = NULL;	/* command queuing disallowed */
2438 		else {
2439 			for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2440 				if (!rp->parentfp)
2441 					break;
2442 			}
2443 			if (k < SG_MAX_QUEUE) {
2444 				memset(rp, 0, sizeof (Sg_request));
2445 				rp->parentfp = sfp;
2446 				while (resp->nextrp)
2447 					resp = resp->nextrp;
2448 				resp->nextrp = rp;
2449 				resp = rp;
2450 			} else
2451 				resp = NULL;
2452 		}
2453 	}
2454 	if (resp) {
2455 		resp->nextrp = NULL;
2456 		resp->header.duration = jiffies_to_msecs(jiffies);
2457 		resp->my_cmdp = NULL;
2458 	}
2459 	write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2460 	return resp;
2461 }
2462 
2463 /* Return of 1 for found; 0 for not found */
2464 static int
2465 sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2466 {
2467 	Sg_request *prev_rp;
2468 	Sg_request *rp;
2469 	unsigned long iflags;
2470 	int res = 0;
2471 
2472 	if ((!sfp) || (!srp) || (!sfp->headrp))
2473 		return res;
2474 	write_lock_irqsave(&sfp->rq_list_lock, iflags);
2475 	if (srp->my_cmdp)
2476 		srp->my_cmdp->upper_private_data = NULL;
2477 	prev_rp = sfp->headrp;
2478 	if (srp == prev_rp) {
2479 		sfp->headrp = prev_rp->nextrp;
2480 		prev_rp->parentfp = NULL;
2481 		res = 1;
2482 	} else {
2483 		while ((rp = prev_rp->nextrp)) {
2484 			if (srp == rp) {
2485 				prev_rp->nextrp = rp->nextrp;
2486 				rp->parentfp = NULL;
2487 				res = 1;
2488 				break;
2489 			}
2490 			prev_rp = rp;
2491 		}
2492 	}
2493 	write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2494 	return res;
2495 }
2496 
2497 #ifdef CONFIG_SCSI_PROC_FS
2498 static Sg_fd *
2499 sg_get_nth_sfp(Sg_device * sdp, int nth)
2500 {
2501 	Sg_fd *resp;
2502 	unsigned long iflags;
2503 	int k;
2504 
2505 	read_lock_irqsave(&sg_dev_arr_lock, iflags);
2506 	for (k = 0, resp = sdp->headfp; resp && (k < nth);
2507 	     ++k, resp = resp->nextfp) ;
2508 	read_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2509 	return resp;
2510 }
2511 #endif
2512 
2513 static Sg_fd *
2514 sg_add_sfp(Sg_device * sdp, int dev)
2515 {
2516 	Sg_fd *sfp;
2517 	unsigned long iflags;
2518 
2519 	sfp = (Sg_fd *) sg_page_malloc(sizeof (Sg_fd), 0, NULL);
2520 	if (!sfp)
2521 		return NULL;
2522 	memset(sfp, 0, sizeof (Sg_fd));
2523 	init_waitqueue_head(&sfp->read_wait);
2524 	rwlock_init(&sfp->rq_list_lock);
2525 
2526 	sfp->timeout = SG_DEFAULT_TIMEOUT;
2527 	sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2528 	sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2529 	sfp->low_dma = (SG_DEF_FORCE_LOW_DMA == 0) ?
2530 	    sdp->device->host->unchecked_isa_dma : 1;
2531 	sfp->cmd_q = SG_DEF_COMMAND_Q;
2532 	sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2533 	sfp->parentdp = sdp;
2534 	write_lock_irqsave(&sg_dev_arr_lock, iflags);
2535 	if (!sdp->headfp)
2536 		sdp->headfp = sfp;
2537 	else {			/* add to tail of existing list */
2538 		Sg_fd *pfp = sdp->headfp;
2539 		while (pfp->nextfp)
2540 			pfp = pfp->nextfp;
2541 		pfp->nextfp = sfp;
2542 	}
2543 	write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2544 	SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp: sfp=0x%p\n", sfp));
2545 	sg_build_reserve(sfp, sg_big_buff);
2546 	SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp:   bufflen=%d, k_use_sg=%d\n",
2547 			   sfp->reserve.bufflen, sfp->reserve.k_use_sg));
2548 	return sfp;
2549 }
2550 
2551 static void
2552 __sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp)
2553 {
2554 	Sg_fd *fp;
2555 	Sg_fd *prev_fp;
2556 
2557 	prev_fp = sdp->headfp;
2558 	if (sfp == prev_fp)
2559 		sdp->headfp = prev_fp->nextfp;
2560 	else {
2561 		while ((fp = prev_fp->nextfp)) {
2562 			if (sfp == fp) {
2563 				prev_fp->nextfp = fp->nextfp;
2564 				break;
2565 			}
2566 			prev_fp = fp;
2567 		}
2568 	}
2569 	if (sfp->reserve.bufflen > 0) {
2570 		SCSI_LOG_TIMEOUT(6,
2571 			printk("__sg_remove_sfp:    bufflen=%d, k_use_sg=%d\n",
2572 			(int) sfp->reserve.bufflen, (int) sfp->reserve.k_use_sg));
2573 		if (sfp->mmap_called)
2574 			sg_rb_correct4mmap(&sfp->reserve, 0);	/* undo correction */
2575 		sg_remove_scat(&sfp->reserve);
2576 	}
2577 	sfp->parentdp = NULL;
2578 	SCSI_LOG_TIMEOUT(6, printk("__sg_remove_sfp:    sfp=0x%p\n", sfp));
2579 	sg_page_free((char *) sfp, sizeof (Sg_fd));
2580 }
2581 
2582 /* Returns 0 in normal case, 1 when detached and sdp object removed */
2583 static int
2584 sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp)
2585 {
2586 	Sg_request *srp;
2587 	Sg_request *tsrp;
2588 	int dirty = 0;
2589 	int res = 0;
2590 
2591 	for (srp = sfp->headrp; srp; srp = tsrp) {
2592 		tsrp = srp->nextrp;
2593 		if (sg_srp_done(srp, sfp))
2594 			sg_finish_rem_req(srp);
2595 		else
2596 			++dirty;
2597 	}
2598 	if (0 == dirty) {
2599 		unsigned long iflags;
2600 
2601 		write_lock_irqsave(&sg_dev_arr_lock, iflags);
2602 		__sg_remove_sfp(sdp, sfp);
2603 		if (sdp->detached && (NULL == sdp->headfp)) {
2604 			int k, maxd;
2605 
2606 			maxd = sg_dev_max;
2607 			for (k = 0; k < maxd; ++k) {
2608 				if (sdp == sg_dev_arr[k])
2609 					break;
2610 			}
2611 			if (k < maxd)
2612 				sg_dev_arr[k] = NULL;
2613 			kfree((char *) sdp);
2614 			res = 1;
2615 		}
2616 		write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2617 	} else {
2618 		/* MOD_INC's to inhibit unloading sg and associated adapter driver */
2619 		/* only bump the access_count if we actually succeeded in
2620 		 * throwing another counter on the host module */
2621 		scsi_device_get(sdp->device);	/* XXX: retval ignored? */
2622 		sfp->closed = 1;	/* flag dirty state on this fd */
2623 		SCSI_LOG_TIMEOUT(1, printk("sg_remove_sfp: worrisome, %d writes pending\n",
2624 				  dirty));
2625 	}
2626 	return res;
2627 }
2628 
2629 static int
2630 sg_res_in_use(Sg_fd * sfp)
2631 {
2632 	const Sg_request *srp;
2633 	unsigned long iflags;
2634 
2635 	read_lock_irqsave(&sfp->rq_list_lock, iflags);
2636 	for (srp = sfp->headrp; srp; srp = srp->nextrp)
2637 		if (srp->res_used)
2638 			break;
2639 	read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2640 	return srp ? 1 : 0;
2641 }
2642 
2643 /* If retSzp==NULL want exact size or fail */
2644 static char *
2645 sg_page_malloc(int rqSz, int lowDma, int *retSzp)
2646 {
2647 	char *resp = NULL;
2648 	int page_mask;
2649 	int order, a_size;
2650 	int resSz = rqSz;
2651 
2652 	if (rqSz <= 0)
2653 		return resp;
2654 
2655 	if (lowDma)
2656 		page_mask = GFP_ATOMIC | GFP_DMA | __GFP_NOWARN;
2657 	else
2658 		page_mask = GFP_ATOMIC | __GFP_NOWARN;
2659 
2660 	for (order = 0, a_size = PAGE_SIZE; a_size < rqSz;
2661 	     order++, a_size <<= 1) ;
2662 	resp = (char *) __get_free_pages(page_mask, order);
2663 	while ((!resp) && order && retSzp) {
2664 		--order;
2665 		a_size >>= 1;	/* divide by 2, until PAGE_SIZE */
2666 		resp = (char *) __get_free_pages(page_mask, order);	/* try half */
2667 		resSz = a_size;
2668 	}
2669 	if (resp) {
2670 		if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2671 			memset(resp, 0, resSz);
2672 		if (retSzp)
2673 			*retSzp = resSz;
2674 	}
2675 	return resp;
2676 }
2677 
2678 static void
2679 sg_page_free(char *buff, int size)
2680 {
2681 	int order, a_size;
2682 
2683 	if (!buff)
2684 		return;
2685 	for (order = 0, a_size = PAGE_SIZE; a_size < size;
2686 	     order++, a_size <<= 1) ;
2687 	free_pages((unsigned long) buff, order);
2688 }
2689 
2690 #ifndef MAINTENANCE_IN_CMD
2691 #define MAINTENANCE_IN_CMD 0xa3
2692 #endif
2693 
2694 static unsigned char allow_ops[] = { TEST_UNIT_READY, REQUEST_SENSE,
2695 	INQUIRY, READ_CAPACITY, READ_BUFFER, READ_6, READ_10, READ_12,
2696 	READ_16, MODE_SENSE, MODE_SENSE_10, LOG_SENSE, REPORT_LUNS,
2697 	SERVICE_ACTION_IN, RECEIVE_DIAGNOSTIC, READ_LONG, MAINTENANCE_IN_CMD
2698 };
2699 
2700 static int
2701 sg_allow_access(unsigned char opcode, char dev_type)
2702 {
2703 	int k;
2704 
2705 	if (TYPE_SCANNER == dev_type)	/* TYPE_ROM maybe burner */
2706 		return 1;
2707 	for (k = 0; k < sizeof (allow_ops); ++k) {
2708 		if (opcode == allow_ops[k])
2709 			return 1;
2710 	}
2711 	return 0;
2712 }
2713 
2714 #ifdef CONFIG_SCSI_PROC_FS
2715 static int
2716 sg_last_dev(void)
2717 {
2718 	int k;
2719 	unsigned long iflags;
2720 
2721 	read_lock_irqsave(&sg_dev_arr_lock, iflags);
2722 	for (k = sg_dev_max - 1; k >= 0; --k)
2723 		if (sg_dev_arr[k] && sg_dev_arr[k]->device)
2724 			break;
2725 	read_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2726 	return k + 1;		/* origin 1 */
2727 }
2728 #endif
2729 
2730 static Sg_device *
2731 sg_get_dev(int dev)
2732 {
2733 	Sg_device *sdp = NULL;
2734 	unsigned long iflags;
2735 
2736 	if (sg_dev_arr && (dev >= 0)) {
2737 		read_lock_irqsave(&sg_dev_arr_lock, iflags);
2738 		if (dev < sg_dev_max)
2739 			sdp = sg_dev_arr[dev];
2740 		read_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2741 	}
2742 	return sdp;
2743 }
2744 
2745 #ifdef CONFIG_SCSI_PROC_FS
2746 
2747 static struct proc_dir_entry *sg_proc_sgp = NULL;
2748 
2749 static char sg_proc_sg_dirname[] = "scsi/sg";
2750 
2751 static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2752 
2753 static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2754 static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2755 			          size_t count, loff_t *off);
2756 static struct file_operations adio_fops = {
2757 	/* .owner, .read and .llseek added in sg_proc_init() */
2758 	.open = sg_proc_single_open_adio,
2759 	.write = sg_proc_write_adio,
2760 	.release = single_release,
2761 };
2762 
2763 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2764 static ssize_t sg_proc_write_dressz(struct file *filp,
2765 		const char __user *buffer, size_t count, loff_t *off);
2766 static struct file_operations dressz_fops = {
2767 	.open = sg_proc_single_open_dressz,
2768 	.write = sg_proc_write_dressz,
2769 	.release = single_release,
2770 };
2771 
2772 static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2773 static int sg_proc_single_open_version(struct inode *inode, struct file *file);
2774 static struct file_operations version_fops = {
2775 	.open = sg_proc_single_open_version,
2776 	.release = single_release,
2777 };
2778 
2779 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2780 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file);
2781 static struct file_operations devhdr_fops = {
2782 	.open = sg_proc_single_open_devhdr,
2783 	.release = single_release,
2784 };
2785 
2786 static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2787 static int sg_proc_open_dev(struct inode *inode, struct file *file);
2788 static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2789 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2790 static void dev_seq_stop(struct seq_file *s, void *v);
2791 static struct file_operations dev_fops = {
2792 	.open = sg_proc_open_dev,
2793 	.release = seq_release,
2794 };
2795 static struct seq_operations dev_seq_ops = {
2796 	.start = dev_seq_start,
2797 	.next  = dev_seq_next,
2798 	.stop  = dev_seq_stop,
2799 	.show  = sg_proc_seq_show_dev,
2800 };
2801 
2802 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2803 static int sg_proc_open_devstrs(struct inode *inode, struct file *file);
2804 static struct file_operations devstrs_fops = {
2805 	.open = sg_proc_open_devstrs,
2806 	.release = seq_release,
2807 };
2808 static struct seq_operations devstrs_seq_ops = {
2809 	.start = dev_seq_start,
2810 	.next  = dev_seq_next,
2811 	.stop  = dev_seq_stop,
2812 	.show  = sg_proc_seq_show_devstrs,
2813 };
2814 
2815 static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2816 static int sg_proc_open_debug(struct inode *inode, struct file *file);
2817 static struct file_operations debug_fops = {
2818 	.open = sg_proc_open_debug,
2819 	.release = seq_release,
2820 };
2821 static struct seq_operations debug_seq_ops = {
2822 	.start = dev_seq_start,
2823 	.next  = dev_seq_next,
2824 	.stop  = dev_seq_stop,
2825 	.show  = sg_proc_seq_show_debug,
2826 };
2827 
2828 
2829 struct sg_proc_leaf {
2830 	const char * name;
2831 	struct file_operations * fops;
2832 };
2833 
2834 static struct sg_proc_leaf sg_proc_leaf_arr[] = {
2835 	{"allow_dio", &adio_fops},
2836 	{"debug", &debug_fops},
2837 	{"def_reserved_size", &dressz_fops},
2838 	{"device_hdr", &devhdr_fops},
2839 	{"devices", &dev_fops},
2840 	{"device_strs", &devstrs_fops},
2841 	{"version", &version_fops}
2842 };
2843 
2844 static int
2845 sg_proc_init(void)
2846 {
2847 	int k, mask;
2848 	int num_leaves =
2849 	    sizeof (sg_proc_leaf_arr) / sizeof (sg_proc_leaf_arr[0]);
2850 	struct proc_dir_entry *pdep;
2851 	struct sg_proc_leaf * leaf;
2852 
2853 	sg_proc_sgp = create_proc_entry(sg_proc_sg_dirname,
2854 					S_IFDIR | S_IRUGO | S_IXUGO, NULL);
2855 	if (!sg_proc_sgp)
2856 		return 1;
2857 	for (k = 0; k < num_leaves; ++k) {
2858 		leaf = &sg_proc_leaf_arr[k];
2859 		mask = leaf->fops->write ? S_IRUGO | S_IWUSR : S_IRUGO;
2860 		pdep = create_proc_entry(leaf->name, mask, sg_proc_sgp);
2861 		if (pdep) {
2862 			leaf->fops->owner = THIS_MODULE,
2863 			leaf->fops->read = seq_read,
2864 			leaf->fops->llseek = seq_lseek,
2865 			pdep->proc_fops = leaf->fops;
2866 		}
2867 	}
2868 	return 0;
2869 }
2870 
2871 static void
2872 sg_proc_cleanup(void)
2873 {
2874 	int k;
2875 	int num_leaves =
2876 	    sizeof (sg_proc_leaf_arr) / sizeof (sg_proc_leaf_arr[0]);
2877 
2878 	if (!sg_proc_sgp)
2879 		return;
2880 	for (k = 0; k < num_leaves; ++k)
2881 		remove_proc_entry(sg_proc_leaf_arr[k].name, sg_proc_sgp);
2882 	remove_proc_entry(sg_proc_sg_dirname, NULL);
2883 }
2884 
2885 
2886 static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2887 {
2888 	seq_printf(s, "%d\n", *((int *)s->private));
2889 	return 0;
2890 }
2891 
2892 static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2893 {
2894 	return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2895 }
2896 
2897 static ssize_t
2898 sg_proc_write_adio(struct file *filp, const char __user *buffer,
2899 		   size_t count, loff_t *off)
2900 {
2901 	int num;
2902 	char buff[11];
2903 
2904 	if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2905 		return -EACCES;
2906 	num = (count < 10) ? count : 10;
2907 	if (copy_from_user(buff, buffer, num))
2908 		return -EFAULT;
2909 	buff[num] = '\0';
2910 	sg_allow_dio = simple_strtoul(buff, NULL, 10) ? 1 : 0;
2911 	return count;
2912 }
2913 
2914 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2915 {
2916 	return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2917 }
2918 
2919 static ssize_t
2920 sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2921 		     size_t count, loff_t *off)
2922 {
2923 	int num;
2924 	unsigned long k = ULONG_MAX;
2925 	char buff[11];
2926 
2927 	if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2928 		return -EACCES;
2929 	num = (count < 10) ? count : 10;
2930 	if (copy_from_user(buff, buffer, num))
2931 		return -EFAULT;
2932 	buff[num] = '\0';
2933 	k = simple_strtoul(buff, NULL, 10);
2934 	if (k <= 1048576) {	/* limit "big buff" to 1 MB */
2935 		sg_big_buff = k;
2936 		return count;
2937 	}
2938 	return -ERANGE;
2939 }
2940 
2941 static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2942 {
2943 	seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2944 		   sg_version_date);
2945 	return 0;
2946 }
2947 
2948 static int sg_proc_single_open_version(struct inode *inode, struct file *file)
2949 {
2950 	return single_open(file, sg_proc_seq_show_version, NULL);
2951 }
2952 
2953 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2954 {
2955 	seq_printf(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\t"
2956 		   "online\n");
2957 	return 0;
2958 }
2959 
2960 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file)
2961 {
2962 	return single_open(file, sg_proc_seq_show_devhdr, NULL);
2963 }
2964 
2965 struct sg_proc_deviter {
2966 	loff_t	index;
2967 	size_t	max;
2968 };
2969 
2970 static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2971 {
2972 	struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2973 
2974 	if (! it)
2975 		return NULL;
2976 	if (NULL == sg_dev_arr)
2977 		goto err1;
2978 	it->index = *pos;
2979 	it->max = sg_last_dev();
2980 	if (it->index >= it->max)
2981 		goto err1;
2982 	return it;
2983 err1:
2984 	kfree(it);
2985 	return NULL;
2986 }
2987 
2988 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2989 {
2990 	struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2991 
2992 	*pos = ++it->index;
2993 	return (it->index < it->max) ? it : NULL;
2994 }
2995 
2996 static void dev_seq_stop(struct seq_file *s, void *v)
2997 {
2998 	kfree (v);
2999 }
3000 
3001 static int sg_proc_open_dev(struct inode *inode, struct file *file)
3002 {
3003         return seq_open(file, &dev_seq_ops);
3004 }
3005 
3006 static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
3007 {
3008 	struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
3009 	Sg_device *sdp;
3010 	struct scsi_device *scsidp;
3011 
3012 	sdp = it ? sg_get_dev(it->index) : NULL;
3013 	if (sdp && (scsidp = sdp->device) && (!sdp->detached))
3014 		seq_printf(s, "%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\n",
3015 			      scsidp->host->host_no, scsidp->channel,
3016 			      scsidp->id, scsidp->lun, (int) scsidp->type,
3017 			      1,
3018 			      (int) scsidp->queue_depth,
3019 			      (int) scsidp->device_busy,
3020 			      (int) scsi_device_online(scsidp));
3021 	else
3022 		seq_printf(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
3023 	return 0;
3024 }
3025 
3026 static int sg_proc_open_devstrs(struct inode *inode, struct file *file)
3027 {
3028         return seq_open(file, &devstrs_seq_ops);
3029 }
3030 
3031 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
3032 {
3033 	struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
3034 	Sg_device *sdp;
3035 	struct scsi_device *scsidp;
3036 
3037 	sdp = it ? sg_get_dev(it->index) : NULL;
3038 	if (sdp && (scsidp = sdp->device) && (!sdp->detached))
3039 		seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
3040 			   scsidp->vendor, scsidp->model, scsidp->rev);
3041 	else
3042 		seq_printf(s, "<no active device>\n");
3043 	return 0;
3044 }
3045 
3046 static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
3047 {
3048 	int k, m, new_interface, blen, usg;
3049 	Sg_request *srp;
3050 	Sg_fd *fp;
3051 	const sg_io_hdr_t *hp;
3052 	const char * cp;
3053 	unsigned int ms;
3054 
3055 	for (k = 0; (fp = sg_get_nth_sfp(sdp, k)); ++k) {
3056 		seq_printf(s, "   FD(%d): timeout=%dms bufflen=%d "
3057 			   "(res)sgat=%d low_dma=%d\n", k + 1,
3058 			   jiffies_to_msecs(fp->timeout),
3059 			   fp->reserve.bufflen,
3060 			   (int) fp->reserve.k_use_sg,
3061 			   (int) fp->low_dma);
3062 		seq_printf(s, "   cmd_q=%d f_packid=%d k_orphan=%d closed=%d\n",
3063 			   (int) fp->cmd_q, (int) fp->force_packid,
3064 			   (int) fp->keep_orphan, (int) fp->closed);
3065 		for (m = 0; (srp = sg_get_nth_request(fp, m)); ++m) {
3066 			hp = &srp->header;
3067 			new_interface = (hp->interface_id == '\0') ? 0 : 1;
3068 			if (srp->res_used) {
3069 				if (new_interface &&
3070 				    (SG_FLAG_MMAP_IO & hp->flags))
3071 					cp = "     mmap>> ";
3072 				else
3073 					cp = "     rb>> ";
3074 			} else {
3075 				if (SG_INFO_DIRECT_IO_MASK & hp->info)
3076 					cp = "     dio>> ";
3077 				else
3078 					cp = "     ";
3079 			}
3080 			seq_printf(s, cp);
3081 			blen = srp->my_cmdp ?
3082 				srp->my_cmdp->sr_bufflen : srp->data.bufflen;
3083 			usg = srp->my_cmdp ?
3084 				srp->my_cmdp->sr_use_sg : srp->data.k_use_sg;
3085 			seq_printf(s, srp->done ?
3086 				   ((1 == srp->done) ?  "rcv:" : "fin:")
3087 				   : (srp->my_cmdp ? "act:" : "prior:"));
3088 			seq_printf(s, " id=%d blen=%d",
3089 				   srp->header.pack_id, blen);
3090 			if (srp->done)
3091 				seq_printf(s, " dur=%d", hp->duration);
3092 			else {
3093 				ms = jiffies_to_msecs(jiffies);
3094 				seq_printf(s, " t_o/elap=%d/%d",
3095 					(new_interface ? hp->timeout :
3096 						  jiffies_to_msecs(fp->timeout)),
3097 					(ms > hp->duration ? ms - hp->duration : 0));
3098 			}
3099 			seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
3100 				   (int) srp->data.cmd_opcode);
3101 		}
3102 		if (0 == m)
3103 			seq_printf(s, "     No requests active\n");
3104 	}
3105 }
3106 
3107 static int sg_proc_open_debug(struct inode *inode, struct file *file)
3108 {
3109         return seq_open(file, &debug_seq_ops);
3110 }
3111 
3112 static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
3113 {
3114 	struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
3115 	Sg_device *sdp;
3116 
3117 	if (it && (0 == it->index)) {
3118 		seq_printf(s, "dev_max(currently)=%d max_active_device=%d "
3119 			   "(origin 1)\n", sg_dev_max, (int)it->max);
3120 		seq_printf(s, " def_reserved_size=%d\n", sg_big_buff);
3121 	}
3122 	sdp = it ? sg_get_dev(it->index) : NULL;
3123 	if (sdp) {
3124 		struct scsi_device *scsidp = sdp->device;
3125 
3126 		if (NULL == scsidp) {
3127 			seq_printf(s, "device %d detached ??\n",
3128 				   (int)it->index);
3129 			return 0;
3130 		}
3131 
3132 		if (sg_get_nth_sfp(sdp, 0)) {
3133 			seq_printf(s, " >>> device=%s ",
3134 				sdp->disk->disk_name);
3135 			if (sdp->detached)
3136 				seq_printf(s, "detached pending close ");
3137 			else
3138 				seq_printf
3139 				    (s, "scsi%d chan=%d id=%d lun=%d   em=%d",
3140 				     scsidp->host->host_no,
3141 				     scsidp->channel, scsidp->id,
3142 				     scsidp->lun,
3143 				     scsidp->host->hostt->emulated);
3144 			seq_printf(s, " sg_tablesize=%d excl=%d\n",
3145 				   sdp->sg_tablesize, sdp->exclude);
3146 		}
3147 		sg_proc_debug_helper(s, sdp);
3148 	}
3149 	return 0;
3150 }
3151 
3152 #endif				/* CONFIG_SCSI_PROC_FS */
3153 
3154 module_init(init_sg);
3155 module_exit(exit_sg);
3156 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
3157